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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 <asm/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/cgroup.h>
77#include <linux/cpuset.h>
78#include <linux/audit.h>
79#include <linux/poll.h>
80#include <linux/nsproxy.h>
81#include <linux/oom.h>
82#include <linux/elf.h>
83#include <linux/pid_namespace.h>
84#include <linux/fs_struct.h>
85#include <linux/slab.h>
86#ifdef CONFIG_HARDWALL
87#include <asm/hardwall.h>
88#endif
89#include "internal.h"
90
91/* NOTE:
92 * Implementing inode permission operations in /proc is almost
93 * certainly an error. Permission checks need to happen during
94 * each system call not at open time. The reason is that most of
95 * what we wish to check for permissions in /proc varies at runtime.
96 *
97 * The classic example of a problem is opening file descriptors
98 * in /proc for a task before it execs a suid executable.
99 */
100
101struct pid_entry {
102 char *name;
103 int len;
104 mode_t mode;
105 const struct inode_operations *iop;
106 const struct file_operations *fop;
107 union proc_op op;
108};
109
110#define NOD(NAME, MODE, IOP, FOP, OP) { \
111 .name = (NAME), \
112 .len = sizeof(NAME) - 1, \
113 .mode = MODE, \
114 .iop = IOP, \
115 .fop = FOP, \
116 .op = OP, \
117}
118
119#define DIR(NAME, MODE, iops, fops) \
120 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
121#define LNK(NAME, get_link) \
122 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
123 &proc_pid_link_inode_operations, NULL, \
124 { .proc_get_link = get_link } )
125#define REG(NAME, MODE, fops) \
126 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
127#define INF(NAME, MODE, read) \
128 NOD(NAME, (S_IFREG|(MODE)), \
129 NULL, &proc_info_file_operations, \
130 { .proc_read = read } )
131#define ONE(NAME, MODE, show) \
132 NOD(NAME, (S_IFREG|(MODE)), \
133 NULL, &proc_single_file_operations, \
134 { .proc_show = show } )
135
136/*
137 * Count the number of hardlinks for the pid_entry table, excluding the .
138 * and .. links.
139 */
140static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
141 unsigned int n)
142{
143 unsigned int i;
144 unsigned int count;
145
146 count = 0;
147 for (i = 0; i < n; ++i) {
148 if (S_ISDIR(entries[i].mode))
149 ++count;
150 }
151
152 return count;
153}
154
155static int get_task_root(struct task_struct *task, struct path *root)
156{
157 int result = -ENOENT;
158
159 task_lock(task);
160 if (task->fs) {
161 get_fs_root(task->fs, root);
162 result = 0;
163 }
164 task_unlock(task);
165 return result;
166}
167
168static int proc_cwd_link(struct inode *inode, struct path *path)
169{
170 struct task_struct *task = get_proc_task(inode);
171 int result = -ENOENT;
172
173 if (task) {
174 task_lock(task);
175 if (task->fs) {
176 get_fs_pwd(task->fs, path);
177 result = 0;
178 }
179 task_unlock(task);
180 put_task_struct(task);
181 }
182 return result;
183}
184
185static int proc_root_link(struct inode *inode, struct path *path)
186{
187 struct task_struct *task = get_proc_task(inode);
188 int result = -ENOENT;
189
190 if (task) {
191 result = get_task_root(task, path);
192 put_task_struct(task);
193 }
194 return result;
195}
196
197static struct mm_struct *__check_mem_permission(struct task_struct *task)
198{
199 struct mm_struct *mm;
200
201 mm = get_task_mm(task);
202 if (!mm)
203 return ERR_PTR(-EINVAL);
204
205 /*
206 * A task can always look at itself, in case it chooses
207 * to use system calls instead of load instructions.
208 */
209 if (task == current)
210 return mm;
211
212 /*
213 * If current is actively ptrace'ing, and would also be
214 * permitted to freshly attach with ptrace now, permit it.
215 */
216 if (task_is_stopped_or_traced(task)) {
217 int match;
218 rcu_read_lock();
219 match = (ptrace_parent(task) == current);
220 rcu_read_unlock();
221 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
222 return mm;
223 }
224
225 /*
226 * No one else is allowed.
227 */
228 mmput(mm);
229 return ERR_PTR(-EPERM);
230}
231
232/*
233 * If current may access user memory in @task return a reference to the
234 * corresponding mm, otherwise ERR_PTR.
235 */
236static struct mm_struct *check_mem_permission(struct task_struct *task)
237{
238 struct mm_struct *mm;
239 int err;
240
241 /*
242 * Avoid racing if task exec's as we might get a new mm but validate
243 * against old credentials.
244 */
245 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
246 if (err)
247 return ERR_PTR(err);
248
249 mm = __check_mem_permission(task);
250 mutex_unlock(&task->signal->cred_guard_mutex);
251
252 return mm;
253}
254
255struct mm_struct *mm_for_maps(struct task_struct *task)
256{
257 struct mm_struct *mm;
258 int err;
259
260 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
261 if (err)
262 return ERR_PTR(err);
263
264 mm = get_task_mm(task);
265 if (mm && mm != current->mm &&
266 !ptrace_may_access(task, PTRACE_MODE_READ)) {
267 mmput(mm);
268 mm = ERR_PTR(-EACCES);
269 }
270 mutex_unlock(&task->signal->cred_guard_mutex);
271
272 return mm;
273}
274
275static int proc_pid_cmdline(struct task_struct *task, char * buffer)
276{
277 int res = 0;
278 unsigned int len;
279 struct mm_struct *mm = get_task_mm(task);
280 if (!mm)
281 goto out;
282 if (!mm->arg_end)
283 goto out_mm; /* Shh! No looking before we're done */
284
285 len = mm->arg_end - mm->arg_start;
286
287 if (len > PAGE_SIZE)
288 len = PAGE_SIZE;
289
290 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
291
292 // If the nul at the end of args has been overwritten, then
293 // assume application is using setproctitle(3).
294 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
295 len = strnlen(buffer, res);
296 if (len < res) {
297 res = len;
298 } else {
299 len = mm->env_end - mm->env_start;
300 if (len > PAGE_SIZE - res)
301 len = PAGE_SIZE - res;
302 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
303 res = strnlen(buffer, res);
304 }
305 }
306out_mm:
307 mmput(mm);
308out:
309 return res;
310}
311
312static int proc_pid_auxv(struct task_struct *task, char *buffer)
313{
314 struct mm_struct *mm = mm_for_maps(task);
315 int res = PTR_ERR(mm);
316 if (mm && !IS_ERR(mm)) {
317 unsigned int nwords = 0;
318 do {
319 nwords += 2;
320 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
321 res = nwords * sizeof(mm->saved_auxv[0]);
322 if (res > PAGE_SIZE)
323 res = PAGE_SIZE;
324 memcpy(buffer, mm->saved_auxv, res);
325 mmput(mm);
326 }
327 return res;
328}
329
330
331#ifdef CONFIG_KALLSYMS
332/*
333 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
334 * Returns the resolved symbol. If that fails, simply return the address.
335 */
336static int proc_pid_wchan(struct task_struct *task, char *buffer)
337{
338 unsigned long wchan;
339 char symname[KSYM_NAME_LEN];
340
341 wchan = get_wchan(task);
342
343 if (lookup_symbol_name(wchan, symname) < 0)
344 if (!ptrace_may_access(task, PTRACE_MODE_READ))
345 return 0;
346 else
347 return sprintf(buffer, "%lu", wchan);
348 else
349 return sprintf(buffer, "%s", symname);
350}
351#endif /* CONFIG_KALLSYMS */
352
353static int lock_trace(struct task_struct *task)
354{
355 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
356 if (err)
357 return err;
358 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
359 mutex_unlock(&task->signal->cred_guard_mutex);
360 return -EPERM;
361 }
362 return 0;
363}
364
365static void unlock_trace(struct task_struct *task)
366{
367 mutex_unlock(&task->signal->cred_guard_mutex);
368}
369
370#ifdef CONFIG_STACKTRACE
371
372#define MAX_STACK_TRACE_DEPTH 64
373
374static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
375 struct pid *pid, struct task_struct *task)
376{
377 struct stack_trace trace;
378 unsigned long *entries;
379 int err;
380 int i;
381
382 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
383 if (!entries)
384 return -ENOMEM;
385
386 trace.nr_entries = 0;
387 trace.max_entries = MAX_STACK_TRACE_DEPTH;
388 trace.entries = entries;
389 trace.skip = 0;
390
391 err = lock_trace(task);
392 if (!err) {
393 save_stack_trace_tsk(task, &trace);
394
395 for (i = 0; i < trace.nr_entries; i++) {
396 seq_printf(m, "[<%pK>] %pS\n",
397 (void *)entries[i], (void *)entries[i]);
398 }
399 unlock_trace(task);
400 }
401 kfree(entries);
402
403 return err;
404}
405#endif
406
407#ifdef CONFIG_SCHEDSTATS
408/*
409 * Provides /proc/PID/schedstat
410 */
411static int proc_pid_schedstat(struct task_struct *task, char *buffer)
412{
413 return sprintf(buffer, "%llu %llu %lu\n",
414 (unsigned long long)task->se.sum_exec_runtime,
415 (unsigned long long)task->sched_info.run_delay,
416 task->sched_info.pcount);
417}
418#endif
419
420#ifdef CONFIG_LATENCYTOP
421static int lstats_show_proc(struct seq_file *m, void *v)
422{
423 int i;
424 struct inode *inode = m->private;
425 struct task_struct *task = get_proc_task(inode);
426
427 if (!task)
428 return -ESRCH;
429 seq_puts(m, "Latency Top version : v0.1\n");
430 for (i = 0; i < 32; i++) {
431 struct latency_record *lr = &task->latency_record[i];
432 if (lr->backtrace[0]) {
433 int q;
434 seq_printf(m, "%i %li %li",
435 lr->count, lr->time, lr->max);
436 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
437 unsigned long bt = lr->backtrace[q];
438 if (!bt)
439 break;
440 if (bt == ULONG_MAX)
441 break;
442 seq_printf(m, " %ps", (void *)bt);
443 }
444 seq_putc(m, '\n');
445 }
446
447 }
448 put_task_struct(task);
449 return 0;
450}
451
452static int lstats_open(struct inode *inode, struct file *file)
453{
454 return single_open(file, lstats_show_proc, inode);
455}
456
457static ssize_t lstats_write(struct file *file, const char __user *buf,
458 size_t count, loff_t *offs)
459{
460 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
461
462 if (!task)
463 return -ESRCH;
464 clear_all_latency_tracing(task);
465 put_task_struct(task);
466
467 return count;
468}
469
470static const struct file_operations proc_lstats_operations = {
471 .open = lstats_open,
472 .read = seq_read,
473 .write = lstats_write,
474 .llseek = seq_lseek,
475 .release = single_release,
476};
477
478#endif
479
480static int proc_oom_score(struct task_struct *task, char *buffer)
481{
482 unsigned long points = 0;
483
484 read_lock(&tasklist_lock);
485 if (pid_alive(task))
486 points = oom_badness(task, NULL, NULL,
487 totalram_pages + total_swap_pages);
488 read_unlock(&tasklist_lock);
489 return sprintf(buffer, "%lu\n", points);
490}
491
492struct limit_names {
493 char *name;
494 char *unit;
495};
496
497static const struct limit_names lnames[RLIM_NLIMITS] = {
498 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
499 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
500 [RLIMIT_DATA] = {"Max data size", "bytes"},
501 [RLIMIT_STACK] = {"Max stack size", "bytes"},
502 [RLIMIT_CORE] = {"Max core file size", "bytes"},
503 [RLIMIT_RSS] = {"Max resident set", "bytes"},
504 [RLIMIT_NPROC] = {"Max processes", "processes"},
505 [RLIMIT_NOFILE] = {"Max open files", "files"},
506 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
507 [RLIMIT_AS] = {"Max address space", "bytes"},
508 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
509 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
510 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
511 [RLIMIT_NICE] = {"Max nice priority", NULL},
512 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
513 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
514};
515
516/* Display limits for a process */
517static int proc_pid_limits(struct task_struct *task, char *buffer)
518{
519 unsigned int i;
520 int count = 0;
521 unsigned long flags;
522 char *bufptr = buffer;
523
524 struct rlimit rlim[RLIM_NLIMITS];
525
526 if (!lock_task_sighand(task, &flags))
527 return 0;
528 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
529 unlock_task_sighand(task, &flags);
530
531 /*
532 * print the file header
533 */
534 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
535 "Limit", "Soft Limit", "Hard Limit", "Units");
536
537 for (i = 0; i < RLIM_NLIMITS; i++) {
538 if (rlim[i].rlim_cur == RLIM_INFINITY)
539 count += sprintf(&bufptr[count], "%-25s %-20s ",
540 lnames[i].name, "unlimited");
541 else
542 count += sprintf(&bufptr[count], "%-25s %-20lu ",
543 lnames[i].name, rlim[i].rlim_cur);
544
545 if (rlim[i].rlim_max == RLIM_INFINITY)
546 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
547 else
548 count += sprintf(&bufptr[count], "%-20lu ",
549 rlim[i].rlim_max);
550
551 if (lnames[i].unit)
552 count += sprintf(&bufptr[count], "%-10s\n",
553 lnames[i].unit);
554 else
555 count += sprintf(&bufptr[count], "\n");
556 }
557
558 return count;
559}
560
561#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
562static int proc_pid_syscall(struct task_struct *task, char *buffer)
563{
564 long nr;
565 unsigned long args[6], sp, pc;
566 int res = lock_trace(task);
567 if (res)
568 return res;
569
570 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
571 res = sprintf(buffer, "running\n");
572 else if (nr < 0)
573 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
574 else
575 res = sprintf(buffer,
576 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
577 nr,
578 args[0], args[1], args[2], args[3], args[4], args[5],
579 sp, pc);
580 unlock_trace(task);
581 return res;
582}
583#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
584
585/************************************************************************/
586/* Here the fs part begins */
587/************************************************************************/
588
589/* permission checks */
590static int proc_fd_access_allowed(struct inode *inode)
591{
592 struct task_struct *task;
593 int allowed = 0;
594 /* Allow access to a task's file descriptors if it is us or we
595 * may use ptrace attach to the process and find out that
596 * information.
597 */
598 task = get_proc_task(inode);
599 if (task) {
600 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
601 put_task_struct(task);
602 }
603 return allowed;
604}
605
606int proc_setattr(struct dentry *dentry, struct iattr *attr)
607{
608 int error;
609 struct inode *inode = dentry->d_inode;
610
611 if (attr->ia_valid & ATTR_MODE)
612 return -EPERM;
613
614 error = inode_change_ok(inode, attr);
615 if (error)
616 return error;
617
618 if ((attr->ia_valid & ATTR_SIZE) &&
619 attr->ia_size != i_size_read(inode)) {
620 error = vmtruncate(inode, attr->ia_size);
621 if (error)
622 return error;
623 }
624
625 setattr_copy(inode, attr);
626 mark_inode_dirty(inode);
627 return 0;
628}
629
630static const struct inode_operations proc_def_inode_operations = {
631 .setattr = proc_setattr,
632};
633
634static int mounts_open_common(struct inode *inode, struct file *file,
635 const struct seq_operations *op)
636{
637 struct task_struct *task = get_proc_task(inode);
638 struct nsproxy *nsp;
639 struct mnt_namespace *ns = NULL;
640 struct path root;
641 struct proc_mounts *p;
642 int ret = -EINVAL;
643
644 if (task) {
645 rcu_read_lock();
646 nsp = task_nsproxy(task);
647 if (nsp) {
648 ns = nsp->mnt_ns;
649 if (ns)
650 get_mnt_ns(ns);
651 }
652 rcu_read_unlock();
653 if (ns && get_task_root(task, &root) == 0)
654 ret = 0;
655 put_task_struct(task);
656 }
657
658 if (!ns)
659 goto err;
660 if (ret)
661 goto err_put_ns;
662
663 ret = -ENOMEM;
664 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
665 if (!p)
666 goto err_put_path;
667
668 file->private_data = &p->m;
669 ret = seq_open(file, op);
670 if (ret)
671 goto err_free;
672
673 p->m.private = p;
674 p->ns = ns;
675 p->root = root;
676 p->m.poll_event = ns->event;
677
678 return 0;
679
680 err_free:
681 kfree(p);
682 err_put_path:
683 path_put(&root);
684 err_put_ns:
685 put_mnt_ns(ns);
686 err:
687 return ret;
688}
689
690static int mounts_release(struct inode *inode, struct file *file)
691{
692 struct proc_mounts *p = file->private_data;
693 path_put(&p->root);
694 put_mnt_ns(p->ns);
695 return seq_release(inode, file);
696}
697
698static unsigned mounts_poll(struct file *file, poll_table *wait)
699{
700 struct proc_mounts *p = file->private_data;
701 unsigned res = POLLIN | POLLRDNORM;
702
703 poll_wait(file, &p->ns->poll, wait);
704 if (mnt_had_events(p))
705 res |= POLLERR | POLLPRI;
706
707 return res;
708}
709
710static int mounts_open(struct inode *inode, struct file *file)
711{
712 return mounts_open_common(inode, file, &mounts_op);
713}
714
715static const struct file_operations proc_mounts_operations = {
716 .open = mounts_open,
717 .read = seq_read,
718 .llseek = seq_lseek,
719 .release = mounts_release,
720 .poll = mounts_poll,
721};
722
723static int mountinfo_open(struct inode *inode, struct file *file)
724{
725 return mounts_open_common(inode, file, &mountinfo_op);
726}
727
728static const struct file_operations proc_mountinfo_operations = {
729 .open = mountinfo_open,
730 .read = seq_read,
731 .llseek = seq_lseek,
732 .release = mounts_release,
733 .poll = mounts_poll,
734};
735
736static int mountstats_open(struct inode *inode, struct file *file)
737{
738 return mounts_open_common(inode, file, &mountstats_op);
739}
740
741static const struct file_operations proc_mountstats_operations = {
742 .open = mountstats_open,
743 .read = seq_read,
744 .llseek = seq_lseek,
745 .release = mounts_release,
746};
747
748#define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
749
750static ssize_t proc_info_read(struct file * file, char __user * buf,
751 size_t count, loff_t *ppos)
752{
753 struct inode * inode = file->f_path.dentry->d_inode;
754 unsigned long page;
755 ssize_t length;
756 struct task_struct *task = get_proc_task(inode);
757
758 length = -ESRCH;
759 if (!task)
760 goto out_no_task;
761
762 if (count > PROC_BLOCK_SIZE)
763 count = PROC_BLOCK_SIZE;
764
765 length = -ENOMEM;
766 if (!(page = __get_free_page(GFP_TEMPORARY)))
767 goto out;
768
769 length = PROC_I(inode)->op.proc_read(task, (char*)page);
770
771 if (length >= 0)
772 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
773 free_page(page);
774out:
775 put_task_struct(task);
776out_no_task:
777 return length;
778}
779
780static const struct file_operations proc_info_file_operations = {
781 .read = proc_info_read,
782 .llseek = generic_file_llseek,
783};
784
785static int proc_single_show(struct seq_file *m, void *v)
786{
787 struct inode *inode = m->private;
788 struct pid_namespace *ns;
789 struct pid *pid;
790 struct task_struct *task;
791 int ret;
792
793 ns = inode->i_sb->s_fs_info;
794 pid = proc_pid(inode);
795 task = get_pid_task(pid, PIDTYPE_PID);
796 if (!task)
797 return -ESRCH;
798
799 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
800
801 put_task_struct(task);
802 return ret;
803}
804
805static int proc_single_open(struct inode *inode, struct file *filp)
806{
807 return single_open(filp, proc_single_show, inode);
808}
809
810static const struct file_operations proc_single_file_operations = {
811 .open = proc_single_open,
812 .read = seq_read,
813 .llseek = seq_lseek,
814 .release = single_release,
815};
816
817static int mem_open(struct inode* inode, struct file* file)
818{
819 file->private_data = (void*)((long)current->self_exec_id);
820 /* OK to pass negative loff_t, we can catch out-of-range */
821 file->f_mode |= FMODE_UNSIGNED_OFFSET;
822 return 0;
823}
824
825static ssize_t mem_read(struct file * file, char __user * buf,
826 size_t count, loff_t *ppos)
827{
828 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
829 char *page;
830 unsigned long src = *ppos;
831 int ret = -ESRCH;
832 struct mm_struct *mm;
833
834 if (!task)
835 goto out_no_task;
836
837 ret = -ENOMEM;
838 page = (char *)__get_free_page(GFP_TEMPORARY);
839 if (!page)
840 goto out;
841
842 mm = check_mem_permission(task);
843 ret = PTR_ERR(mm);
844 if (IS_ERR(mm))
845 goto out_free;
846
847 ret = -EIO;
848
849 if (file->private_data != (void*)((long)current->self_exec_id))
850 goto out_put;
851
852 ret = 0;
853
854 while (count > 0) {
855 int this_len, retval;
856
857 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
858 retval = access_remote_vm(mm, src, page, this_len, 0);
859 if (!retval) {
860 if (!ret)
861 ret = -EIO;
862 break;
863 }
864
865 if (copy_to_user(buf, page, retval)) {
866 ret = -EFAULT;
867 break;
868 }
869
870 ret += retval;
871 src += retval;
872 buf += retval;
873 count -= retval;
874 }
875 *ppos = src;
876
877out_put:
878 mmput(mm);
879out_free:
880 free_page((unsigned long) page);
881out:
882 put_task_struct(task);
883out_no_task:
884 return ret;
885}
886
887static ssize_t mem_write(struct file * file, const char __user *buf,
888 size_t count, loff_t *ppos)
889{
890 int copied;
891 char *page;
892 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
893 unsigned long dst = *ppos;
894 struct mm_struct *mm;
895
896 copied = -ESRCH;
897 if (!task)
898 goto out_no_task;
899
900 copied = -ENOMEM;
901 page = (char *)__get_free_page(GFP_TEMPORARY);
902 if (!page)
903 goto out_task;
904
905 mm = check_mem_permission(task);
906 copied = PTR_ERR(mm);
907 if (IS_ERR(mm))
908 goto out_free;
909
910 copied = -EIO;
911 if (file->private_data != (void *)((long)current->self_exec_id))
912 goto out_mm;
913
914 copied = 0;
915 while (count > 0) {
916 int this_len, retval;
917
918 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
919 if (copy_from_user(page, buf, this_len)) {
920 copied = -EFAULT;
921 break;
922 }
923 retval = access_remote_vm(mm, dst, page, this_len, 1);
924 if (!retval) {
925 if (!copied)
926 copied = -EIO;
927 break;
928 }
929 copied += retval;
930 buf += retval;
931 dst += retval;
932 count -= retval;
933 }
934 *ppos = dst;
935
936out_mm:
937 mmput(mm);
938out_free:
939 free_page((unsigned long) page);
940out_task:
941 put_task_struct(task);
942out_no_task:
943 return copied;
944}
945
946loff_t mem_lseek(struct file *file, loff_t offset, int orig)
947{
948 switch (orig) {
949 case 0:
950 file->f_pos = offset;
951 break;
952 case 1:
953 file->f_pos += offset;
954 break;
955 default:
956 return -EINVAL;
957 }
958 force_successful_syscall_return();
959 return file->f_pos;
960}
961
962static const struct file_operations proc_mem_operations = {
963 .llseek = mem_lseek,
964 .read = mem_read,
965 .write = mem_write,
966 .open = mem_open,
967};
968
969static ssize_t environ_read(struct file *file, char __user *buf,
970 size_t count, loff_t *ppos)
971{
972 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
973 char *page;
974 unsigned long src = *ppos;
975 int ret = -ESRCH;
976 struct mm_struct *mm;
977
978 if (!task)
979 goto out_no_task;
980
981 ret = -ENOMEM;
982 page = (char *)__get_free_page(GFP_TEMPORARY);
983 if (!page)
984 goto out;
985
986
987 mm = mm_for_maps(task);
988 ret = PTR_ERR(mm);
989 if (!mm || IS_ERR(mm))
990 goto out_free;
991
992 ret = 0;
993 while (count > 0) {
994 int this_len, retval, max_len;
995
996 this_len = mm->env_end - (mm->env_start + src);
997
998 if (this_len <= 0)
999 break;
1000
1001 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
1002 this_len = (this_len > max_len) ? max_len : this_len;
1003
1004 retval = access_process_vm(task, (mm->env_start + src),
1005 page, this_len, 0);
1006
1007 if (retval <= 0) {
1008 ret = retval;
1009 break;
1010 }
1011
1012 if (copy_to_user(buf, page, retval)) {
1013 ret = -EFAULT;
1014 break;
1015 }
1016
1017 ret += retval;
1018 src += retval;
1019 buf += retval;
1020 count -= retval;
1021 }
1022 *ppos = src;
1023
1024 mmput(mm);
1025out_free:
1026 free_page((unsigned long) page);
1027out:
1028 put_task_struct(task);
1029out_no_task:
1030 return ret;
1031}
1032
1033static const struct file_operations proc_environ_operations = {
1034 .read = environ_read,
1035 .llseek = generic_file_llseek,
1036};
1037
1038static ssize_t oom_adjust_read(struct file *file, char __user *buf,
1039 size_t count, loff_t *ppos)
1040{
1041 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1042 char buffer[PROC_NUMBUF];
1043 size_t len;
1044 int oom_adjust = OOM_DISABLE;
1045 unsigned long flags;
1046
1047 if (!task)
1048 return -ESRCH;
1049
1050 if (lock_task_sighand(task, &flags)) {
1051 oom_adjust = task->signal->oom_adj;
1052 unlock_task_sighand(task, &flags);
1053 }
1054
1055 put_task_struct(task);
1056
1057 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
1058
1059 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1060}
1061
1062static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1063 size_t count, loff_t *ppos)
1064{
1065 struct task_struct *task;
1066 char buffer[PROC_NUMBUF];
1067 int oom_adjust;
1068 unsigned long flags;
1069 int err;
1070
1071 memset(buffer, 0, sizeof(buffer));
1072 if (count > sizeof(buffer) - 1)
1073 count = sizeof(buffer) - 1;
1074 if (copy_from_user(buffer, buf, count)) {
1075 err = -EFAULT;
1076 goto out;
1077 }
1078
1079 err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
1080 if (err)
1081 goto out;
1082 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1083 oom_adjust != OOM_DISABLE) {
1084 err = -EINVAL;
1085 goto out;
1086 }
1087
1088 task = get_proc_task(file->f_path.dentry->d_inode);
1089 if (!task) {
1090 err = -ESRCH;
1091 goto out;
1092 }
1093
1094 task_lock(task);
1095 if (!task->mm) {
1096 err = -EINVAL;
1097 goto err_task_lock;
1098 }
1099
1100 if (!lock_task_sighand(task, &flags)) {
1101 err = -ESRCH;
1102 goto err_task_lock;
1103 }
1104
1105 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1106 err = -EACCES;
1107 goto err_sighand;
1108 }
1109
1110 if (oom_adjust != task->signal->oom_adj) {
1111 if (oom_adjust == OOM_DISABLE)
1112 atomic_inc(&task->mm->oom_disable_count);
1113 if (task->signal->oom_adj == OOM_DISABLE)
1114 atomic_dec(&task->mm->oom_disable_count);
1115 }
1116
1117 /*
1118 * Warn that /proc/pid/oom_adj is deprecated, see
1119 * Documentation/feature-removal-schedule.txt.
1120 */
1121 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1122 current->comm, task_pid_nr(current), task_pid_nr(task),
1123 task_pid_nr(task));
1124 task->signal->oom_adj = oom_adjust;
1125 /*
1126 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1127 * value is always attainable.
1128 */
1129 if (task->signal->oom_adj == OOM_ADJUST_MAX)
1130 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
1131 else
1132 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
1133 -OOM_DISABLE;
1134err_sighand:
1135 unlock_task_sighand(task, &flags);
1136err_task_lock:
1137 task_unlock(task);
1138 put_task_struct(task);
1139out:
1140 return err < 0 ? err : count;
1141}
1142
1143static const struct file_operations proc_oom_adjust_operations = {
1144 .read = oom_adjust_read,
1145 .write = oom_adjust_write,
1146 .llseek = generic_file_llseek,
1147};
1148
1149static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1150 size_t count, loff_t *ppos)
1151{
1152 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1153 char buffer[PROC_NUMBUF];
1154 int oom_score_adj = OOM_SCORE_ADJ_MIN;
1155 unsigned long flags;
1156 size_t len;
1157
1158 if (!task)
1159 return -ESRCH;
1160 if (lock_task_sighand(task, &flags)) {
1161 oom_score_adj = task->signal->oom_score_adj;
1162 unlock_task_sighand(task, &flags);
1163 }
1164 put_task_struct(task);
1165 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
1166 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1167}
1168
1169static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1170 size_t count, loff_t *ppos)
1171{
1172 struct task_struct *task;
1173 char buffer[PROC_NUMBUF];
1174 unsigned long flags;
1175 int oom_score_adj;
1176 int err;
1177
1178 memset(buffer, 0, sizeof(buffer));
1179 if (count > sizeof(buffer) - 1)
1180 count = sizeof(buffer) - 1;
1181 if (copy_from_user(buffer, buf, count)) {
1182 err = -EFAULT;
1183 goto out;
1184 }
1185
1186 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1187 if (err)
1188 goto out;
1189 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1190 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1191 err = -EINVAL;
1192 goto out;
1193 }
1194
1195 task = get_proc_task(file->f_path.dentry->d_inode);
1196 if (!task) {
1197 err = -ESRCH;
1198 goto out;
1199 }
1200
1201 task_lock(task);
1202 if (!task->mm) {
1203 err = -EINVAL;
1204 goto err_task_lock;
1205 }
1206
1207 if (!lock_task_sighand(task, &flags)) {
1208 err = -ESRCH;
1209 goto err_task_lock;
1210 }
1211
1212 if (oom_score_adj < task->signal->oom_score_adj_min &&
1213 !capable(CAP_SYS_RESOURCE)) {
1214 err = -EACCES;
1215 goto err_sighand;
1216 }
1217
1218 if (oom_score_adj != task->signal->oom_score_adj) {
1219 if (oom_score_adj == OOM_SCORE_ADJ_MIN)
1220 atomic_inc(&task->mm->oom_disable_count);
1221 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1222 atomic_dec(&task->mm->oom_disable_count);
1223 }
1224 task->signal->oom_score_adj = oom_score_adj;
1225 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1226 task->signal->oom_score_adj_min = oom_score_adj;
1227 /*
1228 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1229 * always attainable.
1230 */
1231 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1232 task->signal->oom_adj = OOM_DISABLE;
1233 else
1234 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1235 OOM_SCORE_ADJ_MAX;
1236err_sighand:
1237 unlock_task_sighand(task, &flags);
1238err_task_lock:
1239 task_unlock(task);
1240 put_task_struct(task);
1241out:
1242 return err < 0 ? err : count;
1243}
1244
1245static const struct file_operations proc_oom_score_adj_operations = {
1246 .read = oom_score_adj_read,
1247 .write = oom_score_adj_write,
1248 .llseek = default_llseek,
1249};
1250
1251#ifdef CONFIG_AUDITSYSCALL
1252#define TMPBUFLEN 21
1253static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1254 size_t count, loff_t *ppos)
1255{
1256 struct inode * inode = file->f_path.dentry->d_inode;
1257 struct task_struct *task = get_proc_task(inode);
1258 ssize_t length;
1259 char tmpbuf[TMPBUFLEN];
1260
1261 if (!task)
1262 return -ESRCH;
1263 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1264 audit_get_loginuid(task));
1265 put_task_struct(task);
1266 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1267}
1268
1269static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1270 size_t count, loff_t *ppos)
1271{
1272 struct inode * inode = file->f_path.dentry->d_inode;
1273 char *page, *tmp;
1274 ssize_t length;
1275 uid_t loginuid;
1276
1277 if (!capable(CAP_AUDIT_CONTROL))
1278 return -EPERM;
1279
1280 rcu_read_lock();
1281 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1282 rcu_read_unlock();
1283 return -EPERM;
1284 }
1285 rcu_read_unlock();
1286
1287 if (count >= PAGE_SIZE)
1288 count = PAGE_SIZE - 1;
1289
1290 if (*ppos != 0) {
1291 /* No partial writes. */
1292 return -EINVAL;
1293 }
1294 page = (char*)__get_free_page(GFP_TEMPORARY);
1295 if (!page)
1296 return -ENOMEM;
1297 length = -EFAULT;
1298 if (copy_from_user(page, buf, count))
1299 goto out_free_page;
1300
1301 page[count] = '\0';
1302 loginuid = simple_strtoul(page, &tmp, 10);
1303 if (tmp == page) {
1304 length = -EINVAL;
1305 goto out_free_page;
1306
1307 }
1308 length = audit_set_loginuid(current, loginuid);
1309 if (likely(length == 0))
1310 length = count;
1311
1312out_free_page:
1313 free_page((unsigned long) page);
1314 return length;
1315}
1316
1317static const struct file_operations proc_loginuid_operations = {
1318 .read = proc_loginuid_read,
1319 .write = proc_loginuid_write,
1320 .llseek = generic_file_llseek,
1321};
1322
1323static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1324 size_t count, loff_t *ppos)
1325{
1326 struct inode * inode = file->f_path.dentry->d_inode;
1327 struct task_struct *task = get_proc_task(inode);
1328 ssize_t length;
1329 char tmpbuf[TMPBUFLEN];
1330
1331 if (!task)
1332 return -ESRCH;
1333 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1334 audit_get_sessionid(task));
1335 put_task_struct(task);
1336 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1337}
1338
1339static const struct file_operations proc_sessionid_operations = {
1340 .read = proc_sessionid_read,
1341 .llseek = generic_file_llseek,
1342};
1343#endif
1344
1345#ifdef CONFIG_FAULT_INJECTION
1346static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1347 size_t count, loff_t *ppos)
1348{
1349 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1350 char buffer[PROC_NUMBUF];
1351 size_t len;
1352 int make_it_fail;
1353
1354 if (!task)
1355 return -ESRCH;
1356 make_it_fail = task->make_it_fail;
1357 put_task_struct(task);
1358
1359 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1360
1361 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1362}
1363
1364static ssize_t proc_fault_inject_write(struct file * file,
1365 const char __user * buf, size_t count, loff_t *ppos)
1366{
1367 struct task_struct *task;
1368 char buffer[PROC_NUMBUF], *end;
1369 int make_it_fail;
1370
1371 if (!capable(CAP_SYS_RESOURCE))
1372 return -EPERM;
1373 memset(buffer, 0, sizeof(buffer));
1374 if (count > sizeof(buffer) - 1)
1375 count = sizeof(buffer) - 1;
1376 if (copy_from_user(buffer, buf, count))
1377 return -EFAULT;
1378 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1379 if (*end)
1380 return -EINVAL;
1381 task = get_proc_task(file->f_dentry->d_inode);
1382 if (!task)
1383 return -ESRCH;
1384 task->make_it_fail = make_it_fail;
1385 put_task_struct(task);
1386
1387 return count;
1388}
1389
1390static const struct file_operations proc_fault_inject_operations = {
1391 .read = proc_fault_inject_read,
1392 .write = proc_fault_inject_write,
1393 .llseek = generic_file_llseek,
1394};
1395#endif
1396
1397
1398#ifdef CONFIG_SCHED_DEBUG
1399/*
1400 * Print out various scheduling related per-task fields:
1401 */
1402static int sched_show(struct seq_file *m, void *v)
1403{
1404 struct inode *inode = m->private;
1405 struct task_struct *p;
1406
1407 p = get_proc_task(inode);
1408 if (!p)
1409 return -ESRCH;
1410 proc_sched_show_task(p, m);
1411
1412 put_task_struct(p);
1413
1414 return 0;
1415}
1416
1417static ssize_t
1418sched_write(struct file *file, const char __user *buf,
1419 size_t count, loff_t *offset)
1420{
1421 struct inode *inode = file->f_path.dentry->d_inode;
1422 struct task_struct *p;
1423
1424 p = get_proc_task(inode);
1425 if (!p)
1426 return -ESRCH;
1427 proc_sched_set_task(p);
1428
1429 put_task_struct(p);
1430
1431 return count;
1432}
1433
1434static int sched_open(struct inode *inode, struct file *filp)
1435{
1436 return single_open(filp, sched_show, inode);
1437}
1438
1439static const struct file_operations proc_pid_sched_operations = {
1440 .open = sched_open,
1441 .read = seq_read,
1442 .write = sched_write,
1443 .llseek = seq_lseek,
1444 .release = single_release,
1445};
1446
1447#endif
1448
1449#ifdef CONFIG_SCHED_AUTOGROUP
1450/*
1451 * Print out autogroup related information:
1452 */
1453static int sched_autogroup_show(struct seq_file *m, void *v)
1454{
1455 struct inode *inode = m->private;
1456 struct task_struct *p;
1457
1458 p = get_proc_task(inode);
1459 if (!p)
1460 return -ESRCH;
1461 proc_sched_autogroup_show_task(p, m);
1462
1463 put_task_struct(p);
1464
1465 return 0;
1466}
1467
1468static ssize_t
1469sched_autogroup_write(struct file *file, const char __user *buf,
1470 size_t count, loff_t *offset)
1471{
1472 struct inode *inode = file->f_path.dentry->d_inode;
1473 struct task_struct *p;
1474 char buffer[PROC_NUMBUF];
1475 int nice;
1476 int err;
1477
1478 memset(buffer, 0, sizeof(buffer));
1479 if (count > sizeof(buffer) - 1)
1480 count = sizeof(buffer) - 1;
1481 if (copy_from_user(buffer, buf, count))
1482 return -EFAULT;
1483
1484 err = kstrtoint(strstrip(buffer), 0, &nice);
1485 if (err < 0)
1486 return err;
1487
1488 p = get_proc_task(inode);
1489 if (!p)
1490 return -ESRCH;
1491
1492 err = nice;
1493 err = proc_sched_autogroup_set_nice(p, &err);
1494 if (err)
1495 count = err;
1496
1497 put_task_struct(p);
1498
1499 return count;
1500}
1501
1502static int sched_autogroup_open(struct inode *inode, struct file *filp)
1503{
1504 int ret;
1505
1506 ret = single_open(filp, sched_autogroup_show, NULL);
1507 if (!ret) {
1508 struct seq_file *m = filp->private_data;
1509
1510 m->private = inode;
1511 }
1512 return ret;
1513}
1514
1515static const struct file_operations proc_pid_sched_autogroup_operations = {
1516 .open = sched_autogroup_open,
1517 .read = seq_read,
1518 .write = sched_autogroup_write,
1519 .llseek = seq_lseek,
1520 .release = single_release,
1521};
1522
1523#endif /* CONFIG_SCHED_AUTOGROUP */
1524
1525static ssize_t comm_write(struct file *file, const char __user *buf,
1526 size_t count, loff_t *offset)
1527{
1528 struct inode *inode = file->f_path.dentry->d_inode;
1529 struct task_struct *p;
1530 char buffer[TASK_COMM_LEN];
1531
1532 memset(buffer, 0, sizeof(buffer));
1533 if (count > sizeof(buffer) - 1)
1534 count = sizeof(buffer) - 1;
1535 if (copy_from_user(buffer, buf, count))
1536 return -EFAULT;
1537
1538 p = get_proc_task(inode);
1539 if (!p)
1540 return -ESRCH;
1541
1542 if (same_thread_group(current, p))
1543 set_task_comm(p, buffer);
1544 else
1545 count = -EINVAL;
1546
1547 put_task_struct(p);
1548
1549 return count;
1550}
1551
1552static int comm_show(struct seq_file *m, void *v)
1553{
1554 struct inode *inode = m->private;
1555 struct task_struct *p;
1556
1557 p = get_proc_task(inode);
1558 if (!p)
1559 return -ESRCH;
1560
1561 task_lock(p);
1562 seq_printf(m, "%s\n", p->comm);
1563 task_unlock(p);
1564
1565 put_task_struct(p);
1566
1567 return 0;
1568}
1569
1570static int comm_open(struct inode *inode, struct file *filp)
1571{
1572 return single_open(filp, comm_show, inode);
1573}
1574
1575static const struct file_operations proc_pid_set_comm_operations = {
1576 .open = comm_open,
1577 .read = seq_read,
1578 .write = comm_write,
1579 .llseek = seq_lseek,
1580 .release = single_release,
1581};
1582
1583static int proc_exe_link(struct inode *inode, struct path *exe_path)
1584{
1585 struct task_struct *task;
1586 struct mm_struct *mm;
1587 struct file *exe_file;
1588
1589 task = get_proc_task(inode);
1590 if (!task)
1591 return -ENOENT;
1592 mm = get_task_mm(task);
1593 put_task_struct(task);
1594 if (!mm)
1595 return -ENOENT;
1596 exe_file = get_mm_exe_file(mm);
1597 mmput(mm);
1598 if (exe_file) {
1599 *exe_path = exe_file->f_path;
1600 path_get(&exe_file->f_path);
1601 fput(exe_file);
1602 return 0;
1603 } else
1604 return -ENOENT;
1605}
1606
1607static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1608{
1609 struct inode *inode = dentry->d_inode;
1610 int error = -EACCES;
1611
1612 /* We don't need a base pointer in the /proc filesystem */
1613 path_put(&nd->path);
1614
1615 /* Are we allowed to snoop on the tasks file descriptors? */
1616 if (!proc_fd_access_allowed(inode))
1617 goto out;
1618
1619 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1620out:
1621 return ERR_PTR(error);
1622}
1623
1624static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1625{
1626 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1627 char *pathname;
1628 int len;
1629
1630 if (!tmp)
1631 return -ENOMEM;
1632
1633 pathname = d_path(path, tmp, PAGE_SIZE);
1634 len = PTR_ERR(pathname);
1635 if (IS_ERR(pathname))
1636 goto out;
1637 len = tmp + PAGE_SIZE - 1 - pathname;
1638
1639 if (len > buflen)
1640 len = buflen;
1641 if (copy_to_user(buffer, pathname, len))
1642 len = -EFAULT;
1643 out:
1644 free_page((unsigned long)tmp);
1645 return len;
1646}
1647
1648static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1649{
1650 int error = -EACCES;
1651 struct inode *inode = dentry->d_inode;
1652 struct path path;
1653
1654 /* Are we allowed to snoop on the tasks file descriptors? */
1655 if (!proc_fd_access_allowed(inode))
1656 goto out;
1657
1658 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1659 if (error)
1660 goto out;
1661
1662 error = do_proc_readlink(&path, buffer, buflen);
1663 path_put(&path);
1664out:
1665 return error;
1666}
1667
1668static const struct inode_operations proc_pid_link_inode_operations = {
1669 .readlink = proc_pid_readlink,
1670 .follow_link = proc_pid_follow_link,
1671 .setattr = proc_setattr,
1672};
1673
1674
1675/* building an inode */
1676
1677static int task_dumpable(struct task_struct *task)
1678{
1679 int dumpable = 0;
1680 struct mm_struct *mm;
1681
1682 task_lock(task);
1683 mm = task->mm;
1684 if (mm)
1685 dumpable = get_dumpable(mm);
1686 task_unlock(task);
1687 if(dumpable == 1)
1688 return 1;
1689 return 0;
1690}
1691
1692struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1693{
1694 struct inode * inode;
1695 struct proc_inode *ei;
1696 const struct cred *cred;
1697
1698 /* We need a new inode */
1699
1700 inode = new_inode(sb);
1701 if (!inode)
1702 goto out;
1703
1704 /* Common stuff */
1705 ei = PROC_I(inode);
1706 inode->i_ino = get_next_ino();
1707 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1708 inode->i_op = &proc_def_inode_operations;
1709
1710 /*
1711 * grab the reference to task.
1712 */
1713 ei->pid = get_task_pid(task, PIDTYPE_PID);
1714 if (!ei->pid)
1715 goto out_unlock;
1716
1717 if (task_dumpable(task)) {
1718 rcu_read_lock();
1719 cred = __task_cred(task);
1720 inode->i_uid = cred->euid;
1721 inode->i_gid = cred->egid;
1722 rcu_read_unlock();
1723 }
1724 security_task_to_inode(task, inode);
1725
1726out:
1727 return inode;
1728
1729out_unlock:
1730 iput(inode);
1731 return NULL;
1732}
1733
1734int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1735{
1736 struct inode *inode = dentry->d_inode;
1737 struct task_struct *task;
1738 const struct cred *cred;
1739
1740 generic_fillattr(inode, stat);
1741
1742 rcu_read_lock();
1743 stat->uid = 0;
1744 stat->gid = 0;
1745 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1746 if (task) {
1747 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1748 task_dumpable(task)) {
1749 cred = __task_cred(task);
1750 stat->uid = cred->euid;
1751 stat->gid = cred->egid;
1752 }
1753 }
1754 rcu_read_unlock();
1755 return 0;
1756}
1757
1758/* dentry stuff */
1759
1760/*
1761 * Exceptional case: normally we are not allowed to unhash a busy
1762 * directory. In this case, however, we can do it - no aliasing problems
1763 * due to the way we treat inodes.
1764 *
1765 * Rewrite the inode's ownerships here because the owning task may have
1766 * performed a setuid(), etc.
1767 *
1768 * Before the /proc/pid/status file was created the only way to read
1769 * the effective uid of a /process was to stat /proc/pid. Reading
1770 * /proc/pid/status is slow enough that procps and other packages
1771 * kept stating /proc/pid. To keep the rules in /proc simple I have
1772 * made this apply to all per process world readable and executable
1773 * directories.
1774 */
1775int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1776{
1777 struct inode *inode;
1778 struct task_struct *task;
1779 const struct cred *cred;
1780
1781 if (nd && nd->flags & LOOKUP_RCU)
1782 return -ECHILD;
1783
1784 inode = dentry->d_inode;
1785 task = get_proc_task(inode);
1786
1787 if (task) {
1788 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1789 task_dumpable(task)) {
1790 rcu_read_lock();
1791 cred = __task_cred(task);
1792 inode->i_uid = cred->euid;
1793 inode->i_gid = cred->egid;
1794 rcu_read_unlock();
1795 } else {
1796 inode->i_uid = 0;
1797 inode->i_gid = 0;
1798 }
1799 inode->i_mode &= ~(S_ISUID | S_ISGID);
1800 security_task_to_inode(task, inode);
1801 put_task_struct(task);
1802 return 1;
1803 }
1804 d_drop(dentry);
1805 return 0;
1806}
1807
1808static int pid_delete_dentry(const struct dentry * dentry)
1809{
1810 /* Is the task we represent dead?
1811 * If so, then don't put the dentry on the lru list,
1812 * kill it immediately.
1813 */
1814 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1815}
1816
1817const struct dentry_operations pid_dentry_operations =
1818{
1819 .d_revalidate = pid_revalidate,
1820 .d_delete = pid_delete_dentry,
1821};
1822
1823/* Lookups */
1824
1825/*
1826 * Fill a directory entry.
1827 *
1828 * If possible create the dcache entry and derive our inode number and
1829 * file type from dcache entry.
1830 *
1831 * Since all of the proc inode numbers are dynamically generated, the inode
1832 * numbers do not exist until the inode is cache. This means creating the
1833 * the dcache entry in readdir is necessary to keep the inode numbers
1834 * reported by readdir in sync with the inode numbers reported
1835 * by stat.
1836 */
1837int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1838 const char *name, int len,
1839 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1840{
1841 struct dentry *child, *dir = filp->f_path.dentry;
1842 struct inode *inode;
1843 struct qstr qname;
1844 ino_t ino = 0;
1845 unsigned type = DT_UNKNOWN;
1846
1847 qname.name = name;
1848 qname.len = len;
1849 qname.hash = full_name_hash(name, len);
1850
1851 child = d_lookup(dir, &qname);
1852 if (!child) {
1853 struct dentry *new;
1854 new = d_alloc(dir, &qname);
1855 if (new) {
1856 child = instantiate(dir->d_inode, new, task, ptr);
1857 if (child)
1858 dput(new);
1859 else
1860 child = new;
1861 }
1862 }
1863 if (!child || IS_ERR(child) || !child->d_inode)
1864 goto end_instantiate;
1865 inode = child->d_inode;
1866 if (inode) {
1867 ino = inode->i_ino;
1868 type = inode->i_mode >> 12;
1869 }
1870 dput(child);
1871end_instantiate:
1872 if (!ino)
1873 ino = find_inode_number(dir, &qname);
1874 if (!ino)
1875 ino = 1;
1876 return filldir(dirent, name, len, filp->f_pos, ino, type);
1877}
1878
1879static unsigned name_to_int(struct dentry *dentry)
1880{
1881 const char *name = dentry->d_name.name;
1882 int len = dentry->d_name.len;
1883 unsigned n = 0;
1884
1885 if (len > 1 && *name == '0')
1886 goto out;
1887 while (len-- > 0) {
1888 unsigned c = *name++ - '0';
1889 if (c > 9)
1890 goto out;
1891 if (n >= (~0U-9)/10)
1892 goto out;
1893 n *= 10;
1894 n += c;
1895 }
1896 return n;
1897out:
1898 return ~0U;
1899}
1900
1901#define PROC_FDINFO_MAX 64
1902
1903static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1904{
1905 struct task_struct *task = get_proc_task(inode);
1906 struct files_struct *files = NULL;
1907 struct file *file;
1908 int fd = proc_fd(inode);
1909
1910 if (task) {
1911 files = get_files_struct(task);
1912 put_task_struct(task);
1913 }
1914 if (files) {
1915 /*
1916 * We are not taking a ref to the file structure, so we must
1917 * hold ->file_lock.
1918 */
1919 spin_lock(&files->file_lock);
1920 file = fcheck_files(files, fd);
1921 if (file) {
1922 unsigned int f_flags;
1923 struct fdtable *fdt;
1924
1925 fdt = files_fdtable(files);
1926 f_flags = file->f_flags & ~O_CLOEXEC;
1927 if (FD_ISSET(fd, fdt->close_on_exec))
1928 f_flags |= O_CLOEXEC;
1929
1930 if (path) {
1931 *path = file->f_path;
1932 path_get(&file->f_path);
1933 }
1934 if (info)
1935 snprintf(info, PROC_FDINFO_MAX,
1936 "pos:\t%lli\n"
1937 "flags:\t0%o\n",
1938 (long long) file->f_pos,
1939 f_flags);
1940 spin_unlock(&files->file_lock);
1941 put_files_struct(files);
1942 return 0;
1943 }
1944 spin_unlock(&files->file_lock);
1945 put_files_struct(files);
1946 }
1947 return -ENOENT;
1948}
1949
1950static int proc_fd_link(struct inode *inode, struct path *path)
1951{
1952 return proc_fd_info(inode, path, NULL);
1953}
1954
1955static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1956{
1957 struct inode *inode;
1958 struct task_struct *task;
1959 int fd;
1960 struct files_struct *files;
1961 const struct cred *cred;
1962
1963 if (nd && nd->flags & LOOKUP_RCU)
1964 return -ECHILD;
1965
1966 inode = dentry->d_inode;
1967 task = get_proc_task(inode);
1968 fd = proc_fd(inode);
1969
1970 if (task) {
1971 files = get_files_struct(task);
1972 if (files) {
1973 rcu_read_lock();
1974 if (fcheck_files(files, fd)) {
1975 rcu_read_unlock();
1976 put_files_struct(files);
1977 if (task_dumpable(task)) {
1978 rcu_read_lock();
1979 cred = __task_cred(task);
1980 inode->i_uid = cred->euid;
1981 inode->i_gid = cred->egid;
1982 rcu_read_unlock();
1983 } else {
1984 inode->i_uid = 0;
1985 inode->i_gid = 0;
1986 }
1987 inode->i_mode &= ~(S_ISUID | S_ISGID);
1988 security_task_to_inode(task, inode);
1989 put_task_struct(task);
1990 return 1;
1991 }
1992 rcu_read_unlock();
1993 put_files_struct(files);
1994 }
1995 put_task_struct(task);
1996 }
1997 d_drop(dentry);
1998 return 0;
1999}
2000
2001static const struct dentry_operations tid_fd_dentry_operations =
2002{
2003 .d_revalidate = tid_fd_revalidate,
2004 .d_delete = pid_delete_dentry,
2005};
2006
2007static struct dentry *proc_fd_instantiate(struct inode *dir,
2008 struct dentry *dentry, struct task_struct *task, const void *ptr)
2009{
2010 unsigned fd = *(const unsigned *)ptr;
2011 struct file *file;
2012 struct files_struct *files;
2013 struct inode *inode;
2014 struct proc_inode *ei;
2015 struct dentry *error = ERR_PTR(-ENOENT);
2016
2017 inode = proc_pid_make_inode(dir->i_sb, task);
2018 if (!inode)
2019 goto out;
2020 ei = PROC_I(inode);
2021 ei->fd = fd;
2022 files = get_files_struct(task);
2023 if (!files)
2024 goto out_iput;
2025 inode->i_mode = S_IFLNK;
2026
2027 /*
2028 * We are not taking a ref to the file structure, so we must
2029 * hold ->file_lock.
2030 */
2031 spin_lock(&files->file_lock);
2032 file = fcheck_files(files, fd);
2033 if (!file)
2034 goto out_unlock;
2035 if (file->f_mode & FMODE_READ)
2036 inode->i_mode |= S_IRUSR | S_IXUSR;
2037 if (file->f_mode & FMODE_WRITE)
2038 inode->i_mode |= S_IWUSR | S_IXUSR;
2039 spin_unlock(&files->file_lock);
2040 put_files_struct(files);
2041
2042 inode->i_op = &proc_pid_link_inode_operations;
2043 inode->i_size = 64;
2044 ei->op.proc_get_link = proc_fd_link;
2045 d_set_d_op(dentry, &tid_fd_dentry_operations);
2046 d_add(dentry, inode);
2047 /* Close the race of the process dying before we return the dentry */
2048 if (tid_fd_revalidate(dentry, NULL))
2049 error = NULL;
2050
2051 out:
2052 return error;
2053out_unlock:
2054 spin_unlock(&files->file_lock);
2055 put_files_struct(files);
2056out_iput:
2057 iput(inode);
2058 goto out;
2059}
2060
2061static struct dentry *proc_lookupfd_common(struct inode *dir,
2062 struct dentry *dentry,
2063 instantiate_t instantiate)
2064{
2065 struct task_struct *task = get_proc_task(dir);
2066 unsigned fd = name_to_int(dentry);
2067 struct dentry *result = ERR_PTR(-ENOENT);
2068
2069 if (!task)
2070 goto out_no_task;
2071 if (fd == ~0U)
2072 goto out;
2073
2074 result = instantiate(dir, dentry, task, &fd);
2075out:
2076 put_task_struct(task);
2077out_no_task:
2078 return result;
2079}
2080
2081static int proc_readfd_common(struct file * filp, void * dirent,
2082 filldir_t filldir, instantiate_t instantiate)
2083{
2084 struct dentry *dentry = filp->f_path.dentry;
2085 struct inode *inode = dentry->d_inode;
2086 struct task_struct *p = get_proc_task(inode);
2087 unsigned int fd, ino;
2088 int retval;
2089 struct files_struct * files;
2090
2091 retval = -ENOENT;
2092 if (!p)
2093 goto out_no_task;
2094 retval = 0;
2095
2096 fd = filp->f_pos;
2097 switch (fd) {
2098 case 0:
2099 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
2100 goto out;
2101 filp->f_pos++;
2102 case 1:
2103 ino = parent_ino(dentry);
2104 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2105 goto out;
2106 filp->f_pos++;
2107 default:
2108 files = get_files_struct(p);
2109 if (!files)
2110 goto out;
2111 rcu_read_lock();
2112 for (fd = filp->f_pos-2;
2113 fd < files_fdtable(files)->max_fds;
2114 fd++, filp->f_pos++) {
2115 char name[PROC_NUMBUF];
2116 int len;
2117
2118 if (!fcheck_files(files, fd))
2119 continue;
2120 rcu_read_unlock();
2121
2122 len = snprintf(name, sizeof(name), "%d", fd);
2123 if (proc_fill_cache(filp, dirent, filldir,
2124 name, len, instantiate,
2125 p, &fd) < 0) {
2126 rcu_read_lock();
2127 break;
2128 }
2129 rcu_read_lock();
2130 }
2131 rcu_read_unlock();
2132 put_files_struct(files);
2133 }
2134out:
2135 put_task_struct(p);
2136out_no_task:
2137 return retval;
2138}
2139
2140static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
2141 struct nameidata *nd)
2142{
2143 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
2144}
2145
2146static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
2147{
2148 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
2149}
2150
2151static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
2152 size_t len, loff_t *ppos)
2153{
2154 char tmp[PROC_FDINFO_MAX];
2155 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
2156 if (!err)
2157 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
2158 return err;
2159}
2160
2161static const struct file_operations proc_fdinfo_file_operations = {
2162 .open = nonseekable_open,
2163 .read = proc_fdinfo_read,
2164 .llseek = no_llseek,
2165};
2166
2167static const struct file_operations proc_fd_operations = {
2168 .read = generic_read_dir,
2169 .readdir = proc_readfd,
2170 .llseek = default_llseek,
2171};
2172
2173/*
2174 * /proc/pid/fd needs a special permission handler so that a process can still
2175 * access /proc/self/fd after it has executed a setuid().
2176 */
2177static int proc_fd_permission(struct inode *inode, int mask)
2178{
2179 int rv = generic_permission(inode, mask);
2180 if (rv == 0)
2181 return 0;
2182 if (task_pid(current) == proc_pid(inode))
2183 rv = 0;
2184 return rv;
2185}
2186
2187/*
2188 * proc directories can do almost nothing..
2189 */
2190static const struct inode_operations proc_fd_inode_operations = {
2191 .lookup = proc_lookupfd,
2192 .permission = proc_fd_permission,
2193 .setattr = proc_setattr,
2194};
2195
2196static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2197 struct dentry *dentry, struct task_struct *task, const void *ptr)
2198{
2199 unsigned fd = *(unsigned *)ptr;
2200 struct inode *inode;
2201 struct proc_inode *ei;
2202 struct dentry *error = ERR_PTR(-ENOENT);
2203
2204 inode = proc_pid_make_inode(dir->i_sb, task);
2205 if (!inode)
2206 goto out;
2207 ei = PROC_I(inode);
2208 ei->fd = fd;
2209 inode->i_mode = S_IFREG | S_IRUSR;
2210 inode->i_fop = &proc_fdinfo_file_operations;
2211 d_set_d_op(dentry, &tid_fd_dentry_operations);
2212 d_add(dentry, inode);
2213 /* Close the race of the process dying before we return the dentry */
2214 if (tid_fd_revalidate(dentry, NULL))
2215 error = NULL;
2216
2217 out:
2218 return error;
2219}
2220
2221static struct dentry *proc_lookupfdinfo(struct inode *dir,
2222 struct dentry *dentry,
2223 struct nameidata *nd)
2224{
2225 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2226}
2227
2228static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2229{
2230 return proc_readfd_common(filp, dirent, filldir,
2231 proc_fdinfo_instantiate);
2232}
2233
2234static const struct file_operations proc_fdinfo_operations = {
2235 .read = generic_read_dir,
2236 .readdir = proc_readfdinfo,
2237 .llseek = default_llseek,
2238};
2239
2240/*
2241 * proc directories can do almost nothing..
2242 */
2243static const struct inode_operations proc_fdinfo_inode_operations = {
2244 .lookup = proc_lookupfdinfo,
2245 .setattr = proc_setattr,
2246};
2247
2248
2249static struct dentry *proc_pident_instantiate(struct inode *dir,
2250 struct dentry *dentry, struct task_struct *task, const void *ptr)
2251{
2252 const struct pid_entry *p = ptr;
2253 struct inode *inode;
2254 struct proc_inode *ei;
2255 struct dentry *error = ERR_PTR(-ENOENT);
2256
2257 inode = proc_pid_make_inode(dir->i_sb, task);
2258 if (!inode)
2259 goto out;
2260
2261 ei = PROC_I(inode);
2262 inode->i_mode = p->mode;
2263 if (S_ISDIR(inode->i_mode))
2264 inode->i_nlink = 2; /* Use getattr to fix if necessary */
2265 if (p->iop)
2266 inode->i_op = p->iop;
2267 if (p->fop)
2268 inode->i_fop = p->fop;
2269 ei->op = p->op;
2270 d_set_d_op(dentry, &pid_dentry_operations);
2271 d_add(dentry, inode);
2272 /* Close the race of the process dying before we return the dentry */
2273 if (pid_revalidate(dentry, NULL))
2274 error = NULL;
2275out:
2276 return error;
2277}
2278
2279static struct dentry *proc_pident_lookup(struct inode *dir,
2280 struct dentry *dentry,
2281 const struct pid_entry *ents,
2282 unsigned int nents)
2283{
2284 struct dentry *error;
2285 struct task_struct *task = get_proc_task(dir);
2286 const struct pid_entry *p, *last;
2287
2288 error = ERR_PTR(-ENOENT);
2289
2290 if (!task)
2291 goto out_no_task;
2292
2293 /*
2294 * Yes, it does not scale. And it should not. Don't add
2295 * new entries into /proc/<tgid>/ without very good reasons.
2296 */
2297 last = &ents[nents - 1];
2298 for (p = ents; p <= last; p++) {
2299 if (p->len != dentry->d_name.len)
2300 continue;
2301 if (!memcmp(dentry->d_name.name, p->name, p->len))
2302 break;
2303 }
2304 if (p > last)
2305 goto out;
2306
2307 error = proc_pident_instantiate(dir, dentry, task, p);
2308out:
2309 put_task_struct(task);
2310out_no_task:
2311 return error;
2312}
2313
2314static int proc_pident_fill_cache(struct file *filp, void *dirent,
2315 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2316{
2317 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2318 proc_pident_instantiate, task, p);
2319}
2320
2321static int proc_pident_readdir(struct file *filp,
2322 void *dirent, filldir_t filldir,
2323 const struct pid_entry *ents, unsigned int nents)
2324{
2325 int i;
2326 struct dentry *dentry = filp->f_path.dentry;
2327 struct inode *inode = dentry->d_inode;
2328 struct task_struct *task = get_proc_task(inode);
2329 const struct pid_entry *p, *last;
2330 ino_t ino;
2331 int ret;
2332
2333 ret = -ENOENT;
2334 if (!task)
2335 goto out_no_task;
2336
2337 ret = 0;
2338 i = filp->f_pos;
2339 switch (i) {
2340 case 0:
2341 ino = inode->i_ino;
2342 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2343 goto out;
2344 i++;
2345 filp->f_pos++;
2346 /* fall through */
2347 case 1:
2348 ino = parent_ino(dentry);
2349 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2350 goto out;
2351 i++;
2352 filp->f_pos++;
2353 /* fall through */
2354 default:
2355 i -= 2;
2356 if (i >= nents) {
2357 ret = 1;
2358 goto out;
2359 }
2360 p = ents + i;
2361 last = &ents[nents - 1];
2362 while (p <= last) {
2363 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2364 goto out;
2365 filp->f_pos++;
2366 p++;
2367 }
2368 }
2369
2370 ret = 1;
2371out:
2372 put_task_struct(task);
2373out_no_task:
2374 return ret;
2375}
2376
2377#ifdef CONFIG_SECURITY
2378static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2379 size_t count, loff_t *ppos)
2380{
2381 struct inode * inode = file->f_path.dentry->d_inode;
2382 char *p = NULL;
2383 ssize_t length;
2384 struct task_struct *task = get_proc_task(inode);
2385
2386 if (!task)
2387 return -ESRCH;
2388
2389 length = security_getprocattr(task,
2390 (char*)file->f_path.dentry->d_name.name,
2391 &p);
2392 put_task_struct(task);
2393 if (length > 0)
2394 length = simple_read_from_buffer(buf, count, ppos, p, length);
2395 kfree(p);
2396 return length;
2397}
2398
2399static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2400 size_t count, loff_t *ppos)
2401{
2402 struct inode * inode = file->f_path.dentry->d_inode;
2403 char *page;
2404 ssize_t length;
2405 struct task_struct *task = get_proc_task(inode);
2406
2407 length = -ESRCH;
2408 if (!task)
2409 goto out_no_task;
2410 if (count > PAGE_SIZE)
2411 count = PAGE_SIZE;
2412
2413 /* No partial writes. */
2414 length = -EINVAL;
2415 if (*ppos != 0)
2416 goto out;
2417
2418 length = -ENOMEM;
2419 page = (char*)__get_free_page(GFP_TEMPORARY);
2420 if (!page)
2421 goto out;
2422
2423 length = -EFAULT;
2424 if (copy_from_user(page, buf, count))
2425 goto out_free;
2426
2427 /* Guard against adverse ptrace interaction */
2428 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2429 if (length < 0)
2430 goto out_free;
2431
2432 length = security_setprocattr(task,
2433 (char*)file->f_path.dentry->d_name.name,
2434 (void*)page, count);
2435 mutex_unlock(&task->signal->cred_guard_mutex);
2436out_free:
2437 free_page((unsigned long) page);
2438out:
2439 put_task_struct(task);
2440out_no_task:
2441 return length;
2442}
2443
2444static const struct file_operations proc_pid_attr_operations = {
2445 .read = proc_pid_attr_read,
2446 .write = proc_pid_attr_write,
2447 .llseek = generic_file_llseek,
2448};
2449
2450static const struct pid_entry attr_dir_stuff[] = {
2451 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2452 REG("prev", S_IRUGO, proc_pid_attr_operations),
2453 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2454 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2455 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2456 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2457};
2458
2459static int proc_attr_dir_readdir(struct file * filp,
2460 void * dirent, filldir_t filldir)
2461{
2462 return proc_pident_readdir(filp,dirent,filldir,
2463 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2464}
2465
2466static const struct file_operations proc_attr_dir_operations = {
2467 .read = generic_read_dir,
2468 .readdir = proc_attr_dir_readdir,
2469 .llseek = default_llseek,
2470};
2471
2472static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2473 struct dentry *dentry, struct nameidata *nd)
2474{
2475 return proc_pident_lookup(dir, dentry,
2476 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2477}
2478
2479static const struct inode_operations proc_attr_dir_inode_operations = {
2480 .lookup = proc_attr_dir_lookup,
2481 .getattr = pid_getattr,
2482 .setattr = proc_setattr,
2483};
2484
2485#endif
2486
2487#ifdef CONFIG_ELF_CORE
2488static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2489 size_t count, loff_t *ppos)
2490{
2491 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2492 struct mm_struct *mm;
2493 char buffer[PROC_NUMBUF];
2494 size_t len;
2495 int ret;
2496
2497 if (!task)
2498 return -ESRCH;
2499
2500 ret = 0;
2501 mm = get_task_mm(task);
2502 if (mm) {
2503 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2504 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2505 MMF_DUMP_FILTER_SHIFT));
2506 mmput(mm);
2507 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2508 }
2509
2510 put_task_struct(task);
2511
2512 return ret;
2513}
2514
2515static ssize_t proc_coredump_filter_write(struct file *file,
2516 const char __user *buf,
2517 size_t count,
2518 loff_t *ppos)
2519{
2520 struct task_struct *task;
2521 struct mm_struct *mm;
2522 char buffer[PROC_NUMBUF], *end;
2523 unsigned int val;
2524 int ret;
2525 int i;
2526 unsigned long mask;
2527
2528 ret = -EFAULT;
2529 memset(buffer, 0, sizeof(buffer));
2530 if (count > sizeof(buffer) - 1)
2531 count = sizeof(buffer) - 1;
2532 if (copy_from_user(buffer, buf, count))
2533 goto out_no_task;
2534
2535 ret = -EINVAL;
2536 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2537 if (*end == '\n')
2538 end++;
2539 if (end - buffer == 0)
2540 goto out_no_task;
2541
2542 ret = -ESRCH;
2543 task = get_proc_task(file->f_dentry->d_inode);
2544 if (!task)
2545 goto out_no_task;
2546
2547 ret = end - buffer;
2548 mm = get_task_mm(task);
2549 if (!mm)
2550 goto out_no_mm;
2551
2552 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2553 if (val & mask)
2554 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2555 else
2556 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2557 }
2558
2559 mmput(mm);
2560 out_no_mm:
2561 put_task_struct(task);
2562 out_no_task:
2563 return ret;
2564}
2565
2566static const struct file_operations proc_coredump_filter_operations = {
2567 .read = proc_coredump_filter_read,
2568 .write = proc_coredump_filter_write,
2569 .llseek = generic_file_llseek,
2570};
2571#endif
2572
2573/*
2574 * /proc/self:
2575 */
2576static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2577 int buflen)
2578{
2579 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2580 pid_t tgid = task_tgid_nr_ns(current, ns);
2581 char tmp[PROC_NUMBUF];
2582 if (!tgid)
2583 return -ENOENT;
2584 sprintf(tmp, "%d", tgid);
2585 return vfs_readlink(dentry,buffer,buflen,tmp);
2586}
2587
2588static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2589{
2590 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2591 pid_t tgid = task_tgid_nr_ns(current, ns);
2592 char *name = ERR_PTR(-ENOENT);
2593 if (tgid) {
2594 name = __getname();
2595 if (!name)
2596 name = ERR_PTR(-ENOMEM);
2597 else
2598 sprintf(name, "%d", tgid);
2599 }
2600 nd_set_link(nd, name);
2601 return NULL;
2602}
2603
2604static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2605 void *cookie)
2606{
2607 char *s = nd_get_link(nd);
2608 if (!IS_ERR(s))
2609 __putname(s);
2610}
2611
2612static const struct inode_operations proc_self_inode_operations = {
2613 .readlink = proc_self_readlink,
2614 .follow_link = proc_self_follow_link,
2615 .put_link = proc_self_put_link,
2616};
2617
2618/*
2619 * proc base
2620 *
2621 * These are the directory entries in the root directory of /proc
2622 * that properly belong to the /proc filesystem, as they describe
2623 * describe something that is process related.
2624 */
2625static const struct pid_entry proc_base_stuff[] = {
2626 NOD("self", S_IFLNK|S_IRWXUGO,
2627 &proc_self_inode_operations, NULL, {}),
2628};
2629
2630static struct dentry *proc_base_instantiate(struct inode *dir,
2631 struct dentry *dentry, struct task_struct *task, const void *ptr)
2632{
2633 const struct pid_entry *p = ptr;
2634 struct inode *inode;
2635 struct proc_inode *ei;
2636 struct dentry *error;
2637
2638 /* Allocate the inode */
2639 error = ERR_PTR(-ENOMEM);
2640 inode = new_inode(dir->i_sb);
2641 if (!inode)
2642 goto out;
2643
2644 /* Initialize the inode */
2645 ei = PROC_I(inode);
2646 inode->i_ino = get_next_ino();
2647 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2648
2649 /*
2650 * grab the reference to the task.
2651 */
2652 ei->pid = get_task_pid(task, PIDTYPE_PID);
2653 if (!ei->pid)
2654 goto out_iput;
2655
2656 inode->i_mode = p->mode;
2657 if (S_ISDIR(inode->i_mode))
2658 inode->i_nlink = 2;
2659 if (S_ISLNK(inode->i_mode))
2660 inode->i_size = 64;
2661 if (p->iop)
2662 inode->i_op = p->iop;
2663 if (p->fop)
2664 inode->i_fop = p->fop;
2665 ei->op = p->op;
2666 d_add(dentry, inode);
2667 error = NULL;
2668out:
2669 return error;
2670out_iput:
2671 iput(inode);
2672 goto out;
2673}
2674
2675static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2676{
2677 struct dentry *error;
2678 struct task_struct *task = get_proc_task(dir);
2679 const struct pid_entry *p, *last;
2680
2681 error = ERR_PTR(-ENOENT);
2682
2683 if (!task)
2684 goto out_no_task;
2685
2686 /* Lookup the directory entry */
2687 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2688 for (p = proc_base_stuff; p <= last; p++) {
2689 if (p->len != dentry->d_name.len)
2690 continue;
2691 if (!memcmp(dentry->d_name.name, p->name, p->len))
2692 break;
2693 }
2694 if (p > last)
2695 goto out;
2696
2697 error = proc_base_instantiate(dir, dentry, task, p);
2698
2699out:
2700 put_task_struct(task);
2701out_no_task:
2702 return error;
2703}
2704
2705static int proc_base_fill_cache(struct file *filp, void *dirent,
2706 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2707{
2708 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2709 proc_base_instantiate, task, p);
2710}
2711
2712#ifdef CONFIG_TASK_IO_ACCOUNTING
2713static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2714{
2715 struct task_io_accounting acct = task->ioac;
2716 unsigned long flags;
2717 int result;
2718
2719 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2720 if (result)
2721 return result;
2722
2723 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2724 result = -EACCES;
2725 goto out_unlock;
2726 }
2727
2728 if (whole && lock_task_sighand(task, &flags)) {
2729 struct task_struct *t = task;
2730
2731 task_io_accounting_add(&acct, &task->signal->ioac);
2732 while_each_thread(task, t)
2733 task_io_accounting_add(&acct, &t->ioac);
2734
2735 unlock_task_sighand(task, &flags);
2736 }
2737 result = sprintf(buffer,
2738 "rchar: %llu\n"
2739 "wchar: %llu\n"
2740 "syscr: %llu\n"
2741 "syscw: %llu\n"
2742 "read_bytes: %llu\n"
2743 "write_bytes: %llu\n"
2744 "cancelled_write_bytes: %llu\n",
2745 (unsigned long long)acct.rchar,
2746 (unsigned long long)acct.wchar,
2747 (unsigned long long)acct.syscr,
2748 (unsigned long long)acct.syscw,
2749 (unsigned long long)acct.read_bytes,
2750 (unsigned long long)acct.write_bytes,
2751 (unsigned long long)acct.cancelled_write_bytes);
2752out_unlock:
2753 mutex_unlock(&task->signal->cred_guard_mutex);
2754 return result;
2755}
2756
2757static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2758{
2759 return do_io_accounting(task, buffer, 0);
2760}
2761
2762static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2763{
2764 return do_io_accounting(task, buffer, 1);
2765}
2766#endif /* CONFIG_TASK_IO_ACCOUNTING */
2767
2768static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2769 struct pid *pid, struct task_struct *task)
2770{
2771 int err = lock_trace(task);
2772 if (!err) {
2773 seq_printf(m, "%08x\n", task->personality);
2774 unlock_trace(task);
2775 }
2776 return err;
2777}
2778
2779/*
2780 * Thread groups
2781 */
2782static const struct file_operations proc_task_operations;
2783static const struct inode_operations proc_task_inode_operations;
2784
2785static const struct pid_entry tgid_base_stuff[] = {
2786 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2787 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2788 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2789 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2790#ifdef CONFIG_NET
2791 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2792#endif
2793 REG("environ", S_IRUSR, proc_environ_operations),
2794 INF("auxv", S_IRUSR, proc_pid_auxv),
2795 ONE("status", S_IRUGO, proc_pid_status),
2796 ONE("personality", S_IRUGO, proc_pid_personality),
2797 INF("limits", S_IRUGO, proc_pid_limits),
2798#ifdef CONFIG_SCHED_DEBUG
2799 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2800#endif
2801#ifdef CONFIG_SCHED_AUTOGROUP
2802 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2803#endif
2804 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2805#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2806 INF("syscall", S_IRUGO, proc_pid_syscall),
2807#endif
2808 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2809 ONE("stat", S_IRUGO, proc_tgid_stat),
2810 ONE("statm", S_IRUGO, proc_pid_statm),
2811 REG("maps", S_IRUGO, proc_maps_operations),
2812#ifdef CONFIG_NUMA
2813 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2814#endif
2815 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2816 LNK("cwd", proc_cwd_link),
2817 LNK("root", proc_root_link),
2818 LNK("exe", proc_exe_link),
2819 REG("mounts", S_IRUGO, proc_mounts_operations),
2820 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2821 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2822#ifdef CONFIG_PROC_PAGE_MONITOR
2823 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2824 REG("smaps", S_IRUGO, proc_smaps_operations),
2825 REG("pagemap", S_IRUGO, proc_pagemap_operations),
2826#endif
2827#ifdef CONFIG_SECURITY
2828 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2829#endif
2830#ifdef CONFIG_KALLSYMS
2831 INF("wchan", S_IRUGO, proc_pid_wchan),
2832#endif
2833#ifdef CONFIG_STACKTRACE
2834 ONE("stack", S_IRUGO, proc_pid_stack),
2835#endif
2836#ifdef CONFIG_SCHEDSTATS
2837 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2838#endif
2839#ifdef CONFIG_LATENCYTOP
2840 REG("latency", S_IRUGO, proc_lstats_operations),
2841#endif
2842#ifdef CONFIG_PROC_PID_CPUSET
2843 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2844#endif
2845#ifdef CONFIG_CGROUPS
2846 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2847#endif
2848 INF("oom_score", S_IRUGO, proc_oom_score),
2849 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2850 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2851#ifdef CONFIG_AUDITSYSCALL
2852 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2853 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2854#endif
2855#ifdef CONFIG_FAULT_INJECTION
2856 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2857#endif
2858#ifdef CONFIG_ELF_CORE
2859 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2860#endif
2861#ifdef CONFIG_TASK_IO_ACCOUNTING
2862 INF("io", S_IRUSR, proc_tgid_io_accounting),
2863#endif
2864#ifdef CONFIG_HARDWALL
2865 INF("hardwall", S_IRUGO, proc_pid_hardwall),
2866#endif
2867};
2868
2869static int proc_tgid_base_readdir(struct file * filp,
2870 void * dirent, filldir_t filldir)
2871{
2872 return proc_pident_readdir(filp,dirent,filldir,
2873 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2874}
2875
2876static const struct file_operations proc_tgid_base_operations = {
2877 .read = generic_read_dir,
2878 .readdir = proc_tgid_base_readdir,
2879 .llseek = default_llseek,
2880};
2881
2882static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2883 return proc_pident_lookup(dir, dentry,
2884 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2885}
2886
2887static const struct inode_operations proc_tgid_base_inode_operations = {
2888 .lookup = proc_tgid_base_lookup,
2889 .getattr = pid_getattr,
2890 .setattr = proc_setattr,
2891};
2892
2893static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2894{
2895 struct dentry *dentry, *leader, *dir;
2896 char buf[PROC_NUMBUF];
2897 struct qstr name;
2898
2899 name.name = buf;
2900 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2901 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2902 if (dentry) {
2903 shrink_dcache_parent(dentry);
2904 d_drop(dentry);
2905 dput(dentry);
2906 }
2907
2908 name.name = buf;
2909 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2910 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2911 if (!leader)
2912 goto out;
2913
2914 name.name = "task";
2915 name.len = strlen(name.name);
2916 dir = d_hash_and_lookup(leader, &name);
2917 if (!dir)
2918 goto out_put_leader;
2919
2920 name.name = buf;
2921 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2922 dentry = d_hash_and_lookup(dir, &name);
2923 if (dentry) {
2924 shrink_dcache_parent(dentry);
2925 d_drop(dentry);
2926 dput(dentry);
2927 }
2928
2929 dput(dir);
2930out_put_leader:
2931 dput(leader);
2932out:
2933 return;
2934}
2935
2936/**
2937 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2938 * @task: task that should be flushed.
2939 *
2940 * When flushing dentries from proc, one needs to flush them from global
2941 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2942 * in. This call is supposed to do all of this job.
2943 *
2944 * Looks in the dcache for
2945 * /proc/@pid
2946 * /proc/@tgid/task/@pid
2947 * if either directory is present flushes it and all of it'ts children
2948 * from the dcache.
2949 *
2950 * It is safe and reasonable to cache /proc entries for a task until
2951 * that task exits. After that they just clog up the dcache with
2952 * useless entries, possibly causing useful dcache entries to be
2953 * flushed instead. This routine is proved to flush those useless
2954 * dcache entries at process exit time.
2955 *
2956 * NOTE: This routine is just an optimization so it does not guarantee
2957 * that no dcache entries will exist at process exit time it
2958 * just makes it very unlikely that any will persist.
2959 */
2960
2961void proc_flush_task(struct task_struct *task)
2962{
2963 int i;
2964 struct pid *pid, *tgid;
2965 struct upid *upid;
2966
2967 pid = task_pid(task);
2968 tgid = task_tgid(task);
2969
2970 for (i = 0; i <= pid->level; i++) {
2971 upid = &pid->numbers[i];
2972 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2973 tgid->numbers[i].nr);
2974 }
2975
2976 upid = &pid->numbers[pid->level];
2977 if (upid->nr == 1)
2978 pid_ns_release_proc(upid->ns);
2979}
2980
2981static struct dentry *proc_pid_instantiate(struct inode *dir,
2982 struct dentry * dentry,
2983 struct task_struct *task, const void *ptr)
2984{
2985 struct dentry *error = ERR_PTR(-ENOENT);
2986 struct inode *inode;
2987
2988 inode = proc_pid_make_inode(dir->i_sb, task);
2989 if (!inode)
2990 goto out;
2991
2992 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2993 inode->i_op = &proc_tgid_base_inode_operations;
2994 inode->i_fop = &proc_tgid_base_operations;
2995 inode->i_flags|=S_IMMUTABLE;
2996
2997 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2998 ARRAY_SIZE(tgid_base_stuff));
2999
3000 d_set_d_op(dentry, &pid_dentry_operations);
3001
3002 d_add(dentry, inode);
3003 /* Close the race of the process dying before we return the dentry */
3004 if (pid_revalidate(dentry, NULL))
3005 error = NULL;
3006out:
3007 return error;
3008}
3009
3010struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3011{
3012 struct dentry *result;
3013 struct task_struct *task;
3014 unsigned tgid;
3015 struct pid_namespace *ns;
3016
3017 result = proc_base_lookup(dir, dentry);
3018 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
3019 goto out;
3020
3021 tgid = name_to_int(dentry);
3022 if (tgid == ~0U)
3023 goto out;
3024
3025 ns = dentry->d_sb->s_fs_info;
3026 rcu_read_lock();
3027 task = find_task_by_pid_ns(tgid, ns);
3028 if (task)
3029 get_task_struct(task);
3030 rcu_read_unlock();
3031 if (!task)
3032 goto out;
3033
3034 result = proc_pid_instantiate(dir, dentry, task, NULL);
3035 put_task_struct(task);
3036out:
3037 return result;
3038}
3039
3040/*
3041 * Find the first task with tgid >= tgid
3042 *
3043 */
3044struct tgid_iter {
3045 unsigned int tgid;
3046 struct task_struct *task;
3047};
3048static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3049{
3050 struct pid *pid;
3051
3052 if (iter.task)
3053 put_task_struct(iter.task);
3054 rcu_read_lock();
3055retry:
3056 iter.task = NULL;
3057 pid = find_ge_pid(iter.tgid, ns);
3058 if (pid) {
3059 iter.tgid = pid_nr_ns(pid, ns);
3060 iter.task = pid_task(pid, PIDTYPE_PID);
3061 /* What we to know is if the pid we have find is the
3062 * pid of a thread_group_leader. Testing for task
3063 * being a thread_group_leader is the obvious thing
3064 * todo but there is a window when it fails, due to
3065 * the pid transfer logic in de_thread.
3066 *
3067 * So we perform the straight forward test of seeing
3068 * if the pid we have found is the pid of a thread
3069 * group leader, and don't worry if the task we have
3070 * found doesn't happen to be a thread group leader.
3071 * As we don't care in the case of readdir.
3072 */
3073 if (!iter.task || !has_group_leader_pid(iter.task)) {
3074 iter.tgid += 1;
3075 goto retry;
3076 }
3077 get_task_struct(iter.task);
3078 }
3079 rcu_read_unlock();
3080 return iter;
3081}
3082
3083#define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3084
3085static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3086 struct tgid_iter iter)
3087{
3088 char name[PROC_NUMBUF];
3089 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3090 return proc_fill_cache(filp, dirent, filldir, name, len,
3091 proc_pid_instantiate, iter.task, NULL);
3092}
3093
3094/* for the /proc/ directory itself, after non-process stuff has been done */
3095int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3096{
3097 unsigned int nr;
3098 struct task_struct *reaper;
3099 struct tgid_iter iter;
3100 struct pid_namespace *ns;
3101
3102 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3103 goto out_no_task;
3104 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3105
3106 reaper = get_proc_task(filp->f_path.dentry->d_inode);
3107 if (!reaper)
3108 goto out_no_task;
3109
3110 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3111 const struct pid_entry *p = &proc_base_stuff[nr];
3112 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3113 goto out;
3114 }
3115
3116 ns = filp->f_dentry->d_sb->s_fs_info;
3117 iter.task = NULL;
3118 iter.tgid = filp->f_pos - TGID_OFFSET;
3119 for (iter = next_tgid(ns, iter);
3120 iter.task;
3121 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3122 filp->f_pos = iter.tgid + TGID_OFFSET;
3123 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
3124 put_task_struct(iter.task);
3125 goto out;
3126 }
3127 }
3128 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3129out:
3130 put_task_struct(reaper);
3131out_no_task:
3132 return 0;
3133}
3134
3135/*
3136 * Tasks
3137 */
3138static const struct pid_entry tid_base_stuff[] = {
3139 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3140 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3141 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3142 REG("environ", S_IRUSR, proc_environ_operations),
3143 INF("auxv", S_IRUSR, proc_pid_auxv),
3144 ONE("status", S_IRUGO, proc_pid_status),
3145 ONE("personality", S_IRUGO, proc_pid_personality),
3146 INF("limits", S_IRUGO, proc_pid_limits),
3147#ifdef CONFIG_SCHED_DEBUG
3148 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3149#endif
3150 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3151#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3152 INF("syscall", S_IRUGO, proc_pid_syscall),
3153#endif
3154 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3155 ONE("stat", S_IRUGO, proc_tid_stat),
3156 ONE("statm", S_IRUGO, proc_pid_statm),
3157 REG("maps", S_IRUGO, proc_maps_operations),
3158#ifdef CONFIG_NUMA
3159 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3160#endif
3161 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3162 LNK("cwd", proc_cwd_link),
3163 LNK("root", proc_root_link),
3164 LNK("exe", proc_exe_link),
3165 REG("mounts", S_IRUGO, proc_mounts_operations),
3166 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3167#ifdef CONFIG_PROC_PAGE_MONITOR
3168 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3169 REG("smaps", S_IRUGO, proc_smaps_operations),
3170 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3171#endif
3172#ifdef CONFIG_SECURITY
3173 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3174#endif
3175#ifdef CONFIG_KALLSYMS
3176 INF("wchan", S_IRUGO, proc_pid_wchan),
3177#endif
3178#ifdef CONFIG_STACKTRACE
3179 ONE("stack", S_IRUGO, proc_pid_stack),
3180#endif
3181#ifdef CONFIG_SCHEDSTATS
3182 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3183#endif
3184#ifdef CONFIG_LATENCYTOP
3185 REG("latency", S_IRUGO, proc_lstats_operations),
3186#endif
3187#ifdef CONFIG_PROC_PID_CPUSET
3188 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3189#endif
3190#ifdef CONFIG_CGROUPS
3191 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3192#endif
3193 INF("oom_score", S_IRUGO, proc_oom_score),
3194 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3195 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3196#ifdef CONFIG_AUDITSYSCALL
3197 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3198 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3199#endif
3200#ifdef CONFIG_FAULT_INJECTION
3201 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3202#endif
3203#ifdef CONFIG_TASK_IO_ACCOUNTING
3204 INF("io", S_IRUSR, proc_tid_io_accounting),
3205#endif
3206#ifdef CONFIG_HARDWALL
3207 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3208#endif
3209};
3210
3211static int proc_tid_base_readdir(struct file * filp,
3212 void * dirent, filldir_t filldir)
3213{
3214 return proc_pident_readdir(filp,dirent,filldir,
3215 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3216}
3217
3218static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3219 return proc_pident_lookup(dir, dentry,
3220 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3221}
3222
3223static const struct file_operations proc_tid_base_operations = {
3224 .read = generic_read_dir,
3225 .readdir = proc_tid_base_readdir,
3226 .llseek = default_llseek,
3227};
3228
3229static const struct inode_operations proc_tid_base_inode_operations = {
3230 .lookup = proc_tid_base_lookup,
3231 .getattr = pid_getattr,
3232 .setattr = proc_setattr,
3233};
3234
3235static struct dentry *proc_task_instantiate(struct inode *dir,
3236 struct dentry *dentry, struct task_struct *task, const void *ptr)
3237{
3238 struct dentry *error = ERR_PTR(-ENOENT);
3239 struct inode *inode;
3240 inode = proc_pid_make_inode(dir->i_sb, task);
3241
3242 if (!inode)
3243 goto out;
3244 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3245 inode->i_op = &proc_tid_base_inode_operations;
3246 inode->i_fop = &proc_tid_base_operations;
3247 inode->i_flags|=S_IMMUTABLE;
3248
3249 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3250 ARRAY_SIZE(tid_base_stuff));
3251
3252 d_set_d_op(dentry, &pid_dentry_operations);
3253
3254 d_add(dentry, inode);
3255 /* Close the race of the process dying before we return the dentry */
3256 if (pid_revalidate(dentry, NULL))
3257 error = NULL;
3258out:
3259 return error;
3260}
3261
3262static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3263{
3264 struct dentry *result = ERR_PTR(-ENOENT);
3265 struct task_struct *task;
3266 struct task_struct *leader = get_proc_task(dir);
3267 unsigned tid;
3268 struct pid_namespace *ns;
3269
3270 if (!leader)
3271 goto out_no_task;
3272
3273 tid = name_to_int(dentry);
3274 if (tid == ~0U)
3275 goto out;
3276
3277 ns = dentry->d_sb->s_fs_info;
3278 rcu_read_lock();
3279 task = find_task_by_pid_ns(tid, ns);
3280 if (task)
3281 get_task_struct(task);
3282 rcu_read_unlock();
3283 if (!task)
3284 goto out;
3285 if (!same_thread_group(leader, task))
3286 goto out_drop_task;
3287
3288 result = proc_task_instantiate(dir, dentry, task, NULL);
3289out_drop_task:
3290 put_task_struct(task);
3291out:
3292 put_task_struct(leader);
3293out_no_task:
3294 return result;
3295}
3296
3297/*
3298 * Find the first tid of a thread group to return to user space.
3299 *
3300 * Usually this is just the thread group leader, but if the users
3301 * buffer was too small or there was a seek into the middle of the
3302 * directory we have more work todo.
3303 *
3304 * In the case of a short read we start with find_task_by_pid.
3305 *
3306 * In the case of a seek we start with the leader and walk nr
3307 * threads past it.
3308 */
3309static struct task_struct *first_tid(struct task_struct *leader,
3310 int tid, int nr, struct pid_namespace *ns)
3311{
3312 struct task_struct *pos;
3313
3314 rcu_read_lock();
3315 /* Attempt to start with the pid of a thread */
3316 if (tid && (nr > 0)) {
3317 pos = find_task_by_pid_ns(tid, ns);
3318 if (pos && (pos->group_leader == leader))
3319 goto found;
3320 }
3321
3322 /* If nr exceeds the number of threads there is nothing todo */
3323 pos = NULL;
3324 if (nr && nr >= get_nr_threads(leader))
3325 goto out;
3326
3327 /* If we haven't found our starting place yet start
3328 * with the leader and walk nr threads forward.
3329 */
3330 for (pos = leader; nr > 0; --nr) {
3331 pos = next_thread(pos);
3332 if (pos == leader) {
3333 pos = NULL;
3334 goto out;
3335 }
3336 }
3337found:
3338 get_task_struct(pos);
3339out:
3340 rcu_read_unlock();
3341 return pos;
3342}
3343
3344/*
3345 * Find the next thread in the thread list.
3346 * Return NULL if there is an error or no next thread.
3347 *
3348 * The reference to the input task_struct is released.
3349 */
3350static struct task_struct *next_tid(struct task_struct *start)
3351{
3352 struct task_struct *pos = NULL;
3353 rcu_read_lock();
3354 if (pid_alive(start)) {
3355 pos = next_thread(start);
3356 if (thread_group_leader(pos))
3357 pos = NULL;
3358 else
3359 get_task_struct(pos);
3360 }
3361 rcu_read_unlock();
3362 put_task_struct(start);
3363 return pos;
3364}
3365
3366static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3367 struct task_struct *task, int tid)
3368{
3369 char name[PROC_NUMBUF];
3370 int len = snprintf(name, sizeof(name), "%d", tid);
3371 return proc_fill_cache(filp, dirent, filldir, name, len,
3372 proc_task_instantiate, task, NULL);
3373}
3374
3375/* for the /proc/TGID/task/ directories */
3376static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3377{
3378 struct dentry *dentry = filp->f_path.dentry;
3379 struct inode *inode = dentry->d_inode;
3380 struct task_struct *leader = NULL;
3381 struct task_struct *task;
3382 int retval = -ENOENT;
3383 ino_t ino;
3384 int tid;
3385 struct pid_namespace *ns;
3386
3387 task = get_proc_task(inode);
3388 if (!task)
3389 goto out_no_task;
3390 rcu_read_lock();
3391 if (pid_alive(task)) {
3392 leader = task->group_leader;
3393 get_task_struct(leader);
3394 }
3395 rcu_read_unlock();
3396 put_task_struct(task);
3397 if (!leader)
3398 goto out_no_task;
3399 retval = 0;
3400
3401 switch ((unsigned long)filp->f_pos) {
3402 case 0:
3403 ino = inode->i_ino;
3404 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3405 goto out;
3406 filp->f_pos++;
3407 /* fall through */
3408 case 1:
3409 ino = parent_ino(dentry);
3410 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3411 goto out;
3412 filp->f_pos++;
3413 /* fall through */
3414 }
3415
3416 /* f_version caches the tgid value that the last readdir call couldn't
3417 * return. lseek aka telldir automagically resets f_version to 0.
3418 */
3419 ns = filp->f_dentry->d_sb->s_fs_info;
3420 tid = (int)filp->f_version;
3421 filp->f_version = 0;
3422 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3423 task;
3424 task = next_tid(task), filp->f_pos++) {
3425 tid = task_pid_nr_ns(task, ns);
3426 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3427 /* returning this tgid failed, save it as the first
3428 * pid for the next readir call */
3429 filp->f_version = (u64)tid;
3430 put_task_struct(task);
3431 break;
3432 }
3433 }
3434out:
3435 put_task_struct(leader);
3436out_no_task:
3437 return retval;
3438}
3439
3440static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3441{
3442 struct inode *inode = dentry->d_inode;
3443 struct task_struct *p = get_proc_task(inode);
3444 generic_fillattr(inode, stat);
3445
3446 if (p) {
3447 stat->nlink += get_nr_threads(p);
3448 put_task_struct(p);
3449 }
3450
3451 return 0;
3452}
3453
3454static const struct inode_operations proc_task_inode_operations = {
3455 .lookup = proc_task_lookup,
3456 .getattr = proc_task_getattr,
3457 .setattr = proc_setattr,
3458};
3459
3460static const struct file_operations proc_task_operations = {
3461 .read = generic_read_dir,
3462 .readdir = proc_task_readdir,
3463 .llseek = default_llseek,
3464};
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/tracehook.h>
78#include <linux/printk.h>
79#include <linux/cache.h>
80#include <linux/cgroup.h>
81#include <linux/cpuset.h>
82#include <linux/audit.h>
83#include <linux/poll.h>
84#include <linux/nsproxy.h>
85#include <linux/oom.h>
86#include <linux/elf.h>
87#include <linux/pid_namespace.h>
88#include <linux/user_namespace.h>
89#include <linux/fs_struct.h>
90#include <linux/slab.h>
91#include <linux/sched/autogroup.h>
92#include <linux/sched/mm.h>
93#include <linux/sched/coredump.h>
94#include <linux/sched/debug.h>
95#include <linux/sched/stat.h>
96#include <linux/posix-timers.h>
97#include <trace/events/oom.h>
98#include "internal.h"
99#include "fd.h"
100
101#include "../../lib/kstrtox.h"
102
103/* NOTE:
104 * Implementing inode permission operations in /proc is almost
105 * certainly an error. Permission checks need to happen during
106 * each system call not at open time. The reason is that most of
107 * what we wish to check for permissions in /proc varies at runtime.
108 *
109 * The classic example of a problem is opening file descriptors
110 * in /proc for a task before it execs a suid executable.
111 */
112
113static u8 nlink_tid __ro_after_init;
114static u8 nlink_tgid __ro_after_init;
115
116struct pid_entry {
117 const char *name;
118 unsigned int len;
119 umode_t mode;
120 const struct inode_operations *iop;
121 const struct file_operations *fop;
122 union proc_op op;
123};
124
125#define NOD(NAME, MODE, IOP, FOP, OP) { \
126 .name = (NAME), \
127 .len = sizeof(NAME) - 1, \
128 .mode = MODE, \
129 .iop = IOP, \
130 .fop = FOP, \
131 .op = OP, \
132}
133
134#define DIR(NAME, MODE, iops, fops) \
135 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
136#define LNK(NAME, get_link) \
137 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
138 &proc_pid_link_inode_operations, NULL, \
139 { .proc_get_link = get_link } )
140#define REG(NAME, MODE, fops) \
141 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
142#define ONE(NAME, MODE, show) \
143 NOD(NAME, (S_IFREG|(MODE)), \
144 NULL, &proc_single_file_operations, \
145 { .proc_show = show } )
146#define ATTR(LSM, NAME, MODE) \
147 NOD(NAME, (S_IFREG|(MODE)), \
148 NULL, &proc_pid_attr_operations, \
149 { .lsm = LSM })
150
151/*
152 * Count the number of hardlinks for the pid_entry table, excluding the .
153 * and .. links.
154 */
155static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
156 unsigned int n)
157{
158 unsigned int i;
159 unsigned int count;
160
161 count = 2;
162 for (i = 0; i < n; ++i) {
163 if (S_ISDIR(entries[i].mode))
164 ++count;
165 }
166
167 return count;
168}
169
170static int get_task_root(struct task_struct *task, struct path *root)
171{
172 int result = -ENOENT;
173
174 task_lock(task);
175 if (task->fs) {
176 get_fs_root(task->fs, root);
177 result = 0;
178 }
179 task_unlock(task);
180 return result;
181}
182
183static int proc_cwd_link(struct dentry *dentry, struct path *path)
184{
185 struct task_struct *task = get_proc_task(d_inode(dentry));
186 int result = -ENOENT;
187
188 if (task) {
189 task_lock(task);
190 if (task->fs) {
191 get_fs_pwd(task->fs, path);
192 result = 0;
193 }
194 task_unlock(task);
195 put_task_struct(task);
196 }
197 return result;
198}
199
200static int proc_root_link(struct dentry *dentry, struct path *path)
201{
202 struct task_struct *task = get_proc_task(d_inode(dentry));
203 int result = -ENOENT;
204
205 if (task) {
206 result = get_task_root(task, path);
207 put_task_struct(task);
208 }
209 return result;
210}
211
212/*
213 * If the user used setproctitle(), we just get the string from
214 * user space at arg_start, and limit it to a maximum of one page.
215 */
216static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
217 size_t count, unsigned long pos,
218 unsigned long arg_start)
219{
220 char *page;
221 int ret, got;
222
223 if (pos >= PAGE_SIZE)
224 return 0;
225
226 page = (char *)__get_free_page(GFP_KERNEL);
227 if (!page)
228 return -ENOMEM;
229
230 ret = 0;
231 got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
232 if (got > 0) {
233 int len = strnlen(page, got);
234
235 /* Include the NUL character if it was found */
236 if (len < got)
237 len++;
238
239 if (len > pos) {
240 len -= pos;
241 if (len > count)
242 len = count;
243 len -= copy_to_user(buf, page+pos, len);
244 if (!len)
245 len = -EFAULT;
246 ret = len;
247 }
248 }
249 free_page((unsigned long)page);
250 return ret;
251}
252
253static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
254 size_t count, loff_t *ppos)
255{
256 unsigned long arg_start, arg_end, env_start, env_end;
257 unsigned long pos, len;
258 char *page, c;
259
260 /* Check if process spawned far enough to have cmdline. */
261 if (!mm->env_end)
262 return 0;
263
264 spin_lock(&mm->arg_lock);
265 arg_start = mm->arg_start;
266 arg_end = mm->arg_end;
267 env_start = mm->env_start;
268 env_end = mm->env_end;
269 spin_unlock(&mm->arg_lock);
270
271 if (arg_start >= arg_end)
272 return 0;
273
274 /*
275 * We allow setproctitle() to overwrite the argument
276 * strings, and overflow past the original end. But
277 * only when it overflows into the environment area.
278 */
279 if (env_start != arg_end || env_end < env_start)
280 env_start = env_end = arg_end;
281 len = env_end - arg_start;
282
283 /* We're not going to care if "*ppos" has high bits set */
284 pos = *ppos;
285 if (pos >= len)
286 return 0;
287 if (count > len - pos)
288 count = len - pos;
289 if (!count)
290 return 0;
291
292 /*
293 * Magical special case: if the argv[] end byte is not
294 * zero, the user has overwritten it with setproctitle(3).
295 *
296 * Possible future enhancement: do this only once when
297 * pos is 0, and set a flag in the 'struct file'.
298 */
299 if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
300 return get_mm_proctitle(mm, buf, count, pos, arg_start);
301
302 /*
303 * For the non-setproctitle() case we limit things strictly
304 * to the [arg_start, arg_end[ range.
305 */
306 pos += arg_start;
307 if (pos < arg_start || pos >= arg_end)
308 return 0;
309 if (count > arg_end - pos)
310 count = arg_end - pos;
311
312 page = (char *)__get_free_page(GFP_KERNEL);
313 if (!page)
314 return -ENOMEM;
315
316 len = 0;
317 while (count) {
318 int got;
319 size_t size = min_t(size_t, PAGE_SIZE, count);
320
321 got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
322 if (got <= 0)
323 break;
324 got -= copy_to_user(buf, page, got);
325 if (unlikely(!got)) {
326 if (!len)
327 len = -EFAULT;
328 break;
329 }
330 pos += got;
331 buf += got;
332 len += got;
333 count -= got;
334 }
335
336 free_page((unsigned long)page);
337 return len;
338}
339
340static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
341 size_t count, loff_t *pos)
342{
343 struct mm_struct *mm;
344 ssize_t ret;
345
346 mm = get_task_mm(tsk);
347 if (!mm)
348 return 0;
349
350 ret = get_mm_cmdline(mm, buf, count, pos);
351 mmput(mm);
352 return ret;
353}
354
355static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
356 size_t count, loff_t *pos)
357{
358 struct task_struct *tsk;
359 ssize_t ret;
360
361 BUG_ON(*pos < 0);
362
363 tsk = get_proc_task(file_inode(file));
364 if (!tsk)
365 return -ESRCH;
366 ret = get_task_cmdline(tsk, buf, count, pos);
367 put_task_struct(tsk);
368 if (ret > 0)
369 *pos += ret;
370 return ret;
371}
372
373static const struct file_operations proc_pid_cmdline_ops = {
374 .read = proc_pid_cmdline_read,
375 .llseek = generic_file_llseek,
376};
377
378#ifdef CONFIG_KALLSYMS
379/*
380 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
381 * Returns the resolved symbol. If that fails, simply return the address.
382 */
383static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
384 struct pid *pid, struct task_struct *task)
385{
386 unsigned long wchan;
387 char symname[KSYM_NAME_LEN];
388
389 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
390 goto print0;
391
392 wchan = get_wchan(task);
393 if (wchan && !lookup_symbol_name(wchan, symname)) {
394 seq_puts(m, symname);
395 return 0;
396 }
397
398print0:
399 seq_putc(m, '0');
400 return 0;
401}
402#endif /* CONFIG_KALLSYMS */
403
404static int lock_trace(struct task_struct *task)
405{
406 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
407 if (err)
408 return err;
409 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
410 mutex_unlock(&task->signal->cred_guard_mutex);
411 return -EPERM;
412 }
413 return 0;
414}
415
416static void unlock_trace(struct task_struct *task)
417{
418 mutex_unlock(&task->signal->cred_guard_mutex);
419}
420
421#ifdef CONFIG_STACKTRACE
422
423#define MAX_STACK_TRACE_DEPTH 64
424
425static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
426 struct pid *pid, struct task_struct *task)
427{
428 unsigned long *entries;
429 int err;
430
431 /*
432 * The ability to racily run the kernel stack unwinder on a running task
433 * and then observe the unwinder output is scary; while it is useful for
434 * debugging kernel issues, it can also allow an attacker to leak kernel
435 * stack contents.
436 * Doing this in a manner that is at least safe from races would require
437 * some work to ensure that the remote task can not be scheduled; and
438 * even then, this would still expose the unwinder as local attack
439 * surface.
440 * Therefore, this interface is restricted to root.
441 */
442 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
443 return -EACCES;
444
445 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
446 GFP_KERNEL);
447 if (!entries)
448 return -ENOMEM;
449
450 err = lock_trace(task);
451 if (!err) {
452 unsigned int i, nr_entries;
453
454 nr_entries = stack_trace_save_tsk(task, entries,
455 MAX_STACK_TRACE_DEPTH, 0);
456
457 for (i = 0; i < nr_entries; i++) {
458 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
459 }
460
461 unlock_trace(task);
462 }
463 kfree(entries);
464
465 return err;
466}
467#endif
468
469#ifdef CONFIG_SCHED_INFO
470/*
471 * Provides /proc/PID/schedstat
472 */
473static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
474 struct pid *pid, struct task_struct *task)
475{
476 if (unlikely(!sched_info_on()))
477 seq_puts(m, "0 0 0\n");
478 else
479 seq_printf(m, "%llu %llu %lu\n",
480 (unsigned long long)task->se.sum_exec_runtime,
481 (unsigned long long)task->sched_info.run_delay,
482 task->sched_info.pcount);
483
484 return 0;
485}
486#endif
487
488#ifdef CONFIG_LATENCYTOP
489static int lstats_show_proc(struct seq_file *m, void *v)
490{
491 int i;
492 struct inode *inode = m->private;
493 struct task_struct *task = get_proc_task(inode);
494
495 if (!task)
496 return -ESRCH;
497 seq_puts(m, "Latency Top version : v0.1\n");
498 for (i = 0; i < LT_SAVECOUNT; i++) {
499 struct latency_record *lr = &task->latency_record[i];
500 if (lr->backtrace[0]) {
501 int q;
502 seq_printf(m, "%i %li %li",
503 lr->count, lr->time, lr->max);
504 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
505 unsigned long bt = lr->backtrace[q];
506
507 if (!bt)
508 break;
509 seq_printf(m, " %ps", (void *)bt);
510 }
511 seq_putc(m, '\n');
512 }
513
514 }
515 put_task_struct(task);
516 return 0;
517}
518
519static int lstats_open(struct inode *inode, struct file *file)
520{
521 return single_open(file, lstats_show_proc, inode);
522}
523
524static ssize_t lstats_write(struct file *file, const char __user *buf,
525 size_t count, loff_t *offs)
526{
527 struct task_struct *task = get_proc_task(file_inode(file));
528
529 if (!task)
530 return -ESRCH;
531 clear_tsk_latency_tracing(task);
532 put_task_struct(task);
533
534 return count;
535}
536
537static const struct file_operations proc_lstats_operations = {
538 .open = lstats_open,
539 .read = seq_read,
540 .write = lstats_write,
541 .llseek = seq_lseek,
542 .release = single_release,
543};
544
545#endif
546
547static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
548 struct pid *pid, struct task_struct *task)
549{
550 unsigned long totalpages = totalram_pages() + total_swap_pages;
551 unsigned long points = 0;
552
553 points = oom_badness(task, totalpages) * 1000 / totalpages;
554 seq_printf(m, "%lu\n", points);
555
556 return 0;
557}
558
559struct limit_names {
560 const char *name;
561 const char *unit;
562};
563
564static const struct limit_names lnames[RLIM_NLIMITS] = {
565 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
566 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
567 [RLIMIT_DATA] = {"Max data size", "bytes"},
568 [RLIMIT_STACK] = {"Max stack size", "bytes"},
569 [RLIMIT_CORE] = {"Max core file size", "bytes"},
570 [RLIMIT_RSS] = {"Max resident set", "bytes"},
571 [RLIMIT_NPROC] = {"Max processes", "processes"},
572 [RLIMIT_NOFILE] = {"Max open files", "files"},
573 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
574 [RLIMIT_AS] = {"Max address space", "bytes"},
575 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
576 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
577 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
578 [RLIMIT_NICE] = {"Max nice priority", NULL},
579 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
580 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
581};
582
583/* Display limits for a process */
584static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
585 struct pid *pid, struct task_struct *task)
586{
587 unsigned int i;
588 unsigned long flags;
589
590 struct rlimit rlim[RLIM_NLIMITS];
591
592 if (!lock_task_sighand(task, &flags))
593 return 0;
594 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
595 unlock_task_sighand(task, &flags);
596
597 /*
598 * print the file header
599 */
600 seq_puts(m, "Limit "
601 "Soft Limit "
602 "Hard Limit "
603 "Units \n");
604
605 for (i = 0; i < RLIM_NLIMITS; i++) {
606 if (rlim[i].rlim_cur == RLIM_INFINITY)
607 seq_printf(m, "%-25s %-20s ",
608 lnames[i].name, "unlimited");
609 else
610 seq_printf(m, "%-25s %-20lu ",
611 lnames[i].name, rlim[i].rlim_cur);
612
613 if (rlim[i].rlim_max == RLIM_INFINITY)
614 seq_printf(m, "%-20s ", "unlimited");
615 else
616 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
617
618 if (lnames[i].unit)
619 seq_printf(m, "%-10s\n", lnames[i].unit);
620 else
621 seq_putc(m, '\n');
622 }
623
624 return 0;
625}
626
627#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
628static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
629 struct pid *pid, struct task_struct *task)
630{
631 struct syscall_info info;
632 u64 *args = &info.data.args[0];
633 int res;
634
635 res = lock_trace(task);
636 if (res)
637 return res;
638
639 if (task_current_syscall(task, &info))
640 seq_puts(m, "running\n");
641 else if (info.data.nr < 0)
642 seq_printf(m, "%d 0x%llx 0x%llx\n",
643 info.data.nr, info.sp, info.data.instruction_pointer);
644 else
645 seq_printf(m,
646 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
647 info.data.nr,
648 args[0], args[1], args[2], args[3], args[4], args[5],
649 info.sp, info.data.instruction_pointer);
650 unlock_trace(task);
651
652 return 0;
653}
654#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
655
656/************************************************************************/
657/* Here the fs part begins */
658/************************************************************************/
659
660/* permission checks */
661static int proc_fd_access_allowed(struct inode *inode)
662{
663 struct task_struct *task;
664 int allowed = 0;
665 /* Allow access to a task's file descriptors if it is us or we
666 * may use ptrace attach to the process and find out that
667 * information.
668 */
669 task = get_proc_task(inode);
670 if (task) {
671 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
672 put_task_struct(task);
673 }
674 return allowed;
675}
676
677int proc_setattr(struct dentry *dentry, struct iattr *attr)
678{
679 int error;
680 struct inode *inode = d_inode(dentry);
681
682 if (attr->ia_valid & ATTR_MODE)
683 return -EPERM;
684
685 error = setattr_prepare(dentry, attr);
686 if (error)
687 return error;
688
689 setattr_copy(inode, attr);
690 mark_inode_dirty(inode);
691 return 0;
692}
693
694/*
695 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
696 * or euid/egid (for hide_pid_min=2)?
697 */
698static bool has_pid_permissions(struct pid_namespace *pid,
699 struct task_struct *task,
700 int hide_pid_min)
701{
702 if (pid->hide_pid < hide_pid_min)
703 return true;
704 if (in_group_p(pid->pid_gid))
705 return true;
706 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
707}
708
709
710static int proc_pid_permission(struct inode *inode, int mask)
711{
712 struct pid_namespace *pid = proc_pid_ns(inode);
713 struct task_struct *task;
714 bool has_perms;
715
716 task = get_proc_task(inode);
717 if (!task)
718 return -ESRCH;
719 has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS);
720 put_task_struct(task);
721
722 if (!has_perms) {
723 if (pid->hide_pid == HIDEPID_INVISIBLE) {
724 /*
725 * Let's make getdents(), stat(), and open()
726 * consistent with each other. If a process
727 * may not stat() a file, it shouldn't be seen
728 * in procfs at all.
729 */
730 return -ENOENT;
731 }
732
733 return -EPERM;
734 }
735 return generic_permission(inode, mask);
736}
737
738
739
740static const struct inode_operations proc_def_inode_operations = {
741 .setattr = proc_setattr,
742};
743
744static int proc_single_show(struct seq_file *m, void *v)
745{
746 struct inode *inode = m->private;
747 struct pid_namespace *ns = proc_pid_ns(inode);
748 struct pid *pid = proc_pid(inode);
749 struct task_struct *task;
750 int ret;
751
752 task = get_pid_task(pid, PIDTYPE_PID);
753 if (!task)
754 return -ESRCH;
755
756 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
757
758 put_task_struct(task);
759 return ret;
760}
761
762static int proc_single_open(struct inode *inode, struct file *filp)
763{
764 return single_open(filp, proc_single_show, inode);
765}
766
767static const struct file_operations proc_single_file_operations = {
768 .open = proc_single_open,
769 .read = seq_read,
770 .llseek = seq_lseek,
771 .release = single_release,
772};
773
774
775struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
776{
777 struct task_struct *task = get_proc_task(inode);
778 struct mm_struct *mm = ERR_PTR(-ESRCH);
779
780 if (task) {
781 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
782 put_task_struct(task);
783
784 if (!IS_ERR_OR_NULL(mm)) {
785 /* ensure this mm_struct can't be freed */
786 mmgrab(mm);
787 /* but do not pin its memory */
788 mmput(mm);
789 }
790 }
791
792 return mm;
793}
794
795static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
796{
797 struct mm_struct *mm = proc_mem_open(inode, mode);
798
799 if (IS_ERR(mm))
800 return PTR_ERR(mm);
801
802 file->private_data = mm;
803 return 0;
804}
805
806static int mem_open(struct inode *inode, struct file *file)
807{
808 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
809
810 /* OK to pass negative loff_t, we can catch out-of-range */
811 file->f_mode |= FMODE_UNSIGNED_OFFSET;
812
813 return ret;
814}
815
816static ssize_t mem_rw(struct file *file, char __user *buf,
817 size_t count, loff_t *ppos, int write)
818{
819 struct mm_struct *mm = file->private_data;
820 unsigned long addr = *ppos;
821 ssize_t copied;
822 char *page;
823 unsigned int flags;
824
825 if (!mm)
826 return 0;
827
828 page = (char *)__get_free_page(GFP_KERNEL);
829 if (!page)
830 return -ENOMEM;
831
832 copied = 0;
833 if (!mmget_not_zero(mm))
834 goto free;
835
836 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
837
838 while (count > 0) {
839 int this_len = min_t(int, count, PAGE_SIZE);
840
841 if (write && copy_from_user(page, buf, this_len)) {
842 copied = -EFAULT;
843 break;
844 }
845
846 this_len = access_remote_vm(mm, addr, page, this_len, flags);
847 if (!this_len) {
848 if (!copied)
849 copied = -EIO;
850 break;
851 }
852
853 if (!write && copy_to_user(buf, page, this_len)) {
854 copied = -EFAULT;
855 break;
856 }
857
858 buf += this_len;
859 addr += this_len;
860 copied += this_len;
861 count -= this_len;
862 }
863 *ppos = addr;
864
865 mmput(mm);
866free:
867 free_page((unsigned long) page);
868 return copied;
869}
870
871static ssize_t mem_read(struct file *file, char __user *buf,
872 size_t count, loff_t *ppos)
873{
874 return mem_rw(file, buf, count, ppos, 0);
875}
876
877static ssize_t mem_write(struct file *file, const char __user *buf,
878 size_t count, loff_t *ppos)
879{
880 return mem_rw(file, (char __user*)buf, count, ppos, 1);
881}
882
883loff_t mem_lseek(struct file *file, loff_t offset, int orig)
884{
885 switch (orig) {
886 case 0:
887 file->f_pos = offset;
888 break;
889 case 1:
890 file->f_pos += offset;
891 break;
892 default:
893 return -EINVAL;
894 }
895 force_successful_syscall_return();
896 return file->f_pos;
897}
898
899static int mem_release(struct inode *inode, struct file *file)
900{
901 struct mm_struct *mm = file->private_data;
902 if (mm)
903 mmdrop(mm);
904 return 0;
905}
906
907static const struct file_operations proc_mem_operations = {
908 .llseek = mem_lseek,
909 .read = mem_read,
910 .write = mem_write,
911 .open = mem_open,
912 .release = mem_release,
913};
914
915static int environ_open(struct inode *inode, struct file *file)
916{
917 return __mem_open(inode, file, PTRACE_MODE_READ);
918}
919
920static ssize_t environ_read(struct file *file, char __user *buf,
921 size_t count, loff_t *ppos)
922{
923 char *page;
924 unsigned long src = *ppos;
925 int ret = 0;
926 struct mm_struct *mm = file->private_data;
927 unsigned long env_start, env_end;
928
929 /* Ensure the process spawned far enough to have an environment. */
930 if (!mm || !mm->env_end)
931 return 0;
932
933 page = (char *)__get_free_page(GFP_KERNEL);
934 if (!page)
935 return -ENOMEM;
936
937 ret = 0;
938 if (!mmget_not_zero(mm))
939 goto free;
940
941 spin_lock(&mm->arg_lock);
942 env_start = mm->env_start;
943 env_end = mm->env_end;
944 spin_unlock(&mm->arg_lock);
945
946 while (count > 0) {
947 size_t this_len, max_len;
948 int retval;
949
950 if (src >= (env_end - env_start))
951 break;
952
953 this_len = env_end - (env_start + src);
954
955 max_len = min_t(size_t, PAGE_SIZE, count);
956 this_len = min(max_len, this_len);
957
958 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
959
960 if (retval <= 0) {
961 ret = retval;
962 break;
963 }
964
965 if (copy_to_user(buf, page, retval)) {
966 ret = -EFAULT;
967 break;
968 }
969
970 ret += retval;
971 src += retval;
972 buf += retval;
973 count -= retval;
974 }
975 *ppos = src;
976 mmput(mm);
977
978free:
979 free_page((unsigned long) page);
980 return ret;
981}
982
983static const struct file_operations proc_environ_operations = {
984 .open = environ_open,
985 .read = environ_read,
986 .llseek = generic_file_llseek,
987 .release = mem_release,
988};
989
990static int auxv_open(struct inode *inode, struct file *file)
991{
992 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
993}
994
995static ssize_t auxv_read(struct file *file, char __user *buf,
996 size_t count, loff_t *ppos)
997{
998 struct mm_struct *mm = file->private_data;
999 unsigned int nwords = 0;
1000
1001 if (!mm)
1002 return 0;
1003 do {
1004 nwords += 2;
1005 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1006 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1007 nwords * sizeof(mm->saved_auxv[0]));
1008}
1009
1010static const struct file_operations proc_auxv_operations = {
1011 .open = auxv_open,
1012 .read = auxv_read,
1013 .llseek = generic_file_llseek,
1014 .release = mem_release,
1015};
1016
1017static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1018 loff_t *ppos)
1019{
1020 struct task_struct *task = get_proc_task(file_inode(file));
1021 char buffer[PROC_NUMBUF];
1022 int oom_adj = OOM_ADJUST_MIN;
1023 size_t len;
1024
1025 if (!task)
1026 return -ESRCH;
1027 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1028 oom_adj = OOM_ADJUST_MAX;
1029 else
1030 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1031 OOM_SCORE_ADJ_MAX;
1032 put_task_struct(task);
1033 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1034 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1035}
1036
1037static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1038{
1039 static DEFINE_MUTEX(oom_adj_mutex);
1040 struct mm_struct *mm = NULL;
1041 struct task_struct *task;
1042 int err = 0;
1043
1044 task = get_proc_task(file_inode(file));
1045 if (!task)
1046 return -ESRCH;
1047
1048 mutex_lock(&oom_adj_mutex);
1049 if (legacy) {
1050 if (oom_adj < task->signal->oom_score_adj &&
1051 !capable(CAP_SYS_RESOURCE)) {
1052 err = -EACCES;
1053 goto err_unlock;
1054 }
1055 /*
1056 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1057 * /proc/pid/oom_score_adj instead.
1058 */
1059 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1060 current->comm, task_pid_nr(current), task_pid_nr(task),
1061 task_pid_nr(task));
1062 } else {
1063 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1064 !capable(CAP_SYS_RESOURCE)) {
1065 err = -EACCES;
1066 goto err_unlock;
1067 }
1068 }
1069
1070 /*
1071 * Make sure we will check other processes sharing the mm if this is
1072 * not vfrok which wants its own oom_score_adj.
1073 * pin the mm so it doesn't go away and get reused after task_unlock
1074 */
1075 if (!task->vfork_done) {
1076 struct task_struct *p = find_lock_task_mm(task);
1077
1078 if (p) {
1079 if (atomic_read(&p->mm->mm_users) > 1) {
1080 mm = p->mm;
1081 mmgrab(mm);
1082 }
1083 task_unlock(p);
1084 }
1085 }
1086
1087 task->signal->oom_score_adj = oom_adj;
1088 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1089 task->signal->oom_score_adj_min = (short)oom_adj;
1090 trace_oom_score_adj_update(task);
1091
1092 if (mm) {
1093 struct task_struct *p;
1094
1095 rcu_read_lock();
1096 for_each_process(p) {
1097 if (same_thread_group(task, p))
1098 continue;
1099
1100 /* do not touch kernel threads or the global init */
1101 if (p->flags & PF_KTHREAD || is_global_init(p))
1102 continue;
1103
1104 task_lock(p);
1105 if (!p->vfork_done && process_shares_mm(p, mm)) {
1106 p->signal->oom_score_adj = oom_adj;
1107 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1108 p->signal->oom_score_adj_min = (short)oom_adj;
1109 }
1110 task_unlock(p);
1111 }
1112 rcu_read_unlock();
1113 mmdrop(mm);
1114 }
1115err_unlock:
1116 mutex_unlock(&oom_adj_mutex);
1117 put_task_struct(task);
1118 return err;
1119}
1120
1121/*
1122 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1123 * kernels. The effective policy is defined by oom_score_adj, which has a
1124 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1125 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1126 * Processes that become oom disabled via oom_adj will still be oom disabled
1127 * with this implementation.
1128 *
1129 * oom_adj cannot be removed since existing userspace binaries use it.
1130 */
1131static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1132 size_t count, loff_t *ppos)
1133{
1134 char buffer[PROC_NUMBUF];
1135 int oom_adj;
1136 int err;
1137
1138 memset(buffer, 0, sizeof(buffer));
1139 if (count > sizeof(buffer) - 1)
1140 count = sizeof(buffer) - 1;
1141 if (copy_from_user(buffer, buf, count)) {
1142 err = -EFAULT;
1143 goto out;
1144 }
1145
1146 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1147 if (err)
1148 goto out;
1149 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1150 oom_adj != OOM_DISABLE) {
1151 err = -EINVAL;
1152 goto out;
1153 }
1154
1155 /*
1156 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1157 * value is always attainable.
1158 */
1159 if (oom_adj == OOM_ADJUST_MAX)
1160 oom_adj = OOM_SCORE_ADJ_MAX;
1161 else
1162 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1163
1164 err = __set_oom_adj(file, oom_adj, true);
1165out:
1166 return err < 0 ? err : count;
1167}
1168
1169static const struct file_operations proc_oom_adj_operations = {
1170 .read = oom_adj_read,
1171 .write = oom_adj_write,
1172 .llseek = generic_file_llseek,
1173};
1174
1175static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1176 size_t count, loff_t *ppos)
1177{
1178 struct task_struct *task = get_proc_task(file_inode(file));
1179 char buffer[PROC_NUMBUF];
1180 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1181 size_t len;
1182
1183 if (!task)
1184 return -ESRCH;
1185 oom_score_adj = task->signal->oom_score_adj;
1186 put_task_struct(task);
1187 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1188 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1189}
1190
1191static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1192 size_t count, loff_t *ppos)
1193{
1194 char buffer[PROC_NUMBUF];
1195 int oom_score_adj;
1196 int err;
1197
1198 memset(buffer, 0, sizeof(buffer));
1199 if (count > sizeof(buffer) - 1)
1200 count = sizeof(buffer) - 1;
1201 if (copy_from_user(buffer, buf, count)) {
1202 err = -EFAULT;
1203 goto out;
1204 }
1205
1206 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1207 if (err)
1208 goto out;
1209 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1210 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1211 err = -EINVAL;
1212 goto out;
1213 }
1214
1215 err = __set_oom_adj(file, oom_score_adj, false);
1216out:
1217 return err < 0 ? err : count;
1218}
1219
1220static const struct file_operations proc_oom_score_adj_operations = {
1221 .read = oom_score_adj_read,
1222 .write = oom_score_adj_write,
1223 .llseek = default_llseek,
1224};
1225
1226#ifdef CONFIG_AUDIT
1227#define TMPBUFLEN 11
1228static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1229 size_t count, loff_t *ppos)
1230{
1231 struct inode * inode = file_inode(file);
1232 struct task_struct *task = get_proc_task(inode);
1233 ssize_t length;
1234 char tmpbuf[TMPBUFLEN];
1235
1236 if (!task)
1237 return -ESRCH;
1238 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1239 from_kuid(file->f_cred->user_ns,
1240 audit_get_loginuid(task)));
1241 put_task_struct(task);
1242 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1243}
1244
1245static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1246 size_t count, loff_t *ppos)
1247{
1248 struct inode * inode = file_inode(file);
1249 uid_t loginuid;
1250 kuid_t kloginuid;
1251 int rv;
1252
1253 rcu_read_lock();
1254 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1255 rcu_read_unlock();
1256 return -EPERM;
1257 }
1258 rcu_read_unlock();
1259
1260 if (*ppos != 0) {
1261 /* No partial writes. */
1262 return -EINVAL;
1263 }
1264
1265 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1266 if (rv < 0)
1267 return rv;
1268
1269 /* is userspace tring to explicitly UNSET the loginuid? */
1270 if (loginuid == AUDIT_UID_UNSET) {
1271 kloginuid = INVALID_UID;
1272 } else {
1273 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1274 if (!uid_valid(kloginuid))
1275 return -EINVAL;
1276 }
1277
1278 rv = audit_set_loginuid(kloginuid);
1279 if (rv < 0)
1280 return rv;
1281 return count;
1282}
1283
1284static const struct file_operations proc_loginuid_operations = {
1285 .read = proc_loginuid_read,
1286 .write = proc_loginuid_write,
1287 .llseek = generic_file_llseek,
1288};
1289
1290static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1291 size_t count, loff_t *ppos)
1292{
1293 struct inode * inode = file_inode(file);
1294 struct task_struct *task = get_proc_task(inode);
1295 ssize_t length;
1296 char tmpbuf[TMPBUFLEN];
1297
1298 if (!task)
1299 return -ESRCH;
1300 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1301 audit_get_sessionid(task));
1302 put_task_struct(task);
1303 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1304}
1305
1306static const struct file_operations proc_sessionid_operations = {
1307 .read = proc_sessionid_read,
1308 .llseek = generic_file_llseek,
1309};
1310#endif
1311
1312#ifdef CONFIG_FAULT_INJECTION
1313static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1314 size_t count, loff_t *ppos)
1315{
1316 struct task_struct *task = get_proc_task(file_inode(file));
1317 char buffer[PROC_NUMBUF];
1318 size_t len;
1319 int make_it_fail;
1320
1321 if (!task)
1322 return -ESRCH;
1323 make_it_fail = task->make_it_fail;
1324 put_task_struct(task);
1325
1326 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1327
1328 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1329}
1330
1331static ssize_t proc_fault_inject_write(struct file * file,
1332 const char __user * buf, size_t count, loff_t *ppos)
1333{
1334 struct task_struct *task;
1335 char buffer[PROC_NUMBUF];
1336 int make_it_fail;
1337 int rv;
1338
1339 if (!capable(CAP_SYS_RESOURCE))
1340 return -EPERM;
1341 memset(buffer, 0, sizeof(buffer));
1342 if (count > sizeof(buffer) - 1)
1343 count = sizeof(buffer) - 1;
1344 if (copy_from_user(buffer, buf, count))
1345 return -EFAULT;
1346 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1347 if (rv < 0)
1348 return rv;
1349 if (make_it_fail < 0 || make_it_fail > 1)
1350 return -EINVAL;
1351
1352 task = get_proc_task(file_inode(file));
1353 if (!task)
1354 return -ESRCH;
1355 task->make_it_fail = make_it_fail;
1356 put_task_struct(task);
1357
1358 return count;
1359}
1360
1361static const struct file_operations proc_fault_inject_operations = {
1362 .read = proc_fault_inject_read,
1363 .write = proc_fault_inject_write,
1364 .llseek = generic_file_llseek,
1365};
1366
1367static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1368 size_t count, loff_t *ppos)
1369{
1370 struct task_struct *task;
1371 int err;
1372 unsigned int n;
1373
1374 err = kstrtouint_from_user(buf, count, 0, &n);
1375 if (err)
1376 return err;
1377
1378 task = get_proc_task(file_inode(file));
1379 if (!task)
1380 return -ESRCH;
1381 task->fail_nth = n;
1382 put_task_struct(task);
1383
1384 return count;
1385}
1386
1387static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1388 size_t count, loff_t *ppos)
1389{
1390 struct task_struct *task;
1391 char numbuf[PROC_NUMBUF];
1392 ssize_t len;
1393
1394 task = get_proc_task(file_inode(file));
1395 if (!task)
1396 return -ESRCH;
1397 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1398 put_task_struct(task);
1399 return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1400}
1401
1402static const struct file_operations proc_fail_nth_operations = {
1403 .read = proc_fail_nth_read,
1404 .write = proc_fail_nth_write,
1405};
1406#endif
1407
1408
1409#ifdef CONFIG_SCHED_DEBUG
1410/*
1411 * Print out various scheduling related per-task fields:
1412 */
1413static int sched_show(struct seq_file *m, void *v)
1414{
1415 struct inode *inode = m->private;
1416 struct pid_namespace *ns = proc_pid_ns(inode);
1417 struct task_struct *p;
1418
1419 p = get_proc_task(inode);
1420 if (!p)
1421 return -ESRCH;
1422 proc_sched_show_task(p, ns, m);
1423
1424 put_task_struct(p);
1425
1426 return 0;
1427}
1428
1429static ssize_t
1430sched_write(struct file *file, const char __user *buf,
1431 size_t count, loff_t *offset)
1432{
1433 struct inode *inode = file_inode(file);
1434 struct task_struct *p;
1435
1436 p = get_proc_task(inode);
1437 if (!p)
1438 return -ESRCH;
1439 proc_sched_set_task(p);
1440
1441 put_task_struct(p);
1442
1443 return count;
1444}
1445
1446static int sched_open(struct inode *inode, struct file *filp)
1447{
1448 return single_open(filp, sched_show, inode);
1449}
1450
1451static const struct file_operations proc_pid_sched_operations = {
1452 .open = sched_open,
1453 .read = seq_read,
1454 .write = sched_write,
1455 .llseek = seq_lseek,
1456 .release = single_release,
1457};
1458
1459#endif
1460
1461#ifdef CONFIG_SCHED_AUTOGROUP
1462/*
1463 * Print out autogroup related information:
1464 */
1465static int sched_autogroup_show(struct seq_file *m, void *v)
1466{
1467 struct inode *inode = m->private;
1468 struct task_struct *p;
1469
1470 p = get_proc_task(inode);
1471 if (!p)
1472 return -ESRCH;
1473 proc_sched_autogroup_show_task(p, m);
1474
1475 put_task_struct(p);
1476
1477 return 0;
1478}
1479
1480static ssize_t
1481sched_autogroup_write(struct file *file, const char __user *buf,
1482 size_t count, loff_t *offset)
1483{
1484 struct inode *inode = file_inode(file);
1485 struct task_struct *p;
1486 char buffer[PROC_NUMBUF];
1487 int nice;
1488 int err;
1489
1490 memset(buffer, 0, sizeof(buffer));
1491 if (count > sizeof(buffer) - 1)
1492 count = sizeof(buffer) - 1;
1493 if (copy_from_user(buffer, buf, count))
1494 return -EFAULT;
1495
1496 err = kstrtoint(strstrip(buffer), 0, &nice);
1497 if (err < 0)
1498 return err;
1499
1500 p = get_proc_task(inode);
1501 if (!p)
1502 return -ESRCH;
1503
1504 err = proc_sched_autogroup_set_nice(p, nice);
1505 if (err)
1506 count = err;
1507
1508 put_task_struct(p);
1509
1510 return count;
1511}
1512
1513static int sched_autogroup_open(struct inode *inode, struct file *filp)
1514{
1515 int ret;
1516
1517 ret = single_open(filp, sched_autogroup_show, NULL);
1518 if (!ret) {
1519 struct seq_file *m = filp->private_data;
1520
1521 m->private = inode;
1522 }
1523 return ret;
1524}
1525
1526static const struct file_operations proc_pid_sched_autogroup_operations = {
1527 .open = sched_autogroup_open,
1528 .read = seq_read,
1529 .write = sched_autogroup_write,
1530 .llseek = seq_lseek,
1531 .release = single_release,
1532};
1533
1534#endif /* CONFIG_SCHED_AUTOGROUP */
1535
1536static ssize_t comm_write(struct file *file, const char __user *buf,
1537 size_t count, loff_t *offset)
1538{
1539 struct inode *inode = file_inode(file);
1540 struct task_struct *p;
1541 char buffer[TASK_COMM_LEN];
1542 const size_t maxlen = sizeof(buffer) - 1;
1543
1544 memset(buffer, 0, sizeof(buffer));
1545 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1546 return -EFAULT;
1547
1548 p = get_proc_task(inode);
1549 if (!p)
1550 return -ESRCH;
1551
1552 if (same_thread_group(current, p))
1553 set_task_comm(p, buffer);
1554 else
1555 count = -EINVAL;
1556
1557 put_task_struct(p);
1558
1559 return count;
1560}
1561
1562static int comm_show(struct seq_file *m, void *v)
1563{
1564 struct inode *inode = m->private;
1565 struct task_struct *p;
1566
1567 p = get_proc_task(inode);
1568 if (!p)
1569 return -ESRCH;
1570
1571 proc_task_name(m, p, false);
1572 seq_putc(m, '\n');
1573
1574 put_task_struct(p);
1575
1576 return 0;
1577}
1578
1579static int comm_open(struct inode *inode, struct file *filp)
1580{
1581 return single_open(filp, comm_show, inode);
1582}
1583
1584static const struct file_operations proc_pid_set_comm_operations = {
1585 .open = comm_open,
1586 .read = seq_read,
1587 .write = comm_write,
1588 .llseek = seq_lseek,
1589 .release = single_release,
1590};
1591
1592static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1593{
1594 struct task_struct *task;
1595 struct file *exe_file;
1596
1597 task = get_proc_task(d_inode(dentry));
1598 if (!task)
1599 return -ENOENT;
1600 exe_file = get_task_exe_file(task);
1601 put_task_struct(task);
1602 if (exe_file) {
1603 *exe_path = exe_file->f_path;
1604 path_get(&exe_file->f_path);
1605 fput(exe_file);
1606 return 0;
1607 } else
1608 return -ENOENT;
1609}
1610
1611static const char *proc_pid_get_link(struct dentry *dentry,
1612 struct inode *inode,
1613 struct delayed_call *done)
1614{
1615 struct path path;
1616 int error = -EACCES;
1617
1618 if (!dentry)
1619 return ERR_PTR(-ECHILD);
1620
1621 /* Are we allowed to snoop on the tasks file descriptors? */
1622 if (!proc_fd_access_allowed(inode))
1623 goto out;
1624
1625 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1626 if (error)
1627 goto out;
1628
1629 nd_jump_link(&path);
1630 return NULL;
1631out:
1632 return ERR_PTR(error);
1633}
1634
1635static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1636{
1637 char *tmp = (char *)__get_free_page(GFP_KERNEL);
1638 char *pathname;
1639 int len;
1640
1641 if (!tmp)
1642 return -ENOMEM;
1643
1644 pathname = d_path(path, tmp, PAGE_SIZE);
1645 len = PTR_ERR(pathname);
1646 if (IS_ERR(pathname))
1647 goto out;
1648 len = tmp + PAGE_SIZE - 1 - pathname;
1649
1650 if (len > buflen)
1651 len = buflen;
1652 if (copy_to_user(buffer, pathname, len))
1653 len = -EFAULT;
1654 out:
1655 free_page((unsigned long)tmp);
1656 return len;
1657}
1658
1659static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1660{
1661 int error = -EACCES;
1662 struct inode *inode = d_inode(dentry);
1663 struct path path;
1664
1665 /* Are we allowed to snoop on the tasks file descriptors? */
1666 if (!proc_fd_access_allowed(inode))
1667 goto out;
1668
1669 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1670 if (error)
1671 goto out;
1672
1673 error = do_proc_readlink(&path, buffer, buflen);
1674 path_put(&path);
1675out:
1676 return error;
1677}
1678
1679const struct inode_operations proc_pid_link_inode_operations = {
1680 .readlink = proc_pid_readlink,
1681 .get_link = proc_pid_get_link,
1682 .setattr = proc_setattr,
1683};
1684
1685
1686/* building an inode */
1687
1688void task_dump_owner(struct task_struct *task, umode_t mode,
1689 kuid_t *ruid, kgid_t *rgid)
1690{
1691 /* Depending on the state of dumpable compute who should own a
1692 * proc file for a task.
1693 */
1694 const struct cred *cred;
1695 kuid_t uid;
1696 kgid_t gid;
1697
1698 if (unlikely(task->flags & PF_KTHREAD)) {
1699 *ruid = GLOBAL_ROOT_UID;
1700 *rgid = GLOBAL_ROOT_GID;
1701 return;
1702 }
1703
1704 /* Default to the tasks effective ownership */
1705 rcu_read_lock();
1706 cred = __task_cred(task);
1707 uid = cred->euid;
1708 gid = cred->egid;
1709 rcu_read_unlock();
1710
1711 /*
1712 * Before the /proc/pid/status file was created the only way to read
1713 * the effective uid of a /process was to stat /proc/pid. Reading
1714 * /proc/pid/status is slow enough that procps and other packages
1715 * kept stating /proc/pid. To keep the rules in /proc simple I have
1716 * made this apply to all per process world readable and executable
1717 * directories.
1718 */
1719 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1720 struct mm_struct *mm;
1721 task_lock(task);
1722 mm = task->mm;
1723 /* Make non-dumpable tasks owned by some root */
1724 if (mm) {
1725 if (get_dumpable(mm) != SUID_DUMP_USER) {
1726 struct user_namespace *user_ns = mm->user_ns;
1727
1728 uid = make_kuid(user_ns, 0);
1729 if (!uid_valid(uid))
1730 uid = GLOBAL_ROOT_UID;
1731
1732 gid = make_kgid(user_ns, 0);
1733 if (!gid_valid(gid))
1734 gid = GLOBAL_ROOT_GID;
1735 }
1736 } else {
1737 uid = GLOBAL_ROOT_UID;
1738 gid = GLOBAL_ROOT_GID;
1739 }
1740 task_unlock(task);
1741 }
1742 *ruid = uid;
1743 *rgid = gid;
1744}
1745
1746struct inode *proc_pid_make_inode(struct super_block * sb,
1747 struct task_struct *task, umode_t mode)
1748{
1749 struct inode * inode;
1750 struct proc_inode *ei;
1751
1752 /* We need a new inode */
1753
1754 inode = new_inode(sb);
1755 if (!inode)
1756 goto out;
1757
1758 /* Common stuff */
1759 ei = PROC_I(inode);
1760 inode->i_mode = mode;
1761 inode->i_ino = get_next_ino();
1762 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1763 inode->i_op = &proc_def_inode_operations;
1764
1765 /*
1766 * grab the reference to task.
1767 */
1768 ei->pid = get_task_pid(task, PIDTYPE_PID);
1769 if (!ei->pid)
1770 goto out_unlock;
1771
1772 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1773 security_task_to_inode(task, inode);
1774
1775out:
1776 return inode;
1777
1778out_unlock:
1779 iput(inode);
1780 return NULL;
1781}
1782
1783int pid_getattr(const struct path *path, struct kstat *stat,
1784 u32 request_mask, unsigned int query_flags)
1785{
1786 struct inode *inode = d_inode(path->dentry);
1787 struct pid_namespace *pid = proc_pid_ns(inode);
1788 struct task_struct *task;
1789
1790 generic_fillattr(inode, stat);
1791
1792 stat->uid = GLOBAL_ROOT_UID;
1793 stat->gid = GLOBAL_ROOT_GID;
1794 rcu_read_lock();
1795 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1796 if (task) {
1797 if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) {
1798 rcu_read_unlock();
1799 /*
1800 * This doesn't prevent learning whether PID exists,
1801 * it only makes getattr() consistent with readdir().
1802 */
1803 return -ENOENT;
1804 }
1805 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1806 }
1807 rcu_read_unlock();
1808 return 0;
1809}
1810
1811/* dentry stuff */
1812
1813/*
1814 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1815 */
1816void pid_update_inode(struct task_struct *task, struct inode *inode)
1817{
1818 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1819
1820 inode->i_mode &= ~(S_ISUID | S_ISGID);
1821 security_task_to_inode(task, inode);
1822}
1823
1824/*
1825 * Rewrite the inode's ownerships here because the owning task may have
1826 * performed a setuid(), etc.
1827 *
1828 */
1829static int pid_revalidate(struct dentry *dentry, unsigned int flags)
1830{
1831 struct inode *inode;
1832 struct task_struct *task;
1833
1834 if (flags & LOOKUP_RCU)
1835 return -ECHILD;
1836
1837 inode = d_inode(dentry);
1838 task = get_proc_task(inode);
1839
1840 if (task) {
1841 pid_update_inode(task, inode);
1842 put_task_struct(task);
1843 return 1;
1844 }
1845 return 0;
1846}
1847
1848static inline bool proc_inode_is_dead(struct inode *inode)
1849{
1850 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1851}
1852
1853int pid_delete_dentry(const struct dentry *dentry)
1854{
1855 /* Is the task we represent dead?
1856 * If so, then don't put the dentry on the lru list,
1857 * kill it immediately.
1858 */
1859 return proc_inode_is_dead(d_inode(dentry));
1860}
1861
1862const struct dentry_operations pid_dentry_operations =
1863{
1864 .d_revalidate = pid_revalidate,
1865 .d_delete = pid_delete_dentry,
1866};
1867
1868/* Lookups */
1869
1870/*
1871 * Fill a directory entry.
1872 *
1873 * If possible create the dcache entry and derive our inode number and
1874 * file type from dcache entry.
1875 *
1876 * Since all of the proc inode numbers are dynamically generated, the inode
1877 * numbers do not exist until the inode is cache. This means creating the
1878 * the dcache entry in readdir is necessary to keep the inode numbers
1879 * reported by readdir in sync with the inode numbers reported
1880 * by stat.
1881 */
1882bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1883 const char *name, unsigned int len,
1884 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1885{
1886 struct dentry *child, *dir = file->f_path.dentry;
1887 struct qstr qname = QSTR_INIT(name, len);
1888 struct inode *inode;
1889 unsigned type = DT_UNKNOWN;
1890 ino_t ino = 1;
1891
1892 child = d_hash_and_lookup(dir, &qname);
1893 if (!child) {
1894 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
1895 child = d_alloc_parallel(dir, &qname, &wq);
1896 if (IS_ERR(child))
1897 goto end_instantiate;
1898 if (d_in_lookup(child)) {
1899 struct dentry *res;
1900 res = instantiate(child, task, ptr);
1901 d_lookup_done(child);
1902 if (unlikely(res)) {
1903 dput(child);
1904 child = res;
1905 if (IS_ERR(child))
1906 goto end_instantiate;
1907 }
1908 }
1909 }
1910 inode = d_inode(child);
1911 ino = inode->i_ino;
1912 type = inode->i_mode >> 12;
1913 dput(child);
1914end_instantiate:
1915 return dir_emit(ctx, name, len, ino, type);
1916}
1917
1918/*
1919 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1920 * which represent vma start and end addresses.
1921 */
1922static int dname_to_vma_addr(struct dentry *dentry,
1923 unsigned long *start, unsigned long *end)
1924{
1925 const char *str = dentry->d_name.name;
1926 unsigned long long sval, eval;
1927 unsigned int len;
1928
1929 if (str[0] == '0' && str[1] != '-')
1930 return -EINVAL;
1931 len = _parse_integer(str, 16, &sval);
1932 if (len & KSTRTOX_OVERFLOW)
1933 return -EINVAL;
1934 if (sval != (unsigned long)sval)
1935 return -EINVAL;
1936 str += len;
1937
1938 if (*str != '-')
1939 return -EINVAL;
1940 str++;
1941
1942 if (str[0] == '0' && str[1])
1943 return -EINVAL;
1944 len = _parse_integer(str, 16, &eval);
1945 if (len & KSTRTOX_OVERFLOW)
1946 return -EINVAL;
1947 if (eval != (unsigned long)eval)
1948 return -EINVAL;
1949 str += len;
1950
1951 if (*str != '\0')
1952 return -EINVAL;
1953
1954 *start = sval;
1955 *end = eval;
1956
1957 return 0;
1958}
1959
1960static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1961{
1962 unsigned long vm_start, vm_end;
1963 bool exact_vma_exists = false;
1964 struct mm_struct *mm = NULL;
1965 struct task_struct *task;
1966 struct inode *inode;
1967 int status = 0;
1968
1969 if (flags & LOOKUP_RCU)
1970 return -ECHILD;
1971
1972 inode = d_inode(dentry);
1973 task = get_proc_task(inode);
1974 if (!task)
1975 goto out_notask;
1976
1977 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
1978 if (IS_ERR_OR_NULL(mm))
1979 goto out;
1980
1981 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1982 status = down_read_killable(&mm->mmap_sem);
1983 if (!status) {
1984 exact_vma_exists = !!find_exact_vma(mm, vm_start,
1985 vm_end);
1986 up_read(&mm->mmap_sem);
1987 }
1988 }
1989
1990 mmput(mm);
1991
1992 if (exact_vma_exists) {
1993 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1994
1995 security_task_to_inode(task, inode);
1996 status = 1;
1997 }
1998
1999out:
2000 put_task_struct(task);
2001
2002out_notask:
2003 return status;
2004}
2005
2006static const struct dentry_operations tid_map_files_dentry_operations = {
2007 .d_revalidate = map_files_d_revalidate,
2008 .d_delete = pid_delete_dentry,
2009};
2010
2011static int map_files_get_link(struct dentry *dentry, struct path *path)
2012{
2013 unsigned long vm_start, vm_end;
2014 struct vm_area_struct *vma;
2015 struct task_struct *task;
2016 struct mm_struct *mm;
2017 int rc;
2018
2019 rc = -ENOENT;
2020 task = get_proc_task(d_inode(dentry));
2021 if (!task)
2022 goto out;
2023
2024 mm = get_task_mm(task);
2025 put_task_struct(task);
2026 if (!mm)
2027 goto out;
2028
2029 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2030 if (rc)
2031 goto out_mmput;
2032
2033 rc = down_read_killable(&mm->mmap_sem);
2034 if (rc)
2035 goto out_mmput;
2036
2037 rc = -ENOENT;
2038 vma = find_exact_vma(mm, vm_start, vm_end);
2039 if (vma && vma->vm_file) {
2040 *path = vma->vm_file->f_path;
2041 path_get(path);
2042 rc = 0;
2043 }
2044 up_read(&mm->mmap_sem);
2045
2046out_mmput:
2047 mmput(mm);
2048out:
2049 return rc;
2050}
2051
2052struct map_files_info {
2053 unsigned long start;
2054 unsigned long end;
2055 fmode_t mode;
2056};
2057
2058/*
2059 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
2060 * symlinks may be used to bypass permissions on ancestor directories in the
2061 * path to the file in question.
2062 */
2063static const char *
2064proc_map_files_get_link(struct dentry *dentry,
2065 struct inode *inode,
2066 struct delayed_call *done)
2067{
2068 if (!capable(CAP_SYS_ADMIN))
2069 return ERR_PTR(-EPERM);
2070
2071 return proc_pid_get_link(dentry, inode, done);
2072}
2073
2074/*
2075 * Identical to proc_pid_link_inode_operations except for get_link()
2076 */
2077static const struct inode_operations proc_map_files_link_inode_operations = {
2078 .readlink = proc_pid_readlink,
2079 .get_link = proc_map_files_get_link,
2080 .setattr = proc_setattr,
2081};
2082
2083static struct dentry *
2084proc_map_files_instantiate(struct dentry *dentry,
2085 struct task_struct *task, const void *ptr)
2086{
2087 fmode_t mode = (fmode_t)(unsigned long)ptr;
2088 struct proc_inode *ei;
2089 struct inode *inode;
2090
2091 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2092 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2093 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2094 if (!inode)
2095 return ERR_PTR(-ENOENT);
2096
2097 ei = PROC_I(inode);
2098 ei->op.proc_get_link = map_files_get_link;
2099
2100 inode->i_op = &proc_map_files_link_inode_operations;
2101 inode->i_size = 64;
2102
2103 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2104 return d_splice_alias(inode, dentry);
2105}
2106
2107static struct dentry *proc_map_files_lookup(struct inode *dir,
2108 struct dentry *dentry, unsigned int flags)
2109{
2110 unsigned long vm_start, vm_end;
2111 struct vm_area_struct *vma;
2112 struct task_struct *task;
2113 struct dentry *result;
2114 struct mm_struct *mm;
2115
2116 result = ERR_PTR(-ENOENT);
2117 task = get_proc_task(dir);
2118 if (!task)
2119 goto out;
2120
2121 result = ERR_PTR(-EACCES);
2122 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2123 goto out_put_task;
2124
2125 result = ERR_PTR(-ENOENT);
2126 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2127 goto out_put_task;
2128
2129 mm = get_task_mm(task);
2130 if (!mm)
2131 goto out_put_task;
2132
2133 result = ERR_PTR(-EINTR);
2134 if (down_read_killable(&mm->mmap_sem))
2135 goto out_put_mm;
2136
2137 result = ERR_PTR(-ENOENT);
2138 vma = find_exact_vma(mm, vm_start, vm_end);
2139 if (!vma)
2140 goto out_no_vma;
2141
2142 if (vma->vm_file)
2143 result = proc_map_files_instantiate(dentry, task,
2144 (void *)(unsigned long)vma->vm_file->f_mode);
2145
2146out_no_vma:
2147 up_read(&mm->mmap_sem);
2148out_put_mm:
2149 mmput(mm);
2150out_put_task:
2151 put_task_struct(task);
2152out:
2153 return result;
2154}
2155
2156static const struct inode_operations proc_map_files_inode_operations = {
2157 .lookup = proc_map_files_lookup,
2158 .permission = proc_fd_permission,
2159 .setattr = proc_setattr,
2160};
2161
2162static int
2163proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2164{
2165 struct vm_area_struct *vma;
2166 struct task_struct *task;
2167 struct mm_struct *mm;
2168 unsigned long nr_files, pos, i;
2169 GENRADIX(struct map_files_info) fa;
2170 struct map_files_info *p;
2171 int ret;
2172
2173 genradix_init(&fa);
2174
2175 ret = -ENOENT;
2176 task = get_proc_task(file_inode(file));
2177 if (!task)
2178 goto out;
2179
2180 ret = -EACCES;
2181 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2182 goto out_put_task;
2183
2184 ret = 0;
2185 if (!dir_emit_dots(file, ctx))
2186 goto out_put_task;
2187
2188 mm = get_task_mm(task);
2189 if (!mm)
2190 goto out_put_task;
2191
2192 ret = down_read_killable(&mm->mmap_sem);
2193 if (ret) {
2194 mmput(mm);
2195 goto out_put_task;
2196 }
2197
2198 nr_files = 0;
2199
2200 /*
2201 * We need two passes here:
2202 *
2203 * 1) Collect vmas of mapped files with mmap_sem taken
2204 * 2) Release mmap_sem and instantiate entries
2205 *
2206 * otherwise we get lockdep complained, since filldir()
2207 * routine might require mmap_sem taken in might_fault().
2208 */
2209
2210 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2211 if (!vma->vm_file)
2212 continue;
2213 if (++pos <= ctx->pos)
2214 continue;
2215
2216 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2217 if (!p) {
2218 ret = -ENOMEM;
2219 up_read(&mm->mmap_sem);
2220 mmput(mm);
2221 goto out_put_task;
2222 }
2223
2224 p->start = vma->vm_start;
2225 p->end = vma->vm_end;
2226 p->mode = vma->vm_file->f_mode;
2227 }
2228 up_read(&mm->mmap_sem);
2229 mmput(mm);
2230
2231 for (i = 0; i < nr_files; i++) {
2232 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2233 unsigned int len;
2234
2235 p = genradix_ptr(&fa, i);
2236 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2237 if (!proc_fill_cache(file, ctx,
2238 buf, len,
2239 proc_map_files_instantiate,
2240 task,
2241 (void *)(unsigned long)p->mode))
2242 break;
2243 ctx->pos++;
2244 }
2245
2246out_put_task:
2247 put_task_struct(task);
2248out:
2249 genradix_free(&fa);
2250 return ret;
2251}
2252
2253static const struct file_operations proc_map_files_operations = {
2254 .read = generic_read_dir,
2255 .iterate_shared = proc_map_files_readdir,
2256 .llseek = generic_file_llseek,
2257};
2258
2259#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2260struct timers_private {
2261 struct pid *pid;
2262 struct task_struct *task;
2263 struct sighand_struct *sighand;
2264 struct pid_namespace *ns;
2265 unsigned long flags;
2266};
2267
2268static void *timers_start(struct seq_file *m, loff_t *pos)
2269{
2270 struct timers_private *tp = m->private;
2271
2272 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2273 if (!tp->task)
2274 return ERR_PTR(-ESRCH);
2275
2276 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2277 if (!tp->sighand)
2278 return ERR_PTR(-ESRCH);
2279
2280 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2281}
2282
2283static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2284{
2285 struct timers_private *tp = m->private;
2286 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2287}
2288
2289static void timers_stop(struct seq_file *m, void *v)
2290{
2291 struct timers_private *tp = m->private;
2292
2293 if (tp->sighand) {
2294 unlock_task_sighand(tp->task, &tp->flags);
2295 tp->sighand = NULL;
2296 }
2297
2298 if (tp->task) {
2299 put_task_struct(tp->task);
2300 tp->task = NULL;
2301 }
2302}
2303
2304static int show_timer(struct seq_file *m, void *v)
2305{
2306 struct k_itimer *timer;
2307 struct timers_private *tp = m->private;
2308 int notify;
2309 static const char * const nstr[] = {
2310 [SIGEV_SIGNAL] = "signal",
2311 [SIGEV_NONE] = "none",
2312 [SIGEV_THREAD] = "thread",
2313 };
2314
2315 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2316 notify = timer->it_sigev_notify;
2317
2318 seq_printf(m, "ID: %d\n", timer->it_id);
2319 seq_printf(m, "signal: %d/%px\n",
2320 timer->sigq->info.si_signo,
2321 timer->sigq->info.si_value.sival_ptr);
2322 seq_printf(m, "notify: %s/%s.%d\n",
2323 nstr[notify & ~SIGEV_THREAD_ID],
2324 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2325 pid_nr_ns(timer->it_pid, tp->ns));
2326 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2327
2328 return 0;
2329}
2330
2331static const struct seq_operations proc_timers_seq_ops = {
2332 .start = timers_start,
2333 .next = timers_next,
2334 .stop = timers_stop,
2335 .show = show_timer,
2336};
2337
2338static int proc_timers_open(struct inode *inode, struct file *file)
2339{
2340 struct timers_private *tp;
2341
2342 tp = __seq_open_private(file, &proc_timers_seq_ops,
2343 sizeof(struct timers_private));
2344 if (!tp)
2345 return -ENOMEM;
2346
2347 tp->pid = proc_pid(inode);
2348 tp->ns = proc_pid_ns(inode);
2349 return 0;
2350}
2351
2352static const struct file_operations proc_timers_operations = {
2353 .open = proc_timers_open,
2354 .read = seq_read,
2355 .llseek = seq_lseek,
2356 .release = seq_release_private,
2357};
2358#endif
2359
2360static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2361 size_t count, loff_t *offset)
2362{
2363 struct inode *inode = file_inode(file);
2364 struct task_struct *p;
2365 u64 slack_ns;
2366 int err;
2367
2368 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2369 if (err < 0)
2370 return err;
2371
2372 p = get_proc_task(inode);
2373 if (!p)
2374 return -ESRCH;
2375
2376 if (p != current) {
2377 rcu_read_lock();
2378 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2379 rcu_read_unlock();
2380 count = -EPERM;
2381 goto out;
2382 }
2383 rcu_read_unlock();
2384
2385 err = security_task_setscheduler(p);
2386 if (err) {
2387 count = err;
2388 goto out;
2389 }
2390 }
2391
2392 task_lock(p);
2393 if (slack_ns == 0)
2394 p->timer_slack_ns = p->default_timer_slack_ns;
2395 else
2396 p->timer_slack_ns = slack_ns;
2397 task_unlock(p);
2398
2399out:
2400 put_task_struct(p);
2401
2402 return count;
2403}
2404
2405static int timerslack_ns_show(struct seq_file *m, void *v)
2406{
2407 struct inode *inode = m->private;
2408 struct task_struct *p;
2409 int err = 0;
2410
2411 p = get_proc_task(inode);
2412 if (!p)
2413 return -ESRCH;
2414
2415 if (p != current) {
2416 rcu_read_lock();
2417 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2418 rcu_read_unlock();
2419 err = -EPERM;
2420 goto out;
2421 }
2422 rcu_read_unlock();
2423
2424 err = security_task_getscheduler(p);
2425 if (err)
2426 goto out;
2427 }
2428
2429 task_lock(p);
2430 seq_printf(m, "%llu\n", p->timer_slack_ns);
2431 task_unlock(p);
2432
2433out:
2434 put_task_struct(p);
2435
2436 return err;
2437}
2438
2439static int timerslack_ns_open(struct inode *inode, struct file *filp)
2440{
2441 return single_open(filp, timerslack_ns_show, inode);
2442}
2443
2444static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2445 .open = timerslack_ns_open,
2446 .read = seq_read,
2447 .write = timerslack_ns_write,
2448 .llseek = seq_lseek,
2449 .release = single_release,
2450};
2451
2452static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2453 struct task_struct *task, const void *ptr)
2454{
2455 const struct pid_entry *p = ptr;
2456 struct inode *inode;
2457 struct proc_inode *ei;
2458
2459 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2460 if (!inode)
2461 return ERR_PTR(-ENOENT);
2462
2463 ei = PROC_I(inode);
2464 if (S_ISDIR(inode->i_mode))
2465 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2466 if (p->iop)
2467 inode->i_op = p->iop;
2468 if (p->fop)
2469 inode->i_fop = p->fop;
2470 ei->op = p->op;
2471 pid_update_inode(task, inode);
2472 d_set_d_op(dentry, &pid_dentry_operations);
2473 return d_splice_alias(inode, dentry);
2474}
2475
2476static struct dentry *proc_pident_lookup(struct inode *dir,
2477 struct dentry *dentry,
2478 const struct pid_entry *p,
2479 const struct pid_entry *end)
2480{
2481 struct task_struct *task = get_proc_task(dir);
2482 struct dentry *res = ERR_PTR(-ENOENT);
2483
2484 if (!task)
2485 goto out_no_task;
2486
2487 /*
2488 * Yes, it does not scale. And it should not. Don't add
2489 * new entries into /proc/<tgid>/ without very good reasons.
2490 */
2491 for (; p < end; p++) {
2492 if (p->len != dentry->d_name.len)
2493 continue;
2494 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2495 res = proc_pident_instantiate(dentry, task, p);
2496 break;
2497 }
2498 }
2499 put_task_struct(task);
2500out_no_task:
2501 return res;
2502}
2503
2504static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2505 const struct pid_entry *ents, unsigned int nents)
2506{
2507 struct task_struct *task = get_proc_task(file_inode(file));
2508 const struct pid_entry *p;
2509
2510 if (!task)
2511 return -ENOENT;
2512
2513 if (!dir_emit_dots(file, ctx))
2514 goto out;
2515
2516 if (ctx->pos >= nents + 2)
2517 goto out;
2518
2519 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2520 if (!proc_fill_cache(file, ctx, p->name, p->len,
2521 proc_pident_instantiate, task, p))
2522 break;
2523 ctx->pos++;
2524 }
2525out:
2526 put_task_struct(task);
2527 return 0;
2528}
2529
2530#ifdef CONFIG_SECURITY
2531static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2532 size_t count, loff_t *ppos)
2533{
2534 struct inode * inode = file_inode(file);
2535 char *p = NULL;
2536 ssize_t length;
2537 struct task_struct *task = get_proc_task(inode);
2538
2539 if (!task)
2540 return -ESRCH;
2541
2542 length = security_getprocattr(task, PROC_I(inode)->op.lsm,
2543 (char*)file->f_path.dentry->d_name.name,
2544 &p);
2545 put_task_struct(task);
2546 if (length > 0)
2547 length = simple_read_from_buffer(buf, count, ppos, p, length);
2548 kfree(p);
2549 return length;
2550}
2551
2552static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2553 size_t count, loff_t *ppos)
2554{
2555 struct inode * inode = file_inode(file);
2556 struct task_struct *task;
2557 void *page;
2558 int rv;
2559
2560 rcu_read_lock();
2561 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2562 if (!task) {
2563 rcu_read_unlock();
2564 return -ESRCH;
2565 }
2566 /* A task may only write its own attributes. */
2567 if (current != task) {
2568 rcu_read_unlock();
2569 return -EACCES;
2570 }
2571 /* Prevent changes to overridden credentials. */
2572 if (current_cred() != current_real_cred()) {
2573 rcu_read_unlock();
2574 return -EBUSY;
2575 }
2576 rcu_read_unlock();
2577
2578 if (count > PAGE_SIZE)
2579 count = PAGE_SIZE;
2580
2581 /* No partial writes. */
2582 if (*ppos != 0)
2583 return -EINVAL;
2584
2585 page = memdup_user(buf, count);
2586 if (IS_ERR(page)) {
2587 rv = PTR_ERR(page);
2588 goto out;
2589 }
2590
2591 /* Guard against adverse ptrace interaction */
2592 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex);
2593 if (rv < 0)
2594 goto out_free;
2595
2596 rv = security_setprocattr(PROC_I(inode)->op.lsm,
2597 file->f_path.dentry->d_name.name, page,
2598 count);
2599 mutex_unlock(¤t->signal->cred_guard_mutex);
2600out_free:
2601 kfree(page);
2602out:
2603 return rv;
2604}
2605
2606static const struct file_operations proc_pid_attr_operations = {
2607 .read = proc_pid_attr_read,
2608 .write = proc_pid_attr_write,
2609 .llseek = generic_file_llseek,
2610};
2611
2612#define LSM_DIR_OPS(LSM) \
2613static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2614 struct dir_context *ctx) \
2615{ \
2616 return proc_pident_readdir(filp, ctx, \
2617 LSM##_attr_dir_stuff, \
2618 ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2619} \
2620\
2621static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2622 .read = generic_read_dir, \
2623 .iterate = proc_##LSM##_attr_dir_iterate, \
2624 .llseek = default_llseek, \
2625}; \
2626\
2627static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2628 struct dentry *dentry, unsigned int flags) \
2629{ \
2630 return proc_pident_lookup(dir, dentry, \
2631 LSM##_attr_dir_stuff, \
2632 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2633} \
2634\
2635static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2636 .lookup = proc_##LSM##_attr_dir_lookup, \
2637 .getattr = pid_getattr, \
2638 .setattr = proc_setattr, \
2639}
2640
2641#ifdef CONFIG_SECURITY_SMACK
2642static const struct pid_entry smack_attr_dir_stuff[] = {
2643 ATTR("smack", "current", 0666),
2644};
2645LSM_DIR_OPS(smack);
2646#endif
2647
2648static const struct pid_entry attr_dir_stuff[] = {
2649 ATTR(NULL, "current", 0666),
2650 ATTR(NULL, "prev", 0444),
2651 ATTR(NULL, "exec", 0666),
2652 ATTR(NULL, "fscreate", 0666),
2653 ATTR(NULL, "keycreate", 0666),
2654 ATTR(NULL, "sockcreate", 0666),
2655#ifdef CONFIG_SECURITY_SMACK
2656 DIR("smack", 0555,
2657 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2658#endif
2659};
2660
2661static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2662{
2663 return proc_pident_readdir(file, ctx,
2664 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2665}
2666
2667static const struct file_operations proc_attr_dir_operations = {
2668 .read = generic_read_dir,
2669 .iterate_shared = proc_attr_dir_readdir,
2670 .llseek = generic_file_llseek,
2671};
2672
2673static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2674 struct dentry *dentry, unsigned int flags)
2675{
2676 return proc_pident_lookup(dir, dentry,
2677 attr_dir_stuff,
2678 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2679}
2680
2681static const struct inode_operations proc_attr_dir_inode_operations = {
2682 .lookup = proc_attr_dir_lookup,
2683 .getattr = pid_getattr,
2684 .setattr = proc_setattr,
2685};
2686
2687#endif
2688
2689#ifdef CONFIG_ELF_CORE
2690static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2691 size_t count, loff_t *ppos)
2692{
2693 struct task_struct *task = get_proc_task(file_inode(file));
2694 struct mm_struct *mm;
2695 char buffer[PROC_NUMBUF];
2696 size_t len;
2697 int ret;
2698
2699 if (!task)
2700 return -ESRCH;
2701
2702 ret = 0;
2703 mm = get_task_mm(task);
2704 if (mm) {
2705 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2706 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2707 MMF_DUMP_FILTER_SHIFT));
2708 mmput(mm);
2709 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2710 }
2711
2712 put_task_struct(task);
2713
2714 return ret;
2715}
2716
2717static ssize_t proc_coredump_filter_write(struct file *file,
2718 const char __user *buf,
2719 size_t count,
2720 loff_t *ppos)
2721{
2722 struct task_struct *task;
2723 struct mm_struct *mm;
2724 unsigned int val;
2725 int ret;
2726 int i;
2727 unsigned long mask;
2728
2729 ret = kstrtouint_from_user(buf, count, 0, &val);
2730 if (ret < 0)
2731 return ret;
2732
2733 ret = -ESRCH;
2734 task = get_proc_task(file_inode(file));
2735 if (!task)
2736 goto out_no_task;
2737
2738 mm = get_task_mm(task);
2739 if (!mm)
2740 goto out_no_mm;
2741 ret = 0;
2742
2743 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2744 if (val & mask)
2745 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2746 else
2747 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2748 }
2749
2750 mmput(mm);
2751 out_no_mm:
2752 put_task_struct(task);
2753 out_no_task:
2754 if (ret < 0)
2755 return ret;
2756 return count;
2757}
2758
2759static const struct file_operations proc_coredump_filter_operations = {
2760 .read = proc_coredump_filter_read,
2761 .write = proc_coredump_filter_write,
2762 .llseek = generic_file_llseek,
2763};
2764#endif
2765
2766#ifdef CONFIG_TASK_IO_ACCOUNTING
2767static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2768{
2769 struct task_io_accounting acct = task->ioac;
2770 unsigned long flags;
2771 int result;
2772
2773 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2774 if (result)
2775 return result;
2776
2777 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2778 result = -EACCES;
2779 goto out_unlock;
2780 }
2781
2782 if (whole && lock_task_sighand(task, &flags)) {
2783 struct task_struct *t = task;
2784
2785 task_io_accounting_add(&acct, &task->signal->ioac);
2786 while_each_thread(task, t)
2787 task_io_accounting_add(&acct, &t->ioac);
2788
2789 unlock_task_sighand(task, &flags);
2790 }
2791 seq_printf(m,
2792 "rchar: %llu\n"
2793 "wchar: %llu\n"
2794 "syscr: %llu\n"
2795 "syscw: %llu\n"
2796 "read_bytes: %llu\n"
2797 "write_bytes: %llu\n"
2798 "cancelled_write_bytes: %llu\n",
2799 (unsigned long long)acct.rchar,
2800 (unsigned long long)acct.wchar,
2801 (unsigned long long)acct.syscr,
2802 (unsigned long long)acct.syscw,
2803 (unsigned long long)acct.read_bytes,
2804 (unsigned long long)acct.write_bytes,
2805 (unsigned long long)acct.cancelled_write_bytes);
2806 result = 0;
2807
2808out_unlock:
2809 mutex_unlock(&task->signal->cred_guard_mutex);
2810 return result;
2811}
2812
2813static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2814 struct pid *pid, struct task_struct *task)
2815{
2816 return do_io_accounting(task, m, 0);
2817}
2818
2819static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2820 struct pid *pid, struct task_struct *task)
2821{
2822 return do_io_accounting(task, m, 1);
2823}
2824#endif /* CONFIG_TASK_IO_ACCOUNTING */
2825
2826#ifdef CONFIG_USER_NS
2827static int proc_id_map_open(struct inode *inode, struct file *file,
2828 const struct seq_operations *seq_ops)
2829{
2830 struct user_namespace *ns = NULL;
2831 struct task_struct *task;
2832 struct seq_file *seq;
2833 int ret = -EINVAL;
2834
2835 task = get_proc_task(inode);
2836 if (task) {
2837 rcu_read_lock();
2838 ns = get_user_ns(task_cred_xxx(task, user_ns));
2839 rcu_read_unlock();
2840 put_task_struct(task);
2841 }
2842 if (!ns)
2843 goto err;
2844
2845 ret = seq_open(file, seq_ops);
2846 if (ret)
2847 goto err_put_ns;
2848
2849 seq = file->private_data;
2850 seq->private = ns;
2851
2852 return 0;
2853err_put_ns:
2854 put_user_ns(ns);
2855err:
2856 return ret;
2857}
2858
2859static int proc_id_map_release(struct inode *inode, struct file *file)
2860{
2861 struct seq_file *seq = file->private_data;
2862 struct user_namespace *ns = seq->private;
2863 put_user_ns(ns);
2864 return seq_release(inode, file);
2865}
2866
2867static int proc_uid_map_open(struct inode *inode, struct file *file)
2868{
2869 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2870}
2871
2872static int proc_gid_map_open(struct inode *inode, struct file *file)
2873{
2874 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2875}
2876
2877static int proc_projid_map_open(struct inode *inode, struct file *file)
2878{
2879 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2880}
2881
2882static const struct file_operations proc_uid_map_operations = {
2883 .open = proc_uid_map_open,
2884 .write = proc_uid_map_write,
2885 .read = seq_read,
2886 .llseek = seq_lseek,
2887 .release = proc_id_map_release,
2888};
2889
2890static const struct file_operations proc_gid_map_operations = {
2891 .open = proc_gid_map_open,
2892 .write = proc_gid_map_write,
2893 .read = seq_read,
2894 .llseek = seq_lseek,
2895 .release = proc_id_map_release,
2896};
2897
2898static const struct file_operations proc_projid_map_operations = {
2899 .open = proc_projid_map_open,
2900 .write = proc_projid_map_write,
2901 .read = seq_read,
2902 .llseek = seq_lseek,
2903 .release = proc_id_map_release,
2904};
2905
2906static int proc_setgroups_open(struct inode *inode, struct file *file)
2907{
2908 struct user_namespace *ns = NULL;
2909 struct task_struct *task;
2910 int ret;
2911
2912 ret = -ESRCH;
2913 task = get_proc_task(inode);
2914 if (task) {
2915 rcu_read_lock();
2916 ns = get_user_ns(task_cred_xxx(task, user_ns));
2917 rcu_read_unlock();
2918 put_task_struct(task);
2919 }
2920 if (!ns)
2921 goto err;
2922
2923 if (file->f_mode & FMODE_WRITE) {
2924 ret = -EACCES;
2925 if (!ns_capable(ns, CAP_SYS_ADMIN))
2926 goto err_put_ns;
2927 }
2928
2929 ret = single_open(file, &proc_setgroups_show, ns);
2930 if (ret)
2931 goto err_put_ns;
2932
2933 return 0;
2934err_put_ns:
2935 put_user_ns(ns);
2936err:
2937 return ret;
2938}
2939
2940static int proc_setgroups_release(struct inode *inode, struct file *file)
2941{
2942 struct seq_file *seq = file->private_data;
2943 struct user_namespace *ns = seq->private;
2944 int ret = single_release(inode, file);
2945 put_user_ns(ns);
2946 return ret;
2947}
2948
2949static const struct file_operations proc_setgroups_operations = {
2950 .open = proc_setgroups_open,
2951 .write = proc_setgroups_write,
2952 .read = seq_read,
2953 .llseek = seq_lseek,
2954 .release = proc_setgroups_release,
2955};
2956#endif /* CONFIG_USER_NS */
2957
2958static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2959 struct pid *pid, struct task_struct *task)
2960{
2961 int err = lock_trace(task);
2962 if (!err) {
2963 seq_printf(m, "%08x\n", task->personality);
2964 unlock_trace(task);
2965 }
2966 return err;
2967}
2968
2969#ifdef CONFIG_LIVEPATCH
2970static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
2971 struct pid *pid, struct task_struct *task)
2972{
2973 seq_printf(m, "%d\n", task->patch_state);
2974 return 0;
2975}
2976#endif /* CONFIG_LIVEPATCH */
2977
2978#ifdef CONFIG_STACKLEAK_METRICS
2979static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
2980 struct pid *pid, struct task_struct *task)
2981{
2982 unsigned long prev_depth = THREAD_SIZE -
2983 (task->prev_lowest_stack & (THREAD_SIZE - 1));
2984 unsigned long depth = THREAD_SIZE -
2985 (task->lowest_stack & (THREAD_SIZE - 1));
2986
2987 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
2988 prev_depth, depth);
2989 return 0;
2990}
2991#endif /* CONFIG_STACKLEAK_METRICS */
2992
2993/*
2994 * Thread groups
2995 */
2996static const struct file_operations proc_task_operations;
2997static const struct inode_operations proc_task_inode_operations;
2998
2999static const struct pid_entry tgid_base_stuff[] = {
3000 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3001 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3002 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3003 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3004 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3005#ifdef CONFIG_NET
3006 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3007#endif
3008 REG("environ", S_IRUSR, proc_environ_operations),
3009 REG("auxv", S_IRUSR, proc_auxv_operations),
3010 ONE("status", S_IRUGO, proc_pid_status),
3011 ONE("personality", S_IRUSR, proc_pid_personality),
3012 ONE("limits", S_IRUGO, proc_pid_limits),
3013#ifdef CONFIG_SCHED_DEBUG
3014 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3015#endif
3016#ifdef CONFIG_SCHED_AUTOGROUP
3017 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3018#endif
3019 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3020#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3021 ONE("syscall", S_IRUSR, proc_pid_syscall),
3022#endif
3023 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3024 ONE("stat", S_IRUGO, proc_tgid_stat),
3025 ONE("statm", S_IRUGO, proc_pid_statm),
3026 REG("maps", S_IRUGO, proc_pid_maps_operations),
3027#ifdef CONFIG_NUMA
3028 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3029#endif
3030 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3031 LNK("cwd", proc_cwd_link),
3032 LNK("root", proc_root_link),
3033 LNK("exe", proc_exe_link),
3034 REG("mounts", S_IRUGO, proc_mounts_operations),
3035 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3036 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3037#ifdef CONFIG_PROC_PAGE_MONITOR
3038 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3039 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3040 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3041 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3042#endif
3043#ifdef CONFIG_SECURITY
3044 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3045#endif
3046#ifdef CONFIG_KALLSYMS
3047 ONE("wchan", S_IRUGO, proc_pid_wchan),
3048#endif
3049#ifdef CONFIG_STACKTRACE
3050 ONE("stack", S_IRUSR, proc_pid_stack),
3051#endif
3052#ifdef CONFIG_SCHED_INFO
3053 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3054#endif
3055#ifdef CONFIG_LATENCYTOP
3056 REG("latency", S_IRUGO, proc_lstats_operations),
3057#endif
3058#ifdef CONFIG_PROC_PID_CPUSET
3059 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3060#endif
3061#ifdef CONFIG_CGROUPS
3062 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3063#endif
3064 ONE("oom_score", S_IRUGO, proc_oom_score),
3065 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3066 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3067#ifdef CONFIG_AUDIT
3068 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3069 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3070#endif
3071#ifdef CONFIG_FAULT_INJECTION
3072 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3073 REG("fail-nth", 0644, proc_fail_nth_operations),
3074#endif
3075#ifdef CONFIG_ELF_CORE
3076 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3077#endif
3078#ifdef CONFIG_TASK_IO_ACCOUNTING
3079 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3080#endif
3081#ifdef CONFIG_USER_NS
3082 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3083 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3084 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3085 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3086#endif
3087#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3088 REG("timers", S_IRUGO, proc_timers_operations),
3089#endif
3090 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3091#ifdef CONFIG_LIVEPATCH
3092 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3093#endif
3094#ifdef CONFIG_STACKLEAK_METRICS
3095 ONE("stack_depth", S_IRUGO, proc_stack_depth),
3096#endif
3097#ifdef CONFIG_PROC_PID_ARCH_STATUS
3098 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3099#endif
3100};
3101
3102static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3103{
3104 return proc_pident_readdir(file, ctx,
3105 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3106}
3107
3108static const struct file_operations proc_tgid_base_operations = {
3109 .read = generic_read_dir,
3110 .iterate_shared = proc_tgid_base_readdir,
3111 .llseek = generic_file_llseek,
3112};
3113
3114struct pid *tgid_pidfd_to_pid(const struct file *file)
3115{
3116 if (file->f_op != &proc_tgid_base_operations)
3117 return ERR_PTR(-EBADF);
3118
3119 return proc_pid(file_inode(file));
3120}
3121
3122static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3123{
3124 return proc_pident_lookup(dir, dentry,
3125 tgid_base_stuff,
3126 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3127}
3128
3129static const struct inode_operations proc_tgid_base_inode_operations = {
3130 .lookup = proc_tgid_base_lookup,
3131 .getattr = pid_getattr,
3132 .setattr = proc_setattr,
3133 .permission = proc_pid_permission,
3134};
3135
3136static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
3137{
3138 struct dentry *dentry, *leader, *dir;
3139 char buf[10 + 1];
3140 struct qstr name;
3141
3142 name.name = buf;
3143 name.len = snprintf(buf, sizeof(buf), "%u", pid);
3144 /* no ->d_hash() rejects on procfs */
3145 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
3146 if (dentry) {
3147 d_invalidate(dentry);
3148 dput(dentry);
3149 }
3150
3151 if (pid == tgid)
3152 return;
3153
3154 name.name = buf;
3155 name.len = snprintf(buf, sizeof(buf), "%u", tgid);
3156 leader = d_hash_and_lookup(mnt->mnt_root, &name);
3157 if (!leader)
3158 goto out;
3159
3160 name.name = "task";
3161 name.len = strlen(name.name);
3162 dir = d_hash_and_lookup(leader, &name);
3163 if (!dir)
3164 goto out_put_leader;
3165
3166 name.name = buf;
3167 name.len = snprintf(buf, sizeof(buf), "%u", pid);
3168 dentry = d_hash_and_lookup(dir, &name);
3169 if (dentry) {
3170 d_invalidate(dentry);
3171 dput(dentry);
3172 }
3173
3174 dput(dir);
3175out_put_leader:
3176 dput(leader);
3177out:
3178 return;
3179}
3180
3181/**
3182 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3183 * @task: task that should be flushed.
3184 *
3185 * When flushing dentries from proc, one needs to flush them from global
3186 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3187 * in. This call is supposed to do all of this job.
3188 *
3189 * Looks in the dcache for
3190 * /proc/@pid
3191 * /proc/@tgid/task/@pid
3192 * if either directory is present flushes it and all of it'ts children
3193 * from the dcache.
3194 *
3195 * It is safe and reasonable to cache /proc entries for a task until
3196 * that task exits. After that they just clog up the dcache with
3197 * useless entries, possibly causing useful dcache entries to be
3198 * flushed instead. This routine is proved to flush those useless
3199 * dcache entries at process exit time.
3200 *
3201 * NOTE: This routine is just an optimization so it does not guarantee
3202 * that no dcache entries will exist at process exit time it
3203 * just makes it very unlikely that any will persist.
3204 */
3205
3206void proc_flush_task(struct task_struct *task)
3207{
3208 int i;
3209 struct pid *pid, *tgid;
3210 struct upid *upid;
3211
3212 pid = task_pid(task);
3213 tgid = task_tgid(task);
3214
3215 for (i = 0; i <= pid->level; i++) {
3216 upid = &pid->numbers[i];
3217 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3218 tgid->numbers[i].nr);
3219 }
3220}
3221
3222static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3223 struct task_struct *task, const void *ptr)
3224{
3225 struct inode *inode;
3226
3227 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3228 if (!inode)
3229 return ERR_PTR(-ENOENT);
3230
3231 inode->i_op = &proc_tgid_base_inode_operations;
3232 inode->i_fop = &proc_tgid_base_operations;
3233 inode->i_flags|=S_IMMUTABLE;
3234
3235 set_nlink(inode, nlink_tgid);
3236 pid_update_inode(task, inode);
3237
3238 d_set_d_op(dentry, &pid_dentry_operations);
3239 return d_splice_alias(inode, dentry);
3240}
3241
3242struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3243{
3244 struct task_struct *task;
3245 unsigned tgid;
3246 struct pid_namespace *ns;
3247 struct dentry *result = ERR_PTR(-ENOENT);
3248
3249 tgid = name_to_int(&dentry->d_name);
3250 if (tgid == ~0U)
3251 goto out;
3252
3253 ns = dentry->d_sb->s_fs_info;
3254 rcu_read_lock();
3255 task = find_task_by_pid_ns(tgid, ns);
3256 if (task)
3257 get_task_struct(task);
3258 rcu_read_unlock();
3259 if (!task)
3260 goto out;
3261
3262 result = proc_pid_instantiate(dentry, task, NULL);
3263 put_task_struct(task);
3264out:
3265 return result;
3266}
3267
3268/*
3269 * Find the first task with tgid >= tgid
3270 *
3271 */
3272struct tgid_iter {
3273 unsigned int tgid;
3274 struct task_struct *task;
3275};
3276static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3277{
3278 struct pid *pid;
3279
3280 if (iter.task)
3281 put_task_struct(iter.task);
3282 rcu_read_lock();
3283retry:
3284 iter.task = NULL;
3285 pid = find_ge_pid(iter.tgid, ns);
3286 if (pid) {
3287 iter.tgid = pid_nr_ns(pid, ns);
3288 iter.task = pid_task(pid, PIDTYPE_PID);
3289 /* What we to know is if the pid we have find is the
3290 * pid of a thread_group_leader. Testing for task
3291 * being a thread_group_leader is the obvious thing
3292 * todo but there is a window when it fails, due to
3293 * the pid transfer logic in de_thread.
3294 *
3295 * So we perform the straight forward test of seeing
3296 * if the pid we have found is the pid of a thread
3297 * group leader, and don't worry if the task we have
3298 * found doesn't happen to be a thread group leader.
3299 * As we don't care in the case of readdir.
3300 */
3301 if (!iter.task || !has_group_leader_pid(iter.task)) {
3302 iter.tgid += 1;
3303 goto retry;
3304 }
3305 get_task_struct(iter.task);
3306 }
3307 rcu_read_unlock();
3308 return iter;
3309}
3310
3311#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3312
3313/* for the /proc/ directory itself, after non-process stuff has been done */
3314int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3315{
3316 struct tgid_iter iter;
3317 struct pid_namespace *ns = proc_pid_ns(file_inode(file));
3318 loff_t pos = ctx->pos;
3319
3320 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3321 return 0;
3322
3323 if (pos == TGID_OFFSET - 2) {
3324 struct inode *inode = d_inode(ns->proc_self);
3325 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3326 return 0;
3327 ctx->pos = pos = pos + 1;
3328 }
3329 if (pos == TGID_OFFSET - 1) {
3330 struct inode *inode = d_inode(ns->proc_thread_self);
3331 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3332 return 0;
3333 ctx->pos = pos = pos + 1;
3334 }
3335 iter.tgid = pos - TGID_OFFSET;
3336 iter.task = NULL;
3337 for (iter = next_tgid(ns, iter);
3338 iter.task;
3339 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3340 char name[10 + 1];
3341 unsigned int len;
3342
3343 cond_resched();
3344 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE))
3345 continue;
3346
3347 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3348 ctx->pos = iter.tgid + TGID_OFFSET;
3349 if (!proc_fill_cache(file, ctx, name, len,
3350 proc_pid_instantiate, iter.task, NULL)) {
3351 put_task_struct(iter.task);
3352 return 0;
3353 }
3354 }
3355 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3356 return 0;
3357}
3358
3359/*
3360 * proc_tid_comm_permission is a special permission function exclusively
3361 * used for the node /proc/<pid>/task/<tid>/comm.
3362 * It bypasses generic permission checks in the case where a task of the same
3363 * task group attempts to access the node.
3364 * The rationale behind this is that glibc and bionic access this node for
3365 * cross thread naming (pthread_set/getname_np(!self)). However, if
3366 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3367 * which locks out the cross thread naming implementation.
3368 * This function makes sure that the node is always accessible for members of
3369 * same thread group.
3370 */
3371static int proc_tid_comm_permission(struct inode *inode, int mask)
3372{
3373 bool is_same_tgroup;
3374 struct task_struct *task;
3375
3376 task = get_proc_task(inode);
3377 if (!task)
3378 return -ESRCH;
3379 is_same_tgroup = same_thread_group(current, task);
3380 put_task_struct(task);
3381
3382 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3383 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3384 * read or written by the members of the corresponding
3385 * thread group.
3386 */
3387 return 0;
3388 }
3389
3390 return generic_permission(inode, mask);
3391}
3392
3393static const struct inode_operations proc_tid_comm_inode_operations = {
3394 .permission = proc_tid_comm_permission,
3395};
3396
3397/*
3398 * Tasks
3399 */
3400static const struct pid_entry tid_base_stuff[] = {
3401 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3402 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3403 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3404#ifdef CONFIG_NET
3405 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3406#endif
3407 REG("environ", S_IRUSR, proc_environ_operations),
3408 REG("auxv", S_IRUSR, proc_auxv_operations),
3409 ONE("status", S_IRUGO, proc_pid_status),
3410 ONE("personality", S_IRUSR, proc_pid_personality),
3411 ONE("limits", S_IRUGO, proc_pid_limits),
3412#ifdef CONFIG_SCHED_DEBUG
3413 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3414#endif
3415 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3416 &proc_tid_comm_inode_operations,
3417 &proc_pid_set_comm_operations, {}),
3418#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3419 ONE("syscall", S_IRUSR, proc_pid_syscall),
3420#endif
3421 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3422 ONE("stat", S_IRUGO, proc_tid_stat),
3423 ONE("statm", S_IRUGO, proc_pid_statm),
3424 REG("maps", S_IRUGO, proc_pid_maps_operations),
3425#ifdef CONFIG_PROC_CHILDREN
3426 REG("children", S_IRUGO, proc_tid_children_operations),
3427#endif
3428#ifdef CONFIG_NUMA
3429 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3430#endif
3431 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3432 LNK("cwd", proc_cwd_link),
3433 LNK("root", proc_root_link),
3434 LNK("exe", proc_exe_link),
3435 REG("mounts", S_IRUGO, proc_mounts_operations),
3436 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3437#ifdef CONFIG_PROC_PAGE_MONITOR
3438 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3439 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3440 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3441 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3442#endif
3443#ifdef CONFIG_SECURITY
3444 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3445#endif
3446#ifdef CONFIG_KALLSYMS
3447 ONE("wchan", S_IRUGO, proc_pid_wchan),
3448#endif
3449#ifdef CONFIG_STACKTRACE
3450 ONE("stack", S_IRUSR, proc_pid_stack),
3451#endif
3452#ifdef CONFIG_SCHED_INFO
3453 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3454#endif
3455#ifdef CONFIG_LATENCYTOP
3456 REG("latency", S_IRUGO, proc_lstats_operations),
3457#endif
3458#ifdef CONFIG_PROC_PID_CPUSET
3459 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3460#endif
3461#ifdef CONFIG_CGROUPS
3462 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3463#endif
3464 ONE("oom_score", S_IRUGO, proc_oom_score),
3465 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3466 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3467#ifdef CONFIG_AUDIT
3468 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3469 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3470#endif
3471#ifdef CONFIG_FAULT_INJECTION
3472 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3473 REG("fail-nth", 0644, proc_fail_nth_operations),
3474#endif
3475#ifdef CONFIG_TASK_IO_ACCOUNTING
3476 ONE("io", S_IRUSR, proc_tid_io_accounting),
3477#endif
3478#ifdef CONFIG_USER_NS
3479 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3480 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3481 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3482 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3483#endif
3484#ifdef CONFIG_LIVEPATCH
3485 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3486#endif
3487#ifdef CONFIG_PROC_PID_ARCH_STATUS
3488 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3489#endif
3490};
3491
3492static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3493{
3494 return proc_pident_readdir(file, ctx,
3495 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3496}
3497
3498static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3499{
3500 return proc_pident_lookup(dir, dentry,
3501 tid_base_stuff,
3502 tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3503}
3504
3505static const struct file_operations proc_tid_base_operations = {
3506 .read = generic_read_dir,
3507 .iterate_shared = proc_tid_base_readdir,
3508 .llseek = generic_file_llseek,
3509};
3510
3511static const struct inode_operations proc_tid_base_inode_operations = {
3512 .lookup = proc_tid_base_lookup,
3513 .getattr = pid_getattr,
3514 .setattr = proc_setattr,
3515};
3516
3517static struct dentry *proc_task_instantiate(struct dentry *dentry,
3518 struct task_struct *task, const void *ptr)
3519{
3520 struct inode *inode;
3521 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3522 if (!inode)
3523 return ERR_PTR(-ENOENT);
3524
3525 inode->i_op = &proc_tid_base_inode_operations;
3526 inode->i_fop = &proc_tid_base_operations;
3527 inode->i_flags |= S_IMMUTABLE;
3528
3529 set_nlink(inode, nlink_tid);
3530 pid_update_inode(task, inode);
3531
3532 d_set_d_op(dentry, &pid_dentry_operations);
3533 return d_splice_alias(inode, dentry);
3534}
3535
3536static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3537{
3538 struct task_struct *task;
3539 struct task_struct *leader = get_proc_task(dir);
3540 unsigned tid;
3541 struct pid_namespace *ns;
3542 struct dentry *result = ERR_PTR(-ENOENT);
3543
3544 if (!leader)
3545 goto out_no_task;
3546
3547 tid = name_to_int(&dentry->d_name);
3548 if (tid == ~0U)
3549 goto out;
3550
3551 ns = dentry->d_sb->s_fs_info;
3552 rcu_read_lock();
3553 task = find_task_by_pid_ns(tid, ns);
3554 if (task)
3555 get_task_struct(task);
3556 rcu_read_unlock();
3557 if (!task)
3558 goto out;
3559 if (!same_thread_group(leader, task))
3560 goto out_drop_task;
3561
3562 result = proc_task_instantiate(dentry, task, NULL);
3563out_drop_task:
3564 put_task_struct(task);
3565out:
3566 put_task_struct(leader);
3567out_no_task:
3568 return result;
3569}
3570
3571/*
3572 * Find the first tid of a thread group to return to user space.
3573 *
3574 * Usually this is just the thread group leader, but if the users
3575 * buffer was too small or there was a seek into the middle of the
3576 * directory we have more work todo.
3577 *
3578 * In the case of a short read we start with find_task_by_pid.
3579 *
3580 * In the case of a seek we start with the leader and walk nr
3581 * threads past it.
3582 */
3583static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3584 struct pid_namespace *ns)
3585{
3586 struct task_struct *pos, *task;
3587 unsigned long nr = f_pos;
3588
3589 if (nr != f_pos) /* 32bit overflow? */
3590 return NULL;
3591
3592 rcu_read_lock();
3593 task = pid_task(pid, PIDTYPE_PID);
3594 if (!task)
3595 goto fail;
3596
3597 /* Attempt to start with the tid of a thread */
3598 if (tid && nr) {
3599 pos = find_task_by_pid_ns(tid, ns);
3600 if (pos && same_thread_group(pos, task))
3601 goto found;
3602 }
3603
3604 /* If nr exceeds the number of threads there is nothing todo */
3605 if (nr >= get_nr_threads(task))
3606 goto fail;
3607
3608 /* If we haven't found our starting place yet start
3609 * with the leader and walk nr threads forward.
3610 */
3611 pos = task = task->group_leader;
3612 do {
3613 if (!nr--)
3614 goto found;
3615 } while_each_thread(task, pos);
3616fail:
3617 pos = NULL;
3618 goto out;
3619found:
3620 get_task_struct(pos);
3621out:
3622 rcu_read_unlock();
3623 return pos;
3624}
3625
3626/*
3627 * Find the next thread in the thread list.
3628 * Return NULL if there is an error or no next thread.
3629 *
3630 * The reference to the input task_struct is released.
3631 */
3632static struct task_struct *next_tid(struct task_struct *start)
3633{
3634 struct task_struct *pos = NULL;
3635 rcu_read_lock();
3636 if (pid_alive(start)) {
3637 pos = next_thread(start);
3638 if (thread_group_leader(pos))
3639 pos = NULL;
3640 else
3641 get_task_struct(pos);
3642 }
3643 rcu_read_unlock();
3644 put_task_struct(start);
3645 return pos;
3646}
3647
3648/* for the /proc/TGID/task/ directories */
3649static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3650{
3651 struct inode *inode = file_inode(file);
3652 struct task_struct *task;
3653 struct pid_namespace *ns;
3654 int tid;
3655
3656 if (proc_inode_is_dead(inode))
3657 return -ENOENT;
3658
3659 if (!dir_emit_dots(file, ctx))
3660 return 0;
3661
3662 /* f_version caches the tgid value that the last readdir call couldn't
3663 * return. lseek aka telldir automagically resets f_version to 0.
3664 */
3665 ns = proc_pid_ns(inode);
3666 tid = (int)file->f_version;
3667 file->f_version = 0;
3668 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3669 task;
3670 task = next_tid(task), ctx->pos++) {
3671 char name[10 + 1];
3672 unsigned int len;
3673 tid = task_pid_nr_ns(task, ns);
3674 len = snprintf(name, sizeof(name), "%u", tid);
3675 if (!proc_fill_cache(file, ctx, name, len,
3676 proc_task_instantiate, task, NULL)) {
3677 /* returning this tgid failed, save it as the first
3678 * pid for the next readir call */
3679 file->f_version = (u64)tid;
3680 put_task_struct(task);
3681 break;
3682 }
3683 }
3684
3685 return 0;
3686}
3687
3688static int proc_task_getattr(const struct path *path, struct kstat *stat,
3689 u32 request_mask, unsigned int query_flags)
3690{
3691 struct inode *inode = d_inode(path->dentry);
3692 struct task_struct *p = get_proc_task(inode);
3693 generic_fillattr(inode, stat);
3694
3695 if (p) {
3696 stat->nlink += get_nr_threads(p);
3697 put_task_struct(p);
3698 }
3699
3700 return 0;
3701}
3702
3703static const struct inode_operations proc_task_inode_operations = {
3704 .lookup = proc_task_lookup,
3705 .getattr = proc_task_getattr,
3706 .setattr = proc_setattr,
3707 .permission = proc_pid_permission,
3708};
3709
3710static const struct file_operations proc_task_operations = {
3711 .read = generic_read_dir,
3712 .iterate_shared = proc_task_readdir,
3713 .llseek = generic_file_llseek,
3714};
3715
3716void __init set_proc_pid_nlink(void)
3717{
3718 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3719 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3720}