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