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1/*
2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18*/
19#include <linux/export.h>
20#include <linux/moduleloader.h>
21#include <linux/ftrace_event.h>
22#include <linux/init.h>
23#include <linux/kallsyms.h>
24#include <linux/fs.h>
25#include <linux/sysfs.h>
26#include <linux/kernel.h>
27#include <linux/slab.h>
28#include <linux/vmalloc.h>
29#include <linux/elf.h>
30#include <linux/proc_fs.h>
31#include <linux/seq_file.h>
32#include <linux/syscalls.h>
33#include <linux/fcntl.h>
34#include <linux/rcupdate.h>
35#include <linux/capability.h>
36#include <linux/cpu.h>
37#include <linux/moduleparam.h>
38#include <linux/errno.h>
39#include <linux/err.h>
40#include <linux/vermagic.h>
41#include <linux/notifier.h>
42#include <linux/sched.h>
43#include <linux/stop_machine.h>
44#include <linux/device.h>
45#include <linux/string.h>
46#include <linux/mutex.h>
47#include <linux/rculist.h>
48#include <asm/uaccess.h>
49#include <asm/cacheflush.h>
50#include <asm/mmu_context.h>
51#include <linux/license.h>
52#include <asm/sections.h>
53#include <linux/tracepoint.h>
54#include <linux/ftrace.h>
55#include <linux/async.h>
56#include <linux/percpu.h>
57#include <linux/kmemleak.h>
58#include <linux/jump_label.h>
59#include <linux/pfn.h>
60#include <linux/bsearch.h>
61
62#define CREATE_TRACE_POINTS
63#include <trace/events/module.h>
64
65#ifndef ARCH_SHF_SMALL
66#define ARCH_SHF_SMALL 0
67#endif
68
69/*
70 * Modules' sections will be aligned on page boundaries
71 * to ensure complete separation of code and data, but
72 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
73 */
74#ifdef CONFIG_DEBUG_SET_MODULE_RONX
75# define debug_align(X) ALIGN(X, PAGE_SIZE)
76#else
77# define debug_align(X) (X)
78#endif
79
80/*
81 * Given BASE and SIZE this macro calculates the number of pages the
82 * memory regions occupies
83 */
84#define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ? \
85 (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
86 PFN_DOWN((unsigned long)BASE) + 1) \
87 : (0UL))
88
89/* If this is set, the section belongs in the init part of the module */
90#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
91
92/*
93 * Mutex protects:
94 * 1) List of modules (also safely readable with preempt_disable),
95 * 2) module_use links,
96 * 3) module_addr_min/module_addr_max.
97 * (delete uses stop_machine/add uses RCU list operations). */
98DEFINE_MUTEX(module_mutex);
99EXPORT_SYMBOL_GPL(module_mutex);
100static LIST_HEAD(modules);
101#ifdef CONFIG_KGDB_KDB
102struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
103#endif /* CONFIG_KGDB_KDB */
104
105
106/* Block module loading/unloading? */
107int modules_disabled = 0;
108core_param(nomodule, modules_disabled, bint, 0);
109
110/* Waiting for a module to finish initializing? */
111static DECLARE_WAIT_QUEUE_HEAD(module_wq);
112
113static BLOCKING_NOTIFIER_HEAD(module_notify_list);
114
115/* Bounds of module allocation, for speeding __module_address.
116 * Protected by module_mutex. */
117static unsigned long module_addr_min = -1UL, module_addr_max = 0;
118
119int register_module_notifier(struct notifier_block * nb)
120{
121 return blocking_notifier_chain_register(&module_notify_list, nb);
122}
123EXPORT_SYMBOL(register_module_notifier);
124
125int unregister_module_notifier(struct notifier_block * nb)
126{
127 return blocking_notifier_chain_unregister(&module_notify_list, nb);
128}
129EXPORT_SYMBOL(unregister_module_notifier);
130
131struct load_info {
132 Elf_Ehdr *hdr;
133 unsigned long len;
134 Elf_Shdr *sechdrs;
135 char *secstrings, *strtab;
136 unsigned long symoffs, stroffs;
137 struct _ddebug *debug;
138 unsigned int num_debug;
139 struct {
140 unsigned int sym, str, mod, vers, info, pcpu;
141 } index;
142};
143
144/* We require a truly strong try_module_get(): 0 means failure due to
145 ongoing or failed initialization etc. */
146static inline int strong_try_module_get(struct module *mod)
147{
148 if (mod && mod->state == MODULE_STATE_COMING)
149 return -EBUSY;
150 if (try_module_get(mod))
151 return 0;
152 else
153 return -ENOENT;
154}
155
156static inline void add_taint_module(struct module *mod, unsigned flag)
157{
158 add_taint(flag);
159 mod->taints |= (1U << flag);
160}
161
162/*
163 * A thread that wants to hold a reference to a module only while it
164 * is running can call this to safely exit. nfsd and lockd use this.
165 */
166void __module_put_and_exit(struct module *mod, long code)
167{
168 module_put(mod);
169 do_exit(code);
170}
171EXPORT_SYMBOL(__module_put_and_exit);
172
173/* Find a module section: 0 means not found. */
174static unsigned int find_sec(const struct load_info *info, const char *name)
175{
176 unsigned int i;
177
178 for (i = 1; i < info->hdr->e_shnum; i++) {
179 Elf_Shdr *shdr = &info->sechdrs[i];
180 /* Alloc bit cleared means "ignore it." */
181 if ((shdr->sh_flags & SHF_ALLOC)
182 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
183 return i;
184 }
185 return 0;
186}
187
188/* Find a module section, or NULL. */
189static void *section_addr(const struct load_info *info, const char *name)
190{
191 /* Section 0 has sh_addr 0. */
192 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
193}
194
195/* Find a module section, or NULL. Fill in number of "objects" in section. */
196static void *section_objs(const struct load_info *info,
197 const char *name,
198 size_t object_size,
199 unsigned int *num)
200{
201 unsigned int sec = find_sec(info, name);
202
203 /* Section 0 has sh_addr 0 and sh_size 0. */
204 *num = info->sechdrs[sec].sh_size / object_size;
205 return (void *)info->sechdrs[sec].sh_addr;
206}
207
208/* Provided by the linker */
209extern const struct kernel_symbol __start___ksymtab[];
210extern const struct kernel_symbol __stop___ksymtab[];
211extern const struct kernel_symbol __start___ksymtab_gpl[];
212extern const struct kernel_symbol __stop___ksymtab_gpl[];
213extern const struct kernel_symbol __start___ksymtab_gpl_future[];
214extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
215extern const unsigned long __start___kcrctab[];
216extern const unsigned long __start___kcrctab_gpl[];
217extern const unsigned long __start___kcrctab_gpl_future[];
218#ifdef CONFIG_UNUSED_SYMBOLS
219extern const struct kernel_symbol __start___ksymtab_unused[];
220extern const struct kernel_symbol __stop___ksymtab_unused[];
221extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
222extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
223extern const unsigned long __start___kcrctab_unused[];
224extern const unsigned long __start___kcrctab_unused_gpl[];
225#endif
226
227#ifndef CONFIG_MODVERSIONS
228#define symversion(base, idx) NULL
229#else
230#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
231#endif
232
233static bool each_symbol_in_section(const struct symsearch *arr,
234 unsigned int arrsize,
235 struct module *owner,
236 bool (*fn)(const struct symsearch *syms,
237 struct module *owner,
238 void *data),
239 void *data)
240{
241 unsigned int j;
242
243 for (j = 0; j < arrsize; j++) {
244 if (fn(&arr[j], owner, data))
245 return true;
246 }
247
248 return false;
249}
250
251/* Returns true as soon as fn returns true, otherwise false. */
252bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
253 struct module *owner,
254 void *data),
255 void *data)
256{
257 struct module *mod;
258 static const struct symsearch arr[] = {
259 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
260 NOT_GPL_ONLY, false },
261 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
262 __start___kcrctab_gpl,
263 GPL_ONLY, false },
264 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
265 __start___kcrctab_gpl_future,
266 WILL_BE_GPL_ONLY, false },
267#ifdef CONFIG_UNUSED_SYMBOLS
268 { __start___ksymtab_unused, __stop___ksymtab_unused,
269 __start___kcrctab_unused,
270 NOT_GPL_ONLY, true },
271 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
272 __start___kcrctab_unused_gpl,
273 GPL_ONLY, true },
274#endif
275 };
276
277 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
278 return true;
279
280 list_for_each_entry_rcu(mod, &modules, list) {
281 struct symsearch arr[] = {
282 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
283 NOT_GPL_ONLY, false },
284 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
285 mod->gpl_crcs,
286 GPL_ONLY, false },
287 { mod->gpl_future_syms,
288 mod->gpl_future_syms + mod->num_gpl_future_syms,
289 mod->gpl_future_crcs,
290 WILL_BE_GPL_ONLY, false },
291#ifdef CONFIG_UNUSED_SYMBOLS
292 { mod->unused_syms,
293 mod->unused_syms + mod->num_unused_syms,
294 mod->unused_crcs,
295 NOT_GPL_ONLY, true },
296 { mod->unused_gpl_syms,
297 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
298 mod->unused_gpl_crcs,
299 GPL_ONLY, true },
300#endif
301 };
302
303 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
304 return true;
305 }
306 return false;
307}
308EXPORT_SYMBOL_GPL(each_symbol_section);
309
310struct find_symbol_arg {
311 /* Input */
312 const char *name;
313 bool gplok;
314 bool warn;
315
316 /* Output */
317 struct module *owner;
318 const unsigned long *crc;
319 const struct kernel_symbol *sym;
320};
321
322static bool check_symbol(const struct symsearch *syms,
323 struct module *owner,
324 unsigned int symnum, void *data)
325{
326 struct find_symbol_arg *fsa = data;
327
328 if (!fsa->gplok) {
329 if (syms->licence == GPL_ONLY)
330 return false;
331 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
332 printk(KERN_WARNING "Symbol %s is being used "
333 "by a non-GPL module, which will not "
334 "be allowed in the future\n", fsa->name);
335 printk(KERN_WARNING "Please see the file "
336 "Documentation/feature-removal-schedule.txt "
337 "in the kernel source tree for more details.\n");
338 }
339 }
340
341#ifdef CONFIG_UNUSED_SYMBOLS
342 if (syms->unused && fsa->warn) {
343 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
344 "however this module is using it.\n", fsa->name);
345 printk(KERN_WARNING
346 "This symbol will go away in the future.\n");
347 printk(KERN_WARNING
348 "Please evalute if this is the right api to use and if "
349 "it really is, submit a report the linux kernel "
350 "mailinglist together with submitting your code for "
351 "inclusion.\n");
352 }
353#endif
354
355 fsa->owner = owner;
356 fsa->crc = symversion(syms->crcs, symnum);
357 fsa->sym = &syms->start[symnum];
358 return true;
359}
360
361static int cmp_name(const void *va, const void *vb)
362{
363 const char *a;
364 const struct kernel_symbol *b;
365 a = va; b = vb;
366 return strcmp(a, b->name);
367}
368
369static bool find_symbol_in_section(const struct symsearch *syms,
370 struct module *owner,
371 void *data)
372{
373 struct find_symbol_arg *fsa = data;
374 struct kernel_symbol *sym;
375
376 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
377 sizeof(struct kernel_symbol), cmp_name);
378
379 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
380 return true;
381
382 return false;
383}
384
385/* Find a symbol and return it, along with, (optional) crc and
386 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
387const struct kernel_symbol *find_symbol(const char *name,
388 struct module **owner,
389 const unsigned long **crc,
390 bool gplok,
391 bool warn)
392{
393 struct find_symbol_arg fsa;
394
395 fsa.name = name;
396 fsa.gplok = gplok;
397 fsa.warn = warn;
398
399 if (each_symbol_section(find_symbol_in_section, &fsa)) {
400 if (owner)
401 *owner = fsa.owner;
402 if (crc)
403 *crc = fsa.crc;
404 return fsa.sym;
405 }
406
407 pr_debug("Failed to find symbol %s\n", name);
408 return NULL;
409}
410EXPORT_SYMBOL_GPL(find_symbol);
411
412/* Search for module by name: must hold module_mutex. */
413struct module *find_module(const char *name)
414{
415 struct module *mod;
416
417 list_for_each_entry(mod, &modules, list) {
418 if (strcmp(mod->name, name) == 0)
419 return mod;
420 }
421 return NULL;
422}
423EXPORT_SYMBOL_GPL(find_module);
424
425#ifdef CONFIG_SMP
426
427static inline void __percpu *mod_percpu(struct module *mod)
428{
429 return mod->percpu;
430}
431
432static int percpu_modalloc(struct module *mod,
433 unsigned long size, unsigned long align)
434{
435 if (align > PAGE_SIZE) {
436 printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
437 mod->name, align, PAGE_SIZE);
438 align = PAGE_SIZE;
439 }
440
441 mod->percpu = __alloc_reserved_percpu(size, align);
442 if (!mod->percpu) {
443 printk(KERN_WARNING
444 "%s: Could not allocate %lu bytes percpu data\n",
445 mod->name, size);
446 return -ENOMEM;
447 }
448 mod->percpu_size = size;
449 return 0;
450}
451
452static void percpu_modfree(struct module *mod)
453{
454 free_percpu(mod->percpu);
455}
456
457static unsigned int find_pcpusec(struct load_info *info)
458{
459 return find_sec(info, ".data..percpu");
460}
461
462static void percpu_modcopy(struct module *mod,
463 const void *from, unsigned long size)
464{
465 int cpu;
466
467 for_each_possible_cpu(cpu)
468 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
469}
470
471/**
472 * is_module_percpu_address - test whether address is from module static percpu
473 * @addr: address to test
474 *
475 * Test whether @addr belongs to module static percpu area.
476 *
477 * RETURNS:
478 * %true if @addr is from module static percpu area
479 */
480bool is_module_percpu_address(unsigned long addr)
481{
482 struct module *mod;
483 unsigned int cpu;
484
485 preempt_disable();
486
487 list_for_each_entry_rcu(mod, &modules, list) {
488 if (!mod->percpu_size)
489 continue;
490 for_each_possible_cpu(cpu) {
491 void *start = per_cpu_ptr(mod->percpu, cpu);
492
493 if ((void *)addr >= start &&
494 (void *)addr < start + mod->percpu_size) {
495 preempt_enable();
496 return true;
497 }
498 }
499 }
500
501 preempt_enable();
502 return false;
503}
504
505#else /* ... !CONFIG_SMP */
506
507static inline void __percpu *mod_percpu(struct module *mod)
508{
509 return NULL;
510}
511static inline int percpu_modalloc(struct module *mod,
512 unsigned long size, unsigned long align)
513{
514 return -ENOMEM;
515}
516static inline void percpu_modfree(struct module *mod)
517{
518}
519static unsigned int find_pcpusec(struct load_info *info)
520{
521 return 0;
522}
523static inline void percpu_modcopy(struct module *mod,
524 const void *from, unsigned long size)
525{
526 /* pcpusec should be 0, and size of that section should be 0. */
527 BUG_ON(size != 0);
528}
529bool is_module_percpu_address(unsigned long addr)
530{
531 return false;
532}
533
534#endif /* CONFIG_SMP */
535
536#define MODINFO_ATTR(field) \
537static void setup_modinfo_##field(struct module *mod, const char *s) \
538{ \
539 mod->field = kstrdup(s, GFP_KERNEL); \
540} \
541static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
542 struct module_kobject *mk, char *buffer) \
543{ \
544 return sprintf(buffer, "%s\n", mk->mod->field); \
545} \
546static int modinfo_##field##_exists(struct module *mod) \
547{ \
548 return mod->field != NULL; \
549} \
550static void free_modinfo_##field(struct module *mod) \
551{ \
552 kfree(mod->field); \
553 mod->field = NULL; \
554} \
555static struct module_attribute modinfo_##field = { \
556 .attr = { .name = __stringify(field), .mode = 0444 }, \
557 .show = show_modinfo_##field, \
558 .setup = setup_modinfo_##field, \
559 .test = modinfo_##field##_exists, \
560 .free = free_modinfo_##field, \
561};
562
563MODINFO_ATTR(version);
564MODINFO_ATTR(srcversion);
565
566static char last_unloaded_module[MODULE_NAME_LEN+1];
567
568#ifdef CONFIG_MODULE_UNLOAD
569
570EXPORT_TRACEPOINT_SYMBOL(module_get);
571
572/* Init the unload section of the module. */
573static int module_unload_init(struct module *mod)
574{
575 mod->refptr = alloc_percpu(struct module_ref);
576 if (!mod->refptr)
577 return -ENOMEM;
578
579 INIT_LIST_HEAD(&mod->source_list);
580 INIT_LIST_HEAD(&mod->target_list);
581
582 /* Hold reference count during initialization. */
583 __this_cpu_write(mod->refptr->incs, 1);
584 /* Backwards compatibility macros put refcount during init. */
585 mod->waiter = current;
586
587 return 0;
588}
589
590/* Does a already use b? */
591static int already_uses(struct module *a, struct module *b)
592{
593 struct module_use *use;
594
595 list_for_each_entry(use, &b->source_list, source_list) {
596 if (use->source == a) {
597 pr_debug("%s uses %s!\n", a->name, b->name);
598 return 1;
599 }
600 }
601 pr_debug("%s does not use %s!\n", a->name, b->name);
602 return 0;
603}
604
605/*
606 * Module a uses b
607 * - we add 'a' as a "source", 'b' as a "target" of module use
608 * - the module_use is added to the list of 'b' sources (so
609 * 'b' can walk the list to see who sourced them), and of 'a'
610 * targets (so 'a' can see what modules it targets).
611 */
612static int add_module_usage(struct module *a, struct module *b)
613{
614 struct module_use *use;
615
616 pr_debug("Allocating new usage for %s.\n", a->name);
617 use = kmalloc(sizeof(*use), GFP_ATOMIC);
618 if (!use) {
619 printk(KERN_WARNING "%s: out of memory loading\n", a->name);
620 return -ENOMEM;
621 }
622
623 use->source = a;
624 use->target = b;
625 list_add(&use->source_list, &b->source_list);
626 list_add(&use->target_list, &a->target_list);
627 return 0;
628}
629
630/* Module a uses b: caller needs module_mutex() */
631int ref_module(struct module *a, struct module *b)
632{
633 int err;
634
635 if (b == NULL || already_uses(a, b))
636 return 0;
637
638 /* If module isn't available, we fail. */
639 err = strong_try_module_get(b);
640 if (err)
641 return err;
642
643 err = add_module_usage(a, b);
644 if (err) {
645 module_put(b);
646 return err;
647 }
648 return 0;
649}
650EXPORT_SYMBOL_GPL(ref_module);
651
652/* Clear the unload stuff of the module. */
653static void module_unload_free(struct module *mod)
654{
655 struct module_use *use, *tmp;
656
657 mutex_lock(&module_mutex);
658 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
659 struct module *i = use->target;
660 pr_debug("%s unusing %s\n", mod->name, i->name);
661 module_put(i);
662 list_del(&use->source_list);
663 list_del(&use->target_list);
664 kfree(use);
665 }
666 mutex_unlock(&module_mutex);
667
668 free_percpu(mod->refptr);
669}
670
671#ifdef CONFIG_MODULE_FORCE_UNLOAD
672static inline int try_force_unload(unsigned int flags)
673{
674 int ret = (flags & O_TRUNC);
675 if (ret)
676 add_taint(TAINT_FORCED_RMMOD);
677 return ret;
678}
679#else
680static inline int try_force_unload(unsigned int flags)
681{
682 return 0;
683}
684#endif /* CONFIG_MODULE_FORCE_UNLOAD */
685
686struct stopref
687{
688 struct module *mod;
689 int flags;
690 int *forced;
691};
692
693/* Whole machine is stopped with interrupts off when this runs. */
694static int __try_stop_module(void *_sref)
695{
696 struct stopref *sref = _sref;
697
698 /* If it's not unused, quit unless we're forcing. */
699 if (module_refcount(sref->mod) != 0) {
700 if (!(*sref->forced = try_force_unload(sref->flags)))
701 return -EWOULDBLOCK;
702 }
703
704 /* Mark it as dying. */
705 sref->mod->state = MODULE_STATE_GOING;
706 return 0;
707}
708
709static int try_stop_module(struct module *mod, int flags, int *forced)
710{
711 if (flags & O_NONBLOCK) {
712 struct stopref sref = { mod, flags, forced };
713
714 return stop_machine(__try_stop_module, &sref, NULL);
715 } else {
716 /* We don't need to stop the machine for this. */
717 mod->state = MODULE_STATE_GOING;
718 synchronize_sched();
719 return 0;
720 }
721}
722
723unsigned long module_refcount(struct module *mod)
724{
725 unsigned long incs = 0, decs = 0;
726 int cpu;
727
728 for_each_possible_cpu(cpu)
729 decs += per_cpu_ptr(mod->refptr, cpu)->decs;
730 /*
731 * ensure the incs are added up after the decs.
732 * module_put ensures incs are visible before decs with smp_wmb.
733 *
734 * This 2-count scheme avoids the situation where the refcount
735 * for CPU0 is read, then CPU0 increments the module refcount,
736 * then CPU1 drops that refcount, then the refcount for CPU1 is
737 * read. We would record a decrement but not its corresponding
738 * increment so we would see a low count (disaster).
739 *
740 * Rare situation? But module_refcount can be preempted, and we
741 * might be tallying up 4096+ CPUs. So it is not impossible.
742 */
743 smp_rmb();
744 for_each_possible_cpu(cpu)
745 incs += per_cpu_ptr(mod->refptr, cpu)->incs;
746 return incs - decs;
747}
748EXPORT_SYMBOL(module_refcount);
749
750/* This exists whether we can unload or not */
751static void free_module(struct module *mod);
752
753static void wait_for_zero_refcount(struct module *mod)
754{
755 /* Since we might sleep for some time, release the mutex first */
756 mutex_unlock(&module_mutex);
757 for (;;) {
758 pr_debug("Looking at refcount...\n");
759 set_current_state(TASK_UNINTERRUPTIBLE);
760 if (module_refcount(mod) == 0)
761 break;
762 schedule();
763 }
764 current->state = TASK_RUNNING;
765 mutex_lock(&module_mutex);
766}
767
768SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
769 unsigned int, flags)
770{
771 struct module *mod;
772 char name[MODULE_NAME_LEN];
773 int ret, forced = 0;
774
775 if (!capable(CAP_SYS_MODULE) || modules_disabled)
776 return -EPERM;
777
778 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
779 return -EFAULT;
780 name[MODULE_NAME_LEN-1] = '\0';
781
782 if (mutex_lock_interruptible(&module_mutex) != 0)
783 return -EINTR;
784
785 mod = find_module(name);
786 if (!mod) {
787 ret = -ENOENT;
788 goto out;
789 }
790
791 if (!list_empty(&mod->source_list)) {
792 /* Other modules depend on us: get rid of them first. */
793 ret = -EWOULDBLOCK;
794 goto out;
795 }
796
797 /* Doing init or already dying? */
798 if (mod->state != MODULE_STATE_LIVE) {
799 /* FIXME: if (force), slam module count and wake up
800 waiter --RR */
801 pr_debug("%s already dying\n", mod->name);
802 ret = -EBUSY;
803 goto out;
804 }
805
806 /* If it has an init func, it must have an exit func to unload */
807 if (mod->init && !mod->exit) {
808 forced = try_force_unload(flags);
809 if (!forced) {
810 /* This module can't be removed */
811 ret = -EBUSY;
812 goto out;
813 }
814 }
815
816 /* Set this up before setting mod->state */
817 mod->waiter = current;
818
819 /* Stop the machine so refcounts can't move and disable module. */
820 ret = try_stop_module(mod, flags, &forced);
821 if (ret != 0)
822 goto out;
823
824 /* Never wait if forced. */
825 if (!forced && module_refcount(mod) != 0)
826 wait_for_zero_refcount(mod);
827
828 mutex_unlock(&module_mutex);
829 /* Final destruction now no one is using it. */
830 if (mod->exit != NULL)
831 mod->exit();
832 blocking_notifier_call_chain(&module_notify_list,
833 MODULE_STATE_GOING, mod);
834 async_synchronize_full();
835
836 /* Store the name of the last unloaded module for diagnostic purposes */
837 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
838
839 free_module(mod);
840 return 0;
841out:
842 mutex_unlock(&module_mutex);
843 return ret;
844}
845
846static inline void print_unload_info(struct seq_file *m, struct module *mod)
847{
848 struct module_use *use;
849 int printed_something = 0;
850
851 seq_printf(m, " %lu ", module_refcount(mod));
852
853 /* Always include a trailing , so userspace can differentiate
854 between this and the old multi-field proc format. */
855 list_for_each_entry(use, &mod->source_list, source_list) {
856 printed_something = 1;
857 seq_printf(m, "%s,", use->source->name);
858 }
859
860 if (mod->init != NULL && mod->exit == NULL) {
861 printed_something = 1;
862 seq_printf(m, "[permanent],");
863 }
864
865 if (!printed_something)
866 seq_printf(m, "-");
867}
868
869void __symbol_put(const char *symbol)
870{
871 struct module *owner;
872
873 preempt_disable();
874 if (!find_symbol(symbol, &owner, NULL, true, false))
875 BUG();
876 module_put(owner);
877 preempt_enable();
878}
879EXPORT_SYMBOL(__symbol_put);
880
881/* Note this assumes addr is a function, which it currently always is. */
882void symbol_put_addr(void *addr)
883{
884 struct module *modaddr;
885 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
886
887 if (core_kernel_text(a))
888 return;
889
890 /* module_text_address is safe here: we're supposed to have reference
891 * to module from symbol_get, so it can't go away. */
892 modaddr = __module_text_address(a);
893 BUG_ON(!modaddr);
894 module_put(modaddr);
895}
896EXPORT_SYMBOL_GPL(symbol_put_addr);
897
898static ssize_t show_refcnt(struct module_attribute *mattr,
899 struct module_kobject *mk, char *buffer)
900{
901 return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
902}
903
904static struct module_attribute modinfo_refcnt =
905 __ATTR(refcnt, 0444, show_refcnt, NULL);
906
907void __module_get(struct module *module)
908{
909 if (module) {
910 preempt_disable();
911 __this_cpu_inc(module->refptr->incs);
912 trace_module_get(module, _RET_IP_);
913 preempt_enable();
914 }
915}
916EXPORT_SYMBOL(__module_get);
917
918bool try_module_get(struct module *module)
919{
920 bool ret = true;
921
922 if (module) {
923 preempt_disable();
924
925 if (likely(module_is_live(module))) {
926 __this_cpu_inc(module->refptr->incs);
927 trace_module_get(module, _RET_IP_);
928 } else
929 ret = false;
930
931 preempt_enable();
932 }
933 return ret;
934}
935EXPORT_SYMBOL(try_module_get);
936
937void module_put(struct module *module)
938{
939 if (module) {
940 preempt_disable();
941 smp_wmb(); /* see comment in module_refcount */
942 __this_cpu_inc(module->refptr->decs);
943
944 trace_module_put(module, _RET_IP_);
945 /* Maybe they're waiting for us to drop reference? */
946 if (unlikely(!module_is_live(module)))
947 wake_up_process(module->waiter);
948 preempt_enable();
949 }
950}
951EXPORT_SYMBOL(module_put);
952
953#else /* !CONFIG_MODULE_UNLOAD */
954static inline void print_unload_info(struct seq_file *m, struct module *mod)
955{
956 /* We don't know the usage count, or what modules are using. */
957 seq_printf(m, " - -");
958}
959
960static inline void module_unload_free(struct module *mod)
961{
962}
963
964int ref_module(struct module *a, struct module *b)
965{
966 return strong_try_module_get(b);
967}
968EXPORT_SYMBOL_GPL(ref_module);
969
970static inline int module_unload_init(struct module *mod)
971{
972 return 0;
973}
974#endif /* CONFIG_MODULE_UNLOAD */
975
976static size_t module_flags_taint(struct module *mod, char *buf)
977{
978 size_t l = 0;
979
980 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
981 buf[l++] = 'P';
982 if (mod->taints & (1 << TAINT_OOT_MODULE))
983 buf[l++] = 'O';
984 if (mod->taints & (1 << TAINT_FORCED_MODULE))
985 buf[l++] = 'F';
986 if (mod->taints & (1 << TAINT_CRAP))
987 buf[l++] = 'C';
988 /*
989 * TAINT_FORCED_RMMOD: could be added.
990 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
991 * apply to modules.
992 */
993 return l;
994}
995
996static ssize_t show_initstate(struct module_attribute *mattr,
997 struct module_kobject *mk, char *buffer)
998{
999 const char *state = "unknown";
1000
1001 switch (mk->mod->state) {
1002 case MODULE_STATE_LIVE:
1003 state = "live";
1004 break;
1005 case MODULE_STATE_COMING:
1006 state = "coming";
1007 break;
1008 case MODULE_STATE_GOING:
1009 state = "going";
1010 break;
1011 }
1012 return sprintf(buffer, "%s\n", state);
1013}
1014
1015static struct module_attribute modinfo_initstate =
1016 __ATTR(initstate, 0444, show_initstate, NULL);
1017
1018static ssize_t store_uevent(struct module_attribute *mattr,
1019 struct module_kobject *mk,
1020 const char *buffer, size_t count)
1021{
1022 enum kobject_action action;
1023
1024 if (kobject_action_type(buffer, count, &action) == 0)
1025 kobject_uevent(&mk->kobj, action);
1026 return count;
1027}
1028
1029struct module_attribute module_uevent =
1030 __ATTR(uevent, 0200, NULL, store_uevent);
1031
1032static ssize_t show_coresize(struct module_attribute *mattr,
1033 struct module_kobject *mk, char *buffer)
1034{
1035 return sprintf(buffer, "%u\n", mk->mod->core_size);
1036}
1037
1038static struct module_attribute modinfo_coresize =
1039 __ATTR(coresize, 0444, show_coresize, NULL);
1040
1041static ssize_t show_initsize(struct module_attribute *mattr,
1042 struct module_kobject *mk, char *buffer)
1043{
1044 return sprintf(buffer, "%u\n", mk->mod->init_size);
1045}
1046
1047static struct module_attribute modinfo_initsize =
1048 __ATTR(initsize, 0444, show_initsize, NULL);
1049
1050static ssize_t show_taint(struct module_attribute *mattr,
1051 struct module_kobject *mk, char *buffer)
1052{
1053 size_t l;
1054
1055 l = module_flags_taint(mk->mod, buffer);
1056 buffer[l++] = '\n';
1057 return l;
1058}
1059
1060static struct module_attribute modinfo_taint =
1061 __ATTR(taint, 0444, show_taint, NULL);
1062
1063static struct module_attribute *modinfo_attrs[] = {
1064 &module_uevent,
1065 &modinfo_version,
1066 &modinfo_srcversion,
1067 &modinfo_initstate,
1068 &modinfo_coresize,
1069 &modinfo_initsize,
1070 &modinfo_taint,
1071#ifdef CONFIG_MODULE_UNLOAD
1072 &modinfo_refcnt,
1073#endif
1074 NULL,
1075};
1076
1077static const char vermagic[] = VERMAGIC_STRING;
1078
1079static int try_to_force_load(struct module *mod, const char *reason)
1080{
1081#ifdef CONFIG_MODULE_FORCE_LOAD
1082 if (!test_taint(TAINT_FORCED_MODULE))
1083 printk(KERN_WARNING "%s: %s: kernel tainted.\n",
1084 mod->name, reason);
1085 add_taint_module(mod, TAINT_FORCED_MODULE);
1086 return 0;
1087#else
1088 return -ENOEXEC;
1089#endif
1090}
1091
1092#ifdef CONFIG_MODVERSIONS
1093/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1094static unsigned long maybe_relocated(unsigned long crc,
1095 const struct module *crc_owner)
1096{
1097#ifdef ARCH_RELOCATES_KCRCTAB
1098 if (crc_owner == NULL)
1099 return crc - (unsigned long)reloc_start;
1100#endif
1101 return crc;
1102}
1103
1104static int check_version(Elf_Shdr *sechdrs,
1105 unsigned int versindex,
1106 const char *symname,
1107 struct module *mod,
1108 const unsigned long *crc,
1109 const struct module *crc_owner)
1110{
1111 unsigned int i, num_versions;
1112 struct modversion_info *versions;
1113
1114 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1115 if (!crc)
1116 return 1;
1117
1118 /* No versions at all? modprobe --force does this. */
1119 if (versindex == 0)
1120 return try_to_force_load(mod, symname) == 0;
1121
1122 versions = (void *) sechdrs[versindex].sh_addr;
1123 num_versions = sechdrs[versindex].sh_size
1124 / sizeof(struct modversion_info);
1125
1126 for (i = 0; i < num_versions; i++) {
1127 if (strcmp(versions[i].name, symname) != 0)
1128 continue;
1129
1130 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1131 return 1;
1132 pr_debug("Found checksum %lX vs module %lX\n",
1133 maybe_relocated(*crc, crc_owner), versions[i].crc);
1134 goto bad_version;
1135 }
1136
1137 printk(KERN_WARNING "%s: no symbol version for %s\n",
1138 mod->name, symname);
1139 return 0;
1140
1141bad_version:
1142 printk("%s: disagrees about version of symbol %s\n",
1143 mod->name, symname);
1144 return 0;
1145}
1146
1147static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1148 unsigned int versindex,
1149 struct module *mod)
1150{
1151 const unsigned long *crc;
1152
1153 /* Since this should be found in kernel (which can't be removed),
1154 * no locking is necessary. */
1155 if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
1156 &crc, true, false))
1157 BUG();
1158 return check_version(sechdrs, versindex, "module_layout", mod, crc,
1159 NULL);
1160}
1161
1162/* First part is kernel version, which we ignore if module has crcs. */
1163static inline int same_magic(const char *amagic, const char *bmagic,
1164 bool has_crcs)
1165{
1166 if (has_crcs) {
1167 amagic += strcspn(amagic, " ");
1168 bmagic += strcspn(bmagic, " ");
1169 }
1170 return strcmp(amagic, bmagic) == 0;
1171}
1172#else
1173static inline int check_version(Elf_Shdr *sechdrs,
1174 unsigned int versindex,
1175 const char *symname,
1176 struct module *mod,
1177 const unsigned long *crc,
1178 const struct module *crc_owner)
1179{
1180 return 1;
1181}
1182
1183static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1184 unsigned int versindex,
1185 struct module *mod)
1186{
1187 return 1;
1188}
1189
1190static inline int same_magic(const char *amagic, const char *bmagic,
1191 bool has_crcs)
1192{
1193 return strcmp(amagic, bmagic) == 0;
1194}
1195#endif /* CONFIG_MODVERSIONS */
1196
1197/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1198static const struct kernel_symbol *resolve_symbol(struct module *mod,
1199 const struct load_info *info,
1200 const char *name,
1201 char ownername[])
1202{
1203 struct module *owner;
1204 const struct kernel_symbol *sym;
1205 const unsigned long *crc;
1206 int err;
1207
1208 mutex_lock(&module_mutex);
1209 sym = find_symbol(name, &owner, &crc,
1210 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1211 if (!sym)
1212 goto unlock;
1213
1214 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1215 owner)) {
1216 sym = ERR_PTR(-EINVAL);
1217 goto getname;
1218 }
1219
1220 err = ref_module(mod, owner);
1221 if (err) {
1222 sym = ERR_PTR(err);
1223 goto getname;
1224 }
1225
1226getname:
1227 /* We must make copy under the lock if we failed to get ref. */
1228 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1229unlock:
1230 mutex_unlock(&module_mutex);
1231 return sym;
1232}
1233
1234static const struct kernel_symbol *
1235resolve_symbol_wait(struct module *mod,
1236 const struct load_info *info,
1237 const char *name)
1238{
1239 const struct kernel_symbol *ksym;
1240 char owner[MODULE_NAME_LEN];
1241
1242 if (wait_event_interruptible_timeout(module_wq,
1243 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1244 || PTR_ERR(ksym) != -EBUSY,
1245 30 * HZ) <= 0) {
1246 printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1247 mod->name, owner);
1248 }
1249 return ksym;
1250}
1251
1252/*
1253 * /sys/module/foo/sections stuff
1254 * J. Corbet <corbet@lwn.net>
1255 */
1256#ifdef CONFIG_SYSFS
1257
1258#ifdef CONFIG_KALLSYMS
1259static inline bool sect_empty(const Elf_Shdr *sect)
1260{
1261 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1262}
1263
1264struct module_sect_attr
1265{
1266 struct module_attribute mattr;
1267 char *name;
1268 unsigned long address;
1269};
1270
1271struct module_sect_attrs
1272{
1273 struct attribute_group grp;
1274 unsigned int nsections;
1275 struct module_sect_attr attrs[0];
1276};
1277
1278static ssize_t module_sect_show(struct module_attribute *mattr,
1279 struct module_kobject *mk, char *buf)
1280{
1281 struct module_sect_attr *sattr =
1282 container_of(mattr, struct module_sect_attr, mattr);
1283 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1284}
1285
1286static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1287{
1288 unsigned int section;
1289
1290 for (section = 0; section < sect_attrs->nsections; section++)
1291 kfree(sect_attrs->attrs[section].name);
1292 kfree(sect_attrs);
1293}
1294
1295static void add_sect_attrs(struct module *mod, const struct load_info *info)
1296{
1297 unsigned int nloaded = 0, i, size[2];
1298 struct module_sect_attrs *sect_attrs;
1299 struct module_sect_attr *sattr;
1300 struct attribute **gattr;
1301
1302 /* Count loaded sections and allocate structures */
1303 for (i = 0; i < info->hdr->e_shnum; i++)
1304 if (!sect_empty(&info->sechdrs[i]))
1305 nloaded++;
1306 size[0] = ALIGN(sizeof(*sect_attrs)
1307 + nloaded * sizeof(sect_attrs->attrs[0]),
1308 sizeof(sect_attrs->grp.attrs[0]));
1309 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1310 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1311 if (sect_attrs == NULL)
1312 return;
1313
1314 /* Setup section attributes. */
1315 sect_attrs->grp.name = "sections";
1316 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1317
1318 sect_attrs->nsections = 0;
1319 sattr = §_attrs->attrs[0];
1320 gattr = §_attrs->grp.attrs[0];
1321 for (i = 0; i < info->hdr->e_shnum; i++) {
1322 Elf_Shdr *sec = &info->sechdrs[i];
1323 if (sect_empty(sec))
1324 continue;
1325 sattr->address = sec->sh_addr;
1326 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1327 GFP_KERNEL);
1328 if (sattr->name == NULL)
1329 goto out;
1330 sect_attrs->nsections++;
1331 sysfs_attr_init(&sattr->mattr.attr);
1332 sattr->mattr.show = module_sect_show;
1333 sattr->mattr.store = NULL;
1334 sattr->mattr.attr.name = sattr->name;
1335 sattr->mattr.attr.mode = S_IRUGO;
1336 *(gattr++) = &(sattr++)->mattr.attr;
1337 }
1338 *gattr = NULL;
1339
1340 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1341 goto out;
1342
1343 mod->sect_attrs = sect_attrs;
1344 return;
1345 out:
1346 free_sect_attrs(sect_attrs);
1347}
1348
1349static void remove_sect_attrs(struct module *mod)
1350{
1351 if (mod->sect_attrs) {
1352 sysfs_remove_group(&mod->mkobj.kobj,
1353 &mod->sect_attrs->grp);
1354 /* We are positive that no one is using any sect attrs
1355 * at this point. Deallocate immediately. */
1356 free_sect_attrs(mod->sect_attrs);
1357 mod->sect_attrs = NULL;
1358 }
1359}
1360
1361/*
1362 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1363 */
1364
1365struct module_notes_attrs {
1366 struct kobject *dir;
1367 unsigned int notes;
1368 struct bin_attribute attrs[0];
1369};
1370
1371static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1372 struct bin_attribute *bin_attr,
1373 char *buf, loff_t pos, size_t count)
1374{
1375 /*
1376 * The caller checked the pos and count against our size.
1377 */
1378 memcpy(buf, bin_attr->private + pos, count);
1379 return count;
1380}
1381
1382static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1383 unsigned int i)
1384{
1385 if (notes_attrs->dir) {
1386 while (i-- > 0)
1387 sysfs_remove_bin_file(notes_attrs->dir,
1388 ¬es_attrs->attrs[i]);
1389 kobject_put(notes_attrs->dir);
1390 }
1391 kfree(notes_attrs);
1392}
1393
1394static void add_notes_attrs(struct module *mod, const struct load_info *info)
1395{
1396 unsigned int notes, loaded, i;
1397 struct module_notes_attrs *notes_attrs;
1398 struct bin_attribute *nattr;
1399
1400 /* failed to create section attributes, so can't create notes */
1401 if (!mod->sect_attrs)
1402 return;
1403
1404 /* Count notes sections and allocate structures. */
1405 notes = 0;
1406 for (i = 0; i < info->hdr->e_shnum; i++)
1407 if (!sect_empty(&info->sechdrs[i]) &&
1408 (info->sechdrs[i].sh_type == SHT_NOTE))
1409 ++notes;
1410
1411 if (notes == 0)
1412 return;
1413
1414 notes_attrs = kzalloc(sizeof(*notes_attrs)
1415 + notes * sizeof(notes_attrs->attrs[0]),
1416 GFP_KERNEL);
1417 if (notes_attrs == NULL)
1418 return;
1419
1420 notes_attrs->notes = notes;
1421 nattr = ¬es_attrs->attrs[0];
1422 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1423 if (sect_empty(&info->sechdrs[i]))
1424 continue;
1425 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1426 sysfs_bin_attr_init(nattr);
1427 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1428 nattr->attr.mode = S_IRUGO;
1429 nattr->size = info->sechdrs[i].sh_size;
1430 nattr->private = (void *) info->sechdrs[i].sh_addr;
1431 nattr->read = module_notes_read;
1432 ++nattr;
1433 }
1434 ++loaded;
1435 }
1436
1437 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1438 if (!notes_attrs->dir)
1439 goto out;
1440
1441 for (i = 0; i < notes; ++i)
1442 if (sysfs_create_bin_file(notes_attrs->dir,
1443 ¬es_attrs->attrs[i]))
1444 goto out;
1445
1446 mod->notes_attrs = notes_attrs;
1447 return;
1448
1449 out:
1450 free_notes_attrs(notes_attrs, i);
1451}
1452
1453static void remove_notes_attrs(struct module *mod)
1454{
1455 if (mod->notes_attrs)
1456 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1457}
1458
1459#else
1460
1461static inline void add_sect_attrs(struct module *mod,
1462 const struct load_info *info)
1463{
1464}
1465
1466static inline void remove_sect_attrs(struct module *mod)
1467{
1468}
1469
1470static inline void add_notes_attrs(struct module *mod,
1471 const struct load_info *info)
1472{
1473}
1474
1475static inline void remove_notes_attrs(struct module *mod)
1476{
1477}
1478#endif /* CONFIG_KALLSYMS */
1479
1480static void add_usage_links(struct module *mod)
1481{
1482#ifdef CONFIG_MODULE_UNLOAD
1483 struct module_use *use;
1484 int nowarn;
1485
1486 mutex_lock(&module_mutex);
1487 list_for_each_entry(use, &mod->target_list, target_list) {
1488 nowarn = sysfs_create_link(use->target->holders_dir,
1489 &mod->mkobj.kobj, mod->name);
1490 }
1491 mutex_unlock(&module_mutex);
1492#endif
1493}
1494
1495static void del_usage_links(struct module *mod)
1496{
1497#ifdef CONFIG_MODULE_UNLOAD
1498 struct module_use *use;
1499
1500 mutex_lock(&module_mutex);
1501 list_for_each_entry(use, &mod->target_list, target_list)
1502 sysfs_remove_link(use->target->holders_dir, mod->name);
1503 mutex_unlock(&module_mutex);
1504#endif
1505}
1506
1507static int module_add_modinfo_attrs(struct module *mod)
1508{
1509 struct module_attribute *attr;
1510 struct module_attribute *temp_attr;
1511 int error = 0;
1512 int i;
1513
1514 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1515 (ARRAY_SIZE(modinfo_attrs) + 1)),
1516 GFP_KERNEL);
1517 if (!mod->modinfo_attrs)
1518 return -ENOMEM;
1519
1520 temp_attr = mod->modinfo_attrs;
1521 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1522 if (!attr->test ||
1523 (attr->test && attr->test(mod))) {
1524 memcpy(temp_attr, attr, sizeof(*temp_attr));
1525 sysfs_attr_init(&temp_attr->attr);
1526 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1527 ++temp_attr;
1528 }
1529 }
1530 return error;
1531}
1532
1533static void module_remove_modinfo_attrs(struct module *mod)
1534{
1535 struct module_attribute *attr;
1536 int i;
1537
1538 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1539 /* pick a field to test for end of list */
1540 if (!attr->attr.name)
1541 break;
1542 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1543 if (attr->free)
1544 attr->free(mod);
1545 }
1546 kfree(mod->modinfo_attrs);
1547}
1548
1549static int mod_sysfs_init(struct module *mod)
1550{
1551 int err;
1552 struct kobject *kobj;
1553
1554 if (!module_sysfs_initialized) {
1555 printk(KERN_ERR "%s: module sysfs not initialized\n",
1556 mod->name);
1557 err = -EINVAL;
1558 goto out;
1559 }
1560
1561 kobj = kset_find_obj(module_kset, mod->name);
1562 if (kobj) {
1563 printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1564 kobject_put(kobj);
1565 err = -EINVAL;
1566 goto out;
1567 }
1568
1569 mod->mkobj.mod = mod;
1570
1571 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1572 mod->mkobj.kobj.kset = module_kset;
1573 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1574 "%s", mod->name);
1575 if (err)
1576 kobject_put(&mod->mkobj.kobj);
1577
1578 /* delay uevent until full sysfs population */
1579out:
1580 return err;
1581}
1582
1583static int mod_sysfs_setup(struct module *mod,
1584 const struct load_info *info,
1585 struct kernel_param *kparam,
1586 unsigned int num_params)
1587{
1588 int err;
1589
1590 err = mod_sysfs_init(mod);
1591 if (err)
1592 goto out;
1593
1594 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1595 if (!mod->holders_dir) {
1596 err = -ENOMEM;
1597 goto out_unreg;
1598 }
1599
1600 err = module_param_sysfs_setup(mod, kparam, num_params);
1601 if (err)
1602 goto out_unreg_holders;
1603
1604 err = module_add_modinfo_attrs(mod);
1605 if (err)
1606 goto out_unreg_param;
1607
1608 add_usage_links(mod);
1609 add_sect_attrs(mod, info);
1610 add_notes_attrs(mod, info);
1611
1612 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1613 return 0;
1614
1615out_unreg_param:
1616 module_param_sysfs_remove(mod);
1617out_unreg_holders:
1618 kobject_put(mod->holders_dir);
1619out_unreg:
1620 kobject_put(&mod->mkobj.kobj);
1621out:
1622 return err;
1623}
1624
1625static void mod_sysfs_fini(struct module *mod)
1626{
1627 remove_notes_attrs(mod);
1628 remove_sect_attrs(mod);
1629 kobject_put(&mod->mkobj.kobj);
1630}
1631
1632#else /* !CONFIG_SYSFS */
1633
1634static int mod_sysfs_setup(struct module *mod,
1635 const struct load_info *info,
1636 struct kernel_param *kparam,
1637 unsigned int num_params)
1638{
1639 return 0;
1640}
1641
1642static void mod_sysfs_fini(struct module *mod)
1643{
1644}
1645
1646static void module_remove_modinfo_attrs(struct module *mod)
1647{
1648}
1649
1650static void del_usage_links(struct module *mod)
1651{
1652}
1653
1654#endif /* CONFIG_SYSFS */
1655
1656static void mod_sysfs_teardown(struct module *mod)
1657{
1658 del_usage_links(mod);
1659 module_remove_modinfo_attrs(mod);
1660 module_param_sysfs_remove(mod);
1661 kobject_put(mod->mkobj.drivers_dir);
1662 kobject_put(mod->holders_dir);
1663 mod_sysfs_fini(mod);
1664}
1665
1666/*
1667 * unlink the module with the whole machine is stopped with interrupts off
1668 * - this defends against kallsyms not taking locks
1669 */
1670static int __unlink_module(void *_mod)
1671{
1672 struct module *mod = _mod;
1673 list_del(&mod->list);
1674 module_bug_cleanup(mod);
1675 return 0;
1676}
1677
1678#ifdef CONFIG_DEBUG_SET_MODULE_RONX
1679/*
1680 * LKM RO/NX protection: protect module's text/ro-data
1681 * from modification and any data from execution.
1682 */
1683void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1684{
1685 unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1686 unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1687
1688 if (end_pfn > begin_pfn)
1689 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1690}
1691
1692static void set_section_ro_nx(void *base,
1693 unsigned long text_size,
1694 unsigned long ro_size,
1695 unsigned long total_size)
1696{
1697 /* begin and end PFNs of the current subsection */
1698 unsigned long begin_pfn;
1699 unsigned long end_pfn;
1700
1701 /*
1702 * Set RO for module text and RO-data:
1703 * - Always protect first page.
1704 * - Do not protect last partial page.
1705 */
1706 if (ro_size > 0)
1707 set_page_attributes(base, base + ro_size, set_memory_ro);
1708
1709 /*
1710 * Set NX permissions for module data:
1711 * - Do not protect first partial page.
1712 * - Always protect last page.
1713 */
1714 if (total_size > text_size) {
1715 begin_pfn = PFN_UP((unsigned long)base + text_size);
1716 end_pfn = PFN_UP((unsigned long)base + total_size);
1717 if (end_pfn > begin_pfn)
1718 set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1719 }
1720}
1721
1722static void unset_module_core_ro_nx(struct module *mod)
1723{
1724 set_page_attributes(mod->module_core + mod->core_text_size,
1725 mod->module_core + mod->core_size,
1726 set_memory_x);
1727 set_page_attributes(mod->module_core,
1728 mod->module_core + mod->core_ro_size,
1729 set_memory_rw);
1730}
1731
1732static void unset_module_init_ro_nx(struct module *mod)
1733{
1734 set_page_attributes(mod->module_init + mod->init_text_size,
1735 mod->module_init + mod->init_size,
1736 set_memory_x);
1737 set_page_attributes(mod->module_init,
1738 mod->module_init + mod->init_ro_size,
1739 set_memory_rw);
1740}
1741
1742/* Iterate through all modules and set each module's text as RW */
1743void set_all_modules_text_rw(void)
1744{
1745 struct module *mod;
1746
1747 mutex_lock(&module_mutex);
1748 list_for_each_entry_rcu(mod, &modules, list) {
1749 if ((mod->module_core) && (mod->core_text_size)) {
1750 set_page_attributes(mod->module_core,
1751 mod->module_core + mod->core_text_size,
1752 set_memory_rw);
1753 }
1754 if ((mod->module_init) && (mod->init_text_size)) {
1755 set_page_attributes(mod->module_init,
1756 mod->module_init + mod->init_text_size,
1757 set_memory_rw);
1758 }
1759 }
1760 mutex_unlock(&module_mutex);
1761}
1762
1763/* Iterate through all modules and set each module's text as RO */
1764void set_all_modules_text_ro(void)
1765{
1766 struct module *mod;
1767
1768 mutex_lock(&module_mutex);
1769 list_for_each_entry_rcu(mod, &modules, list) {
1770 if ((mod->module_core) && (mod->core_text_size)) {
1771 set_page_attributes(mod->module_core,
1772 mod->module_core + mod->core_text_size,
1773 set_memory_ro);
1774 }
1775 if ((mod->module_init) && (mod->init_text_size)) {
1776 set_page_attributes(mod->module_init,
1777 mod->module_init + mod->init_text_size,
1778 set_memory_ro);
1779 }
1780 }
1781 mutex_unlock(&module_mutex);
1782}
1783#else
1784static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1785static void unset_module_core_ro_nx(struct module *mod) { }
1786static void unset_module_init_ro_nx(struct module *mod) { }
1787#endif
1788
1789void __weak module_free(struct module *mod, void *module_region)
1790{
1791 vfree(module_region);
1792}
1793
1794void __weak module_arch_cleanup(struct module *mod)
1795{
1796}
1797
1798/* Free a module, remove from lists, etc. */
1799static void free_module(struct module *mod)
1800{
1801 trace_module_free(mod);
1802
1803 /* Delete from various lists */
1804 mutex_lock(&module_mutex);
1805 stop_machine(__unlink_module, mod, NULL);
1806 mutex_unlock(&module_mutex);
1807 mod_sysfs_teardown(mod);
1808
1809 /* Remove dynamic debug info */
1810 ddebug_remove_module(mod->name);
1811
1812 /* Arch-specific cleanup. */
1813 module_arch_cleanup(mod);
1814
1815 /* Module unload stuff */
1816 module_unload_free(mod);
1817
1818 /* Free any allocated parameters. */
1819 destroy_params(mod->kp, mod->num_kp);
1820
1821 /* This may be NULL, but that's OK */
1822 unset_module_init_ro_nx(mod);
1823 module_free(mod, mod->module_init);
1824 kfree(mod->args);
1825 percpu_modfree(mod);
1826
1827 /* Free lock-classes: */
1828 lockdep_free_key_range(mod->module_core, mod->core_size);
1829
1830 /* Finally, free the core (containing the module structure) */
1831 unset_module_core_ro_nx(mod);
1832 module_free(mod, mod->module_core);
1833
1834#ifdef CONFIG_MPU
1835 update_protections(current->mm);
1836#endif
1837}
1838
1839void *__symbol_get(const char *symbol)
1840{
1841 struct module *owner;
1842 const struct kernel_symbol *sym;
1843
1844 preempt_disable();
1845 sym = find_symbol(symbol, &owner, NULL, true, true);
1846 if (sym && strong_try_module_get(owner))
1847 sym = NULL;
1848 preempt_enable();
1849
1850 return sym ? (void *)sym->value : NULL;
1851}
1852EXPORT_SYMBOL_GPL(__symbol_get);
1853
1854/*
1855 * Ensure that an exported symbol [global namespace] does not already exist
1856 * in the kernel or in some other module's exported symbol table.
1857 *
1858 * You must hold the module_mutex.
1859 */
1860static int verify_export_symbols(struct module *mod)
1861{
1862 unsigned int i;
1863 struct module *owner;
1864 const struct kernel_symbol *s;
1865 struct {
1866 const struct kernel_symbol *sym;
1867 unsigned int num;
1868 } arr[] = {
1869 { mod->syms, mod->num_syms },
1870 { mod->gpl_syms, mod->num_gpl_syms },
1871 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1872#ifdef CONFIG_UNUSED_SYMBOLS
1873 { mod->unused_syms, mod->num_unused_syms },
1874 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1875#endif
1876 };
1877
1878 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1879 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1880 if (find_symbol(s->name, &owner, NULL, true, false)) {
1881 printk(KERN_ERR
1882 "%s: exports duplicate symbol %s"
1883 " (owned by %s)\n",
1884 mod->name, s->name, module_name(owner));
1885 return -ENOEXEC;
1886 }
1887 }
1888 }
1889 return 0;
1890}
1891
1892/* Change all symbols so that st_value encodes the pointer directly. */
1893static int simplify_symbols(struct module *mod, const struct load_info *info)
1894{
1895 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1896 Elf_Sym *sym = (void *)symsec->sh_addr;
1897 unsigned long secbase;
1898 unsigned int i;
1899 int ret = 0;
1900 const struct kernel_symbol *ksym;
1901
1902 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1903 const char *name = info->strtab + sym[i].st_name;
1904
1905 switch (sym[i].st_shndx) {
1906 case SHN_COMMON:
1907 /* We compiled with -fno-common. These are not
1908 supposed to happen. */
1909 pr_debug("Common symbol: %s\n", name);
1910 printk("%s: please compile with -fno-common\n",
1911 mod->name);
1912 ret = -ENOEXEC;
1913 break;
1914
1915 case SHN_ABS:
1916 /* Don't need to do anything */
1917 pr_debug("Absolute symbol: 0x%08lx\n",
1918 (long)sym[i].st_value);
1919 break;
1920
1921 case SHN_UNDEF:
1922 ksym = resolve_symbol_wait(mod, info, name);
1923 /* Ok if resolved. */
1924 if (ksym && !IS_ERR(ksym)) {
1925 sym[i].st_value = ksym->value;
1926 break;
1927 }
1928
1929 /* Ok if weak. */
1930 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1931 break;
1932
1933 printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
1934 mod->name, name, PTR_ERR(ksym));
1935 ret = PTR_ERR(ksym) ?: -ENOENT;
1936 break;
1937
1938 default:
1939 /* Divert to percpu allocation if a percpu var. */
1940 if (sym[i].st_shndx == info->index.pcpu)
1941 secbase = (unsigned long)mod_percpu(mod);
1942 else
1943 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1944 sym[i].st_value += secbase;
1945 break;
1946 }
1947 }
1948
1949 return ret;
1950}
1951
1952int __weak apply_relocate(Elf_Shdr *sechdrs,
1953 const char *strtab,
1954 unsigned int symindex,
1955 unsigned int relsec,
1956 struct module *me)
1957{
1958 pr_err("module %s: REL relocation unsupported\n", me->name);
1959 return -ENOEXEC;
1960}
1961
1962int __weak apply_relocate_add(Elf_Shdr *sechdrs,
1963 const char *strtab,
1964 unsigned int symindex,
1965 unsigned int relsec,
1966 struct module *me)
1967{
1968 pr_err("module %s: RELA relocation unsupported\n", me->name);
1969 return -ENOEXEC;
1970}
1971
1972static int apply_relocations(struct module *mod, const struct load_info *info)
1973{
1974 unsigned int i;
1975 int err = 0;
1976
1977 /* Now do relocations. */
1978 for (i = 1; i < info->hdr->e_shnum; i++) {
1979 unsigned int infosec = info->sechdrs[i].sh_info;
1980
1981 /* Not a valid relocation section? */
1982 if (infosec >= info->hdr->e_shnum)
1983 continue;
1984
1985 /* Don't bother with non-allocated sections */
1986 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1987 continue;
1988
1989 if (info->sechdrs[i].sh_type == SHT_REL)
1990 err = apply_relocate(info->sechdrs, info->strtab,
1991 info->index.sym, i, mod);
1992 else if (info->sechdrs[i].sh_type == SHT_RELA)
1993 err = apply_relocate_add(info->sechdrs, info->strtab,
1994 info->index.sym, i, mod);
1995 if (err < 0)
1996 break;
1997 }
1998 return err;
1999}
2000
2001/* Additional bytes needed by arch in front of individual sections */
2002unsigned int __weak arch_mod_section_prepend(struct module *mod,
2003 unsigned int section)
2004{
2005 /* default implementation just returns zero */
2006 return 0;
2007}
2008
2009/* Update size with this section: return offset. */
2010static long get_offset(struct module *mod, unsigned int *size,
2011 Elf_Shdr *sechdr, unsigned int section)
2012{
2013 long ret;
2014
2015 *size += arch_mod_section_prepend(mod, section);
2016 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2017 *size = ret + sechdr->sh_size;
2018 return ret;
2019}
2020
2021/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2022 might -- code, read-only data, read-write data, small data. Tally
2023 sizes, and place the offsets into sh_entsize fields: high bit means it
2024 belongs in init. */
2025static void layout_sections(struct module *mod, struct load_info *info)
2026{
2027 static unsigned long const masks[][2] = {
2028 /* NOTE: all executable code must be the first section
2029 * in this array; otherwise modify the text_size
2030 * finder in the two loops below */
2031 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2032 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2033 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2034 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2035 };
2036 unsigned int m, i;
2037
2038 for (i = 0; i < info->hdr->e_shnum; i++)
2039 info->sechdrs[i].sh_entsize = ~0UL;
2040
2041 pr_debug("Core section allocation order:\n");
2042 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2043 for (i = 0; i < info->hdr->e_shnum; ++i) {
2044 Elf_Shdr *s = &info->sechdrs[i];
2045 const char *sname = info->secstrings + s->sh_name;
2046
2047 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2048 || (s->sh_flags & masks[m][1])
2049 || s->sh_entsize != ~0UL
2050 || strstarts(sname, ".init"))
2051 continue;
2052 s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2053 pr_debug("\t%s\n", sname);
2054 }
2055 switch (m) {
2056 case 0: /* executable */
2057 mod->core_size = debug_align(mod->core_size);
2058 mod->core_text_size = mod->core_size;
2059 break;
2060 case 1: /* RO: text and ro-data */
2061 mod->core_size = debug_align(mod->core_size);
2062 mod->core_ro_size = mod->core_size;
2063 break;
2064 case 3: /* whole core */
2065 mod->core_size = debug_align(mod->core_size);
2066 break;
2067 }
2068 }
2069
2070 pr_debug("Init section allocation order:\n");
2071 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2072 for (i = 0; i < info->hdr->e_shnum; ++i) {
2073 Elf_Shdr *s = &info->sechdrs[i];
2074 const char *sname = info->secstrings + s->sh_name;
2075
2076 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2077 || (s->sh_flags & masks[m][1])
2078 || s->sh_entsize != ~0UL
2079 || !strstarts(sname, ".init"))
2080 continue;
2081 s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2082 | INIT_OFFSET_MASK);
2083 pr_debug("\t%s\n", sname);
2084 }
2085 switch (m) {
2086 case 0: /* executable */
2087 mod->init_size = debug_align(mod->init_size);
2088 mod->init_text_size = mod->init_size;
2089 break;
2090 case 1: /* RO: text and ro-data */
2091 mod->init_size = debug_align(mod->init_size);
2092 mod->init_ro_size = mod->init_size;
2093 break;
2094 case 3: /* whole init */
2095 mod->init_size = debug_align(mod->init_size);
2096 break;
2097 }
2098 }
2099}
2100
2101static void set_license(struct module *mod, const char *license)
2102{
2103 if (!license)
2104 license = "unspecified";
2105
2106 if (!license_is_gpl_compatible(license)) {
2107 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2108 printk(KERN_WARNING "%s: module license '%s' taints "
2109 "kernel.\n", mod->name, license);
2110 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2111 }
2112}
2113
2114/* Parse tag=value strings from .modinfo section */
2115static char *next_string(char *string, unsigned long *secsize)
2116{
2117 /* Skip non-zero chars */
2118 while (string[0]) {
2119 string++;
2120 if ((*secsize)-- <= 1)
2121 return NULL;
2122 }
2123
2124 /* Skip any zero padding. */
2125 while (!string[0]) {
2126 string++;
2127 if ((*secsize)-- <= 1)
2128 return NULL;
2129 }
2130 return string;
2131}
2132
2133static char *get_modinfo(struct load_info *info, const char *tag)
2134{
2135 char *p;
2136 unsigned int taglen = strlen(tag);
2137 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2138 unsigned long size = infosec->sh_size;
2139
2140 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2141 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2142 return p + taglen + 1;
2143 }
2144 return NULL;
2145}
2146
2147static void setup_modinfo(struct module *mod, struct load_info *info)
2148{
2149 struct module_attribute *attr;
2150 int i;
2151
2152 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2153 if (attr->setup)
2154 attr->setup(mod, get_modinfo(info, attr->attr.name));
2155 }
2156}
2157
2158static void free_modinfo(struct module *mod)
2159{
2160 struct module_attribute *attr;
2161 int i;
2162
2163 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2164 if (attr->free)
2165 attr->free(mod);
2166 }
2167}
2168
2169#ifdef CONFIG_KALLSYMS
2170
2171/* lookup symbol in given range of kernel_symbols */
2172static const struct kernel_symbol *lookup_symbol(const char *name,
2173 const struct kernel_symbol *start,
2174 const struct kernel_symbol *stop)
2175{
2176 return bsearch(name, start, stop - start,
2177 sizeof(struct kernel_symbol), cmp_name);
2178}
2179
2180static int is_exported(const char *name, unsigned long value,
2181 const struct module *mod)
2182{
2183 const struct kernel_symbol *ks;
2184 if (!mod)
2185 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2186 else
2187 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2188 return ks != NULL && ks->value == value;
2189}
2190
2191/* As per nm */
2192static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2193{
2194 const Elf_Shdr *sechdrs = info->sechdrs;
2195
2196 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2197 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2198 return 'v';
2199 else
2200 return 'w';
2201 }
2202 if (sym->st_shndx == SHN_UNDEF)
2203 return 'U';
2204 if (sym->st_shndx == SHN_ABS)
2205 return 'a';
2206 if (sym->st_shndx >= SHN_LORESERVE)
2207 return '?';
2208 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2209 return 't';
2210 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2211 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2212 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2213 return 'r';
2214 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2215 return 'g';
2216 else
2217 return 'd';
2218 }
2219 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2220 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2221 return 's';
2222 else
2223 return 'b';
2224 }
2225 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2226 ".debug")) {
2227 return 'n';
2228 }
2229 return '?';
2230}
2231
2232static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2233 unsigned int shnum)
2234{
2235 const Elf_Shdr *sec;
2236
2237 if (src->st_shndx == SHN_UNDEF
2238 || src->st_shndx >= shnum
2239 || !src->st_name)
2240 return false;
2241
2242 sec = sechdrs + src->st_shndx;
2243 if (!(sec->sh_flags & SHF_ALLOC)
2244#ifndef CONFIG_KALLSYMS_ALL
2245 || !(sec->sh_flags & SHF_EXECINSTR)
2246#endif
2247 || (sec->sh_entsize & INIT_OFFSET_MASK))
2248 return false;
2249
2250 return true;
2251}
2252
2253/*
2254 * We only allocate and copy the strings needed by the parts of symtab
2255 * we keep. This is simple, but has the effect of making multiple
2256 * copies of duplicates. We could be more sophisticated, see
2257 * linux-kernel thread starting with
2258 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2259 */
2260static void layout_symtab(struct module *mod, struct load_info *info)
2261{
2262 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2263 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2264 const Elf_Sym *src;
2265 unsigned int i, nsrc, ndst, strtab_size;
2266
2267 /* Put symbol section at end of init part of module. */
2268 symsect->sh_flags |= SHF_ALLOC;
2269 symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2270 info->index.sym) | INIT_OFFSET_MASK;
2271 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2272
2273 src = (void *)info->hdr + symsect->sh_offset;
2274 nsrc = symsect->sh_size / sizeof(*src);
2275
2276 /* Compute total space required for the core symbols' strtab. */
2277 for (ndst = i = strtab_size = 1; i < nsrc; ++i, ++src)
2278 if (is_core_symbol(src, info->sechdrs, info->hdr->e_shnum)) {
2279 strtab_size += strlen(&info->strtab[src->st_name]) + 1;
2280 ndst++;
2281 }
2282
2283 /* Append room for core symbols at end of core part. */
2284 info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2285 info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2286 mod->core_size += strtab_size;
2287
2288 /* Put string table section at end of init part of module. */
2289 strsect->sh_flags |= SHF_ALLOC;
2290 strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2291 info->index.str) | INIT_OFFSET_MASK;
2292 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2293}
2294
2295static void add_kallsyms(struct module *mod, const struct load_info *info)
2296{
2297 unsigned int i, ndst;
2298 const Elf_Sym *src;
2299 Elf_Sym *dst;
2300 char *s;
2301 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2302
2303 mod->symtab = (void *)symsec->sh_addr;
2304 mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2305 /* Make sure we get permanent strtab: don't use info->strtab. */
2306 mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2307
2308 /* Set types up while we still have access to sections. */
2309 for (i = 0; i < mod->num_symtab; i++)
2310 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2311
2312 mod->core_symtab = dst = mod->module_core + info->symoffs;
2313 mod->core_strtab = s = mod->module_core + info->stroffs;
2314 src = mod->symtab;
2315 *dst = *src;
2316 *s++ = 0;
2317 for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
2318 if (!is_core_symbol(src, info->sechdrs, info->hdr->e_shnum))
2319 continue;
2320
2321 dst[ndst] = *src;
2322 dst[ndst++].st_name = s - mod->core_strtab;
2323 s += strlcpy(s, &mod->strtab[src->st_name], KSYM_NAME_LEN) + 1;
2324 }
2325 mod->core_num_syms = ndst;
2326}
2327#else
2328static inline void layout_symtab(struct module *mod, struct load_info *info)
2329{
2330}
2331
2332static void add_kallsyms(struct module *mod, const struct load_info *info)
2333{
2334}
2335#endif /* CONFIG_KALLSYMS */
2336
2337static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2338{
2339 if (!debug)
2340 return;
2341#ifdef CONFIG_DYNAMIC_DEBUG
2342 if (ddebug_add_module(debug, num, debug->modname))
2343 printk(KERN_ERR "dynamic debug error adding module: %s\n",
2344 debug->modname);
2345#endif
2346}
2347
2348static void dynamic_debug_remove(struct _ddebug *debug)
2349{
2350 if (debug)
2351 ddebug_remove_module(debug->modname);
2352}
2353
2354void * __weak module_alloc(unsigned long size)
2355{
2356 return size == 0 ? NULL : vmalloc_exec(size);
2357}
2358
2359static void *module_alloc_update_bounds(unsigned long size)
2360{
2361 void *ret = module_alloc(size);
2362
2363 if (ret) {
2364 mutex_lock(&module_mutex);
2365 /* Update module bounds. */
2366 if ((unsigned long)ret < module_addr_min)
2367 module_addr_min = (unsigned long)ret;
2368 if ((unsigned long)ret + size > module_addr_max)
2369 module_addr_max = (unsigned long)ret + size;
2370 mutex_unlock(&module_mutex);
2371 }
2372 return ret;
2373}
2374
2375#ifdef CONFIG_DEBUG_KMEMLEAK
2376static void kmemleak_load_module(const struct module *mod,
2377 const struct load_info *info)
2378{
2379 unsigned int i;
2380
2381 /* only scan the sections containing data */
2382 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2383
2384 for (i = 1; i < info->hdr->e_shnum; i++) {
2385 const char *name = info->secstrings + info->sechdrs[i].sh_name;
2386 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC))
2387 continue;
2388 if (!strstarts(name, ".data") && !strstarts(name, ".bss"))
2389 continue;
2390
2391 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2392 info->sechdrs[i].sh_size, GFP_KERNEL);
2393 }
2394}
2395#else
2396static inline void kmemleak_load_module(const struct module *mod,
2397 const struct load_info *info)
2398{
2399}
2400#endif
2401
2402/* Sets info->hdr and info->len. */
2403static int copy_and_check(struct load_info *info,
2404 const void __user *umod, unsigned long len,
2405 const char __user *uargs)
2406{
2407 int err;
2408 Elf_Ehdr *hdr;
2409
2410 if (len < sizeof(*hdr))
2411 return -ENOEXEC;
2412
2413 /* Suck in entire file: we'll want most of it. */
2414 if ((hdr = vmalloc(len)) == NULL)
2415 return -ENOMEM;
2416
2417 if (copy_from_user(hdr, umod, len) != 0) {
2418 err = -EFAULT;
2419 goto free_hdr;
2420 }
2421
2422 /* Sanity checks against insmoding binaries or wrong arch,
2423 weird elf version */
2424 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
2425 || hdr->e_type != ET_REL
2426 || !elf_check_arch(hdr)
2427 || hdr->e_shentsize != sizeof(Elf_Shdr)) {
2428 err = -ENOEXEC;
2429 goto free_hdr;
2430 }
2431
2432 if (hdr->e_shoff >= len ||
2433 hdr->e_shnum * sizeof(Elf_Shdr) > len - hdr->e_shoff) {
2434 err = -ENOEXEC;
2435 goto free_hdr;
2436 }
2437
2438 info->hdr = hdr;
2439 info->len = len;
2440 return 0;
2441
2442free_hdr:
2443 vfree(hdr);
2444 return err;
2445}
2446
2447static void free_copy(struct load_info *info)
2448{
2449 vfree(info->hdr);
2450}
2451
2452static int rewrite_section_headers(struct load_info *info)
2453{
2454 unsigned int i;
2455
2456 /* This should always be true, but let's be sure. */
2457 info->sechdrs[0].sh_addr = 0;
2458
2459 for (i = 1; i < info->hdr->e_shnum; i++) {
2460 Elf_Shdr *shdr = &info->sechdrs[i];
2461 if (shdr->sh_type != SHT_NOBITS
2462 && info->len < shdr->sh_offset + shdr->sh_size) {
2463 printk(KERN_ERR "Module len %lu truncated\n",
2464 info->len);
2465 return -ENOEXEC;
2466 }
2467
2468 /* Mark all sections sh_addr with their address in the
2469 temporary image. */
2470 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2471
2472#ifndef CONFIG_MODULE_UNLOAD
2473 /* Don't load .exit sections */
2474 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2475 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2476#endif
2477 }
2478
2479 /* Track but don't keep modinfo and version sections. */
2480 info->index.vers = find_sec(info, "__versions");
2481 info->index.info = find_sec(info, ".modinfo");
2482 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2483 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2484 return 0;
2485}
2486
2487/*
2488 * Set up our basic convenience variables (pointers to section headers,
2489 * search for module section index etc), and do some basic section
2490 * verification.
2491 *
2492 * Return the temporary module pointer (we'll replace it with the final
2493 * one when we move the module sections around).
2494 */
2495static struct module *setup_load_info(struct load_info *info)
2496{
2497 unsigned int i;
2498 int err;
2499 struct module *mod;
2500
2501 /* Set up the convenience variables */
2502 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2503 info->secstrings = (void *)info->hdr
2504 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2505
2506 err = rewrite_section_headers(info);
2507 if (err)
2508 return ERR_PTR(err);
2509
2510 /* Find internal symbols and strings. */
2511 for (i = 1; i < info->hdr->e_shnum; i++) {
2512 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2513 info->index.sym = i;
2514 info->index.str = info->sechdrs[i].sh_link;
2515 info->strtab = (char *)info->hdr
2516 + info->sechdrs[info->index.str].sh_offset;
2517 break;
2518 }
2519 }
2520
2521 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2522 if (!info->index.mod) {
2523 printk(KERN_WARNING "No module found in object\n");
2524 return ERR_PTR(-ENOEXEC);
2525 }
2526 /* This is temporary: point mod into copy of data. */
2527 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2528
2529 if (info->index.sym == 0) {
2530 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
2531 mod->name);
2532 return ERR_PTR(-ENOEXEC);
2533 }
2534
2535 info->index.pcpu = find_pcpusec(info);
2536
2537 /* Check module struct version now, before we try to use module. */
2538 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2539 return ERR_PTR(-ENOEXEC);
2540
2541 return mod;
2542}
2543
2544static int check_modinfo(struct module *mod, struct load_info *info)
2545{
2546 const char *modmagic = get_modinfo(info, "vermagic");
2547 int err;
2548
2549 /* This is allowed: modprobe --force will invalidate it. */
2550 if (!modmagic) {
2551 err = try_to_force_load(mod, "bad vermagic");
2552 if (err)
2553 return err;
2554 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2555 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
2556 mod->name, modmagic, vermagic);
2557 return -ENOEXEC;
2558 }
2559
2560 if (!get_modinfo(info, "intree"))
2561 add_taint_module(mod, TAINT_OOT_MODULE);
2562
2563 if (get_modinfo(info, "staging")) {
2564 add_taint_module(mod, TAINT_CRAP);
2565 printk(KERN_WARNING "%s: module is from the staging directory,"
2566 " the quality is unknown, you have been warned.\n",
2567 mod->name);
2568 }
2569
2570 /* Set up license info based on the info section */
2571 set_license(mod, get_modinfo(info, "license"));
2572
2573 return 0;
2574}
2575
2576static void find_module_sections(struct module *mod, struct load_info *info)
2577{
2578 mod->kp = section_objs(info, "__param",
2579 sizeof(*mod->kp), &mod->num_kp);
2580 mod->syms = section_objs(info, "__ksymtab",
2581 sizeof(*mod->syms), &mod->num_syms);
2582 mod->crcs = section_addr(info, "__kcrctab");
2583 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2584 sizeof(*mod->gpl_syms),
2585 &mod->num_gpl_syms);
2586 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2587 mod->gpl_future_syms = section_objs(info,
2588 "__ksymtab_gpl_future",
2589 sizeof(*mod->gpl_future_syms),
2590 &mod->num_gpl_future_syms);
2591 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2592
2593#ifdef CONFIG_UNUSED_SYMBOLS
2594 mod->unused_syms = section_objs(info, "__ksymtab_unused",
2595 sizeof(*mod->unused_syms),
2596 &mod->num_unused_syms);
2597 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2598 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2599 sizeof(*mod->unused_gpl_syms),
2600 &mod->num_unused_gpl_syms);
2601 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2602#endif
2603#ifdef CONFIG_CONSTRUCTORS
2604 mod->ctors = section_objs(info, ".ctors",
2605 sizeof(*mod->ctors), &mod->num_ctors);
2606#endif
2607
2608#ifdef CONFIG_TRACEPOINTS
2609 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2610 sizeof(*mod->tracepoints_ptrs),
2611 &mod->num_tracepoints);
2612#endif
2613#ifdef HAVE_JUMP_LABEL
2614 mod->jump_entries = section_objs(info, "__jump_table",
2615 sizeof(*mod->jump_entries),
2616 &mod->num_jump_entries);
2617#endif
2618#ifdef CONFIG_EVENT_TRACING
2619 mod->trace_events = section_objs(info, "_ftrace_events",
2620 sizeof(*mod->trace_events),
2621 &mod->num_trace_events);
2622 /*
2623 * This section contains pointers to allocated objects in the trace
2624 * code and not scanning it leads to false positives.
2625 */
2626 kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
2627 mod->num_trace_events, GFP_KERNEL);
2628#endif
2629#ifdef CONFIG_TRACING
2630 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2631 sizeof(*mod->trace_bprintk_fmt_start),
2632 &mod->num_trace_bprintk_fmt);
2633 /*
2634 * This section contains pointers to allocated objects in the trace
2635 * code and not scanning it leads to false positives.
2636 */
2637 kmemleak_scan_area(mod->trace_bprintk_fmt_start,
2638 sizeof(*mod->trace_bprintk_fmt_start) *
2639 mod->num_trace_bprintk_fmt, GFP_KERNEL);
2640#endif
2641#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2642 /* sechdrs[0].sh_size is always zero */
2643 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2644 sizeof(*mod->ftrace_callsites),
2645 &mod->num_ftrace_callsites);
2646#endif
2647
2648 mod->extable = section_objs(info, "__ex_table",
2649 sizeof(*mod->extable), &mod->num_exentries);
2650
2651 if (section_addr(info, "__obsparm"))
2652 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2653 mod->name);
2654
2655 info->debug = section_objs(info, "__verbose",
2656 sizeof(*info->debug), &info->num_debug);
2657}
2658
2659static int move_module(struct module *mod, struct load_info *info)
2660{
2661 int i;
2662 void *ptr;
2663
2664 /* Do the allocs. */
2665 ptr = module_alloc_update_bounds(mod->core_size);
2666 /*
2667 * The pointer to this block is stored in the module structure
2668 * which is inside the block. Just mark it as not being a
2669 * leak.
2670 */
2671 kmemleak_not_leak(ptr);
2672 if (!ptr)
2673 return -ENOMEM;
2674
2675 memset(ptr, 0, mod->core_size);
2676 mod->module_core = ptr;
2677
2678 ptr = module_alloc_update_bounds(mod->init_size);
2679 /*
2680 * The pointer to this block is stored in the module structure
2681 * which is inside the block. This block doesn't need to be
2682 * scanned as it contains data and code that will be freed
2683 * after the module is initialized.
2684 */
2685 kmemleak_ignore(ptr);
2686 if (!ptr && mod->init_size) {
2687 module_free(mod, mod->module_core);
2688 return -ENOMEM;
2689 }
2690 memset(ptr, 0, mod->init_size);
2691 mod->module_init = ptr;
2692
2693 /* Transfer each section which specifies SHF_ALLOC */
2694 pr_debug("final section addresses:\n");
2695 for (i = 0; i < info->hdr->e_shnum; i++) {
2696 void *dest;
2697 Elf_Shdr *shdr = &info->sechdrs[i];
2698
2699 if (!(shdr->sh_flags & SHF_ALLOC))
2700 continue;
2701
2702 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2703 dest = mod->module_init
2704 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2705 else
2706 dest = mod->module_core + shdr->sh_entsize;
2707
2708 if (shdr->sh_type != SHT_NOBITS)
2709 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2710 /* Update sh_addr to point to copy in image. */
2711 shdr->sh_addr = (unsigned long)dest;
2712 pr_debug("\t0x%lx %s\n",
2713 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2714 }
2715
2716 return 0;
2717}
2718
2719static int check_module_license_and_versions(struct module *mod)
2720{
2721 /*
2722 * ndiswrapper is under GPL by itself, but loads proprietary modules.
2723 * Don't use add_taint_module(), as it would prevent ndiswrapper from
2724 * using GPL-only symbols it needs.
2725 */
2726 if (strcmp(mod->name, "ndiswrapper") == 0)
2727 add_taint(TAINT_PROPRIETARY_MODULE);
2728
2729 /* driverloader was caught wrongly pretending to be under GPL */
2730 if (strcmp(mod->name, "driverloader") == 0)
2731 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2732
2733#ifdef CONFIG_MODVERSIONS
2734 if ((mod->num_syms && !mod->crcs)
2735 || (mod->num_gpl_syms && !mod->gpl_crcs)
2736 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2737#ifdef CONFIG_UNUSED_SYMBOLS
2738 || (mod->num_unused_syms && !mod->unused_crcs)
2739 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2740#endif
2741 ) {
2742 return try_to_force_load(mod,
2743 "no versions for exported symbols");
2744 }
2745#endif
2746 return 0;
2747}
2748
2749static void flush_module_icache(const struct module *mod)
2750{
2751 mm_segment_t old_fs;
2752
2753 /* flush the icache in correct context */
2754 old_fs = get_fs();
2755 set_fs(KERNEL_DS);
2756
2757 /*
2758 * Flush the instruction cache, since we've played with text.
2759 * Do it before processing of module parameters, so the module
2760 * can provide parameter accessor functions of its own.
2761 */
2762 if (mod->module_init)
2763 flush_icache_range((unsigned long)mod->module_init,
2764 (unsigned long)mod->module_init
2765 + mod->init_size);
2766 flush_icache_range((unsigned long)mod->module_core,
2767 (unsigned long)mod->module_core + mod->core_size);
2768
2769 set_fs(old_fs);
2770}
2771
2772int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2773 Elf_Shdr *sechdrs,
2774 char *secstrings,
2775 struct module *mod)
2776{
2777 return 0;
2778}
2779
2780static struct module *layout_and_allocate(struct load_info *info)
2781{
2782 /* Module within temporary copy. */
2783 struct module *mod;
2784 Elf_Shdr *pcpusec;
2785 int err;
2786
2787 mod = setup_load_info(info);
2788 if (IS_ERR(mod))
2789 return mod;
2790
2791 err = check_modinfo(mod, info);
2792 if (err)
2793 return ERR_PTR(err);
2794
2795 /* Allow arches to frob section contents and sizes. */
2796 err = module_frob_arch_sections(info->hdr, info->sechdrs,
2797 info->secstrings, mod);
2798 if (err < 0)
2799 goto out;
2800
2801 pcpusec = &info->sechdrs[info->index.pcpu];
2802 if (pcpusec->sh_size) {
2803 /* We have a special allocation for this section. */
2804 err = percpu_modalloc(mod,
2805 pcpusec->sh_size, pcpusec->sh_addralign);
2806 if (err)
2807 goto out;
2808 pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
2809 }
2810
2811 /* Determine total sizes, and put offsets in sh_entsize. For now
2812 this is done generically; there doesn't appear to be any
2813 special cases for the architectures. */
2814 layout_sections(mod, info);
2815 layout_symtab(mod, info);
2816
2817 /* Allocate and move to the final place */
2818 err = move_module(mod, info);
2819 if (err)
2820 goto free_percpu;
2821
2822 /* Module has been copied to its final place now: return it. */
2823 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2824 kmemleak_load_module(mod, info);
2825 return mod;
2826
2827free_percpu:
2828 percpu_modfree(mod);
2829out:
2830 return ERR_PTR(err);
2831}
2832
2833/* mod is no longer valid after this! */
2834static void module_deallocate(struct module *mod, struct load_info *info)
2835{
2836 percpu_modfree(mod);
2837 module_free(mod, mod->module_init);
2838 module_free(mod, mod->module_core);
2839}
2840
2841int __weak module_finalize(const Elf_Ehdr *hdr,
2842 const Elf_Shdr *sechdrs,
2843 struct module *me)
2844{
2845 return 0;
2846}
2847
2848static int post_relocation(struct module *mod, const struct load_info *info)
2849{
2850 /* Sort exception table now relocations are done. */
2851 sort_extable(mod->extable, mod->extable + mod->num_exentries);
2852
2853 /* Copy relocated percpu area over. */
2854 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2855 info->sechdrs[info->index.pcpu].sh_size);
2856
2857 /* Setup kallsyms-specific fields. */
2858 add_kallsyms(mod, info);
2859
2860 /* Arch-specific module finalizing. */
2861 return module_finalize(info->hdr, info->sechdrs, mod);
2862}
2863
2864/* Allocate and load the module: note that size of section 0 is always
2865 zero, and we rely on this for optional sections. */
2866static struct module *load_module(void __user *umod,
2867 unsigned long len,
2868 const char __user *uargs)
2869{
2870 struct load_info info = { NULL, };
2871 struct module *mod;
2872 long err;
2873
2874 pr_debug("load_module: umod=%p, len=%lu, uargs=%p\n",
2875 umod, len, uargs);
2876
2877 /* Copy in the blobs from userspace, check they are vaguely sane. */
2878 err = copy_and_check(&info, umod, len, uargs);
2879 if (err)
2880 return ERR_PTR(err);
2881
2882 /* Figure out module layout, and allocate all the memory. */
2883 mod = layout_and_allocate(&info);
2884 if (IS_ERR(mod)) {
2885 err = PTR_ERR(mod);
2886 goto free_copy;
2887 }
2888
2889 /* Now module is in final location, initialize linked lists, etc. */
2890 err = module_unload_init(mod);
2891 if (err)
2892 goto free_module;
2893
2894 /* Now we've got everything in the final locations, we can
2895 * find optional sections. */
2896 find_module_sections(mod, &info);
2897
2898 err = check_module_license_and_versions(mod);
2899 if (err)
2900 goto free_unload;
2901
2902 /* Set up MODINFO_ATTR fields */
2903 setup_modinfo(mod, &info);
2904
2905 /* Fix up syms, so that st_value is a pointer to location. */
2906 err = simplify_symbols(mod, &info);
2907 if (err < 0)
2908 goto free_modinfo;
2909
2910 err = apply_relocations(mod, &info);
2911 if (err < 0)
2912 goto free_modinfo;
2913
2914 err = post_relocation(mod, &info);
2915 if (err < 0)
2916 goto free_modinfo;
2917
2918 flush_module_icache(mod);
2919
2920 /* Now copy in args */
2921 mod->args = strndup_user(uargs, ~0UL >> 1);
2922 if (IS_ERR(mod->args)) {
2923 err = PTR_ERR(mod->args);
2924 goto free_arch_cleanup;
2925 }
2926
2927 /* Mark state as coming so strong_try_module_get() ignores us. */
2928 mod->state = MODULE_STATE_COMING;
2929
2930 /* Now sew it into the lists so we can get lockdep and oops
2931 * info during argument parsing. No one should access us, since
2932 * strong_try_module_get() will fail.
2933 * lockdep/oops can run asynchronous, so use the RCU list insertion
2934 * function to insert in a way safe to concurrent readers.
2935 * The mutex protects against concurrent writers.
2936 */
2937 mutex_lock(&module_mutex);
2938 if (find_module(mod->name)) {
2939 err = -EEXIST;
2940 goto unlock;
2941 }
2942
2943 /* This has to be done once we're sure module name is unique. */
2944 dynamic_debug_setup(info.debug, info.num_debug);
2945
2946 /* Find duplicate symbols */
2947 err = verify_export_symbols(mod);
2948 if (err < 0)
2949 goto ddebug;
2950
2951 module_bug_finalize(info.hdr, info.sechdrs, mod);
2952 list_add_rcu(&mod->list, &modules);
2953 mutex_unlock(&module_mutex);
2954
2955 /* Module is ready to execute: parsing args may do that. */
2956 err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
2957 -32768, 32767, &ddebug_dyndbg_module_param_cb);
2958 if (err < 0)
2959 goto unlink;
2960
2961 /* Link in to syfs. */
2962 err = mod_sysfs_setup(mod, &info, mod->kp, mod->num_kp);
2963 if (err < 0)
2964 goto unlink;
2965
2966 /* Get rid of temporary copy. */
2967 free_copy(&info);
2968
2969 /* Done! */
2970 trace_module_load(mod);
2971 return mod;
2972
2973 unlink:
2974 mutex_lock(&module_mutex);
2975 /* Unlink carefully: kallsyms could be walking list. */
2976 list_del_rcu(&mod->list);
2977 module_bug_cleanup(mod);
2978
2979 ddebug:
2980 dynamic_debug_remove(info.debug);
2981 unlock:
2982 mutex_unlock(&module_mutex);
2983 synchronize_sched();
2984 kfree(mod->args);
2985 free_arch_cleanup:
2986 module_arch_cleanup(mod);
2987 free_modinfo:
2988 free_modinfo(mod);
2989 free_unload:
2990 module_unload_free(mod);
2991 free_module:
2992 module_deallocate(mod, &info);
2993 free_copy:
2994 free_copy(&info);
2995 return ERR_PTR(err);
2996}
2997
2998/* Call module constructors. */
2999static void do_mod_ctors(struct module *mod)
3000{
3001#ifdef CONFIG_CONSTRUCTORS
3002 unsigned long i;
3003
3004 for (i = 0; i < mod->num_ctors; i++)
3005 mod->ctors[i]();
3006#endif
3007}
3008
3009/* This is where the real work happens */
3010SYSCALL_DEFINE3(init_module, void __user *, umod,
3011 unsigned long, len, const char __user *, uargs)
3012{
3013 struct module *mod;
3014 int ret = 0;
3015
3016 /* Must have permission */
3017 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3018 return -EPERM;
3019
3020 /* Do all the hard work */
3021 mod = load_module(umod, len, uargs);
3022 if (IS_ERR(mod))
3023 return PTR_ERR(mod);
3024
3025 blocking_notifier_call_chain(&module_notify_list,
3026 MODULE_STATE_COMING, mod);
3027
3028 /* Set RO and NX regions for core */
3029 set_section_ro_nx(mod->module_core,
3030 mod->core_text_size,
3031 mod->core_ro_size,
3032 mod->core_size);
3033
3034 /* Set RO and NX regions for init */
3035 set_section_ro_nx(mod->module_init,
3036 mod->init_text_size,
3037 mod->init_ro_size,
3038 mod->init_size);
3039
3040 do_mod_ctors(mod);
3041 /* Start the module */
3042 if (mod->init != NULL)
3043 ret = do_one_initcall(mod->init);
3044 if (ret < 0) {
3045 /* Init routine failed: abort. Try to protect us from
3046 buggy refcounters. */
3047 mod->state = MODULE_STATE_GOING;
3048 synchronize_sched();
3049 module_put(mod);
3050 blocking_notifier_call_chain(&module_notify_list,
3051 MODULE_STATE_GOING, mod);
3052 free_module(mod);
3053 wake_up(&module_wq);
3054 return ret;
3055 }
3056 if (ret > 0) {
3057 printk(KERN_WARNING
3058"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
3059"%s: loading module anyway...\n",
3060 __func__, mod->name, ret,
3061 __func__);
3062 dump_stack();
3063 }
3064
3065 /* Now it's a first class citizen! Wake up anyone waiting for it. */
3066 mod->state = MODULE_STATE_LIVE;
3067 wake_up(&module_wq);
3068 blocking_notifier_call_chain(&module_notify_list,
3069 MODULE_STATE_LIVE, mod);
3070
3071 /* We need to finish all async code before the module init sequence is done */
3072 async_synchronize_full();
3073
3074 mutex_lock(&module_mutex);
3075 /* Drop initial reference. */
3076 module_put(mod);
3077 trim_init_extable(mod);
3078#ifdef CONFIG_KALLSYMS
3079 mod->num_symtab = mod->core_num_syms;
3080 mod->symtab = mod->core_symtab;
3081 mod->strtab = mod->core_strtab;
3082#endif
3083 unset_module_init_ro_nx(mod);
3084 module_free(mod, mod->module_init);
3085 mod->module_init = NULL;
3086 mod->init_size = 0;
3087 mod->init_ro_size = 0;
3088 mod->init_text_size = 0;
3089 mutex_unlock(&module_mutex);
3090
3091 return 0;
3092}
3093
3094static inline int within(unsigned long addr, void *start, unsigned long size)
3095{
3096 return ((void *)addr >= start && (void *)addr < start + size);
3097}
3098
3099#ifdef CONFIG_KALLSYMS
3100/*
3101 * This ignores the intensely annoying "mapping symbols" found
3102 * in ARM ELF files: $a, $t and $d.
3103 */
3104static inline int is_arm_mapping_symbol(const char *str)
3105{
3106 return str[0] == '$' && strchr("atd", str[1])
3107 && (str[2] == '\0' || str[2] == '.');
3108}
3109
3110static const char *get_ksymbol(struct module *mod,
3111 unsigned long addr,
3112 unsigned long *size,
3113 unsigned long *offset)
3114{
3115 unsigned int i, best = 0;
3116 unsigned long nextval;
3117
3118 /* At worse, next value is at end of module */
3119 if (within_module_init(addr, mod))
3120 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3121 else
3122 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3123
3124 /* Scan for closest preceding symbol, and next symbol. (ELF
3125 starts real symbols at 1). */
3126 for (i = 1; i < mod->num_symtab; i++) {
3127 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3128 continue;
3129
3130 /* We ignore unnamed symbols: they're uninformative
3131 * and inserted at a whim. */
3132 if (mod->symtab[i].st_value <= addr
3133 && mod->symtab[i].st_value > mod->symtab[best].st_value
3134 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3135 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3136 best = i;
3137 if (mod->symtab[i].st_value > addr
3138 && mod->symtab[i].st_value < nextval
3139 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3140 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3141 nextval = mod->symtab[i].st_value;
3142 }
3143
3144 if (!best)
3145 return NULL;
3146
3147 if (size)
3148 *size = nextval - mod->symtab[best].st_value;
3149 if (offset)
3150 *offset = addr - mod->symtab[best].st_value;
3151 return mod->strtab + mod->symtab[best].st_name;
3152}
3153
3154/* For kallsyms to ask for address resolution. NULL means not found. Careful
3155 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3156const char *module_address_lookup(unsigned long addr,
3157 unsigned long *size,
3158 unsigned long *offset,
3159 char **modname,
3160 char *namebuf)
3161{
3162 struct module *mod;
3163 const char *ret = NULL;
3164
3165 preempt_disable();
3166 list_for_each_entry_rcu(mod, &modules, list) {
3167 if (within_module_init(addr, mod) ||
3168 within_module_core(addr, mod)) {
3169 if (modname)
3170 *modname = mod->name;
3171 ret = get_ksymbol(mod, addr, size, offset);
3172 break;
3173 }
3174 }
3175 /* Make a copy in here where it's safe */
3176 if (ret) {
3177 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3178 ret = namebuf;
3179 }
3180 preempt_enable();
3181 return ret;
3182}
3183
3184int lookup_module_symbol_name(unsigned long addr, char *symname)
3185{
3186 struct module *mod;
3187
3188 preempt_disable();
3189 list_for_each_entry_rcu(mod, &modules, list) {
3190 if (within_module_init(addr, mod) ||
3191 within_module_core(addr, mod)) {
3192 const char *sym;
3193
3194 sym = get_ksymbol(mod, addr, NULL, NULL);
3195 if (!sym)
3196 goto out;
3197 strlcpy(symname, sym, KSYM_NAME_LEN);
3198 preempt_enable();
3199 return 0;
3200 }
3201 }
3202out:
3203 preempt_enable();
3204 return -ERANGE;
3205}
3206
3207int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3208 unsigned long *offset, char *modname, char *name)
3209{
3210 struct module *mod;
3211
3212 preempt_disable();
3213 list_for_each_entry_rcu(mod, &modules, list) {
3214 if (within_module_init(addr, mod) ||
3215 within_module_core(addr, mod)) {
3216 const char *sym;
3217
3218 sym = get_ksymbol(mod, addr, size, offset);
3219 if (!sym)
3220 goto out;
3221 if (modname)
3222 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3223 if (name)
3224 strlcpy(name, sym, KSYM_NAME_LEN);
3225 preempt_enable();
3226 return 0;
3227 }
3228 }
3229out:
3230 preempt_enable();
3231 return -ERANGE;
3232}
3233
3234int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3235 char *name, char *module_name, int *exported)
3236{
3237 struct module *mod;
3238
3239 preempt_disable();
3240 list_for_each_entry_rcu(mod, &modules, list) {
3241 if (symnum < mod->num_symtab) {
3242 *value = mod->symtab[symnum].st_value;
3243 *type = mod->symtab[symnum].st_info;
3244 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3245 KSYM_NAME_LEN);
3246 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3247 *exported = is_exported(name, *value, mod);
3248 preempt_enable();
3249 return 0;
3250 }
3251 symnum -= mod->num_symtab;
3252 }
3253 preempt_enable();
3254 return -ERANGE;
3255}
3256
3257static unsigned long mod_find_symname(struct module *mod, const char *name)
3258{
3259 unsigned int i;
3260
3261 for (i = 0; i < mod->num_symtab; i++)
3262 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3263 mod->symtab[i].st_info != 'U')
3264 return mod->symtab[i].st_value;
3265 return 0;
3266}
3267
3268/* Look for this name: can be of form module:name. */
3269unsigned long module_kallsyms_lookup_name(const char *name)
3270{
3271 struct module *mod;
3272 char *colon;
3273 unsigned long ret = 0;
3274
3275 /* Don't lock: we're in enough trouble already. */
3276 preempt_disable();
3277 if ((colon = strchr(name, ':')) != NULL) {
3278 *colon = '\0';
3279 if ((mod = find_module(name)) != NULL)
3280 ret = mod_find_symname(mod, colon+1);
3281 *colon = ':';
3282 } else {
3283 list_for_each_entry_rcu(mod, &modules, list)
3284 if ((ret = mod_find_symname(mod, name)) != 0)
3285 break;
3286 }
3287 preempt_enable();
3288 return ret;
3289}
3290
3291int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3292 struct module *, unsigned long),
3293 void *data)
3294{
3295 struct module *mod;
3296 unsigned int i;
3297 int ret;
3298
3299 list_for_each_entry(mod, &modules, list) {
3300 for (i = 0; i < mod->num_symtab; i++) {
3301 ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3302 mod, mod->symtab[i].st_value);
3303 if (ret != 0)
3304 return ret;
3305 }
3306 }
3307 return 0;
3308}
3309#endif /* CONFIG_KALLSYMS */
3310
3311static char *module_flags(struct module *mod, char *buf)
3312{
3313 int bx = 0;
3314
3315 if (mod->taints ||
3316 mod->state == MODULE_STATE_GOING ||
3317 mod->state == MODULE_STATE_COMING) {
3318 buf[bx++] = '(';
3319 bx += module_flags_taint(mod, buf + bx);
3320 /* Show a - for module-is-being-unloaded */
3321 if (mod->state == MODULE_STATE_GOING)
3322 buf[bx++] = '-';
3323 /* Show a + for module-is-being-loaded */
3324 if (mod->state == MODULE_STATE_COMING)
3325 buf[bx++] = '+';
3326 buf[bx++] = ')';
3327 }
3328 buf[bx] = '\0';
3329
3330 return buf;
3331}
3332
3333#ifdef CONFIG_PROC_FS
3334/* Called by the /proc file system to return a list of modules. */
3335static void *m_start(struct seq_file *m, loff_t *pos)
3336{
3337 mutex_lock(&module_mutex);
3338 return seq_list_start(&modules, *pos);
3339}
3340
3341static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3342{
3343 return seq_list_next(p, &modules, pos);
3344}
3345
3346static void m_stop(struct seq_file *m, void *p)
3347{
3348 mutex_unlock(&module_mutex);
3349}
3350
3351static int m_show(struct seq_file *m, void *p)
3352{
3353 struct module *mod = list_entry(p, struct module, list);
3354 char buf[8];
3355
3356 seq_printf(m, "%s %u",
3357 mod->name, mod->init_size + mod->core_size);
3358 print_unload_info(m, mod);
3359
3360 /* Informative for users. */
3361 seq_printf(m, " %s",
3362 mod->state == MODULE_STATE_GOING ? "Unloading":
3363 mod->state == MODULE_STATE_COMING ? "Loading":
3364 "Live");
3365 /* Used by oprofile and other similar tools. */
3366 seq_printf(m, " 0x%pK", mod->module_core);
3367
3368 /* Taints info */
3369 if (mod->taints)
3370 seq_printf(m, " %s", module_flags(mod, buf));
3371
3372 seq_printf(m, "\n");
3373 return 0;
3374}
3375
3376/* Format: modulename size refcount deps address
3377
3378 Where refcount is a number or -, and deps is a comma-separated list
3379 of depends or -.
3380*/
3381static const struct seq_operations modules_op = {
3382 .start = m_start,
3383 .next = m_next,
3384 .stop = m_stop,
3385 .show = m_show
3386};
3387
3388static int modules_open(struct inode *inode, struct file *file)
3389{
3390 return seq_open(file, &modules_op);
3391}
3392
3393static const struct file_operations proc_modules_operations = {
3394 .open = modules_open,
3395 .read = seq_read,
3396 .llseek = seq_lseek,
3397 .release = seq_release,
3398};
3399
3400static int __init proc_modules_init(void)
3401{
3402 proc_create("modules", 0, NULL, &proc_modules_operations);
3403 return 0;
3404}
3405module_init(proc_modules_init);
3406#endif
3407
3408/* Given an address, look for it in the module exception tables. */
3409const struct exception_table_entry *search_module_extables(unsigned long addr)
3410{
3411 const struct exception_table_entry *e = NULL;
3412 struct module *mod;
3413
3414 preempt_disable();
3415 list_for_each_entry_rcu(mod, &modules, list) {
3416 if (mod->num_exentries == 0)
3417 continue;
3418
3419 e = search_extable(mod->extable,
3420 mod->extable + mod->num_exentries - 1,
3421 addr);
3422 if (e)
3423 break;
3424 }
3425 preempt_enable();
3426
3427 /* Now, if we found one, we are running inside it now, hence
3428 we cannot unload the module, hence no refcnt needed. */
3429 return e;
3430}
3431
3432/*
3433 * is_module_address - is this address inside a module?
3434 * @addr: the address to check.
3435 *
3436 * See is_module_text_address() if you simply want to see if the address
3437 * is code (not data).
3438 */
3439bool is_module_address(unsigned long addr)
3440{
3441 bool ret;
3442
3443 preempt_disable();
3444 ret = __module_address(addr) != NULL;
3445 preempt_enable();
3446
3447 return ret;
3448}
3449
3450/*
3451 * __module_address - get the module which contains an address.
3452 * @addr: the address.
3453 *
3454 * Must be called with preempt disabled or module mutex held so that
3455 * module doesn't get freed during this.
3456 */
3457struct module *__module_address(unsigned long addr)
3458{
3459 struct module *mod;
3460
3461 if (addr < module_addr_min || addr > module_addr_max)
3462 return NULL;
3463
3464 list_for_each_entry_rcu(mod, &modules, list)
3465 if (within_module_core(addr, mod)
3466 || within_module_init(addr, mod))
3467 return mod;
3468 return NULL;
3469}
3470EXPORT_SYMBOL_GPL(__module_address);
3471
3472/*
3473 * is_module_text_address - is this address inside module code?
3474 * @addr: the address to check.
3475 *
3476 * See is_module_address() if you simply want to see if the address is
3477 * anywhere in a module. See kernel_text_address() for testing if an
3478 * address corresponds to kernel or module code.
3479 */
3480bool is_module_text_address(unsigned long addr)
3481{
3482 bool ret;
3483
3484 preempt_disable();
3485 ret = __module_text_address(addr) != NULL;
3486 preempt_enable();
3487
3488 return ret;
3489}
3490
3491/*
3492 * __module_text_address - get the module whose code contains an address.
3493 * @addr: the address.
3494 *
3495 * Must be called with preempt disabled or module mutex held so that
3496 * module doesn't get freed during this.
3497 */
3498struct module *__module_text_address(unsigned long addr)
3499{
3500 struct module *mod = __module_address(addr);
3501 if (mod) {
3502 /* Make sure it's within the text section. */
3503 if (!within(addr, mod->module_init, mod->init_text_size)
3504 && !within(addr, mod->module_core, mod->core_text_size))
3505 mod = NULL;
3506 }
3507 return mod;
3508}
3509EXPORT_SYMBOL_GPL(__module_text_address);
3510
3511/* Don't grab lock, we're oopsing. */
3512void print_modules(void)
3513{
3514 struct module *mod;
3515 char buf[8];
3516
3517 printk(KERN_DEFAULT "Modules linked in:");
3518 /* Most callers should already have preempt disabled, but make sure */
3519 preempt_disable();
3520 list_for_each_entry_rcu(mod, &modules, list)
3521 printk(" %s%s", mod->name, module_flags(mod, buf));
3522 preempt_enable();
3523 if (last_unloaded_module[0])
3524 printk(" [last unloaded: %s]", last_unloaded_module);
3525 printk("\n");
3526}
3527
3528#ifdef CONFIG_MODVERSIONS
3529/* Generate the signature for all relevant module structures here.
3530 * If these change, we don't want to try to parse the module. */
3531void module_layout(struct module *mod,
3532 struct modversion_info *ver,
3533 struct kernel_param *kp,
3534 struct kernel_symbol *ks,
3535 struct tracepoint * const *tp)
3536{
3537}
3538EXPORT_SYMBOL(module_layout);
3539#endif
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2002 Richard Henderson
4 * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
5 */
6
7#define INCLUDE_VERMAGIC
8
9#include <linux/export.h>
10#include <linux/extable.h>
11#include <linux/moduleloader.h>
12#include <linux/module_signature.h>
13#include <linux/trace_events.h>
14#include <linux/init.h>
15#include <linux/kallsyms.h>
16#include <linux/buildid.h>
17#include <linux/file.h>
18#include <linux/fs.h>
19#include <linux/sysfs.h>
20#include <linux/kernel.h>
21#include <linux/kernel_read_file.h>
22#include <linux/slab.h>
23#include <linux/vmalloc.h>
24#include <linux/elf.h>
25#include <linux/proc_fs.h>
26#include <linux/security.h>
27#include <linux/seq_file.h>
28#include <linux/syscalls.h>
29#include <linux/fcntl.h>
30#include <linux/rcupdate.h>
31#include <linux/capability.h>
32#include <linux/cpu.h>
33#include <linux/moduleparam.h>
34#include <linux/errno.h>
35#include <linux/err.h>
36#include <linux/vermagic.h>
37#include <linux/notifier.h>
38#include <linux/sched.h>
39#include <linux/device.h>
40#include <linux/string.h>
41#include <linux/mutex.h>
42#include <linux/rculist.h>
43#include <linux/uaccess.h>
44#include <asm/cacheflush.h>
45#include <linux/set_memory.h>
46#include <asm/mmu_context.h>
47#include <linux/license.h>
48#include <asm/sections.h>
49#include <linux/tracepoint.h>
50#include <linux/ftrace.h>
51#include <linux/livepatch.h>
52#include <linux/async.h>
53#include <linux/percpu.h>
54#include <linux/kmemleak.h>
55#include <linux/jump_label.h>
56#include <linux/pfn.h>
57#include <linux/bsearch.h>
58#include <linux/dynamic_debug.h>
59#include <linux/audit.h>
60#include <uapi/linux/module.h>
61#include "module-internal.h"
62
63#define CREATE_TRACE_POINTS
64#include <trace/events/module.h>
65
66#ifndef ARCH_SHF_SMALL
67#define ARCH_SHF_SMALL 0
68#endif
69
70/*
71 * Modules' sections will be aligned on page boundaries
72 * to ensure complete separation of code and data, but
73 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
74 */
75#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
76# define debug_align(X) ALIGN(X, PAGE_SIZE)
77#else
78# define debug_align(X) (X)
79#endif
80
81/* If this is set, the section belongs in the init part of the module */
82#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
83
84/*
85 * Mutex protects:
86 * 1) List of modules (also safely readable with preempt_disable),
87 * 2) module_use links,
88 * 3) module_addr_min/module_addr_max.
89 * (delete and add uses RCU list operations).
90 */
91static DEFINE_MUTEX(module_mutex);
92static LIST_HEAD(modules);
93
94/* Work queue for freeing init sections in success case */
95static void do_free_init(struct work_struct *w);
96static DECLARE_WORK(init_free_wq, do_free_init);
97static LLIST_HEAD(init_free_list);
98
99#ifdef CONFIG_MODULES_TREE_LOOKUP
100
101/*
102 * Use a latched RB-tree for __module_address(); this allows us to use
103 * RCU-sched lookups of the address from any context.
104 *
105 * This is conditional on PERF_EVENTS || TRACING because those can really hit
106 * __module_address() hard by doing a lot of stack unwinding; potentially from
107 * NMI context.
108 */
109
110static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
111{
112 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
113
114 return (unsigned long)layout->base;
115}
116
117static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
118{
119 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
120
121 return (unsigned long)layout->size;
122}
123
124static __always_inline bool
125mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
126{
127 return __mod_tree_val(a) < __mod_tree_val(b);
128}
129
130static __always_inline int
131mod_tree_comp(void *key, struct latch_tree_node *n)
132{
133 unsigned long val = (unsigned long)key;
134 unsigned long start, end;
135
136 start = __mod_tree_val(n);
137 if (val < start)
138 return -1;
139
140 end = start + __mod_tree_size(n);
141 if (val >= end)
142 return 1;
143
144 return 0;
145}
146
147static const struct latch_tree_ops mod_tree_ops = {
148 .less = mod_tree_less,
149 .comp = mod_tree_comp,
150};
151
152static struct mod_tree_root {
153 struct latch_tree_root root;
154 unsigned long addr_min;
155 unsigned long addr_max;
156} mod_tree __cacheline_aligned = {
157 .addr_min = -1UL,
158};
159
160#define module_addr_min mod_tree.addr_min
161#define module_addr_max mod_tree.addr_max
162
163static noinline void __mod_tree_insert(struct mod_tree_node *node)
164{
165 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
166}
167
168static void __mod_tree_remove(struct mod_tree_node *node)
169{
170 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
171}
172
173/*
174 * These modifications: insert, remove_init and remove; are serialized by the
175 * module_mutex.
176 */
177static void mod_tree_insert(struct module *mod)
178{
179 mod->core_layout.mtn.mod = mod;
180 mod->init_layout.mtn.mod = mod;
181
182 __mod_tree_insert(&mod->core_layout.mtn);
183 if (mod->init_layout.size)
184 __mod_tree_insert(&mod->init_layout.mtn);
185}
186
187static void mod_tree_remove_init(struct module *mod)
188{
189 if (mod->init_layout.size)
190 __mod_tree_remove(&mod->init_layout.mtn);
191}
192
193static void mod_tree_remove(struct module *mod)
194{
195 __mod_tree_remove(&mod->core_layout.mtn);
196 mod_tree_remove_init(mod);
197}
198
199static struct module *mod_find(unsigned long addr)
200{
201 struct latch_tree_node *ltn;
202
203 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
204 if (!ltn)
205 return NULL;
206
207 return container_of(ltn, struct mod_tree_node, node)->mod;
208}
209
210#else /* MODULES_TREE_LOOKUP */
211
212static unsigned long module_addr_min = -1UL, module_addr_max = 0;
213
214static void mod_tree_insert(struct module *mod) { }
215static void mod_tree_remove_init(struct module *mod) { }
216static void mod_tree_remove(struct module *mod) { }
217
218static struct module *mod_find(unsigned long addr)
219{
220 struct module *mod;
221
222 list_for_each_entry_rcu(mod, &modules, list,
223 lockdep_is_held(&module_mutex)) {
224 if (within_module(addr, mod))
225 return mod;
226 }
227
228 return NULL;
229}
230
231#endif /* MODULES_TREE_LOOKUP */
232
233/*
234 * Bounds of module text, for speeding up __module_address.
235 * Protected by module_mutex.
236 */
237static void __mod_update_bounds(void *base, unsigned int size)
238{
239 unsigned long min = (unsigned long)base;
240 unsigned long max = min + size;
241
242 if (min < module_addr_min)
243 module_addr_min = min;
244 if (max > module_addr_max)
245 module_addr_max = max;
246}
247
248static void mod_update_bounds(struct module *mod)
249{
250 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
251 if (mod->init_layout.size)
252 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
253}
254
255#ifdef CONFIG_KGDB_KDB
256struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
257#endif /* CONFIG_KGDB_KDB */
258
259static void module_assert_mutex_or_preempt(void)
260{
261#ifdef CONFIG_LOCKDEP
262 if (unlikely(!debug_locks))
263 return;
264
265 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
266 !lockdep_is_held(&module_mutex));
267#endif
268}
269
270#ifdef CONFIG_MODULE_SIG
271static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
272module_param(sig_enforce, bool_enable_only, 0644);
273
274void set_module_sig_enforced(void)
275{
276 sig_enforce = true;
277}
278#else
279#define sig_enforce false
280#endif
281
282/*
283 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
284 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
285 */
286bool is_module_sig_enforced(void)
287{
288 return sig_enforce;
289}
290EXPORT_SYMBOL(is_module_sig_enforced);
291
292/* Block module loading/unloading? */
293int modules_disabled = 0;
294core_param(nomodule, modules_disabled, bint, 0);
295
296/* Waiting for a module to finish initializing? */
297static DECLARE_WAIT_QUEUE_HEAD(module_wq);
298
299static BLOCKING_NOTIFIER_HEAD(module_notify_list);
300
301int register_module_notifier(struct notifier_block *nb)
302{
303 return blocking_notifier_chain_register(&module_notify_list, nb);
304}
305EXPORT_SYMBOL(register_module_notifier);
306
307int unregister_module_notifier(struct notifier_block *nb)
308{
309 return blocking_notifier_chain_unregister(&module_notify_list, nb);
310}
311EXPORT_SYMBOL(unregister_module_notifier);
312
313/*
314 * We require a truly strong try_module_get(): 0 means success.
315 * Otherwise an error is returned due to ongoing or failed
316 * initialization etc.
317 */
318static inline int strong_try_module_get(struct module *mod)
319{
320 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
321 if (mod && mod->state == MODULE_STATE_COMING)
322 return -EBUSY;
323 if (try_module_get(mod))
324 return 0;
325 else
326 return -ENOENT;
327}
328
329static inline void add_taint_module(struct module *mod, unsigned flag,
330 enum lockdep_ok lockdep_ok)
331{
332 add_taint(flag, lockdep_ok);
333 set_bit(flag, &mod->taints);
334}
335
336/*
337 * A thread that wants to hold a reference to a module only while it
338 * is running can call this to safely exit. nfsd and lockd use this.
339 */
340void __noreturn __module_put_and_exit(struct module *mod, long code)
341{
342 module_put(mod);
343 do_exit(code);
344}
345EXPORT_SYMBOL(__module_put_and_exit);
346
347/* Find a module section: 0 means not found. */
348static unsigned int find_sec(const struct load_info *info, const char *name)
349{
350 unsigned int i;
351
352 for (i = 1; i < info->hdr->e_shnum; i++) {
353 Elf_Shdr *shdr = &info->sechdrs[i];
354 /* Alloc bit cleared means "ignore it." */
355 if ((shdr->sh_flags & SHF_ALLOC)
356 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
357 return i;
358 }
359 return 0;
360}
361
362/* Find a module section, or NULL. */
363static void *section_addr(const struct load_info *info, const char *name)
364{
365 /* Section 0 has sh_addr 0. */
366 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
367}
368
369/* Find a module section, or NULL. Fill in number of "objects" in section. */
370static void *section_objs(const struct load_info *info,
371 const char *name,
372 size_t object_size,
373 unsigned int *num)
374{
375 unsigned int sec = find_sec(info, name);
376
377 /* Section 0 has sh_addr 0 and sh_size 0. */
378 *num = info->sechdrs[sec].sh_size / object_size;
379 return (void *)info->sechdrs[sec].sh_addr;
380}
381
382/* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
383static unsigned int find_any_sec(const struct load_info *info, const char *name)
384{
385 unsigned int i;
386
387 for (i = 1; i < info->hdr->e_shnum; i++) {
388 Elf_Shdr *shdr = &info->sechdrs[i];
389 if (strcmp(info->secstrings + shdr->sh_name, name) == 0)
390 return i;
391 }
392 return 0;
393}
394
395/*
396 * Find a module section, or NULL. Fill in number of "objects" in section.
397 * Ignores SHF_ALLOC flag.
398 */
399static __maybe_unused void *any_section_objs(const struct load_info *info,
400 const char *name,
401 size_t object_size,
402 unsigned int *num)
403{
404 unsigned int sec = find_any_sec(info, name);
405
406 /* Section 0 has sh_addr 0 and sh_size 0. */
407 *num = info->sechdrs[sec].sh_size / object_size;
408 return (void *)info->sechdrs[sec].sh_addr;
409}
410
411/* Provided by the linker */
412extern const struct kernel_symbol __start___ksymtab[];
413extern const struct kernel_symbol __stop___ksymtab[];
414extern const struct kernel_symbol __start___ksymtab_gpl[];
415extern const struct kernel_symbol __stop___ksymtab_gpl[];
416extern const s32 __start___kcrctab[];
417extern const s32 __start___kcrctab_gpl[];
418
419#ifndef CONFIG_MODVERSIONS
420#define symversion(base, idx) NULL
421#else
422#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
423#endif
424
425struct symsearch {
426 const struct kernel_symbol *start, *stop;
427 const s32 *crcs;
428 enum mod_license {
429 NOT_GPL_ONLY,
430 GPL_ONLY,
431 } license;
432};
433
434struct find_symbol_arg {
435 /* Input */
436 const char *name;
437 bool gplok;
438 bool warn;
439
440 /* Output */
441 struct module *owner;
442 const s32 *crc;
443 const struct kernel_symbol *sym;
444 enum mod_license license;
445};
446
447static bool check_exported_symbol(const struct symsearch *syms,
448 struct module *owner,
449 unsigned int symnum, void *data)
450{
451 struct find_symbol_arg *fsa = data;
452
453 if (!fsa->gplok && syms->license == GPL_ONLY)
454 return false;
455 fsa->owner = owner;
456 fsa->crc = symversion(syms->crcs, symnum);
457 fsa->sym = &syms->start[symnum];
458 fsa->license = syms->license;
459 return true;
460}
461
462static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
463{
464#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
465 return (unsigned long)offset_to_ptr(&sym->value_offset);
466#else
467 return sym->value;
468#endif
469}
470
471static const char *kernel_symbol_name(const struct kernel_symbol *sym)
472{
473#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
474 return offset_to_ptr(&sym->name_offset);
475#else
476 return sym->name;
477#endif
478}
479
480static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
481{
482#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
483 if (!sym->namespace_offset)
484 return NULL;
485 return offset_to_ptr(&sym->namespace_offset);
486#else
487 return sym->namespace;
488#endif
489}
490
491static int cmp_name(const void *name, const void *sym)
492{
493 return strcmp(name, kernel_symbol_name(sym));
494}
495
496static bool find_exported_symbol_in_section(const struct symsearch *syms,
497 struct module *owner,
498 void *data)
499{
500 struct find_symbol_arg *fsa = data;
501 struct kernel_symbol *sym;
502
503 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
504 sizeof(struct kernel_symbol), cmp_name);
505
506 if (sym != NULL && check_exported_symbol(syms, owner,
507 sym - syms->start, data))
508 return true;
509
510 return false;
511}
512
513/*
514 * Find an exported symbol and return it, along with, (optional) crc and
515 * (optional) module which owns it. Needs preempt disabled or module_mutex.
516 */
517static bool find_symbol(struct find_symbol_arg *fsa)
518{
519 static const struct symsearch arr[] = {
520 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
521 NOT_GPL_ONLY },
522 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
523 __start___kcrctab_gpl,
524 GPL_ONLY },
525 };
526 struct module *mod;
527 unsigned int i;
528
529 module_assert_mutex_or_preempt();
530
531 for (i = 0; i < ARRAY_SIZE(arr); i++)
532 if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
533 return true;
534
535 list_for_each_entry_rcu(mod, &modules, list,
536 lockdep_is_held(&module_mutex)) {
537 struct symsearch arr[] = {
538 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
539 NOT_GPL_ONLY },
540 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
541 mod->gpl_crcs,
542 GPL_ONLY },
543 };
544
545 if (mod->state == MODULE_STATE_UNFORMED)
546 continue;
547
548 for (i = 0; i < ARRAY_SIZE(arr); i++)
549 if (find_exported_symbol_in_section(&arr[i], mod, fsa))
550 return true;
551 }
552
553 pr_debug("Failed to find symbol %s\n", fsa->name);
554 return false;
555}
556
557/*
558 * Search for module by name: must hold module_mutex (or preempt disabled
559 * for read-only access).
560 */
561static struct module *find_module_all(const char *name, size_t len,
562 bool even_unformed)
563{
564 struct module *mod;
565
566 module_assert_mutex_or_preempt();
567
568 list_for_each_entry_rcu(mod, &modules, list,
569 lockdep_is_held(&module_mutex)) {
570 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
571 continue;
572 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
573 return mod;
574 }
575 return NULL;
576}
577
578struct module *find_module(const char *name)
579{
580 return find_module_all(name, strlen(name), false);
581}
582
583#ifdef CONFIG_SMP
584
585static inline void __percpu *mod_percpu(struct module *mod)
586{
587 return mod->percpu;
588}
589
590static int percpu_modalloc(struct module *mod, struct load_info *info)
591{
592 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
593 unsigned long align = pcpusec->sh_addralign;
594
595 if (!pcpusec->sh_size)
596 return 0;
597
598 if (align > PAGE_SIZE) {
599 pr_warn("%s: per-cpu alignment %li > %li\n",
600 mod->name, align, PAGE_SIZE);
601 align = PAGE_SIZE;
602 }
603
604 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
605 if (!mod->percpu) {
606 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
607 mod->name, (unsigned long)pcpusec->sh_size);
608 return -ENOMEM;
609 }
610 mod->percpu_size = pcpusec->sh_size;
611 return 0;
612}
613
614static void percpu_modfree(struct module *mod)
615{
616 free_percpu(mod->percpu);
617}
618
619static unsigned int find_pcpusec(struct load_info *info)
620{
621 return find_sec(info, ".data..percpu");
622}
623
624static void percpu_modcopy(struct module *mod,
625 const void *from, unsigned long size)
626{
627 int cpu;
628
629 for_each_possible_cpu(cpu)
630 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
631}
632
633bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
634{
635 struct module *mod;
636 unsigned int cpu;
637
638 preempt_disable();
639
640 list_for_each_entry_rcu(mod, &modules, list) {
641 if (mod->state == MODULE_STATE_UNFORMED)
642 continue;
643 if (!mod->percpu_size)
644 continue;
645 for_each_possible_cpu(cpu) {
646 void *start = per_cpu_ptr(mod->percpu, cpu);
647 void *va = (void *)addr;
648
649 if (va >= start && va < start + mod->percpu_size) {
650 if (can_addr) {
651 *can_addr = (unsigned long) (va - start);
652 *can_addr += (unsigned long)
653 per_cpu_ptr(mod->percpu,
654 get_boot_cpu_id());
655 }
656 preempt_enable();
657 return true;
658 }
659 }
660 }
661
662 preempt_enable();
663 return false;
664}
665
666/**
667 * is_module_percpu_address() - test whether address is from module static percpu
668 * @addr: address to test
669 *
670 * Test whether @addr belongs to module static percpu area.
671 *
672 * Return: %true if @addr is from module static percpu area
673 */
674bool is_module_percpu_address(unsigned long addr)
675{
676 return __is_module_percpu_address(addr, NULL);
677}
678
679#else /* ... !CONFIG_SMP */
680
681static inline void __percpu *mod_percpu(struct module *mod)
682{
683 return NULL;
684}
685static int percpu_modalloc(struct module *mod, struct load_info *info)
686{
687 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
688 if (info->sechdrs[info->index.pcpu].sh_size != 0)
689 return -ENOMEM;
690 return 0;
691}
692static inline void percpu_modfree(struct module *mod)
693{
694}
695static unsigned int find_pcpusec(struct load_info *info)
696{
697 return 0;
698}
699static inline void percpu_modcopy(struct module *mod,
700 const void *from, unsigned long size)
701{
702 /* pcpusec should be 0, and size of that section should be 0. */
703 BUG_ON(size != 0);
704}
705bool is_module_percpu_address(unsigned long addr)
706{
707 return false;
708}
709
710bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
711{
712 return false;
713}
714
715#endif /* CONFIG_SMP */
716
717#define MODINFO_ATTR(field) \
718static void setup_modinfo_##field(struct module *mod, const char *s) \
719{ \
720 mod->field = kstrdup(s, GFP_KERNEL); \
721} \
722static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
723 struct module_kobject *mk, char *buffer) \
724{ \
725 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
726} \
727static int modinfo_##field##_exists(struct module *mod) \
728{ \
729 return mod->field != NULL; \
730} \
731static void free_modinfo_##field(struct module *mod) \
732{ \
733 kfree(mod->field); \
734 mod->field = NULL; \
735} \
736static struct module_attribute modinfo_##field = { \
737 .attr = { .name = __stringify(field), .mode = 0444 }, \
738 .show = show_modinfo_##field, \
739 .setup = setup_modinfo_##field, \
740 .test = modinfo_##field##_exists, \
741 .free = free_modinfo_##field, \
742};
743
744MODINFO_ATTR(version);
745MODINFO_ATTR(srcversion);
746
747static char last_unloaded_module[MODULE_NAME_LEN+1];
748
749#ifdef CONFIG_MODULE_UNLOAD
750
751EXPORT_TRACEPOINT_SYMBOL(module_get);
752
753/* MODULE_REF_BASE is the base reference count by kmodule loader. */
754#define MODULE_REF_BASE 1
755
756/* Init the unload section of the module. */
757static int module_unload_init(struct module *mod)
758{
759 /*
760 * Initialize reference counter to MODULE_REF_BASE.
761 * refcnt == 0 means module is going.
762 */
763 atomic_set(&mod->refcnt, MODULE_REF_BASE);
764
765 INIT_LIST_HEAD(&mod->source_list);
766 INIT_LIST_HEAD(&mod->target_list);
767
768 /* Hold reference count during initialization. */
769 atomic_inc(&mod->refcnt);
770
771 return 0;
772}
773
774/* Does a already use b? */
775static int already_uses(struct module *a, struct module *b)
776{
777 struct module_use *use;
778
779 list_for_each_entry(use, &b->source_list, source_list) {
780 if (use->source == a) {
781 pr_debug("%s uses %s!\n", a->name, b->name);
782 return 1;
783 }
784 }
785 pr_debug("%s does not use %s!\n", a->name, b->name);
786 return 0;
787}
788
789/*
790 * Module a uses b
791 * - we add 'a' as a "source", 'b' as a "target" of module use
792 * - the module_use is added to the list of 'b' sources (so
793 * 'b' can walk the list to see who sourced them), and of 'a'
794 * targets (so 'a' can see what modules it targets).
795 */
796static int add_module_usage(struct module *a, struct module *b)
797{
798 struct module_use *use;
799
800 pr_debug("Allocating new usage for %s.\n", a->name);
801 use = kmalloc(sizeof(*use), GFP_ATOMIC);
802 if (!use)
803 return -ENOMEM;
804
805 use->source = a;
806 use->target = b;
807 list_add(&use->source_list, &b->source_list);
808 list_add(&use->target_list, &a->target_list);
809 return 0;
810}
811
812/* Module a uses b: caller needs module_mutex() */
813static int ref_module(struct module *a, struct module *b)
814{
815 int err;
816
817 if (b == NULL || already_uses(a, b))
818 return 0;
819
820 /* If module isn't available, we fail. */
821 err = strong_try_module_get(b);
822 if (err)
823 return err;
824
825 err = add_module_usage(a, b);
826 if (err) {
827 module_put(b);
828 return err;
829 }
830 return 0;
831}
832
833/* Clear the unload stuff of the module. */
834static void module_unload_free(struct module *mod)
835{
836 struct module_use *use, *tmp;
837
838 mutex_lock(&module_mutex);
839 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
840 struct module *i = use->target;
841 pr_debug("%s unusing %s\n", mod->name, i->name);
842 module_put(i);
843 list_del(&use->source_list);
844 list_del(&use->target_list);
845 kfree(use);
846 }
847 mutex_unlock(&module_mutex);
848}
849
850#ifdef CONFIG_MODULE_FORCE_UNLOAD
851static inline int try_force_unload(unsigned int flags)
852{
853 int ret = (flags & O_TRUNC);
854 if (ret)
855 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
856 return ret;
857}
858#else
859static inline int try_force_unload(unsigned int flags)
860{
861 return 0;
862}
863#endif /* CONFIG_MODULE_FORCE_UNLOAD */
864
865/* Try to release refcount of module, 0 means success. */
866static int try_release_module_ref(struct module *mod)
867{
868 int ret;
869
870 /* Try to decrement refcnt which we set at loading */
871 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
872 BUG_ON(ret < 0);
873 if (ret)
874 /* Someone can put this right now, recover with checking */
875 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
876
877 return ret;
878}
879
880static int try_stop_module(struct module *mod, int flags, int *forced)
881{
882 /* If it's not unused, quit unless we're forcing. */
883 if (try_release_module_ref(mod) != 0) {
884 *forced = try_force_unload(flags);
885 if (!(*forced))
886 return -EWOULDBLOCK;
887 }
888
889 /* Mark it as dying. */
890 mod->state = MODULE_STATE_GOING;
891
892 return 0;
893}
894
895/**
896 * module_refcount() - return the refcount or -1 if unloading
897 * @mod: the module we're checking
898 *
899 * Return:
900 * -1 if the module is in the process of unloading
901 * otherwise the number of references in the kernel to the module
902 */
903int module_refcount(struct module *mod)
904{
905 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
906}
907EXPORT_SYMBOL(module_refcount);
908
909/* This exists whether we can unload or not */
910static void free_module(struct module *mod);
911
912SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
913 unsigned int, flags)
914{
915 struct module *mod;
916 char name[MODULE_NAME_LEN];
917 int ret, forced = 0;
918
919 if (!capable(CAP_SYS_MODULE) || modules_disabled)
920 return -EPERM;
921
922 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
923 return -EFAULT;
924 name[MODULE_NAME_LEN-1] = '\0';
925
926 audit_log_kern_module(name);
927
928 if (mutex_lock_interruptible(&module_mutex) != 0)
929 return -EINTR;
930
931 mod = find_module(name);
932 if (!mod) {
933 ret = -ENOENT;
934 goto out;
935 }
936
937 if (!list_empty(&mod->source_list)) {
938 /* Other modules depend on us: get rid of them first. */
939 ret = -EWOULDBLOCK;
940 goto out;
941 }
942
943 /* Doing init or already dying? */
944 if (mod->state != MODULE_STATE_LIVE) {
945 /* FIXME: if (force), slam module count damn the torpedoes */
946 pr_debug("%s already dying\n", mod->name);
947 ret = -EBUSY;
948 goto out;
949 }
950
951 /* If it has an init func, it must have an exit func to unload */
952 if (mod->init && !mod->exit) {
953 forced = try_force_unload(flags);
954 if (!forced) {
955 /* This module can't be removed */
956 ret = -EBUSY;
957 goto out;
958 }
959 }
960
961 /* Stop the machine so refcounts can't move and disable module. */
962 ret = try_stop_module(mod, flags, &forced);
963 if (ret != 0)
964 goto out;
965
966 mutex_unlock(&module_mutex);
967 /* Final destruction now no one is using it. */
968 if (mod->exit != NULL)
969 mod->exit();
970 blocking_notifier_call_chain(&module_notify_list,
971 MODULE_STATE_GOING, mod);
972 klp_module_going(mod);
973 ftrace_release_mod(mod);
974
975 async_synchronize_full();
976
977 /* Store the name of the last unloaded module for diagnostic purposes */
978 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
979
980 free_module(mod);
981 /* someone could wait for the module in add_unformed_module() */
982 wake_up_all(&module_wq);
983 return 0;
984out:
985 mutex_unlock(&module_mutex);
986 return ret;
987}
988
989static inline void print_unload_info(struct seq_file *m, struct module *mod)
990{
991 struct module_use *use;
992 int printed_something = 0;
993
994 seq_printf(m, " %i ", module_refcount(mod));
995
996 /*
997 * Always include a trailing , so userspace can differentiate
998 * between this and the old multi-field proc format.
999 */
1000 list_for_each_entry(use, &mod->source_list, source_list) {
1001 printed_something = 1;
1002 seq_printf(m, "%s,", use->source->name);
1003 }
1004
1005 if (mod->init != NULL && mod->exit == NULL) {
1006 printed_something = 1;
1007 seq_puts(m, "[permanent],");
1008 }
1009
1010 if (!printed_something)
1011 seq_puts(m, "-");
1012}
1013
1014void __symbol_put(const char *symbol)
1015{
1016 struct find_symbol_arg fsa = {
1017 .name = symbol,
1018 .gplok = true,
1019 };
1020
1021 preempt_disable();
1022 BUG_ON(!find_symbol(&fsa));
1023 module_put(fsa.owner);
1024 preempt_enable();
1025}
1026EXPORT_SYMBOL(__symbol_put);
1027
1028/* Note this assumes addr is a function, which it currently always is. */
1029void symbol_put_addr(void *addr)
1030{
1031 struct module *modaddr;
1032 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1033
1034 if (core_kernel_text(a))
1035 return;
1036
1037 /*
1038 * Even though we hold a reference on the module; we still need to
1039 * disable preemption in order to safely traverse the data structure.
1040 */
1041 preempt_disable();
1042 modaddr = __module_text_address(a);
1043 BUG_ON(!modaddr);
1044 module_put(modaddr);
1045 preempt_enable();
1046}
1047EXPORT_SYMBOL_GPL(symbol_put_addr);
1048
1049static ssize_t show_refcnt(struct module_attribute *mattr,
1050 struct module_kobject *mk, char *buffer)
1051{
1052 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1053}
1054
1055static struct module_attribute modinfo_refcnt =
1056 __ATTR(refcnt, 0444, show_refcnt, NULL);
1057
1058void __module_get(struct module *module)
1059{
1060 if (module) {
1061 preempt_disable();
1062 atomic_inc(&module->refcnt);
1063 trace_module_get(module, _RET_IP_);
1064 preempt_enable();
1065 }
1066}
1067EXPORT_SYMBOL(__module_get);
1068
1069bool try_module_get(struct module *module)
1070{
1071 bool ret = true;
1072
1073 if (module) {
1074 preempt_disable();
1075 /* Note: here, we can fail to get a reference */
1076 if (likely(module_is_live(module) &&
1077 atomic_inc_not_zero(&module->refcnt) != 0))
1078 trace_module_get(module, _RET_IP_);
1079 else
1080 ret = false;
1081
1082 preempt_enable();
1083 }
1084 return ret;
1085}
1086EXPORT_SYMBOL(try_module_get);
1087
1088void module_put(struct module *module)
1089{
1090 int ret;
1091
1092 if (module) {
1093 preempt_disable();
1094 ret = atomic_dec_if_positive(&module->refcnt);
1095 WARN_ON(ret < 0); /* Failed to put refcount */
1096 trace_module_put(module, _RET_IP_);
1097 preempt_enable();
1098 }
1099}
1100EXPORT_SYMBOL(module_put);
1101
1102#else /* !CONFIG_MODULE_UNLOAD */
1103static inline void print_unload_info(struct seq_file *m, struct module *mod)
1104{
1105 /* We don't know the usage count, or what modules are using. */
1106 seq_puts(m, " - -");
1107}
1108
1109static inline void module_unload_free(struct module *mod)
1110{
1111}
1112
1113static int ref_module(struct module *a, struct module *b)
1114{
1115 return strong_try_module_get(b);
1116}
1117
1118static inline int module_unload_init(struct module *mod)
1119{
1120 return 0;
1121}
1122#endif /* CONFIG_MODULE_UNLOAD */
1123
1124static size_t module_flags_taint(struct module *mod, char *buf)
1125{
1126 size_t l = 0;
1127 int i;
1128
1129 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1130 if (taint_flags[i].module && test_bit(i, &mod->taints))
1131 buf[l++] = taint_flags[i].c_true;
1132 }
1133
1134 return l;
1135}
1136
1137static ssize_t show_initstate(struct module_attribute *mattr,
1138 struct module_kobject *mk, char *buffer)
1139{
1140 const char *state = "unknown";
1141
1142 switch (mk->mod->state) {
1143 case MODULE_STATE_LIVE:
1144 state = "live";
1145 break;
1146 case MODULE_STATE_COMING:
1147 state = "coming";
1148 break;
1149 case MODULE_STATE_GOING:
1150 state = "going";
1151 break;
1152 default:
1153 BUG();
1154 }
1155 return sprintf(buffer, "%s\n", state);
1156}
1157
1158static struct module_attribute modinfo_initstate =
1159 __ATTR(initstate, 0444, show_initstate, NULL);
1160
1161static ssize_t store_uevent(struct module_attribute *mattr,
1162 struct module_kobject *mk,
1163 const char *buffer, size_t count)
1164{
1165 int rc;
1166
1167 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1168 return rc ? rc : count;
1169}
1170
1171struct module_attribute module_uevent =
1172 __ATTR(uevent, 0200, NULL, store_uevent);
1173
1174static ssize_t show_coresize(struct module_attribute *mattr,
1175 struct module_kobject *mk, char *buffer)
1176{
1177 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1178}
1179
1180static struct module_attribute modinfo_coresize =
1181 __ATTR(coresize, 0444, show_coresize, NULL);
1182
1183static ssize_t show_initsize(struct module_attribute *mattr,
1184 struct module_kobject *mk, char *buffer)
1185{
1186 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1187}
1188
1189static struct module_attribute modinfo_initsize =
1190 __ATTR(initsize, 0444, show_initsize, NULL);
1191
1192static ssize_t show_taint(struct module_attribute *mattr,
1193 struct module_kobject *mk, char *buffer)
1194{
1195 size_t l;
1196
1197 l = module_flags_taint(mk->mod, buffer);
1198 buffer[l++] = '\n';
1199 return l;
1200}
1201
1202static struct module_attribute modinfo_taint =
1203 __ATTR(taint, 0444, show_taint, NULL);
1204
1205static struct module_attribute *modinfo_attrs[] = {
1206 &module_uevent,
1207 &modinfo_version,
1208 &modinfo_srcversion,
1209 &modinfo_initstate,
1210 &modinfo_coresize,
1211 &modinfo_initsize,
1212 &modinfo_taint,
1213#ifdef CONFIG_MODULE_UNLOAD
1214 &modinfo_refcnt,
1215#endif
1216 NULL,
1217};
1218
1219static const char vermagic[] = VERMAGIC_STRING;
1220
1221static int try_to_force_load(struct module *mod, const char *reason)
1222{
1223#ifdef CONFIG_MODULE_FORCE_LOAD
1224 if (!test_taint(TAINT_FORCED_MODULE))
1225 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1226 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1227 return 0;
1228#else
1229 return -ENOEXEC;
1230#endif
1231}
1232
1233#ifdef CONFIG_MODVERSIONS
1234
1235static u32 resolve_rel_crc(const s32 *crc)
1236{
1237 return *(u32 *)((void *)crc + *crc);
1238}
1239
1240static int check_version(const struct load_info *info,
1241 const char *symname,
1242 struct module *mod,
1243 const s32 *crc)
1244{
1245 Elf_Shdr *sechdrs = info->sechdrs;
1246 unsigned int versindex = info->index.vers;
1247 unsigned int i, num_versions;
1248 struct modversion_info *versions;
1249
1250 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1251 if (!crc)
1252 return 1;
1253
1254 /* No versions at all? modprobe --force does this. */
1255 if (versindex == 0)
1256 return try_to_force_load(mod, symname) == 0;
1257
1258 versions = (void *) sechdrs[versindex].sh_addr;
1259 num_versions = sechdrs[versindex].sh_size
1260 / sizeof(struct modversion_info);
1261
1262 for (i = 0; i < num_versions; i++) {
1263 u32 crcval;
1264
1265 if (strcmp(versions[i].name, symname) != 0)
1266 continue;
1267
1268 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1269 crcval = resolve_rel_crc(crc);
1270 else
1271 crcval = *crc;
1272 if (versions[i].crc == crcval)
1273 return 1;
1274 pr_debug("Found checksum %X vs module %lX\n",
1275 crcval, versions[i].crc);
1276 goto bad_version;
1277 }
1278
1279 /* Broken toolchain. Warn once, then let it go.. */
1280 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1281 return 1;
1282
1283bad_version:
1284 pr_warn("%s: disagrees about version of symbol %s\n",
1285 info->name, symname);
1286 return 0;
1287}
1288
1289static inline int check_modstruct_version(const struct load_info *info,
1290 struct module *mod)
1291{
1292 struct find_symbol_arg fsa = {
1293 .name = "module_layout",
1294 .gplok = true,
1295 };
1296
1297 /*
1298 * Since this should be found in kernel (which can't be removed), no
1299 * locking is necessary -- use preempt_disable() to placate lockdep.
1300 */
1301 preempt_disable();
1302 if (!find_symbol(&fsa)) {
1303 preempt_enable();
1304 BUG();
1305 }
1306 preempt_enable();
1307 return check_version(info, "module_layout", mod, fsa.crc);
1308}
1309
1310/* First part is kernel version, which we ignore if module has crcs. */
1311static inline int same_magic(const char *amagic, const char *bmagic,
1312 bool has_crcs)
1313{
1314 if (has_crcs) {
1315 amagic += strcspn(amagic, " ");
1316 bmagic += strcspn(bmagic, " ");
1317 }
1318 return strcmp(amagic, bmagic) == 0;
1319}
1320#else
1321static inline int check_version(const struct load_info *info,
1322 const char *symname,
1323 struct module *mod,
1324 const s32 *crc)
1325{
1326 return 1;
1327}
1328
1329static inline int check_modstruct_version(const struct load_info *info,
1330 struct module *mod)
1331{
1332 return 1;
1333}
1334
1335static inline int same_magic(const char *amagic, const char *bmagic,
1336 bool has_crcs)
1337{
1338 return strcmp(amagic, bmagic) == 0;
1339}
1340#endif /* CONFIG_MODVERSIONS */
1341
1342static char *get_modinfo(const struct load_info *info, const char *tag);
1343static char *get_next_modinfo(const struct load_info *info, const char *tag,
1344 char *prev);
1345
1346static int verify_namespace_is_imported(const struct load_info *info,
1347 const struct kernel_symbol *sym,
1348 struct module *mod)
1349{
1350 const char *namespace;
1351 char *imported_namespace;
1352
1353 namespace = kernel_symbol_namespace(sym);
1354 if (namespace && namespace[0]) {
1355 imported_namespace = get_modinfo(info, "import_ns");
1356 while (imported_namespace) {
1357 if (strcmp(namespace, imported_namespace) == 0)
1358 return 0;
1359 imported_namespace = get_next_modinfo(
1360 info, "import_ns", imported_namespace);
1361 }
1362#ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1363 pr_warn(
1364#else
1365 pr_err(
1366#endif
1367 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1368 mod->name, kernel_symbol_name(sym), namespace);
1369#ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1370 return -EINVAL;
1371#endif
1372 }
1373 return 0;
1374}
1375
1376static bool inherit_taint(struct module *mod, struct module *owner)
1377{
1378 if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1379 return true;
1380
1381 if (mod->using_gplonly_symbols) {
1382 pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n",
1383 mod->name, owner->name);
1384 return false;
1385 }
1386
1387 if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1388 pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n",
1389 mod->name, owner->name);
1390 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1391 }
1392 return true;
1393}
1394
1395/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1396static const struct kernel_symbol *resolve_symbol(struct module *mod,
1397 const struct load_info *info,
1398 const char *name,
1399 char ownername[])
1400{
1401 struct find_symbol_arg fsa = {
1402 .name = name,
1403 .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)),
1404 .warn = true,
1405 };
1406 int err;
1407
1408 /*
1409 * The module_mutex should not be a heavily contended lock;
1410 * if we get the occasional sleep here, we'll go an extra iteration
1411 * in the wait_event_interruptible(), which is harmless.
1412 */
1413 sched_annotate_sleep();
1414 mutex_lock(&module_mutex);
1415 if (!find_symbol(&fsa))
1416 goto unlock;
1417
1418 if (fsa.license == GPL_ONLY)
1419 mod->using_gplonly_symbols = true;
1420
1421 if (!inherit_taint(mod, fsa.owner)) {
1422 fsa.sym = NULL;
1423 goto getname;
1424 }
1425
1426 if (!check_version(info, name, mod, fsa.crc)) {
1427 fsa.sym = ERR_PTR(-EINVAL);
1428 goto getname;
1429 }
1430
1431 err = verify_namespace_is_imported(info, fsa.sym, mod);
1432 if (err) {
1433 fsa.sym = ERR_PTR(err);
1434 goto getname;
1435 }
1436
1437 err = ref_module(mod, fsa.owner);
1438 if (err) {
1439 fsa.sym = ERR_PTR(err);
1440 goto getname;
1441 }
1442
1443getname:
1444 /* We must make copy under the lock if we failed to get ref. */
1445 strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
1446unlock:
1447 mutex_unlock(&module_mutex);
1448 return fsa.sym;
1449}
1450
1451static const struct kernel_symbol *
1452resolve_symbol_wait(struct module *mod,
1453 const struct load_info *info,
1454 const char *name)
1455{
1456 const struct kernel_symbol *ksym;
1457 char owner[MODULE_NAME_LEN];
1458
1459 if (wait_event_interruptible_timeout(module_wq,
1460 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1461 || PTR_ERR(ksym) != -EBUSY,
1462 30 * HZ) <= 0) {
1463 pr_warn("%s: gave up waiting for init of module %s.\n",
1464 mod->name, owner);
1465 }
1466 return ksym;
1467}
1468
1469#ifdef CONFIG_KALLSYMS
1470static inline bool sect_empty(const Elf_Shdr *sect)
1471{
1472 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1473}
1474#endif
1475
1476/*
1477 * /sys/module/foo/sections stuff
1478 * J. Corbet <corbet@lwn.net>
1479 */
1480#ifdef CONFIG_SYSFS
1481
1482#ifdef CONFIG_KALLSYMS
1483struct module_sect_attr {
1484 struct bin_attribute battr;
1485 unsigned long address;
1486};
1487
1488struct module_sect_attrs {
1489 struct attribute_group grp;
1490 unsigned int nsections;
1491 struct module_sect_attr attrs[];
1492};
1493
1494#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
1495static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
1496 struct bin_attribute *battr,
1497 char *buf, loff_t pos, size_t count)
1498{
1499 struct module_sect_attr *sattr =
1500 container_of(battr, struct module_sect_attr, battr);
1501 char bounce[MODULE_SECT_READ_SIZE + 1];
1502 size_t wrote;
1503
1504 if (pos != 0)
1505 return -EINVAL;
1506
1507 /*
1508 * Since we're a binary read handler, we must account for the
1509 * trailing NUL byte that sprintf will write: if "buf" is
1510 * too small to hold the NUL, or the NUL is exactly the last
1511 * byte, the read will look like it got truncated by one byte.
1512 * Since there is no way to ask sprintf nicely to not write
1513 * the NUL, we have to use a bounce buffer.
1514 */
1515 wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
1516 kallsyms_show_value(file->f_cred)
1517 ? (void *)sattr->address : NULL);
1518 count = min(count, wrote);
1519 memcpy(buf, bounce, count);
1520
1521 return count;
1522}
1523
1524static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1525{
1526 unsigned int section;
1527
1528 for (section = 0; section < sect_attrs->nsections; section++)
1529 kfree(sect_attrs->attrs[section].battr.attr.name);
1530 kfree(sect_attrs);
1531}
1532
1533static void add_sect_attrs(struct module *mod, const struct load_info *info)
1534{
1535 unsigned int nloaded = 0, i, size[2];
1536 struct module_sect_attrs *sect_attrs;
1537 struct module_sect_attr *sattr;
1538 struct bin_attribute **gattr;
1539
1540 /* Count loaded sections and allocate structures */
1541 for (i = 0; i < info->hdr->e_shnum; i++)
1542 if (!sect_empty(&info->sechdrs[i]))
1543 nloaded++;
1544 size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
1545 sizeof(sect_attrs->grp.bin_attrs[0]));
1546 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
1547 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1548 if (sect_attrs == NULL)
1549 return;
1550
1551 /* Setup section attributes. */
1552 sect_attrs->grp.name = "sections";
1553 sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
1554
1555 sect_attrs->nsections = 0;
1556 sattr = §_attrs->attrs[0];
1557 gattr = §_attrs->grp.bin_attrs[0];
1558 for (i = 0; i < info->hdr->e_shnum; i++) {
1559 Elf_Shdr *sec = &info->sechdrs[i];
1560 if (sect_empty(sec))
1561 continue;
1562 sysfs_bin_attr_init(&sattr->battr);
1563 sattr->address = sec->sh_addr;
1564 sattr->battr.attr.name =
1565 kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
1566 if (sattr->battr.attr.name == NULL)
1567 goto out;
1568 sect_attrs->nsections++;
1569 sattr->battr.read = module_sect_read;
1570 sattr->battr.size = MODULE_SECT_READ_SIZE;
1571 sattr->battr.attr.mode = 0400;
1572 *(gattr++) = &(sattr++)->battr;
1573 }
1574 *gattr = NULL;
1575
1576 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1577 goto out;
1578
1579 mod->sect_attrs = sect_attrs;
1580 return;
1581 out:
1582 free_sect_attrs(sect_attrs);
1583}
1584
1585static void remove_sect_attrs(struct module *mod)
1586{
1587 if (mod->sect_attrs) {
1588 sysfs_remove_group(&mod->mkobj.kobj,
1589 &mod->sect_attrs->grp);
1590 /*
1591 * We are positive that no one is using any sect attrs
1592 * at this point. Deallocate immediately.
1593 */
1594 free_sect_attrs(mod->sect_attrs);
1595 mod->sect_attrs = NULL;
1596 }
1597}
1598
1599/*
1600 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1601 */
1602
1603struct module_notes_attrs {
1604 struct kobject *dir;
1605 unsigned int notes;
1606 struct bin_attribute attrs[];
1607};
1608
1609static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1610 struct bin_attribute *bin_attr,
1611 char *buf, loff_t pos, size_t count)
1612{
1613 /*
1614 * The caller checked the pos and count against our size.
1615 */
1616 memcpy(buf, bin_attr->private + pos, count);
1617 return count;
1618}
1619
1620static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1621 unsigned int i)
1622{
1623 if (notes_attrs->dir) {
1624 while (i-- > 0)
1625 sysfs_remove_bin_file(notes_attrs->dir,
1626 ¬es_attrs->attrs[i]);
1627 kobject_put(notes_attrs->dir);
1628 }
1629 kfree(notes_attrs);
1630}
1631
1632static void add_notes_attrs(struct module *mod, const struct load_info *info)
1633{
1634 unsigned int notes, loaded, i;
1635 struct module_notes_attrs *notes_attrs;
1636 struct bin_attribute *nattr;
1637
1638 /* failed to create section attributes, so can't create notes */
1639 if (!mod->sect_attrs)
1640 return;
1641
1642 /* Count notes sections and allocate structures. */
1643 notes = 0;
1644 for (i = 0; i < info->hdr->e_shnum; i++)
1645 if (!sect_empty(&info->sechdrs[i]) &&
1646 (info->sechdrs[i].sh_type == SHT_NOTE))
1647 ++notes;
1648
1649 if (notes == 0)
1650 return;
1651
1652 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1653 GFP_KERNEL);
1654 if (notes_attrs == NULL)
1655 return;
1656
1657 notes_attrs->notes = notes;
1658 nattr = ¬es_attrs->attrs[0];
1659 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1660 if (sect_empty(&info->sechdrs[i]))
1661 continue;
1662 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1663 sysfs_bin_attr_init(nattr);
1664 nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
1665 nattr->attr.mode = S_IRUGO;
1666 nattr->size = info->sechdrs[i].sh_size;
1667 nattr->private = (void *) info->sechdrs[i].sh_addr;
1668 nattr->read = module_notes_read;
1669 ++nattr;
1670 }
1671 ++loaded;
1672 }
1673
1674 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1675 if (!notes_attrs->dir)
1676 goto out;
1677
1678 for (i = 0; i < notes; ++i)
1679 if (sysfs_create_bin_file(notes_attrs->dir,
1680 ¬es_attrs->attrs[i]))
1681 goto out;
1682
1683 mod->notes_attrs = notes_attrs;
1684 return;
1685
1686 out:
1687 free_notes_attrs(notes_attrs, i);
1688}
1689
1690static void remove_notes_attrs(struct module *mod)
1691{
1692 if (mod->notes_attrs)
1693 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1694}
1695
1696#else
1697
1698static inline void add_sect_attrs(struct module *mod,
1699 const struct load_info *info)
1700{
1701}
1702
1703static inline void remove_sect_attrs(struct module *mod)
1704{
1705}
1706
1707static inline void add_notes_attrs(struct module *mod,
1708 const struct load_info *info)
1709{
1710}
1711
1712static inline void remove_notes_attrs(struct module *mod)
1713{
1714}
1715#endif /* CONFIG_KALLSYMS */
1716
1717static void del_usage_links(struct module *mod)
1718{
1719#ifdef CONFIG_MODULE_UNLOAD
1720 struct module_use *use;
1721
1722 mutex_lock(&module_mutex);
1723 list_for_each_entry(use, &mod->target_list, target_list)
1724 sysfs_remove_link(use->target->holders_dir, mod->name);
1725 mutex_unlock(&module_mutex);
1726#endif
1727}
1728
1729static int add_usage_links(struct module *mod)
1730{
1731 int ret = 0;
1732#ifdef CONFIG_MODULE_UNLOAD
1733 struct module_use *use;
1734
1735 mutex_lock(&module_mutex);
1736 list_for_each_entry(use, &mod->target_list, target_list) {
1737 ret = sysfs_create_link(use->target->holders_dir,
1738 &mod->mkobj.kobj, mod->name);
1739 if (ret)
1740 break;
1741 }
1742 mutex_unlock(&module_mutex);
1743 if (ret)
1744 del_usage_links(mod);
1745#endif
1746 return ret;
1747}
1748
1749static void module_remove_modinfo_attrs(struct module *mod, int end);
1750
1751static int module_add_modinfo_attrs(struct module *mod)
1752{
1753 struct module_attribute *attr;
1754 struct module_attribute *temp_attr;
1755 int error = 0;
1756 int i;
1757
1758 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1759 (ARRAY_SIZE(modinfo_attrs) + 1)),
1760 GFP_KERNEL);
1761 if (!mod->modinfo_attrs)
1762 return -ENOMEM;
1763
1764 temp_attr = mod->modinfo_attrs;
1765 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1766 if (!attr->test || attr->test(mod)) {
1767 memcpy(temp_attr, attr, sizeof(*temp_attr));
1768 sysfs_attr_init(&temp_attr->attr);
1769 error = sysfs_create_file(&mod->mkobj.kobj,
1770 &temp_attr->attr);
1771 if (error)
1772 goto error_out;
1773 ++temp_attr;
1774 }
1775 }
1776
1777 return 0;
1778
1779error_out:
1780 if (i > 0)
1781 module_remove_modinfo_attrs(mod, --i);
1782 else
1783 kfree(mod->modinfo_attrs);
1784 return error;
1785}
1786
1787static void module_remove_modinfo_attrs(struct module *mod, int end)
1788{
1789 struct module_attribute *attr;
1790 int i;
1791
1792 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1793 if (end >= 0 && i > end)
1794 break;
1795 /* pick a field to test for end of list */
1796 if (!attr->attr.name)
1797 break;
1798 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1799 if (attr->free)
1800 attr->free(mod);
1801 }
1802 kfree(mod->modinfo_attrs);
1803}
1804
1805static void mod_kobject_put(struct module *mod)
1806{
1807 DECLARE_COMPLETION_ONSTACK(c);
1808 mod->mkobj.kobj_completion = &c;
1809 kobject_put(&mod->mkobj.kobj);
1810 wait_for_completion(&c);
1811}
1812
1813static int mod_sysfs_init(struct module *mod)
1814{
1815 int err;
1816 struct kobject *kobj;
1817
1818 if (!module_sysfs_initialized) {
1819 pr_err("%s: module sysfs not initialized\n", mod->name);
1820 err = -EINVAL;
1821 goto out;
1822 }
1823
1824 kobj = kset_find_obj(module_kset, mod->name);
1825 if (kobj) {
1826 pr_err("%s: module is already loaded\n", mod->name);
1827 kobject_put(kobj);
1828 err = -EINVAL;
1829 goto out;
1830 }
1831
1832 mod->mkobj.mod = mod;
1833
1834 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1835 mod->mkobj.kobj.kset = module_kset;
1836 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1837 "%s", mod->name);
1838 if (err)
1839 mod_kobject_put(mod);
1840
1841out:
1842 return err;
1843}
1844
1845static int mod_sysfs_setup(struct module *mod,
1846 const struct load_info *info,
1847 struct kernel_param *kparam,
1848 unsigned int num_params)
1849{
1850 int err;
1851
1852 err = mod_sysfs_init(mod);
1853 if (err)
1854 goto out;
1855
1856 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1857 if (!mod->holders_dir) {
1858 err = -ENOMEM;
1859 goto out_unreg;
1860 }
1861
1862 err = module_param_sysfs_setup(mod, kparam, num_params);
1863 if (err)
1864 goto out_unreg_holders;
1865
1866 err = module_add_modinfo_attrs(mod);
1867 if (err)
1868 goto out_unreg_param;
1869
1870 err = add_usage_links(mod);
1871 if (err)
1872 goto out_unreg_modinfo_attrs;
1873
1874 add_sect_attrs(mod, info);
1875 add_notes_attrs(mod, info);
1876
1877 return 0;
1878
1879out_unreg_modinfo_attrs:
1880 module_remove_modinfo_attrs(mod, -1);
1881out_unreg_param:
1882 module_param_sysfs_remove(mod);
1883out_unreg_holders:
1884 kobject_put(mod->holders_dir);
1885out_unreg:
1886 mod_kobject_put(mod);
1887out:
1888 return err;
1889}
1890
1891static void mod_sysfs_fini(struct module *mod)
1892{
1893 remove_notes_attrs(mod);
1894 remove_sect_attrs(mod);
1895 mod_kobject_put(mod);
1896}
1897
1898static void init_param_lock(struct module *mod)
1899{
1900 mutex_init(&mod->param_lock);
1901}
1902#else /* !CONFIG_SYSFS */
1903
1904static int mod_sysfs_setup(struct module *mod,
1905 const struct load_info *info,
1906 struct kernel_param *kparam,
1907 unsigned int num_params)
1908{
1909 return 0;
1910}
1911
1912static void mod_sysfs_fini(struct module *mod)
1913{
1914}
1915
1916static void module_remove_modinfo_attrs(struct module *mod, int end)
1917{
1918}
1919
1920static void del_usage_links(struct module *mod)
1921{
1922}
1923
1924static void init_param_lock(struct module *mod)
1925{
1926}
1927#endif /* CONFIG_SYSFS */
1928
1929static void mod_sysfs_teardown(struct module *mod)
1930{
1931 del_usage_links(mod);
1932 module_remove_modinfo_attrs(mod, -1);
1933 module_param_sysfs_remove(mod);
1934 kobject_put(mod->mkobj.drivers_dir);
1935 kobject_put(mod->holders_dir);
1936 mod_sysfs_fini(mod);
1937}
1938
1939/*
1940 * LKM RO/NX protection: protect module's text/ro-data
1941 * from modification and any data from execution.
1942 *
1943 * General layout of module is:
1944 * [text] [read-only-data] [ro-after-init] [writable data]
1945 * text_size -----^ ^ ^ ^
1946 * ro_size ------------------------| | |
1947 * ro_after_init_size -----------------------------| |
1948 * size -----------------------------------------------------------|
1949 *
1950 * These values are always page-aligned (as is base)
1951 */
1952
1953/*
1954 * Since some arches are moving towards PAGE_KERNEL module allocations instead
1955 * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
1956 * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
1957 * whether we are strict.
1958 */
1959#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
1960static void frob_text(const struct module_layout *layout,
1961 int (*set_memory)(unsigned long start, int num_pages))
1962{
1963 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1964 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1965 set_memory((unsigned long)layout->base,
1966 layout->text_size >> PAGE_SHIFT);
1967}
1968
1969static void module_enable_x(const struct module *mod)
1970{
1971 frob_text(&mod->core_layout, set_memory_x);
1972 frob_text(&mod->init_layout, set_memory_x);
1973}
1974#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
1975static void module_enable_x(const struct module *mod) { }
1976#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
1977
1978#ifdef CONFIG_STRICT_MODULE_RWX
1979static void frob_rodata(const struct module_layout *layout,
1980 int (*set_memory)(unsigned long start, int num_pages))
1981{
1982 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1983 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1984 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1985 set_memory((unsigned long)layout->base + layout->text_size,
1986 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1987}
1988
1989static void frob_ro_after_init(const struct module_layout *layout,
1990 int (*set_memory)(unsigned long start, int num_pages))
1991{
1992 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1993 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1994 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1995 set_memory((unsigned long)layout->base + layout->ro_size,
1996 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1997}
1998
1999static void frob_writable_data(const struct module_layout *layout,
2000 int (*set_memory)(unsigned long start, int num_pages))
2001{
2002 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2003 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
2004 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
2005 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
2006 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
2007}
2008
2009static void module_enable_ro(const struct module *mod, bool after_init)
2010{
2011 if (!rodata_enabled)
2012 return;
2013
2014 set_vm_flush_reset_perms(mod->core_layout.base);
2015 set_vm_flush_reset_perms(mod->init_layout.base);
2016 frob_text(&mod->core_layout, set_memory_ro);
2017
2018 frob_rodata(&mod->core_layout, set_memory_ro);
2019 frob_text(&mod->init_layout, set_memory_ro);
2020 frob_rodata(&mod->init_layout, set_memory_ro);
2021
2022 if (after_init)
2023 frob_ro_after_init(&mod->core_layout, set_memory_ro);
2024}
2025
2026static void module_enable_nx(const struct module *mod)
2027{
2028 frob_rodata(&mod->core_layout, set_memory_nx);
2029 frob_ro_after_init(&mod->core_layout, set_memory_nx);
2030 frob_writable_data(&mod->core_layout, set_memory_nx);
2031 frob_rodata(&mod->init_layout, set_memory_nx);
2032 frob_writable_data(&mod->init_layout, set_memory_nx);
2033}
2034
2035static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
2036 char *secstrings, struct module *mod)
2037{
2038 const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
2039 int i;
2040
2041 for (i = 0; i < hdr->e_shnum; i++) {
2042 if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {
2043 pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
2044 mod->name, secstrings + sechdrs[i].sh_name, i);
2045 return -ENOEXEC;
2046 }
2047 }
2048
2049 return 0;
2050}
2051
2052#else /* !CONFIG_STRICT_MODULE_RWX */
2053static void module_enable_nx(const struct module *mod) { }
2054static void module_enable_ro(const struct module *mod, bool after_init) {}
2055static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
2056 char *secstrings, struct module *mod)
2057{
2058 return 0;
2059}
2060#endif /* CONFIG_STRICT_MODULE_RWX */
2061
2062#ifdef CONFIG_LIVEPATCH
2063/*
2064 * Persist Elf information about a module. Copy the Elf header,
2065 * section header table, section string table, and symtab section
2066 * index from info to mod->klp_info.
2067 */
2068static int copy_module_elf(struct module *mod, struct load_info *info)
2069{
2070 unsigned int size, symndx;
2071 int ret;
2072
2073 size = sizeof(*mod->klp_info);
2074 mod->klp_info = kmalloc(size, GFP_KERNEL);
2075 if (mod->klp_info == NULL)
2076 return -ENOMEM;
2077
2078 /* Elf header */
2079 size = sizeof(mod->klp_info->hdr);
2080 memcpy(&mod->klp_info->hdr, info->hdr, size);
2081
2082 /* Elf section header table */
2083 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2084 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2085 if (mod->klp_info->sechdrs == NULL) {
2086 ret = -ENOMEM;
2087 goto free_info;
2088 }
2089
2090 /* Elf section name string table */
2091 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2092 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2093 if (mod->klp_info->secstrings == NULL) {
2094 ret = -ENOMEM;
2095 goto free_sechdrs;
2096 }
2097
2098 /* Elf symbol section index */
2099 symndx = info->index.sym;
2100 mod->klp_info->symndx = symndx;
2101
2102 /*
2103 * For livepatch modules, core_kallsyms.symtab is a complete
2104 * copy of the original symbol table. Adjust sh_addr to point
2105 * to core_kallsyms.symtab since the copy of the symtab in module
2106 * init memory is freed at the end of do_init_module().
2107 */
2108 mod->klp_info->sechdrs[symndx].sh_addr = \
2109 (unsigned long) mod->core_kallsyms.symtab;
2110
2111 return 0;
2112
2113free_sechdrs:
2114 kfree(mod->klp_info->sechdrs);
2115free_info:
2116 kfree(mod->klp_info);
2117 return ret;
2118}
2119
2120static void free_module_elf(struct module *mod)
2121{
2122 kfree(mod->klp_info->sechdrs);
2123 kfree(mod->klp_info->secstrings);
2124 kfree(mod->klp_info);
2125}
2126#else /* !CONFIG_LIVEPATCH */
2127static int copy_module_elf(struct module *mod, struct load_info *info)
2128{
2129 return 0;
2130}
2131
2132static void free_module_elf(struct module *mod)
2133{
2134}
2135#endif /* CONFIG_LIVEPATCH */
2136
2137void __weak module_memfree(void *module_region)
2138{
2139 /*
2140 * This memory may be RO, and freeing RO memory in an interrupt is not
2141 * supported by vmalloc.
2142 */
2143 WARN_ON(in_interrupt());
2144 vfree(module_region);
2145}
2146
2147void __weak module_arch_cleanup(struct module *mod)
2148{
2149}
2150
2151void __weak module_arch_freeing_init(struct module *mod)
2152{
2153}
2154
2155static void cfi_cleanup(struct module *mod);
2156
2157/* Free a module, remove from lists, etc. */
2158static void free_module(struct module *mod)
2159{
2160 trace_module_free(mod);
2161
2162 mod_sysfs_teardown(mod);
2163
2164 /*
2165 * We leave it in list to prevent duplicate loads, but make sure
2166 * that noone uses it while it's being deconstructed.
2167 */
2168 mutex_lock(&module_mutex);
2169 mod->state = MODULE_STATE_UNFORMED;
2170 mutex_unlock(&module_mutex);
2171
2172 /* Remove dynamic debug info */
2173 ddebug_remove_module(mod->name);
2174
2175 /* Arch-specific cleanup. */
2176 module_arch_cleanup(mod);
2177
2178 /* Module unload stuff */
2179 module_unload_free(mod);
2180
2181 /* Free any allocated parameters. */
2182 destroy_params(mod->kp, mod->num_kp);
2183
2184 if (is_livepatch_module(mod))
2185 free_module_elf(mod);
2186
2187 /* Now we can delete it from the lists */
2188 mutex_lock(&module_mutex);
2189 /* Unlink carefully: kallsyms could be walking list. */
2190 list_del_rcu(&mod->list);
2191 mod_tree_remove(mod);
2192 /* Remove this module from bug list, this uses list_del_rcu */
2193 module_bug_cleanup(mod);
2194 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2195 synchronize_rcu();
2196 mutex_unlock(&module_mutex);
2197
2198 /* Clean up CFI for the module. */
2199 cfi_cleanup(mod);
2200
2201 /* This may be empty, but that's OK */
2202 module_arch_freeing_init(mod);
2203 module_memfree(mod->init_layout.base);
2204 kfree(mod->args);
2205 percpu_modfree(mod);
2206
2207 /* Free lock-classes; relies on the preceding sync_rcu(). */
2208 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2209
2210 /* Finally, free the core (containing the module structure) */
2211 module_memfree(mod->core_layout.base);
2212}
2213
2214void *__symbol_get(const char *symbol)
2215{
2216 struct find_symbol_arg fsa = {
2217 .name = symbol,
2218 .gplok = true,
2219 .warn = true,
2220 };
2221
2222 preempt_disable();
2223 if (!find_symbol(&fsa) || strong_try_module_get(fsa.owner)) {
2224 preempt_enable();
2225 return NULL;
2226 }
2227 preempt_enable();
2228 return (void *)kernel_symbol_value(fsa.sym);
2229}
2230EXPORT_SYMBOL_GPL(__symbol_get);
2231
2232/*
2233 * Ensure that an exported symbol [global namespace] does not already exist
2234 * in the kernel or in some other module's exported symbol table.
2235 *
2236 * You must hold the module_mutex.
2237 */
2238static int verify_exported_symbols(struct module *mod)
2239{
2240 unsigned int i;
2241 const struct kernel_symbol *s;
2242 struct {
2243 const struct kernel_symbol *sym;
2244 unsigned int num;
2245 } arr[] = {
2246 { mod->syms, mod->num_syms },
2247 { mod->gpl_syms, mod->num_gpl_syms },
2248 };
2249
2250 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2251 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2252 struct find_symbol_arg fsa = {
2253 .name = kernel_symbol_name(s),
2254 .gplok = true,
2255 };
2256 if (find_symbol(&fsa)) {
2257 pr_err("%s: exports duplicate symbol %s"
2258 " (owned by %s)\n",
2259 mod->name, kernel_symbol_name(s),
2260 module_name(fsa.owner));
2261 return -ENOEXEC;
2262 }
2263 }
2264 }
2265 return 0;
2266}
2267
2268static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
2269{
2270 /*
2271 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
2272 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
2273 * i386 has a similar problem but may not deserve a fix.
2274 *
2275 * If we ever have to ignore many symbols, consider refactoring the code to
2276 * only warn if referenced by a relocation.
2277 */
2278 if (emachine == EM_386 || emachine == EM_X86_64)
2279 return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
2280 return false;
2281}
2282
2283/* Change all symbols so that st_value encodes the pointer directly. */
2284static int simplify_symbols(struct module *mod, const struct load_info *info)
2285{
2286 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2287 Elf_Sym *sym = (void *)symsec->sh_addr;
2288 unsigned long secbase;
2289 unsigned int i;
2290 int ret = 0;
2291 const struct kernel_symbol *ksym;
2292
2293 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2294 const char *name = info->strtab + sym[i].st_name;
2295
2296 switch (sym[i].st_shndx) {
2297 case SHN_COMMON:
2298 /* Ignore common symbols */
2299 if (!strncmp(name, "__gnu_lto", 9))
2300 break;
2301
2302 /*
2303 * We compiled with -fno-common. These are not
2304 * supposed to happen.
2305 */
2306 pr_debug("Common symbol: %s\n", name);
2307 pr_warn("%s: please compile with -fno-common\n",
2308 mod->name);
2309 ret = -ENOEXEC;
2310 break;
2311
2312 case SHN_ABS:
2313 /* Don't need to do anything */
2314 pr_debug("Absolute symbol: 0x%08lx\n",
2315 (long)sym[i].st_value);
2316 break;
2317
2318 case SHN_LIVEPATCH:
2319 /* Livepatch symbols are resolved by livepatch */
2320 break;
2321
2322 case SHN_UNDEF:
2323 ksym = resolve_symbol_wait(mod, info, name);
2324 /* Ok if resolved. */
2325 if (ksym && !IS_ERR(ksym)) {
2326 sym[i].st_value = kernel_symbol_value(ksym);
2327 break;
2328 }
2329
2330 /* Ok if weak or ignored. */
2331 if (!ksym &&
2332 (ELF_ST_BIND(sym[i].st_info) == STB_WEAK ||
2333 ignore_undef_symbol(info->hdr->e_machine, name)))
2334 break;
2335
2336 ret = PTR_ERR(ksym) ?: -ENOENT;
2337 pr_warn("%s: Unknown symbol %s (err %d)\n",
2338 mod->name, name, ret);
2339 break;
2340
2341 default:
2342 /* Divert to percpu allocation if a percpu var. */
2343 if (sym[i].st_shndx == info->index.pcpu)
2344 secbase = (unsigned long)mod_percpu(mod);
2345 else
2346 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2347 sym[i].st_value += secbase;
2348 break;
2349 }
2350 }
2351
2352 return ret;
2353}
2354
2355static int apply_relocations(struct module *mod, const struct load_info *info)
2356{
2357 unsigned int i;
2358 int err = 0;
2359
2360 /* Now do relocations. */
2361 for (i = 1; i < info->hdr->e_shnum; i++) {
2362 unsigned int infosec = info->sechdrs[i].sh_info;
2363
2364 /* Not a valid relocation section? */
2365 if (infosec >= info->hdr->e_shnum)
2366 continue;
2367
2368 /* Don't bother with non-allocated sections */
2369 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2370 continue;
2371
2372 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2373 err = klp_apply_section_relocs(mod, info->sechdrs,
2374 info->secstrings,
2375 info->strtab,
2376 info->index.sym, i,
2377 NULL);
2378 else if (info->sechdrs[i].sh_type == SHT_REL)
2379 err = apply_relocate(info->sechdrs, info->strtab,
2380 info->index.sym, i, mod);
2381 else if (info->sechdrs[i].sh_type == SHT_RELA)
2382 err = apply_relocate_add(info->sechdrs, info->strtab,
2383 info->index.sym, i, mod);
2384 if (err < 0)
2385 break;
2386 }
2387 return err;
2388}
2389
2390/* Additional bytes needed by arch in front of individual sections */
2391unsigned int __weak arch_mod_section_prepend(struct module *mod,
2392 unsigned int section)
2393{
2394 /* default implementation just returns zero */
2395 return 0;
2396}
2397
2398/* Update size with this section: return offset. */
2399static long get_offset(struct module *mod, unsigned int *size,
2400 Elf_Shdr *sechdr, unsigned int section)
2401{
2402 long ret;
2403
2404 *size += arch_mod_section_prepend(mod, section);
2405 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2406 *size = ret + sechdr->sh_size;
2407 return ret;
2408}
2409
2410static bool module_init_layout_section(const char *sname)
2411{
2412#ifndef CONFIG_MODULE_UNLOAD
2413 if (module_exit_section(sname))
2414 return true;
2415#endif
2416 return module_init_section(sname);
2417}
2418
2419/*
2420 * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2421 * might -- code, read-only data, read-write data, small data. Tally
2422 * sizes, and place the offsets into sh_entsize fields: high bit means it
2423 * belongs in init.
2424 */
2425static void layout_sections(struct module *mod, struct load_info *info)
2426{
2427 static unsigned long const masks[][2] = {
2428 /*
2429 * NOTE: all executable code must be the first section
2430 * in this array; otherwise modify the text_size
2431 * finder in the two loops below
2432 */
2433 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2434 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2435 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2436 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2437 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2438 };
2439 unsigned int m, i;
2440
2441 for (i = 0; i < info->hdr->e_shnum; i++)
2442 info->sechdrs[i].sh_entsize = ~0UL;
2443
2444 pr_debug("Core section allocation order:\n");
2445 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2446 for (i = 0; i < info->hdr->e_shnum; ++i) {
2447 Elf_Shdr *s = &info->sechdrs[i];
2448 const char *sname = info->secstrings + s->sh_name;
2449
2450 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2451 || (s->sh_flags & masks[m][1])
2452 || s->sh_entsize != ~0UL
2453 || module_init_layout_section(sname))
2454 continue;
2455 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2456 pr_debug("\t%s\n", sname);
2457 }
2458 switch (m) {
2459 case 0: /* executable */
2460 mod->core_layout.size = debug_align(mod->core_layout.size);
2461 mod->core_layout.text_size = mod->core_layout.size;
2462 break;
2463 case 1: /* RO: text and ro-data */
2464 mod->core_layout.size = debug_align(mod->core_layout.size);
2465 mod->core_layout.ro_size = mod->core_layout.size;
2466 break;
2467 case 2: /* RO after init */
2468 mod->core_layout.size = debug_align(mod->core_layout.size);
2469 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2470 break;
2471 case 4: /* whole core */
2472 mod->core_layout.size = debug_align(mod->core_layout.size);
2473 break;
2474 }
2475 }
2476
2477 pr_debug("Init section allocation order:\n");
2478 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2479 for (i = 0; i < info->hdr->e_shnum; ++i) {
2480 Elf_Shdr *s = &info->sechdrs[i];
2481 const char *sname = info->secstrings + s->sh_name;
2482
2483 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2484 || (s->sh_flags & masks[m][1])
2485 || s->sh_entsize != ~0UL
2486 || !module_init_layout_section(sname))
2487 continue;
2488 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2489 | INIT_OFFSET_MASK);
2490 pr_debug("\t%s\n", sname);
2491 }
2492 switch (m) {
2493 case 0: /* executable */
2494 mod->init_layout.size = debug_align(mod->init_layout.size);
2495 mod->init_layout.text_size = mod->init_layout.size;
2496 break;
2497 case 1: /* RO: text and ro-data */
2498 mod->init_layout.size = debug_align(mod->init_layout.size);
2499 mod->init_layout.ro_size = mod->init_layout.size;
2500 break;
2501 case 2:
2502 /*
2503 * RO after init doesn't apply to init_layout (only
2504 * core_layout), so it just takes the value of ro_size.
2505 */
2506 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2507 break;
2508 case 4: /* whole init */
2509 mod->init_layout.size = debug_align(mod->init_layout.size);
2510 break;
2511 }
2512 }
2513}
2514
2515static void set_license(struct module *mod, const char *license)
2516{
2517 if (!license)
2518 license = "unspecified";
2519
2520 if (!license_is_gpl_compatible(license)) {
2521 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2522 pr_warn("%s: module license '%s' taints kernel.\n",
2523 mod->name, license);
2524 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2525 LOCKDEP_NOW_UNRELIABLE);
2526 }
2527}
2528
2529/* Parse tag=value strings from .modinfo section */
2530static char *next_string(char *string, unsigned long *secsize)
2531{
2532 /* Skip non-zero chars */
2533 while (string[0]) {
2534 string++;
2535 if ((*secsize)-- <= 1)
2536 return NULL;
2537 }
2538
2539 /* Skip any zero padding. */
2540 while (!string[0]) {
2541 string++;
2542 if ((*secsize)-- <= 1)
2543 return NULL;
2544 }
2545 return string;
2546}
2547
2548static char *get_next_modinfo(const struct load_info *info, const char *tag,
2549 char *prev)
2550{
2551 char *p;
2552 unsigned int taglen = strlen(tag);
2553 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2554 unsigned long size = infosec->sh_size;
2555
2556 /*
2557 * get_modinfo() calls made before rewrite_section_headers()
2558 * must use sh_offset, as sh_addr isn't set!
2559 */
2560 char *modinfo = (char *)info->hdr + infosec->sh_offset;
2561
2562 if (prev) {
2563 size -= prev - modinfo;
2564 modinfo = next_string(prev, &size);
2565 }
2566
2567 for (p = modinfo; p; p = next_string(p, &size)) {
2568 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2569 return p + taglen + 1;
2570 }
2571 return NULL;
2572}
2573
2574static char *get_modinfo(const struct load_info *info, const char *tag)
2575{
2576 return get_next_modinfo(info, tag, NULL);
2577}
2578
2579static void setup_modinfo(struct module *mod, struct load_info *info)
2580{
2581 struct module_attribute *attr;
2582 int i;
2583
2584 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2585 if (attr->setup)
2586 attr->setup(mod, get_modinfo(info, attr->attr.name));
2587 }
2588}
2589
2590static void free_modinfo(struct module *mod)
2591{
2592 struct module_attribute *attr;
2593 int i;
2594
2595 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2596 if (attr->free)
2597 attr->free(mod);
2598 }
2599}
2600
2601#ifdef CONFIG_KALLSYMS
2602
2603/* Lookup exported symbol in given range of kernel_symbols */
2604static const struct kernel_symbol *lookup_exported_symbol(const char *name,
2605 const struct kernel_symbol *start,
2606 const struct kernel_symbol *stop)
2607{
2608 return bsearch(name, start, stop - start,
2609 sizeof(struct kernel_symbol), cmp_name);
2610}
2611
2612static int is_exported(const char *name, unsigned long value,
2613 const struct module *mod)
2614{
2615 const struct kernel_symbol *ks;
2616 if (!mod)
2617 ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
2618 else
2619 ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
2620
2621 return ks != NULL && kernel_symbol_value(ks) == value;
2622}
2623
2624/* As per nm */
2625static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2626{
2627 const Elf_Shdr *sechdrs = info->sechdrs;
2628
2629 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2630 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2631 return 'v';
2632 else
2633 return 'w';
2634 }
2635 if (sym->st_shndx == SHN_UNDEF)
2636 return 'U';
2637 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2638 return 'a';
2639 if (sym->st_shndx >= SHN_LORESERVE)
2640 return '?';
2641 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2642 return 't';
2643 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2644 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2645 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2646 return 'r';
2647 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2648 return 'g';
2649 else
2650 return 'd';
2651 }
2652 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2653 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2654 return 's';
2655 else
2656 return 'b';
2657 }
2658 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2659 ".debug")) {
2660 return 'n';
2661 }
2662 return '?';
2663}
2664
2665static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2666 unsigned int shnum, unsigned int pcpundx)
2667{
2668 const Elf_Shdr *sec;
2669
2670 if (src->st_shndx == SHN_UNDEF
2671 || src->st_shndx >= shnum
2672 || !src->st_name)
2673 return false;
2674
2675#ifdef CONFIG_KALLSYMS_ALL
2676 if (src->st_shndx == pcpundx)
2677 return true;
2678#endif
2679
2680 sec = sechdrs + src->st_shndx;
2681 if (!(sec->sh_flags & SHF_ALLOC)
2682#ifndef CONFIG_KALLSYMS_ALL
2683 || !(sec->sh_flags & SHF_EXECINSTR)
2684#endif
2685 || (sec->sh_entsize & INIT_OFFSET_MASK))
2686 return false;
2687
2688 return true;
2689}
2690
2691/*
2692 * We only allocate and copy the strings needed by the parts of symtab
2693 * we keep. This is simple, but has the effect of making multiple
2694 * copies of duplicates. We could be more sophisticated, see
2695 * linux-kernel thread starting with
2696 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2697 */
2698static void layout_symtab(struct module *mod, struct load_info *info)
2699{
2700 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2701 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2702 const Elf_Sym *src;
2703 unsigned int i, nsrc, ndst, strtab_size = 0;
2704
2705 /* Put symbol section at end of init part of module. */
2706 symsect->sh_flags |= SHF_ALLOC;
2707 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2708 info->index.sym) | INIT_OFFSET_MASK;
2709 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2710
2711 src = (void *)info->hdr + symsect->sh_offset;
2712 nsrc = symsect->sh_size / sizeof(*src);
2713
2714 /* Compute total space required for the core symbols' strtab. */
2715 for (ndst = i = 0; i < nsrc; i++) {
2716 if (i == 0 || is_livepatch_module(mod) ||
2717 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2718 info->index.pcpu)) {
2719 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2720 ndst++;
2721 }
2722 }
2723
2724 /* Append room for core symbols at end of core part. */
2725 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2726 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2727 mod->core_layout.size += strtab_size;
2728 info->core_typeoffs = mod->core_layout.size;
2729 mod->core_layout.size += ndst * sizeof(char);
2730 mod->core_layout.size = debug_align(mod->core_layout.size);
2731
2732 /* Put string table section at end of init part of module. */
2733 strsect->sh_flags |= SHF_ALLOC;
2734 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2735 info->index.str) | INIT_OFFSET_MASK;
2736 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2737
2738 /* We'll tack temporary mod_kallsyms on the end. */
2739 mod->init_layout.size = ALIGN(mod->init_layout.size,
2740 __alignof__(struct mod_kallsyms));
2741 info->mod_kallsyms_init_off = mod->init_layout.size;
2742 mod->init_layout.size += sizeof(struct mod_kallsyms);
2743 info->init_typeoffs = mod->init_layout.size;
2744 mod->init_layout.size += nsrc * sizeof(char);
2745 mod->init_layout.size = debug_align(mod->init_layout.size);
2746}
2747
2748/*
2749 * We use the full symtab and strtab which layout_symtab arranged to
2750 * be appended to the init section. Later we switch to the cut-down
2751 * core-only ones.
2752 */
2753static void add_kallsyms(struct module *mod, const struct load_info *info)
2754{
2755 unsigned int i, ndst;
2756 const Elf_Sym *src;
2757 Elf_Sym *dst;
2758 char *s;
2759 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2760
2761 /* Set up to point into init section. */
2762 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2763
2764 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2765 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2766 /* Make sure we get permanent strtab: don't use info->strtab. */
2767 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2768 mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
2769
2770 /*
2771 * Now populate the cut down core kallsyms for after init
2772 * and set types up while we still have access to sections.
2773 */
2774 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2775 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2776 mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
2777 src = mod->kallsyms->symtab;
2778 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2779 mod->kallsyms->typetab[i] = elf_type(src + i, info);
2780 if (i == 0 || is_livepatch_module(mod) ||
2781 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2782 info->index.pcpu)) {
2783 mod->core_kallsyms.typetab[ndst] =
2784 mod->kallsyms->typetab[i];
2785 dst[ndst] = src[i];
2786 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2787 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2788 KSYM_NAME_LEN) + 1;
2789 }
2790 }
2791 mod->core_kallsyms.num_symtab = ndst;
2792}
2793#else
2794static inline void layout_symtab(struct module *mod, struct load_info *info)
2795{
2796}
2797
2798static void add_kallsyms(struct module *mod, const struct load_info *info)
2799{
2800}
2801#endif /* CONFIG_KALLSYMS */
2802
2803#if IS_ENABLED(CONFIG_KALLSYMS) && IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
2804static void init_build_id(struct module *mod, const struct load_info *info)
2805{
2806 const Elf_Shdr *sechdr;
2807 unsigned int i;
2808
2809 for (i = 0; i < info->hdr->e_shnum; i++) {
2810 sechdr = &info->sechdrs[i];
2811 if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE &&
2812 !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id,
2813 sechdr->sh_size))
2814 break;
2815 }
2816}
2817#else
2818static void init_build_id(struct module *mod, const struct load_info *info)
2819{
2820}
2821#endif
2822
2823static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2824{
2825 if (!debug)
2826 return;
2827 ddebug_add_module(debug, num, mod->name);
2828}
2829
2830static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2831{
2832 if (debug)
2833 ddebug_remove_module(mod->name);
2834}
2835
2836void * __weak module_alloc(unsigned long size)
2837{
2838 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
2839 GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
2840 NUMA_NO_NODE, __builtin_return_address(0));
2841}
2842
2843bool __weak module_init_section(const char *name)
2844{
2845 return strstarts(name, ".init");
2846}
2847
2848bool __weak module_exit_section(const char *name)
2849{
2850 return strstarts(name, ".exit");
2851}
2852
2853#ifdef CONFIG_DEBUG_KMEMLEAK
2854static void kmemleak_load_module(const struct module *mod,
2855 const struct load_info *info)
2856{
2857 unsigned int i;
2858
2859 /* only scan the sections containing data */
2860 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2861
2862 for (i = 1; i < info->hdr->e_shnum; i++) {
2863 /* Scan all writable sections that's not executable */
2864 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2865 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2866 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2867 continue;
2868
2869 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2870 info->sechdrs[i].sh_size, GFP_KERNEL);
2871 }
2872}
2873#else
2874static inline void kmemleak_load_module(const struct module *mod,
2875 const struct load_info *info)
2876{
2877}
2878#endif
2879
2880#ifdef CONFIG_MODULE_SIG
2881static int module_sig_check(struct load_info *info, int flags)
2882{
2883 int err = -ENODATA;
2884 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2885 const char *reason;
2886 const void *mod = info->hdr;
2887
2888 /*
2889 * Require flags == 0, as a module with version information
2890 * removed is no longer the module that was signed
2891 */
2892 if (flags == 0 &&
2893 info->len > markerlen &&
2894 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2895 /* We truncate the module to discard the signature */
2896 info->len -= markerlen;
2897 err = mod_verify_sig(mod, info);
2898 if (!err) {
2899 info->sig_ok = true;
2900 return 0;
2901 }
2902 }
2903
2904 /*
2905 * We don't permit modules to be loaded into the trusted kernels
2906 * without a valid signature on them, but if we're not enforcing,
2907 * certain errors are non-fatal.
2908 */
2909 switch (err) {
2910 case -ENODATA:
2911 reason = "unsigned module";
2912 break;
2913 case -ENOPKG:
2914 reason = "module with unsupported crypto";
2915 break;
2916 case -ENOKEY:
2917 reason = "module with unavailable key";
2918 break;
2919
2920 default:
2921 /*
2922 * All other errors are fatal, including lack of memory,
2923 * unparseable signatures, and signature check failures --
2924 * even if signatures aren't required.
2925 */
2926 return err;
2927 }
2928
2929 if (is_module_sig_enforced()) {
2930 pr_notice("Loading of %s is rejected\n", reason);
2931 return -EKEYREJECTED;
2932 }
2933
2934 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
2935}
2936#else /* !CONFIG_MODULE_SIG */
2937static int module_sig_check(struct load_info *info, int flags)
2938{
2939 return 0;
2940}
2941#endif /* !CONFIG_MODULE_SIG */
2942
2943static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
2944{
2945 unsigned long secend;
2946
2947 /*
2948 * Check for both overflow and offset/size being
2949 * too large.
2950 */
2951 secend = shdr->sh_offset + shdr->sh_size;
2952 if (secend < shdr->sh_offset || secend > info->len)
2953 return -ENOEXEC;
2954
2955 return 0;
2956}
2957
2958/*
2959 * Sanity checks against invalid binaries, wrong arch, weird elf version.
2960 *
2961 * Also do basic validity checks against section offsets and sizes, the
2962 * section name string table, and the indices used for it (sh_name).
2963 */
2964static int elf_validity_check(struct load_info *info)
2965{
2966 unsigned int i;
2967 Elf_Shdr *shdr, *strhdr;
2968 int err;
2969
2970 if (info->len < sizeof(*(info->hdr)))
2971 return -ENOEXEC;
2972
2973 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2974 || info->hdr->e_type != ET_REL
2975 || !elf_check_arch(info->hdr)
2976 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2977 return -ENOEXEC;
2978
2979 /*
2980 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
2981 * known and small. So e_shnum * sizeof(Elf_Shdr)
2982 * will not overflow unsigned long on any platform.
2983 */
2984 if (info->hdr->e_shoff >= info->len
2985 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2986 info->len - info->hdr->e_shoff))
2987 return -ENOEXEC;
2988
2989 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2990
2991 /*
2992 * Verify if the section name table index is valid.
2993 */
2994 if (info->hdr->e_shstrndx == SHN_UNDEF
2995 || info->hdr->e_shstrndx >= info->hdr->e_shnum)
2996 return -ENOEXEC;
2997
2998 strhdr = &info->sechdrs[info->hdr->e_shstrndx];
2999 err = validate_section_offset(info, strhdr);
3000 if (err < 0)
3001 return err;
3002
3003 /*
3004 * The section name table must be NUL-terminated, as required
3005 * by the spec. This makes strcmp and pr_* calls that access
3006 * strings in the section safe.
3007 */
3008 info->secstrings = (void *)info->hdr + strhdr->sh_offset;
3009 if (info->secstrings[strhdr->sh_size - 1] != '\0')
3010 return -ENOEXEC;
3011
3012 /*
3013 * The code assumes that section 0 has a length of zero and
3014 * an addr of zero, so check for it.
3015 */
3016 if (info->sechdrs[0].sh_type != SHT_NULL
3017 || info->sechdrs[0].sh_size != 0
3018 || info->sechdrs[0].sh_addr != 0)
3019 return -ENOEXEC;
3020
3021 for (i = 1; i < info->hdr->e_shnum; i++) {
3022 shdr = &info->sechdrs[i];
3023 switch (shdr->sh_type) {
3024 case SHT_NULL:
3025 case SHT_NOBITS:
3026 continue;
3027 case SHT_SYMTAB:
3028 if (shdr->sh_link == SHN_UNDEF
3029 || shdr->sh_link >= info->hdr->e_shnum)
3030 return -ENOEXEC;
3031 fallthrough;
3032 default:
3033 err = validate_section_offset(info, shdr);
3034 if (err < 0) {
3035 pr_err("Invalid ELF section in module (section %u type %u)\n",
3036 i, shdr->sh_type);
3037 return err;
3038 }
3039
3040 if (shdr->sh_flags & SHF_ALLOC) {
3041 if (shdr->sh_name >= strhdr->sh_size) {
3042 pr_err("Invalid ELF section name in module (section %u type %u)\n",
3043 i, shdr->sh_type);
3044 return -ENOEXEC;
3045 }
3046 }
3047 break;
3048 }
3049 }
3050
3051 return 0;
3052}
3053
3054#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
3055
3056static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
3057{
3058 do {
3059 unsigned long n = min(len, COPY_CHUNK_SIZE);
3060
3061 if (copy_from_user(dst, usrc, n) != 0)
3062 return -EFAULT;
3063 cond_resched();
3064 dst += n;
3065 usrc += n;
3066 len -= n;
3067 } while (len);
3068 return 0;
3069}
3070
3071#ifdef CONFIG_LIVEPATCH
3072static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
3073{
3074 if (get_modinfo(info, "livepatch")) {
3075 mod->klp = true;
3076 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
3077 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
3078 mod->name);
3079 }
3080
3081 return 0;
3082}
3083#else /* !CONFIG_LIVEPATCH */
3084static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
3085{
3086 if (get_modinfo(info, "livepatch")) {
3087 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
3088 mod->name);
3089 return -ENOEXEC;
3090 }
3091
3092 return 0;
3093}
3094#endif /* CONFIG_LIVEPATCH */
3095
3096static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
3097{
3098 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
3099 return;
3100
3101 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
3102 mod->name);
3103}
3104
3105/* Sets info->hdr and info->len. */
3106static int copy_module_from_user(const void __user *umod, unsigned long len,
3107 struct load_info *info)
3108{
3109 int err;
3110
3111 info->len = len;
3112 if (info->len < sizeof(*(info->hdr)))
3113 return -ENOEXEC;
3114
3115 err = security_kernel_load_data(LOADING_MODULE, true);
3116 if (err)
3117 return err;
3118
3119 /* Suck in entire file: we'll want most of it. */
3120 info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
3121 if (!info->hdr)
3122 return -ENOMEM;
3123
3124 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
3125 err = -EFAULT;
3126 goto out;
3127 }
3128
3129 err = security_kernel_post_load_data((char *)info->hdr, info->len,
3130 LOADING_MODULE, "init_module");
3131out:
3132 if (err)
3133 vfree(info->hdr);
3134
3135 return err;
3136}
3137
3138static void free_copy(struct load_info *info)
3139{
3140 vfree(info->hdr);
3141}
3142
3143static int rewrite_section_headers(struct load_info *info, int flags)
3144{
3145 unsigned int i;
3146
3147 /* This should always be true, but let's be sure. */
3148 info->sechdrs[0].sh_addr = 0;
3149
3150 for (i = 1; i < info->hdr->e_shnum; i++) {
3151 Elf_Shdr *shdr = &info->sechdrs[i];
3152
3153 /*
3154 * Mark all sections sh_addr with their address in the
3155 * temporary image.
3156 */
3157 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
3158
3159 }
3160
3161 /* Track but don't keep modinfo and version sections. */
3162 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
3163 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
3164
3165 return 0;
3166}
3167
3168/*
3169 * Set up our basic convenience variables (pointers to section headers,
3170 * search for module section index etc), and do some basic section
3171 * verification.
3172 *
3173 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3174 * will be allocated in move_module().
3175 */
3176static int setup_load_info(struct load_info *info, int flags)
3177{
3178 unsigned int i;
3179
3180 /* Try to find a name early so we can log errors with a module name */
3181 info->index.info = find_sec(info, ".modinfo");
3182 if (info->index.info)
3183 info->name = get_modinfo(info, "name");
3184
3185 /* Find internal symbols and strings. */
3186 for (i = 1; i < info->hdr->e_shnum; i++) {
3187 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
3188 info->index.sym = i;
3189 info->index.str = info->sechdrs[i].sh_link;
3190 info->strtab = (char *)info->hdr
3191 + info->sechdrs[info->index.str].sh_offset;
3192 break;
3193 }
3194 }
3195
3196 if (info->index.sym == 0) {
3197 pr_warn("%s: module has no symbols (stripped?)\n",
3198 info->name ?: "(missing .modinfo section or name field)");
3199 return -ENOEXEC;
3200 }
3201
3202 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
3203 if (!info->index.mod) {
3204 pr_warn("%s: No module found in object\n",
3205 info->name ?: "(missing .modinfo section or name field)");
3206 return -ENOEXEC;
3207 }
3208 /* This is temporary: point mod into copy of data. */
3209 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
3210
3211 /*
3212 * If we didn't load the .modinfo 'name' field earlier, fall back to
3213 * on-disk struct mod 'name' field.
3214 */
3215 if (!info->name)
3216 info->name = info->mod->name;
3217
3218 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
3219 info->index.vers = 0; /* Pretend no __versions section! */
3220 else
3221 info->index.vers = find_sec(info, "__versions");
3222
3223 info->index.pcpu = find_pcpusec(info);
3224
3225 return 0;
3226}
3227
3228static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3229{
3230 const char *modmagic = get_modinfo(info, "vermagic");
3231 int err;
3232
3233 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3234 modmagic = NULL;
3235
3236 /* This is allowed: modprobe --force will invalidate it. */
3237 if (!modmagic) {
3238 err = try_to_force_load(mod, "bad vermagic");
3239 if (err)
3240 return err;
3241 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3242 pr_err("%s: version magic '%s' should be '%s'\n",
3243 info->name, modmagic, vermagic);
3244 return -ENOEXEC;
3245 }
3246
3247 if (!get_modinfo(info, "intree")) {
3248 if (!test_taint(TAINT_OOT_MODULE))
3249 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3250 mod->name);
3251 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3252 }
3253
3254 check_modinfo_retpoline(mod, info);
3255
3256 if (get_modinfo(info, "staging")) {
3257 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3258 pr_warn("%s: module is from the staging directory, the quality "
3259 "is unknown, you have been warned.\n", mod->name);
3260 }
3261
3262 err = check_modinfo_livepatch(mod, info);
3263 if (err)
3264 return err;
3265
3266 /* Set up license info based on the info section */
3267 set_license(mod, get_modinfo(info, "license"));
3268
3269 return 0;
3270}
3271
3272static int find_module_sections(struct module *mod, struct load_info *info)
3273{
3274 mod->kp = section_objs(info, "__param",
3275 sizeof(*mod->kp), &mod->num_kp);
3276 mod->syms = section_objs(info, "__ksymtab",
3277 sizeof(*mod->syms), &mod->num_syms);
3278 mod->crcs = section_addr(info, "__kcrctab");
3279 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3280 sizeof(*mod->gpl_syms),
3281 &mod->num_gpl_syms);
3282 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3283
3284#ifdef CONFIG_CONSTRUCTORS
3285 mod->ctors = section_objs(info, ".ctors",
3286 sizeof(*mod->ctors), &mod->num_ctors);
3287 if (!mod->ctors)
3288 mod->ctors = section_objs(info, ".init_array",
3289 sizeof(*mod->ctors), &mod->num_ctors);
3290 else if (find_sec(info, ".init_array")) {
3291 /*
3292 * This shouldn't happen with same compiler and binutils
3293 * building all parts of the module.
3294 */
3295 pr_warn("%s: has both .ctors and .init_array.\n",
3296 mod->name);
3297 return -EINVAL;
3298 }
3299#endif
3300
3301 mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
3302 &mod->noinstr_text_size);
3303
3304#ifdef CONFIG_TRACEPOINTS
3305 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3306 sizeof(*mod->tracepoints_ptrs),
3307 &mod->num_tracepoints);
3308#endif
3309#ifdef CONFIG_TREE_SRCU
3310 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
3311 sizeof(*mod->srcu_struct_ptrs),
3312 &mod->num_srcu_structs);
3313#endif
3314#ifdef CONFIG_BPF_EVENTS
3315 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
3316 sizeof(*mod->bpf_raw_events),
3317 &mod->num_bpf_raw_events);
3318#endif
3319#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3320 mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size);
3321#endif
3322#ifdef CONFIG_JUMP_LABEL
3323 mod->jump_entries = section_objs(info, "__jump_table",
3324 sizeof(*mod->jump_entries),
3325 &mod->num_jump_entries);
3326#endif
3327#ifdef CONFIG_EVENT_TRACING
3328 mod->trace_events = section_objs(info, "_ftrace_events",
3329 sizeof(*mod->trace_events),
3330 &mod->num_trace_events);
3331 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3332 sizeof(*mod->trace_evals),
3333 &mod->num_trace_evals);
3334#endif
3335#ifdef CONFIG_TRACING
3336 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3337 sizeof(*mod->trace_bprintk_fmt_start),
3338 &mod->num_trace_bprintk_fmt);
3339#endif
3340#ifdef CONFIG_FTRACE_MCOUNT_RECORD
3341 /* sechdrs[0].sh_size is always zero */
3342 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
3343 sizeof(*mod->ftrace_callsites),
3344 &mod->num_ftrace_callsites);
3345#endif
3346#ifdef CONFIG_FUNCTION_ERROR_INJECTION
3347 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3348 sizeof(*mod->ei_funcs),
3349 &mod->num_ei_funcs);
3350#endif
3351#ifdef CONFIG_KPROBES
3352 mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
3353 &mod->kprobes_text_size);
3354 mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
3355 sizeof(unsigned long),
3356 &mod->num_kprobe_blacklist);
3357#endif
3358#ifdef CONFIG_HAVE_STATIC_CALL_INLINE
3359 mod->static_call_sites = section_objs(info, ".static_call_sites",
3360 sizeof(*mod->static_call_sites),
3361 &mod->num_static_call_sites);
3362#endif
3363 mod->extable = section_objs(info, "__ex_table",
3364 sizeof(*mod->extable), &mod->num_exentries);
3365
3366 if (section_addr(info, "__obsparm"))
3367 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3368
3369 info->debug = section_objs(info, "__dyndbg",
3370 sizeof(*info->debug), &info->num_debug);
3371
3372 return 0;
3373}
3374
3375static int move_module(struct module *mod, struct load_info *info)
3376{
3377 int i;
3378 void *ptr;
3379
3380 /* Do the allocs. */
3381 ptr = module_alloc(mod->core_layout.size);
3382 /*
3383 * The pointer to this block is stored in the module structure
3384 * which is inside the block. Just mark it as not being a
3385 * leak.
3386 */
3387 kmemleak_not_leak(ptr);
3388 if (!ptr)
3389 return -ENOMEM;
3390
3391 memset(ptr, 0, mod->core_layout.size);
3392 mod->core_layout.base = ptr;
3393
3394 if (mod->init_layout.size) {
3395 ptr = module_alloc(mod->init_layout.size);
3396 /*
3397 * The pointer to this block is stored in the module structure
3398 * which is inside the block. This block doesn't need to be
3399 * scanned as it contains data and code that will be freed
3400 * after the module is initialized.
3401 */
3402 kmemleak_ignore(ptr);
3403 if (!ptr) {
3404 module_memfree(mod->core_layout.base);
3405 return -ENOMEM;
3406 }
3407 memset(ptr, 0, mod->init_layout.size);
3408 mod->init_layout.base = ptr;
3409 } else
3410 mod->init_layout.base = NULL;
3411
3412 /* Transfer each section which specifies SHF_ALLOC */
3413 pr_debug("final section addresses:\n");
3414 for (i = 0; i < info->hdr->e_shnum; i++) {
3415 void *dest;
3416 Elf_Shdr *shdr = &info->sechdrs[i];
3417
3418 if (!(shdr->sh_flags & SHF_ALLOC))
3419 continue;
3420
3421 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3422 dest = mod->init_layout.base
3423 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3424 else
3425 dest = mod->core_layout.base + shdr->sh_entsize;
3426
3427 if (shdr->sh_type != SHT_NOBITS)
3428 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3429 /* Update sh_addr to point to copy in image. */
3430 shdr->sh_addr = (unsigned long)dest;
3431 pr_debug("\t0x%lx %s\n",
3432 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3433 }
3434
3435 return 0;
3436}
3437
3438static int check_module_license_and_versions(struct module *mod)
3439{
3440 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3441
3442 /*
3443 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3444 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3445 * using GPL-only symbols it needs.
3446 */
3447 if (strcmp(mod->name, "ndiswrapper") == 0)
3448 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3449
3450 /* driverloader was caught wrongly pretending to be under GPL */
3451 if (strcmp(mod->name, "driverloader") == 0)
3452 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3453 LOCKDEP_NOW_UNRELIABLE);
3454
3455 /* lve claims to be GPL but upstream won't provide source */
3456 if (strcmp(mod->name, "lve") == 0)
3457 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3458 LOCKDEP_NOW_UNRELIABLE);
3459
3460 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3461 pr_warn("%s: module license taints kernel.\n", mod->name);
3462
3463#ifdef CONFIG_MODVERSIONS
3464 if ((mod->num_syms && !mod->crcs) ||
3465 (mod->num_gpl_syms && !mod->gpl_crcs)) {
3466 return try_to_force_load(mod,
3467 "no versions for exported symbols");
3468 }
3469#endif
3470 return 0;
3471}
3472
3473static void flush_module_icache(const struct module *mod)
3474{
3475 /*
3476 * Flush the instruction cache, since we've played with text.
3477 * Do it before processing of module parameters, so the module
3478 * can provide parameter accessor functions of its own.
3479 */
3480 if (mod->init_layout.base)
3481 flush_icache_range((unsigned long)mod->init_layout.base,
3482 (unsigned long)mod->init_layout.base
3483 + mod->init_layout.size);
3484 flush_icache_range((unsigned long)mod->core_layout.base,
3485 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3486}
3487
3488int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3489 Elf_Shdr *sechdrs,
3490 char *secstrings,
3491 struct module *mod)
3492{
3493 return 0;
3494}
3495
3496/* module_blacklist is a comma-separated list of module names */
3497static char *module_blacklist;
3498static bool blacklisted(const char *module_name)
3499{
3500 const char *p;
3501 size_t len;
3502
3503 if (!module_blacklist)
3504 return false;
3505
3506 for (p = module_blacklist; *p; p += len) {
3507 len = strcspn(p, ",");
3508 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3509 return true;
3510 if (p[len] == ',')
3511 len++;
3512 }
3513 return false;
3514}
3515core_param(module_blacklist, module_blacklist, charp, 0400);
3516
3517static struct module *layout_and_allocate(struct load_info *info, int flags)
3518{
3519 struct module *mod;
3520 unsigned int ndx;
3521 int err;
3522
3523 err = check_modinfo(info->mod, info, flags);
3524 if (err)
3525 return ERR_PTR(err);
3526
3527 /* Allow arches to frob section contents and sizes. */
3528 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3529 info->secstrings, info->mod);
3530 if (err < 0)
3531 return ERR_PTR(err);
3532
3533 err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
3534 info->secstrings, info->mod);
3535 if (err < 0)
3536 return ERR_PTR(err);
3537
3538 /* We will do a special allocation for per-cpu sections later. */
3539 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3540
3541 /*
3542 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3543 * layout_sections() can put it in the right place.
3544 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3545 */
3546 ndx = find_sec(info, ".data..ro_after_init");
3547 if (ndx)
3548 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3549 /*
3550 * Mark the __jump_table section as ro_after_init as well: these data
3551 * structures are never modified, with the exception of entries that
3552 * refer to code in the __init section, which are annotated as such
3553 * at module load time.
3554 */
3555 ndx = find_sec(info, "__jump_table");
3556 if (ndx)
3557 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3558
3559 /*
3560 * Determine total sizes, and put offsets in sh_entsize. For now
3561 * this is done generically; there doesn't appear to be any
3562 * special cases for the architectures.
3563 */
3564 layout_sections(info->mod, info);
3565 layout_symtab(info->mod, info);
3566
3567 /* Allocate and move to the final place */
3568 err = move_module(info->mod, info);
3569 if (err)
3570 return ERR_PTR(err);
3571
3572 /* Module has been copied to its final place now: return it. */
3573 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3574 kmemleak_load_module(mod, info);
3575 return mod;
3576}
3577
3578/* mod is no longer valid after this! */
3579static void module_deallocate(struct module *mod, struct load_info *info)
3580{
3581 percpu_modfree(mod);
3582 module_arch_freeing_init(mod);
3583 module_memfree(mod->init_layout.base);
3584 module_memfree(mod->core_layout.base);
3585}
3586
3587int __weak module_finalize(const Elf_Ehdr *hdr,
3588 const Elf_Shdr *sechdrs,
3589 struct module *me)
3590{
3591 return 0;
3592}
3593
3594static int post_relocation(struct module *mod, const struct load_info *info)
3595{
3596 /* Sort exception table now relocations are done. */
3597 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3598
3599 /* Copy relocated percpu area over. */
3600 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3601 info->sechdrs[info->index.pcpu].sh_size);
3602
3603 /* Setup kallsyms-specific fields. */
3604 add_kallsyms(mod, info);
3605
3606 /* Arch-specific module finalizing. */
3607 return module_finalize(info->hdr, info->sechdrs, mod);
3608}
3609
3610/* Is this module of this name done loading? No locks held. */
3611static bool finished_loading(const char *name)
3612{
3613 struct module *mod;
3614 bool ret;
3615
3616 /*
3617 * The module_mutex should not be a heavily contended lock;
3618 * if we get the occasional sleep here, we'll go an extra iteration
3619 * in the wait_event_interruptible(), which is harmless.
3620 */
3621 sched_annotate_sleep();
3622 mutex_lock(&module_mutex);
3623 mod = find_module_all(name, strlen(name), true);
3624 ret = !mod || mod->state == MODULE_STATE_LIVE;
3625 mutex_unlock(&module_mutex);
3626
3627 return ret;
3628}
3629
3630/* Call module constructors. */
3631static void do_mod_ctors(struct module *mod)
3632{
3633#ifdef CONFIG_CONSTRUCTORS
3634 unsigned long i;
3635
3636 for (i = 0; i < mod->num_ctors; i++)
3637 mod->ctors[i]();
3638#endif
3639}
3640
3641/* For freeing module_init on success, in case kallsyms traversing */
3642struct mod_initfree {
3643 struct llist_node node;
3644 void *module_init;
3645};
3646
3647static void do_free_init(struct work_struct *w)
3648{
3649 struct llist_node *pos, *n, *list;
3650 struct mod_initfree *initfree;
3651
3652 list = llist_del_all(&init_free_list);
3653
3654 synchronize_rcu();
3655
3656 llist_for_each_safe(pos, n, list) {
3657 initfree = container_of(pos, struct mod_initfree, node);
3658 module_memfree(initfree->module_init);
3659 kfree(initfree);
3660 }
3661}
3662
3663/*
3664 * This is where the real work happens.
3665 *
3666 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3667 * helper command 'lx-symbols'.
3668 */
3669static noinline int do_init_module(struct module *mod)
3670{
3671 int ret = 0;
3672 struct mod_initfree *freeinit;
3673
3674 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3675 if (!freeinit) {
3676 ret = -ENOMEM;
3677 goto fail;
3678 }
3679 freeinit->module_init = mod->init_layout.base;
3680
3681 /*
3682 * We want to find out whether @mod uses async during init. Clear
3683 * PF_USED_ASYNC. async_schedule*() will set it.
3684 */
3685 current->flags &= ~PF_USED_ASYNC;
3686
3687 do_mod_ctors(mod);
3688 /* Start the module */
3689 if (mod->init != NULL)
3690 ret = do_one_initcall(mod->init);
3691 if (ret < 0) {
3692 goto fail_free_freeinit;
3693 }
3694 if (ret > 0) {
3695 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3696 "follow 0/-E convention\n"
3697 "%s: loading module anyway...\n",
3698 __func__, mod->name, ret, __func__);
3699 dump_stack();
3700 }
3701
3702 /* Now it's a first class citizen! */
3703 mod->state = MODULE_STATE_LIVE;
3704 blocking_notifier_call_chain(&module_notify_list,
3705 MODULE_STATE_LIVE, mod);
3706
3707 /* Delay uevent until module has finished its init routine */
3708 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
3709
3710 /*
3711 * We need to finish all async code before the module init sequence
3712 * is done. This has potential to deadlock. For example, a newly
3713 * detected block device can trigger request_module() of the
3714 * default iosched from async probing task. Once userland helper
3715 * reaches here, async_synchronize_full() will wait on the async
3716 * task waiting on request_module() and deadlock.
3717 *
3718 * This deadlock is avoided by perfomring async_synchronize_full()
3719 * iff module init queued any async jobs. This isn't a full
3720 * solution as it will deadlock the same if module loading from
3721 * async jobs nests more than once; however, due to the various
3722 * constraints, this hack seems to be the best option for now.
3723 * Please refer to the following thread for details.
3724 *
3725 * http://thread.gmane.org/gmane.linux.kernel/1420814
3726 */
3727 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3728 async_synchronize_full();
3729
3730 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3731 mod->init_layout.size);
3732 mutex_lock(&module_mutex);
3733 /* Drop initial reference. */
3734 module_put(mod);
3735 trim_init_extable(mod);
3736#ifdef CONFIG_KALLSYMS
3737 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3738 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3739#endif
3740 module_enable_ro(mod, true);
3741 mod_tree_remove_init(mod);
3742 module_arch_freeing_init(mod);
3743 mod->init_layout.base = NULL;
3744 mod->init_layout.size = 0;
3745 mod->init_layout.ro_size = 0;
3746 mod->init_layout.ro_after_init_size = 0;
3747 mod->init_layout.text_size = 0;
3748#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3749 /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */
3750 mod->btf_data = NULL;
3751#endif
3752 /*
3753 * We want to free module_init, but be aware that kallsyms may be
3754 * walking this with preempt disabled. In all the failure paths, we
3755 * call synchronize_rcu(), but we don't want to slow down the success
3756 * path. module_memfree() cannot be called in an interrupt, so do the
3757 * work and call synchronize_rcu() in a work queue.
3758 *
3759 * Note that module_alloc() on most architectures creates W+X page
3760 * mappings which won't be cleaned up until do_free_init() runs. Any
3761 * code such as mark_rodata_ro() which depends on those mappings to
3762 * be cleaned up needs to sync with the queued work - ie
3763 * rcu_barrier()
3764 */
3765 if (llist_add(&freeinit->node, &init_free_list))
3766 schedule_work(&init_free_wq);
3767
3768 mutex_unlock(&module_mutex);
3769 wake_up_all(&module_wq);
3770
3771 return 0;
3772
3773fail_free_freeinit:
3774 kfree(freeinit);
3775fail:
3776 /* Try to protect us from buggy refcounters. */
3777 mod->state = MODULE_STATE_GOING;
3778 synchronize_rcu();
3779 module_put(mod);
3780 blocking_notifier_call_chain(&module_notify_list,
3781 MODULE_STATE_GOING, mod);
3782 klp_module_going(mod);
3783 ftrace_release_mod(mod);
3784 free_module(mod);
3785 wake_up_all(&module_wq);
3786 return ret;
3787}
3788
3789static int may_init_module(void)
3790{
3791 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3792 return -EPERM;
3793
3794 return 0;
3795}
3796
3797/*
3798 * We try to place it in the list now to make sure it's unique before
3799 * we dedicate too many resources. In particular, temporary percpu
3800 * memory exhaustion.
3801 */
3802static int add_unformed_module(struct module *mod)
3803{
3804 int err;
3805 struct module *old;
3806
3807 mod->state = MODULE_STATE_UNFORMED;
3808
3809again:
3810 mutex_lock(&module_mutex);
3811 old = find_module_all(mod->name, strlen(mod->name), true);
3812 if (old != NULL) {
3813 if (old->state != MODULE_STATE_LIVE) {
3814 /* Wait in case it fails to load. */
3815 mutex_unlock(&module_mutex);
3816 err = wait_event_interruptible(module_wq,
3817 finished_loading(mod->name));
3818 if (err)
3819 goto out_unlocked;
3820 goto again;
3821 }
3822 err = -EEXIST;
3823 goto out;
3824 }
3825 mod_update_bounds(mod);
3826 list_add_rcu(&mod->list, &modules);
3827 mod_tree_insert(mod);
3828 err = 0;
3829
3830out:
3831 mutex_unlock(&module_mutex);
3832out_unlocked:
3833 return err;
3834}
3835
3836static int complete_formation(struct module *mod, struct load_info *info)
3837{
3838 int err;
3839
3840 mutex_lock(&module_mutex);
3841
3842 /* Find duplicate symbols (must be called under lock). */
3843 err = verify_exported_symbols(mod);
3844 if (err < 0)
3845 goto out;
3846
3847 /* This relies on module_mutex for list integrity. */
3848 module_bug_finalize(info->hdr, info->sechdrs, mod);
3849
3850 module_enable_ro(mod, false);
3851 module_enable_nx(mod);
3852 module_enable_x(mod);
3853
3854 /*
3855 * Mark state as coming so strong_try_module_get() ignores us,
3856 * but kallsyms etc. can see us.
3857 */
3858 mod->state = MODULE_STATE_COMING;
3859 mutex_unlock(&module_mutex);
3860
3861 return 0;
3862
3863out:
3864 mutex_unlock(&module_mutex);
3865 return err;
3866}
3867
3868static int prepare_coming_module(struct module *mod)
3869{
3870 int err;
3871
3872 ftrace_module_enable(mod);
3873 err = klp_module_coming(mod);
3874 if (err)
3875 return err;
3876
3877 err = blocking_notifier_call_chain_robust(&module_notify_list,
3878 MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
3879 err = notifier_to_errno(err);
3880 if (err)
3881 klp_module_going(mod);
3882
3883 return err;
3884}
3885
3886static int unknown_module_param_cb(char *param, char *val, const char *modname,
3887 void *arg)
3888{
3889 struct module *mod = arg;
3890 int ret;
3891
3892 if (strcmp(param, "async_probe") == 0) {
3893 mod->async_probe_requested = true;
3894 return 0;
3895 }
3896
3897 /* Check for magic 'dyndbg' arg */
3898 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3899 if (ret != 0)
3900 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3901 return 0;
3902}
3903
3904static void cfi_init(struct module *mod);
3905
3906/*
3907 * Allocate and load the module: note that size of section 0 is always
3908 * zero, and we rely on this for optional sections.
3909 */
3910static int load_module(struct load_info *info, const char __user *uargs,
3911 int flags)
3912{
3913 struct module *mod;
3914 long err = 0;
3915 char *after_dashes;
3916
3917 /*
3918 * Do the signature check (if any) first. All that
3919 * the signature check needs is info->len, it does
3920 * not need any of the section info. That can be
3921 * set up later. This will minimize the chances
3922 * of a corrupt module causing problems before
3923 * we even get to the signature check.
3924 *
3925 * The check will also adjust info->len by stripping
3926 * off the sig length at the end of the module, making
3927 * checks against info->len more correct.
3928 */
3929 err = module_sig_check(info, flags);
3930 if (err)
3931 goto free_copy;
3932
3933 /*
3934 * Do basic sanity checks against the ELF header and
3935 * sections.
3936 */
3937 err = elf_validity_check(info);
3938 if (err) {
3939 pr_err("Module has invalid ELF structures\n");
3940 goto free_copy;
3941 }
3942
3943 /*
3944 * Everything checks out, so set up the section info
3945 * in the info structure.
3946 */
3947 err = setup_load_info(info, flags);
3948 if (err)
3949 goto free_copy;
3950
3951 /*
3952 * Now that we know we have the correct module name, check
3953 * if it's blacklisted.
3954 */
3955 if (blacklisted(info->name)) {
3956 err = -EPERM;
3957 pr_err("Module %s is blacklisted\n", info->name);
3958 goto free_copy;
3959 }
3960
3961 err = rewrite_section_headers(info, flags);
3962 if (err)
3963 goto free_copy;
3964
3965 /* Check module struct version now, before we try to use module. */
3966 if (!check_modstruct_version(info, info->mod)) {
3967 err = -ENOEXEC;
3968 goto free_copy;
3969 }
3970
3971 /* Figure out module layout, and allocate all the memory. */
3972 mod = layout_and_allocate(info, flags);
3973 if (IS_ERR(mod)) {
3974 err = PTR_ERR(mod);
3975 goto free_copy;
3976 }
3977
3978 audit_log_kern_module(mod->name);
3979
3980 /* Reserve our place in the list. */
3981 err = add_unformed_module(mod);
3982 if (err)
3983 goto free_module;
3984
3985#ifdef CONFIG_MODULE_SIG
3986 mod->sig_ok = info->sig_ok;
3987 if (!mod->sig_ok) {
3988 pr_notice_once("%s: module verification failed: signature "
3989 "and/or required key missing - tainting "
3990 "kernel\n", mod->name);
3991 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3992 }
3993#endif
3994
3995 /* To avoid stressing percpu allocator, do this once we're unique. */
3996 err = percpu_modalloc(mod, info);
3997 if (err)
3998 goto unlink_mod;
3999
4000 /* Now module is in final location, initialize linked lists, etc. */
4001 err = module_unload_init(mod);
4002 if (err)
4003 goto unlink_mod;
4004
4005 init_param_lock(mod);
4006
4007 /*
4008 * Now we've got everything in the final locations, we can
4009 * find optional sections.
4010 */
4011 err = find_module_sections(mod, info);
4012 if (err)
4013 goto free_unload;
4014
4015 err = check_module_license_and_versions(mod);
4016 if (err)
4017 goto free_unload;
4018
4019 /* Set up MODINFO_ATTR fields */
4020 setup_modinfo(mod, info);
4021
4022 /* Fix up syms, so that st_value is a pointer to location. */
4023 err = simplify_symbols(mod, info);
4024 if (err < 0)
4025 goto free_modinfo;
4026
4027 err = apply_relocations(mod, info);
4028 if (err < 0)
4029 goto free_modinfo;
4030
4031 err = post_relocation(mod, info);
4032 if (err < 0)
4033 goto free_modinfo;
4034
4035 flush_module_icache(mod);
4036
4037 /* Setup CFI for the module. */
4038 cfi_init(mod);
4039
4040 /* Now copy in args */
4041 mod->args = strndup_user(uargs, ~0UL >> 1);
4042 if (IS_ERR(mod->args)) {
4043 err = PTR_ERR(mod->args);
4044 goto free_arch_cleanup;
4045 }
4046
4047 init_build_id(mod, info);
4048 dynamic_debug_setup(mod, info->debug, info->num_debug);
4049
4050 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
4051 ftrace_module_init(mod);
4052
4053 /* Finally it's fully formed, ready to start executing. */
4054 err = complete_formation(mod, info);
4055 if (err)
4056 goto ddebug_cleanup;
4057
4058 err = prepare_coming_module(mod);
4059 if (err)
4060 goto bug_cleanup;
4061
4062 /* Module is ready to execute: parsing args may do that. */
4063 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
4064 -32768, 32767, mod,
4065 unknown_module_param_cb);
4066 if (IS_ERR(after_dashes)) {
4067 err = PTR_ERR(after_dashes);
4068 goto coming_cleanup;
4069 } else if (after_dashes) {
4070 pr_warn("%s: parameters '%s' after `--' ignored\n",
4071 mod->name, after_dashes);
4072 }
4073
4074 /* Link in to sysfs. */
4075 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
4076 if (err < 0)
4077 goto coming_cleanup;
4078
4079 if (is_livepatch_module(mod)) {
4080 err = copy_module_elf(mod, info);
4081 if (err < 0)
4082 goto sysfs_cleanup;
4083 }
4084
4085 /* Get rid of temporary copy. */
4086 free_copy(info);
4087
4088 /* Done! */
4089 trace_module_load(mod);
4090
4091 return do_init_module(mod);
4092
4093 sysfs_cleanup:
4094 mod_sysfs_teardown(mod);
4095 coming_cleanup:
4096 mod->state = MODULE_STATE_GOING;
4097 destroy_params(mod->kp, mod->num_kp);
4098 blocking_notifier_call_chain(&module_notify_list,
4099 MODULE_STATE_GOING, mod);
4100 klp_module_going(mod);
4101 bug_cleanup:
4102 mod->state = MODULE_STATE_GOING;
4103 /* module_bug_cleanup needs module_mutex protection */
4104 mutex_lock(&module_mutex);
4105 module_bug_cleanup(mod);
4106 mutex_unlock(&module_mutex);
4107
4108 ddebug_cleanup:
4109 ftrace_release_mod(mod);
4110 dynamic_debug_remove(mod, info->debug);
4111 synchronize_rcu();
4112 kfree(mod->args);
4113 free_arch_cleanup:
4114 cfi_cleanup(mod);
4115 module_arch_cleanup(mod);
4116 free_modinfo:
4117 free_modinfo(mod);
4118 free_unload:
4119 module_unload_free(mod);
4120 unlink_mod:
4121 mutex_lock(&module_mutex);
4122 /* Unlink carefully: kallsyms could be walking list. */
4123 list_del_rcu(&mod->list);
4124 mod_tree_remove(mod);
4125 wake_up_all(&module_wq);
4126 /* Wait for RCU-sched synchronizing before releasing mod->list. */
4127 synchronize_rcu();
4128 mutex_unlock(&module_mutex);
4129 free_module:
4130 /* Free lock-classes; relies on the preceding sync_rcu() */
4131 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
4132
4133 module_deallocate(mod, info);
4134 free_copy:
4135 free_copy(info);
4136 return err;
4137}
4138
4139SYSCALL_DEFINE3(init_module, void __user *, umod,
4140 unsigned long, len, const char __user *, uargs)
4141{
4142 int err;
4143 struct load_info info = { };
4144
4145 err = may_init_module();
4146 if (err)
4147 return err;
4148
4149 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
4150 umod, len, uargs);
4151
4152 err = copy_module_from_user(umod, len, &info);
4153 if (err)
4154 return err;
4155
4156 return load_module(&info, uargs, 0);
4157}
4158
4159SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
4160{
4161 struct load_info info = { };
4162 void *hdr = NULL;
4163 int err;
4164
4165 err = may_init_module();
4166 if (err)
4167 return err;
4168
4169 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
4170
4171 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
4172 |MODULE_INIT_IGNORE_VERMAGIC))
4173 return -EINVAL;
4174
4175 err = kernel_read_file_from_fd(fd, 0, &hdr, INT_MAX, NULL,
4176 READING_MODULE);
4177 if (err < 0)
4178 return err;
4179 info.hdr = hdr;
4180 info.len = err;
4181
4182 return load_module(&info, uargs, flags);
4183}
4184
4185static inline int within(unsigned long addr, void *start, unsigned long size)
4186{
4187 return ((void *)addr >= start && (void *)addr < start + size);
4188}
4189
4190#ifdef CONFIG_KALLSYMS
4191/*
4192 * This ignores the intensely annoying "mapping symbols" found
4193 * in ARM ELF files: $a, $t and $d.
4194 */
4195static inline int is_arm_mapping_symbol(const char *str)
4196{
4197 if (str[0] == '.' && str[1] == 'L')
4198 return true;
4199 return str[0] == '$' && strchr("axtd", str[1])
4200 && (str[2] == '\0' || str[2] == '.');
4201}
4202
4203static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
4204{
4205 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
4206}
4207
4208/*
4209 * Given a module and address, find the corresponding symbol and return its name
4210 * while providing its size and offset if needed.
4211 */
4212static const char *find_kallsyms_symbol(struct module *mod,
4213 unsigned long addr,
4214 unsigned long *size,
4215 unsigned long *offset)
4216{
4217 unsigned int i, best = 0;
4218 unsigned long nextval, bestval;
4219 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4220
4221 /* At worse, next value is at end of module */
4222 if (within_module_init(addr, mod))
4223 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
4224 else
4225 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
4226
4227 bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
4228
4229 /*
4230 * Scan for closest preceding symbol, and next symbol. (ELF
4231 * starts real symbols at 1).
4232 */
4233 for (i = 1; i < kallsyms->num_symtab; i++) {
4234 const Elf_Sym *sym = &kallsyms->symtab[i];
4235 unsigned long thisval = kallsyms_symbol_value(sym);
4236
4237 if (sym->st_shndx == SHN_UNDEF)
4238 continue;
4239
4240 /*
4241 * We ignore unnamed symbols: they're uninformative
4242 * and inserted at a whim.
4243 */
4244 if (*kallsyms_symbol_name(kallsyms, i) == '\0'
4245 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
4246 continue;
4247
4248 if (thisval <= addr && thisval > bestval) {
4249 best = i;
4250 bestval = thisval;
4251 }
4252 if (thisval > addr && thisval < nextval)
4253 nextval = thisval;
4254 }
4255
4256 if (!best)
4257 return NULL;
4258
4259 if (size)
4260 *size = nextval - bestval;
4261 if (offset)
4262 *offset = addr - bestval;
4263
4264 return kallsyms_symbol_name(kallsyms, best);
4265}
4266
4267void * __weak dereference_module_function_descriptor(struct module *mod,
4268 void *ptr)
4269{
4270 return ptr;
4271}
4272
4273/*
4274 * For kallsyms to ask for address resolution. NULL means not found. Careful
4275 * not to lock to avoid deadlock on oopses, simply disable preemption.
4276 */
4277const char *module_address_lookup(unsigned long addr,
4278 unsigned long *size,
4279 unsigned long *offset,
4280 char **modname,
4281 const unsigned char **modbuildid,
4282 char *namebuf)
4283{
4284 const char *ret = NULL;
4285 struct module *mod;
4286
4287 preempt_disable();
4288 mod = __module_address(addr);
4289 if (mod) {
4290 if (modname)
4291 *modname = mod->name;
4292 if (modbuildid) {
4293#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
4294 *modbuildid = mod->build_id;
4295#else
4296 *modbuildid = NULL;
4297#endif
4298 }
4299
4300 ret = find_kallsyms_symbol(mod, addr, size, offset);
4301 }
4302 /* Make a copy in here where it's safe */
4303 if (ret) {
4304 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
4305 ret = namebuf;
4306 }
4307 preempt_enable();
4308
4309 return ret;
4310}
4311
4312int lookup_module_symbol_name(unsigned long addr, char *symname)
4313{
4314 struct module *mod;
4315
4316 preempt_disable();
4317 list_for_each_entry_rcu(mod, &modules, list) {
4318 if (mod->state == MODULE_STATE_UNFORMED)
4319 continue;
4320 if (within_module(addr, mod)) {
4321 const char *sym;
4322
4323 sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
4324 if (!sym)
4325 goto out;
4326
4327 strlcpy(symname, sym, KSYM_NAME_LEN);
4328 preempt_enable();
4329 return 0;
4330 }
4331 }
4332out:
4333 preempt_enable();
4334 return -ERANGE;
4335}
4336
4337int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4338 unsigned long *offset, char *modname, char *name)
4339{
4340 struct module *mod;
4341
4342 preempt_disable();
4343 list_for_each_entry_rcu(mod, &modules, list) {
4344 if (mod->state == MODULE_STATE_UNFORMED)
4345 continue;
4346 if (within_module(addr, mod)) {
4347 const char *sym;
4348
4349 sym = find_kallsyms_symbol(mod, addr, size, offset);
4350 if (!sym)
4351 goto out;
4352 if (modname)
4353 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4354 if (name)
4355 strlcpy(name, sym, KSYM_NAME_LEN);
4356 preempt_enable();
4357 return 0;
4358 }
4359 }
4360out:
4361 preempt_enable();
4362 return -ERANGE;
4363}
4364
4365int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4366 char *name, char *module_name, int *exported)
4367{
4368 struct module *mod;
4369
4370 preempt_disable();
4371 list_for_each_entry_rcu(mod, &modules, list) {
4372 struct mod_kallsyms *kallsyms;
4373
4374 if (mod->state == MODULE_STATE_UNFORMED)
4375 continue;
4376 kallsyms = rcu_dereference_sched(mod->kallsyms);
4377 if (symnum < kallsyms->num_symtab) {
4378 const Elf_Sym *sym = &kallsyms->symtab[symnum];
4379
4380 *value = kallsyms_symbol_value(sym);
4381 *type = kallsyms->typetab[symnum];
4382 strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
4383 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4384 *exported = is_exported(name, *value, mod);
4385 preempt_enable();
4386 return 0;
4387 }
4388 symnum -= kallsyms->num_symtab;
4389 }
4390 preempt_enable();
4391 return -ERANGE;
4392}
4393
4394/* Given a module and name of symbol, find and return the symbol's value */
4395static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
4396{
4397 unsigned int i;
4398 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4399
4400 for (i = 0; i < kallsyms->num_symtab; i++) {
4401 const Elf_Sym *sym = &kallsyms->symtab[i];
4402
4403 if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
4404 sym->st_shndx != SHN_UNDEF)
4405 return kallsyms_symbol_value(sym);
4406 }
4407 return 0;
4408}
4409
4410/* Look for this name: can be of form module:name. */
4411unsigned long module_kallsyms_lookup_name(const char *name)
4412{
4413 struct module *mod;
4414 char *colon;
4415 unsigned long ret = 0;
4416
4417 /* Don't lock: we're in enough trouble already. */
4418 preempt_disable();
4419 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4420 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4421 ret = find_kallsyms_symbol_value(mod, colon+1);
4422 } else {
4423 list_for_each_entry_rcu(mod, &modules, list) {
4424 if (mod->state == MODULE_STATE_UNFORMED)
4425 continue;
4426 if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
4427 break;
4428 }
4429 }
4430 preempt_enable();
4431 return ret;
4432}
4433
4434#ifdef CONFIG_LIVEPATCH
4435int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4436 struct module *, unsigned long),
4437 void *data)
4438{
4439 struct module *mod;
4440 unsigned int i;
4441 int ret = 0;
4442
4443 mutex_lock(&module_mutex);
4444 list_for_each_entry(mod, &modules, list) {
4445 /* We hold module_mutex: no need for rcu_dereference_sched */
4446 struct mod_kallsyms *kallsyms = mod->kallsyms;
4447
4448 if (mod->state == MODULE_STATE_UNFORMED)
4449 continue;
4450 for (i = 0; i < kallsyms->num_symtab; i++) {
4451 const Elf_Sym *sym = &kallsyms->symtab[i];
4452
4453 if (sym->st_shndx == SHN_UNDEF)
4454 continue;
4455
4456 ret = fn(data, kallsyms_symbol_name(kallsyms, i),
4457 mod, kallsyms_symbol_value(sym));
4458 if (ret != 0)
4459 goto out;
4460 }
4461 }
4462out:
4463 mutex_unlock(&module_mutex);
4464 return ret;
4465}
4466#endif /* CONFIG_LIVEPATCH */
4467#endif /* CONFIG_KALLSYMS */
4468
4469static void cfi_init(struct module *mod)
4470{
4471#ifdef CONFIG_CFI_CLANG
4472 initcall_t *init;
4473 exitcall_t *exit;
4474
4475 rcu_read_lock_sched();
4476 mod->cfi_check = (cfi_check_fn)
4477 find_kallsyms_symbol_value(mod, "__cfi_check");
4478 init = (initcall_t *)
4479 find_kallsyms_symbol_value(mod, "__cfi_jt_init_module");
4480 exit = (exitcall_t *)
4481 find_kallsyms_symbol_value(mod, "__cfi_jt_cleanup_module");
4482 rcu_read_unlock_sched();
4483
4484 /* Fix init/exit functions to point to the CFI jump table */
4485 if (init)
4486 mod->init = *init;
4487#ifdef CONFIG_MODULE_UNLOAD
4488 if (exit)
4489 mod->exit = *exit;
4490#endif
4491
4492 cfi_module_add(mod, module_addr_min);
4493#endif
4494}
4495
4496static void cfi_cleanup(struct module *mod)
4497{
4498#ifdef CONFIG_CFI_CLANG
4499 cfi_module_remove(mod, module_addr_min);
4500#endif
4501}
4502
4503/* Maximum number of characters written by module_flags() */
4504#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4505
4506/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4507static char *module_flags(struct module *mod, char *buf)
4508{
4509 int bx = 0;
4510
4511 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4512 if (mod->taints ||
4513 mod->state == MODULE_STATE_GOING ||
4514 mod->state == MODULE_STATE_COMING) {
4515 buf[bx++] = '(';
4516 bx += module_flags_taint(mod, buf + bx);
4517 /* Show a - for module-is-being-unloaded */
4518 if (mod->state == MODULE_STATE_GOING)
4519 buf[bx++] = '-';
4520 /* Show a + for module-is-being-loaded */
4521 if (mod->state == MODULE_STATE_COMING)
4522 buf[bx++] = '+';
4523 buf[bx++] = ')';
4524 }
4525 buf[bx] = '\0';
4526
4527 return buf;
4528}
4529
4530#ifdef CONFIG_PROC_FS
4531/* Called by the /proc file system to return a list of modules. */
4532static void *m_start(struct seq_file *m, loff_t *pos)
4533{
4534 mutex_lock(&module_mutex);
4535 return seq_list_start(&modules, *pos);
4536}
4537
4538static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4539{
4540 return seq_list_next(p, &modules, pos);
4541}
4542
4543static void m_stop(struct seq_file *m, void *p)
4544{
4545 mutex_unlock(&module_mutex);
4546}
4547
4548static int m_show(struct seq_file *m, void *p)
4549{
4550 struct module *mod = list_entry(p, struct module, list);
4551 char buf[MODULE_FLAGS_BUF_SIZE];
4552 void *value;
4553
4554 /* We always ignore unformed modules. */
4555 if (mod->state == MODULE_STATE_UNFORMED)
4556 return 0;
4557
4558 seq_printf(m, "%s %u",
4559 mod->name, mod->init_layout.size + mod->core_layout.size);
4560 print_unload_info(m, mod);
4561
4562 /* Informative for users. */
4563 seq_printf(m, " %s",
4564 mod->state == MODULE_STATE_GOING ? "Unloading" :
4565 mod->state == MODULE_STATE_COMING ? "Loading" :
4566 "Live");
4567 /* Used by oprofile and other similar tools. */
4568 value = m->private ? NULL : mod->core_layout.base;
4569 seq_printf(m, " 0x%px", value);
4570
4571 /* Taints info */
4572 if (mod->taints)
4573 seq_printf(m, " %s", module_flags(mod, buf));
4574
4575 seq_puts(m, "\n");
4576 return 0;
4577}
4578
4579/*
4580 * Format: modulename size refcount deps address
4581 *
4582 * Where refcount is a number or -, and deps is a comma-separated list
4583 * of depends or -.
4584 */
4585static const struct seq_operations modules_op = {
4586 .start = m_start,
4587 .next = m_next,
4588 .stop = m_stop,
4589 .show = m_show
4590};
4591
4592/*
4593 * This also sets the "private" pointer to non-NULL if the
4594 * kernel pointers should be hidden (so you can just test
4595 * "m->private" to see if you should keep the values private).
4596 *
4597 * We use the same logic as for /proc/kallsyms.
4598 */
4599static int modules_open(struct inode *inode, struct file *file)
4600{
4601 int err = seq_open(file, &modules_op);
4602
4603 if (!err) {
4604 struct seq_file *m = file->private_data;
4605 m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
4606 }
4607
4608 return err;
4609}
4610
4611static const struct proc_ops modules_proc_ops = {
4612 .proc_flags = PROC_ENTRY_PERMANENT,
4613 .proc_open = modules_open,
4614 .proc_read = seq_read,
4615 .proc_lseek = seq_lseek,
4616 .proc_release = seq_release,
4617};
4618
4619static int __init proc_modules_init(void)
4620{
4621 proc_create("modules", 0, NULL, &modules_proc_ops);
4622 return 0;
4623}
4624module_init(proc_modules_init);
4625#endif
4626
4627/* Given an address, look for it in the module exception tables. */
4628const struct exception_table_entry *search_module_extables(unsigned long addr)
4629{
4630 const struct exception_table_entry *e = NULL;
4631 struct module *mod;
4632
4633 preempt_disable();
4634 mod = __module_address(addr);
4635 if (!mod)
4636 goto out;
4637
4638 if (!mod->num_exentries)
4639 goto out;
4640
4641 e = search_extable(mod->extable,
4642 mod->num_exentries,
4643 addr);
4644out:
4645 preempt_enable();
4646
4647 /*
4648 * Now, if we found one, we are running inside it now, hence
4649 * we cannot unload the module, hence no refcnt needed.
4650 */
4651 return e;
4652}
4653
4654/**
4655 * is_module_address() - is this address inside a module?
4656 * @addr: the address to check.
4657 *
4658 * See is_module_text_address() if you simply want to see if the address
4659 * is code (not data).
4660 */
4661bool is_module_address(unsigned long addr)
4662{
4663 bool ret;
4664
4665 preempt_disable();
4666 ret = __module_address(addr) != NULL;
4667 preempt_enable();
4668
4669 return ret;
4670}
4671
4672/**
4673 * __module_address() - get the module which contains an address.
4674 * @addr: the address.
4675 *
4676 * Must be called with preempt disabled or module mutex held so that
4677 * module doesn't get freed during this.
4678 */
4679struct module *__module_address(unsigned long addr)
4680{
4681 struct module *mod;
4682
4683 if (addr < module_addr_min || addr > module_addr_max)
4684 return NULL;
4685
4686 module_assert_mutex_or_preempt();
4687
4688 mod = mod_find(addr);
4689 if (mod) {
4690 BUG_ON(!within_module(addr, mod));
4691 if (mod->state == MODULE_STATE_UNFORMED)
4692 mod = NULL;
4693 }
4694 return mod;
4695}
4696
4697/**
4698 * is_module_text_address() - is this address inside module code?
4699 * @addr: the address to check.
4700 *
4701 * See is_module_address() if you simply want to see if the address is
4702 * anywhere in a module. See kernel_text_address() for testing if an
4703 * address corresponds to kernel or module code.
4704 */
4705bool is_module_text_address(unsigned long addr)
4706{
4707 bool ret;
4708
4709 preempt_disable();
4710 ret = __module_text_address(addr) != NULL;
4711 preempt_enable();
4712
4713 return ret;
4714}
4715
4716/**
4717 * __module_text_address() - get the module whose code contains an address.
4718 * @addr: the address.
4719 *
4720 * Must be called with preempt disabled or module mutex held so that
4721 * module doesn't get freed during this.
4722 */
4723struct module *__module_text_address(unsigned long addr)
4724{
4725 struct module *mod = __module_address(addr);
4726 if (mod) {
4727 /* Make sure it's within the text section. */
4728 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4729 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4730 mod = NULL;
4731 }
4732 return mod;
4733}
4734
4735/* Don't grab lock, we're oopsing. */
4736void print_modules(void)
4737{
4738 struct module *mod;
4739 char buf[MODULE_FLAGS_BUF_SIZE];
4740
4741 printk(KERN_DEFAULT "Modules linked in:");
4742 /* Most callers should already have preempt disabled, but make sure */
4743 preempt_disable();
4744 list_for_each_entry_rcu(mod, &modules, list) {
4745 if (mod->state == MODULE_STATE_UNFORMED)
4746 continue;
4747 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4748 }
4749 preempt_enable();
4750 if (last_unloaded_module[0])
4751 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4752 pr_cont("\n");
4753}
4754
4755#ifdef CONFIG_MODVERSIONS
4756/*
4757 * Generate the signature for all relevant module structures here.
4758 * If these change, we don't want to try to parse the module.
4759 */
4760void module_layout(struct module *mod,
4761 struct modversion_info *ver,
4762 struct kernel_param *kp,
4763 struct kernel_symbol *ks,
4764 struct tracepoint * const *tp)
4765{
4766}
4767EXPORT_SYMBOL(module_layout);
4768#endif