Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/proc/base.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * proc base directory handling functions
8 *
9 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
10 * Instead of using magical inumbers to determine the kind of object
11 * we allocate and fill in-core inodes upon lookup. They don't even
12 * go into icache. We cache the reference to task_struct upon lookup too.
13 * Eventually it should become a filesystem in its own. We don't use the
14 * rest of procfs anymore.
15 *
16 *
17 * Changelog:
18 * 17-Jan-2005
19 * Allan Bezerra
20 * Bruna Moreira <bruna.moreira@indt.org.br>
21 * Edjard Mota <edjard.mota@indt.org.br>
22 * Ilias Biris <ilias.biris@indt.org.br>
23 * Mauricio Lin <mauricio.lin@indt.org.br>
24 *
25 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
26 *
27 * A new process specific entry (smaps) included in /proc. It shows the
28 * size of rss for each memory area. The maps entry lacks information
29 * about physical memory size (rss) for each mapped file, i.e.,
30 * rss information for executables and library files.
31 * This additional information is useful for any tools that need to know
32 * about physical memory consumption for a process specific library.
33 *
34 * Changelog:
35 * 21-Feb-2005
36 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
37 * Pud inclusion in the page table walking.
38 *
39 * ChangeLog:
40 * 10-Mar-2005
41 * 10LE Instituto Nokia de Tecnologia - INdT:
42 * A better way to walks through the page table as suggested by Hugh Dickins.
43 *
44 * Simo Piiroinen <simo.piiroinen@nokia.com>:
45 * Smaps information related to shared, private, clean and dirty pages.
46 *
47 * Paul Mundt <paul.mundt@nokia.com>:
48 * Overall revision about smaps.
49 */
50
51#include <linux/uaccess.h>
52
53#include <linux/errno.h>
54#include <linux/time.h>
55#include <linux/proc_fs.h>
56#include <linux/stat.h>
57#include <linux/task_io_accounting_ops.h>
58#include <linux/init.h>
59#include <linux/capability.h>
60#include <linux/file.h>
61#include <linux/fdtable.h>
62#include <linux/string.h>
63#include <linux/seq_file.h>
64#include <linux/namei.h>
65#include <linux/mnt_namespace.h>
66#include <linux/mm.h>
67#include <linux/swap.h>
68#include <linux/rcupdate.h>
69#include <linux/kallsyms.h>
70#include <linux/stacktrace.h>
71#include <linux/resource.h>
72#include <linux/module.h>
73#include <linux/mount.h>
74#include <linux/security.h>
75#include <linux/ptrace.h>
76#include <linux/tracehook.h>
77#include <linux/printk.h>
78#include <linux/cache.h>
79#include <linux/cgroup.h>
80#include <linux/cpuset.h>
81#include <linux/audit.h>
82#include <linux/poll.h>
83#include <linux/nsproxy.h>
84#include <linux/oom.h>
85#include <linux/elf.h>
86#include <linux/pid_namespace.h>
87#include <linux/user_namespace.h>
88#include <linux/fs_struct.h>
89#include <linux/slab.h>
90#include <linux/sched/autogroup.h>
91#include <linux/sched/mm.h>
92#include <linux/sched/coredump.h>
93#include <linux/sched/debug.h>
94#include <linux/sched/stat.h>
95#include <linux/flex_array.h>
96#include <linux/posix-timers.h>
97#include <trace/events/oom.h>
98#include "internal.h"
99#include "fd.h"
100
101#include "../../lib/kstrtox.h"
102
103/* NOTE:
104 * Implementing inode permission operations in /proc is almost
105 * certainly an error. Permission checks need to happen during
106 * each system call not at open time. The reason is that most of
107 * what we wish to check for permissions in /proc varies at runtime.
108 *
109 * The classic example of a problem is opening file descriptors
110 * in /proc for a task before it execs a suid executable.
111 */
112
113static u8 nlink_tid __ro_after_init;
114static u8 nlink_tgid __ro_after_init;
115
116struct pid_entry {
117 const char *name;
118 unsigned int len;
119 umode_t mode;
120 const struct inode_operations *iop;
121 const struct file_operations *fop;
122 union proc_op op;
123};
124
125#define NOD(NAME, MODE, IOP, FOP, OP) { \
126 .name = (NAME), \
127 .len = sizeof(NAME) - 1, \
128 .mode = MODE, \
129 .iop = IOP, \
130 .fop = FOP, \
131 .op = OP, \
132}
133
134#define DIR(NAME, MODE, iops, fops) \
135 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
136#define LNK(NAME, get_link) \
137 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
138 &proc_pid_link_inode_operations, NULL, \
139 { .proc_get_link = get_link } )
140#define REG(NAME, MODE, fops) \
141 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
142#define ONE(NAME, MODE, show) \
143 NOD(NAME, (S_IFREG|(MODE)), \
144 NULL, &proc_single_file_operations, \
145 { .proc_show = show } )
146
147/*
148 * Count the number of hardlinks for the pid_entry table, excluding the .
149 * and .. links.
150 */
151static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
152 unsigned int n)
153{
154 unsigned int i;
155 unsigned int count;
156
157 count = 2;
158 for (i = 0; i < n; ++i) {
159 if (S_ISDIR(entries[i].mode))
160 ++count;
161 }
162
163 return count;
164}
165
166static int get_task_root(struct task_struct *task, struct path *root)
167{
168 int result = -ENOENT;
169
170 task_lock(task);
171 if (task->fs) {
172 get_fs_root(task->fs, root);
173 result = 0;
174 }
175 task_unlock(task);
176 return result;
177}
178
179static int proc_cwd_link(struct dentry *dentry, struct path *path)
180{
181 struct task_struct *task = get_proc_task(d_inode(dentry));
182 int result = -ENOENT;
183
184 if (task) {
185 task_lock(task);
186 if (task->fs) {
187 get_fs_pwd(task->fs, path);
188 result = 0;
189 }
190 task_unlock(task);
191 put_task_struct(task);
192 }
193 return result;
194}
195
196static int proc_root_link(struct dentry *dentry, struct path *path)
197{
198 struct task_struct *task = get_proc_task(d_inode(dentry));
199 int result = -ENOENT;
200
201 if (task) {
202 result = get_task_root(task, path);
203 put_task_struct(task);
204 }
205 return result;
206}
207
208static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
209 size_t _count, loff_t *pos)
210{
211 struct task_struct *tsk;
212 struct mm_struct *mm;
213 char *page;
214 unsigned long count = _count;
215 unsigned long arg_start, arg_end, env_start, env_end;
216 unsigned long len1, len2, len;
217 unsigned long p;
218 char c;
219 ssize_t rv;
220
221 BUG_ON(*pos < 0);
222
223 tsk = get_proc_task(file_inode(file));
224 if (!tsk)
225 return -ESRCH;
226 mm = get_task_mm(tsk);
227 put_task_struct(tsk);
228 if (!mm)
229 return 0;
230 /* Check if process spawned far enough to have cmdline. */
231 if (!mm->env_end) {
232 rv = 0;
233 goto out_mmput;
234 }
235
236 page = (char *)__get_free_page(GFP_KERNEL);
237 if (!page) {
238 rv = -ENOMEM;
239 goto out_mmput;
240 }
241
242 down_read(&mm->mmap_sem);
243 arg_start = mm->arg_start;
244 arg_end = mm->arg_end;
245 env_start = mm->env_start;
246 env_end = mm->env_end;
247 up_read(&mm->mmap_sem);
248
249 BUG_ON(arg_start > arg_end);
250 BUG_ON(env_start > env_end);
251
252 len1 = arg_end - arg_start;
253 len2 = env_end - env_start;
254
255 /* Empty ARGV. */
256 if (len1 == 0) {
257 rv = 0;
258 goto out_free_page;
259 }
260 /*
261 * Inherently racy -- command line shares address space
262 * with code and data.
263 */
264 rv = access_remote_vm(mm, arg_end - 1, &c, 1, FOLL_ANON);
265 if (rv <= 0)
266 goto out_free_page;
267
268 rv = 0;
269
270 if (c == '\0') {
271 /* Command line (set of strings) occupies whole ARGV. */
272 if (len1 <= *pos)
273 goto out_free_page;
274
275 p = arg_start + *pos;
276 len = len1 - *pos;
277 while (count > 0 && len > 0) {
278 unsigned int _count;
279 int nr_read;
280
281 _count = min3(count, len, PAGE_SIZE);
282 nr_read = access_remote_vm(mm, p, page, _count, FOLL_ANON);
283 if (nr_read < 0)
284 rv = nr_read;
285 if (nr_read <= 0)
286 goto out_free_page;
287
288 if (copy_to_user(buf, page, nr_read)) {
289 rv = -EFAULT;
290 goto out_free_page;
291 }
292
293 p += nr_read;
294 len -= nr_read;
295 buf += nr_read;
296 count -= nr_read;
297 rv += nr_read;
298 }
299 } else {
300 /*
301 * Command line (1 string) occupies ARGV and
302 * extends into ENVP.
303 */
304 struct {
305 unsigned long p;
306 unsigned long len;
307 } cmdline[2] = {
308 { .p = arg_start, .len = len1 },
309 { .p = env_start, .len = len2 },
310 };
311 loff_t pos1 = *pos;
312 unsigned int i;
313
314 i = 0;
315 while (i < 2 && pos1 >= cmdline[i].len) {
316 pos1 -= cmdline[i].len;
317 i++;
318 }
319 while (i < 2) {
320 p = cmdline[i].p + pos1;
321 len = cmdline[i].len - pos1;
322 while (count > 0 && len > 0) {
323 unsigned int _count, l;
324 int nr_read;
325 bool final;
326
327 _count = min3(count, len, PAGE_SIZE);
328 nr_read = access_remote_vm(mm, p, page, _count, FOLL_ANON);
329 if (nr_read < 0)
330 rv = nr_read;
331 if (nr_read <= 0)
332 goto out_free_page;
333
334 /*
335 * Command line can be shorter than whole ARGV
336 * even if last "marker" byte says it is not.
337 */
338 final = false;
339 l = strnlen(page, nr_read);
340 if (l < nr_read) {
341 nr_read = l;
342 final = true;
343 }
344
345 if (copy_to_user(buf, page, nr_read)) {
346 rv = -EFAULT;
347 goto out_free_page;
348 }
349
350 p += nr_read;
351 len -= nr_read;
352 buf += nr_read;
353 count -= nr_read;
354 rv += nr_read;
355
356 if (final)
357 goto out_free_page;
358 }
359
360 /* Only first chunk can be read partially. */
361 pos1 = 0;
362 i++;
363 }
364 }
365
366out_free_page:
367 free_page((unsigned long)page);
368out_mmput:
369 mmput(mm);
370 if (rv > 0)
371 *pos += rv;
372 return rv;
373}
374
375static const struct file_operations proc_pid_cmdline_ops = {
376 .read = proc_pid_cmdline_read,
377 .llseek = generic_file_llseek,
378};
379
380#ifdef CONFIG_KALLSYMS
381/*
382 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
383 * Returns the resolved symbol. If that fails, simply return the address.
384 */
385static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
386 struct pid *pid, struct task_struct *task)
387{
388 unsigned long wchan;
389 char symname[KSYM_NAME_LEN];
390
391 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
392 goto print0;
393
394 wchan = get_wchan(task);
395 if (wchan && !lookup_symbol_name(wchan, symname)) {
396 seq_puts(m, symname);
397 return 0;
398 }
399
400print0:
401 seq_putc(m, '0');
402 return 0;
403}
404#endif /* CONFIG_KALLSYMS */
405
406static int lock_trace(struct task_struct *task)
407{
408 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
409 if (err)
410 return err;
411 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
412 mutex_unlock(&task->signal->cred_guard_mutex);
413 return -EPERM;
414 }
415 return 0;
416}
417
418static void unlock_trace(struct task_struct *task)
419{
420 mutex_unlock(&task->signal->cred_guard_mutex);
421}
422
423#ifdef CONFIG_STACKTRACE
424
425#define MAX_STACK_TRACE_DEPTH 64
426
427static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
428 struct pid *pid, struct task_struct *task)
429{
430 struct stack_trace trace;
431 unsigned long *entries;
432 int err;
433 int i;
434
435 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
436 if (!entries)
437 return -ENOMEM;
438
439 trace.nr_entries = 0;
440 trace.max_entries = MAX_STACK_TRACE_DEPTH;
441 trace.entries = entries;
442 trace.skip = 0;
443
444 err = lock_trace(task);
445 if (!err) {
446 save_stack_trace_tsk(task, &trace);
447
448 for (i = 0; i < trace.nr_entries; i++) {
449 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
450 }
451 unlock_trace(task);
452 }
453 kfree(entries);
454
455 return err;
456}
457#endif
458
459#ifdef CONFIG_SCHED_INFO
460/*
461 * Provides /proc/PID/schedstat
462 */
463static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
464 struct pid *pid, struct task_struct *task)
465{
466 if (unlikely(!sched_info_on()))
467 seq_printf(m, "0 0 0\n");
468 else
469 seq_printf(m, "%llu %llu %lu\n",
470 (unsigned long long)task->se.sum_exec_runtime,
471 (unsigned long long)task->sched_info.run_delay,
472 task->sched_info.pcount);
473
474 return 0;
475}
476#endif
477
478#ifdef CONFIG_LATENCYTOP
479static int lstats_show_proc(struct seq_file *m, void *v)
480{
481 int i;
482 struct inode *inode = m->private;
483 struct task_struct *task = get_proc_task(inode);
484
485 if (!task)
486 return -ESRCH;
487 seq_puts(m, "Latency Top version : v0.1\n");
488 for (i = 0; i < 32; i++) {
489 struct latency_record *lr = &task->latency_record[i];
490 if (lr->backtrace[0]) {
491 int q;
492 seq_printf(m, "%i %li %li",
493 lr->count, lr->time, lr->max);
494 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
495 unsigned long bt = lr->backtrace[q];
496 if (!bt)
497 break;
498 if (bt == ULONG_MAX)
499 break;
500 seq_printf(m, " %ps", (void *)bt);
501 }
502 seq_putc(m, '\n');
503 }
504
505 }
506 put_task_struct(task);
507 return 0;
508}
509
510static int lstats_open(struct inode *inode, struct file *file)
511{
512 return single_open(file, lstats_show_proc, inode);
513}
514
515static ssize_t lstats_write(struct file *file, const char __user *buf,
516 size_t count, loff_t *offs)
517{
518 struct task_struct *task = get_proc_task(file_inode(file));
519
520 if (!task)
521 return -ESRCH;
522 clear_all_latency_tracing(task);
523 put_task_struct(task);
524
525 return count;
526}
527
528static const struct file_operations proc_lstats_operations = {
529 .open = lstats_open,
530 .read = seq_read,
531 .write = lstats_write,
532 .llseek = seq_lseek,
533 .release = single_release,
534};
535
536#endif
537
538static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
539 struct pid *pid, struct task_struct *task)
540{
541 unsigned long totalpages = totalram_pages + total_swap_pages;
542 unsigned long points = 0;
543
544 points = oom_badness(task, NULL, NULL, totalpages) *
545 1000 / totalpages;
546 seq_printf(m, "%lu\n", points);
547
548 return 0;
549}
550
551struct limit_names {
552 const char *name;
553 const char *unit;
554};
555
556static const struct limit_names lnames[RLIM_NLIMITS] = {
557 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
558 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
559 [RLIMIT_DATA] = {"Max data size", "bytes"},
560 [RLIMIT_STACK] = {"Max stack size", "bytes"},
561 [RLIMIT_CORE] = {"Max core file size", "bytes"},
562 [RLIMIT_RSS] = {"Max resident set", "bytes"},
563 [RLIMIT_NPROC] = {"Max processes", "processes"},
564 [RLIMIT_NOFILE] = {"Max open files", "files"},
565 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
566 [RLIMIT_AS] = {"Max address space", "bytes"},
567 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
568 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
569 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
570 [RLIMIT_NICE] = {"Max nice priority", NULL},
571 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
572 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
573};
574
575/* Display limits for a process */
576static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
577 struct pid *pid, struct task_struct *task)
578{
579 unsigned int i;
580 unsigned long flags;
581
582 struct rlimit rlim[RLIM_NLIMITS];
583
584 if (!lock_task_sighand(task, &flags))
585 return 0;
586 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
587 unlock_task_sighand(task, &flags);
588
589 /*
590 * print the file header
591 */
592 seq_printf(m, "%-25s %-20s %-20s %-10s\n",
593 "Limit", "Soft Limit", "Hard Limit", "Units");
594
595 for (i = 0; i < RLIM_NLIMITS; i++) {
596 if (rlim[i].rlim_cur == RLIM_INFINITY)
597 seq_printf(m, "%-25s %-20s ",
598 lnames[i].name, "unlimited");
599 else
600 seq_printf(m, "%-25s %-20lu ",
601 lnames[i].name, rlim[i].rlim_cur);
602
603 if (rlim[i].rlim_max == RLIM_INFINITY)
604 seq_printf(m, "%-20s ", "unlimited");
605 else
606 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
607
608 if (lnames[i].unit)
609 seq_printf(m, "%-10s\n", lnames[i].unit);
610 else
611 seq_putc(m, '\n');
612 }
613
614 return 0;
615}
616
617#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
618static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
619 struct pid *pid, struct task_struct *task)
620{
621 long nr;
622 unsigned long args[6], sp, pc;
623 int res;
624
625 res = lock_trace(task);
626 if (res)
627 return res;
628
629 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
630 seq_puts(m, "running\n");
631 else if (nr < 0)
632 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
633 else
634 seq_printf(m,
635 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
636 nr,
637 args[0], args[1], args[2], args[3], args[4], args[5],
638 sp, pc);
639 unlock_trace(task);
640
641 return 0;
642}
643#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
644
645/************************************************************************/
646/* Here the fs part begins */
647/************************************************************************/
648
649/* permission checks */
650static int proc_fd_access_allowed(struct inode *inode)
651{
652 struct task_struct *task;
653 int allowed = 0;
654 /* Allow access to a task's file descriptors if it is us or we
655 * may use ptrace attach to the process and find out that
656 * information.
657 */
658 task = get_proc_task(inode);
659 if (task) {
660 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
661 put_task_struct(task);
662 }
663 return allowed;
664}
665
666int proc_setattr(struct dentry *dentry, struct iattr *attr)
667{
668 int error;
669 struct inode *inode = d_inode(dentry);
670
671 if (attr->ia_valid & ATTR_MODE)
672 return -EPERM;
673
674 error = setattr_prepare(dentry, attr);
675 if (error)
676 return error;
677
678 setattr_copy(inode, attr);
679 mark_inode_dirty(inode);
680 return 0;
681}
682
683/*
684 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
685 * or euid/egid (for hide_pid_min=2)?
686 */
687static bool has_pid_permissions(struct pid_namespace *pid,
688 struct task_struct *task,
689 int hide_pid_min)
690{
691 if (pid->hide_pid < hide_pid_min)
692 return true;
693 if (in_group_p(pid->pid_gid))
694 return true;
695 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
696}
697
698
699static int proc_pid_permission(struct inode *inode, int mask)
700{
701 struct pid_namespace *pid = inode->i_sb->s_fs_info;
702 struct task_struct *task;
703 bool has_perms;
704
705 task = get_proc_task(inode);
706 if (!task)
707 return -ESRCH;
708 has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS);
709 put_task_struct(task);
710
711 if (!has_perms) {
712 if (pid->hide_pid == HIDEPID_INVISIBLE) {
713 /*
714 * Let's make getdents(), stat(), and open()
715 * consistent with each other. If a process
716 * may not stat() a file, it shouldn't be seen
717 * in procfs at all.
718 */
719 return -ENOENT;
720 }
721
722 return -EPERM;
723 }
724 return generic_permission(inode, mask);
725}
726
727
728
729static const struct inode_operations proc_def_inode_operations = {
730 .setattr = proc_setattr,
731};
732
733static int proc_single_show(struct seq_file *m, void *v)
734{
735 struct inode *inode = m->private;
736 struct pid_namespace *ns;
737 struct pid *pid;
738 struct task_struct *task;
739 int ret;
740
741 ns = inode->i_sb->s_fs_info;
742 pid = proc_pid(inode);
743 task = get_pid_task(pid, PIDTYPE_PID);
744 if (!task)
745 return -ESRCH;
746
747 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
748
749 put_task_struct(task);
750 return ret;
751}
752
753static int proc_single_open(struct inode *inode, struct file *filp)
754{
755 return single_open(filp, proc_single_show, inode);
756}
757
758static const struct file_operations proc_single_file_operations = {
759 .open = proc_single_open,
760 .read = seq_read,
761 .llseek = seq_lseek,
762 .release = single_release,
763};
764
765
766struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
767{
768 struct task_struct *task = get_proc_task(inode);
769 struct mm_struct *mm = ERR_PTR(-ESRCH);
770
771 if (task) {
772 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
773 put_task_struct(task);
774
775 if (!IS_ERR_OR_NULL(mm)) {
776 /* ensure this mm_struct can't be freed */
777 mmgrab(mm);
778 /* but do not pin its memory */
779 mmput(mm);
780 }
781 }
782
783 return mm;
784}
785
786static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
787{
788 struct mm_struct *mm = proc_mem_open(inode, mode);
789
790 if (IS_ERR(mm))
791 return PTR_ERR(mm);
792
793 file->private_data = mm;
794 return 0;
795}
796
797static int mem_open(struct inode *inode, struct file *file)
798{
799 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
800
801 /* OK to pass negative loff_t, we can catch out-of-range */
802 file->f_mode |= FMODE_UNSIGNED_OFFSET;
803
804 return ret;
805}
806
807static ssize_t mem_rw(struct file *file, char __user *buf,
808 size_t count, loff_t *ppos, int write)
809{
810 struct mm_struct *mm = file->private_data;
811 unsigned long addr = *ppos;
812 ssize_t copied;
813 char *page;
814 unsigned int flags;
815
816 if (!mm)
817 return 0;
818
819 page = (char *)__get_free_page(GFP_KERNEL);
820 if (!page)
821 return -ENOMEM;
822
823 copied = 0;
824 if (!mmget_not_zero(mm))
825 goto free;
826
827 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
828
829 while (count > 0) {
830 int this_len = min_t(int, count, PAGE_SIZE);
831
832 if (write && copy_from_user(page, buf, this_len)) {
833 copied = -EFAULT;
834 break;
835 }
836
837 this_len = access_remote_vm(mm, addr, page, this_len, flags);
838 if (!this_len) {
839 if (!copied)
840 copied = -EIO;
841 break;
842 }
843
844 if (!write && copy_to_user(buf, page, this_len)) {
845 copied = -EFAULT;
846 break;
847 }
848
849 buf += this_len;
850 addr += this_len;
851 copied += this_len;
852 count -= this_len;
853 }
854 *ppos = addr;
855
856 mmput(mm);
857free:
858 free_page((unsigned long) page);
859 return copied;
860}
861
862static ssize_t mem_read(struct file *file, char __user *buf,
863 size_t count, loff_t *ppos)
864{
865 return mem_rw(file, buf, count, ppos, 0);
866}
867
868static ssize_t mem_write(struct file *file, const char __user *buf,
869 size_t count, loff_t *ppos)
870{
871 return mem_rw(file, (char __user*)buf, count, ppos, 1);
872}
873
874loff_t mem_lseek(struct file *file, loff_t offset, int orig)
875{
876 switch (orig) {
877 case 0:
878 file->f_pos = offset;
879 break;
880 case 1:
881 file->f_pos += offset;
882 break;
883 default:
884 return -EINVAL;
885 }
886 force_successful_syscall_return();
887 return file->f_pos;
888}
889
890static int mem_release(struct inode *inode, struct file *file)
891{
892 struct mm_struct *mm = file->private_data;
893 if (mm)
894 mmdrop(mm);
895 return 0;
896}
897
898static const struct file_operations proc_mem_operations = {
899 .llseek = mem_lseek,
900 .read = mem_read,
901 .write = mem_write,
902 .open = mem_open,
903 .release = mem_release,
904};
905
906static int environ_open(struct inode *inode, struct file *file)
907{
908 return __mem_open(inode, file, PTRACE_MODE_READ);
909}
910
911static ssize_t environ_read(struct file *file, char __user *buf,
912 size_t count, loff_t *ppos)
913{
914 char *page;
915 unsigned long src = *ppos;
916 int ret = 0;
917 struct mm_struct *mm = file->private_data;
918 unsigned long env_start, env_end;
919
920 /* Ensure the process spawned far enough to have an environment. */
921 if (!mm || !mm->env_end)
922 return 0;
923
924 page = (char *)__get_free_page(GFP_KERNEL);
925 if (!page)
926 return -ENOMEM;
927
928 ret = 0;
929 if (!mmget_not_zero(mm))
930 goto free;
931
932 down_read(&mm->mmap_sem);
933 env_start = mm->env_start;
934 env_end = mm->env_end;
935 up_read(&mm->mmap_sem);
936
937 while (count > 0) {
938 size_t this_len, max_len;
939 int retval;
940
941 if (src >= (env_end - env_start))
942 break;
943
944 this_len = env_end - (env_start + src);
945
946 max_len = min_t(size_t, PAGE_SIZE, count);
947 this_len = min(max_len, this_len);
948
949 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
950
951 if (retval <= 0) {
952 ret = retval;
953 break;
954 }
955
956 if (copy_to_user(buf, page, retval)) {
957 ret = -EFAULT;
958 break;
959 }
960
961 ret += retval;
962 src += retval;
963 buf += retval;
964 count -= retval;
965 }
966 *ppos = src;
967 mmput(mm);
968
969free:
970 free_page((unsigned long) page);
971 return ret;
972}
973
974static const struct file_operations proc_environ_operations = {
975 .open = environ_open,
976 .read = environ_read,
977 .llseek = generic_file_llseek,
978 .release = mem_release,
979};
980
981static int auxv_open(struct inode *inode, struct file *file)
982{
983 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
984}
985
986static ssize_t auxv_read(struct file *file, char __user *buf,
987 size_t count, loff_t *ppos)
988{
989 struct mm_struct *mm = file->private_data;
990 unsigned int nwords = 0;
991
992 if (!mm)
993 return 0;
994 do {
995 nwords += 2;
996 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
997 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
998 nwords * sizeof(mm->saved_auxv[0]));
999}
1000
1001static const struct file_operations proc_auxv_operations = {
1002 .open = auxv_open,
1003 .read = auxv_read,
1004 .llseek = generic_file_llseek,
1005 .release = mem_release,
1006};
1007
1008static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1009 loff_t *ppos)
1010{
1011 struct task_struct *task = get_proc_task(file_inode(file));
1012 char buffer[PROC_NUMBUF];
1013 int oom_adj = OOM_ADJUST_MIN;
1014 size_t len;
1015
1016 if (!task)
1017 return -ESRCH;
1018 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1019 oom_adj = OOM_ADJUST_MAX;
1020 else
1021 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1022 OOM_SCORE_ADJ_MAX;
1023 put_task_struct(task);
1024 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1025 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1026}
1027
1028static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1029{
1030 static DEFINE_MUTEX(oom_adj_mutex);
1031 struct mm_struct *mm = NULL;
1032 struct task_struct *task;
1033 int err = 0;
1034
1035 task = get_proc_task(file_inode(file));
1036 if (!task)
1037 return -ESRCH;
1038
1039 mutex_lock(&oom_adj_mutex);
1040 if (legacy) {
1041 if (oom_adj < task->signal->oom_score_adj &&
1042 !capable(CAP_SYS_RESOURCE)) {
1043 err = -EACCES;
1044 goto err_unlock;
1045 }
1046 /*
1047 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1048 * /proc/pid/oom_score_adj instead.
1049 */
1050 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1051 current->comm, task_pid_nr(current), task_pid_nr(task),
1052 task_pid_nr(task));
1053 } else {
1054 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1055 !capable(CAP_SYS_RESOURCE)) {
1056 err = -EACCES;
1057 goto err_unlock;
1058 }
1059 }
1060
1061 /*
1062 * Make sure we will check other processes sharing the mm if this is
1063 * not vfrok which wants its own oom_score_adj.
1064 * pin the mm so it doesn't go away and get reused after task_unlock
1065 */
1066 if (!task->vfork_done) {
1067 struct task_struct *p = find_lock_task_mm(task);
1068
1069 if (p) {
1070 if (atomic_read(&p->mm->mm_users) > 1) {
1071 mm = p->mm;
1072 mmgrab(mm);
1073 }
1074 task_unlock(p);
1075 }
1076 }
1077
1078 task->signal->oom_score_adj = oom_adj;
1079 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1080 task->signal->oom_score_adj_min = (short)oom_adj;
1081 trace_oom_score_adj_update(task);
1082
1083 if (mm) {
1084 struct task_struct *p;
1085
1086 rcu_read_lock();
1087 for_each_process(p) {
1088 if (same_thread_group(task, p))
1089 continue;
1090
1091 /* do not touch kernel threads or the global init */
1092 if (p->flags & PF_KTHREAD || is_global_init(p))
1093 continue;
1094
1095 task_lock(p);
1096 if (!p->vfork_done && process_shares_mm(p, mm)) {
1097 pr_info("updating oom_score_adj for %d (%s) from %d to %d because it shares mm with %d (%s). Report if this is unexpected.\n",
1098 task_pid_nr(p), p->comm,
1099 p->signal->oom_score_adj, oom_adj,
1100 task_pid_nr(task), task->comm);
1101 p->signal->oom_score_adj = oom_adj;
1102 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1103 p->signal->oom_score_adj_min = (short)oom_adj;
1104 }
1105 task_unlock(p);
1106 }
1107 rcu_read_unlock();
1108 mmdrop(mm);
1109 }
1110err_unlock:
1111 mutex_unlock(&oom_adj_mutex);
1112 put_task_struct(task);
1113 return err;
1114}
1115
1116/*
1117 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1118 * kernels. The effective policy is defined by oom_score_adj, which has a
1119 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1120 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1121 * Processes that become oom disabled via oom_adj will still be oom disabled
1122 * with this implementation.
1123 *
1124 * oom_adj cannot be removed since existing userspace binaries use it.
1125 */
1126static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1127 size_t count, loff_t *ppos)
1128{
1129 char buffer[PROC_NUMBUF];
1130 int oom_adj;
1131 int err;
1132
1133 memset(buffer, 0, sizeof(buffer));
1134 if (count > sizeof(buffer) - 1)
1135 count = sizeof(buffer) - 1;
1136 if (copy_from_user(buffer, buf, count)) {
1137 err = -EFAULT;
1138 goto out;
1139 }
1140
1141 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1142 if (err)
1143 goto out;
1144 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1145 oom_adj != OOM_DISABLE) {
1146 err = -EINVAL;
1147 goto out;
1148 }
1149
1150 /*
1151 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1152 * value is always attainable.
1153 */
1154 if (oom_adj == OOM_ADJUST_MAX)
1155 oom_adj = OOM_SCORE_ADJ_MAX;
1156 else
1157 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1158
1159 err = __set_oom_adj(file, oom_adj, true);
1160out:
1161 return err < 0 ? err : count;
1162}
1163
1164static const struct file_operations proc_oom_adj_operations = {
1165 .read = oom_adj_read,
1166 .write = oom_adj_write,
1167 .llseek = generic_file_llseek,
1168};
1169
1170static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1171 size_t count, loff_t *ppos)
1172{
1173 struct task_struct *task = get_proc_task(file_inode(file));
1174 char buffer[PROC_NUMBUF];
1175 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1176 size_t len;
1177
1178 if (!task)
1179 return -ESRCH;
1180 oom_score_adj = task->signal->oom_score_adj;
1181 put_task_struct(task);
1182 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1183 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1184}
1185
1186static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1187 size_t count, loff_t *ppos)
1188{
1189 char buffer[PROC_NUMBUF];
1190 int oom_score_adj;
1191 int err;
1192
1193 memset(buffer, 0, sizeof(buffer));
1194 if (count > sizeof(buffer) - 1)
1195 count = sizeof(buffer) - 1;
1196 if (copy_from_user(buffer, buf, count)) {
1197 err = -EFAULT;
1198 goto out;
1199 }
1200
1201 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1202 if (err)
1203 goto out;
1204 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1205 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1206 err = -EINVAL;
1207 goto out;
1208 }
1209
1210 err = __set_oom_adj(file, oom_score_adj, false);
1211out:
1212 return err < 0 ? err : count;
1213}
1214
1215static const struct file_operations proc_oom_score_adj_operations = {
1216 .read = oom_score_adj_read,
1217 .write = oom_score_adj_write,
1218 .llseek = default_llseek,
1219};
1220
1221#ifdef CONFIG_AUDITSYSCALL
1222#define TMPBUFLEN 11
1223static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1224 size_t count, loff_t *ppos)
1225{
1226 struct inode * inode = file_inode(file);
1227 struct task_struct *task = get_proc_task(inode);
1228 ssize_t length;
1229 char tmpbuf[TMPBUFLEN];
1230
1231 if (!task)
1232 return -ESRCH;
1233 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1234 from_kuid(file->f_cred->user_ns,
1235 audit_get_loginuid(task)));
1236 put_task_struct(task);
1237 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1238}
1239
1240static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1241 size_t count, loff_t *ppos)
1242{
1243 struct inode * inode = file_inode(file);
1244 uid_t loginuid;
1245 kuid_t kloginuid;
1246 int rv;
1247
1248 rcu_read_lock();
1249 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1250 rcu_read_unlock();
1251 return -EPERM;
1252 }
1253 rcu_read_unlock();
1254
1255 if (*ppos != 0) {
1256 /* No partial writes. */
1257 return -EINVAL;
1258 }
1259
1260 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1261 if (rv < 0)
1262 return rv;
1263
1264 /* is userspace tring to explicitly UNSET the loginuid? */
1265 if (loginuid == AUDIT_UID_UNSET) {
1266 kloginuid = INVALID_UID;
1267 } else {
1268 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1269 if (!uid_valid(kloginuid))
1270 return -EINVAL;
1271 }
1272
1273 rv = audit_set_loginuid(kloginuid);
1274 if (rv < 0)
1275 return rv;
1276 return count;
1277}
1278
1279static const struct file_operations proc_loginuid_operations = {
1280 .read = proc_loginuid_read,
1281 .write = proc_loginuid_write,
1282 .llseek = generic_file_llseek,
1283};
1284
1285static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1286 size_t count, loff_t *ppos)
1287{
1288 struct inode * inode = file_inode(file);
1289 struct task_struct *task = get_proc_task(inode);
1290 ssize_t length;
1291 char tmpbuf[TMPBUFLEN];
1292
1293 if (!task)
1294 return -ESRCH;
1295 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1296 audit_get_sessionid(task));
1297 put_task_struct(task);
1298 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1299}
1300
1301static const struct file_operations proc_sessionid_operations = {
1302 .read = proc_sessionid_read,
1303 .llseek = generic_file_llseek,
1304};
1305#endif
1306
1307#ifdef CONFIG_FAULT_INJECTION
1308static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1309 size_t count, loff_t *ppos)
1310{
1311 struct task_struct *task = get_proc_task(file_inode(file));
1312 char buffer[PROC_NUMBUF];
1313 size_t len;
1314 int make_it_fail;
1315
1316 if (!task)
1317 return -ESRCH;
1318 make_it_fail = task->make_it_fail;
1319 put_task_struct(task);
1320
1321 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1322
1323 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1324}
1325
1326static ssize_t proc_fault_inject_write(struct file * file,
1327 const char __user * buf, size_t count, loff_t *ppos)
1328{
1329 struct task_struct *task;
1330 char buffer[PROC_NUMBUF];
1331 int make_it_fail;
1332 int rv;
1333
1334 if (!capable(CAP_SYS_RESOURCE))
1335 return -EPERM;
1336 memset(buffer, 0, sizeof(buffer));
1337 if (count > sizeof(buffer) - 1)
1338 count = sizeof(buffer) - 1;
1339 if (copy_from_user(buffer, buf, count))
1340 return -EFAULT;
1341 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1342 if (rv < 0)
1343 return rv;
1344 if (make_it_fail < 0 || make_it_fail > 1)
1345 return -EINVAL;
1346
1347 task = get_proc_task(file_inode(file));
1348 if (!task)
1349 return -ESRCH;
1350 task->make_it_fail = make_it_fail;
1351 put_task_struct(task);
1352
1353 return count;
1354}
1355
1356static const struct file_operations proc_fault_inject_operations = {
1357 .read = proc_fault_inject_read,
1358 .write = proc_fault_inject_write,
1359 .llseek = generic_file_llseek,
1360};
1361
1362static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1363 size_t count, loff_t *ppos)
1364{
1365 struct task_struct *task;
1366 int err;
1367 unsigned int n;
1368
1369 err = kstrtouint_from_user(buf, count, 0, &n);
1370 if (err)
1371 return err;
1372
1373 task = get_proc_task(file_inode(file));
1374 if (!task)
1375 return -ESRCH;
1376 task->fail_nth = n;
1377 put_task_struct(task);
1378
1379 return count;
1380}
1381
1382static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1383 size_t count, loff_t *ppos)
1384{
1385 struct task_struct *task;
1386 char numbuf[PROC_NUMBUF];
1387 ssize_t len;
1388
1389 task = get_proc_task(file_inode(file));
1390 if (!task)
1391 return -ESRCH;
1392 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1393 len = simple_read_from_buffer(buf, count, ppos, numbuf, len);
1394 put_task_struct(task);
1395
1396 return len;
1397}
1398
1399static const struct file_operations proc_fail_nth_operations = {
1400 .read = proc_fail_nth_read,
1401 .write = proc_fail_nth_write,
1402};
1403#endif
1404
1405
1406#ifdef CONFIG_SCHED_DEBUG
1407/*
1408 * Print out various scheduling related per-task fields:
1409 */
1410static int sched_show(struct seq_file *m, void *v)
1411{
1412 struct inode *inode = m->private;
1413 struct pid_namespace *ns = inode->i_sb->s_fs_info;
1414 struct task_struct *p;
1415
1416 p = get_proc_task(inode);
1417 if (!p)
1418 return -ESRCH;
1419 proc_sched_show_task(p, ns, m);
1420
1421 put_task_struct(p);
1422
1423 return 0;
1424}
1425
1426static ssize_t
1427sched_write(struct file *file, const char __user *buf,
1428 size_t count, loff_t *offset)
1429{
1430 struct inode *inode = file_inode(file);
1431 struct task_struct *p;
1432
1433 p = get_proc_task(inode);
1434 if (!p)
1435 return -ESRCH;
1436 proc_sched_set_task(p);
1437
1438 put_task_struct(p);
1439
1440 return count;
1441}
1442
1443static int sched_open(struct inode *inode, struct file *filp)
1444{
1445 return single_open(filp, sched_show, inode);
1446}
1447
1448static const struct file_operations proc_pid_sched_operations = {
1449 .open = sched_open,
1450 .read = seq_read,
1451 .write = sched_write,
1452 .llseek = seq_lseek,
1453 .release = single_release,
1454};
1455
1456#endif
1457
1458#ifdef CONFIG_SCHED_AUTOGROUP
1459/*
1460 * Print out autogroup related information:
1461 */
1462static int sched_autogroup_show(struct seq_file *m, void *v)
1463{
1464 struct inode *inode = m->private;
1465 struct task_struct *p;
1466
1467 p = get_proc_task(inode);
1468 if (!p)
1469 return -ESRCH;
1470 proc_sched_autogroup_show_task(p, m);
1471
1472 put_task_struct(p);
1473
1474 return 0;
1475}
1476
1477static ssize_t
1478sched_autogroup_write(struct file *file, const char __user *buf,
1479 size_t count, loff_t *offset)
1480{
1481 struct inode *inode = file_inode(file);
1482 struct task_struct *p;
1483 char buffer[PROC_NUMBUF];
1484 int nice;
1485 int err;
1486
1487 memset(buffer, 0, sizeof(buffer));
1488 if (count > sizeof(buffer) - 1)
1489 count = sizeof(buffer) - 1;
1490 if (copy_from_user(buffer, buf, count))
1491 return -EFAULT;
1492
1493 err = kstrtoint(strstrip(buffer), 0, &nice);
1494 if (err < 0)
1495 return err;
1496
1497 p = get_proc_task(inode);
1498 if (!p)
1499 return -ESRCH;
1500
1501 err = proc_sched_autogroup_set_nice(p, nice);
1502 if (err)
1503 count = err;
1504
1505 put_task_struct(p);
1506
1507 return count;
1508}
1509
1510static int sched_autogroup_open(struct inode *inode, struct file *filp)
1511{
1512 int ret;
1513
1514 ret = single_open(filp, sched_autogroup_show, NULL);
1515 if (!ret) {
1516 struct seq_file *m = filp->private_data;
1517
1518 m->private = inode;
1519 }
1520 return ret;
1521}
1522
1523static const struct file_operations proc_pid_sched_autogroup_operations = {
1524 .open = sched_autogroup_open,
1525 .read = seq_read,
1526 .write = sched_autogroup_write,
1527 .llseek = seq_lseek,
1528 .release = single_release,
1529};
1530
1531#endif /* CONFIG_SCHED_AUTOGROUP */
1532
1533static ssize_t comm_write(struct file *file, const char __user *buf,
1534 size_t count, loff_t *offset)
1535{
1536 struct inode *inode = file_inode(file);
1537 struct task_struct *p;
1538 char buffer[TASK_COMM_LEN];
1539 const size_t maxlen = sizeof(buffer) - 1;
1540
1541 memset(buffer, 0, sizeof(buffer));
1542 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1543 return -EFAULT;
1544
1545 p = get_proc_task(inode);
1546 if (!p)
1547 return -ESRCH;
1548
1549 if (same_thread_group(current, p))
1550 set_task_comm(p, buffer);
1551 else
1552 count = -EINVAL;
1553
1554 put_task_struct(p);
1555
1556 return count;
1557}
1558
1559static int comm_show(struct seq_file *m, void *v)
1560{
1561 struct inode *inode = m->private;
1562 struct task_struct *p;
1563
1564 p = get_proc_task(inode);
1565 if (!p)
1566 return -ESRCH;
1567
1568 task_lock(p);
1569 seq_printf(m, "%s\n", p->comm);
1570 task_unlock(p);
1571
1572 put_task_struct(p);
1573
1574 return 0;
1575}
1576
1577static int comm_open(struct inode *inode, struct file *filp)
1578{
1579 return single_open(filp, comm_show, inode);
1580}
1581
1582static const struct file_operations proc_pid_set_comm_operations = {
1583 .open = comm_open,
1584 .read = seq_read,
1585 .write = comm_write,
1586 .llseek = seq_lseek,
1587 .release = single_release,
1588};
1589
1590static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1591{
1592 struct task_struct *task;
1593 struct file *exe_file;
1594
1595 task = get_proc_task(d_inode(dentry));
1596 if (!task)
1597 return -ENOENT;
1598 exe_file = get_task_exe_file(task);
1599 put_task_struct(task);
1600 if (exe_file) {
1601 *exe_path = exe_file->f_path;
1602 path_get(&exe_file->f_path);
1603 fput(exe_file);
1604 return 0;
1605 } else
1606 return -ENOENT;
1607}
1608
1609static const char *proc_pid_get_link(struct dentry *dentry,
1610 struct inode *inode,
1611 struct delayed_call *done)
1612{
1613 struct path path;
1614 int error = -EACCES;
1615
1616 if (!dentry)
1617 return ERR_PTR(-ECHILD);
1618
1619 /* Are we allowed to snoop on the tasks file descriptors? */
1620 if (!proc_fd_access_allowed(inode))
1621 goto out;
1622
1623 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1624 if (error)
1625 goto out;
1626
1627 nd_jump_link(&path);
1628 return NULL;
1629out:
1630 return ERR_PTR(error);
1631}
1632
1633static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1634{
1635 char *tmp = (char *)__get_free_page(GFP_KERNEL);
1636 char *pathname;
1637 int len;
1638
1639 if (!tmp)
1640 return -ENOMEM;
1641
1642 pathname = d_path(path, tmp, PAGE_SIZE);
1643 len = PTR_ERR(pathname);
1644 if (IS_ERR(pathname))
1645 goto out;
1646 len = tmp + PAGE_SIZE - 1 - pathname;
1647
1648 if (len > buflen)
1649 len = buflen;
1650 if (copy_to_user(buffer, pathname, len))
1651 len = -EFAULT;
1652 out:
1653 free_page((unsigned long)tmp);
1654 return len;
1655}
1656
1657static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1658{
1659 int error = -EACCES;
1660 struct inode *inode = d_inode(dentry);
1661 struct path path;
1662
1663 /* Are we allowed to snoop on the tasks file descriptors? */
1664 if (!proc_fd_access_allowed(inode))
1665 goto out;
1666
1667 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1668 if (error)
1669 goto out;
1670
1671 error = do_proc_readlink(&path, buffer, buflen);
1672 path_put(&path);
1673out:
1674 return error;
1675}
1676
1677const struct inode_operations proc_pid_link_inode_operations = {
1678 .readlink = proc_pid_readlink,
1679 .get_link = proc_pid_get_link,
1680 .setattr = proc_setattr,
1681};
1682
1683
1684/* building an inode */
1685
1686void task_dump_owner(struct task_struct *task, umode_t mode,
1687 kuid_t *ruid, kgid_t *rgid)
1688{
1689 /* Depending on the state of dumpable compute who should own a
1690 * proc file for a task.
1691 */
1692 const struct cred *cred;
1693 kuid_t uid;
1694 kgid_t gid;
1695
1696 if (unlikely(task->flags & PF_KTHREAD)) {
1697 *ruid = GLOBAL_ROOT_UID;
1698 *rgid = GLOBAL_ROOT_GID;
1699 return;
1700 }
1701
1702 /* Default to the tasks effective ownership */
1703 rcu_read_lock();
1704 cred = __task_cred(task);
1705 uid = cred->euid;
1706 gid = cred->egid;
1707 rcu_read_unlock();
1708
1709 /*
1710 * Before the /proc/pid/status file was created the only way to read
1711 * the effective uid of a /process was to stat /proc/pid. Reading
1712 * /proc/pid/status is slow enough that procps and other packages
1713 * kept stating /proc/pid. To keep the rules in /proc simple I have
1714 * made this apply to all per process world readable and executable
1715 * directories.
1716 */
1717 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1718 struct mm_struct *mm;
1719 task_lock(task);
1720 mm = task->mm;
1721 /* Make non-dumpable tasks owned by some root */
1722 if (mm) {
1723 if (get_dumpable(mm) != SUID_DUMP_USER) {
1724 struct user_namespace *user_ns = mm->user_ns;
1725
1726 uid = make_kuid(user_ns, 0);
1727 if (!uid_valid(uid))
1728 uid = GLOBAL_ROOT_UID;
1729
1730 gid = make_kgid(user_ns, 0);
1731 if (!gid_valid(gid))
1732 gid = GLOBAL_ROOT_GID;
1733 }
1734 } else {
1735 uid = GLOBAL_ROOT_UID;
1736 gid = GLOBAL_ROOT_GID;
1737 }
1738 task_unlock(task);
1739 }
1740 *ruid = uid;
1741 *rgid = gid;
1742}
1743
1744struct inode *proc_pid_make_inode(struct super_block * sb,
1745 struct task_struct *task, umode_t mode)
1746{
1747 struct inode * inode;
1748 struct proc_inode *ei;
1749
1750 /* We need a new inode */
1751
1752 inode = new_inode(sb);
1753 if (!inode)
1754 goto out;
1755
1756 /* Common stuff */
1757 ei = PROC_I(inode);
1758 inode->i_mode = mode;
1759 inode->i_ino = get_next_ino();
1760 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1761 inode->i_op = &proc_def_inode_operations;
1762
1763 /*
1764 * grab the reference to task.
1765 */
1766 ei->pid = get_task_pid(task, PIDTYPE_PID);
1767 if (!ei->pid)
1768 goto out_unlock;
1769
1770 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1771 security_task_to_inode(task, inode);
1772
1773out:
1774 return inode;
1775
1776out_unlock:
1777 iput(inode);
1778 return NULL;
1779}
1780
1781int pid_getattr(const struct path *path, struct kstat *stat,
1782 u32 request_mask, unsigned int query_flags)
1783{
1784 struct inode *inode = d_inode(path->dentry);
1785 struct task_struct *task;
1786 struct pid_namespace *pid = path->dentry->d_sb->s_fs_info;
1787
1788 generic_fillattr(inode, stat);
1789
1790 rcu_read_lock();
1791 stat->uid = GLOBAL_ROOT_UID;
1792 stat->gid = GLOBAL_ROOT_GID;
1793 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1794 if (task) {
1795 if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) {
1796 rcu_read_unlock();
1797 /*
1798 * This doesn't prevent learning whether PID exists,
1799 * it only makes getattr() consistent with readdir().
1800 */
1801 return -ENOENT;
1802 }
1803 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1804 }
1805 rcu_read_unlock();
1806 return 0;
1807}
1808
1809/* dentry stuff */
1810
1811/*
1812 * Exceptional case: normally we are not allowed to unhash a busy
1813 * directory. In this case, however, we can do it - no aliasing problems
1814 * due to the way we treat inodes.
1815 *
1816 * Rewrite the inode's ownerships here because the owning task may have
1817 * performed a setuid(), etc.
1818 *
1819 */
1820int pid_revalidate(struct dentry *dentry, unsigned int flags)
1821{
1822 struct inode *inode;
1823 struct task_struct *task;
1824
1825 if (flags & LOOKUP_RCU)
1826 return -ECHILD;
1827
1828 inode = d_inode(dentry);
1829 task = get_proc_task(inode);
1830
1831 if (task) {
1832 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1833
1834 inode->i_mode &= ~(S_ISUID | S_ISGID);
1835 security_task_to_inode(task, inode);
1836 put_task_struct(task);
1837 return 1;
1838 }
1839 return 0;
1840}
1841
1842static inline bool proc_inode_is_dead(struct inode *inode)
1843{
1844 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1845}
1846
1847int pid_delete_dentry(const struct dentry *dentry)
1848{
1849 /* Is the task we represent dead?
1850 * If so, then don't put the dentry on the lru list,
1851 * kill it immediately.
1852 */
1853 return proc_inode_is_dead(d_inode(dentry));
1854}
1855
1856const struct dentry_operations pid_dentry_operations =
1857{
1858 .d_revalidate = pid_revalidate,
1859 .d_delete = pid_delete_dentry,
1860};
1861
1862/* Lookups */
1863
1864/*
1865 * Fill a directory entry.
1866 *
1867 * If possible create the dcache entry and derive our inode number and
1868 * file type from dcache entry.
1869 *
1870 * Since all of the proc inode numbers are dynamically generated, the inode
1871 * numbers do not exist until the inode is cache. This means creating the
1872 * the dcache entry in readdir is necessary to keep the inode numbers
1873 * reported by readdir in sync with the inode numbers reported
1874 * by stat.
1875 */
1876bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1877 const char *name, int len,
1878 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1879{
1880 struct dentry *child, *dir = file->f_path.dentry;
1881 struct qstr qname = QSTR_INIT(name, len);
1882 struct inode *inode;
1883 unsigned type;
1884 ino_t ino;
1885
1886 child = d_hash_and_lookup(dir, &qname);
1887 if (!child) {
1888 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
1889 child = d_alloc_parallel(dir, &qname, &wq);
1890 if (IS_ERR(child))
1891 goto end_instantiate;
1892 if (d_in_lookup(child)) {
1893 int err = instantiate(d_inode(dir), child, task, ptr);
1894 d_lookup_done(child);
1895 if (err < 0) {
1896 dput(child);
1897 goto end_instantiate;
1898 }
1899 }
1900 }
1901 inode = d_inode(child);
1902 ino = inode->i_ino;
1903 type = inode->i_mode >> 12;
1904 dput(child);
1905 return dir_emit(ctx, name, len, ino, type);
1906
1907end_instantiate:
1908 return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1909}
1910
1911/*
1912 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1913 * which represent vma start and end addresses.
1914 */
1915static int dname_to_vma_addr(struct dentry *dentry,
1916 unsigned long *start, unsigned long *end)
1917{
1918 const char *str = dentry->d_name.name;
1919 unsigned long long sval, eval;
1920 unsigned int len;
1921
1922 if (str[0] == '0' && str[1] != '-')
1923 return -EINVAL;
1924 len = _parse_integer(str, 16, &sval);
1925 if (len & KSTRTOX_OVERFLOW)
1926 return -EINVAL;
1927 if (sval != (unsigned long)sval)
1928 return -EINVAL;
1929 str += len;
1930
1931 if (*str != '-')
1932 return -EINVAL;
1933 str++;
1934
1935 if (str[0] == '0' && str[1])
1936 return -EINVAL;
1937 len = _parse_integer(str, 16, &eval);
1938 if (len & KSTRTOX_OVERFLOW)
1939 return -EINVAL;
1940 if (eval != (unsigned long)eval)
1941 return -EINVAL;
1942 str += len;
1943
1944 if (*str != '\0')
1945 return -EINVAL;
1946
1947 *start = sval;
1948 *end = eval;
1949
1950 return 0;
1951}
1952
1953static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1954{
1955 unsigned long vm_start, vm_end;
1956 bool exact_vma_exists = false;
1957 struct mm_struct *mm = NULL;
1958 struct task_struct *task;
1959 struct inode *inode;
1960 int status = 0;
1961
1962 if (flags & LOOKUP_RCU)
1963 return -ECHILD;
1964
1965 inode = d_inode(dentry);
1966 task = get_proc_task(inode);
1967 if (!task)
1968 goto out_notask;
1969
1970 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
1971 if (IS_ERR_OR_NULL(mm))
1972 goto out;
1973
1974 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1975 down_read(&mm->mmap_sem);
1976 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1977 up_read(&mm->mmap_sem);
1978 }
1979
1980 mmput(mm);
1981
1982 if (exact_vma_exists) {
1983 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1984
1985 security_task_to_inode(task, inode);
1986 status = 1;
1987 }
1988
1989out:
1990 put_task_struct(task);
1991
1992out_notask:
1993 return status;
1994}
1995
1996static const struct dentry_operations tid_map_files_dentry_operations = {
1997 .d_revalidate = map_files_d_revalidate,
1998 .d_delete = pid_delete_dentry,
1999};
2000
2001static int map_files_get_link(struct dentry *dentry, struct path *path)
2002{
2003 unsigned long vm_start, vm_end;
2004 struct vm_area_struct *vma;
2005 struct task_struct *task;
2006 struct mm_struct *mm;
2007 int rc;
2008
2009 rc = -ENOENT;
2010 task = get_proc_task(d_inode(dentry));
2011 if (!task)
2012 goto out;
2013
2014 mm = get_task_mm(task);
2015 put_task_struct(task);
2016 if (!mm)
2017 goto out;
2018
2019 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2020 if (rc)
2021 goto out_mmput;
2022
2023 rc = -ENOENT;
2024 down_read(&mm->mmap_sem);
2025 vma = find_exact_vma(mm, vm_start, vm_end);
2026 if (vma && vma->vm_file) {
2027 *path = vma->vm_file->f_path;
2028 path_get(path);
2029 rc = 0;
2030 }
2031 up_read(&mm->mmap_sem);
2032
2033out_mmput:
2034 mmput(mm);
2035out:
2036 return rc;
2037}
2038
2039struct map_files_info {
2040 unsigned long start;
2041 unsigned long end;
2042 fmode_t mode;
2043};
2044
2045/*
2046 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
2047 * symlinks may be used to bypass permissions on ancestor directories in the
2048 * path to the file in question.
2049 */
2050static const char *
2051proc_map_files_get_link(struct dentry *dentry,
2052 struct inode *inode,
2053 struct delayed_call *done)
2054{
2055 if (!capable(CAP_SYS_ADMIN))
2056 return ERR_PTR(-EPERM);
2057
2058 return proc_pid_get_link(dentry, inode, done);
2059}
2060
2061/*
2062 * Identical to proc_pid_link_inode_operations except for get_link()
2063 */
2064static const struct inode_operations proc_map_files_link_inode_operations = {
2065 .readlink = proc_pid_readlink,
2066 .get_link = proc_map_files_get_link,
2067 .setattr = proc_setattr,
2068};
2069
2070static int
2071proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
2072 struct task_struct *task, const void *ptr)
2073{
2074 fmode_t mode = (fmode_t)(unsigned long)ptr;
2075 struct proc_inode *ei;
2076 struct inode *inode;
2077
2078 inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK |
2079 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2080 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2081 if (!inode)
2082 return -ENOENT;
2083
2084 ei = PROC_I(inode);
2085 ei->op.proc_get_link = map_files_get_link;
2086
2087 inode->i_op = &proc_map_files_link_inode_operations;
2088 inode->i_size = 64;
2089
2090 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2091 d_add(dentry, inode);
2092
2093 return 0;
2094}
2095
2096static struct dentry *proc_map_files_lookup(struct inode *dir,
2097 struct dentry *dentry, unsigned int flags)
2098{
2099 unsigned long vm_start, vm_end;
2100 struct vm_area_struct *vma;
2101 struct task_struct *task;
2102 int result;
2103 struct mm_struct *mm;
2104
2105 result = -ENOENT;
2106 task = get_proc_task(dir);
2107 if (!task)
2108 goto out;
2109
2110 result = -EACCES;
2111 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2112 goto out_put_task;
2113
2114 result = -ENOENT;
2115 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2116 goto out_put_task;
2117
2118 mm = get_task_mm(task);
2119 if (!mm)
2120 goto out_put_task;
2121
2122 down_read(&mm->mmap_sem);
2123 vma = find_exact_vma(mm, vm_start, vm_end);
2124 if (!vma)
2125 goto out_no_vma;
2126
2127 if (vma->vm_file)
2128 result = proc_map_files_instantiate(dir, dentry, task,
2129 (void *)(unsigned long)vma->vm_file->f_mode);
2130
2131out_no_vma:
2132 up_read(&mm->mmap_sem);
2133 mmput(mm);
2134out_put_task:
2135 put_task_struct(task);
2136out:
2137 return ERR_PTR(result);
2138}
2139
2140static const struct inode_operations proc_map_files_inode_operations = {
2141 .lookup = proc_map_files_lookup,
2142 .permission = proc_fd_permission,
2143 .setattr = proc_setattr,
2144};
2145
2146static int
2147proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2148{
2149 struct vm_area_struct *vma;
2150 struct task_struct *task;
2151 struct mm_struct *mm;
2152 unsigned long nr_files, pos, i;
2153 struct flex_array *fa = NULL;
2154 struct map_files_info info;
2155 struct map_files_info *p;
2156 int ret;
2157
2158 ret = -ENOENT;
2159 task = get_proc_task(file_inode(file));
2160 if (!task)
2161 goto out;
2162
2163 ret = -EACCES;
2164 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2165 goto out_put_task;
2166
2167 ret = 0;
2168 if (!dir_emit_dots(file, ctx))
2169 goto out_put_task;
2170
2171 mm = get_task_mm(task);
2172 if (!mm)
2173 goto out_put_task;
2174 down_read(&mm->mmap_sem);
2175
2176 nr_files = 0;
2177
2178 /*
2179 * We need two passes here:
2180 *
2181 * 1) Collect vmas of mapped files with mmap_sem taken
2182 * 2) Release mmap_sem and instantiate entries
2183 *
2184 * otherwise we get lockdep complained, since filldir()
2185 * routine might require mmap_sem taken in might_fault().
2186 */
2187
2188 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2189 if (vma->vm_file && ++pos > ctx->pos)
2190 nr_files++;
2191 }
2192
2193 if (nr_files) {
2194 fa = flex_array_alloc(sizeof(info), nr_files,
2195 GFP_KERNEL);
2196 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2197 GFP_KERNEL)) {
2198 ret = -ENOMEM;
2199 if (fa)
2200 flex_array_free(fa);
2201 up_read(&mm->mmap_sem);
2202 mmput(mm);
2203 goto out_put_task;
2204 }
2205 for (i = 0, vma = mm->mmap, pos = 2; vma;
2206 vma = vma->vm_next) {
2207 if (!vma->vm_file)
2208 continue;
2209 if (++pos <= ctx->pos)
2210 continue;
2211
2212 info.start = vma->vm_start;
2213 info.end = vma->vm_end;
2214 info.mode = vma->vm_file->f_mode;
2215 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2216 BUG();
2217 }
2218 }
2219 up_read(&mm->mmap_sem);
2220 mmput(mm);
2221
2222 for (i = 0; i < nr_files; i++) {
2223 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2224 unsigned int len;
2225
2226 p = flex_array_get(fa, i);
2227 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2228 if (!proc_fill_cache(file, ctx,
2229 buf, len,
2230 proc_map_files_instantiate,
2231 task,
2232 (void *)(unsigned long)p->mode))
2233 break;
2234 ctx->pos++;
2235 }
2236 if (fa)
2237 flex_array_free(fa);
2238
2239out_put_task:
2240 put_task_struct(task);
2241out:
2242 return ret;
2243}
2244
2245static const struct file_operations proc_map_files_operations = {
2246 .read = generic_read_dir,
2247 .iterate_shared = proc_map_files_readdir,
2248 .llseek = generic_file_llseek,
2249};
2250
2251#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2252struct timers_private {
2253 struct pid *pid;
2254 struct task_struct *task;
2255 struct sighand_struct *sighand;
2256 struct pid_namespace *ns;
2257 unsigned long flags;
2258};
2259
2260static void *timers_start(struct seq_file *m, loff_t *pos)
2261{
2262 struct timers_private *tp = m->private;
2263
2264 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2265 if (!tp->task)
2266 return ERR_PTR(-ESRCH);
2267
2268 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2269 if (!tp->sighand)
2270 return ERR_PTR(-ESRCH);
2271
2272 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2273}
2274
2275static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2276{
2277 struct timers_private *tp = m->private;
2278 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2279}
2280
2281static void timers_stop(struct seq_file *m, void *v)
2282{
2283 struct timers_private *tp = m->private;
2284
2285 if (tp->sighand) {
2286 unlock_task_sighand(tp->task, &tp->flags);
2287 tp->sighand = NULL;
2288 }
2289
2290 if (tp->task) {
2291 put_task_struct(tp->task);
2292 tp->task = NULL;
2293 }
2294}
2295
2296static int show_timer(struct seq_file *m, void *v)
2297{
2298 struct k_itimer *timer;
2299 struct timers_private *tp = m->private;
2300 int notify;
2301 static const char * const nstr[] = {
2302 [SIGEV_SIGNAL] = "signal",
2303 [SIGEV_NONE] = "none",
2304 [SIGEV_THREAD] = "thread",
2305 };
2306
2307 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2308 notify = timer->it_sigev_notify;
2309
2310 seq_printf(m, "ID: %d\n", timer->it_id);
2311 seq_printf(m, "signal: %d/%px\n",
2312 timer->sigq->info.si_signo,
2313 timer->sigq->info.si_value.sival_ptr);
2314 seq_printf(m, "notify: %s/%s.%d\n",
2315 nstr[notify & ~SIGEV_THREAD_ID],
2316 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2317 pid_nr_ns(timer->it_pid, tp->ns));
2318 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2319
2320 return 0;
2321}
2322
2323static const struct seq_operations proc_timers_seq_ops = {
2324 .start = timers_start,
2325 .next = timers_next,
2326 .stop = timers_stop,
2327 .show = show_timer,
2328};
2329
2330static int proc_timers_open(struct inode *inode, struct file *file)
2331{
2332 struct timers_private *tp;
2333
2334 tp = __seq_open_private(file, &proc_timers_seq_ops,
2335 sizeof(struct timers_private));
2336 if (!tp)
2337 return -ENOMEM;
2338
2339 tp->pid = proc_pid(inode);
2340 tp->ns = inode->i_sb->s_fs_info;
2341 return 0;
2342}
2343
2344static const struct file_operations proc_timers_operations = {
2345 .open = proc_timers_open,
2346 .read = seq_read,
2347 .llseek = seq_lseek,
2348 .release = seq_release_private,
2349};
2350#endif
2351
2352static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2353 size_t count, loff_t *offset)
2354{
2355 struct inode *inode = file_inode(file);
2356 struct task_struct *p;
2357 u64 slack_ns;
2358 int err;
2359
2360 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2361 if (err < 0)
2362 return err;
2363
2364 p = get_proc_task(inode);
2365 if (!p)
2366 return -ESRCH;
2367
2368 if (p != current) {
2369 if (!capable(CAP_SYS_NICE)) {
2370 count = -EPERM;
2371 goto out;
2372 }
2373
2374 err = security_task_setscheduler(p);
2375 if (err) {
2376 count = err;
2377 goto out;
2378 }
2379 }
2380
2381 task_lock(p);
2382 if (slack_ns == 0)
2383 p->timer_slack_ns = p->default_timer_slack_ns;
2384 else
2385 p->timer_slack_ns = slack_ns;
2386 task_unlock(p);
2387
2388out:
2389 put_task_struct(p);
2390
2391 return count;
2392}
2393
2394static int timerslack_ns_show(struct seq_file *m, void *v)
2395{
2396 struct inode *inode = m->private;
2397 struct task_struct *p;
2398 int err = 0;
2399
2400 p = get_proc_task(inode);
2401 if (!p)
2402 return -ESRCH;
2403
2404 if (p != current) {
2405
2406 if (!capable(CAP_SYS_NICE)) {
2407 err = -EPERM;
2408 goto out;
2409 }
2410 err = security_task_getscheduler(p);
2411 if (err)
2412 goto out;
2413 }
2414
2415 task_lock(p);
2416 seq_printf(m, "%llu\n", p->timer_slack_ns);
2417 task_unlock(p);
2418
2419out:
2420 put_task_struct(p);
2421
2422 return err;
2423}
2424
2425static int timerslack_ns_open(struct inode *inode, struct file *filp)
2426{
2427 return single_open(filp, timerslack_ns_show, inode);
2428}
2429
2430static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2431 .open = timerslack_ns_open,
2432 .read = seq_read,
2433 .write = timerslack_ns_write,
2434 .llseek = seq_lseek,
2435 .release = single_release,
2436};
2437
2438static int proc_pident_instantiate(struct inode *dir,
2439 struct dentry *dentry, struct task_struct *task, const void *ptr)
2440{
2441 const struct pid_entry *p = ptr;
2442 struct inode *inode;
2443 struct proc_inode *ei;
2444
2445 inode = proc_pid_make_inode(dir->i_sb, task, p->mode);
2446 if (!inode)
2447 goto out;
2448
2449 ei = PROC_I(inode);
2450 if (S_ISDIR(inode->i_mode))
2451 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2452 if (p->iop)
2453 inode->i_op = p->iop;
2454 if (p->fop)
2455 inode->i_fop = p->fop;
2456 ei->op = p->op;
2457 d_set_d_op(dentry, &pid_dentry_operations);
2458 d_add(dentry, inode);
2459 /* Close the race of the process dying before we return the dentry */
2460 if (pid_revalidate(dentry, 0))
2461 return 0;
2462out:
2463 return -ENOENT;
2464}
2465
2466static struct dentry *proc_pident_lookup(struct inode *dir,
2467 struct dentry *dentry,
2468 const struct pid_entry *ents,
2469 unsigned int nents)
2470{
2471 int error;
2472 struct task_struct *task = get_proc_task(dir);
2473 const struct pid_entry *p, *last;
2474
2475 error = -ENOENT;
2476
2477 if (!task)
2478 goto out_no_task;
2479
2480 /*
2481 * Yes, it does not scale. And it should not. Don't add
2482 * new entries into /proc/<tgid>/ without very good reasons.
2483 */
2484 last = &ents[nents];
2485 for (p = ents; p < last; p++) {
2486 if (p->len != dentry->d_name.len)
2487 continue;
2488 if (!memcmp(dentry->d_name.name, p->name, p->len))
2489 break;
2490 }
2491 if (p >= last)
2492 goto out;
2493
2494 error = proc_pident_instantiate(dir, dentry, task, p);
2495out:
2496 put_task_struct(task);
2497out_no_task:
2498 return ERR_PTR(error);
2499}
2500
2501static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2502 const struct pid_entry *ents, unsigned int nents)
2503{
2504 struct task_struct *task = get_proc_task(file_inode(file));
2505 const struct pid_entry *p;
2506
2507 if (!task)
2508 return -ENOENT;
2509
2510 if (!dir_emit_dots(file, ctx))
2511 goto out;
2512
2513 if (ctx->pos >= nents + 2)
2514 goto out;
2515
2516 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2517 if (!proc_fill_cache(file, ctx, p->name, p->len,
2518 proc_pident_instantiate, task, p))
2519 break;
2520 ctx->pos++;
2521 }
2522out:
2523 put_task_struct(task);
2524 return 0;
2525}
2526
2527#ifdef CONFIG_SECURITY
2528static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2529 size_t count, loff_t *ppos)
2530{
2531 struct inode * inode = file_inode(file);
2532 char *p = NULL;
2533 ssize_t length;
2534 struct task_struct *task = get_proc_task(inode);
2535
2536 if (!task)
2537 return -ESRCH;
2538
2539 length = security_getprocattr(task,
2540 (char*)file->f_path.dentry->d_name.name,
2541 &p);
2542 put_task_struct(task);
2543 if (length > 0)
2544 length = simple_read_from_buffer(buf, count, ppos, p, length);
2545 kfree(p);
2546 return length;
2547}
2548
2549static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2550 size_t count, loff_t *ppos)
2551{
2552 struct inode * inode = file_inode(file);
2553 void *page;
2554 ssize_t length;
2555 struct task_struct *task = get_proc_task(inode);
2556
2557 length = -ESRCH;
2558 if (!task)
2559 goto out_no_task;
2560
2561 /* A task may only write its own attributes. */
2562 length = -EACCES;
2563 if (current != task)
2564 goto out;
2565
2566 if (count > PAGE_SIZE)
2567 count = PAGE_SIZE;
2568
2569 /* No partial writes. */
2570 length = -EINVAL;
2571 if (*ppos != 0)
2572 goto out;
2573
2574 page = memdup_user(buf, count);
2575 if (IS_ERR(page)) {
2576 length = PTR_ERR(page);
2577 goto out;
2578 }
2579
2580 /* Guard against adverse ptrace interaction */
2581 length = mutex_lock_interruptible(¤t->signal->cred_guard_mutex);
2582 if (length < 0)
2583 goto out_free;
2584
2585 length = security_setprocattr(file->f_path.dentry->d_name.name,
2586 page, count);
2587 mutex_unlock(¤t->signal->cred_guard_mutex);
2588out_free:
2589 kfree(page);
2590out:
2591 put_task_struct(task);
2592out_no_task:
2593 return length;
2594}
2595
2596static const struct file_operations proc_pid_attr_operations = {
2597 .read = proc_pid_attr_read,
2598 .write = proc_pid_attr_write,
2599 .llseek = generic_file_llseek,
2600};
2601
2602static const struct pid_entry attr_dir_stuff[] = {
2603 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2604 REG("prev", S_IRUGO, proc_pid_attr_operations),
2605 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2606 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2607 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2608 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2609};
2610
2611static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2612{
2613 return proc_pident_readdir(file, ctx,
2614 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2615}
2616
2617static const struct file_operations proc_attr_dir_operations = {
2618 .read = generic_read_dir,
2619 .iterate_shared = proc_attr_dir_readdir,
2620 .llseek = generic_file_llseek,
2621};
2622
2623static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2624 struct dentry *dentry, unsigned int flags)
2625{
2626 return proc_pident_lookup(dir, dentry,
2627 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2628}
2629
2630static const struct inode_operations proc_attr_dir_inode_operations = {
2631 .lookup = proc_attr_dir_lookup,
2632 .getattr = pid_getattr,
2633 .setattr = proc_setattr,
2634};
2635
2636#endif
2637
2638#ifdef CONFIG_ELF_CORE
2639static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2640 size_t count, loff_t *ppos)
2641{
2642 struct task_struct *task = get_proc_task(file_inode(file));
2643 struct mm_struct *mm;
2644 char buffer[PROC_NUMBUF];
2645 size_t len;
2646 int ret;
2647
2648 if (!task)
2649 return -ESRCH;
2650
2651 ret = 0;
2652 mm = get_task_mm(task);
2653 if (mm) {
2654 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2655 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2656 MMF_DUMP_FILTER_SHIFT));
2657 mmput(mm);
2658 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2659 }
2660
2661 put_task_struct(task);
2662
2663 return ret;
2664}
2665
2666static ssize_t proc_coredump_filter_write(struct file *file,
2667 const char __user *buf,
2668 size_t count,
2669 loff_t *ppos)
2670{
2671 struct task_struct *task;
2672 struct mm_struct *mm;
2673 unsigned int val;
2674 int ret;
2675 int i;
2676 unsigned long mask;
2677
2678 ret = kstrtouint_from_user(buf, count, 0, &val);
2679 if (ret < 0)
2680 return ret;
2681
2682 ret = -ESRCH;
2683 task = get_proc_task(file_inode(file));
2684 if (!task)
2685 goto out_no_task;
2686
2687 mm = get_task_mm(task);
2688 if (!mm)
2689 goto out_no_mm;
2690 ret = 0;
2691
2692 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2693 if (val & mask)
2694 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2695 else
2696 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2697 }
2698
2699 mmput(mm);
2700 out_no_mm:
2701 put_task_struct(task);
2702 out_no_task:
2703 if (ret < 0)
2704 return ret;
2705 return count;
2706}
2707
2708static const struct file_operations proc_coredump_filter_operations = {
2709 .read = proc_coredump_filter_read,
2710 .write = proc_coredump_filter_write,
2711 .llseek = generic_file_llseek,
2712};
2713#endif
2714
2715#ifdef CONFIG_TASK_IO_ACCOUNTING
2716static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2717{
2718 struct task_io_accounting acct = task->ioac;
2719 unsigned long flags;
2720 int result;
2721
2722 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2723 if (result)
2724 return result;
2725
2726 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2727 result = -EACCES;
2728 goto out_unlock;
2729 }
2730
2731 if (whole && lock_task_sighand(task, &flags)) {
2732 struct task_struct *t = task;
2733
2734 task_io_accounting_add(&acct, &task->signal->ioac);
2735 while_each_thread(task, t)
2736 task_io_accounting_add(&acct, &t->ioac);
2737
2738 unlock_task_sighand(task, &flags);
2739 }
2740 seq_printf(m,
2741 "rchar: %llu\n"
2742 "wchar: %llu\n"
2743 "syscr: %llu\n"
2744 "syscw: %llu\n"
2745 "read_bytes: %llu\n"
2746 "write_bytes: %llu\n"
2747 "cancelled_write_bytes: %llu\n",
2748 (unsigned long long)acct.rchar,
2749 (unsigned long long)acct.wchar,
2750 (unsigned long long)acct.syscr,
2751 (unsigned long long)acct.syscw,
2752 (unsigned long long)acct.read_bytes,
2753 (unsigned long long)acct.write_bytes,
2754 (unsigned long long)acct.cancelled_write_bytes);
2755 result = 0;
2756
2757out_unlock:
2758 mutex_unlock(&task->signal->cred_guard_mutex);
2759 return result;
2760}
2761
2762static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2763 struct pid *pid, struct task_struct *task)
2764{
2765 return do_io_accounting(task, m, 0);
2766}
2767
2768static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2769 struct pid *pid, struct task_struct *task)
2770{
2771 return do_io_accounting(task, m, 1);
2772}
2773#endif /* CONFIG_TASK_IO_ACCOUNTING */
2774
2775#ifdef CONFIG_USER_NS
2776static int proc_id_map_open(struct inode *inode, struct file *file,
2777 const struct seq_operations *seq_ops)
2778{
2779 struct user_namespace *ns = NULL;
2780 struct task_struct *task;
2781 struct seq_file *seq;
2782 int ret = -EINVAL;
2783
2784 task = get_proc_task(inode);
2785 if (task) {
2786 rcu_read_lock();
2787 ns = get_user_ns(task_cred_xxx(task, user_ns));
2788 rcu_read_unlock();
2789 put_task_struct(task);
2790 }
2791 if (!ns)
2792 goto err;
2793
2794 ret = seq_open(file, seq_ops);
2795 if (ret)
2796 goto err_put_ns;
2797
2798 seq = file->private_data;
2799 seq->private = ns;
2800
2801 return 0;
2802err_put_ns:
2803 put_user_ns(ns);
2804err:
2805 return ret;
2806}
2807
2808static int proc_id_map_release(struct inode *inode, struct file *file)
2809{
2810 struct seq_file *seq = file->private_data;
2811 struct user_namespace *ns = seq->private;
2812 put_user_ns(ns);
2813 return seq_release(inode, file);
2814}
2815
2816static int proc_uid_map_open(struct inode *inode, struct file *file)
2817{
2818 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2819}
2820
2821static int proc_gid_map_open(struct inode *inode, struct file *file)
2822{
2823 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2824}
2825
2826static int proc_projid_map_open(struct inode *inode, struct file *file)
2827{
2828 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2829}
2830
2831static const struct file_operations proc_uid_map_operations = {
2832 .open = proc_uid_map_open,
2833 .write = proc_uid_map_write,
2834 .read = seq_read,
2835 .llseek = seq_lseek,
2836 .release = proc_id_map_release,
2837};
2838
2839static const struct file_operations proc_gid_map_operations = {
2840 .open = proc_gid_map_open,
2841 .write = proc_gid_map_write,
2842 .read = seq_read,
2843 .llseek = seq_lseek,
2844 .release = proc_id_map_release,
2845};
2846
2847static const struct file_operations proc_projid_map_operations = {
2848 .open = proc_projid_map_open,
2849 .write = proc_projid_map_write,
2850 .read = seq_read,
2851 .llseek = seq_lseek,
2852 .release = proc_id_map_release,
2853};
2854
2855static int proc_setgroups_open(struct inode *inode, struct file *file)
2856{
2857 struct user_namespace *ns = NULL;
2858 struct task_struct *task;
2859 int ret;
2860
2861 ret = -ESRCH;
2862 task = get_proc_task(inode);
2863 if (task) {
2864 rcu_read_lock();
2865 ns = get_user_ns(task_cred_xxx(task, user_ns));
2866 rcu_read_unlock();
2867 put_task_struct(task);
2868 }
2869 if (!ns)
2870 goto err;
2871
2872 if (file->f_mode & FMODE_WRITE) {
2873 ret = -EACCES;
2874 if (!ns_capable(ns, CAP_SYS_ADMIN))
2875 goto err_put_ns;
2876 }
2877
2878 ret = single_open(file, &proc_setgroups_show, ns);
2879 if (ret)
2880 goto err_put_ns;
2881
2882 return 0;
2883err_put_ns:
2884 put_user_ns(ns);
2885err:
2886 return ret;
2887}
2888
2889static int proc_setgroups_release(struct inode *inode, struct file *file)
2890{
2891 struct seq_file *seq = file->private_data;
2892 struct user_namespace *ns = seq->private;
2893 int ret = single_release(inode, file);
2894 put_user_ns(ns);
2895 return ret;
2896}
2897
2898static const struct file_operations proc_setgroups_operations = {
2899 .open = proc_setgroups_open,
2900 .write = proc_setgroups_write,
2901 .read = seq_read,
2902 .llseek = seq_lseek,
2903 .release = proc_setgroups_release,
2904};
2905#endif /* CONFIG_USER_NS */
2906
2907static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2908 struct pid *pid, struct task_struct *task)
2909{
2910 int err = lock_trace(task);
2911 if (!err) {
2912 seq_printf(m, "%08x\n", task->personality);
2913 unlock_trace(task);
2914 }
2915 return err;
2916}
2917
2918#ifdef CONFIG_LIVEPATCH
2919static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
2920 struct pid *pid, struct task_struct *task)
2921{
2922 seq_printf(m, "%d\n", task->patch_state);
2923 return 0;
2924}
2925#endif /* CONFIG_LIVEPATCH */
2926
2927/*
2928 * Thread groups
2929 */
2930static const struct file_operations proc_task_operations;
2931static const struct inode_operations proc_task_inode_operations;
2932
2933static const struct pid_entry tgid_base_stuff[] = {
2934 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2935 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2936 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2937 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2938 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2939#ifdef CONFIG_NET
2940 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2941#endif
2942 REG("environ", S_IRUSR, proc_environ_operations),
2943 REG("auxv", S_IRUSR, proc_auxv_operations),
2944 ONE("status", S_IRUGO, proc_pid_status),
2945 ONE("personality", S_IRUSR, proc_pid_personality),
2946 ONE("limits", S_IRUGO, proc_pid_limits),
2947#ifdef CONFIG_SCHED_DEBUG
2948 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2949#endif
2950#ifdef CONFIG_SCHED_AUTOGROUP
2951 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2952#endif
2953 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2954#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2955 ONE("syscall", S_IRUSR, proc_pid_syscall),
2956#endif
2957 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
2958 ONE("stat", S_IRUGO, proc_tgid_stat),
2959 ONE("statm", S_IRUGO, proc_pid_statm),
2960 REG("maps", S_IRUGO, proc_pid_maps_operations),
2961#ifdef CONFIG_NUMA
2962 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2963#endif
2964 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2965 LNK("cwd", proc_cwd_link),
2966 LNK("root", proc_root_link),
2967 LNK("exe", proc_exe_link),
2968 REG("mounts", S_IRUGO, proc_mounts_operations),
2969 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2970 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2971#ifdef CONFIG_PROC_PAGE_MONITOR
2972 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2973 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2974 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
2975 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2976#endif
2977#ifdef CONFIG_SECURITY
2978 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2979#endif
2980#ifdef CONFIG_KALLSYMS
2981 ONE("wchan", S_IRUGO, proc_pid_wchan),
2982#endif
2983#ifdef CONFIG_STACKTRACE
2984 ONE("stack", S_IRUSR, proc_pid_stack),
2985#endif
2986#ifdef CONFIG_SCHED_INFO
2987 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
2988#endif
2989#ifdef CONFIG_LATENCYTOP
2990 REG("latency", S_IRUGO, proc_lstats_operations),
2991#endif
2992#ifdef CONFIG_PROC_PID_CPUSET
2993 ONE("cpuset", S_IRUGO, proc_cpuset_show),
2994#endif
2995#ifdef CONFIG_CGROUPS
2996 ONE("cgroup", S_IRUGO, proc_cgroup_show),
2997#endif
2998 ONE("oom_score", S_IRUGO, proc_oom_score),
2999 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3000 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3001#ifdef CONFIG_AUDITSYSCALL
3002 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3003 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3004#endif
3005#ifdef CONFIG_FAULT_INJECTION
3006 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3007 REG("fail-nth", 0644, proc_fail_nth_operations),
3008#endif
3009#ifdef CONFIG_ELF_CORE
3010 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3011#endif
3012#ifdef CONFIG_TASK_IO_ACCOUNTING
3013 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3014#endif
3015#ifdef CONFIG_USER_NS
3016 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3017 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3018 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3019 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3020#endif
3021#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3022 REG("timers", S_IRUGO, proc_timers_operations),
3023#endif
3024 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3025#ifdef CONFIG_LIVEPATCH
3026 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3027#endif
3028};
3029
3030static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3031{
3032 return proc_pident_readdir(file, ctx,
3033 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3034}
3035
3036static const struct file_operations proc_tgid_base_operations = {
3037 .read = generic_read_dir,
3038 .iterate_shared = proc_tgid_base_readdir,
3039 .llseek = generic_file_llseek,
3040};
3041
3042static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3043{
3044 return proc_pident_lookup(dir, dentry,
3045 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3046}
3047
3048static const struct inode_operations proc_tgid_base_inode_operations = {
3049 .lookup = proc_tgid_base_lookup,
3050 .getattr = pid_getattr,
3051 .setattr = proc_setattr,
3052 .permission = proc_pid_permission,
3053};
3054
3055static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
3056{
3057 struct dentry *dentry, *leader, *dir;
3058 char buf[10 + 1];
3059 struct qstr name;
3060
3061 name.name = buf;
3062 name.len = snprintf(buf, sizeof(buf), "%u", pid);
3063 /* no ->d_hash() rejects on procfs */
3064 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
3065 if (dentry) {
3066 d_invalidate(dentry);
3067 dput(dentry);
3068 }
3069
3070 if (pid == tgid)
3071 return;
3072
3073 name.name = buf;
3074 name.len = snprintf(buf, sizeof(buf), "%u", tgid);
3075 leader = d_hash_and_lookup(mnt->mnt_root, &name);
3076 if (!leader)
3077 goto out;
3078
3079 name.name = "task";
3080 name.len = strlen(name.name);
3081 dir = d_hash_and_lookup(leader, &name);
3082 if (!dir)
3083 goto out_put_leader;
3084
3085 name.name = buf;
3086 name.len = snprintf(buf, sizeof(buf), "%u", pid);
3087 dentry = d_hash_and_lookup(dir, &name);
3088 if (dentry) {
3089 d_invalidate(dentry);
3090 dput(dentry);
3091 }
3092
3093 dput(dir);
3094out_put_leader:
3095 dput(leader);
3096out:
3097 return;
3098}
3099
3100/**
3101 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3102 * @task: task that should be flushed.
3103 *
3104 * When flushing dentries from proc, one needs to flush them from global
3105 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3106 * in. This call is supposed to do all of this job.
3107 *
3108 * Looks in the dcache for
3109 * /proc/@pid
3110 * /proc/@tgid/task/@pid
3111 * if either directory is present flushes it and all of it'ts children
3112 * from the dcache.
3113 *
3114 * It is safe and reasonable to cache /proc entries for a task until
3115 * that task exits. After that they just clog up the dcache with
3116 * useless entries, possibly causing useful dcache entries to be
3117 * flushed instead. This routine is proved to flush those useless
3118 * dcache entries at process exit time.
3119 *
3120 * NOTE: This routine is just an optimization so it does not guarantee
3121 * that no dcache entries will exist at process exit time it
3122 * just makes it very unlikely that any will persist.
3123 */
3124
3125void proc_flush_task(struct task_struct *task)
3126{
3127 int i;
3128 struct pid *pid, *tgid;
3129 struct upid *upid;
3130
3131 pid = task_pid(task);
3132 tgid = task_tgid(task);
3133
3134 for (i = 0; i <= pid->level; i++) {
3135 upid = &pid->numbers[i];
3136 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3137 tgid->numbers[i].nr);
3138 }
3139}
3140
3141static int proc_pid_instantiate(struct inode *dir,
3142 struct dentry * dentry,
3143 struct task_struct *task, const void *ptr)
3144{
3145 struct inode *inode;
3146
3147 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3148 if (!inode)
3149 goto out;
3150
3151 inode->i_op = &proc_tgid_base_inode_operations;
3152 inode->i_fop = &proc_tgid_base_operations;
3153 inode->i_flags|=S_IMMUTABLE;
3154
3155 set_nlink(inode, nlink_tgid);
3156
3157 d_set_d_op(dentry, &pid_dentry_operations);
3158
3159 d_add(dentry, inode);
3160 /* Close the race of the process dying before we return the dentry */
3161 if (pid_revalidate(dentry, 0))
3162 return 0;
3163out:
3164 return -ENOENT;
3165}
3166
3167struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3168{
3169 int result = -ENOENT;
3170 struct task_struct *task;
3171 unsigned tgid;
3172 struct pid_namespace *ns;
3173
3174 tgid = name_to_int(&dentry->d_name);
3175 if (tgid == ~0U)
3176 goto out;
3177
3178 ns = dentry->d_sb->s_fs_info;
3179 rcu_read_lock();
3180 task = find_task_by_pid_ns(tgid, ns);
3181 if (task)
3182 get_task_struct(task);
3183 rcu_read_unlock();
3184 if (!task)
3185 goto out;
3186
3187 result = proc_pid_instantiate(dir, dentry, task, NULL);
3188 put_task_struct(task);
3189out:
3190 return ERR_PTR(result);
3191}
3192
3193/*
3194 * Find the first task with tgid >= tgid
3195 *
3196 */
3197struct tgid_iter {
3198 unsigned int tgid;
3199 struct task_struct *task;
3200};
3201static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3202{
3203 struct pid *pid;
3204
3205 if (iter.task)
3206 put_task_struct(iter.task);
3207 rcu_read_lock();
3208retry:
3209 iter.task = NULL;
3210 pid = find_ge_pid(iter.tgid, ns);
3211 if (pid) {
3212 iter.tgid = pid_nr_ns(pid, ns);
3213 iter.task = pid_task(pid, PIDTYPE_PID);
3214 /* What we to know is if the pid we have find is the
3215 * pid of a thread_group_leader. Testing for task
3216 * being a thread_group_leader is the obvious thing
3217 * todo but there is a window when it fails, due to
3218 * the pid transfer logic in de_thread.
3219 *
3220 * So we perform the straight forward test of seeing
3221 * if the pid we have found is the pid of a thread
3222 * group leader, and don't worry if the task we have
3223 * found doesn't happen to be a thread group leader.
3224 * As we don't care in the case of readdir.
3225 */
3226 if (!iter.task || !has_group_leader_pid(iter.task)) {
3227 iter.tgid += 1;
3228 goto retry;
3229 }
3230 get_task_struct(iter.task);
3231 }
3232 rcu_read_unlock();
3233 return iter;
3234}
3235
3236#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3237
3238/* for the /proc/ directory itself, after non-process stuff has been done */
3239int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3240{
3241 struct tgid_iter iter;
3242 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
3243 loff_t pos = ctx->pos;
3244
3245 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3246 return 0;
3247
3248 if (pos == TGID_OFFSET - 2) {
3249 struct inode *inode = d_inode(ns->proc_self);
3250 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3251 return 0;
3252 ctx->pos = pos = pos + 1;
3253 }
3254 if (pos == TGID_OFFSET - 1) {
3255 struct inode *inode = d_inode(ns->proc_thread_self);
3256 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3257 return 0;
3258 ctx->pos = pos = pos + 1;
3259 }
3260 iter.tgid = pos - TGID_OFFSET;
3261 iter.task = NULL;
3262 for (iter = next_tgid(ns, iter);
3263 iter.task;
3264 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3265 char name[10 + 1];
3266 int len;
3267
3268 cond_resched();
3269 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE))
3270 continue;
3271
3272 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3273 ctx->pos = iter.tgid + TGID_OFFSET;
3274 if (!proc_fill_cache(file, ctx, name, len,
3275 proc_pid_instantiate, iter.task, NULL)) {
3276 put_task_struct(iter.task);
3277 return 0;
3278 }
3279 }
3280 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3281 return 0;
3282}
3283
3284/*
3285 * proc_tid_comm_permission is a special permission function exclusively
3286 * used for the node /proc/<pid>/task/<tid>/comm.
3287 * It bypasses generic permission checks in the case where a task of the same
3288 * task group attempts to access the node.
3289 * The rationale behind this is that glibc and bionic access this node for
3290 * cross thread naming (pthread_set/getname_np(!self)). However, if
3291 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3292 * which locks out the cross thread naming implementation.
3293 * This function makes sure that the node is always accessible for members of
3294 * same thread group.
3295 */
3296static int proc_tid_comm_permission(struct inode *inode, int mask)
3297{
3298 bool is_same_tgroup;
3299 struct task_struct *task;
3300
3301 task = get_proc_task(inode);
3302 if (!task)
3303 return -ESRCH;
3304 is_same_tgroup = same_thread_group(current, task);
3305 put_task_struct(task);
3306
3307 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3308 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3309 * read or written by the members of the corresponding
3310 * thread group.
3311 */
3312 return 0;
3313 }
3314
3315 return generic_permission(inode, mask);
3316}
3317
3318static const struct inode_operations proc_tid_comm_inode_operations = {
3319 .permission = proc_tid_comm_permission,
3320};
3321
3322/*
3323 * Tasks
3324 */
3325static const struct pid_entry tid_base_stuff[] = {
3326 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3327 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3328 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3329#ifdef CONFIG_NET
3330 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3331#endif
3332 REG("environ", S_IRUSR, proc_environ_operations),
3333 REG("auxv", S_IRUSR, proc_auxv_operations),
3334 ONE("status", S_IRUGO, proc_pid_status),
3335 ONE("personality", S_IRUSR, proc_pid_personality),
3336 ONE("limits", S_IRUGO, proc_pid_limits),
3337#ifdef CONFIG_SCHED_DEBUG
3338 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3339#endif
3340 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3341 &proc_tid_comm_inode_operations,
3342 &proc_pid_set_comm_operations, {}),
3343#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3344 ONE("syscall", S_IRUSR, proc_pid_syscall),
3345#endif
3346 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3347 ONE("stat", S_IRUGO, proc_tid_stat),
3348 ONE("statm", S_IRUGO, proc_pid_statm),
3349 REG("maps", S_IRUGO, proc_tid_maps_operations),
3350#ifdef CONFIG_PROC_CHILDREN
3351 REG("children", S_IRUGO, proc_tid_children_operations),
3352#endif
3353#ifdef CONFIG_NUMA
3354 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3355#endif
3356 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3357 LNK("cwd", proc_cwd_link),
3358 LNK("root", proc_root_link),
3359 LNK("exe", proc_exe_link),
3360 REG("mounts", S_IRUGO, proc_mounts_operations),
3361 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3362#ifdef CONFIG_PROC_PAGE_MONITOR
3363 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3364 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3365 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3366 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3367#endif
3368#ifdef CONFIG_SECURITY
3369 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3370#endif
3371#ifdef CONFIG_KALLSYMS
3372 ONE("wchan", S_IRUGO, proc_pid_wchan),
3373#endif
3374#ifdef CONFIG_STACKTRACE
3375 ONE("stack", S_IRUSR, proc_pid_stack),
3376#endif
3377#ifdef CONFIG_SCHED_INFO
3378 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3379#endif
3380#ifdef CONFIG_LATENCYTOP
3381 REG("latency", S_IRUGO, proc_lstats_operations),
3382#endif
3383#ifdef CONFIG_PROC_PID_CPUSET
3384 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3385#endif
3386#ifdef CONFIG_CGROUPS
3387 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3388#endif
3389 ONE("oom_score", S_IRUGO, proc_oom_score),
3390 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3391 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3392#ifdef CONFIG_AUDITSYSCALL
3393 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3394 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3395#endif
3396#ifdef CONFIG_FAULT_INJECTION
3397 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3398 REG("fail-nth", 0644, proc_fail_nth_operations),
3399#endif
3400#ifdef CONFIG_TASK_IO_ACCOUNTING
3401 ONE("io", S_IRUSR, proc_tid_io_accounting),
3402#endif
3403#ifdef CONFIG_USER_NS
3404 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3405 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3406 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3407 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3408#endif
3409#ifdef CONFIG_LIVEPATCH
3410 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3411#endif
3412};
3413
3414static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3415{
3416 return proc_pident_readdir(file, ctx,
3417 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3418}
3419
3420static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3421{
3422 return proc_pident_lookup(dir, dentry,
3423 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3424}
3425
3426static const struct file_operations proc_tid_base_operations = {
3427 .read = generic_read_dir,
3428 .iterate_shared = proc_tid_base_readdir,
3429 .llseek = generic_file_llseek,
3430};
3431
3432static const struct inode_operations proc_tid_base_inode_operations = {
3433 .lookup = proc_tid_base_lookup,
3434 .getattr = pid_getattr,
3435 .setattr = proc_setattr,
3436};
3437
3438static int proc_task_instantiate(struct inode *dir,
3439 struct dentry *dentry, struct task_struct *task, const void *ptr)
3440{
3441 struct inode *inode;
3442 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3443
3444 if (!inode)
3445 goto out;
3446 inode->i_op = &proc_tid_base_inode_operations;
3447 inode->i_fop = &proc_tid_base_operations;
3448 inode->i_flags|=S_IMMUTABLE;
3449
3450 set_nlink(inode, nlink_tid);
3451
3452 d_set_d_op(dentry, &pid_dentry_operations);
3453
3454 d_add(dentry, inode);
3455 /* Close the race of the process dying before we return the dentry */
3456 if (pid_revalidate(dentry, 0))
3457 return 0;
3458out:
3459 return -ENOENT;
3460}
3461
3462static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3463{
3464 int result = -ENOENT;
3465 struct task_struct *task;
3466 struct task_struct *leader = get_proc_task(dir);
3467 unsigned tid;
3468 struct pid_namespace *ns;
3469
3470 if (!leader)
3471 goto out_no_task;
3472
3473 tid = name_to_int(&dentry->d_name);
3474 if (tid == ~0U)
3475 goto out;
3476
3477 ns = dentry->d_sb->s_fs_info;
3478 rcu_read_lock();
3479 task = find_task_by_pid_ns(tid, ns);
3480 if (task)
3481 get_task_struct(task);
3482 rcu_read_unlock();
3483 if (!task)
3484 goto out;
3485 if (!same_thread_group(leader, task))
3486 goto out_drop_task;
3487
3488 result = proc_task_instantiate(dir, dentry, task, NULL);
3489out_drop_task:
3490 put_task_struct(task);
3491out:
3492 put_task_struct(leader);
3493out_no_task:
3494 return ERR_PTR(result);
3495}
3496
3497/*
3498 * Find the first tid of a thread group to return to user space.
3499 *
3500 * Usually this is just the thread group leader, but if the users
3501 * buffer was too small or there was a seek into the middle of the
3502 * directory we have more work todo.
3503 *
3504 * In the case of a short read we start with find_task_by_pid.
3505 *
3506 * In the case of a seek we start with the leader and walk nr
3507 * threads past it.
3508 */
3509static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3510 struct pid_namespace *ns)
3511{
3512 struct task_struct *pos, *task;
3513 unsigned long nr = f_pos;
3514
3515 if (nr != f_pos) /* 32bit overflow? */
3516 return NULL;
3517
3518 rcu_read_lock();
3519 task = pid_task(pid, PIDTYPE_PID);
3520 if (!task)
3521 goto fail;
3522
3523 /* Attempt to start with the tid of a thread */
3524 if (tid && nr) {
3525 pos = find_task_by_pid_ns(tid, ns);
3526 if (pos && same_thread_group(pos, task))
3527 goto found;
3528 }
3529
3530 /* If nr exceeds the number of threads there is nothing todo */
3531 if (nr >= get_nr_threads(task))
3532 goto fail;
3533
3534 /* If we haven't found our starting place yet start
3535 * with the leader and walk nr threads forward.
3536 */
3537 pos = task = task->group_leader;
3538 do {
3539 if (!nr--)
3540 goto found;
3541 } while_each_thread(task, pos);
3542fail:
3543 pos = NULL;
3544 goto out;
3545found:
3546 get_task_struct(pos);
3547out:
3548 rcu_read_unlock();
3549 return pos;
3550}
3551
3552/*
3553 * Find the next thread in the thread list.
3554 * Return NULL if there is an error or no next thread.
3555 *
3556 * The reference to the input task_struct is released.
3557 */
3558static struct task_struct *next_tid(struct task_struct *start)
3559{
3560 struct task_struct *pos = NULL;
3561 rcu_read_lock();
3562 if (pid_alive(start)) {
3563 pos = next_thread(start);
3564 if (thread_group_leader(pos))
3565 pos = NULL;
3566 else
3567 get_task_struct(pos);
3568 }
3569 rcu_read_unlock();
3570 put_task_struct(start);
3571 return pos;
3572}
3573
3574/* for the /proc/TGID/task/ directories */
3575static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3576{
3577 struct inode *inode = file_inode(file);
3578 struct task_struct *task;
3579 struct pid_namespace *ns;
3580 int tid;
3581
3582 if (proc_inode_is_dead(inode))
3583 return -ENOENT;
3584
3585 if (!dir_emit_dots(file, ctx))
3586 return 0;
3587
3588 /* f_version caches the tgid value that the last readdir call couldn't
3589 * return. lseek aka telldir automagically resets f_version to 0.
3590 */
3591 ns = inode->i_sb->s_fs_info;
3592 tid = (int)file->f_version;
3593 file->f_version = 0;
3594 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3595 task;
3596 task = next_tid(task), ctx->pos++) {
3597 char name[10 + 1];
3598 int len;
3599 tid = task_pid_nr_ns(task, ns);
3600 len = snprintf(name, sizeof(name), "%u", tid);
3601 if (!proc_fill_cache(file, ctx, name, len,
3602 proc_task_instantiate, task, NULL)) {
3603 /* returning this tgid failed, save it as the first
3604 * pid for the next readir call */
3605 file->f_version = (u64)tid;
3606 put_task_struct(task);
3607 break;
3608 }
3609 }
3610
3611 return 0;
3612}
3613
3614static int proc_task_getattr(const struct path *path, struct kstat *stat,
3615 u32 request_mask, unsigned int query_flags)
3616{
3617 struct inode *inode = d_inode(path->dentry);
3618 struct task_struct *p = get_proc_task(inode);
3619 generic_fillattr(inode, stat);
3620
3621 if (p) {
3622 stat->nlink += get_nr_threads(p);
3623 put_task_struct(p);
3624 }
3625
3626 return 0;
3627}
3628
3629static const struct inode_operations proc_task_inode_operations = {
3630 .lookup = proc_task_lookup,
3631 .getattr = proc_task_getattr,
3632 .setattr = proc_setattr,
3633 .permission = proc_pid_permission,
3634};
3635
3636static const struct file_operations proc_task_operations = {
3637 .read = generic_read_dir,
3638 .iterate_shared = proc_task_readdir,
3639 .llseek = generic_file_llseek,
3640};
3641
3642void __init set_proc_pid_nlink(void)
3643{
3644 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3645 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3646}
1/*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50#include <asm/uaccess.h>
51
52#include <linux/errno.h>
53#include <linux/time.h>
54#include <linux/proc_fs.h>
55#include <linux/stat.h>
56#include <linux/task_io_accounting_ops.h>
57#include <linux/init.h>
58#include <linux/capability.h>
59#include <linux/file.h>
60#include <linux/fdtable.h>
61#include <linux/string.h>
62#include <linux/seq_file.h>
63#include <linux/namei.h>
64#include <linux/mnt_namespace.h>
65#include <linux/mm.h>
66#include <linux/swap.h>
67#include <linux/rcupdate.h>
68#include <linux/kallsyms.h>
69#include <linux/stacktrace.h>
70#include <linux/resource.h>
71#include <linux/module.h>
72#include <linux/mount.h>
73#include <linux/security.h>
74#include <linux/ptrace.h>
75#include <linux/tracehook.h>
76#include <linux/cgroup.h>
77#include <linux/cpuset.h>
78#include <linux/audit.h>
79#include <linux/poll.h>
80#include <linux/nsproxy.h>
81#include <linux/oom.h>
82#include <linux/elf.h>
83#include <linux/pid_namespace.h>
84#include <linux/fs_struct.h>
85#include <linux/slab.h>
86#ifdef CONFIG_HARDWALL
87#include <asm/hardwall.h>
88#endif
89#include "internal.h"
90
91/* NOTE:
92 * Implementing inode permission operations in /proc is almost
93 * certainly an error. Permission checks need to happen during
94 * each system call not at open time. The reason is that most of
95 * what we wish to check for permissions in /proc varies at runtime.
96 *
97 * The classic example of a problem is opening file descriptors
98 * in /proc for a task before it execs a suid executable.
99 */
100
101struct pid_entry {
102 char *name;
103 int len;
104 mode_t mode;
105 const struct inode_operations *iop;
106 const struct file_operations *fop;
107 union proc_op op;
108};
109
110#define NOD(NAME, MODE, IOP, FOP, OP) { \
111 .name = (NAME), \
112 .len = sizeof(NAME) - 1, \
113 .mode = MODE, \
114 .iop = IOP, \
115 .fop = FOP, \
116 .op = OP, \
117}
118
119#define DIR(NAME, MODE, iops, fops) \
120 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
121#define LNK(NAME, get_link) \
122 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
123 &proc_pid_link_inode_operations, NULL, \
124 { .proc_get_link = get_link } )
125#define REG(NAME, MODE, fops) \
126 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
127#define INF(NAME, MODE, read) \
128 NOD(NAME, (S_IFREG|(MODE)), \
129 NULL, &proc_info_file_operations, \
130 { .proc_read = read } )
131#define ONE(NAME, MODE, show) \
132 NOD(NAME, (S_IFREG|(MODE)), \
133 NULL, &proc_single_file_operations, \
134 { .proc_show = show } )
135
136/*
137 * Count the number of hardlinks for the pid_entry table, excluding the .
138 * and .. links.
139 */
140static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
141 unsigned int n)
142{
143 unsigned int i;
144 unsigned int count;
145
146 count = 0;
147 for (i = 0; i < n; ++i) {
148 if (S_ISDIR(entries[i].mode))
149 ++count;
150 }
151
152 return count;
153}
154
155static int get_task_root(struct task_struct *task, struct path *root)
156{
157 int result = -ENOENT;
158
159 task_lock(task);
160 if (task->fs) {
161 get_fs_root(task->fs, root);
162 result = 0;
163 }
164 task_unlock(task);
165 return result;
166}
167
168static int proc_cwd_link(struct inode *inode, struct path *path)
169{
170 struct task_struct *task = get_proc_task(inode);
171 int result = -ENOENT;
172
173 if (task) {
174 task_lock(task);
175 if (task->fs) {
176 get_fs_pwd(task->fs, path);
177 result = 0;
178 }
179 task_unlock(task);
180 put_task_struct(task);
181 }
182 return result;
183}
184
185static int proc_root_link(struct inode *inode, struct path *path)
186{
187 struct task_struct *task = get_proc_task(inode);
188 int result = -ENOENT;
189
190 if (task) {
191 result = get_task_root(task, path);
192 put_task_struct(task);
193 }
194 return result;
195}
196
197static struct mm_struct *__check_mem_permission(struct task_struct *task)
198{
199 struct mm_struct *mm;
200
201 mm = get_task_mm(task);
202 if (!mm)
203 return ERR_PTR(-EINVAL);
204
205 /*
206 * A task can always look at itself, in case it chooses
207 * to use system calls instead of load instructions.
208 */
209 if (task == current)
210 return mm;
211
212 /*
213 * If current is actively ptrace'ing, and would also be
214 * permitted to freshly attach with ptrace now, permit it.
215 */
216 if (task_is_stopped_or_traced(task)) {
217 int match;
218 rcu_read_lock();
219 match = (ptrace_parent(task) == current);
220 rcu_read_unlock();
221 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
222 return mm;
223 }
224
225 /*
226 * No one else is allowed.
227 */
228 mmput(mm);
229 return ERR_PTR(-EPERM);
230}
231
232/*
233 * If current may access user memory in @task return a reference to the
234 * corresponding mm, otherwise ERR_PTR.
235 */
236static struct mm_struct *check_mem_permission(struct task_struct *task)
237{
238 struct mm_struct *mm;
239 int err;
240
241 /*
242 * Avoid racing if task exec's as we might get a new mm but validate
243 * against old credentials.
244 */
245 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
246 if (err)
247 return ERR_PTR(err);
248
249 mm = __check_mem_permission(task);
250 mutex_unlock(&task->signal->cred_guard_mutex);
251
252 return mm;
253}
254
255struct mm_struct *mm_for_maps(struct task_struct *task)
256{
257 struct mm_struct *mm;
258 int err;
259
260 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
261 if (err)
262 return ERR_PTR(err);
263
264 mm = get_task_mm(task);
265 if (mm && mm != current->mm &&
266 !ptrace_may_access(task, PTRACE_MODE_READ)) {
267 mmput(mm);
268 mm = ERR_PTR(-EACCES);
269 }
270 mutex_unlock(&task->signal->cred_guard_mutex);
271
272 return mm;
273}
274
275static int proc_pid_cmdline(struct task_struct *task, char * buffer)
276{
277 int res = 0;
278 unsigned int len;
279 struct mm_struct *mm = get_task_mm(task);
280 if (!mm)
281 goto out;
282 if (!mm->arg_end)
283 goto out_mm; /* Shh! No looking before we're done */
284
285 len = mm->arg_end - mm->arg_start;
286
287 if (len > PAGE_SIZE)
288 len = PAGE_SIZE;
289
290 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
291
292 // If the nul at the end of args has been overwritten, then
293 // assume application is using setproctitle(3).
294 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
295 len = strnlen(buffer, res);
296 if (len < res) {
297 res = len;
298 } else {
299 len = mm->env_end - mm->env_start;
300 if (len > PAGE_SIZE - res)
301 len = PAGE_SIZE - res;
302 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
303 res = strnlen(buffer, res);
304 }
305 }
306out_mm:
307 mmput(mm);
308out:
309 return res;
310}
311
312static int proc_pid_auxv(struct task_struct *task, char *buffer)
313{
314 struct mm_struct *mm = mm_for_maps(task);
315 int res = PTR_ERR(mm);
316 if (mm && !IS_ERR(mm)) {
317 unsigned int nwords = 0;
318 do {
319 nwords += 2;
320 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
321 res = nwords * sizeof(mm->saved_auxv[0]);
322 if (res > PAGE_SIZE)
323 res = PAGE_SIZE;
324 memcpy(buffer, mm->saved_auxv, res);
325 mmput(mm);
326 }
327 return res;
328}
329
330
331#ifdef CONFIG_KALLSYMS
332/*
333 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
334 * Returns the resolved symbol. If that fails, simply return the address.
335 */
336static int proc_pid_wchan(struct task_struct *task, char *buffer)
337{
338 unsigned long wchan;
339 char symname[KSYM_NAME_LEN];
340
341 wchan = get_wchan(task);
342
343 if (lookup_symbol_name(wchan, symname) < 0)
344 if (!ptrace_may_access(task, PTRACE_MODE_READ))
345 return 0;
346 else
347 return sprintf(buffer, "%lu", wchan);
348 else
349 return sprintf(buffer, "%s", symname);
350}
351#endif /* CONFIG_KALLSYMS */
352
353static int lock_trace(struct task_struct *task)
354{
355 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
356 if (err)
357 return err;
358 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
359 mutex_unlock(&task->signal->cred_guard_mutex);
360 return -EPERM;
361 }
362 return 0;
363}
364
365static void unlock_trace(struct task_struct *task)
366{
367 mutex_unlock(&task->signal->cred_guard_mutex);
368}
369
370#ifdef CONFIG_STACKTRACE
371
372#define MAX_STACK_TRACE_DEPTH 64
373
374static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
375 struct pid *pid, struct task_struct *task)
376{
377 struct stack_trace trace;
378 unsigned long *entries;
379 int err;
380 int i;
381
382 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
383 if (!entries)
384 return -ENOMEM;
385
386 trace.nr_entries = 0;
387 trace.max_entries = MAX_STACK_TRACE_DEPTH;
388 trace.entries = entries;
389 trace.skip = 0;
390
391 err = lock_trace(task);
392 if (!err) {
393 save_stack_trace_tsk(task, &trace);
394
395 for (i = 0; i < trace.nr_entries; i++) {
396 seq_printf(m, "[<%pK>] %pS\n",
397 (void *)entries[i], (void *)entries[i]);
398 }
399 unlock_trace(task);
400 }
401 kfree(entries);
402
403 return err;
404}
405#endif
406
407#ifdef CONFIG_SCHEDSTATS
408/*
409 * Provides /proc/PID/schedstat
410 */
411static int proc_pid_schedstat(struct task_struct *task, char *buffer)
412{
413 return sprintf(buffer, "%llu %llu %lu\n",
414 (unsigned long long)task->se.sum_exec_runtime,
415 (unsigned long long)task->sched_info.run_delay,
416 task->sched_info.pcount);
417}
418#endif
419
420#ifdef CONFIG_LATENCYTOP
421static int lstats_show_proc(struct seq_file *m, void *v)
422{
423 int i;
424 struct inode *inode = m->private;
425 struct task_struct *task = get_proc_task(inode);
426
427 if (!task)
428 return -ESRCH;
429 seq_puts(m, "Latency Top version : v0.1\n");
430 for (i = 0; i < 32; i++) {
431 struct latency_record *lr = &task->latency_record[i];
432 if (lr->backtrace[0]) {
433 int q;
434 seq_printf(m, "%i %li %li",
435 lr->count, lr->time, lr->max);
436 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
437 unsigned long bt = lr->backtrace[q];
438 if (!bt)
439 break;
440 if (bt == ULONG_MAX)
441 break;
442 seq_printf(m, " %ps", (void *)bt);
443 }
444 seq_putc(m, '\n');
445 }
446
447 }
448 put_task_struct(task);
449 return 0;
450}
451
452static int lstats_open(struct inode *inode, struct file *file)
453{
454 return single_open(file, lstats_show_proc, inode);
455}
456
457static ssize_t lstats_write(struct file *file, const char __user *buf,
458 size_t count, loff_t *offs)
459{
460 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
461
462 if (!task)
463 return -ESRCH;
464 clear_all_latency_tracing(task);
465 put_task_struct(task);
466
467 return count;
468}
469
470static const struct file_operations proc_lstats_operations = {
471 .open = lstats_open,
472 .read = seq_read,
473 .write = lstats_write,
474 .llseek = seq_lseek,
475 .release = single_release,
476};
477
478#endif
479
480static int proc_oom_score(struct task_struct *task, char *buffer)
481{
482 unsigned long points = 0;
483
484 read_lock(&tasklist_lock);
485 if (pid_alive(task))
486 points = oom_badness(task, NULL, NULL,
487 totalram_pages + total_swap_pages);
488 read_unlock(&tasklist_lock);
489 return sprintf(buffer, "%lu\n", points);
490}
491
492struct limit_names {
493 char *name;
494 char *unit;
495};
496
497static const struct limit_names lnames[RLIM_NLIMITS] = {
498 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
499 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
500 [RLIMIT_DATA] = {"Max data size", "bytes"},
501 [RLIMIT_STACK] = {"Max stack size", "bytes"},
502 [RLIMIT_CORE] = {"Max core file size", "bytes"},
503 [RLIMIT_RSS] = {"Max resident set", "bytes"},
504 [RLIMIT_NPROC] = {"Max processes", "processes"},
505 [RLIMIT_NOFILE] = {"Max open files", "files"},
506 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
507 [RLIMIT_AS] = {"Max address space", "bytes"},
508 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
509 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
510 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
511 [RLIMIT_NICE] = {"Max nice priority", NULL},
512 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
513 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
514};
515
516/* Display limits for a process */
517static int proc_pid_limits(struct task_struct *task, char *buffer)
518{
519 unsigned int i;
520 int count = 0;
521 unsigned long flags;
522 char *bufptr = buffer;
523
524 struct rlimit rlim[RLIM_NLIMITS];
525
526 if (!lock_task_sighand(task, &flags))
527 return 0;
528 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
529 unlock_task_sighand(task, &flags);
530
531 /*
532 * print the file header
533 */
534 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
535 "Limit", "Soft Limit", "Hard Limit", "Units");
536
537 for (i = 0; i < RLIM_NLIMITS; i++) {
538 if (rlim[i].rlim_cur == RLIM_INFINITY)
539 count += sprintf(&bufptr[count], "%-25s %-20s ",
540 lnames[i].name, "unlimited");
541 else
542 count += sprintf(&bufptr[count], "%-25s %-20lu ",
543 lnames[i].name, rlim[i].rlim_cur);
544
545 if (rlim[i].rlim_max == RLIM_INFINITY)
546 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
547 else
548 count += sprintf(&bufptr[count], "%-20lu ",
549 rlim[i].rlim_max);
550
551 if (lnames[i].unit)
552 count += sprintf(&bufptr[count], "%-10s\n",
553 lnames[i].unit);
554 else
555 count += sprintf(&bufptr[count], "\n");
556 }
557
558 return count;
559}
560
561#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
562static int proc_pid_syscall(struct task_struct *task, char *buffer)
563{
564 long nr;
565 unsigned long args[6], sp, pc;
566 int res = lock_trace(task);
567 if (res)
568 return res;
569
570 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
571 res = sprintf(buffer, "running\n");
572 else if (nr < 0)
573 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
574 else
575 res = sprintf(buffer,
576 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
577 nr,
578 args[0], args[1], args[2], args[3], args[4], args[5],
579 sp, pc);
580 unlock_trace(task);
581 return res;
582}
583#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
584
585/************************************************************************/
586/* Here the fs part begins */
587/************************************************************************/
588
589/* permission checks */
590static int proc_fd_access_allowed(struct inode *inode)
591{
592 struct task_struct *task;
593 int allowed = 0;
594 /* Allow access to a task's file descriptors if it is us or we
595 * may use ptrace attach to the process and find out that
596 * information.
597 */
598 task = get_proc_task(inode);
599 if (task) {
600 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
601 put_task_struct(task);
602 }
603 return allowed;
604}
605
606int proc_setattr(struct dentry *dentry, struct iattr *attr)
607{
608 int error;
609 struct inode *inode = dentry->d_inode;
610
611 if (attr->ia_valid & ATTR_MODE)
612 return -EPERM;
613
614 error = inode_change_ok(inode, attr);
615 if (error)
616 return error;
617
618 if ((attr->ia_valid & ATTR_SIZE) &&
619 attr->ia_size != i_size_read(inode)) {
620 error = vmtruncate(inode, attr->ia_size);
621 if (error)
622 return error;
623 }
624
625 setattr_copy(inode, attr);
626 mark_inode_dirty(inode);
627 return 0;
628}
629
630static const struct inode_operations proc_def_inode_operations = {
631 .setattr = proc_setattr,
632};
633
634static int mounts_open_common(struct inode *inode, struct file *file,
635 const struct seq_operations *op)
636{
637 struct task_struct *task = get_proc_task(inode);
638 struct nsproxy *nsp;
639 struct mnt_namespace *ns = NULL;
640 struct path root;
641 struct proc_mounts *p;
642 int ret = -EINVAL;
643
644 if (task) {
645 rcu_read_lock();
646 nsp = task_nsproxy(task);
647 if (nsp) {
648 ns = nsp->mnt_ns;
649 if (ns)
650 get_mnt_ns(ns);
651 }
652 rcu_read_unlock();
653 if (ns && get_task_root(task, &root) == 0)
654 ret = 0;
655 put_task_struct(task);
656 }
657
658 if (!ns)
659 goto err;
660 if (ret)
661 goto err_put_ns;
662
663 ret = -ENOMEM;
664 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
665 if (!p)
666 goto err_put_path;
667
668 file->private_data = &p->m;
669 ret = seq_open(file, op);
670 if (ret)
671 goto err_free;
672
673 p->m.private = p;
674 p->ns = ns;
675 p->root = root;
676 p->m.poll_event = ns->event;
677
678 return 0;
679
680 err_free:
681 kfree(p);
682 err_put_path:
683 path_put(&root);
684 err_put_ns:
685 put_mnt_ns(ns);
686 err:
687 return ret;
688}
689
690static int mounts_release(struct inode *inode, struct file *file)
691{
692 struct proc_mounts *p = file->private_data;
693 path_put(&p->root);
694 put_mnt_ns(p->ns);
695 return seq_release(inode, file);
696}
697
698static unsigned mounts_poll(struct file *file, poll_table *wait)
699{
700 struct proc_mounts *p = file->private_data;
701 unsigned res = POLLIN | POLLRDNORM;
702
703 poll_wait(file, &p->ns->poll, wait);
704 if (mnt_had_events(p))
705 res |= POLLERR | POLLPRI;
706
707 return res;
708}
709
710static int mounts_open(struct inode *inode, struct file *file)
711{
712 return mounts_open_common(inode, file, &mounts_op);
713}
714
715static const struct file_operations proc_mounts_operations = {
716 .open = mounts_open,
717 .read = seq_read,
718 .llseek = seq_lseek,
719 .release = mounts_release,
720 .poll = mounts_poll,
721};
722
723static int mountinfo_open(struct inode *inode, struct file *file)
724{
725 return mounts_open_common(inode, file, &mountinfo_op);
726}
727
728static const struct file_operations proc_mountinfo_operations = {
729 .open = mountinfo_open,
730 .read = seq_read,
731 .llseek = seq_lseek,
732 .release = mounts_release,
733 .poll = mounts_poll,
734};
735
736static int mountstats_open(struct inode *inode, struct file *file)
737{
738 return mounts_open_common(inode, file, &mountstats_op);
739}
740
741static const struct file_operations proc_mountstats_operations = {
742 .open = mountstats_open,
743 .read = seq_read,
744 .llseek = seq_lseek,
745 .release = mounts_release,
746};
747
748#define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
749
750static ssize_t proc_info_read(struct file * file, char __user * buf,
751 size_t count, loff_t *ppos)
752{
753 struct inode * inode = file->f_path.dentry->d_inode;
754 unsigned long page;
755 ssize_t length;
756 struct task_struct *task = get_proc_task(inode);
757
758 length = -ESRCH;
759 if (!task)
760 goto out_no_task;
761
762 if (count > PROC_BLOCK_SIZE)
763 count = PROC_BLOCK_SIZE;
764
765 length = -ENOMEM;
766 if (!(page = __get_free_page(GFP_TEMPORARY)))
767 goto out;
768
769 length = PROC_I(inode)->op.proc_read(task, (char*)page);
770
771 if (length >= 0)
772 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
773 free_page(page);
774out:
775 put_task_struct(task);
776out_no_task:
777 return length;
778}
779
780static const struct file_operations proc_info_file_operations = {
781 .read = proc_info_read,
782 .llseek = generic_file_llseek,
783};
784
785static int proc_single_show(struct seq_file *m, void *v)
786{
787 struct inode *inode = m->private;
788 struct pid_namespace *ns;
789 struct pid *pid;
790 struct task_struct *task;
791 int ret;
792
793 ns = inode->i_sb->s_fs_info;
794 pid = proc_pid(inode);
795 task = get_pid_task(pid, PIDTYPE_PID);
796 if (!task)
797 return -ESRCH;
798
799 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
800
801 put_task_struct(task);
802 return ret;
803}
804
805static int proc_single_open(struct inode *inode, struct file *filp)
806{
807 return single_open(filp, proc_single_show, inode);
808}
809
810static const struct file_operations proc_single_file_operations = {
811 .open = proc_single_open,
812 .read = seq_read,
813 .llseek = seq_lseek,
814 .release = single_release,
815};
816
817static int mem_open(struct inode* inode, struct file* file)
818{
819 file->private_data = (void*)((long)current->self_exec_id);
820 /* OK to pass negative loff_t, we can catch out-of-range */
821 file->f_mode |= FMODE_UNSIGNED_OFFSET;
822 return 0;
823}
824
825static ssize_t mem_read(struct file * file, char __user * buf,
826 size_t count, loff_t *ppos)
827{
828 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
829 char *page;
830 unsigned long src = *ppos;
831 int ret = -ESRCH;
832 struct mm_struct *mm;
833
834 if (!task)
835 goto out_no_task;
836
837 ret = -ENOMEM;
838 page = (char *)__get_free_page(GFP_TEMPORARY);
839 if (!page)
840 goto out;
841
842 mm = check_mem_permission(task);
843 ret = PTR_ERR(mm);
844 if (IS_ERR(mm))
845 goto out_free;
846
847 ret = -EIO;
848
849 if (file->private_data != (void*)((long)current->self_exec_id))
850 goto out_put;
851
852 ret = 0;
853
854 while (count > 0) {
855 int this_len, retval;
856
857 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
858 retval = access_remote_vm(mm, src, page, this_len, 0);
859 if (!retval) {
860 if (!ret)
861 ret = -EIO;
862 break;
863 }
864
865 if (copy_to_user(buf, page, retval)) {
866 ret = -EFAULT;
867 break;
868 }
869
870 ret += retval;
871 src += retval;
872 buf += retval;
873 count -= retval;
874 }
875 *ppos = src;
876
877out_put:
878 mmput(mm);
879out_free:
880 free_page((unsigned long) page);
881out:
882 put_task_struct(task);
883out_no_task:
884 return ret;
885}
886
887static ssize_t mem_write(struct file * file, const char __user *buf,
888 size_t count, loff_t *ppos)
889{
890 int copied;
891 char *page;
892 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
893 unsigned long dst = *ppos;
894 struct mm_struct *mm;
895
896 copied = -ESRCH;
897 if (!task)
898 goto out_no_task;
899
900 copied = -ENOMEM;
901 page = (char *)__get_free_page(GFP_TEMPORARY);
902 if (!page)
903 goto out_task;
904
905 mm = check_mem_permission(task);
906 copied = PTR_ERR(mm);
907 if (IS_ERR(mm))
908 goto out_free;
909
910 copied = -EIO;
911 if (file->private_data != (void *)((long)current->self_exec_id))
912 goto out_mm;
913
914 copied = 0;
915 while (count > 0) {
916 int this_len, retval;
917
918 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
919 if (copy_from_user(page, buf, this_len)) {
920 copied = -EFAULT;
921 break;
922 }
923 retval = access_remote_vm(mm, dst, page, this_len, 1);
924 if (!retval) {
925 if (!copied)
926 copied = -EIO;
927 break;
928 }
929 copied += retval;
930 buf += retval;
931 dst += retval;
932 count -= retval;
933 }
934 *ppos = dst;
935
936out_mm:
937 mmput(mm);
938out_free:
939 free_page((unsigned long) page);
940out_task:
941 put_task_struct(task);
942out_no_task:
943 return copied;
944}
945
946loff_t mem_lseek(struct file *file, loff_t offset, int orig)
947{
948 switch (orig) {
949 case 0:
950 file->f_pos = offset;
951 break;
952 case 1:
953 file->f_pos += offset;
954 break;
955 default:
956 return -EINVAL;
957 }
958 force_successful_syscall_return();
959 return file->f_pos;
960}
961
962static const struct file_operations proc_mem_operations = {
963 .llseek = mem_lseek,
964 .read = mem_read,
965 .write = mem_write,
966 .open = mem_open,
967};
968
969static ssize_t environ_read(struct file *file, char __user *buf,
970 size_t count, loff_t *ppos)
971{
972 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
973 char *page;
974 unsigned long src = *ppos;
975 int ret = -ESRCH;
976 struct mm_struct *mm;
977
978 if (!task)
979 goto out_no_task;
980
981 ret = -ENOMEM;
982 page = (char *)__get_free_page(GFP_TEMPORARY);
983 if (!page)
984 goto out;
985
986
987 mm = mm_for_maps(task);
988 ret = PTR_ERR(mm);
989 if (!mm || IS_ERR(mm))
990 goto out_free;
991
992 ret = 0;
993 while (count > 0) {
994 int this_len, retval, max_len;
995
996 this_len = mm->env_end - (mm->env_start + src);
997
998 if (this_len <= 0)
999 break;
1000
1001 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
1002 this_len = (this_len > max_len) ? max_len : this_len;
1003
1004 retval = access_process_vm(task, (mm->env_start + src),
1005 page, this_len, 0);
1006
1007 if (retval <= 0) {
1008 ret = retval;
1009 break;
1010 }
1011
1012 if (copy_to_user(buf, page, retval)) {
1013 ret = -EFAULT;
1014 break;
1015 }
1016
1017 ret += retval;
1018 src += retval;
1019 buf += retval;
1020 count -= retval;
1021 }
1022 *ppos = src;
1023
1024 mmput(mm);
1025out_free:
1026 free_page((unsigned long) page);
1027out:
1028 put_task_struct(task);
1029out_no_task:
1030 return ret;
1031}
1032
1033static const struct file_operations proc_environ_operations = {
1034 .read = environ_read,
1035 .llseek = generic_file_llseek,
1036};
1037
1038static ssize_t oom_adjust_read(struct file *file, char __user *buf,
1039 size_t count, loff_t *ppos)
1040{
1041 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1042 char buffer[PROC_NUMBUF];
1043 size_t len;
1044 int oom_adjust = OOM_DISABLE;
1045 unsigned long flags;
1046
1047 if (!task)
1048 return -ESRCH;
1049
1050 if (lock_task_sighand(task, &flags)) {
1051 oom_adjust = task->signal->oom_adj;
1052 unlock_task_sighand(task, &flags);
1053 }
1054
1055 put_task_struct(task);
1056
1057 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
1058
1059 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1060}
1061
1062static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1063 size_t count, loff_t *ppos)
1064{
1065 struct task_struct *task;
1066 char buffer[PROC_NUMBUF];
1067 int oom_adjust;
1068 unsigned long flags;
1069 int err;
1070
1071 memset(buffer, 0, sizeof(buffer));
1072 if (count > sizeof(buffer) - 1)
1073 count = sizeof(buffer) - 1;
1074 if (copy_from_user(buffer, buf, count)) {
1075 err = -EFAULT;
1076 goto out;
1077 }
1078
1079 err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
1080 if (err)
1081 goto out;
1082 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1083 oom_adjust != OOM_DISABLE) {
1084 err = -EINVAL;
1085 goto out;
1086 }
1087
1088 task = get_proc_task(file->f_path.dentry->d_inode);
1089 if (!task) {
1090 err = -ESRCH;
1091 goto out;
1092 }
1093
1094 task_lock(task);
1095 if (!task->mm) {
1096 err = -EINVAL;
1097 goto err_task_lock;
1098 }
1099
1100 if (!lock_task_sighand(task, &flags)) {
1101 err = -ESRCH;
1102 goto err_task_lock;
1103 }
1104
1105 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1106 err = -EACCES;
1107 goto err_sighand;
1108 }
1109
1110 if (oom_adjust != task->signal->oom_adj) {
1111 if (oom_adjust == OOM_DISABLE)
1112 atomic_inc(&task->mm->oom_disable_count);
1113 if (task->signal->oom_adj == OOM_DISABLE)
1114 atomic_dec(&task->mm->oom_disable_count);
1115 }
1116
1117 /*
1118 * Warn that /proc/pid/oom_adj is deprecated, see
1119 * Documentation/feature-removal-schedule.txt.
1120 */
1121 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1122 current->comm, task_pid_nr(current), task_pid_nr(task),
1123 task_pid_nr(task));
1124 task->signal->oom_adj = oom_adjust;
1125 /*
1126 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1127 * value is always attainable.
1128 */
1129 if (task->signal->oom_adj == OOM_ADJUST_MAX)
1130 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
1131 else
1132 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
1133 -OOM_DISABLE;
1134err_sighand:
1135 unlock_task_sighand(task, &flags);
1136err_task_lock:
1137 task_unlock(task);
1138 put_task_struct(task);
1139out:
1140 return err < 0 ? err : count;
1141}
1142
1143static const struct file_operations proc_oom_adjust_operations = {
1144 .read = oom_adjust_read,
1145 .write = oom_adjust_write,
1146 .llseek = generic_file_llseek,
1147};
1148
1149static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1150 size_t count, loff_t *ppos)
1151{
1152 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1153 char buffer[PROC_NUMBUF];
1154 int oom_score_adj = OOM_SCORE_ADJ_MIN;
1155 unsigned long flags;
1156 size_t len;
1157
1158 if (!task)
1159 return -ESRCH;
1160 if (lock_task_sighand(task, &flags)) {
1161 oom_score_adj = task->signal->oom_score_adj;
1162 unlock_task_sighand(task, &flags);
1163 }
1164 put_task_struct(task);
1165 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
1166 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1167}
1168
1169static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1170 size_t count, loff_t *ppos)
1171{
1172 struct task_struct *task;
1173 char buffer[PROC_NUMBUF];
1174 unsigned long flags;
1175 int oom_score_adj;
1176 int err;
1177
1178 memset(buffer, 0, sizeof(buffer));
1179 if (count > sizeof(buffer) - 1)
1180 count = sizeof(buffer) - 1;
1181 if (copy_from_user(buffer, buf, count)) {
1182 err = -EFAULT;
1183 goto out;
1184 }
1185
1186 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1187 if (err)
1188 goto out;
1189 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1190 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1191 err = -EINVAL;
1192 goto out;
1193 }
1194
1195 task = get_proc_task(file->f_path.dentry->d_inode);
1196 if (!task) {
1197 err = -ESRCH;
1198 goto out;
1199 }
1200
1201 task_lock(task);
1202 if (!task->mm) {
1203 err = -EINVAL;
1204 goto err_task_lock;
1205 }
1206
1207 if (!lock_task_sighand(task, &flags)) {
1208 err = -ESRCH;
1209 goto err_task_lock;
1210 }
1211
1212 if (oom_score_adj < task->signal->oom_score_adj_min &&
1213 !capable(CAP_SYS_RESOURCE)) {
1214 err = -EACCES;
1215 goto err_sighand;
1216 }
1217
1218 if (oom_score_adj != task->signal->oom_score_adj) {
1219 if (oom_score_adj == OOM_SCORE_ADJ_MIN)
1220 atomic_inc(&task->mm->oom_disable_count);
1221 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1222 atomic_dec(&task->mm->oom_disable_count);
1223 }
1224 task->signal->oom_score_adj = oom_score_adj;
1225 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1226 task->signal->oom_score_adj_min = oom_score_adj;
1227 /*
1228 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1229 * always attainable.
1230 */
1231 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1232 task->signal->oom_adj = OOM_DISABLE;
1233 else
1234 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1235 OOM_SCORE_ADJ_MAX;
1236err_sighand:
1237 unlock_task_sighand(task, &flags);
1238err_task_lock:
1239 task_unlock(task);
1240 put_task_struct(task);
1241out:
1242 return err < 0 ? err : count;
1243}
1244
1245static const struct file_operations proc_oom_score_adj_operations = {
1246 .read = oom_score_adj_read,
1247 .write = oom_score_adj_write,
1248 .llseek = default_llseek,
1249};
1250
1251#ifdef CONFIG_AUDITSYSCALL
1252#define TMPBUFLEN 21
1253static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1254 size_t count, loff_t *ppos)
1255{
1256 struct inode * inode = file->f_path.dentry->d_inode;
1257 struct task_struct *task = get_proc_task(inode);
1258 ssize_t length;
1259 char tmpbuf[TMPBUFLEN];
1260
1261 if (!task)
1262 return -ESRCH;
1263 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1264 audit_get_loginuid(task));
1265 put_task_struct(task);
1266 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1267}
1268
1269static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1270 size_t count, loff_t *ppos)
1271{
1272 struct inode * inode = file->f_path.dentry->d_inode;
1273 char *page, *tmp;
1274 ssize_t length;
1275 uid_t loginuid;
1276
1277 if (!capable(CAP_AUDIT_CONTROL))
1278 return -EPERM;
1279
1280 rcu_read_lock();
1281 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1282 rcu_read_unlock();
1283 return -EPERM;
1284 }
1285 rcu_read_unlock();
1286
1287 if (count >= PAGE_SIZE)
1288 count = PAGE_SIZE - 1;
1289
1290 if (*ppos != 0) {
1291 /* No partial writes. */
1292 return -EINVAL;
1293 }
1294 page = (char*)__get_free_page(GFP_TEMPORARY);
1295 if (!page)
1296 return -ENOMEM;
1297 length = -EFAULT;
1298 if (copy_from_user(page, buf, count))
1299 goto out_free_page;
1300
1301 page[count] = '\0';
1302 loginuid = simple_strtoul(page, &tmp, 10);
1303 if (tmp == page) {
1304 length = -EINVAL;
1305 goto out_free_page;
1306
1307 }
1308 length = audit_set_loginuid(current, loginuid);
1309 if (likely(length == 0))
1310 length = count;
1311
1312out_free_page:
1313 free_page((unsigned long) page);
1314 return length;
1315}
1316
1317static const struct file_operations proc_loginuid_operations = {
1318 .read = proc_loginuid_read,
1319 .write = proc_loginuid_write,
1320 .llseek = generic_file_llseek,
1321};
1322
1323static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1324 size_t count, loff_t *ppos)
1325{
1326 struct inode * inode = file->f_path.dentry->d_inode;
1327 struct task_struct *task = get_proc_task(inode);
1328 ssize_t length;
1329 char tmpbuf[TMPBUFLEN];
1330
1331 if (!task)
1332 return -ESRCH;
1333 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1334 audit_get_sessionid(task));
1335 put_task_struct(task);
1336 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1337}
1338
1339static const struct file_operations proc_sessionid_operations = {
1340 .read = proc_sessionid_read,
1341 .llseek = generic_file_llseek,
1342};
1343#endif
1344
1345#ifdef CONFIG_FAULT_INJECTION
1346static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1347 size_t count, loff_t *ppos)
1348{
1349 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1350 char buffer[PROC_NUMBUF];
1351 size_t len;
1352 int make_it_fail;
1353
1354 if (!task)
1355 return -ESRCH;
1356 make_it_fail = task->make_it_fail;
1357 put_task_struct(task);
1358
1359 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1360
1361 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1362}
1363
1364static ssize_t proc_fault_inject_write(struct file * file,
1365 const char __user * buf, size_t count, loff_t *ppos)
1366{
1367 struct task_struct *task;
1368 char buffer[PROC_NUMBUF], *end;
1369 int make_it_fail;
1370
1371 if (!capable(CAP_SYS_RESOURCE))
1372 return -EPERM;
1373 memset(buffer, 0, sizeof(buffer));
1374 if (count > sizeof(buffer) - 1)
1375 count = sizeof(buffer) - 1;
1376 if (copy_from_user(buffer, buf, count))
1377 return -EFAULT;
1378 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1379 if (*end)
1380 return -EINVAL;
1381 task = get_proc_task(file->f_dentry->d_inode);
1382 if (!task)
1383 return -ESRCH;
1384 task->make_it_fail = make_it_fail;
1385 put_task_struct(task);
1386
1387 return count;
1388}
1389
1390static const struct file_operations proc_fault_inject_operations = {
1391 .read = proc_fault_inject_read,
1392 .write = proc_fault_inject_write,
1393 .llseek = generic_file_llseek,
1394};
1395#endif
1396
1397
1398#ifdef CONFIG_SCHED_DEBUG
1399/*
1400 * Print out various scheduling related per-task fields:
1401 */
1402static int sched_show(struct seq_file *m, void *v)
1403{
1404 struct inode *inode = m->private;
1405 struct task_struct *p;
1406
1407 p = get_proc_task(inode);
1408 if (!p)
1409 return -ESRCH;
1410 proc_sched_show_task(p, m);
1411
1412 put_task_struct(p);
1413
1414 return 0;
1415}
1416
1417static ssize_t
1418sched_write(struct file *file, const char __user *buf,
1419 size_t count, loff_t *offset)
1420{
1421 struct inode *inode = file->f_path.dentry->d_inode;
1422 struct task_struct *p;
1423
1424 p = get_proc_task(inode);
1425 if (!p)
1426 return -ESRCH;
1427 proc_sched_set_task(p);
1428
1429 put_task_struct(p);
1430
1431 return count;
1432}
1433
1434static int sched_open(struct inode *inode, struct file *filp)
1435{
1436 return single_open(filp, sched_show, inode);
1437}
1438
1439static const struct file_operations proc_pid_sched_operations = {
1440 .open = sched_open,
1441 .read = seq_read,
1442 .write = sched_write,
1443 .llseek = seq_lseek,
1444 .release = single_release,
1445};
1446
1447#endif
1448
1449#ifdef CONFIG_SCHED_AUTOGROUP
1450/*
1451 * Print out autogroup related information:
1452 */
1453static int sched_autogroup_show(struct seq_file *m, void *v)
1454{
1455 struct inode *inode = m->private;
1456 struct task_struct *p;
1457
1458 p = get_proc_task(inode);
1459 if (!p)
1460 return -ESRCH;
1461 proc_sched_autogroup_show_task(p, m);
1462
1463 put_task_struct(p);
1464
1465 return 0;
1466}
1467
1468static ssize_t
1469sched_autogroup_write(struct file *file, const char __user *buf,
1470 size_t count, loff_t *offset)
1471{
1472 struct inode *inode = file->f_path.dentry->d_inode;
1473 struct task_struct *p;
1474 char buffer[PROC_NUMBUF];
1475 int nice;
1476 int err;
1477
1478 memset(buffer, 0, sizeof(buffer));
1479 if (count > sizeof(buffer) - 1)
1480 count = sizeof(buffer) - 1;
1481 if (copy_from_user(buffer, buf, count))
1482 return -EFAULT;
1483
1484 err = kstrtoint(strstrip(buffer), 0, &nice);
1485 if (err < 0)
1486 return err;
1487
1488 p = get_proc_task(inode);
1489 if (!p)
1490 return -ESRCH;
1491
1492 err = nice;
1493 err = proc_sched_autogroup_set_nice(p, &err);
1494 if (err)
1495 count = err;
1496
1497 put_task_struct(p);
1498
1499 return count;
1500}
1501
1502static int sched_autogroup_open(struct inode *inode, struct file *filp)
1503{
1504 int ret;
1505
1506 ret = single_open(filp, sched_autogroup_show, NULL);
1507 if (!ret) {
1508 struct seq_file *m = filp->private_data;
1509
1510 m->private = inode;
1511 }
1512 return ret;
1513}
1514
1515static const struct file_operations proc_pid_sched_autogroup_operations = {
1516 .open = sched_autogroup_open,
1517 .read = seq_read,
1518 .write = sched_autogroup_write,
1519 .llseek = seq_lseek,
1520 .release = single_release,
1521};
1522
1523#endif /* CONFIG_SCHED_AUTOGROUP */
1524
1525static ssize_t comm_write(struct file *file, const char __user *buf,
1526 size_t count, loff_t *offset)
1527{
1528 struct inode *inode = file->f_path.dentry->d_inode;
1529 struct task_struct *p;
1530 char buffer[TASK_COMM_LEN];
1531
1532 memset(buffer, 0, sizeof(buffer));
1533 if (count > sizeof(buffer) - 1)
1534 count = sizeof(buffer) - 1;
1535 if (copy_from_user(buffer, buf, count))
1536 return -EFAULT;
1537
1538 p = get_proc_task(inode);
1539 if (!p)
1540 return -ESRCH;
1541
1542 if (same_thread_group(current, p))
1543 set_task_comm(p, buffer);
1544 else
1545 count = -EINVAL;
1546
1547 put_task_struct(p);
1548
1549 return count;
1550}
1551
1552static int comm_show(struct seq_file *m, void *v)
1553{
1554 struct inode *inode = m->private;
1555 struct task_struct *p;
1556
1557 p = get_proc_task(inode);
1558 if (!p)
1559 return -ESRCH;
1560
1561 task_lock(p);
1562 seq_printf(m, "%s\n", p->comm);
1563 task_unlock(p);
1564
1565 put_task_struct(p);
1566
1567 return 0;
1568}
1569
1570static int comm_open(struct inode *inode, struct file *filp)
1571{
1572 return single_open(filp, comm_show, inode);
1573}
1574
1575static const struct file_operations proc_pid_set_comm_operations = {
1576 .open = comm_open,
1577 .read = seq_read,
1578 .write = comm_write,
1579 .llseek = seq_lseek,
1580 .release = single_release,
1581};
1582
1583static int proc_exe_link(struct inode *inode, struct path *exe_path)
1584{
1585 struct task_struct *task;
1586 struct mm_struct *mm;
1587 struct file *exe_file;
1588
1589 task = get_proc_task(inode);
1590 if (!task)
1591 return -ENOENT;
1592 mm = get_task_mm(task);
1593 put_task_struct(task);
1594 if (!mm)
1595 return -ENOENT;
1596 exe_file = get_mm_exe_file(mm);
1597 mmput(mm);
1598 if (exe_file) {
1599 *exe_path = exe_file->f_path;
1600 path_get(&exe_file->f_path);
1601 fput(exe_file);
1602 return 0;
1603 } else
1604 return -ENOENT;
1605}
1606
1607static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1608{
1609 struct inode *inode = dentry->d_inode;
1610 int error = -EACCES;
1611
1612 /* We don't need a base pointer in the /proc filesystem */
1613 path_put(&nd->path);
1614
1615 /* Are we allowed to snoop on the tasks file descriptors? */
1616 if (!proc_fd_access_allowed(inode))
1617 goto out;
1618
1619 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1620out:
1621 return ERR_PTR(error);
1622}
1623
1624static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1625{
1626 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1627 char *pathname;
1628 int len;
1629
1630 if (!tmp)
1631 return -ENOMEM;
1632
1633 pathname = d_path(path, tmp, PAGE_SIZE);
1634 len = PTR_ERR(pathname);
1635 if (IS_ERR(pathname))
1636 goto out;
1637 len = tmp + PAGE_SIZE - 1 - pathname;
1638
1639 if (len > buflen)
1640 len = buflen;
1641 if (copy_to_user(buffer, pathname, len))
1642 len = -EFAULT;
1643 out:
1644 free_page((unsigned long)tmp);
1645 return len;
1646}
1647
1648static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1649{
1650 int error = -EACCES;
1651 struct inode *inode = dentry->d_inode;
1652 struct path path;
1653
1654 /* Are we allowed to snoop on the tasks file descriptors? */
1655 if (!proc_fd_access_allowed(inode))
1656 goto out;
1657
1658 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1659 if (error)
1660 goto out;
1661
1662 error = do_proc_readlink(&path, buffer, buflen);
1663 path_put(&path);
1664out:
1665 return error;
1666}
1667
1668static const struct inode_operations proc_pid_link_inode_operations = {
1669 .readlink = proc_pid_readlink,
1670 .follow_link = proc_pid_follow_link,
1671 .setattr = proc_setattr,
1672};
1673
1674
1675/* building an inode */
1676
1677static int task_dumpable(struct task_struct *task)
1678{
1679 int dumpable = 0;
1680 struct mm_struct *mm;
1681
1682 task_lock(task);
1683 mm = task->mm;
1684 if (mm)
1685 dumpable = get_dumpable(mm);
1686 task_unlock(task);
1687 if(dumpable == 1)
1688 return 1;
1689 return 0;
1690}
1691
1692struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1693{
1694 struct inode * inode;
1695 struct proc_inode *ei;
1696 const struct cred *cred;
1697
1698 /* We need a new inode */
1699
1700 inode = new_inode(sb);
1701 if (!inode)
1702 goto out;
1703
1704 /* Common stuff */
1705 ei = PROC_I(inode);
1706 inode->i_ino = get_next_ino();
1707 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1708 inode->i_op = &proc_def_inode_operations;
1709
1710 /*
1711 * grab the reference to task.
1712 */
1713 ei->pid = get_task_pid(task, PIDTYPE_PID);
1714 if (!ei->pid)
1715 goto out_unlock;
1716
1717 if (task_dumpable(task)) {
1718 rcu_read_lock();
1719 cred = __task_cred(task);
1720 inode->i_uid = cred->euid;
1721 inode->i_gid = cred->egid;
1722 rcu_read_unlock();
1723 }
1724 security_task_to_inode(task, inode);
1725
1726out:
1727 return inode;
1728
1729out_unlock:
1730 iput(inode);
1731 return NULL;
1732}
1733
1734int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1735{
1736 struct inode *inode = dentry->d_inode;
1737 struct task_struct *task;
1738 const struct cred *cred;
1739
1740 generic_fillattr(inode, stat);
1741
1742 rcu_read_lock();
1743 stat->uid = 0;
1744 stat->gid = 0;
1745 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1746 if (task) {
1747 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1748 task_dumpable(task)) {
1749 cred = __task_cred(task);
1750 stat->uid = cred->euid;
1751 stat->gid = cred->egid;
1752 }
1753 }
1754 rcu_read_unlock();
1755 return 0;
1756}
1757
1758/* dentry stuff */
1759
1760/*
1761 * Exceptional case: normally we are not allowed to unhash a busy
1762 * directory. In this case, however, we can do it - no aliasing problems
1763 * due to the way we treat inodes.
1764 *
1765 * Rewrite the inode's ownerships here because the owning task may have
1766 * performed a setuid(), etc.
1767 *
1768 * Before the /proc/pid/status file was created the only way to read
1769 * the effective uid of a /process was to stat /proc/pid. Reading
1770 * /proc/pid/status is slow enough that procps and other packages
1771 * kept stating /proc/pid. To keep the rules in /proc simple I have
1772 * made this apply to all per process world readable and executable
1773 * directories.
1774 */
1775int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1776{
1777 struct inode *inode;
1778 struct task_struct *task;
1779 const struct cred *cred;
1780
1781 if (nd && nd->flags & LOOKUP_RCU)
1782 return -ECHILD;
1783
1784 inode = dentry->d_inode;
1785 task = get_proc_task(inode);
1786
1787 if (task) {
1788 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1789 task_dumpable(task)) {
1790 rcu_read_lock();
1791 cred = __task_cred(task);
1792 inode->i_uid = cred->euid;
1793 inode->i_gid = cred->egid;
1794 rcu_read_unlock();
1795 } else {
1796 inode->i_uid = 0;
1797 inode->i_gid = 0;
1798 }
1799 inode->i_mode &= ~(S_ISUID | S_ISGID);
1800 security_task_to_inode(task, inode);
1801 put_task_struct(task);
1802 return 1;
1803 }
1804 d_drop(dentry);
1805 return 0;
1806}
1807
1808static int pid_delete_dentry(const struct dentry * dentry)
1809{
1810 /* Is the task we represent dead?
1811 * If so, then don't put the dentry on the lru list,
1812 * kill it immediately.
1813 */
1814 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1815}
1816
1817const struct dentry_operations pid_dentry_operations =
1818{
1819 .d_revalidate = pid_revalidate,
1820 .d_delete = pid_delete_dentry,
1821};
1822
1823/* Lookups */
1824
1825/*
1826 * Fill a directory entry.
1827 *
1828 * If possible create the dcache entry and derive our inode number and
1829 * file type from dcache entry.
1830 *
1831 * Since all of the proc inode numbers are dynamically generated, the inode
1832 * numbers do not exist until the inode is cache. This means creating the
1833 * the dcache entry in readdir is necessary to keep the inode numbers
1834 * reported by readdir in sync with the inode numbers reported
1835 * by stat.
1836 */
1837int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1838 const char *name, int len,
1839 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1840{
1841 struct dentry *child, *dir = filp->f_path.dentry;
1842 struct inode *inode;
1843 struct qstr qname;
1844 ino_t ino = 0;
1845 unsigned type = DT_UNKNOWN;
1846
1847 qname.name = name;
1848 qname.len = len;
1849 qname.hash = full_name_hash(name, len);
1850
1851 child = d_lookup(dir, &qname);
1852 if (!child) {
1853 struct dentry *new;
1854 new = d_alloc(dir, &qname);
1855 if (new) {
1856 child = instantiate(dir->d_inode, new, task, ptr);
1857 if (child)
1858 dput(new);
1859 else
1860 child = new;
1861 }
1862 }
1863 if (!child || IS_ERR(child) || !child->d_inode)
1864 goto end_instantiate;
1865 inode = child->d_inode;
1866 if (inode) {
1867 ino = inode->i_ino;
1868 type = inode->i_mode >> 12;
1869 }
1870 dput(child);
1871end_instantiate:
1872 if (!ino)
1873 ino = find_inode_number(dir, &qname);
1874 if (!ino)
1875 ino = 1;
1876 return filldir(dirent, name, len, filp->f_pos, ino, type);
1877}
1878
1879static unsigned name_to_int(struct dentry *dentry)
1880{
1881 const char *name = dentry->d_name.name;
1882 int len = dentry->d_name.len;
1883 unsigned n = 0;
1884
1885 if (len > 1 && *name == '0')
1886 goto out;
1887 while (len-- > 0) {
1888 unsigned c = *name++ - '0';
1889 if (c > 9)
1890 goto out;
1891 if (n >= (~0U-9)/10)
1892 goto out;
1893 n *= 10;
1894 n += c;
1895 }
1896 return n;
1897out:
1898 return ~0U;
1899}
1900
1901#define PROC_FDINFO_MAX 64
1902
1903static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1904{
1905 struct task_struct *task = get_proc_task(inode);
1906 struct files_struct *files = NULL;
1907 struct file *file;
1908 int fd = proc_fd(inode);
1909
1910 if (task) {
1911 files = get_files_struct(task);
1912 put_task_struct(task);
1913 }
1914 if (files) {
1915 /*
1916 * We are not taking a ref to the file structure, so we must
1917 * hold ->file_lock.
1918 */
1919 spin_lock(&files->file_lock);
1920 file = fcheck_files(files, fd);
1921 if (file) {
1922 unsigned int f_flags;
1923 struct fdtable *fdt;
1924
1925 fdt = files_fdtable(files);
1926 f_flags = file->f_flags & ~O_CLOEXEC;
1927 if (FD_ISSET(fd, fdt->close_on_exec))
1928 f_flags |= O_CLOEXEC;
1929
1930 if (path) {
1931 *path = file->f_path;
1932 path_get(&file->f_path);
1933 }
1934 if (info)
1935 snprintf(info, PROC_FDINFO_MAX,
1936 "pos:\t%lli\n"
1937 "flags:\t0%o\n",
1938 (long long) file->f_pos,
1939 f_flags);
1940 spin_unlock(&files->file_lock);
1941 put_files_struct(files);
1942 return 0;
1943 }
1944 spin_unlock(&files->file_lock);
1945 put_files_struct(files);
1946 }
1947 return -ENOENT;
1948}
1949
1950static int proc_fd_link(struct inode *inode, struct path *path)
1951{
1952 return proc_fd_info(inode, path, NULL);
1953}
1954
1955static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1956{
1957 struct inode *inode;
1958 struct task_struct *task;
1959 int fd;
1960 struct files_struct *files;
1961 const struct cred *cred;
1962
1963 if (nd && nd->flags & LOOKUP_RCU)
1964 return -ECHILD;
1965
1966 inode = dentry->d_inode;
1967 task = get_proc_task(inode);
1968 fd = proc_fd(inode);
1969
1970 if (task) {
1971 files = get_files_struct(task);
1972 if (files) {
1973 rcu_read_lock();
1974 if (fcheck_files(files, fd)) {
1975 rcu_read_unlock();
1976 put_files_struct(files);
1977 if (task_dumpable(task)) {
1978 rcu_read_lock();
1979 cred = __task_cred(task);
1980 inode->i_uid = cred->euid;
1981 inode->i_gid = cred->egid;
1982 rcu_read_unlock();
1983 } else {
1984 inode->i_uid = 0;
1985 inode->i_gid = 0;
1986 }
1987 inode->i_mode &= ~(S_ISUID | S_ISGID);
1988 security_task_to_inode(task, inode);
1989 put_task_struct(task);
1990 return 1;
1991 }
1992 rcu_read_unlock();
1993 put_files_struct(files);
1994 }
1995 put_task_struct(task);
1996 }
1997 d_drop(dentry);
1998 return 0;
1999}
2000
2001static const struct dentry_operations tid_fd_dentry_operations =
2002{
2003 .d_revalidate = tid_fd_revalidate,
2004 .d_delete = pid_delete_dentry,
2005};
2006
2007static struct dentry *proc_fd_instantiate(struct inode *dir,
2008 struct dentry *dentry, struct task_struct *task, const void *ptr)
2009{
2010 unsigned fd = *(const unsigned *)ptr;
2011 struct file *file;
2012 struct files_struct *files;
2013 struct inode *inode;
2014 struct proc_inode *ei;
2015 struct dentry *error = ERR_PTR(-ENOENT);
2016
2017 inode = proc_pid_make_inode(dir->i_sb, task);
2018 if (!inode)
2019 goto out;
2020 ei = PROC_I(inode);
2021 ei->fd = fd;
2022 files = get_files_struct(task);
2023 if (!files)
2024 goto out_iput;
2025 inode->i_mode = S_IFLNK;
2026
2027 /*
2028 * We are not taking a ref to the file structure, so we must
2029 * hold ->file_lock.
2030 */
2031 spin_lock(&files->file_lock);
2032 file = fcheck_files(files, fd);
2033 if (!file)
2034 goto out_unlock;
2035 if (file->f_mode & FMODE_READ)
2036 inode->i_mode |= S_IRUSR | S_IXUSR;
2037 if (file->f_mode & FMODE_WRITE)
2038 inode->i_mode |= S_IWUSR | S_IXUSR;
2039 spin_unlock(&files->file_lock);
2040 put_files_struct(files);
2041
2042 inode->i_op = &proc_pid_link_inode_operations;
2043 inode->i_size = 64;
2044 ei->op.proc_get_link = proc_fd_link;
2045 d_set_d_op(dentry, &tid_fd_dentry_operations);
2046 d_add(dentry, inode);
2047 /* Close the race of the process dying before we return the dentry */
2048 if (tid_fd_revalidate(dentry, NULL))
2049 error = NULL;
2050
2051 out:
2052 return error;
2053out_unlock:
2054 spin_unlock(&files->file_lock);
2055 put_files_struct(files);
2056out_iput:
2057 iput(inode);
2058 goto out;
2059}
2060
2061static struct dentry *proc_lookupfd_common(struct inode *dir,
2062 struct dentry *dentry,
2063 instantiate_t instantiate)
2064{
2065 struct task_struct *task = get_proc_task(dir);
2066 unsigned fd = name_to_int(dentry);
2067 struct dentry *result = ERR_PTR(-ENOENT);
2068
2069 if (!task)
2070 goto out_no_task;
2071 if (fd == ~0U)
2072 goto out;
2073
2074 result = instantiate(dir, dentry, task, &fd);
2075out:
2076 put_task_struct(task);
2077out_no_task:
2078 return result;
2079}
2080
2081static int proc_readfd_common(struct file * filp, void * dirent,
2082 filldir_t filldir, instantiate_t instantiate)
2083{
2084 struct dentry *dentry = filp->f_path.dentry;
2085 struct inode *inode = dentry->d_inode;
2086 struct task_struct *p = get_proc_task(inode);
2087 unsigned int fd, ino;
2088 int retval;
2089 struct files_struct * files;
2090
2091 retval = -ENOENT;
2092 if (!p)
2093 goto out_no_task;
2094 retval = 0;
2095
2096 fd = filp->f_pos;
2097 switch (fd) {
2098 case 0:
2099 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
2100 goto out;
2101 filp->f_pos++;
2102 case 1:
2103 ino = parent_ino(dentry);
2104 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2105 goto out;
2106 filp->f_pos++;
2107 default:
2108 files = get_files_struct(p);
2109 if (!files)
2110 goto out;
2111 rcu_read_lock();
2112 for (fd = filp->f_pos-2;
2113 fd < files_fdtable(files)->max_fds;
2114 fd++, filp->f_pos++) {
2115 char name[PROC_NUMBUF];
2116 int len;
2117
2118 if (!fcheck_files(files, fd))
2119 continue;
2120 rcu_read_unlock();
2121
2122 len = snprintf(name, sizeof(name), "%d", fd);
2123 if (proc_fill_cache(filp, dirent, filldir,
2124 name, len, instantiate,
2125 p, &fd) < 0) {
2126 rcu_read_lock();
2127 break;
2128 }
2129 rcu_read_lock();
2130 }
2131 rcu_read_unlock();
2132 put_files_struct(files);
2133 }
2134out:
2135 put_task_struct(p);
2136out_no_task:
2137 return retval;
2138}
2139
2140static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
2141 struct nameidata *nd)
2142{
2143 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
2144}
2145
2146static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
2147{
2148 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
2149}
2150
2151static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
2152 size_t len, loff_t *ppos)
2153{
2154 char tmp[PROC_FDINFO_MAX];
2155 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
2156 if (!err)
2157 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
2158 return err;
2159}
2160
2161static const struct file_operations proc_fdinfo_file_operations = {
2162 .open = nonseekable_open,
2163 .read = proc_fdinfo_read,
2164 .llseek = no_llseek,
2165};
2166
2167static const struct file_operations proc_fd_operations = {
2168 .read = generic_read_dir,
2169 .readdir = proc_readfd,
2170 .llseek = default_llseek,
2171};
2172
2173/*
2174 * /proc/pid/fd needs a special permission handler so that a process can still
2175 * access /proc/self/fd after it has executed a setuid().
2176 */
2177static int proc_fd_permission(struct inode *inode, int mask)
2178{
2179 int rv = generic_permission(inode, mask);
2180 if (rv == 0)
2181 return 0;
2182 if (task_pid(current) == proc_pid(inode))
2183 rv = 0;
2184 return rv;
2185}
2186
2187/*
2188 * proc directories can do almost nothing..
2189 */
2190static const struct inode_operations proc_fd_inode_operations = {
2191 .lookup = proc_lookupfd,
2192 .permission = proc_fd_permission,
2193 .setattr = proc_setattr,
2194};
2195
2196static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2197 struct dentry *dentry, struct task_struct *task, const void *ptr)
2198{
2199 unsigned fd = *(unsigned *)ptr;
2200 struct inode *inode;
2201 struct proc_inode *ei;
2202 struct dentry *error = ERR_PTR(-ENOENT);
2203
2204 inode = proc_pid_make_inode(dir->i_sb, task);
2205 if (!inode)
2206 goto out;
2207 ei = PROC_I(inode);
2208 ei->fd = fd;
2209 inode->i_mode = S_IFREG | S_IRUSR;
2210 inode->i_fop = &proc_fdinfo_file_operations;
2211 d_set_d_op(dentry, &tid_fd_dentry_operations);
2212 d_add(dentry, inode);
2213 /* Close the race of the process dying before we return the dentry */
2214 if (tid_fd_revalidate(dentry, NULL))
2215 error = NULL;
2216
2217 out:
2218 return error;
2219}
2220
2221static struct dentry *proc_lookupfdinfo(struct inode *dir,
2222 struct dentry *dentry,
2223 struct nameidata *nd)
2224{
2225 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2226}
2227
2228static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2229{
2230 return proc_readfd_common(filp, dirent, filldir,
2231 proc_fdinfo_instantiate);
2232}
2233
2234static const struct file_operations proc_fdinfo_operations = {
2235 .read = generic_read_dir,
2236 .readdir = proc_readfdinfo,
2237 .llseek = default_llseek,
2238};
2239
2240/*
2241 * proc directories can do almost nothing..
2242 */
2243static const struct inode_operations proc_fdinfo_inode_operations = {
2244 .lookup = proc_lookupfdinfo,
2245 .setattr = proc_setattr,
2246};
2247
2248
2249static struct dentry *proc_pident_instantiate(struct inode *dir,
2250 struct dentry *dentry, struct task_struct *task, const void *ptr)
2251{
2252 const struct pid_entry *p = ptr;
2253 struct inode *inode;
2254 struct proc_inode *ei;
2255 struct dentry *error = ERR_PTR(-ENOENT);
2256
2257 inode = proc_pid_make_inode(dir->i_sb, task);
2258 if (!inode)
2259 goto out;
2260
2261 ei = PROC_I(inode);
2262 inode->i_mode = p->mode;
2263 if (S_ISDIR(inode->i_mode))
2264 inode->i_nlink = 2; /* Use getattr to fix if necessary */
2265 if (p->iop)
2266 inode->i_op = p->iop;
2267 if (p->fop)
2268 inode->i_fop = p->fop;
2269 ei->op = p->op;
2270 d_set_d_op(dentry, &pid_dentry_operations);
2271 d_add(dentry, inode);
2272 /* Close the race of the process dying before we return the dentry */
2273 if (pid_revalidate(dentry, NULL))
2274 error = NULL;
2275out:
2276 return error;
2277}
2278
2279static struct dentry *proc_pident_lookup(struct inode *dir,
2280 struct dentry *dentry,
2281 const struct pid_entry *ents,
2282 unsigned int nents)
2283{
2284 struct dentry *error;
2285 struct task_struct *task = get_proc_task(dir);
2286 const struct pid_entry *p, *last;
2287
2288 error = ERR_PTR(-ENOENT);
2289
2290 if (!task)
2291 goto out_no_task;
2292
2293 /*
2294 * Yes, it does not scale. And it should not. Don't add
2295 * new entries into /proc/<tgid>/ without very good reasons.
2296 */
2297 last = &ents[nents - 1];
2298 for (p = ents; p <= last; p++) {
2299 if (p->len != dentry->d_name.len)
2300 continue;
2301 if (!memcmp(dentry->d_name.name, p->name, p->len))
2302 break;
2303 }
2304 if (p > last)
2305 goto out;
2306
2307 error = proc_pident_instantiate(dir, dentry, task, p);
2308out:
2309 put_task_struct(task);
2310out_no_task:
2311 return error;
2312}
2313
2314static int proc_pident_fill_cache(struct file *filp, void *dirent,
2315 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2316{
2317 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2318 proc_pident_instantiate, task, p);
2319}
2320
2321static int proc_pident_readdir(struct file *filp,
2322 void *dirent, filldir_t filldir,
2323 const struct pid_entry *ents, unsigned int nents)
2324{
2325 int i;
2326 struct dentry *dentry = filp->f_path.dentry;
2327 struct inode *inode = dentry->d_inode;
2328 struct task_struct *task = get_proc_task(inode);
2329 const struct pid_entry *p, *last;
2330 ino_t ino;
2331 int ret;
2332
2333 ret = -ENOENT;
2334 if (!task)
2335 goto out_no_task;
2336
2337 ret = 0;
2338 i = filp->f_pos;
2339 switch (i) {
2340 case 0:
2341 ino = inode->i_ino;
2342 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2343 goto out;
2344 i++;
2345 filp->f_pos++;
2346 /* fall through */
2347 case 1:
2348 ino = parent_ino(dentry);
2349 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2350 goto out;
2351 i++;
2352 filp->f_pos++;
2353 /* fall through */
2354 default:
2355 i -= 2;
2356 if (i >= nents) {
2357 ret = 1;
2358 goto out;
2359 }
2360 p = ents + i;
2361 last = &ents[nents - 1];
2362 while (p <= last) {
2363 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2364 goto out;
2365 filp->f_pos++;
2366 p++;
2367 }
2368 }
2369
2370 ret = 1;
2371out:
2372 put_task_struct(task);
2373out_no_task:
2374 return ret;
2375}
2376
2377#ifdef CONFIG_SECURITY
2378static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2379 size_t count, loff_t *ppos)
2380{
2381 struct inode * inode = file->f_path.dentry->d_inode;
2382 char *p = NULL;
2383 ssize_t length;
2384 struct task_struct *task = get_proc_task(inode);
2385
2386 if (!task)
2387 return -ESRCH;
2388
2389 length = security_getprocattr(task,
2390 (char*)file->f_path.dentry->d_name.name,
2391 &p);
2392 put_task_struct(task);
2393 if (length > 0)
2394 length = simple_read_from_buffer(buf, count, ppos, p, length);
2395 kfree(p);
2396 return length;
2397}
2398
2399static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2400 size_t count, loff_t *ppos)
2401{
2402 struct inode * inode = file->f_path.dentry->d_inode;
2403 char *page;
2404 ssize_t length;
2405 struct task_struct *task = get_proc_task(inode);
2406
2407 length = -ESRCH;
2408 if (!task)
2409 goto out_no_task;
2410 if (count > PAGE_SIZE)
2411 count = PAGE_SIZE;
2412
2413 /* No partial writes. */
2414 length = -EINVAL;
2415 if (*ppos != 0)
2416 goto out;
2417
2418 length = -ENOMEM;
2419 page = (char*)__get_free_page(GFP_TEMPORARY);
2420 if (!page)
2421 goto out;
2422
2423 length = -EFAULT;
2424 if (copy_from_user(page, buf, count))
2425 goto out_free;
2426
2427 /* Guard against adverse ptrace interaction */
2428 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2429 if (length < 0)
2430 goto out_free;
2431
2432 length = security_setprocattr(task,
2433 (char*)file->f_path.dentry->d_name.name,
2434 (void*)page, count);
2435 mutex_unlock(&task->signal->cred_guard_mutex);
2436out_free:
2437 free_page((unsigned long) page);
2438out:
2439 put_task_struct(task);
2440out_no_task:
2441 return length;
2442}
2443
2444static const struct file_operations proc_pid_attr_operations = {
2445 .read = proc_pid_attr_read,
2446 .write = proc_pid_attr_write,
2447 .llseek = generic_file_llseek,
2448};
2449
2450static const struct pid_entry attr_dir_stuff[] = {
2451 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2452 REG("prev", S_IRUGO, proc_pid_attr_operations),
2453 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2454 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2455 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2456 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2457};
2458
2459static int proc_attr_dir_readdir(struct file * filp,
2460 void * dirent, filldir_t filldir)
2461{
2462 return proc_pident_readdir(filp,dirent,filldir,
2463 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2464}
2465
2466static const struct file_operations proc_attr_dir_operations = {
2467 .read = generic_read_dir,
2468 .readdir = proc_attr_dir_readdir,
2469 .llseek = default_llseek,
2470};
2471
2472static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2473 struct dentry *dentry, struct nameidata *nd)
2474{
2475 return proc_pident_lookup(dir, dentry,
2476 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2477}
2478
2479static const struct inode_operations proc_attr_dir_inode_operations = {
2480 .lookup = proc_attr_dir_lookup,
2481 .getattr = pid_getattr,
2482 .setattr = proc_setattr,
2483};
2484
2485#endif
2486
2487#ifdef CONFIG_ELF_CORE
2488static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2489 size_t count, loff_t *ppos)
2490{
2491 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2492 struct mm_struct *mm;
2493 char buffer[PROC_NUMBUF];
2494 size_t len;
2495 int ret;
2496
2497 if (!task)
2498 return -ESRCH;
2499
2500 ret = 0;
2501 mm = get_task_mm(task);
2502 if (mm) {
2503 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2504 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2505 MMF_DUMP_FILTER_SHIFT));
2506 mmput(mm);
2507 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2508 }
2509
2510 put_task_struct(task);
2511
2512 return ret;
2513}
2514
2515static ssize_t proc_coredump_filter_write(struct file *file,
2516 const char __user *buf,
2517 size_t count,
2518 loff_t *ppos)
2519{
2520 struct task_struct *task;
2521 struct mm_struct *mm;
2522 char buffer[PROC_NUMBUF], *end;
2523 unsigned int val;
2524 int ret;
2525 int i;
2526 unsigned long mask;
2527
2528 ret = -EFAULT;
2529 memset(buffer, 0, sizeof(buffer));
2530 if (count > sizeof(buffer) - 1)
2531 count = sizeof(buffer) - 1;
2532 if (copy_from_user(buffer, buf, count))
2533 goto out_no_task;
2534
2535 ret = -EINVAL;
2536 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2537 if (*end == '\n')
2538 end++;
2539 if (end - buffer == 0)
2540 goto out_no_task;
2541
2542 ret = -ESRCH;
2543 task = get_proc_task(file->f_dentry->d_inode);
2544 if (!task)
2545 goto out_no_task;
2546
2547 ret = end - buffer;
2548 mm = get_task_mm(task);
2549 if (!mm)
2550 goto out_no_mm;
2551
2552 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2553 if (val & mask)
2554 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2555 else
2556 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2557 }
2558
2559 mmput(mm);
2560 out_no_mm:
2561 put_task_struct(task);
2562 out_no_task:
2563 return ret;
2564}
2565
2566static const struct file_operations proc_coredump_filter_operations = {
2567 .read = proc_coredump_filter_read,
2568 .write = proc_coredump_filter_write,
2569 .llseek = generic_file_llseek,
2570};
2571#endif
2572
2573/*
2574 * /proc/self:
2575 */
2576static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2577 int buflen)
2578{
2579 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2580 pid_t tgid = task_tgid_nr_ns(current, ns);
2581 char tmp[PROC_NUMBUF];
2582 if (!tgid)
2583 return -ENOENT;
2584 sprintf(tmp, "%d", tgid);
2585 return vfs_readlink(dentry,buffer,buflen,tmp);
2586}
2587
2588static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2589{
2590 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2591 pid_t tgid = task_tgid_nr_ns(current, ns);
2592 char *name = ERR_PTR(-ENOENT);
2593 if (tgid) {
2594 name = __getname();
2595 if (!name)
2596 name = ERR_PTR(-ENOMEM);
2597 else
2598 sprintf(name, "%d", tgid);
2599 }
2600 nd_set_link(nd, name);
2601 return NULL;
2602}
2603
2604static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2605 void *cookie)
2606{
2607 char *s = nd_get_link(nd);
2608 if (!IS_ERR(s))
2609 __putname(s);
2610}
2611
2612static const struct inode_operations proc_self_inode_operations = {
2613 .readlink = proc_self_readlink,
2614 .follow_link = proc_self_follow_link,
2615 .put_link = proc_self_put_link,
2616};
2617
2618/*
2619 * proc base
2620 *
2621 * These are the directory entries in the root directory of /proc
2622 * that properly belong to the /proc filesystem, as they describe
2623 * describe something that is process related.
2624 */
2625static const struct pid_entry proc_base_stuff[] = {
2626 NOD("self", S_IFLNK|S_IRWXUGO,
2627 &proc_self_inode_operations, NULL, {}),
2628};
2629
2630static struct dentry *proc_base_instantiate(struct inode *dir,
2631 struct dentry *dentry, struct task_struct *task, const void *ptr)
2632{
2633 const struct pid_entry *p = ptr;
2634 struct inode *inode;
2635 struct proc_inode *ei;
2636 struct dentry *error;
2637
2638 /* Allocate the inode */
2639 error = ERR_PTR(-ENOMEM);
2640 inode = new_inode(dir->i_sb);
2641 if (!inode)
2642 goto out;
2643
2644 /* Initialize the inode */
2645 ei = PROC_I(inode);
2646 inode->i_ino = get_next_ino();
2647 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2648
2649 /*
2650 * grab the reference to the task.
2651 */
2652 ei->pid = get_task_pid(task, PIDTYPE_PID);
2653 if (!ei->pid)
2654 goto out_iput;
2655
2656 inode->i_mode = p->mode;
2657 if (S_ISDIR(inode->i_mode))
2658 inode->i_nlink = 2;
2659 if (S_ISLNK(inode->i_mode))
2660 inode->i_size = 64;
2661 if (p->iop)
2662 inode->i_op = p->iop;
2663 if (p->fop)
2664 inode->i_fop = p->fop;
2665 ei->op = p->op;
2666 d_add(dentry, inode);
2667 error = NULL;
2668out:
2669 return error;
2670out_iput:
2671 iput(inode);
2672 goto out;
2673}
2674
2675static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2676{
2677 struct dentry *error;
2678 struct task_struct *task = get_proc_task(dir);
2679 const struct pid_entry *p, *last;
2680
2681 error = ERR_PTR(-ENOENT);
2682
2683 if (!task)
2684 goto out_no_task;
2685
2686 /* Lookup the directory entry */
2687 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2688 for (p = proc_base_stuff; p <= last; p++) {
2689 if (p->len != dentry->d_name.len)
2690 continue;
2691 if (!memcmp(dentry->d_name.name, p->name, p->len))
2692 break;
2693 }
2694 if (p > last)
2695 goto out;
2696
2697 error = proc_base_instantiate(dir, dentry, task, p);
2698
2699out:
2700 put_task_struct(task);
2701out_no_task:
2702 return error;
2703}
2704
2705static int proc_base_fill_cache(struct file *filp, void *dirent,
2706 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2707{
2708 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2709 proc_base_instantiate, task, p);
2710}
2711
2712#ifdef CONFIG_TASK_IO_ACCOUNTING
2713static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2714{
2715 struct task_io_accounting acct = task->ioac;
2716 unsigned long flags;
2717 int result;
2718
2719 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2720 if (result)
2721 return result;
2722
2723 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2724 result = -EACCES;
2725 goto out_unlock;
2726 }
2727
2728 if (whole && lock_task_sighand(task, &flags)) {
2729 struct task_struct *t = task;
2730
2731 task_io_accounting_add(&acct, &task->signal->ioac);
2732 while_each_thread(task, t)
2733 task_io_accounting_add(&acct, &t->ioac);
2734
2735 unlock_task_sighand(task, &flags);
2736 }
2737 result = sprintf(buffer,
2738 "rchar: %llu\n"
2739 "wchar: %llu\n"
2740 "syscr: %llu\n"
2741 "syscw: %llu\n"
2742 "read_bytes: %llu\n"
2743 "write_bytes: %llu\n"
2744 "cancelled_write_bytes: %llu\n",
2745 (unsigned long long)acct.rchar,
2746 (unsigned long long)acct.wchar,
2747 (unsigned long long)acct.syscr,
2748 (unsigned long long)acct.syscw,
2749 (unsigned long long)acct.read_bytes,
2750 (unsigned long long)acct.write_bytes,
2751 (unsigned long long)acct.cancelled_write_bytes);
2752out_unlock:
2753 mutex_unlock(&task->signal->cred_guard_mutex);
2754 return result;
2755}
2756
2757static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2758{
2759 return do_io_accounting(task, buffer, 0);
2760}
2761
2762static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2763{
2764 return do_io_accounting(task, buffer, 1);
2765}
2766#endif /* CONFIG_TASK_IO_ACCOUNTING */
2767
2768static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2769 struct pid *pid, struct task_struct *task)
2770{
2771 int err = lock_trace(task);
2772 if (!err) {
2773 seq_printf(m, "%08x\n", task->personality);
2774 unlock_trace(task);
2775 }
2776 return err;
2777}
2778
2779/*
2780 * Thread groups
2781 */
2782static const struct file_operations proc_task_operations;
2783static const struct inode_operations proc_task_inode_operations;
2784
2785static const struct pid_entry tgid_base_stuff[] = {
2786 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2787 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2788 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2789 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2790#ifdef CONFIG_NET
2791 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2792#endif
2793 REG("environ", S_IRUSR, proc_environ_operations),
2794 INF("auxv", S_IRUSR, proc_pid_auxv),
2795 ONE("status", S_IRUGO, proc_pid_status),
2796 ONE("personality", S_IRUGO, proc_pid_personality),
2797 INF("limits", S_IRUGO, proc_pid_limits),
2798#ifdef CONFIG_SCHED_DEBUG
2799 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2800#endif
2801#ifdef CONFIG_SCHED_AUTOGROUP
2802 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2803#endif
2804 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2805#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2806 INF("syscall", S_IRUGO, proc_pid_syscall),
2807#endif
2808 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2809 ONE("stat", S_IRUGO, proc_tgid_stat),
2810 ONE("statm", S_IRUGO, proc_pid_statm),
2811 REG("maps", S_IRUGO, proc_maps_operations),
2812#ifdef CONFIG_NUMA
2813 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2814#endif
2815 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2816 LNK("cwd", proc_cwd_link),
2817 LNK("root", proc_root_link),
2818 LNK("exe", proc_exe_link),
2819 REG("mounts", S_IRUGO, proc_mounts_operations),
2820 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2821 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2822#ifdef CONFIG_PROC_PAGE_MONITOR
2823 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2824 REG("smaps", S_IRUGO, proc_smaps_operations),
2825 REG("pagemap", S_IRUGO, proc_pagemap_operations),
2826#endif
2827#ifdef CONFIG_SECURITY
2828 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2829#endif
2830#ifdef CONFIG_KALLSYMS
2831 INF("wchan", S_IRUGO, proc_pid_wchan),
2832#endif
2833#ifdef CONFIG_STACKTRACE
2834 ONE("stack", S_IRUGO, proc_pid_stack),
2835#endif
2836#ifdef CONFIG_SCHEDSTATS
2837 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2838#endif
2839#ifdef CONFIG_LATENCYTOP
2840 REG("latency", S_IRUGO, proc_lstats_operations),
2841#endif
2842#ifdef CONFIG_PROC_PID_CPUSET
2843 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2844#endif
2845#ifdef CONFIG_CGROUPS
2846 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2847#endif
2848 INF("oom_score", S_IRUGO, proc_oom_score),
2849 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2850 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2851#ifdef CONFIG_AUDITSYSCALL
2852 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2853 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2854#endif
2855#ifdef CONFIG_FAULT_INJECTION
2856 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2857#endif
2858#ifdef CONFIG_ELF_CORE
2859 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2860#endif
2861#ifdef CONFIG_TASK_IO_ACCOUNTING
2862 INF("io", S_IRUSR, proc_tgid_io_accounting),
2863#endif
2864#ifdef CONFIG_HARDWALL
2865 INF("hardwall", S_IRUGO, proc_pid_hardwall),
2866#endif
2867};
2868
2869static int proc_tgid_base_readdir(struct file * filp,
2870 void * dirent, filldir_t filldir)
2871{
2872 return proc_pident_readdir(filp,dirent,filldir,
2873 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2874}
2875
2876static const struct file_operations proc_tgid_base_operations = {
2877 .read = generic_read_dir,
2878 .readdir = proc_tgid_base_readdir,
2879 .llseek = default_llseek,
2880};
2881
2882static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2883 return proc_pident_lookup(dir, dentry,
2884 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2885}
2886
2887static const struct inode_operations proc_tgid_base_inode_operations = {
2888 .lookup = proc_tgid_base_lookup,
2889 .getattr = pid_getattr,
2890 .setattr = proc_setattr,
2891};
2892
2893static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2894{
2895 struct dentry *dentry, *leader, *dir;
2896 char buf[PROC_NUMBUF];
2897 struct qstr name;
2898
2899 name.name = buf;
2900 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2901 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2902 if (dentry) {
2903 shrink_dcache_parent(dentry);
2904 d_drop(dentry);
2905 dput(dentry);
2906 }
2907
2908 name.name = buf;
2909 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2910 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2911 if (!leader)
2912 goto out;
2913
2914 name.name = "task";
2915 name.len = strlen(name.name);
2916 dir = d_hash_and_lookup(leader, &name);
2917 if (!dir)
2918 goto out_put_leader;
2919
2920 name.name = buf;
2921 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2922 dentry = d_hash_and_lookup(dir, &name);
2923 if (dentry) {
2924 shrink_dcache_parent(dentry);
2925 d_drop(dentry);
2926 dput(dentry);
2927 }
2928
2929 dput(dir);
2930out_put_leader:
2931 dput(leader);
2932out:
2933 return;
2934}
2935
2936/**
2937 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2938 * @task: task that should be flushed.
2939 *
2940 * When flushing dentries from proc, one needs to flush them from global
2941 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2942 * in. This call is supposed to do all of this job.
2943 *
2944 * Looks in the dcache for
2945 * /proc/@pid
2946 * /proc/@tgid/task/@pid
2947 * if either directory is present flushes it and all of it'ts children
2948 * from the dcache.
2949 *
2950 * It is safe and reasonable to cache /proc entries for a task until
2951 * that task exits. After that they just clog up the dcache with
2952 * useless entries, possibly causing useful dcache entries to be
2953 * flushed instead. This routine is proved to flush those useless
2954 * dcache entries at process exit time.
2955 *
2956 * NOTE: This routine is just an optimization so it does not guarantee
2957 * that no dcache entries will exist at process exit time it
2958 * just makes it very unlikely that any will persist.
2959 */
2960
2961void proc_flush_task(struct task_struct *task)
2962{
2963 int i;
2964 struct pid *pid, *tgid;
2965 struct upid *upid;
2966
2967 pid = task_pid(task);
2968 tgid = task_tgid(task);
2969
2970 for (i = 0; i <= pid->level; i++) {
2971 upid = &pid->numbers[i];
2972 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2973 tgid->numbers[i].nr);
2974 }
2975
2976 upid = &pid->numbers[pid->level];
2977 if (upid->nr == 1)
2978 pid_ns_release_proc(upid->ns);
2979}
2980
2981static struct dentry *proc_pid_instantiate(struct inode *dir,
2982 struct dentry * dentry,
2983 struct task_struct *task, const void *ptr)
2984{
2985 struct dentry *error = ERR_PTR(-ENOENT);
2986 struct inode *inode;
2987
2988 inode = proc_pid_make_inode(dir->i_sb, task);
2989 if (!inode)
2990 goto out;
2991
2992 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2993 inode->i_op = &proc_tgid_base_inode_operations;
2994 inode->i_fop = &proc_tgid_base_operations;
2995 inode->i_flags|=S_IMMUTABLE;
2996
2997 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2998 ARRAY_SIZE(tgid_base_stuff));
2999
3000 d_set_d_op(dentry, &pid_dentry_operations);
3001
3002 d_add(dentry, inode);
3003 /* Close the race of the process dying before we return the dentry */
3004 if (pid_revalidate(dentry, NULL))
3005 error = NULL;
3006out:
3007 return error;
3008}
3009
3010struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3011{
3012 struct dentry *result;
3013 struct task_struct *task;
3014 unsigned tgid;
3015 struct pid_namespace *ns;
3016
3017 result = proc_base_lookup(dir, dentry);
3018 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
3019 goto out;
3020
3021 tgid = name_to_int(dentry);
3022 if (tgid == ~0U)
3023 goto out;
3024
3025 ns = dentry->d_sb->s_fs_info;
3026 rcu_read_lock();
3027 task = find_task_by_pid_ns(tgid, ns);
3028 if (task)
3029 get_task_struct(task);
3030 rcu_read_unlock();
3031 if (!task)
3032 goto out;
3033
3034 result = proc_pid_instantiate(dir, dentry, task, NULL);
3035 put_task_struct(task);
3036out:
3037 return result;
3038}
3039
3040/*
3041 * Find the first task with tgid >= tgid
3042 *
3043 */
3044struct tgid_iter {
3045 unsigned int tgid;
3046 struct task_struct *task;
3047};
3048static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3049{
3050 struct pid *pid;
3051
3052 if (iter.task)
3053 put_task_struct(iter.task);
3054 rcu_read_lock();
3055retry:
3056 iter.task = NULL;
3057 pid = find_ge_pid(iter.tgid, ns);
3058 if (pid) {
3059 iter.tgid = pid_nr_ns(pid, ns);
3060 iter.task = pid_task(pid, PIDTYPE_PID);
3061 /* What we to know is if the pid we have find is the
3062 * pid of a thread_group_leader. Testing for task
3063 * being a thread_group_leader is the obvious thing
3064 * todo but there is a window when it fails, due to
3065 * the pid transfer logic in de_thread.
3066 *
3067 * So we perform the straight forward test of seeing
3068 * if the pid we have found is the pid of a thread
3069 * group leader, and don't worry if the task we have
3070 * found doesn't happen to be a thread group leader.
3071 * As we don't care in the case of readdir.
3072 */
3073 if (!iter.task || !has_group_leader_pid(iter.task)) {
3074 iter.tgid += 1;
3075 goto retry;
3076 }
3077 get_task_struct(iter.task);
3078 }
3079 rcu_read_unlock();
3080 return iter;
3081}
3082
3083#define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3084
3085static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3086 struct tgid_iter iter)
3087{
3088 char name[PROC_NUMBUF];
3089 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3090 return proc_fill_cache(filp, dirent, filldir, name, len,
3091 proc_pid_instantiate, iter.task, NULL);
3092}
3093
3094/* for the /proc/ directory itself, after non-process stuff has been done */
3095int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3096{
3097 unsigned int nr;
3098 struct task_struct *reaper;
3099 struct tgid_iter iter;
3100 struct pid_namespace *ns;
3101
3102 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3103 goto out_no_task;
3104 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3105
3106 reaper = get_proc_task(filp->f_path.dentry->d_inode);
3107 if (!reaper)
3108 goto out_no_task;
3109
3110 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3111 const struct pid_entry *p = &proc_base_stuff[nr];
3112 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3113 goto out;
3114 }
3115
3116 ns = filp->f_dentry->d_sb->s_fs_info;
3117 iter.task = NULL;
3118 iter.tgid = filp->f_pos - TGID_OFFSET;
3119 for (iter = next_tgid(ns, iter);
3120 iter.task;
3121 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3122 filp->f_pos = iter.tgid + TGID_OFFSET;
3123 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
3124 put_task_struct(iter.task);
3125 goto out;
3126 }
3127 }
3128 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3129out:
3130 put_task_struct(reaper);
3131out_no_task:
3132 return 0;
3133}
3134
3135/*
3136 * Tasks
3137 */
3138static const struct pid_entry tid_base_stuff[] = {
3139 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3140 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3141 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3142 REG("environ", S_IRUSR, proc_environ_operations),
3143 INF("auxv", S_IRUSR, proc_pid_auxv),
3144 ONE("status", S_IRUGO, proc_pid_status),
3145 ONE("personality", S_IRUGO, proc_pid_personality),
3146 INF("limits", S_IRUGO, proc_pid_limits),
3147#ifdef CONFIG_SCHED_DEBUG
3148 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3149#endif
3150 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3151#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3152 INF("syscall", S_IRUGO, proc_pid_syscall),
3153#endif
3154 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3155 ONE("stat", S_IRUGO, proc_tid_stat),
3156 ONE("statm", S_IRUGO, proc_pid_statm),
3157 REG("maps", S_IRUGO, proc_maps_operations),
3158#ifdef CONFIG_NUMA
3159 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3160#endif
3161 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3162 LNK("cwd", proc_cwd_link),
3163 LNK("root", proc_root_link),
3164 LNK("exe", proc_exe_link),
3165 REG("mounts", S_IRUGO, proc_mounts_operations),
3166 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3167#ifdef CONFIG_PROC_PAGE_MONITOR
3168 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3169 REG("smaps", S_IRUGO, proc_smaps_operations),
3170 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3171#endif
3172#ifdef CONFIG_SECURITY
3173 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3174#endif
3175#ifdef CONFIG_KALLSYMS
3176 INF("wchan", S_IRUGO, proc_pid_wchan),
3177#endif
3178#ifdef CONFIG_STACKTRACE
3179 ONE("stack", S_IRUGO, proc_pid_stack),
3180#endif
3181#ifdef CONFIG_SCHEDSTATS
3182 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3183#endif
3184#ifdef CONFIG_LATENCYTOP
3185 REG("latency", S_IRUGO, proc_lstats_operations),
3186#endif
3187#ifdef CONFIG_PROC_PID_CPUSET
3188 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3189#endif
3190#ifdef CONFIG_CGROUPS
3191 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3192#endif
3193 INF("oom_score", S_IRUGO, proc_oom_score),
3194 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3195 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3196#ifdef CONFIG_AUDITSYSCALL
3197 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3198 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3199#endif
3200#ifdef CONFIG_FAULT_INJECTION
3201 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3202#endif
3203#ifdef CONFIG_TASK_IO_ACCOUNTING
3204 INF("io", S_IRUSR, proc_tid_io_accounting),
3205#endif
3206#ifdef CONFIG_HARDWALL
3207 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3208#endif
3209};
3210
3211static int proc_tid_base_readdir(struct file * filp,
3212 void * dirent, filldir_t filldir)
3213{
3214 return proc_pident_readdir(filp,dirent,filldir,
3215 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3216}
3217
3218static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3219 return proc_pident_lookup(dir, dentry,
3220 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3221}
3222
3223static const struct file_operations proc_tid_base_operations = {
3224 .read = generic_read_dir,
3225 .readdir = proc_tid_base_readdir,
3226 .llseek = default_llseek,
3227};
3228
3229static const struct inode_operations proc_tid_base_inode_operations = {
3230 .lookup = proc_tid_base_lookup,
3231 .getattr = pid_getattr,
3232 .setattr = proc_setattr,
3233};
3234
3235static struct dentry *proc_task_instantiate(struct inode *dir,
3236 struct dentry *dentry, struct task_struct *task, const void *ptr)
3237{
3238 struct dentry *error = ERR_PTR(-ENOENT);
3239 struct inode *inode;
3240 inode = proc_pid_make_inode(dir->i_sb, task);
3241
3242 if (!inode)
3243 goto out;
3244 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3245 inode->i_op = &proc_tid_base_inode_operations;
3246 inode->i_fop = &proc_tid_base_operations;
3247 inode->i_flags|=S_IMMUTABLE;
3248
3249 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3250 ARRAY_SIZE(tid_base_stuff));
3251
3252 d_set_d_op(dentry, &pid_dentry_operations);
3253
3254 d_add(dentry, inode);
3255 /* Close the race of the process dying before we return the dentry */
3256 if (pid_revalidate(dentry, NULL))
3257 error = NULL;
3258out:
3259 return error;
3260}
3261
3262static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3263{
3264 struct dentry *result = ERR_PTR(-ENOENT);
3265 struct task_struct *task;
3266 struct task_struct *leader = get_proc_task(dir);
3267 unsigned tid;
3268 struct pid_namespace *ns;
3269
3270 if (!leader)
3271 goto out_no_task;
3272
3273 tid = name_to_int(dentry);
3274 if (tid == ~0U)
3275 goto out;
3276
3277 ns = dentry->d_sb->s_fs_info;
3278 rcu_read_lock();
3279 task = find_task_by_pid_ns(tid, ns);
3280 if (task)
3281 get_task_struct(task);
3282 rcu_read_unlock();
3283 if (!task)
3284 goto out;
3285 if (!same_thread_group(leader, task))
3286 goto out_drop_task;
3287
3288 result = proc_task_instantiate(dir, dentry, task, NULL);
3289out_drop_task:
3290 put_task_struct(task);
3291out:
3292 put_task_struct(leader);
3293out_no_task:
3294 return result;
3295}
3296
3297/*
3298 * Find the first tid of a thread group to return to user space.
3299 *
3300 * Usually this is just the thread group leader, but if the users
3301 * buffer was too small or there was a seek into the middle of the
3302 * directory we have more work todo.
3303 *
3304 * In the case of a short read we start with find_task_by_pid.
3305 *
3306 * In the case of a seek we start with the leader and walk nr
3307 * threads past it.
3308 */
3309static struct task_struct *first_tid(struct task_struct *leader,
3310 int tid, int nr, struct pid_namespace *ns)
3311{
3312 struct task_struct *pos;
3313
3314 rcu_read_lock();
3315 /* Attempt to start with the pid of a thread */
3316 if (tid && (nr > 0)) {
3317 pos = find_task_by_pid_ns(tid, ns);
3318 if (pos && (pos->group_leader == leader))
3319 goto found;
3320 }
3321
3322 /* If nr exceeds the number of threads there is nothing todo */
3323 pos = NULL;
3324 if (nr && nr >= get_nr_threads(leader))
3325 goto out;
3326
3327 /* If we haven't found our starting place yet start
3328 * with the leader and walk nr threads forward.
3329 */
3330 for (pos = leader; nr > 0; --nr) {
3331 pos = next_thread(pos);
3332 if (pos == leader) {
3333 pos = NULL;
3334 goto out;
3335 }
3336 }
3337found:
3338 get_task_struct(pos);
3339out:
3340 rcu_read_unlock();
3341 return pos;
3342}
3343
3344/*
3345 * Find the next thread in the thread list.
3346 * Return NULL if there is an error or no next thread.
3347 *
3348 * The reference to the input task_struct is released.
3349 */
3350static struct task_struct *next_tid(struct task_struct *start)
3351{
3352 struct task_struct *pos = NULL;
3353 rcu_read_lock();
3354 if (pid_alive(start)) {
3355 pos = next_thread(start);
3356 if (thread_group_leader(pos))
3357 pos = NULL;
3358 else
3359 get_task_struct(pos);
3360 }
3361 rcu_read_unlock();
3362 put_task_struct(start);
3363 return pos;
3364}
3365
3366static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3367 struct task_struct *task, int tid)
3368{
3369 char name[PROC_NUMBUF];
3370 int len = snprintf(name, sizeof(name), "%d", tid);
3371 return proc_fill_cache(filp, dirent, filldir, name, len,
3372 proc_task_instantiate, task, NULL);
3373}
3374
3375/* for the /proc/TGID/task/ directories */
3376static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3377{
3378 struct dentry *dentry = filp->f_path.dentry;
3379 struct inode *inode = dentry->d_inode;
3380 struct task_struct *leader = NULL;
3381 struct task_struct *task;
3382 int retval = -ENOENT;
3383 ino_t ino;
3384 int tid;
3385 struct pid_namespace *ns;
3386
3387 task = get_proc_task(inode);
3388 if (!task)
3389 goto out_no_task;
3390 rcu_read_lock();
3391 if (pid_alive(task)) {
3392 leader = task->group_leader;
3393 get_task_struct(leader);
3394 }
3395 rcu_read_unlock();
3396 put_task_struct(task);
3397 if (!leader)
3398 goto out_no_task;
3399 retval = 0;
3400
3401 switch ((unsigned long)filp->f_pos) {
3402 case 0:
3403 ino = inode->i_ino;
3404 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3405 goto out;
3406 filp->f_pos++;
3407 /* fall through */
3408 case 1:
3409 ino = parent_ino(dentry);
3410 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3411 goto out;
3412 filp->f_pos++;
3413 /* fall through */
3414 }
3415
3416 /* f_version caches the tgid value that the last readdir call couldn't
3417 * return. lseek aka telldir automagically resets f_version to 0.
3418 */
3419 ns = filp->f_dentry->d_sb->s_fs_info;
3420 tid = (int)filp->f_version;
3421 filp->f_version = 0;
3422 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3423 task;
3424 task = next_tid(task), filp->f_pos++) {
3425 tid = task_pid_nr_ns(task, ns);
3426 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3427 /* returning this tgid failed, save it as the first
3428 * pid for the next readir call */
3429 filp->f_version = (u64)tid;
3430 put_task_struct(task);
3431 break;
3432 }
3433 }
3434out:
3435 put_task_struct(leader);
3436out_no_task:
3437 return retval;
3438}
3439
3440static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3441{
3442 struct inode *inode = dentry->d_inode;
3443 struct task_struct *p = get_proc_task(inode);
3444 generic_fillattr(inode, stat);
3445
3446 if (p) {
3447 stat->nlink += get_nr_threads(p);
3448 put_task_struct(p);
3449 }
3450
3451 return 0;
3452}
3453
3454static const struct inode_operations proc_task_inode_operations = {
3455 .lookup = proc_task_lookup,
3456 .getattr = proc_task_getattr,
3457 .setattr = proc_setattr,
3458};
3459
3460static const struct file_operations proc_task_operations = {
3461 .read = generic_read_dir,
3462 .readdir = proc_task_readdir,
3463 .llseek = default_llseek,
3464};