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Merge tag 'pwm/for-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry...
[linux-2.6-block.git] / fs / proc / base.c
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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/printk.h>
77#include <linux/cgroup.h>
78#include <linux/cpuset.h>
79#include <linux/audit.h>
80#include <linux/poll.h>
81#include <linux/nsproxy.h>
82#include <linux/oom.h>
83#include <linux/elf.h>
84#include <linux/pid_namespace.h>
85#include <linux/user_namespace.h>
86#include <linux/fs_struct.h>
87#include <linux/slab.h>
88#include <linux/flex_array.h>
89#include <linux/posix-timers.h>
90#ifdef CONFIG_HARDWALL
91#include <asm/hardwall.h>
92#endif
93#include <trace/events/oom.h>
94#include "internal.h"
95#include "fd.h"
96
97/* NOTE:
98 * Implementing inode permission operations in /proc is almost
99 * certainly an error. Permission checks need to happen during
100 * each system call not at open time. The reason is that most of
101 * what we wish to check for permissions in /proc varies at runtime.
102 *
103 * The classic example of a problem is opening file descriptors
104 * in /proc for a task before it execs a suid executable.
105 */
106
107struct pid_entry {
108 const char *name;
109 int len;
110 umode_t mode;
111 const struct inode_operations *iop;
112 const struct file_operations *fop;
113 union proc_op op;
114};
115
116#define NOD(NAME, MODE, IOP, FOP, OP) { \
117 .name = (NAME), \
118 .len = sizeof(NAME) - 1, \
119 .mode = MODE, \
120 .iop = IOP, \
121 .fop = FOP, \
122 .op = OP, \
123}
124
125#define DIR(NAME, MODE, iops, fops) \
126 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
127#define LNK(NAME, get_link) \
128 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
129 &proc_pid_link_inode_operations, NULL, \
130 { .proc_get_link = get_link } )
131#define REG(NAME, MODE, fops) \
132 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
133#define ONE(NAME, MODE, show) \
134 NOD(NAME, (S_IFREG|(MODE)), \
135 NULL, &proc_single_file_operations, \
136 { .proc_show = show } )
137
138/*
139 * Count the number of hardlinks for the pid_entry table, excluding the .
140 * and .. links.
141 */
142static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
143 unsigned int n)
144{
145 unsigned int i;
146 unsigned int count;
147
148 count = 0;
149 for (i = 0; i < n; ++i) {
150 if (S_ISDIR(entries[i].mode))
151 ++count;
152 }
153
154 return count;
155}
156
157static int get_task_root(struct task_struct *task, struct path *root)
158{
159 int result = -ENOENT;
160
161 task_lock(task);
162 if (task->fs) {
163 get_fs_root(task->fs, root);
164 result = 0;
165 }
166 task_unlock(task);
167 return result;
168}
169
170static int proc_cwd_link(struct dentry *dentry, struct path *path)
171{
172 struct task_struct *task = get_proc_task(d_inode(dentry));
173 int result = -ENOENT;
174
175 if (task) {
176 task_lock(task);
177 if (task->fs) {
178 get_fs_pwd(task->fs, path);
179 result = 0;
180 }
181 task_unlock(task);
182 put_task_struct(task);
183 }
184 return result;
185}
186
187static int proc_root_link(struct dentry *dentry, struct path *path)
188{
189 struct task_struct *task = get_proc_task(d_inode(dentry));
190 int result = -ENOENT;
191
192 if (task) {
193 result = get_task_root(task, path);
194 put_task_struct(task);
195 }
196 return result;
197}
198
199static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
200 size_t _count, loff_t *pos)
201{
202 struct task_struct *tsk;
203 struct mm_struct *mm;
204 char *page;
205 unsigned long count = _count;
206 unsigned long arg_start, arg_end, env_start, env_end;
207 unsigned long len1, len2, len;
208 unsigned long p;
209 char c;
210 ssize_t rv;
211
212 BUG_ON(*pos < 0);
213
214 tsk = get_proc_task(file_inode(file));
215 if (!tsk)
216 return -ESRCH;
217 mm = get_task_mm(tsk);
218 put_task_struct(tsk);
219 if (!mm)
220 return 0;
221 /* Check if process spawned far enough to have cmdline. */
222 if (!mm->env_end) {
223 rv = 0;
224 goto out_mmput;
225 }
226
227 page = (char *)__get_free_page(GFP_TEMPORARY);
228 if (!page) {
229 rv = -ENOMEM;
230 goto out_mmput;
231 }
232
233 down_read(&mm->mmap_sem);
234 arg_start = mm->arg_start;
235 arg_end = mm->arg_end;
236 env_start = mm->env_start;
237 env_end = mm->env_end;
238 up_read(&mm->mmap_sem);
239
240 BUG_ON(arg_start > arg_end);
241 BUG_ON(env_start > env_end);
242
243 len1 = arg_end - arg_start;
244 len2 = env_end - env_start;
245
246 /* Empty ARGV. */
247 if (len1 == 0) {
248 rv = 0;
249 goto out_free_page;
250 }
251 /*
252 * Inherently racy -- command line shares address space
253 * with code and data.
254 */
255 rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0);
256 if (rv <= 0)
257 goto out_free_page;
258
259 rv = 0;
260
261 if (c == '\0') {
262 /* Command line (set of strings) occupies whole ARGV. */
263 if (len1 <= *pos)
264 goto out_free_page;
265
266 p = arg_start + *pos;
267 len = len1 - *pos;
268 while (count > 0 && len > 0) {
269 unsigned int _count;
270 int nr_read;
271
272 _count = min3(count, len, PAGE_SIZE);
273 nr_read = access_remote_vm(mm, p, page, _count, 0);
274 if (nr_read < 0)
275 rv = nr_read;
276 if (nr_read <= 0)
277 goto out_free_page;
278
279 if (copy_to_user(buf, page, nr_read)) {
280 rv = -EFAULT;
281 goto out_free_page;
282 }
283
284 p += nr_read;
285 len -= nr_read;
286 buf += nr_read;
287 count -= nr_read;
288 rv += nr_read;
289 }
290 } else {
291 /*
292 * Command line (1 string) occupies ARGV and maybe
293 * extends into ENVP.
294 */
295 if (len1 + len2 <= *pos)
296 goto skip_argv_envp;
297 if (len1 <= *pos)
298 goto skip_argv;
299
300 p = arg_start + *pos;
301 len = len1 - *pos;
302 while (count > 0 && len > 0) {
303 unsigned int _count, l;
304 int nr_read;
305 bool final;
306
307 _count = min3(count, len, PAGE_SIZE);
308 nr_read = access_remote_vm(mm, p, page, _count, 0);
309 if (nr_read < 0)
310 rv = nr_read;
311 if (nr_read <= 0)
312 goto out_free_page;
313
314 /*
315 * Command line can be shorter than whole ARGV
316 * even if last "marker" byte says it is not.
317 */
318 final = false;
319 l = strnlen(page, nr_read);
320 if (l < nr_read) {
321 nr_read = l;
322 final = true;
323 }
324
325 if (copy_to_user(buf, page, nr_read)) {
326 rv = -EFAULT;
327 goto out_free_page;
328 }
329
330 p += nr_read;
331 len -= nr_read;
332 buf += nr_read;
333 count -= nr_read;
334 rv += nr_read;
335
336 if (final)
337 goto out_free_page;
338 }
339skip_argv:
340 /*
341 * Command line (1 string) occupies ARGV and
342 * extends into ENVP.
343 */
344 if (len1 <= *pos) {
345 p = env_start + *pos - len1;
346 len = len1 + len2 - *pos;
347 } else {
348 p = env_start;
349 len = len2;
350 }
351 while (count > 0 && len > 0) {
352 unsigned int _count, l;
353 int nr_read;
354 bool final;
355
356 _count = min3(count, len, PAGE_SIZE);
357 nr_read = access_remote_vm(mm, p, page, _count, 0);
358 if (nr_read < 0)
359 rv = nr_read;
360 if (nr_read <= 0)
361 goto out_free_page;
362
363 /* Find EOS. */
364 final = false;
365 l = strnlen(page, nr_read);
366 if (l < nr_read) {
367 nr_read = l;
368 final = true;
369 }
370
371 if (copy_to_user(buf, page, nr_read)) {
372 rv = -EFAULT;
373 goto out_free_page;
374 }
375
376 p += nr_read;
377 len -= nr_read;
378 buf += nr_read;
379 count -= nr_read;
380 rv += nr_read;
381
382 if (final)
383 goto out_free_page;
384 }
385skip_argv_envp:
386 ;
387 }
388
389out_free_page:
390 free_page((unsigned long)page);
391out_mmput:
392 mmput(mm);
393 if (rv > 0)
394 *pos += rv;
395 return rv;
396}
397
398static const struct file_operations proc_pid_cmdline_ops = {
399 .read = proc_pid_cmdline_read,
400 .llseek = generic_file_llseek,
401};
402
403static int proc_pid_auxv(struct seq_file *m, struct pid_namespace *ns,
404 struct pid *pid, struct task_struct *task)
405{
406 struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
407 if (mm && !IS_ERR(mm)) {
408 unsigned int nwords = 0;
409 do {
410 nwords += 2;
411 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
412 seq_write(m, mm->saved_auxv, nwords * sizeof(mm->saved_auxv[0]));
413 mmput(mm);
414 return 0;
415 } else
416 return PTR_ERR(mm);
417}
418
419
420#ifdef CONFIG_KALLSYMS
421/*
422 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
423 * Returns the resolved symbol. If that fails, simply return the address.
424 */
425static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
426 struct pid *pid, struct task_struct *task)
427{
428 unsigned long wchan;
429 char symname[KSYM_NAME_LEN];
430
431 wchan = get_wchan(task);
432
433 if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)
434 && !lookup_symbol_name(wchan, symname))
435 seq_printf(m, "%s", symname);
436 else
437 seq_putc(m, '0');
438
439 return 0;
440}
441#endif /* CONFIG_KALLSYMS */
442
443static int lock_trace(struct task_struct *task)
444{
445 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
446 if (err)
447 return err;
448 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
449 mutex_unlock(&task->signal->cred_guard_mutex);
450 return -EPERM;
451 }
452 return 0;
453}
454
455static void unlock_trace(struct task_struct *task)
456{
457 mutex_unlock(&task->signal->cred_guard_mutex);
458}
459
460#ifdef CONFIG_STACKTRACE
461
462#define MAX_STACK_TRACE_DEPTH 64
463
464static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
465 struct pid *pid, struct task_struct *task)
466{
467 struct stack_trace trace;
468 unsigned long *entries;
469 int err;
470 int i;
471
472 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
473 if (!entries)
474 return -ENOMEM;
475
476 trace.nr_entries = 0;
477 trace.max_entries = MAX_STACK_TRACE_DEPTH;
478 trace.entries = entries;
479 trace.skip = 0;
480
481 err = lock_trace(task);
482 if (!err) {
483 save_stack_trace_tsk(task, &trace);
484
485 for (i = 0; i < trace.nr_entries; i++) {
486 seq_printf(m, "[<%pK>] %pS\n",
487 (void *)entries[i], (void *)entries[i]);
488 }
489 unlock_trace(task);
490 }
491 kfree(entries);
492
493 return err;
494}
495#endif
496
497#ifdef CONFIG_SCHED_INFO
498/*
499 * Provides /proc/PID/schedstat
500 */
501static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
502 struct pid *pid, struct task_struct *task)
503{
504 if (unlikely(!sched_info_on()))
505 seq_printf(m, "0 0 0\n");
506 else
507 seq_printf(m, "%llu %llu %lu\n",
508 (unsigned long long)task->se.sum_exec_runtime,
509 (unsigned long long)task->sched_info.run_delay,
510 task->sched_info.pcount);
511
512 return 0;
513}
514#endif
515
516#ifdef CONFIG_LATENCYTOP
517static int lstats_show_proc(struct seq_file *m, void *v)
518{
519 int i;
520 struct inode *inode = m->private;
521 struct task_struct *task = get_proc_task(inode);
522
523 if (!task)
524 return -ESRCH;
525 seq_puts(m, "Latency Top version : v0.1\n");
526 for (i = 0; i < 32; i++) {
527 struct latency_record *lr = &task->latency_record[i];
528 if (lr->backtrace[0]) {
529 int q;
530 seq_printf(m, "%i %li %li",
531 lr->count, lr->time, lr->max);
532 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
533 unsigned long bt = lr->backtrace[q];
534 if (!bt)
535 break;
536 if (bt == ULONG_MAX)
537 break;
538 seq_printf(m, " %ps", (void *)bt);
539 }
540 seq_putc(m, '\n');
541 }
542
543 }
544 put_task_struct(task);
545 return 0;
546}
547
548static int lstats_open(struct inode *inode, struct file *file)
549{
550 return single_open(file, lstats_show_proc, inode);
551}
552
553static ssize_t lstats_write(struct file *file, const char __user *buf,
554 size_t count, loff_t *offs)
555{
556 struct task_struct *task = get_proc_task(file_inode(file));
557
558 if (!task)
559 return -ESRCH;
560 clear_all_latency_tracing(task);
561 put_task_struct(task);
562
563 return count;
564}
565
566static const struct file_operations proc_lstats_operations = {
567 .open = lstats_open,
568 .read = seq_read,
569 .write = lstats_write,
570 .llseek = seq_lseek,
571 .release = single_release,
572};
573
574#endif
575
576static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
577 struct pid *pid, struct task_struct *task)
578{
579 unsigned long totalpages = totalram_pages + total_swap_pages;
580 unsigned long points = 0;
581
582 read_lock(&tasklist_lock);
583 if (pid_alive(task))
584 points = oom_badness(task, NULL, NULL, totalpages) *
585 1000 / totalpages;
586 read_unlock(&tasklist_lock);
587 seq_printf(m, "%lu\n", points);
588
589 return 0;
590}
591
592struct limit_names {
593 const char *name;
594 const char *unit;
595};
596
597static const struct limit_names lnames[RLIM_NLIMITS] = {
598 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
599 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
600 [RLIMIT_DATA] = {"Max data size", "bytes"},
601 [RLIMIT_STACK] = {"Max stack size", "bytes"},
602 [RLIMIT_CORE] = {"Max core file size", "bytes"},
603 [RLIMIT_RSS] = {"Max resident set", "bytes"},
604 [RLIMIT_NPROC] = {"Max processes", "processes"},
605 [RLIMIT_NOFILE] = {"Max open files", "files"},
606 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
607 [RLIMIT_AS] = {"Max address space", "bytes"},
608 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
609 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
610 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
611 [RLIMIT_NICE] = {"Max nice priority", NULL},
612 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
613 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
614};
615
616/* Display limits for a process */
617static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
618 struct pid *pid, struct task_struct *task)
619{
620 unsigned int i;
621 unsigned long flags;
622
623 struct rlimit rlim[RLIM_NLIMITS];
624
625 if (!lock_task_sighand(task, &flags))
626 return 0;
627 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
628 unlock_task_sighand(task, &flags);
629
630 /*
631 * print the file header
632 */
633 seq_printf(m, "%-25s %-20s %-20s %-10s\n",
634 "Limit", "Soft Limit", "Hard Limit", "Units");
635
636 for (i = 0; i < RLIM_NLIMITS; i++) {
637 if (rlim[i].rlim_cur == RLIM_INFINITY)
638 seq_printf(m, "%-25s %-20s ",
639 lnames[i].name, "unlimited");
640 else
641 seq_printf(m, "%-25s %-20lu ",
642 lnames[i].name, rlim[i].rlim_cur);
643
644 if (rlim[i].rlim_max == RLIM_INFINITY)
645 seq_printf(m, "%-20s ", "unlimited");
646 else
647 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
648
649 if (lnames[i].unit)
650 seq_printf(m, "%-10s\n", lnames[i].unit);
651 else
652 seq_putc(m, '\n');
653 }
654
655 return 0;
656}
657
658#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
659static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
660 struct pid *pid, struct task_struct *task)
661{
662 long nr;
663 unsigned long args[6], sp, pc;
664 int res;
665
666 res = lock_trace(task);
667 if (res)
668 return res;
669
670 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
671 seq_puts(m, "running\n");
672 else if (nr < 0)
673 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
674 else
675 seq_printf(m,
676 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
677 nr,
678 args[0], args[1], args[2], args[3], args[4], args[5],
679 sp, pc);
680 unlock_trace(task);
681
682 return 0;
683}
684#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
685
686/************************************************************************/
687/* Here the fs part begins */
688/************************************************************************/
689
690/* permission checks */
691static int proc_fd_access_allowed(struct inode *inode)
692{
693 struct task_struct *task;
694 int allowed = 0;
695 /* Allow access to a task's file descriptors if it is us or we
696 * may use ptrace attach to the process and find out that
697 * information.
698 */
699 task = get_proc_task(inode);
700 if (task) {
701 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
702 put_task_struct(task);
703 }
704 return allowed;
705}
706
707int proc_setattr(struct dentry *dentry, struct iattr *attr)
708{
709 int error;
710 struct inode *inode = d_inode(dentry);
711
712 if (attr->ia_valid & ATTR_MODE)
713 return -EPERM;
714
715 error = inode_change_ok(inode, attr);
716 if (error)
717 return error;
718
719 setattr_copy(inode, attr);
720 mark_inode_dirty(inode);
721 return 0;
722}
723
724/*
725 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
726 * or euid/egid (for hide_pid_min=2)?
727 */
728static bool has_pid_permissions(struct pid_namespace *pid,
729 struct task_struct *task,
730 int hide_pid_min)
731{
732 if (pid->hide_pid < hide_pid_min)
733 return true;
734 if (in_group_p(pid->pid_gid))
735 return true;
736 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
737}
738
739
740static int proc_pid_permission(struct inode *inode, int mask)
741{
742 struct pid_namespace *pid = inode->i_sb->s_fs_info;
743 struct task_struct *task;
744 bool has_perms;
745
746 task = get_proc_task(inode);
747 if (!task)
748 return -ESRCH;
749 has_perms = has_pid_permissions(pid, task, 1);
750 put_task_struct(task);
751
752 if (!has_perms) {
753 if (pid->hide_pid == 2) {
754 /*
755 * Let's make getdents(), stat(), and open()
756 * consistent with each other. If a process
757 * may not stat() a file, it shouldn't be seen
758 * in procfs at all.
759 */
760 return -ENOENT;
761 }
762
763 return -EPERM;
764 }
765 return generic_permission(inode, mask);
766}
767
768
769
770static const struct inode_operations proc_def_inode_operations = {
771 .setattr = proc_setattr,
772};
773
774static int proc_single_show(struct seq_file *m, void *v)
775{
776 struct inode *inode = m->private;
777 struct pid_namespace *ns;
778 struct pid *pid;
779 struct task_struct *task;
780 int ret;
781
782 ns = inode->i_sb->s_fs_info;
783 pid = proc_pid(inode);
784 task = get_pid_task(pid, PIDTYPE_PID);
785 if (!task)
786 return -ESRCH;
787
788 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
789
790 put_task_struct(task);
791 return ret;
792}
793
794static int proc_single_open(struct inode *inode, struct file *filp)
795{
796 return single_open(filp, proc_single_show, inode);
797}
798
799static const struct file_operations proc_single_file_operations = {
800 .open = proc_single_open,
801 .read = seq_read,
802 .llseek = seq_lseek,
803 .release = single_release,
804};
805
806
807struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
808{
809 struct task_struct *task = get_proc_task(inode);
810 struct mm_struct *mm = ERR_PTR(-ESRCH);
811
812 if (task) {
813 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
814 put_task_struct(task);
815
816 if (!IS_ERR_OR_NULL(mm)) {
817 /* ensure this mm_struct can't be freed */
818 atomic_inc(&mm->mm_count);
819 /* but do not pin its memory */
820 mmput(mm);
821 }
822 }
823
824 return mm;
825}
826
827static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
828{
829 struct mm_struct *mm = proc_mem_open(inode, mode);
830
831 if (IS_ERR(mm))
832 return PTR_ERR(mm);
833
834 file->private_data = mm;
835 return 0;
836}
837
838static int mem_open(struct inode *inode, struct file *file)
839{
840 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
841
842 /* OK to pass negative loff_t, we can catch out-of-range */
843 file->f_mode |= FMODE_UNSIGNED_OFFSET;
844
845 return ret;
846}
847
848static ssize_t mem_rw(struct file *file, char __user *buf,
849 size_t count, loff_t *ppos, int write)
850{
851 struct mm_struct *mm = file->private_data;
852 unsigned long addr = *ppos;
853 ssize_t copied;
854 char *page;
855
856 if (!mm)
857 return 0;
858
859 page = (char *)__get_free_page(GFP_TEMPORARY);
860 if (!page)
861 return -ENOMEM;
862
863 copied = 0;
864 if (!atomic_inc_not_zero(&mm->mm_users))
865 goto free;
866
867 while (count > 0) {
868 int this_len = min_t(int, count, PAGE_SIZE);
869
870 if (write && copy_from_user(page, buf, this_len)) {
871 copied = -EFAULT;
872 break;
873 }
874
875 this_len = access_remote_vm(mm, addr, page, this_len, write);
876 if (!this_len) {
877 if (!copied)
878 copied = -EIO;
879 break;
880 }
881
882 if (!write && copy_to_user(buf, page, this_len)) {
883 copied = -EFAULT;
884 break;
885 }
886
887 buf += this_len;
888 addr += this_len;
889 copied += this_len;
890 count -= this_len;
891 }
892 *ppos = addr;
893
894 mmput(mm);
895free:
896 free_page((unsigned long) page);
897 return copied;
898}
899
900static ssize_t mem_read(struct file *file, char __user *buf,
901 size_t count, loff_t *ppos)
902{
903 return mem_rw(file, buf, count, ppos, 0);
904}
905
906static ssize_t mem_write(struct file *file, const char __user *buf,
907 size_t count, loff_t *ppos)
908{
909 return mem_rw(file, (char __user*)buf, count, ppos, 1);
910}
911
912loff_t mem_lseek(struct file *file, loff_t offset, int orig)
913{
914 switch (orig) {
915 case 0:
916 file->f_pos = offset;
917 break;
918 case 1:
919 file->f_pos += offset;
920 break;
921 default:
922 return -EINVAL;
923 }
924 force_successful_syscall_return();
925 return file->f_pos;
926}
927
928static int mem_release(struct inode *inode, struct file *file)
929{
930 struct mm_struct *mm = file->private_data;
931 if (mm)
932 mmdrop(mm);
933 return 0;
934}
935
936static const struct file_operations proc_mem_operations = {
937 .llseek = mem_lseek,
938 .read = mem_read,
939 .write = mem_write,
940 .open = mem_open,
941 .release = mem_release,
942};
943
944static int environ_open(struct inode *inode, struct file *file)
945{
946 return __mem_open(inode, file, PTRACE_MODE_READ);
947}
948
949static ssize_t environ_read(struct file *file, char __user *buf,
950 size_t count, loff_t *ppos)
951{
952 char *page;
953 unsigned long src = *ppos;
954 int ret = 0;
955 struct mm_struct *mm = file->private_data;
956 unsigned long env_start, env_end;
957
958 /* Ensure the process spawned far enough to have an environment. */
959 if (!mm || !mm->env_end)
960 return 0;
961
962 page = (char *)__get_free_page(GFP_TEMPORARY);
963 if (!page)
964 return -ENOMEM;
965
966 ret = 0;
967 if (!atomic_inc_not_zero(&mm->mm_users))
968 goto free;
969
970 down_read(&mm->mmap_sem);
971 env_start = mm->env_start;
972 env_end = mm->env_end;
973 up_read(&mm->mmap_sem);
974
975 while (count > 0) {
976 size_t this_len, max_len;
977 int retval;
978
979 if (src >= (env_end - env_start))
980 break;
981
982 this_len = env_end - (env_start + src);
983
984 max_len = min_t(size_t, PAGE_SIZE, count);
985 this_len = min(max_len, this_len);
986
987 retval = access_remote_vm(mm, (env_start + src),
988 page, this_len, 0);
989
990 if (retval <= 0) {
991 ret = retval;
992 break;
993 }
994
995 if (copy_to_user(buf, page, retval)) {
996 ret = -EFAULT;
997 break;
998 }
999
1000 ret += retval;
1001 src += retval;
1002 buf += retval;
1003 count -= retval;
1004 }
1005 *ppos = src;
1006 mmput(mm);
1007
1008free:
1009 free_page((unsigned long) page);
1010 return ret;
1011}
1012
1013static const struct file_operations proc_environ_operations = {
1014 .open = environ_open,
1015 .read = environ_read,
1016 .llseek = generic_file_llseek,
1017 .release = mem_release,
1018};
1019
1020static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1021 loff_t *ppos)
1022{
1023 struct task_struct *task = get_proc_task(file_inode(file));
1024 char buffer[PROC_NUMBUF];
1025 int oom_adj = OOM_ADJUST_MIN;
1026 size_t len;
1027 unsigned long flags;
1028
1029 if (!task)
1030 return -ESRCH;
1031 if (lock_task_sighand(task, &flags)) {
1032 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1033 oom_adj = OOM_ADJUST_MAX;
1034 else
1035 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1036 OOM_SCORE_ADJ_MAX;
1037 unlock_task_sighand(task, &flags);
1038 }
1039 put_task_struct(task);
1040 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1041 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1042}
1043
1044/*
1045 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1046 * kernels. The effective policy is defined by oom_score_adj, which has a
1047 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1048 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1049 * Processes that become oom disabled via oom_adj will still be oom disabled
1050 * with this implementation.
1051 *
1052 * oom_adj cannot be removed since existing userspace binaries use it.
1053 */
1054static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1055 size_t count, loff_t *ppos)
1056{
1057 struct task_struct *task;
1058 char buffer[PROC_NUMBUF];
1059 int oom_adj;
1060 unsigned long flags;
1061 int err;
1062
1063 memset(buffer, 0, sizeof(buffer));
1064 if (count > sizeof(buffer) - 1)
1065 count = sizeof(buffer) - 1;
1066 if (copy_from_user(buffer, buf, count)) {
1067 err = -EFAULT;
1068 goto out;
1069 }
1070
1071 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1072 if (err)
1073 goto out;
1074 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1075 oom_adj != OOM_DISABLE) {
1076 err = -EINVAL;
1077 goto out;
1078 }
1079
1080 task = get_proc_task(file_inode(file));
1081 if (!task) {
1082 err = -ESRCH;
1083 goto out;
1084 }
1085
1086 task_lock(task);
1087 if (!task->mm) {
1088 err = -EINVAL;
1089 goto err_task_lock;
1090 }
1091
1092 if (!lock_task_sighand(task, &flags)) {
1093 err = -ESRCH;
1094 goto err_task_lock;
1095 }
1096
1097 /*
1098 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1099 * value is always attainable.
1100 */
1101 if (oom_adj == OOM_ADJUST_MAX)
1102 oom_adj = OOM_SCORE_ADJ_MAX;
1103 else
1104 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1105
1106 if (oom_adj < task->signal->oom_score_adj &&
1107 !capable(CAP_SYS_RESOURCE)) {
1108 err = -EACCES;
1109 goto err_sighand;
1110 }
1111
1112 /*
1113 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1114 * /proc/pid/oom_score_adj instead.
1115 */
1116 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1117 current->comm, task_pid_nr(current), task_pid_nr(task),
1118 task_pid_nr(task));
1119
1120 task->signal->oom_score_adj = oom_adj;
1121 trace_oom_score_adj_update(task);
1122err_sighand:
1123 unlock_task_sighand(task, &flags);
1124err_task_lock:
1125 task_unlock(task);
1126 put_task_struct(task);
1127out:
1128 return err < 0 ? err : count;
1129}
1130
1131static const struct file_operations proc_oom_adj_operations = {
1132 .read = oom_adj_read,
1133 .write = oom_adj_write,
1134 .llseek = generic_file_llseek,
1135};
1136
1137static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1138 size_t count, loff_t *ppos)
1139{
1140 struct task_struct *task = get_proc_task(file_inode(file));
1141 char buffer[PROC_NUMBUF];
1142 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1143 unsigned long flags;
1144 size_t len;
1145
1146 if (!task)
1147 return -ESRCH;
1148 if (lock_task_sighand(task, &flags)) {
1149 oom_score_adj = task->signal->oom_score_adj;
1150 unlock_task_sighand(task, &flags);
1151 }
1152 put_task_struct(task);
1153 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1154 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1155}
1156
1157static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1158 size_t count, loff_t *ppos)
1159{
1160 struct task_struct *task;
1161 char buffer[PROC_NUMBUF];
1162 unsigned long flags;
1163 int oom_score_adj;
1164 int err;
1165
1166 memset(buffer, 0, sizeof(buffer));
1167 if (count > sizeof(buffer) - 1)
1168 count = sizeof(buffer) - 1;
1169 if (copy_from_user(buffer, buf, count)) {
1170 err = -EFAULT;
1171 goto out;
1172 }
1173
1174 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1175 if (err)
1176 goto out;
1177 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1178 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1179 err = -EINVAL;
1180 goto out;
1181 }
1182
1183 task = get_proc_task(file_inode(file));
1184 if (!task) {
1185 err = -ESRCH;
1186 goto out;
1187 }
1188
1189 task_lock(task);
1190 if (!task->mm) {
1191 err = -EINVAL;
1192 goto err_task_lock;
1193 }
1194
1195 if (!lock_task_sighand(task, &flags)) {
1196 err = -ESRCH;
1197 goto err_task_lock;
1198 }
1199
1200 if ((short)oom_score_adj < task->signal->oom_score_adj_min &&
1201 !capable(CAP_SYS_RESOURCE)) {
1202 err = -EACCES;
1203 goto err_sighand;
1204 }
1205
1206 task->signal->oom_score_adj = (short)oom_score_adj;
1207 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1208 task->signal->oom_score_adj_min = (short)oom_score_adj;
1209 trace_oom_score_adj_update(task);
1210
1211err_sighand:
1212 unlock_task_sighand(task, &flags);
1213err_task_lock:
1214 task_unlock(task);
1215 put_task_struct(task);
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_AUDITSYSCALL
1227#define TMPBUFLEN 21
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#endif
1367
1368
1369#ifdef CONFIG_SCHED_DEBUG
1370/*
1371 * Print out various scheduling related per-task fields:
1372 */
1373static int sched_show(struct seq_file *m, void *v)
1374{
1375 struct inode *inode = m->private;
1376 struct task_struct *p;
1377
1378 p = get_proc_task(inode);
1379 if (!p)
1380 return -ESRCH;
1381 proc_sched_show_task(p, m);
1382
1383 put_task_struct(p);
1384
1385 return 0;
1386}
1387
1388static ssize_t
1389sched_write(struct file *file, const char __user *buf,
1390 size_t count, loff_t *offset)
1391{
1392 struct inode *inode = file_inode(file);
1393 struct task_struct *p;
1394
1395 p = get_proc_task(inode);
1396 if (!p)
1397 return -ESRCH;
1398 proc_sched_set_task(p);
1399
1400 put_task_struct(p);
1401
1402 return count;
1403}
1404
1405static int sched_open(struct inode *inode, struct file *filp)
1406{
1407 return single_open(filp, sched_show, inode);
1408}
1409
1410static const struct file_operations proc_pid_sched_operations = {
1411 .open = sched_open,
1412 .read = seq_read,
1413 .write = sched_write,
1414 .llseek = seq_lseek,
1415 .release = single_release,
1416};
1417
1418#endif
1419
1420#ifdef CONFIG_SCHED_AUTOGROUP
1421/*
1422 * Print out autogroup related information:
1423 */
1424static int sched_autogroup_show(struct seq_file *m, void *v)
1425{
1426 struct inode *inode = m->private;
1427 struct task_struct *p;
1428
1429 p = get_proc_task(inode);
1430 if (!p)
1431 return -ESRCH;
1432 proc_sched_autogroup_show_task(p, m);
1433
1434 put_task_struct(p);
1435
1436 return 0;
1437}
1438
1439static ssize_t
1440sched_autogroup_write(struct file *file, const char __user *buf,
1441 size_t count, loff_t *offset)
1442{
1443 struct inode *inode = file_inode(file);
1444 struct task_struct *p;
1445 char buffer[PROC_NUMBUF];
1446 int nice;
1447 int err;
1448
1449 memset(buffer, 0, sizeof(buffer));
1450 if (count > sizeof(buffer) - 1)
1451 count = sizeof(buffer) - 1;
1452 if (copy_from_user(buffer, buf, count))
1453 return -EFAULT;
1454
1455 err = kstrtoint(strstrip(buffer), 0, &nice);
1456 if (err < 0)
1457 return err;
1458
1459 p = get_proc_task(inode);
1460 if (!p)
1461 return -ESRCH;
1462
1463 err = proc_sched_autogroup_set_nice(p, nice);
1464 if (err)
1465 count = err;
1466
1467 put_task_struct(p);
1468
1469 return count;
1470}
1471
1472static int sched_autogroup_open(struct inode *inode, struct file *filp)
1473{
1474 int ret;
1475
1476 ret = single_open(filp, sched_autogroup_show, NULL);
1477 if (!ret) {
1478 struct seq_file *m = filp->private_data;
1479
1480 m->private = inode;
1481 }
1482 return ret;
1483}
1484
1485static const struct file_operations proc_pid_sched_autogroup_operations = {
1486 .open = sched_autogroup_open,
1487 .read = seq_read,
1488 .write = sched_autogroup_write,
1489 .llseek = seq_lseek,
1490 .release = single_release,
1491};
1492
1493#endif /* CONFIG_SCHED_AUTOGROUP */
1494
1495static ssize_t comm_write(struct file *file, const char __user *buf,
1496 size_t count, loff_t *offset)
1497{
1498 struct inode *inode = file_inode(file);
1499 struct task_struct *p;
1500 char buffer[TASK_COMM_LEN];
1501 const size_t maxlen = sizeof(buffer) - 1;
1502
1503 memset(buffer, 0, sizeof(buffer));
1504 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1505 return -EFAULT;
1506
1507 p = get_proc_task(inode);
1508 if (!p)
1509 return -ESRCH;
1510
1511 if (same_thread_group(current, p))
1512 set_task_comm(p, buffer);
1513 else
1514 count = -EINVAL;
1515
1516 put_task_struct(p);
1517
1518 return count;
1519}
1520
1521static int comm_show(struct seq_file *m, void *v)
1522{
1523 struct inode *inode = m->private;
1524 struct task_struct *p;
1525
1526 p = get_proc_task(inode);
1527 if (!p)
1528 return -ESRCH;
1529
1530 task_lock(p);
1531 seq_printf(m, "%s\n", p->comm);
1532 task_unlock(p);
1533
1534 put_task_struct(p);
1535
1536 return 0;
1537}
1538
1539static int comm_open(struct inode *inode, struct file *filp)
1540{
1541 return single_open(filp, comm_show, inode);
1542}
1543
1544static const struct file_operations proc_pid_set_comm_operations = {
1545 .open = comm_open,
1546 .read = seq_read,
1547 .write = comm_write,
1548 .llseek = seq_lseek,
1549 .release = single_release,
1550};
1551
1552static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1553{
1554 struct task_struct *task;
1555 struct mm_struct *mm;
1556 struct file *exe_file;
1557
1558 task = get_proc_task(d_inode(dentry));
1559 if (!task)
1560 return -ENOENT;
1561 mm = get_task_mm(task);
1562 put_task_struct(task);
1563 if (!mm)
1564 return -ENOENT;
1565 exe_file = get_mm_exe_file(mm);
1566 mmput(mm);
1567 if (exe_file) {
1568 *exe_path = exe_file->f_path;
1569 path_get(&exe_file->f_path);
1570 fput(exe_file);
1571 return 0;
1572 } else
1573 return -ENOENT;
1574}
1575
1576static const char *proc_pid_get_link(struct dentry *dentry,
1577 struct inode *inode,
1578 struct delayed_call *done)
1579{
1580 struct path path;
1581 int error = -EACCES;
1582
1583 if (!dentry)
1584 return ERR_PTR(-ECHILD);
1585
1586 /* Are we allowed to snoop on the tasks file descriptors? */
1587 if (!proc_fd_access_allowed(inode))
1588 goto out;
1589
1590 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1591 if (error)
1592 goto out;
1593
1594 nd_jump_link(&path);
1595 return NULL;
1596out:
1597 return ERR_PTR(error);
1598}
1599
1600static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1601{
1602 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1603 char *pathname;
1604 int len;
1605
1606 if (!tmp)
1607 return -ENOMEM;
1608
1609 pathname = d_path(path, tmp, PAGE_SIZE);
1610 len = PTR_ERR(pathname);
1611 if (IS_ERR(pathname))
1612 goto out;
1613 len = tmp + PAGE_SIZE - 1 - pathname;
1614
1615 if (len > buflen)
1616 len = buflen;
1617 if (copy_to_user(buffer, pathname, len))
1618 len = -EFAULT;
1619 out:
1620 free_page((unsigned long)tmp);
1621 return len;
1622}
1623
1624static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1625{
1626 int error = -EACCES;
1627 struct inode *inode = d_inode(dentry);
1628 struct path path;
1629
1630 /* Are we allowed to snoop on the tasks file descriptors? */
1631 if (!proc_fd_access_allowed(inode))
1632 goto out;
1633
1634 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1635 if (error)
1636 goto out;
1637
1638 error = do_proc_readlink(&path, buffer, buflen);
1639 path_put(&path);
1640out:
1641 return error;
1642}
1643
1644const struct inode_operations proc_pid_link_inode_operations = {
1645 .readlink = proc_pid_readlink,
1646 .get_link = proc_pid_get_link,
1647 .setattr = proc_setattr,
1648};
1649
1650
1651/* building an inode */
1652
1653struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1654{
1655 struct inode * inode;
1656 struct proc_inode *ei;
1657 const struct cred *cred;
1658
1659 /* We need a new inode */
1660
1661 inode = new_inode(sb);
1662 if (!inode)
1663 goto out;
1664
1665 /* Common stuff */
1666 ei = PROC_I(inode);
1667 inode->i_ino = get_next_ino();
1668 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1669 inode->i_op = &proc_def_inode_operations;
1670
1671 /*
1672 * grab the reference to task.
1673 */
1674 ei->pid = get_task_pid(task, PIDTYPE_PID);
1675 if (!ei->pid)
1676 goto out_unlock;
1677
1678 if (task_dumpable(task)) {
1679 rcu_read_lock();
1680 cred = __task_cred(task);
1681 inode->i_uid = cred->euid;
1682 inode->i_gid = cred->egid;
1683 rcu_read_unlock();
1684 }
1685 security_task_to_inode(task, inode);
1686
1687out:
1688 return inode;
1689
1690out_unlock:
1691 iput(inode);
1692 return NULL;
1693}
1694
1695int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1696{
1697 struct inode *inode = d_inode(dentry);
1698 struct task_struct *task;
1699 const struct cred *cred;
1700 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1701
1702 generic_fillattr(inode, stat);
1703
1704 rcu_read_lock();
1705 stat->uid = GLOBAL_ROOT_UID;
1706 stat->gid = GLOBAL_ROOT_GID;
1707 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1708 if (task) {
1709 if (!has_pid_permissions(pid, task, 2)) {
1710 rcu_read_unlock();
1711 /*
1712 * This doesn't prevent learning whether PID exists,
1713 * it only makes getattr() consistent with readdir().
1714 */
1715 return -ENOENT;
1716 }
1717 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1718 task_dumpable(task)) {
1719 cred = __task_cred(task);
1720 stat->uid = cred->euid;
1721 stat->gid = cred->egid;
1722 }
1723 }
1724 rcu_read_unlock();
1725 return 0;
1726}
1727
1728/* dentry stuff */
1729
1730/*
1731 * Exceptional case: normally we are not allowed to unhash a busy
1732 * directory. In this case, however, we can do it - no aliasing problems
1733 * due to the way we treat inodes.
1734 *
1735 * Rewrite the inode's ownerships here because the owning task may have
1736 * performed a setuid(), etc.
1737 *
1738 * Before the /proc/pid/status file was created the only way to read
1739 * the effective uid of a /process was to stat /proc/pid. Reading
1740 * /proc/pid/status is slow enough that procps and other packages
1741 * kept stating /proc/pid. To keep the rules in /proc simple I have
1742 * made this apply to all per process world readable and executable
1743 * directories.
1744 */
1745int pid_revalidate(struct dentry *dentry, unsigned int flags)
1746{
1747 struct inode *inode;
1748 struct task_struct *task;
1749 const struct cred *cred;
1750
1751 if (flags & LOOKUP_RCU)
1752 return -ECHILD;
1753
1754 inode = d_inode(dentry);
1755 task = get_proc_task(inode);
1756
1757 if (task) {
1758 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1759 task_dumpable(task)) {
1760 rcu_read_lock();
1761 cred = __task_cred(task);
1762 inode->i_uid = cred->euid;
1763 inode->i_gid = cred->egid;
1764 rcu_read_unlock();
1765 } else {
1766 inode->i_uid = GLOBAL_ROOT_UID;
1767 inode->i_gid = GLOBAL_ROOT_GID;
1768 }
1769 inode->i_mode &= ~(S_ISUID | S_ISGID);
1770 security_task_to_inode(task, inode);
1771 put_task_struct(task);
1772 return 1;
1773 }
1774 return 0;
1775}
1776
1777static inline bool proc_inode_is_dead(struct inode *inode)
1778{
1779 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1780}
1781
1782int pid_delete_dentry(const struct dentry *dentry)
1783{
1784 /* Is the task we represent dead?
1785 * If so, then don't put the dentry on the lru list,
1786 * kill it immediately.
1787 */
1788 return proc_inode_is_dead(d_inode(dentry));
1789}
1790
1791const struct dentry_operations pid_dentry_operations =
1792{
1793 .d_revalidate = pid_revalidate,
1794 .d_delete = pid_delete_dentry,
1795};
1796
1797/* Lookups */
1798
1799/*
1800 * Fill a directory entry.
1801 *
1802 * If possible create the dcache entry and derive our inode number and
1803 * file type from dcache entry.
1804 *
1805 * Since all of the proc inode numbers are dynamically generated, the inode
1806 * numbers do not exist until the inode is cache. This means creating the
1807 * the dcache entry in readdir is necessary to keep the inode numbers
1808 * reported by readdir in sync with the inode numbers reported
1809 * by stat.
1810 */
1811bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1812 const char *name, int len,
1813 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1814{
1815 struct dentry *child, *dir = file->f_path.dentry;
1816 struct qstr qname = QSTR_INIT(name, len);
1817 struct inode *inode;
1818 unsigned type;
1819 ino_t ino;
1820
1821 child = d_hash_and_lookup(dir, &qname);
1822 if (!child) {
1823 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
1824 child = d_alloc_parallel(dir, &qname, &wq);
1825 if (IS_ERR(child))
1826 goto end_instantiate;
1827 if (d_in_lookup(child)) {
1828 int err = instantiate(d_inode(dir), child, task, ptr);
1829 d_lookup_done(child);
1830 if (err < 0) {
1831 dput(child);
1832 goto end_instantiate;
1833 }
1834 }
1835 }
1836 inode = d_inode(child);
1837 ino = inode->i_ino;
1838 type = inode->i_mode >> 12;
1839 dput(child);
1840 return dir_emit(ctx, name, len, ino, type);
1841
1842end_instantiate:
1843 return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1844}
1845
1846/*
1847 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1848 * which represent vma start and end addresses.
1849 */
1850static int dname_to_vma_addr(struct dentry *dentry,
1851 unsigned long *start, unsigned long *end)
1852{
1853 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1854 return -EINVAL;
1855
1856 return 0;
1857}
1858
1859static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1860{
1861 unsigned long vm_start, vm_end;
1862 bool exact_vma_exists = false;
1863 struct mm_struct *mm = NULL;
1864 struct task_struct *task;
1865 const struct cred *cred;
1866 struct inode *inode;
1867 int status = 0;
1868
1869 if (flags & LOOKUP_RCU)
1870 return -ECHILD;
1871
1872 inode = d_inode(dentry);
1873 task = get_proc_task(inode);
1874 if (!task)
1875 goto out_notask;
1876
1877 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
1878 if (IS_ERR_OR_NULL(mm))
1879 goto out;
1880
1881 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1882 down_read(&mm->mmap_sem);
1883 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1884 up_read(&mm->mmap_sem);
1885 }
1886
1887 mmput(mm);
1888
1889 if (exact_vma_exists) {
1890 if (task_dumpable(task)) {
1891 rcu_read_lock();
1892 cred = __task_cred(task);
1893 inode->i_uid = cred->euid;
1894 inode->i_gid = cred->egid;
1895 rcu_read_unlock();
1896 } else {
1897 inode->i_uid = GLOBAL_ROOT_UID;
1898 inode->i_gid = GLOBAL_ROOT_GID;
1899 }
1900 security_task_to_inode(task, inode);
1901 status = 1;
1902 }
1903
1904out:
1905 put_task_struct(task);
1906
1907out_notask:
1908 return status;
1909}
1910
1911static const struct dentry_operations tid_map_files_dentry_operations = {
1912 .d_revalidate = map_files_d_revalidate,
1913 .d_delete = pid_delete_dentry,
1914};
1915
1916static int map_files_get_link(struct dentry *dentry, struct path *path)
1917{
1918 unsigned long vm_start, vm_end;
1919 struct vm_area_struct *vma;
1920 struct task_struct *task;
1921 struct mm_struct *mm;
1922 int rc;
1923
1924 rc = -ENOENT;
1925 task = get_proc_task(d_inode(dentry));
1926 if (!task)
1927 goto out;
1928
1929 mm = get_task_mm(task);
1930 put_task_struct(task);
1931 if (!mm)
1932 goto out;
1933
1934 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
1935 if (rc)
1936 goto out_mmput;
1937
1938 rc = -ENOENT;
1939 down_read(&mm->mmap_sem);
1940 vma = find_exact_vma(mm, vm_start, vm_end);
1941 if (vma && vma->vm_file) {
1942 *path = vma->vm_file->f_path;
1943 path_get(path);
1944 rc = 0;
1945 }
1946 up_read(&mm->mmap_sem);
1947
1948out_mmput:
1949 mmput(mm);
1950out:
1951 return rc;
1952}
1953
1954struct map_files_info {
1955 fmode_t mode;
1956 unsigned long len;
1957 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
1958};
1959
1960/*
1961 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
1962 * symlinks may be used to bypass permissions on ancestor directories in the
1963 * path to the file in question.
1964 */
1965static const char *
1966proc_map_files_get_link(struct dentry *dentry,
1967 struct inode *inode,
1968 struct delayed_call *done)
1969{
1970 if (!capable(CAP_SYS_ADMIN))
1971 return ERR_PTR(-EPERM);
1972
1973 return proc_pid_get_link(dentry, inode, done);
1974}
1975
1976/*
1977 * Identical to proc_pid_link_inode_operations except for get_link()
1978 */
1979static const struct inode_operations proc_map_files_link_inode_operations = {
1980 .readlink = proc_pid_readlink,
1981 .get_link = proc_map_files_get_link,
1982 .setattr = proc_setattr,
1983};
1984
1985static int
1986proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
1987 struct task_struct *task, const void *ptr)
1988{
1989 fmode_t mode = (fmode_t)(unsigned long)ptr;
1990 struct proc_inode *ei;
1991 struct inode *inode;
1992
1993 inode = proc_pid_make_inode(dir->i_sb, task);
1994 if (!inode)
1995 return -ENOENT;
1996
1997 ei = PROC_I(inode);
1998 ei->op.proc_get_link = map_files_get_link;
1999
2000 inode->i_op = &proc_map_files_link_inode_operations;
2001 inode->i_size = 64;
2002 inode->i_mode = S_IFLNK;
2003
2004 if (mode & FMODE_READ)
2005 inode->i_mode |= S_IRUSR;
2006 if (mode & FMODE_WRITE)
2007 inode->i_mode |= S_IWUSR;
2008
2009 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2010 d_add(dentry, inode);
2011
2012 return 0;
2013}
2014
2015static struct dentry *proc_map_files_lookup(struct inode *dir,
2016 struct dentry *dentry, unsigned int flags)
2017{
2018 unsigned long vm_start, vm_end;
2019 struct vm_area_struct *vma;
2020 struct task_struct *task;
2021 int result;
2022 struct mm_struct *mm;
2023
2024 result = -ENOENT;
2025 task = get_proc_task(dir);
2026 if (!task)
2027 goto out;
2028
2029 result = -EACCES;
2030 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2031 goto out_put_task;
2032
2033 result = -ENOENT;
2034 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2035 goto out_put_task;
2036
2037 mm = get_task_mm(task);
2038 if (!mm)
2039 goto out_put_task;
2040
2041 down_read(&mm->mmap_sem);
2042 vma = find_exact_vma(mm, vm_start, vm_end);
2043 if (!vma)
2044 goto out_no_vma;
2045
2046 if (vma->vm_file)
2047 result = proc_map_files_instantiate(dir, dentry, task,
2048 (void *)(unsigned long)vma->vm_file->f_mode);
2049
2050out_no_vma:
2051 up_read(&mm->mmap_sem);
2052 mmput(mm);
2053out_put_task:
2054 put_task_struct(task);
2055out:
2056 return ERR_PTR(result);
2057}
2058
2059static const struct inode_operations proc_map_files_inode_operations = {
2060 .lookup = proc_map_files_lookup,
2061 .permission = proc_fd_permission,
2062 .setattr = proc_setattr,
2063};
2064
2065static int
2066proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2067{
2068 struct vm_area_struct *vma;
2069 struct task_struct *task;
2070 struct mm_struct *mm;
2071 unsigned long nr_files, pos, i;
2072 struct flex_array *fa = NULL;
2073 struct map_files_info info;
2074 struct map_files_info *p;
2075 int ret;
2076
2077 ret = -ENOENT;
2078 task = get_proc_task(file_inode(file));
2079 if (!task)
2080 goto out;
2081
2082 ret = -EACCES;
2083 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2084 goto out_put_task;
2085
2086 ret = 0;
2087 if (!dir_emit_dots(file, ctx))
2088 goto out_put_task;
2089
2090 mm = get_task_mm(task);
2091 if (!mm)
2092 goto out_put_task;
2093 down_read(&mm->mmap_sem);
2094
2095 nr_files = 0;
2096
2097 /*
2098 * We need two passes here:
2099 *
2100 * 1) Collect vmas of mapped files with mmap_sem taken
2101 * 2) Release mmap_sem and instantiate entries
2102 *
2103 * otherwise we get lockdep complained, since filldir()
2104 * routine might require mmap_sem taken in might_fault().
2105 */
2106
2107 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2108 if (vma->vm_file && ++pos > ctx->pos)
2109 nr_files++;
2110 }
2111
2112 if (nr_files) {
2113 fa = flex_array_alloc(sizeof(info), nr_files,
2114 GFP_KERNEL);
2115 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2116 GFP_KERNEL)) {
2117 ret = -ENOMEM;
2118 if (fa)
2119 flex_array_free(fa);
2120 up_read(&mm->mmap_sem);
2121 mmput(mm);
2122 goto out_put_task;
2123 }
2124 for (i = 0, vma = mm->mmap, pos = 2; vma;
2125 vma = vma->vm_next) {
2126 if (!vma->vm_file)
2127 continue;
2128 if (++pos <= ctx->pos)
2129 continue;
2130
2131 info.mode = vma->vm_file->f_mode;
2132 info.len = snprintf(info.name,
2133 sizeof(info.name), "%lx-%lx",
2134 vma->vm_start, vma->vm_end);
2135 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2136 BUG();
2137 }
2138 }
2139 up_read(&mm->mmap_sem);
2140
2141 for (i = 0; i < nr_files; i++) {
2142 p = flex_array_get(fa, i);
2143 if (!proc_fill_cache(file, ctx,
2144 p->name, p->len,
2145 proc_map_files_instantiate,
2146 task,
2147 (void *)(unsigned long)p->mode))
2148 break;
2149 ctx->pos++;
2150 }
2151 if (fa)
2152 flex_array_free(fa);
2153 mmput(mm);
2154
2155out_put_task:
2156 put_task_struct(task);
2157out:
2158 return ret;
2159}
2160
2161static const struct file_operations proc_map_files_operations = {
2162 .read = generic_read_dir,
2163 .iterate_shared = proc_map_files_readdir,
2164 .llseek = generic_file_llseek,
2165};
2166
2167#ifdef CONFIG_CHECKPOINT_RESTORE
2168struct timers_private {
2169 struct pid *pid;
2170 struct task_struct *task;
2171 struct sighand_struct *sighand;
2172 struct pid_namespace *ns;
2173 unsigned long flags;
2174};
2175
2176static void *timers_start(struct seq_file *m, loff_t *pos)
2177{
2178 struct timers_private *tp = m->private;
2179
2180 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2181 if (!tp->task)
2182 return ERR_PTR(-ESRCH);
2183
2184 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2185 if (!tp->sighand)
2186 return ERR_PTR(-ESRCH);
2187
2188 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2189}
2190
2191static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2192{
2193 struct timers_private *tp = m->private;
2194 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2195}
2196
2197static void timers_stop(struct seq_file *m, void *v)
2198{
2199 struct timers_private *tp = m->private;
2200
2201 if (tp->sighand) {
2202 unlock_task_sighand(tp->task, &tp->flags);
2203 tp->sighand = NULL;
2204 }
2205
2206 if (tp->task) {
2207 put_task_struct(tp->task);
2208 tp->task = NULL;
2209 }
2210}
2211
2212static int show_timer(struct seq_file *m, void *v)
2213{
2214 struct k_itimer *timer;
2215 struct timers_private *tp = m->private;
2216 int notify;
2217 static const char * const nstr[] = {
2218 [SIGEV_SIGNAL] = "signal",
2219 [SIGEV_NONE] = "none",
2220 [SIGEV_THREAD] = "thread",
2221 };
2222
2223 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2224 notify = timer->it_sigev_notify;
2225
2226 seq_printf(m, "ID: %d\n", timer->it_id);
2227 seq_printf(m, "signal: %d/%p\n",
2228 timer->sigq->info.si_signo,
2229 timer->sigq->info.si_value.sival_ptr);
2230 seq_printf(m, "notify: %s/%s.%d\n",
2231 nstr[notify & ~SIGEV_THREAD_ID],
2232 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2233 pid_nr_ns(timer->it_pid, tp->ns));
2234 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2235
2236 return 0;
2237}
2238
2239static const struct seq_operations proc_timers_seq_ops = {
2240 .start = timers_start,
2241 .next = timers_next,
2242 .stop = timers_stop,
2243 .show = show_timer,
2244};
2245
2246static int proc_timers_open(struct inode *inode, struct file *file)
2247{
2248 struct timers_private *tp;
2249
2250 tp = __seq_open_private(file, &proc_timers_seq_ops,
2251 sizeof(struct timers_private));
2252 if (!tp)
2253 return -ENOMEM;
2254
2255 tp->pid = proc_pid(inode);
2256 tp->ns = inode->i_sb->s_fs_info;
2257 return 0;
2258}
2259
2260static const struct file_operations proc_timers_operations = {
2261 .open = proc_timers_open,
2262 .read = seq_read,
2263 .llseek = seq_lseek,
2264 .release = seq_release_private,
2265};
2266#endif
2267
2268static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2269 size_t count, loff_t *offset)
2270{
2271 struct inode *inode = file_inode(file);
2272 struct task_struct *p;
2273 u64 slack_ns;
2274 int err;
2275
2276 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2277 if (err < 0)
2278 return err;
2279
2280 p = get_proc_task(inode);
2281 if (!p)
2282 return -ESRCH;
2283
2284 if (ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS)) {
2285 task_lock(p);
2286 if (slack_ns == 0)
2287 p->timer_slack_ns = p->default_timer_slack_ns;
2288 else
2289 p->timer_slack_ns = slack_ns;
2290 task_unlock(p);
2291 } else
2292 count = -EPERM;
2293
2294 put_task_struct(p);
2295
2296 return count;
2297}
2298
2299static int timerslack_ns_show(struct seq_file *m, void *v)
2300{
2301 struct inode *inode = m->private;
2302 struct task_struct *p;
2303 int err = 0;
2304
2305 p = get_proc_task(inode);
2306 if (!p)
2307 return -ESRCH;
2308
2309 if (ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS)) {
2310 task_lock(p);
2311 seq_printf(m, "%llu\n", p->timer_slack_ns);
2312 task_unlock(p);
2313 } else
2314 err = -EPERM;
2315
2316 put_task_struct(p);
2317
2318 return err;
2319}
2320
2321static int timerslack_ns_open(struct inode *inode, struct file *filp)
2322{
2323 return single_open(filp, timerslack_ns_show, inode);
2324}
2325
2326static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2327 .open = timerslack_ns_open,
2328 .read = seq_read,
2329 .write = timerslack_ns_write,
2330 .llseek = seq_lseek,
2331 .release = single_release,
2332};
2333
2334static int proc_pident_instantiate(struct inode *dir,
2335 struct dentry *dentry, struct task_struct *task, const void *ptr)
2336{
2337 const struct pid_entry *p = ptr;
2338 struct inode *inode;
2339 struct proc_inode *ei;
2340
2341 inode = proc_pid_make_inode(dir->i_sb, task);
2342 if (!inode)
2343 goto out;
2344
2345 ei = PROC_I(inode);
2346 inode->i_mode = p->mode;
2347 if (S_ISDIR(inode->i_mode))
2348 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2349 if (p->iop)
2350 inode->i_op = p->iop;
2351 if (p->fop)
2352 inode->i_fop = p->fop;
2353 ei->op = p->op;
2354 d_set_d_op(dentry, &pid_dentry_operations);
2355 d_add(dentry, inode);
2356 /* Close the race of the process dying before we return the dentry */
2357 if (pid_revalidate(dentry, 0))
2358 return 0;
2359out:
2360 return -ENOENT;
2361}
2362
2363static struct dentry *proc_pident_lookup(struct inode *dir,
2364 struct dentry *dentry,
2365 const struct pid_entry *ents,
2366 unsigned int nents)
2367{
2368 int error;
2369 struct task_struct *task = get_proc_task(dir);
2370 const struct pid_entry *p, *last;
2371
2372 error = -ENOENT;
2373
2374 if (!task)
2375 goto out_no_task;
2376
2377 /*
2378 * Yes, it does not scale. And it should not. Don't add
2379 * new entries into /proc/<tgid>/ without very good reasons.
2380 */
2381 last = &ents[nents - 1];
2382 for (p = ents; p <= last; p++) {
2383 if (p->len != dentry->d_name.len)
2384 continue;
2385 if (!memcmp(dentry->d_name.name, p->name, p->len))
2386 break;
2387 }
2388 if (p > last)
2389 goto out;
2390
2391 error = proc_pident_instantiate(dir, dentry, task, p);
2392out:
2393 put_task_struct(task);
2394out_no_task:
2395 return ERR_PTR(error);
2396}
2397
2398static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2399 const struct pid_entry *ents, unsigned int nents)
2400{
2401 struct task_struct *task = get_proc_task(file_inode(file));
2402 const struct pid_entry *p;
2403
2404 if (!task)
2405 return -ENOENT;
2406
2407 if (!dir_emit_dots(file, ctx))
2408 goto out;
2409
2410 if (ctx->pos >= nents + 2)
2411 goto out;
2412
2413 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) {
2414 if (!proc_fill_cache(file, ctx, p->name, p->len,
2415 proc_pident_instantiate, task, p))
2416 break;
2417 ctx->pos++;
2418 }
2419out:
2420 put_task_struct(task);
2421 return 0;
2422}
2423
2424#ifdef CONFIG_SECURITY
2425static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2426 size_t count, loff_t *ppos)
2427{
2428 struct inode * inode = file_inode(file);
2429 char *p = NULL;
2430 ssize_t length;
2431 struct task_struct *task = get_proc_task(inode);
2432
2433 if (!task)
2434 return -ESRCH;
2435
2436 length = security_getprocattr(task,
2437 (char*)file->f_path.dentry->d_name.name,
2438 &p);
2439 put_task_struct(task);
2440 if (length > 0)
2441 length = simple_read_from_buffer(buf, count, ppos, p, length);
2442 kfree(p);
2443 return length;
2444}
2445
2446static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2447 size_t count, loff_t *ppos)
2448{
2449 struct inode * inode = file_inode(file);
2450 void *page;
2451 ssize_t length;
2452 struct task_struct *task = get_proc_task(inode);
2453
2454 length = -ESRCH;
2455 if (!task)
2456 goto out_no_task;
2457 if (count > PAGE_SIZE)
2458 count = PAGE_SIZE;
2459
2460 /* No partial writes. */
2461 length = -EINVAL;
2462 if (*ppos != 0)
2463 goto out;
2464
2465 page = memdup_user(buf, count);
2466 if (IS_ERR(page)) {
2467 length = PTR_ERR(page);
2468 goto out;
2469 }
2470
2471 /* Guard against adverse ptrace interaction */
2472 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2473 if (length < 0)
2474 goto out_free;
2475
2476 length = security_setprocattr(task,
2477 (char*)file->f_path.dentry->d_name.name,
2478 page, count);
2479 mutex_unlock(&task->signal->cred_guard_mutex);
2480out_free:
2481 kfree(page);
2482out:
2483 put_task_struct(task);
2484out_no_task:
2485 return length;
2486}
2487
2488static const struct file_operations proc_pid_attr_operations = {
2489 .read = proc_pid_attr_read,
2490 .write = proc_pid_attr_write,
2491 .llseek = generic_file_llseek,
2492};
2493
2494static const struct pid_entry attr_dir_stuff[] = {
2495 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2496 REG("prev", S_IRUGO, proc_pid_attr_operations),
2497 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2498 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2499 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2500 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2501};
2502
2503static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2504{
2505 return proc_pident_readdir(file, ctx,
2506 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2507}
2508
2509static const struct file_operations proc_attr_dir_operations = {
2510 .read = generic_read_dir,
2511 .iterate_shared = proc_attr_dir_readdir,
2512 .llseek = generic_file_llseek,
2513};
2514
2515static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2516 struct dentry *dentry, unsigned int flags)
2517{
2518 return proc_pident_lookup(dir, dentry,
2519 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2520}
2521
2522static const struct inode_operations proc_attr_dir_inode_operations = {
2523 .lookup = proc_attr_dir_lookup,
2524 .getattr = pid_getattr,
2525 .setattr = proc_setattr,
2526};
2527
2528#endif
2529
2530#ifdef CONFIG_ELF_CORE
2531static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2532 size_t count, loff_t *ppos)
2533{
2534 struct task_struct *task = get_proc_task(file_inode(file));
2535 struct mm_struct *mm;
2536 char buffer[PROC_NUMBUF];
2537 size_t len;
2538 int ret;
2539
2540 if (!task)
2541 return -ESRCH;
2542
2543 ret = 0;
2544 mm = get_task_mm(task);
2545 if (mm) {
2546 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2547 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2548 MMF_DUMP_FILTER_SHIFT));
2549 mmput(mm);
2550 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2551 }
2552
2553 put_task_struct(task);
2554
2555 return ret;
2556}
2557
2558static ssize_t proc_coredump_filter_write(struct file *file,
2559 const char __user *buf,
2560 size_t count,
2561 loff_t *ppos)
2562{
2563 struct task_struct *task;
2564 struct mm_struct *mm;
2565 unsigned int val;
2566 int ret;
2567 int i;
2568 unsigned long mask;
2569
2570 ret = kstrtouint_from_user(buf, count, 0, &val);
2571 if (ret < 0)
2572 return ret;
2573
2574 ret = -ESRCH;
2575 task = get_proc_task(file_inode(file));
2576 if (!task)
2577 goto out_no_task;
2578
2579 mm = get_task_mm(task);
2580 if (!mm)
2581 goto out_no_mm;
2582 ret = 0;
2583
2584 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2585 if (val & mask)
2586 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2587 else
2588 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2589 }
2590
2591 mmput(mm);
2592 out_no_mm:
2593 put_task_struct(task);
2594 out_no_task:
2595 if (ret < 0)
2596 return ret;
2597 return count;
2598}
2599
2600static const struct file_operations proc_coredump_filter_operations = {
2601 .read = proc_coredump_filter_read,
2602 .write = proc_coredump_filter_write,
2603 .llseek = generic_file_llseek,
2604};
2605#endif
2606
2607#ifdef CONFIG_TASK_IO_ACCOUNTING
2608static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2609{
2610 struct task_io_accounting acct = task->ioac;
2611 unsigned long flags;
2612 int result;
2613
2614 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2615 if (result)
2616 return result;
2617
2618 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2619 result = -EACCES;
2620 goto out_unlock;
2621 }
2622
2623 if (whole && lock_task_sighand(task, &flags)) {
2624 struct task_struct *t = task;
2625
2626 task_io_accounting_add(&acct, &task->signal->ioac);
2627 while_each_thread(task, t)
2628 task_io_accounting_add(&acct, &t->ioac);
2629
2630 unlock_task_sighand(task, &flags);
2631 }
2632 seq_printf(m,
2633 "rchar: %llu\n"
2634 "wchar: %llu\n"
2635 "syscr: %llu\n"
2636 "syscw: %llu\n"
2637 "read_bytes: %llu\n"
2638 "write_bytes: %llu\n"
2639 "cancelled_write_bytes: %llu\n",
2640 (unsigned long long)acct.rchar,
2641 (unsigned long long)acct.wchar,
2642 (unsigned long long)acct.syscr,
2643 (unsigned long long)acct.syscw,
2644 (unsigned long long)acct.read_bytes,
2645 (unsigned long long)acct.write_bytes,
2646 (unsigned long long)acct.cancelled_write_bytes);
2647 result = 0;
2648
2649out_unlock:
2650 mutex_unlock(&task->signal->cred_guard_mutex);
2651 return result;
2652}
2653
2654static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2655 struct pid *pid, struct task_struct *task)
2656{
2657 return do_io_accounting(task, m, 0);
2658}
2659
2660static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2661 struct pid *pid, struct task_struct *task)
2662{
2663 return do_io_accounting(task, m, 1);
2664}
2665#endif /* CONFIG_TASK_IO_ACCOUNTING */
2666
2667#ifdef CONFIG_USER_NS
2668static int proc_id_map_open(struct inode *inode, struct file *file,
2669 const struct seq_operations *seq_ops)
2670{
2671 struct user_namespace *ns = NULL;
2672 struct task_struct *task;
2673 struct seq_file *seq;
2674 int ret = -EINVAL;
2675
2676 task = get_proc_task(inode);
2677 if (task) {
2678 rcu_read_lock();
2679 ns = get_user_ns(task_cred_xxx(task, user_ns));
2680 rcu_read_unlock();
2681 put_task_struct(task);
2682 }
2683 if (!ns)
2684 goto err;
2685
2686 ret = seq_open(file, seq_ops);
2687 if (ret)
2688 goto err_put_ns;
2689
2690 seq = file->private_data;
2691 seq->private = ns;
2692
2693 return 0;
2694err_put_ns:
2695 put_user_ns(ns);
2696err:
2697 return ret;
2698}
2699
2700static int proc_id_map_release(struct inode *inode, struct file *file)
2701{
2702 struct seq_file *seq = file->private_data;
2703 struct user_namespace *ns = seq->private;
2704 put_user_ns(ns);
2705 return seq_release(inode, file);
2706}
2707
2708static int proc_uid_map_open(struct inode *inode, struct file *file)
2709{
2710 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2711}
2712
2713static int proc_gid_map_open(struct inode *inode, struct file *file)
2714{
2715 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2716}
2717
2718static int proc_projid_map_open(struct inode *inode, struct file *file)
2719{
2720 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2721}
2722
2723static const struct file_operations proc_uid_map_operations = {
2724 .open = proc_uid_map_open,
2725 .write = proc_uid_map_write,
2726 .read = seq_read,
2727 .llseek = seq_lseek,
2728 .release = proc_id_map_release,
2729};
2730
2731static const struct file_operations proc_gid_map_operations = {
2732 .open = proc_gid_map_open,
2733 .write = proc_gid_map_write,
2734 .read = seq_read,
2735 .llseek = seq_lseek,
2736 .release = proc_id_map_release,
2737};
2738
2739static const struct file_operations proc_projid_map_operations = {
2740 .open = proc_projid_map_open,
2741 .write = proc_projid_map_write,
2742 .read = seq_read,
2743 .llseek = seq_lseek,
2744 .release = proc_id_map_release,
2745};
2746
2747static int proc_setgroups_open(struct inode *inode, struct file *file)
2748{
2749 struct user_namespace *ns = NULL;
2750 struct task_struct *task;
2751 int ret;
2752
2753 ret = -ESRCH;
2754 task = get_proc_task(inode);
2755 if (task) {
2756 rcu_read_lock();
2757 ns = get_user_ns(task_cred_xxx(task, user_ns));
2758 rcu_read_unlock();
2759 put_task_struct(task);
2760 }
2761 if (!ns)
2762 goto err;
2763
2764 if (file->f_mode & FMODE_WRITE) {
2765 ret = -EACCES;
2766 if (!ns_capable(ns, CAP_SYS_ADMIN))
2767 goto err_put_ns;
2768 }
2769
2770 ret = single_open(file, &proc_setgroups_show, ns);
2771 if (ret)
2772 goto err_put_ns;
2773
2774 return 0;
2775err_put_ns:
2776 put_user_ns(ns);
2777err:
2778 return ret;
2779}
2780
2781static int proc_setgroups_release(struct inode *inode, struct file *file)
2782{
2783 struct seq_file *seq = file->private_data;
2784 struct user_namespace *ns = seq->private;
2785 int ret = single_release(inode, file);
2786 put_user_ns(ns);
2787 return ret;
2788}
2789
2790static const struct file_operations proc_setgroups_operations = {
2791 .open = proc_setgroups_open,
2792 .write = proc_setgroups_write,
2793 .read = seq_read,
2794 .llseek = seq_lseek,
2795 .release = proc_setgroups_release,
2796};
2797#endif /* CONFIG_USER_NS */
2798
2799static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2800 struct pid *pid, struct task_struct *task)
2801{
2802 int err = lock_trace(task);
2803 if (!err) {
2804 seq_printf(m, "%08x\n", task->personality);
2805 unlock_trace(task);
2806 }
2807 return err;
2808}
2809
2810/*
2811 * Thread groups
2812 */
2813static const struct file_operations proc_task_operations;
2814static const struct inode_operations proc_task_inode_operations;
2815
2816static const struct pid_entry tgid_base_stuff[] = {
2817 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2818 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2819 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2820 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2821 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2822#ifdef CONFIG_NET
2823 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2824#endif
2825 REG("environ", S_IRUSR, proc_environ_operations),
2826 ONE("auxv", S_IRUSR, proc_pid_auxv),
2827 ONE("status", S_IRUGO, proc_pid_status),
2828 ONE("personality", S_IRUSR, proc_pid_personality),
2829 ONE("limits", S_IRUGO, proc_pid_limits),
2830#ifdef CONFIG_SCHED_DEBUG
2831 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2832#endif
2833#ifdef CONFIG_SCHED_AUTOGROUP
2834 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2835#endif
2836 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2837#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2838 ONE("syscall", S_IRUSR, proc_pid_syscall),
2839#endif
2840 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
2841 ONE("stat", S_IRUGO, proc_tgid_stat),
2842 ONE("statm", S_IRUGO, proc_pid_statm),
2843 REG("maps", S_IRUGO, proc_pid_maps_operations),
2844#ifdef CONFIG_NUMA
2845 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2846#endif
2847 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2848 LNK("cwd", proc_cwd_link),
2849 LNK("root", proc_root_link),
2850 LNK("exe", proc_exe_link),
2851 REG("mounts", S_IRUGO, proc_mounts_operations),
2852 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2853 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2854#ifdef CONFIG_PROC_PAGE_MONITOR
2855 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2856 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2857 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2858#endif
2859#ifdef CONFIG_SECURITY
2860 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2861#endif
2862#ifdef CONFIG_KALLSYMS
2863 ONE("wchan", S_IRUGO, proc_pid_wchan),
2864#endif
2865#ifdef CONFIG_STACKTRACE
2866 ONE("stack", S_IRUSR, proc_pid_stack),
2867#endif
2868#ifdef CONFIG_SCHED_INFO
2869 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
2870#endif
2871#ifdef CONFIG_LATENCYTOP
2872 REG("latency", S_IRUGO, proc_lstats_operations),
2873#endif
2874#ifdef CONFIG_PROC_PID_CPUSET
2875 ONE("cpuset", S_IRUGO, proc_cpuset_show),
2876#endif
2877#ifdef CONFIG_CGROUPS
2878 ONE("cgroup", S_IRUGO, proc_cgroup_show),
2879#endif
2880 ONE("oom_score", S_IRUGO, proc_oom_score),
2881 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2882 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2883#ifdef CONFIG_AUDITSYSCALL
2884 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2885 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2886#endif
2887#ifdef CONFIG_FAULT_INJECTION
2888 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2889#endif
2890#ifdef CONFIG_ELF_CORE
2891 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2892#endif
2893#ifdef CONFIG_TASK_IO_ACCOUNTING
2894 ONE("io", S_IRUSR, proc_tgid_io_accounting),
2895#endif
2896#ifdef CONFIG_HARDWALL
2897 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
2898#endif
2899#ifdef CONFIG_USER_NS
2900 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2901 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2902 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2903 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
2904#endif
2905#ifdef CONFIG_CHECKPOINT_RESTORE
2906 REG("timers", S_IRUGO, proc_timers_operations),
2907#endif
2908 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
2909};
2910
2911static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
2912{
2913 return proc_pident_readdir(file, ctx,
2914 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2915}
2916
2917static const struct file_operations proc_tgid_base_operations = {
2918 .read = generic_read_dir,
2919 .iterate_shared = proc_tgid_base_readdir,
2920 .llseek = generic_file_llseek,
2921};
2922
2923static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2924{
2925 return proc_pident_lookup(dir, dentry,
2926 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2927}
2928
2929static const struct inode_operations proc_tgid_base_inode_operations = {
2930 .lookup = proc_tgid_base_lookup,
2931 .getattr = pid_getattr,
2932 .setattr = proc_setattr,
2933 .permission = proc_pid_permission,
2934};
2935
2936static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2937{
2938 struct dentry *dentry, *leader, *dir;
2939 char buf[PROC_NUMBUF];
2940 struct qstr name;
2941
2942 name.name = buf;
2943 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2944 /* no ->d_hash() rejects on procfs */
2945 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2946 if (dentry) {
2947 d_invalidate(dentry);
2948 dput(dentry);
2949 }
2950
2951 if (pid == tgid)
2952 return;
2953
2954 name.name = buf;
2955 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2956 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2957 if (!leader)
2958 goto out;
2959
2960 name.name = "task";
2961 name.len = strlen(name.name);
2962 dir = d_hash_and_lookup(leader, &name);
2963 if (!dir)
2964 goto out_put_leader;
2965
2966 name.name = buf;
2967 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2968 dentry = d_hash_and_lookup(dir, &name);
2969 if (dentry) {
2970 d_invalidate(dentry);
2971 dput(dentry);
2972 }
2973
2974 dput(dir);
2975out_put_leader:
2976 dput(leader);
2977out:
2978 return;
2979}
2980
2981/**
2982 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2983 * @task: task that should be flushed.
2984 *
2985 * When flushing dentries from proc, one needs to flush them from global
2986 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2987 * in. This call is supposed to do all of this job.
2988 *
2989 * Looks in the dcache for
2990 * /proc/@pid
2991 * /proc/@tgid/task/@pid
2992 * if either directory is present flushes it and all of it'ts children
2993 * from the dcache.
2994 *
2995 * It is safe and reasonable to cache /proc entries for a task until
2996 * that task exits. After that they just clog up the dcache with
2997 * useless entries, possibly causing useful dcache entries to be
2998 * flushed instead. This routine is proved to flush those useless
2999 * dcache entries at process exit time.
3000 *
3001 * NOTE: This routine is just an optimization so it does not guarantee
3002 * that no dcache entries will exist at process exit time it
3003 * just makes it very unlikely that any will persist.
3004 */
3005
3006void proc_flush_task(struct task_struct *task)
3007{
3008 int i;
3009 struct pid *pid, *tgid;
3010 struct upid *upid;
3011
3012 pid = task_pid(task);
3013 tgid = task_tgid(task);
3014
3015 for (i = 0; i <= pid->level; i++) {
3016 upid = &pid->numbers[i];
3017 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3018 tgid->numbers[i].nr);
3019 }
3020}
3021
3022static int proc_pid_instantiate(struct inode *dir,
3023 struct dentry * dentry,
3024 struct task_struct *task, const void *ptr)
3025{
3026 struct inode *inode;
3027
3028 inode = proc_pid_make_inode(dir->i_sb, task);
3029 if (!inode)
3030 goto out;
3031
3032 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3033 inode->i_op = &proc_tgid_base_inode_operations;
3034 inode->i_fop = &proc_tgid_base_operations;
3035 inode->i_flags|=S_IMMUTABLE;
3036
3037 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
3038 ARRAY_SIZE(tgid_base_stuff)));
3039
3040 d_set_d_op(dentry, &pid_dentry_operations);
3041
3042 d_add(dentry, inode);
3043 /* Close the race of the process dying before we return the dentry */
3044 if (pid_revalidate(dentry, 0))
3045 return 0;
3046out:
3047 return -ENOENT;
3048}
3049
3050struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3051{
3052 int result = -ENOENT;
3053 struct task_struct *task;
3054 unsigned tgid;
3055 struct pid_namespace *ns;
3056
3057 tgid = name_to_int(&dentry->d_name);
3058 if (tgid == ~0U)
3059 goto out;
3060
3061 ns = dentry->d_sb->s_fs_info;
3062 rcu_read_lock();
3063 task = find_task_by_pid_ns(tgid, ns);
3064 if (task)
3065 get_task_struct(task);
3066 rcu_read_unlock();
3067 if (!task)
3068 goto out;
3069
3070 result = proc_pid_instantiate(dir, dentry, task, NULL);
3071 put_task_struct(task);
3072out:
3073 return ERR_PTR(result);
3074}
3075
3076/*
3077 * Find the first task with tgid >= tgid
3078 *
3079 */
3080struct tgid_iter {
3081 unsigned int tgid;
3082 struct task_struct *task;
3083};
3084static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3085{
3086 struct pid *pid;
3087
3088 if (iter.task)
3089 put_task_struct(iter.task);
3090 rcu_read_lock();
3091retry:
3092 iter.task = NULL;
3093 pid = find_ge_pid(iter.tgid, ns);
3094 if (pid) {
3095 iter.tgid = pid_nr_ns(pid, ns);
3096 iter.task = pid_task(pid, PIDTYPE_PID);
3097 /* What we to know is if the pid we have find is the
3098 * pid of a thread_group_leader. Testing for task
3099 * being a thread_group_leader is the obvious thing
3100 * todo but there is a window when it fails, due to
3101 * the pid transfer logic in de_thread.
3102 *
3103 * So we perform the straight forward test of seeing
3104 * if the pid we have found is the pid of a thread
3105 * group leader, and don't worry if the task we have
3106 * found doesn't happen to be a thread group leader.
3107 * As we don't care in the case of readdir.
3108 */
3109 if (!iter.task || !has_group_leader_pid(iter.task)) {
3110 iter.tgid += 1;
3111 goto retry;
3112 }
3113 get_task_struct(iter.task);
3114 }
3115 rcu_read_unlock();
3116 return iter;
3117}
3118
3119#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3120
3121/* for the /proc/ directory itself, after non-process stuff has been done */
3122int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3123{
3124 struct tgid_iter iter;
3125 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
3126 loff_t pos = ctx->pos;
3127
3128 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3129 return 0;
3130
3131 if (pos == TGID_OFFSET - 2) {
3132 struct inode *inode = d_inode(ns->proc_self);
3133 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3134 return 0;
3135 ctx->pos = pos = pos + 1;
3136 }
3137 if (pos == TGID_OFFSET - 1) {
3138 struct inode *inode = d_inode(ns->proc_thread_self);
3139 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3140 return 0;
3141 ctx->pos = pos = pos + 1;
3142 }
3143 iter.tgid = pos - TGID_OFFSET;
3144 iter.task = NULL;
3145 for (iter = next_tgid(ns, iter);
3146 iter.task;
3147 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3148 char name[PROC_NUMBUF];
3149 int len;
3150 if (!has_pid_permissions(ns, iter.task, 2))
3151 continue;
3152
3153 len = snprintf(name, sizeof(name), "%d", iter.tgid);
3154 ctx->pos = iter.tgid + TGID_OFFSET;
3155 if (!proc_fill_cache(file, ctx, name, len,
3156 proc_pid_instantiate, iter.task, NULL)) {
3157 put_task_struct(iter.task);
3158 return 0;
3159 }
3160 }
3161 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3162 return 0;
3163}
3164
3165/*
3166 * proc_tid_comm_permission is a special permission function exclusively
3167 * used for the node /proc/<pid>/task/<tid>/comm.
3168 * It bypasses generic permission checks in the case where a task of the same
3169 * task group attempts to access the node.
3170 * The rationale behind this is that glibc and bionic access this node for
3171 * cross thread naming (pthread_set/getname_np(!self)). However, if
3172 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3173 * which locks out the cross thread naming implementation.
3174 * This function makes sure that the node is always accessible for members of
3175 * same thread group.
3176 */
3177static int proc_tid_comm_permission(struct inode *inode, int mask)
3178{
3179 bool is_same_tgroup;
3180 struct task_struct *task;
3181
3182 task = get_proc_task(inode);
3183 if (!task)
3184 return -ESRCH;
3185 is_same_tgroup = same_thread_group(current, task);
3186 put_task_struct(task);
3187
3188 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3189 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3190 * read or written by the members of the corresponding
3191 * thread group.
3192 */
3193 return 0;
3194 }
3195
3196 return generic_permission(inode, mask);
3197}
3198
3199static const struct inode_operations proc_tid_comm_inode_operations = {
3200 .permission = proc_tid_comm_permission,
3201};
3202
3203/*
3204 * Tasks
3205 */
3206static const struct pid_entry tid_base_stuff[] = {
3207 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3208 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3209 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3210#ifdef CONFIG_NET
3211 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3212#endif
3213 REG("environ", S_IRUSR, proc_environ_operations),
3214 ONE("auxv", S_IRUSR, proc_pid_auxv),
3215 ONE("status", S_IRUGO, proc_pid_status),
3216 ONE("personality", S_IRUSR, proc_pid_personality),
3217 ONE("limits", S_IRUGO, proc_pid_limits),
3218#ifdef CONFIG_SCHED_DEBUG
3219 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3220#endif
3221 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3222 &proc_tid_comm_inode_operations,
3223 &proc_pid_set_comm_operations, {}),
3224#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3225 ONE("syscall", S_IRUSR, proc_pid_syscall),
3226#endif
3227 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3228 ONE("stat", S_IRUGO, proc_tid_stat),
3229 ONE("statm", S_IRUGO, proc_pid_statm),
3230 REG("maps", S_IRUGO, proc_tid_maps_operations),
3231#ifdef CONFIG_PROC_CHILDREN
3232 REG("children", S_IRUGO, proc_tid_children_operations),
3233#endif
3234#ifdef CONFIG_NUMA
3235 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3236#endif
3237 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3238 LNK("cwd", proc_cwd_link),
3239 LNK("root", proc_root_link),
3240 LNK("exe", proc_exe_link),
3241 REG("mounts", S_IRUGO, proc_mounts_operations),
3242 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3243#ifdef CONFIG_PROC_PAGE_MONITOR
3244 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3245 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3246 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3247#endif
3248#ifdef CONFIG_SECURITY
3249 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3250#endif
3251#ifdef CONFIG_KALLSYMS
3252 ONE("wchan", S_IRUGO, proc_pid_wchan),
3253#endif
3254#ifdef CONFIG_STACKTRACE
3255 ONE("stack", S_IRUSR, proc_pid_stack),
3256#endif
3257#ifdef CONFIG_SCHED_INFO
3258 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3259#endif
3260#ifdef CONFIG_LATENCYTOP
3261 REG("latency", S_IRUGO, proc_lstats_operations),
3262#endif
3263#ifdef CONFIG_PROC_PID_CPUSET
3264 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3265#endif
3266#ifdef CONFIG_CGROUPS
3267 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3268#endif
3269 ONE("oom_score", S_IRUGO, proc_oom_score),
3270 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3271 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3272#ifdef CONFIG_AUDITSYSCALL
3273 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3274 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3275#endif
3276#ifdef CONFIG_FAULT_INJECTION
3277 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3278#endif
3279#ifdef CONFIG_TASK_IO_ACCOUNTING
3280 ONE("io", S_IRUSR, proc_tid_io_accounting),
3281#endif
3282#ifdef CONFIG_HARDWALL
3283 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
3284#endif
3285#ifdef CONFIG_USER_NS
3286 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3287 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3288 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3289 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3290#endif
3291};
3292
3293static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3294{
3295 return proc_pident_readdir(file, ctx,
3296 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3297}
3298
3299static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3300{
3301 return proc_pident_lookup(dir, dentry,
3302 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3303}
3304
3305static const struct file_operations proc_tid_base_operations = {
3306 .read = generic_read_dir,
3307 .iterate_shared = proc_tid_base_readdir,
3308 .llseek = generic_file_llseek,
3309};
3310
3311static const struct inode_operations proc_tid_base_inode_operations = {
3312 .lookup = proc_tid_base_lookup,
3313 .getattr = pid_getattr,
3314 .setattr = proc_setattr,
3315};
3316
3317static int proc_task_instantiate(struct inode *dir,
3318 struct dentry *dentry, struct task_struct *task, const void *ptr)
3319{
3320 struct inode *inode;
3321 inode = proc_pid_make_inode(dir->i_sb, task);
3322
3323 if (!inode)
3324 goto out;
3325 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3326 inode->i_op = &proc_tid_base_inode_operations;
3327 inode->i_fop = &proc_tid_base_operations;
3328 inode->i_flags|=S_IMMUTABLE;
3329
3330 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3331 ARRAY_SIZE(tid_base_stuff)));
3332
3333 d_set_d_op(dentry, &pid_dentry_operations);
3334
3335 d_add(dentry, inode);
3336 /* Close the race of the process dying before we return the dentry */
3337 if (pid_revalidate(dentry, 0))
3338 return 0;
3339out:
3340 return -ENOENT;
3341}
3342
3343static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3344{
3345 int result = -ENOENT;
3346 struct task_struct *task;
3347 struct task_struct *leader = get_proc_task(dir);
3348 unsigned tid;
3349 struct pid_namespace *ns;
3350
3351 if (!leader)
3352 goto out_no_task;
3353
3354 tid = name_to_int(&dentry->d_name);
3355 if (tid == ~0U)
3356 goto out;
3357
3358 ns = dentry->d_sb->s_fs_info;
3359 rcu_read_lock();
3360 task = find_task_by_pid_ns(tid, ns);
3361 if (task)
3362 get_task_struct(task);
3363 rcu_read_unlock();
3364 if (!task)
3365 goto out;
3366 if (!same_thread_group(leader, task))
3367 goto out_drop_task;
3368
3369 result = proc_task_instantiate(dir, dentry, task, NULL);
3370out_drop_task:
3371 put_task_struct(task);
3372out:
3373 put_task_struct(leader);
3374out_no_task:
3375 return ERR_PTR(result);
3376}
3377
3378/*
3379 * Find the first tid of a thread group to return to user space.
3380 *
3381 * Usually this is just the thread group leader, but if the users
3382 * buffer was too small or there was a seek into the middle of the
3383 * directory we have more work todo.
3384 *
3385 * In the case of a short read we start with find_task_by_pid.
3386 *
3387 * In the case of a seek we start with the leader and walk nr
3388 * threads past it.
3389 */
3390static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3391 struct pid_namespace *ns)
3392{
3393 struct task_struct *pos, *task;
3394 unsigned long nr = f_pos;
3395
3396 if (nr != f_pos) /* 32bit overflow? */
3397 return NULL;
3398
3399 rcu_read_lock();
3400 task = pid_task(pid, PIDTYPE_PID);
3401 if (!task)
3402 goto fail;
3403
3404 /* Attempt to start with the tid of a thread */
3405 if (tid && nr) {
3406 pos = find_task_by_pid_ns(tid, ns);
3407 if (pos && same_thread_group(pos, task))
3408 goto found;
3409 }
3410
3411 /* If nr exceeds the number of threads there is nothing todo */
3412 if (nr >= get_nr_threads(task))
3413 goto fail;
3414
3415 /* If we haven't found our starting place yet start
3416 * with the leader and walk nr threads forward.
3417 */
3418 pos = task = task->group_leader;
3419 do {
3420 if (!nr--)
3421 goto found;
3422 } while_each_thread(task, pos);
3423fail:
3424 pos = NULL;
3425 goto out;
3426found:
3427 get_task_struct(pos);
3428out:
3429 rcu_read_unlock();
3430 return pos;
3431}
3432
3433/*
3434 * Find the next thread in the thread list.
3435 * Return NULL if there is an error or no next thread.
3436 *
3437 * The reference to the input task_struct is released.
3438 */
3439static struct task_struct *next_tid(struct task_struct *start)
3440{
3441 struct task_struct *pos = NULL;
3442 rcu_read_lock();
3443 if (pid_alive(start)) {
3444 pos = next_thread(start);
3445 if (thread_group_leader(pos))
3446 pos = NULL;
3447 else
3448 get_task_struct(pos);
3449 }
3450 rcu_read_unlock();
3451 put_task_struct(start);
3452 return pos;
3453}
3454
3455/* for the /proc/TGID/task/ directories */
3456static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3457{
3458 struct inode *inode = file_inode(file);
3459 struct task_struct *task;
3460 struct pid_namespace *ns;
3461 int tid;
3462
3463 if (proc_inode_is_dead(inode))
3464 return -ENOENT;
3465
3466 if (!dir_emit_dots(file, ctx))
3467 return 0;
3468
3469 /* f_version caches the tgid value that the last readdir call couldn't
3470 * return. lseek aka telldir automagically resets f_version to 0.
3471 */
3472 ns = inode->i_sb->s_fs_info;
3473 tid = (int)file->f_version;
3474 file->f_version = 0;
3475 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3476 task;
3477 task = next_tid(task), ctx->pos++) {
3478 char name[PROC_NUMBUF];
3479 int len;
3480 tid = task_pid_nr_ns(task, ns);
3481 len = snprintf(name, sizeof(name), "%d", tid);
3482 if (!proc_fill_cache(file, ctx, name, len,
3483 proc_task_instantiate, task, NULL)) {
3484 /* returning this tgid failed, save it as the first
3485 * pid for the next readir call */
3486 file->f_version = (u64)tid;
3487 put_task_struct(task);
3488 break;
3489 }
3490 }
3491
3492 return 0;
3493}
3494
3495static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3496{
3497 struct inode *inode = d_inode(dentry);
3498 struct task_struct *p = get_proc_task(inode);
3499 generic_fillattr(inode, stat);
3500
3501 if (p) {
3502 stat->nlink += get_nr_threads(p);
3503 put_task_struct(p);
3504 }
3505
3506 return 0;
3507}
3508
3509static const struct inode_operations proc_task_inode_operations = {
3510 .lookup = proc_task_lookup,
3511 .getattr = proc_task_getattr,
3512 .setattr = proc_setattr,
3513 .permission = proc_pid_permission,
3514};
3515
3516static const struct file_operations proc_task_operations = {
3517 .read = generic_read_dir,
3518 .iterate_shared = proc_task_readdir,
3519 .llseek = generic_file_llseek,
3520};
Linux 6.x block layer and io_uring tree(s)