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[mirror_ubuntu-artful-kernel.git] / fs / proc / base.c
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
107 static u8 nlink_tid;
108 static u8 nlink_tgid;
109
110 struct 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 */
145 static 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
160 static 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
173 static 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
190 static 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
202 static 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 }
342 skip_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 }
388 skip_argv_envp:
389 ;
390 }
391
392 out_free_page:
393 free_page((unsigned long)page);
394 out_mmput:
395 mmput(mm);
396 if (rv > 0)
397 *pos += rv;
398 return rv;
399 }
400
401 static 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 */
411 static 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
429 static 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
441 static 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
450 static 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 */
487 static 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
503 static 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
534 static int lstats_open(struct inode *inode, struct file *file)
535 {
536 return single_open(file, lstats_show_proc, inode);
537 }
538
539 static 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
552 static 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
562 static 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
575 struct limit_names {
576 const char *name;
577 const char *unit;
578 };
579
580 static 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 */
600 static 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
642 static 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 */
674 static 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
690 int 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 */
711 static 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
723 static 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
753 static const struct inode_operations proc_def_inode_operations = {
754 .setattr = proc_setattr,
755 };
756
757 static 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
777 static int proc_single_open(struct inode *inode, struct file *filp)
778 {
779 return single_open(filp, proc_single_show, inode);
780 }
781
782 static 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
790 struct 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
810 static 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
821 static 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
831 static 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);
884 free:
885 free_page((unsigned long) page);
886 return copied;
887 }
888
889 static 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
895 static 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
901 loff_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
917 static 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
925 static 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
933 static int environ_open(struct inode *inode, struct file *file)
934 {
935 return __mem_open(inode, file, PTRACE_MODE_READ);
936 }
937
938 static 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
996 free:
997 free_page((unsigned long) page);
998 return ret;
999 }
1000
1001 static 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
1008 static int auxv_open(struct inode *inode, struct file *file)
1009 {
1010 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1011 }
1012
1013 static 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
1028 static 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
1035 static 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
1055 static 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 }
1137 err_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 */
1153 static 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);
1187 out:
1188 return err < 0 ? err : count;
1189 }
1190
1191 static 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
1197 static 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
1213 static 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);
1238 out:
1239 return err < 0 ? err : count;
1240 }
1241
1242 static 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
1250 static 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
1267 static 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
1306 static const struct file_operations proc_loginuid_operations = {
1307 .read = proc_loginuid_read,
1308 .write = proc_loginuid_write,
1309 .llseek = generic_file_llseek,
1310 };
1311
1312 static 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
1328 static 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
1335 static 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
1353 static 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
1383 static 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 */
1395 static 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
1410 static ssize_t
1411 sched_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
1427 static int sched_open(struct inode *inode, struct file *filp)
1428 {
1429 return single_open(filp, sched_show, inode);
1430 }
1431
1432 static 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 */
1446 static 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
1461 static ssize_t
1462 sched_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
1494 static 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
1507 static 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
1517 static 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
1543 static 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
1561 static int comm_open(struct inode *inode, struct file *filp)
1562 {
1563 return single_open(filp, comm_show, inode);
1564 }
1565
1566 static 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
1574 static 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
1593 static 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;
1613 out:
1614 return ERR_PTR(error);
1615 }
1616
1617 static 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
1641 static 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);
1657 out:
1658 return error;
1659 }
1660
1661 const 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
1670 struct 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
1706 out:
1707 return inode;
1708
1709 out_unlock:
1710 iput(inode);
1711 return NULL;
1712 }
1713
1714 int 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 */
1764 int 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
1796 static inline bool proc_inode_is_dead(struct inode *inode)
1797 {
1798 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1799 }
1800
1801 int 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
1810 const 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 */
1830 bool 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
1861 end_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 */
1869 static 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
1878 static 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
1923 out:
1924 put_task_struct(task);
1925
1926 out_notask:
1927 return status;
1928 }
1929
1930 static const struct dentry_operations tid_map_files_dentry_operations = {
1931 .d_revalidate = map_files_d_revalidate,
1932 .d_delete = pid_delete_dentry,
1933 };
1934
1935 static 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
1967 out_mmput:
1968 mmput(mm);
1969 out:
1970 return rc;
1971 }
1972
1973 struct 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 */
1984 static const char *
1985 proc_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 */
1998 static 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
2004 static int
2005 proc_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
2030 static 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
2065 out_no_vma:
2066 up_read(&mm->mmap_sem);
2067 mmput(mm);
2068 out_put_task:
2069 put_task_struct(task);
2070 out:
2071 return ERR_PTR(result);
2072 }
2073
2074 static 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
2080 static int
2081 proc_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
2170 out_put_task:
2171 put_task_struct(task);
2172 out:
2173 return ret;
2174 }
2175
2176 static 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 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2183 struct 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
2191 static 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
2206 static 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
2212 static 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
2227 static 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
2254 static 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
2261 static 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
2275 static 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
2283 static 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
2319 out:
2320 put_task_struct(p);
2321
2322 return count;
2323 }
2324
2325 static 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
2350 out:
2351 put_task_struct(p);
2352
2353 return err;
2354 }
2355
2356 static int timerslack_ns_open(struct inode *inode, struct file *filp)
2357 {
2358 return single_open(filp, timerslack_ns_show, inode);
2359 }
2360
2361 static 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
2369 static 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;
2393 out:
2394 return -ENOENT;
2395 }
2396
2397 static 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);
2426 out:
2427 put_task_struct(task);
2428 out_no_task:
2429 return ERR_PTR(error);
2430 }
2431
2432 static 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 }
2453 out:
2454 put_task_struct(task);
2455 return 0;
2456 }
2457
2458 #ifdef CONFIG_SECURITY
2459 static 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
2480 static 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
2492 /* A task may only write its own attributes. */
2493 length = -EACCES;
2494 if (current != task)
2495 goto out;
2496
2497 if (count > PAGE_SIZE)
2498 count = PAGE_SIZE;
2499
2500 /* No partial writes. */
2501 length = -EINVAL;
2502 if (*ppos != 0)
2503 goto out;
2504
2505 page = memdup_user(buf, count);
2506 if (IS_ERR(page)) {
2507 length = PTR_ERR(page);
2508 goto out;
2509 }
2510
2511 /* Guard against adverse ptrace interaction */
2512 length = mutex_lock_interruptible(&current->signal->cred_guard_mutex);
2513 if (length < 0)
2514 goto out_free;
2515
2516 length = security_setprocattr(file->f_path.dentry->d_name.name,
2517 page, count);
2518 mutex_unlock(&current->signal->cred_guard_mutex);
2519 out_free:
2520 kfree(page);
2521 out:
2522 put_task_struct(task);
2523 out_no_task:
2524 return length;
2525 }
2526
2527 static const struct file_operations proc_pid_attr_operations = {
2528 .read = proc_pid_attr_read,
2529 .write = proc_pid_attr_write,
2530 .llseek = generic_file_llseek,
2531 };
2532
2533 static const struct pid_entry attr_dir_stuff[] = {
2534 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2535 REG("prev", S_IRUGO, proc_pid_attr_operations),
2536 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2537 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2538 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2539 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2540 };
2541
2542 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2543 {
2544 return proc_pident_readdir(file, ctx,
2545 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2546 }
2547
2548 static const struct file_operations proc_attr_dir_operations = {
2549 .read = generic_read_dir,
2550 .iterate_shared = proc_attr_dir_readdir,
2551 .llseek = generic_file_llseek,
2552 };
2553
2554 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2555 struct dentry *dentry, unsigned int flags)
2556 {
2557 return proc_pident_lookup(dir, dentry,
2558 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2559 }
2560
2561 static const struct inode_operations proc_attr_dir_inode_operations = {
2562 .lookup = proc_attr_dir_lookup,
2563 .getattr = pid_getattr,
2564 .setattr = proc_setattr,
2565 };
2566
2567 #endif
2568
2569 #ifdef CONFIG_ELF_CORE
2570 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2571 size_t count, loff_t *ppos)
2572 {
2573 struct task_struct *task = get_proc_task(file_inode(file));
2574 struct mm_struct *mm;
2575 char buffer[PROC_NUMBUF];
2576 size_t len;
2577 int ret;
2578
2579 if (!task)
2580 return -ESRCH;
2581
2582 ret = 0;
2583 mm = get_task_mm(task);
2584 if (mm) {
2585 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2586 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2587 MMF_DUMP_FILTER_SHIFT));
2588 mmput(mm);
2589 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2590 }
2591
2592 put_task_struct(task);
2593
2594 return ret;
2595 }
2596
2597 static ssize_t proc_coredump_filter_write(struct file *file,
2598 const char __user *buf,
2599 size_t count,
2600 loff_t *ppos)
2601 {
2602 struct task_struct *task;
2603 struct mm_struct *mm;
2604 unsigned int val;
2605 int ret;
2606 int i;
2607 unsigned long mask;
2608
2609 ret = kstrtouint_from_user(buf, count, 0, &val);
2610 if (ret < 0)
2611 return ret;
2612
2613 ret = -ESRCH;
2614 task = get_proc_task(file_inode(file));
2615 if (!task)
2616 goto out_no_task;
2617
2618 mm = get_task_mm(task);
2619 if (!mm)
2620 goto out_no_mm;
2621 ret = 0;
2622
2623 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2624 if (val & mask)
2625 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2626 else
2627 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2628 }
2629
2630 mmput(mm);
2631 out_no_mm:
2632 put_task_struct(task);
2633 out_no_task:
2634 if (ret < 0)
2635 return ret;
2636 return count;
2637 }
2638
2639 static const struct file_operations proc_coredump_filter_operations = {
2640 .read = proc_coredump_filter_read,
2641 .write = proc_coredump_filter_write,
2642 .llseek = generic_file_llseek,
2643 };
2644 #endif
2645
2646 #ifdef CONFIG_TASK_IO_ACCOUNTING
2647 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2648 {
2649 struct task_io_accounting acct = task->ioac;
2650 unsigned long flags;
2651 int result;
2652
2653 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2654 if (result)
2655 return result;
2656
2657 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2658 result = -EACCES;
2659 goto out_unlock;
2660 }
2661
2662 if (whole && lock_task_sighand(task, &flags)) {
2663 struct task_struct *t = task;
2664
2665 task_io_accounting_add(&acct, &task->signal->ioac);
2666 while_each_thread(task, t)
2667 task_io_accounting_add(&acct, &t->ioac);
2668
2669 unlock_task_sighand(task, &flags);
2670 }
2671 seq_printf(m,
2672 "rchar: %llu\n"
2673 "wchar: %llu\n"
2674 "syscr: %llu\n"
2675 "syscw: %llu\n"
2676 "read_bytes: %llu\n"
2677 "write_bytes: %llu\n"
2678 "cancelled_write_bytes: %llu\n",
2679 (unsigned long long)acct.rchar,
2680 (unsigned long long)acct.wchar,
2681 (unsigned long long)acct.syscr,
2682 (unsigned long long)acct.syscw,
2683 (unsigned long long)acct.read_bytes,
2684 (unsigned long long)acct.write_bytes,
2685 (unsigned long long)acct.cancelled_write_bytes);
2686 result = 0;
2687
2688 out_unlock:
2689 mutex_unlock(&task->signal->cred_guard_mutex);
2690 return result;
2691 }
2692
2693 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2694 struct pid *pid, struct task_struct *task)
2695 {
2696 return do_io_accounting(task, m, 0);
2697 }
2698
2699 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2700 struct pid *pid, struct task_struct *task)
2701 {
2702 return do_io_accounting(task, m, 1);
2703 }
2704 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2705
2706 #ifdef CONFIG_USER_NS
2707 static int proc_id_map_open(struct inode *inode, struct file *file,
2708 const struct seq_operations *seq_ops)
2709 {
2710 struct user_namespace *ns = NULL;
2711 struct task_struct *task;
2712 struct seq_file *seq;
2713 int ret = -EINVAL;
2714
2715 task = get_proc_task(inode);
2716 if (task) {
2717 rcu_read_lock();
2718 ns = get_user_ns(task_cred_xxx(task, user_ns));
2719 rcu_read_unlock();
2720 put_task_struct(task);
2721 }
2722 if (!ns)
2723 goto err;
2724
2725 ret = seq_open(file, seq_ops);
2726 if (ret)
2727 goto err_put_ns;
2728
2729 seq = file->private_data;
2730 seq->private = ns;
2731
2732 return 0;
2733 err_put_ns:
2734 put_user_ns(ns);
2735 err:
2736 return ret;
2737 }
2738
2739 static int proc_id_map_release(struct inode *inode, struct file *file)
2740 {
2741 struct seq_file *seq = file->private_data;
2742 struct user_namespace *ns = seq->private;
2743 put_user_ns(ns);
2744 return seq_release(inode, file);
2745 }
2746
2747 static int proc_uid_map_open(struct inode *inode, struct file *file)
2748 {
2749 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2750 }
2751
2752 static int proc_gid_map_open(struct inode *inode, struct file *file)
2753 {
2754 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2755 }
2756
2757 static int proc_projid_map_open(struct inode *inode, struct file *file)
2758 {
2759 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2760 }
2761
2762 static const struct file_operations proc_uid_map_operations = {
2763 .open = proc_uid_map_open,
2764 .write = proc_uid_map_write,
2765 .read = seq_read,
2766 .llseek = seq_lseek,
2767 .release = proc_id_map_release,
2768 };
2769
2770 static const struct file_operations proc_gid_map_operations = {
2771 .open = proc_gid_map_open,
2772 .write = proc_gid_map_write,
2773 .read = seq_read,
2774 .llseek = seq_lseek,
2775 .release = proc_id_map_release,
2776 };
2777
2778 static const struct file_operations proc_projid_map_operations = {
2779 .open = proc_projid_map_open,
2780 .write = proc_projid_map_write,
2781 .read = seq_read,
2782 .llseek = seq_lseek,
2783 .release = proc_id_map_release,
2784 };
2785
2786 static int proc_setgroups_open(struct inode *inode, struct file *file)
2787 {
2788 struct user_namespace *ns = NULL;
2789 struct task_struct *task;
2790 int ret;
2791
2792 ret = -ESRCH;
2793 task = get_proc_task(inode);
2794 if (task) {
2795 rcu_read_lock();
2796 ns = get_user_ns(task_cred_xxx(task, user_ns));
2797 rcu_read_unlock();
2798 put_task_struct(task);
2799 }
2800 if (!ns)
2801 goto err;
2802
2803 if (file->f_mode & FMODE_WRITE) {
2804 ret = -EACCES;
2805 if (!ns_capable(ns, CAP_SYS_ADMIN))
2806 goto err_put_ns;
2807 }
2808
2809 ret = single_open(file, &proc_setgroups_show, ns);
2810 if (ret)
2811 goto err_put_ns;
2812
2813 return 0;
2814 err_put_ns:
2815 put_user_ns(ns);
2816 err:
2817 return ret;
2818 }
2819
2820 static int proc_setgroups_release(struct inode *inode, struct file *file)
2821 {
2822 struct seq_file *seq = file->private_data;
2823 struct user_namespace *ns = seq->private;
2824 int ret = single_release(inode, file);
2825 put_user_ns(ns);
2826 return ret;
2827 }
2828
2829 static const struct file_operations proc_setgroups_operations = {
2830 .open = proc_setgroups_open,
2831 .write = proc_setgroups_write,
2832 .read = seq_read,
2833 .llseek = seq_lseek,
2834 .release = proc_setgroups_release,
2835 };
2836 #endif /* CONFIG_USER_NS */
2837
2838 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2839 struct pid *pid, struct task_struct *task)
2840 {
2841 int err = lock_trace(task);
2842 if (!err) {
2843 seq_printf(m, "%08x\n", task->personality);
2844 unlock_trace(task);
2845 }
2846 return err;
2847 }
2848
2849 /*
2850 * Thread groups
2851 */
2852 static const struct file_operations proc_task_operations;
2853 static const struct inode_operations proc_task_inode_operations;
2854
2855 static const struct pid_entry tgid_base_stuff[] = {
2856 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2857 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2858 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2859 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2860 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2861 #ifdef CONFIG_NET
2862 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2863 #endif
2864 REG("environ", S_IRUSR, proc_environ_operations),
2865 REG("auxv", S_IRUSR, proc_auxv_operations),
2866 ONE("status", S_IRUGO, proc_pid_status),
2867 ONE("personality", S_IRUSR, proc_pid_personality),
2868 ONE("limits", S_IRUGO, proc_pid_limits),
2869 #ifdef CONFIG_SCHED_DEBUG
2870 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2871 #endif
2872 #ifdef CONFIG_SCHED_AUTOGROUP
2873 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2874 #endif
2875 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2876 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2877 ONE("syscall", S_IRUSR, proc_pid_syscall),
2878 #endif
2879 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
2880 ONE("stat", S_IRUGO, proc_tgid_stat),
2881 ONE("statm", S_IRUGO, proc_pid_statm),
2882 REG("maps", S_IRUGO, proc_pid_maps_operations),
2883 #ifdef CONFIG_NUMA
2884 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2885 #endif
2886 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2887 LNK("cwd", proc_cwd_link),
2888 LNK("root", proc_root_link),
2889 LNK("exe", proc_exe_link),
2890 REG("mounts", S_IRUGO, proc_mounts_operations),
2891 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2892 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2893 #ifdef CONFIG_PROC_PAGE_MONITOR
2894 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2895 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2896 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2897 #endif
2898 #ifdef CONFIG_SECURITY
2899 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2900 #endif
2901 #ifdef CONFIG_KALLSYMS
2902 ONE("wchan", S_IRUGO, proc_pid_wchan),
2903 #endif
2904 #ifdef CONFIG_STACKTRACE
2905 ONE("stack", S_IRUSR, proc_pid_stack),
2906 #endif
2907 #ifdef CONFIG_SCHED_INFO
2908 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
2909 #endif
2910 #ifdef CONFIG_LATENCYTOP
2911 REG("latency", S_IRUGO, proc_lstats_operations),
2912 #endif
2913 #ifdef CONFIG_PROC_PID_CPUSET
2914 ONE("cpuset", S_IRUGO, proc_cpuset_show),
2915 #endif
2916 #ifdef CONFIG_CGROUPS
2917 ONE("cgroup", S_IRUGO, proc_cgroup_show),
2918 #endif
2919 ONE("oom_score", S_IRUGO, proc_oom_score),
2920 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2921 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2922 #ifdef CONFIG_AUDITSYSCALL
2923 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2924 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2925 #endif
2926 #ifdef CONFIG_FAULT_INJECTION
2927 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2928 #endif
2929 #ifdef CONFIG_ELF_CORE
2930 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2931 #endif
2932 #ifdef CONFIG_TASK_IO_ACCOUNTING
2933 ONE("io", S_IRUSR, proc_tgid_io_accounting),
2934 #endif
2935 #ifdef CONFIG_HARDWALL
2936 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
2937 #endif
2938 #ifdef CONFIG_USER_NS
2939 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2940 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2941 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2942 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
2943 #endif
2944 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2945 REG("timers", S_IRUGO, proc_timers_operations),
2946 #endif
2947 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
2948 };
2949
2950 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
2951 {
2952 return proc_pident_readdir(file, ctx,
2953 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2954 }
2955
2956 static const struct file_operations proc_tgid_base_operations = {
2957 .read = generic_read_dir,
2958 .iterate_shared = proc_tgid_base_readdir,
2959 .llseek = generic_file_llseek,
2960 };
2961
2962 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2963 {
2964 return proc_pident_lookup(dir, dentry,
2965 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2966 }
2967
2968 static const struct inode_operations proc_tgid_base_inode_operations = {
2969 .lookup = proc_tgid_base_lookup,
2970 .getattr = pid_getattr,
2971 .setattr = proc_setattr,
2972 .permission = proc_pid_permission,
2973 };
2974
2975 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2976 {
2977 struct dentry *dentry, *leader, *dir;
2978 char buf[PROC_NUMBUF];
2979 struct qstr name;
2980
2981 name.name = buf;
2982 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2983 /* no ->d_hash() rejects on procfs */
2984 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2985 if (dentry) {
2986 d_invalidate(dentry);
2987 dput(dentry);
2988 }
2989
2990 if (pid == tgid)
2991 return;
2992
2993 name.name = buf;
2994 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2995 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2996 if (!leader)
2997 goto out;
2998
2999 name.name = "task";
3000 name.len = strlen(name.name);
3001 dir = d_hash_and_lookup(leader, &name);
3002 if (!dir)
3003 goto out_put_leader;
3004
3005 name.name = buf;
3006 name.len = snprintf(buf, sizeof(buf), "%d", pid);
3007 dentry = d_hash_and_lookup(dir, &name);
3008 if (dentry) {
3009 d_invalidate(dentry);
3010 dput(dentry);
3011 }
3012
3013 dput(dir);
3014 out_put_leader:
3015 dput(leader);
3016 out:
3017 return;
3018 }
3019
3020 /**
3021 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3022 * @task: task that should be flushed.
3023 *
3024 * When flushing dentries from proc, one needs to flush them from global
3025 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3026 * in. This call is supposed to do all of this job.
3027 *
3028 * Looks in the dcache for
3029 * /proc/@pid
3030 * /proc/@tgid/task/@pid
3031 * if either directory is present flushes it and all of it'ts children
3032 * from the dcache.
3033 *
3034 * It is safe and reasonable to cache /proc entries for a task until
3035 * that task exits. After that they just clog up the dcache with
3036 * useless entries, possibly causing useful dcache entries to be
3037 * flushed instead. This routine is proved to flush those useless
3038 * dcache entries at process exit time.
3039 *
3040 * NOTE: This routine is just an optimization so it does not guarantee
3041 * that no dcache entries will exist at process exit time it
3042 * just makes it very unlikely that any will persist.
3043 */
3044
3045 void proc_flush_task(struct task_struct *task)
3046 {
3047 int i;
3048 struct pid *pid, *tgid;
3049 struct upid *upid;
3050
3051 pid = task_pid(task);
3052 tgid = task_tgid(task);
3053
3054 for (i = 0; i <= pid->level; i++) {
3055 upid = &pid->numbers[i];
3056 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3057 tgid->numbers[i].nr);
3058 }
3059 }
3060
3061 static int proc_pid_instantiate(struct inode *dir,
3062 struct dentry * dentry,
3063 struct task_struct *task, const void *ptr)
3064 {
3065 struct inode *inode;
3066
3067 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3068 if (!inode)
3069 goto out;
3070
3071 inode->i_op = &proc_tgid_base_inode_operations;
3072 inode->i_fop = &proc_tgid_base_operations;
3073 inode->i_flags|=S_IMMUTABLE;
3074
3075 set_nlink(inode, nlink_tgid);
3076
3077 d_set_d_op(dentry, &pid_dentry_operations);
3078
3079 d_add(dentry, inode);
3080 /* Close the race of the process dying before we return the dentry */
3081 if (pid_revalidate(dentry, 0))
3082 return 0;
3083 out:
3084 return -ENOENT;
3085 }
3086
3087 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3088 {
3089 int result = -ENOENT;
3090 struct task_struct *task;
3091 unsigned tgid;
3092 struct pid_namespace *ns;
3093
3094 tgid = name_to_int(&dentry->d_name);
3095 if (tgid == ~0U)
3096 goto out;
3097
3098 ns = dentry->d_sb->s_fs_info;
3099 rcu_read_lock();
3100 task = find_task_by_pid_ns(tgid, ns);
3101 if (task)
3102 get_task_struct(task);
3103 rcu_read_unlock();
3104 if (!task)
3105 goto out;
3106
3107 result = proc_pid_instantiate(dir, dentry, task, NULL);
3108 put_task_struct(task);
3109 out:
3110 return ERR_PTR(result);
3111 }
3112
3113 /*
3114 * Find the first task with tgid >= tgid
3115 *
3116 */
3117 struct tgid_iter {
3118 unsigned int tgid;
3119 struct task_struct *task;
3120 };
3121 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3122 {
3123 struct pid *pid;
3124
3125 if (iter.task)
3126 put_task_struct(iter.task);
3127 rcu_read_lock();
3128 retry:
3129 iter.task = NULL;
3130 pid = find_ge_pid(iter.tgid, ns);
3131 if (pid) {
3132 iter.tgid = pid_nr_ns(pid, ns);
3133 iter.task = pid_task(pid, PIDTYPE_PID);
3134 /* What we to know is if the pid we have find is the
3135 * pid of a thread_group_leader. Testing for task
3136 * being a thread_group_leader is the obvious thing
3137 * todo but there is a window when it fails, due to
3138 * the pid transfer logic in de_thread.
3139 *
3140 * So we perform the straight forward test of seeing
3141 * if the pid we have found is the pid of a thread
3142 * group leader, and don't worry if the task we have
3143 * found doesn't happen to be a thread group leader.
3144 * As we don't care in the case of readdir.
3145 */
3146 if (!iter.task || !has_group_leader_pid(iter.task)) {
3147 iter.tgid += 1;
3148 goto retry;
3149 }
3150 get_task_struct(iter.task);
3151 }
3152 rcu_read_unlock();
3153 return iter;
3154 }
3155
3156 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3157
3158 /* for the /proc/ directory itself, after non-process stuff has been done */
3159 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3160 {
3161 struct tgid_iter iter;
3162 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
3163 loff_t pos = ctx->pos;
3164
3165 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3166 return 0;
3167
3168 if (pos == TGID_OFFSET - 2) {
3169 struct inode *inode = d_inode(ns->proc_self);
3170 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3171 return 0;
3172 ctx->pos = pos = pos + 1;
3173 }
3174 if (pos == TGID_OFFSET - 1) {
3175 struct inode *inode = d_inode(ns->proc_thread_self);
3176 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3177 return 0;
3178 ctx->pos = pos = pos + 1;
3179 }
3180 iter.tgid = pos - TGID_OFFSET;
3181 iter.task = NULL;
3182 for (iter = next_tgid(ns, iter);
3183 iter.task;
3184 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3185 char name[PROC_NUMBUF];
3186 int len;
3187
3188 cond_resched();
3189 if (!has_pid_permissions(ns, iter.task, 2))
3190 continue;
3191
3192 len = snprintf(name, sizeof(name), "%d", iter.tgid);
3193 ctx->pos = iter.tgid + TGID_OFFSET;
3194 if (!proc_fill_cache(file, ctx, name, len,
3195 proc_pid_instantiate, iter.task, NULL)) {
3196 put_task_struct(iter.task);
3197 return 0;
3198 }
3199 }
3200 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3201 return 0;
3202 }
3203
3204 /*
3205 * proc_tid_comm_permission is a special permission function exclusively
3206 * used for the node /proc/<pid>/task/<tid>/comm.
3207 * It bypasses generic permission checks in the case where a task of the same
3208 * task group attempts to access the node.
3209 * The rationale behind this is that glibc and bionic access this node for
3210 * cross thread naming (pthread_set/getname_np(!self)). However, if
3211 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3212 * which locks out the cross thread naming implementation.
3213 * This function makes sure that the node is always accessible for members of
3214 * same thread group.
3215 */
3216 static int proc_tid_comm_permission(struct inode *inode, int mask)
3217 {
3218 bool is_same_tgroup;
3219 struct task_struct *task;
3220
3221 task = get_proc_task(inode);
3222 if (!task)
3223 return -ESRCH;
3224 is_same_tgroup = same_thread_group(current, task);
3225 put_task_struct(task);
3226
3227 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3228 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3229 * read or written by the members of the corresponding
3230 * thread group.
3231 */
3232 return 0;
3233 }
3234
3235 return generic_permission(inode, mask);
3236 }
3237
3238 static const struct inode_operations proc_tid_comm_inode_operations = {
3239 .permission = proc_tid_comm_permission,
3240 };
3241
3242 /*
3243 * Tasks
3244 */
3245 static const struct pid_entry tid_base_stuff[] = {
3246 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3247 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3248 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3249 #ifdef CONFIG_NET
3250 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3251 #endif
3252 REG("environ", S_IRUSR, proc_environ_operations),
3253 REG("auxv", S_IRUSR, proc_auxv_operations),
3254 ONE("status", S_IRUGO, proc_pid_status),
3255 ONE("personality", S_IRUSR, proc_pid_personality),
3256 ONE("limits", S_IRUGO, proc_pid_limits),
3257 #ifdef CONFIG_SCHED_DEBUG
3258 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3259 #endif
3260 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3261 &proc_tid_comm_inode_operations,
3262 &proc_pid_set_comm_operations, {}),
3263 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3264 ONE("syscall", S_IRUSR, proc_pid_syscall),
3265 #endif
3266 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3267 ONE("stat", S_IRUGO, proc_tid_stat),
3268 ONE("statm", S_IRUGO, proc_pid_statm),
3269 REG("maps", S_IRUGO, proc_tid_maps_operations),
3270 #ifdef CONFIG_PROC_CHILDREN
3271 REG("children", S_IRUGO, proc_tid_children_operations),
3272 #endif
3273 #ifdef CONFIG_NUMA
3274 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3275 #endif
3276 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3277 LNK("cwd", proc_cwd_link),
3278 LNK("root", proc_root_link),
3279 LNK("exe", proc_exe_link),
3280 REG("mounts", S_IRUGO, proc_mounts_operations),
3281 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3282 #ifdef CONFIG_PROC_PAGE_MONITOR
3283 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3284 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3285 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3286 #endif
3287 #ifdef CONFIG_SECURITY
3288 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3289 #endif
3290 #ifdef CONFIG_KALLSYMS
3291 ONE("wchan", S_IRUGO, proc_pid_wchan),
3292 #endif
3293 #ifdef CONFIG_STACKTRACE
3294 ONE("stack", S_IRUSR, proc_pid_stack),
3295 #endif
3296 #ifdef CONFIG_SCHED_INFO
3297 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3298 #endif
3299 #ifdef CONFIG_LATENCYTOP
3300 REG("latency", S_IRUGO, proc_lstats_operations),
3301 #endif
3302 #ifdef CONFIG_PROC_PID_CPUSET
3303 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3304 #endif
3305 #ifdef CONFIG_CGROUPS
3306 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3307 #endif
3308 ONE("oom_score", S_IRUGO, proc_oom_score),
3309 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3310 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3311 #ifdef CONFIG_AUDITSYSCALL
3312 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3313 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3314 #endif
3315 #ifdef CONFIG_FAULT_INJECTION
3316 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3317 #endif
3318 #ifdef CONFIG_TASK_IO_ACCOUNTING
3319 ONE("io", S_IRUSR, proc_tid_io_accounting),
3320 #endif
3321 #ifdef CONFIG_HARDWALL
3322 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
3323 #endif
3324 #ifdef CONFIG_USER_NS
3325 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3326 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3327 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3328 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3329 #endif
3330 };
3331
3332 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3333 {
3334 return proc_pident_readdir(file, ctx,
3335 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3336 }
3337
3338 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3339 {
3340 return proc_pident_lookup(dir, dentry,
3341 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3342 }
3343
3344 static const struct file_operations proc_tid_base_operations = {
3345 .read = generic_read_dir,
3346 .iterate_shared = proc_tid_base_readdir,
3347 .llseek = generic_file_llseek,
3348 };
3349
3350 static const struct inode_operations proc_tid_base_inode_operations = {
3351 .lookup = proc_tid_base_lookup,
3352 .getattr = pid_getattr,
3353 .setattr = proc_setattr,
3354 };
3355
3356 static int proc_task_instantiate(struct inode *dir,
3357 struct dentry *dentry, struct task_struct *task, const void *ptr)
3358 {
3359 struct inode *inode;
3360 inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3361
3362 if (!inode)
3363 goto out;
3364 inode->i_op = &proc_tid_base_inode_operations;
3365 inode->i_fop = &proc_tid_base_operations;
3366 inode->i_flags|=S_IMMUTABLE;
3367
3368 set_nlink(inode, nlink_tid);
3369
3370 d_set_d_op(dentry, &pid_dentry_operations);
3371
3372 d_add(dentry, inode);
3373 /* Close the race of the process dying before we return the dentry */
3374 if (pid_revalidate(dentry, 0))
3375 return 0;
3376 out:
3377 return -ENOENT;
3378 }
3379
3380 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3381 {
3382 int result = -ENOENT;
3383 struct task_struct *task;
3384 struct task_struct *leader = get_proc_task(dir);
3385 unsigned tid;
3386 struct pid_namespace *ns;
3387
3388 if (!leader)
3389 goto out_no_task;
3390
3391 tid = name_to_int(&dentry->d_name);
3392 if (tid == ~0U)
3393 goto out;
3394
3395 ns = dentry->d_sb->s_fs_info;
3396 rcu_read_lock();
3397 task = find_task_by_pid_ns(tid, ns);
3398 if (task)
3399 get_task_struct(task);
3400 rcu_read_unlock();
3401 if (!task)
3402 goto out;
3403 if (!same_thread_group(leader, task))
3404 goto out_drop_task;
3405
3406 result = proc_task_instantiate(dir, dentry, task, NULL);
3407 out_drop_task:
3408 put_task_struct(task);
3409 out:
3410 put_task_struct(leader);
3411 out_no_task:
3412 return ERR_PTR(result);
3413 }
3414
3415 /*
3416 * Find the first tid of a thread group to return to user space.
3417 *
3418 * Usually this is just the thread group leader, but if the users
3419 * buffer was too small or there was a seek into the middle of the
3420 * directory we have more work todo.
3421 *
3422 * In the case of a short read we start with find_task_by_pid.
3423 *
3424 * In the case of a seek we start with the leader and walk nr
3425 * threads past it.
3426 */
3427 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3428 struct pid_namespace *ns)
3429 {
3430 struct task_struct *pos, *task;
3431 unsigned long nr = f_pos;
3432
3433 if (nr != f_pos) /* 32bit overflow? */
3434 return NULL;
3435
3436 rcu_read_lock();
3437 task = pid_task(pid, PIDTYPE_PID);
3438 if (!task)
3439 goto fail;
3440
3441 /* Attempt to start with the tid of a thread */
3442 if (tid && nr) {
3443 pos = find_task_by_pid_ns(tid, ns);
3444 if (pos && same_thread_group(pos, task))
3445 goto found;
3446 }
3447
3448 /* If nr exceeds the number of threads there is nothing todo */
3449 if (nr >= get_nr_threads(task))
3450 goto fail;
3451
3452 /* If we haven't found our starting place yet start
3453 * with the leader and walk nr threads forward.
3454 */
3455 pos = task = task->group_leader;
3456 do {
3457 if (!nr--)
3458 goto found;
3459 } while_each_thread(task, pos);
3460 fail:
3461 pos = NULL;
3462 goto out;
3463 found:
3464 get_task_struct(pos);
3465 out:
3466 rcu_read_unlock();
3467 return pos;
3468 }
3469
3470 /*
3471 * Find the next thread in the thread list.
3472 * Return NULL if there is an error or no next thread.
3473 *
3474 * The reference to the input task_struct is released.
3475 */
3476 static struct task_struct *next_tid(struct task_struct *start)
3477 {
3478 struct task_struct *pos = NULL;
3479 rcu_read_lock();
3480 if (pid_alive(start)) {
3481 pos = next_thread(start);
3482 if (thread_group_leader(pos))
3483 pos = NULL;
3484 else
3485 get_task_struct(pos);
3486 }
3487 rcu_read_unlock();
3488 put_task_struct(start);
3489 return pos;
3490 }
3491
3492 /* for the /proc/TGID/task/ directories */
3493 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3494 {
3495 struct inode *inode = file_inode(file);
3496 struct task_struct *task;
3497 struct pid_namespace *ns;
3498 int tid;
3499
3500 if (proc_inode_is_dead(inode))
3501 return -ENOENT;
3502
3503 if (!dir_emit_dots(file, ctx))
3504 return 0;
3505
3506 /* f_version caches the tgid value that the last readdir call couldn't
3507 * return. lseek aka telldir automagically resets f_version to 0.
3508 */
3509 ns = inode->i_sb->s_fs_info;
3510 tid = (int)file->f_version;
3511 file->f_version = 0;
3512 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3513 task;
3514 task = next_tid(task), ctx->pos++) {
3515 char name[PROC_NUMBUF];
3516 int len;
3517 tid = task_pid_nr_ns(task, ns);
3518 len = snprintf(name, sizeof(name), "%d", tid);
3519 if (!proc_fill_cache(file, ctx, name, len,
3520 proc_task_instantiate, task, NULL)) {
3521 /* returning this tgid failed, save it as the first
3522 * pid for the next readir call */
3523 file->f_version = (u64)tid;
3524 put_task_struct(task);
3525 break;
3526 }
3527 }
3528
3529 return 0;
3530 }
3531
3532 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3533 {
3534 struct inode *inode = d_inode(dentry);
3535 struct task_struct *p = get_proc_task(inode);
3536 generic_fillattr(inode, stat);
3537
3538 if (p) {
3539 stat->nlink += get_nr_threads(p);
3540 put_task_struct(p);
3541 }
3542
3543 return 0;
3544 }
3545
3546 static const struct inode_operations proc_task_inode_operations = {
3547 .lookup = proc_task_lookup,
3548 .getattr = proc_task_getattr,
3549 .setattr = proc_setattr,
3550 .permission = proc_pid_permission,
3551 };
3552
3553 static const struct file_operations proc_task_operations = {
3554 .read = generic_read_dir,
3555 .iterate_shared = proc_task_readdir,
3556 .llseek = generic_file_llseek,
3557 };
3558
3559 void __init set_proc_pid_nlink(void)
3560 {
3561 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3562 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3563 }
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