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