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1/*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50#include <linux/uaccess.h>
51
52#include <linux/errno.h>
53#include <linux/time.h>
54#include <linux/proc_fs.h>
55#include <linux/stat.h>
56#include <linux/task_io_accounting_ops.h>
57#include <linux/init.h>
58#include <linux/capability.h>
59#include <linux/file.h>
60#include <linux/fdtable.h>
61#include <linux/string.h>
62#include <linux/seq_file.h>
63#include <linux/namei.h>
64#include <linux/mnt_namespace.h>
65#include <linux/mm.h>
66#include <linux/swap.h>
67#include <linux/rcupdate.h>
68#include <linux/kallsyms.h>
69#include <linux/stacktrace.h>
70#include <linux/resource.h>
71#include <linux/module.h>
72#include <linux/mount.h>
73#include <linux/security.h>
74#include <linux/ptrace.h>
75#include <linux/tracehook.h>
76#include <linux/printk.h>
77#include <linux/cgroup.h>
78#include <linux/cpuset.h>
79#include <linux/audit.h>
80#include <linux/poll.h>
81#include <linux/nsproxy.h>
82#include <linux/oom.h>
83#include <linux/elf.h>
84#include <linux/pid_namespace.h>
85#include <linux/user_namespace.h>
86#include <linux/fs_struct.h>
87#include <linux/slab.h>
88#include <linux/flex_array.h>
89#include <linux/posix-timers.h>
90#ifdef CONFIG_HARDWALL
91#include <asm/hardwall.h>
92#endif
93#include <trace/events/oom.h>
94#include "internal.h"
95#include "fd.h"
96
97/* NOTE:
98 * Implementing inode permission operations in /proc is almost
99 * certainly an error. Permission checks need to happen during
100 * each system call not at open time. The reason is that most of
101 * what we wish to check for permissions in /proc varies at runtime.
102 *
103 * The classic example of a problem is opening file descriptors
104 * in /proc for a task before it execs a suid executable.
105 */
106
107static u8 nlink_tid;
108static u8 nlink_tgid;
109
110struct pid_entry {
111 const char *name;
112 unsigned int len;
113 umode_t mode;
114 const struct inode_operations *iop;
115 const struct file_operations *fop;
116 union proc_op op;
117};
118
119#define NOD(NAME, MODE, IOP, FOP, OP) { \
120 .name = (NAME), \
121 .len = sizeof(NAME) - 1, \
122 .mode = MODE, \
123 .iop = IOP, \
124 .fop = FOP, \
125 .op = OP, \
126}
127
128#define DIR(NAME, MODE, iops, fops) \
129 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
130#define LNK(NAME, get_link) \
131 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
132 &proc_pid_link_inode_operations, NULL, \
133 { .proc_get_link = get_link } )
134#define REG(NAME, MODE, fops) \
135 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
136#define ONE(NAME, MODE, show) \
137 NOD(NAME, (S_IFREG|(MODE)), \
138 NULL, &proc_single_file_operations, \
139 { .proc_show = show } )
140
141/*
142 * Count the number of hardlinks for the pid_entry table, excluding the .
143 * and .. links.
144 */
145static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
146 unsigned int n)
147{
148 unsigned int i;
149 unsigned int count;
150
151 count = 2;
152 for (i = 0; i < n; ++i) {
153 if (S_ISDIR(entries[i].mode))
154 ++count;
155 }
156
157 return count;
158}
159
160static int get_task_root(struct task_struct *task, struct path *root)
161{
162 int result = -ENOENT;
163
164 task_lock(task);
165 if (task->fs) {
166 get_fs_root(task->fs, root);
167 result = 0;
168 }
169 task_unlock(task);
170 return result;
171}
172
173static int proc_cwd_link(struct dentry *dentry, struct path *path)
174{
175 struct task_struct *task = get_proc_task(d_inode(dentry));
176 int result = -ENOENT;
177
178 if (task) {
179 task_lock(task);
180 if (task->fs) {
181 get_fs_pwd(task->fs, path);
182 result = 0;
183 }
184 task_unlock(task);
185 put_task_struct(task);
186 }
187 return result;
188}
189
190static int proc_root_link(struct dentry *dentry, struct path *path)
191{
192 struct task_struct *task = get_proc_task(d_inode(dentry));
193 int result = -ENOENT;
194
195 if (task) {
196 result = get_task_root(task, path);
197 put_task_struct(task);
198 }
199 return result;
200}
201
202static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
203 size_t _count, loff_t *pos)
204{
205 struct task_struct *tsk;
206 struct mm_struct *mm;
207 char *page;
208 unsigned long count = _count;
209 unsigned long arg_start, arg_end, env_start, env_end;
210 unsigned long len1, len2, len;
211 unsigned long p;
212 char c;
213 ssize_t rv;
214
215 BUG_ON(*pos < 0);
216
217 tsk = get_proc_task(file_inode(file));
218 if (!tsk)
219 return -ESRCH;
220 mm = get_task_mm(tsk);
221 put_task_struct(tsk);
222 if (!mm)
223 return 0;
224 /* Check if process spawned far enough to have cmdline. */
225 if (!mm->env_end) {
226 rv = 0;
227 goto out_mmput;
228 }
229
230 page = (char *)__get_free_page(GFP_TEMPORARY);
231 if (!page) {
232 rv = -ENOMEM;
233 goto out_mmput;
234 }
235
236 down_read(&mm->mmap_sem);
237 arg_start = mm->arg_start;
238 arg_end = mm->arg_end;
239 env_start = mm->env_start;
240 env_end = mm->env_end;
241 up_read(&mm->mmap_sem);
242
243 BUG_ON(arg_start > arg_end);
244 BUG_ON(env_start > env_end);
245
246 len1 = arg_end - arg_start;
247 len2 = env_end - env_start;
248
249 /* Empty ARGV. */
250 if (len1 == 0) {
251 rv = 0;
252 goto out_free_page;
253 }
254 /*
255 * Inherently racy -- command line shares address space
256 * with code and data.
257 */
258 rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0);
259 if (rv <= 0)
260 goto out_free_page;
261
262 rv = 0;
263
264 if (c == '\0') {
265 /* Command line (set of strings) occupies whole ARGV. */
266 if (len1 <= *pos)
267 goto out_free_page;
268
269 p = arg_start + *pos;
270 len = len1 - *pos;
271 while (count > 0 && len > 0) {
272 unsigned int _count;
273 int nr_read;
274
275 _count = min3(count, len, PAGE_SIZE);
276 nr_read = access_remote_vm(mm, p, page, _count, 0);
277 if (nr_read < 0)
278 rv = nr_read;
279 if (nr_read <= 0)
280 goto out_free_page;
281
282 if (copy_to_user(buf, page, nr_read)) {
283 rv = -EFAULT;
284 goto out_free_page;
285 }
286
287 p += nr_read;
288 len -= nr_read;
289 buf += nr_read;
290 count -= nr_read;
291 rv += nr_read;
292 }
293 } else {
294 /*
295 * Command line (1 string) occupies ARGV and maybe
296 * extends into ENVP.
297 */
298 if (len1 + len2 <= *pos)
299 goto skip_argv_envp;
300 if (len1 <= *pos)
301 goto skip_argv;
302
303 p = arg_start + *pos;
304 len = len1 - *pos;
305 while (count > 0 && len > 0) {
306 unsigned int _count, l;
307 int nr_read;
308 bool final;
309
310 _count = min3(count, len, PAGE_SIZE);
311 nr_read = access_remote_vm(mm, p, page, _count, 0);
312 if (nr_read < 0)
313 rv = nr_read;
314 if (nr_read <= 0)
315 goto out_free_page;
316
317 /*
318 * Command line can be shorter than whole ARGV
319 * even if last "marker" byte says it is not.
320 */
321 final = false;
322 l = strnlen(page, nr_read);
323 if (l < nr_read) {
324 nr_read = l;
325 final = true;
326 }
327
328 if (copy_to_user(buf, page, nr_read)) {
329 rv = -EFAULT;
330 goto out_free_page;
331 }
332
333 p += nr_read;
334 len -= nr_read;
335 buf += nr_read;
336 count -= nr_read;
337 rv += nr_read;
338
339 if (final)
340 goto out_free_page;
341 }
342skip_argv:
343 /*
344 * Command line (1 string) occupies ARGV and
345 * extends into ENVP.
346 */
347 if (len1 <= *pos) {
348 p = env_start + *pos - len1;
349 len = len1 + len2 - *pos;
350 } else {
351 p = env_start;
352 len = len2;
353 }
354 while (count > 0 && len > 0) {
355 unsigned int _count, l;
356 int nr_read;
357 bool final;
358
359 _count = min3(count, len, PAGE_SIZE);
360 nr_read = access_remote_vm(mm, p, page, _count, 0);
361 if (nr_read < 0)
362 rv = nr_read;
363 if (nr_read <= 0)
364 goto out_free_page;
365
366 /* Find EOS. */
367 final = false;
368 l = strnlen(page, nr_read);
369 if (l < nr_read) {
370 nr_read = l;
371 final = true;
372 }
373
374 if (copy_to_user(buf, page, nr_read)) {
375 rv = -EFAULT;
376 goto out_free_page;
377 }
378
379 p += nr_read;
380 len -= nr_read;
381 buf += nr_read;
382 count -= nr_read;
383 rv += nr_read;
384
385 if (final)
386 goto out_free_page;
387 }
388skip_argv_envp:
389 ;
390 }
391
392out_free_page:
393 free_page((unsigned long)page);
394out_mmput:
395 mmput(mm);
396 if (rv > 0)
397 *pos += rv;
398 return rv;
399}
400
401static const struct file_operations proc_pid_cmdline_ops = {
402 .read = proc_pid_cmdline_read,
403 .llseek = generic_file_llseek,
404};
405
406#ifdef CONFIG_KALLSYMS
407/*
408 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
409 * Returns the resolved symbol. If that fails, simply return the address.
410 */
411static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
412 struct pid *pid, struct task_struct *task)
413{
414 unsigned long wchan;
415 char symname[KSYM_NAME_LEN];
416
417 wchan = get_wchan(task);
418
419 if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)
420 && !lookup_symbol_name(wchan, symname))
421 seq_printf(m, "%s", symname);
422 else
423 seq_putc(m, '0');
424
425 return 0;
426}
427#endif /* CONFIG_KALLSYMS */
428
429static int lock_trace(struct task_struct *task)
430{
431 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
432 if (err)
433 return err;
434 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
435 mutex_unlock(&task->signal->cred_guard_mutex);
436 return -EPERM;
437 }
438 return 0;
439}
440
441static void unlock_trace(struct task_struct *task)
442{
443 mutex_unlock(&task->signal->cred_guard_mutex);
444}
445
446#ifdef CONFIG_STACKTRACE
447
448#define MAX_STACK_TRACE_DEPTH 64
449
450static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
451 struct pid *pid, struct task_struct *task)
452{
453 struct stack_trace trace;
454 unsigned long *entries;
455 int err;
456 int i;
457
458 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
459 if (!entries)
460 return -ENOMEM;
461
462 trace.nr_entries = 0;
463 trace.max_entries = MAX_STACK_TRACE_DEPTH;
464 trace.entries = entries;
465 trace.skip = 0;
466
467 err = lock_trace(task);
468 if (!err) {
469 save_stack_trace_tsk(task, &trace);
470
471 for (i = 0; i < trace.nr_entries; i++) {
472 seq_printf(m, "[<%pK>] %pB\n",
473 (void *)entries[i], (void *)entries[i]);
474 }
475 unlock_trace(task);
476 }
477 kfree(entries);
478
479 return err;
480}
481#endif
482
483#ifdef CONFIG_SCHED_INFO
484/*
485 * Provides /proc/PID/schedstat
486 */
487static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
488 struct pid *pid, struct task_struct *task)
489{
490 if (unlikely(!sched_info_on()))
491 seq_printf(m, "0 0 0\n");
492 else
493 seq_printf(m, "%llu %llu %lu\n",
494 (unsigned long long)task->se.sum_exec_runtime,
495 (unsigned long long)task->sched_info.run_delay,
496 task->sched_info.pcount);
497
498 return 0;
499}
500#endif
501
502#ifdef CONFIG_LATENCYTOP
503static int lstats_show_proc(struct seq_file *m, void *v)
504{
505 int i;
506 struct inode *inode = m->private;
507 struct task_struct *task = get_proc_task(inode);
508
509 if (!task)
510 return -ESRCH;
511 seq_puts(m, "Latency Top version : v0.1\n");
512 for (i = 0; i < 32; i++) {
513 struct latency_record *lr = &task->latency_record[i];
514 if (lr->backtrace[0]) {
515 int q;
516 seq_printf(m, "%i %li %li",
517 lr->count, lr->time, lr->max);
518 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
519 unsigned long bt = lr->backtrace[q];
520 if (!bt)
521 break;
522 if (bt == ULONG_MAX)
523 break;
524 seq_printf(m, " %ps", (void *)bt);
525 }
526 seq_putc(m, '\n');
527 }
528
529 }
530 put_task_struct(task);
531 return 0;
532}
533
534static int lstats_open(struct inode *inode, struct file *file)
535{
536 return single_open(file, lstats_show_proc, inode);
537}
538
539static ssize_t lstats_write(struct file *file, const char __user *buf,
540 size_t count, loff_t *offs)
541{
542 struct task_struct *task = get_proc_task(file_inode(file));
543
544 if (!task)
545 return -ESRCH;
546 clear_all_latency_tracing(task);
547 put_task_struct(task);
548
549 return count;
550}
551
552static const struct file_operations proc_lstats_operations = {
553 .open = lstats_open,
554 .read = seq_read,
555 .write = lstats_write,
556 .llseek = seq_lseek,
557 .release = single_release,
558};
559
560#endif
561
562static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
563 struct pid *pid, struct task_struct *task)
564{
565 unsigned long totalpages = totalram_pages + total_swap_pages;
566 unsigned long points = 0;
567
568 points = oom_badness(task, NULL, NULL, totalpages) *
569 1000 / totalpages;
570 seq_printf(m, "%lu\n", points);
571
572 return 0;
573}
574
575struct limit_names {
576 const char *name;
577 const char *unit;
578};
579
580static const struct limit_names lnames[RLIM_NLIMITS] = {
581 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
582 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
583 [RLIMIT_DATA] = {"Max data size", "bytes"},
584 [RLIMIT_STACK] = {"Max stack size", "bytes"},
585 [RLIMIT_CORE] = {"Max core file size", "bytes"},
586 [RLIMIT_RSS] = {"Max resident set", "bytes"},
587 [RLIMIT_NPROC] = {"Max processes", "processes"},
588 [RLIMIT_NOFILE] = {"Max open files", "files"},
589 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
590 [RLIMIT_AS] = {"Max address space", "bytes"},
591 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
592 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
593 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
594 [RLIMIT_NICE] = {"Max nice priority", NULL},
595 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
596 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
597};
598
599/* Display limits for a process */
600static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
601 struct pid *pid, struct task_struct *task)
602{
603 unsigned int i;
604 unsigned long flags;
605
606 struct rlimit rlim[RLIM_NLIMITS];
607
608 if (!lock_task_sighand(task, &flags))
609 return 0;
610 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
611 unlock_task_sighand(task, &flags);
612
613 /*
614 * print the file header
615 */
616 seq_printf(m, "%-25s %-20s %-20s %-10s\n",
617 "Limit", "Soft Limit", "Hard Limit", "Units");
618
619 for (i = 0; i < RLIM_NLIMITS; i++) {
620 if (rlim[i].rlim_cur == RLIM_INFINITY)
621 seq_printf(m, "%-25s %-20s ",
622 lnames[i].name, "unlimited");
623 else
624 seq_printf(m, "%-25s %-20lu ",
625 lnames[i].name, rlim[i].rlim_cur);
626
627 if (rlim[i].rlim_max == RLIM_INFINITY)
628 seq_printf(m, "%-20s ", "unlimited");
629 else
630 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
631
632 if (lnames[i].unit)
633 seq_printf(m, "%-10s\n", lnames[i].unit);
634 else
635 seq_putc(m, '\n');
636 }
637
638 return 0;
639}
640
641#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
642static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
643 struct pid *pid, struct task_struct *task)
644{
645 long nr;
646 unsigned long args[6], sp, pc;
647 int res;
648
649 res = lock_trace(task);
650 if (res)
651 return res;
652
653 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
654 seq_puts(m, "running\n");
655 else if (nr < 0)
656 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
657 else
658 seq_printf(m,
659 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
660 nr,
661 args[0], args[1], args[2], args[3], args[4], args[5],
662 sp, pc);
663 unlock_trace(task);
664
665 return 0;
666}
667#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
668
669/************************************************************************/
670/* Here the fs part begins */
671/************************************************************************/
672
673/* permission checks */
674static int proc_fd_access_allowed(struct inode *inode)
675{
676 struct task_struct *task;
677 int allowed = 0;
678 /* Allow access to a task's file descriptors if it is us or we
679 * may use ptrace attach to the process and find out that
680 * information.
681 */
682 task = get_proc_task(inode);
683 if (task) {
684 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
685 put_task_struct(task);
686 }
687 return allowed;
688}
689
690int proc_setattr(struct dentry *dentry, struct iattr *attr)
691{
692 int error;
693 struct inode *inode = d_inode(dentry);
694
695 if (attr->ia_valid & ATTR_MODE)
696 return -EPERM;
697
698 error = setattr_prepare(dentry, attr);
699 if (error)
700 return error;
701
702 setattr_copy(inode, attr);
703 mark_inode_dirty(inode);
704 return 0;
705}
706
707/*
708 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
709 * or euid/egid (for hide_pid_min=2)?
710 */
711static bool has_pid_permissions(struct pid_namespace *pid,
712 struct task_struct *task,
713 int hide_pid_min)
714{
715 if (pid->hide_pid < hide_pid_min)
716 return true;
717 if (in_group_p(pid->pid_gid))
718 return true;
719 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
720}
721
722
723static int proc_pid_permission(struct inode *inode, int mask)
724{
725 struct pid_namespace *pid = inode->i_sb->s_fs_info;
726 struct task_struct *task;
727 bool has_perms;
728
729 task = get_proc_task(inode);
730 if (!task)
731 return -ESRCH;
732 has_perms = has_pid_permissions(pid, task, 1);
733 put_task_struct(task);
734
735 if (!has_perms) {
736 if (pid->hide_pid == 2) {
737 /*
738 * Let's make getdents(), stat(), and open()
739 * consistent with each other. If a process
740 * may not stat() a file, it shouldn't be seen
741 * in procfs at all.
742 */
743 return -ENOENT;
744 }
745
746 return -EPERM;
747 }
748 return generic_permission(inode, mask);
749}
750
751
752
753static const struct inode_operations proc_def_inode_operations = {
754 .setattr = proc_setattr,
755};
756
757static int proc_single_show(struct seq_file *m, void *v)
758{
759 struct inode *inode = m->private;
760 struct pid_namespace *ns;
761 struct pid *pid;
762 struct task_struct *task;
763 int ret;
764
765 ns = inode->i_sb->s_fs_info;
766 pid = proc_pid(inode);
767 task = get_pid_task(pid, PIDTYPE_PID);
768 if (!task)
769 return -ESRCH;
770
771 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
772
773 put_task_struct(task);
774 return ret;
775}
776
777static int proc_single_open(struct inode *inode, struct file *filp)
778{
779 return single_open(filp, proc_single_show, inode);
780}
781
782static const struct file_operations proc_single_file_operations = {
783 .open = proc_single_open,
784 .read = seq_read,
785 .llseek = seq_lseek,
786 .release = single_release,
787};
788
789
790struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
791{
792 struct task_struct *task = get_proc_task(inode);
793 struct mm_struct *mm = ERR_PTR(-ESRCH);
794
795 if (task) {
796 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
797 put_task_struct(task);
798
799 if (!IS_ERR_OR_NULL(mm)) {
800 /* ensure this mm_struct can't be freed */
801 atomic_inc(&mm->mm_count);
802 /* but do not pin its memory */
803 mmput(mm);
804 }
805 }
806
807 return mm;
808}
809
810static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
811{
812 struct mm_struct *mm = proc_mem_open(inode, mode);
813
814 if (IS_ERR(mm))
815 return PTR_ERR(mm);
816
817 file->private_data = mm;
818 return 0;
819}
820
821static int mem_open(struct inode *inode, struct file *file)
822{
823 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
824
825 /* OK to pass negative loff_t, we can catch out-of-range */
826 file->f_mode |= FMODE_UNSIGNED_OFFSET;
827
828 return ret;
829}
830
831static ssize_t mem_rw(struct file *file, char __user *buf,
832 size_t count, loff_t *ppos, int write)
833{
834 struct mm_struct *mm = file->private_data;
835 unsigned long addr = *ppos;
836 ssize_t copied;
837 char *page;
838 unsigned int flags;
839
840 if (!mm)
841 return 0;
842
843 page = (char *)__get_free_page(GFP_TEMPORARY);
844 if (!page)
845 return -ENOMEM;
846
847 copied = 0;
848 if (!atomic_inc_not_zero(&mm->mm_users))
849 goto free;
850
851 /* Maybe we should limit FOLL_FORCE to actual ptrace users? */
852 flags = FOLL_FORCE;
853 if (write)
854 flags |= FOLL_WRITE;
855
856 while (count > 0) {
857 int this_len = min_t(int, count, PAGE_SIZE);
858
859 if (write && copy_from_user(page, buf, this_len)) {
860 copied = -EFAULT;
861 break;
862 }
863
864 this_len = access_remote_vm(mm, addr, page, this_len, flags);
865 if (!this_len) {
866 if (!copied)
867 copied = -EIO;
868 break;
869 }
870
871 if (!write && copy_to_user(buf, page, this_len)) {
872 copied = -EFAULT;
873 break;
874 }
875
876 buf += this_len;
877 addr += this_len;
878 copied += this_len;
879 count -= this_len;
880 }
881 *ppos = addr;
882
883 mmput(mm);
884free:
885 free_page((unsigned long) page);
886 return copied;
887}
888
889static ssize_t mem_read(struct file *file, char __user *buf,
890 size_t count, loff_t *ppos)
891{
892 return mem_rw(file, buf, count, ppos, 0);
893}
894
895static ssize_t mem_write(struct file *file, const char __user *buf,
896 size_t count, loff_t *ppos)
897{
898 return mem_rw(file, (char __user*)buf, count, ppos, 1);
899}
900
901loff_t mem_lseek(struct file *file, loff_t offset, int orig)
902{
903 switch (orig) {
904 case 0:
905 file->f_pos = offset;
906 break;
907 case 1:
908 file->f_pos += offset;
909 break;
910 default:
911 return -EINVAL;
912 }
913 force_successful_syscall_return();
914 return file->f_pos;
915}
916
917static int mem_release(struct inode *inode, struct file *file)
918{
919 struct mm_struct *mm = file->private_data;
920 if (mm)
921 mmdrop(mm);
922 return 0;
923}
924
925static const struct file_operations proc_mem_operations = {
926 .llseek = mem_lseek,
927 .read = mem_read,
928 .write = mem_write,
929 .open = mem_open,
930 .release = mem_release,
931};
932
933static int environ_open(struct inode *inode, struct file *file)
934{
935 return __mem_open(inode, file, PTRACE_MODE_READ);
936}
937
938static ssize_t environ_read(struct file *file, char __user *buf,
939 size_t count, loff_t *ppos)
940{
941 char *page;
942 unsigned long src = *ppos;
943 int ret = 0;
944 struct mm_struct *mm = file->private_data;
945 unsigned long env_start, env_end;
946
947 /* Ensure the process spawned far enough to have an environment. */
948 if (!mm || !mm->env_end)
949 return 0;
950
951 page = (char *)__get_free_page(GFP_TEMPORARY);
952 if (!page)
953 return -ENOMEM;
954
955 ret = 0;
956 if (!atomic_inc_not_zero(&mm->mm_users))
957 goto free;
958
959 down_read(&mm->mmap_sem);
960 env_start = mm->env_start;
961 env_end = mm->env_end;
962 up_read(&mm->mmap_sem);
963
964 while (count > 0) {
965 size_t this_len, max_len;
966 int retval;
967
968 if (src >= (env_end - env_start))
969 break;
970
971 this_len = env_end - (env_start + src);
972
973 max_len = min_t(size_t, PAGE_SIZE, count);
974 this_len = min(max_len, this_len);
975
976 retval = access_remote_vm(mm, (env_start + src), page, this_len, 0);
977
978 if (retval <= 0) {
979 ret = retval;
980 break;
981 }
982
983 if (copy_to_user(buf, page, retval)) {
984 ret = -EFAULT;
985 break;
986 }
987
988 ret += retval;
989 src += retval;
990 buf += retval;
991 count -= retval;
992 }
993 *ppos = src;
994 mmput(mm);
995
996free:
997 free_page((unsigned long) page);
998 return ret;
999}
1000
1001static const struct file_operations proc_environ_operations = {
1002 .open = environ_open,
1003 .read = environ_read,
1004 .llseek = generic_file_llseek,
1005 .release = mem_release,
1006};
1007
1008static int auxv_open(struct inode *inode, struct file *file)
1009{
1010 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1011}
1012
1013static ssize_t auxv_read(struct file *file, char __user *buf,
1014 size_t count, loff_t *ppos)
1015{
1016 struct mm_struct *mm = file->private_data;
1017 unsigned int nwords = 0;
1018
1019 if (!mm)
1020 return 0;
1021 do {
1022 nwords += 2;
1023 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1024 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1025 nwords * sizeof(mm->saved_auxv[0]));
1026}
1027
1028static const struct file_operations proc_auxv_operations = {
1029 .open = auxv_open,
1030 .read = auxv_read,
1031 .llseek = generic_file_llseek,
1032 .release = mem_release,
1033};
1034
1035static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1036 loff_t *ppos)
1037{
1038 struct task_struct *task = get_proc_task(file_inode(file));
1039 char buffer[PROC_NUMBUF];
1040 int oom_adj = OOM_ADJUST_MIN;
1041 size_t len;
1042
1043 if (!task)
1044 return -ESRCH;
1045 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1046 oom_adj = OOM_ADJUST_MAX;
1047 else
1048 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1049 OOM_SCORE_ADJ_MAX;
1050 put_task_struct(task);
1051 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1052 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1053}
1054
1055static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1056{
1057 static DEFINE_MUTEX(oom_adj_mutex);
1058 struct mm_struct *mm = NULL;
1059 struct task_struct *task;
1060 int err = 0;
1061
1062 task = get_proc_task(file_inode(file));
1063 if (!task)
1064 return -ESRCH;
1065
1066 mutex_lock(&oom_adj_mutex);
1067 if (legacy) {
1068 if (oom_adj < task->signal->oom_score_adj &&
1069 !capable(CAP_SYS_RESOURCE)) {
1070 err = -EACCES;
1071 goto err_unlock;
1072 }
1073 /*
1074 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1075 * /proc/pid/oom_score_adj instead.
1076 */
1077 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1078 current->comm, task_pid_nr(current), task_pid_nr(task),
1079 task_pid_nr(task));
1080 } else {
1081 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1082 !capable(CAP_SYS_RESOURCE)) {
1083 err = -EACCES;
1084 goto err_unlock;
1085 }
1086 }
1087
1088 /*
1089 * Make sure we will check other processes sharing the mm if this is
1090 * not vfrok which wants its own oom_score_adj.
1091 * pin the mm so it doesn't go away and get reused after task_unlock
1092 */
1093 if (!task->vfork_done) {
1094 struct task_struct *p = find_lock_task_mm(task);
1095
1096 if (p) {
1097 if (atomic_read(&p->mm->mm_users) > 1) {
1098 mm = p->mm;
1099 atomic_inc(&mm->mm_count);
1100 }
1101 task_unlock(p);
1102 }
1103 }
1104
1105 task->signal->oom_score_adj = oom_adj;
1106 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1107 task->signal->oom_score_adj_min = (short)oom_adj;
1108 trace_oom_score_adj_update(task);
1109
1110 if (mm) {
1111 struct task_struct *p;
1112
1113 rcu_read_lock();
1114 for_each_process(p) {
1115 if (same_thread_group(task, p))
1116 continue;
1117
1118 /* do not touch kernel threads or the global init */
1119 if (p->flags & PF_KTHREAD || is_global_init(p))
1120 continue;
1121
1122 task_lock(p);
1123 if (!p->vfork_done && process_shares_mm(p, mm)) {
1124 pr_info("updating oom_score_adj for %d (%s) from %d to %d because it shares mm with %d (%s). Report if this is unexpected.\n",
1125 task_pid_nr(p), p->comm,
1126 p->signal->oom_score_adj, oom_adj,
1127 task_pid_nr(task), task->comm);
1128 p->signal->oom_score_adj = oom_adj;
1129 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1130 p->signal->oom_score_adj_min = (short)oom_adj;
1131 }
1132 task_unlock(p);
1133 }
1134 rcu_read_unlock();
1135 mmdrop(mm);
1136 }
1137err_unlock:
1138 mutex_unlock(&oom_adj_mutex);
1139 put_task_struct(task);
1140 return err;
1141}
1142
1143/*
1144 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1145 * kernels. The effective policy is defined by oom_score_adj, which has a
1146 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1147 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1148 * Processes that become oom disabled via oom_adj will still be oom disabled
1149 * with this implementation.
1150 *
1151 * oom_adj cannot be removed since existing userspace binaries use it.
1152 */
1153static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1154 size_t count, loff_t *ppos)
1155{
1156 char buffer[PROC_NUMBUF];
1157 int oom_adj;
1158 int err;
1159
1160 memset(buffer, 0, sizeof(buffer));
1161 if (count > sizeof(buffer) - 1)
1162 count = sizeof(buffer) - 1;
1163 if (copy_from_user(buffer, buf, count)) {
1164 err = -EFAULT;
1165 goto out;
1166 }
1167
1168 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1169 if (err)
1170 goto out;
1171 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1172 oom_adj != OOM_DISABLE) {
1173 err = -EINVAL;
1174 goto out;
1175 }
1176
1177 /*
1178 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1179 * value is always attainable.
1180 */
1181 if (oom_adj == OOM_ADJUST_MAX)
1182 oom_adj = OOM_SCORE_ADJ_MAX;
1183 else
1184 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1185
1186 err = __set_oom_adj(file, oom_adj, true);
1187out:
1188 return err < 0 ? err : count;
1189}
1190
1191static const struct file_operations proc_oom_adj_operations = {
1192 .read = oom_adj_read,
1193 .write = oom_adj_write,
1194 .llseek = generic_file_llseek,
1195};
1196
1197static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1198 size_t count, loff_t *ppos)
1199{
1200 struct task_struct *task = get_proc_task(file_inode(file));
1201 char buffer[PROC_NUMBUF];
1202 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1203 size_t len;
1204
1205 if (!task)
1206 return -ESRCH;
1207 oom_score_adj = task->signal->oom_score_adj;
1208 put_task_struct(task);
1209 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1210 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1211}
1212
1213static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1214 size_t count, loff_t *ppos)
1215{
1216 char buffer[PROC_NUMBUF];
1217 int oom_score_adj;
1218 int err;
1219
1220 memset(buffer, 0, sizeof(buffer));
1221 if (count > sizeof(buffer) - 1)
1222 count = sizeof(buffer) - 1;
1223 if (copy_from_user(buffer, buf, count)) {
1224 err = -EFAULT;
1225 goto out;
1226 }
1227
1228 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1229 if (err)
1230 goto out;
1231 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1232 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1233 err = -EINVAL;
1234 goto out;
1235 }
1236
1237 err = __set_oom_adj(file, oom_score_adj, false);
1238out:
1239 return err < 0 ? err : count;
1240}
1241
1242static const struct file_operations proc_oom_score_adj_operations = {
1243 .read = oom_score_adj_read,
1244 .write = oom_score_adj_write,
1245 .llseek = default_llseek,
1246};
1247
1248#ifdef CONFIG_AUDITSYSCALL
1249#define TMPBUFLEN 11
1250static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1251 size_t count, loff_t *ppos)
1252{
1253 struct inode * inode = file_inode(file);
1254 struct task_struct *task = get_proc_task(inode);
1255 ssize_t length;
1256 char tmpbuf[TMPBUFLEN];
1257
1258 if (!task)
1259 return -ESRCH;
1260 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1261 from_kuid(file->f_cred->user_ns,
1262 audit_get_loginuid(task)));
1263 put_task_struct(task);
1264 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1265}
1266
1267static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1268 size_t count, loff_t *ppos)
1269{
1270 struct inode * inode = file_inode(file);
1271 uid_t loginuid;
1272 kuid_t kloginuid;
1273 int rv;
1274
1275 rcu_read_lock();
1276 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1277 rcu_read_unlock();
1278 return -EPERM;
1279 }
1280 rcu_read_unlock();
1281
1282 if (*ppos != 0) {
1283 /* No partial writes. */
1284 return -EINVAL;
1285 }
1286
1287 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1288 if (rv < 0)
1289 return rv;
1290
1291 /* is userspace tring to explicitly UNSET the loginuid? */
1292 if (loginuid == AUDIT_UID_UNSET) {
1293 kloginuid = INVALID_UID;
1294 } else {
1295 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1296 if (!uid_valid(kloginuid))
1297 return -EINVAL;
1298 }
1299
1300 rv = audit_set_loginuid(kloginuid);
1301 if (rv < 0)
1302 return rv;
1303 return count;
1304}
1305
1306static const struct file_operations proc_loginuid_operations = {
1307 .read = proc_loginuid_read,
1308 .write = proc_loginuid_write,
1309 .llseek = generic_file_llseek,
1310};
1311
1312static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1313 size_t count, loff_t *ppos)
1314{
1315 struct inode * inode = file_inode(file);
1316 struct task_struct *task = get_proc_task(inode);
1317 ssize_t length;
1318 char tmpbuf[TMPBUFLEN];
1319
1320 if (!task)
1321 return -ESRCH;
1322 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1323 audit_get_sessionid(task));
1324 put_task_struct(task);
1325 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1326}
1327
1328static const struct file_operations proc_sessionid_operations = {
1329 .read = proc_sessionid_read,
1330 .llseek = generic_file_llseek,
1331};
1332#endif
1333
1334#ifdef CONFIG_FAULT_INJECTION
1335static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1336 size_t count, loff_t *ppos)
1337{
1338 struct task_struct *task = get_proc_task(file_inode(file));
1339 char buffer[PROC_NUMBUF];
1340 size_t len;
1341 int make_it_fail;
1342
1343 if (!task)
1344 return -ESRCH;
1345 make_it_fail = task->make_it_fail;
1346 put_task_struct(task);
1347
1348 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1349
1350 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1351}
1352
1353static ssize_t proc_fault_inject_write(struct file * file,
1354 const char __user * buf, size_t count, loff_t *ppos)
1355{
1356 struct task_struct *task;
1357 char buffer[PROC_NUMBUF];
1358 int make_it_fail;
1359 int rv;
1360
1361 if (!capable(CAP_SYS_RESOURCE))
1362 return -EPERM;
1363 memset(buffer, 0, sizeof(buffer));
1364 if (count > sizeof(buffer) - 1)
1365 count = sizeof(buffer) - 1;
1366 if (copy_from_user(buffer, buf, count))
1367 return -EFAULT;
1368 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1369 if (rv < 0)
1370 return rv;
1371 if (make_it_fail < 0 || make_it_fail > 1)
1372 return -EINVAL;
1373
1374 task = get_proc_task(file_inode(file));
1375 if (!task)
1376 return -ESRCH;
1377 task->make_it_fail = make_it_fail;
1378 put_task_struct(task);
1379
1380 return count;
1381}
1382
1383static const struct file_operations proc_fault_inject_operations = {
1384 .read = proc_fault_inject_read,
1385 .write = proc_fault_inject_write,
1386 .llseek = generic_file_llseek,
1387};
1388#endif
1389
1390
1391#ifdef CONFIG_SCHED_DEBUG
1392/*
1393 * Print out various scheduling related per-task fields:
1394 */
1395static int sched_show(struct seq_file *m, void *v)
1396{
1397 struct inode *inode = m->private;
1398 struct task_struct *p;
1399
1400 p = get_proc_task(inode);
1401 if (!p)
1402 return -ESRCH;
1403 proc_sched_show_task(p, m);
1404
1405 put_task_struct(p);
1406
1407 return 0;
1408}
1409
1410static ssize_t
1411sched_write(struct file *file, const char __user *buf,
1412 size_t count, loff_t *offset)
1413{
1414 struct inode *inode = file_inode(file);
1415 struct task_struct *p;
1416
1417 p = get_proc_task(inode);
1418 if (!p)
1419 return -ESRCH;
1420 proc_sched_set_task(p);
1421
1422 put_task_struct(p);
1423
1424 return count;
1425}
1426
1427static int sched_open(struct inode *inode, struct file *filp)
1428{
1429 return single_open(filp, sched_show, inode);
1430}
1431
1432static const struct file_operations proc_pid_sched_operations = {
1433 .open = sched_open,
1434 .read = seq_read,
1435 .write = sched_write,
1436 .llseek = seq_lseek,
1437 .release = single_release,
1438};
1439
1440#endif
1441
1442#ifdef CONFIG_SCHED_AUTOGROUP
1443/*
1444 * Print out autogroup related information:
1445 */
1446static int sched_autogroup_show(struct seq_file *m, void *v)
1447{
1448 struct inode *inode = m->private;
1449 struct task_struct *p;
1450
1451 p = get_proc_task(inode);
1452 if (!p)
1453 return -ESRCH;
1454 proc_sched_autogroup_show_task(p, m);
1455
1456 put_task_struct(p);
1457
1458 return 0;
1459}
1460
1461static ssize_t
1462sched_autogroup_write(struct file *file, const char __user *buf,
1463 size_t count, loff_t *offset)
1464{
1465 struct inode *inode = file_inode(file);
1466 struct task_struct *p;
1467 char buffer[PROC_NUMBUF];
1468 int nice;
1469 int err;
1470
1471 memset(buffer, 0, sizeof(buffer));
1472 if (count > sizeof(buffer) - 1)
1473 count = sizeof(buffer) - 1;
1474 if (copy_from_user(buffer, buf, count))
1475 return -EFAULT;
1476
1477 err = kstrtoint(strstrip(buffer), 0, &nice);
1478 if (err < 0)
1479 return err;
1480
1481 p = get_proc_task(inode);
1482 if (!p)
1483 return -ESRCH;
1484
1485 err = proc_sched_autogroup_set_nice(p, nice);
1486 if (err)
1487 count = err;
1488
1489 put_task_struct(p);
1490
1491 return count;
1492}
1493
1494static int sched_autogroup_open(struct inode *inode, struct file *filp)
1495{
1496 int ret;
1497
1498 ret = single_open(filp, sched_autogroup_show, NULL);
1499 if (!ret) {
1500 struct seq_file *m = filp->private_data;
1501
1502 m->private = inode;
1503 }
1504 return ret;
1505}
1506
1507static const struct file_operations proc_pid_sched_autogroup_operations = {
1508 .open = sched_autogroup_open,
1509 .read = seq_read,
1510 .write = sched_autogroup_write,
1511 .llseek = seq_lseek,
1512 .release = single_release,
1513};
1514
1515#endif /* CONFIG_SCHED_AUTOGROUP */
1516
1517static ssize_t comm_write(struct file *file, const char __user *buf,
1518 size_t count, loff_t *offset)
1519{
1520 struct inode *inode = file_inode(file);
1521 struct task_struct *p;
1522 char buffer[TASK_COMM_LEN];
1523 const size_t maxlen = sizeof(buffer) - 1;
1524
1525 memset(buffer, 0, sizeof(buffer));
1526 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1527 return -EFAULT;
1528
1529 p = get_proc_task(inode);
1530 if (!p)
1531 return -ESRCH;
1532
1533 if (same_thread_group(current, p))
1534 set_task_comm(p, buffer);
1535 else
1536 count = -EINVAL;
1537
1538 put_task_struct(p);
1539
1540 return count;
1541}
1542
1543static int comm_show(struct seq_file *m, void *v)
1544{
1545 struct inode *inode = m->private;
1546 struct task_struct *p;
1547
1548 p = get_proc_task(inode);
1549 if (!p)
1550 return -ESRCH;
1551
1552 task_lock(p);
1553 seq_printf(m, "%s\n", p->comm);
1554 task_unlock(p);
1555
1556 put_task_struct(p);
1557
1558 return 0;
1559}
1560
1561static int comm_open(struct inode *inode, struct file *filp)
1562{
1563 return single_open(filp, comm_show, inode);
1564}
1565
1566static const struct file_operations proc_pid_set_comm_operations = {
1567 .open = comm_open,
1568 .read = seq_read,
1569 .write = comm_write,
1570 .llseek = seq_lseek,
1571 .release = single_release,
1572};
1573
1574static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1575{
1576 struct task_struct *task;
1577 struct file *exe_file;
1578
1579 task = get_proc_task(d_inode(dentry));
1580 if (!task)
1581 return -ENOENT;
1582 exe_file = get_task_exe_file(task);
1583 put_task_struct(task);
1584 if (exe_file) {
1585 *exe_path = exe_file->f_path;
1586 path_get(&exe_file->f_path);
1587 fput(exe_file);
1588 return 0;
1589 } else
1590 return -ENOENT;
1591}
1592
1593static const char *proc_pid_get_link(struct dentry *dentry,
1594 struct inode *inode,
1595 struct delayed_call *done)
1596{
1597 struct path path;
1598 int error = -EACCES;
1599
1600 if (!dentry)
1601 return ERR_PTR(-ECHILD);
1602
1603 /* Are we allowed to snoop on the tasks file descriptors? */
1604 if (!proc_fd_access_allowed(inode))
1605 goto out;
1606
1607 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1608 if (error)
1609 goto out;
1610
1611 nd_jump_link(&path);
1612 return NULL;
1613out:
1614 return ERR_PTR(error);
1615}
1616
1617static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1618{
1619 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1620 char *pathname;
1621 int len;
1622
1623 if (!tmp)
1624 return -ENOMEM;
1625
1626 pathname = d_path(path, tmp, PAGE_SIZE);
1627 len = PTR_ERR(pathname);
1628 if (IS_ERR(pathname))
1629 goto out;
1630 len = tmp + PAGE_SIZE - 1 - pathname;
1631
1632 if (len > buflen)
1633 len = buflen;
1634 if (copy_to_user(buffer, pathname, len))
1635 len = -EFAULT;
1636 out:
1637 free_page((unsigned long)tmp);
1638 return len;
1639}
1640
1641static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1642{
1643 int error = -EACCES;
1644 struct inode *inode = d_inode(dentry);
1645 struct path path;
1646
1647 /* Are we allowed to snoop on the tasks file descriptors? */
1648 if (!proc_fd_access_allowed(inode))
1649 goto out;
1650
1651 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1652 if (error)
1653 goto out;
1654
1655 error = do_proc_readlink(&path, buffer, buflen);
1656 path_put(&path);
1657out:
1658 return error;
1659}
1660
1661const struct inode_operations proc_pid_link_inode_operations = {
1662 .readlink = proc_pid_readlink,
1663 .get_link = proc_pid_get_link,
1664 .setattr = proc_setattr,
1665};
1666
1667
1668/* building an inode */
1669
1670struct inode *proc_pid_make_inode(struct super_block * sb,
1671 struct task_struct *task, umode_t mode)
1672{
1673 struct inode * inode;
1674 struct proc_inode *ei;
1675 const struct cred *cred;
1676
1677 /* We need a new inode */
1678
1679 inode = new_inode(sb);
1680 if (!inode)
1681 goto out;
1682
1683 /* Common stuff */
1684 ei = PROC_I(inode);
1685 inode->i_mode = mode;
1686 inode->i_ino = get_next_ino();
1687 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1688 inode->i_op = &proc_def_inode_operations;
1689
1690 /*
1691 * grab the reference to task.
1692 */
1693 ei->pid = get_task_pid(task, PIDTYPE_PID);
1694 if (!ei->pid)
1695 goto out_unlock;
1696
1697 if (task_dumpable(task)) {
1698 rcu_read_lock();
1699 cred = __task_cred(task);
1700 inode->i_uid = cred->euid;
1701 inode->i_gid = cred->egid;
1702 rcu_read_unlock();
1703 }
1704 security_task_to_inode(task, inode);
1705
1706out:
1707 return inode;
1708
1709out_unlock:
1710 iput(inode);
1711 return NULL;
1712}
1713
1714int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1715{
1716 struct inode *inode = d_inode(dentry);
1717 struct task_struct *task;
1718 const struct cred *cred;
1719 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1720
1721 generic_fillattr(inode, stat);
1722
1723 rcu_read_lock();
1724 stat->uid = GLOBAL_ROOT_UID;
1725 stat->gid = GLOBAL_ROOT_GID;
1726 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1727 if (task) {
1728 if (!has_pid_permissions(pid, task, 2)) {
1729 rcu_read_unlock();
1730 /*
1731 * This doesn't prevent learning whether PID exists,
1732 * it only makes getattr() consistent with readdir().
1733 */
1734 return -ENOENT;
1735 }
1736 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1737 task_dumpable(task)) {
1738 cred = __task_cred(task);
1739 stat->uid = cred->euid;
1740 stat->gid = cred->egid;
1741 }
1742 }
1743 rcu_read_unlock();
1744 return 0;
1745}
1746
1747/* dentry stuff */
1748
1749/*
1750 * Exceptional case: normally we are not allowed to unhash a busy
1751 * directory. In this case, however, we can do it - no aliasing problems
1752 * due to the way we treat inodes.
1753 *
1754 * Rewrite the inode's ownerships here because the owning task may have
1755 * performed a setuid(), etc.
1756 *
1757 * Before the /proc/pid/status file was created the only way to read
1758 * the effective uid of a /process was to stat /proc/pid. Reading
1759 * /proc/pid/status is slow enough that procps and other packages
1760 * kept stating /proc/pid. To keep the rules in /proc simple I have
1761 * made this apply to all per process world readable and executable
1762 * directories.
1763 */
1764int pid_revalidate(struct dentry *dentry, unsigned int flags)
1765{
1766 struct inode *inode;
1767 struct task_struct *task;
1768 const struct cred *cred;
1769
1770 if (flags & LOOKUP_RCU)
1771 return -ECHILD;
1772
1773 inode = d_inode(dentry);
1774 task = get_proc_task(inode);
1775
1776 if (task) {
1777 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1778 task_dumpable(task)) {
1779 rcu_read_lock();
1780 cred = __task_cred(task);
1781 inode->i_uid = cred->euid;
1782 inode->i_gid = cred->egid;
1783 rcu_read_unlock();
1784 } else {
1785 inode->i_uid = GLOBAL_ROOT_UID;
1786 inode->i_gid = GLOBAL_ROOT_GID;
1787 }
1788 inode->i_mode &= ~(S_ISUID | S_ISGID);
1789 security_task_to_inode(task, inode);
1790 put_task_struct(task);
1791 return 1;
1792 }
1793 return 0;
1794}
1795
1796static inline bool proc_inode_is_dead(struct inode *inode)
1797{
1798 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1799}
1800
1801int pid_delete_dentry(const struct dentry *dentry)
1802{
1803 /* Is the task we represent dead?
1804 * If so, then don't put the dentry on the lru list,
1805 * kill it immediately.
1806 */
1807 return proc_inode_is_dead(d_inode(dentry));
1808}
1809
1810const struct dentry_operations pid_dentry_operations =
1811{
1812 .d_revalidate = pid_revalidate,
1813 .d_delete = pid_delete_dentry,
1814};
1815
1816/* Lookups */
1817
1818/*
1819 * Fill a directory entry.
1820 *
1821 * If possible create the dcache entry and derive our inode number and
1822 * file type from dcache entry.
1823 *
1824 * Since all of the proc inode numbers are dynamically generated, the inode
1825 * numbers do not exist until the inode is cache. This means creating the
1826 * the dcache entry in readdir is necessary to keep the inode numbers
1827 * reported by readdir in sync with the inode numbers reported
1828 * by stat.
1829 */
1830bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1831 const char *name, int len,
1832 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1833{
1834 struct dentry *child, *dir = file->f_path.dentry;
1835 struct qstr qname = QSTR_INIT(name, len);
1836 struct inode *inode;
1837 unsigned type;
1838 ino_t ino;
1839
1840 child = d_hash_and_lookup(dir, &qname);
1841 if (!child) {
1842 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
1843 child = d_alloc_parallel(dir, &qname, &wq);
1844 if (IS_ERR(child))
1845 goto end_instantiate;
1846 if (d_in_lookup(child)) {
1847 int err = instantiate(d_inode(dir), child, task, ptr);
1848 d_lookup_done(child);
1849 if (err < 0) {
1850 dput(child);
1851 goto end_instantiate;
1852 }
1853 }
1854 }
1855 inode = d_inode(child);
1856 ino = inode->i_ino;
1857 type = inode->i_mode >> 12;
1858 dput(child);
1859 return dir_emit(ctx, name, len, ino, type);
1860
1861end_instantiate:
1862 return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1863}
1864
1865/*
1866 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1867 * which represent vma start and end addresses.
1868 */
1869static int dname_to_vma_addr(struct dentry *dentry,
1870 unsigned long *start, unsigned long *end)
1871{
1872 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1873 return -EINVAL;
1874
1875 return 0;
1876}
1877
1878static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1879{
1880 unsigned long vm_start, vm_end;
1881 bool exact_vma_exists = false;
1882 struct mm_struct *mm = NULL;
1883 struct task_struct *task;
1884 const struct cred *cred;
1885 struct inode *inode;
1886 int status = 0;
1887
1888 if (flags & LOOKUP_RCU)
1889 return -ECHILD;
1890
1891 inode = d_inode(dentry);
1892 task = get_proc_task(inode);
1893 if (!task)
1894 goto out_notask;
1895
1896 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
1897 if (IS_ERR_OR_NULL(mm))
1898 goto out;
1899
1900 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1901 down_read(&mm->mmap_sem);
1902 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1903 up_read(&mm->mmap_sem);
1904 }
1905
1906 mmput(mm);
1907
1908 if (exact_vma_exists) {
1909 if (task_dumpable(task)) {
1910 rcu_read_lock();
1911 cred = __task_cred(task);
1912 inode->i_uid = cred->euid;
1913 inode->i_gid = cred->egid;
1914 rcu_read_unlock();
1915 } else {
1916 inode->i_uid = GLOBAL_ROOT_UID;
1917 inode->i_gid = GLOBAL_ROOT_GID;
1918 }
1919 security_task_to_inode(task, inode);
1920 status = 1;
1921 }
1922
1923out:
1924 put_task_struct(task);
1925
1926out_notask:
1927 return status;
1928}
1929
1930static const struct dentry_operations tid_map_files_dentry_operations = {
1931 .d_revalidate = map_files_d_revalidate,
1932 .d_delete = pid_delete_dentry,
1933};
1934
1935static int map_files_get_link(struct dentry *dentry, struct path *path)
1936{
1937 unsigned long vm_start, vm_end;
1938 struct vm_area_struct *vma;
1939 struct task_struct *task;
1940 struct mm_struct *mm;
1941 int rc;
1942
1943 rc = -ENOENT;
1944 task = get_proc_task(d_inode(dentry));
1945 if (!task)
1946 goto out;
1947
1948 mm = get_task_mm(task);
1949 put_task_struct(task);
1950 if (!mm)
1951 goto out;
1952
1953 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
1954 if (rc)
1955 goto out_mmput;
1956
1957 rc = -ENOENT;
1958 down_read(&mm->mmap_sem);
1959 vma = find_exact_vma(mm, vm_start, vm_end);
1960 if (vma && vma->vm_file) {
1961 *path = vma->vm_file->f_path;
1962 path_get(path);
1963 rc = 0;
1964 }
1965 up_read(&mm->mmap_sem);
1966
1967out_mmput:
1968 mmput(mm);
1969out:
1970 return rc;
1971}
1972
1973struct map_files_info {
1974 fmode_t mode;
1975 unsigned int len;
1976 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
1977};
1978
1979/*
1980 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
1981 * symlinks may be used to bypass permissions on ancestor directories in the
1982 * path to the file in question.
1983 */
1984static const char *
1985proc_map_files_get_link(struct dentry *dentry,
1986 struct inode *inode,
1987 struct delayed_call *done)
1988{
1989 if (!capable(CAP_SYS_ADMIN))
1990 return ERR_PTR(-EPERM);
1991
1992 return proc_pid_get_link(dentry, inode, done);
1993}
1994
1995/*
1996 * Identical to proc_pid_link_inode_operations except for get_link()
1997 */
1998static const struct inode_operations proc_map_files_link_inode_operations = {
1999 .readlink = proc_pid_readlink,
2000 .get_link = proc_map_files_get_link,
2001 .setattr = proc_setattr,
2002};
2003
2004static int
2005proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
2006 struct task_struct *task, const void *ptr)
2007{
2008 fmode_t mode = (fmode_t)(unsigned long)ptr;
2009 struct proc_inode *ei;
2010 struct inode *inode;
2011
2012 inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK |
2013 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2014 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2015 if (!inode)
2016 return -ENOENT;
2017
2018 ei = PROC_I(inode);
2019 ei->op.proc_get_link = map_files_get_link;
2020
2021 inode->i_op = &proc_map_files_link_inode_operations;
2022 inode->i_size = 64;
2023
2024 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2025 d_add(dentry, inode);
2026
2027 return 0;
2028}
2029
2030static struct dentry *proc_map_files_lookup(struct inode *dir,
2031 struct dentry *dentry, unsigned int flags)
2032{
2033 unsigned long vm_start, vm_end;
2034 struct vm_area_struct *vma;
2035 struct task_struct *task;
2036 int result;
2037 struct mm_struct *mm;
2038
2039 result = -ENOENT;
2040 task = get_proc_task(dir);
2041 if (!task)
2042 goto out;
2043
2044 result = -EACCES;
2045 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2046 goto out_put_task;
2047
2048 result = -ENOENT;
2049 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2050 goto out_put_task;
2051
2052 mm = get_task_mm(task);
2053 if (!mm)
2054 goto out_put_task;
2055
2056 down_read(&mm->mmap_sem);
2057 vma = find_exact_vma(mm, vm_start, vm_end);
2058 if (!vma)
2059 goto out_no_vma;
2060
2061 if (vma->vm_file)
2062 result = proc_map_files_instantiate(dir, dentry, task,
2063 (void *)(unsigned long)vma->vm_file->f_mode);
2064
2065out_no_vma:
2066 up_read(&mm->mmap_sem);
2067 mmput(mm);
2068out_put_task:
2069 put_task_struct(task);
2070out:
2071 return ERR_PTR(result);
2072}
2073
2074static const struct inode_operations proc_map_files_inode_operations = {
2075 .lookup = proc_map_files_lookup,
2076 .permission = proc_fd_permission,
2077 .setattr = proc_setattr,
2078};
2079
2080static int
2081proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2082{
2083 struct vm_area_struct *vma;
2084 struct task_struct *task;
2085 struct mm_struct *mm;
2086 unsigned long nr_files, pos, i;
2087 struct flex_array *fa = NULL;
2088 struct map_files_info info;
2089 struct map_files_info *p;
2090 int ret;
2091
2092 ret = -ENOENT;
2093 task = get_proc_task(file_inode(file));
2094 if (!task)
2095 goto out;
2096
2097 ret = -EACCES;
2098 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2099 goto out_put_task;
2100
2101 ret = 0;
2102 if (!dir_emit_dots(file, ctx))
2103 goto out_put_task;
2104
2105 mm = get_task_mm(task);
2106 if (!mm)
2107 goto out_put_task;
2108 down_read(&mm->mmap_sem);
2109
2110 nr_files = 0;
2111
2112 /*
2113 * We need two passes here:
2114 *
2115 * 1) Collect vmas of mapped files with mmap_sem taken
2116 * 2) Release mmap_sem and instantiate entries
2117 *
2118 * otherwise we get lockdep complained, since filldir()
2119 * routine might require mmap_sem taken in might_fault().
2120 */
2121
2122 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2123 if (vma->vm_file && ++pos > ctx->pos)
2124 nr_files++;
2125 }
2126
2127 if (nr_files) {
2128 fa = flex_array_alloc(sizeof(info), nr_files,
2129 GFP_KERNEL);
2130 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2131 GFP_KERNEL)) {
2132 ret = -ENOMEM;
2133 if (fa)
2134 flex_array_free(fa);
2135 up_read(&mm->mmap_sem);
2136 mmput(mm);
2137 goto out_put_task;
2138 }
2139 for (i = 0, vma = mm->mmap, pos = 2; vma;
2140 vma = vma->vm_next) {
2141 if (!vma->vm_file)
2142 continue;
2143 if (++pos <= ctx->pos)
2144 continue;
2145
2146 info.mode = vma->vm_file->f_mode;
2147 info.len = snprintf(info.name,
2148 sizeof(info.name), "%lx-%lx",
2149 vma->vm_start, vma->vm_end);
2150 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2151 BUG();
2152 }
2153 }
2154 up_read(&mm->mmap_sem);
2155
2156 for (i = 0; i < nr_files; i++) {
2157 p = flex_array_get(fa, i);
2158 if (!proc_fill_cache(file, ctx,
2159 p->name, p->len,
2160 proc_map_files_instantiate,
2161 task,
2162 (void *)(unsigned long)p->mode))
2163 break;
2164 ctx->pos++;
2165 }
2166 if (fa)
2167 flex_array_free(fa);
2168 mmput(mm);
2169
2170out_put_task:
2171 put_task_struct(task);
2172out:
2173 return ret;
2174}
2175
2176static const struct file_operations proc_map_files_operations = {
2177 .read = generic_read_dir,
2178 .iterate_shared = proc_map_files_readdir,
2179 .llseek = generic_file_llseek,
2180};
2181
2182#ifdef CONFIG_CHECKPOINT_RESTORE
2183struct timers_private {
2184 struct pid *pid;
2185 struct task_struct *task;
2186 struct sighand_struct *sighand;
2187 struct pid_namespace *ns;
2188 unsigned long flags;
2189};
2190
2191static void *timers_start(struct seq_file *m, loff_t *pos)
2192{
2193 struct timers_private *tp = m->private;
2194
2195 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2196 if (!tp->task)
2197 return ERR_PTR(-ESRCH);
2198
2199 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2200 if (!tp->sighand)
2201 return ERR_PTR(-ESRCH);
2202
2203 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2204}
2205
2206static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2207{
2208 struct timers_private *tp = m->private;
2209 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2210}
2211
2212static void timers_stop(struct seq_file *m, void *v)
2213{
2214 struct timers_private *tp = m->private;
2215
2216 if (tp->sighand) {
2217 unlock_task_sighand(tp->task, &tp->flags);
2218 tp->sighand = NULL;
2219 }
2220
2221 if (tp->task) {
2222 put_task_struct(tp->task);
2223 tp->task = NULL;
2224 }
2225}
2226
2227static int show_timer(struct seq_file *m, void *v)
2228{
2229 struct k_itimer *timer;
2230 struct timers_private *tp = m->private;
2231 int notify;
2232 static const char * const nstr[] = {
2233 [SIGEV_SIGNAL] = "signal",
2234 [SIGEV_NONE] = "none",
2235 [SIGEV_THREAD] = "thread",
2236 };
2237
2238 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2239 notify = timer->it_sigev_notify;
2240
2241 seq_printf(m, "ID: %d\n", timer->it_id);
2242 seq_printf(m, "signal: %d/%p\n",
2243 timer->sigq->info.si_signo,
2244 timer->sigq->info.si_value.sival_ptr);
2245 seq_printf(m, "notify: %s/%s.%d\n",
2246 nstr[notify & ~SIGEV_THREAD_ID],
2247 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2248 pid_nr_ns(timer->it_pid, tp->ns));
2249 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2250
2251 return 0;
2252}
2253
2254static const struct seq_operations proc_timers_seq_ops = {
2255 .start = timers_start,
2256 .next = timers_next,
2257 .stop = timers_stop,
2258 .show = show_timer,
2259};
2260
2261static int proc_timers_open(struct inode *inode, struct file *file)
2262{
2263 struct timers_private *tp;
2264
2265 tp = __seq_open_private(file, &proc_timers_seq_ops,
2266 sizeof(struct timers_private));
2267 if (!tp)
2268 return -ENOMEM;
2269
2270 tp->pid = proc_pid(inode);
2271 tp->ns = inode->i_sb->s_fs_info;
2272 return 0;
2273}
2274
2275static const struct file_operations proc_timers_operations = {
2276 .open = proc_timers_open,
2277 .read = seq_read,
2278 .llseek = seq_lseek,
2279 .release = seq_release_private,
2280};
2281#endif
2282
2283static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2284 size_t count, loff_t *offset)
2285{
2286 struct inode *inode = file_inode(file);
2287 struct task_struct *p;
2288 u64 slack_ns;
2289 int err;
2290
2291 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2292 if (err < 0)
2293 return err;
2294
2295 p = get_proc_task(inode);
2296 if (!p)
2297 return -ESRCH;
2298
2299 if (p != current) {
2300 if (!capable(CAP_SYS_NICE)) {
2301 count = -EPERM;
2302 goto out;
2303 }
2304
2305 err = security_task_setscheduler(p);
2306 if (err) {
2307 count = err;
2308 goto out;
2309 }
2310 }
2311
2312 task_lock(p);
2313 if (slack_ns == 0)
2314 p->timer_slack_ns = p->default_timer_slack_ns;
2315 else
2316 p->timer_slack_ns = slack_ns;
2317 task_unlock(p);
2318
2319out:
2320 put_task_struct(p);
2321
2322 return count;
2323}
2324
2325static int timerslack_ns_show(struct seq_file *m, void *v)
2326{
2327 struct inode *inode = m->private;
2328 struct task_struct *p;
2329 int err = 0;
2330
2331 p = get_proc_task(inode);
2332 if (!p)
2333 return -ESRCH;
2334
2335 if (p != current) {
2336
2337 if (!capable(CAP_SYS_NICE)) {
2338 err = -EPERM;
2339 goto out;
2340 }
2341 err = security_task_getscheduler(p);
2342 if (err)
2343 goto out;
2344 }
2345
2346 task_lock(p);
2347 seq_printf(m, "%llu\n", p->timer_slack_ns);
2348 task_unlock(p);
2349
2350out:
2351 put_task_struct(p);
2352
2353 return err;
2354}
2355
2356static int timerslack_ns_open(struct inode *inode, struct file *filp)
2357{
2358 return single_open(filp, timerslack_ns_show, inode);
2359}
2360
2361static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2362 .open = timerslack_ns_open,
2363 .read = seq_read,
2364 .write = timerslack_ns_write,
2365 .llseek = seq_lseek,
2366 .release = single_release,
2367};
2368
2369static int proc_pident_instantiate(struct inode *dir,
2370 struct dentry *dentry, struct task_struct *task, const void *ptr)
2371{
2372 const struct pid_entry *p = ptr;
2373 struct inode *inode;
2374 struct proc_inode *ei;
2375
2376 inode = proc_pid_make_inode(dir->i_sb, task, p->mode);
2377 if (!inode)
2378 goto out;
2379
2380 ei = PROC_I(inode);
2381 if (S_ISDIR(inode->i_mode))
2382 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2383 if (p->iop)
2384 inode->i_op = p->iop;
2385 if (p->fop)
2386 inode->i_fop = p->fop;
2387 ei->op = p->op;
2388 d_set_d_op(dentry, &pid_dentry_operations);
2389 d_add(dentry, inode);
2390 /* Close the race of the process dying before we return the dentry */
2391 if (pid_revalidate(dentry, 0))
2392 return 0;
2393out:
2394 return -ENOENT;
2395}
2396
2397static struct dentry *proc_pident_lookup(struct inode *dir,
2398 struct dentry *dentry,
2399 const struct pid_entry *ents,
2400 unsigned int nents)
2401{
2402 int error;
2403 struct task_struct *task = get_proc_task(dir);
2404 const struct pid_entry *p, *last;
2405
2406 error = -ENOENT;
2407
2408 if (!task)
2409 goto out_no_task;
2410
2411 /*
2412 * Yes, it does not scale. And it should not. Don't add
2413 * new entries into /proc/<tgid>/ without very good reasons.
2414 */
2415 last = &ents[nents];
2416 for (p = ents; p < last; p++) {
2417 if (p->len != dentry->d_name.len)
2418 continue;
2419 if (!memcmp(dentry->d_name.name, p->name, p->len))
2420 break;
2421 }
2422 if (p >= last)
2423 goto out;
2424
2425 error = proc_pident_instantiate(dir, dentry, task, p);
2426out:
2427 put_task_struct(task);
2428out_no_task:
2429 return ERR_PTR(error);
2430}
2431
2432static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2433 const struct pid_entry *ents, unsigned int nents)
2434{
2435 struct task_struct *task = get_proc_task(file_inode(file));
2436 const struct pid_entry *p;
2437
2438 if (!task)
2439 return -ENOENT;
2440
2441 if (!dir_emit_dots(file, ctx))
2442 goto out;
2443
2444 if (ctx->pos >= nents + 2)
2445 goto out;
2446
2447 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2448 if (!proc_fill_cache(file, ctx, p->name, p->len,
2449 proc_pident_instantiate, task, p))
2450 break;
2451 ctx->pos++;
2452 }
2453out:
2454 put_task_struct(task);
2455 return 0;
2456}
2457
2458#ifdef CONFIG_SECURITY
2459static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2460 size_t count, loff_t *ppos)
2461{
2462 struct inode * inode = file_inode(file);
2463 char *p = NULL;
2464 ssize_t length;
2465 struct task_struct *task = get_proc_task(inode);
2466
2467 if (!task)
2468 return -ESRCH;
2469
2470 length = security_getprocattr(task,
2471 (char*)file->f_path.dentry->d_name.name,
2472 &p);
2473 put_task_struct(task);
2474 if (length > 0)
2475 length = simple_read_from_buffer(buf, count, ppos, p, length);
2476 kfree(p);
2477 return length;
2478}
2479
2480static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2481 size_t count, loff_t *ppos)
2482{
2483 struct inode * inode = file_inode(file);
2484 void *page;
2485 ssize_t length;
2486 struct task_struct *task = get_proc_task(inode);
2487
2488 length = -ESRCH;
2489 if (!task)
2490 goto out_no_task;
2491 if (count > PAGE_SIZE)
2492 count = PAGE_SIZE;
2493
2494 /* No partial writes. */
2495 length = -EINVAL;
2496 if (*ppos != 0)
2497 goto out;
2498
2499 page = memdup_user(buf, count);
2500 if (IS_ERR(page)) {
2501 length = PTR_ERR(page);
2502 goto out;
2503 }
2504
2505 /* Guard against adverse ptrace interaction */
2506 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2507 if (length < 0)
2508 goto out_free;
2509
2510 length = security_setprocattr(task,
2511 (char*)file->f_path.dentry->d_name.name,
2512 page, count);
2513 mutex_unlock(&task->signal->cred_guard_mutex);
2514out_free:
2515 kfree(page);
2516out:
2517 put_task_struct(task);
2518out_no_task:
2519 return length;
2520}
2521
2522static const struct file_operations proc_pid_attr_operations = {
2523 .read = proc_pid_attr_read,
2524 .write = proc_pid_attr_write,
2525 .llseek = generic_file_llseek,
2526};
2527
2528static const struct pid_entry attr_dir_stuff[] = {
2529 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2530 REG("prev", S_IRUGO, proc_pid_attr_operations),
2531 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2532 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2533 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2534 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2535};
2536
2537static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2538{
2539 return proc_pident_readdir(file, ctx,
2540 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2541}
2542
2543static const struct file_operations proc_attr_dir_operations = {
2544 .read = generic_read_dir,
2545 .iterate_shared = proc_attr_dir_readdir,
2546 .llseek = generic_file_llseek,
2547};
2548
2549static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2550 struct dentry *dentry, unsigned int flags)
2551{
2552 return proc_pident_lookup(dir, dentry,
2553 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2554}
2555
2556static const struct inode_operations proc_attr_dir_inode_operations = {
2557 .lookup = proc_attr_dir_lookup,
2558 .getattr = pid_getattr,
2559 .setattr = proc_setattr,
2560};
2561
2562#endif
2563
2564#ifdef CONFIG_ELF_CORE
2565static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2566 size_t count, loff_t *ppos)
2567{
2568 struct task_struct *task = get_proc_task(file_inode(file));
2569 struct mm_struct *mm;
2570 char buffer[PROC_NUMBUF];
2571 size_t len;
2572 int ret;
2573
2574 if (!task)
2575 return -ESRCH;
2576
2577 ret = 0;
2578 mm = get_task_mm(task);
2579 if (mm) {
2580 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2581 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2582 MMF_DUMP_FILTER_SHIFT));
2583 mmput(mm);
2584 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2585 }
2586
2587 put_task_struct(task);
2588
2589 return ret;
2590}
2591
2592static ssize_t proc_coredump_filter_write(struct file *file,
2593 const char __user *buf,
2594 size_t count,
2595 loff_t *ppos)
2596{
2597 struct task_struct *task;
2598 struct mm_struct *mm;
2599 unsigned int val;
2600 int ret;
2601 int i;
2602 unsigned long mask;
2603
2604 ret = kstrtouint_from_user(buf, count, 0, &val);
2605 if (ret < 0)
2606 return ret;
2607
2608 ret = -ESRCH;
2609 task = get_proc_task(file_inode(file));
2610 if (!task)
2611 goto out_no_task;
2612
2613 mm = get_task_mm(task);
2614 if (!mm)
2615 goto out_no_mm;
2616 ret = 0;
2617
2618 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2619 if (val & mask)
2620 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2621 else
2622 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2623 }
2624
2625 mmput(mm);
2626 out_no_mm:
2627 put_task_struct(task);
2628 out_no_task:
2629 if (ret < 0)
2630 return ret;
2631 return count;
2632}
2633
2634static const struct file_operations proc_coredump_filter_operations = {
2635 .read = proc_coredump_filter_read,
2636 .write = proc_coredump_filter_write,
2637 .llseek = generic_file_llseek,
2638};
2639#endif
2640
2641#ifdef CONFIG_TASK_IO_ACCOUNTING
2642static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2643{
2644 struct task_io_accounting acct = task->ioac;
2645 unsigned long flags;
2646 int result;
2647
2648 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2649 if (result)
2650 return result;
2651
2652 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2653 result = -EACCES;
2654 goto out_unlock;
2655 }
2656
2657 if (whole && lock_task_sighand(task, &flags)) {
2658 struct task_struct *t = task;
2659
2660 task_io_accounting_add(&acct, &task->signal->ioac);
2661 while_each_thread(task, t)
2662 task_io_accounting_add(&acct, &t->ioac);
2663
2664 unlock_task_sighand(task, &flags);
2665 }
2666 seq_printf(m,
2667 "rchar: %llu\n"
2668 "wchar: %llu\n"
2669 "syscr: %llu\n"
2670 "syscw: %llu\n"
2671 "read_bytes: %llu\n"
2672 "write_bytes: %llu\n"
2673 "cancelled_write_bytes: %llu\n",
2674 (unsigned long long)acct.rchar,
2675 (unsigned long long)acct.wchar,
2676 (unsigned long long)acct.syscr,
2677 (unsigned long long)acct.syscw,
2678 (unsigned long long)acct.read_bytes,
2679 (unsigned long long)acct.write_bytes,
2680 (unsigned long long)acct.cancelled_write_bytes);
2681 result = 0;
2682
2683out_unlock:
2684 mutex_unlock(&task->signal->cred_guard_mutex);
2685 return result;
2686}
2687
2688static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2689 struct pid *pid, struct task_struct *task)
2690{
2691 return do_io_accounting(task, m, 0);
2692}
2693
2694static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2695 struct pid *pid, struct task_struct *task)
2696{
2697 return do_io_accounting(task, m, 1);
2698}
2699#endif /* CONFIG_TASK_IO_ACCOUNTING */
2700
2701#ifdef CONFIG_USER_NS
2702static int proc_id_map_open(struct inode *inode, struct file *file,
2703 const struct seq_operations *seq_ops)
2704{
2705 struct user_namespace *ns = NULL;
2706 struct task_struct *task;
2707 struct seq_file *seq;
2708 int ret = -EINVAL;
2709
2710 task = get_proc_task(inode);
2711 if (task) {
2712 rcu_read_lock();
2713 ns = get_user_ns(task_cred_xxx(task, user_ns));
2714 rcu_read_unlock();
2715 put_task_struct(task);
2716 }
2717 if (!ns)
2718 goto err;
2719
2720 ret = seq_open(file, seq_ops);
2721 if (ret)
2722 goto err_put_ns;
2723
2724 seq = file->private_data;
2725 seq->private = ns;
2726
2727 return 0;
2728err_put_ns:
2729 put_user_ns(ns);
2730err:
2731 return ret;
2732}
2733
2734static int proc_id_map_release(struct inode *inode, struct file *file)
2735{
2736 struct seq_file *seq = file->private_data;
2737 struct user_namespace *ns = seq->private;
2738 put_user_ns(ns);
2739 return seq_release(inode, file);
2740}
2741
2742static int proc_uid_map_open(struct inode *inode, struct file *file)
2743{
2744 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2745}
2746
2747static int proc_gid_map_open(struct inode *inode, struct file *file)
2748{
2749 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2750}
2751
2752static int proc_projid_map_open(struct inode *inode, struct file *file)
2753{
2754 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2755}
2756
2757static const struct file_operations proc_uid_map_operations = {
2758 .open = proc_uid_map_open,
2759 .write = proc_uid_map_write,
2760 .read = seq_read,
2761 .llseek = seq_lseek,
2762 .release = proc_id_map_release,
2763};
2764
2765static const struct file_operations proc_gid_map_operations = {
2766 .open = proc_gid_map_open,
2767 .write = proc_gid_map_write,
2768 .read = seq_read,
2769 .llseek = seq_lseek,
2770 .release = proc_id_map_release,
2771};
2772
2773static const struct file_operations proc_projid_map_operations = {
2774 .open = proc_projid_map_open,
2775 .write = proc_projid_map_write,
2776 .read = seq_read,
2777 .llseek = seq_lseek,
2778 .release = proc_id_map_release,
2779};
2780
2781static int proc_setgroups_open(struct inode *inode, struct file *file)
2782{
2783 struct user_namespace *ns = NULL;
2784 struct task_struct *task;
2785 int ret;
2786
2787 ret = -ESRCH;
2788 task = get_proc_task(inode);
2789 if (task) {
2790 rcu_read_lock();
2791 ns = get_user_ns(task_cred_xxx(task, user_ns));
2792 rcu_read_unlock();
2793 put_task_struct(task);
2794 }
2795 if (!ns)
2796 goto err;
2797
2798 if (file->f_mode & FMODE_WRITE) {
2799 ret = -EACCES;
2800 if (!ns_capable(ns, CAP_SYS_ADMIN))
2801 goto err_put_ns;
2802 }
2803
2804 ret = single_open(file, &proc_setgroups_show, ns);
2805 if (ret)
2806 goto err_put_ns;
2807
2808 return 0;
2809err_put_ns:
2810 put_user_ns(ns);
2811err:
2812 return ret;
2813}
2814
2815static int proc_setgroups_release(struct inode *inode, struct file *file)
2816{
2817 struct seq_file *seq = file->private_data;
2818 struct user_namespace *ns = seq->private;
2819 int ret = single_release(inode, file);
2820 put_user_ns(ns);
2821 return ret;
2822}
2823
2824static const struct file_operations proc_setgroups_operations = {
2825 .open = proc_setgroups_open,
2826 .write = proc_setgroups_write,
2827 .read = seq_read,
2828 .llseek = seq_lseek,
2829 .release = proc_setgroups_release,
2830};
2831#endif /* CONFIG_USER_NS */
2832
2833static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2834 struct pid *pid, struct task_struct *task)
2835{
2836 int err = lock_trace(task);
2837 if (!err) {
2838 seq_printf(m, "%08x\n", task->personality);
2839 unlock_trace(task);
2840 }
2841 return err;
2842}
2843
2844/*
2845 * Thread groups
2846 */
2847static const struct file_operations proc_task_operations;
2848static const struct inode_operations proc_task_inode_operations;
2849
2850static const struct pid_entry tgid_base_stuff[] = {
2851 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2852 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2853 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2854 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2855 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2856#ifdef CONFIG_NET
2857 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2858#endif
2859 REG("environ", S_IRUSR, proc_environ_operations),
2860 REG("auxv", S_IRUSR, proc_auxv_operations),
2861 ONE("status", S_IRUGO, proc_pid_status),
2862 ONE("personality", S_IRUSR, proc_pid_personality),
2863 ONE("limits", S_IRUGO, proc_pid_limits),
2864#ifdef CONFIG_SCHED_DEBUG
2865 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2866#endif
2867#ifdef CONFIG_SCHED_AUTOGROUP
2868 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2869#endif
2870 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2871#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2872 ONE("syscall", S_IRUSR, proc_pid_syscall),
2873#endif
2874 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
2875 ONE("stat", S_IRUGO, proc_tgid_stat),
2876 ONE("statm", S_IRUGO, proc_pid_statm),
2877 REG("maps", S_IRUGO, proc_pid_maps_operations),
2878#ifdef CONFIG_NUMA
2879 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2880#endif
2881 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2882 LNK("cwd", proc_cwd_link),
2883 LNK("root", proc_root_link),
2884 LNK("exe", proc_exe_link),
2885 REG("mounts", S_IRUGO, proc_mounts_operations),
2886 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2887 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2888#ifdef CONFIG_PROC_PAGE_MONITOR
2889 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2890 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2891 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2892#endif
2893#ifdef CONFIG_SECURITY
2894 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2895#endif
2896#ifdef CONFIG_KALLSYMS
2897 ONE("wchan", S_IRUGO, proc_pid_wchan),
2898#endif
2899#ifdef CONFIG_STACKTRACE
2900 ONE("stack", S_IRUSR, proc_pid_stack),
2901#endif
2902#ifdef CONFIG_SCHED_INFO
2903 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
2904#endif
2905#ifdef CONFIG_LATENCYTOP
2906 REG("latency", S_IRUGO, proc_lstats_operations),
2907#endif
2908#ifdef CONFIG_PROC_PID_CPUSET
2909 ONE("cpuset", S_IRUGO, proc_cpuset_show),
2910#endif
2911#ifdef CONFIG_CGROUPS
2912 ONE("cgroup", S_IRUGO, proc_cgroup_show),
2913#endif
2914 ONE("oom_score", S_IRUGO, proc_oom_score),
2915 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2916 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2917#ifdef CONFIG_AUDITSYSCALL
2918 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2919 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2920#endif
2921#ifdef CONFIG_FAULT_INJECTION
2922 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2923#endif
2924#ifdef CONFIG_ELF_CORE
2925 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2926#endif
2927#ifdef CONFIG_TASK_IO_ACCOUNTING
2928 ONE("io", S_IRUSR, proc_tgid_io_accounting),
2929#endif
2930#ifdef CONFIG_HARDWALL
2931 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
2932#endif
2933#ifdef CONFIG_USER_NS
2934 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2935 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2936 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2937 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
2938#endif
2939#ifdef CONFIG_CHECKPOINT_RESTORE
2940 REG("timers", S_IRUGO, proc_timers_operations),
2941#endif
2942 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
2943};
2944
2945static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
2946{
2947 return proc_pident_readdir(file, ctx,
2948 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2949}
2950
2951static const struct file_operations proc_tgid_base_operations = {
2952 .read = generic_read_dir,
2953 .iterate_shared = proc_tgid_base_readdir,
2954 .llseek = generic_file_llseek,
2955};
2956
2957static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2958{
2959 return proc_pident_lookup(dir, dentry,
2960 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2961}
2962
2963static const struct inode_operations proc_tgid_base_inode_operations = {
2964 .lookup = proc_tgid_base_lookup,
2965 .getattr = pid_getattr,
2966 .setattr = proc_setattr,
2967 .permission = proc_pid_permission,
2968};
2969
2970static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2971{
2972 struct dentry *dentry, *leader, *dir;
2973 char buf[PROC_NUMBUF];
2974 struct qstr name;
2975
2976 name.name = buf;
2977 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2978 /* no ->d_hash() rejects on procfs */
2979 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2980 if (dentry) {
2981 d_invalidate(dentry);
2982 dput(dentry);
2983 }
2984
2985 if (pid == tgid)
2986 return;
2987
2988 name.name = buf;
2989 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2990 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2991 if (!leader)
2992 goto out;
2993
2994 name.name = "task";
2995 name.len = strlen(name.name);
2996 dir = d_hash_and_lookup(leader, &name);
2997 if (!dir)
2998 goto out_put_leader;
2999
3000 name.name = buf;
3001 name.len = snprintf(buf, sizeof(buf), "%d", pid);
3002 dentry = d_hash_and_lookup(dir, &name);
3003 if (dentry) {
3004 d_invalidate(dentry);
3005 dput(dentry);
3006 }
3007
3008 dput(dir);
3009out_put_leader:
3010 dput(leader);
3011out:
3012 return;
3013}
3014
3015/**
3016 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3017 * @task: task that should be flushed.
3018 *
3019 * When flushing dentries from proc, one needs to flush them from global
3020 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3021 * in. This call is supposed to do all of this job.
3022 *
3023 * Looks in the dcache for
3024 * /proc/@pid
3025 * /proc/@tgid/task/@pid
3026 * if either directory is present flushes it and all of it'ts children
3027 * from the dcache.
3028 *
3029 * It is safe and reasonable to cache /proc entries for a task until
3030 * that task exits. After that they just clog up the dcache with
3031 * useless entries, possibly causing useful dcache entries to be
3032 * flushed instead. This routine is proved to flush those useless
3033 * dcache entries at process exit time.
3034 *
3035 * NOTE: This routine is just an optimization so it does not guarantee
3036 * that no dcache entries will exist at process exit time it
3037 * just makes it very unlikely that any will persist.
3038 */
3039
3040void proc_flush_task(struct task_struct *task)
3041{
3042 int i;
3043 struct pid *pid, *tgid;
3044 struct upid *upid;
3045
3046 pid = task_pid(task);
3047 tgid = task_tgid(task);
3048
3049 for (i = 0; i <= pid->level; i++) {
3050 upid = &pid->numbers[i];
3051 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3052 tgid->numbers[i].nr);
3053 }
3054}
3055
3056static int proc_pid_instantiate(struct inode *dir,
3057 struct dentry * dentry,
3058 struct task_struct *task, const void *ptr)
3059{
3060 struct inode *inode;
3061
3062 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3063 if (!inode)
3064 goto out;
3065
3066 inode->i_op = &proc_tgid_base_inode_operations;
3067 inode->i_fop = &proc_tgid_base_operations;
3068 inode->i_flags|=S_IMMUTABLE;
3069
3070 set_nlink(inode, nlink_tgid);
3071
3072 d_set_d_op(dentry, &pid_dentry_operations);
3073
3074 d_add(dentry, inode);
3075 /* Close the race of the process dying before we return the dentry */
3076 if (pid_revalidate(dentry, 0))
3077 return 0;
3078out:
3079 return -ENOENT;
3080}
3081
3082struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3083{
3084 int result = -ENOENT;
3085 struct task_struct *task;
3086 unsigned tgid;
3087 struct pid_namespace *ns;
3088
3089 tgid = name_to_int(&dentry->d_name);
3090 if (tgid == ~0U)
3091 goto out;
3092
3093 ns = dentry->d_sb->s_fs_info;
3094 rcu_read_lock();
3095 task = find_task_by_pid_ns(tgid, ns);
3096 if (task)
3097 get_task_struct(task);
3098 rcu_read_unlock();
3099 if (!task)
3100 goto out;
3101
3102 result = proc_pid_instantiate(dir, dentry, task, NULL);
3103 put_task_struct(task);
3104out:
3105 return ERR_PTR(result);
3106}
3107
3108/*
3109 * Find the first task with tgid >= tgid
3110 *
3111 */
3112struct tgid_iter {
3113 unsigned int tgid;
3114 struct task_struct *task;
3115};
3116static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3117{
3118 struct pid *pid;
3119
3120 if (iter.task)
3121 put_task_struct(iter.task);
3122 rcu_read_lock();
3123retry:
3124 iter.task = NULL;
3125 pid = find_ge_pid(iter.tgid, ns);
3126 if (pid) {
3127 iter.tgid = pid_nr_ns(pid, ns);
3128 iter.task = pid_task(pid, PIDTYPE_PID);
3129 /* What we to know is if the pid we have find is the
3130 * pid of a thread_group_leader. Testing for task
3131 * being a thread_group_leader is the obvious thing
3132 * todo but there is a window when it fails, due to
3133 * the pid transfer logic in de_thread.
3134 *
3135 * So we perform the straight forward test of seeing
3136 * if the pid we have found is the pid of a thread
3137 * group leader, and don't worry if the task we have
3138 * found doesn't happen to be a thread group leader.
3139 * As we don't care in the case of readdir.
3140 */
3141 if (!iter.task || !has_group_leader_pid(iter.task)) {
3142 iter.tgid += 1;
3143 goto retry;
3144 }
3145 get_task_struct(iter.task);
3146 }
3147 rcu_read_unlock();
3148 return iter;
3149}
3150
3151#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3152
3153/* for the /proc/ directory itself, after non-process stuff has been done */
3154int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3155{
3156 struct tgid_iter iter;
3157 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
3158 loff_t pos = ctx->pos;
3159
3160 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3161 return 0;
3162
3163 if (pos == TGID_OFFSET - 2) {
3164 struct inode *inode = d_inode(ns->proc_self);
3165 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3166 return 0;
3167 ctx->pos = pos = pos + 1;
3168 }
3169 if (pos == TGID_OFFSET - 1) {
3170 struct inode *inode = d_inode(ns->proc_thread_self);
3171 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3172 return 0;
3173 ctx->pos = pos = pos + 1;
3174 }
3175 iter.tgid = pos - TGID_OFFSET;
3176 iter.task = NULL;
3177 for (iter = next_tgid(ns, iter);
3178 iter.task;
3179 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3180 char name[PROC_NUMBUF];
3181 int len;
3182
3183 cond_resched();
3184 if (!has_pid_permissions(ns, iter.task, 2))
3185 continue;
3186
3187 len = snprintf(name, sizeof(name), "%d", iter.tgid);
3188 ctx->pos = iter.tgid + TGID_OFFSET;
3189 if (!proc_fill_cache(file, ctx, name, len,
3190 proc_pid_instantiate, iter.task, NULL)) {
3191 put_task_struct(iter.task);
3192 return 0;
3193 }
3194 }
3195 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3196 return 0;
3197}
3198
3199/*
3200 * proc_tid_comm_permission is a special permission function exclusively
3201 * used for the node /proc/<pid>/task/<tid>/comm.
3202 * It bypasses generic permission checks in the case where a task of the same
3203 * task group attempts to access the node.
3204 * The rationale behind this is that glibc and bionic access this node for
3205 * cross thread naming (pthread_set/getname_np(!self)). However, if
3206 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3207 * which locks out the cross thread naming implementation.
3208 * This function makes sure that the node is always accessible for members of
3209 * same thread group.
3210 */
3211static int proc_tid_comm_permission(struct inode *inode, int mask)
3212{
3213 bool is_same_tgroup;
3214 struct task_struct *task;
3215
3216 task = get_proc_task(inode);
3217 if (!task)
3218 return -ESRCH;
3219 is_same_tgroup = same_thread_group(current, task);
3220 put_task_struct(task);
3221
3222 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3223 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3224 * read or written by the members of the corresponding
3225 * thread group.
3226 */
3227 return 0;
3228 }
3229
3230 return generic_permission(inode, mask);
3231}
3232
3233static const struct inode_operations proc_tid_comm_inode_operations = {
3234 .permission = proc_tid_comm_permission,
3235};
3236
3237/*
3238 * Tasks
3239 */
3240static const struct pid_entry tid_base_stuff[] = {
3241 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3242 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3243 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3244#ifdef CONFIG_NET
3245 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3246#endif
3247 REG("environ", S_IRUSR, proc_environ_operations),
3248 REG("auxv", S_IRUSR, proc_auxv_operations),
3249 ONE("status", S_IRUGO, proc_pid_status),
3250 ONE("personality", S_IRUSR, proc_pid_personality),
3251 ONE("limits", S_IRUGO, proc_pid_limits),
3252#ifdef CONFIG_SCHED_DEBUG
3253 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3254#endif
3255 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3256 &proc_tid_comm_inode_operations,
3257 &proc_pid_set_comm_operations, {}),
3258#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3259 ONE("syscall", S_IRUSR, proc_pid_syscall),
3260#endif
3261 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3262 ONE("stat", S_IRUGO, proc_tid_stat),
3263 ONE("statm", S_IRUGO, proc_pid_statm),
3264 REG("maps", S_IRUGO, proc_tid_maps_operations),
3265#ifdef CONFIG_PROC_CHILDREN
3266 REG("children", S_IRUGO, proc_tid_children_operations),
3267#endif
3268#ifdef CONFIG_NUMA
3269 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3270#endif
3271 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3272 LNK("cwd", proc_cwd_link),
3273 LNK("root", proc_root_link),
3274 LNK("exe", proc_exe_link),
3275 REG("mounts", S_IRUGO, proc_mounts_operations),
3276 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3277#ifdef CONFIG_PROC_PAGE_MONITOR
3278 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3279 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3280 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3281#endif
3282#ifdef CONFIG_SECURITY
3283 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3284#endif
3285#ifdef CONFIG_KALLSYMS
3286 ONE("wchan", S_IRUGO, proc_pid_wchan),
3287#endif
3288#ifdef CONFIG_STACKTRACE
3289 ONE("stack", S_IRUSR, proc_pid_stack),
3290#endif
3291#ifdef CONFIG_SCHED_INFO
3292 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3293#endif
3294#ifdef CONFIG_LATENCYTOP
3295 REG("latency", S_IRUGO, proc_lstats_operations),
3296#endif
3297#ifdef CONFIG_PROC_PID_CPUSET
3298 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3299#endif
3300#ifdef CONFIG_CGROUPS
3301 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3302#endif
3303 ONE("oom_score", S_IRUGO, proc_oom_score),
3304 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3305 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3306#ifdef CONFIG_AUDITSYSCALL
3307 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3308 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3309#endif
3310#ifdef CONFIG_FAULT_INJECTION
3311 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3312#endif
3313#ifdef CONFIG_TASK_IO_ACCOUNTING
3314 ONE("io", S_IRUSR, proc_tid_io_accounting),
3315#endif
3316#ifdef CONFIG_HARDWALL
3317 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
3318#endif
3319#ifdef CONFIG_USER_NS
3320 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3321 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3322 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3323 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3324#endif
3325};
3326
3327static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3328{
3329 return proc_pident_readdir(file, ctx,
3330 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3331}
3332
3333static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3334{
3335 return proc_pident_lookup(dir, dentry,
3336 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3337}
3338
3339static const struct file_operations proc_tid_base_operations = {
3340 .read = generic_read_dir,
3341 .iterate_shared = proc_tid_base_readdir,
3342 .llseek = generic_file_llseek,
3343};
3344
3345static const struct inode_operations proc_tid_base_inode_operations = {
3346 .lookup = proc_tid_base_lookup,
3347 .getattr = pid_getattr,
3348 .setattr = proc_setattr,
3349};
3350
3351static int proc_task_instantiate(struct inode *dir,
3352 struct dentry *dentry, struct task_struct *task, const void *ptr)
3353{
3354 struct inode *inode;
3355 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3356
3357 if (!inode)
3358 goto out;
3359 inode->i_op = &proc_tid_base_inode_operations;
3360 inode->i_fop = &proc_tid_base_operations;
3361 inode->i_flags|=S_IMMUTABLE;
3362
3363 set_nlink(inode, nlink_tid);
3364
3365 d_set_d_op(dentry, &pid_dentry_operations);
3366
3367 d_add(dentry, inode);
3368 /* Close the race of the process dying before we return the dentry */
3369 if (pid_revalidate(dentry, 0))
3370 return 0;
3371out:
3372 return -ENOENT;
3373}
3374
3375static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3376{
3377 int result = -ENOENT;
3378 struct task_struct *task;
3379 struct task_struct *leader = get_proc_task(dir);
3380 unsigned tid;
3381 struct pid_namespace *ns;
3382
3383 if (!leader)
3384 goto out_no_task;
3385
3386 tid = name_to_int(&dentry->d_name);
3387 if (tid == ~0U)
3388 goto out;
3389
3390 ns = dentry->d_sb->s_fs_info;
3391 rcu_read_lock();
3392 task = find_task_by_pid_ns(tid, ns);
3393 if (task)
3394 get_task_struct(task);
3395 rcu_read_unlock();
3396 if (!task)
3397 goto out;
3398 if (!same_thread_group(leader, task))
3399 goto out_drop_task;
3400
3401 result = proc_task_instantiate(dir, dentry, task, NULL);
3402out_drop_task:
3403 put_task_struct(task);
3404out:
3405 put_task_struct(leader);
3406out_no_task:
3407 return ERR_PTR(result);
3408}
3409
3410/*
3411 * Find the first tid of a thread group to return to user space.
3412 *
3413 * Usually this is just the thread group leader, but if the users
3414 * buffer was too small or there was a seek into the middle of the
3415 * directory we have more work todo.
3416 *
3417 * In the case of a short read we start with find_task_by_pid.
3418 *
3419 * In the case of a seek we start with the leader and walk nr
3420 * threads past it.
3421 */
3422static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3423 struct pid_namespace *ns)
3424{
3425 struct task_struct *pos, *task;
3426 unsigned long nr = f_pos;
3427
3428 if (nr != f_pos) /* 32bit overflow? */
3429 return NULL;
3430
3431 rcu_read_lock();
3432 task = pid_task(pid, PIDTYPE_PID);
3433 if (!task)
3434 goto fail;
3435
3436 /* Attempt to start with the tid of a thread */
3437 if (tid && nr) {
3438 pos = find_task_by_pid_ns(tid, ns);
3439 if (pos && same_thread_group(pos, task))
3440 goto found;
3441 }
3442
3443 /* If nr exceeds the number of threads there is nothing todo */
3444 if (nr >= get_nr_threads(task))
3445 goto fail;
3446
3447 /* If we haven't found our starting place yet start
3448 * with the leader and walk nr threads forward.
3449 */
3450 pos = task = task->group_leader;
3451 do {
3452 if (!nr--)
3453 goto found;
3454 } while_each_thread(task, pos);
3455fail:
3456 pos = NULL;
3457 goto out;
3458found:
3459 get_task_struct(pos);
3460out:
3461 rcu_read_unlock();
3462 return pos;
3463}
3464
3465/*
3466 * Find the next thread in the thread list.
3467 * Return NULL if there is an error or no next thread.
3468 *
3469 * The reference to the input task_struct is released.
3470 */
3471static struct task_struct *next_tid(struct task_struct *start)
3472{
3473 struct task_struct *pos = NULL;
3474 rcu_read_lock();
3475 if (pid_alive(start)) {
3476 pos = next_thread(start);
3477 if (thread_group_leader(pos))
3478 pos = NULL;
3479 else
3480 get_task_struct(pos);
3481 }
3482 rcu_read_unlock();
3483 put_task_struct(start);
3484 return pos;
3485}
3486
3487/* for the /proc/TGID/task/ directories */
3488static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3489{
3490 struct inode *inode = file_inode(file);
3491 struct task_struct *task;
3492 struct pid_namespace *ns;
3493 int tid;
3494
3495 if (proc_inode_is_dead(inode))
3496 return -ENOENT;
3497
3498 if (!dir_emit_dots(file, ctx))
3499 return 0;
3500
3501 /* f_version caches the tgid value that the last readdir call couldn't
3502 * return. lseek aka telldir automagically resets f_version to 0.
3503 */
3504 ns = inode->i_sb->s_fs_info;
3505 tid = (int)file->f_version;
3506 file->f_version = 0;
3507 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3508 task;
3509 task = next_tid(task), ctx->pos++) {
3510 char name[PROC_NUMBUF];
3511 int len;
3512 tid = task_pid_nr_ns(task, ns);
3513 len = snprintf(name, sizeof(name), "%d", tid);
3514 if (!proc_fill_cache(file, ctx, name, len,
3515 proc_task_instantiate, task, NULL)) {
3516 /* returning this tgid failed, save it as the first
3517 * pid for the next readir call */
3518 file->f_version = (u64)tid;
3519 put_task_struct(task);
3520 break;
3521 }
3522 }
3523
3524 return 0;
3525}
3526
3527static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3528{
3529 struct inode *inode = d_inode(dentry);
3530 struct task_struct *p = get_proc_task(inode);
3531 generic_fillattr(inode, stat);
3532
3533 if (p) {
3534 stat->nlink += get_nr_threads(p);
3535 put_task_struct(p);
3536 }
3537
3538 return 0;
3539}
3540
3541static const struct inode_operations proc_task_inode_operations = {
3542 .lookup = proc_task_lookup,
3543 .getattr = proc_task_getattr,
3544 .setattr = proc_setattr,
3545 .permission = proc_pid_permission,
3546};
3547
3548static const struct file_operations proc_task_operations = {
3549 .read = generic_read_dir,
3550 .iterate_shared = proc_task_readdir,
3551 .llseek = generic_file_llseek,
3552};
3553
3554void __init set_proc_pid_nlink(void)
3555{
3556 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3557 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3558}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/proc/base.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * proc base directory handling functions
8 *
9 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
10 * Instead of using magical inumbers to determine the kind of object
11 * we allocate and fill in-core inodes upon lookup. They don't even
12 * go into icache. We cache the reference to task_struct upon lookup too.
13 * Eventually it should become a filesystem in its own. We don't use the
14 * rest of procfs anymore.
15 *
16 *
17 * Changelog:
18 * 17-Jan-2005
19 * Allan Bezerra
20 * Bruna Moreira <bruna.moreira@indt.org.br>
21 * Edjard Mota <edjard.mota@indt.org.br>
22 * Ilias Biris <ilias.biris@indt.org.br>
23 * Mauricio Lin <mauricio.lin@indt.org.br>
24 *
25 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
26 *
27 * A new process specific entry (smaps) included in /proc. It shows the
28 * size of rss for each memory area. The maps entry lacks information
29 * about physical memory size (rss) for each mapped file, i.e.,
30 * rss information for executables and library files.
31 * This additional information is useful for any tools that need to know
32 * about physical memory consumption for a process specific library.
33 *
34 * Changelog:
35 * 21-Feb-2005
36 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
37 * Pud inclusion in the page table walking.
38 *
39 * ChangeLog:
40 * 10-Mar-2005
41 * 10LE Instituto Nokia de Tecnologia - INdT:
42 * A better way to walks through the page table as suggested by Hugh Dickins.
43 *
44 * Simo Piiroinen <simo.piiroinen@nokia.com>:
45 * Smaps information related to shared, private, clean and dirty pages.
46 *
47 * Paul Mundt <paul.mundt@nokia.com>:
48 * Overall revision about smaps.
49 */
50
51#include <linux/uaccess.h>
52
53#include <linux/errno.h>
54#include <linux/time.h>
55#include <linux/proc_fs.h>
56#include <linux/stat.h>
57#include <linux/task_io_accounting_ops.h>
58#include <linux/init.h>
59#include <linux/capability.h>
60#include <linux/file.h>
61#include <linux/fdtable.h>
62#include <linux/generic-radix-tree.h>
63#include <linux/string.h>
64#include <linux/seq_file.h>
65#include <linux/namei.h>
66#include <linux/mnt_namespace.h>
67#include <linux/mm.h>
68#include <linux/swap.h>
69#include <linux/rcupdate.h>
70#include <linux/kallsyms.h>
71#include <linux/stacktrace.h>
72#include <linux/resource.h>
73#include <linux/module.h>
74#include <linux/mount.h>
75#include <linux/security.h>
76#include <linux/ptrace.h>
77#include <linux/printk.h>
78#include <linux/cache.h>
79#include <linux/cgroup.h>
80#include <linux/cpuset.h>
81#include <linux/audit.h>
82#include <linux/poll.h>
83#include <linux/nsproxy.h>
84#include <linux/oom.h>
85#include <linux/elf.h>
86#include <linux/pid_namespace.h>
87#include <linux/user_namespace.h>
88#include <linux/fs_struct.h>
89#include <linux/slab.h>
90#include <linux/sched/autogroup.h>
91#include <linux/sched/mm.h>
92#include <linux/sched/coredump.h>
93#include <linux/sched/debug.h>
94#include <linux/sched/stat.h>
95#include <linux/posix-timers.h>
96#include <linux/time_namespace.h>
97#include <linux/resctrl.h>
98#include <linux/cn_proc.h>
99#include <linux/ksm.h>
100#include <uapi/linux/lsm.h>
101#include <trace/events/oom.h>
102#include "internal.h"
103#include "fd.h"
104
105#include "../../lib/kstrtox.h"
106
107/* NOTE:
108 * Implementing inode permission operations in /proc is almost
109 * certainly an error. Permission checks need to happen during
110 * each system call not at open time. The reason is that most of
111 * what we wish to check for permissions in /proc varies at runtime.
112 *
113 * The classic example of a problem is opening file descriptors
114 * in /proc for a task before it execs a suid executable.
115 */
116
117static u8 nlink_tid __ro_after_init;
118static u8 nlink_tgid __ro_after_init;
119
120struct pid_entry {
121 const char *name;
122 unsigned int len;
123 umode_t mode;
124 const struct inode_operations *iop;
125 const struct file_operations *fop;
126 union proc_op op;
127};
128
129#define NOD(NAME, MODE, IOP, FOP, OP) { \
130 .name = (NAME), \
131 .len = sizeof(NAME) - 1, \
132 .mode = MODE, \
133 .iop = IOP, \
134 .fop = FOP, \
135 .op = OP, \
136}
137
138#define DIR(NAME, MODE, iops, fops) \
139 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
140#define LNK(NAME, get_link) \
141 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
142 &proc_pid_link_inode_operations, NULL, \
143 { .proc_get_link = get_link } )
144#define REG(NAME, MODE, fops) \
145 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
146#define ONE(NAME, MODE, show) \
147 NOD(NAME, (S_IFREG|(MODE)), \
148 NULL, &proc_single_file_operations, \
149 { .proc_show = show } )
150#define ATTR(LSMID, NAME, MODE) \
151 NOD(NAME, (S_IFREG|(MODE)), \
152 NULL, &proc_pid_attr_operations, \
153 { .lsmid = LSMID })
154
155/*
156 * Count the number of hardlinks for the pid_entry table, excluding the .
157 * and .. links.
158 */
159static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
160 unsigned int n)
161{
162 unsigned int i;
163 unsigned int count;
164
165 count = 2;
166 for (i = 0; i < n; ++i) {
167 if (S_ISDIR(entries[i].mode))
168 ++count;
169 }
170
171 return count;
172}
173
174static int get_task_root(struct task_struct *task, struct path *root)
175{
176 int result = -ENOENT;
177
178 task_lock(task);
179 if (task->fs) {
180 get_fs_root(task->fs, root);
181 result = 0;
182 }
183 task_unlock(task);
184 return result;
185}
186
187static int proc_cwd_link(struct dentry *dentry, struct path *path)
188{
189 struct task_struct *task = get_proc_task(d_inode(dentry));
190 int result = -ENOENT;
191
192 if (task) {
193 task_lock(task);
194 if (task->fs) {
195 get_fs_pwd(task->fs, path);
196 result = 0;
197 }
198 task_unlock(task);
199 put_task_struct(task);
200 }
201 return result;
202}
203
204static int proc_root_link(struct dentry *dentry, struct path *path)
205{
206 struct task_struct *task = get_proc_task(d_inode(dentry));
207 int result = -ENOENT;
208
209 if (task) {
210 result = get_task_root(task, path);
211 put_task_struct(task);
212 }
213 return result;
214}
215
216/*
217 * If the user used setproctitle(), we just get the string from
218 * user space at arg_start, and limit it to a maximum of one page.
219 */
220static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
221 size_t count, unsigned long pos,
222 unsigned long arg_start)
223{
224 char *page;
225 int ret, got;
226
227 if (pos >= PAGE_SIZE)
228 return 0;
229
230 page = (char *)__get_free_page(GFP_KERNEL);
231 if (!page)
232 return -ENOMEM;
233
234 ret = 0;
235 got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
236 if (got > 0) {
237 int len = strnlen(page, got);
238
239 /* Include the NUL character if it was found */
240 if (len < got)
241 len++;
242
243 if (len > pos) {
244 len -= pos;
245 if (len > count)
246 len = count;
247 len -= copy_to_user(buf, page+pos, len);
248 if (!len)
249 len = -EFAULT;
250 ret = len;
251 }
252 }
253 free_page((unsigned long)page);
254 return ret;
255}
256
257static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
258 size_t count, loff_t *ppos)
259{
260 unsigned long arg_start, arg_end, env_start, env_end;
261 unsigned long pos, len;
262 char *page, c;
263
264 /* Check if process spawned far enough to have cmdline. */
265 if (!mm->env_end)
266 return 0;
267
268 spin_lock(&mm->arg_lock);
269 arg_start = mm->arg_start;
270 arg_end = mm->arg_end;
271 env_start = mm->env_start;
272 env_end = mm->env_end;
273 spin_unlock(&mm->arg_lock);
274
275 if (arg_start >= arg_end)
276 return 0;
277
278 /*
279 * We allow setproctitle() to overwrite the argument
280 * strings, and overflow past the original end. But
281 * only when it overflows into the environment area.
282 */
283 if (env_start != arg_end || env_end < env_start)
284 env_start = env_end = arg_end;
285 len = env_end - arg_start;
286
287 /* We're not going to care if "*ppos" has high bits set */
288 pos = *ppos;
289 if (pos >= len)
290 return 0;
291 if (count > len - pos)
292 count = len - pos;
293 if (!count)
294 return 0;
295
296 /*
297 * Magical special case: if the argv[] end byte is not
298 * zero, the user has overwritten it with setproctitle(3).
299 *
300 * Possible future enhancement: do this only once when
301 * pos is 0, and set a flag in the 'struct file'.
302 */
303 if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
304 return get_mm_proctitle(mm, buf, count, pos, arg_start);
305
306 /*
307 * For the non-setproctitle() case we limit things strictly
308 * to the [arg_start, arg_end[ range.
309 */
310 pos += arg_start;
311 if (pos < arg_start || pos >= arg_end)
312 return 0;
313 if (count > arg_end - pos)
314 count = arg_end - pos;
315
316 page = (char *)__get_free_page(GFP_KERNEL);
317 if (!page)
318 return -ENOMEM;
319
320 len = 0;
321 while (count) {
322 int got;
323 size_t size = min_t(size_t, PAGE_SIZE, count);
324
325 got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
326 if (got <= 0)
327 break;
328 got -= copy_to_user(buf, page, got);
329 if (unlikely(!got)) {
330 if (!len)
331 len = -EFAULT;
332 break;
333 }
334 pos += got;
335 buf += got;
336 len += got;
337 count -= got;
338 }
339
340 free_page((unsigned long)page);
341 return len;
342}
343
344static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
345 size_t count, loff_t *pos)
346{
347 struct mm_struct *mm;
348 ssize_t ret;
349
350 mm = get_task_mm(tsk);
351 if (!mm)
352 return 0;
353
354 ret = get_mm_cmdline(mm, buf, count, pos);
355 mmput(mm);
356 return ret;
357}
358
359static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
360 size_t count, loff_t *pos)
361{
362 struct task_struct *tsk;
363 ssize_t ret;
364
365 BUG_ON(*pos < 0);
366
367 tsk = get_proc_task(file_inode(file));
368 if (!tsk)
369 return -ESRCH;
370 ret = get_task_cmdline(tsk, buf, count, pos);
371 put_task_struct(tsk);
372 if (ret > 0)
373 *pos += ret;
374 return ret;
375}
376
377static const struct file_operations proc_pid_cmdline_ops = {
378 .read = proc_pid_cmdline_read,
379 .llseek = generic_file_llseek,
380};
381
382#ifdef CONFIG_KALLSYMS
383/*
384 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
385 * Returns the resolved symbol. If that fails, simply return the address.
386 */
387static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
388 struct pid *pid, struct task_struct *task)
389{
390 unsigned long wchan;
391 char symname[KSYM_NAME_LEN];
392
393 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
394 goto print0;
395
396 wchan = get_wchan(task);
397 if (wchan && !lookup_symbol_name(wchan, symname)) {
398 seq_puts(m, symname);
399 return 0;
400 }
401
402print0:
403 seq_putc(m, '0');
404 return 0;
405}
406#endif /* CONFIG_KALLSYMS */
407
408static int lock_trace(struct task_struct *task)
409{
410 int err = down_read_killable(&task->signal->exec_update_lock);
411 if (err)
412 return err;
413 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
414 up_read(&task->signal->exec_update_lock);
415 return -EPERM;
416 }
417 return 0;
418}
419
420static void unlock_trace(struct task_struct *task)
421{
422 up_read(&task->signal->exec_update_lock);
423}
424
425#ifdef CONFIG_STACKTRACE
426
427#define MAX_STACK_TRACE_DEPTH 64
428
429static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
430 struct pid *pid, struct task_struct *task)
431{
432 unsigned long *entries;
433 int err;
434
435 /*
436 * The ability to racily run the kernel stack unwinder on a running task
437 * and then observe the unwinder output is scary; while it is useful for
438 * debugging kernel issues, it can also allow an attacker to leak kernel
439 * stack contents.
440 * Doing this in a manner that is at least safe from races would require
441 * some work to ensure that the remote task can not be scheduled; and
442 * even then, this would still expose the unwinder as local attack
443 * surface.
444 * Therefore, this interface is restricted to root.
445 */
446 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
447 return -EACCES;
448
449 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
450 GFP_KERNEL);
451 if (!entries)
452 return -ENOMEM;
453
454 err = lock_trace(task);
455 if (!err) {
456 unsigned int i, nr_entries;
457
458 nr_entries = stack_trace_save_tsk(task, entries,
459 MAX_STACK_TRACE_DEPTH, 0);
460
461 for (i = 0; i < nr_entries; i++) {
462 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
463 }
464
465 unlock_trace(task);
466 }
467 kfree(entries);
468
469 return err;
470}
471#endif
472
473#ifdef CONFIG_SCHED_INFO
474/*
475 * Provides /proc/PID/schedstat
476 */
477static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
478 struct pid *pid, struct task_struct *task)
479{
480 if (unlikely(!sched_info_on()))
481 seq_puts(m, "0 0 0\n");
482 else
483 seq_printf(m, "%llu %llu %lu\n",
484 (unsigned long long)task->se.sum_exec_runtime,
485 (unsigned long long)task->sched_info.run_delay,
486 task->sched_info.pcount);
487
488 return 0;
489}
490#endif
491
492#ifdef CONFIG_LATENCYTOP
493static int lstats_show_proc(struct seq_file *m, void *v)
494{
495 int i;
496 struct inode *inode = m->private;
497 struct task_struct *task = get_proc_task(inode);
498
499 if (!task)
500 return -ESRCH;
501 seq_puts(m, "Latency Top version : v0.1\n");
502 for (i = 0; i < LT_SAVECOUNT; i++) {
503 struct latency_record *lr = &task->latency_record[i];
504 if (lr->backtrace[0]) {
505 int q;
506 seq_printf(m, "%i %li %li",
507 lr->count, lr->time, lr->max);
508 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
509 unsigned long bt = lr->backtrace[q];
510
511 if (!bt)
512 break;
513 seq_printf(m, " %ps", (void *)bt);
514 }
515 seq_putc(m, '\n');
516 }
517
518 }
519 put_task_struct(task);
520 return 0;
521}
522
523static int lstats_open(struct inode *inode, struct file *file)
524{
525 return single_open(file, lstats_show_proc, inode);
526}
527
528static ssize_t lstats_write(struct file *file, const char __user *buf,
529 size_t count, loff_t *offs)
530{
531 struct task_struct *task = get_proc_task(file_inode(file));
532
533 if (!task)
534 return -ESRCH;
535 clear_tsk_latency_tracing(task);
536 put_task_struct(task);
537
538 return count;
539}
540
541static const struct file_operations proc_lstats_operations = {
542 .open = lstats_open,
543 .read = seq_read,
544 .write = lstats_write,
545 .llseek = seq_lseek,
546 .release = single_release,
547};
548
549#endif
550
551static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
552 struct pid *pid, struct task_struct *task)
553{
554 unsigned long totalpages = totalram_pages() + total_swap_pages;
555 unsigned long points = 0;
556 long badness;
557
558 badness = oom_badness(task, totalpages);
559 /*
560 * Special case OOM_SCORE_ADJ_MIN for all others scale the
561 * badness value into [0, 2000] range which we have been
562 * exporting for a long time so userspace might depend on it.
563 */
564 if (badness != LONG_MIN)
565 points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
566
567 seq_printf(m, "%lu\n", points);
568
569 return 0;
570}
571
572struct limit_names {
573 const char *name;
574 const char *unit;
575};
576
577static const struct limit_names lnames[RLIM_NLIMITS] = {
578 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
579 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
580 [RLIMIT_DATA] = {"Max data size", "bytes"},
581 [RLIMIT_STACK] = {"Max stack size", "bytes"},
582 [RLIMIT_CORE] = {"Max core file size", "bytes"},
583 [RLIMIT_RSS] = {"Max resident set", "bytes"},
584 [RLIMIT_NPROC] = {"Max processes", "processes"},
585 [RLIMIT_NOFILE] = {"Max open files", "files"},
586 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
587 [RLIMIT_AS] = {"Max address space", "bytes"},
588 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
589 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
590 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
591 [RLIMIT_NICE] = {"Max nice priority", NULL},
592 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
593 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
594};
595
596/* Display limits for a process */
597static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
598 struct pid *pid, struct task_struct *task)
599{
600 unsigned int i;
601 unsigned long flags;
602
603 struct rlimit rlim[RLIM_NLIMITS];
604
605 if (!lock_task_sighand(task, &flags))
606 return 0;
607 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
608 unlock_task_sighand(task, &flags);
609
610 /*
611 * print the file header
612 */
613 seq_puts(m, "Limit "
614 "Soft Limit "
615 "Hard Limit "
616 "Units \n");
617
618 for (i = 0; i < RLIM_NLIMITS; i++) {
619 if (rlim[i].rlim_cur == RLIM_INFINITY)
620 seq_printf(m, "%-25s %-20s ",
621 lnames[i].name, "unlimited");
622 else
623 seq_printf(m, "%-25s %-20lu ",
624 lnames[i].name, rlim[i].rlim_cur);
625
626 if (rlim[i].rlim_max == RLIM_INFINITY)
627 seq_printf(m, "%-20s ", "unlimited");
628 else
629 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
630
631 if (lnames[i].unit)
632 seq_printf(m, "%-10s\n", lnames[i].unit);
633 else
634 seq_putc(m, '\n');
635 }
636
637 return 0;
638}
639
640#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
641static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
642 struct pid *pid, struct task_struct *task)
643{
644 struct syscall_info info;
645 u64 *args = &info.data.args[0];
646 int res;
647
648 res = lock_trace(task);
649 if (res)
650 return res;
651
652 if (task_current_syscall(task, &info))
653 seq_puts(m, "running\n");
654 else if (info.data.nr < 0)
655 seq_printf(m, "%d 0x%llx 0x%llx\n",
656 info.data.nr, info.sp, info.data.instruction_pointer);
657 else
658 seq_printf(m,
659 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
660 info.data.nr,
661 args[0], args[1], args[2], args[3], args[4], args[5],
662 info.sp, info.data.instruction_pointer);
663 unlock_trace(task);
664
665 return 0;
666}
667#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
668
669/************************************************************************/
670/* Here the fs part begins */
671/************************************************************************/
672
673/* permission checks */
674static bool proc_fd_access_allowed(struct inode *inode)
675{
676 struct task_struct *task;
677 bool allowed = false;
678 /* Allow access to a task's file descriptors if it is us or we
679 * may use ptrace attach to the process and find out that
680 * information.
681 */
682 task = get_proc_task(inode);
683 if (task) {
684 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
685 put_task_struct(task);
686 }
687 return allowed;
688}
689
690int proc_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
691 struct iattr *attr)
692{
693 int error;
694 struct inode *inode = d_inode(dentry);
695
696 if (attr->ia_valid & ATTR_MODE)
697 return -EPERM;
698
699 error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
700 if (error)
701 return error;
702
703 setattr_copy(&nop_mnt_idmap, inode, attr);
704 return 0;
705}
706
707/*
708 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
709 * or euid/egid (for hide_pid_min=2)?
710 */
711static bool has_pid_permissions(struct proc_fs_info *fs_info,
712 struct task_struct *task,
713 enum proc_hidepid hide_pid_min)
714{
715 /*
716 * If 'hidpid' mount option is set force a ptrace check,
717 * we indicate that we are using a filesystem syscall
718 * by passing PTRACE_MODE_READ_FSCREDS
719 */
720 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE)
721 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
722
723 if (fs_info->hide_pid < hide_pid_min)
724 return true;
725 if (in_group_p(fs_info->pid_gid))
726 return true;
727 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
728}
729
730
731static int proc_pid_permission(struct mnt_idmap *idmap,
732 struct inode *inode, int mask)
733{
734 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
735 struct task_struct *task;
736 bool has_perms;
737
738 task = get_proc_task(inode);
739 if (!task)
740 return -ESRCH;
741 has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS);
742 put_task_struct(task);
743
744 if (!has_perms) {
745 if (fs_info->hide_pid == HIDEPID_INVISIBLE) {
746 /*
747 * Let's make getdents(), stat(), and open()
748 * consistent with each other. If a process
749 * may not stat() a file, it shouldn't be seen
750 * in procfs at all.
751 */
752 return -ENOENT;
753 }
754
755 return -EPERM;
756 }
757 return generic_permission(&nop_mnt_idmap, inode, mask);
758}
759
760
761
762static const struct inode_operations proc_def_inode_operations = {
763 .setattr = proc_setattr,
764};
765
766static int proc_single_show(struct seq_file *m, void *v)
767{
768 struct inode *inode = m->private;
769 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
770 struct pid *pid = proc_pid(inode);
771 struct task_struct *task;
772 int ret;
773
774 task = get_pid_task(pid, PIDTYPE_PID);
775 if (!task)
776 return -ESRCH;
777
778 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
779
780 put_task_struct(task);
781 return ret;
782}
783
784static int proc_single_open(struct inode *inode, struct file *filp)
785{
786 return single_open(filp, proc_single_show, inode);
787}
788
789static const struct file_operations proc_single_file_operations = {
790 .open = proc_single_open,
791 .read = seq_read,
792 .llseek = seq_lseek,
793 .release = single_release,
794};
795
796
797struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
798{
799 struct task_struct *task = get_proc_task(inode);
800 struct mm_struct *mm = ERR_PTR(-ESRCH);
801
802 if (task) {
803 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
804 put_task_struct(task);
805
806 if (!IS_ERR_OR_NULL(mm)) {
807 /* ensure this mm_struct can't be freed */
808 mmgrab(mm);
809 /* but do not pin its memory */
810 mmput(mm);
811 }
812 }
813
814 return mm;
815}
816
817static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
818{
819 struct mm_struct *mm = proc_mem_open(inode, mode);
820
821 if (IS_ERR(mm))
822 return PTR_ERR(mm);
823
824 file->private_data = mm;
825 return 0;
826}
827
828static int mem_open(struct inode *inode, struct file *file)
829{
830 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
831
832 /* OK to pass negative loff_t, we can catch out-of-range */
833 file->f_mode |= FMODE_UNSIGNED_OFFSET;
834
835 return ret;
836}
837
838static ssize_t mem_rw(struct file *file, char __user *buf,
839 size_t count, loff_t *ppos, int write)
840{
841 struct mm_struct *mm = file->private_data;
842 unsigned long addr = *ppos;
843 ssize_t copied;
844 char *page;
845 unsigned int flags;
846
847 if (!mm)
848 return 0;
849
850 page = (char *)__get_free_page(GFP_KERNEL);
851 if (!page)
852 return -ENOMEM;
853
854 copied = 0;
855 if (!mmget_not_zero(mm))
856 goto free;
857
858 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
859
860 while (count > 0) {
861 size_t this_len = min_t(size_t, count, PAGE_SIZE);
862
863 if (write && copy_from_user(page, buf, this_len)) {
864 copied = -EFAULT;
865 break;
866 }
867
868 this_len = access_remote_vm(mm, addr, page, this_len, flags);
869 if (!this_len) {
870 if (!copied)
871 copied = -EIO;
872 break;
873 }
874
875 if (!write && copy_to_user(buf, page, this_len)) {
876 copied = -EFAULT;
877 break;
878 }
879
880 buf += this_len;
881 addr += this_len;
882 copied += this_len;
883 count -= this_len;
884 }
885 *ppos = addr;
886
887 mmput(mm);
888free:
889 free_page((unsigned long) page);
890 return copied;
891}
892
893static ssize_t mem_read(struct file *file, char __user *buf,
894 size_t count, loff_t *ppos)
895{
896 return mem_rw(file, buf, count, ppos, 0);
897}
898
899static ssize_t mem_write(struct file *file, const char __user *buf,
900 size_t count, loff_t *ppos)
901{
902 return mem_rw(file, (char __user*)buf, count, ppos, 1);
903}
904
905loff_t mem_lseek(struct file *file, loff_t offset, int orig)
906{
907 switch (orig) {
908 case 0:
909 file->f_pos = offset;
910 break;
911 case 1:
912 file->f_pos += offset;
913 break;
914 default:
915 return -EINVAL;
916 }
917 force_successful_syscall_return();
918 return file->f_pos;
919}
920
921static int mem_release(struct inode *inode, struct file *file)
922{
923 struct mm_struct *mm = file->private_data;
924 if (mm)
925 mmdrop(mm);
926 return 0;
927}
928
929static const struct file_operations proc_mem_operations = {
930 .llseek = mem_lseek,
931 .read = mem_read,
932 .write = mem_write,
933 .open = mem_open,
934 .release = mem_release,
935};
936
937static int environ_open(struct inode *inode, struct file *file)
938{
939 return __mem_open(inode, file, PTRACE_MODE_READ);
940}
941
942static ssize_t environ_read(struct file *file, char __user *buf,
943 size_t count, loff_t *ppos)
944{
945 char *page;
946 unsigned long src = *ppos;
947 int ret = 0;
948 struct mm_struct *mm = file->private_data;
949 unsigned long env_start, env_end;
950
951 /* Ensure the process spawned far enough to have an environment. */
952 if (!mm || !mm->env_end)
953 return 0;
954
955 page = (char *)__get_free_page(GFP_KERNEL);
956 if (!page)
957 return -ENOMEM;
958
959 ret = 0;
960 if (!mmget_not_zero(mm))
961 goto free;
962
963 spin_lock(&mm->arg_lock);
964 env_start = mm->env_start;
965 env_end = mm->env_end;
966 spin_unlock(&mm->arg_lock);
967
968 while (count > 0) {
969 size_t this_len, max_len;
970 int retval;
971
972 if (src >= (env_end - env_start))
973 break;
974
975 this_len = env_end - (env_start + src);
976
977 max_len = min_t(size_t, PAGE_SIZE, count);
978 this_len = min(max_len, this_len);
979
980 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
981
982 if (retval <= 0) {
983 ret = retval;
984 break;
985 }
986
987 if (copy_to_user(buf, page, retval)) {
988 ret = -EFAULT;
989 break;
990 }
991
992 ret += retval;
993 src += retval;
994 buf += retval;
995 count -= retval;
996 }
997 *ppos = src;
998 mmput(mm);
999
1000free:
1001 free_page((unsigned long) page);
1002 return ret;
1003}
1004
1005static const struct file_operations proc_environ_operations = {
1006 .open = environ_open,
1007 .read = environ_read,
1008 .llseek = generic_file_llseek,
1009 .release = mem_release,
1010};
1011
1012static int auxv_open(struct inode *inode, struct file *file)
1013{
1014 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1015}
1016
1017static ssize_t auxv_read(struct file *file, char __user *buf,
1018 size_t count, loff_t *ppos)
1019{
1020 struct mm_struct *mm = file->private_data;
1021 unsigned int nwords = 0;
1022
1023 if (!mm)
1024 return 0;
1025 do {
1026 nwords += 2;
1027 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1028 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1029 nwords * sizeof(mm->saved_auxv[0]));
1030}
1031
1032static const struct file_operations proc_auxv_operations = {
1033 .open = auxv_open,
1034 .read = auxv_read,
1035 .llseek = generic_file_llseek,
1036 .release = mem_release,
1037};
1038
1039static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1040 loff_t *ppos)
1041{
1042 struct task_struct *task = get_proc_task(file_inode(file));
1043 char buffer[PROC_NUMBUF];
1044 int oom_adj = OOM_ADJUST_MIN;
1045 size_t len;
1046
1047 if (!task)
1048 return -ESRCH;
1049 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1050 oom_adj = OOM_ADJUST_MAX;
1051 else
1052 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1053 OOM_SCORE_ADJ_MAX;
1054 put_task_struct(task);
1055 if (oom_adj > OOM_ADJUST_MAX)
1056 oom_adj = OOM_ADJUST_MAX;
1057 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1058 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1059}
1060
1061static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1062{
1063 struct mm_struct *mm = NULL;
1064 struct task_struct *task;
1065 int err = 0;
1066
1067 task = get_proc_task(file_inode(file));
1068 if (!task)
1069 return -ESRCH;
1070
1071 mutex_lock(&oom_adj_mutex);
1072 if (legacy) {
1073 if (oom_adj < task->signal->oom_score_adj &&
1074 !capable(CAP_SYS_RESOURCE)) {
1075 err = -EACCES;
1076 goto err_unlock;
1077 }
1078 /*
1079 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1080 * /proc/pid/oom_score_adj instead.
1081 */
1082 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1083 current->comm, task_pid_nr(current), task_pid_nr(task),
1084 task_pid_nr(task));
1085 } else {
1086 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1087 !capable(CAP_SYS_RESOURCE)) {
1088 err = -EACCES;
1089 goto err_unlock;
1090 }
1091 }
1092
1093 /*
1094 * Make sure we will check other processes sharing the mm if this is
1095 * not vfrok which wants its own oom_score_adj.
1096 * pin the mm so it doesn't go away and get reused after task_unlock
1097 */
1098 if (!task->vfork_done) {
1099 struct task_struct *p = find_lock_task_mm(task);
1100
1101 if (p) {
1102 if (test_bit(MMF_MULTIPROCESS, &p->mm->flags)) {
1103 mm = p->mm;
1104 mmgrab(mm);
1105 }
1106 task_unlock(p);
1107 }
1108 }
1109
1110 task->signal->oom_score_adj = oom_adj;
1111 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1112 task->signal->oom_score_adj_min = (short)oom_adj;
1113 trace_oom_score_adj_update(task);
1114
1115 if (mm) {
1116 struct task_struct *p;
1117
1118 rcu_read_lock();
1119 for_each_process(p) {
1120 if (same_thread_group(task, p))
1121 continue;
1122
1123 /* do not touch kernel threads or the global init */
1124 if (p->flags & PF_KTHREAD || is_global_init(p))
1125 continue;
1126
1127 task_lock(p);
1128 if (!p->vfork_done && process_shares_mm(p, mm)) {
1129 p->signal->oom_score_adj = oom_adj;
1130 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1131 p->signal->oom_score_adj_min = (short)oom_adj;
1132 }
1133 task_unlock(p);
1134 }
1135 rcu_read_unlock();
1136 mmdrop(mm);
1137 }
1138err_unlock:
1139 mutex_unlock(&oom_adj_mutex);
1140 put_task_struct(task);
1141 return err;
1142}
1143
1144/*
1145 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1146 * kernels. The effective policy is defined by oom_score_adj, which has a
1147 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1148 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1149 * Processes that become oom disabled via oom_adj will still be oom disabled
1150 * with this implementation.
1151 *
1152 * oom_adj cannot be removed since existing userspace binaries use it.
1153 */
1154static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1155 size_t count, loff_t *ppos)
1156{
1157 char buffer[PROC_NUMBUF] = {};
1158 int oom_adj;
1159 int err;
1160
1161 if (count > sizeof(buffer) - 1)
1162 count = sizeof(buffer) - 1;
1163 if (copy_from_user(buffer, buf, count)) {
1164 err = -EFAULT;
1165 goto out;
1166 }
1167
1168 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1169 if (err)
1170 goto out;
1171 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1172 oom_adj != OOM_DISABLE) {
1173 err = -EINVAL;
1174 goto out;
1175 }
1176
1177 /*
1178 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1179 * value is always attainable.
1180 */
1181 if (oom_adj == OOM_ADJUST_MAX)
1182 oom_adj = OOM_SCORE_ADJ_MAX;
1183 else
1184 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1185
1186 err = __set_oom_adj(file, oom_adj, true);
1187out:
1188 return err < 0 ? err : count;
1189}
1190
1191static const struct file_operations proc_oom_adj_operations = {
1192 .read = oom_adj_read,
1193 .write = oom_adj_write,
1194 .llseek = generic_file_llseek,
1195};
1196
1197static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1198 size_t count, loff_t *ppos)
1199{
1200 struct task_struct *task = get_proc_task(file_inode(file));
1201 char buffer[PROC_NUMBUF];
1202 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1203 size_t len;
1204
1205 if (!task)
1206 return -ESRCH;
1207 oom_score_adj = task->signal->oom_score_adj;
1208 put_task_struct(task);
1209 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1210 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1211}
1212
1213static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1214 size_t count, loff_t *ppos)
1215{
1216 char buffer[PROC_NUMBUF] = {};
1217 int oom_score_adj;
1218 int err;
1219
1220 if (count > sizeof(buffer) - 1)
1221 count = sizeof(buffer) - 1;
1222 if (copy_from_user(buffer, buf, count)) {
1223 err = -EFAULT;
1224 goto out;
1225 }
1226
1227 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1228 if (err)
1229 goto out;
1230 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1231 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1232 err = -EINVAL;
1233 goto out;
1234 }
1235
1236 err = __set_oom_adj(file, oom_score_adj, false);
1237out:
1238 return err < 0 ? err : count;
1239}
1240
1241static const struct file_operations proc_oom_score_adj_operations = {
1242 .read = oom_score_adj_read,
1243 .write = oom_score_adj_write,
1244 .llseek = default_llseek,
1245};
1246
1247#ifdef CONFIG_AUDIT
1248#define TMPBUFLEN 11
1249static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1250 size_t count, loff_t *ppos)
1251{
1252 struct inode * inode = file_inode(file);
1253 struct task_struct *task = get_proc_task(inode);
1254 ssize_t length;
1255 char tmpbuf[TMPBUFLEN];
1256
1257 if (!task)
1258 return -ESRCH;
1259 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1260 from_kuid(file->f_cred->user_ns,
1261 audit_get_loginuid(task)));
1262 put_task_struct(task);
1263 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1264}
1265
1266static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1267 size_t count, loff_t *ppos)
1268{
1269 struct inode * inode = file_inode(file);
1270 uid_t loginuid;
1271 kuid_t kloginuid;
1272 int rv;
1273
1274 /* Don't let kthreads write their own loginuid */
1275 if (current->flags & PF_KTHREAD)
1276 return -EPERM;
1277
1278 rcu_read_lock();
1279 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1280 rcu_read_unlock();
1281 return -EPERM;
1282 }
1283 rcu_read_unlock();
1284
1285 if (*ppos != 0) {
1286 /* No partial writes. */
1287 return -EINVAL;
1288 }
1289
1290 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1291 if (rv < 0)
1292 return rv;
1293
1294 /* is userspace tring to explicitly UNSET the loginuid? */
1295 if (loginuid == AUDIT_UID_UNSET) {
1296 kloginuid = INVALID_UID;
1297 } else {
1298 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1299 if (!uid_valid(kloginuid))
1300 return -EINVAL;
1301 }
1302
1303 rv = audit_set_loginuid(kloginuid);
1304 if (rv < 0)
1305 return rv;
1306 return count;
1307}
1308
1309static const struct file_operations proc_loginuid_operations = {
1310 .read = proc_loginuid_read,
1311 .write = proc_loginuid_write,
1312 .llseek = generic_file_llseek,
1313};
1314
1315static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1316 size_t count, loff_t *ppos)
1317{
1318 struct inode * inode = file_inode(file);
1319 struct task_struct *task = get_proc_task(inode);
1320 ssize_t length;
1321 char tmpbuf[TMPBUFLEN];
1322
1323 if (!task)
1324 return -ESRCH;
1325 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1326 audit_get_sessionid(task));
1327 put_task_struct(task);
1328 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1329}
1330
1331static const struct file_operations proc_sessionid_operations = {
1332 .read = proc_sessionid_read,
1333 .llseek = generic_file_llseek,
1334};
1335#endif
1336
1337#ifdef CONFIG_FAULT_INJECTION
1338static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1339 size_t count, loff_t *ppos)
1340{
1341 struct task_struct *task = get_proc_task(file_inode(file));
1342 char buffer[PROC_NUMBUF];
1343 size_t len;
1344 int make_it_fail;
1345
1346 if (!task)
1347 return -ESRCH;
1348 make_it_fail = task->make_it_fail;
1349 put_task_struct(task);
1350
1351 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1352
1353 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1354}
1355
1356static ssize_t proc_fault_inject_write(struct file * file,
1357 const char __user * buf, size_t count, loff_t *ppos)
1358{
1359 struct task_struct *task;
1360 char buffer[PROC_NUMBUF] = {};
1361 int make_it_fail;
1362 int rv;
1363
1364 if (!capable(CAP_SYS_RESOURCE))
1365 return -EPERM;
1366
1367 if (count > sizeof(buffer) - 1)
1368 count = sizeof(buffer) - 1;
1369 if (copy_from_user(buffer, buf, count))
1370 return -EFAULT;
1371 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1372 if (rv < 0)
1373 return rv;
1374 if (make_it_fail < 0 || make_it_fail > 1)
1375 return -EINVAL;
1376
1377 task = get_proc_task(file_inode(file));
1378 if (!task)
1379 return -ESRCH;
1380 task->make_it_fail = make_it_fail;
1381 put_task_struct(task);
1382
1383 return count;
1384}
1385
1386static const struct file_operations proc_fault_inject_operations = {
1387 .read = proc_fault_inject_read,
1388 .write = proc_fault_inject_write,
1389 .llseek = generic_file_llseek,
1390};
1391
1392static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1393 size_t count, loff_t *ppos)
1394{
1395 struct task_struct *task;
1396 int err;
1397 unsigned int n;
1398
1399 err = kstrtouint_from_user(buf, count, 0, &n);
1400 if (err)
1401 return err;
1402
1403 task = get_proc_task(file_inode(file));
1404 if (!task)
1405 return -ESRCH;
1406 task->fail_nth = n;
1407 put_task_struct(task);
1408
1409 return count;
1410}
1411
1412static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1413 size_t count, loff_t *ppos)
1414{
1415 struct task_struct *task;
1416 char numbuf[PROC_NUMBUF];
1417 ssize_t len;
1418
1419 task = get_proc_task(file_inode(file));
1420 if (!task)
1421 return -ESRCH;
1422 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1423 put_task_struct(task);
1424 return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1425}
1426
1427static const struct file_operations proc_fail_nth_operations = {
1428 .read = proc_fail_nth_read,
1429 .write = proc_fail_nth_write,
1430};
1431#endif
1432
1433
1434#ifdef CONFIG_SCHED_DEBUG
1435/*
1436 * Print out various scheduling related per-task fields:
1437 */
1438static int sched_show(struct seq_file *m, void *v)
1439{
1440 struct inode *inode = m->private;
1441 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
1442 struct task_struct *p;
1443
1444 p = get_proc_task(inode);
1445 if (!p)
1446 return -ESRCH;
1447 proc_sched_show_task(p, ns, m);
1448
1449 put_task_struct(p);
1450
1451 return 0;
1452}
1453
1454static ssize_t
1455sched_write(struct file *file, const char __user *buf,
1456 size_t count, loff_t *offset)
1457{
1458 struct inode *inode = file_inode(file);
1459 struct task_struct *p;
1460
1461 p = get_proc_task(inode);
1462 if (!p)
1463 return -ESRCH;
1464 proc_sched_set_task(p);
1465
1466 put_task_struct(p);
1467
1468 return count;
1469}
1470
1471static int sched_open(struct inode *inode, struct file *filp)
1472{
1473 return single_open(filp, sched_show, inode);
1474}
1475
1476static const struct file_operations proc_pid_sched_operations = {
1477 .open = sched_open,
1478 .read = seq_read,
1479 .write = sched_write,
1480 .llseek = seq_lseek,
1481 .release = single_release,
1482};
1483
1484#endif
1485
1486#ifdef CONFIG_SCHED_AUTOGROUP
1487/*
1488 * Print out autogroup related information:
1489 */
1490static int sched_autogroup_show(struct seq_file *m, void *v)
1491{
1492 struct inode *inode = m->private;
1493 struct task_struct *p;
1494
1495 p = get_proc_task(inode);
1496 if (!p)
1497 return -ESRCH;
1498 proc_sched_autogroup_show_task(p, m);
1499
1500 put_task_struct(p);
1501
1502 return 0;
1503}
1504
1505static ssize_t
1506sched_autogroup_write(struct file *file, const char __user *buf,
1507 size_t count, loff_t *offset)
1508{
1509 struct inode *inode = file_inode(file);
1510 struct task_struct *p;
1511 char buffer[PROC_NUMBUF] = {};
1512 int nice;
1513 int err;
1514
1515 if (count > sizeof(buffer) - 1)
1516 count = sizeof(buffer) - 1;
1517 if (copy_from_user(buffer, buf, count))
1518 return -EFAULT;
1519
1520 err = kstrtoint(strstrip(buffer), 0, &nice);
1521 if (err < 0)
1522 return err;
1523
1524 p = get_proc_task(inode);
1525 if (!p)
1526 return -ESRCH;
1527
1528 err = proc_sched_autogroup_set_nice(p, nice);
1529 if (err)
1530 count = err;
1531
1532 put_task_struct(p);
1533
1534 return count;
1535}
1536
1537static int sched_autogroup_open(struct inode *inode, struct file *filp)
1538{
1539 int ret;
1540
1541 ret = single_open(filp, sched_autogroup_show, NULL);
1542 if (!ret) {
1543 struct seq_file *m = filp->private_data;
1544
1545 m->private = inode;
1546 }
1547 return ret;
1548}
1549
1550static const struct file_operations proc_pid_sched_autogroup_operations = {
1551 .open = sched_autogroup_open,
1552 .read = seq_read,
1553 .write = sched_autogroup_write,
1554 .llseek = seq_lseek,
1555 .release = single_release,
1556};
1557
1558#endif /* CONFIG_SCHED_AUTOGROUP */
1559
1560#ifdef CONFIG_TIME_NS
1561static int timens_offsets_show(struct seq_file *m, void *v)
1562{
1563 struct task_struct *p;
1564
1565 p = get_proc_task(file_inode(m->file));
1566 if (!p)
1567 return -ESRCH;
1568 proc_timens_show_offsets(p, m);
1569
1570 put_task_struct(p);
1571
1572 return 0;
1573}
1574
1575static ssize_t timens_offsets_write(struct file *file, const char __user *buf,
1576 size_t count, loff_t *ppos)
1577{
1578 struct inode *inode = file_inode(file);
1579 struct proc_timens_offset offsets[2];
1580 char *kbuf = NULL, *pos, *next_line;
1581 struct task_struct *p;
1582 int ret, noffsets;
1583
1584 /* Only allow < page size writes at the beginning of the file */
1585 if ((*ppos != 0) || (count >= PAGE_SIZE))
1586 return -EINVAL;
1587
1588 /* Slurp in the user data */
1589 kbuf = memdup_user_nul(buf, count);
1590 if (IS_ERR(kbuf))
1591 return PTR_ERR(kbuf);
1592
1593 /* Parse the user data */
1594 ret = -EINVAL;
1595 noffsets = 0;
1596 for (pos = kbuf; pos; pos = next_line) {
1597 struct proc_timens_offset *off = &offsets[noffsets];
1598 char clock[10];
1599 int err;
1600
1601 /* Find the end of line and ensure we don't look past it */
1602 next_line = strchr(pos, '\n');
1603 if (next_line) {
1604 *next_line = '\0';
1605 next_line++;
1606 if (*next_line == '\0')
1607 next_line = NULL;
1608 }
1609
1610 err = sscanf(pos, "%9s %lld %lu", clock,
1611 &off->val.tv_sec, &off->val.tv_nsec);
1612 if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
1613 goto out;
1614
1615 clock[sizeof(clock) - 1] = 0;
1616 if (strcmp(clock, "monotonic") == 0 ||
1617 strcmp(clock, __stringify(CLOCK_MONOTONIC)) == 0)
1618 off->clockid = CLOCK_MONOTONIC;
1619 else if (strcmp(clock, "boottime") == 0 ||
1620 strcmp(clock, __stringify(CLOCK_BOOTTIME)) == 0)
1621 off->clockid = CLOCK_BOOTTIME;
1622 else
1623 goto out;
1624
1625 noffsets++;
1626 if (noffsets == ARRAY_SIZE(offsets)) {
1627 if (next_line)
1628 count = next_line - kbuf;
1629 break;
1630 }
1631 }
1632
1633 ret = -ESRCH;
1634 p = get_proc_task(inode);
1635 if (!p)
1636 goto out;
1637 ret = proc_timens_set_offset(file, p, offsets, noffsets);
1638 put_task_struct(p);
1639 if (ret)
1640 goto out;
1641
1642 ret = count;
1643out:
1644 kfree(kbuf);
1645 return ret;
1646}
1647
1648static int timens_offsets_open(struct inode *inode, struct file *filp)
1649{
1650 return single_open(filp, timens_offsets_show, inode);
1651}
1652
1653static const struct file_operations proc_timens_offsets_operations = {
1654 .open = timens_offsets_open,
1655 .read = seq_read,
1656 .write = timens_offsets_write,
1657 .llseek = seq_lseek,
1658 .release = single_release,
1659};
1660#endif /* CONFIG_TIME_NS */
1661
1662static ssize_t comm_write(struct file *file, const char __user *buf,
1663 size_t count, loff_t *offset)
1664{
1665 struct inode *inode = file_inode(file);
1666 struct task_struct *p;
1667 char buffer[TASK_COMM_LEN] = {};
1668 const size_t maxlen = sizeof(buffer) - 1;
1669
1670 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1671 return -EFAULT;
1672
1673 p = get_proc_task(inode);
1674 if (!p)
1675 return -ESRCH;
1676
1677 if (same_thread_group(current, p)) {
1678 set_task_comm(p, buffer);
1679 proc_comm_connector(p);
1680 }
1681 else
1682 count = -EINVAL;
1683
1684 put_task_struct(p);
1685
1686 return count;
1687}
1688
1689static int comm_show(struct seq_file *m, void *v)
1690{
1691 struct inode *inode = m->private;
1692 struct task_struct *p;
1693
1694 p = get_proc_task(inode);
1695 if (!p)
1696 return -ESRCH;
1697
1698 proc_task_name(m, p, false);
1699 seq_putc(m, '\n');
1700
1701 put_task_struct(p);
1702
1703 return 0;
1704}
1705
1706static int comm_open(struct inode *inode, struct file *filp)
1707{
1708 return single_open(filp, comm_show, inode);
1709}
1710
1711static const struct file_operations proc_pid_set_comm_operations = {
1712 .open = comm_open,
1713 .read = seq_read,
1714 .write = comm_write,
1715 .llseek = seq_lseek,
1716 .release = single_release,
1717};
1718
1719static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1720{
1721 struct task_struct *task;
1722 struct file *exe_file;
1723
1724 task = get_proc_task(d_inode(dentry));
1725 if (!task)
1726 return -ENOENT;
1727 exe_file = get_task_exe_file(task);
1728 put_task_struct(task);
1729 if (exe_file) {
1730 *exe_path = exe_file->f_path;
1731 path_get(&exe_file->f_path);
1732 fput(exe_file);
1733 return 0;
1734 } else
1735 return -ENOENT;
1736}
1737
1738static const char *proc_pid_get_link(struct dentry *dentry,
1739 struct inode *inode,
1740 struct delayed_call *done)
1741{
1742 struct path path;
1743 int error = -EACCES;
1744
1745 if (!dentry)
1746 return ERR_PTR(-ECHILD);
1747
1748 /* Are we allowed to snoop on the tasks file descriptors? */
1749 if (!proc_fd_access_allowed(inode))
1750 goto out;
1751
1752 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1753 if (error)
1754 goto out;
1755
1756 error = nd_jump_link(&path);
1757out:
1758 return ERR_PTR(error);
1759}
1760
1761static int do_proc_readlink(const struct path *path, char __user *buffer, int buflen)
1762{
1763 char *tmp = kmalloc(PATH_MAX, GFP_KERNEL);
1764 char *pathname;
1765 int len;
1766
1767 if (!tmp)
1768 return -ENOMEM;
1769
1770 pathname = d_path(path, tmp, PATH_MAX);
1771 len = PTR_ERR(pathname);
1772 if (IS_ERR(pathname))
1773 goto out;
1774 len = tmp + PATH_MAX - 1 - pathname;
1775
1776 if (len > buflen)
1777 len = buflen;
1778 if (copy_to_user(buffer, pathname, len))
1779 len = -EFAULT;
1780 out:
1781 kfree(tmp);
1782 return len;
1783}
1784
1785static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1786{
1787 int error = -EACCES;
1788 struct inode *inode = d_inode(dentry);
1789 struct path path;
1790
1791 /* Are we allowed to snoop on the tasks file descriptors? */
1792 if (!proc_fd_access_allowed(inode))
1793 goto out;
1794
1795 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1796 if (error)
1797 goto out;
1798
1799 error = do_proc_readlink(&path, buffer, buflen);
1800 path_put(&path);
1801out:
1802 return error;
1803}
1804
1805const struct inode_operations proc_pid_link_inode_operations = {
1806 .readlink = proc_pid_readlink,
1807 .get_link = proc_pid_get_link,
1808 .setattr = proc_setattr,
1809};
1810
1811
1812/* building an inode */
1813
1814void task_dump_owner(struct task_struct *task, umode_t mode,
1815 kuid_t *ruid, kgid_t *rgid)
1816{
1817 /* Depending on the state of dumpable compute who should own a
1818 * proc file for a task.
1819 */
1820 const struct cred *cred;
1821 kuid_t uid;
1822 kgid_t gid;
1823
1824 if (unlikely(task->flags & PF_KTHREAD)) {
1825 *ruid = GLOBAL_ROOT_UID;
1826 *rgid = GLOBAL_ROOT_GID;
1827 return;
1828 }
1829
1830 /* Default to the tasks effective ownership */
1831 rcu_read_lock();
1832 cred = __task_cred(task);
1833 uid = cred->euid;
1834 gid = cred->egid;
1835 rcu_read_unlock();
1836
1837 /*
1838 * Before the /proc/pid/status file was created the only way to read
1839 * the effective uid of a /process was to stat /proc/pid. Reading
1840 * /proc/pid/status is slow enough that procps and other packages
1841 * kept stating /proc/pid. To keep the rules in /proc simple I have
1842 * made this apply to all per process world readable and executable
1843 * directories.
1844 */
1845 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1846 struct mm_struct *mm;
1847 task_lock(task);
1848 mm = task->mm;
1849 /* Make non-dumpable tasks owned by some root */
1850 if (mm) {
1851 if (get_dumpable(mm) != SUID_DUMP_USER) {
1852 struct user_namespace *user_ns = mm->user_ns;
1853
1854 uid = make_kuid(user_ns, 0);
1855 if (!uid_valid(uid))
1856 uid = GLOBAL_ROOT_UID;
1857
1858 gid = make_kgid(user_ns, 0);
1859 if (!gid_valid(gid))
1860 gid = GLOBAL_ROOT_GID;
1861 }
1862 } else {
1863 uid = GLOBAL_ROOT_UID;
1864 gid = GLOBAL_ROOT_GID;
1865 }
1866 task_unlock(task);
1867 }
1868 *ruid = uid;
1869 *rgid = gid;
1870}
1871
1872void proc_pid_evict_inode(struct proc_inode *ei)
1873{
1874 struct pid *pid = ei->pid;
1875
1876 if (S_ISDIR(ei->vfs_inode.i_mode)) {
1877 spin_lock(&pid->lock);
1878 hlist_del_init_rcu(&ei->sibling_inodes);
1879 spin_unlock(&pid->lock);
1880 }
1881}
1882
1883struct inode *proc_pid_make_inode(struct super_block *sb,
1884 struct task_struct *task, umode_t mode)
1885{
1886 struct inode * inode;
1887 struct proc_inode *ei;
1888 struct pid *pid;
1889
1890 /* We need a new inode */
1891
1892 inode = new_inode(sb);
1893 if (!inode)
1894 goto out;
1895
1896 /* Common stuff */
1897 ei = PROC_I(inode);
1898 inode->i_mode = mode;
1899 inode->i_ino = get_next_ino();
1900 simple_inode_init_ts(inode);
1901 inode->i_op = &proc_def_inode_operations;
1902
1903 /*
1904 * grab the reference to task.
1905 */
1906 pid = get_task_pid(task, PIDTYPE_PID);
1907 if (!pid)
1908 goto out_unlock;
1909
1910 /* Let the pid remember us for quick removal */
1911 ei->pid = pid;
1912
1913 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1914 security_task_to_inode(task, inode);
1915
1916out:
1917 return inode;
1918
1919out_unlock:
1920 iput(inode);
1921 return NULL;
1922}
1923
1924/*
1925 * Generating an inode and adding it into @pid->inodes, so that task will
1926 * invalidate inode's dentry before being released.
1927 *
1928 * This helper is used for creating dir-type entries under '/proc' and
1929 * '/proc/<tgid>/task'. Other entries(eg. fd, stat) under '/proc/<tgid>'
1930 * can be released by invalidating '/proc/<tgid>' dentry.
1931 * In theory, dentries under '/proc/<tgid>/task' can also be released by
1932 * invalidating '/proc/<tgid>' dentry, we reserve it to handle single
1933 * thread exiting situation: Any one of threads should invalidate its
1934 * '/proc/<tgid>/task/<pid>' dentry before released.
1935 */
1936static struct inode *proc_pid_make_base_inode(struct super_block *sb,
1937 struct task_struct *task, umode_t mode)
1938{
1939 struct inode *inode;
1940 struct proc_inode *ei;
1941 struct pid *pid;
1942
1943 inode = proc_pid_make_inode(sb, task, mode);
1944 if (!inode)
1945 return NULL;
1946
1947 /* Let proc_flush_pid find this directory inode */
1948 ei = PROC_I(inode);
1949 pid = ei->pid;
1950 spin_lock(&pid->lock);
1951 hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
1952 spin_unlock(&pid->lock);
1953
1954 return inode;
1955}
1956
1957int pid_getattr(struct mnt_idmap *idmap, const struct path *path,
1958 struct kstat *stat, u32 request_mask, unsigned int query_flags)
1959{
1960 struct inode *inode = d_inode(path->dentry);
1961 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
1962 struct task_struct *task;
1963
1964 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
1965
1966 stat->uid = GLOBAL_ROOT_UID;
1967 stat->gid = GLOBAL_ROOT_GID;
1968 rcu_read_lock();
1969 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1970 if (task) {
1971 if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) {
1972 rcu_read_unlock();
1973 /*
1974 * This doesn't prevent learning whether PID exists,
1975 * it only makes getattr() consistent with readdir().
1976 */
1977 return -ENOENT;
1978 }
1979 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1980 }
1981 rcu_read_unlock();
1982 return 0;
1983}
1984
1985/* dentry stuff */
1986
1987/*
1988 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1989 */
1990void pid_update_inode(struct task_struct *task, struct inode *inode)
1991{
1992 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1993
1994 inode->i_mode &= ~(S_ISUID | S_ISGID);
1995 security_task_to_inode(task, inode);
1996}
1997
1998/*
1999 * Rewrite the inode's ownerships here because the owning task may have
2000 * performed a setuid(), etc.
2001 *
2002 */
2003static int pid_revalidate(struct dentry *dentry, unsigned int flags)
2004{
2005 struct inode *inode;
2006 struct task_struct *task;
2007 int ret = 0;
2008
2009 rcu_read_lock();
2010 inode = d_inode_rcu(dentry);
2011 if (!inode)
2012 goto out;
2013 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2014
2015 if (task) {
2016 pid_update_inode(task, inode);
2017 ret = 1;
2018 }
2019out:
2020 rcu_read_unlock();
2021 return ret;
2022}
2023
2024static inline bool proc_inode_is_dead(struct inode *inode)
2025{
2026 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
2027}
2028
2029int pid_delete_dentry(const struct dentry *dentry)
2030{
2031 /* Is the task we represent dead?
2032 * If so, then don't put the dentry on the lru list,
2033 * kill it immediately.
2034 */
2035 return proc_inode_is_dead(d_inode(dentry));
2036}
2037
2038const struct dentry_operations pid_dentry_operations =
2039{
2040 .d_revalidate = pid_revalidate,
2041 .d_delete = pid_delete_dentry,
2042};
2043
2044/* Lookups */
2045
2046/*
2047 * Fill a directory entry.
2048 *
2049 * If possible create the dcache entry and derive our inode number and
2050 * file type from dcache entry.
2051 *
2052 * Since all of the proc inode numbers are dynamically generated, the inode
2053 * numbers do not exist until the inode is cache. This means creating
2054 * the dcache entry in readdir is necessary to keep the inode numbers
2055 * reported by readdir in sync with the inode numbers reported
2056 * by stat.
2057 */
2058bool proc_fill_cache(struct file *file, struct dir_context *ctx,
2059 const char *name, unsigned int len,
2060 instantiate_t instantiate, struct task_struct *task, const void *ptr)
2061{
2062 struct dentry *child, *dir = file->f_path.dentry;
2063 struct qstr qname = QSTR_INIT(name, len);
2064 struct inode *inode;
2065 unsigned type = DT_UNKNOWN;
2066 ino_t ino = 1;
2067
2068 child = d_hash_and_lookup(dir, &qname);
2069 if (!child) {
2070 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
2071 child = d_alloc_parallel(dir, &qname, &wq);
2072 if (IS_ERR(child))
2073 goto end_instantiate;
2074 if (d_in_lookup(child)) {
2075 struct dentry *res;
2076 res = instantiate(child, task, ptr);
2077 d_lookup_done(child);
2078 if (unlikely(res)) {
2079 dput(child);
2080 child = res;
2081 if (IS_ERR(child))
2082 goto end_instantiate;
2083 }
2084 }
2085 }
2086 inode = d_inode(child);
2087 ino = inode->i_ino;
2088 type = inode->i_mode >> 12;
2089 dput(child);
2090end_instantiate:
2091 return dir_emit(ctx, name, len, ino, type);
2092}
2093
2094/*
2095 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2096 * which represent vma start and end addresses.
2097 */
2098static int dname_to_vma_addr(struct dentry *dentry,
2099 unsigned long *start, unsigned long *end)
2100{
2101 const char *str = dentry->d_name.name;
2102 unsigned long long sval, eval;
2103 unsigned int len;
2104
2105 if (str[0] == '0' && str[1] != '-')
2106 return -EINVAL;
2107 len = _parse_integer(str, 16, &sval);
2108 if (len & KSTRTOX_OVERFLOW)
2109 return -EINVAL;
2110 if (sval != (unsigned long)sval)
2111 return -EINVAL;
2112 str += len;
2113
2114 if (*str != '-')
2115 return -EINVAL;
2116 str++;
2117
2118 if (str[0] == '0' && str[1])
2119 return -EINVAL;
2120 len = _parse_integer(str, 16, &eval);
2121 if (len & KSTRTOX_OVERFLOW)
2122 return -EINVAL;
2123 if (eval != (unsigned long)eval)
2124 return -EINVAL;
2125 str += len;
2126
2127 if (*str != '\0')
2128 return -EINVAL;
2129
2130 *start = sval;
2131 *end = eval;
2132
2133 return 0;
2134}
2135
2136static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
2137{
2138 unsigned long vm_start, vm_end;
2139 bool exact_vma_exists = false;
2140 struct mm_struct *mm = NULL;
2141 struct task_struct *task;
2142 struct inode *inode;
2143 int status = 0;
2144
2145 if (flags & LOOKUP_RCU)
2146 return -ECHILD;
2147
2148 inode = d_inode(dentry);
2149 task = get_proc_task(inode);
2150 if (!task)
2151 goto out_notask;
2152
2153 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2154 if (IS_ERR_OR_NULL(mm))
2155 goto out;
2156
2157 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2158 status = mmap_read_lock_killable(mm);
2159 if (!status) {
2160 exact_vma_exists = !!find_exact_vma(mm, vm_start,
2161 vm_end);
2162 mmap_read_unlock(mm);
2163 }
2164 }
2165
2166 mmput(mm);
2167
2168 if (exact_vma_exists) {
2169 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
2170
2171 security_task_to_inode(task, inode);
2172 status = 1;
2173 }
2174
2175out:
2176 put_task_struct(task);
2177
2178out_notask:
2179 return status;
2180}
2181
2182static const struct dentry_operations tid_map_files_dentry_operations = {
2183 .d_revalidate = map_files_d_revalidate,
2184 .d_delete = pid_delete_dentry,
2185};
2186
2187static int map_files_get_link(struct dentry *dentry, struct path *path)
2188{
2189 unsigned long vm_start, vm_end;
2190 struct vm_area_struct *vma;
2191 struct task_struct *task;
2192 struct mm_struct *mm;
2193 int rc;
2194
2195 rc = -ENOENT;
2196 task = get_proc_task(d_inode(dentry));
2197 if (!task)
2198 goto out;
2199
2200 mm = get_task_mm(task);
2201 put_task_struct(task);
2202 if (!mm)
2203 goto out;
2204
2205 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2206 if (rc)
2207 goto out_mmput;
2208
2209 rc = mmap_read_lock_killable(mm);
2210 if (rc)
2211 goto out_mmput;
2212
2213 rc = -ENOENT;
2214 vma = find_exact_vma(mm, vm_start, vm_end);
2215 if (vma && vma->vm_file) {
2216 *path = *file_user_path(vma->vm_file);
2217 path_get(path);
2218 rc = 0;
2219 }
2220 mmap_read_unlock(mm);
2221
2222out_mmput:
2223 mmput(mm);
2224out:
2225 return rc;
2226}
2227
2228struct map_files_info {
2229 unsigned long start;
2230 unsigned long end;
2231 fmode_t mode;
2232};
2233
2234/*
2235 * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
2236 * to concerns about how the symlinks may be used to bypass permissions on
2237 * ancestor directories in the path to the file in question.
2238 */
2239static const char *
2240proc_map_files_get_link(struct dentry *dentry,
2241 struct inode *inode,
2242 struct delayed_call *done)
2243{
2244 if (!checkpoint_restore_ns_capable(&init_user_ns))
2245 return ERR_PTR(-EPERM);
2246
2247 return proc_pid_get_link(dentry, inode, done);
2248}
2249
2250/*
2251 * Identical to proc_pid_link_inode_operations except for get_link()
2252 */
2253static const struct inode_operations proc_map_files_link_inode_operations = {
2254 .readlink = proc_pid_readlink,
2255 .get_link = proc_map_files_get_link,
2256 .setattr = proc_setattr,
2257};
2258
2259static struct dentry *
2260proc_map_files_instantiate(struct dentry *dentry,
2261 struct task_struct *task, const void *ptr)
2262{
2263 fmode_t mode = (fmode_t)(unsigned long)ptr;
2264 struct proc_inode *ei;
2265 struct inode *inode;
2266
2267 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2268 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2269 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2270 if (!inode)
2271 return ERR_PTR(-ENOENT);
2272
2273 ei = PROC_I(inode);
2274 ei->op.proc_get_link = map_files_get_link;
2275
2276 inode->i_op = &proc_map_files_link_inode_operations;
2277 inode->i_size = 64;
2278
2279 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2280 return d_splice_alias(inode, dentry);
2281}
2282
2283static struct dentry *proc_map_files_lookup(struct inode *dir,
2284 struct dentry *dentry, unsigned int flags)
2285{
2286 unsigned long vm_start, vm_end;
2287 struct vm_area_struct *vma;
2288 struct task_struct *task;
2289 struct dentry *result;
2290 struct mm_struct *mm;
2291
2292 result = ERR_PTR(-ENOENT);
2293 task = get_proc_task(dir);
2294 if (!task)
2295 goto out;
2296
2297 result = ERR_PTR(-EACCES);
2298 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2299 goto out_put_task;
2300
2301 result = ERR_PTR(-ENOENT);
2302 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2303 goto out_put_task;
2304
2305 mm = get_task_mm(task);
2306 if (!mm)
2307 goto out_put_task;
2308
2309 result = ERR_PTR(-EINTR);
2310 if (mmap_read_lock_killable(mm))
2311 goto out_put_mm;
2312
2313 result = ERR_PTR(-ENOENT);
2314 vma = find_exact_vma(mm, vm_start, vm_end);
2315 if (!vma)
2316 goto out_no_vma;
2317
2318 if (vma->vm_file)
2319 result = proc_map_files_instantiate(dentry, task,
2320 (void *)(unsigned long)vma->vm_file->f_mode);
2321
2322out_no_vma:
2323 mmap_read_unlock(mm);
2324out_put_mm:
2325 mmput(mm);
2326out_put_task:
2327 put_task_struct(task);
2328out:
2329 return result;
2330}
2331
2332static const struct inode_operations proc_map_files_inode_operations = {
2333 .lookup = proc_map_files_lookup,
2334 .permission = proc_fd_permission,
2335 .setattr = proc_setattr,
2336};
2337
2338static int
2339proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2340{
2341 struct vm_area_struct *vma;
2342 struct task_struct *task;
2343 struct mm_struct *mm;
2344 unsigned long nr_files, pos, i;
2345 GENRADIX(struct map_files_info) fa;
2346 struct map_files_info *p;
2347 int ret;
2348 struct vma_iterator vmi;
2349
2350 genradix_init(&fa);
2351
2352 ret = -ENOENT;
2353 task = get_proc_task(file_inode(file));
2354 if (!task)
2355 goto out;
2356
2357 ret = -EACCES;
2358 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2359 goto out_put_task;
2360
2361 ret = 0;
2362 if (!dir_emit_dots(file, ctx))
2363 goto out_put_task;
2364
2365 mm = get_task_mm(task);
2366 if (!mm)
2367 goto out_put_task;
2368
2369 ret = mmap_read_lock_killable(mm);
2370 if (ret) {
2371 mmput(mm);
2372 goto out_put_task;
2373 }
2374
2375 nr_files = 0;
2376
2377 /*
2378 * We need two passes here:
2379 *
2380 * 1) Collect vmas of mapped files with mmap_lock taken
2381 * 2) Release mmap_lock and instantiate entries
2382 *
2383 * otherwise we get lockdep complained, since filldir()
2384 * routine might require mmap_lock taken in might_fault().
2385 */
2386
2387 pos = 2;
2388 vma_iter_init(&vmi, mm, 0);
2389 for_each_vma(vmi, vma) {
2390 if (!vma->vm_file)
2391 continue;
2392 if (++pos <= ctx->pos)
2393 continue;
2394
2395 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2396 if (!p) {
2397 ret = -ENOMEM;
2398 mmap_read_unlock(mm);
2399 mmput(mm);
2400 goto out_put_task;
2401 }
2402
2403 p->start = vma->vm_start;
2404 p->end = vma->vm_end;
2405 p->mode = vma->vm_file->f_mode;
2406 }
2407 mmap_read_unlock(mm);
2408 mmput(mm);
2409
2410 for (i = 0; i < nr_files; i++) {
2411 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2412 unsigned int len;
2413
2414 p = genradix_ptr(&fa, i);
2415 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2416 if (!proc_fill_cache(file, ctx,
2417 buf, len,
2418 proc_map_files_instantiate,
2419 task,
2420 (void *)(unsigned long)p->mode))
2421 break;
2422 ctx->pos++;
2423 }
2424
2425out_put_task:
2426 put_task_struct(task);
2427out:
2428 genradix_free(&fa);
2429 return ret;
2430}
2431
2432static const struct file_operations proc_map_files_operations = {
2433 .read = generic_read_dir,
2434 .iterate_shared = proc_map_files_readdir,
2435 .llseek = generic_file_llseek,
2436};
2437
2438#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2439struct timers_private {
2440 struct pid *pid;
2441 struct task_struct *task;
2442 struct sighand_struct *sighand;
2443 struct pid_namespace *ns;
2444 unsigned long flags;
2445};
2446
2447static void *timers_start(struct seq_file *m, loff_t *pos)
2448{
2449 struct timers_private *tp = m->private;
2450
2451 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2452 if (!tp->task)
2453 return ERR_PTR(-ESRCH);
2454
2455 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2456 if (!tp->sighand)
2457 return ERR_PTR(-ESRCH);
2458
2459 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2460}
2461
2462static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2463{
2464 struct timers_private *tp = m->private;
2465 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2466}
2467
2468static void timers_stop(struct seq_file *m, void *v)
2469{
2470 struct timers_private *tp = m->private;
2471
2472 if (tp->sighand) {
2473 unlock_task_sighand(tp->task, &tp->flags);
2474 tp->sighand = NULL;
2475 }
2476
2477 if (tp->task) {
2478 put_task_struct(tp->task);
2479 tp->task = NULL;
2480 }
2481}
2482
2483static int show_timer(struct seq_file *m, void *v)
2484{
2485 struct k_itimer *timer;
2486 struct timers_private *tp = m->private;
2487 int notify;
2488 static const char * const nstr[] = {
2489 [SIGEV_SIGNAL] = "signal",
2490 [SIGEV_NONE] = "none",
2491 [SIGEV_THREAD] = "thread",
2492 };
2493
2494 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2495 notify = timer->it_sigev_notify;
2496
2497 seq_printf(m, "ID: %d\n", timer->it_id);
2498 seq_printf(m, "signal: %d/%px\n",
2499 timer->sigq->info.si_signo,
2500 timer->sigq->info.si_value.sival_ptr);
2501 seq_printf(m, "notify: %s/%s.%d\n",
2502 nstr[notify & ~SIGEV_THREAD_ID],
2503 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2504 pid_nr_ns(timer->it_pid, tp->ns));
2505 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2506
2507 return 0;
2508}
2509
2510static const struct seq_operations proc_timers_seq_ops = {
2511 .start = timers_start,
2512 .next = timers_next,
2513 .stop = timers_stop,
2514 .show = show_timer,
2515};
2516
2517static int proc_timers_open(struct inode *inode, struct file *file)
2518{
2519 struct timers_private *tp;
2520
2521 tp = __seq_open_private(file, &proc_timers_seq_ops,
2522 sizeof(struct timers_private));
2523 if (!tp)
2524 return -ENOMEM;
2525
2526 tp->pid = proc_pid(inode);
2527 tp->ns = proc_pid_ns(inode->i_sb);
2528 return 0;
2529}
2530
2531static const struct file_operations proc_timers_operations = {
2532 .open = proc_timers_open,
2533 .read = seq_read,
2534 .llseek = seq_lseek,
2535 .release = seq_release_private,
2536};
2537#endif
2538
2539static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2540 size_t count, loff_t *offset)
2541{
2542 struct inode *inode = file_inode(file);
2543 struct task_struct *p;
2544 u64 slack_ns;
2545 int err;
2546
2547 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2548 if (err < 0)
2549 return err;
2550
2551 p = get_proc_task(inode);
2552 if (!p)
2553 return -ESRCH;
2554
2555 if (p != current) {
2556 rcu_read_lock();
2557 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2558 rcu_read_unlock();
2559 count = -EPERM;
2560 goto out;
2561 }
2562 rcu_read_unlock();
2563
2564 err = security_task_setscheduler(p);
2565 if (err) {
2566 count = err;
2567 goto out;
2568 }
2569 }
2570
2571 task_lock(p);
2572 if (slack_ns == 0)
2573 p->timer_slack_ns = p->default_timer_slack_ns;
2574 else
2575 p->timer_slack_ns = slack_ns;
2576 task_unlock(p);
2577
2578out:
2579 put_task_struct(p);
2580
2581 return count;
2582}
2583
2584static int timerslack_ns_show(struct seq_file *m, void *v)
2585{
2586 struct inode *inode = m->private;
2587 struct task_struct *p;
2588 int err = 0;
2589
2590 p = get_proc_task(inode);
2591 if (!p)
2592 return -ESRCH;
2593
2594 if (p != current) {
2595 rcu_read_lock();
2596 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2597 rcu_read_unlock();
2598 err = -EPERM;
2599 goto out;
2600 }
2601 rcu_read_unlock();
2602
2603 err = security_task_getscheduler(p);
2604 if (err)
2605 goto out;
2606 }
2607
2608 task_lock(p);
2609 seq_printf(m, "%llu\n", p->timer_slack_ns);
2610 task_unlock(p);
2611
2612out:
2613 put_task_struct(p);
2614
2615 return err;
2616}
2617
2618static int timerslack_ns_open(struct inode *inode, struct file *filp)
2619{
2620 return single_open(filp, timerslack_ns_show, inode);
2621}
2622
2623static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2624 .open = timerslack_ns_open,
2625 .read = seq_read,
2626 .write = timerslack_ns_write,
2627 .llseek = seq_lseek,
2628 .release = single_release,
2629};
2630
2631static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2632 struct task_struct *task, const void *ptr)
2633{
2634 const struct pid_entry *p = ptr;
2635 struct inode *inode;
2636 struct proc_inode *ei;
2637
2638 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2639 if (!inode)
2640 return ERR_PTR(-ENOENT);
2641
2642 ei = PROC_I(inode);
2643 if (S_ISDIR(inode->i_mode))
2644 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2645 if (p->iop)
2646 inode->i_op = p->iop;
2647 if (p->fop)
2648 inode->i_fop = p->fop;
2649 ei->op = p->op;
2650 pid_update_inode(task, inode);
2651 d_set_d_op(dentry, &pid_dentry_operations);
2652 return d_splice_alias(inode, dentry);
2653}
2654
2655static struct dentry *proc_pident_lookup(struct inode *dir,
2656 struct dentry *dentry,
2657 const struct pid_entry *p,
2658 const struct pid_entry *end)
2659{
2660 struct task_struct *task = get_proc_task(dir);
2661 struct dentry *res = ERR_PTR(-ENOENT);
2662
2663 if (!task)
2664 goto out_no_task;
2665
2666 /*
2667 * Yes, it does not scale. And it should not. Don't add
2668 * new entries into /proc/<tgid>/ without very good reasons.
2669 */
2670 for (; p < end; p++) {
2671 if (p->len != dentry->d_name.len)
2672 continue;
2673 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2674 res = proc_pident_instantiate(dentry, task, p);
2675 break;
2676 }
2677 }
2678 put_task_struct(task);
2679out_no_task:
2680 return res;
2681}
2682
2683static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2684 const struct pid_entry *ents, unsigned int nents)
2685{
2686 struct task_struct *task = get_proc_task(file_inode(file));
2687 const struct pid_entry *p;
2688
2689 if (!task)
2690 return -ENOENT;
2691
2692 if (!dir_emit_dots(file, ctx))
2693 goto out;
2694
2695 if (ctx->pos >= nents + 2)
2696 goto out;
2697
2698 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2699 if (!proc_fill_cache(file, ctx, p->name, p->len,
2700 proc_pident_instantiate, task, p))
2701 break;
2702 ctx->pos++;
2703 }
2704out:
2705 put_task_struct(task);
2706 return 0;
2707}
2708
2709#ifdef CONFIG_SECURITY
2710static int proc_pid_attr_open(struct inode *inode, struct file *file)
2711{
2712 file->private_data = NULL;
2713 __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
2714 return 0;
2715}
2716
2717static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2718 size_t count, loff_t *ppos)
2719{
2720 struct inode * inode = file_inode(file);
2721 char *p = NULL;
2722 ssize_t length;
2723 struct task_struct *task = get_proc_task(inode);
2724
2725 if (!task)
2726 return -ESRCH;
2727
2728 length = security_getprocattr(task, PROC_I(inode)->op.lsmid,
2729 file->f_path.dentry->d_name.name,
2730 &p);
2731 put_task_struct(task);
2732 if (length > 0)
2733 length = simple_read_from_buffer(buf, count, ppos, p, length);
2734 kfree(p);
2735 return length;
2736}
2737
2738static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2739 size_t count, loff_t *ppos)
2740{
2741 struct inode * inode = file_inode(file);
2742 struct task_struct *task;
2743 void *page;
2744 int rv;
2745
2746 /* A task may only write when it was the opener. */
2747 if (file->private_data != current->mm)
2748 return -EPERM;
2749
2750 rcu_read_lock();
2751 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2752 if (!task) {
2753 rcu_read_unlock();
2754 return -ESRCH;
2755 }
2756 /* A task may only write its own attributes. */
2757 if (current != task) {
2758 rcu_read_unlock();
2759 return -EACCES;
2760 }
2761 /* Prevent changes to overridden credentials. */
2762 if (current_cred() != current_real_cred()) {
2763 rcu_read_unlock();
2764 return -EBUSY;
2765 }
2766 rcu_read_unlock();
2767
2768 if (count > PAGE_SIZE)
2769 count = PAGE_SIZE;
2770
2771 /* No partial writes. */
2772 if (*ppos != 0)
2773 return -EINVAL;
2774
2775 page = memdup_user(buf, count);
2776 if (IS_ERR(page)) {
2777 rv = PTR_ERR(page);
2778 goto out;
2779 }
2780
2781 /* Guard against adverse ptrace interaction */
2782 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex);
2783 if (rv < 0)
2784 goto out_free;
2785
2786 rv = security_setprocattr(PROC_I(inode)->op.lsmid,
2787 file->f_path.dentry->d_name.name, page,
2788 count);
2789 mutex_unlock(¤t->signal->cred_guard_mutex);
2790out_free:
2791 kfree(page);
2792out:
2793 return rv;
2794}
2795
2796static const struct file_operations proc_pid_attr_operations = {
2797 .open = proc_pid_attr_open,
2798 .read = proc_pid_attr_read,
2799 .write = proc_pid_attr_write,
2800 .llseek = generic_file_llseek,
2801 .release = mem_release,
2802};
2803
2804#define LSM_DIR_OPS(LSM) \
2805static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2806 struct dir_context *ctx) \
2807{ \
2808 return proc_pident_readdir(filp, ctx, \
2809 LSM##_attr_dir_stuff, \
2810 ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2811} \
2812\
2813static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2814 .read = generic_read_dir, \
2815 .iterate_shared = proc_##LSM##_attr_dir_iterate, \
2816 .llseek = default_llseek, \
2817}; \
2818\
2819static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2820 struct dentry *dentry, unsigned int flags) \
2821{ \
2822 return proc_pident_lookup(dir, dentry, \
2823 LSM##_attr_dir_stuff, \
2824 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2825} \
2826\
2827static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2828 .lookup = proc_##LSM##_attr_dir_lookup, \
2829 .getattr = pid_getattr, \
2830 .setattr = proc_setattr, \
2831}
2832
2833#ifdef CONFIG_SECURITY_SMACK
2834static const struct pid_entry smack_attr_dir_stuff[] = {
2835 ATTR(LSM_ID_SMACK, "current", 0666),
2836};
2837LSM_DIR_OPS(smack);
2838#endif
2839
2840#ifdef CONFIG_SECURITY_APPARMOR
2841static const struct pid_entry apparmor_attr_dir_stuff[] = {
2842 ATTR(LSM_ID_APPARMOR, "current", 0666),
2843 ATTR(LSM_ID_APPARMOR, "prev", 0444),
2844 ATTR(LSM_ID_APPARMOR, "exec", 0666),
2845};
2846LSM_DIR_OPS(apparmor);
2847#endif
2848
2849static const struct pid_entry attr_dir_stuff[] = {
2850 ATTR(LSM_ID_UNDEF, "current", 0666),
2851 ATTR(LSM_ID_UNDEF, "prev", 0444),
2852 ATTR(LSM_ID_UNDEF, "exec", 0666),
2853 ATTR(LSM_ID_UNDEF, "fscreate", 0666),
2854 ATTR(LSM_ID_UNDEF, "keycreate", 0666),
2855 ATTR(LSM_ID_UNDEF, "sockcreate", 0666),
2856#ifdef CONFIG_SECURITY_SMACK
2857 DIR("smack", 0555,
2858 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2859#endif
2860#ifdef CONFIG_SECURITY_APPARMOR
2861 DIR("apparmor", 0555,
2862 proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
2863#endif
2864};
2865
2866static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2867{
2868 return proc_pident_readdir(file, ctx,
2869 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2870}
2871
2872static const struct file_operations proc_attr_dir_operations = {
2873 .read = generic_read_dir,
2874 .iterate_shared = proc_attr_dir_readdir,
2875 .llseek = generic_file_llseek,
2876};
2877
2878static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2879 struct dentry *dentry, unsigned int flags)
2880{
2881 return proc_pident_lookup(dir, dentry,
2882 attr_dir_stuff,
2883 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2884}
2885
2886static const struct inode_operations proc_attr_dir_inode_operations = {
2887 .lookup = proc_attr_dir_lookup,
2888 .getattr = pid_getattr,
2889 .setattr = proc_setattr,
2890};
2891
2892#endif
2893
2894#ifdef CONFIG_ELF_CORE
2895static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2896 size_t count, loff_t *ppos)
2897{
2898 struct task_struct *task = get_proc_task(file_inode(file));
2899 struct mm_struct *mm;
2900 char buffer[PROC_NUMBUF];
2901 size_t len;
2902 int ret;
2903
2904 if (!task)
2905 return -ESRCH;
2906
2907 ret = 0;
2908 mm = get_task_mm(task);
2909 if (mm) {
2910 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2911 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2912 MMF_DUMP_FILTER_SHIFT));
2913 mmput(mm);
2914 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2915 }
2916
2917 put_task_struct(task);
2918
2919 return ret;
2920}
2921
2922static ssize_t proc_coredump_filter_write(struct file *file,
2923 const char __user *buf,
2924 size_t count,
2925 loff_t *ppos)
2926{
2927 struct task_struct *task;
2928 struct mm_struct *mm;
2929 unsigned int val;
2930 int ret;
2931 int i;
2932 unsigned long mask;
2933
2934 ret = kstrtouint_from_user(buf, count, 0, &val);
2935 if (ret < 0)
2936 return ret;
2937
2938 ret = -ESRCH;
2939 task = get_proc_task(file_inode(file));
2940 if (!task)
2941 goto out_no_task;
2942
2943 mm = get_task_mm(task);
2944 if (!mm)
2945 goto out_no_mm;
2946 ret = 0;
2947
2948 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2949 if (val & mask)
2950 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2951 else
2952 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2953 }
2954
2955 mmput(mm);
2956 out_no_mm:
2957 put_task_struct(task);
2958 out_no_task:
2959 if (ret < 0)
2960 return ret;
2961 return count;
2962}
2963
2964static const struct file_operations proc_coredump_filter_operations = {
2965 .read = proc_coredump_filter_read,
2966 .write = proc_coredump_filter_write,
2967 .llseek = generic_file_llseek,
2968};
2969#endif
2970
2971#ifdef CONFIG_TASK_IO_ACCOUNTING
2972static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2973{
2974 struct task_io_accounting acct;
2975 int result;
2976
2977 result = down_read_killable(&task->signal->exec_update_lock);
2978 if (result)
2979 return result;
2980
2981 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2982 result = -EACCES;
2983 goto out_unlock;
2984 }
2985
2986 if (whole) {
2987 struct signal_struct *sig = task->signal;
2988 struct task_struct *t;
2989 unsigned int seq = 1;
2990 unsigned long flags;
2991
2992 rcu_read_lock();
2993 do {
2994 seq++; /* 2 on the 1st/lockless path, otherwise odd */
2995 flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq);
2996
2997 acct = sig->ioac;
2998 __for_each_thread(sig, t)
2999 task_io_accounting_add(&acct, &t->ioac);
3000
3001 } while (need_seqretry(&sig->stats_lock, seq));
3002 done_seqretry_irqrestore(&sig->stats_lock, seq, flags);
3003 rcu_read_unlock();
3004 } else {
3005 acct = task->ioac;
3006 }
3007
3008 seq_printf(m,
3009 "rchar: %llu\n"
3010 "wchar: %llu\n"
3011 "syscr: %llu\n"
3012 "syscw: %llu\n"
3013 "read_bytes: %llu\n"
3014 "write_bytes: %llu\n"
3015 "cancelled_write_bytes: %llu\n",
3016 (unsigned long long)acct.rchar,
3017 (unsigned long long)acct.wchar,
3018 (unsigned long long)acct.syscr,
3019 (unsigned long long)acct.syscw,
3020 (unsigned long long)acct.read_bytes,
3021 (unsigned long long)acct.write_bytes,
3022 (unsigned long long)acct.cancelled_write_bytes);
3023 result = 0;
3024
3025out_unlock:
3026 up_read(&task->signal->exec_update_lock);
3027 return result;
3028}
3029
3030static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
3031 struct pid *pid, struct task_struct *task)
3032{
3033 return do_io_accounting(task, m, 0);
3034}
3035
3036static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
3037 struct pid *pid, struct task_struct *task)
3038{
3039 return do_io_accounting(task, m, 1);
3040}
3041#endif /* CONFIG_TASK_IO_ACCOUNTING */
3042
3043#ifdef CONFIG_USER_NS
3044static int proc_id_map_open(struct inode *inode, struct file *file,
3045 const struct seq_operations *seq_ops)
3046{
3047 struct user_namespace *ns = NULL;
3048 struct task_struct *task;
3049 struct seq_file *seq;
3050 int ret = -EINVAL;
3051
3052 task = get_proc_task(inode);
3053 if (task) {
3054 rcu_read_lock();
3055 ns = get_user_ns(task_cred_xxx(task, user_ns));
3056 rcu_read_unlock();
3057 put_task_struct(task);
3058 }
3059 if (!ns)
3060 goto err;
3061
3062 ret = seq_open(file, seq_ops);
3063 if (ret)
3064 goto err_put_ns;
3065
3066 seq = file->private_data;
3067 seq->private = ns;
3068
3069 return 0;
3070err_put_ns:
3071 put_user_ns(ns);
3072err:
3073 return ret;
3074}
3075
3076static int proc_id_map_release(struct inode *inode, struct file *file)
3077{
3078 struct seq_file *seq = file->private_data;
3079 struct user_namespace *ns = seq->private;
3080 put_user_ns(ns);
3081 return seq_release(inode, file);
3082}
3083
3084static int proc_uid_map_open(struct inode *inode, struct file *file)
3085{
3086 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
3087}
3088
3089static int proc_gid_map_open(struct inode *inode, struct file *file)
3090{
3091 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
3092}
3093
3094static int proc_projid_map_open(struct inode *inode, struct file *file)
3095{
3096 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
3097}
3098
3099static const struct file_operations proc_uid_map_operations = {
3100 .open = proc_uid_map_open,
3101 .write = proc_uid_map_write,
3102 .read = seq_read,
3103 .llseek = seq_lseek,
3104 .release = proc_id_map_release,
3105};
3106
3107static const struct file_operations proc_gid_map_operations = {
3108 .open = proc_gid_map_open,
3109 .write = proc_gid_map_write,
3110 .read = seq_read,
3111 .llseek = seq_lseek,
3112 .release = proc_id_map_release,
3113};
3114
3115static const struct file_operations proc_projid_map_operations = {
3116 .open = proc_projid_map_open,
3117 .write = proc_projid_map_write,
3118 .read = seq_read,
3119 .llseek = seq_lseek,
3120 .release = proc_id_map_release,
3121};
3122
3123static int proc_setgroups_open(struct inode *inode, struct file *file)
3124{
3125 struct user_namespace *ns = NULL;
3126 struct task_struct *task;
3127 int ret;
3128
3129 ret = -ESRCH;
3130 task = get_proc_task(inode);
3131 if (task) {
3132 rcu_read_lock();
3133 ns = get_user_ns(task_cred_xxx(task, user_ns));
3134 rcu_read_unlock();
3135 put_task_struct(task);
3136 }
3137 if (!ns)
3138 goto err;
3139
3140 if (file->f_mode & FMODE_WRITE) {
3141 ret = -EACCES;
3142 if (!ns_capable(ns, CAP_SYS_ADMIN))
3143 goto err_put_ns;
3144 }
3145
3146 ret = single_open(file, &proc_setgroups_show, ns);
3147 if (ret)
3148 goto err_put_ns;
3149
3150 return 0;
3151err_put_ns:
3152 put_user_ns(ns);
3153err:
3154 return ret;
3155}
3156
3157static int proc_setgroups_release(struct inode *inode, struct file *file)
3158{
3159 struct seq_file *seq = file->private_data;
3160 struct user_namespace *ns = seq->private;
3161 int ret = single_release(inode, file);
3162 put_user_ns(ns);
3163 return ret;
3164}
3165
3166static const struct file_operations proc_setgroups_operations = {
3167 .open = proc_setgroups_open,
3168 .write = proc_setgroups_write,
3169 .read = seq_read,
3170 .llseek = seq_lseek,
3171 .release = proc_setgroups_release,
3172};
3173#endif /* CONFIG_USER_NS */
3174
3175static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3176 struct pid *pid, struct task_struct *task)
3177{
3178 int err = lock_trace(task);
3179 if (!err) {
3180 seq_printf(m, "%08x\n", task->personality);
3181 unlock_trace(task);
3182 }
3183 return err;
3184}
3185
3186#ifdef CONFIG_LIVEPATCH
3187static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
3188 struct pid *pid, struct task_struct *task)
3189{
3190 seq_printf(m, "%d\n", task->patch_state);
3191 return 0;
3192}
3193#endif /* CONFIG_LIVEPATCH */
3194
3195#ifdef CONFIG_KSM
3196static int proc_pid_ksm_merging_pages(struct seq_file *m, struct pid_namespace *ns,
3197 struct pid *pid, struct task_struct *task)
3198{
3199 struct mm_struct *mm;
3200
3201 mm = get_task_mm(task);
3202 if (mm) {
3203 seq_printf(m, "%lu\n", mm->ksm_merging_pages);
3204 mmput(mm);
3205 }
3206
3207 return 0;
3208}
3209static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns,
3210 struct pid *pid, struct task_struct *task)
3211{
3212 struct mm_struct *mm;
3213
3214 mm = get_task_mm(task);
3215 if (mm) {
3216 seq_printf(m, "ksm_rmap_items %lu\n", mm->ksm_rmap_items);
3217 seq_printf(m, "ksm_zero_pages %lu\n", mm->ksm_zero_pages);
3218 seq_printf(m, "ksm_merging_pages %lu\n", mm->ksm_merging_pages);
3219 seq_printf(m, "ksm_process_profit %ld\n", ksm_process_profit(mm));
3220 mmput(mm);
3221 }
3222
3223 return 0;
3224}
3225#endif /* CONFIG_KSM */
3226
3227#ifdef CONFIG_STACKLEAK_METRICS
3228static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
3229 struct pid *pid, struct task_struct *task)
3230{
3231 unsigned long prev_depth = THREAD_SIZE -
3232 (task->prev_lowest_stack & (THREAD_SIZE - 1));
3233 unsigned long depth = THREAD_SIZE -
3234 (task->lowest_stack & (THREAD_SIZE - 1));
3235
3236 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
3237 prev_depth, depth);
3238 return 0;
3239}
3240#endif /* CONFIG_STACKLEAK_METRICS */
3241
3242/*
3243 * Thread groups
3244 */
3245static const struct file_operations proc_task_operations;
3246static const struct inode_operations proc_task_inode_operations;
3247
3248static const struct pid_entry tgid_base_stuff[] = {
3249 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3250 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3251 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3252 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3253 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3254#ifdef CONFIG_NET
3255 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3256#endif
3257 REG("environ", S_IRUSR, proc_environ_operations),
3258 REG("auxv", S_IRUSR, proc_auxv_operations),
3259 ONE("status", S_IRUGO, proc_pid_status),
3260 ONE("personality", S_IRUSR, proc_pid_personality),
3261 ONE("limits", S_IRUGO, proc_pid_limits),
3262#ifdef CONFIG_SCHED_DEBUG
3263 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3264#endif
3265#ifdef CONFIG_SCHED_AUTOGROUP
3266 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3267#endif
3268#ifdef CONFIG_TIME_NS
3269 REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
3270#endif
3271 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3272#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3273 ONE("syscall", S_IRUSR, proc_pid_syscall),
3274#endif
3275 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3276 ONE("stat", S_IRUGO, proc_tgid_stat),
3277 ONE("statm", S_IRUGO, proc_pid_statm),
3278 REG("maps", S_IRUGO, proc_pid_maps_operations),
3279#ifdef CONFIG_NUMA
3280 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3281#endif
3282 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3283 LNK("cwd", proc_cwd_link),
3284 LNK("root", proc_root_link),
3285 LNK("exe", proc_exe_link),
3286 REG("mounts", S_IRUGO, proc_mounts_operations),
3287 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3288 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3289#ifdef CONFIG_PROC_PAGE_MONITOR
3290 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3291 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3292 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3293 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3294#endif
3295#ifdef CONFIG_SECURITY
3296 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3297#endif
3298#ifdef CONFIG_KALLSYMS
3299 ONE("wchan", S_IRUGO, proc_pid_wchan),
3300#endif
3301#ifdef CONFIG_STACKTRACE
3302 ONE("stack", S_IRUSR, proc_pid_stack),
3303#endif
3304#ifdef CONFIG_SCHED_INFO
3305 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3306#endif
3307#ifdef CONFIG_LATENCYTOP
3308 REG("latency", S_IRUGO, proc_lstats_operations),
3309#endif
3310#ifdef CONFIG_PROC_PID_CPUSET
3311 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3312#endif
3313#ifdef CONFIG_CGROUPS
3314 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3315#endif
3316#ifdef CONFIG_PROC_CPU_RESCTRL
3317 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3318#endif
3319 ONE("oom_score", S_IRUGO, proc_oom_score),
3320 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3321 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3322#ifdef CONFIG_AUDIT
3323 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3324 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3325#endif
3326#ifdef CONFIG_FAULT_INJECTION
3327 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3328 REG("fail-nth", 0644, proc_fail_nth_operations),
3329#endif
3330#ifdef CONFIG_ELF_CORE
3331 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3332#endif
3333#ifdef CONFIG_TASK_IO_ACCOUNTING
3334 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3335#endif
3336#ifdef CONFIG_USER_NS
3337 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3338 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3339 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3340 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3341#endif
3342#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3343 REG("timers", S_IRUGO, proc_timers_operations),
3344#endif
3345 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3346#ifdef CONFIG_LIVEPATCH
3347 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3348#endif
3349#ifdef CONFIG_STACKLEAK_METRICS
3350 ONE("stack_depth", S_IRUGO, proc_stack_depth),
3351#endif
3352#ifdef CONFIG_PROC_PID_ARCH_STATUS
3353 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3354#endif
3355#ifdef CONFIG_SECCOMP_CACHE_DEBUG
3356 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3357#endif
3358#ifdef CONFIG_KSM
3359 ONE("ksm_merging_pages", S_IRUSR, proc_pid_ksm_merging_pages),
3360 ONE("ksm_stat", S_IRUSR, proc_pid_ksm_stat),
3361#endif
3362};
3363
3364static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3365{
3366 return proc_pident_readdir(file, ctx,
3367 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3368}
3369
3370static const struct file_operations proc_tgid_base_operations = {
3371 .read = generic_read_dir,
3372 .iterate_shared = proc_tgid_base_readdir,
3373 .llseek = generic_file_llseek,
3374};
3375
3376struct pid *tgid_pidfd_to_pid(const struct file *file)
3377{
3378 if (file->f_op != &proc_tgid_base_operations)
3379 return ERR_PTR(-EBADF);
3380
3381 return proc_pid(file_inode(file));
3382}
3383
3384static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3385{
3386 return proc_pident_lookup(dir, dentry,
3387 tgid_base_stuff,
3388 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3389}
3390
3391static const struct inode_operations proc_tgid_base_inode_operations = {
3392 .lookup = proc_tgid_base_lookup,
3393 .getattr = pid_getattr,
3394 .setattr = proc_setattr,
3395 .permission = proc_pid_permission,
3396};
3397
3398/**
3399 * proc_flush_pid - Remove dcache entries for @pid from the /proc dcache.
3400 * @pid: pid that should be flushed.
3401 *
3402 * This function walks a list of inodes (that belong to any proc
3403 * filesystem) that are attached to the pid and flushes them from
3404 * the dentry cache.
3405 *
3406 * It is safe and reasonable to cache /proc entries for a task until
3407 * that task exits. After that they just clog up the dcache with
3408 * useless entries, possibly causing useful dcache entries to be
3409 * flushed instead. This routine is provided to flush those useless
3410 * dcache entries when a process is reaped.
3411 *
3412 * NOTE: This routine is just an optimization so it does not guarantee
3413 * that no dcache entries will exist after a process is reaped
3414 * it just makes it very unlikely that any will persist.
3415 */
3416
3417void proc_flush_pid(struct pid *pid)
3418{
3419 proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
3420}
3421
3422static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3423 struct task_struct *task, const void *ptr)
3424{
3425 struct inode *inode;
3426
3427 inode = proc_pid_make_base_inode(dentry->d_sb, task,
3428 S_IFDIR | S_IRUGO | S_IXUGO);
3429 if (!inode)
3430 return ERR_PTR(-ENOENT);
3431
3432 inode->i_op = &proc_tgid_base_inode_operations;
3433 inode->i_fop = &proc_tgid_base_operations;
3434 inode->i_flags|=S_IMMUTABLE;
3435
3436 set_nlink(inode, nlink_tgid);
3437 pid_update_inode(task, inode);
3438
3439 d_set_d_op(dentry, &pid_dentry_operations);
3440 return d_splice_alias(inode, dentry);
3441}
3442
3443struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3444{
3445 struct task_struct *task;
3446 unsigned tgid;
3447 struct proc_fs_info *fs_info;
3448 struct pid_namespace *ns;
3449 struct dentry *result = ERR_PTR(-ENOENT);
3450
3451 tgid = name_to_int(&dentry->d_name);
3452 if (tgid == ~0U)
3453 goto out;
3454
3455 fs_info = proc_sb_info(dentry->d_sb);
3456 ns = fs_info->pid_ns;
3457 rcu_read_lock();
3458 task = find_task_by_pid_ns(tgid, ns);
3459 if (task)
3460 get_task_struct(task);
3461 rcu_read_unlock();
3462 if (!task)
3463 goto out;
3464
3465 /* Limit procfs to only ptraceable tasks */
3466 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) {
3467 if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
3468 goto out_put_task;
3469 }
3470
3471 result = proc_pid_instantiate(dentry, task, NULL);
3472out_put_task:
3473 put_task_struct(task);
3474out:
3475 return result;
3476}
3477
3478/*
3479 * Find the first task with tgid >= tgid
3480 *
3481 */
3482struct tgid_iter {
3483 unsigned int tgid;
3484 struct task_struct *task;
3485};
3486static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3487{
3488 struct pid *pid;
3489
3490 if (iter.task)
3491 put_task_struct(iter.task);
3492 rcu_read_lock();
3493retry:
3494 iter.task = NULL;
3495 pid = find_ge_pid(iter.tgid, ns);
3496 if (pid) {
3497 iter.tgid = pid_nr_ns(pid, ns);
3498 iter.task = pid_task(pid, PIDTYPE_TGID);
3499 if (!iter.task) {
3500 iter.tgid += 1;
3501 goto retry;
3502 }
3503 get_task_struct(iter.task);
3504 }
3505 rcu_read_unlock();
3506 return iter;
3507}
3508
3509#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3510
3511/* for the /proc/ directory itself, after non-process stuff has been done */
3512int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3513{
3514 struct tgid_iter iter;
3515 struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
3516 struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb);
3517 loff_t pos = ctx->pos;
3518
3519 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3520 return 0;
3521
3522 if (pos == TGID_OFFSET - 2) {
3523 struct inode *inode = d_inode(fs_info->proc_self);
3524 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3525 return 0;
3526 ctx->pos = pos = pos + 1;
3527 }
3528 if (pos == TGID_OFFSET - 1) {
3529 struct inode *inode = d_inode(fs_info->proc_thread_self);
3530 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3531 return 0;
3532 ctx->pos = pos = pos + 1;
3533 }
3534 iter.tgid = pos - TGID_OFFSET;
3535 iter.task = NULL;
3536 for (iter = next_tgid(ns, iter);
3537 iter.task;
3538 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3539 char name[10 + 1];
3540 unsigned int len;
3541
3542 cond_resched();
3543 if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE))
3544 continue;
3545
3546 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3547 ctx->pos = iter.tgid + TGID_OFFSET;
3548 if (!proc_fill_cache(file, ctx, name, len,
3549 proc_pid_instantiate, iter.task, NULL)) {
3550 put_task_struct(iter.task);
3551 return 0;
3552 }
3553 }
3554 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3555 return 0;
3556}
3557
3558/*
3559 * proc_tid_comm_permission is a special permission function exclusively
3560 * used for the node /proc/<pid>/task/<tid>/comm.
3561 * It bypasses generic permission checks in the case where a task of the same
3562 * task group attempts to access the node.
3563 * The rationale behind this is that glibc and bionic access this node for
3564 * cross thread naming (pthread_set/getname_np(!self)). However, if
3565 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3566 * which locks out the cross thread naming implementation.
3567 * This function makes sure that the node is always accessible for members of
3568 * same thread group.
3569 */
3570static int proc_tid_comm_permission(struct mnt_idmap *idmap,
3571 struct inode *inode, int mask)
3572{
3573 bool is_same_tgroup;
3574 struct task_struct *task;
3575
3576 task = get_proc_task(inode);
3577 if (!task)
3578 return -ESRCH;
3579 is_same_tgroup = same_thread_group(current, task);
3580 put_task_struct(task);
3581
3582 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3583 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3584 * read or written by the members of the corresponding
3585 * thread group.
3586 */
3587 return 0;
3588 }
3589
3590 return generic_permission(&nop_mnt_idmap, inode, mask);
3591}
3592
3593static const struct inode_operations proc_tid_comm_inode_operations = {
3594 .setattr = proc_setattr,
3595 .permission = proc_tid_comm_permission,
3596};
3597
3598/*
3599 * Tasks
3600 */
3601static const struct pid_entry tid_base_stuff[] = {
3602 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3603 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3604 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3605#ifdef CONFIG_NET
3606 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3607#endif
3608 REG("environ", S_IRUSR, proc_environ_operations),
3609 REG("auxv", S_IRUSR, proc_auxv_operations),
3610 ONE("status", S_IRUGO, proc_pid_status),
3611 ONE("personality", S_IRUSR, proc_pid_personality),
3612 ONE("limits", S_IRUGO, proc_pid_limits),
3613#ifdef CONFIG_SCHED_DEBUG
3614 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3615#endif
3616 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3617 &proc_tid_comm_inode_operations,
3618 &proc_pid_set_comm_operations, {}),
3619#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3620 ONE("syscall", S_IRUSR, proc_pid_syscall),
3621#endif
3622 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3623 ONE("stat", S_IRUGO, proc_tid_stat),
3624 ONE("statm", S_IRUGO, proc_pid_statm),
3625 REG("maps", S_IRUGO, proc_pid_maps_operations),
3626#ifdef CONFIG_PROC_CHILDREN
3627 REG("children", S_IRUGO, proc_tid_children_operations),
3628#endif
3629#ifdef CONFIG_NUMA
3630 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3631#endif
3632 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3633 LNK("cwd", proc_cwd_link),
3634 LNK("root", proc_root_link),
3635 LNK("exe", proc_exe_link),
3636 REG("mounts", S_IRUGO, proc_mounts_operations),
3637 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3638#ifdef CONFIG_PROC_PAGE_MONITOR
3639 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3640 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3641 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3642 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3643#endif
3644#ifdef CONFIG_SECURITY
3645 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3646#endif
3647#ifdef CONFIG_KALLSYMS
3648 ONE("wchan", S_IRUGO, proc_pid_wchan),
3649#endif
3650#ifdef CONFIG_STACKTRACE
3651 ONE("stack", S_IRUSR, proc_pid_stack),
3652#endif
3653#ifdef CONFIG_SCHED_INFO
3654 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3655#endif
3656#ifdef CONFIG_LATENCYTOP
3657 REG("latency", S_IRUGO, proc_lstats_operations),
3658#endif
3659#ifdef CONFIG_PROC_PID_CPUSET
3660 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3661#endif
3662#ifdef CONFIG_CGROUPS
3663 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3664#endif
3665#ifdef CONFIG_PROC_CPU_RESCTRL
3666 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3667#endif
3668 ONE("oom_score", S_IRUGO, proc_oom_score),
3669 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3670 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3671#ifdef CONFIG_AUDIT
3672 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3673 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3674#endif
3675#ifdef CONFIG_FAULT_INJECTION
3676 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3677 REG("fail-nth", 0644, proc_fail_nth_operations),
3678#endif
3679#ifdef CONFIG_TASK_IO_ACCOUNTING
3680 ONE("io", S_IRUSR, proc_tid_io_accounting),
3681#endif
3682#ifdef CONFIG_USER_NS
3683 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3684 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3685 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3686 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3687#endif
3688#ifdef CONFIG_LIVEPATCH
3689 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3690#endif
3691#ifdef CONFIG_PROC_PID_ARCH_STATUS
3692 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3693#endif
3694#ifdef CONFIG_SECCOMP_CACHE_DEBUG
3695 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3696#endif
3697#ifdef CONFIG_KSM
3698 ONE("ksm_merging_pages", S_IRUSR, proc_pid_ksm_merging_pages),
3699 ONE("ksm_stat", S_IRUSR, proc_pid_ksm_stat),
3700#endif
3701};
3702
3703static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3704{
3705 return proc_pident_readdir(file, ctx,
3706 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3707}
3708
3709static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3710{
3711 return proc_pident_lookup(dir, dentry,
3712 tid_base_stuff,
3713 tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3714}
3715
3716static const struct file_operations proc_tid_base_operations = {
3717 .read = generic_read_dir,
3718 .iterate_shared = proc_tid_base_readdir,
3719 .llseek = generic_file_llseek,
3720};
3721
3722static const struct inode_operations proc_tid_base_inode_operations = {
3723 .lookup = proc_tid_base_lookup,
3724 .getattr = pid_getattr,
3725 .setattr = proc_setattr,
3726};
3727
3728static struct dentry *proc_task_instantiate(struct dentry *dentry,
3729 struct task_struct *task, const void *ptr)
3730{
3731 struct inode *inode;
3732 inode = proc_pid_make_base_inode(dentry->d_sb, task,
3733 S_IFDIR | S_IRUGO | S_IXUGO);
3734 if (!inode)
3735 return ERR_PTR(-ENOENT);
3736
3737 inode->i_op = &proc_tid_base_inode_operations;
3738 inode->i_fop = &proc_tid_base_operations;
3739 inode->i_flags |= S_IMMUTABLE;
3740
3741 set_nlink(inode, nlink_tid);
3742 pid_update_inode(task, inode);
3743
3744 d_set_d_op(dentry, &pid_dentry_operations);
3745 return d_splice_alias(inode, dentry);
3746}
3747
3748static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3749{
3750 struct task_struct *task;
3751 struct task_struct *leader = get_proc_task(dir);
3752 unsigned tid;
3753 struct proc_fs_info *fs_info;
3754 struct pid_namespace *ns;
3755 struct dentry *result = ERR_PTR(-ENOENT);
3756
3757 if (!leader)
3758 goto out_no_task;
3759
3760 tid = name_to_int(&dentry->d_name);
3761 if (tid == ~0U)
3762 goto out;
3763
3764 fs_info = proc_sb_info(dentry->d_sb);
3765 ns = fs_info->pid_ns;
3766 rcu_read_lock();
3767 task = find_task_by_pid_ns(tid, ns);
3768 if (task)
3769 get_task_struct(task);
3770 rcu_read_unlock();
3771 if (!task)
3772 goto out;
3773 if (!same_thread_group(leader, task))
3774 goto out_drop_task;
3775
3776 result = proc_task_instantiate(dentry, task, NULL);
3777out_drop_task:
3778 put_task_struct(task);
3779out:
3780 put_task_struct(leader);
3781out_no_task:
3782 return result;
3783}
3784
3785/*
3786 * Find the first tid of a thread group to return to user space.
3787 *
3788 * Usually this is just the thread group leader, but if the users
3789 * buffer was too small or there was a seek into the middle of the
3790 * directory we have more work todo.
3791 *
3792 * In the case of a short read we start with find_task_by_pid.
3793 *
3794 * In the case of a seek we start with the leader and walk nr
3795 * threads past it.
3796 */
3797static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3798 struct pid_namespace *ns)
3799{
3800 struct task_struct *pos, *task;
3801 unsigned long nr = f_pos;
3802
3803 if (nr != f_pos) /* 32bit overflow? */
3804 return NULL;
3805
3806 rcu_read_lock();
3807 task = pid_task(pid, PIDTYPE_PID);
3808 if (!task)
3809 goto fail;
3810
3811 /* Attempt to start with the tid of a thread */
3812 if (tid && nr) {
3813 pos = find_task_by_pid_ns(tid, ns);
3814 if (pos && same_thread_group(pos, task))
3815 goto found;
3816 }
3817
3818 /* If nr exceeds the number of threads there is nothing todo */
3819 if (nr >= get_nr_threads(task))
3820 goto fail;
3821
3822 /* If we haven't found our starting place yet start
3823 * with the leader and walk nr threads forward.
3824 */
3825 for_each_thread(task, pos) {
3826 if (!nr--)
3827 goto found;
3828 }
3829fail:
3830 pos = NULL;
3831 goto out;
3832found:
3833 get_task_struct(pos);
3834out:
3835 rcu_read_unlock();
3836 return pos;
3837}
3838
3839/*
3840 * Find the next thread in the thread list.
3841 * Return NULL if there is an error or no next thread.
3842 *
3843 * The reference to the input task_struct is released.
3844 */
3845static struct task_struct *next_tid(struct task_struct *start)
3846{
3847 struct task_struct *pos = NULL;
3848 rcu_read_lock();
3849 if (pid_alive(start)) {
3850 pos = __next_thread(start);
3851 if (pos)
3852 get_task_struct(pos);
3853 }
3854 rcu_read_unlock();
3855 put_task_struct(start);
3856 return pos;
3857}
3858
3859/* for the /proc/TGID/task/ directories */
3860static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3861{
3862 struct inode *inode = file_inode(file);
3863 struct task_struct *task;
3864 struct pid_namespace *ns;
3865 int tid;
3866
3867 if (proc_inode_is_dead(inode))
3868 return -ENOENT;
3869
3870 if (!dir_emit_dots(file, ctx))
3871 return 0;
3872
3873 /* f_version caches the tgid value that the last readdir call couldn't
3874 * return. lseek aka telldir automagically resets f_version to 0.
3875 */
3876 ns = proc_pid_ns(inode->i_sb);
3877 tid = (int)file->f_version;
3878 file->f_version = 0;
3879 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3880 task;
3881 task = next_tid(task), ctx->pos++) {
3882 char name[10 + 1];
3883 unsigned int len;
3884
3885 tid = task_pid_nr_ns(task, ns);
3886 if (!tid)
3887 continue; /* The task has just exited. */
3888 len = snprintf(name, sizeof(name), "%u", tid);
3889 if (!proc_fill_cache(file, ctx, name, len,
3890 proc_task_instantiate, task, NULL)) {
3891 /* returning this tgid failed, save it as the first
3892 * pid for the next readir call */
3893 file->f_version = (u64)tid;
3894 put_task_struct(task);
3895 break;
3896 }
3897 }
3898
3899 return 0;
3900}
3901
3902static int proc_task_getattr(struct mnt_idmap *idmap,
3903 const struct path *path, struct kstat *stat,
3904 u32 request_mask, unsigned int query_flags)
3905{
3906 struct inode *inode = d_inode(path->dentry);
3907 struct task_struct *p = get_proc_task(inode);
3908 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
3909
3910 if (p) {
3911 stat->nlink += get_nr_threads(p);
3912 put_task_struct(p);
3913 }
3914
3915 return 0;
3916}
3917
3918static const struct inode_operations proc_task_inode_operations = {
3919 .lookup = proc_task_lookup,
3920 .getattr = proc_task_getattr,
3921 .setattr = proc_setattr,
3922 .permission = proc_pid_permission,
3923};
3924
3925static const struct file_operations proc_task_operations = {
3926 .read = generic_read_dir,
3927 .iterate_shared = proc_task_readdir,
3928 .llseek = generic_file_llseek,
3929};
3930
3931void __init set_proc_pid_nlink(void)
3932{
3933 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3934 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3935}