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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 child = d_alloc(dir, &qname);
1824 if (!child)
1825 goto end_instantiate;
1826 if (instantiate(d_inode(dir), child, task, ptr) < 0) {
1827 dput(child);
1828 goto end_instantiate;
1829 }
1830 }
1831 inode = d_inode(child);
1832 ino = inode->i_ino;
1833 type = inode->i_mode >> 12;
1834 dput(child);
1835 return dir_emit(ctx, name, len, ino, type);
1836
1837end_instantiate:
1838 return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1839}
1840
1841/*
1842 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1843 * which represent vma start and end addresses.
1844 */
1845static int dname_to_vma_addr(struct dentry *dentry,
1846 unsigned long *start, unsigned long *end)
1847{
1848 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1849 return -EINVAL;
1850
1851 return 0;
1852}
1853
1854static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1855{
1856 unsigned long vm_start, vm_end;
1857 bool exact_vma_exists = false;
1858 struct mm_struct *mm = NULL;
1859 struct task_struct *task;
1860 const struct cred *cred;
1861 struct inode *inode;
1862 int status = 0;
1863
1864 if (flags & LOOKUP_RCU)
1865 return -ECHILD;
1866
1867 inode = d_inode(dentry);
1868 task = get_proc_task(inode);
1869 if (!task)
1870 goto out_notask;
1871
1872 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
1873 if (IS_ERR_OR_NULL(mm))
1874 goto out;
1875
1876 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1877 down_read(&mm->mmap_sem);
1878 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1879 up_read(&mm->mmap_sem);
1880 }
1881
1882 mmput(mm);
1883
1884 if (exact_vma_exists) {
1885 if (task_dumpable(task)) {
1886 rcu_read_lock();
1887 cred = __task_cred(task);
1888 inode->i_uid = cred->euid;
1889 inode->i_gid = cred->egid;
1890 rcu_read_unlock();
1891 } else {
1892 inode->i_uid = GLOBAL_ROOT_UID;
1893 inode->i_gid = GLOBAL_ROOT_GID;
1894 }
1895 security_task_to_inode(task, inode);
1896 status = 1;
1897 }
1898
1899out:
1900 put_task_struct(task);
1901
1902out_notask:
1903 return status;
1904}
1905
1906static const struct dentry_operations tid_map_files_dentry_operations = {
1907 .d_revalidate = map_files_d_revalidate,
1908 .d_delete = pid_delete_dentry,
1909};
1910
1911static int map_files_get_link(struct dentry *dentry, struct path *path)
1912{
1913 unsigned long vm_start, vm_end;
1914 struct vm_area_struct *vma;
1915 struct task_struct *task;
1916 struct mm_struct *mm;
1917 int rc;
1918
1919 rc = -ENOENT;
1920 task = get_proc_task(d_inode(dentry));
1921 if (!task)
1922 goto out;
1923
1924 mm = get_task_mm(task);
1925 put_task_struct(task);
1926 if (!mm)
1927 goto out;
1928
1929 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
1930 if (rc)
1931 goto out_mmput;
1932
1933 rc = -ENOENT;
1934 down_read(&mm->mmap_sem);
1935 vma = find_exact_vma(mm, vm_start, vm_end);
1936 if (vma && vma->vm_file) {
1937 *path = vma->vm_file->f_path;
1938 path_get(path);
1939 rc = 0;
1940 }
1941 up_read(&mm->mmap_sem);
1942
1943out_mmput:
1944 mmput(mm);
1945out:
1946 return rc;
1947}
1948
1949struct map_files_info {
1950 fmode_t mode;
1951 unsigned long len;
1952 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
1953};
1954
1955/*
1956 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
1957 * symlinks may be used to bypass permissions on ancestor directories in the
1958 * path to the file in question.
1959 */
1960static const char *
1961proc_map_files_get_link(struct dentry *dentry,
1962 struct inode *inode,
1963 struct delayed_call *done)
1964{
1965 if (!capable(CAP_SYS_ADMIN))
1966 return ERR_PTR(-EPERM);
1967
1968 return proc_pid_get_link(dentry, inode, done);
1969}
1970
1971/*
1972 * Identical to proc_pid_link_inode_operations except for get_link()
1973 */
1974static const struct inode_operations proc_map_files_link_inode_operations = {
1975 .readlink = proc_pid_readlink,
1976 .get_link = proc_map_files_get_link,
1977 .setattr = proc_setattr,
1978};
1979
1980static int
1981proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
1982 struct task_struct *task, const void *ptr)
1983{
1984 fmode_t mode = (fmode_t)(unsigned long)ptr;
1985 struct proc_inode *ei;
1986 struct inode *inode;
1987
1988 inode = proc_pid_make_inode(dir->i_sb, task);
1989 if (!inode)
1990 return -ENOENT;
1991
1992 ei = PROC_I(inode);
1993 ei->op.proc_get_link = map_files_get_link;
1994
1995 inode->i_op = &proc_map_files_link_inode_operations;
1996 inode->i_size = 64;
1997 inode->i_mode = S_IFLNK;
1998
1999 if (mode & FMODE_READ)
2000 inode->i_mode |= S_IRUSR;
2001 if (mode & FMODE_WRITE)
2002 inode->i_mode |= S_IWUSR;
2003
2004 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2005 d_add(dentry, inode);
2006
2007 return 0;
2008}
2009
2010static struct dentry *proc_map_files_lookup(struct inode *dir,
2011 struct dentry *dentry, unsigned int flags)
2012{
2013 unsigned long vm_start, vm_end;
2014 struct vm_area_struct *vma;
2015 struct task_struct *task;
2016 int result;
2017 struct mm_struct *mm;
2018
2019 result = -ENOENT;
2020 task = get_proc_task(dir);
2021 if (!task)
2022 goto out;
2023
2024 result = -EACCES;
2025 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2026 goto out_put_task;
2027
2028 result = -ENOENT;
2029 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2030 goto out_put_task;
2031
2032 mm = get_task_mm(task);
2033 if (!mm)
2034 goto out_put_task;
2035
2036 down_read(&mm->mmap_sem);
2037 vma = find_exact_vma(mm, vm_start, vm_end);
2038 if (!vma)
2039 goto out_no_vma;
2040
2041 if (vma->vm_file)
2042 result = proc_map_files_instantiate(dir, dentry, task,
2043 (void *)(unsigned long)vma->vm_file->f_mode);
2044
2045out_no_vma:
2046 up_read(&mm->mmap_sem);
2047 mmput(mm);
2048out_put_task:
2049 put_task_struct(task);
2050out:
2051 return ERR_PTR(result);
2052}
2053
2054static const struct inode_operations proc_map_files_inode_operations = {
2055 .lookup = proc_map_files_lookup,
2056 .permission = proc_fd_permission,
2057 .setattr = proc_setattr,
2058};
2059
2060static int
2061proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2062{
2063 struct vm_area_struct *vma;
2064 struct task_struct *task;
2065 struct mm_struct *mm;
2066 unsigned long nr_files, pos, i;
2067 struct flex_array *fa = NULL;
2068 struct map_files_info info;
2069 struct map_files_info *p;
2070 int ret;
2071
2072 ret = -ENOENT;
2073 task = get_proc_task(file_inode(file));
2074 if (!task)
2075 goto out;
2076
2077 ret = -EACCES;
2078 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2079 goto out_put_task;
2080
2081 ret = 0;
2082 if (!dir_emit_dots(file, ctx))
2083 goto out_put_task;
2084
2085 mm = get_task_mm(task);
2086 if (!mm)
2087 goto out_put_task;
2088 down_read(&mm->mmap_sem);
2089
2090 nr_files = 0;
2091
2092 /*
2093 * We need two passes here:
2094 *
2095 * 1) Collect vmas of mapped files with mmap_sem taken
2096 * 2) Release mmap_sem and instantiate entries
2097 *
2098 * otherwise we get lockdep complained, since filldir()
2099 * routine might require mmap_sem taken in might_fault().
2100 */
2101
2102 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2103 if (vma->vm_file && ++pos > ctx->pos)
2104 nr_files++;
2105 }
2106
2107 if (nr_files) {
2108 fa = flex_array_alloc(sizeof(info), nr_files,
2109 GFP_KERNEL);
2110 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2111 GFP_KERNEL)) {
2112 ret = -ENOMEM;
2113 if (fa)
2114 flex_array_free(fa);
2115 up_read(&mm->mmap_sem);
2116 mmput(mm);
2117 goto out_put_task;
2118 }
2119 for (i = 0, vma = mm->mmap, pos = 2; vma;
2120 vma = vma->vm_next) {
2121 if (!vma->vm_file)
2122 continue;
2123 if (++pos <= ctx->pos)
2124 continue;
2125
2126 info.mode = vma->vm_file->f_mode;
2127 info.len = snprintf(info.name,
2128 sizeof(info.name), "%lx-%lx",
2129 vma->vm_start, vma->vm_end);
2130 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2131 BUG();
2132 }
2133 }
2134 up_read(&mm->mmap_sem);
2135
2136 for (i = 0; i < nr_files; i++) {
2137 p = flex_array_get(fa, i);
2138 if (!proc_fill_cache(file, ctx,
2139 p->name, p->len,
2140 proc_map_files_instantiate,
2141 task,
2142 (void *)(unsigned long)p->mode))
2143 break;
2144 ctx->pos++;
2145 }
2146 if (fa)
2147 flex_array_free(fa);
2148 mmput(mm);
2149
2150out_put_task:
2151 put_task_struct(task);
2152out:
2153 return ret;
2154}
2155
2156static const struct file_operations proc_map_files_operations = {
2157 .read = generic_read_dir,
2158 .iterate = proc_map_files_readdir,
2159 .llseek = default_llseek,
2160};
2161
2162#ifdef CONFIG_CHECKPOINT_RESTORE
2163struct timers_private {
2164 struct pid *pid;
2165 struct task_struct *task;
2166 struct sighand_struct *sighand;
2167 struct pid_namespace *ns;
2168 unsigned long flags;
2169};
2170
2171static void *timers_start(struct seq_file *m, loff_t *pos)
2172{
2173 struct timers_private *tp = m->private;
2174
2175 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2176 if (!tp->task)
2177 return ERR_PTR(-ESRCH);
2178
2179 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2180 if (!tp->sighand)
2181 return ERR_PTR(-ESRCH);
2182
2183 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2184}
2185
2186static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2187{
2188 struct timers_private *tp = m->private;
2189 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2190}
2191
2192static void timers_stop(struct seq_file *m, void *v)
2193{
2194 struct timers_private *tp = m->private;
2195
2196 if (tp->sighand) {
2197 unlock_task_sighand(tp->task, &tp->flags);
2198 tp->sighand = NULL;
2199 }
2200
2201 if (tp->task) {
2202 put_task_struct(tp->task);
2203 tp->task = NULL;
2204 }
2205}
2206
2207static int show_timer(struct seq_file *m, void *v)
2208{
2209 struct k_itimer *timer;
2210 struct timers_private *tp = m->private;
2211 int notify;
2212 static const char * const nstr[] = {
2213 [SIGEV_SIGNAL] = "signal",
2214 [SIGEV_NONE] = "none",
2215 [SIGEV_THREAD] = "thread",
2216 };
2217
2218 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2219 notify = timer->it_sigev_notify;
2220
2221 seq_printf(m, "ID: %d\n", timer->it_id);
2222 seq_printf(m, "signal: %d/%p\n",
2223 timer->sigq->info.si_signo,
2224 timer->sigq->info.si_value.sival_ptr);
2225 seq_printf(m, "notify: %s/%s.%d\n",
2226 nstr[notify & ~SIGEV_THREAD_ID],
2227 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2228 pid_nr_ns(timer->it_pid, tp->ns));
2229 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2230
2231 return 0;
2232}
2233
2234static const struct seq_operations proc_timers_seq_ops = {
2235 .start = timers_start,
2236 .next = timers_next,
2237 .stop = timers_stop,
2238 .show = show_timer,
2239};
2240
2241static int proc_timers_open(struct inode *inode, struct file *file)
2242{
2243 struct timers_private *tp;
2244
2245 tp = __seq_open_private(file, &proc_timers_seq_ops,
2246 sizeof(struct timers_private));
2247 if (!tp)
2248 return -ENOMEM;
2249
2250 tp->pid = proc_pid(inode);
2251 tp->ns = inode->i_sb->s_fs_info;
2252 return 0;
2253}
2254
2255static const struct file_operations proc_timers_operations = {
2256 .open = proc_timers_open,
2257 .read = seq_read,
2258 .llseek = seq_lseek,
2259 .release = seq_release_private,
2260};
2261#endif
2262
2263static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2264 size_t count, loff_t *offset)
2265{
2266 struct inode *inode = file_inode(file);
2267 struct task_struct *p;
2268 u64 slack_ns;
2269 int err;
2270
2271 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2272 if (err < 0)
2273 return err;
2274
2275 p = get_proc_task(inode);
2276 if (!p)
2277 return -ESRCH;
2278
2279 if (ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS)) {
2280 task_lock(p);
2281 if (slack_ns == 0)
2282 p->timer_slack_ns = p->default_timer_slack_ns;
2283 else
2284 p->timer_slack_ns = slack_ns;
2285 task_unlock(p);
2286 } else
2287 count = -EPERM;
2288
2289 put_task_struct(p);
2290
2291 return count;
2292}
2293
2294static int timerslack_ns_show(struct seq_file *m, void *v)
2295{
2296 struct inode *inode = m->private;
2297 struct task_struct *p;
2298 int err = 0;
2299
2300 p = get_proc_task(inode);
2301 if (!p)
2302 return -ESRCH;
2303
2304 if (ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS)) {
2305 task_lock(p);
2306 seq_printf(m, "%llu\n", p->timer_slack_ns);
2307 task_unlock(p);
2308 } else
2309 err = -EPERM;
2310
2311 put_task_struct(p);
2312
2313 return err;
2314}
2315
2316static int timerslack_ns_open(struct inode *inode, struct file *filp)
2317{
2318 return single_open(filp, timerslack_ns_show, inode);
2319}
2320
2321static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2322 .open = timerslack_ns_open,
2323 .read = seq_read,
2324 .write = timerslack_ns_write,
2325 .llseek = seq_lseek,
2326 .release = single_release,
2327};
2328
2329static int proc_pident_instantiate(struct inode *dir,
2330 struct dentry *dentry, struct task_struct *task, const void *ptr)
2331{
2332 const struct pid_entry *p = ptr;
2333 struct inode *inode;
2334 struct proc_inode *ei;
2335
2336 inode = proc_pid_make_inode(dir->i_sb, task);
2337 if (!inode)
2338 goto out;
2339
2340 ei = PROC_I(inode);
2341 inode->i_mode = p->mode;
2342 if (S_ISDIR(inode->i_mode))
2343 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2344 if (p->iop)
2345 inode->i_op = p->iop;
2346 if (p->fop)
2347 inode->i_fop = p->fop;
2348 ei->op = p->op;
2349 d_set_d_op(dentry, &pid_dentry_operations);
2350 d_add(dentry, inode);
2351 /* Close the race of the process dying before we return the dentry */
2352 if (pid_revalidate(dentry, 0))
2353 return 0;
2354out:
2355 return -ENOENT;
2356}
2357
2358static struct dentry *proc_pident_lookup(struct inode *dir,
2359 struct dentry *dentry,
2360 const struct pid_entry *ents,
2361 unsigned int nents)
2362{
2363 int error;
2364 struct task_struct *task = get_proc_task(dir);
2365 const struct pid_entry *p, *last;
2366
2367 error = -ENOENT;
2368
2369 if (!task)
2370 goto out_no_task;
2371
2372 /*
2373 * Yes, it does not scale. And it should not. Don't add
2374 * new entries into /proc/<tgid>/ without very good reasons.
2375 */
2376 last = &ents[nents - 1];
2377 for (p = ents; p <= last; p++) {
2378 if (p->len != dentry->d_name.len)
2379 continue;
2380 if (!memcmp(dentry->d_name.name, p->name, p->len))
2381 break;
2382 }
2383 if (p > last)
2384 goto out;
2385
2386 error = proc_pident_instantiate(dir, dentry, task, p);
2387out:
2388 put_task_struct(task);
2389out_no_task:
2390 return ERR_PTR(error);
2391}
2392
2393static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2394 const struct pid_entry *ents, unsigned int nents)
2395{
2396 struct task_struct *task = get_proc_task(file_inode(file));
2397 const struct pid_entry *p;
2398
2399 if (!task)
2400 return -ENOENT;
2401
2402 if (!dir_emit_dots(file, ctx))
2403 goto out;
2404
2405 if (ctx->pos >= nents + 2)
2406 goto out;
2407
2408 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) {
2409 if (!proc_fill_cache(file, ctx, p->name, p->len,
2410 proc_pident_instantiate, task, p))
2411 break;
2412 ctx->pos++;
2413 }
2414out:
2415 put_task_struct(task);
2416 return 0;
2417}
2418
2419#ifdef CONFIG_SECURITY
2420static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2421 size_t count, loff_t *ppos)
2422{
2423 struct inode * inode = file_inode(file);
2424 char *p = NULL;
2425 ssize_t length;
2426 struct task_struct *task = get_proc_task(inode);
2427
2428 if (!task)
2429 return -ESRCH;
2430
2431 length = security_getprocattr(task,
2432 (char*)file->f_path.dentry->d_name.name,
2433 &p);
2434 put_task_struct(task);
2435 if (length > 0)
2436 length = simple_read_from_buffer(buf, count, ppos, p, length);
2437 kfree(p);
2438 return length;
2439}
2440
2441static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2442 size_t count, loff_t *ppos)
2443{
2444 struct inode * inode = file_inode(file);
2445 void *page;
2446 ssize_t length;
2447 struct task_struct *task = get_proc_task(inode);
2448
2449 length = -ESRCH;
2450 if (!task)
2451 goto out_no_task;
2452 if (count > PAGE_SIZE)
2453 count = PAGE_SIZE;
2454
2455 /* No partial writes. */
2456 length = -EINVAL;
2457 if (*ppos != 0)
2458 goto out;
2459
2460 page = memdup_user(buf, count);
2461 if (IS_ERR(page)) {
2462 length = PTR_ERR(page);
2463 goto out;
2464 }
2465
2466 /* Guard against adverse ptrace interaction */
2467 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2468 if (length < 0)
2469 goto out_free;
2470
2471 length = security_setprocattr(task,
2472 (char*)file->f_path.dentry->d_name.name,
2473 page, count);
2474 mutex_unlock(&task->signal->cred_guard_mutex);
2475out_free:
2476 kfree(page);
2477out:
2478 put_task_struct(task);
2479out_no_task:
2480 return length;
2481}
2482
2483static const struct file_operations proc_pid_attr_operations = {
2484 .read = proc_pid_attr_read,
2485 .write = proc_pid_attr_write,
2486 .llseek = generic_file_llseek,
2487};
2488
2489static const struct pid_entry attr_dir_stuff[] = {
2490 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2491 REG("prev", S_IRUGO, proc_pid_attr_operations),
2492 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2493 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2494 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2495 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2496};
2497
2498static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2499{
2500 return proc_pident_readdir(file, ctx,
2501 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2502}
2503
2504static const struct file_operations proc_attr_dir_operations = {
2505 .read = generic_read_dir,
2506 .iterate = proc_attr_dir_readdir,
2507 .llseek = default_llseek,
2508};
2509
2510static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2511 struct dentry *dentry, unsigned int flags)
2512{
2513 return proc_pident_lookup(dir, dentry,
2514 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2515}
2516
2517static const struct inode_operations proc_attr_dir_inode_operations = {
2518 .lookup = proc_attr_dir_lookup,
2519 .getattr = pid_getattr,
2520 .setattr = proc_setattr,
2521};
2522
2523#endif
2524
2525#ifdef CONFIG_ELF_CORE
2526static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2527 size_t count, loff_t *ppos)
2528{
2529 struct task_struct *task = get_proc_task(file_inode(file));
2530 struct mm_struct *mm;
2531 char buffer[PROC_NUMBUF];
2532 size_t len;
2533 int ret;
2534
2535 if (!task)
2536 return -ESRCH;
2537
2538 ret = 0;
2539 mm = get_task_mm(task);
2540 if (mm) {
2541 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2542 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2543 MMF_DUMP_FILTER_SHIFT));
2544 mmput(mm);
2545 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2546 }
2547
2548 put_task_struct(task);
2549
2550 return ret;
2551}
2552
2553static ssize_t proc_coredump_filter_write(struct file *file,
2554 const char __user *buf,
2555 size_t count,
2556 loff_t *ppos)
2557{
2558 struct task_struct *task;
2559 struct mm_struct *mm;
2560 unsigned int val;
2561 int ret;
2562 int i;
2563 unsigned long mask;
2564
2565 ret = kstrtouint_from_user(buf, count, 0, &val);
2566 if (ret < 0)
2567 return ret;
2568
2569 ret = -ESRCH;
2570 task = get_proc_task(file_inode(file));
2571 if (!task)
2572 goto out_no_task;
2573
2574 mm = get_task_mm(task);
2575 if (!mm)
2576 goto out_no_mm;
2577 ret = 0;
2578
2579 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2580 if (val & mask)
2581 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2582 else
2583 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2584 }
2585
2586 mmput(mm);
2587 out_no_mm:
2588 put_task_struct(task);
2589 out_no_task:
2590 if (ret < 0)
2591 return ret;
2592 return count;
2593}
2594
2595static const struct file_operations proc_coredump_filter_operations = {
2596 .read = proc_coredump_filter_read,
2597 .write = proc_coredump_filter_write,
2598 .llseek = generic_file_llseek,
2599};
2600#endif
2601
2602#ifdef CONFIG_TASK_IO_ACCOUNTING
2603static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2604{
2605 struct task_io_accounting acct = task->ioac;
2606 unsigned long flags;
2607 int result;
2608
2609 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2610 if (result)
2611 return result;
2612
2613 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2614 result = -EACCES;
2615 goto out_unlock;
2616 }
2617
2618 if (whole && lock_task_sighand(task, &flags)) {
2619 struct task_struct *t = task;
2620
2621 task_io_accounting_add(&acct, &task->signal->ioac);
2622 while_each_thread(task, t)
2623 task_io_accounting_add(&acct, &t->ioac);
2624
2625 unlock_task_sighand(task, &flags);
2626 }
2627 seq_printf(m,
2628 "rchar: %llu\n"
2629 "wchar: %llu\n"
2630 "syscr: %llu\n"
2631 "syscw: %llu\n"
2632 "read_bytes: %llu\n"
2633 "write_bytes: %llu\n"
2634 "cancelled_write_bytes: %llu\n",
2635 (unsigned long long)acct.rchar,
2636 (unsigned long long)acct.wchar,
2637 (unsigned long long)acct.syscr,
2638 (unsigned long long)acct.syscw,
2639 (unsigned long long)acct.read_bytes,
2640 (unsigned long long)acct.write_bytes,
2641 (unsigned long long)acct.cancelled_write_bytes);
2642 result = 0;
2643
2644out_unlock:
2645 mutex_unlock(&task->signal->cred_guard_mutex);
2646 return result;
2647}
2648
2649static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2650 struct pid *pid, struct task_struct *task)
2651{
2652 return do_io_accounting(task, m, 0);
2653}
2654
2655static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2656 struct pid *pid, struct task_struct *task)
2657{
2658 return do_io_accounting(task, m, 1);
2659}
2660#endif /* CONFIG_TASK_IO_ACCOUNTING */
2661
2662#ifdef CONFIG_USER_NS
2663static int proc_id_map_open(struct inode *inode, struct file *file,
2664 const struct seq_operations *seq_ops)
2665{
2666 struct user_namespace *ns = NULL;
2667 struct task_struct *task;
2668 struct seq_file *seq;
2669 int ret = -EINVAL;
2670
2671 task = get_proc_task(inode);
2672 if (task) {
2673 rcu_read_lock();
2674 ns = get_user_ns(task_cred_xxx(task, user_ns));
2675 rcu_read_unlock();
2676 put_task_struct(task);
2677 }
2678 if (!ns)
2679 goto err;
2680
2681 ret = seq_open(file, seq_ops);
2682 if (ret)
2683 goto err_put_ns;
2684
2685 seq = file->private_data;
2686 seq->private = ns;
2687
2688 return 0;
2689err_put_ns:
2690 put_user_ns(ns);
2691err:
2692 return ret;
2693}
2694
2695static int proc_id_map_release(struct inode *inode, struct file *file)
2696{
2697 struct seq_file *seq = file->private_data;
2698 struct user_namespace *ns = seq->private;
2699 put_user_ns(ns);
2700 return seq_release(inode, file);
2701}
2702
2703static int proc_uid_map_open(struct inode *inode, struct file *file)
2704{
2705 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2706}
2707
2708static int proc_gid_map_open(struct inode *inode, struct file *file)
2709{
2710 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2711}
2712
2713static int proc_projid_map_open(struct inode *inode, struct file *file)
2714{
2715 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2716}
2717
2718static const struct file_operations proc_uid_map_operations = {
2719 .open = proc_uid_map_open,
2720 .write = proc_uid_map_write,
2721 .read = seq_read,
2722 .llseek = seq_lseek,
2723 .release = proc_id_map_release,
2724};
2725
2726static const struct file_operations proc_gid_map_operations = {
2727 .open = proc_gid_map_open,
2728 .write = proc_gid_map_write,
2729 .read = seq_read,
2730 .llseek = seq_lseek,
2731 .release = proc_id_map_release,
2732};
2733
2734static const struct file_operations proc_projid_map_operations = {
2735 .open = proc_projid_map_open,
2736 .write = proc_projid_map_write,
2737 .read = seq_read,
2738 .llseek = seq_lseek,
2739 .release = proc_id_map_release,
2740};
2741
2742static int proc_setgroups_open(struct inode *inode, struct file *file)
2743{
2744 struct user_namespace *ns = NULL;
2745 struct task_struct *task;
2746 int ret;
2747
2748 ret = -ESRCH;
2749 task = get_proc_task(inode);
2750 if (task) {
2751 rcu_read_lock();
2752 ns = get_user_ns(task_cred_xxx(task, user_ns));
2753 rcu_read_unlock();
2754 put_task_struct(task);
2755 }
2756 if (!ns)
2757 goto err;
2758
2759 if (file->f_mode & FMODE_WRITE) {
2760 ret = -EACCES;
2761 if (!ns_capable(ns, CAP_SYS_ADMIN))
2762 goto err_put_ns;
2763 }
2764
2765 ret = single_open(file, &proc_setgroups_show, ns);
2766 if (ret)
2767 goto err_put_ns;
2768
2769 return 0;
2770err_put_ns:
2771 put_user_ns(ns);
2772err:
2773 return ret;
2774}
2775
2776static int proc_setgroups_release(struct inode *inode, struct file *file)
2777{
2778 struct seq_file *seq = file->private_data;
2779 struct user_namespace *ns = seq->private;
2780 int ret = single_release(inode, file);
2781 put_user_ns(ns);
2782 return ret;
2783}
2784
2785static const struct file_operations proc_setgroups_operations = {
2786 .open = proc_setgroups_open,
2787 .write = proc_setgroups_write,
2788 .read = seq_read,
2789 .llseek = seq_lseek,
2790 .release = proc_setgroups_release,
2791};
2792#endif /* CONFIG_USER_NS */
2793
2794static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2795 struct pid *pid, struct task_struct *task)
2796{
2797 int err = lock_trace(task);
2798 if (!err) {
2799 seq_printf(m, "%08x\n", task->personality);
2800 unlock_trace(task);
2801 }
2802 return err;
2803}
2804
2805/*
2806 * Thread groups
2807 */
2808static const struct file_operations proc_task_operations;
2809static const struct inode_operations proc_task_inode_operations;
2810
2811static const struct pid_entry tgid_base_stuff[] = {
2812 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2813 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2814 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2815 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2816 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2817#ifdef CONFIG_NET
2818 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2819#endif
2820 REG("environ", S_IRUSR, proc_environ_operations),
2821 ONE("auxv", S_IRUSR, proc_pid_auxv),
2822 ONE("status", S_IRUGO, proc_pid_status),
2823 ONE("personality", S_IRUSR, proc_pid_personality),
2824 ONE("limits", S_IRUGO, proc_pid_limits),
2825#ifdef CONFIG_SCHED_DEBUG
2826 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2827#endif
2828#ifdef CONFIG_SCHED_AUTOGROUP
2829 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2830#endif
2831 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2832#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2833 ONE("syscall", S_IRUSR, proc_pid_syscall),
2834#endif
2835 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
2836 ONE("stat", S_IRUGO, proc_tgid_stat),
2837 ONE("statm", S_IRUGO, proc_pid_statm),
2838 REG("maps", S_IRUGO, proc_pid_maps_operations),
2839#ifdef CONFIG_NUMA
2840 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2841#endif
2842 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2843 LNK("cwd", proc_cwd_link),
2844 LNK("root", proc_root_link),
2845 LNK("exe", proc_exe_link),
2846 REG("mounts", S_IRUGO, proc_mounts_operations),
2847 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2848 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2849#ifdef CONFIG_PROC_PAGE_MONITOR
2850 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2851 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2852 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2853#endif
2854#ifdef CONFIG_SECURITY
2855 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2856#endif
2857#ifdef CONFIG_KALLSYMS
2858 ONE("wchan", S_IRUGO, proc_pid_wchan),
2859#endif
2860#ifdef CONFIG_STACKTRACE
2861 ONE("stack", S_IRUSR, proc_pid_stack),
2862#endif
2863#ifdef CONFIG_SCHED_INFO
2864 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
2865#endif
2866#ifdef CONFIG_LATENCYTOP
2867 REG("latency", S_IRUGO, proc_lstats_operations),
2868#endif
2869#ifdef CONFIG_PROC_PID_CPUSET
2870 ONE("cpuset", S_IRUGO, proc_cpuset_show),
2871#endif
2872#ifdef CONFIG_CGROUPS
2873 ONE("cgroup", S_IRUGO, proc_cgroup_show),
2874#endif
2875 ONE("oom_score", S_IRUGO, proc_oom_score),
2876 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2877 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2878#ifdef CONFIG_AUDITSYSCALL
2879 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2880 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2881#endif
2882#ifdef CONFIG_FAULT_INJECTION
2883 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2884#endif
2885#ifdef CONFIG_ELF_CORE
2886 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2887#endif
2888#ifdef CONFIG_TASK_IO_ACCOUNTING
2889 ONE("io", S_IRUSR, proc_tgid_io_accounting),
2890#endif
2891#ifdef CONFIG_HARDWALL
2892 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
2893#endif
2894#ifdef CONFIG_USER_NS
2895 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2896 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2897 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2898 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
2899#endif
2900#ifdef CONFIG_CHECKPOINT_RESTORE
2901 REG("timers", S_IRUGO, proc_timers_operations),
2902#endif
2903 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
2904};
2905
2906static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
2907{
2908 return proc_pident_readdir(file, ctx,
2909 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2910}
2911
2912static const struct file_operations proc_tgid_base_operations = {
2913 .read = generic_read_dir,
2914 .iterate = proc_tgid_base_readdir,
2915 .llseek = default_llseek,
2916};
2917
2918static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2919{
2920 return proc_pident_lookup(dir, dentry,
2921 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2922}
2923
2924static const struct inode_operations proc_tgid_base_inode_operations = {
2925 .lookup = proc_tgid_base_lookup,
2926 .getattr = pid_getattr,
2927 .setattr = proc_setattr,
2928 .permission = proc_pid_permission,
2929};
2930
2931static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2932{
2933 struct dentry *dentry, *leader, *dir;
2934 char buf[PROC_NUMBUF];
2935 struct qstr name;
2936
2937 name.name = buf;
2938 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2939 /* no ->d_hash() rejects on procfs */
2940 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2941 if (dentry) {
2942 d_invalidate(dentry);
2943 dput(dentry);
2944 }
2945
2946 if (pid == tgid)
2947 return;
2948
2949 name.name = buf;
2950 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2951 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2952 if (!leader)
2953 goto out;
2954
2955 name.name = "task";
2956 name.len = strlen(name.name);
2957 dir = d_hash_and_lookup(leader, &name);
2958 if (!dir)
2959 goto out_put_leader;
2960
2961 name.name = buf;
2962 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2963 dentry = d_hash_and_lookup(dir, &name);
2964 if (dentry) {
2965 d_invalidate(dentry);
2966 dput(dentry);
2967 }
2968
2969 dput(dir);
2970out_put_leader:
2971 dput(leader);
2972out:
2973 return;
2974}
2975
2976/**
2977 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2978 * @task: task that should be flushed.
2979 *
2980 * When flushing dentries from proc, one needs to flush them from global
2981 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2982 * in. This call is supposed to do all of this job.
2983 *
2984 * Looks in the dcache for
2985 * /proc/@pid
2986 * /proc/@tgid/task/@pid
2987 * if either directory is present flushes it and all of it'ts children
2988 * from the dcache.
2989 *
2990 * It is safe and reasonable to cache /proc entries for a task until
2991 * that task exits. After that they just clog up the dcache with
2992 * useless entries, possibly causing useful dcache entries to be
2993 * flushed instead. This routine is proved to flush those useless
2994 * dcache entries at process exit time.
2995 *
2996 * NOTE: This routine is just an optimization so it does not guarantee
2997 * that no dcache entries will exist at process exit time it
2998 * just makes it very unlikely that any will persist.
2999 */
3000
3001void proc_flush_task(struct task_struct *task)
3002{
3003 int i;
3004 struct pid *pid, *tgid;
3005 struct upid *upid;
3006
3007 pid = task_pid(task);
3008 tgid = task_tgid(task);
3009
3010 for (i = 0; i <= pid->level; i++) {
3011 upid = &pid->numbers[i];
3012 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3013 tgid->numbers[i].nr);
3014 }
3015}
3016
3017static int proc_pid_instantiate(struct inode *dir,
3018 struct dentry * dentry,
3019 struct task_struct *task, const void *ptr)
3020{
3021 struct inode *inode;
3022
3023 inode = proc_pid_make_inode(dir->i_sb, task);
3024 if (!inode)
3025 goto out;
3026
3027 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3028 inode->i_op = &proc_tgid_base_inode_operations;
3029 inode->i_fop = &proc_tgid_base_operations;
3030 inode->i_flags|=S_IMMUTABLE;
3031
3032 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
3033 ARRAY_SIZE(tgid_base_stuff)));
3034
3035 d_set_d_op(dentry, &pid_dentry_operations);
3036
3037 d_add(dentry, inode);
3038 /* Close the race of the process dying before we return the dentry */
3039 if (pid_revalidate(dentry, 0))
3040 return 0;
3041out:
3042 return -ENOENT;
3043}
3044
3045struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3046{
3047 int result = -ENOENT;
3048 struct task_struct *task;
3049 unsigned tgid;
3050 struct pid_namespace *ns;
3051
3052 tgid = name_to_int(&dentry->d_name);
3053 if (tgid == ~0U)
3054 goto out;
3055
3056 ns = dentry->d_sb->s_fs_info;
3057 rcu_read_lock();
3058 task = find_task_by_pid_ns(tgid, ns);
3059 if (task)
3060 get_task_struct(task);
3061 rcu_read_unlock();
3062 if (!task)
3063 goto out;
3064
3065 result = proc_pid_instantiate(dir, dentry, task, NULL);
3066 put_task_struct(task);
3067out:
3068 return ERR_PTR(result);
3069}
3070
3071/*
3072 * Find the first task with tgid >= tgid
3073 *
3074 */
3075struct tgid_iter {
3076 unsigned int tgid;
3077 struct task_struct *task;
3078};
3079static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3080{
3081 struct pid *pid;
3082
3083 if (iter.task)
3084 put_task_struct(iter.task);
3085 rcu_read_lock();
3086retry:
3087 iter.task = NULL;
3088 pid = find_ge_pid(iter.tgid, ns);
3089 if (pid) {
3090 iter.tgid = pid_nr_ns(pid, ns);
3091 iter.task = pid_task(pid, PIDTYPE_PID);
3092 /* What we to know is if the pid we have find is the
3093 * pid of a thread_group_leader. Testing for task
3094 * being a thread_group_leader is the obvious thing
3095 * todo but there is a window when it fails, due to
3096 * the pid transfer logic in de_thread.
3097 *
3098 * So we perform the straight forward test of seeing
3099 * if the pid we have found is the pid of a thread
3100 * group leader, and don't worry if the task we have
3101 * found doesn't happen to be a thread group leader.
3102 * As we don't care in the case of readdir.
3103 */
3104 if (!iter.task || !has_group_leader_pid(iter.task)) {
3105 iter.tgid += 1;
3106 goto retry;
3107 }
3108 get_task_struct(iter.task);
3109 }
3110 rcu_read_unlock();
3111 return iter;
3112}
3113
3114#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3115
3116/* for the /proc/ directory itself, after non-process stuff has been done */
3117int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3118{
3119 struct tgid_iter iter;
3120 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
3121 loff_t pos = ctx->pos;
3122
3123 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3124 return 0;
3125
3126 if (pos == TGID_OFFSET - 2) {
3127 struct inode *inode = d_inode(ns->proc_self);
3128 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3129 return 0;
3130 ctx->pos = pos = pos + 1;
3131 }
3132 if (pos == TGID_OFFSET - 1) {
3133 struct inode *inode = d_inode(ns->proc_thread_self);
3134 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3135 return 0;
3136 ctx->pos = pos = pos + 1;
3137 }
3138 iter.tgid = pos - TGID_OFFSET;
3139 iter.task = NULL;
3140 for (iter = next_tgid(ns, iter);
3141 iter.task;
3142 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3143 char name[PROC_NUMBUF];
3144 int len;
3145 if (!has_pid_permissions(ns, iter.task, 2))
3146 continue;
3147
3148 len = snprintf(name, sizeof(name), "%d", iter.tgid);
3149 ctx->pos = iter.tgid + TGID_OFFSET;
3150 if (!proc_fill_cache(file, ctx, name, len,
3151 proc_pid_instantiate, iter.task, NULL)) {
3152 put_task_struct(iter.task);
3153 return 0;
3154 }
3155 }
3156 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3157 return 0;
3158}
3159
3160/*
3161 * Tasks
3162 */
3163static const struct pid_entry tid_base_stuff[] = {
3164 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3165 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3166 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3167#ifdef CONFIG_NET
3168 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3169#endif
3170 REG("environ", S_IRUSR, proc_environ_operations),
3171 ONE("auxv", S_IRUSR, proc_pid_auxv),
3172 ONE("status", S_IRUGO, proc_pid_status),
3173 ONE("personality", S_IRUSR, proc_pid_personality),
3174 ONE("limits", S_IRUGO, proc_pid_limits),
3175#ifdef CONFIG_SCHED_DEBUG
3176 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3177#endif
3178 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3179#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3180 ONE("syscall", S_IRUSR, proc_pid_syscall),
3181#endif
3182 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3183 ONE("stat", S_IRUGO, proc_tid_stat),
3184 ONE("statm", S_IRUGO, proc_pid_statm),
3185 REG("maps", S_IRUGO, proc_tid_maps_operations),
3186#ifdef CONFIG_PROC_CHILDREN
3187 REG("children", S_IRUGO, proc_tid_children_operations),
3188#endif
3189#ifdef CONFIG_NUMA
3190 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3191#endif
3192 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3193 LNK("cwd", proc_cwd_link),
3194 LNK("root", proc_root_link),
3195 LNK("exe", proc_exe_link),
3196 REG("mounts", S_IRUGO, proc_mounts_operations),
3197 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3198#ifdef CONFIG_PROC_PAGE_MONITOR
3199 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3200 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3201 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3202#endif
3203#ifdef CONFIG_SECURITY
3204 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3205#endif
3206#ifdef CONFIG_KALLSYMS
3207 ONE("wchan", S_IRUGO, proc_pid_wchan),
3208#endif
3209#ifdef CONFIG_STACKTRACE
3210 ONE("stack", S_IRUSR, proc_pid_stack),
3211#endif
3212#ifdef CONFIG_SCHED_INFO
3213 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3214#endif
3215#ifdef CONFIG_LATENCYTOP
3216 REG("latency", S_IRUGO, proc_lstats_operations),
3217#endif
3218#ifdef CONFIG_PROC_PID_CPUSET
3219 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3220#endif
3221#ifdef CONFIG_CGROUPS
3222 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3223#endif
3224 ONE("oom_score", S_IRUGO, proc_oom_score),
3225 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3226 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3227#ifdef CONFIG_AUDITSYSCALL
3228 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3229 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3230#endif
3231#ifdef CONFIG_FAULT_INJECTION
3232 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3233#endif
3234#ifdef CONFIG_TASK_IO_ACCOUNTING
3235 ONE("io", S_IRUSR, proc_tid_io_accounting),
3236#endif
3237#ifdef CONFIG_HARDWALL
3238 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
3239#endif
3240#ifdef CONFIG_USER_NS
3241 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3242 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3243 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3244 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3245#endif
3246};
3247
3248static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3249{
3250 return proc_pident_readdir(file, ctx,
3251 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3252}
3253
3254static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3255{
3256 return proc_pident_lookup(dir, dentry,
3257 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3258}
3259
3260static const struct file_operations proc_tid_base_operations = {
3261 .read = generic_read_dir,
3262 .iterate = proc_tid_base_readdir,
3263 .llseek = default_llseek,
3264};
3265
3266static const struct inode_operations proc_tid_base_inode_operations = {
3267 .lookup = proc_tid_base_lookup,
3268 .getattr = pid_getattr,
3269 .setattr = proc_setattr,
3270};
3271
3272static int proc_task_instantiate(struct inode *dir,
3273 struct dentry *dentry, struct task_struct *task, const void *ptr)
3274{
3275 struct inode *inode;
3276 inode = proc_pid_make_inode(dir->i_sb, task);
3277
3278 if (!inode)
3279 goto out;
3280 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3281 inode->i_op = &proc_tid_base_inode_operations;
3282 inode->i_fop = &proc_tid_base_operations;
3283 inode->i_flags|=S_IMMUTABLE;
3284
3285 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3286 ARRAY_SIZE(tid_base_stuff)));
3287
3288 d_set_d_op(dentry, &pid_dentry_operations);
3289
3290 d_add(dentry, inode);
3291 /* Close the race of the process dying before we return the dentry */
3292 if (pid_revalidate(dentry, 0))
3293 return 0;
3294out:
3295 return -ENOENT;
3296}
3297
3298static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3299{
3300 int result = -ENOENT;
3301 struct task_struct *task;
3302 struct task_struct *leader = get_proc_task(dir);
3303 unsigned tid;
3304 struct pid_namespace *ns;
3305
3306 if (!leader)
3307 goto out_no_task;
3308
3309 tid = name_to_int(&dentry->d_name);
3310 if (tid == ~0U)
3311 goto out;
3312
3313 ns = dentry->d_sb->s_fs_info;
3314 rcu_read_lock();
3315 task = find_task_by_pid_ns(tid, ns);
3316 if (task)
3317 get_task_struct(task);
3318 rcu_read_unlock();
3319 if (!task)
3320 goto out;
3321 if (!same_thread_group(leader, task))
3322 goto out_drop_task;
3323
3324 result = proc_task_instantiate(dir, dentry, task, NULL);
3325out_drop_task:
3326 put_task_struct(task);
3327out:
3328 put_task_struct(leader);
3329out_no_task:
3330 return ERR_PTR(result);
3331}
3332
3333/*
3334 * Find the first tid of a thread group to return to user space.
3335 *
3336 * Usually this is just the thread group leader, but if the users
3337 * buffer was too small or there was a seek into the middle of the
3338 * directory we have more work todo.
3339 *
3340 * In the case of a short read we start with find_task_by_pid.
3341 *
3342 * In the case of a seek we start with the leader and walk nr
3343 * threads past it.
3344 */
3345static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3346 struct pid_namespace *ns)
3347{
3348 struct task_struct *pos, *task;
3349 unsigned long nr = f_pos;
3350
3351 if (nr != f_pos) /* 32bit overflow? */
3352 return NULL;
3353
3354 rcu_read_lock();
3355 task = pid_task(pid, PIDTYPE_PID);
3356 if (!task)
3357 goto fail;
3358
3359 /* Attempt to start with the tid of a thread */
3360 if (tid && nr) {
3361 pos = find_task_by_pid_ns(tid, ns);
3362 if (pos && same_thread_group(pos, task))
3363 goto found;
3364 }
3365
3366 /* If nr exceeds the number of threads there is nothing todo */
3367 if (nr >= get_nr_threads(task))
3368 goto fail;
3369
3370 /* If we haven't found our starting place yet start
3371 * with the leader and walk nr threads forward.
3372 */
3373 pos = task = task->group_leader;
3374 do {
3375 if (!nr--)
3376 goto found;
3377 } while_each_thread(task, pos);
3378fail:
3379 pos = NULL;
3380 goto out;
3381found:
3382 get_task_struct(pos);
3383out:
3384 rcu_read_unlock();
3385 return pos;
3386}
3387
3388/*
3389 * Find the next thread in the thread list.
3390 * Return NULL if there is an error or no next thread.
3391 *
3392 * The reference to the input task_struct is released.
3393 */
3394static struct task_struct *next_tid(struct task_struct *start)
3395{
3396 struct task_struct *pos = NULL;
3397 rcu_read_lock();
3398 if (pid_alive(start)) {
3399 pos = next_thread(start);
3400 if (thread_group_leader(pos))
3401 pos = NULL;
3402 else
3403 get_task_struct(pos);
3404 }
3405 rcu_read_unlock();
3406 put_task_struct(start);
3407 return pos;
3408}
3409
3410/* for the /proc/TGID/task/ directories */
3411static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3412{
3413 struct inode *inode = file_inode(file);
3414 struct task_struct *task;
3415 struct pid_namespace *ns;
3416 int tid;
3417
3418 if (proc_inode_is_dead(inode))
3419 return -ENOENT;
3420
3421 if (!dir_emit_dots(file, ctx))
3422 return 0;
3423
3424 /* f_version caches the tgid value that the last readdir call couldn't
3425 * return. lseek aka telldir automagically resets f_version to 0.
3426 */
3427 ns = inode->i_sb->s_fs_info;
3428 tid = (int)file->f_version;
3429 file->f_version = 0;
3430 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3431 task;
3432 task = next_tid(task), ctx->pos++) {
3433 char name[PROC_NUMBUF];
3434 int len;
3435 tid = task_pid_nr_ns(task, ns);
3436 len = snprintf(name, sizeof(name), "%d", tid);
3437 if (!proc_fill_cache(file, ctx, name, len,
3438 proc_task_instantiate, task, NULL)) {
3439 /* returning this tgid failed, save it as the first
3440 * pid for the next readir call */
3441 file->f_version = (u64)tid;
3442 put_task_struct(task);
3443 break;
3444 }
3445 }
3446
3447 return 0;
3448}
3449
3450static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3451{
3452 struct inode *inode = d_inode(dentry);
3453 struct task_struct *p = get_proc_task(inode);
3454 generic_fillattr(inode, stat);
3455
3456 if (p) {
3457 stat->nlink += get_nr_threads(p);
3458 put_task_struct(p);
3459 }
3460
3461 return 0;
3462}
3463
3464static const struct inode_operations proc_task_inode_operations = {
3465 .lookup = proc_task_lookup,
3466 .getattr = proc_task_getattr,
3467 .setattr = proc_setattr,
3468 .permission = proc_pid_permission,
3469};
3470
3471static const struct file_operations proc_task_operations = {
3472 .read = generic_read_dir,
3473 .iterate = proc_task_readdir,
3474 .llseek = default_llseek,
3475};
1/*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50#include <asm/uaccess.h>
51
52#include <linux/errno.h>
53#include <linux/time.h>
54#include <linux/proc_fs.h>
55#include <linux/stat.h>
56#include <linux/task_io_accounting_ops.h>
57#include <linux/init.h>
58#include <linux/capability.h>
59#include <linux/file.h>
60#include <linux/fdtable.h>
61#include <linux/string.h>
62#include <linux/seq_file.h>
63#include <linux/namei.h>
64#include <linux/mnt_namespace.h>
65#include <linux/mm.h>
66#include <linux/swap.h>
67#include <linux/rcupdate.h>
68#include <linux/kallsyms.h>
69#include <linux/stacktrace.h>
70#include <linux/resource.h>
71#include <linux/module.h>
72#include <linux/mount.h>
73#include <linux/security.h>
74#include <linux/ptrace.h>
75#include <linux/tracehook.h>
76#include <linux/cgroup.h>
77#include <linux/cpuset.h>
78#include <linux/audit.h>
79#include <linux/poll.h>
80#include <linux/nsproxy.h>
81#include <linux/oom.h>
82#include <linux/elf.h>
83#include <linux/pid_namespace.h>
84#include <linux/user_namespace.h>
85#include <linux/fs_struct.h>
86#include <linux/slab.h>
87#include <linux/flex_array.h>
88#ifdef CONFIG_HARDWALL
89#include <asm/hardwall.h>
90#endif
91#include <trace/events/oom.h>
92#include "internal.h"
93
94/* NOTE:
95 * Implementing inode permission operations in /proc is almost
96 * certainly an error. Permission checks need to happen during
97 * each system call not at open time. The reason is that most of
98 * what we wish to check for permissions in /proc varies at runtime.
99 *
100 * The classic example of a problem is opening file descriptors
101 * in /proc for a task before it execs a suid executable.
102 */
103
104struct pid_entry {
105 char *name;
106 int len;
107 umode_t mode;
108 const struct inode_operations *iop;
109 const struct file_operations *fop;
110 union proc_op op;
111};
112
113#define NOD(NAME, MODE, IOP, FOP, OP) { \
114 .name = (NAME), \
115 .len = sizeof(NAME) - 1, \
116 .mode = MODE, \
117 .iop = IOP, \
118 .fop = FOP, \
119 .op = OP, \
120}
121
122#define DIR(NAME, MODE, iops, fops) \
123 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
124#define LNK(NAME, get_link) \
125 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
126 &proc_pid_link_inode_operations, NULL, \
127 { .proc_get_link = get_link } )
128#define REG(NAME, MODE, fops) \
129 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
130#define INF(NAME, MODE, read) \
131 NOD(NAME, (S_IFREG|(MODE)), \
132 NULL, &proc_info_file_operations, \
133 { .proc_read = read } )
134#define ONE(NAME, MODE, show) \
135 NOD(NAME, (S_IFREG|(MODE)), \
136 NULL, &proc_single_file_operations, \
137 { .proc_show = show } )
138
139static int proc_fd_permission(struct inode *inode, int mask);
140
141/*
142 * Count the number of hardlinks for the pid_entry table, excluding the .
143 * and .. links.
144 */
145static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
146 unsigned int n)
147{
148 unsigned int i;
149 unsigned int count;
150
151 count = 0;
152 for (i = 0; i < n; ++i) {
153 if (S_ISDIR(entries[i].mode))
154 ++count;
155 }
156
157 return count;
158}
159
160static int get_task_root(struct task_struct *task, struct path *root)
161{
162 int result = -ENOENT;
163
164 task_lock(task);
165 if (task->fs) {
166 get_fs_root(task->fs, root);
167 result = 0;
168 }
169 task_unlock(task);
170 return result;
171}
172
173static int proc_cwd_link(struct dentry *dentry, struct path *path)
174{
175 struct task_struct *task = get_proc_task(dentry->d_inode);
176 int result = -ENOENT;
177
178 if (task) {
179 task_lock(task);
180 if (task->fs) {
181 get_fs_pwd(task->fs, path);
182 result = 0;
183 }
184 task_unlock(task);
185 put_task_struct(task);
186 }
187 return result;
188}
189
190static int proc_root_link(struct dentry *dentry, struct path *path)
191{
192 struct task_struct *task = get_proc_task(dentry->d_inode);
193 int result = -ENOENT;
194
195 if (task) {
196 result = get_task_root(task, path);
197 put_task_struct(task);
198 }
199 return result;
200}
201
202static int proc_pid_cmdline(struct task_struct *task, char * buffer)
203{
204 int res = 0;
205 unsigned int len;
206 struct mm_struct *mm = get_task_mm(task);
207 if (!mm)
208 goto out;
209 if (!mm->arg_end)
210 goto out_mm; /* Shh! No looking before we're done */
211
212 len = mm->arg_end - mm->arg_start;
213
214 if (len > PAGE_SIZE)
215 len = PAGE_SIZE;
216
217 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
218
219 // If the nul at the end of args has been overwritten, then
220 // assume application is using setproctitle(3).
221 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
222 len = strnlen(buffer, res);
223 if (len < res) {
224 res = len;
225 } else {
226 len = mm->env_end - mm->env_start;
227 if (len > PAGE_SIZE - res)
228 len = PAGE_SIZE - res;
229 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
230 res = strnlen(buffer, res);
231 }
232 }
233out_mm:
234 mmput(mm);
235out:
236 return res;
237}
238
239static int proc_pid_auxv(struct task_struct *task, char *buffer)
240{
241 struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ);
242 int res = PTR_ERR(mm);
243 if (mm && !IS_ERR(mm)) {
244 unsigned int nwords = 0;
245 do {
246 nwords += 2;
247 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
248 res = nwords * sizeof(mm->saved_auxv[0]);
249 if (res > PAGE_SIZE)
250 res = PAGE_SIZE;
251 memcpy(buffer, mm->saved_auxv, res);
252 mmput(mm);
253 }
254 return res;
255}
256
257
258#ifdef CONFIG_KALLSYMS
259/*
260 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
261 * Returns the resolved symbol. If that fails, simply return the address.
262 */
263static int proc_pid_wchan(struct task_struct *task, char *buffer)
264{
265 unsigned long wchan;
266 char symname[KSYM_NAME_LEN];
267
268 wchan = get_wchan(task);
269
270 if (lookup_symbol_name(wchan, symname) < 0)
271 if (!ptrace_may_access(task, PTRACE_MODE_READ))
272 return 0;
273 else
274 return sprintf(buffer, "%lu", wchan);
275 else
276 return sprintf(buffer, "%s", symname);
277}
278#endif /* CONFIG_KALLSYMS */
279
280static int lock_trace(struct task_struct *task)
281{
282 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
283 if (err)
284 return err;
285 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
286 mutex_unlock(&task->signal->cred_guard_mutex);
287 return -EPERM;
288 }
289 return 0;
290}
291
292static void unlock_trace(struct task_struct *task)
293{
294 mutex_unlock(&task->signal->cred_guard_mutex);
295}
296
297#ifdef CONFIG_STACKTRACE
298
299#define MAX_STACK_TRACE_DEPTH 64
300
301static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
302 struct pid *pid, struct task_struct *task)
303{
304 struct stack_trace trace;
305 unsigned long *entries;
306 int err;
307 int i;
308
309 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
310 if (!entries)
311 return -ENOMEM;
312
313 trace.nr_entries = 0;
314 trace.max_entries = MAX_STACK_TRACE_DEPTH;
315 trace.entries = entries;
316 trace.skip = 0;
317
318 err = lock_trace(task);
319 if (!err) {
320 save_stack_trace_tsk(task, &trace);
321
322 for (i = 0; i < trace.nr_entries; i++) {
323 seq_printf(m, "[<%pK>] %pS\n",
324 (void *)entries[i], (void *)entries[i]);
325 }
326 unlock_trace(task);
327 }
328 kfree(entries);
329
330 return err;
331}
332#endif
333
334#ifdef CONFIG_SCHEDSTATS
335/*
336 * Provides /proc/PID/schedstat
337 */
338static int proc_pid_schedstat(struct task_struct *task, char *buffer)
339{
340 return sprintf(buffer, "%llu %llu %lu\n",
341 (unsigned long long)task->se.sum_exec_runtime,
342 (unsigned long long)task->sched_info.run_delay,
343 task->sched_info.pcount);
344}
345#endif
346
347#ifdef CONFIG_LATENCYTOP
348static int lstats_show_proc(struct seq_file *m, void *v)
349{
350 int i;
351 struct inode *inode = m->private;
352 struct task_struct *task = get_proc_task(inode);
353
354 if (!task)
355 return -ESRCH;
356 seq_puts(m, "Latency Top version : v0.1\n");
357 for (i = 0; i < 32; i++) {
358 struct latency_record *lr = &task->latency_record[i];
359 if (lr->backtrace[0]) {
360 int q;
361 seq_printf(m, "%i %li %li",
362 lr->count, lr->time, lr->max);
363 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
364 unsigned long bt = lr->backtrace[q];
365 if (!bt)
366 break;
367 if (bt == ULONG_MAX)
368 break;
369 seq_printf(m, " %ps", (void *)bt);
370 }
371 seq_putc(m, '\n');
372 }
373
374 }
375 put_task_struct(task);
376 return 0;
377}
378
379static int lstats_open(struct inode *inode, struct file *file)
380{
381 return single_open(file, lstats_show_proc, inode);
382}
383
384static ssize_t lstats_write(struct file *file, const char __user *buf,
385 size_t count, loff_t *offs)
386{
387 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
388
389 if (!task)
390 return -ESRCH;
391 clear_all_latency_tracing(task);
392 put_task_struct(task);
393
394 return count;
395}
396
397static const struct file_operations proc_lstats_operations = {
398 .open = lstats_open,
399 .read = seq_read,
400 .write = lstats_write,
401 .llseek = seq_lseek,
402 .release = single_release,
403};
404
405#endif
406
407static int proc_oom_score(struct task_struct *task, char *buffer)
408{
409 unsigned long totalpages = totalram_pages + total_swap_pages;
410 unsigned long points = 0;
411
412 read_lock(&tasklist_lock);
413 if (pid_alive(task))
414 points = oom_badness(task, NULL, NULL, totalpages) *
415 1000 / totalpages;
416 read_unlock(&tasklist_lock);
417 return sprintf(buffer, "%lu\n", points);
418}
419
420struct limit_names {
421 char *name;
422 char *unit;
423};
424
425static const struct limit_names lnames[RLIM_NLIMITS] = {
426 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
427 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
428 [RLIMIT_DATA] = {"Max data size", "bytes"},
429 [RLIMIT_STACK] = {"Max stack size", "bytes"},
430 [RLIMIT_CORE] = {"Max core file size", "bytes"},
431 [RLIMIT_RSS] = {"Max resident set", "bytes"},
432 [RLIMIT_NPROC] = {"Max processes", "processes"},
433 [RLIMIT_NOFILE] = {"Max open files", "files"},
434 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
435 [RLIMIT_AS] = {"Max address space", "bytes"},
436 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
437 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
438 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
439 [RLIMIT_NICE] = {"Max nice priority", NULL},
440 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
441 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
442};
443
444/* Display limits for a process */
445static int proc_pid_limits(struct task_struct *task, char *buffer)
446{
447 unsigned int i;
448 int count = 0;
449 unsigned long flags;
450 char *bufptr = buffer;
451
452 struct rlimit rlim[RLIM_NLIMITS];
453
454 if (!lock_task_sighand(task, &flags))
455 return 0;
456 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
457 unlock_task_sighand(task, &flags);
458
459 /*
460 * print the file header
461 */
462 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
463 "Limit", "Soft Limit", "Hard Limit", "Units");
464
465 for (i = 0; i < RLIM_NLIMITS; i++) {
466 if (rlim[i].rlim_cur == RLIM_INFINITY)
467 count += sprintf(&bufptr[count], "%-25s %-20s ",
468 lnames[i].name, "unlimited");
469 else
470 count += sprintf(&bufptr[count], "%-25s %-20lu ",
471 lnames[i].name, rlim[i].rlim_cur);
472
473 if (rlim[i].rlim_max == RLIM_INFINITY)
474 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
475 else
476 count += sprintf(&bufptr[count], "%-20lu ",
477 rlim[i].rlim_max);
478
479 if (lnames[i].unit)
480 count += sprintf(&bufptr[count], "%-10s\n",
481 lnames[i].unit);
482 else
483 count += sprintf(&bufptr[count], "\n");
484 }
485
486 return count;
487}
488
489#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
490static int proc_pid_syscall(struct task_struct *task, char *buffer)
491{
492 long nr;
493 unsigned long args[6], sp, pc;
494 int res = lock_trace(task);
495 if (res)
496 return res;
497
498 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
499 res = sprintf(buffer, "running\n");
500 else if (nr < 0)
501 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
502 else
503 res = sprintf(buffer,
504 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
505 nr,
506 args[0], args[1], args[2], args[3], args[4], args[5],
507 sp, pc);
508 unlock_trace(task);
509 return res;
510}
511#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
512
513/************************************************************************/
514/* Here the fs part begins */
515/************************************************************************/
516
517/* permission checks */
518static int proc_fd_access_allowed(struct inode *inode)
519{
520 struct task_struct *task;
521 int allowed = 0;
522 /* Allow access to a task's file descriptors if it is us or we
523 * may use ptrace attach to the process and find out that
524 * information.
525 */
526 task = get_proc_task(inode);
527 if (task) {
528 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
529 put_task_struct(task);
530 }
531 return allowed;
532}
533
534int proc_setattr(struct dentry *dentry, struct iattr *attr)
535{
536 int error;
537 struct inode *inode = dentry->d_inode;
538
539 if (attr->ia_valid & ATTR_MODE)
540 return -EPERM;
541
542 error = inode_change_ok(inode, attr);
543 if (error)
544 return error;
545
546 if ((attr->ia_valid & ATTR_SIZE) &&
547 attr->ia_size != i_size_read(inode)) {
548 error = vmtruncate(inode, attr->ia_size);
549 if (error)
550 return error;
551 }
552
553 setattr_copy(inode, attr);
554 mark_inode_dirty(inode);
555 return 0;
556}
557
558/*
559 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
560 * or euid/egid (for hide_pid_min=2)?
561 */
562static bool has_pid_permissions(struct pid_namespace *pid,
563 struct task_struct *task,
564 int hide_pid_min)
565{
566 if (pid->hide_pid < hide_pid_min)
567 return true;
568 if (in_group_p(pid->pid_gid))
569 return true;
570 return ptrace_may_access(task, PTRACE_MODE_READ);
571}
572
573
574static int proc_pid_permission(struct inode *inode, int mask)
575{
576 struct pid_namespace *pid = inode->i_sb->s_fs_info;
577 struct task_struct *task;
578 bool has_perms;
579
580 task = get_proc_task(inode);
581 if (!task)
582 return -ESRCH;
583 has_perms = has_pid_permissions(pid, task, 1);
584 put_task_struct(task);
585
586 if (!has_perms) {
587 if (pid->hide_pid == 2) {
588 /*
589 * Let's make getdents(), stat(), and open()
590 * consistent with each other. If a process
591 * may not stat() a file, it shouldn't be seen
592 * in procfs at all.
593 */
594 return -ENOENT;
595 }
596
597 return -EPERM;
598 }
599 return generic_permission(inode, mask);
600}
601
602
603
604static const struct inode_operations proc_def_inode_operations = {
605 .setattr = proc_setattr,
606};
607
608#define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
609
610static ssize_t proc_info_read(struct file * file, char __user * buf,
611 size_t count, loff_t *ppos)
612{
613 struct inode * inode = file->f_path.dentry->d_inode;
614 unsigned long page;
615 ssize_t length;
616 struct task_struct *task = get_proc_task(inode);
617
618 length = -ESRCH;
619 if (!task)
620 goto out_no_task;
621
622 if (count > PROC_BLOCK_SIZE)
623 count = PROC_BLOCK_SIZE;
624
625 length = -ENOMEM;
626 if (!(page = __get_free_page(GFP_TEMPORARY)))
627 goto out;
628
629 length = PROC_I(inode)->op.proc_read(task, (char*)page);
630
631 if (length >= 0)
632 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
633 free_page(page);
634out:
635 put_task_struct(task);
636out_no_task:
637 return length;
638}
639
640static const struct file_operations proc_info_file_operations = {
641 .read = proc_info_read,
642 .llseek = generic_file_llseek,
643};
644
645static int proc_single_show(struct seq_file *m, void *v)
646{
647 struct inode *inode = m->private;
648 struct pid_namespace *ns;
649 struct pid *pid;
650 struct task_struct *task;
651 int ret;
652
653 ns = inode->i_sb->s_fs_info;
654 pid = proc_pid(inode);
655 task = get_pid_task(pid, PIDTYPE_PID);
656 if (!task)
657 return -ESRCH;
658
659 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
660
661 put_task_struct(task);
662 return ret;
663}
664
665static int proc_single_open(struct inode *inode, struct file *filp)
666{
667 return single_open(filp, proc_single_show, inode);
668}
669
670static const struct file_operations proc_single_file_operations = {
671 .open = proc_single_open,
672 .read = seq_read,
673 .llseek = seq_lseek,
674 .release = single_release,
675};
676
677static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
678{
679 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
680 struct mm_struct *mm;
681
682 if (!task)
683 return -ESRCH;
684
685 mm = mm_access(task, mode);
686 put_task_struct(task);
687
688 if (IS_ERR(mm))
689 return PTR_ERR(mm);
690
691 if (mm) {
692 /* ensure this mm_struct can't be freed */
693 atomic_inc(&mm->mm_count);
694 /* but do not pin its memory */
695 mmput(mm);
696 }
697
698 /* OK to pass negative loff_t, we can catch out-of-range */
699 file->f_mode |= FMODE_UNSIGNED_OFFSET;
700 file->private_data = mm;
701
702 return 0;
703}
704
705static int mem_open(struct inode *inode, struct file *file)
706{
707 return __mem_open(inode, file, PTRACE_MODE_ATTACH);
708}
709
710static ssize_t mem_rw(struct file *file, char __user *buf,
711 size_t count, loff_t *ppos, int write)
712{
713 struct mm_struct *mm = file->private_data;
714 unsigned long addr = *ppos;
715 ssize_t copied;
716 char *page;
717
718 if (!mm)
719 return 0;
720
721 page = (char *)__get_free_page(GFP_TEMPORARY);
722 if (!page)
723 return -ENOMEM;
724
725 copied = 0;
726 if (!atomic_inc_not_zero(&mm->mm_users))
727 goto free;
728
729 while (count > 0) {
730 int this_len = min_t(int, count, PAGE_SIZE);
731
732 if (write && copy_from_user(page, buf, this_len)) {
733 copied = -EFAULT;
734 break;
735 }
736
737 this_len = access_remote_vm(mm, addr, page, this_len, write);
738 if (!this_len) {
739 if (!copied)
740 copied = -EIO;
741 break;
742 }
743
744 if (!write && copy_to_user(buf, page, this_len)) {
745 copied = -EFAULT;
746 break;
747 }
748
749 buf += this_len;
750 addr += this_len;
751 copied += this_len;
752 count -= this_len;
753 }
754 *ppos = addr;
755
756 mmput(mm);
757free:
758 free_page((unsigned long) page);
759 return copied;
760}
761
762static ssize_t mem_read(struct file *file, char __user *buf,
763 size_t count, loff_t *ppos)
764{
765 return mem_rw(file, buf, count, ppos, 0);
766}
767
768static ssize_t mem_write(struct file *file, const char __user *buf,
769 size_t count, loff_t *ppos)
770{
771 return mem_rw(file, (char __user*)buf, count, ppos, 1);
772}
773
774loff_t mem_lseek(struct file *file, loff_t offset, int orig)
775{
776 switch (orig) {
777 case 0:
778 file->f_pos = offset;
779 break;
780 case 1:
781 file->f_pos += offset;
782 break;
783 default:
784 return -EINVAL;
785 }
786 force_successful_syscall_return();
787 return file->f_pos;
788}
789
790static int mem_release(struct inode *inode, struct file *file)
791{
792 struct mm_struct *mm = file->private_data;
793 if (mm)
794 mmdrop(mm);
795 return 0;
796}
797
798static const struct file_operations proc_mem_operations = {
799 .llseek = mem_lseek,
800 .read = mem_read,
801 .write = mem_write,
802 .open = mem_open,
803 .release = mem_release,
804};
805
806static int environ_open(struct inode *inode, struct file *file)
807{
808 return __mem_open(inode, file, PTRACE_MODE_READ);
809}
810
811static ssize_t environ_read(struct file *file, char __user *buf,
812 size_t count, loff_t *ppos)
813{
814 char *page;
815 unsigned long src = *ppos;
816 int ret = 0;
817 struct mm_struct *mm = file->private_data;
818
819 if (!mm)
820 return 0;
821
822 page = (char *)__get_free_page(GFP_TEMPORARY);
823 if (!page)
824 return -ENOMEM;
825
826 ret = 0;
827 if (!atomic_inc_not_zero(&mm->mm_users))
828 goto free;
829 while (count > 0) {
830 int this_len, retval, max_len;
831
832 this_len = mm->env_end - (mm->env_start + src);
833
834 if (this_len <= 0)
835 break;
836
837 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
838 this_len = (this_len > max_len) ? max_len : this_len;
839
840 retval = access_remote_vm(mm, (mm->env_start + src),
841 page, this_len, 0);
842
843 if (retval <= 0) {
844 ret = retval;
845 break;
846 }
847
848 if (copy_to_user(buf, page, retval)) {
849 ret = -EFAULT;
850 break;
851 }
852
853 ret += retval;
854 src += retval;
855 buf += retval;
856 count -= retval;
857 }
858 *ppos = src;
859 mmput(mm);
860
861free:
862 free_page((unsigned long) page);
863 return ret;
864}
865
866static const struct file_operations proc_environ_operations = {
867 .open = environ_open,
868 .read = environ_read,
869 .llseek = generic_file_llseek,
870 .release = mem_release,
871};
872
873static ssize_t oom_adjust_read(struct file *file, char __user *buf,
874 size_t count, loff_t *ppos)
875{
876 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
877 char buffer[PROC_NUMBUF];
878 size_t len;
879 int oom_adjust = OOM_DISABLE;
880 unsigned long flags;
881
882 if (!task)
883 return -ESRCH;
884
885 if (lock_task_sighand(task, &flags)) {
886 oom_adjust = task->signal->oom_adj;
887 unlock_task_sighand(task, &flags);
888 }
889
890 put_task_struct(task);
891
892 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
893
894 return simple_read_from_buffer(buf, count, ppos, buffer, len);
895}
896
897static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
898 size_t count, loff_t *ppos)
899{
900 struct task_struct *task;
901 char buffer[PROC_NUMBUF];
902 int oom_adjust;
903 unsigned long flags;
904 int err;
905
906 memset(buffer, 0, sizeof(buffer));
907 if (count > sizeof(buffer) - 1)
908 count = sizeof(buffer) - 1;
909 if (copy_from_user(buffer, buf, count)) {
910 err = -EFAULT;
911 goto out;
912 }
913
914 err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
915 if (err)
916 goto out;
917 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
918 oom_adjust != OOM_DISABLE) {
919 err = -EINVAL;
920 goto out;
921 }
922
923 task = get_proc_task(file->f_path.dentry->d_inode);
924 if (!task) {
925 err = -ESRCH;
926 goto out;
927 }
928
929 task_lock(task);
930 if (!task->mm) {
931 err = -EINVAL;
932 goto err_task_lock;
933 }
934
935 if (!lock_task_sighand(task, &flags)) {
936 err = -ESRCH;
937 goto err_task_lock;
938 }
939
940 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
941 err = -EACCES;
942 goto err_sighand;
943 }
944
945 /*
946 * Warn that /proc/pid/oom_adj is deprecated, see
947 * Documentation/feature-removal-schedule.txt.
948 */
949 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
950 current->comm, task_pid_nr(current), task_pid_nr(task),
951 task_pid_nr(task));
952 task->signal->oom_adj = oom_adjust;
953 /*
954 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
955 * value is always attainable.
956 */
957 if (task->signal->oom_adj == OOM_ADJUST_MAX)
958 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
959 else
960 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
961 -OOM_DISABLE;
962 trace_oom_score_adj_update(task);
963err_sighand:
964 unlock_task_sighand(task, &flags);
965err_task_lock:
966 task_unlock(task);
967 put_task_struct(task);
968out:
969 return err < 0 ? err : count;
970}
971
972static const struct file_operations proc_oom_adjust_operations = {
973 .read = oom_adjust_read,
974 .write = oom_adjust_write,
975 .llseek = generic_file_llseek,
976};
977
978static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
979 size_t count, loff_t *ppos)
980{
981 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
982 char buffer[PROC_NUMBUF];
983 int oom_score_adj = OOM_SCORE_ADJ_MIN;
984 unsigned long flags;
985 size_t len;
986
987 if (!task)
988 return -ESRCH;
989 if (lock_task_sighand(task, &flags)) {
990 oom_score_adj = task->signal->oom_score_adj;
991 unlock_task_sighand(task, &flags);
992 }
993 put_task_struct(task);
994 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
995 return simple_read_from_buffer(buf, count, ppos, buffer, len);
996}
997
998static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
999 size_t count, loff_t *ppos)
1000{
1001 struct task_struct *task;
1002 char buffer[PROC_NUMBUF];
1003 unsigned long flags;
1004 int oom_score_adj;
1005 int err;
1006
1007 memset(buffer, 0, sizeof(buffer));
1008 if (count > sizeof(buffer) - 1)
1009 count = sizeof(buffer) - 1;
1010 if (copy_from_user(buffer, buf, count)) {
1011 err = -EFAULT;
1012 goto out;
1013 }
1014
1015 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1016 if (err)
1017 goto out;
1018 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1019 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1020 err = -EINVAL;
1021 goto out;
1022 }
1023
1024 task = get_proc_task(file->f_path.dentry->d_inode);
1025 if (!task) {
1026 err = -ESRCH;
1027 goto out;
1028 }
1029
1030 task_lock(task);
1031 if (!task->mm) {
1032 err = -EINVAL;
1033 goto err_task_lock;
1034 }
1035
1036 if (!lock_task_sighand(task, &flags)) {
1037 err = -ESRCH;
1038 goto err_task_lock;
1039 }
1040
1041 if (oom_score_adj < task->signal->oom_score_adj_min &&
1042 !capable(CAP_SYS_RESOURCE)) {
1043 err = -EACCES;
1044 goto err_sighand;
1045 }
1046
1047 task->signal->oom_score_adj = oom_score_adj;
1048 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1049 task->signal->oom_score_adj_min = oom_score_adj;
1050 trace_oom_score_adj_update(task);
1051 /*
1052 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1053 * always attainable.
1054 */
1055 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1056 task->signal->oom_adj = OOM_DISABLE;
1057 else
1058 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1059 OOM_SCORE_ADJ_MAX;
1060err_sighand:
1061 unlock_task_sighand(task, &flags);
1062err_task_lock:
1063 task_unlock(task);
1064 put_task_struct(task);
1065out:
1066 return err < 0 ? err : count;
1067}
1068
1069static const struct file_operations proc_oom_score_adj_operations = {
1070 .read = oom_score_adj_read,
1071 .write = oom_score_adj_write,
1072 .llseek = default_llseek,
1073};
1074
1075#ifdef CONFIG_AUDITSYSCALL
1076#define TMPBUFLEN 21
1077static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1078 size_t count, loff_t *ppos)
1079{
1080 struct inode * inode = file->f_path.dentry->d_inode;
1081 struct task_struct *task = get_proc_task(inode);
1082 ssize_t length;
1083 char tmpbuf[TMPBUFLEN];
1084
1085 if (!task)
1086 return -ESRCH;
1087 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1088 audit_get_loginuid(task));
1089 put_task_struct(task);
1090 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1091}
1092
1093static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1094 size_t count, loff_t *ppos)
1095{
1096 struct inode * inode = file->f_path.dentry->d_inode;
1097 char *page, *tmp;
1098 ssize_t length;
1099 uid_t loginuid;
1100
1101 rcu_read_lock();
1102 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1103 rcu_read_unlock();
1104 return -EPERM;
1105 }
1106 rcu_read_unlock();
1107
1108 if (count >= PAGE_SIZE)
1109 count = PAGE_SIZE - 1;
1110
1111 if (*ppos != 0) {
1112 /* No partial writes. */
1113 return -EINVAL;
1114 }
1115 page = (char*)__get_free_page(GFP_TEMPORARY);
1116 if (!page)
1117 return -ENOMEM;
1118 length = -EFAULT;
1119 if (copy_from_user(page, buf, count))
1120 goto out_free_page;
1121
1122 page[count] = '\0';
1123 loginuid = simple_strtoul(page, &tmp, 10);
1124 if (tmp == page) {
1125 length = -EINVAL;
1126 goto out_free_page;
1127
1128 }
1129 length = audit_set_loginuid(loginuid);
1130 if (likely(length == 0))
1131 length = count;
1132
1133out_free_page:
1134 free_page((unsigned long) page);
1135 return length;
1136}
1137
1138static const struct file_operations proc_loginuid_operations = {
1139 .read = proc_loginuid_read,
1140 .write = proc_loginuid_write,
1141 .llseek = generic_file_llseek,
1142};
1143
1144static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1145 size_t count, loff_t *ppos)
1146{
1147 struct inode * inode = file->f_path.dentry->d_inode;
1148 struct task_struct *task = get_proc_task(inode);
1149 ssize_t length;
1150 char tmpbuf[TMPBUFLEN];
1151
1152 if (!task)
1153 return -ESRCH;
1154 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1155 audit_get_sessionid(task));
1156 put_task_struct(task);
1157 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1158}
1159
1160static const struct file_operations proc_sessionid_operations = {
1161 .read = proc_sessionid_read,
1162 .llseek = generic_file_llseek,
1163};
1164#endif
1165
1166#ifdef CONFIG_FAULT_INJECTION
1167static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1168 size_t count, loff_t *ppos)
1169{
1170 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1171 char buffer[PROC_NUMBUF];
1172 size_t len;
1173 int make_it_fail;
1174
1175 if (!task)
1176 return -ESRCH;
1177 make_it_fail = task->make_it_fail;
1178 put_task_struct(task);
1179
1180 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1181
1182 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1183}
1184
1185static ssize_t proc_fault_inject_write(struct file * file,
1186 const char __user * buf, size_t count, loff_t *ppos)
1187{
1188 struct task_struct *task;
1189 char buffer[PROC_NUMBUF], *end;
1190 int make_it_fail;
1191
1192 if (!capable(CAP_SYS_RESOURCE))
1193 return -EPERM;
1194 memset(buffer, 0, sizeof(buffer));
1195 if (count > sizeof(buffer) - 1)
1196 count = sizeof(buffer) - 1;
1197 if (copy_from_user(buffer, buf, count))
1198 return -EFAULT;
1199 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1200 if (*end)
1201 return -EINVAL;
1202 task = get_proc_task(file->f_dentry->d_inode);
1203 if (!task)
1204 return -ESRCH;
1205 task->make_it_fail = make_it_fail;
1206 put_task_struct(task);
1207
1208 return count;
1209}
1210
1211static const struct file_operations proc_fault_inject_operations = {
1212 .read = proc_fault_inject_read,
1213 .write = proc_fault_inject_write,
1214 .llseek = generic_file_llseek,
1215};
1216#endif
1217
1218
1219#ifdef CONFIG_SCHED_DEBUG
1220/*
1221 * Print out various scheduling related per-task fields:
1222 */
1223static int sched_show(struct seq_file *m, void *v)
1224{
1225 struct inode *inode = m->private;
1226 struct task_struct *p;
1227
1228 p = get_proc_task(inode);
1229 if (!p)
1230 return -ESRCH;
1231 proc_sched_show_task(p, m);
1232
1233 put_task_struct(p);
1234
1235 return 0;
1236}
1237
1238static ssize_t
1239sched_write(struct file *file, const char __user *buf,
1240 size_t count, loff_t *offset)
1241{
1242 struct inode *inode = file->f_path.dentry->d_inode;
1243 struct task_struct *p;
1244
1245 p = get_proc_task(inode);
1246 if (!p)
1247 return -ESRCH;
1248 proc_sched_set_task(p);
1249
1250 put_task_struct(p);
1251
1252 return count;
1253}
1254
1255static int sched_open(struct inode *inode, struct file *filp)
1256{
1257 return single_open(filp, sched_show, inode);
1258}
1259
1260static const struct file_operations proc_pid_sched_operations = {
1261 .open = sched_open,
1262 .read = seq_read,
1263 .write = sched_write,
1264 .llseek = seq_lseek,
1265 .release = single_release,
1266};
1267
1268#endif
1269
1270#ifdef CONFIG_SCHED_AUTOGROUP
1271/*
1272 * Print out autogroup related information:
1273 */
1274static int sched_autogroup_show(struct seq_file *m, void *v)
1275{
1276 struct inode *inode = m->private;
1277 struct task_struct *p;
1278
1279 p = get_proc_task(inode);
1280 if (!p)
1281 return -ESRCH;
1282 proc_sched_autogroup_show_task(p, m);
1283
1284 put_task_struct(p);
1285
1286 return 0;
1287}
1288
1289static ssize_t
1290sched_autogroup_write(struct file *file, const char __user *buf,
1291 size_t count, loff_t *offset)
1292{
1293 struct inode *inode = file->f_path.dentry->d_inode;
1294 struct task_struct *p;
1295 char buffer[PROC_NUMBUF];
1296 int nice;
1297 int err;
1298
1299 memset(buffer, 0, sizeof(buffer));
1300 if (count > sizeof(buffer) - 1)
1301 count = sizeof(buffer) - 1;
1302 if (copy_from_user(buffer, buf, count))
1303 return -EFAULT;
1304
1305 err = kstrtoint(strstrip(buffer), 0, &nice);
1306 if (err < 0)
1307 return err;
1308
1309 p = get_proc_task(inode);
1310 if (!p)
1311 return -ESRCH;
1312
1313 err = proc_sched_autogroup_set_nice(p, nice);
1314 if (err)
1315 count = err;
1316
1317 put_task_struct(p);
1318
1319 return count;
1320}
1321
1322static int sched_autogroup_open(struct inode *inode, struct file *filp)
1323{
1324 int ret;
1325
1326 ret = single_open(filp, sched_autogroup_show, NULL);
1327 if (!ret) {
1328 struct seq_file *m = filp->private_data;
1329
1330 m->private = inode;
1331 }
1332 return ret;
1333}
1334
1335static const struct file_operations proc_pid_sched_autogroup_operations = {
1336 .open = sched_autogroup_open,
1337 .read = seq_read,
1338 .write = sched_autogroup_write,
1339 .llseek = seq_lseek,
1340 .release = single_release,
1341};
1342
1343#endif /* CONFIG_SCHED_AUTOGROUP */
1344
1345static ssize_t comm_write(struct file *file, const char __user *buf,
1346 size_t count, loff_t *offset)
1347{
1348 struct inode *inode = file->f_path.dentry->d_inode;
1349 struct task_struct *p;
1350 char buffer[TASK_COMM_LEN];
1351
1352 memset(buffer, 0, sizeof(buffer));
1353 if (count > sizeof(buffer) - 1)
1354 count = sizeof(buffer) - 1;
1355 if (copy_from_user(buffer, buf, count))
1356 return -EFAULT;
1357
1358 p = get_proc_task(inode);
1359 if (!p)
1360 return -ESRCH;
1361
1362 if (same_thread_group(current, p))
1363 set_task_comm(p, buffer);
1364 else
1365 count = -EINVAL;
1366
1367 put_task_struct(p);
1368
1369 return count;
1370}
1371
1372static int comm_show(struct seq_file *m, void *v)
1373{
1374 struct inode *inode = m->private;
1375 struct task_struct *p;
1376
1377 p = get_proc_task(inode);
1378 if (!p)
1379 return -ESRCH;
1380
1381 task_lock(p);
1382 seq_printf(m, "%s\n", p->comm);
1383 task_unlock(p);
1384
1385 put_task_struct(p);
1386
1387 return 0;
1388}
1389
1390static int comm_open(struct inode *inode, struct file *filp)
1391{
1392 return single_open(filp, comm_show, inode);
1393}
1394
1395static const struct file_operations proc_pid_set_comm_operations = {
1396 .open = comm_open,
1397 .read = seq_read,
1398 .write = comm_write,
1399 .llseek = seq_lseek,
1400 .release = single_release,
1401};
1402
1403static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1404{
1405 struct task_struct *task;
1406 struct mm_struct *mm;
1407 struct file *exe_file;
1408
1409 task = get_proc_task(dentry->d_inode);
1410 if (!task)
1411 return -ENOENT;
1412 mm = get_task_mm(task);
1413 put_task_struct(task);
1414 if (!mm)
1415 return -ENOENT;
1416 exe_file = get_mm_exe_file(mm);
1417 mmput(mm);
1418 if (exe_file) {
1419 *exe_path = exe_file->f_path;
1420 path_get(&exe_file->f_path);
1421 fput(exe_file);
1422 return 0;
1423 } else
1424 return -ENOENT;
1425}
1426
1427static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1428{
1429 struct inode *inode = dentry->d_inode;
1430 int error = -EACCES;
1431
1432 /* We don't need a base pointer in the /proc filesystem */
1433 path_put(&nd->path);
1434
1435 /* Are we allowed to snoop on the tasks file descriptors? */
1436 if (!proc_fd_access_allowed(inode))
1437 goto out;
1438
1439 error = PROC_I(inode)->op.proc_get_link(dentry, &nd->path);
1440out:
1441 return ERR_PTR(error);
1442}
1443
1444static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1445{
1446 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1447 char *pathname;
1448 int len;
1449
1450 if (!tmp)
1451 return -ENOMEM;
1452
1453 pathname = d_path(path, tmp, PAGE_SIZE);
1454 len = PTR_ERR(pathname);
1455 if (IS_ERR(pathname))
1456 goto out;
1457 len = tmp + PAGE_SIZE - 1 - pathname;
1458
1459 if (len > buflen)
1460 len = buflen;
1461 if (copy_to_user(buffer, pathname, len))
1462 len = -EFAULT;
1463 out:
1464 free_page((unsigned long)tmp);
1465 return len;
1466}
1467
1468static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1469{
1470 int error = -EACCES;
1471 struct inode *inode = dentry->d_inode;
1472 struct path path;
1473
1474 /* Are we allowed to snoop on the tasks file descriptors? */
1475 if (!proc_fd_access_allowed(inode))
1476 goto out;
1477
1478 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1479 if (error)
1480 goto out;
1481
1482 error = do_proc_readlink(&path, buffer, buflen);
1483 path_put(&path);
1484out:
1485 return error;
1486}
1487
1488static const struct inode_operations proc_pid_link_inode_operations = {
1489 .readlink = proc_pid_readlink,
1490 .follow_link = proc_pid_follow_link,
1491 .setattr = proc_setattr,
1492};
1493
1494
1495/* building an inode */
1496
1497static int task_dumpable(struct task_struct *task)
1498{
1499 int dumpable = 0;
1500 struct mm_struct *mm;
1501
1502 task_lock(task);
1503 mm = task->mm;
1504 if (mm)
1505 dumpable = get_dumpable(mm);
1506 task_unlock(task);
1507 if(dumpable == 1)
1508 return 1;
1509 return 0;
1510}
1511
1512struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1513{
1514 struct inode * inode;
1515 struct proc_inode *ei;
1516 const struct cred *cred;
1517
1518 /* We need a new inode */
1519
1520 inode = new_inode(sb);
1521 if (!inode)
1522 goto out;
1523
1524 /* Common stuff */
1525 ei = PROC_I(inode);
1526 inode->i_ino = get_next_ino();
1527 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1528 inode->i_op = &proc_def_inode_operations;
1529
1530 /*
1531 * grab the reference to task.
1532 */
1533 ei->pid = get_task_pid(task, PIDTYPE_PID);
1534 if (!ei->pid)
1535 goto out_unlock;
1536
1537 if (task_dumpable(task)) {
1538 rcu_read_lock();
1539 cred = __task_cred(task);
1540 inode->i_uid = cred->euid;
1541 inode->i_gid = cred->egid;
1542 rcu_read_unlock();
1543 }
1544 security_task_to_inode(task, inode);
1545
1546out:
1547 return inode;
1548
1549out_unlock:
1550 iput(inode);
1551 return NULL;
1552}
1553
1554int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1555{
1556 struct inode *inode = dentry->d_inode;
1557 struct task_struct *task;
1558 const struct cred *cred;
1559 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1560
1561 generic_fillattr(inode, stat);
1562
1563 rcu_read_lock();
1564 stat->uid = GLOBAL_ROOT_UID;
1565 stat->gid = GLOBAL_ROOT_GID;
1566 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1567 if (task) {
1568 if (!has_pid_permissions(pid, task, 2)) {
1569 rcu_read_unlock();
1570 /*
1571 * This doesn't prevent learning whether PID exists,
1572 * it only makes getattr() consistent with readdir().
1573 */
1574 return -ENOENT;
1575 }
1576 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1577 task_dumpable(task)) {
1578 cred = __task_cred(task);
1579 stat->uid = cred->euid;
1580 stat->gid = cred->egid;
1581 }
1582 }
1583 rcu_read_unlock();
1584 return 0;
1585}
1586
1587/* dentry stuff */
1588
1589/*
1590 * Exceptional case: normally we are not allowed to unhash a busy
1591 * directory. In this case, however, we can do it - no aliasing problems
1592 * due to the way we treat inodes.
1593 *
1594 * Rewrite the inode's ownerships here because the owning task may have
1595 * performed a setuid(), etc.
1596 *
1597 * Before the /proc/pid/status file was created the only way to read
1598 * the effective uid of a /process was to stat /proc/pid. Reading
1599 * /proc/pid/status is slow enough that procps and other packages
1600 * kept stating /proc/pid. To keep the rules in /proc simple I have
1601 * made this apply to all per process world readable and executable
1602 * directories.
1603 */
1604int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1605{
1606 struct inode *inode;
1607 struct task_struct *task;
1608 const struct cred *cred;
1609
1610 if (nd && nd->flags & LOOKUP_RCU)
1611 return -ECHILD;
1612
1613 inode = dentry->d_inode;
1614 task = get_proc_task(inode);
1615
1616 if (task) {
1617 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1618 task_dumpable(task)) {
1619 rcu_read_lock();
1620 cred = __task_cred(task);
1621 inode->i_uid = cred->euid;
1622 inode->i_gid = cred->egid;
1623 rcu_read_unlock();
1624 } else {
1625 inode->i_uid = GLOBAL_ROOT_UID;
1626 inode->i_gid = GLOBAL_ROOT_GID;
1627 }
1628 inode->i_mode &= ~(S_ISUID | S_ISGID);
1629 security_task_to_inode(task, inode);
1630 put_task_struct(task);
1631 return 1;
1632 }
1633 d_drop(dentry);
1634 return 0;
1635}
1636
1637static int pid_delete_dentry(const struct dentry * dentry)
1638{
1639 /* Is the task we represent dead?
1640 * If so, then don't put the dentry on the lru list,
1641 * kill it immediately.
1642 */
1643 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1644}
1645
1646const struct dentry_operations pid_dentry_operations =
1647{
1648 .d_revalidate = pid_revalidate,
1649 .d_delete = pid_delete_dentry,
1650};
1651
1652/* Lookups */
1653
1654/*
1655 * Fill a directory entry.
1656 *
1657 * If possible create the dcache entry and derive our inode number and
1658 * file type from dcache entry.
1659 *
1660 * Since all of the proc inode numbers are dynamically generated, the inode
1661 * numbers do not exist until the inode is cache. This means creating the
1662 * the dcache entry in readdir is necessary to keep the inode numbers
1663 * reported by readdir in sync with the inode numbers reported
1664 * by stat.
1665 */
1666int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1667 const char *name, int len,
1668 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1669{
1670 struct dentry *child, *dir = filp->f_path.dentry;
1671 struct inode *inode;
1672 struct qstr qname;
1673 ino_t ino = 0;
1674 unsigned type = DT_UNKNOWN;
1675
1676 qname.name = name;
1677 qname.len = len;
1678 qname.hash = full_name_hash(name, len);
1679
1680 child = d_lookup(dir, &qname);
1681 if (!child) {
1682 struct dentry *new;
1683 new = d_alloc(dir, &qname);
1684 if (new) {
1685 child = instantiate(dir->d_inode, new, task, ptr);
1686 if (child)
1687 dput(new);
1688 else
1689 child = new;
1690 }
1691 }
1692 if (!child || IS_ERR(child) || !child->d_inode)
1693 goto end_instantiate;
1694 inode = child->d_inode;
1695 if (inode) {
1696 ino = inode->i_ino;
1697 type = inode->i_mode >> 12;
1698 }
1699 dput(child);
1700end_instantiate:
1701 if (!ino)
1702 ino = find_inode_number(dir, &qname);
1703 if (!ino)
1704 ino = 1;
1705 return filldir(dirent, name, len, filp->f_pos, ino, type);
1706}
1707
1708static unsigned name_to_int(struct dentry *dentry)
1709{
1710 const char *name = dentry->d_name.name;
1711 int len = dentry->d_name.len;
1712 unsigned n = 0;
1713
1714 if (len > 1 && *name == '0')
1715 goto out;
1716 while (len-- > 0) {
1717 unsigned c = *name++ - '0';
1718 if (c > 9)
1719 goto out;
1720 if (n >= (~0U-9)/10)
1721 goto out;
1722 n *= 10;
1723 n += c;
1724 }
1725 return n;
1726out:
1727 return ~0U;
1728}
1729
1730#define PROC_FDINFO_MAX 64
1731
1732static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1733{
1734 struct task_struct *task = get_proc_task(inode);
1735 struct files_struct *files = NULL;
1736 struct file *file;
1737 int fd = proc_fd(inode);
1738
1739 if (task) {
1740 files = get_files_struct(task);
1741 put_task_struct(task);
1742 }
1743 if (files) {
1744 /*
1745 * We are not taking a ref to the file structure, so we must
1746 * hold ->file_lock.
1747 */
1748 spin_lock(&files->file_lock);
1749 file = fcheck_files(files, fd);
1750 if (file) {
1751 unsigned int f_flags;
1752 struct fdtable *fdt;
1753
1754 fdt = files_fdtable(files);
1755 f_flags = file->f_flags & ~O_CLOEXEC;
1756 if (close_on_exec(fd, fdt))
1757 f_flags |= O_CLOEXEC;
1758
1759 if (path) {
1760 *path = file->f_path;
1761 path_get(&file->f_path);
1762 }
1763 if (info)
1764 snprintf(info, PROC_FDINFO_MAX,
1765 "pos:\t%lli\n"
1766 "flags:\t0%o\n",
1767 (long long) file->f_pos,
1768 f_flags);
1769 spin_unlock(&files->file_lock);
1770 put_files_struct(files);
1771 return 0;
1772 }
1773 spin_unlock(&files->file_lock);
1774 put_files_struct(files);
1775 }
1776 return -ENOENT;
1777}
1778
1779static int proc_fd_link(struct dentry *dentry, struct path *path)
1780{
1781 return proc_fd_info(dentry->d_inode, path, NULL);
1782}
1783
1784static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1785{
1786 struct inode *inode;
1787 struct task_struct *task;
1788 int fd;
1789 struct files_struct *files;
1790 const struct cred *cred;
1791
1792 if (nd && nd->flags & LOOKUP_RCU)
1793 return -ECHILD;
1794
1795 inode = dentry->d_inode;
1796 task = get_proc_task(inode);
1797 fd = proc_fd(inode);
1798
1799 if (task) {
1800 files = get_files_struct(task);
1801 if (files) {
1802 struct file *file;
1803 rcu_read_lock();
1804 file = fcheck_files(files, fd);
1805 if (file) {
1806 unsigned f_mode = file->f_mode;
1807
1808 rcu_read_unlock();
1809 put_files_struct(files);
1810
1811 if (task_dumpable(task)) {
1812 rcu_read_lock();
1813 cred = __task_cred(task);
1814 inode->i_uid = cred->euid;
1815 inode->i_gid = cred->egid;
1816 rcu_read_unlock();
1817 } else {
1818 inode->i_uid = GLOBAL_ROOT_UID;
1819 inode->i_gid = GLOBAL_ROOT_GID;
1820 }
1821
1822 if (S_ISLNK(inode->i_mode)) {
1823 unsigned i_mode = S_IFLNK;
1824 if (f_mode & FMODE_READ)
1825 i_mode |= S_IRUSR | S_IXUSR;
1826 if (f_mode & FMODE_WRITE)
1827 i_mode |= S_IWUSR | S_IXUSR;
1828 inode->i_mode = i_mode;
1829 }
1830
1831 security_task_to_inode(task, inode);
1832 put_task_struct(task);
1833 return 1;
1834 }
1835 rcu_read_unlock();
1836 put_files_struct(files);
1837 }
1838 put_task_struct(task);
1839 }
1840 d_drop(dentry);
1841 return 0;
1842}
1843
1844static const struct dentry_operations tid_fd_dentry_operations =
1845{
1846 .d_revalidate = tid_fd_revalidate,
1847 .d_delete = pid_delete_dentry,
1848};
1849
1850static struct dentry *proc_fd_instantiate(struct inode *dir,
1851 struct dentry *dentry, struct task_struct *task, const void *ptr)
1852{
1853 unsigned fd = (unsigned long)ptr;
1854 struct inode *inode;
1855 struct proc_inode *ei;
1856 struct dentry *error = ERR_PTR(-ENOENT);
1857
1858 inode = proc_pid_make_inode(dir->i_sb, task);
1859 if (!inode)
1860 goto out;
1861 ei = PROC_I(inode);
1862 ei->fd = fd;
1863
1864 inode->i_mode = S_IFLNK;
1865 inode->i_op = &proc_pid_link_inode_operations;
1866 inode->i_size = 64;
1867 ei->op.proc_get_link = proc_fd_link;
1868 d_set_d_op(dentry, &tid_fd_dentry_operations);
1869 d_add(dentry, inode);
1870 /* Close the race of the process dying before we return the dentry */
1871 if (tid_fd_revalidate(dentry, NULL))
1872 error = NULL;
1873
1874 out:
1875 return error;
1876}
1877
1878static struct dentry *proc_lookupfd_common(struct inode *dir,
1879 struct dentry *dentry,
1880 instantiate_t instantiate)
1881{
1882 struct task_struct *task = get_proc_task(dir);
1883 unsigned fd = name_to_int(dentry);
1884 struct dentry *result = ERR_PTR(-ENOENT);
1885
1886 if (!task)
1887 goto out_no_task;
1888 if (fd == ~0U)
1889 goto out;
1890
1891 result = instantiate(dir, dentry, task, (void *)(unsigned long)fd);
1892out:
1893 put_task_struct(task);
1894out_no_task:
1895 return result;
1896}
1897
1898static int proc_readfd_common(struct file * filp, void * dirent,
1899 filldir_t filldir, instantiate_t instantiate)
1900{
1901 struct dentry *dentry = filp->f_path.dentry;
1902 struct inode *inode = dentry->d_inode;
1903 struct task_struct *p = get_proc_task(inode);
1904 unsigned int fd, ino;
1905 int retval;
1906 struct files_struct * files;
1907
1908 retval = -ENOENT;
1909 if (!p)
1910 goto out_no_task;
1911 retval = 0;
1912
1913 fd = filp->f_pos;
1914 switch (fd) {
1915 case 0:
1916 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1917 goto out;
1918 filp->f_pos++;
1919 case 1:
1920 ino = parent_ino(dentry);
1921 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1922 goto out;
1923 filp->f_pos++;
1924 default:
1925 files = get_files_struct(p);
1926 if (!files)
1927 goto out;
1928 rcu_read_lock();
1929 for (fd = filp->f_pos-2;
1930 fd < files_fdtable(files)->max_fds;
1931 fd++, filp->f_pos++) {
1932 char name[PROC_NUMBUF];
1933 int len;
1934 int rv;
1935
1936 if (!fcheck_files(files, fd))
1937 continue;
1938 rcu_read_unlock();
1939
1940 len = snprintf(name, sizeof(name), "%d", fd);
1941 rv = proc_fill_cache(filp, dirent, filldir,
1942 name, len, instantiate, p,
1943 (void *)(unsigned long)fd);
1944 if (rv < 0)
1945 goto out_fd_loop;
1946 rcu_read_lock();
1947 }
1948 rcu_read_unlock();
1949out_fd_loop:
1950 put_files_struct(files);
1951 }
1952out:
1953 put_task_struct(p);
1954out_no_task:
1955 return retval;
1956}
1957
1958static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1959 struct nameidata *nd)
1960{
1961 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1962}
1963
1964static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1965{
1966 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1967}
1968
1969static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1970 size_t len, loff_t *ppos)
1971{
1972 char tmp[PROC_FDINFO_MAX];
1973 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
1974 if (!err)
1975 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1976 return err;
1977}
1978
1979static const struct file_operations proc_fdinfo_file_operations = {
1980 .open = nonseekable_open,
1981 .read = proc_fdinfo_read,
1982 .llseek = no_llseek,
1983};
1984
1985static const struct file_operations proc_fd_operations = {
1986 .read = generic_read_dir,
1987 .readdir = proc_readfd,
1988 .llseek = default_llseek,
1989};
1990
1991#ifdef CONFIG_CHECKPOINT_RESTORE
1992
1993/*
1994 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1995 * which represent vma start and end addresses.
1996 */
1997static int dname_to_vma_addr(struct dentry *dentry,
1998 unsigned long *start, unsigned long *end)
1999{
2000 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
2001 return -EINVAL;
2002
2003 return 0;
2004}
2005
2006static int map_files_d_revalidate(struct dentry *dentry, struct nameidata *nd)
2007{
2008 unsigned long vm_start, vm_end;
2009 bool exact_vma_exists = false;
2010 struct mm_struct *mm = NULL;
2011 struct task_struct *task;
2012 const struct cred *cred;
2013 struct inode *inode;
2014 int status = 0;
2015
2016 if (nd && nd->flags & LOOKUP_RCU)
2017 return -ECHILD;
2018
2019 if (!capable(CAP_SYS_ADMIN)) {
2020 status = -EACCES;
2021 goto out_notask;
2022 }
2023
2024 inode = dentry->d_inode;
2025 task = get_proc_task(inode);
2026 if (!task)
2027 goto out_notask;
2028
2029 mm = mm_access(task, PTRACE_MODE_READ);
2030 if (IS_ERR_OR_NULL(mm))
2031 goto out;
2032
2033 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2034 down_read(&mm->mmap_sem);
2035 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
2036 up_read(&mm->mmap_sem);
2037 }
2038
2039 mmput(mm);
2040
2041 if (exact_vma_exists) {
2042 if (task_dumpable(task)) {
2043 rcu_read_lock();
2044 cred = __task_cred(task);
2045 inode->i_uid = cred->euid;
2046 inode->i_gid = cred->egid;
2047 rcu_read_unlock();
2048 } else {
2049 inode->i_uid = GLOBAL_ROOT_UID;
2050 inode->i_gid = GLOBAL_ROOT_GID;
2051 }
2052 security_task_to_inode(task, inode);
2053 status = 1;
2054 }
2055
2056out:
2057 put_task_struct(task);
2058
2059out_notask:
2060 if (status <= 0)
2061 d_drop(dentry);
2062
2063 return status;
2064}
2065
2066static const struct dentry_operations tid_map_files_dentry_operations = {
2067 .d_revalidate = map_files_d_revalidate,
2068 .d_delete = pid_delete_dentry,
2069};
2070
2071static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
2072{
2073 unsigned long vm_start, vm_end;
2074 struct vm_area_struct *vma;
2075 struct task_struct *task;
2076 struct mm_struct *mm;
2077 int rc;
2078
2079 rc = -ENOENT;
2080 task = get_proc_task(dentry->d_inode);
2081 if (!task)
2082 goto out;
2083
2084 mm = get_task_mm(task);
2085 put_task_struct(task);
2086 if (!mm)
2087 goto out;
2088
2089 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2090 if (rc)
2091 goto out_mmput;
2092
2093 down_read(&mm->mmap_sem);
2094 vma = find_exact_vma(mm, vm_start, vm_end);
2095 if (vma && vma->vm_file) {
2096 *path = vma->vm_file->f_path;
2097 path_get(path);
2098 rc = 0;
2099 }
2100 up_read(&mm->mmap_sem);
2101
2102out_mmput:
2103 mmput(mm);
2104out:
2105 return rc;
2106}
2107
2108struct map_files_info {
2109 struct file *file;
2110 unsigned long len;
2111 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
2112};
2113
2114static struct dentry *
2115proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
2116 struct task_struct *task, const void *ptr)
2117{
2118 const struct file *file = ptr;
2119 struct proc_inode *ei;
2120 struct inode *inode;
2121
2122 if (!file)
2123 return ERR_PTR(-ENOENT);
2124
2125 inode = proc_pid_make_inode(dir->i_sb, task);
2126 if (!inode)
2127 return ERR_PTR(-ENOENT);
2128
2129 ei = PROC_I(inode);
2130 ei->op.proc_get_link = proc_map_files_get_link;
2131
2132 inode->i_op = &proc_pid_link_inode_operations;
2133 inode->i_size = 64;
2134 inode->i_mode = S_IFLNK;
2135
2136 if (file->f_mode & FMODE_READ)
2137 inode->i_mode |= S_IRUSR;
2138 if (file->f_mode & FMODE_WRITE)
2139 inode->i_mode |= S_IWUSR;
2140
2141 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2142 d_add(dentry, inode);
2143
2144 return NULL;
2145}
2146
2147static struct dentry *proc_map_files_lookup(struct inode *dir,
2148 struct dentry *dentry, struct nameidata *nd)
2149{
2150 unsigned long vm_start, vm_end;
2151 struct vm_area_struct *vma;
2152 struct task_struct *task;
2153 struct dentry *result;
2154 struct mm_struct *mm;
2155
2156 result = ERR_PTR(-EACCES);
2157 if (!capable(CAP_SYS_ADMIN))
2158 goto out;
2159
2160 result = ERR_PTR(-ENOENT);
2161 task = get_proc_task(dir);
2162 if (!task)
2163 goto out;
2164
2165 result = ERR_PTR(-EACCES);
2166 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2167 goto out_put_task;
2168
2169 result = ERR_PTR(-ENOENT);
2170 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2171 goto out_put_task;
2172
2173 mm = get_task_mm(task);
2174 if (!mm)
2175 goto out_put_task;
2176
2177 down_read(&mm->mmap_sem);
2178 vma = find_exact_vma(mm, vm_start, vm_end);
2179 if (!vma)
2180 goto out_no_vma;
2181
2182 result = proc_map_files_instantiate(dir, dentry, task, vma->vm_file);
2183
2184out_no_vma:
2185 up_read(&mm->mmap_sem);
2186 mmput(mm);
2187out_put_task:
2188 put_task_struct(task);
2189out:
2190 return result;
2191}
2192
2193static const struct inode_operations proc_map_files_inode_operations = {
2194 .lookup = proc_map_files_lookup,
2195 .permission = proc_fd_permission,
2196 .setattr = proc_setattr,
2197};
2198
2199static int
2200proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
2201{
2202 struct dentry *dentry = filp->f_path.dentry;
2203 struct inode *inode = dentry->d_inode;
2204 struct vm_area_struct *vma;
2205 struct task_struct *task;
2206 struct mm_struct *mm;
2207 ino_t ino;
2208 int ret;
2209
2210 ret = -EACCES;
2211 if (!capable(CAP_SYS_ADMIN))
2212 goto out;
2213
2214 ret = -ENOENT;
2215 task = get_proc_task(inode);
2216 if (!task)
2217 goto out;
2218
2219 ret = -EACCES;
2220 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2221 goto out_put_task;
2222
2223 ret = 0;
2224 switch (filp->f_pos) {
2225 case 0:
2226 ino = inode->i_ino;
2227 if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0)
2228 goto out_put_task;
2229 filp->f_pos++;
2230 case 1:
2231 ino = parent_ino(dentry);
2232 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2233 goto out_put_task;
2234 filp->f_pos++;
2235 default:
2236 {
2237 unsigned long nr_files, pos, i;
2238 struct flex_array *fa = NULL;
2239 struct map_files_info info;
2240 struct map_files_info *p;
2241
2242 mm = get_task_mm(task);
2243 if (!mm)
2244 goto out_put_task;
2245 down_read(&mm->mmap_sem);
2246
2247 nr_files = 0;
2248
2249 /*
2250 * We need two passes here:
2251 *
2252 * 1) Collect vmas of mapped files with mmap_sem taken
2253 * 2) Release mmap_sem and instantiate entries
2254 *
2255 * otherwise we get lockdep complained, since filldir()
2256 * routine might require mmap_sem taken in might_fault().
2257 */
2258
2259 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2260 if (vma->vm_file && ++pos > filp->f_pos)
2261 nr_files++;
2262 }
2263
2264 if (nr_files) {
2265 fa = flex_array_alloc(sizeof(info), nr_files,
2266 GFP_KERNEL);
2267 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2268 GFP_KERNEL)) {
2269 ret = -ENOMEM;
2270 if (fa)
2271 flex_array_free(fa);
2272 up_read(&mm->mmap_sem);
2273 mmput(mm);
2274 goto out_put_task;
2275 }
2276 for (i = 0, vma = mm->mmap, pos = 2; vma;
2277 vma = vma->vm_next) {
2278 if (!vma->vm_file)
2279 continue;
2280 if (++pos <= filp->f_pos)
2281 continue;
2282
2283 get_file(vma->vm_file);
2284 info.file = vma->vm_file;
2285 info.len = snprintf(info.name,
2286 sizeof(info.name), "%lx-%lx",
2287 vma->vm_start, vma->vm_end);
2288 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2289 BUG();
2290 }
2291 }
2292 up_read(&mm->mmap_sem);
2293
2294 for (i = 0; i < nr_files; i++) {
2295 p = flex_array_get(fa, i);
2296 ret = proc_fill_cache(filp, dirent, filldir,
2297 p->name, p->len,
2298 proc_map_files_instantiate,
2299 task, p->file);
2300 if (ret)
2301 break;
2302 filp->f_pos++;
2303 fput(p->file);
2304 }
2305 for (; i < nr_files; i++) {
2306 /*
2307 * In case of error don't forget
2308 * to put rest of file refs.
2309 */
2310 p = flex_array_get(fa, i);
2311 fput(p->file);
2312 }
2313 if (fa)
2314 flex_array_free(fa);
2315 mmput(mm);
2316 }
2317 }
2318
2319out_put_task:
2320 put_task_struct(task);
2321out:
2322 return ret;
2323}
2324
2325static const struct file_operations proc_map_files_operations = {
2326 .read = generic_read_dir,
2327 .readdir = proc_map_files_readdir,
2328 .llseek = default_llseek,
2329};
2330
2331#endif /* CONFIG_CHECKPOINT_RESTORE */
2332
2333/*
2334 * /proc/pid/fd needs a special permission handler so that a process can still
2335 * access /proc/self/fd after it has executed a setuid().
2336 */
2337static int proc_fd_permission(struct inode *inode, int mask)
2338{
2339 int rv = generic_permission(inode, mask);
2340 if (rv == 0)
2341 return 0;
2342 if (task_pid(current) == proc_pid(inode))
2343 rv = 0;
2344 return rv;
2345}
2346
2347/*
2348 * proc directories can do almost nothing..
2349 */
2350static const struct inode_operations proc_fd_inode_operations = {
2351 .lookup = proc_lookupfd,
2352 .permission = proc_fd_permission,
2353 .setattr = proc_setattr,
2354};
2355
2356static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2357 struct dentry *dentry, struct task_struct *task, const void *ptr)
2358{
2359 unsigned fd = (unsigned long)ptr;
2360 struct inode *inode;
2361 struct proc_inode *ei;
2362 struct dentry *error = ERR_PTR(-ENOENT);
2363
2364 inode = proc_pid_make_inode(dir->i_sb, task);
2365 if (!inode)
2366 goto out;
2367 ei = PROC_I(inode);
2368 ei->fd = fd;
2369 inode->i_mode = S_IFREG | S_IRUSR;
2370 inode->i_fop = &proc_fdinfo_file_operations;
2371 d_set_d_op(dentry, &tid_fd_dentry_operations);
2372 d_add(dentry, inode);
2373 /* Close the race of the process dying before we return the dentry */
2374 if (tid_fd_revalidate(dentry, NULL))
2375 error = NULL;
2376
2377 out:
2378 return error;
2379}
2380
2381static struct dentry *proc_lookupfdinfo(struct inode *dir,
2382 struct dentry *dentry,
2383 struct nameidata *nd)
2384{
2385 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2386}
2387
2388static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2389{
2390 return proc_readfd_common(filp, dirent, filldir,
2391 proc_fdinfo_instantiate);
2392}
2393
2394static const struct file_operations proc_fdinfo_operations = {
2395 .read = generic_read_dir,
2396 .readdir = proc_readfdinfo,
2397 .llseek = default_llseek,
2398};
2399
2400/*
2401 * proc directories can do almost nothing..
2402 */
2403static const struct inode_operations proc_fdinfo_inode_operations = {
2404 .lookup = proc_lookupfdinfo,
2405 .setattr = proc_setattr,
2406};
2407
2408
2409static struct dentry *proc_pident_instantiate(struct inode *dir,
2410 struct dentry *dentry, struct task_struct *task, const void *ptr)
2411{
2412 const struct pid_entry *p = ptr;
2413 struct inode *inode;
2414 struct proc_inode *ei;
2415 struct dentry *error = ERR_PTR(-ENOENT);
2416
2417 inode = proc_pid_make_inode(dir->i_sb, task);
2418 if (!inode)
2419 goto out;
2420
2421 ei = PROC_I(inode);
2422 inode->i_mode = p->mode;
2423 if (S_ISDIR(inode->i_mode))
2424 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2425 if (p->iop)
2426 inode->i_op = p->iop;
2427 if (p->fop)
2428 inode->i_fop = p->fop;
2429 ei->op = p->op;
2430 d_set_d_op(dentry, &pid_dentry_operations);
2431 d_add(dentry, inode);
2432 /* Close the race of the process dying before we return the dentry */
2433 if (pid_revalidate(dentry, NULL))
2434 error = NULL;
2435out:
2436 return error;
2437}
2438
2439static struct dentry *proc_pident_lookup(struct inode *dir,
2440 struct dentry *dentry,
2441 const struct pid_entry *ents,
2442 unsigned int nents)
2443{
2444 struct dentry *error;
2445 struct task_struct *task = get_proc_task(dir);
2446 const struct pid_entry *p, *last;
2447
2448 error = ERR_PTR(-ENOENT);
2449
2450 if (!task)
2451 goto out_no_task;
2452
2453 /*
2454 * Yes, it does not scale. And it should not. Don't add
2455 * new entries into /proc/<tgid>/ without very good reasons.
2456 */
2457 last = &ents[nents - 1];
2458 for (p = ents; p <= last; p++) {
2459 if (p->len != dentry->d_name.len)
2460 continue;
2461 if (!memcmp(dentry->d_name.name, p->name, p->len))
2462 break;
2463 }
2464 if (p > last)
2465 goto out;
2466
2467 error = proc_pident_instantiate(dir, dentry, task, p);
2468out:
2469 put_task_struct(task);
2470out_no_task:
2471 return error;
2472}
2473
2474static int proc_pident_fill_cache(struct file *filp, void *dirent,
2475 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2476{
2477 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2478 proc_pident_instantiate, task, p);
2479}
2480
2481static int proc_pident_readdir(struct file *filp,
2482 void *dirent, filldir_t filldir,
2483 const struct pid_entry *ents, unsigned int nents)
2484{
2485 int i;
2486 struct dentry *dentry = filp->f_path.dentry;
2487 struct inode *inode = dentry->d_inode;
2488 struct task_struct *task = get_proc_task(inode);
2489 const struct pid_entry *p, *last;
2490 ino_t ino;
2491 int ret;
2492
2493 ret = -ENOENT;
2494 if (!task)
2495 goto out_no_task;
2496
2497 ret = 0;
2498 i = filp->f_pos;
2499 switch (i) {
2500 case 0:
2501 ino = inode->i_ino;
2502 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2503 goto out;
2504 i++;
2505 filp->f_pos++;
2506 /* fall through */
2507 case 1:
2508 ino = parent_ino(dentry);
2509 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2510 goto out;
2511 i++;
2512 filp->f_pos++;
2513 /* fall through */
2514 default:
2515 i -= 2;
2516 if (i >= nents) {
2517 ret = 1;
2518 goto out;
2519 }
2520 p = ents + i;
2521 last = &ents[nents - 1];
2522 while (p <= last) {
2523 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2524 goto out;
2525 filp->f_pos++;
2526 p++;
2527 }
2528 }
2529
2530 ret = 1;
2531out:
2532 put_task_struct(task);
2533out_no_task:
2534 return ret;
2535}
2536
2537#ifdef CONFIG_SECURITY
2538static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2539 size_t count, loff_t *ppos)
2540{
2541 struct inode * inode = file->f_path.dentry->d_inode;
2542 char *p = NULL;
2543 ssize_t length;
2544 struct task_struct *task = get_proc_task(inode);
2545
2546 if (!task)
2547 return -ESRCH;
2548
2549 length = security_getprocattr(task,
2550 (char*)file->f_path.dentry->d_name.name,
2551 &p);
2552 put_task_struct(task);
2553 if (length > 0)
2554 length = simple_read_from_buffer(buf, count, ppos, p, length);
2555 kfree(p);
2556 return length;
2557}
2558
2559static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2560 size_t count, loff_t *ppos)
2561{
2562 struct inode * inode = file->f_path.dentry->d_inode;
2563 char *page;
2564 ssize_t length;
2565 struct task_struct *task = get_proc_task(inode);
2566
2567 length = -ESRCH;
2568 if (!task)
2569 goto out_no_task;
2570 if (count > PAGE_SIZE)
2571 count = PAGE_SIZE;
2572
2573 /* No partial writes. */
2574 length = -EINVAL;
2575 if (*ppos != 0)
2576 goto out;
2577
2578 length = -ENOMEM;
2579 page = (char*)__get_free_page(GFP_TEMPORARY);
2580 if (!page)
2581 goto out;
2582
2583 length = -EFAULT;
2584 if (copy_from_user(page, buf, count))
2585 goto out_free;
2586
2587 /* Guard against adverse ptrace interaction */
2588 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2589 if (length < 0)
2590 goto out_free;
2591
2592 length = security_setprocattr(task,
2593 (char*)file->f_path.dentry->d_name.name,
2594 (void*)page, count);
2595 mutex_unlock(&task->signal->cred_guard_mutex);
2596out_free:
2597 free_page((unsigned long) page);
2598out:
2599 put_task_struct(task);
2600out_no_task:
2601 return length;
2602}
2603
2604static const struct file_operations proc_pid_attr_operations = {
2605 .read = proc_pid_attr_read,
2606 .write = proc_pid_attr_write,
2607 .llseek = generic_file_llseek,
2608};
2609
2610static const struct pid_entry attr_dir_stuff[] = {
2611 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2612 REG("prev", S_IRUGO, proc_pid_attr_operations),
2613 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2614 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2615 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2616 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2617};
2618
2619static int proc_attr_dir_readdir(struct file * filp,
2620 void * dirent, filldir_t filldir)
2621{
2622 return proc_pident_readdir(filp,dirent,filldir,
2623 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2624}
2625
2626static const struct file_operations proc_attr_dir_operations = {
2627 .read = generic_read_dir,
2628 .readdir = proc_attr_dir_readdir,
2629 .llseek = default_llseek,
2630};
2631
2632static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2633 struct dentry *dentry, struct nameidata *nd)
2634{
2635 return proc_pident_lookup(dir, dentry,
2636 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2637}
2638
2639static const struct inode_operations proc_attr_dir_inode_operations = {
2640 .lookup = proc_attr_dir_lookup,
2641 .getattr = pid_getattr,
2642 .setattr = proc_setattr,
2643};
2644
2645#endif
2646
2647#ifdef CONFIG_ELF_CORE
2648static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2649 size_t count, loff_t *ppos)
2650{
2651 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2652 struct mm_struct *mm;
2653 char buffer[PROC_NUMBUF];
2654 size_t len;
2655 int ret;
2656
2657 if (!task)
2658 return -ESRCH;
2659
2660 ret = 0;
2661 mm = get_task_mm(task);
2662 if (mm) {
2663 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2664 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2665 MMF_DUMP_FILTER_SHIFT));
2666 mmput(mm);
2667 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2668 }
2669
2670 put_task_struct(task);
2671
2672 return ret;
2673}
2674
2675static ssize_t proc_coredump_filter_write(struct file *file,
2676 const char __user *buf,
2677 size_t count,
2678 loff_t *ppos)
2679{
2680 struct task_struct *task;
2681 struct mm_struct *mm;
2682 char buffer[PROC_NUMBUF], *end;
2683 unsigned int val;
2684 int ret;
2685 int i;
2686 unsigned long mask;
2687
2688 ret = -EFAULT;
2689 memset(buffer, 0, sizeof(buffer));
2690 if (count > sizeof(buffer) - 1)
2691 count = sizeof(buffer) - 1;
2692 if (copy_from_user(buffer, buf, count))
2693 goto out_no_task;
2694
2695 ret = -EINVAL;
2696 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2697 if (*end == '\n')
2698 end++;
2699 if (end - buffer == 0)
2700 goto out_no_task;
2701
2702 ret = -ESRCH;
2703 task = get_proc_task(file->f_dentry->d_inode);
2704 if (!task)
2705 goto out_no_task;
2706
2707 ret = end - buffer;
2708 mm = get_task_mm(task);
2709 if (!mm)
2710 goto out_no_mm;
2711
2712 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2713 if (val & mask)
2714 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2715 else
2716 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2717 }
2718
2719 mmput(mm);
2720 out_no_mm:
2721 put_task_struct(task);
2722 out_no_task:
2723 return ret;
2724}
2725
2726static const struct file_operations proc_coredump_filter_operations = {
2727 .read = proc_coredump_filter_read,
2728 .write = proc_coredump_filter_write,
2729 .llseek = generic_file_llseek,
2730};
2731#endif
2732
2733/*
2734 * /proc/self:
2735 */
2736static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2737 int buflen)
2738{
2739 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2740 pid_t tgid = task_tgid_nr_ns(current, ns);
2741 char tmp[PROC_NUMBUF];
2742 if (!tgid)
2743 return -ENOENT;
2744 sprintf(tmp, "%d", tgid);
2745 return vfs_readlink(dentry,buffer,buflen,tmp);
2746}
2747
2748static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2749{
2750 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2751 pid_t tgid = task_tgid_nr_ns(current, ns);
2752 char *name = ERR_PTR(-ENOENT);
2753 if (tgid) {
2754 name = __getname();
2755 if (!name)
2756 name = ERR_PTR(-ENOMEM);
2757 else
2758 sprintf(name, "%d", tgid);
2759 }
2760 nd_set_link(nd, name);
2761 return NULL;
2762}
2763
2764static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2765 void *cookie)
2766{
2767 char *s = nd_get_link(nd);
2768 if (!IS_ERR(s))
2769 __putname(s);
2770}
2771
2772static const struct inode_operations proc_self_inode_operations = {
2773 .readlink = proc_self_readlink,
2774 .follow_link = proc_self_follow_link,
2775 .put_link = proc_self_put_link,
2776};
2777
2778/*
2779 * proc base
2780 *
2781 * These are the directory entries in the root directory of /proc
2782 * that properly belong to the /proc filesystem, as they describe
2783 * describe something that is process related.
2784 */
2785static const struct pid_entry proc_base_stuff[] = {
2786 NOD("self", S_IFLNK|S_IRWXUGO,
2787 &proc_self_inode_operations, NULL, {}),
2788};
2789
2790static struct dentry *proc_base_instantiate(struct inode *dir,
2791 struct dentry *dentry, struct task_struct *task, const void *ptr)
2792{
2793 const struct pid_entry *p = ptr;
2794 struct inode *inode;
2795 struct proc_inode *ei;
2796 struct dentry *error;
2797
2798 /* Allocate the inode */
2799 error = ERR_PTR(-ENOMEM);
2800 inode = new_inode(dir->i_sb);
2801 if (!inode)
2802 goto out;
2803
2804 /* Initialize the inode */
2805 ei = PROC_I(inode);
2806 inode->i_ino = get_next_ino();
2807 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2808
2809 /*
2810 * grab the reference to the task.
2811 */
2812 ei->pid = get_task_pid(task, PIDTYPE_PID);
2813 if (!ei->pid)
2814 goto out_iput;
2815
2816 inode->i_mode = p->mode;
2817 if (S_ISDIR(inode->i_mode))
2818 set_nlink(inode, 2);
2819 if (S_ISLNK(inode->i_mode))
2820 inode->i_size = 64;
2821 if (p->iop)
2822 inode->i_op = p->iop;
2823 if (p->fop)
2824 inode->i_fop = p->fop;
2825 ei->op = p->op;
2826 d_add(dentry, inode);
2827 error = NULL;
2828out:
2829 return error;
2830out_iput:
2831 iput(inode);
2832 goto out;
2833}
2834
2835static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2836{
2837 struct dentry *error;
2838 struct task_struct *task = get_proc_task(dir);
2839 const struct pid_entry *p, *last;
2840
2841 error = ERR_PTR(-ENOENT);
2842
2843 if (!task)
2844 goto out_no_task;
2845
2846 /* Lookup the directory entry */
2847 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2848 for (p = proc_base_stuff; p <= last; p++) {
2849 if (p->len != dentry->d_name.len)
2850 continue;
2851 if (!memcmp(dentry->d_name.name, p->name, p->len))
2852 break;
2853 }
2854 if (p > last)
2855 goto out;
2856
2857 error = proc_base_instantiate(dir, dentry, task, p);
2858
2859out:
2860 put_task_struct(task);
2861out_no_task:
2862 return error;
2863}
2864
2865static int proc_base_fill_cache(struct file *filp, void *dirent,
2866 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2867{
2868 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2869 proc_base_instantiate, task, p);
2870}
2871
2872#ifdef CONFIG_TASK_IO_ACCOUNTING
2873static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2874{
2875 struct task_io_accounting acct = task->ioac;
2876 unsigned long flags;
2877 int result;
2878
2879 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2880 if (result)
2881 return result;
2882
2883 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2884 result = -EACCES;
2885 goto out_unlock;
2886 }
2887
2888 if (whole && lock_task_sighand(task, &flags)) {
2889 struct task_struct *t = task;
2890
2891 task_io_accounting_add(&acct, &task->signal->ioac);
2892 while_each_thread(task, t)
2893 task_io_accounting_add(&acct, &t->ioac);
2894
2895 unlock_task_sighand(task, &flags);
2896 }
2897 result = sprintf(buffer,
2898 "rchar: %llu\n"
2899 "wchar: %llu\n"
2900 "syscr: %llu\n"
2901 "syscw: %llu\n"
2902 "read_bytes: %llu\n"
2903 "write_bytes: %llu\n"
2904 "cancelled_write_bytes: %llu\n",
2905 (unsigned long long)acct.rchar,
2906 (unsigned long long)acct.wchar,
2907 (unsigned long long)acct.syscr,
2908 (unsigned long long)acct.syscw,
2909 (unsigned long long)acct.read_bytes,
2910 (unsigned long long)acct.write_bytes,
2911 (unsigned long long)acct.cancelled_write_bytes);
2912out_unlock:
2913 mutex_unlock(&task->signal->cred_guard_mutex);
2914 return result;
2915}
2916
2917static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2918{
2919 return do_io_accounting(task, buffer, 0);
2920}
2921
2922static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2923{
2924 return do_io_accounting(task, buffer, 1);
2925}
2926#endif /* CONFIG_TASK_IO_ACCOUNTING */
2927
2928#ifdef CONFIG_USER_NS
2929static int proc_id_map_open(struct inode *inode, struct file *file,
2930 struct seq_operations *seq_ops)
2931{
2932 struct user_namespace *ns = NULL;
2933 struct task_struct *task;
2934 struct seq_file *seq;
2935 int ret = -EINVAL;
2936
2937 task = get_proc_task(inode);
2938 if (task) {
2939 rcu_read_lock();
2940 ns = get_user_ns(task_cred_xxx(task, user_ns));
2941 rcu_read_unlock();
2942 put_task_struct(task);
2943 }
2944 if (!ns)
2945 goto err;
2946
2947 ret = seq_open(file, seq_ops);
2948 if (ret)
2949 goto err_put_ns;
2950
2951 seq = file->private_data;
2952 seq->private = ns;
2953
2954 return 0;
2955err_put_ns:
2956 put_user_ns(ns);
2957err:
2958 return ret;
2959}
2960
2961static int proc_id_map_release(struct inode *inode, struct file *file)
2962{
2963 struct seq_file *seq = file->private_data;
2964 struct user_namespace *ns = seq->private;
2965 put_user_ns(ns);
2966 return seq_release(inode, file);
2967}
2968
2969static int proc_uid_map_open(struct inode *inode, struct file *file)
2970{
2971 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2972}
2973
2974static int proc_gid_map_open(struct inode *inode, struct file *file)
2975{
2976 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2977}
2978
2979static const struct file_operations proc_uid_map_operations = {
2980 .open = proc_uid_map_open,
2981 .write = proc_uid_map_write,
2982 .read = seq_read,
2983 .llseek = seq_lseek,
2984 .release = proc_id_map_release,
2985};
2986
2987static const struct file_operations proc_gid_map_operations = {
2988 .open = proc_gid_map_open,
2989 .write = proc_gid_map_write,
2990 .read = seq_read,
2991 .llseek = seq_lseek,
2992 .release = proc_id_map_release,
2993};
2994#endif /* CONFIG_USER_NS */
2995
2996static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2997 struct pid *pid, struct task_struct *task)
2998{
2999 int err = lock_trace(task);
3000 if (!err) {
3001 seq_printf(m, "%08x\n", task->personality);
3002 unlock_trace(task);
3003 }
3004 return err;
3005}
3006
3007/*
3008 * Thread groups
3009 */
3010static const struct file_operations proc_task_operations;
3011static const struct inode_operations proc_task_inode_operations;
3012
3013static const struct pid_entry tgid_base_stuff[] = {
3014 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3015 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3016#ifdef CONFIG_CHECKPOINT_RESTORE
3017 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3018#endif
3019 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3020 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3021#ifdef CONFIG_NET
3022 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3023#endif
3024 REG("environ", S_IRUSR, proc_environ_operations),
3025 INF("auxv", S_IRUSR, proc_pid_auxv),
3026 ONE("status", S_IRUGO, proc_pid_status),
3027 ONE("personality", S_IRUGO, proc_pid_personality),
3028 INF("limits", S_IRUGO, proc_pid_limits),
3029#ifdef CONFIG_SCHED_DEBUG
3030 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3031#endif
3032#ifdef CONFIG_SCHED_AUTOGROUP
3033 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3034#endif
3035 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3036#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3037 INF("syscall", S_IRUGO, proc_pid_syscall),
3038#endif
3039 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3040 ONE("stat", S_IRUGO, proc_tgid_stat),
3041 ONE("statm", S_IRUGO, proc_pid_statm),
3042 REG("maps", S_IRUGO, proc_pid_maps_operations),
3043#ifdef CONFIG_NUMA
3044 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3045#endif
3046 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3047 LNK("cwd", proc_cwd_link),
3048 LNK("root", proc_root_link),
3049 LNK("exe", proc_exe_link),
3050 REG("mounts", S_IRUGO, proc_mounts_operations),
3051 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3052 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3053#ifdef CONFIG_PROC_PAGE_MONITOR
3054 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3055 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3056 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3057#endif
3058#ifdef CONFIG_SECURITY
3059 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3060#endif
3061#ifdef CONFIG_KALLSYMS
3062 INF("wchan", S_IRUGO, proc_pid_wchan),
3063#endif
3064#ifdef CONFIG_STACKTRACE
3065 ONE("stack", S_IRUGO, proc_pid_stack),
3066#endif
3067#ifdef CONFIG_SCHEDSTATS
3068 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3069#endif
3070#ifdef CONFIG_LATENCYTOP
3071 REG("latency", S_IRUGO, proc_lstats_operations),
3072#endif
3073#ifdef CONFIG_PROC_PID_CPUSET
3074 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3075#endif
3076#ifdef CONFIG_CGROUPS
3077 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3078#endif
3079 INF("oom_score", S_IRUGO, proc_oom_score),
3080 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3081 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3082#ifdef CONFIG_AUDITSYSCALL
3083 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3084 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3085#endif
3086#ifdef CONFIG_FAULT_INJECTION
3087 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3088#endif
3089#ifdef CONFIG_ELF_CORE
3090 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3091#endif
3092#ifdef CONFIG_TASK_IO_ACCOUNTING
3093 INF("io", S_IRUSR, proc_tgid_io_accounting),
3094#endif
3095#ifdef CONFIG_HARDWALL
3096 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3097#endif
3098#ifdef CONFIG_USER_NS
3099 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3100 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3101#endif
3102};
3103
3104static int proc_tgid_base_readdir(struct file * filp,
3105 void * dirent, filldir_t filldir)
3106{
3107 return proc_pident_readdir(filp,dirent,filldir,
3108 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
3109}
3110
3111static const struct file_operations proc_tgid_base_operations = {
3112 .read = generic_read_dir,
3113 .readdir = proc_tgid_base_readdir,
3114 .llseek = default_llseek,
3115};
3116
3117static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3118 return proc_pident_lookup(dir, dentry,
3119 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3120}
3121
3122static const struct inode_operations proc_tgid_base_inode_operations = {
3123 .lookup = proc_tgid_base_lookup,
3124 .getattr = pid_getattr,
3125 .setattr = proc_setattr,
3126 .permission = proc_pid_permission,
3127};
3128
3129static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
3130{
3131 struct dentry *dentry, *leader, *dir;
3132 char buf[PROC_NUMBUF];
3133 struct qstr name;
3134
3135 name.name = buf;
3136 name.len = snprintf(buf, sizeof(buf), "%d", pid);
3137 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
3138 if (dentry) {
3139 shrink_dcache_parent(dentry);
3140 d_drop(dentry);
3141 dput(dentry);
3142 }
3143
3144 name.name = buf;
3145 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
3146 leader = d_hash_and_lookup(mnt->mnt_root, &name);
3147 if (!leader)
3148 goto out;
3149
3150 name.name = "task";
3151 name.len = strlen(name.name);
3152 dir = d_hash_and_lookup(leader, &name);
3153 if (!dir)
3154 goto out_put_leader;
3155
3156 name.name = buf;
3157 name.len = snprintf(buf, sizeof(buf), "%d", pid);
3158 dentry = d_hash_and_lookup(dir, &name);
3159 if (dentry) {
3160 shrink_dcache_parent(dentry);
3161 d_drop(dentry);
3162 dput(dentry);
3163 }
3164
3165 dput(dir);
3166out_put_leader:
3167 dput(leader);
3168out:
3169 return;
3170}
3171
3172/**
3173 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3174 * @task: task that should be flushed.
3175 *
3176 * When flushing dentries from proc, one needs to flush them from global
3177 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3178 * in. This call is supposed to do all of this job.
3179 *
3180 * Looks in the dcache for
3181 * /proc/@pid
3182 * /proc/@tgid/task/@pid
3183 * if either directory is present flushes it and all of it'ts children
3184 * from the dcache.
3185 *
3186 * It is safe and reasonable to cache /proc entries for a task until
3187 * that task exits. After that they just clog up the dcache with
3188 * useless entries, possibly causing useful dcache entries to be
3189 * flushed instead. This routine is proved to flush those useless
3190 * dcache entries at process exit time.
3191 *
3192 * NOTE: This routine is just an optimization so it does not guarantee
3193 * that no dcache entries will exist at process exit time it
3194 * just makes it very unlikely that any will persist.
3195 */
3196
3197void proc_flush_task(struct task_struct *task)
3198{
3199 int i;
3200 struct pid *pid, *tgid;
3201 struct upid *upid;
3202
3203 pid = task_pid(task);
3204 tgid = task_tgid(task);
3205
3206 for (i = 0; i <= pid->level; i++) {
3207 upid = &pid->numbers[i];
3208 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3209 tgid->numbers[i].nr);
3210 }
3211
3212 upid = &pid->numbers[pid->level];
3213 if (upid->nr == 1)
3214 pid_ns_release_proc(upid->ns);
3215}
3216
3217static struct dentry *proc_pid_instantiate(struct inode *dir,
3218 struct dentry * dentry,
3219 struct task_struct *task, const void *ptr)
3220{
3221 struct dentry *error = ERR_PTR(-ENOENT);
3222 struct inode *inode;
3223
3224 inode = proc_pid_make_inode(dir->i_sb, task);
3225 if (!inode)
3226 goto out;
3227
3228 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3229 inode->i_op = &proc_tgid_base_inode_operations;
3230 inode->i_fop = &proc_tgid_base_operations;
3231 inode->i_flags|=S_IMMUTABLE;
3232
3233 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
3234 ARRAY_SIZE(tgid_base_stuff)));
3235
3236 d_set_d_op(dentry, &pid_dentry_operations);
3237
3238 d_add(dentry, inode);
3239 /* Close the race of the process dying before we return the dentry */
3240 if (pid_revalidate(dentry, NULL))
3241 error = NULL;
3242out:
3243 return error;
3244}
3245
3246struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3247{
3248 struct dentry *result;
3249 struct task_struct *task;
3250 unsigned tgid;
3251 struct pid_namespace *ns;
3252
3253 result = proc_base_lookup(dir, dentry);
3254 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
3255 goto out;
3256
3257 tgid = name_to_int(dentry);
3258 if (tgid == ~0U)
3259 goto out;
3260
3261 ns = dentry->d_sb->s_fs_info;
3262 rcu_read_lock();
3263 task = find_task_by_pid_ns(tgid, ns);
3264 if (task)
3265 get_task_struct(task);
3266 rcu_read_unlock();
3267 if (!task)
3268 goto out;
3269
3270 result = proc_pid_instantiate(dir, dentry, task, NULL);
3271 put_task_struct(task);
3272out:
3273 return result;
3274}
3275
3276/*
3277 * Find the first task with tgid >= tgid
3278 *
3279 */
3280struct tgid_iter {
3281 unsigned int tgid;
3282 struct task_struct *task;
3283};
3284static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3285{
3286 struct pid *pid;
3287
3288 if (iter.task)
3289 put_task_struct(iter.task);
3290 rcu_read_lock();
3291retry:
3292 iter.task = NULL;
3293 pid = find_ge_pid(iter.tgid, ns);
3294 if (pid) {
3295 iter.tgid = pid_nr_ns(pid, ns);
3296 iter.task = pid_task(pid, PIDTYPE_PID);
3297 /* What we to know is if the pid we have find is the
3298 * pid of a thread_group_leader. Testing for task
3299 * being a thread_group_leader is the obvious thing
3300 * todo but there is a window when it fails, due to
3301 * the pid transfer logic in de_thread.
3302 *
3303 * So we perform the straight forward test of seeing
3304 * if the pid we have found is the pid of a thread
3305 * group leader, and don't worry if the task we have
3306 * found doesn't happen to be a thread group leader.
3307 * As we don't care in the case of readdir.
3308 */
3309 if (!iter.task || !has_group_leader_pid(iter.task)) {
3310 iter.tgid += 1;
3311 goto retry;
3312 }
3313 get_task_struct(iter.task);
3314 }
3315 rcu_read_unlock();
3316 return iter;
3317}
3318
3319#define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3320
3321static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3322 struct tgid_iter iter)
3323{
3324 char name[PROC_NUMBUF];
3325 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3326 return proc_fill_cache(filp, dirent, filldir, name, len,
3327 proc_pid_instantiate, iter.task, NULL);
3328}
3329
3330static int fake_filldir(void *buf, const char *name, int namelen,
3331 loff_t offset, u64 ino, unsigned d_type)
3332{
3333 return 0;
3334}
3335
3336/* for the /proc/ directory itself, after non-process stuff has been done */
3337int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3338{
3339 unsigned int nr;
3340 struct task_struct *reaper;
3341 struct tgid_iter iter;
3342 struct pid_namespace *ns;
3343 filldir_t __filldir;
3344
3345 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3346 goto out_no_task;
3347 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3348
3349 reaper = get_proc_task(filp->f_path.dentry->d_inode);
3350 if (!reaper)
3351 goto out_no_task;
3352
3353 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3354 const struct pid_entry *p = &proc_base_stuff[nr];
3355 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3356 goto out;
3357 }
3358
3359 ns = filp->f_dentry->d_sb->s_fs_info;
3360 iter.task = NULL;
3361 iter.tgid = filp->f_pos - TGID_OFFSET;
3362 for (iter = next_tgid(ns, iter);
3363 iter.task;
3364 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3365 if (has_pid_permissions(ns, iter.task, 2))
3366 __filldir = filldir;
3367 else
3368 __filldir = fake_filldir;
3369
3370 filp->f_pos = iter.tgid + TGID_OFFSET;
3371 if (proc_pid_fill_cache(filp, dirent, __filldir, iter) < 0) {
3372 put_task_struct(iter.task);
3373 goto out;
3374 }
3375 }
3376 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3377out:
3378 put_task_struct(reaper);
3379out_no_task:
3380 return 0;
3381}
3382
3383/*
3384 * Tasks
3385 */
3386static const struct pid_entry tid_base_stuff[] = {
3387 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3388 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3389 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3390 REG("environ", S_IRUSR, proc_environ_operations),
3391 INF("auxv", S_IRUSR, proc_pid_auxv),
3392 ONE("status", S_IRUGO, proc_pid_status),
3393 ONE("personality", S_IRUGO, proc_pid_personality),
3394 INF("limits", S_IRUGO, proc_pid_limits),
3395#ifdef CONFIG_SCHED_DEBUG
3396 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3397#endif
3398 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3399#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3400 INF("syscall", S_IRUGO, proc_pid_syscall),
3401#endif
3402 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3403 ONE("stat", S_IRUGO, proc_tid_stat),
3404 ONE("statm", S_IRUGO, proc_pid_statm),
3405 REG("maps", S_IRUGO, proc_tid_maps_operations),
3406#ifdef CONFIG_CHECKPOINT_RESTORE
3407 REG("children", S_IRUGO, proc_tid_children_operations),
3408#endif
3409#ifdef CONFIG_NUMA
3410 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3411#endif
3412 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3413 LNK("cwd", proc_cwd_link),
3414 LNK("root", proc_root_link),
3415 LNK("exe", proc_exe_link),
3416 REG("mounts", S_IRUGO, proc_mounts_operations),
3417 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3418#ifdef CONFIG_PROC_PAGE_MONITOR
3419 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3420 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3421 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3422#endif
3423#ifdef CONFIG_SECURITY
3424 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3425#endif
3426#ifdef CONFIG_KALLSYMS
3427 INF("wchan", S_IRUGO, proc_pid_wchan),
3428#endif
3429#ifdef CONFIG_STACKTRACE
3430 ONE("stack", S_IRUGO, proc_pid_stack),
3431#endif
3432#ifdef CONFIG_SCHEDSTATS
3433 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3434#endif
3435#ifdef CONFIG_LATENCYTOP
3436 REG("latency", S_IRUGO, proc_lstats_operations),
3437#endif
3438#ifdef CONFIG_PROC_PID_CPUSET
3439 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3440#endif
3441#ifdef CONFIG_CGROUPS
3442 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3443#endif
3444 INF("oom_score", S_IRUGO, proc_oom_score),
3445 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3446 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3447#ifdef CONFIG_AUDITSYSCALL
3448 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3449 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3450#endif
3451#ifdef CONFIG_FAULT_INJECTION
3452 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3453#endif
3454#ifdef CONFIG_TASK_IO_ACCOUNTING
3455 INF("io", S_IRUSR, proc_tid_io_accounting),
3456#endif
3457#ifdef CONFIG_HARDWALL
3458 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3459#endif
3460#ifdef CONFIG_USER_NS
3461 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3462 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3463#endif
3464};
3465
3466static int proc_tid_base_readdir(struct file * filp,
3467 void * dirent, filldir_t filldir)
3468{
3469 return proc_pident_readdir(filp,dirent,filldir,
3470 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3471}
3472
3473static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3474 return proc_pident_lookup(dir, dentry,
3475 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3476}
3477
3478static const struct file_operations proc_tid_base_operations = {
3479 .read = generic_read_dir,
3480 .readdir = proc_tid_base_readdir,
3481 .llseek = default_llseek,
3482};
3483
3484static const struct inode_operations proc_tid_base_inode_operations = {
3485 .lookup = proc_tid_base_lookup,
3486 .getattr = pid_getattr,
3487 .setattr = proc_setattr,
3488};
3489
3490static struct dentry *proc_task_instantiate(struct inode *dir,
3491 struct dentry *dentry, struct task_struct *task, const void *ptr)
3492{
3493 struct dentry *error = ERR_PTR(-ENOENT);
3494 struct inode *inode;
3495 inode = proc_pid_make_inode(dir->i_sb, task);
3496
3497 if (!inode)
3498 goto out;
3499 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3500 inode->i_op = &proc_tid_base_inode_operations;
3501 inode->i_fop = &proc_tid_base_operations;
3502 inode->i_flags|=S_IMMUTABLE;
3503
3504 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3505 ARRAY_SIZE(tid_base_stuff)));
3506
3507 d_set_d_op(dentry, &pid_dentry_operations);
3508
3509 d_add(dentry, inode);
3510 /* Close the race of the process dying before we return the dentry */
3511 if (pid_revalidate(dentry, NULL))
3512 error = NULL;
3513out:
3514 return error;
3515}
3516
3517static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3518{
3519 struct dentry *result = ERR_PTR(-ENOENT);
3520 struct task_struct *task;
3521 struct task_struct *leader = get_proc_task(dir);
3522 unsigned tid;
3523 struct pid_namespace *ns;
3524
3525 if (!leader)
3526 goto out_no_task;
3527
3528 tid = name_to_int(dentry);
3529 if (tid == ~0U)
3530 goto out;
3531
3532 ns = dentry->d_sb->s_fs_info;
3533 rcu_read_lock();
3534 task = find_task_by_pid_ns(tid, ns);
3535 if (task)
3536 get_task_struct(task);
3537 rcu_read_unlock();
3538 if (!task)
3539 goto out;
3540 if (!same_thread_group(leader, task))
3541 goto out_drop_task;
3542
3543 result = proc_task_instantiate(dir, dentry, task, NULL);
3544out_drop_task:
3545 put_task_struct(task);
3546out:
3547 put_task_struct(leader);
3548out_no_task:
3549 return result;
3550}
3551
3552/*
3553 * Find the first tid of a thread group to return to user space.
3554 *
3555 * Usually this is just the thread group leader, but if the users
3556 * buffer was too small or there was a seek into the middle of the
3557 * directory we have more work todo.
3558 *
3559 * In the case of a short read we start with find_task_by_pid.
3560 *
3561 * In the case of a seek we start with the leader and walk nr
3562 * threads past it.
3563 */
3564static struct task_struct *first_tid(struct task_struct *leader,
3565 int tid, int nr, struct pid_namespace *ns)
3566{
3567 struct task_struct *pos;
3568
3569 rcu_read_lock();
3570 /* Attempt to start with the pid of a thread */
3571 if (tid && (nr > 0)) {
3572 pos = find_task_by_pid_ns(tid, ns);
3573 if (pos && (pos->group_leader == leader))
3574 goto found;
3575 }
3576
3577 /* If nr exceeds the number of threads there is nothing todo */
3578 pos = NULL;
3579 if (nr && nr >= get_nr_threads(leader))
3580 goto out;
3581
3582 /* If we haven't found our starting place yet start
3583 * with the leader and walk nr threads forward.
3584 */
3585 for (pos = leader; nr > 0; --nr) {
3586 pos = next_thread(pos);
3587 if (pos == leader) {
3588 pos = NULL;
3589 goto out;
3590 }
3591 }
3592found:
3593 get_task_struct(pos);
3594out:
3595 rcu_read_unlock();
3596 return pos;
3597}
3598
3599/*
3600 * Find the next thread in the thread list.
3601 * Return NULL if there is an error or no next thread.
3602 *
3603 * The reference to the input task_struct is released.
3604 */
3605static struct task_struct *next_tid(struct task_struct *start)
3606{
3607 struct task_struct *pos = NULL;
3608 rcu_read_lock();
3609 if (pid_alive(start)) {
3610 pos = next_thread(start);
3611 if (thread_group_leader(pos))
3612 pos = NULL;
3613 else
3614 get_task_struct(pos);
3615 }
3616 rcu_read_unlock();
3617 put_task_struct(start);
3618 return pos;
3619}
3620
3621static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3622 struct task_struct *task, int tid)
3623{
3624 char name[PROC_NUMBUF];
3625 int len = snprintf(name, sizeof(name), "%d", tid);
3626 return proc_fill_cache(filp, dirent, filldir, name, len,
3627 proc_task_instantiate, task, NULL);
3628}
3629
3630/* for the /proc/TGID/task/ directories */
3631static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3632{
3633 struct dentry *dentry = filp->f_path.dentry;
3634 struct inode *inode = dentry->d_inode;
3635 struct task_struct *leader = NULL;
3636 struct task_struct *task;
3637 int retval = -ENOENT;
3638 ino_t ino;
3639 int tid;
3640 struct pid_namespace *ns;
3641
3642 task = get_proc_task(inode);
3643 if (!task)
3644 goto out_no_task;
3645 rcu_read_lock();
3646 if (pid_alive(task)) {
3647 leader = task->group_leader;
3648 get_task_struct(leader);
3649 }
3650 rcu_read_unlock();
3651 put_task_struct(task);
3652 if (!leader)
3653 goto out_no_task;
3654 retval = 0;
3655
3656 switch ((unsigned long)filp->f_pos) {
3657 case 0:
3658 ino = inode->i_ino;
3659 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3660 goto out;
3661 filp->f_pos++;
3662 /* fall through */
3663 case 1:
3664 ino = parent_ino(dentry);
3665 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3666 goto out;
3667 filp->f_pos++;
3668 /* fall through */
3669 }
3670
3671 /* f_version caches the tgid value that the last readdir call couldn't
3672 * return. lseek aka telldir automagically resets f_version to 0.
3673 */
3674 ns = filp->f_dentry->d_sb->s_fs_info;
3675 tid = (int)filp->f_version;
3676 filp->f_version = 0;
3677 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3678 task;
3679 task = next_tid(task), filp->f_pos++) {
3680 tid = task_pid_nr_ns(task, ns);
3681 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3682 /* returning this tgid failed, save it as the first
3683 * pid for the next readir call */
3684 filp->f_version = (u64)tid;
3685 put_task_struct(task);
3686 break;
3687 }
3688 }
3689out:
3690 put_task_struct(leader);
3691out_no_task:
3692 return retval;
3693}
3694
3695static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3696{
3697 struct inode *inode = dentry->d_inode;
3698 struct task_struct *p = get_proc_task(inode);
3699 generic_fillattr(inode, stat);
3700
3701 if (p) {
3702 stat->nlink += get_nr_threads(p);
3703 put_task_struct(p);
3704 }
3705
3706 return 0;
3707}
3708
3709static const struct inode_operations proc_task_inode_operations = {
3710 .lookup = proc_task_lookup,
3711 .getattr = proc_task_getattr,
3712 .setattr = proc_setattr,
3713 .permission = proc_pid_permission,
3714};
3715
3716static const struct file_operations proc_task_operations = {
3717 .read = generic_read_dir,
3718 .readdir = proc_task_readdir,
3719 .llseek = default_llseek,
3720};