?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
staging: rtl8723bs: os_dep: change return type of rtw_suspend_ap_wow
[linux/fpc-iii.git] / fs / proc / base.c
blobebea9501afb84cd8969d2a4a4a25361a91e353c3
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/proc/base.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * proc base directory handling functions
8 *
9 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
10 * Instead of using magical inumbers to determine the kind of object
11 * we allocate and fill in-core inodes upon lookup. They don't even
12 * go into icache. We cache the reference to task_struct upon lookup too.
13 * Eventually it should become a filesystem in its own. We don't use the
14 * rest of procfs anymore.
15 *
16 *
17 * Changelog:
18 * 17-Jan-2005
19 * Allan Bezerra
20 * Bruna Moreira <bruna.moreira@indt.org.br>
21 * Edjard Mota <edjard.mota@indt.org.br>
22 * Ilias Biris <ilias.biris@indt.org.br>
23 * Mauricio Lin <mauricio.lin@indt.org.br>
24 *
25 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
26 *
27 * A new process specific entry (smaps) included in /proc. It shows the
28 * size of rss for each memory area. The maps entry lacks information
29 * about physical memory size (rss) for each mapped file, i.e.,
30 * rss information for executables and library files.
31 * This additional information is useful for any tools that need to know
32 * about physical memory consumption for a process specific library.
33 *
34 * Changelog:
35 * 21-Feb-2005
36 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
37 * Pud inclusion in the page table walking.
38 *
39 * ChangeLog:
40 * 10-Mar-2005
41 * 10LE Instituto Nokia de Tecnologia - INdT:
42 * A better way to walks through the page table as suggested by Hugh Dickins.
43 *
44 * Simo Piiroinen <simo.piiroinen@nokia.com>:
45 * Smaps information related to shared, private, clean and dirty pages.
46 *
47 * Paul Mundt <paul.mundt@nokia.com>:
48 * Overall revision about smaps.
49 */
50
51 #include <linux/uaccess.h>
52
53 #include <linux/errno.h>
54 #include <linux/time.h>
55 #include <linux/proc_fs.h>
56 #include <linux/stat.h>
57 #include <linux/task_io_accounting_ops.h>
58 #include <linux/init.h>
59 #include <linux/capability.h>
60 #include <linux/file.h>
61 #include <linux/fdtable.h>
62 #include <linux/generic-radix-tree.h>
63 #include <linux/string.h>
64 #include <linux/seq_file.h>
65 #include <linux/namei.h>
66 #include <linux/mnt_namespace.h>
67 #include <linux/mm.h>
68 #include <linux/swap.h>
69 #include <linux/rcupdate.h>
70 #include <linux/kallsyms.h>
71 #include <linux/stacktrace.h>
72 #include <linux/resource.h>
73 #include <linux/module.h>
74 #include <linux/mount.h>
75 #include <linux/security.h>
76 #include <linux/ptrace.h>
77 #include <linux/tracehook.h>
78 #include <linux/printk.h>
79 #include <linux/cache.h>
80 #include <linux/cgroup.h>
81 #include <linux/cpuset.h>
82 #include <linux/audit.h>
83 #include <linux/poll.h>
84 #include <linux/nsproxy.h>
85 #include <linux/oom.h>
86 #include <linux/elf.h>
87 #include <linux/pid_namespace.h>
88 #include <linux/user_namespace.h>
89 #include <linux/fs_struct.h>
90 #include <linux/slab.h>
91 #include <linux/sched/autogroup.h>
92 #include <linux/sched/mm.h>
93 #include <linux/sched/coredump.h>
94 #include <linux/sched/debug.h>
95 #include <linux/sched/stat.h>
96 #include <linux/posix-timers.h>
97 #include <trace/events/oom.h>
98 #include "internal.h"
99 #include "fd.h"
100
101 #include "../../lib/kstrtox.h"
102
103 /* NOTE:
104 * Implementing inode permission operations in /proc is almost
105 * certainly an error. Permission checks need to happen during
106 * each system call not at open time. The reason is that most of
107 * what we wish to check for permissions in /proc varies at runtime.
108 *
109 * The classic example of a problem is opening file descriptors
110 * in /proc for a task before it execs a suid executable.
111 */
112
113 static u8 nlink_tid __ro_after_init;
114 static u8 nlink_tgid __ro_after_init;
115
116 struct pid_entry {
117 const char *name;
118 unsigned int len;
119 umode_t mode;
120 const struct inode_operations *iop;
121 const struct file_operations *fop;
122 union proc_op op;
123 };
124
125 #define NOD(NAME, MODE, IOP, FOP, OP) { \
126 .name = (NAME), \
127 .len = sizeof(NAME) - 1, \
128 .mode = MODE, \
129 .iop = IOP, \
130 .fop = FOP, \
131 .op = OP, \
132 }
133
134 #define DIR(NAME, MODE, iops, fops) \
135 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
136 #define LNK(NAME, get_link) \
137 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
138 &proc_pid_link_inode_operations, NULL, \
139 { .proc_get_link = get_link } )
140 #define REG(NAME, MODE, fops) \
141 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
142 #define ONE(NAME, MODE, show) \
143 NOD(NAME, (S_IFREG|(MODE)), \
144 NULL, &proc_single_file_operations, \
145 { .proc_show = show } )
146 #define ATTR(LSM, NAME, MODE) \
147 NOD(NAME, (S_IFREG|(MODE)), \
148 NULL, &proc_pid_attr_operations, \
149 { .lsm = LSM })
150
151 /*
152 * Count the number of hardlinks for the pid_entry table, excluding the .
153 * and .. links.
154 */
155 static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
156 unsigned int n)
157 {
158 unsigned int i;
159 unsigned int count;
160
161 count = 2;
162 for (i = 0; i < n; ++i) {
163 if (S_ISDIR(entries[i].mode))
164 ++count;
165 }
166
167 return count;
168 }
169
170 static int get_task_root(struct task_struct *task, struct path *root)
171 {
172 int result = -ENOENT;
173
174 task_lock(task);
175 if (task->fs) {
176 get_fs_root(task->fs, root);
177 result = 0;
178 }
179 task_unlock(task);
180 return result;
181 }
182
183 static int proc_cwd_link(struct dentry *dentry, struct path *path)
184 {
185 struct task_struct *task = get_proc_task(d_inode(dentry));
186 int result = -ENOENT;
187
188 if (task) {
189 task_lock(task);
190 if (task->fs) {
191 get_fs_pwd(task->fs, path);
192 result = 0;
193 }
194 task_unlock(task);
195 put_task_struct(task);
196 }
197 return result;
198 }
199
200 static int proc_root_link(struct dentry *dentry, struct path *path)
201 {
202 struct task_struct *task = get_proc_task(d_inode(dentry));
203 int result = -ENOENT;
204
205 if (task) {
206 result = get_task_root(task, path);
207 put_task_struct(task);
208 }
209 return result;
210 }
211
212 /*
213 * If the user used setproctitle(), we just get the string from
214 * user space at arg_start, and limit it to a maximum of one page.
215 */
216 static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
217 size_t count, unsigned long pos,
218 unsigned long arg_start)
219 {
220 char *page;
221 int ret, got;
222
223 if (pos >= PAGE_SIZE)
224 return 0;
225
226 page = (char *)__get_free_page(GFP_KERNEL);
227 if (!page)
228 return -ENOMEM;
229
230 ret = 0;
231 got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
232 if (got > 0) {
233 int len = strnlen(page, got);
234
235 /* Include the NUL character if it was found */
236 if (len < got)
237 len++;
238
239 if (len > pos) {
240 len -= pos;
241 if (len > count)
242 len = count;
243 len -= copy_to_user(buf, page+pos, len);
244 if (!len)
245 len = -EFAULT;
246 ret = len;
247 }
248 }
249 free_page((unsigned long)page);
250 return ret;
251 }
252
253 static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
254 size_t count, loff_t *ppos)
255 {
256 unsigned long arg_start, arg_end, env_start, env_end;
257 unsigned long pos, len;
258 char *page, c;
259
260 /* Check if process spawned far enough to have cmdline. */
261 if (!mm->env_end)
262 return 0;
263
264 spin_lock(&mm->arg_lock);
265 arg_start = mm->arg_start;
266 arg_end = mm->arg_end;
267 env_start = mm->env_start;
268 env_end = mm->env_end;
269 spin_unlock(&mm->arg_lock);
270
271 if (arg_start >= arg_end)
272 return 0;
273
274 /*
275 * We allow setproctitle() to overwrite the argument
276 * strings, and overflow past the original end. But
277 * only when it overflows into the environment area.
278 */
279 if (env_start != arg_end || env_end < env_start)
280 env_start = env_end = arg_end;
281 len = env_end - arg_start;
282
283 /* We're not going to care if "*ppos" has high bits set */
284 pos = *ppos;
285 if (pos >= len)
286 return 0;
287 if (count > len - pos)
288 count = len - pos;
289 if (!count)
290 return 0;
291
292 /*
293 * Magical special case: if the argv[] end byte is not
294 * zero, the user has overwritten it with setproctitle(3).
295 *
296 * Possible future enhancement: do this only once when
297 * pos is 0, and set a flag in the 'struct file'.
298 */
299 if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
300 return get_mm_proctitle(mm, buf, count, pos, arg_start);
301
302 /*
303 * For the non-setproctitle() case we limit things strictly
304 * to the [arg_start, arg_end[ range.
305 */
306 pos += arg_start;
307 if (pos < arg_start || pos >= arg_end)
308 return 0;
309 if (count > arg_end - pos)
310 count = arg_end - pos;
311
312 page = (char *)__get_free_page(GFP_KERNEL);
313 if (!page)
314 return -ENOMEM;
315
316 len = 0;
317 while (count) {
318 int got;
319 size_t size = min_t(size_t, PAGE_SIZE, count);
320
321 got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
322 if (got <= 0)
323 break;
324 got -= copy_to_user(buf, page, got);
325 if (unlikely(!got)) {
326 if (!len)
327 len = -EFAULT;
328 break;
329 }
330 pos += got;
331 buf += got;
332 len += got;
333 count -= got;
334 }
335
336 free_page((unsigned long)page);
337 return len;
338 }
339
340 static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
341 size_t count, loff_t *pos)
342 {
343 struct mm_struct *mm;
344 ssize_t ret;
345
346 mm = get_task_mm(tsk);
347 if (!mm)
348 return 0;
349
350 ret = get_mm_cmdline(mm, buf, count, pos);
351 mmput(mm);
352 return ret;
353 }
354
355 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
356 size_t count, loff_t *pos)
357 {
358 struct task_struct *tsk;
359 ssize_t ret;
360
361 BUG_ON(*pos < 0);
362
363 tsk = get_proc_task(file_inode(file));
364 if (!tsk)
365 return -ESRCH;
366 ret = get_task_cmdline(tsk, buf, count, pos);
367 put_task_struct(tsk);
368 if (ret > 0)
369 *pos += ret;
370 return ret;
371 }
372
373 static const struct file_operations proc_pid_cmdline_ops = {
374 .read = proc_pid_cmdline_read,
375 .llseek = generic_file_llseek,
376 };
377
378 #ifdef CONFIG_KALLSYMS
379 /*
380 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
381 * Returns the resolved symbol. If that fails, simply return the address.
382 */
383 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
384 struct pid *pid, struct task_struct *task)
385 {
386 unsigned long wchan;
387 char symname[KSYM_NAME_LEN];
388
389 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
390 goto print0;
391
392 wchan = get_wchan(task);
393 if (wchan && !lookup_symbol_name(wchan, symname)) {
394 seq_puts(m, symname);
395 return 0;
396 }
397
398 print0:
399 seq_putc(m, '0');
400 return 0;
401 }
402 #endif /* CONFIG_KALLSYMS */
403
404 static int lock_trace(struct task_struct *task)
405 {
406 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
407 if (err)
408 return err;
409 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
410 mutex_unlock(&task->signal->cred_guard_mutex);
411 return -EPERM;
412 }
413 return 0;
414 }
415
416 static void unlock_trace(struct task_struct *task)
417 {
418 mutex_unlock(&task->signal->cred_guard_mutex);
419 }
420
421 #ifdef CONFIG_STACKTRACE
422
423 #define MAX_STACK_TRACE_DEPTH 64
424
425 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
426 struct pid *pid, struct task_struct *task)
427 {
428 unsigned long *entries;
429 int err;
430
431 /*
432 * The ability to racily run the kernel stack unwinder on a running task
433 * and then observe the unwinder output is scary; while it is useful for
434 * debugging kernel issues, it can also allow an attacker to leak kernel
435 * stack contents.
436 * Doing this in a manner that is at least safe from races would require
437 * some work to ensure that the remote task can not be scheduled; and
438 * even then, this would still expose the unwinder as local attack
439 * surface.
440 * Therefore, this interface is restricted to root.
441 */
442 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
443 return -EACCES;
444
445 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
446 GFP_KERNEL);
447 if (!entries)
448 return -ENOMEM;
449
450 err = lock_trace(task);
451 if (!err) {
452 unsigned int i, nr_entries;
453
454 nr_entries = stack_trace_save_tsk(task, entries,
455 MAX_STACK_TRACE_DEPTH, 0);
456
457 for (i = 0; i < nr_entries; i++) {
458 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
459 }
460
461 unlock_trace(task);
462 }
463 kfree(entries);
464
465 return err;
466 }
467 #endif
468
469 #ifdef CONFIG_SCHED_INFO
470 /*
471 * Provides /proc/PID/schedstat
472 */
473 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
474 struct pid *pid, struct task_struct *task)
475 {
476 if (unlikely(!sched_info_on()))
477 seq_puts(m, "0 0 0\n");
478 else
479 seq_printf(m, "%llu %llu %lu\n",
480 (unsigned long long)task->se.sum_exec_runtime,
481 (unsigned long long)task->sched_info.run_delay,
482 task->sched_info.pcount);
483
484 return 0;
485 }
486 #endif
487
488 #ifdef CONFIG_LATENCYTOP
489 static int lstats_show_proc(struct seq_file *m, void *v)
490 {
491 int i;
492 struct inode *inode = m->private;
493 struct task_struct *task = get_proc_task(inode);
494
495 if (!task)
496 return -ESRCH;
497 seq_puts(m, "Latency Top version : v0.1\n");
498 for (i = 0; i < LT_SAVECOUNT; i++) {
499 struct latency_record *lr = &task->latency_record[i];
500 if (lr->backtrace[0]) {
501 int q;
502 seq_printf(m, "%i %li %li",
503 lr->count, lr->time, lr->max);
504 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
505 unsigned long bt = lr->backtrace[q];
506
507 if (!bt)
508 break;
509 seq_printf(m, " %ps", (void *)bt);
510 }
511 seq_putc(m, '\n');
512 }
513
514 }
515 put_task_struct(task);
516 return 0;
517 }
518
519 static int lstats_open(struct inode *inode, struct file *file)
520 {
521 return single_open(file, lstats_show_proc, inode);
522 }
523
524 static ssize_t lstats_write(struct file *file, const char __user *buf,
525 size_t count, loff_t *offs)
526 {
527 struct task_struct *task = get_proc_task(file_inode(file));
528
529 if (!task)
530 return -ESRCH;
531 clear_tsk_latency_tracing(task);
532 put_task_struct(task);
533
534 return count;
535 }
536
537 static const struct file_operations proc_lstats_operations = {
538 .open = lstats_open,
539 .read = seq_read,
540 .write = lstats_write,
541 .llseek = seq_lseek,
542 .release = single_release,
543 };
544
545 #endif
546
547 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
548 struct pid *pid, struct task_struct *task)
549 {
550 unsigned long totalpages = totalram_pages() + total_swap_pages;
551 unsigned long points = 0;
552
553 points = oom_badness(task, totalpages) * 1000 / totalpages;
554 seq_printf(m, "%lu\n", points);
555
556 return 0;
557 }
558
559 struct limit_names {
560 const char *name;
561 const char *unit;
562 };
563
564 static const struct limit_names lnames[RLIM_NLIMITS] = {
565 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
566 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
567 [RLIMIT_DATA] = {"Max data size", "bytes"},
568 [RLIMIT_STACK] = {"Max stack size", "bytes"},
569 [RLIMIT_CORE] = {"Max core file size", "bytes"},
570 [RLIMIT_RSS] = {"Max resident set", "bytes"},
571 [RLIMIT_NPROC] = {"Max processes", "processes"},
572 [RLIMIT_NOFILE] = {"Max open files", "files"},
573 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
574 [RLIMIT_AS] = {"Max address space", "bytes"},
575 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
576 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
577 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
578 [RLIMIT_NICE] = {"Max nice priority", NULL},
579 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
580 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
581 };
582
583 /* Display limits for a process */
584 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
585 struct pid *pid, struct task_struct *task)
586 {
587 unsigned int i;
588 unsigned long flags;
589
590 struct rlimit rlim[RLIM_NLIMITS];
591
592 if (!lock_task_sighand(task, &flags))
593 return 0;
594 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
595 unlock_task_sighand(task, &flags);
596
597 /*
598 * print the file header
599 */
600 seq_puts(m, "Limit "
601 "Soft Limit "
602 "Hard Limit "
603 "Units \n");
604
605 for (i = 0; i < RLIM_NLIMITS; i++) {
606 if (rlim[i].rlim_cur == RLIM_INFINITY)
607 seq_printf(m, "%-25s %-20s ",
608 lnames[i].name, "unlimited");
609 else
610 seq_printf(m, "%-25s %-20lu ",
611 lnames[i].name, rlim[i].rlim_cur);
612
613 if (rlim[i].rlim_max == RLIM_INFINITY)
614 seq_printf(m, "%-20s ", "unlimited");
615 else
616 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
617
618 if (lnames[i].unit)
619 seq_printf(m, "%-10s\n", lnames[i].unit);
620 else
621 seq_putc(m, '\n');
622 }
623
624 return 0;
625 }
626
627 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
628 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
629 struct pid *pid, struct task_struct *task)
630 {
631 struct syscall_info info;
632 u64 *args = &info.data.args[0];
633 int res;
634
635 res = lock_trace(task);
636 if (res)
637 return res;
638
639 if (task_current_syscall(task, &info))
640 seq_puts(m, "running\n");
641 else if (info.data.nr < 0)
642 seq_printf(m, "%d 0x%llx 0x%llx\n",
643 info.data.nr, info.sp, info.data.instruction_pointer);
644 else
645 seq_printf(m,
646 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
647 info.data.nr,
648 args[0], args[1], args[2], args[3], args[4], args[5],
649 info.sp, info.data.instruction_pointer);
650 unlock_trace(task);
651
652 return 0;
653 }
654 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
655
656 /************************************************************************/
657 /* Here the fs part begins */
658 /************************************************************************/
659
660 /* permission checks */
661 static int proc_fd_access_allowed(struct inode *inode)
662 {
663 struct task_struct *task;
664 int allowed = 0;
665 /* Allow access to a task's file descriptors if it is us or we
666 * may use ptrace attach to the process and find out that
667 * information.
668 */
669 task = get_proc_task(inode);
670 if (task) {
671 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
672 put_task_struct(task);
673 }
674 return allowed;
675 }
676
677 int proc_setattr(struct dentry *dentry, struct iattr *attr)
678 {
679 int error;
680 struct inode *inode = d_inode(dentry);
681
682 if (attr->ia_valid & ATTR_MODE)
683 return -EPERM;
684
685 error = setattr_prepare(dentry, attr);
686 if (error)
687 return error;
688
689 setattr_copy(inode, attr);
690 mark_inode_dirty(inode);
691 return 0;
692 }
693
694 /*
695 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
696 * or euid/egid (for hide_pid_min=2)?
697 */
698 static bool has_pid_permissions(struct pid_namespace *pid,
699 struct task_struct *task,
700 int hide_pid_min)
701 {
702 if (pid->hide_pid < hide_pid_min)
703 return true;
704 if (in_group_p(pid->pid_gid))
705 return true;
706 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
707 }
708
709
710 static int proc_pid_permission(struct inode *inode, int mask)
711 {
712 struct pid_namespace *pid = proc_pid_ns(inode);
713 struct task_struct *task;
714 bool has_perms;
715
716 task = get_proc_task(inode);
717 if (!task)
718 return -ESRCH;
719 has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS);
720 put_task_struct(task);
721
722 if (!has_perms) {
723 if (pid->hide_pid == HIDEPID_INVISIBLE) {
724 /*
725 * Let's make getdents(), stat(), and open()
726 * consistent with each other. If a process
727 * may not stat() a file, it shouldn't be seen
728 * in procfs at all.
729 */
730 return -ENOENT;
731 }
732
733 return -EPERM;
734 }
735 return generic_permission(inode, mask);
736 }
737
738
739
740 static const struct inode_operations proc_def_inode_operations = {
741 .setattr = proc_setattr,
742 };
743
744 static int proc_single_show(struct seq_file *m, void *v)
745 {
746 struct inode *inode = m->private;
747 struct pid_namespace *ns = proc_pid_ns(inode);
748 struct pid *pid = proc_pid(inode);
749 struct task_struct *task;
750 int ret;
751
752 task = get_pid_task(pid, PIDTYPE_PID);
753 if (!task)
754 return -ESRCH;
755
756 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
757
758 put_task_struct(task);
759 return ret;
760 }
761
762 static int proc_single_open(struct inode *inode, struct file *filp)
763 {
764 return single_open(filp, proc_single_show, inode);
765 }
766
767 static const struct file_operations proc_single_file_operations = {
768 .open = proc_single_open,
769 .read = seq_read,
770 .llseek = seq_lseek,
771 .release = single_release,
772 };
773
774
775 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
776 {
777 struct task_struct *task = get_proc_task(inode);
778 struct mm_struct *mm = ERR_PTR(-ESRCH);
779
780 if (task) {
781 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
782 put_task_struct(task);
783
784 if (!IS_ERR_OR_NULL(mm)) {
785 /* ensure this mm_struct can't be freed */
786 mmgrab(mm);
787 /* but do not pin its memory */
788 mmput(mm);
789 }
790 }
791
792 return mm;
793 }
794
795 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
796 {
797 struct mm_struct *mm = proc_mem_open(inode, mode);
798
799 if (IS_ERR(mm))
800 return PTR_ERR(mm);
801
802 file->private_data = mm;
803 return 0;
804 }
805
806 static int mem_open(struct inode *inode, struct file *file)
807 {
808 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
809
810 /* OK to pass negative loff_t, we can catch out-of-range */
811 file->f_mode |= FMODE_UNSIGNED_OFFSET;
812
813 return ret;
814 }
815
816 static ssize_t mem_rw(struct file *file, char __user *buf,
817 size_t count, loff_t *ppos, int write)
818 {
819 struct mm_struct *mm = file->private_data;
820 unsigned long addr = *ppos;
821 ssize_t copied;
822 char *page;
823 unsigned int flags;
824
825 if (!mm)
826 return 0;
827
828 page = (char *)__get_free_page(GFP_KERNEL);
829 if (!page)
830 return -ENOMEM;
831
832 copied = 0;
833 if (!mmget_not_zero(mm))
834 goto free;
835
836 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
837
838 while (count > 0) {
839 int this_len = min_t(int, count, PAGE_SIZE);
840
841 if (write && copy_from_user(page, buf, this_len)) {
842 copied = -EFAULT;
843 break;
844 }
845
846 this_len = access_remote_vm(mm, addr, page, this_len, flags);
847 if (!this_len) {
848 if (!copied)
849 copied = -EIO;
850 break;
851 }
852
853 if (!write && copy_to_user(buf, page, this_len)) {
854 copied = -EFAULT;
855 break;
856 }
857
858 buf += this_len;
859 addr += this_len;
860 copied += this_len;
861 count -= this_len;
862 }
863 *ppos = addr;
864
865 mmput(mm);
866 free:
867 free_page((unsigned long) page);
868 return copied;
869 }
870
871 static ssize_t mem_read(struct file *file, char __user *buf,
872 size_t count, loff_t *ppos)
873 {
874 return mem_rw(file, buf, count, ppos, 0);
875 }
876
877 static ssize_t mem_write(struct file *file, const char __user *buf,
878 size_t count, loff_t *ppos)
879 {
880 return mem_rw(file, (char __user*)buf, count, ppos, 1);
881 }
882
883 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
884 {
885 switch (orig) {
886 case 0:
887 file->f_pos = offset;
888 break;
889 case 1:
890 file->f_pos += offset;
891 break;
892 default:
893 return -EINVAL;
894 }
895 force_successful_syscall_return();
896 return file->f_pos;
897 }
898
899 static int mem_release(struct inode *inode, struct file *file)
900 {
901 struct mm_struct *mm = file->private_data;
902 if (mm)
903 mmdrop(mm);
904 return 0;
905 }
906
907 static const struct file_operations proc_mem_operations = {
908 .llseek = mem_lseek,
909 .read = mem_read,
910 .write = mem_write,
911 .open = mem_open,
912 .release = mem_release,
913 };
914
915 static int environ_open(struct inode *inode, struct file *file)
916 {
917 return __mem_open(inode, file, PTRACE_MODE_READ);
918 }
919
920 static ssize_t environ_read(struct file *file, char __user *buf,
921 size_t count, loff_t *ppos)
922 {
923 char *page;
924 unsigned long src = *ppos;
925 int ret = 0;
926 struct mm_struct *mm = file->private_data;
927 unsigned long env_start, env_end;
928
929 /* Ensure the process spawned far enough to have an environment. */
930 if (!mm || !mm->env_end)
931 return 0;
932
933 page = (char *)__get_free_page(GFP_KERNEL);
934 if (!page)
935 return -ENOMEM;
936
937 ret = 0;
938 if (!mmget_not_zero(mm))
939 goto free;
940
941 spin_lock(&mm->arg_lock);
942 env_start = mm->env_start;
943 env_end = mm->env_end;
944 spin_unlock(&mm->arg_lock);
945
946 while (count > 0) {
947 size_t this_len, max_len;
948 int retval;
949
950 if (src >= (env_end - env_start))
951 break;
952
953 this_len = env_end - (env_start + src);
954
955 max_len = min_t(size_t, PAGE_SIZE, count);
956 this_len = min(max_len, this_len);
957
958 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
959
960 if (retval <= 0) {
961 ret = retval;
962 break;
963 }
964
965 if (copy_to_user(buf, page, retval)) {
966 ret = -EFAULT;
967 break;
968 }
969
970 ret += retval;
971 src += retval;
972 buf += retval;
973 count -= retval;
974 }
975 *ppos = src;
976 mmput(mm);
977
978 free:
979 free_page((unsigned long) page);
980 return ret;
981 }
982
983 static const struct file_operations proc_environ_operations = {
984 .open = environ_open,
985 .read = environ_read,
986 .llseek = generic_file_llseek,
987 .release = mem_release,
988 };
989
990 static int auxv_open(struct inode *inode, struct file *file)
991 {
992 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
993 }
994
995 static ssize_t auxv_read(struct file *file, char __user *buf,
996 size_t count, loff_t *ppos)
997 {
998 struct mm_struct *mm = file->private_data;
999 unsigned int nwords = 0;
1000
1001 if (!mm)
1002 return 0;
1003 do {
1004 nwords += 2;
1005 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1006 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1007 nwords * sizeof(mm->saved_auxv[0]));
1008 }
1009
1010 static const struct file_operations proc_auxv_operations = {
1011 .open = auxv_open,
1012 .read = auxv_read,
1013 .llseek = generic_file_llseek,
1014 .release = mem_release,
1015 };
1016
1017 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1018 loff_t *ppos)
1019 {
1020 struct task_struct *task = get_proc_task(file_inode(file));
1021 char buffer[PROC_NUMBUF];
1022 int oom_adj = OOM_ADJUST_MIN;
1023 size_t len;
1024
1025 if (!task)
1026 return -ESRCH;
1027 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1028 oom_adj = OOM_ADJUST_MAX;
1029 else
1030 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1031 OOM_SCORE_ADJ_MAX;
1032 put_task_struct(task);
1033 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1034 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1035 }
1036
1037 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1038 {
1039 static DEFINE_MUTEX(oom_adj_mutex);
1040 struct mm_struct *mm = NULL;
1041 struct task_struct *task;
1042 int err = 0;
1043
1044 task = get_proc_task(file_inode(file));
1045 if (!task)
1046 return -ESRCH;
1047
1048 mutex_lock(&oom_adj_mutex);
1049 if (legacy) {
1050 if (oom_adj < task->signal->oom_score_adj &&
1051 !capable(CAP_SYS_RESOURCE)) {
1052 err = -EACCES;
1053 goto err_unlock;
1054 }
1055 /*
1056 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1057 * /proc/pid/oom_score_adj instead.
1058 */
1059 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1060 current->comm, task_pid_nr(current), task_pid_nr(task),
1061 task_pid_nr(task));
1062 } else {
1063 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1064 !capable(CAP_SYS_RESOURCE)) {
1065 err = -EACCES;
1066 goto err_unlock;
1067 }
1068 }
1069
1070 /*
1071 * Make sure we will check other processes sharing the mm if this is
1072 * not vfrok which wants its own oom_score_adj.
1073 * pin the mm so it doesn't go away and get reused after task_unlock
1074 */
1075 if (!task->vfork_done) {
1076 struct task_struct *p = find_lock_task_mm(task);
1077
1078 if (p) {
1079 if (atomic_read(&p->mm->mm_users) > 1) {
1080 mm = p->mm;
1081 mmgrab(mm);
1082 }
1083 task_unlock(p);
1084 }
1085 }
1086
1087 task->signal->oom_score_adj = oom_adj;
1088 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1089 task->signal->oom_score_adj_min = (short)oom_adj;
1090 trace_oom_score_adj_update(task);
1091
1092 if (mm) {
1093 struct task_struct *p;
1094
1095 rcu_read_lock();
1096 for_each_process(p) {
1097 if (same_thread_group(task, p))
1098 continue;
1099
1100 /* do not touch kernel threads or the global init */
1101 if (p->flags & PF_KTHREAD || is_global_init(p))
1102 continue;
1103
1104 task_lock(p);
1105 if (!p->vfork_done && process_shares_mm(p, mm)) {
1106 p->signal->oom_score_adj = oom_adj;
1107 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1108 p->signal->oom_score_adj_min = (short)oom_adj;
1109 }
1110 task_unlock(p);
1111 }
1112 rcu_read_unlock();
1113 mmdrop(mm);
1114 }
1115 err_unlock:
1116 mutex_unlock(&oom_adj_mutex);
1117 put_task_struct(task);
1118 return err;
1119 }
1120
1121 /*
1122 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1123 * kernels. The effective policy is defined by oom_score_adj, which has a
1124 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1125 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1126 * Processes that become oom disabled via oom_adj will still be oom disabled
1127 * with this implementation.
1128 *
1129 * oom_adj cannot be removed since existing userspace binaries use it.
1130 */
1131 static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1132 size_t count, loff_t *ppos)
1133 {
1134 char buffer[PROC_NUMBUF];
1135 int oom_adj;
1136 int err;
1137
1138 memset(buffer, 0, sizeof(buffer));
1139 if (count > sizeof(buffer) - 1)
1140 count = sizeof(buffer) - 1;
1141 if (copy_from_user(buffer, buf, count)) {
1142 err = -EFAULT;
1143 goto out;
1144 }
1145
1146 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1147 if (err)
1148 goto out;
1149 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1150 oom_adj != OOM_DISABLE) {
1151 err = -EINVAL;
1152 goto out;
1153 }
1154
1155 /*
1156 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1157 * value is always attainable.
1158 */
1159 if (oom_adj == OOM_ADJUST_MAX)
1160 oom_adj = OOM_SCORE_ADJ_MAX;
1161 else
1162 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1163
1164 err = __set_oom_adj(file, oom_adj, true);
1165 out:
1166 return err < 0 ? err : count;
1167 }
1168
1169 static const struct file_operations proc_oom_adj_operations = {
1170 .read = oom_adj_read,
1171 .write = oom_adj_write,
1172 .llseek = generic_file_llseek,
1173 };
1174
1175 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1176 size_t count, loff_t *ppos)
1177 {
1178 struct task_struct *task = get_proc_task(file_inode(file));
1179 char buffer[PROC_NUMBUF];
1180 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1181 size_t len;
1182
1183 if (!task)
1184 return -ESRCH;
1185 oom_score_adj = task->signal->oom_score_adj;
1186 put_task_struct(task);
1187 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1188 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1189 }
1190
1191 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1192 size_t count, loff_t *ppos)
1193 {
1194 char buffer[PROC_NUMBUF];
1195 int oom_score_adj;
1196 int err;
1197
1198 memset(buffer, 0, sizeof(buffer));
1199 if (count > sizeof(buffer) - 1)
1200 count = sizeof(buffer) - 1;
1201 if (copy_from_user(buffer, buf, count)) {
1202 err = -EFAULT;
1203 goto out;
1204 }
1205
1206 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1207 if (err)
1208 goto out;
1209 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1210 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1211 err = -EINVAL;
1212 goto out;
1213 }
1214
1215 err = __set_oom_adj(file, oom_score_adj, false);
1216 out:
1217 return err < 0 ? err : count;
1218 }
1219
1220 static const struct file_operations proc_oom_score_adj_operations = {
1221 .read = oom_score_adj_read,
1222 .write = oom_score_adj_write,
1223 .llseek = default_llseek,
1224 };
1225
1226 #ifdef CONFIG_AUDIT
1227 #define TMPBUFLEN 11
1228 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1229 size_t count, loff_t *ppos)
1230 {
1231 struct inode * inode = file_inode(file);
1232 struct task_struct *task = get_proc_task(inode);
1233 ssize_t length;
1234 char tmpbuf[TMPBUFLEN];
1235
1236 if (!task)
1237 return -ESRCH;
1238 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1239 from_kuid(file->f_cred->user_ns,
1240 audit_get_loginuid(task)));
1241 put_task_struct(task);
1242 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1243 }
1244
1245 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1246 size_t count, loff_t *ppos)
1247 {
1248 struct inode * inode = file_inode(file);
1249 uid_t loginuid;
1250 kuid_t kloginuid;
1251 int rv;
1252
1253 rcu_read_lock();
1254 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1255 rcu_read_unlock();
1256 return -EPERM;
1257 }
1258 rcu_read_unlock();
1259
1260 if (*ppos != 0) {
1261 /* No partial writes. */
1262 return -EINVAL;
1263 }
1264
1265 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1266 if (rv < 0)
1267 return rv;
1268
1269 /* is userspace tring to explicitly UNSET the loginuid? */
1270 if (loginuid == AUDIT_UID_UNSET) {
1271 kloginuid = INVALID_UID;
1272 } else {
1273 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1274 if (!uid_valid(kloginuid))
1275 return -EINVAL;
1276 }
1277
1278 rv = audit_set_loginuid(kloginuid);
1279 if (rv < 0)
1280 return rv;
1281 return count;
1282 }
1283
1284 static const struct file_operations proc_loginuid_operations = {
1285 .read = proc_loginuid_read,
1286 .write = proc_loginuid_write,
1287 .llseek = generic_file_llseek,
1288 };
1289
1290 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1291 size_t count, loff_t *ppos)
1292 {
1293 struct inode * inode = file_inode(file);
1294 struct task_struct *task = get_proc_task(inode);
1295 ssize_t length;
1296 char tmpbuf[TMPBUFLEN];
1297
1298 if (!task)
1299 return -ESRCH;
1300 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1301 audit_get_sessionid(task));
1302 put_task_struct(task);
1303 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1304 }
1305
1306 static const struct file_operations proc_sessionid_operations = {
1307 .read = proc_sessionid_read,
1308 .llseek = generic_file_llseek,
1309 };
1310 #endif
1311
1312 #ifdef CONFIG_FAULT_INJECTION
1313 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1314 size_t count, loff_t *ppos)
1315 {
1316 struct task_struct *task = get_proc_task(file_inode(file));
1317 char buffer[PROC_NUMBUF];
1318 size_t len;
1319 int make_it_fail;
1320
1321 if (!task)
1322 return -ESRCH;
1323 make_it_fail = task->make_it_fail;
1324 put_task_struct(task);
1325
1326 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1327
1328 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1329 }
1330
1331 static ssize_t proc_fault_inject_write(struct file * file,
1332 const char __user * buf, size_t count, loff_t *ppos)
1333 {
1334 struct task_struct *task;
1335 char buffer[PROC_NUMBUF];
1336 int make_it_fail;
1337 int rv;
1338
1339 if (!capable(CAP_SYS_RESOURCE))
1340 return -EPERM;
1341 memset(buffer, 0, sizeof(buffer));
1342 if (count > sizeof(buffer) - 1)
1343 count = sizeof(buffer) - 1;
1344 if (copy_from_user(buffer, buf, count))
1345 return -EFAULT;
1346 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1347 if (rv < 0)
1348 return rv;
1349 if (make_it_fail < 0 || make_it_fail > 1)
1350 return -EINVAL;
1351
1352 task = get_proc_task(file_inode(file));
1353 if (!task)
1354 return -ESRCH;
1355 task->make_it_fail = make_it_fail;
1356 put_task_struct(task);
1357
1358 return count;
1359 }
1360
1361 static const struct file_operations proc_fault_inject_operations = {
1362 .read = proc_fault_inject_read,
1363 .write = proc_fault_inject_write,
1364 .llseek = generic_file_llseek,
1365 };
1366
1367 static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1368 size_t count, loff_t *ppos)
1369 {
1370 struct task_struct *task;
1371 int err;
1372 unsigned int n;
1373
1374 err = kstrtouint_from_user(buf, count, 0, &n);
1375 if (err)
1376 return err;
1377
1378 task = get_proc_task(file_inode(file));
1379 if (!task)
1380 return -ESRCH;
1381 task->fail_nth = n;
1382 put_task_struct(task);
1383
1384 return count;
1385 }
1386
1387 static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1388 size_t count, loff_t *ppos)
1389 {
1390 struct task_struct *task;
1391 char numbuf[PROC_NUMBUF];
1392 ssize_t len;
1393
1394 task = get_proc_task(file_inode(file));
1395 if (!task)
1396 return -ESRCH;
1397 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1398 put_task_struct(task);
1399 return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1400 }
1401
1402 static const struct file_operations proc_fail_nth_operations = {
1403 .read = proc_fail_nth_read,
1404 .write = proc_fail_nth_write,
1405 };
1406 #endif
1407
1408
1409 #ifdef CONFIG_SCHED_DEBUG
1410 /*
1411 * Print out various scheduling related per-task fields:
1412 */
1413 static int sched_show(struct seq_file *m, void *v)
1414 {
1415 struct inode *inode = m->private;
1416 struct pid_namespace *ns = proc_pid_ns(inode);
1417 struct task_struct *p;
1418
1419 p = get_proc_task(inode);
1420 if (!p)
1421 return -ESRCH;
1422 proc_sched_show_task(p, ns, m);
1423
1424 put_task_struct(p);
1425
1426 return 0;
1427 }
1428
1429 static ssize_t
1430 sched_write(struct file *file, const char __user *buf,
1431 size_t count, loff_t *offset)
1432 {
1433 struct inode *inode = file_inode(file);
1434 struct task_struct *p;
1435
1436 p = get_proc_task(inode);
1437 if (!p)
1438 return -ESRCH;
1439 proc_sched_set_task(p);
1440
1441 put_task_struct(p);
1442
1443 return count;
1444 }
1445
1446 static int sched_open(struct inode *inode, struct file *filp)
1447 {
1448 return single_open(filp, sched_show, inode);
1449 }
1450
1451 static const struct file_operations proc_pid_sched_operations = {
1452 .open = sched_open,
1453 .read = seq_read,
1454 .write = sched_write,
1455 .llseek = seq_lseek,
1456 .release = single_release,
1457 };
1458
1459 #endif
1460
1461 #ifdef CONFIG_SCHED_AUTOGROUP
1462 /*
1463 * Print out autogroup related information:
1464 */
1465 static int sched_autogroup_show(struct seq_file *m, void *v)
1466 {
1467 struct inode *inode = m->private;
1468 struct task_struct *p;
1469
1470 p = get_proc_task(inode);
1471 if (!p)
1472 return -ESRCH;
1473 proc_sched_autogroup_show_task(p, m);
1474
1475 put_task_struct(p);
1476
1477 return 0;
1478 }
1479
1480 static ssize_t
1481 sched_autogroup_write(struct file *file, const char __user *buf,
1482 size_t count, loff_t *offset)
1483 {
1484 struct inode *inode = file_inode(file);
1485 struct task_struct *p;
1486 char buffer[PROC_NUMBUF];
1487 int nice;
1488 int err;
1489
1490 memset(buffer, 0, sizeof(buffer));
1491 if (count > sizeof(buffer) - 1)
1492 count = sizeof(buffer) - 1;
1493 if (copy_from_user(buffer, buf, count))
1494 return -EFAULT;
1495
1496 err = kstrtoint(strstrip(buffer), 0, &nice);
1497 if (err < 0)
1498 return err;
1499
1500 p = get_proc_task(inode);
1501 if (!p)
1502 return -ESRCH;
1503
1504 err = proc_sched_autogroup_set_nice(p, nice);
1505 if (err)
1506 count = err;
1507
1508 put_task_struct(p);
1509
1510 return count;
1511 }
1512
1513 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1514 {
1515 int ret;
1516
1517 ret = single_open(filp, sched_autogroup_show, NULL);
1518 if (!ret) {
1519 struct seq_file *m = filp->private_data;
1520
1521 m->private = inode;
1522 }
1523 return ret;
1524 }
1525
1526 static const struct file_operations proc_pid_sched_autogroup_operations = {
1527 .open = sched_autogroup_open,
1528 .read = seq_read,
1529 .write = sched_autogroup_write,
1530 .llseek = seq_lseek,
1531 .release = single_release,
1532 };
1533
1534 #endif /* CONFIG_SCHED_AUTOGROUP */
1535
1536 static ssize_t comm_write(struct file *file, const char __user *buf,
1537 size_t count, loff_t *offset)
1538 {
1539 struct inode *inode = file_inode(file);
1540 struct task_struct *p;
1541 char buffer[TASK_COMM_LEN];
1542 const size_t maxlen = sizeof(buffer) - 1;
1543
1544 memset(buffer, 0, sizeof(buffer));
1545 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1546 return -EFAULT;
1547
1548 p = get_proc_task(inode);
1549 if (!p)
1550 return -ESRCH;
1551
1552 if (same_thread_group(current, p))
1553 set_task_comm(p, buffer);
1554 else
1555 count = -EINVAL;
1556
1557 put_task_struct(p);
1558
1559 return count;
1560 }
1561
1562 static int comm_show(struct seq_file *m, void *v)
1563 {
1564 struct inode *inode = m->private;
1565 struct task_struct *p;
1566
1567 p = get_proc_task(inode);
1568 if (!p)
1569 return -ESRCH;
1570
1571 proc_task_name(m, p, false);
1572 seq_putc(m, '\n');
1573
1574 put_task_struct(p);
1575
1576 return 0;
1577 }
1578
1579 static int comm_open(struct inode *inode, struct file *filp)
1580 {
1581 return single_open(filp, comm_show, inode);
1582 }
1583
1584 static const struct file_operations proc_pid_set_comm_operations = {
1585 .open = comm_open,
1586 .read = seq_read,
1587 .write = comm_write,
1588 .llseek = seq_lseek,
1589 .release = single_release,
1590 };
1591
1592 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1593 {
1594 struct task_struct *task;
1595 struct file *exe_file;
1596
1597 task = get_proc_task(d_inode(dentry));
1598 if (!task)
1599 return -ENOENT;
1600 exe_file = get_task_exe_file(task);
1601 put_task_struct(task);
1602 if (exe_file) {
1603 *exe_path = exe_file->f_path;
1604 path_get(&exe_file->f_path);
1605 fput(exe_file);
1606 return 0;
1607 } else
1608 return -ENOENT;
1609 }
1610
1611 static const char *proc_pid_get_link(struct dentry *dentry,
1612 struct inode *inode,
1613 struct delayed_call *done)
1614 {
1615 struct path path;
1616 int error = -EACCES;
1617
1618 if (!dentry)
1619 return ERR_PTR(-ECHILD);
1620
1621 /* Are we allowed to snoop on the tasks file descriptors? */
1622 if (!proc_fd_access_allowed(inode))
1623 goto out;
1624
1625 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1626 if (error)
1627 goto out;
1628
1629 nd_jump_link(&path);
1630 return NULL;
1631 out:
1632 return ERR_PTR(error);
1633 }
1634
1635 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1636 {
1637 char *tmp = (char *)__get_free_page(GFP_KERNEL);
1638 char *pathname;
1639 int len;
1640
1641 if (!tmp)
1642 return -ENOMEM;
1643
1644 pathname = d_path(path, tmp, PAGE_SIZE);
1645 len = PTR_ERR(pathname);
1646 if (IS_ERR(pathname))
1647 goto out;
1648 len = tmp + PAGE_SIZE - 1 - pathname;
1649
1650 if (len > buflen)
1651 len = buflen;
1652 if (copy_to_user(buffer, pathname, len))
1653 len = -EFAULT;
1654 out:
1655 free_page((unsigned long)tmp);
1656 return len;
1657 }
1658
1659 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1660 {
1661 int error = -EACCES;
1662 struct inode *inode = d_inode(dentry);
1663 struct path path;
1664
1665 /* Are we allowed to snoop on the tasks file descriptors? */
1666 if (!proc_fd_access_allowed(inode))
1667 goto out;
1668
1669 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1670 if (error)
1671 goto out;
1672
1673 error = do_proc_readlink(&path, buffer, buflen);
1674 path_put(&path);
1675 out:
1676 return error;
1677 }
1678
1679 const struct inode_operations proc_pid_link_inode_operations = {
1680 .readlink = proc_pid_readlink,
1681 .get_link = proc_pid_get_link,
1682 .setattr = proc_setattr,
1683 };
1684
1685
1686 /* building an inode */
1687
1688 void task_dump_owner(struct task_struct *task, umode_t mode,
1689 kuid_t *ruid, kgid_t *rgid)
1690 {
1691 /* Depending on the state of dumpable compute who should own a
1692 * proc file for a task.
1693 */
1694 const struct cred *cred;
1695 kuid_t uid;
1696 kgid_t gid;
1697
1698 if (unlikely(task->flags & PF_KTHREAD)) {
1699 *ruid = GLOBAL_ROOT_UID;
1700 *rgid = GLOBAL_ROOT_GID;
1701 return;
1702 }
1703
1704 /* Default to the tasks effective ownership */
1705 rcu_read_lock();
1706 cred = __task_cred(task);
1707 uid = cred->euid;
1708 gid = cred->egid;
1709 rcu_read_unlock();
1710
1711 /*
1712 * Before the /proc/pid/status file was created the only way to read
1713 * the effective uid of a /process was to stat /proc/pid. Reading
1714 * /proc/pid/status is slow enough that procps and other packages
1715 * kept stating /proc/pid. To keep the rules in /proc simple I have
1716 * made this apply to all per process world readable and executable
1717 * directories.
1718 */
1719 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1720 struct mm_struct *mm;
1721 task_lock(task);
1722 mm = task->mm;
1723 /* Make non-dumpable tasks owned by some root */
1724 if (mm) {
1725 if (get_dumpable(mm) != SUID_DUMP_USER) {
1726 struct user_namespace *user_ns = mm->user_ns;
1727
1728 uid = make_kuid(user_ns, 0);
1729 if (!uid_valid(uid))
1730 uid = GLOBAL_ROOT_UID;
1731
1732 gid = make_kgid(user_ns, 0);
1733 if (!gid_valid(gid))
1734 gid = GLOBAL_ROOT_GID;
1735 }
1736 } else {
1737 uid = GLOBAL_ROOT_UID;
1738 gid = GLOBAL_ROOT_GID;
1739 }
1740 task_unlock(task);
1741 }
1742 *ruid = uid;
1743 *rgid = gid;
1744 }
1745
1746 struct inode *proc_pid_make_inode(struct super_block * sb,
1747 struct task_struct *task, umode_t mode)
1748 {
1749 struct inode * inode;
1750 struct proc_inode *ei;
1751
1752 /* We need a new inode */
1753
1754 inode = new_inode(sb);
1755 if (!inode)
1756 goto out;
1757
1758 /* Common stuff */
1759 ei = PROC_I(inode);
1760 inode->i_mode = mode;
1761 inode->i_ino = get_next_ino();
1762 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1763 inode->i_op = &proc_def_inode_operations;
1764
1765 /*
1766 * grab the reference to task.
1767 */
1768 ei->pid = get_task_pid(task, PIDTYPE_PID);
1769 if (!ei->pid)
1770 goto out_unlock;
1771
1772 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1773 security_task_to_inode(task, inode);
1774
1775 out:
1776 return inode;
1777
1778 out_unlock:
1779 iput(inode);
1780 return NULL;
1781 }
1782
1783 int pid_getattr(const struct path *path, struct kstat *stat,
1784 u32 request_mask, unsigned int query_flags)
1785 {
1786 struct inode *inode = d_inode(path->dentry);
1787 struct pid_namespace *pid = proc_pid_ns(inode);
1788 struct task_struct *task;
1789
1790 generic_fillattr(inode, stat);
1791
1792 stat->uid = GLOBAL_ROOT_UID;
1793 stat->gid = GLOBAL_ROOT_GID;
1794 rcu_read_lock();
1795 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1796 if (task) {
1797 if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) {
1798 rcu_read_unlock();
1799 /*
1800 * This doesn't prevent learning whether PID exists,
1801 * it only makes getattr() consistent with readdir().
1802 */
1803 return -ENOENT;
1804 }
1805 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1806 }
1807 rcu_read_unlock();
1808 return 0;
1809 }
1810
1811 /* dentry stuff */
1812
1813 /*
1814 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1815 */
1816 void pid_update_inode(struct task_struct *task, struct inode *inode)
1817 {
1818 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1819
1820 inode->i_mode &= ~(S_ISUID | S_ISGID);
1821 security_task_to_inode(task, inode);
1822 }
1823
1824 /*
1825 * Rewrite the inode's ownerships here because the owning task may have
1826 * performed a setuid(), etc.
1827 *
1828 */
1829 static int pid_revalidate(struct dentry *dentry, unsigned int flags)
1830 {
1831 struct inode *inode;
1832 struct task_struct *task;
1833
1834 if (flags & LOOKUP_RCU)
1835 return -ECHILD;
1836
1837 inode = d_inode(dentry);
1838 task = get_proc_task(inode);
1839
1840 if (task) {
1841 pid_update_inode(task, inode);
1842 put_task_struct(task);
1843 return 1;
1844 }
1845 return 0;
1846 }
1847
1848 static inline bool proc_inode_is_dead(struct inode *inode)
1849 {
1850 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1851 }
1852
1853 int pid_delete_dentry(const struct dentry *dentry)
1854 {
1855 /* Is the task we represent dead?
1856 * If so, then don't put the dentry on the lru list,
1857 * kill it immediately.
1858 */
1859 return proc_inode_is_dead(d_inode(dentry));
1860 }
1861
1862 const struct dentry_operations pid_dentry_operations =
1863 {
1864 .d_revalidate = pid_revalidate,
1865 .d_delete = pid_delete_dentry,
1866 };
1867
1868 /* Lookups */
1869
1870 /*
1871 * Fill a directory entry.
1872 *
1873 * If possible create the dcache entry and derive our inode number and
1874 * file type from dcache entry.
1875 *
1876 * Since all of the proc inode numbers are dynamically generated, the inode
1877 * numbers do not exist until the inode is cache. This means creating the
1878 * the dcache entry in readdir is necessary to keep the inode numbers
1879 * reported by readdir in sync with the inode numbers reported
1880 * by stat.
1881 */
1882 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1883 const char *name, unsigned int len,
1884 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1885 {
1886 struct dentry *child, *dir = file->f_path.dentry;
1887 struct qstr qname = QSTR_INIT(name, len);
1888 struct inode *inode;
1889 unsigned type = DT_UNKNOWN;
1890 ino_t ino = 1;
1891
1892 child = d_hash_and_lookup(dir, &qname);
1893 if (!child) {
1894 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
1895 child = d_alloc_parallel(dir, &qname, &wq);
1896 if (IS_ERR(child))
1897 goto end_instantiate;
1898 if (d_in_lookup(child)) {
1899 struct dentry *res;
1900 res = instantiate(child, task, ptr);
1901 d_lookup_done(child);
1902 if (unlikely(res)) {
1903 dput(child);
1904 child = res;
1905 if (IS_ERR(child))
1906 goto end_instantiate;
1907 }
1908 }
1909 }
1910 inode = d_inode(child);
1911 ino = inode->i_ino;
1912 type = inode->i_mode >> 12;
1913 dput(child);
1914 end_instantiate:
1915 return dir_emit(ctx, name, len, ino, type);
1916 }
1917
1918 /*
1919 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1920 * which represent vma start and end addresses.
1921 */
1922 static int dname_to_vma_addr(struct dentry *dentry,
1923 unsigned long *start, unsigned long *end)
1924 {
1925 const char *str = dentry->d_name.name;
1926 unsigned long long sval, eval;
1927 unsigned int len;
1928
1929 if (str[0] == '0' && str[1] != '-')
1930 return -EINVAL;
1931 len = _parse_integer(str, 16, &sval);
1932 if (len & KSTRTOX_OVERFLOW)
1933 return -EINVAL;
1934 if (sval != (unsigned long)sval)
1935 return -EINVAL;
1936 str += len;
1937
1938 if (*str != '-')
1939 return -EINVAL;
1940 str++;
1941
1942 if (str[0] == '0' && str[1])
1943 return -EINVAL;
1944 len = _parse_integer(str, 16, &eval);
1945 if (len & KSTRTOX_OVERFLOW)
1946 return -EINVAL;
1947 if (eval != (unsigned long)eval)
1948 return -EINVAL;
1949 str += len;
1950
1951 if (*str != '\0')
1952 return -EINVAL;
1953
1954 *start = sval;
1955 *end = eval;
1956
1957 return 0;
1958 }
1959
1960 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1961 {
1962 unsigned long vm_start, vm_end;
1963 bool exact_vma_exists = false;
1964 struct mm_struct *mm = NULL;
1965 struct task_struct *task;
1966 struct inode *inode;
1967 int status = 0;
1968
1969 if (flags & LOOKUP_RCU)
1970 return -ECHILD;
1971
1972 inode = d_inode(dentry);
1973 task = get_proc_task(inode);
1974 if (!task)
1975 goto out_notask;
1976
1977 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
1978 if (IS_ERR_OR_NULL(mm))
1979 goto out;
1980
1981 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1982 status = down_read_killable(&mm->mmap_sem);
1983 if (!status) {
1984 exact_vma_exists = !!find_exact_vma(mm, vm_start,
1985 vm_end);
1986 up_read(&mm->mmap_sem);
1987 }
1988 }
1989
1990 mmput(mm);
1991
1992 if (exact_vma_exists) {
1993 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1994
1995 security_task_to_inode(task, inode);
1996 status = 1;
1997 }
1998
1999 out:
2000 put_task_struct(task);
2001
2002 out_notask:
2003 return status;
2004 }
2005
2006 static const struct dentry_operations tid_map_files_dentry_operations = {
2007 .d_revalidate = map_files_d_revalidate,
2008 .d_delete = pid_delete_dentry,
2009 };
2010
2011 static int map_files_get_link(struct dentry *dentry, struct path *path)
2012 {
2013 unsigned long vm_start, vm_end;
2014 struct vm_area_struct *vma;
2015 struct task_struct *task;
2016 struct mm_struct *mm;
2017 int rc;
2018
2019 rc = -ENOENT;
2020 task = get_proc_task(d_inode(dentry));
2021 if (!task)
2022 goto out;
2023
2024 mm = get_task_mm(task);
2025 put_task_struct(task);
2026 if (!mm)
2027 goto out;
2028
2029 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2030 if (rc)
2031 goto out_mmput;
2032
2033 rc = down_read_killable(&mm->mmap_sem);
2034 if (rc)
2035 goto out_mmput;
2036
2037 rc = -ENOENT;
2038 vma = find_exact_vma(mm, vm_start, vm_end);
2039 if (vma && vma->vm_file) {
2040 *path = vma->vm_file->f_path;
2041 path_get(path);
2042 rc = 0;
2043 }
2044 up_read(&mm->mmap_sem);
2045
2046 out_mmput:
2047 mmput(mm);
2048 out:
2049 return rc;
2050 }
2051
2052 struct map_files_info {
2053 unsigned long start;
2054 unsigned long end;
2055 fmode_t mode;
2056 };
2057
2058 /*
2059 * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the
2060 * symlinks may be used to bypass permissions on ancestor directories in the
2061 * path to the file in question.
2062 */
2063 static const char *
2064 proc_map_files_get_link(struct dentry *dentry,
2065 struct inode *inode,
2066 struct delayed_call *done)
2067 {
2068 if (!capable(CAP_SYS_ADMIN))
2069 return ERR_PTR(-EPERM);
2070
2071 return proc_pid_get_link(dentry, inode, done);
2072 }
2073
2074 /*
2075 * Identical to proc_pid_link_inode_operations except for get_link()
2076 */
2077 static const struct inode_operations proc_map_files_link_inode_operations = {
2078 .readlink = proc_pid_readlink,
2079 .get_link = proc_map_files_get_link,
2080 .setattr = proc_setattr,
2081 };
2082
2083 static struct dentry *
2084 proc_map_files_instantiate(struct dentry *dentry,
2085 struct task_struct *task, const void *ptr)
2086 {
2087 fmode_t mode = (fmode_t)(unsigned long)ptr;
2088 struct proc_inode *ei;
2089 struct inode *inode;
2090
2091 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2092 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2093 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2094 if (!inode)
2095 return ERR_PTR(-ENOENT);
2096
2097 ei = PROC_I(inode);
2098 ei->op.proc_get_link = map_files_get_link;
2099
2100 inode->i_op = &proc_map_files_link_inode_operations;
2101 inode->i_size = 64;
2102
2103 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2104 return d_splice_alias(inode, dentry);
2105 }
2106
2107 static struct dentry *proc_map_files_lookup(struct inode *dir,
2108 struct dentry *dentry, unsigned int flags)
2109 {
2110 unsigned long vm_start, vm_end;
2111 struct vm_area_struct *vma;
2112 struct task_struct *task;
2113 struct dentry *result;
2114 struct mm_struct *mm;
2115
2116 result = ERR_PTR(-ENOENT);
2117 task = get_proc_task(dir);
2118 if (!task)
2119 goto out;
2120
2121 result = ERR_PTR(-EACCES);
2122 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2123 goto out_put_task;
2124
2125 result = ERR_PTR(-ENOENT);
2126 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2127 goto out_put_task;
2128
2129 mm = get_task_mm(task);
2130 if (!mm)
2131 goto out_put_task;
2132
2133 result = ERR_PTR(-EINTR);
2134 if (down_read_killable(&mm->mmap_sem))
2135 goto out_put_mm;
2136
2137 result = ERR_PTR(-ENOENT);
2138 vma = find_exact_vma(mm, vm_start, vm_end);
2139 if (!vma)
2140 goto out_no_vma;
2141
2142 if (vma->vm_file)
2143 result = proc_map_files_instantiate(dentry, task,
2144 (void *)(unsigned long)vma->vm_file->f_mode);
2145
2146 out_no_vma:
2147 up_read(&mm->mmap_sem);
2148 out_put_mm:
2149 mmput(mm);
2150 out_put_task:
2151 put_task_struct(task);
2152 out:
2153 return result;
2154 }
2155
2156 static const struct inode_operations proc_map_files_inode_operations = {
2157 .lookup = proc_map_files_lookup,
2158 .permission = proc_fd_permission,
2159 .setattr = proc_setattr,
2160 };
2161
2162 static int
2163 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2164 {
2165 struct vm_area_struct *vma;
2166 struct task_struct *task;
2167 struct mm_struct *mm;
2168 unsigned long nr_files, pos, i;
2169 GENRADIX(struct map_files_info) fa;
2170 struct map_files_info *p;
2171 int ret;
2172
2173 genradix_init(&fa);
2174
2175 ret = -ENOENT;
2176 task = get_proc_task(file_inode(file));
2177 if (!task)
2178 goto out;
2179
2180 ret = -EACCES;
2181 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2182 goto out_put_task;
2183
2184 ret = 0;
2185 if (!dir_emit_dots(file, ctx))
2186 goto out_put_task;
2187
2188 mm = get_task_mm(task);
2189 if (!mm)
2190 goto out_put_task;
2191
2192 ret = down_read_killable(&mm->mmap_sem);
2193 if (ret) {
2194 mmput(mm);
2195 goto out_put_task;
2196 }
2197
2198 nr_files = 0;
2199
2200 /*
2201 * We need two passes here:
2202 *
2203 * 1) Collect vmas of mapped files with mmap_sem taken
2204 * 2) Release mmap_sem and instantiate entries
2205 *
2206 * otherwise we get lockdep complained, since filldir()
2207 * routine might require mmap_sem taken in might_fault().
2208 */
2209
2210 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2211 if (!vma->vm_file)
2212 continue;
2213 if (++pos <= ctx->pos)
2214 continue;
2215
2216 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2217 if (!p) {
2218 ret = -ENOMEM;
2219 up_read(&mm->mmap_sem);
2220 mmput(mm);
2221 goto out_put_task;
2222 }
2223
2224 p->start = vma->vm_start;
2225 p->end = vma->vm_end;
2226 p->mode = vma->vm_file->f_mode;
2227 }
2228 up_read(&mm->mmap_sem);
2229 mmput(mm);
2230
2231 for (i = 0; i < nr_files; i++) {
2232 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2233 unsigned int len;
2234
2235 p = genradix_ptr(&fa, i);
2236 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2237 if (!proc_fill_cache(file, ctx,
2238 buf, len,
2239 proc_map_files_instantiate,
2240 task,
2241 (void *)(unsigned long)p->mode))
2242 break;
2243 ctx->pos++;
2244 }
2245
2246 out_put_task:
2247 put_task_struct(task);
2248 out:
2249 genradix_free(&fa);
2250 return ret;
2251 }
2252
2253 static const struct file_operations proc_map_files_operations = {
2254 .read = generic_read_dir,
2255 .iterate_shared = proc_map_files_readdir,
2256 .llseek = generic_file_llseek,
2257 };
2258
2259 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2260 struct timers_private {
2261 struct pid *pid;
2262 struct task_struct *task;
2263 struct sighand_struct *sighand;
2264 struct pid_namespace *ns;
2265 unsigned long flags;
2266 };
2267
2268 static void *timers_start(struct seq_file *m, loff_t *pos)
2269 {
2270 struct timers_private *tp = m->private;
2271
2272 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2273 if (!tp->task)
2274 return ERR_PTR(-ESRCH);
2275
2276 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2277 if (!tp->sighand)
2278 return ERR_PTR(-ESRCH);
2279
2280 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2281 }
2282
2283 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2284 {
2285 struct timers_private *tp = m->private;
2286 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2287 }
2288
2289 static void timers_stop(struct seq_file *m, void *v)
2290 {
2291 struct timers_private *tp = m->private;
2292
2293 if (tp->sighand) {
2294 unlock_task_sighand(tp->task, &tp->flags);
2295 tp->sighand = NULL;
2296 }
2297
2298 if (tp->task) {
2299 put_task_struct(tp->task);
2300 tp->task = NULL;
2301 }
2302 }
2303
2304 static int show_timer(struct seq_file *m, void *v)
2305 {
2306 struct k_itimer *timer;
2307 struct timers_private *tp = m->private;
2308 int notify;
2309 static const char * const nstr[] = {
2310 [SIGEV_SIGNAL] = "signal",
2311 [SIGEV_NONE] = "none",
2312 [SIGEV_THREAD] = "thread",
2313 };
2314
2315 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2316 notify = timer->it_sigev_notify;
2317
2318 seq_printf(m, "ID: %d\n", timer->it_id);
2319 seq_printf(m, "signal: %d/%px\n",
2320 timer->sigq->info.si_signo,
2321 timer->sigq->info.si_value.sival_ptr);
2322 seq_printf(m, "notify: %s/%s.%d\n",
2323 nstr[notify & ~SIGEV_THREAD_ID],
2324 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2325 pid_nr_ns(timer->it_pid, tp->ns));
2326 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2327
2328 return 0;
2329 }
2330
2331 static const struct seq_operations proc_timers_seq_ops = {
2332 .start = timers_start,
2333 .next = timers_next,
2334 .stop = timers_stop,
2335 .show = show_timer,
2336 };
2337
2338 static int proc_timers_open(struct inode *inode, struct file *file)
2339 {
2340 struct timers_private *tp;
2341
2342 tp = __seq_open_private(file, &proc_timers_seq_ops,
2343 sizeof(struct timers_private));
2344 if (!tp)
2345 return -ENOMEM;
2346
2347 tp->pid = proc_pid(inode);
2348 tp->ns = proc_pid_ns(inode);
2349 return 0;
2350 }
2351
2352 static const struct file_operations proc_timers_operations = {
2353 .open = proc_timers_open,
2354 .read = seq_read,
2355 .llseek = seq_lseek,
2356 .release = seq_release_private,
2357 };
2358 #endif
2359
2360 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2361 size_t count, loff_t *offset)
2362 {
2363 struct inode *inode = file_inode(file);
2364 struct task_struct *p;
2365 u64 slack_ns;
2366 int err;
2367
2368 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2369 if (err < 0)
2370 return err;
2371
2372 p = get_proc_task(inode);
2373 if (!p)
2374 return -ESRCH;
2375
2376 if (p != current) {
2377 rcu_read_lock();
2378 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2379 rcu_read_unlock();
2380 count = -EPERM;
2381 goto out;
2382 }
2383 rcu_read_unlock();
2384
2385 err = security_task_setscheduler(p);
2386 if (err) {
2387 count = err;
2388 goto out;
2389 }
2390 }
2391
2392 task_lock(p);
2393 if (slack_ns == 0)
2394 p->timer_slack_ns = p->default_timer_slack_ns;
2395 else
2396 p->timer_slack_ns = slack_ns;
2397 task_unlock(p);
2398
2399 out:
2400 put_task_struct(p);
2401
2402 return count;
2403 }
2404
2405 static int timerslack_ns_show(struct seq_file *m, void *v)
2406 {
2407 struct inode *inode = m->private;
2408 struct task_struct *p;
2409 int err = 0;
2410
2411 p = get_proc_task(inode);
2412 if (!p)
2413 return -ESRCH;
2414
2415 if (p != current) {
2416 rcu_read_lock();
2417 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2418 rcu_read_unlock();
2419 err = -EPERM;
2420 goto out;
2421 }
2422 rcu_read_unlock();
2423
2424 err = security_task_getscheduler(p);
2425 if (err)
2426 goto out;
2427 }
2428
2429 task_lock(p);
2430 seq_printf(m, "%llu\n", p->timer_slack_ns);
2431 task_unlock(p);
2432
2433 out:
2434 put_task_struct(p);
2435
2436 return err;
2437 }
2438
2439 static int timerslack_ns_open(struct inode *inode, struct file *filp)
2440 {
2441 return single_open(filp, timerslack_ns_show, inode);
2442 }
2443
2444 static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2445 .open = timerslack_ns_open,
2446 .read = seq_read,
2447 .write = timerslack_ns_write,
2448 .llseek = seq_lseek,
2449 .release = single_release,
2450 };
2451
2452 static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2453 struct task_struct *task, const void *ptr)
2454 {
2455 const struct pid_entry *p = ptr;
2456 struct inode *inode;
2457 struct proc_inode *ei;
2458
2459 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2460 if (!inode)
2461 return ERR_PTR(-ENOENT);
2462
2463 ei = PROC_I(inode);
2464 if (S_ISDIR(inode->i_mode))
2465 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2466 if (p->iop)
2467 inode->i_op = p->iop;
2468 if (p->fop)
2469 inode->i_fop = p->fop;
2470 ei->op = p->op;
2471 pid_update_inode(task, inode);
2472 d_set_d_op(dentry, &pid_dentry_operations);
2473 return d_splice_alias(inode, dentry);
2474 }
2475
2476 static struct dentry *proc_pident_lookup(struct inode *dir,
2477 struct dentry *dentry,
2478 const struct pid_entry *p,
2479 const struct pid_entry *end)
2480 {
2481 struct task_struct *task = get_proc_task(dir);
2482 struct dentry *res = ERR_PTR(-ENOENT);
2483
2484 if (!task)
2485 goto out_no_task;
2486
2487 /*
2488 * Yes, it does not scale. And it should not. Don't add
2489 * new entries into /proc/<tgid>/ without very good reasons.
2490 */
2491 for (; p < end; p++) {
2492 if (p->len != dentry->d_name.len)
2493 continue;
2494 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2495 res = proc_pident_instantiate(dentry, task, p);
2496 break;
2497 }
2498 }
2499 put_task_struct(task);
2500 out_no_task:
2501 return res;
2502 }
2503
2504 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2505 const struct pid_entry *ents, unsigned int nents)
2506 {
2507 struct task_struct *task = get_proc_task(file_inode(file));
2508 const struct pid_entry *p;
2509
2510 if (!task)
2511 return -ENOENT;
2512
2513 if (!dir_emit_dots(file, ctx))
2514 goto out;
2515
2516 if (ctx->pos >= nents + 2)
2517 goto out;
2518
2519 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2520 if (!proc_fill_cache(file, ctx, p->name, p->len,
2521 proc_pident_instantiate, task, p))
2522 break;
2523 ctx->pos++;
2524 }
2525 out:
2526 put_task_struct(task);
2527 return 0;
2528 }
2529
2530 #ifdef CONFIG_SECURITY
2531 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2532 size_t count, loff_t *ppos)
2533 {
2534 struct inode * inode = file_inode(file);
2535 char *p = NULL;
2536 ssize_t length;
2537 struct task_struct *task = get_proc_task(inode);
2538
2539 if (!task)
2540 return -ESRCH;
2541
2542 length = security_getprocattr(task, PROC_I(inode)->op.lsm,
2543 (char*)file->f_path.dentry->d_name.name,
2544 &p);
2545 put_task_struct(task);
2546 if (length > 0)
2547 length = simple_read_from_buffer(buf, count, ppos, p, length);
2548 kfree(p);
2549 return length;
2550 }
2551
2552 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2553 size_t count, loff_t *ppos)
2554 {
2555 struct inode * inode = file_inode(file);
2556 struct task_struct *task;
2557 void *page;
2558 int rv;
2559
2560 rcu_read_lock();
2561 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2562 if (!task) {
2563 rcu_read_unlock();
2564 return -ESRCH;
2565 }
2566 /* A task may only write its own attributes. */
2567 if (current != task) {
2568 rcu_read_unlock();
2569 return -EACCES;
2570 }
2571 /* Prevent changes to overridden credentials. */
2572 if (current_cred() != current_real_cred()) {
2573 rcu_read_unlock();
2574 return -EBUSY;
2575 }
2576 rcu_read_unlock();
2577
2578 if (count > PAGE_SIZE)
2579 count = PAGE_SIZE;
2580
2581 /* No partial writes. */
2582 if (*ppos != 0)
2583 return -EINVAL;
2584
2585 page = memdup_user(buf, count);
2586 if (IS_ERR(page)) {
2587 rv = PTR_ERR(page);
2588 goto out;
2589 }
2590
2591 /* Guard against adverse ptrace interaction */
2592 rv = mutex_lock_interruptible(&current->signal->cred_guard_mutex);
2593 if (rv < 0)
2594 goto out_free;
2595
2596 rv = security_setprocattr(PROC_I(inode)->op.lsm,
2597 file->f_path.dentry->d_name.name, page,
2598 count);
2599 mutex_unlock(&current->signal->cred_guard_mutex);
2600 out_free:
2601 kfree(page);
2602 out:
2603 return rv;
2604 }
2605
2606 static const struct file_operations proc_pid_attr_operations = {
2607 .read = proc_pid_attr_read,
2608 .write = proc_pid_attr_write,
2609 .llseek = generic_file_llseek,
2610 };
2611
2612 #define LSM_DIR_OPS(LSM) \
2613 static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2614 struct dir_context *ctx) \
2615 { \
2616 return proc_pident_readdir(filp, ctx, \
2617 LSM##_attr_dir_stuff, \
2618 ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2619 } \
2620 \
2621 static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2622 .read = generic_read_dir, \
2623 .iterate = proc_##LSM##_attr_dir_iterate, \
2624 .llseek = default_llseek, \
2625 }; \
2626 \
2627 static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2628 struct dentry *dentry, unsigned int flags) \
2629 { \
2630 return proc_pident_lookup(dir, dentry, \
2631 LSM##_attr_dir_stuff, \
2632 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2633 } \
2634 \
2635 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2636 .lookup = proc_##LSM##_attr_dir_lookup, \
2637 .getattr = pid_getattr, \
2638 .setattr = proc_setattr, \
2639 }
2640
2641 #ifdef CONFIG_SECURITY_SMACK
2642 static const struct pid_entry smack_attr_dir_stuff[] = {
2643 ATTR("smack", "current", 0666),
2644 };
2645 LSM_DIR_OPS(smack);
2646 #endif
2647
2648 static const struct pid_entry attr_dir_stuff[] = {
2649 ATTR(NULL, "current", 0666),
2650 ATTR(NULL, "prev", 0444),
2651 ATTR(NULL, "exec", 0666),
2652 ATTR(NULL, "fscreate", 0666),
2653 ATTR(NULL, "keycreate", 0666),
2654 ATTR(NULL, "sockcreate", 0666),
2655 #ifdef CONFIG_SECURITY_SMACK
2656 DIR("smack", 0555,
2657 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2658 #endif
2659 };
2660
2661 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2662 {
2663 return proc_pident_readdir(file, ctx,
2664 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2665 }
2666
2667 static const struct file_operations proc_attr_dir_operations = {
2668 .read = generic_read_dir,
2669 .iterate_shared = proc_attr_dir_readdir,
2670 .llseek = generic_file_llseek,
2671 };
2672
2673 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2674 struct dentry *dentry, unsigned int flags)
2675 {
2676 return proc_pident_lookup(dir, dentry,
2677 attr_dir_stuff,
2678 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2679 }
2680
2681 static const struct inode_operations proc_attr_dir_inode_operations = {
2682 .lookup = proc_attr_dir_lookup,
2683 .getattr = pid_getattr,
2684 .setattr = proc_setattr,
2685 };
2686
2687 #endif
2688
2689 #ifdef CONFIG_ELF_CORE
2690 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2691 size_t count, loff_t *ppos)
2692 {
2693 struct task_struct *task = get_proc_task(file_inode(file));
2694 struct mm_struct *mm;
2695 char buffer[PROC_NUMBUF];
2696 size_t len;
2697 int ret;
2698
2699 if (!task)
2700 return -ESRCH;
2701
2702 ret = 0;
2703 mm = get_task_mm(task);
2704 if (mm) {
2705 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2706 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2707 MMF_DUMP_FILTER_SHIFT));
2708 mmput(mm);
2709 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2710 }
2711
2712 put_task_struct(task);
2713
2714 return ret;
2715 }
2716
2717 static ssize_t proc_coredump_filter_write(struct file *file,
2718 const char __user *buf,
2719 size_t count,
2720 loff_t *ppos)
2721 {
2722 struct task_struct *task;
2723 struct mm_struct *mm;
2724 unsigned int val;
2725 int ret;
2726 int i;
2727 unsigned long mask;
2728
2729 ret = kstrtouint_from_user(buf, count, 0, &val);
2730 if (ret < 0)
2731 return ret;
2732
2733 ret = -ESRCH;
2734 task = get_proc_task(file_inode(file));
2735 if (!task)
2736 goto out_no_task;
2737
2738 mm = get_task_mm(task);
2739 if (!mm)
2740 goto out_no_mm;
2741 ret = 0;
2742
2743 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2744 if (val & mask)
2745 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2746 else
2747 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2748 }
2749
2750 mmput(mm);
2751 out_no_mm:
2752 put_task_struct(task);
2753 out_no_task:
2754 if (ret < 0)
2755 return ret;
2756 return count;
2757 }
2758
2759 static const struct file_operations proc_coredump_filter_operations = {
2760 .read = proc_coredump_filter_read,
2761 .write = proc_coredump_filter_write,
2762 .llseek = generic_file_llseek,
2763 };
2764 #endif
2765
2766 #ifdef CONFIG_TASK_IO_ACCOUNTING
2767 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2768 {
2769 struct task_io_accounting acct = task->ioac;
2770 unsigned long flags;
2771 int result;
2772
2773 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2774 if (result)
2775 return result;
2776
2777 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2778 result = -EACCES;
2779 goto out_unlock;
2780 }
2781
2782 if (whole && lock_task_sighand(task, &flags)) {
2783 struct task_struct *t = task;
2784
2785 task_io_accounting_add(&acct, &task->signal->ioac);
2786 while_each_thread(task, t)
2787 task_io_accounting_add(&acct, &t->ioac);
2788
2789 unlock_task_sighand(task, &flags);
2790 }
2791 seq_printf(m,
2792 "rchar: %llu\n"
2793 "wchar: %llu\n"
2794 "syscr: %llu\n"
2795 "syscw: %llu\n"
2796 "read_bytes: %llu\n"
2797 "write_bytes: %llu\n"
2798 "cancelled_write_bytes: %llu\n",
2799 (unsigned long long)acct.rchar,
2800 (unsigned long long)acct.wchar,
2801 (unsigned long long)acct.syscr,
2802 (unsigned long long)acct.syscw,
2803 (unsigned long long)acct.read_bytes,
2804 (unsigned long long)acct.write_bytes,
2805 (unsigned long long)acct.cancelled_write_bytes);
2806 result = 0;
2807
2808 out_unlock:
2809 mutex_unlock(&task->signal->cred_guard_mutex);
2810 return result;
2811 }
2812
2813 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2814 struct pid *pid, struct task_struct *task)
2815 {
2816 return do_io_accounting(task, m, 0);
2817 }
2818
2819 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2820 struct pid *pid, struct task_struct *task)
2821 {
2822 return do_io_accounting(task, m, 1);
2823 }
2824 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2825
2826 #ifdef CONFIG_USER_NS
2827 static int proc_id_map_open(struct inode *inode, struct file *file,
2828 const struct seq_operations *seq_ops)
2829 {
2830 struct user_namespace *ns = NULL;
2831 struct task_struct *task;
2832 struct seq_file *seq;
2833 int ret = -EINVAL;
2834
2835 task = get_proc_task(inode);
2836 if (task) {
2837 rcu_read_lock();
2838 ns = get_user_ns(task_cred_xxx(task, user_ns));
2839 rcu_read_unlock();
2840 put_task_struct(task);
2841 }
2842 if (!ns)
2843 goto err;
2844
2845 ret = seq_open(file, seq_ops);
2846 if (ret)
2847 goto err_put_ns;
2848
2849 seq = file->private_data;
2850 seq->private = ns;
2851
2852 return 0;
2853 err_put_ns:
2854 put_user_ns(ns);
2855 err:
2856 return ret;
2857 }
2858
2859 static int proc_id_map_release(struct inode *inode, struct file *file)
2860 {
2861 struct seq_file *seq = file->private_data;
2862 struct user_namespace *ns = seq->private;
2863 put_user_ns(ns);
2864 return seq_release(inode, file);
2865 }
2866
2867 static int proc_uid_map_open(struct inode *inode, struct file *file)
2868 {
2869 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2870 }
2871
2872 static int proc_gid_map_open(struct inode *inode, struct file *file)
2873 {
2874 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2875 }
2876
2877 static int proc_projid_map_open(struct inode *inode, struct file *file)
2878 {
2879 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2880 }
2881
2882 static const struct file_operations proc_uid_map_operations = {
2883 .open = proc_uid_map_open,
2884 .write = proc_uid_map_write,
2885 .read = seq_read,
2886 .llseek = seq_lseek,
2887 .release = proc_id_map_release,
2888 };
2889
2890 static const struct file_operations proc_gid_map_operations = {
2891 .open = proc_gid_map_open,
2892 .write = proc_gid_map_write,
2893 .read = seq_read,
2894 .llseek = seq_lseek,
2895 .release = proc_id_map_release,
2896 };
2897
2898 static const struct file_operations proc_projid_map_operations = {
2899 .open = proc_projid_map_open,
2900 .write = proc_projid_map_write,
2901 .read = seq_read,
2902 .llseek = seq_lseek,
2903 .release = proc_id_map_release,
2904 };
2905
2906 static int proc_setgroups_open(struct inode *inode, struct file *file)
2907 {
2908 struct user_namespace *ns = NULL;
2909 struct task_struct *task;
2910 int ret;
2911
2912 ret = -ESRCH;
2913 task = get_proc_task(inode);
2914 if (task) {
2915 rcu_read_lock();
2916 ns = get_user_ns(task_cred_xxx(task, user_ns));
2917 rcu_read_unlock();
2918 put_task_struct(task);
2919 }
2920 if (!ns)
2921 goto err;
2922
2923 if (file->f_mode & FMODE_WRITE) {
2924 ret = -EACCES;
2925 if (!ns_capable(ns, CAP_SYS_ADMIN))
2926 goto err_put_ns;
2927 }
2928
2929 ret = single_open(file, &proc_setgroups_show, ns);
2930 if (ret)
2931 goto err_put_ns;
2932
2933 return 0;
2934 err_put_ns:
2935 put_user_ns(ns);
2936 err:
2937 return ret;
2938 }
2939
2940 static int proc_setgroups_release(struct inode *inode, struct file *file)
2941 {
2942 struct seq_file *seq = file->private_data;
2943 struct user_namespace *ns = seq->private;
2944 int ret = single_release(inode, file);
2945 put_user_ns(ns);
2946 return ret;
2947 }
2948
2949 static const struct file_operations proc_setgroups_operations = {
2950 .open = proc_setgroups_open,
2951 .write = proc_setgroups_write,
2952 .read = seq_read,
2953 .llseek = seq_lseek,
2954 .release = proc_setgroups_release,
2955 };
2956 #endif /* CONFIG_USER_NS */
2957
2958 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2959 struct pid *pid, struct task_struct *task)
2960 {
2961 int err = lock_trace(task);
2962 if (!err) {
2963 seq_printf(m, "%08x\n", task->personality);
2964 unlock_trace(task);
2965 }
2966 return err;
2967 }
2968
2969 #ifdef CONFIG_LIVEPATCH
2970 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
2971 struct pid *pid, struct task_struct *task)
2972 {
2973 seq_printf(m, "%d\n", task->patch_state);
2974 return 0;
2975 }
2976 #endif /* CONFIG_LIVEPATCH */
2977
2978 #ifdef CONFIG_STACKLEAK_METRICS
2979 static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
2980 struct pid *pid, struct task_struct *task)
2981 {
2982 unsigned long prev_depth = THREAD_SIZE -
2983 (task->prev_lowest_stack & (THREAD_SIZE - 1));
2984 unsigned long depth = THREAD_SIZE -
2985 (task->lowest_stack & (THREAD_SIZE - 1));
2986
2987 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
2988 prev_depth, depth);
2989 return 0;
2990 }
2991 #endif /* CONFIG_STACKLEAK_METRICS */
2992
2993 /*
2994 * Thread groups
2995 */
2996 static const struct file_operations proc_task_operations;
2997 static const struct inode_operations proc_task_inode_operations;
2998
2999 static const struct pid_entry tgid_base_stuff[] = {
3000 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3001 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3002 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3003 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3004 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3005 #ifdef CONFIG_NET
3006 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3007 #endif
3008 REG("environ", S_IRUSR, proc_environ_operations),
3009 REG("auxv", S_IRUSR, proc_auxv_operations),
3010 ONE("status", S_IRUGO, proc_pid_status),
3011 ONE("personality", S_IRUSR, proc_pid_personality),
3012 ONE("limits", S_IRUGO, proc_pid_limits),
3013 #ifdef CONFIG_SCHED_DEBUG
3014 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3015 #endif
3016 #ifdef CONFIG_SCHED_AUTOGROUP
3017 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3018 #endif
3019 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3020 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3021 ONE("syscall", S_IRUSR, proc_pid_syscall),
3022 #endif
3023 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3024 ONE("stat", S_IRUGO, proc_tgid_stat),
3025 ONE("statm", S_IRUGO, proc_pid_statm),
3026 REG("maps", S_IRUGO, proc_pid_maps_operations),
3027 #ifdef CONFIG_NUMA
3028 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3029 #endif
3030 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3031 LNK("cwd", proc_cwd_link),
3032 LNK("root", proc_root_link),
3033 LNK("exe", proc_exe_link),
3034 REG("mounts", S_IRUGO, proc_mounts_operations),
3035 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3036 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3037 #ifdef CONFIG_PROC_PAGE_MONITOR
3038 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3039 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3040 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3041 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3042 #endif
3043 #ifdef CONFIG_SECURITY
3044 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3045 #endif
3046 #ifdef CONFIG_KALLSYMS
3047 ONE("wchan", S_IRUGO, proc_pid_wchan),
3048 #endif
3049 #ifdef CONFIG_STACKTRACE
3050 ONE("stack", S_IRUSR, proc_pid_stack),
3051 #endif
3052 #ifdef CONFIG_SCHED_INFO
3053 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3054 #endif
3055 #ifdef CONFIG_LATENCYTOP
3056 REG("latency", S_IRUGO, proc_lstats_operations),
3057 #endif
3058 #ifdef CONFIG_PROC_PID_CPUSET
3059 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3060 #endif
3061 #ifdef CONFIG_CGROUPS
3062 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3063 #endif
3064 ONE("oom_score", S_IRUGO, proc_oom_score),
3065 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3066 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3067 #ifdef CONFIG_AUDIT
3068 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3069 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3070 #endif
3071 #ifdef CONFIG_FAULT_INJECTION
3072 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3073 REG("fail-nth", 0644, proc_fail_nth_operations),
3074 #endif
3075 #ifdef CONFIG_ELF_CORE
3076 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3077 #endif
3078 #ifdef CONFIG_TASK_IO_ACCOUNTING
3079 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3080 #endif
3081 #ifdef CONFIG_USER_NS
3082 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3083 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3084 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3085 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3086 #endif
3087 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3088 REG("timers", S_IRUGO, proc_timers_operations),
3089 #endif
3090 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3091 #ifdef CONFIG_LIVEPATCH
3092 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3093 #endif
3094 #ifdef CONFIG_STACKLEAK_METRICS
3095 ONE("stack_depth", S_IRUGO, proc_stack_depth),
3096 #endif
3097 #ifdef CONFIG_PROC_PID_ARCH_STATUS
3098 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3099 #endif
3100 };
3101
3102 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3103 {
3104 return proc_pident_readdir(file, ctx,
3105 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3106 }
3107
3108 static const struct file_operations proc_tgid_base_operations = {
3109 .read = generic_read_dir,
3110 .iterate_shared = proc_tgid_base_readdir,
3111 .llseek = generic_file_llseek,
3112 };
3113
3114 struct pid *tgid_pidfd_to_pid(const struct file *file)
3115 {
3116 if (file->f_op != &proc_tgid_base_operations)
3117 return ERR_PTR(-EBADF);
3118
3119 return proc_pid(file_inode(file));
3120 }
3121
3122 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3123 {
3124 return proc_pident_lookup(dir, dentry,
3125 tgid_base_stuff,
3126 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3127 }
3128
3129 static const struct inode_operations proc_tgid_base_inode_operations = {
3130 .lookup = proc_tgid_base_lookup,
3131 .getattr = pid_getattr,
3132 .setattr = proc_setattr,
3133 .permission = proc_pid_permission,
3134 };
3135
3136 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
3137 {
3138 struct dentry *dentry, *leader, *dir;
3139 char buf[10 + 1];
3140 struct qstr name;
3141
3142 name.name = buf;
3143 name.len = snprintf(buf, sizeof(buf), "%u", pid);
3144 /* no ->d_hash() rejects on procfs */
3145 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
3146 if (dentry) {
3147 d_invalidate(dentry);
3148 dput(dentry);
3149 }
3150
3151 if (pid == tgid)
3152 return;
3153
3154 name.name = buf;
3155 name.len = snprintf(buf, sizeof(buf), "%u", tgid);
3156 leader = d_hash_and_lookup(mnt->mnt_root, &name);
3157 if (!leader)
3158 goto out;
3159
3160 name.name = "task";
3161 name.len = strlen(name.name);
3162 dir = d_hash_and_lookup(leader, &name);
3163 if (!dir)
3164 goto out_put_leader;
3165
3166 name.name = buf;
3167 name.len = snprintf(buf, sizeof(buf), "%u", pid);
3168 dentry = d_hash_and_lookup(dir, &name);
3169 if (dentry) {
3170 d_invalidate(dentry);
3171 dput(dentry);
3172 }
3173
3174 dput(dir);
3175 out_put_leader:
3176 dput(leader);
3177 out:
3178 return;
3179 }
3180
3181 /**
3182 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3183 * @task: task that should be flushed.
3184 *
3185 * When flushing dentries from proc, one needs to flush them from global
3186 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3187 * in. This call is supposed to do all of this job.
3188 *
3189 * Looks in the dcache for
3190 * /proc/@pid
3191 * /proc/@tgid/task/@pid
3192 * if either directory is present flushes it and all of it'ts children
3193 * from the dcache.
3194 *
3195 * It is safe and reasonable to cache /proc entries for a task until
3196 * that task exits. After that they just clog up the dcache with
3197 * useless entries, possibly causing useful dcache entries to be
3198 * flushed instead. This routine is proved to flush those useless
3199 * dcache entries at process exit time.
3200 *
3201 * NOTE: This routine is just an optimization so it does not guarantee
3202 * that no dcache entries will exist at process exit time it
3203 * just makes it very unlikely that any will persist.
3204 */
3205
3206 void proc_flush_task(struct task_struct *task)
3207 {
3208 int i;
3209 struct pid *pid, *tgid;
3210 struct upid *upid;
3211
3212 pid = task_pid(task);
3213 tgid = task_tgid(task);
3214
3215 for (i = 0; i <= pid->level; i++) {
3216 upid = &pid->numbers[i];
3217 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3218 tgid->numbers[i].nr);
3219 }
3220 }
3221
3222 static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3223 struct task_struct *task, const void *ptr)
3224 {
3225 struct inode *inode;
3226
3227 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3228 if (!inode)
3229 return ERR_PTR(-ENOENT);
3230
3231 inode->i_op = &proc_tgid_base_inode_operations;
3232 inode->i_fop = &proc_tgid_base_operations;
3233 inode->i_flags|=S_IMMUTABLE;
3234
3235 set_nlink(inode, nlink_tgid);
3236 pid_update_inode(task, inode);
3237
3238 d_set_d_op(dentry, &pid_dentry_operations);
3239 return d_splice_alias(inode, dentry);
3240 }
3241
3242 struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3243 {
3244 struct task_struct *task;
3245 unsigned tgid;
3246 struct pid_namespace *ns;
3247 struct dentry *result = ERR_PTR(-ENOENT);
3248
3249 tgid = name_to_int(&dentry->d_name);
3250 if (tgid == ~0U)
3251 goto out;
3252
3253 ns = dentry->d_sb->s_fs_info;
3254 rcu_read_lock();
3255 task = find_task_by_pid_ns(tgid, ns);
3256 if (task)
3257 get_task_struct(task);
3258 rcu_read_unlock();
3259 if (!task)
3260 goto out;
3261
3262 result = proc_pid_instantiate(dentry, task, NULL);
3263 put_task_struct(task);
3264 out:
3265 return result;
3266 }
3267
3268 /*
3269 * Find the first task with tgid >= tgid
3270 *
3271 */
3272 struct tgid_iter {
3273 unsigned int tgid;
3274 struct task_struct *task;
3275 };
3276 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3277 {
3278 struct pid *pid;
3279
3280 if (iter.task)
3281 put_task_struct(iter.task);
3282 rcu_read_lock();
3283 retry:
3284 iter.task = NULL;
3285 pid = find_ge_pid(iter.tgid, ns);
3286 if (pid) {
3287 iter.tgid = pid_nr_ns(pid, ns);
3288 iter.task = pid_task(pid, PIDTYPE_PID);
3289 /* What we to know is if the pid we have find is the
3290 * pid of a thread_group_leader. Testing for task
3291 * being a thread_group_leader is the obvious thing
3292 * todo but there is a window when it fails, due to
3293 * the pid transfer logic in de_thread.
3294 *
3295 * So we perform the straight forward test of seeing
3296 * if the pid we have found is the pid of a thread
3297 * group leader, and don't worry if the task we have
3298 * found doesn't happen to be a thread group leader.
3299 * As we don't care in the case of readdir.
3300 */
3301 if (!iter.task || !has_group_leader_pid(iter.task)) {
3302 iter.tgid += 1;
3303 goto retry;
3304 }
3305 get_task_struct(iter.task);
3306 }
3307 rcu_read_unlock();
3308 return iter;
3309 }
3310
3311 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3312
3313 /* for the /proc/ directory itself, after non-process stuff has been done */
3314 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3315 {
3316 struct tgid_iter iter;
3317 struct pid_namespace *ns = proc_pid_ns(file_inode(file));
3318 loff_t pos = ctx->pos;
3319
3320 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3321 return 0;
3322
3323 if (pos == TGID_OFFSET - 2) {
3324 struct inode *inode = d_inode(ns->proc_self);
3325 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3326 return 0;
3327 ctx->pos = pos = pos + 1;
3328 }
3329 if (pos == TGID_OFFSET - 1) {
3330 struct inode *inode = d_inode(ns->proc_thread_self);
3331 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3332 return 0;
3333 ctx->pos = pos = pos + 1;
3334 }
3335 iter.tgid = pos - TGID_OFFSET;
3336 iter.task = NULL;
3337 for (iter = next_tgid(ns, iter);
3338 iter.task;
3339 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3340 char name[10 + 1];
3341 unsigned int len;
3342
3343 cond_resched();
3344 if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE))
3345 continue;
3346
3347 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3348 ctx->pos = iter.tgid + TGID_OFFSET;
3349 if (!proc_fill_cache(file, ctx, name, len,
3350 proc_pid_instantiate, iter.task, NULL)) {
3351 put_task_struct(iter.task);
3352 return 0;
3353 }
3354 }
3355 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3356 return 0;
3357 }
3358
3359 /*
3360 * proc_tid_comm_permission is a special permission function exclusively
3361 * used for the node /proc/<pid>/task/<tid>/comm.
3362 * It bypasses generic permission checks in the case where a task of the same
3363 * task group attempts to access the node.
3364 * The rationale behind this is that glibc and bionic access this node for
3365 * cross thread naming (pthread_set/getname_np(!self)). However, if
3366 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3367 * which locks out the cross thread naming implementation.
3368 * This function makes sure that the node is always accessible for members of
3369 * same thread group.
3370 */
3371 static int proc_tid_comm_permission(struct inode *inode, int mask)
3372 {
3373 bool is_same_tgroup;
3374 struct task_struct *task;
3375
3376 task = get_proc_task(inode);
3377 if (!task)
3378 return -ESRCH;
3379 is_same_tgroup = same_thread_group(current, task);
3380 put_task_struct(task);
3381
3382 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3383 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3384 * read or written by the members of the corresponding
3385 * thread group.
3386 */
3387 return 0;
3388 }
3389
3390 return generic_permission(inode, mask);
3391 }
3392
3393 static const struct inode_operations proc_tid_comm_inode_operations = {
3394 .permission = proc_tid_comm_permission,
3395 };
3396
3397 /*
3398 * Tasks
3399 */
3400 static const struct pid_entry tid_base_stuff[] = {
3401 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3402 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3403 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3404 #ifdef CONFIG_NET
3405 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3406 #endif
3407 REG("environ", S_IRUSR, proc_environ_operations),
3408 REG("auxv", S_IRUSR, proc_auxv_operations),
3409 ONE("status", S_IRUGO, proc_pid_status),
3410 ONE("personality", S_IRUSR, proc_pid_personality),
3411 ONE("limits", S_IRUGO, proc_pid_limits),
3412 #ifdef CONFIG_SCHED_DEBUG
3413 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3414 #endif
3415 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3416 &proc_tid_comm_inode_operations,
3417 &proc_pid_set_comm_operations, {}),
3418 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3419 ONE("syscall", S_IRUSR, proc_pid_syscall),
3420 #endif
3421 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3422 ONE("stat", S_IRUGO, proc_tid_stat),
3423 ONE("statm", S_IRUGO, proc_pid_statm),
3424 REG("maps", S_IRUGO, proc_pid_maps_operations),
3425 #ifdef CONFIG_PROC_CHILDREN
3426 REG("children", S_IRUGO, proc_tid_children_operations),
3427 #endif
3428 #ifdef CONFIG_NUMA
3429 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3430 #endif
3431 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3432 LNK("cwd", proc_cwd_link),
3433 LNK("root", proc_root_link),
3434 LNK("exe", proc_exe_link),
3435 REG("mounts", S_IRUGO, proc_mounts_operations),
3436 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3437 #ifdef CONFIG_PROC_PAGE_MONITOR
3438 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3439 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3440 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3441 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3442 #endif
3443 #ifdef CONFIG_SECURITY
3444 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3445 #endif
3446 #ifdef CONFIG_KALLSYMS
3447 ONE("wchan", S_IRUGO, proc_pid_wchan),
3448 #endif
3449 #ifdef CONFIG_STACKTRACE
3450 ONE("stack", S_IRUSR, proc_pid_stack),
3451 #endif
3452 #ifdef CONFIG_SCHED_INFO
3453 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3454 #endif
3455 #ifdef CONFIG_LATENCYTOP
3456 REG("latency", S_IRUGO, proc_lstats_operations),
3457 #endif
3458 #ifdef CONFIG_PROC_PID_CPUSET
3459 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3460 #endif
3461 #ifdef CONFIG_CGROUPS
3462 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3463 #endif
3464 ONE("oom_score", S_IRUGO, proc_oom_score),
3465 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3466 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3467 #ifdef CONFIG_AUDIT
3468 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3469 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3470 #endif
3471 #ifdef CONFIG_FAULT_INJECTION
3472 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3473 REG("fail-nth", 0644, proc_fail_nth_operations),
3474 #endif
3475 #ifdef CONFIG_TASK_IO_ACCOUNTING
3476 ONE("io", S_IRUSR, proc_tid_io_accounting),
3477 #endif
3478 #ifdef CONFIG_USER_NS
3479 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3480 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3481 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3482 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3483 #endif
3484 #ifdef CONFIG_LIVEPATCH
3485 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3486 #endif
3487 #ifdef CONFIG_PROC_PID_ARCH_STATUS
3488 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3489 #endif
3490 };
3491
3492 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3493 {
3494 return proc_pident_readdir(file, ctx,
3495 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3496 }
3497
3498 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3499 {
3500 return proc_pident_lookup(dir, dentry,
3501 tid_base_stuff,
3502 tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3503 }
3504
3505 static const struct file_operations proc_tid_base_operations = {
3506 .read = generic_read_dir,
3507 .iterate_shared = proc_tid_base_readdir,
3508 .llseek = generic_file_llseek,
3509 };
3510
3511 static const struct inode_operations proc_tid_base_inode_operations = {
3512 .lookup = proc_tid_base_lookup,
3513 .getattr = pid_getattr,
3514 .setattr = proc_setattr,
3515 };
3516
3517 static struct dentry *proc_task_instantiate(struct dentry *dentry,
3518 struct task_struct *task, const void *ptr)
3519 {
3520 struct inode *inode;
3521 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3522 if (!inode)
3523 return ERR_PTR(-ENOENT);
3524
3525 inode->i_op = &proc_tid_base_inode_operations;
3526 inode->i_fop = &proc_tid_base_operations;
3527 inode->i_flags |= S_IMMUTABLE;
3528
3529 set_nlink(inode, nlink_tid);
3530 pid_update_inode(task, inode);
3531
3532 d_set_d_op(dentry, &pid_dentry_operations);
3533 return d_splice_alias(inode, dentry);
3534 }
3535
3536 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3537 {
3538 struct task_struct *task;
3539 struct task_struct *leader = get_proc_task(dir);
3540 unsigned tid;
3541 struct pid_namespace *ns;
3542 struct dentry *result = ERR_PTR(-ENOENT);
3543
3544 if (!leader)
3545 goto out_no_task;
3546
3547 tid = name_to_int(&dentry->d_name);
3548 if (tid == ~0U)
3549 goto out;
3550
3551 ns = dentry->d_sb->s_fs_info;
3552 rcu_read_lock();
3553 task = find_task_by_pid_ns(tid, ns);
3554 if (task)
3555 get_task_struct(task);
3556 rcu_read_unlock();
3557 if (!task)
3558 goto out;
3559 if (!same_thread_group(leader, task))
3560 goto out_drop_task;
3561
3562 result = proc_task_instantiate(dentry, task, NULL);
3563 out_drop_task:
3564 put_task_struct(task);
3565 out:
3566 put_task_struct(leader);
3567 out_no_task:
3568 return result;
3569 }
3570
3571 /*
3572 * Find the first tid of a thread group to return to user space.
3573 *
3574 * Usually this is just the thread group leader, but if the users
3575 * buffer was too small or there was a seek into the middle of the
3576 * directory we have more work todo.
3577 *
3578 * In the case of a short read we start with find_task_by_pid.
3579 *
3580 * In the case of a seek we start with the leader and walk nr
3581 * threads past it.
3582 */
3583 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3584 struct pid_namespace *ns)
3585 {
3586 struct task_struct *pos, *task;
3587 unsigned long nr = f_pos;
3588
3589 if (nr != f_pos) /* 32bit overflow? */
3590 return NULL;
3591
3592 rcu_read_lock();
3593 task = pid_task(pid, PIDTYPE_PID);
3594 if (!task)
3595 goto fail;
3596
3597 /* Attempt to start with the tid of a thread */
3598 if (tid && nr) {
3599 pos = find_task_by_pid_ns(tid, ns);
3600 if (pos && same_thread_group(pos, task))
3601 goto found;
3602 }
3603
3604 /* If nr exceeds the number of threads there is nothing todo */
3605 if (nr >= get_nr_threads(task))
3606 goto fail;
3607
3608 /* If we haven't found our starting place yet start
3609 * with the leader and walk nr threads forward.
3610 */
3611 pos = task = task->group_leader;
3612 do {
3613 if (!nr--)
3614 goto found;
3615 } while_each_thread(task, pos);
3616 fail:
3617 pos = NULL;
3618 goto out;
3619 found:
3620 get_task_struct(pos);
3621 out:
3622 rcu_read_unlock();
3623 return pos;
3624 }
3625
3626 /*
3627 * Find the next thread in the thread list.
3628 * Return NULL if there is an error or no next thread.
3629 *
3630 * The reference to the input task_struct is released.
3631 */
3632 static struct task_struct *next_tid(struct task_struct *start)
3633 {
3634 struct task_struct *pos = NULL;
3635 rcu_read_lock();
3636 if (pid_alive(start)) {
3637 pos = next_thread(start);
3638 if (thread_group_leader(pos))
3639 pos = NULL;
3640 else
3641 get_task_struct(pos);
3642 }
3643 rcu_read_unlock();
3644 put_task_struct(start);
3645 return pos;
3646 }
3647
3648 /* for the /proc/TGID/task/ directories */
3649 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3650 {
3651 struct inode *inode = file_inode(file);
3652 struct task_struct *task;
3653 struct pid_namespace *ns;
3654 int tid;
3655
3656 if (proc_inode_is_dead(inode))
3657 return -ENOENT;
3658
3659 if (!dir_emit_dots(file, ctx))
3660 return 0;
3661
3662 /* f_version caches the tgid value that the last readdir call couldn't
3663 * return. lseek aka telldir automagically resets f_version to 0.
3664 */
3665 ns = proc_pid_ns(inode);
3666 tid = (int)file->f_version;
3667 file->f_version = 0;
3668 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3669 task;
3670 task = next_tid(task), ctx->pos++) {
3671 char name[10 + 1];
3672 unsigned int len;
3673 tid = task_pid_nr_ns(task, ns);
3674 len = snprintf(name, sizeof(name), "%u", tid);
3675 if (!proc_fill_cache(file, ctx, name, len,
3676 proc_task_instantiate, task, NULL)) {
3677 /* returning this tgid failed, save it as the first
3678 * pid for the next readir call */
3679 file->f_version = (u64)tid;
3680 put_task_struct(task);
3681 break;
3682 }
3683 }
3684
3685 return 0;
3686 }
3687
3688 static int proc_task_getattr(const struct path *path, struct kstat *stat,
3689 u32 request_mask, unsigned int query_flags)
3690 {
3691 struct inode *inode = d_inode(path->dentry);
3692 struct task_struct *p = get_proc_task(inode);
3693 generic_fillattr(inode, stat);
3694
3695 if (p) {
3696 stat->nlink += get_nr_threads(p);
3697 put_task_struct(p);
3698 }
3699
3700 return 0;
3701 }
3702
3703 static const struct inode_operations proc_task_inode_operations = {
3704 .lookup = proc_task_lookup,
3705 .getattr = proc_task_getattr,
3706 .setattr = proc_setattr,
3707 .permission = proc_pid_permission,
3708 };
3709
3710 static const struct file_operations proc_task_operations = {
3711 .read = generic_read_dir,
3712 .iterate_shared = proc_task_readdir,
3713 .llseek = generic_file_llseek,
3714 };
3715
3716 void __init set_proc_pid_nlink(void)
3717 {
3718 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3719 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3720 }
Linux with added FPC-III support