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Merge tag 'iommu-updates-v4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/joro...
[mirror_ubuntu-zesty-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 <asm/uaccess.h>
51
52 #include <linux/errno.h>
53 #include <linux/time.h>
54 #include <linux/proc_fs.h>
55 #include <linux/stat.h>
56 #include <linux/task_io_accounting_ops.h>
57 #include <linux/init.h>
58 #include <linux/capability.h>
59 #include <linux/file.h>
60 #include <linux/fdtable.h>
61 #include <linux/string.h>
62 #include <linux/seq_file.h>
63 #include <linux/namei.h>
64 #include <linux/mnt_namespace.h>
65 #include <linux/mm.h>
66 #include <linux/swap.h>
67 #include <linux/rcupdate.h>
68 #include <linux/kallsyms.h>
69 #include <linux/stacktrace.h>
70 #include <linux/resource.h>
71 #include <linux/module.h>
72 #include <linux/mount.h>
73 #include <linux/security.h>
74 #include <linux/ptrace.h>
75 #include <linux/tracehook.h>
76 #include <linux/printk.h>
77 #include <linux/cgroup.h>
78 #include <linux/cpuset.h>
79 #include <linux/audit.h>
80 #include <linux/poll.h>
81 #include <linux/nsproxy.h>
82 #include <linux/oom.h>
83 #include <linux/elf.h>
84 #include <linux/pid_namespace.h>
85 #include <linux/user_namespace.h>
86 #include <linux/fs_struct.h>
87 #include <linux/slab.h>
88 #include <linux/flex_array.h>
89 #include <linux/posix-timers.h>
90 #ifdef CONFIG_HARDWALL
91 #include <asm/hardwall.h>
92 #endif
93 #include <trace/events/oom.h>
94 #include "internal.h"
95 #include "fd.h"
96
97 /* NOTE:
98 * Implementing inode permission operations in /proc is almost
99 * certainly an error. Permission checks need to happen during
100 * each system call not at open time. The reason is that most of
101 * what we wish to check for permissions in /proc varies at runtime.
102 *
103 * The classic example of a problem is opening file descriptors
104 * in /proc for a task before it execs a suid executable.
105 */
106
107 struct pid_entry {
108 const char *name;
109 int len;
110 umode_t mode;
111 const struct inode_operations *iop;
112 const struct file_operations *fop;
113 union proc_op op;
114 };
115
116 #define NOD(NAME, MODE, IOP, FOP, OP) { \
117 .name = (NAME), \
118 .len = sizeof(NAME) - 1, \
119 .mode = MODE, \
120 .iop = IOP, \
121 .fop = FOP, \
122 .op = OP, \
123 }
124
125 #define DIR(NAME, MODE, iops, fops) \
126 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
127 #define LNK(NAME, get_link) \
128 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
129 &proc_pid_link_inode_operations, NULL, \
130 { .proc_get_link = get_link } )
131 #define REG(NAME, MODE, fops) \
132 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
133 #define ONE(NAME, MODE, show) \
134 NOD(NAME, (S_IFREG|(MODE)), \
135 NULL, &proc_single_file_operations, \
136 { .proc_show = show } )
137
138 /*
139 * Count the number of hardlinks for the pid_entry table, excluding the .
140 * and .. links.
141 */
142 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
143 unsigned int n)
144 {
145 unsigned int i;
146 unsigned int count;
147
148 count = 0;
149 for (i = 0; i < n; ++i) {
150 if (S_ISDIR(entries[i].mode))
151 ++count;
152 }
153
154 return count;
155 }
156
157 static int get_task_root(struct task_struct *task, struct path *root)
158 {
159 int result = -ENOENT;
160
161 task_lock(task);
162 if (task->fs) {
163 get_fs_root(task->fs, root);
164 result = 0;
165 }
166 task_unlock(task);
167 return result;
168 }
169
170 static int proc_cwd_link(struct dentry *dentry, struct path *path)
171 {
172 struct task_struct *task = get_proc_task(d_inode(dentry));
173 int result = -ENOENT;
174
175 if (task) {
176 task_lock(task);
177 if (task->fs) {
178 get_fs_pwd(task->fs, path);
179 result = 0;
180 }
181 task_unlock(task);
182 put_task_struct(task);
183 }
184 return result;
185 }
186
187 static int proc_root_link(struct dentry *dentry, struct path *path)
188 {
189 struct task_struct *task = get_proc_task(d_inode(dentry));
190 int result = -ENOENT;
191
192 if (task) {
193 result = get_task_root(task, path);
194 put_task_struct(task);
195 }
196 return result;
197 }
198
199 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
200 size_t _count, loff_t *pos)
201 {
202 struct task_struct *tsk;
203 struct mm_struct *mm;
204 char *page;
205 unsigned long count = _count;
206 unsigned long arg_start, arg_end, env_start, env_end;
207 unsigned long len1, len2, len;
208 unsigned long p;
209 char c;
210 ssize_t rv;
211
212 BUG_ON(*pos < 0);
213
214 tsk = get_proc_task(file_inode(file));
215 if (!tsk)
216 return -ESRCH;
217 mm = get_task_mm(tsk);
218 put_task_struct(tsk);
219 if (!mm)
220 return 0;
221 /* Check if process spawned far enough to have cmdline. */
222 if (!mm->env_end) {
223 rv = 0;
224 goto out_mmput;
225 }
226
227 page = (char *)__get_free_page(GFP_TEMPORARY);
228 if (!page) {
229 rv = -ENOMEM;
230 goto out_mmput;
231 }
232
233 down_read(&mm->mmap_sem);
234 arg_start = mm->arg_start;
235 arg_end = mm->arg_end;
236 env_start = mm->env_start;
237 env_end = mm->env_end;
238 up_read(&mm->mmap_sem);
239
240 BUG_ON(arg_start > arg_end);
241 BUG_ON(env_start > env_end);
242
243 len1 = arg_end - arg_start;
244 len2 = env_end - env_start;
245
246 /* Empty ARGV. */
247 if (len1 == 0) {
248 rv = 0;
249 goto out_free_page;
250 }
251 /*
252 * Inherently racy -- command line shares address space
253 * with code and data.
254 */
255 rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0);
256 if (rv <= 0)
257 goto out_free_page;
258
259 rv = 0;
260
261 if (c == '\0') {
262 /* Command line (set of strings) occupies whole ARGV. */
263 if (len1 <= *pos)
264 goto out_free_page;
265
266 p = arg_start + *pos;
267 len = len1 - *pos;
268 while (count > 0 && len > 0) {
269 unsigned int _count;
270 int nr_read;
271
272 _count = min3(count, len, PAGE_SIZE);
273 nr_read = access_remote_vm(mm, p, page, _count, 0);
274 if (nr_read < 0)
275 rv = nr_read;
276 if (nr_read <= 0)
277 goto out_free_page;
278
279 if (copy_to_user(buf, page, nr_read)) {
280 rv = -EFAULT;
281 goto out_free_page;
282 }
283
284 p += nr_read;
285 len -= nr_read;
286 buf += nr_read;
287 count -= nr_read;
288 rv += nr_read;
289 }
290 } else {
291 /*
292 * Command line (1 string) occupies ARGV and maybe
293 * extends into ENVP.
294 */
295 if (len1 + len2 <= *pos)
296 goto skip_argv_envp;
297 if (len1 <= *pos)
298 goto skip_argv;
299
300 p = arg_start + *pos;
301 len = len1 - *pos;
302 while (count > 0 && len > 0) {
303 unsigned int _count, l;
304 int nr_read;
305 bool final;
306
307 _count = min3(count, len, PAGE_SIZE);
308 nr_read = access_remote_vm(mm, p, page, _count, 0);
309 if (nr_read < 0)
310 rv = nr_read;
311 if (nr_read <= 0)
312 goto out_free_page;
313
314 /*
315 * Command line can be shorter than whole ARGV
316 * even if last "marker" byte says it is not.
317 */
318 final = false;
319 l = strnlen(page, nr_read);
320 if (l < nr_read) {
321 nr_read = l;
322 final = true;
323 }
324
325 if (copy_to_user(buf, page, nr_read)) {
326 rv = -EFAULT;
327 goto out_free_page;
328 }
329
330 p += nr_read;
331 len -= nr_read;
332 buf += nr_read;
333 count -= nr_read;
334 rv += nr_read;
335
336 if (final)
337 goto out_free_page;
338 }
339 skip_argv:
340 /*
341 * Command line (1 string) occupies ARGV and
342 * extends into ENVP.
343 */
344 if (len1 <= *pos) {
345 p = env_start + *pos - len1;
346 len = len1 + len2 - *pos;
347 } else {
348 p = env_start;
349 len = len2;
350 }
351 while (count > 0 && len > 0) {
352 unsigned int _count, l;
353 int nr_read;
354 bool final;
355
356 _count = min3(count, len, PAGE_SIZE);
357 nr_read = access_remote_vm(mm, p, page, _count, 0);
358 if (nr_read < 0)
359 rv = nr_read;
360 if (nr_read <= 0)
361 goto out_free_page;
362
363 /* Find EOS. */
364 final = false;
365 l = strnlen(page, nr_read);
366 if (l < nr_read) {
367 nr_read = l;
368 final = true;
369 }
370
371 if (copy_to_user(buf, page, nr_read)) {
372 rv = -EFAULT;
373 goto out_free_page;
374 }
375
376 p += nr_read;
377 len -= nr_read;
378 buf += nr_read;
379 count -= nr_read;
380 rv += nr_read;
381
382 if (final)
383 goto out_free_page;
384 }
385 skip_argv_envp:
386 ;
387 }
388
389 out_free_page:
390 free_page((unsigned long)page);
391 out_mmput:
392 mmput(mm);
393 if (rv > 0)
394 *pos += rv;
395 return rv;
396 }
397
398 static const struct file_operations proc_pid_cmdline_ops = {
399 .read = proc_pid_cmdline_read,
400 .llseek = generic_file_llseek,
401 };
402
403 #ifdef CONFIG_KALLSYMS
404 /*
405 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
406 * Returns the resolved symbol. If that fails, simply return the address.
407 */
408 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
409 struct pid *pid, struct task_struct *task)
410 {
411 unsigned long wchan;
412 char symname[KSYM_NAME_LEN];
413
414 wchan = get_wchan(task);
415
416 if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)
417 && !lookup_symbol_name(wchan, symname))
418 seq_printf(m, "%s", symname);
419 else
420 seq_putc(m, '0');
421
422 return 0;
423 }
424 #endif /* CONFIG_KALLSYMS */
425
426 static int lock_trace(struct task_struct *task)
427 {
428 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
429 if (err)
430 return err;
431 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
432 mutex_unlock(&task->signal->cred_guard_mutex);
433 return -EPERM;
434 }
435 return 0;
436 }
437
438 static void unlock_trace(struct task_struct *task)
439 {
440 mutex_unlock(&task->signal->cred_guard_mutex);
441 }
442
443 #ifdef CONFIG_STACKTRACE
444
445 #define MAX_STACK_TRACE_DEPTH 64
446
447 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
448 struct pid *pid, struct task_struct *task)
449 {
450 struct stack_trace trace;
451 unsigned long *entries;
452 int err;
453 int i;
454
455 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
456 if (!entries)
457 return -ENOMEM;
458
459 trace.nr_entries = 0;
460 trace.max_entries = MAX_STACK_TRACE_DEPTH;
461 trace.entries = entries;
462 trace.skip = 0;
463
464 err = lock_trace(task);
465 if (!err) {
466 save_stack_trace_tsk(task, &trace);
467
468 for (i = 0; i < trace.nr_entries; i++) {
469 seq_printf(m, "[<%pK>] %pB\n",
470 (void *)entries[i], (void *)entries[i]);
471 }
472 unlock_trace(task);
473 }
474 kfree(entries);
475
476 return err;
477 }
478 #endif
479
480 #ifdef CONFIG_SCHED_INFO
481 /*
482 * Provides /proc/PID/schedstat
483 */
484 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
485 struct pid *pid, struct task_struct *task)
486 {
487 if (unlikely(!sched_info_on()))
488 seq_printf(m, "0 0 0\n");
489 else
490 seq_printf(m, "%llu %llu %lu\n",
491 (unsigned long long)task->se.sum_exec_runtime,
492 (unsigned long long)task->sched_info.run_delay,
493 task->sched_info.pcount);
494
495 return 0;
496 }
497 #endif
498
499 #ifdef CONFIG_LATENCYTOP
500 static int lstats_show_proc(struct seq_file *m, void *v)
501 {
502 int i;
503 struct inode *inode = m->private;
504 struct task_struct *task = get_proc_task(inode);
505
506 if (!task)
507 return -ESRCH;
508 seq_puts(m, "Latency Top version : v0.1\n");
509 for (i = 0; i < 32; i++) {
510 struct latency_record *lr = &task->latency_record[i];
511 if (lr->backtrace[0]) {
512 int q;
513 seq_printf(m, "%i %li %li",
514 lr->count, lr->time, lr->max);
515 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
516 unsigned long bt = lr->backtrace[q];
517 if (!bt)
518 break;
519 if (bt == ULONG_MAX)
520 break;
521 seq_printf(m, " %ps", (void *)bt);
522 }
523 seq_putc(m, '\n');
524 }
525
526 }
527 put_task_struct(task);
528 return 0;
529 }
530
531 static int lstats_open(struct inode *inode, struct file *file)
532 {
533 return single_open(file, lstats_show_proc, inode);
534 }
535
536 static ssize_t lstats_write(struct file *file, const char __user *buf,
537 size_t count, loff_t *offs)
538 {
539 struct task_struct *task = get_proc_task(file_inode(file));
540
541 if (!task)
542 return -ESRCH;
543 clear_all_latency_tracing(task);
544 put_task_struct(task);
545
546 return count;
547 }
548
549 static const struct file_operations proc_lstats_operations = {
550 .open = lstats_open,
551 .read = seq_read,
552 .write = lstats_write,
553 .llseek = seq_lseek,
554 .release = single_release,
555 };
556
557 #endif
558
559 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
560 struct pid *pid, struct task_struct *task)
561 {
562 unsigned long totalpages = totalram_pages + total_swap_pages;
563 unsigned long points = 0;
564
565 points = oom_badness(task, NULL, NULL, totalpages) *
566 1000 / totalpages;
567 seq_printf(m, "%lu\n", points);
568
569 return 0;
570 }
571
572 struct limit_names {
573 const char *name;
574 const char *unit;
575 };
576
577 static const struct limit_names lnames[RLIM_NLIMITS] = {
578 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
579 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
580 [RLIMIT_DATA] = {"Max data size", "bytes"},
581 [RLIMIT_STACK] = {"Max stack size", "bytes"},
582 [RLIMIT_CORE] = {"Max core file size", "bytes"},
583 [RLIMIT_RSS] = {"Max resident set", "bytes"},
584 [RLIMIT_NPROC] = {"Max processes", "processes"},
585 [RLIMIT_NOFILE] = {"Max open files", "files"},
586 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
587 [RLIMIT_AS] = {"Max address space", "bytes"},
588 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
589 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
590 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
591 [RLIMIT_NICE] = {"Max nice priority", NULL},
592 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
593 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
594 };
595
596 /* Display limits for a process */
597 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
598 struct pid *pid, struct task_struct *task)
599 {
600 unsigned int i;
601 unsigned long flags;
602
603 struct rlimit rlim[RLIM_NLIMITS];
604
605 if (!lock_task_sighand(task, &flags))
606 return 0;
607 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
608 unlock_task_sighand(task, &flags);
609
610 /*
611 * print the file header
612 */
613 seq_printf(m, "%-25s %-20s %-20s %-10s\n",
614 "Limit", "Soft Limit", "Hard Limit", "Units");
615
616 for (i = 0; i < RLIM_NLIMITS; i++) {
617 if (rlim[i].rlim_cur == RLIM_INFINITY)
618 seq_printf(m, "%-25s %-20s ",
619 lnames[i].name, "unlimited");
620 else
621 seq_printf(m, "%-25s %-20lu ",
622 lnames[i].name, rlim[i].rlim_cur);
623
624 if (rlim[i].rlim_max == RLIM_INFINITY)
625 seq_printf(m, "%-20s ", "unlimited");
626 else
627 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
628
629 if (lnames[i].unit)
630 seq_printf(m, "%-10s\n", lnames[i].unit);
631 else
632 seq_putc(m, '\n');
633 }
634
635 return 0;
636 }
637
638 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
639 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
640 struct pid *pid, struct task_struct *task)
641 {
642 long nr;
643 unsigned long args[6], sp, pc;
644 int res;
645
646 res = lock_trace(task);
647 if (res)
648 return res;
649
650 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
651 seq_puts(m, "running\n");
652 else if (nr < 0)
653 seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
654 else
655 seq_printf(m,
656 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
657 nr,
658 args[0], args[1], args[2], args[3], args[4], args[5],
659 sp, pc);
660 unlock_trace(task);
661
662 return 0;
663 }
664 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
665
666 /************************************************************************/
667 /* Here the fs part begins */
668 /************************************************************************/
669
670 /* permission checks */
671 static int proc_fd_access_allowed(struct inode *inode)
672 {
673 struct task_struct *task;
674 int allowed = 0;
675 /* Allow access to a task's file descriptors if it is us or we
676 * may use ptrace attach to the process and find out that
677 * information.
678 */
679 task = get_proc_task(inode);
680 if (task) {
681 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
682 put_task_struct(task);
683 }
684 return allowed;
685 }
686
687 int proc_setattr(struct dentry *dentry, struct iattr *attr)
688 {
689 int error;
690 struct inode *inode = d_inode(dentry);
691
692 if (attr->ia_valid & ATTR_MODE)
693 return -EPERM;
694
695 error = setattr_prepare(dentry, attr);
696 if (error)
697 return error;
698
699 setattr_copy(inode, attr);
700 mark_inode_dirty(inode);
701 return 0;
702 }
703
704 /*
705 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
706 * or euid/egid (for hide_pid_min=2)?
707 */
708 static bool has_pid_permissions(struct pid_namespace *pid,
709 struct task_struct *task,
710 int hide_pid_min)
711 {
712 if (pid->hide_pid < hide_pid_min)
713 return true;
714 if (in_group_p(pid->pid_gid))
715 return true;
716 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
717 }
718
719
720 static int proc_pid_permission(struct inode *inode, int mask)
721 {
722 struct pid_namespace *pid = inode->i_sb->s_fs_info;
723 struct task_struct *task;
724 bool has_perms;
725
726 task = get_proc_task(inode);
727 if (!task)
728 return -ESRCH;
729 has_perms = has_pid_permissions(pid, task, 1);
730 put_task_struct(task);
731
732 if (!has_perms) {
733 if (pid->hide_pid == 2) {
734 /*
735 * Let's make getdents(), stat(), and open()
736 * consistent with each other. If a process
737 * may not stat() a file, it shouldn't be seen
738 * in procfs at all.
739 */
740 return -ENOENT;
741 }
742
743 return -EPERM;
744 }
745 return generic_permission(inode, mask);
746 }
747
748
749
750 static const struct inode_operations proc_def_inode_operations = {
751 .setattr = proc_setattr,
752 };
753
754 static int proc_single_show(struct seq_file *m, void *v)
755 {
756 struct inode *inode = m->private;
757 struct pid_namespace *ns;
758 struct pid *pid;
759 struct task_struct *task;
760 int ret;
761
762 ns = inode->i_sb->s_fs_info;
763 pid = proc_pid(inode);
764 task = get_pid_task(pid, PIDTYPE_PID);
765 if (!task)
766 return -ESRCH;
767
768 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
769
770 put_task_struct(task);
771 return ret;
772 }
773
774 static int proc_single_open(struct inode *inode, struct file *filp)
775 {
776 return single_open(filp, proc_single_show, inode);
777 }
778
779 static const struct file_operations proc_single_file_operations = {
780 .open = proc_single_open,
781 .read = seq_read,
782 .llseek = seq_lseek,
783 .release = single_release,
784 };
785
786
787 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
788 {
789 struct task_struct *task = get_proc_task(inode);
790 struct mm_struct *mm = ERR_PTR(-ESRCH);
791
792 if (task) {
793 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
794 put_task_struct(task);
795
796 if (!IS_ERR_OR_NULL(mm)) {
797 /* ensure this mm_struct can't be freed */
798 atomic_inc(&mm->mm_count);
799 /* but do not pin its memory */
800 mmput(mm);
801 }
802 }
803
804 return mm;
805 }
806
807 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
808 {
809 struct mm_struct *mm = proc_mem_open(inode, mode);
810
811 if (IS_ERR(mm))
812 return PTR_ERR(mm);
813
814 file->private_data = mm;
815 return 0;
816 }
817
818 static int mem_open(struct inode *inode, struct file *file)
819 {
820 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
821
822 /* OK to pass negative loff_t, we can catch out-of-range */
823 file->f_mode |= FMODE_UNSIGNED_OFFSET;
824
825 return ret;
826 }
827
828 static ssize_t mem_rw(struct file *file, char __user *buf,
829 size_t count, loff_t *ppos, int write)
830 {
831 struct mm_struct *mm = file->private_data;
832 unsigned long addr = *ppos;
833 ssize_t copied;
834 char *page;
835
836 if (!mm)
837 return 0;
838
839 page = (char *)__get_free_page(GFP_TEMPORARY);
840 if (!page)
841 return -ENOMEM;
842
843 copied = 0;
844 if (!atomic_inc_not_zero(&mm->mm_users))
845 goto free;
846
847 while (count > 0) {
848 int this_len = min_t(int, count, PAGE_SIZE);
849
850 if (write && copy_from_user(page, buf, this_len)) {
851 copied = -EFAULT;
852 break;
853 }
854
855 this_len = access_remote_vm(mm, addr, page, this_len, write);
856 if (!this_len) {
857 if (!copied)
858 copied = -EIO;
859 break;
860 }
861
862 if (!write && copy_to_user(buf, page, this_len)) {
863 copied = -EFAULT;
864 break;
865 }
866
867 buf += this_len;
868 addr += this_len;
869 copied += this_len;
870 count -= this_len;
871 }
872 *ppos = addr;
873
874 mmput(mm);
875 free:
876 free_page((unsigned long) page);
877 return copied;
878 }
879
880 static ssize_t mem_read(struct file *file, char __user *buf,
881 size_t count, loff_t *ppos)
882 {
883 return mem_rw(file, buf, count, ppos, 0);
884 }
885
886 static ssize_t mem_write(struct file *file, const char __user *buf,
887 size_t count, loff_t *ppos)
888 {
889 return mem_rw(file, (char __user*)buf, count, ppos, 1);
890 }
891
892 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
893 {
894 switch (orig) {
895 case 0:
896 file->f_pos = offset;
897 break;
898 case 1:
899 file->f_pos += offset;
900 break;
901 default:
902 return -EINVAL;
903 }
904 force_successful_syscall_return();
905 return file->f_pos;
906 }
907
908 static int mem_release(struct inode *inode, struct file *file)
909 {
910 struct mm_struct *mm = file->private_data;
911 if (mm)
912 mmdrop(mm);
913 return 0;
914 }
915
916 static const struct file_operations proc_mem_operations = {
917 .llseek = mem_lseek,
918 .read = mem_read,
919 .write = mem_write,
920 .open = mem_open,
921 .release = mem_release,
922 };
923
924 static int environ_open(struct inode *inode, struct file *file)
925 {
926 return __mem_open(inode, file, PTRACE_MODE_READ);
927 }
928
929 static ssize_t environ_read(struct file *file, char __user *buf,
930 size_t count, loff_t *ppos)
931 {
932 char *page;
933 unsigned long src = *ppos;
934 int ret = 0;
935 struct mm_struct *mm = file->private_data;
936 unsigned long env_start, env_end;
937
938 /* Ensure the process spawned far enough to have an environment. */
939 if (!mm || !mm->env_end)
940 return 0;
941
942 page = (char *)__get_free_page(GFP_TEMPORARY);
943 if (!page)
944 return -ENOMEM;
945
946 ret = 0;
947 if (!atomic_inc_not_zero(&mm->mm_users))
948 goto free;
949
950 down_read(&mm->mmap_sem);
951 env_start = mm->env_start;
952 env_end = mm->env_end;
953 up_read(&mm->mmap_sem);
954
955 while (count > 0) {
956 size_t this_len, max_len;
957 int retval;
958
959 if (src >= (env_end - env_start))
960 break;
961
962 this_len = env_end - (env_start + src);
963
964 max_len = min_t(size_t, PAGE_SIZE, count);
965 this_len = min(max_len, this_len);
966
967 retval = access_remote_vm(mm, (env_start + src),
968 page, this_len, 0);
969
970 if (retval <= 0) {
971 ret = retval;
972 break;
973 }
974
975 if (copy_to_user(buf, page, retval)) {
976 ret = -EFAULT;
977 break;
978 }
979
980 ret += retval;
981 src += retval;
982 buf += retval;
983 count -= retval;
984 }
985 *ppos = src;
986 mmput(mm);
987
988 free:
989 free_page((unsigned long) page);
990 return ret;
991 }
992
993 static const struct file_operations proc_environ_operations = {
994 .open = environ_open,
995 .read = environ_read,
996 .llseek = generic_file_llseek,
997 .release = mem_release,
998 };
999
1000 static int auxv_open(struct inode *inode, struct file *file)
1001 {
1002 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1003 }
1004
1005 static ssize_t auxv_read(struct file *file, char __user *buf,
1006 size_t count, loff_t *ppos)
1007 {
1008 struct mm_struct *mm = file->private_data;
1009 unsigned int nwords = 0;
1010 do {
1011 nwords += 2;
1012 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1013 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1014 nwords * sizeof(mm->saved_auxv[0]));
1015 }
1016
1017 static const struct file_operations proc_auxv_operations = {
1018 .open = auxv_open,
1019 .read = auxv_read,
1020 .llseek = generic_file_llseek,
1021 .release = mem_release,
1022 };
1023
1024 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1025 loff_t *ppos)
1026 {
1027 struct task_struct *task = get_proc_task(file_inode(file));
1028 char buffer[PROC_NUMBUF];
1029 int oom_adj = OOM_ADJUST_MIN;
1030 size_t len;
1031
1032 if (!task)
1033 return -ESRCH;
1034 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1035 oom_adj = OOM_ADJUST_MAX;
1036 else
1037 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1038 OOM_SCORE_ADJ_MAX;
1039 put_task_struct(task);
1040 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1041 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1042 }
1043
1044 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1045 {
1046 static DEFINE_MUTEX(oom_adj_mutex);
1047 struct mm_struct *mm = NULL;
1048 struct task_struct *task;
1049 int err = 0;
1050
1051 task = get_proc_task(file_inode(file));
1052 if (!task)
1053 return -ESRCH;
1054
1055 mutex_lock(&oom_adj_mutex);
1056 if (legacy) {
1057 if (oom_adj < task->signal->oom_score_adj &&
1058 !capable(CAP_SYS_RESOURCE)) {
1059 err = -EACCES;
1060 goto err_unlock;
1061 }
1062 /*
1063 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1064 * /proc/pid/oom_score_adj instead.
1065 */
1066 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1067 current->comm, task_pid_nr(current), task_pid_nr(task),
1068 task_pid_nr(task));
1069 } else {
1070 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1071 !capable(CAP_SYS_RESOURCE)) {
1072 err = -EACCES;
1073 goto err_unlock;
1074 }
1075 }
1076
1077 /*
1078 * Make sure we will check other processes sharing the mm if this is
1079 * not vfrok which wants its own oom_score_adj.
1080 * pin the mm so it doesn't go away and get reused after task_unlock
1081 */
1082 if (!task->vfork_done) {
1083 struct task_struct *p = find_lock_task_mm(task);
1084
1085 if (p) {
1086 if (atomic_read(&p->mm->mm_users) > 1) {
1087 mm = p->mm;
1088 atomic_inc(&mm->mm_count);
1089 }
1090 task_unlock(p);
1091 }
1092 }
1093
1094 task->signal->oom_score_adj = oom_adj;
1095 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1096 task->signal->oom_score_adj_min = (short)oom_adj;
1097 trace_oom_score_adj_update(task);
1098
1099 if (mm) {
1100 struct task_struct *p;
1101
1102 rcu_read_lock();
1103 for_each_process(p) {
1104 if (same_thread_group(task, p))
1105 continue;
1106
1107 /* do not touch kernel threads or the global init */
1108 if (p->flags & PF_KTHREAD || is_global_init(p))
1109 continue;
1110
1111 task_lock(p);
1112 if (!p->vfork_done && process_shares_mm(p, mm)) {
1113 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",
1114 task_pid_nr(p), p->comm,
1115 p->signal->oom_score_adj, oom_adj,
1116 task_pid_nr(task), task->comm);
1117 p->signal->oom_score_adj = oom_adj;
1118 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1119 p->signal->oom_score_adj_min = (short)oom_adj;
1120 }
1121 task_unlock(p);
1122 }
1123 rcu_read_unlock();
1124 mmdrop(mm);
1125 }
1126 err_unlock:
1127 mutex_unlock(&oom_adj_mutex);
1128 put_task_struct(task);
1129 return err;
1130 }
1131
1132 /*
1133 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1134 * kernels. The effective policy is defined by oom_score_adj, which has a
1135 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1136 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1137 * Processes that become oom disabled via oom_adj will still be oom disabled
1138 * with this implementation.
1139 *
1140 * oom_adj cannot be removed since existing userspace binaries use it.
1141 */
1142 static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1143 size_t count, loff_t *ppos)
1144 {
1145 char buffer[PROC_NUMBUF];
1146 int oom_adj;
1147 int err;
1148
1149 memset(buffer, 0, sizeof(buffer));
1150 if (count > sizeof(buffer) - 1)
1151 count = sizeof(buffer) - 1;
1152 if (copy_from_user(buffer, buf, count)) {
1153 err = -EFAULT;
1154 goto out;
1155 }
1156
1157 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1158 if (err)
1159 goto out;
1160 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1161 oom_adj != OOM_DISABLE) {
1162 err = -EINVAL;
1163 goto out;
1164 }
1165
1166 /*
1167 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1168 * value is always attainable.
1169 */
1170 if (oom_adj == OOM_ADJUST_MAX)
1171 oom_adj = OOM_SCORE_ADJ_MAX;
1172 else
1173 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1174
1175 err = __set_oom_adj(file, oom_adj, true);
1176 out:
1177 return err < 0 ? err : count;
1178 }
1179
1180 static const struct file_operations proc_oom_adj_operations = {
1181 .read = oom_adj_read,
1182 .write = oom_adj_write,
1183 .llseek = generic_file_llseek,
1184 };
1185
1186 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1187 size_t count, loff_t *ppos)
1188 {
1189 struct task_struct *task = get_proc_task(file_inode(file));
1190 char buffer[PROC_NUMBUF];
1191 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1192 size_t len;
1193
1194 if (!task)
1195 return -ESRCH;
1196 oom_score_adj = task->signal->oom_score_adj;
1197 put_task_struct(task);
1198 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1199 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1200 }
1201
1202 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1203 size_t count, loff_t *ppos)
1204 {
1205 char buffer[PROC_NUMBUF];
1206 int oom_score_adj;
1207 int err;
1208
1209 memset(buffer, 0, sizeof(buffer));
1210 if (count > sizeof(buffer) - 1)
1211 count = sizeof(buffer) - 1;
1212 if (copy_from_user(buffer, buf, count)) {
1213 err = -EFAULT;
1214 goto out;
1215 }
1216
1217 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1218 if (err)
1219 goto out;
1220 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1221 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1222 err = -EINVAL;
1223 goto out;
1224 }
1225
1226 err = __set_oom_adj(file, oom_score_adj, false);
1227 out:
1228 return err < 0 ? err : count;
1229 }
1230
1231 static const struct file_operations proc_oom_score_adj_operations = {
1232 .read = oom_score_adj_read,
1233 .write = oom_score_adj_write,
1234 .llseek = default_llseek,
1235 };
1236
1237 #ifdef CONFIG_AUDITSYSCALL
1238 #define TMPBUFLEN 21
1239 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1240 size_t count, loff_t *ppos)
1241 {
1242 struct inode * inode = file_inode(file);
1243 struct task_struct *task = get_proc_task(inode);
1244 ssize_t length;
1245 char tmpbuf[TMPBUFLEN];
1246
1247 if (!task)
1248 return -ESRCH;
1249 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1250 from_kuid(file->f_cred->user_ns,
1251 audit_get_loginuid(task)));
1252 put_task_struct(task);
1253 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1254 }
1255
1256 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1257 size_t count, loff_t *ppos)
1258 {
1259 struct inode * inode = file_inode(file);
1260 uid_t loginuid;
1261 kuid_t kloginuid;
1262 int rv;
1263
1264 rcu_read_lock();
1265 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1266 rcu_read_unlock();
1267 return -EPERM;
1268 }
1269 rcu_read_unlock();
1270
1271 if (*ppos != 0) {
1272 /* No partial writes. */
1273 return -EINVAL;
1274 }
1275
1276 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1277 if (rv < 0)
1278 return rv;
1279
1280 /* is userspace tring to explicitly UNSET the loginuid? */
1281 if (loginuid == AUDIT_UID_UNSET) {
1282 kloginuid = INVALID_UID;
1283 } else {
1284 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1285 if (!uid_valid(kloginuid))
1286 return -EINVAL;
1287 }
1288
1289 rv = audit_set_loginuid(kloginuid);
1290 if (rv < 0)
1291 return rv;
1292 return count;
1293 }
1294
1295 static const struct file_operations proc_loginuid_operations = {
1296 .read = proc_loginuid_read,
1297 .write = proc_loginuid_write,
1298 .llseek = generic_file_llseek,
1299 };
1300
1301 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1302 size_t count, loff_t *ppos)
1303 {
1304 struct inode * inode = file_inode(file);
1305 struct task_struct *task = get_proc_task(inode);
1306 ssize_t length;
1307 char tmpbuf[TMPBUFLEN];
1308
1309 if (!task)
1310 return -ESRCH;
1311 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1312 audit_get_sessionid(task));
1313 put_task_struct(task);
1314 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1315 }
1316
1317 static const struct file_operations proc_sessionid_operations = {
1318 .read = proc_sessionid_read,
1319 .llseek = generic_file_llseek,
1320 };
1321 #endif
1322
1323 #ifdef CONFIG_FAULT_INJECTION
1324 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1325 size_t count, loff_t *ppos)
1326 {
1327 struct task_struct *task = get_proc_task(file_inode(file));
1328 char buffer[PROC_NUMBUF];
1329 size_t len;
1330 int make_it_fail;
1331
1332 if (!task)
1333 return -ESRCH;
1334 make_it_fail = task->make_it_fail;
1335 put_task_struct(task);
1336
1337 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1338
1339 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1340 }
1341
1342 static ssize_t proc_fault_inject_write(struct file * file,
1343 const char __user * buf, size_t count, loff_t *ppos)
1344 {
1345 struct task_struct *task;
1346 char buffer[PROC_NUMBUF];
1347 int make_it_fail;
1348 int rv;
1349
1350 if (!capable(CAP_SYS_RESOURCE))
1351 return -EPERM;
1352 memset(buffer, 0, sizeof(buffer));
1353 if (count > sizeof(buffer) - 1)
1354 count = sizeof(buffer) - 1;
1355 if (copy_from_user(buffer, buf, count))
1356 return -EFAULT;
1357 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1358 if (rv < 0)
1359 return rv;
1360 if (make_it_fail < 0 || make_it_fail > 1)
1361 return -EINVAL;
1362
1363 task = get_proc_task(file_inode(file));
1364 if (!task)
1365 return -ESRCH;
1366 task->make_it_fail = make_it_fail;
1367 put_task_struct(task);
1368
1369 return count;
1370 }
1371
1372 static const struct file_operations proc_fault_inject_operations = {
1373 .read = proc_fault_inject_read,
1374 .write = proc_fault_inject_write,
1375 .llseek = generic_file_llseek,
1376 };
1377 #endif
1378
1379
1380 #ifdef CONFIG_SCHED_DEBUG
1381 /*
1382 * Print out various scheduling related per-task fields:
1383 */
1384 static int sched_show(struct seq_file *m, void *v)
1385 {
1386 struct inode *inode = m->private;
1387 struct task_struct *p;
1388
1389 p = get_proc_task(inode);
1390 if (!p)
1391 return -ESRCH;
1392 proc_sched_show_task(p, m);
1393
1394 put_task_struct(p);
1395
1396 return 0;
1397 }
1398
1399 static ssize_t
1400 sched_write(struct file *file, const char __user *buf,
1401 size_t count, loff_t *offset)
1402 {
1403 struct inode *inode = file_inode(file);
1404 struct task_struct *p;
1405
1406 p = get_proc_task(inode);
1407 if (!p)
1408 return -ESRCH;
1409 proc_sched_set_task(p);
1410
1411 put_task_struct(p);
1412
1413 return count;
1414 }
1415
1416 static int sched_open(struct inode *inode, struct file *filp)
1417 {
1418 return single_open(filp, sched_show, inode);
1419 }
1420
1421 static const struct file_operations proc_pid_sched_operations = {
1422 .open = sched_open,
1423 .read = seq_read,
1424 .write = sched_write,
1425 .llseek = seq_lseek,
1426 .release = single_release,
1427 };
1428
1429 #endif
1430
1431 #ifdef CONFIG_SCHED_AUTOGROUP
1432 /*
1433 * Print out autogroup related information:
1434 */
1435 static int sched_autogroup_show(struct seq_file *m, void *v)
1436 {
1437 struct inode *inode = m->private;
1438 struct task_struct *p;
1439
1440 p = get_proc_task(inode);
1441 if (!p)
1442 return -ESRCH;
1443 proc_sched_autogroup_show_task(p, m);
1444
1445 put_task_struct(p);
1446
1447 return 0;
1448 }
1449
1450 static ssize_t
1451 sched_autogroup_write(struct file *file, const char __user *buf,
1452 size_t count, loff_t *offset)
1453 {
1454 struct inode *inode = file_inode(file);
1455 struct task_struct *p;
1456 char buffer[PROC_NUMBUF];
1457 int nice;
1458 int err;
1459
1460 memset(buffer, 0, sizeof(buffer));
1461 if (count > sizeof(buffer) - 1)
1462 count = sizeof(buffer) - 1;
1463 if (copy_from_user(buffer, buf, count))
1464 return -EFAULT;
1465
1466 err = kstrtoint(strstrip(buffer), 0, &nice);
1467 if (err < 0)
1468 return err;
1469
1470 p = get_proc_task(inode);
1471 if (!p)
1472 return -ESRCH;
1473
1474 err = proc_sched_autogroup_set_nice(p, nice);
1475 if (err)
1476 count = err;
1477
1478 put_task_struct(p);
1479
1480 return count;
1481 }
1482
1483 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1484 {
1485 int ret;
1486
1487 ret = single_open(filp, sched_autogroup_show, NULL);
1488 if (!ret) {
1489 struct seq_file *m = filp->private_data;
1490
1491 m->private = inode;
1492 }
1493 return ret;
1494 }
1495
1496 static const struct file_operations proc_pid_sched_autogroup_operations = {
1497 .open = sched_autogroup_open,
1498 .read = seq_read,
1499 .write = sched_autogroup_write,
1500 .llseek = seq_lseek,
1501 .release = single_release,
1502 };
1503
1504 #endif /* CONFIG_SCHED_AUTOGROUP */
1505
1506 static ssize_t comm_write(struct file *file, const char __user *buf,
1507 size_t count, loff_t *offset)
1508 {
1509 struct inode *inode = file_inode(file);
1510 struct task_struct *p;
1511 char buffer[TASK_COMM_LEN];
1512 const size_t maxlen = sizeof(buffer) - 1;
1513
1514 memset(buffer, 0, sizeof(buffer));
1515 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1516 return -EFAULT;
1517
1518 p = get_proc_task(inode);
1519 if (!p)
1520 return -ESRCH;
1521
1522 if (same_thread_group(current, p))
1523 set_task_comm(p, buffer);
1524 else
1525 count = -EINVAL;
1526
1527 put_task_struct(p);
1528
1529 return count;
1530 }
1531
1532 static int comm_show(struct seq_file *m, void *v)
1533 {
1534 struct inode *inode = m->private;
1535 struct task_struct *p;
1536
1537 p = get_proc_task(inode);
1538 if (!p)
1539 return -ESRCH;
1540
1541 task_lock(p);
1542 seq_printf(m, "%s\n", p->comm);
1543 task_unlock(p);
1544
1545 put_task_struct(p);
1546
1547 return 0;
1548 }
1549
1550 static int comm_open(struct inode *inode, struct file *filp)
1551 {
1552 return single_open(filp, comm_show, inode);
1553 }
1554
1555 static const struct file_operations proc_pid_set_comm_operations = {
1556 .open = comm_open,
1557 .read = seq_read,
1558 .write = comm_write,
1559 .llseek = seq_lseek,
1560 .release = single_release,
1561 };
1562
1563 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1564 {
1565 struct task_struct *task;
1566 struct file *exe_file;
1567
1568 task = get_proc_task(d_inode(dentry));
1569 if (!task)
1570 return -ENOENT;
1571 exe_file = get_task_exe_file(task);
1572 put_task_struct(task);
1573 if (exe_file) {
1574 *exe_path = exe_file->f_path;
1575 path_get(&exe_file->f_path);
1576 fput(exe_file);
1577 return 0;
1578 } else
1579 return -ENOENT;
1580 }
1581
1582 static const char *proc_pid_get_link(struct dentry *dentry,
1583 struct inode *inode,
1584 struct delayed_call *done)
1585 {
1586 struct path path;
1587 int error = -EACCES;
1588
1589 if (!dentry)
1590 return ERR_PTR(-ECHILD);
1591
1592 /* Are we allowed to snoop on the tasks file descriptors? */
1593 if (!proc_fd_access_allowed(inode))
1594 goto out;
1595
1596 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1597 if (error)
1598 goto out;
1599
1600 nd_jump_link(&path);
1601 return NULL;
1602 out:
1603 return ERR_PTR(error);
1604 }
1605
1606 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1607 {
1608 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1609 char *pathname;
1610 int len;
1611
1612 if (!tmp)
1613 return -ENOMEM;
1614
1615 pathname = d_path(path, tmp, PAGE_SIZE);
1616 len = PTR_ERR(pathname);
1617 if (IS_ERR(pathname))
1618 goto out;
1619 len = tmp + PAGE_SIZE - 1 - pathname;
1620
1621 if (len > buflen)
1622 len = buflen;
1623 if (copy_to_user(buffer, pathname, len))
1624 len = -EFAULT;
1625 out:
1626 free_page((unsigned long)tmp);
1627 return len;
1628 }
1629
1630 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1631 {
1632 int error = -EACCES;
1633 struct inode *inode = d_inode(dentry);
1634 struct path path;
1635
1636 /* Are we allowed to snoop on the tasks file descriptors? */
1637 if (!proc_fd_access_allowed(inode))
1638 goto out;
1639
1640 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1641 if (error)
1642 goto out;
1643
1644 error = do_proc_readlink(&path, buffer, buflen);
1645 path_put(&path);
1646 out:
1647 return error;
1648 }
1649
1650 const struct inode_operations proc_pid_link_inode_operations = {
1651 .readlink = proc_pid_readlink,
1652 .get_link = proc_pid_get_link,
1653 .setattr = proc_setattr,
1654 };
1655
1656
1657 /* building an inode */
1658
1659 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1660 {
1661 struct inode * inode;
1662 struct proc_inode *ei;
1663 const struct cred *cred;
1664
1665 /* We need a new inode */
1666
1667 inode = new_inode(sb);
1668 if (!inode)
1669 goto out;
1670
1671 /* Common stuff */
1672 ei = PROC_I(inode);
1673 inode->i_ino = get_next_ino();
1674 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1675 inode->i_op = &proc_def_inode_operations;
1676
1677 /*
1678 * grab the reference to task.
1679 */
1680 ei->pid = get_task_pid(task, PIDTYPE_PID);
1681 if (!ei->pid)
1682 goto out_unlock;
1683
1684 if (task_dumpable(task)) {
1685 rcu_read_lock();
1686 cred = __task_cred(task);
1687 inode->i_uid = cred->euid;
1688 inode->i_gid = cred->egid;
1689 rcu_read_unlock();
1690 }
1691 security_task_to_inode(task, inode);
1692
1693 out:
1694 return inode;
1695
1696 out_unlock:
1697 iput(inode);
1698 return NULL;
1699 }
1700
1701 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1702 {
1703 struct inode *inode = d_inode(dentry);
1704 struct task_struct *task;
1705 const struct cred *cred;
1706 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1707
1708 generic_fillattr(inode, stat);
1709
1710 rcu_read_lock();
1711 stat->uid = GLOBAL_ROOT_UID;
1712 stat->gid = GLOBAL_ROOT_GID;
1713 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1714 if (task) {
1715 if (!has_pid_permissions(pid, task, 2)) {
1716 rcu_read_unlock();
1717 /*
1718 * This doesn't prevent learning whether PID exists,
1719 * it only makes getattr() consistent with readdir().
1720 */
1721 return -ENOENT;
1722 }
1723 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1724 task_dumpable(task)) {
1725 cred = __task_cred(task);
1726 stat->uid = cred->euid;
1727 stat->gid = cred->egid;
1728 }
1729 }
1730 rcu_read_unlock();
1731 return 0;
1732 }
1733
1734 /* dentry stuff */
1735
1736 /*
1737 * Exceptional case: normally we are not allowed to unhash a busy
1738 * directory. In this case, however, we can do it - no aliasing problems
1739 * due to the way we treat inodes.
1740 *
1741 * Rewrite the inode's ownerships here because the owning task may have
1742 * performed a setuid(), etc.
1743 *
1744 * Before the /proc/pid/status file was created the only way to read
1745 * the effective uid of a /process was to stat /proc/pid. Reading
1746 * /proc/pid/status is slow enough that procps and other packages
1747 * kept stating /proc/pid. To keep the rules in /proc simple I have
1748 * made this apply to all per process world readable and executable
1749 * directories.
1750 */
1751 int pid_revalidate(struct dentry *dentry, unsigned int flags)
1752 {
1753 struct inode *inode;
1754 struct task_struct *task;
1755 const struct cred *cred;
1756
1757 if (flags & LOOKUP_RCU)
1758 return -ECHILD;
1759
1760 inode = d_inode(dentry);
1761 task = get_proc_task(inode);
1762
1763 if (task) {
1764 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1765 task_dumpable(task)) {
1766 rcu_read_lock();
1767 cred = __task_cred(task);
1768 inode->i_uid = cred->euid;
1769 inode->i_gid = cred->egid;
1770 rcu_read_unlock();
1771 } else {
1772 inode->i_uid = GLOBAL_ROOT_UID;
1773 inode->i_gid = GLOBAL_ROOT_GID;
1774 }
1775 inode->i_mode &= ~(S_ISUID | S_ISGID);
1776 security_task_to_inode(task, inode);
1777 put_task_struct(task);
1778 return 1;
1779 }
1780 return 0;
1781 }
1782
1783 static inline bool proc_inode_is_dead(struct inode *inode)
1784 {
1785 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1786 }
1787
1788 int pid_delete_dentry(const struct dentry *dentry)
1789 {
1790 /* Is the task we represent dead?
1791 * If so, then don't put the dentry on the lru list,
1792 * kill it immediately.
1793 */
1794 return proc_inode_is_dead(d_inode(dentry));
1795 }
1796
1797 const struct dentry_operations pid_dentry_operations =
1798 {
1799 .d_revalidate = pid_revalidate,
1800 .d_delete = pid_delete_dentry,
1801 };
1802
1803 /* Lookups */
1804
1805 /*
1806 * Fill a directory entry.
1807 *
1808 * If possible create the dcache entry and derive our inode number and
1809 * file type from dcache entry.
1810 *
1811 * Since all of the proc inode numbers are dynamically generated, the inode
1812 * numbers do not exist until the inode is cache. This means creating the
1813 * the dcache entry in readdir is necessary to keep the inode numbers
1814 * reported by readdir in sync with the inode numbers reported
1815 * by stat.
1816 */
1817 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1818 const char *name, int len,
1819 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1820 {
1821 struct dentry *child, *dir = file->f_path.dentry;
1822 struct qstr qname = QSTR_INIT(name, len);
1823 struct inode *inode;
1824 unsigned type;
1825 ino_t ino;
1826
1827 child = d_hash_and_lookup(dir, &qname);
1828 if (!child) {
1829 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
1830 child = d_alloc_parallel(dir, &qname, &wq);
1831 if (IS_ERR(child))
1832 goto end_instantiate;
1833 if (d_in_lookup(child)) {
1834 int err = instantiate(d_inode(dir), child, task, ptr);
1835 d_lookup_done(child);
1836 if (err < 0) {
1837 dput(child);
1838 goto end_instantiate;
1839 }
1840 }
1841 }
1842 inode = d_inode(child);
1843 ino = inode->i_ino;
1844 type = inode->i_mode >> 12;
1845 dput(child);
1846 return dir_emit(ctx, name, len, ino, type);
1847
1848 end_instantiate:
1849 return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1850 }
1851
1852 /*
1853 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1854 * which represent vma start and end addresses.
1855 */
1856 static int dname_to_vma_addr(struct dentry *dentry,
1857 unsigned long *start, unsigned long *end)
1858 {
1859 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1860 return -EINVAL;
1861
1862 return 0;
1863 }
1864
1865 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1866 {
1867 unsigned long vm_start, vm_end;
1868 bool exact_vma_exists = false;
1869 struct mm_struct *mm = NULL;
1870 struct task_struct *task;
1871 const struct cred *cred;
1872 struct inode *inode;
1873 int status = 0;
1874
1875 if (flags & LOOKUP_RCU)
1876 return -ECHILD;
1877
1878 inode = d_inode(dentry);
1879 task = get_proc_task(inode);
1880 if (!task)
1881 goto out_notask;
1882
1883 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
1884 if (IS_ERR_OR_NULL(mm))
1885 goto out;
1886
1887 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1888 down_read(&mm->mmap_sem);
1889 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1890 up_read(&mm->mmap_sem);
1891 }
1892
1893 mmput(mm);
1894
1895 if (exact_vma_exists) {
1896 if (task_dumpable(task)) {
1897 rcu_read_lock();
1898 cred = __task_cred(task);
1899 inode->i_uid = cred->euid;
1900 inode->i_gid = cred->egid;
1901 rcu_read_unlock();
1902 } else {
1903 inode->i_uid = GLOBAL_ROOT_UID;
1904 inode->i_gid = GLOBAL_ROOT_GID;
1905 }
1906 security_task_to_inode(task, inode);
1907 status = 1;
1908 }
1909
1910 out:
1911 put_task_struct(task);
1912
1913 out_notask:
1914 return status;
1915 }
1916
1917 static const struct dentry_operations tid_map_files_dentry_operations = {
1918 .d_revalidate = map_files_d_revalidate,
1919 .d_delete = pid_delete_dentry,
1920 };
1921
1922 static int map_files_get_link(struct dentry *dentry, struct path *path)
1923 {
1924 unsigned long vm_start, vm_end;
1925 struct vm_area_struct *vma;
1926 struct task_struct *task;
1927 struct mm_struct *mm;
1928 int rc;
1929
1930 rc = -ENOENT;
1931 task = get_proc_task(d_inode(dentry));
1932 if (!task)
1933 goto out;
1934
1935 mm = get_task_mm(task);
1936 put_task_struct(task);
1937 if (!mm)
1938 goto out;
1939
1940 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
1941 if (rc)
1942 goto out_mmput;
1943
1944 rc = -ENOENT;
1945 down_read(&mm->mmap_sem);
1946 vma = find_exact_vma(mm, vm_start, vm_end);
1947 if (vma && vma->vm_file) {
1948 *path = vma->vm_file->f_path;
1949 path_get(path);
1950 rc = 0;
1951 }
1952 up_read(&mm->mmap_sem);
1953
1954 out_mmput:
1955 mmput(mm);
1956 out:
1957 return rc;
1958 }
1959
1960 struct map_files_info {
1961 fmode_t mode;
1962 unsigned long len;
1963 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
1964 };
1965
1966 /*
1967 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
1968 * symlinks may be used to bypass permissions on ancestor directories in the
1969 * path to the file in question.
1970 */
1971 static const char *
1972 proc_map_files_get_link(struct dentry *dentry,
1973 struct inode *inode,
1974 struct delayed_call *done)
1975 {
1976 if (!capable(CAP_SYS_ADMIN))
1977 return ERR_PTR(-EPERM);
1978
1979 return proc_pid_get_link(dentry, inode, done);
1980 }
1981
1982 /*
1983 * Identical to proc_pid_link_inode_operations except for get_link()
1984 */
1985 static const struct inode_operations proc_map_files_link_inode_operations = {
1986 .readlink = proc_pid_readlink,
1987 .get_link = proc_map_files_get_link,
1988 .setattr = proc_setattr,
1989 };
1990
1991 static int
1992 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
1993 struct task_struct *task, const void *ptr)
1994 {
1995 fmode_t mode = (fmode_t)(unsigned long)ptr;
1996 struct proc_inode *ei;
1997 struct inode *inode;
1998
1999 inode = proc_pid_make_inode(dir->i_sb, task);
2000 if (!inode)
2001 return -ENOENT;
2002
2003 ei = PROC_I(inode);
2004 ei->op.proc_get_link = map_files_get_link;
2005
2006 inode->i_op = &proc_map_files_link_inode_operations;
2007 inode->i_size = 64;
2008 inode->i_mode = S_IFLNK;
2009
2010 if (mode & FMODE_READ)
2011 inode->i_mode |= S_IRUSR;
2012 if (mode & FMODE_WRITE)
2013 inode->i_mode |= S_IWUSR;
2014
2015 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2016 d_add(dentry, inode);
2017
2018 return 0;
2019 }
2020
2021 static struct dentry *proc_map_files_lookup(struct inode *dir,
2022 struct dentry *dentry, unsigned int flags)
2023 {
2024 unsigned long vm_start, vm_end;
2025 struct vm_area_struct *vma;
2026 struct task_struct *task;
2027 int result;
2028 struct mm_struct *mm;
2029
2030 result = -ENOENT;
2031 task = get_proc_task(dir);
2032 if (!task)
2033 goto out;
2034
2035 result = -EACCES;
2036 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2037 goto out_put_task;
2038
2039 result = -ENOENT;
2040 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2041 goto out_put_task;
2042
2043 mm = get_task_mm(task);
2044 if (!mm)
2045 goto out_put_task;
2046
2047 down_read(&mm->mmap_sem);
2048 vma = find_exact_vma(mm, vm_start, vm_end);
2049 if (!vma)
2050 goto out_no_vma;
2051
2052 if (vma->vm_file)
2053 result = proc_map_files_instantiate(dir, dentry, task,
2054 (void *)(unsigned long)vma->vm_file->f_mode);
2055
2056 out_no_vma:
2057 up_read(&mm->mmap_sem);
2058 mmput(mm);
2059 out_put_task:
2060 put_task_struct(task);
2061 out:
2062 return ERR_PTR(result);
2063 }
2064
2065 static const struct inode_operations proc_map_files_inode_operations = {
2066 .lookup = proc_map_files_lookup,
2067 .permission = proc_fd_permission,
2068 .setattr = proc_setattr,
2069 };
2070
2071 static int
2072 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2073 {
2074 struct vm_area_struct *vma;
2075 struct task_struct *task;
2076 struct mm_struct *mm;
2077 unsigned long nr_files, pos, i;
2078 struct flex_array *fa = NULL;
2079 struct map_files_info info;
2080 struct map_files_info *p;
2081 int ret;
2082
2083 ret = -ENOENT;
2084 task = get_proc_task(file_inode(file));
2085 if (!task)
2086 goto out;
2087
2088 ret = -EACCES;
2089 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2090 goto out_put_task;
2091
2092 ret = 0;
2093 if (!dir_emit_dots(file, ctx))
2094 goto out_put_task;
2095
2096 mm = get_task_mm(task);
2097 if (!mm)
2098 goto out_put_task;
2099 down_read(&mm->mmap_sem);
2100
2101 nr_files = 0;
2102
2103 /*
2104 * We need two passes here:
2105 *
2106 * 1) Collect vmas of mapped files with mmap_sem taken
2107 * 2) Release mmap_sem and instantiate entries
2108 *
2109 * otherwise we get lockdep complained, since filldir()
2110 * routine might require mmap_sem taken in might_fault().
2111 */
2112
2113 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2114 if (vma->vm_file && ++pos > ctx->pos)
2115 nr_files++;
2116 }
2117
2118 if (nr_files) {
2119 fa = flex_array_alloc(sizeof(info), nr_files,
2120 GFP_KERNEL);
2121 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2122 GFP_KERNEL)) {
2123 ret = -ENOMEM;
2124 if (fa)
2125 flex_array_free(fa);
2126 up_read(&mm->mmap_sem);
2127 mmput(mm);
2128 goto out_put_task;
2129 }
2130 for (i = 0, vma = mm->mmap, pos = 2; vma;
2131 vma = vma->vm_next) {
2132 if (!vma->vm_file)
2133 continue;
2134 if (++pos <= ctx->pos)
2135 continue;
2136
2137 info.mode = vma->vm_file->f_mode;
2138 info.len = snprintf(info.name,
2139 sizeof(info.name), "%lx-%lx",
2140 vma->vm_start, vma->vm_end);
2141 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2142 BUG();
2143 }
2144 }
2145 up_read(&mm->mmap_sem);
2146
2147 for (i = 0; i < nr_files; i++) {
2148 p = flex_array_get(fa, i);
2149 if (!proc_fill_cache(file, ctx,
2150 p->name, p->len,
2151 proc_map_files_instantiate,
2152 task,
2153 (void *)(unsigned long)p->mode))
2154 break;
2155 ctx->pos++;
2156 }
2157 if (fa)
2158 flex_array_free(fa);
2159 mmput(mm);
2160
2161 out_put_task:
2162 put_task_struct(task);
2163 out:
2164 return ret;
2165 }
2166
2167 static const struct file_operations proc_map_files_operations = {
2168 .read = generic_read_dir,
2169 .iterate_shared = proc_map_files_readdir,
2170 .llseek = generic_file_llseek,
2171 };
2172
2173 #ifdef CONFIG_CHECKPOINT_RESTORE
2174 struct timers_private {
2175 struct pid *pid;
2176 struct task_struct *task;
2177 struct sighand_struct *sighand;
2178 struct pid_namespace *ns;
2179 unsigned long flags;
2180 };
2181
2182 static void *timers_start(struct seq_file *m, loff_t *pos)
2183 {
2184 struct timers_private *tp = m->private;
2185
2186 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2187 if (!tp->task)
2188 return ERR_PTR(-ESRCH);
2189
2190 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2191 if (!tp->sighand)
2192 return ERR_PTR(-ESRCH);
2193
2194 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2195 }
2196
2197 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2198 {
2199 struct timers_private *tp = m->private;
2200 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2201 }
2202
2203 static void timers_stop(struct seq_file *m, void *v)
2204 {
2205 struct timers_private *tp = m->private;
2206
2207 if (tp->sighand) {
2208 unlock_task_sighand(tp->task, &tp->flags);
2209 tp->sighand = NULL;
2210 }
2211
2212 if (tp->task) {
2213 put_task_struct(tp->task);
2214 tp->task = NULL;
2215 }
2216 }
2217
2218 static int show_timer(struct seq_file *m, void *v)
2219 {
2220 struct k_itimer *timer;
2221 struct timers_private *tp = m->private;
2222 int notify;
2223 static const char * const nstr[] = {
2224 [SIGEV_SIGNAL] = "signal",
2225 [SIGEV_NONE] = "none",
2226 [SIGEV_THREAD] = "thread",
2227 };
2228
2229 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2230 notify = timer->it_sigev_notify;
2231
2232 seq_printf(m, "ID: %d\n", timer->it_id);
2233 seq_printf(m, "signal: %d/%p\n",
2234 timer->sigq->info.si_signo,
2235 timer->sigq->info.si_value.sival_ptr);
2236 seq_printf(m, "notify: %s/%s.%d\n",
2237 nstr[notify & ~SIGEV_THREAD_ID],
2238 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2239 pid_nr_ns(timer->it_pid, tp->ns));
2240 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2241
2242 return 0;
2243 }
2244
2245 static const struct seq_operations proc_timers_seq_ops = {
2246 .start = timers_start,
2247 .next = timers_next,
2248 .stop = timers_stop,
2249 .show = show_timer,
2250 };
2251
2252 static int proc_timers_open(struct inode *inode, struct file *file)
2253 {
2254 struct timers_private *tp;
2255
2256 tp = __seq_open_private(file, &proc_timers_seq_ops,
2257 sizeof(struct timers_private));
2258 if (!tp)
2259 return -ENOMEM;
2260
2261 tp->pid = proc_pid(inode);
2262 tp->ns = inode->i_sb->s_fs_info;
2263 return 0;
2264 }
2265
2266 static const struct file_operations proc_timers_operations = {
2267 .open = proc_timers_open,
2268 .read = seq_read,
2269 .llseek = seq_lseek,
2270 .release = seq_release_private,
2271 };
2272 #endif
2273
2274 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2275 size_t count, loff_t *offset)
2276 {
2277 struct inode *inode = file_inode(file);
2278 struct task_struct *p;
2279 u64 slack_ns;
2280 int err;
2281
2282 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2283 if (err < 0)
2284 return err;
2285
2286 p = get_proc_task(inode);
2287 if (!p)
2288 return -ESRCH;
2289
2290 if (p != current) {
2291 if (!capable(CAP_SYS_NICE)) {
2292 count = -EPERM;
2293 goto out;
2294 }
2295
2296 err = security_task_setscheduler(p);
2297 if (err) {
2298 count = err;
2299 goto out;
2300 }
2301 }
2302
2303 task_lock(p);
2304 if (slack_ns == 0)
2305 p->timer_slack_ns = p->default_timer_slack_ns;
2306 else
2307 p->timer_slack_ns = slack_ns;
2308 task_unlock(p);
2309
2310 out:
2311 put_task_struct(p);
2312
2313 return count;
2314 }
2315
2316 static int timerslack_ns_show(struct seq_file *m, void *v)
2317 {
2318 struct inode *inode = m->private;
2319 struct task_struct *p;
2320 int err = 0;
2321
2322 p = get_proc_task(inode);
2323 if (!p)
2324 return -ESRCH;
2325
2326 if (p != current) {
2327
2328 if (!capable(CAP_SYS_NICE)) {
2329 err = -EPERM;
2330 goto out;
2331 }
2332 err = security_task_getscheduler(p);
2333 if (err)
2334 goto out;
2335 }
2336
2337 task_lock(p);
2338 seq_printf(m, "%llu\n", p->timer_slack_ns);
2339 task_unlock(p);
2340
2341 out:
2342 put_task_struct(p);
2343
2344 return err;
2345 }
2346
2347 static int timerslack_ns_open(struct inode *inode, struct file *filp)
2348 {
2349 return single_open(filp, timerslack_ns_show, inode);
2350 }
2351
2352 static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2353 .open = timerslack_ns_open,
2354 .read = seq_read,
2355 .write = timerslack_ns_write,
2356 .llseek = seq_lseek,
2357 .release = single_release,
2358 };
2359
2360 static int proc_pident_instantiate(struct inode *dir,
2361 struct dentry *dentry, struct task_struct *task, const void *ptr)
2362 {
2363 const struct pid_entry *p = ptr;
2364 struct inode *inode;
2365 struct proc_inode *ei;
2366
2367 inode = proc_pid_make_inode(dir->i_sb, task);
2368 if (!inode)
2369 goto out;
2370
2371 ei = PROC_I(inode);
2372 inode->i_mode = p->mode;
2373 if (S_ISDIR(inode->i_mode))
2374 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2375 if (p->iop)
2376 inode->i_op = p->iop;
2377 if (p->fop)
2378 inode->i_fop = p->fop;
2379 ei->op = p->op;
2380 d_set_d_op(dentry, &pid_dentry_operations);
2381 d_add(dentry, inode);
2382 /* Close the race of the process dying before we return the dentry */
2383 if (pid_revalidate(dentry, 0))
2384 return 0;
2385 out:
2386 return -ENOENT;
2387 }
2388
2389 static struct dentry *proc_pident_lookup(struct inode *dir,
2390 struct dentry *dentry,
2391 const struct pid_entry *ents,
2392 unsigned int nents)
2393 {
2394 int error;
2395 struct task_struct *task = get_proc_task(dir);
2396 const struct pid_entry *p, *last;
2397
2398 error = -ENOENT;
2399
2400 if (!task)
2401 goto out_no_task;
2402
2403 /*
2404 * Yes, it does not scale. And it should not. Don't add
2405 * new entries into /proc/<tgid>/ without very good reasons.
2406 */
2407 last = &ents[nents - 1];
2408 for (p = ents; p <= last; p++) {
2409 if (p->len != dentry->d_name.len)
2410 continue;
2411 if (!memcmp(dentry->d_name.name, p->name, p->len))
2412 break;
2413 }
2414 if (p > last)
2415 goto out;
2416
2417 error = proc_pident_instantiate(dir, dentry, task, p);
2418 out:
2419 put_task_struct(task);
2420 out_no_task:
2421 return ERR_PTR(error);
2422 }
2423
2424 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2425 const struct pid_entry *ents, unsigned int nents)
2426 {
2427 struct task_struct *task = get_proc_task(file_inode(file));
2428 const struct pid_entry *p;
2429
2430 if (!task)
2431 return -ENOENT;
2432
2433 if (!dir_emit_dots(file, ctx))
2434 goto out;
2435
2436 if (ctx->pos >= nents + 2)
2437 goto out;
2438
2439 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) {
2440 if (!proc_fill_cache(file, ctx, p->name, p->len,
2441 proc_pident_instantiate, task, p))
2442 break;
2443 ctx->pos++;
2444 }
2445 out:
2446 put_task_struct(task);
2447 return 0;
2448 }
2449
2450 #ifdef CONFIG_SECURITY
2451 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2452 size_t count, loff_t *ppos)
2453 {
2454 struct inode * inode = file_inode(file);
2455 char *p = NULL;
2456 ssize_t length;
2457 struct task_struct *task = get_proc_task(inode);
2458
2459 if (!task)
2460 return -ESRCH;
2461
2462 length = security_getprocattr(task,
2463 (char*)file->f_path.dentry->d_name.name,
2464 &p);
2465 put_task_struct(task);
2466 if (length > 0)
2467 length = simple_read_from_buffer(buf, count, ppos, p, length);
2468 kfree(p);
2469 return length;
2470 }
2471
2472 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2473 size_t count, loff_t *ppos)
2474 {
2475 struct inode * inode = file_inode(file);
2476 void *page;
2477 ssize_t length;
2478 struct task_struct *task = get_proc_task(inode);
2479
2480 length = -ESRCH;
2481 if (!task)
2482 goto out_no_task;
2483 if (count > PAGE_SIZE)
2484 count = PAGE_SIZE;
2485
2486 /* No partial writes. */
2487 length = -EINVAL;
2488 if (*ppos != 0)
2489 goto out;
2490
2491 page = memdup_user(buf, count);
2492 if (IS_ERR(page)) {
2493 length = PTR_ERR(page);
2494 goto out;
2495 }
2496
2497 /* Guard against adverse ptrace interaction */
2498 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2499 if (length < 0)
2500 goto out_free;
2501
2502 length = security_setprocattr(task,
2503 (char*)file->f_path.dentry->d_name.name,
2504 page, count);
2505 mutex_unlock(&task->signal->cred_guard_mutex);
2506 out_free:
2507 kfree(page);
2508 out:
2509 put_task_struct(task);
2510 out_no_task:
2511 return length;
2512 }
2513
2514 static const struct file_operations proc_pid_attr_operations = {
2515 .read = proc_pid_attr_read,
2516 .write = proc_pid_attr_write,
2517 .llseek = generic_file_llseek,
2518 };
2519
2520 static const struct pid_entry attr_dir_stuff[] = {
2521 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2522 REG("prev", S_IRUGO, proc_pid_attr_operations),
2523 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2524 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2525 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2526 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2527 };
2528
2529 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2530 {
2531 return proc_pident_readdir(file, ctx,
2532 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2533 }
2534
2535 static const struct file_operations proc_attr_dir_operations = {
2536 .read = generic_read_dir,
2537 .iterate_shared = proc_attr_dir_readdir,
2538 .llseek = generic_file_llseek,
2539 };
2540
2541 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2542 struct dentry *dentry, unsigned int flags)
2543 {
2544 return proc_pident_lookup(dir, dentry,
2545 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2546 }
2547
2548 static const struct inode_operations proc_attr_dir_inode_operations = {
2549 .lookup = proc_attr_dir_lookup,
2550 .getattr = pid_getattr,
2551 .setattr = proc_setattr,
2552 };
2553
2554 #endif
2555
2556 #ifdef CONFIG_ELF_CORE
2557 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2558 size_t count, loff_t *ppos)
2559 {
2560 struct task_struct *task = get_proc_task(file_inode(file));
2561 struct mm_struct *mm;
2562 char buffer[PROC_NUMBUF];
2563 size_t len;
2564 int ret;
2565
2566 if (!task)
2567 return -ESRCH;
2568
2569 ret = 0;
2570 mm = get_task_mm(task);
2571 if (mm) {
2572 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2573 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2574 MMF_DUMP_FILTER_SHIFT));
2575 mmput(mm);
2576 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2577 }
2578
2579 put_task_struct(task);
2580
2581 return ret;
2582 }
2583
2584 static ssize_t proc_coredump_filter_write(struct file *file,
2585 const char __user *buf,
2586 size_t count,
2587 loff_t *ppos)
2588 {
2589 struct task_struct *task;
2590 struct mm_struct *mm;
2591 unsigned int val;
2592 int ret;
2593 int i;
2594 unsigned long mask;
2595
2596 ret = kstrtouint_from_user(buf, count, 0, &val);
2597 if (ret < 0)
2598 return ret;
2599
2600 ret = -ESRCH;
2601 task = get_proc_task(file_inode(file));
2602 if (!task)
2603 goto out_no_task;
2604
2605 mm = get_task_mm(task);
2606 if (!mm)
2607 goto out_no_mm;
2608 ret = 0;
2609
2610 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2611 if (val & mask)
2612 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2613 else
2614 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2615 }
2616
2617 mmput(mm);
2618 out_no_mm:
2619 put_task_struct(task);
2620 out_no_task:
2621 if (ret < 0)
2622 return ret;
2623 return count;
2624 }
2625
2626 static const struct file_operations proc_coredump_filter_operations = {
2627 .read = proc_coredump_filter_read,
2628 .write = proc_coredump_filter_write,
2629 .llseek = generic_file_llseek,
2630 };
2631 #endif
2632
2633 #ifdef CONFIG_TASK_IO_ACCOUNTING
2634 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2635 {
2636 struct task_io_accounting acct = task->ioac;
2637 unsigned long flags;
2638 int result;
2639
2640 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2641 if (result)
2642 return result;
2643
2644 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2645 result = -EACCES;
2646 goto out_unlock;
2647 }
2648
2649 if (whole && lock_task_sighand(task, &flags)) {
2650 struct task_struct *t = task;
2651
2652 task_io_accounting_add(&acct, &task->signal->ioac);
2653 while_each_thread(task, t)
2654 task_io_accounting_add(&acct, &t->ioac);
2655
2656 unlock_task_sighand(task, &flags);
2657 }
2658 seq_printf(m,
2659 "rchar: %llu\n"
2660 "wchar: %llu\n"
2661 "syscr: %llu\n"
2662 "syscw: %llu\n"
2663 "read_bytes: %llu\n"
2664 "write_bytes: %llu\n"
2665 "cancelled_write_bytes: %llu\n",
2666 (unsigned long long)acct.rchar,
2667 (unsigned long long)acct.wchar,
2668 (unsigned long long)acct.syscr,
2669 (unsigned long long)acct.syscw,
2670 (unsigned long long)acct.read_bytes,
2671 (unsigned long long)acct.write_bytes,
2672 (unsigned long long)acct.cancelled_write_bytes);
2673 result = 0;
2674
2675 out_unlock:
2676 mutex_unlock(&task->signal->cred_guard_mutex);
2677 return result;
2678 }
2679
2680 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2681 struct pid *pid, struct task_struct *task)
2682 {
2683 return do_io_accounting(task, m, 0);
2684 }
2685
2686 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2687 struct pid *pid, struct task_struct *task)
2688 {
2689 return do_io_accounting(task, m, 1);
2690 }
2691 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2692
2693 #ifdef CONFIG_USER_NS
2694 static int proc_id_map_open(struct inode *inode, struct file *file,
2695 const struct seq_operations *seq_ops)
2696 {
2697 struct user_namespace *ns = NULL;
2698 struct task_struct *task;
2699 struct seq_file *seq;
2700 int ret = -EINVAL;
2701
2702 task = get_proc_task(inode);
2703 if (task) {
2704 rcu_read_lock();
2705 ns = get_user_ns(task_cred_xxx(task, user_ns));
2706 rcu_read_unlock();
2707 put_task_struct(task);
2708 }
2709 if (!ns)
2710 goto err;
2711
2712 ret = seq_open(file, seq_ops);
2713 if (ret)
2714 goto err_put_ns;
2715
2716 seq = file->private_data;
2717 seq->private = ns;
2718
2719 return 0;
2720 err_put_ns:
2721 put_user_ns(ns);
2722 err:
2723 return ret;
2724 }
2725
2726 static int proc_id_map_release(struct inode *inode, struct file *file)
2727 {
2728 struct seq_file *seq = file->private_data;
2729 struct user_namespace *ns = seq->private;
2730 put_user_ns(ns);
2731 return seq_release(inode, file);
2732 }
2733
2734 static int proc_uid_map_open(struct inode *inode, struct file *file)
2735 {
2736 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2737 }
2738
2739 static int proc_gid_map_open(struct inode *inode, struct file *file)
2740 {
2741 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2742 }
2743
2744 static int proc_projid_map_open(struct inode *inode, struct file *file)
2745 {
2746 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2747 }
2748
2749 static const struct file_operations proc_uid_map_operations = {
2750 .open = proc_uid_map_open,
2751 .write = proc_uid_map_write,
2752 .read = seq_read,
2753 .llseek = seq_lseek,
2754 .release = proc_id_map_release,
2755 };
2756
2757 static const struct file_operations proc_gid_map_operations = {
2758 .open = proc_gid_map_open,
2759 .write = proc_gid_map_write,
2760 .read = seq_read,
2761 .llseek = seq_lseek,
2762 .release = proc_id_map_release,
2763 };
2764
2765 static const struct file_operations proc_projid_map_operations = {
2766 .open = proc_projid_map_open,
2767 .write = proc_projid_map_write,
2768 .read = seq_read,
2769 .llseek = seq_lseek,
2770 .release = proc_id_map_release,
2771 };
2772
2773 static int proc_setgroups_open(struct inode *inode, struct file *file)
2774 {
2775 struct user_namespace *ns = NULL;
2776 struct task_struct *task;
2777 int ret;
2778
2779 ret = -ESRCH;
2780 task = get_proc_task(inode);
2781 if (task) {
2782 rcu_read_lock();
2783 ns = get_user_ns(task_cred_xxx(task, user_ns));
2784 rcu_read_unlock();
2785 put_task_struct(task);
2786 }
2787 if (!ns)
2788 goto err;
2789
2790 if (file->f_mode & FMODE_WRITE) {
2791 ret = -EACCES;
2792 if (!ns_capable(ns, CAP_SYS_ADMIN))
2793 goto err_put_ns;
2794 }
2795
2796 ret = single_open(file, &proc_setgroups_show, ns);
2797 if (ret)
2798 goto err_put_ns;
2799
2800 return 0;
2801 err_put_ns:
2802 put_user_ns(ns);
2803 err:
2804 return ret;
2805 }
2806
2807 static int proc_setgroups_release(struct inode *inode, struct file *file)
2808 {
2809 struct seq_file *seq = file->private_data;
2810 struct user_namespace *ns = seq->private;
2811 int ret = single_release(inode, file);
2812 put_user_ns(ns);
2813 return ret;
2814 }
2815
2816 static const struct file_operations proc_setgroups_operations = {
2817 .open = proc_setgroups_open,
2818 .write = proc_setgroups_write,
2819 .read = seq_read,
2820 .llseek = seq_lseek,
2821 .release = proc_setgroups_release,
2822 };
2823 #endif /* CONFIG_USER_NS */
2824
2825 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2826 struct pid *pid, struct task_struct *task)
2827 {
2828 int err = lock_trace(task);
2829 if (!err) {
2830 seq_printf(m, "%08x\n", task->personality);
2831 unlock_trace(task);
2832 }
2833 return err;
2834 }
2835
2836 /*
2837 * Thread groups
2838 */
2839 static const struct file_operations proc_task_operations;
2840 static const struct inode_operations proc_task_inode_operations;
2841
2842 static const struct pid_entry tgid_base_stuff[] = {
2843 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2844 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2845 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2846 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2847 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2848 #ifdef CONFIG_NET
2849 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2850 #endif
2851 REG("environ", S_IRUSR, proc_environ_operations),
2852 REG("auxv", S_IRUSR, proc_auxv_operations),
2853 ONE("status", S_IRUGO, proc_pid_status),
2854 ONE("personality", S_IRUSR, proc_pid_personality),
2855 ONE("limits", S_IRUGO, proc_pid_limits),
2856 #ifdef CONFIG_SCHED_DEBUG
2857 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2858 #endif
2859 #ifdef CONFIG_SCHED_AUTOGROUP
2860 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2861 #endif
2862 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2863 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2864 ONE("syscall", S_IRUSR, proc_pid_syscall),
2865 #endif
2866 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
2867 ONE("stat", S_IRUGO, proc_tgid_stat),
2868 ONE("statm", S_IRUGO, proc_pid_statm),
2869 REG("maps", S_IRUGO, proc_pid_maps_operations),
2870 #ifdef CONFIG_NUMA
2871 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2872 #endif
2873 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2874 LNK("cwd", proc_cwd_link),
2875 LNK("root", proc_root_link),
2876 LNK("exe", proc_exe_link),
2877 REG("mounts", S_IRUGO, proc_mounts_operations),
2878 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2879 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2880 #ifdef CONFIG_PROC_PAGE_MONITOR
2881 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2882 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2883 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2884 #endif
2885 #ifdef CONFIG_SECURITY
2886 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2887 #endif
2888 #ifdef CONFIG_KALLSYMS
2889 ONE("wchan", S_IRUGO, proc_pid_wchan),
2890 #endif
2891 #ifdef CONFIG_STACKTRACE
2892 ONE("stack", S_IRUSR, proc_pid_stack),
2893 #endif
2894 #ifdef CONFIG_SCHED_INFO
2895 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
2896 #endif
2897 #ifdef CONFIG_LATENCYTOP
2898 REG("latency", S_IRUGO, proc_lstats_operations),
2899 #endif
2900 #ifdef CONFIG_PROC_PID_CPUSET
2901 ONE("cpuset", S_IRUGO, proc_cpuset_show),
2902 #endif
2903 #ifdef CONFIG_CGROUPS
2904 ONE("cgroup", S_IRUGO, proc_cgroup_show),
2905 #endif
2906 ONE("oom_score", S_IRUGO, proc_oom_score),
2907 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2908 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2909 #ifdef CONFIG_AUDITSYSCALL
2910 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2911 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2912 #endif
2913 #ifdef CONFIG_FAULT_INJECTION
2914 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2915 #endif
2916 #ifdef CONFIG_ELF_CORE
2917 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2918 #endif
2919 #ifdef CONFIG_TASK_IO_ACCOUNTING
2920 ONE("io", S_IRUSR, proc_tgid_io_accounting),
2921 #endif
2922 #ifdef CONFIG_HARDWALL
2923 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
2924 #endif
2925 #ifdef CONFIG_USER_NS
2926 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2927 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2928 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2929 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
2930 #endif
2931 #ifdef CONFIG_CHECKPOINT_RESTORE
2932 REG("timers", S_IRUGO, proc_timers_operations),
2933 #endif
2934 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
2935 };
2936
2937 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
2938 {
2939 return proc_pident_readdir(file, ctx,
2940 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2941 }
2942
2943 static const struct file_operations proc_tgid_base_operations = {
2944 .read = generic_read_dir,
2945 .iterate_shared = proc_tgid_base_readdir,
2946 .llseek = generic_file_llseek,
2947 };
2948
2949 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2950 {
2951 return proc_pident_lookup(dir, dentry,
2952 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2953 }
2954
2955 static const struct inode_operations proc_tgid_base_inode_operations = {
2956 .lookup = proc_tgid_base_lookup,
2957 .getattr = pid_getattr,
2958 .setattr = proc_setattr,
2959 .permission = proc_pid_permission,
2960 };
2961
2962 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2963 {
2964 struct dentry *dentry, *leader, *dir;
2965 char buf[PROC_NUMBUF];
2966 struct qstr name;
2967
2968 name.name = buf;
2969 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2970 /* no ->d_hash() rejects on procfs */
2971 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2972 if (dentry) {
2973 d_invalidate(dentry);
2974 dput(dentry);
2975 }
2976
2977 if (pid == tgid)
2978 return;
2979
2980 name.name = buf;
2981 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2982 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2983 if (!leader)
2984 goto out;
2985
2986 name.name = "task";
2987 name.len = strlen(name.name);
2988 dir = d_hash_and_lookup(leader, &name);
2989 if (!dir)
2990 goto out_put_leader;
2991
2992 name.name = buf;
2993 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2994 dentry = d_hash_and_lookup(dir, &name);
2995 if (dentry) {
2996 d_invalidate(dentry);
2997 dput(dentry);
2998 }
2999
3000 dput(dir);
3001 out_put_leader:
3002 dput(leader);
3003 out:
3004 return;
3005 }
3006
3007 /**
3008 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3009 * @task: task that should be flushed.
3010 *
3011 * When flushing dentries from proc, one needs to flush them from global
3012 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3013 * in. This call is supposed to do all of this job.
3014 *
3015 * Looks in the dcache for
3016 * /proc/@pid
3017 * /proc/@tgid/task/@pid
3018 * if either directory is present flushes it and all of it'ts children
3019 * from the dcache.
3020 *
3021 * It is safe and reasonable to cache /proc entries for a task until
3022 * that task exits. After that they just clog up the dcache with
3023 * useless entries, possibly causing useful dcache entries to be
3024 * flushed instead. This routine is proved to flush those useless
3025 * dcache entries at process exit time.
3026 *
3027 * NOTE: This routine is just an optimization so it does not guarantee
3028 * that no dcache entries will exist at process exit time it
3029 * just makes it very unlikely that any will persist.
3030 */
3031
3032 void proc_flush_task(struct task_struct *task)
3033 {
3034 int i;
3035 struct pid *pid, *tgid;
3036 struct upid *upid;
3037
3038 pid = task_pid(task);
3039 tgid = task_tgid(task);
3040
3041 for (i = 0; i <= pid->level; i++) {
3042 upid = &pid->numbers[i];
3043 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3044 tgid->numbers[i].nr);
3045 }
3046 }
3047
3048 static int proc_pid_instantiate(struct inode *dir,
3049 struct dentry * dentry,
3050 struct task_struct *task, const void *ptr)
3051 {
3052 struct inode *inode;
3053
3054 inode = proc_pid_make_inode(dir->i_sb, task);
3055 if (!inode)
3056 goto out;
3057
3058 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3059 inode->i_op = &proc_tgid_base_inode_operations;
3060 inode->i_fop = &proc_tgid_base_operations;
3061 inode->i_flags|=S_IMMUTABLE;
3062
3063 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
3064 ARRAY_SIZE(tgid_base_stuff)));
3065
3066 d_set_d_op(dentry, &pid_dentry_operations);
3067
3068 d_add(dentry, inode);
3069 /* Close the race of the process dying before we return the dentry */
3070 if (pid_revalidate(dentry, 0))
3071 return 0;
3072 out:
3073 return -ENOENT;
3074 }
3075
3076 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3077 {
3078 int result = -ENOENT;
3079 struct task_struct *task;
3080 unsigned tgid;
3081 struct pid_namespace *ns;
3082
3083 tgid = name_to_int(&dentry->d_name);
3084 if (tgid == ~0U)
3085 goto out;
3086
3087 ns = dentry->d_sb->s_fs_info;
3088 rcu_read_lock();
3089 task = find_task_by_pid_ns(tgid, ns);
3090 if (task)
3091 get_task_struct(task);
3092 rcu_read_unlock();
3093 if (!task)
3094 goto out;
3095
3096 result = proc_pid_instantiate(dir, dentry, task, NULL);
3097 put_task_struct(task);
3098 out:
3099 return ERR_PTR(result);
3100 }
3101
3102 /*
3103 * Find the first task with tgid >= tgid
3104 *
3105 */
3106 struct tgid_iter {
3107 unsigned int tgid;
3108 struct task_struct *task;
3109 };
3110 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3111 {
3112 struct pid *pid;
3113
3114 if (iter.task)
3115 put_task_struct(iter.task);
3116 rcu_read_lock();
3117 retry:
3118 iter.task = NULL;
3119 pid = find_ge_pid(iter.tgid, ns);
3120 if (pid) {
3121 iter.tgid = pid_nr_ns(pid, ns);
3122 iter.task = pid_task(pid, PIDTYPE_PID);
3123 /* What we to know is if the pid we have find is the
3124 * pid of a thread_group_leader. Testing for task
3125 * being a thread_group_leader is the obvious thing
3126 * todo but there is a window when it fails, due to
3127 * the pid transfer logic in de_thread.
3128 *
3129 * So we perform the straight forward test of seeing
3130 * if the pid we have found is the pid of a thread
3131 * group leader, and don't worry if the task we have
3132 * found doesn't happen to be a thread group leader.
3133 * As we don't care in the case of readdir.
3134 */
3135 if (!iter.task || !has_group_leader_pid(iter.task)) {
3136 iter.tgid += 1;
3137 goto retry;
3138 }
3139 get_task_struct(iter.task);
3140 }
3141 rcu_read_unlock();
3142 return iter;
3143 }
3144
3145 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3146
3147 /* for the /proc/ directory itself, after non-process stuff has been done */
3148 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3149 {
3150 struct tgid_iter iter;
3151 struct pid_namespace *ns = file_inode(file)->i_sb->s_fs_info;
3152 loff_t pos = ctx->pos;
3153
3154 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3155 return 0;
3156
3157 if (pos == TGID_OFFSET - 2) {
3158 struct inode *inode = d_inode(ns->proc_self);
3159 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3160 return 0;
3161 ctx->pos = pos = pos + 1;
3162 }
3163 if (pos == TGID_OFFSET - 1) {
3164 struct inode *inode = d_inode(ns->proc_thread_self);
3165 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3166 return 0;
3167 ctx->pos = pos = pos + 1;
3168 }
3169 iter.tgid = pos - TGID_OFFSET;
3170 iter.task = NULL;
3171 for (iter = next_tgid(ns, iter);
3172 iter.task;
3173 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3174 char name[PROC_NUMBUF];
3175 int len;
3176 if (!has_pid_permissions(ns, iter.task, 2))
3177 continue;
3178
3179 len = snprintf(name, sizeof(name), "%d", iter.tgid);
3180 ctx->pos = iter.tgid + TGID_OFFSET;
3181 if (!proc_fill_cache(file, ctx, name, len,
3182 proc_pid_instantiate, iter.task, NULL)) {
3183 put_task_struct(iter.task);
3184 return 0;
3185 }
3186 }
3187 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3188 return 0;
3189 }
3190
3191 /*
3192 * proc_tid_comm_permission is a special permission function exclusively
3193 * used for the node /proc/<pid>/task/<tid>/comm.
3194 * It bypasses generic permission checks in the case where a task of the same
3195 * task group attempts to access the node.
3196 * The rationale behind this is that glibc and bionic access this node for
3197 * cross thread naming (pthread_set/getname_np(!self)). However, if
3198 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3199 * which locks out the cross thread naming implementation.
3200 * This function makes sure that the node is always accessible for members of
3201 * same thread group.
3202 */
3203 static int proc_tid_comm_permission(struct inode *inode, int mask)
3204 {
3205 bool is_same_tgroup;
3206 struct task_struct *task;
3207
3208 task = get_proc_task(inode);
3209 if (!task)
3210 return -ESRCH;
3211 is_same_tgroup = same_thread_group(current, task);
3212 put_task_struct(task);
3213
3214 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3215 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3216 * read or written by the members of the corresponding
3217 * thread group.
3218 */
3219 return 0;
3220 }
3221
3222 return generic_permission(inode, mask);
3223 }
3224
3225 static const struct inode_operations proc_tid_comm_inode_operations = {
3226 .permission = proc_tid_comm_permission,
3227 };
3228
3229 /*
3230 * Tasks
3231 */
3232 static const struct pid_entry tid_base_stuff[] = {
3233 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3234 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3235 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3236 #ifdef CONFIG_NET
3237 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3238 #endif
3239 REG("environ", S_IRUSR, proc_environ_operations),
3240 REG("auxv", S_IRUSR, proc_auxv_operations),
3241 ONE("status", S_IRUGO, proc_pid_status),
3242 ONE("personality", S_IRUSR, proc_pid_personality),
3243 ONE("limits", S_IRUGO, proc_pid_limits),
3244 #ifdef CONFIG_SCHED_DEBUG
3245 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3246 #endif
3247 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3248 &proc_tid_comm_inode_operations,
3249 &proc_pid_set_comm_operations, {}),
3250 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3251 ONE("syscall", S_IRUSR, proc_pid_syscall),
3252 #endif
3253 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3254 ONE("stat", S_IRUGO, proc_tid_stat),
3255 ONE("statm", S_IRUGO, proc_pid_statm),
3256 REG("maps", S_IRUGO, proc_tid_maps_operations),
3257 #ifdef CONFIG_PROC_CHILDREN
3258 REG("children", S_IRUGO, proc_tid_children_operations),
3259 #endif
3260 #ifdef CONFIG_NUMA
3261 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3262 #endif
3263 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3264 LNK("cwd", proc_cwd_link),
3265 LNK("root", proc_root_link),
3266 LNK("exe", proc_exe_link),
3267 REG("mounts", S_IRUGO, proc_mounts_operations),
3268 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3269 #ifdef CONFIG_PROC_PAGE_MONITOR
3270 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3271 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3272 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3273 #endif
3274 #ifdef CONFIG_SECURITY
3275 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3276 #endif
3277 #ifdef CONFIG_KALLSYMS
3278 ONE("wchan", S_IRUGO, proc_pid_wchan),
3279 #endif
3280 #ifdef CONFIG_STACKTRACE
3281 ONE("stack", S_IRUSR, proc_pid_stack),
3282 #endif
3283 #ifdef CONFIG_SCHED_INFO
3284 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3285 #endif
3286 #ifdef CONFIG_LATENCYTOP
3287 REG("latency", S_IRUGO, proc_lstats_operations),
3288 #endif
3289 #ifdef CONFIG_PROC_PID_CPUSET
3290 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3291 #endif
3292 #ifdef CONFIG_CGROUPS
3293 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3294 #endif
3295 ONE("oom_score", S_IRUGO, proc_oom_score),
3296 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3297 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3298 #ifdef CONFIG_AUDITSYSCALL
3299 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3300 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3301 #endif
3302 #ifdef CONFIG_FAULT_INJECTION
3303 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3304 #endif
3305 #ifdef CONFIG_TASK_IO_ACCOUNTING
3306 ONE("io", S_IRUSR, proc_tid_io_accounting),
3307 #endif
3308 #ifdef CONFIG_HARDWALL
3309 ONE("hardwall", S_IRUGO, proc_pid_hardwall),
3310 #endif
3311 #ifdef CONFIG_USER_NS
3312 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3313 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3314 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3315 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3316 #endif
3317 };
3318
3319 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3320 {
3321 return proc_pident_readdir(file, ctx,
3322 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3323 }
3324
3325 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3326 {
3327 return proc_pident_lookup(dir, dentry,
3328 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3329 }
3330
3331 static const struct file_operations proc_tid_base_operations = {
3332 .read = generic_read_dir,
3333 .iterate_shared = proc_tid_base_readdir,
3334 .llseek = generic_file_llseek,
3335 };
3336
3337 static const struct inode_operations proc_tid_base_inode_operations = {
3338 .lookup = proc_tid_base_lookup,
3339 .getattr = pid_getattr,
3340 .setattr = proc_setattr,
3341 };
3342
3343 static int proc_task_instantiate(struct inode *dir,
3344 struct dentry *dentry, struct task_struct *task, const void *ptr)
3345 {
3346 struct inode *inode;
3347 inode = proc_pid_make_inode(dir->i_sb, task);
3348
3349 if (!inode)
3350 goto out;
3351 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3352 inode->i_op = &proc_tid_base_inode_operations;
3353 inode->i_fop = &proc_tid_base_operations;
3354 inode->i_flags|=S_IMMUTABLE;
3355
3356 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3357 ARRAY_SIZE(tid_base_stuff)));
3358
3359 d_set_d_op(dentry, &pid_dentry_operations);
3360
3361 d_add(dentry, inode);
3362 /* Close the race of the process dying before we return the dentry */
3363 if (pid_revalidate(dentry, 0))
3364 return 0;
3365 out:
3366 return -ENOENT;
3367 }
3368
3369 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3370 {
3371 int result = -ENOENT;
3372 struct task_struct *task;
3373 struct task_struct *leader = get_proc_task(dir);
3374 unsigned tid;
3375 struct pid_namespace *ns;
3376
3377 if (!leader)
3378 goto out_no_task;
3379
3380 tid = name_to_int(&dentry->d_name);
3381 if (tid == ~0U)
3382 goto out;
3383
3384 ns = dentry->d_sb->s_fs_info;
3385 rcu_read_lock();
3386 task = find_task_by_pid_ns(tid, ns);
3387 if (task)
3388 get_task_struct(task);
3389 rcu_read_unlock();
3390 if (!task)
3391 goto out;
3392 if (!same_thread_group(leader, task))
3393 goto out_drop_task;
3394
3395 result = proc_task_instantiate(dir, dentry, task, NULL);
3396 out_drop_task:
3397 put_task_struct(task);
3398 out:
3399 put_task_struct(leader);
3400 out_no_task:
3401 return ERR_PTR(result);
3402 }
3403
3404 /*
3405 * Find the first tid of a thread group to return to user space.
3406 *
3407 * Usually this is just the thread group leader, but if the users
3408 * buffer was too small or there was a seek into the middle of the
3409 * directory we have more work todo.
3410 *
3411 * In the case of a short read we start with find_task_by_pid.
3412 *
3413 * In the case of a seek we start with the leader and walk nr
3414 * threads past it.
3415 */
3416 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3417 struct pid_namespace *ns)
3418 {
3419 struct task_struct *pos, *task;
3420 unsigned long nr = f_pos;
3421
3422 if (nr != f_pos) /* 32bit overflow? */
3423 return NULL;
3424
3425 rcu_read_lock();
3426 task = pid_task(pid, PIDTYPE_PID);
3427 if (!task)
3428 goto fail;
3429
3430 /* Attempt to start with the tid of a thread */
3431 if (tid && nr) {
3432 pos = find_task_by_pid_ns(tid, ns);
3433 if (pos && same_thread_group(pos, task))
3434 goto found;
3435 }
3436
3437 /* If nr exceeds the number of threads there is nothing todo */
3438 if (nr >= get_nr_threads(task))
3439 goto fail;
3440
3441 /* If we haven't found our starting place yet start
3442 * with the leader and walk nr threads forward.
3443 */
3444 pos = task = task->group_leader;
3445 do {
3446 if (!nr--)
3447 goto found;
3448 } while_each_thread(task, pos);
3449 fail:
3450 pos = NULL;
3451 goto out;
3452 found:
3453 get_task_struct(pos);
3454 out:
3455 rcu_read_unlock();
3456 return pos;
3457 }
3458
3459 /*
3460 * Find the next thread in the thread list.
3461 * Return NULL if there is an error or no next thread.
3462 *
3463 * The reference to the input task_struct is released.
3464 */
3465 static struct task_struct *next_tid(struct task_struct *start)
3466 {
3467 struct task_struct *pos = NULL;
3468 rcu_read_lock();
3469 if (pid_alive(start)) {
3470 pos = next_thread(start);
3471 if (thread_group_leader(pos))
3472 pos = NULL;
3473 else
3474 get_task_struct(pos);
3475 }
3476 rcu_read_unlock();
3477 put_task_struct(start);
3478 return pos;
3479 }
3480
3481 /* for the /proc/TGID/task/ directories */
3482 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3483 {
3484 struct inode *inode = file_inode(file);
3485 struct task_struct *task;
3486 struct pid_namespace *ns;
3487 int tid;
3488
3489 if (proc_inode_is_dead(inode))
3490 return -ENOENT;
3491
3492 if (!dir_emit_dots(file, ctx))
3493 return 0;
3494
3495 /* f_version caches the tgid value that the last readdir call couldn't
3496 * return. lseek aka telldir automagically resets f_version to 0.
3497 */
3498 ns = inode->i_sb->s_fs_info;
3499 tid = (int)file->f_version;
3500 file->f_version = 0;
3501 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3502 task;
3503 task = next_tid(task), ctx->pos++) {
3504 char name[PROC_NUMBUF];
3505 int len;
3506 tid = task_pid_nr_ns(task, ns);
3507 len = snprintf(name, sizeof(name), "%d", tid);
3508 if (!proc_fill_cache(file, ctx, name, len,
3509 proc_task_instantiate, task, NULL)) {
3510 /* returning this tgid failed, save it as the first
3511 * pid for the next readir call */
3512 file->f_version = (u64)tid;
3513 put_task_struct(task);
3514 break;
3515 }
3516 }
3517
3518 return 0;
3519 }
3520
3521 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3522 {
3523 struct inode *inode = d_inode(dentry);
3524 struct task_struct *p = get_proc_task(inode);
3525 generic_fillattr(inode, stat);
3526
3527 if (p) {
3528 stat->nlink += get_nr_threads(p);
3529 put_task_struct(p);
3530 }
3531
3532 return 0;
3533 }
3534
3535 static const struct inode_operations proc_task_inode_operations = {
3536 .lookup = proc_task_lookup,
3537 .getattr = proc_task_getattr,
3538 .setattr = proc_setattr,
3539 .permission = proc_pid_permission,
3540 };
3541
3542 static const struct file_operations proc_task_operations = {
3543 .read = generic_read_dir,
3544 .iterate_shared = proc_task_readdir,
3545 .llseek = generic_file_llseek,
3546 };
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