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Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[linux/fpc-iii.git] / fs / proc / base.c
bloba333caeca29119b12cd7234750eec057f73a306e
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 <linux/time_namespace.h>
98 #include <linux/resctrl.h>
99 #include <trace/events/oom.h>
100 #include "internal.h"
101 #include "fd.h"
102
103 #include "../../lib/kstrtox.h"
104
105 /* NOTE:
106 * Implementing inode permission operations in /proc is almost
107 * certainly an error. Permission checks need to happen during
108 * each system call not at open time. The reason is that most of
109 * what we wish to check for permissions in /proc varies at runtime.
110 *
111 * The classic example of a problem is opening file descriptors
112 * in /proc for a task before it execs a suid executable.
113 */
114
115 static u8 nlink_tid __ro_after_init;
116 static u8 nlink_tgid __ro_after_init;
117
118 struct pid_entry {
119 const char *name;
120 unsigned int len;
121 umode_t mode;
122 const struct inode_operations *iop;
123 const struct file_operations *fop;
124 union proc_op op;
125 };
126
127 #define NOD(NAME, MODE, IOP, FOP, OP) { \
128 .name = (NAME), \
129 .len = sizeof(NAME) - 1, \
130 .mode = MODE, \
131 .iop = IOP, \
132 .fop = FOP, \
133 .op = OP, \
134 }
135
136 #define DIR(NAME, MODE, iops, fops) \
137 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
138 #define LNK(NAME, get_link) \
139 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
140 &proc_pid_link_inode_operations, NULL, \
141 { .proc_get_link = get_link } )
142 #define REG(NAME, MODE, fops) \
143 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
144 #define ONE(NAME, MODE, show) \
145 NOD(NAME, (S_IFREG|(MODE)), \
146 NULL, &proc_single_file_operations, \
147 { .proc_show = show } )
148 #define ATTR(LSM, NAME, MODE) \
149 NOD(NAME, (S_IFREG|(MODE)), \
150 NULL, &proc_pid_attr_operations, \
151 { .lsm = LSM })
152
153 /*
154 * Count the number of hardlinks for the pid_entry table, excluding the .
155 * and .. links.
156 */
157 static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
158 unsigned int n)
159 {
160 unsigned int i;
161 unsigned int count;
162
163 count = 2;
164 for (i = 0; i < n; ++i) {
165 if (S_ISDIR(entries[i].mode))
166 ++count;
167 }
168
169 return count;
170 }
171
172 static int get_task_root(struct task_struct *task, struct path *root)
173 {
174 int result = -ENOENT;
175
176 task_lock(task);
177 if (task->fs) {
178 get_fs_root(task->fs, root);
179 result = 0;
180 }
181 task_unlock(task);
182 return result;
183 }
184
185 static int proc_cwd_link(struct dentry *dentry, struct path *path)
186 {
187 struct task_struct *task = get_proc_task(d_inode(dentry));
188 int result = -ENOENT;
189
190 if (task) {
191 task_lock(task);
192 if (task->fs) {
193 get_fs_pwd(task->fs, path);
194 result = 0;
195 }
196 task_unlock(task);
197 put_task_struct(task);
198 }
199 return result;
200 }
201
202 static int proc_root_link(struct dentry *dentry, struct path *path)
203 {
204 struct task_struct *task = get_proc_task(d_inode(dentry));
205 int result = -ENOENT;
206
207 if (task) {
208 result = get_task_root(task, path);
209 put_task_struct(task);
210 }
211 return result;
212 }
213
214 /*
215 * If the user used setproctitle(), we just get the string from
216 * user space at arg_start, and limit it to a maximum of one page.
217 */
218 static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
219 size_t count, unsigned long pos,
220 unsigned long arg_start)
221 {
222 char *page;
223 int ret, got;
224
225 if (pos >= PAGE_SIZE)
226 return 0;
227
228 page = (char *)__get_free_page(GFP_KERNEL);
229 if (!page)
230 return -ENOMEM;
231
232 ret = 0;
233 got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
234 if (got > 0) {
235 int len = strnlen(page, got);
236
237 /* Include the NUL character if it was found */
238 if (len < got)
239 len++;
240
241 if (len > pos) {
242 len -= pos;
243 if (len > count)
244 len = count;
245 len -= copy_to_user(buf, page+pos, len);
246 if (!len)
247 len = -EFAULT;
248 ret = len;
249 }
250 }
251 free_page((unsigned long)page);
252 return ret;
253 }
254
255 static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
256 size_t count, loff_t *ppos)
257 {
258 unsigned long arg_start, arg_end, env_start, env_end;
259 unsigned long pos, len;
260 char *page, c;
261
262 /* Check if process spawned far enough to have cmdline. */
263 if (!mm->env_end)
264 return 0;
265
266 spin_lock(&mm->arg_lock);
267 arg_start = mm->arg_start;
268 arg_end = mm->arg_end;
269 env_start = mm->env_start;
270 env_end = mm->env_end;
271 spin_unlock(&mm->arg_lock);
272
273 if (arg_start >= arg_end)
274 return 0;
275
276 /*
277 * We allow setproctitle() to overwrite the argument
278 * strings, and overflow past the original end. But
279 * only when it overflows into the environment area.
280 */
281 if (env_start != arg_end || env_end < env_start)
282 env_start = env_end = arg_end;
283 len = env_end - arg_start;
284
285 /* We're not going to care if "*ppos" has high bits set */
286 pos = *ppos;
287 if (pos >= len)
288 return 0;
289 if (count > len - pos)
290 count = len - pos;
291 if (!count)
292 return 0;
293
294 /*
295 * Magical special case: if the argv[] end byte is not
296 * zero, the user has overwritten it with setproctitle(3).
297 *
298 * Possible future enhancement: do this only once when
299 * pos is 0, and set a flag in the 'struct file'.
300 */
301 if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
302 return get_mm_proctitle(mm, buf, count, pos, arg_start);
303
304 /*
305 * For the non-setproctitle() case we limit things strictly
306 * to the [arg_start, arg_end[ range.
307 */
308 pos += arg_start;
309 if (pos < arg_start || pos >= arg_end)
310 return 0;
311 if (count > arg_end - pos)
312 count = arg_end - pos;
313
314 page = (char *)__get_free_page(GFP_KERNEL);
315 if (!page)
316 return -ENOMEM;
317
318 len = 0;
319 while (count) {
320 int got;
321 size_t size = min_t(size_t, PAGE_SIZE, count);
322
323 got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
324 if (got <= 0)
325 break;
326 got -= copy_to_user(buf, page, got);
327 if (unlikely(!got)) {
328 if (!len)
329 len = -EFAULT;
330 break;
331 }
332 pos += got;
333 buf += got;
334 len += got;
335 count -= got;
336 }
337
338 free_page((unsigned long)page);
339 return len;
340 }
341
342 static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
343 size_t count, loff_t *pos)
344 {
345 struct mm_struct *mm;
346 ssize_t ret;
347
348 mm = get_task_mm(tsk);
349 if (!mm)
350 return 0;
351
352 ret = get_mm_cmdline(mm, buf, count, pos);
353 mmput(mm);
354 return ret;
355 }
356
357 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
358 size_t count, loff_t *pos)
359 {
360 struct task_struct *tsk;
361 ssize_t ret;
362
363 BUG_ON(*pos < 0);
364
365 tsk = get_proc_task(file_inode(file));
366 if (!tsk)
367 return -ESRCH;
368 ret = get_task_cmdline(tsk, buf, count, pos);
369 put_task_struct(tsk);
370 if (ret > 0)
371 *pos += ret;
372 return ret;
373 }
374
375 static const struct file_operations proc_pid_cmdline_ops = {
376 .read = proc_pid_cmdline_read,
377 .llseek = generic_file_llseek,
378 };
379
380 #ifdef CONFIG_KALLSYMS
381 /*
382 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
383 * Returns the resolved symbol. If that fails, simply return the address.
384 */
385 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
386 struct pid *pid, struct task_struct *task)
387 {
388 unsigned long wchan;
389 char symname[KSYM_NAME_LEN];
390
391 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
392 goto print0;
393
394 wchan = get_wchan(task);
395 if (wchan && !lookup_symbol_name(wchan, symname)) {
396 seq_puts(m, symname);
397 return 0;
398 }
399
400 print0:
401 seq_putc(m, '0');
402 return 0;
403 }
404 #endif /* CONFIG_KALLSYMS */
405
406 static int lock_trace(struct task_struct *task)
407 {
408 int err = mutex_lock_killable(&task->signal->exec_update_mutex);
409 if (err)
410 return err;
411 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
412 mutex_unlock(&task->signal->exec_update_mutex);
413 return -EPERM;
414 }
415 return 0;
416 }
417
418 static void unlock_trace(struct task_struct *task)
419 {
420 mutex_unlock(&task->signal->exec_update_mutex);
421 }
422
423 #ifdef CONFIG_STACKTRACE
424
425 #define MAX_STACK_TRACE_DEPTH 64
426
427 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
428 struct pid *pid, struct task_struct *task)
429 {
430 unsigned long *entries;
431 int err;
432
433 /*
434 * The ability to racily run the kernel stack unwinder on a running task
435 * and then observe the unwinder output is scary; while it is useful for
436 * debugging kernel issues, it can also allow an attacker to leak kernel
437 * stack contents.
438 * Doing this in a manner that is at least safe from races would require
439 * some work to ensure that the remote task can not be scheduled; and
440 * even then, this would still expose the unwinder as local attack
441 * surface.
442 * Therefore, this interface is restricted to root.
443 */
444 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
445 return -EACCES;
446
447 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
448 GFP_KERNEL);
449 if (!entries)
450 return -ENOMEM;
451
452 err = lock_trace(task);
453 if (!err) {
454 unsigned int i, nr_entries;
455
456 nr_entries = stack_trace_save_tsk(task, entries,
457 MAX_STACK_TRACE_DEPTH, 0);
458
459 for (i = 0; i < nr_entries; i++) {
460 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
461 }
462
463 unlock_trace(task);
464 }
465 kfree(entries);
466
467 return err;
468 }
469 #endif
470
471 #ifdef CONFIG_SCHED_INFO
472 /*
473 * Provides /proc/PID/schedstat
474 */
475 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
476 struct pid *pid, struct task_struct *task)
477 {
478 if (unlikely(!sched_info_on()))
479 seq_puts(m, "0 0 0\n");
480 else
481 seq_printf(m, "%llu %llu %lu\n",
482 (unsigned long long)task->se.sum_exec_runtime,
483 (unsigned long long)task->sched_info.run_delay,
484 task->sched_info.pcount);
485
486 return 0;
487 }
488 #endif
489
490 #ifdef CONFIG_LATENCYTOP
491 static int lstats_show_proc(struct seq_file *m, void *v)
492 {
493 int i;
494 struct inode *inode = m->private;
495 struct task_struct *task = get_proc_task(inode);
496
497 if (!task)
498 return -ESRCH;
499 seq_puts(m, "Latency Top version : v0.1\n");
500 for (i = 0; i < LT_SAVECOUNT; i++) {
501 struct latency_record *lr = &task->latency_record[i];
502 if (lr->backtrace[0]) {
503 int q;
504 seq_printf(m, "%i %li %li",
505 lr->count, lr->time, lr->max);
506 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
507 unsigned long bt = lr->backtrace[q];
508
509 if (!bt)
510 break;
511 seq_printf(m, " %ps", (void *)bt);
512 }
513 seq_putc(m, '\n');
514 }
515
516 }
517 put_task_struct(task);
518 return 0;
519 }
520
521 static int lstats_open(struct inode *inode, struct file *file)
522 {
523 return single_open(file, lstats_show_proc, inode);
524 }
525
526 static ssize_t lstats_write(struct file *file, const char __user *buf,
527 size_t count, loff_t *offs)
528 {
529 struct task_struct *task = get_proc_task(file_inode(file));
530
531 if (!task)
532 return -ESRCH;
533 clear_tsk_latency_tracing(task);
534 put_task_struct(task);
535
536 return count;
537 }
538
539 static const struct file_operations proc_lstats_operations = {
540 .open = lstats_open,
541 .read = seq_read,
542 .write = lstats_write,
543 .llseek = seq_lseek,
544 .release = single_release,
545 };
546
547 #endif
548
549 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
550 struct pid *pid, struct task_struct *task)
551 {
552 unsigned long totalpages = totalram_pages() + total_swap_pages;
553 unsigned long points = 0;
554
555 points = oom_badness(task, totalpages) * 1000 / totalpages;
556 seq_printf(m, "%lu\n", points);
557
558 return 0;
559 }
560
561 struct limit_names {
562 const char *name;
563 const char *unit;
564 };
565
566 static const struct limit_names lnames[RLIM_NLIMITS] = {
567 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
568 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
569 [RLIMIT_DATA] = {"Max data size", "bytes"},
570 [RLIMIT_STACK] = {"Max stack size", "bytes"},
571 [RLIMIT_CORE] = {"Max core file size", "bytes"},
572 [RLIMIT_RSS] = {"Max resident set", "bytes"},
573 [RLIMIT_NPROC] = {"Max processes", "processes"},
574 [RLIMIT_NOFILE] = {"Max open files", "files"},
575 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
576 [RLIMIT_AS] = {"Max address space", "bytes"},
577 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
578 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
579 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
580 [RLIMIT_NICE] = {"Max nice priority", NULL},
581 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
582 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
583 };
584
585 /* Display limits for a process */
586 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
587 struct pid *pid, struct task_struct *task)
588 {
589 unsigned int i;
590 unsigned long flags;
591
592 struct rlimit rlim[RLIM_NLIMITS];
593
594 if (!lock_task_sighand(task, &flags))
595 return 0;
596 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
597 unlock_task_sighand(task, &flags);
598
599 /*
600 * print the file header
601 */
602 seq_puts(m, "Limit "
603 "Soft Limit "
604 "Hard Limit "
605 "Units \n");
606
607 for (i = 0; i < RLIM_NLIMITS; i++) {
608 if (rlim[i].rlim_cur == RLIM_INFINITY)
609 seq_printf(m, "%-25s %-20s ",
610 lnames[i].name, "unlimited");
611 else
612 seq_printf(m, "%-25s %-20lu ",
613 lnames[i].name, rlim[i].rlim_cur);
614
615 if (rlim[i].rlim_max == RLIM_INFINITY)
616 seq_printf(m, "%-20s ", "unlimited");
617 else
618 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
619
620 if (lnames[i].unit)
621 seq_printf(m, "%-10s\n", lnames[i].unit);
622 else
623 seq_putc(m, '\n');
624 }
625
626 return 0;
627 }
628
629 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
630 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
631 struct pid *pid, struct task_struct *task)
632 {
633 struct syscall_info info;
634 u64 *args = &info.data.args[0];
635 int res;
636
637 res = lock_trace(task);
638 if (res)
639 return res;
640
641 if (task_current_syscall(task, &info))
642 seq_puts(m, "running\n");
643 else if (info.data.nr < 0)
644 seq_printf(m, "%d 0x%llx 0x%llx\n",
645 info.data.nr, info.sp, info.data.instruction_pointer);
646 else
647 seq_printf(m,
648 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
649 info.data.nr,
650 args[0], args[1], args[2], args[3], args[4], args[5],
651 info.sp, info.data.instruction_pointer);
652 unlock_trace(task);
653
654 return 0;
655 }
656 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
657
658 /************************************************************************/
659 /* Here the fs part begins */
660 /************************************************************************/
661
662 /* permission checks */
663 static int proc_fd_access_allowed(struct inode *inode)
664 {
665 struct task_struct *task;
666 int allowed = 0;
667 /* Allow access to a task's file descriptors if it is us or we
668 * may use ptrace attach to the process and find out that
669 * information.
670 */
671 task = get_proc_task(inode);
672 if (task) {
673 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
674 put_task_struct(task);
675 }
676 return allowed;
677 }
678
679 int proc_setattr(struct dentry *dentry, struct iattr *attr)
680 {
681 int error;
682 struct inode *inode = d_inode(dentry);
683
684 if (attr->ia_valid & ATTR_MODE)
685 return -EPERM;
686
687 error = setattr_prepare(dentry, attr);
688 if (error)
689 return error;
690
691 setattr_copy(inode, attr);
692 mark_inode_dirty(inode);
693 return 0;
694 }
695
696 /*
697 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
698 * or euid/egid (for hide_pid_min=2)?
699 */
700 static bool has_pid_permissions(struct proc_fs_info *fs_info,
701 struct task_struct *task,
702 enum proc_hidepid hide_pid_min)
703 {
704 /*
705 * If 'hidpid' mount option is set force a ptrace check,
706 * we indicate that we are using a filesystem syscall
707 * by passing PTRACE_MODE_READ_FSCREDS
708 */
709 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE)
710 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
711
712 if (fs_info->hide_pid < hide_pid_min)
713 return true;
714 if (in_group_p(fs_info->pid_gid))
715 return true;
716 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
717 }
718
719
720 static int proc_pid_permission(struct inode *inode, int mask)
721 {
722 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
723 struct task_struct *task;
724 bool has_perms;
725
726 task = get_proc_task(inode);
727 if (!task)
728 return -ESRCH;
729 has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS);
730 put_task_struct(task);
731
732 if (!has_perms) {
733 if (fs_info->hide_pid == HIDEPID_INVISIBLE) {
734 /*
735 * Let's make getdents(), stat(), and open()
736 * consistent with each other. If a process
737 * may not stat() a file, it shouldn't be seen
738 * in procfs at all.
739 */
740 return -ENOENT;
741 }
742
743 return -EPERM;
744 }
745 return generic_permission(inode, mask);
746 }
747
748
749
750 static const struct inode_operations proc_def_inode_operations = {
751 .setattr = proc_setattr,
752 };
753
754 static int proc_single_show(struct seq_file *m, void *v)
755 {
756 struct inode *inode = m->private;
757 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
758 struct pid *pid = proc_pid(inode);
759 struct task_struct *task;
760 int ret;
761
762 task = get_pid_task(pid, PIDTYPE_PID);
763 if (!task)
764 return -ESRCH;
765
766 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
767
768 put_task_struct(task);
769 return ret;
770 }
771
772 static int proc_single_open(struct inode *inode, struct file *filp)
773 {
774 return single_open(filp, proc_single_show, inode);
775 }
776
777 static const struct file_operations proc_single_file_operations = {
778 .open = proc_single_open,
779 .read = seq_read,
780 .llseek = seq_lseek,
781 .release = single_release,
782 };
783
784
785 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
786 {
787 struct task_struct *task = get_proc_task(inode);
788 struct mm_struct *mm = ERR_PTR(-ESRCH);
789
790 if (task) {
791 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
792 put_task_struct(task);
793
794 if (!IS_ERR_OR_NULL(mm)) {
795 /* ensure this mm_struct can't be freed */
796 mmgrab(mm);
797 /* but do not pin its memory */
798 mmput(mm);
799 }
800 }
801
802 return mm;
803 }
804
805 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
806 {
807 struct mm_struct *mm = proc_mem_open(inode, mode);
808
809 if (IS_ERR(mm))
810 return PTR_ERR(mm);
811
812 file->private_data = mm;
813 return 0;
814 }
815
816 static int mem_open(struct inode *inode, struct file *file)
817 {
818 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
819
820 /* OK to pass negative loff_t, we can catch out-of-range */
821 file->f_mode |= FMODE_UNSIGNED_OFFSET;
822
823 return ret;
824 }
825
826 static ssize_t mem_rw(struct file *file, char __user *buf,
827 size_t count, loff_t *ppos, int write)
828 {
829 struct mm_struct *mm = file->private_data;
830 unsigned long addr = *ppos;
831 ssize_t copied;
832 char *page;
833 unsigned int flags;
834
835 if (!mm)
836 return 0;
837
838 page = (char *)__get_free_page(GFP_KERNEL);
839 if (!page)
840 return -ENOMEM;
841
842 copied = 0;
843 if (!mmget_not_zero(mm))
844 goto free;
845
846 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
847
848 while (count > 0) {
849 int this_len = min_t(int, count, PAGE_SIZE);
850
851 if (write && copy_from_user(page, buf, this_len)) {
852 copied = -EFAULT;
853 break;
854 }
855
856 this_len = access_remote_vm(mm, addr, page, this_len, flags);
857 if (!this_len) {
858 if (!copied)
859 copied = -EIO;
860 break;
861 }
862
863 if (!write && copy_to_user(buf, page, this_len)) {
864 copied = -EFAULT;
865 break;
866 }
867
868 buf += this_len;
869 addr += this_len;
870 copied += this_len;
871 count -= this_len;
872 }
873 *ppos = addr;
874
875 mmput(mm);
876 free:
877 free_page((unsigned long) page);
878 return copied;
879 }
880
881 static ssize_t mem_read(struct file *file, char __user *buf,
882 size_t count, loff_t *ppos)
883 {
884 return mem_rw(file, buf, count, ppos, 0);
885 }
886
887 static ssize_t mem_write(struct file *file, const char __user *buf,
888 size_t count, loff_t *ppos)
889 {
890 return mem_rw(file, (char __user*)buf, count, ppos, 1);
891 }
892
893 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
894 {
895 switch (orig) {
896 case 0:
897 file->f_pos = offset;
898 break;
899 case 1:
900 file->f_pos += offset;
901 break;
902 default:
903 return -EINVAL;
904 }
905 force_successful_syscall_return();
906 return file->f_pos;
907 }
908
909 static int mem_release(struct inode *inode, struct file *file)
910 {
911 struct mm_struct *mm = file->private_data;
912 if (mm)
913 mmdrop(mm);
914 return 0;
915 }
916
917 static const struct file_operations proc_mem_operations = {
918 .llseek = mem_lseek,
919 .read = mem_read,
920 .write = mem_write,
921 .open = mem_open,
922 .release = mem_release,
923 };
924
925 static int environ_open(struct inode *inode, struct file *file)
926 {
927 return __mem_open(inode, file, PTRACE_MODE_READ);
928 }
929
930 static ssize_t environ_read(struct file *file, char __user *buf,
931 size_t count, loff_t *ppos)
932 {
933 char *page;
934 unsigned long src = *ppos;
935 int ret = 0;
936 struct mm_struct *mm = file->private_data;
937 unsigned long env_start, env_end;
938
939 /* Ensure the process spawned far enough to have an environment. */
940 if (!mm || !mm->env_end)
941 return 0;
942
943 page = (char *)__get_free_page(GFP_KERNEL);
944 if (!page)
945 return -ENOMEM;
946
947 ret = 0;
948 if (!mmget_not_zero(mm))
949 goto free;
950
951 spin_lock(&mm->arg_lock);
952 env_start = mm->env_start;
953 env_end = mm->env_end;
954 spin_unlock(&mm->arg_lock);
955
956 while (count > 0) {
957 size_t this_len, max_len;
958 int retval;
959
960 if (src >= (env_end - env_start))
961 break;
962
963 this_len = env_end - (env_start + src);
964
965 max_len = min_t(size_t, PAGE_SIZE, count);
966 this_len = min(max_len, this_len);
967
968 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
969
970 if (retval <= 0) {
971 ret = retval;
972 break;
973 }
974
975 if (copy_to_user(buf, page, retval)) {
976 ret = -EFAULT;
977 break;
978 }
979
980 ret += retval;
981 src += retval;
982 buf += retval;
983 count -= retval;
984 }
985 *ppos = src;
986 mmput(mm);
987
988 free:
989 free_page((unsigned long) page);
990 return ret;
991 }
992
993 static const struct file_operations proc_environ_operations = {
994 .open = environ_open,
995 .read = environ_read,
996 .llseek = generic_file_llseek,
997 .release = mem_release,
998 };
999
1000 static int auxv_open(struct inode *inode, struct file *file)
1001 {
1002 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1003 }
1004
1005 static ssize_t auxv_read(struct file *file, char __user *buf,
1006 size_t count, loff_t *ppos)
1007 {
1008 struct mm_struct *mm = file->private_data;
1009 unsigned int nwords = 0;
1010
1011 if (!mm)
1012 return 0;
1013 do {
1014 nwords += 2;
1015 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1016 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1017 nwords * sizeof(mm->saved_auxv[0]));
1018 }
1019
1020 static const struct file_operations proc_auxv_operations = {
1021 .open = auxv_open,
1022 .read = auxv_read,
1023 .llseek = generic_file_llseek,
1024 .release = mem_release,
1025 };
1026
1027 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1028 loff_t *ppos)
1029 {
1030 struct task_struct *task = get_proc_task(file_inode(file));
1031 char buffer[PROC_NUMBUF];
1032 int oom_adj = OOM_ADJUST_MIN;
1033 size_t len;
1034
1035 if (!task)
1036 return -ESRCH;
1037 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1038 oom_adj = OOM_ADJUST_MAX;
1039 else
1040 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1041 OOM_SCORE_ADJ_MAX;
1042 put_task_struct(task);
1043 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1044 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1045 }
1046
1047 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1048 {
1049 static DEFINE_MUTEX(oom_adj_mutex);
1050 struct mm_struct *mm = NULL;
1051 struct task_struct *task;
1052 int err = 0;
1053
1054 task = get_proc_task(file_inode(file));
1055 if (!task)
1056 return -ESRCH;
1057
1058 mutex_lock(&oom_adj_mutex);
1059 if (legacy) {
1060 if (oom_adj < task->signal->oom_score_adj &&
1061 !capable(CAP_SYS_RESOURCE)) {
1062 err = -EACCES;
1063 goto err_unlock;
1064 }
1065 /*
1066 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1067 * /proc/pid/oom_score_adj instead.
1068 */
1069 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1070 current->comm, task_pid_nr(current), task_pid_nr(task),
1071 task_pid_nr(task));
1072 } else {
1073 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1074 !capable(CAP_SYS_RESOURCE)) {
1075 err = -EACCES;
1076 goto err_unlock;
1077 }
1078 }
1079
1080 /*
1081 * Make sure we will check other processes sharing the mm if this is
1082 * not vfrok which wants its own oom_score_adj.
1083 * pin the mm so it doesn't go away and get reused after task_unlock
1084 */
1085 if (!task->vfork_done) {
1086 struct task_struct *p = find_lock_task_mm(task);
1087
1088 if (p) {
1089 if (atomic_read(&p->mm->mm_users) > 1) {
1090 mm = p->mm;
1091 mmgrab(mm);
1092 }
1093 task_unlock(p);
1094 }
1095 }
1096
1097 task->signal->oom_score_adj = oom_adj;
1098 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1099 task->signal->oom_score_adj_min = (short)oom_adj;
1100 trace_oom_score_adj_update(task);
1101
1102 if (mm) {
1103 struct task_struct *p;
1104
1105 rcu_read_lock();
1106 for_each_process(p) {
1107 if (same_thread_group(task, p))
1108 continue;
1109
1110 /* do not touch kernel threads or the global init */
1111 if (p->flags & PF_KTHREAD || is_global_init(p))
1112 continue;
1113
1114 task_lock(p);
1115 if (!p->vfork_done && process_shares_mm(p, mm)) {
1116 p->signal->oom_score_adj = oom_adj;
1117 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1118 p->signal->oom_score_adj_min = (short)oom_adj;
1119 }
1120 task_unlock(p);
1121 }
1122 rcu_read_unlock();
1123 mmdrop(mm);
1124 }
1125 err_unlock:
1126 mutex_unlock(&oom_adj_mutex);
1127 put_task_struct(task);
1128 return err;
1129 }
1130
1131 /*
1132 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1133 * kernels. The effective policy is defined by oom_score_adj, which has a
1134 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1135 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1136 * Processes that become oom disabled via oom_adj will still be oom disabled
1137 * with this implementation.
1138 *
1139 * oom_adj cannot be removed since existing userspace binaries use it.
1140 */
1141 static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1142 size_t count, loff_t *ppos)
1143 {
1144 char buffer[PROC_NUMBUF];
1145 int oom_adj;
1146 int err;
1147
1148 memset(buffer, 0, sizeof(buffer));
1149 if (count > sizeof(buffer) - 1)
1150 count = sizeof(buffer) - 1;
1151 if (copy_from_user(buffer, buf, count)) {
1152 err = -EFAULT;
1153 goto out;
1154 }
1155
1156 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1157 if (err)
1158 goto out;
1159 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1160 oom_adj != OOM_DISABLE) {
1161 err = -EINVAL;
1162 goto out;
1163 }
1164
1165 /*
1166 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1167 * value is always attainable.
1168 */
1169 if (oom_adj == OOM_ADJUST_MAX)
1170 oom_adj = OOM_SCORE_ADJ_MAX;
1171 else
1172 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1173
1174 err = __set_oom_adj(file, oom_adj, true);
1175 out:
1176 return err < 0 ? err : count;
1177 }
1178
1179 static const struct file_operations proc_oom_adj_operations = {
1180 .read = oom_adj_read,
1181 .write = oom_adj_write,
1182 .llseek = generic_file_llseek,
1183 };
1184
1185 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1186 size_t count, loff_t *ppos)
1187 {
1188 struct task_struct *task = get_proc_task(file_inode(file));
1189 char buffer[PROC_NUMBUF];
1190 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1191 size_t len;
1192
1193 if (!task)
1194 return -ESRCH;
1195 oom_score_adj = task->signal->oom_score_adj;
1196 put_task_struct(task);
1197 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1198 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1199 }
1200
1201 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1202 size_t count, loff_t *ppos)
1203 {
1204 char buffer[PROC_NUMBUF];
1205 int oom_score_adj;
1206 int err;
1207
1208 memset(buffer, 0, sizeof(buffer));
1209 if (count > sizeof(buffer) - 1)
1210 count = sizeof(buffer) - 1;
1211 if (copy_from_user(buffer, buf, count)) {
1212 err = -EFAULT;
1213 goto out;
1214 }
1215
1216 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1217 if (err)
1218 goto out;
1219 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1220 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1221 err = -EINVAL;
1222 goto out;
1223 }
1224
1225 err = __set_oom_adj(file, oom_score_adj, false);
1226 out:
1227 return err < 0 ? err : count;
1228 }
1229
1230 static const struct file_operations proc_oom_score_adj_operations = {
1231 .read = oom_score_adj_read,
1232 .write = oom_score_adj_write,
1233 .llseek = default_llseek,
1234 };
1235
1236 #ifdef CONFIG_AUDIT
1237 #define TMPBUFLEN 11
1238 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1239 size_t count, loff_t *ppos)
1240 {
1241 struct inode * inode = file_inode(file);
1242 struct task_struct *task = get_proc_task(inode);
1243 ssize_t length;
1244 char tmpbuf[TMPBUFLEN];
1245
1246 if (!task)
1247 return -ESRCH;
1248 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1249 from_kuid(file->f_cred->user_ns,
1250 audit_get_loginuid(task)));
1251 put_task_struct(task);
1252 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1253 }
1254
1255 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1256 size_t count, loff_t *ppos)
1257 {
1258 struct inode * inode = file_inode(file);
1259 uid_t loginuid;
1260 kuid_t kloginuid;
1261 int rv;
1262
1263 rcu_read_lock();
1264 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1265 rcu_read_unlock();
1266 return -EPERM;
1267 }
1268 rcu_read_unlock();
1269
1270 if (*ppos != 0) {
1271 /* No partial writes. */
1272 return -EINVAL;
1273 }
1274
1275 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1276 if (rv < 0)
1277 return rv;
1278
1279 /* is userspace tring to explicitly UNSET the loginuid? */
1280 if (loginuid == AUDIT_UID_UNSET) {
1281 kloginuid = INVALID_UID;
1282 } else {
1283 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1284 if (!uid_valid(kloginuid))
1285 return -EINVAL;
1286 }
1287
1288 rv = audit_set_loginuid(kloginuid);
1289 if (rv < 0)
1290 return rv;
1291 return count;
1292 }
1293
1294 static const struct file_operations proc_loginuid_operations = {
1295 .read = proc_loginuid_read,
1296 .write = proc_loginuid_write,
1297 .llseek = generic_file_llseek,
1298 };
1299
1300 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1301 size_t count, loff_t *ppos)
1302 {
1303 struct inode * inode = file_inode(file);
1304 struct task_struct *task = get_proc_task(inode);
1305 ssize_t length;
1306 char tmpbuf[TMPBUFLEN];
1307
1308 if (!task)
1309 return -ESRCH;
1310 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1311 audit_get_sessionid(task));
1312 put_task_struct(task);
1313 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1314 }
1315
1316 static const struct file_operations proc_sessionid_operations = {
1317 .read = proc_sessionid_read,
1318 .llseek = generic_file_llseek,
1319 };
1320 #endif
1321
1322 #ifdef CONFIG_FAULT_INJECTION
1323 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1324 size_t count, loff_t *ppos)
1325 {
1326 struct task_struct *task = get_proc_task(file_inode(file));
1327 char buffer[PROC_NUMBUF];
1328 size_t len;
1329 int make_it_fail;
1330
1331 if (!task)
1332 return -ESRCH;
1333 make_it_fail = task->make_it_fail;
1334 put_task_struct(task);
1335
1336 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1337
1338 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1339 }
1340
1341 static ssize_t proc_fault_inject_write(struct file * file,
1342 const char __user * buf, size_t count, loff_t *ppos)
1343 {
1344 struct task_struct *task;
1345 char buffer[PROC_NUMBUF];
1346 int make_it_fail;
1347 int rv;
1348
1349 if (!capable(CAP_SYS_RESOURCE))
1350 return -EPERM;
1351 memset(buffer, 0, sizeof(buffer));
1352 if (count > sizeof(buffer) - 1)
1353 count = sizeof(buffer) - 1;
1354 if (copy_from_user(buffer, buf, count))
1355 return -EFAULT;
1356 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1357 if (rv < 0)
1358 return rv;
1359 if (make_it_fail < 0 || make_it_fail > 1)
1360 return -EINVAL;
1361
1362 task = get_proc_task(file_inode(file));
1363 if (!task)
1364 return -ESRCH;
1365 task->make_it_fail = make_it_fail;
1366 put_task_struct(task);
1367
1368 return count;
1369 }
1370
1371 static const struct file_operations proc_fault_inject_operations = {
1372 .read = proc_fault_inject_read,
1373 .write = proc_fault_inject_write,
1374 .llseek = generic_file_llseek,
1375 };
1376
1377 static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1378 size_t count, loff_t *ppos)
1379 {
1380 struct task_struct *task;
1381 int err;
1382 unsigned int n;
1383
1384 err = kstrtouint_from_user(buf, count, 0, &n);
1385 if (err)
1386 return err;
1387
1388 task = get_proc_task(file_inode(file));
1389 if (!task)
1390 return -ESRCH;
1391 task->fail_nth = n;
1392 put_task_struct(task);
1393
1394 return count;
1395 }
1396
1397 static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1398 size_t count, loff_t *ppos)
1399 {
1400 struct task_struct *task;
1401 char numbuf[PROC_NUMBUF];
1402 ssize_t len;
1403
1404 task = get_proc_task(file_inode(file));
1405 if (!task)
1406 return -ESRCH;
1407 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1408 put_task_struct(task);
1409 return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1410 }
1411
1412 static const struct file_operations proc_fail_nth_operations = {
1413 .read = proc_fail_nth_read,
1414 .write = proc_fail_nth_write,
1415 };
1416 #endif
1417
1418
1419 #ifdef CONFIG_SCHED_DEBUG
1420 /*
1421 * Print out various scheduling related per-task fields:
1422 */
1423 static int sched_show(struct seq_file *m, void *v)
1424 {
1425 struct inode *inode = m->private;
1426 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
1427 struct task_struct *p;
1428
1429 p = get_proc_task(inode);
1430 if (!p)
1431 return -ESRCH;
1432 proc_sched_show_task(p, ns, m);
1433
1434 put_task_struct(p);
1435
1436 return 0;
1437 }
1438
1439 static ssize_t
1440 sched_write(struct file *file, const char __user *buf,
1441 size_t count, loff_t *offset)
1442 {
1443 struct inode *inode = file_inode(file);
1444 struct task_struct *p;
1445
1446 p = get_proc_task(inode);
1447 if (!p)
1448 return -ESRCH;
1449 proc_sched_set_task(p);
1450
1451 put_task_struct(p);
1452
1453 return count;
1454 }
1455
1456 static int sched_open(struct inode *inode, struct file *filp)
1457 {
1458 return single_open(filp, sched_show, inode);
1459 }
1460
1461 static const struct file_operations proc_pid_sched_operations = {
1462 .open = sched_open,
1463 .read = seq_read,
1464 .write = sched_write,
1465 .llseek = seq_lseek,
1466 .release = single_release,
1467 };
1468
1469 #endif
1470
1471 #ifdef CONFIG_SCHED_AUTOGROUP
1472 /*
1473 * Print out autogroup related information:
1474 */
1475 static int sched_autogroup_show(struct seq_file *m, void *v)
1476 {
1477 struct inode *inode = m->private;
1478 struct task_struct *p;
1479
1480 p = get_proc_task(inode);
1481 if (!p)
1482 return -ESRCH;
1483 proc_sched_autogroup_show_task(p, m);
1484
1485 put_task_struct(p);
1486
1487 return 0;
1488 }
1489
1490 static ssize_t
1491 sched_autogroup_write(struct file *file, const char __user *buf,
1492 size_t count, loff_t *offset)
1493 {
1494 struct inode *inode = file_inode(file);
1495 struct task_struct *p;
1496 char buffer[PROC_NUMBUF];
1497 int nice;
1498 int err;
1499
1500 memset(buffer, 0, sizeof(buffer));
1501 if (count > sizeof(buffer) - 1)
1502 count = sizeof(buffer) - 1;
1503 if (copy_from_user(buffer, buf, count))
1504 return -EFAULT;
1505
1506 err = kstrtoint(strstrip(buffer), 0, &nice);
1507 if (err < 0)
1508 return err;
1509
1510 p = get_proc_task(inode);
1511 if (!p)
1512 return -ESRCH;
1513
1514 err = proc_sched_autogroup_set_nice(p, nice);
1515 if (err)
1516 count = err;
1517
1518 put_task_struct(p);
1519
1520 return count;
1521 }
1522
1523 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1524 {
1525 int ret;
1526
1527 ret = single_open(filp, sched_autogroup_show, NULL);
1528 if (!ret) {
1529 struct seq_file *m = filp->private_data;
1530
1531 m->private = inode;
1532 }
1533 return ret;
1534 }
1535
1536 static const struct file_operations proc_pid_sched_autogroup_operations = {
1537 .open = sched_autogroup_open,
1538 .read = seq_read,
1539 .write = sched_autogroup_write,
1540 .llseek = seq_lseek,
1541 .release = single_release,
1542 };
1543
1544 #endif /* CONFIG_SCHED_AUTOGROUP */
1545
1546 #ifdef CONFIG_TIME_NS
1547 static int timens_offsets_show(struct seq_file *m, void *v)
1548 {
1549 struct task_struct *p;
1550
1551 p = get_proc_task(file_inode(m->file));
1552 if (!p)
1553 return -ESRCH;
1554 proc_timens_show_offsets(p, m);
1555
1556 put_task_struct(p);
1557
1558 return 0;
1559 }
1560
1561 static ssize_t timens_offsets_write(struct file *file, const char __user *buf,
1562 size_t count, loff_t *ppos)
1563 {
1564 struct inode *inode = file_inode(file);
1565 struct proc_timens_offset offsets[2];
1566 char *kbuf = NULL, *pos, *next_line;
1567 struct task_struct *p;
1568 int ret, noffsets;
1569
1570 /* Only allow < page size writes at the beginning of the file */
1571 if ((*ppos != 0) || (count >= PAGE_SIZE))
1572 return -EINVAL;
1573
1574 /* Slurp in the user data */
1575 kbuf = memdup_user_nul(buf, count);
1576 if (IS_ERR(kbuf))
1577 return PTR_ERR(kbuf);
1578
1579 /* Parse the user data */
1580 ret = -EINVAL;
1581 noffsets = 0;
1582 for (pos = kbuf; pos; pos = next_line) {
1583 struct proc_timens_offset *off = &offsets[noffsets];
1584 char clock[10];
1585 int err;
1586
1587 /* Find the end of line and ensure we don't look past it */
1588 next_line = strchr(pos, '\n');
1589 if (next_line) {
1590 *next_line = '\0';
1591 next_line++;
1592 if (*next_line == '\0')
1593 next_line = NULL;
1594 }
1595
1596 err = sscanf(pos, "%9s %lld %lu", clock,
1597 &off->val.tv_sec, &off->val.tv_nsec);
1598 if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
1599 goto out;
1600
1601 clock[sizeof(clock) - 1] = 0;
1602 if (strcmp(clock, "monotonic") == 0 ||
1603 strcmp(clock, __stringify(CLOCK_MONOTONIC)) == 0)
1604 off->clockid = CLOCK_MONOTONIC;
1605 else if (strcmp(clock, "boottime") == 0 ||
1606 strcmp(clock, __stringify(CLOCK_BOOTTIME)) == 0)
1607 off->clockid = CLOCK_BOOTTIME;
1608 else
1609 goto out;
1610
1611 noffsets++;
1612 if (noffsets == ARRAY_SIZE(offsets)) {
1613 if (next_line)
1614 count = next_line - kbuf;
1615 break;
1616 }
1617 }
1618
1619 ret = -ESRCH;
1620 p = get_proc_task(inode);
1621 if (!p)
1622 goto out;
1623 ret = proc_timens_set_offset(file, p, offsets, noffsets);
1624 put_task_struct(p);
1625 if (ret)
1626 goto out;
1627
1628 ret = count;
1629 out:
1630 kfree(kbuf);
1631 return ret;
1632 }
1633
1634 static int timens_offsets_open(struct inode *inode, struct file *filp)
1635 {
1636 return single_open(filp, timens_offsets_show, inode);
1637 }
1638
1639 static const struct file_operations proc_timens_offsets_operations = {
1640 .open = timens_offsets_open,
1641 .read = seq_read,
1642 .write = timens_offsets_write,
1643 .llseek = seq_lseek,
1644 .release = single_release,
1645 };
1646 #endif /* CONFIG_TIME_NS */
1647
1648 static ssize_t comm_write(struct file *file, const char __user *buf,
1649 size_t count, loff_t *offset)
1650 {
1651 struct inode *inode = file_inode(file);
1652 struct task_struct *p;
1653 char buffer[TASK_COMM_LEN];
1654 const size_t maxlen = sizeof(buffer) - 1;
1655
1656 memset(buffer, 0, sizeof(buffer));
1657 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1658 return -EFAULT;
1659
1660 p = get_proc_task(inode);
1661 if (!p)
1662 return -ESRCH;
1663
1664 if (same_thread_group(current, p))
1665 set_task_comm(p, buffer);
1666 else
1667 count = -EINVAL;
1668
1669 put_task_struct(p);
1670
1671 return count;
1672 }
1673
1674 static int comm_show(struct seq_file *m, void *v)
1675 {
1676 struct inode *inode = m->private;
1677 struct task_struct *p;
1678
1679 p = get_proc_task(inode);
1680 if (!p)
1681 return -ESRCH;
1682
1683 proc_task_name(m, p, false);
1684 seq_putc(m, '\n');
1685
1686 put_task_struct(p);
1687
1688 return 0;
1689 }
1690
1691 static int comm_open(struct inode *inode, struct file *filp)
1692 {
1693 return single_open(filp, comm_show, inode);
1694 }
1695
1696 static const struct file_operations proc_pid_set_comm_operations = {
1697 .open = comm_open,
1698 .read = seq_read,
1699 .write = comm_write,
1700 .llseek = seq_lseek,
1701 .release = single_release,
1702 };
1703
1704 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1705 {
1706 struct task_struct *task;
1707 struct file *exe_file;
1708
1709 task = get_proc_task(d_inode(dentry));
1710 if (!task)
1711 return -ENOENT;
1712 exe_file = get_task_exe_file(task);
1713 put_task_struct(task);
1714 if (exe_file) {
1715 *exe_path = exe_file->f_path;
1716 path_get(&exe_file->f_path);
1717 fput(exe_file);
1718 return 0;
1719 } else
1720 return -ENOENT;
1721 }
1722
1723 static const char *proc_pid_get_link(struct dentry *dentry,
1724 struct inode *inode,
1725 struct delayed_call *done)
1726 {
1727 struct path path;
1728 int error = -EACCES;
1729
1730 if (!dentry)
1731 return ERR_PTR(-ECHILD);
1732
1733 /* Are we allowed to snoop on the tasks file descriptors? */
1734 if (!proc_fd_access_allowed(inode))
1735 goto out;
1736
1737 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1738 if (error)
1739 goto out;
1740
1741 error = nd_jump_link(&path);
1742 out:
1743 return ERR_PTR(error);
1744 }
1745
1746 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1747 {
1748 char *tmp = (char *)__get_free_page(GFP_KERNEL);
1749 char *pathname;
1750 int len;
1751
1752 if (!tmp)
1753 return -ENOMEM;
1754
1755 pathname = d_path(path, tmp, PAGE_SIZE);
1756 len = PTR_ERR(pathname);
1757 if (IS_ERR(pathname))
1758 goto out;
1759 len = tmp + PAGE_SIZE - 1 - pathname;
1760
1761 if (len > buflen)
1762 len = buflen;
1763 if (copy_to_user(buffer, pathname, len))
1764 len = -EFAULT;
1765 out:
1766 free_page((unsigned long)tmp);
1767 return len;
1768 }
1769
1770 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1771 {
1772 int error = -EACCES;
1773 struct inode *inode = d_inode(dentry);
1774 struct path path;
1775
1776 /* Are we allowed to snoop on the tasks file descriptors? */
1777 if (!proc_fd_access_allowed(inode))
1778 goto out;
1779
1780 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1781 if (error)
1782 goto out;
1783
1784 error = do_proc_readlink(&path, buffer, buflen);
1785 path_put(&path);
1786 out:
1787 return error;
1788 }
1789
1790 const struct inode_operations proc_pid_link_inode_operations = {
1791 .readlink = proc_pid_readlink,
1792 .get_link = proc_pid_get_link,
1793 .setattr = proc_setattr,
1794 };
1795
1796
1797 /* building an inode */
1798
1799 void task_dump_owner(struct task_struct *task, umode_t mode,
1800 kuid_t *ruid, kgid_t *rgid)
1801 {
1802 /* Depending on the state of dumpable compute who should own a
1803 * proc file for a task.
1804 */
1805 const struct cred *cred;
1806 kuid_t uid;
1807 kgid_t gid;
1808
1809 if (unlikely(task->flags & PF_KTHREAD)) {
1810 *ruid = GLOBAL_ROOT_UID;
1811 *rgid = GLOBAL_ROOT_GID;
1812 return;
1813 }
1814
1815 /* Default to the tasks effective ownership */
1816 rcu_read_lock();
1817 cred = __task_cred(task);
1818 uid = cred->euid;
1819 gid = cred->egid;
1820 rcu_read_unlock();
1821
1822 /*
1823 * Before the /proc/pid/status file was created the only way to read
1824 * the effective uid of a /process was to stat /proc/pid. Reading
1825 * /proc/pid/status is slow enough that procps and other packages
1826 * kept stating /proc/pid. To keep the rules in /proc simple I have
1827 * made this apply to all per process world readable and executable
1828 * directories.
1829 */
1830 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1831 struct mm_struct *mm;
1832 task_lock(task);
1833 mm = task->mm;
1834 /* Make non-dumpable tasks owned by some root */
1835 if (mm) {
1836 if (get_dumpable(mm) != SUID_DUMP_USER) {
1837 struct user_namespace *user_ns = mm->user_ns;
1838
1839 uid = make_kuid(user_ns, 0);
1840 if (!uid_valid(uid))
1841 uid = GLOBAL_ROOT_UID;
1842
1843 gid = make_kgid(user_ns, 0);
1844 if (!gid_valid(gid))
1845 gid = GLOBAL_ROOT_GID;
1846 }
1847 } else {
1848 uid = GLOBAL_ROOT_UID;
1849 gid = GLOBAL_ROOT_GID;
1850 }
1851 task_unlock(task);
1852 }
1853 *ruid = uid;
1854 *rgid = gid;
1855 }
1856
1857 void proc_pid_evict_inode(struct proc_inode *ei)
1858 {
1859 struct pid *pid = ei->pid;
1860
1861 if (S_ISDIR(ei->vfs_inode.i_mode)) {
1862 spin_lock(&pid->lock);
1863 hlist_del_init_rcu(&ei->sibling_inodes);
1864 spin_unlock(&pid->lock);
1865 }
1866
1867 put_pid(pid);
1868 }
1869
1870 struct inode *proc_pid_make_inode(struct super_block * sb,
1871 struct task_struct *task, umode_t mode)
1872 {
1873 struct inode * inode;
1874 struct proc_inode *ei;
1875 struct pid *pid;
1876
1877 /* We need a new inode */
1878
1879 inode = new_inode(sb);
1880 if (!inode)
1881 goto out;
1882
1883 /* Common stuff */
1884 ei = PROC_I(inode);
1885 inode->i_mode = mode;
1886 inode->i_ino = get_next_ino();
1887 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1888 inode->i_op = &proc_def_inode_operations;
1889
1890 /*
1891 * grab the reference to task.
1892 */
1893 pid = get_task_pid(task, PIDTYPE_PID);
1894 if (!pid)
1895 goto out_unlock;
1896
1897 /* Let the pid remember us for quick removal */
1898 ei->pid = pid;
1899 if (S_ISDIR(mode)) {
1900 spin_lock(&pid->lock);
1901 hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
1902 spin_unlock(&pid->lock);
1903 }
1904
1905 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1906 security_task_to_inode(task, inode);
1907
1908 out:
1909 return inode;
1910
1911 out_unlock:
1912 iput(inode);
1913 return NULL;
1914 }
1915
1916 int pid_getattr(const struct path *path, struct kstat *stat,
1917 u32 request_mask, unsigned int query_flags)
1918 {
1919 struct inode *inode = d_inode(path->dentry);
1920 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
1921 struct task_struct *task;
1922
1923 generic_fillattr(inode, stat);
1924
1925 stat->uid = GLOBAL_ROOT_UID;
1926 stat->gid = GLOBAL_ROOT_GID;
1927 rcu_read_lock();
1928 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1929 if (task) {
1930 if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) {
1931 rcu_read_unlock();
1932 /*
1933 * This doesn't prevent learning whether PID exists,
1934 * it only makes getattr() consistent with readdir().
1935 */
1936 return -ENOENT;
1937 }
1938 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1939 }
1940 rcu_read_unlock();
1941 return 0;
1942 }
1943
1944 /* dentry stuff */
1945
1946 /*
1947 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1948 */
1949 void pid_update_inode(struct task_struct *task, struct inode *inode)
1950 {
1951 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1952
1953 inode->i_mode &= ~(S_ISUID | S_ISGID);
1954 security_task_to_inode(task, inode);
1955 }
1956
1957 /*
1958 * Rewrite the inode's ownerships here because the owning task may have
1959 * performed a setuid(), etc.
1960 *
1961 */
1962 static int pid_revalidate(struct dentry *dentry, unsigned int flags)
1963 {
1964 struct inode *inode;
1965 struct task_struct *task;
1966
1967 if (flags & LOOKUP_RCU)
1968 return -ECHILD;
1969
1970 inode = d_inode(dentry);
1971 task = get_proc_task(inode);
1972
1973 if (task) {
1974 pid_update_inode(task, inode);
1975 put_task_struct(task);
1976 return 1;
1977 }
1978 return 0;
1979 }
1980
1981 static inline bool proc_inode_is_dead(struct inode *inode)
1982 {
1983 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1984 }
1985
1986 int pid_delete_dentry(const struct dentry *dentry)
1987 {
1988 /* Is the task we represent dead?
1989 * If so, then don't put the dentry on the lru list,
1990 * kill it immediately.
1991 */
1992 return proc_inode_is_dead(d_inode(dentry));
1993 }
1994
1995 const struct dentry_operations pid_dentry_operations =
1996 {
1997 .d_revalidate = pid_revalidate,
1998 .d_delete = pid_delete_dentry,
1999 };
2000
2001 /* Lookups */
2002
2003 /*
2004 * Fill a directory entry.
2005 *
2006 * If possible create the dcache entry and derive our inode number and
2007 * file type from dcache entry.
2008 *
2009 * Since all of the proc inode numbers are dynamically generated, the inode
2010 * numbers do not exist until the inode is cache. This means creating the
2011 * the dcache entry in readdir is necessary to keep the inode numbers
2012 * reported by readdir in sync with the inode numbers reported
2013 * by stat.
2014 */
2015 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
2016 const char *name, unsigned int len,
2017 instantiate_t instantiate, struct task_struct *task, const void *ptr)
2018 {
2019 struct dentry *child, *dir = file->f_path.dentry;
2020 struct qstr qname = QSTR_INIT(name, len);
2021 struct inode *inode;
2022 unsigned type = DT_UNKNOWN;
2023 ino_t ino = 1;
2024
2025 child = d_hash_and_lookup(dir, &qname);
2026 if (!child) {
2027 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
2028 child = d_alloc_parallel(dir, &qname, &wq);
2029 if (IS_ERR(child))
2030 goto end_instantiate;
2031 if (d_in_lookup(child)) {
2032 struct dentry *res;
2033 res = instantiate(child, task, ptr);
2034 d_lookup_done(child);
2035 if (unlikely(res)) {
2036 dput(child);
2037 child = res;
2038 if (IS_ERR(child))
2039 goto end_instantiate;
2040 }
2041 }
2042 }
2043 inode = d_inode(child);
2044 ino = inode->i_ino;
2045 type = inode->i_mode >> 12;
2046 dput(child);
2047 end_instantiate:
2048 return dir_emit(ctx, name, len, ino, type);
2049 }
2050
2051 /*
2052 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2053 * which represent vma start and end addresses.
2054 */
2055 static int dname_to_vma_addr(struct dentry *dentry,
2056 unsigned long *start, unsigned long *end)
2057 {
2058 const char *str = dentry->d_name.name;
2059 unsigned long long sval, eval;
2060 unsigned int len;
2061
2062 if (str[0] == '0' && str[1] != '-')
2063 return -EINVAL;
2064 len = _parse_integer(str, 16, &sval);
2065 if (len & KSTRTOX_OVERFLOW)
2066 return -EINVAL;
2067 if (sval != (unsigned long)sval)
2068 return -EINVAL;
2069 str += len;
2070
2071 if (*str != '-')
2072 return -EINVAL;
2073 str++;
2074
2075 if (str[0] == '0' && str[1])
2076 return -EINVAL;
2077 len = _parse_integer(str, 16, &eval);
2078 if (len & KSTRTOX_OVERFLOW)
2079 return -EINVAL;
2080 if (eval != (unsigned long)eval)
2081 return -EINVAL;
2082 str += len;
2083
2084 if (*str != '\0')
2085 return -EINVAL;
2086
2087 *start = sval;
2088 *end = eval;
2089
2090 return 0;
2091 }
2092
2093 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
2094 {
2095 unsigned long vm_start, vm_end;
2096 bool exact_vma_exists = false;
2097 struct mm_struct *mm = NULL;
2098 struct task_struct *task;
2099 struct inode *inode;
2100 int status = 0;
2101
2102 if (flags & LOOKUP_RCU)
2103 return -ECHILD;
2104
2105 inode = d_inode(dentry);
2106 task = get_proc_task(inode);
2107 if (!task)
2108 goto out_notask;
2109
2110 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2111 if (IS_ERR_OR_NULL(mm))
2112 goto out;
2113
2114 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2115 status = mmap_read_lock_killable(mm);
2116 if (!status) {
2117 exact_vma_exists = !!find_exact_vma(mm, vm_start,
2118 vm_end);
2119 mmap_read_unlock(mm);
2120 }
2121 }
2122
2123 mmput(mm);
2124
2125 if (exact_vma_exists) {
2126 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
2127
2128 security_task_to_inode(task, inode);
2129 status = 1;
2130 }
2131
2132 out:
2133 put_task_struct(task);
2134
2135 out_notask:
2136 return status;
2137 }
2138
2139 static const struct dentry_operations tid_map_files_dentry_operations = {
2140 .d_revalidate = map_files_d_revalidate,
2141 .d_delete = pid_delete_dentry,
2142 };
2143
2144 static int map_files_get_link(struct dentry *dentry, struct path *path)
2145 {
2146 unsigned long vm_start, vm_end;
2147 struct vm_area_struct *vma;
2148 struct task_struct *task;
2149 struct mm_struct *mm;
2150 int rc;
2151
2152 rc = -ENOENT;
2153 task = get_proc_task(d_inode(dentry));
2154 if (!task)
2155 goto out;
2156
2157 mm = get_task_mm(task);
2158 put_task_struct(task);
2159 if (!mm)
2160 goto out;
2161
2162 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2163 if (rc)
2164 goto out_mmput;
2165
2166 rc = mmap_read_lock_killable(mm);
2167 if (rc)
2168 goto out_mmput;
2169
2170 rc = -ENOENT;
2171 vma = find_exact_vma(mm, vm_start, vm_end);
2172 if (vma && vma->vm_file) {
2173 *path = vma->vm_file->f_path;
2174 path_get(path);
2175 rc = 0;
2176 }
2177 mmap_read_unlock(mm);
2178
2179 out_mmput:
2180 mmput(mm);
2181 out:
2182 return rc;
2183 }
2184
2185 struct map_files_info {
2186 unsigned long start;
2187 unsigned long end;
2188 fmode_t mode;
2189 };
2190
2191 /*
2192 * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
2193 * to concerns about how the symlinks may be used to bypass permissions on
2194 * ancestor directories in the path to the file in question.
2195 */
2196 static const char *
2197 proc_map_files_get_link(struct dentry *dentry,
2198 struct inode *inode,
2199 struct delayed_call *done)
2200 {
2201 if (!checkpoint_restore_ns_capable(&init_user_ns))
2202 return ERR_PTR(-EPERM);
2203
2204 return proc_pid_get_link(dentry, inode, done);
2205 }
2206
2207 /*
2208 * Identical to proc_pid_link_inode_operations except for get_link()
2209 */
2210 static const struct inode_operations proc_map_files_link_inode_operations = {
2211 .readlink = proc_pid_readlink,
2212 .get_link = proc_map_files_get_link,
2213 .setattr = proc_setattr,
2214 };
2215
2216 static struct dentry *
2217 proc_map_files_instantiate(struct dentry *dentry,
2218 struct task_struct *task, const void *ptr)
2219 {
2220 fmode_t mode = (fmode_t)(unsigned long)ptr;
2221 struct proc_inode *ei;
2222 struct inode *inode;
2223
2224 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2225 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2226 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2227 if (!inode)
2228 return ERR_PTR(-ENOENT);
2229
2230 ei = PROC_I(inode);
2231 ei->op.proc_get_link = map_files_get_link;
2232
2233 inode->i_op = &proc_map_files_link_inode_operations;
2234 inode->i_size = 64;
2235
2236 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2237 return d_splice_alias(inode, dentry);
2238 }
2239
2240 static struct dentry *proc_map_files_lookup(struct inode *dir,
2241 struct dentry *dentry, unsigned int flags)
2242 {
2243 unsigned long vm_start, vm_end;
2244 struct vm_area_struct *vma;
2245 struct task_struct *task;
2246 struct dentry *result;
2247 struct mm_struct *mm;
2248
2249 result = ERR_PTR(-ENOENT);
2250 task = get_proc_task(dir);
2251 if (!task)
2252 goto out;
2253
2254 result = ERR_PTR(-EACCES);
2255 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2256 goto out_put_task;
2257
2258 result = ERR_PTR(-ENOENT);
2259 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2260 goto out_put_task;
2261
2262 mm = get_task_mm(task);
2263 if (!mm)
2264 goto out_put_task;
2265
2266 result = ERR_PTR(-EINTR);
2267 if (mmap_read_lock_killable(mm))
2268 goto out_put_mm;
2269
2270 result = ERR_PTR(-ENOENT);
2271 vma = find_exact_vma(mm, vm_start, vm_end);
2272 if (!vma)
2273 goto out_no_vma;
2274
2275 if (vma->vm_file)
2276 result = proc_map_files_instantiate(dentry, task,
2277 (void *)(unsigned long)vma->vm_file->f_mode);
2278
2279 out_no_vma:
2280 mmap_read_unlock(mm);
2281 out_put_mm:
2282 mmput(mm);
2283 out_put_task:
2284 put_task_struct(task);
2285 out:
2286 return result;
2287 }
2288
2289 static const struct inode_operations proc_map_files_inode_operations = {
2290 .lookup = proc_map_files_lookup,
2291 .permission = proc_fd_permission,
2292 .setattr = proc_setattr,
2293 };
2294
2295 static int
2296 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2297 {
2298 struct vm_area_struct *vma;
2299 struct task_struct *task;
2300 struct mm_struct *mm;
2301 unsigned long nr_files, pos, i;
2302 GENRADIX(struct map_files_info) fa;
2303 struct map_files_info *p;
2304 int ret;
2305
2306 genradix_init(&fa);
2307
2308 ret = -ENOENT;
2309 task = get_proc_task(file_inode(file));
2310 if (!task)
2311 goto out;
2312
2313 ret = -EACCES;
2314 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2315 goto out_put_task;
2316
2317 ret = 0;
2318 if (!dir_emit_dots(file, ctx))
2319 goto out_put_task;
2320
2321 mm = get_task_mm(task);
2322 if (!mm)
2323 goto out_put_task;
2324
2325 ret = mmap_read_lock_killable(mm);
2326 if (ret) {
2327 mmput(mm);
2328 goto out_put_task;
2329 }
2330
2331 nr_files = 0;
2332
2333 /*
2334 * We need two passes here:
2335 *
2336 * 1) Collect vmas of mapped files with mmap_lock taken
2337 * 2) Release mmap_lock and instantiate entries
2338 *
2339 * otherwise we get lockdep complained, since filldir()
2340 * routine might require mmap_lock taken in might_fault().
2341 */
2342
2343 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2344 if (!vma->vm_file)
2345 continue;
2346 if (++pos <= ctx->pos)
2347 continue;
2348
2349 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2350 if (!p) {
2351 ret = -ENOMEM;
2352 mmap_read_unlock(mm);
2353 mmput(mm);
2354 goto out_put_task;
2355 }
2356
2357 p->start = vma->vm_start;
2358 p->end = vma->vm_end;
2359 p->mode = vma->vm_file->f_mode;
2360 }
2361 mmap_read_unlock(mm);
2362 mmput(mm);
2363
2364 for (i = 0; i < nr_files; i++) {
2365 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2366 unsigned int len;
2367
2368 p = genradix_ptr(&fa, i);
2369 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2370 if (!proc_fill_cache(file, ctx,
2371 buf, len,
2372 proc_map_files_instantiate,
2373 task,
2374 (void *)(unsigned long)p->mode))
2375 break;
2376 ctx->pos++;
2377 }
2378
2379 out_put_task:
2380 put_task_struct(task);
2381 out:
2382 genradix_free(&fa);
2383 return ret;
2384 }
2385
2386 static const struct file_operations proc_map_files_operations = {
2387 .read = generic_read_dir,
2388 .iterate_shared = proc_map_files_readdir,
2389 .llseek = generic_file_llseek,
2390 };
2391
2392 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2393 struct timers_private {
2394 struct pid *pid;
2395 struct task_struct *task;
2396 struct sighand_struct *sighand;
2397 struct pid_namespace *ns;
2398 unsigned long flags;
2399 };
2400
2401 static void *timers_start(struct seq_file *m, loff_t *pos)
2402 {
2403 struct timers_private *tp = m->private;
2404
2405 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2406 if (!tp->task)
2407 return ERR_PTR(-ESRCH);
2408
2409 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2410 if (!tp->sighand)
2411 return ERR_PTR(-ESRCH);
2412
2413 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2414 }
2415
2416 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2417 {
2418 struct timers_private *tp = m->private;
2419 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2420 }
2421
2422 static void timers_stop(struct seq_file *m, void *v)
2423 {
2424 struct timers_private *tp = m->private;
2425
2426 if (tp->sighand) {
2427 unlock_task_sighand(tp->task, &tp->flags);
2428 tp->sighand = NULL;
2429 }
2430
2431 if (tp->task) {
2432 put_task_struct(tp->task);
2433 tp->task = NULL;
2434 }
2435 }
2436
2437 static int show_timer(struct seq_file *m, void *v)
2438 {
2439 struct k_itimer *timer;
2440 struct timers_private *tp = m->private;
2441 int notify;
2442 static const char * const nstr[] = {
2443 [SIGEV_SIGNAL] = "signal",
2444 [SIGEV_NONE] = "none",
2445 [SIGEV_THREAD] = "thread",
2446 };
2447
2448 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2449 notify = timer->it_sigev_notify;
2450
2451 seq_printf(m, "ID: %d\n", timer->it_id);
2452 seq_printf(m, "signal: %d/%px\n",
2453 timer->sigq->info.si_signo,
2454 timer->sigq->info.si_value.sival_ptr);
2455 seq_printf(m, "notify: %s/%s.%d\n",
2456 nstr[notify & ~SIGEV_THREAD_ID],
2457 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2458 pid_nr_ns(timer->it_pid, tp->ns));
2459 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2460
2461 return 0;
2462 }
2463
2464 static const struct seq_operations proc_timers_seq_ops = {
2465 .start = timers_start,
2466 .next = timers_next,
2467 .stop = timers_stop,
2468 .show = show_timer,
2469 };
2470
2471 static int proc_timers_open(struct inode *inode, struct file *file)
2472 {
2473 struct timers_private *tp;
2474
2475 tp = __seq_open_private(file, &proc_timers_seq_ops,
2476 sizeof(struct timers_private));
2477 if (!tp)
2478 return -ENOMEM;
2479
2480 tp->pid = proc_pid(inode);
2481 tp->ns = proc_pid_ns(inode->i_sb);
2482 return 0;
2483 }
2484
2485 static const struct file_operations proc_timers_operations = {
2486 .open = proc_timers_open,
2487 .read = seq_read,
2488 .llseek = seq_lseek,
2489 .release = seq_release_private,
2490 };
2491 #endif
2492
2493 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2494 size_t count, loff_t *offset)
2495 {
2496 struct inode *inode = file_inode(file);
2497 struct task_struct *p;
2498 u64 slack_ns;
2499 int err;
2500
2501 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2502 if (err < 0)
2503 return err;
2504
2505 p = get_proc_task(inode);
2506 if (!p)
2507 return -ESRCH;
2508
2509 if (p != current) {
2510 rcu_read_lock();
2511 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2512 rcu_read_unlock();
2513 count = -EPERM;
2514 goto out;
2515 }
2516 rcu_read_unlock();
2517
2518 err = security_task_setscheduler(p);
2519 if (err) {
2520 count = err;
2521 goto out;
2522 }
2523 }
2524
2525 task_lock(p);
2526 if (slack_ns == 0)
2527 p->timer_slack_ns = p->default_timer_slack_ns;
2528 else
2529 p->timer_slack_ns = slack_ns;
2530 task_unlock(p);
2531
2532 out:
2533 put_task_struct(p);
2534
2535 return count;
2536 }
2537
2538 static int timerslack_ns_show(struct seq_file *m, void *v)
2539 {
2540 struct inode *inode = m->private;
2541 struct task_struct *p;
2542 int err = 0;
2543
2544 p = get_proc_task(inode);
2545 if (!p)
2546 return -ESRCH;
2547
2548 if (p != current) {
2549 rcu_read_lock();
2550 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2551 rcu_read_unlock();
2552 err = -EPERM;
2553 goto out;
2554 }
2555 rcu_read_unlock();
2556
2557 err = security_task_getscheduler(p);
2558 if (err)
2559 goto out;
2560 }
2561
2562 task_lock(p);
2563 seq_printf(m, "%llu\n", p->timer_slack_ns);
2564 task_unlock(p);
2565
2566 out:
2567 put_task_struct(p);
2568
2569 return err;
2570 }
2571
2572 static int timerslack_ns_open(struct inode *inode, struct file *filp)
2573 {
2574 return single_open(filp, timerslack_ns_show, inode);
2575 }
2576
2577 static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2578 .open = timerslack_ns_open,
2579 .read = seq_read,
2580 .write = timerslack_ns_write,
2581 .llseek = seq_lseek,
2582 .release = single_release,
2583 };
2584
2585 static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2586 struct task_struct *task, const void *ptr)
2587 {
2588 const struct pid_entry *p = ptr;
2589 struct inode *inode;
2590 struct proc_inode *ei;
2591
2592 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2593 if (!inode)
2594 return ERR_PTR(-ENOENT);
2595
2596 ei = PROC_I(inode);
2597 if (S_ISDIR(inode->i_mode))
2598 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2599 if (p->iop)
2600 inode->i_op = p->iop;
2601 if (p->fop)
2602 inode->i_fop = p->fop;
2603 ei->op = p->op;
2604 pid_update_inode(task, inode);
2605 d_set_d_op(dentry, &pid_dentry_operations);
2606 return d_splice_alias(inode, dentry);
2607 }
2608
2609 static struct dentry *proc_pident_lookup(struct inode *dir,
2610 struct dentry *dentry,
2611 const struct pid_entry *p,
2612 const struct pid_entry *end)
2613 {
2614 struct task_struct *task = get_proc_task(dir);
2615 struct dentry *res = ERR_PTR(-ENOENT);
2616
2617 if (!task)
2618 goto out_no_task;
2619
2620 /*
2621 * Yes, it does not scale. And it should not. Don't add
2622 * new entries into /proc/<tgid>/ without very good reasons.
2623 */
2624 for (; p < end; p++) {
2625 if (p->len != dentry->d_name.len)
2626 continue;
2627 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2628 res = proc_pident_instantiate(dentry, task, p);
2629 break;
2630 }
2631 }
2632 put_task_struct(task);
2633 out_no_task:
2634 return res;
2635 }
2636
2637 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2638 const struct pid_entry *ents, unsigned int nents)
2639 {
2640 struct task_struct *task = get_proc_task(file_inode(file));
2641 const struct pid_entry *p;
2642
2643 if (!task)
2644 return -ENOENT;
2645
2646 if (!dir_emit_dots(file, ctx))
2647 goto out;
2648
2649 if (ctx->pos >= nents + 2)
2650 goto out;
2651
2652 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2653 if (!proc_fill_cache(file, ctx, p->name, p->len,
2654 proc_pident_instantiate, task, p))
2655 break;
2656 ctx->pos++;
2657 }
2658 out:
2659 put_task_struct(task);
2660 return 0;
2661 }
2662
2663 #ifdef CONFIG_SECURITY
2664 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2665 size_t count, loff_t *ppos)
2666 {
2667 struct inode * inode = file_inode(file);
2668 char *p = NULL;
2669 ssize_t length;
2670 struct task_struct *task = get_proc_task(inode);
2671
2672 if (!task)
2673 return -ESRCH;
2674
2675 length = security_getprocattr(task, PROC_I(inode)->op.lsm,
2676 (char*)file->f_path.dentry->d_name.name,
2677 &p);
2678 put_task_struct(task);
2679 if (length > 0)
2680 length = simple_read_from_buffer(buf, count, ppos, p, length);
2681 kfree(p);
2682 return length;
2683 }
2684
2685 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2686 size_t count, loff_t *ppos)
2687 {
2688 struct inode * inode = file_inode(file);
2689 struct task_struct *task;
2690 void *page;
2691 int rv;
2692
2693 rcu_read_lock();
2694 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2695 if (!task) {
2696 rcu_read_unlock();
2697 return -ESRCH;
2698 }
2699 /* A task may only write its own attributes. */
2700 if (current != task) {
2701 rcu_read_unlock();
2702 return -EACCES;
2703 }
2704 /* Prevent changes to overridden credentials. */
2705 if (current_cred() != current_real_cred()) {
2706 rcu_read_unlock();
2707 return -EBUSY;
2708 }
2709 rcu_read_unlock();
2710
2711 if (count > PAGE_SIZE)
2712 count = PAGE_SIZE;
2713
2714 /* No partial writes. */
2715 if (*ppos != 0)
2716 return -EINVAL;
2717
2718 page = memdup_user(buf, count);
2719 if (IS_ERR(page)) {
2720 rv = PTR_ERR(page);
2721 goto out;
2722 }
2723
2724 /* Guard against adverse ptrace interaction */
2725 rv = mutex_lock_interruptible(&current->signal->cred_guard_mutex);
2726 if (rv < 0)
2727 goto out_free;
2728
2729 rv = security_setprocattr(PROC_I(inode)->op.lsm,
2730 file->f_path.dentry->d_name.name, page,
2731 count);
2732 mutex_unlock(&current->signal->cred_guard_mutex);
2733 out_free:
2734 kfree(page);
2735 out:
2736 return rv;
2737 }
2738
2739 static const struct file_operations proc_pid_attr_operations = {
2740 .read = proc_pid_attr_read,
2741 .write = proc_pid_attr_write,
2742 .llseek = generic_file_llseek,
2743 };
2744
2745 #define LSM_DIR_OPS(LSM) \
2746 static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2747 struct dir_context *ctx) \
2748 { \
2749 return proc_pident_readdir(filp, ctx, \
2750 LSM##_attr_dir_stuff, \
2751 ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2752 } \
2753 \
2754 static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2755 .read = generic_read_dir, \
2756 .iterate = proc_##LSM##_attr_dir_iterate, \
2757 .llseek = default_llseek, \
2758 }; \
2759 \
2760 static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2761 struct dentry *dentry, unsigned int flags) \
2762 { \
2763 return proc_pident_lookup(dir, dentry, \
2764 LSM##_attr_dir_stuff, \
2765 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2766 } \
2767 \
2768 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2769 .lookup = proc_##LSM##_attr_dir_lookup, \
2770 .getattr = pid_getattr, \
2771 .setattr = proc_setattr, \
2772 }
2773
2774 #ifdef CONFIG_SECURITY_SMACK
2775 static const struct pid_entry smack_attr_dir_stuff[] = {
2776 ATTR("smack", "current", 0666),
2777 };
2778 LSM_DIR_OPS(smack);
2779 #endif
2780
2781 #ifdef CONFIG_SECURITY_APPARMOR
2782 static const struct pid_entry apparmor_attr_dir_stuff[] = {
2783 ATTR("apparmor", "current", 0666),
2784 ATTR("apparmor", "prev", 0444),
2785 ATTR("apparmor", "exec", 0666),
2786 };
2787 LSM_DIR_OPS(apparmor);
2788 #endif
2789
2790 static const struct pid_entry attr_dir_stuff[] = {
2791 ATTR(NULL, "current", 0666),
2792 ATTR(NULL, "prev", 0444),
2793 ATTR(NULL, "exec", 0666),
2794 ATTR(NULL, "fscreate", 0666),
2795 ATTR(NULL, "keycreate", 0666),
2796 ATTR(NULL, "sockcreate", 0666),
2797 #ifdef CONFIG_SECURITY_SMACK
2798 DIR("smack", 0555,
2799 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2800 #endif
2801 #ifdef CONFIG_SECURITY_APPARMOR
2802 DIR("apparmor", 0555,
2803 proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
2804 #endif
2805 };
2806
2807 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2808 {
2809 return proc_pident_readdir(file, ctx,
2810 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2811 }
2812
2813 static const struct file_operations proc_attr_dir_operations = {
2814 .read = generic_read_dir,
2815 .iterate_shared = proc_attr_dir_readdir,
2816 .llseek = generic_file_llseek,
2817 };
2818
2819 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2820 struct dentry *dentry, unsigned int flags)
2821 {
2822 return proc_pident_lookup(dir, dentry,
2823 attr_dir_stuff,
2824 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2825 }
2826
2827 static const struct inode_operations proc_attr_dir_inode_operations = {
2828 .lookup = proc_attr_dir_lookup,
2829 .getattr = pid_getattr,
2830 .setattr = proc_setattr,
2831 };
2832
2833 #endif
2834
2835 #ifdef CONFIG_ELF_CORE
2836 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2837 size_t count, loff_t *ppos)
2838 {
2839 struct task_struct *task = get_proc_task(file_inode(file));
2840 struct mm_struct *mm;
2841 char buffer[PROC_NUMBUF];
2842 size_t len;
2843 int ret;
2844
2845 if (!task)
2846 return -ESRCH;
2847
2848 ret = 0;
2849 mm = get_task_mm(task);
2850 if (mm) {
2851 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2852 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2853 MMF_DUMP_FILTER_SHIFT));
2854 mmput(mm);
2855 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2856 }
2857
2858 put_task_struct(task);
2859
2860 return ret;
2861 }
2862
2863 static ssize_t proc_coredump_filter_write(struct file *file,
2864 const char __user *buf,
2865 size_t count,
2866 loff_t *ppos)
2867 {
2868 struct task_struct *task;
2869 struct mm_struct *mm;
2870 unsigned int val;
2871 int ret;
2872 int i;
2873 unsigned long mask;
2874
2875 ret = kstrtouint_from_user(buf, count, 0, &val);
2876 if (ret < 0)
2877 return ret;
2878
2879 ret = -ESRCH;
2880 task = get_proc_task(file_inode(file));
2881 if (!task)
2882 goto out_no_task;
2883
2884 mm = get_task_mm(task);
2885 if (!mm)
2886 goto out_no_mm;
2887 ret = 0;
2888
2889 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2890 if (val & mask)
2891 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2892 else
2893 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2894 }
2895
2896 mmput(mm);
2897 out_no_mm:
2898 put_task_struct(task);
2899 out_no_task:
2900 if (ret < 0)
2901 return ret;
2902 return count;
2903 }
2904
2905 static const struct file_operations proc_coredump_filter_operations = {
2906 .read = proc_coredump_filter_read,
2907 .write = proc_coredump_filter_write,
2908 .llseek = generic_file_llseek,
2909 };
2910 #endif
2911
2912 #ifdef CONFIG_TASK_IO_ACCOUNTING
2913 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2914 {
2915 struct task_io_accounting acct = task->ioac;
2916 unsigned long flags;
2917 int result;
2918
2919 result = mutex_lock_killable(&task->signal->exec_update_mutex);
2920 if (result)
2921 return result;
2922
2923 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2924 result = -EACCES;
2925 goto out_unlock;
2926 }
2927
2928 if (whole && lock_task_sighand(task, &flags)) {
2929 struct task_struct *t = task;
2930
2931 task_io_accounting_add(&acct, &task->signal->ioac);
2932 while_each_thread(task, t)
2933 task_io_accounting_add(&acct, &t->ioac);
2934
2935 unlock_task_sighand(task, &flags);
2936 }
2937 seq_printf(m,
2938 "rchar: %llu\n"
2939 "wchar: %llu\n"
2940 "syscr: %llu\n"
2941 "syscw: %llu\n"
2942 "read_bytes: %llu\n"
2943 "write_bytes: %llu\n"
2944 "cancelled_write_bytes: %llu\n",
2945 (unsigned long long)acct.rchar,
2946 (unsigned long long)acct.wchar,
2947 (unsigned long long)acct.syscr,
2948 (unsigned long long)acct.syscw,
2949 (unsigned long long)acct.read_bytes,
2950 (unsigned long long)acct.write_bytes,
2951 (unsigned long long)acct.cancelled_write_bytes);
2952 result = 0;
2953
2954 out_unlock:
2955 mutex_unlock(&task->signal->exec_update_mutex);
2956 return result;
2957 }
2958
2959 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2960 struct pid *pid, struct task_struct *task)
2961 {
2962 return do_io_accounting(task, m, 0);
2963 }
2964
2965 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2966 struct pid *pid, struct task_struct *task)
2967 {
2968 return do_io_accounting(task, m, 1);
2969 }
2970 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2971
2972 #ifdef CONFIG_USER_NS
2973 static int proc_id_map_open(struct inode *inode, struct file *file,
2974 const struct seq_operations *seq_ops)
2975 {
2976 struct user_namespace *ns = NULL;
2977 struct task_struct *task;
2978 struct seq_file *seq;
2979 int ret = -EINVAL;
2980
2981 task = get_proc_task(inode);
2982 if (task) {
2983 rcu_read_lock();
2984 ns = get_user_ns(task_cred_xxx(task, user_ns));
2985 rcu_read_unlock();
2986 put_task_struct(task);
2987 }
2988 if (!ns)
2989 goto err;
2990
2991 ret = seq_open(file, seq_ops);
2992 if (ret)
2993 goto err_put_ns;
2994
2995 seq = file->private_data;
2996 seq->private = ns;
2997
2998 return 0;
2999 err_put_ns:
3000 put_user_ns(ns);
3001 err:
3002 return ret;
3003 }
3004
3005 static int proc_id_map_release(struct inode *inode, struct file *file)
3006 {
3007 struct seq_file *seq = file->private_data;
3008 struct user_namespace *ns = seq->private;
3009 put_user_ns(ns);
3010 return seq_release(inode, file);
3011 }
3012
3013 static int proc_uid_map_open(struct inode *inode, struct file *file)
3014 {
3015 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
3016 }
3017
3018 static int proc_gid_map_open(struct inode *inode, struct file *file)
3019 {
3020 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
3021 }
3022
3023 static int proc_projid_map_open(struct inode *inode, struct file *file)
3024 {
3025 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
3026 }
3027
3028 static const struct file_operations proc_uid_map_operations = {
3029 .open = proc_uid_map_open,
3030 .write = proc_uid_map_write,
3031 .read = seq_read,
3032 .llseek = seq_lseek,
3033 .release = proc_id_map_release,
3034 };
3035
3036 static const struct file_operations proc_gid_map_operations = {
3037 .open = proc_gid_map_open,
3038 .write = proc_gid_map_write,
3039 .read = seq_read,
3040 .llseek = seq_lseek,
3041 .release = proc_id_map_release,
3042 };
3043
3044 static const struct file_operations proc_projid_map_operations = {
3045 .open = proc_projid_map_open,
3046 .write = proc_projid_map_write,
3047 .read = seq_read,
3048 .llseek = seq_lseek,
3049 .release = proc_id_map_release,
3050 };
3051
3052 static int proc_setgroups_open(struct inode *inode, struct file *file)
3053 {
3054 struct user_namespace *ns = NULL;
3055 struct task_struct *task;
3056 int ret;
3057
3058 ret = -ESRCH;
3059 task = get_proc_task(inode);
3060 if (task) {
3061 rcu_read_lock();
3062 ns = get_user_ns(task_cred_xxx(task, user_ns));
3063 rcu_read_unlock();
3064 put_task_struct(task);
3065 }
3066 if (!ns)
3067 goto err;
3068
3069 if (file->f_mode & FMODE_WRITE) {
3070 ret = -EACCES;
3071 if (!ns_capable(ns, CAP_SYS_ADMIN))
3072 goto err_put_ns;
3073 }
3074
3075 ret = single_open(file, &proc_setgroups_show, ns);
3076 if (ret)
3077 goto err_put_ns;
3078
3079 return 0;
3080 err_put_ns:
3081 put_user_ns(ns);
3082 err:
3083 return ret;
3084 }
3085
3086 static int proc_setgroups_release(struct inode *inode, struct file *file)
3087 {
3088 struct seq_file *seq = file->private_data;
3089 struct user_namespace *ns = seq->private;
3090 int ret = single_release(inode, file);
3091 put_user_ns(ns);
3092 return ret;
3093 }
3094
3095 static const struct file_operations proc_setgroups_operations = {
3096 .open = proc_setgroups_open,
3097 .write = proc_setgroups_write,
3098 .read = seq_read,
3099 .llseek = seq_lseek,
3100 .release = proc_setgroups_release,
3101 };
3102 #endif /* CONFIG_USER_NS */
3103
3104 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3105 struct pid *pid, struct task_struct *task)
3106 {
3107 int err = lock_trace(task);
3108 if (!err) {
3109 seq_printf(m, "%08x\n", task->personality);
3110 unlock_trace(task);
3111 }
3112 return err;
3113 }
3114
3115 #ifdef CONFIG_LIVEPATCH
3116 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
3117 struct pid *pid, struct task_struct *task)
3118 {
3119 seq_printf(m, "%d\n", task->patch_state);
3120 return 0;
3121 }
3122 #endif /* CONFIG_LIVEPATCH */
3123
3124 #ifdef CONFIG_STACKLEAK_METRICS
3125 static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
3126 struct pid *pid, struct task_struct *task)
3127 {
3128 unsigned long prev_depth = THREAD_SIZE -
3129 (task->prev_lowest_stack & (THREAD_SIZE - 1));
3130 unsigned long depth = THREAD_SIZE -
3131 (task->lowest_stack & (THREAD_SIZE - 1));
3132
3133 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
3134 prev_depth, depth);
3135 return 0;
3136 }
3137 #endif /* CONFIG_STACKLEAK_METRICS */
3138
3139 /*
3140 * Thread groups
3141 */
3142 static const struct file_operations proc_task_operations;
3143 static const struct inode_operations proc_task_inode_operations;
3144
3145 static const struct pid_entry tgid_base_stuff[] = {
3146 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3147 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3148 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3149 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3150 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3151 #ifdef CONFIG_NET
3152 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3153 #endif
3154 REG("environ", S_IRUSR, proc_environ_operations),
3155 REG("auxv", S_IRUSR, proc_auxv_operations),
3156 ONE("status", S_IRUGO, proc_pid_status),
3157 ONE("personality", S_IRUSR, proc_pid_personality),
3158 ONE("limits", S_IRUGO, proc_pid_limits),
3159 #ifdef CONFIG_SCHED_DEBUG
3160 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3161 #endif
3162 #ifdef CONFIG_SCHED_AUTOGROUP
3163 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3164 #endif
3165 #ifdef CONFIG_TIME_NS
3166 REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
3167 #endif
3168 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3169 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3170 ONE("syscall", S_IRUSR, proc_pid_syscall),
3171 #endif
3172 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3173 ONE("stat", S_IRUGO, proc_tgid_stat),
3174 ONE("statm", S_IRUGO, proc_pid_statm),
3175 REG("maps", S_IRUGO, proc_pid_maps_operations),
3176 #ifdef CONFIG_NUMA
3177 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3178 #endif
3179 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3180 LNK("cwd", proc_cwd_link),
3181 LNK("root", proc_root_link),
3182 LNK("exe", proc_exe_link),
3183 REG("mounts", S_IRUGO, proc_mounts_operations),
3184 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3185 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3186 #ifdef CONFIG_PROC_PAGE_MONITOR
3187 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3188 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3189 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3190 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3191 #endif
3192 #ifdef CONFIG_SECURITY
3193 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3194 #endif
3195 #ifdef CONFIG_KALLSYMS
3196 ONE("wchan", S_IRUGO, proc_pid_wchan),
3197 #endif
3198 #ifdef CONFIG_STACKTRACE
3199 ONE("stack", S_IRUSR, proc_pid_stack),
3200 #endif
3201 #ifdef CONFIG_SCHED_INFO
3202 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3203 #endif
3204 #ifdef CONFIG_LATENCYTOP
3205 REG("latency", S_IRUGO, proc_lstats_operations),
3206 #endif
3207 #ifdef CONFIG_PROC_PID_CPUSET
3208 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3209 #endif
3210 #ifdef CONFIG_CGROUPS
3211 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3212 #endif
3213 #ifdef CONFIG_PROC_CPU_RESCTRL
3214 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3215 #endif
3216 ONE("oom_score", S_IRUGO, proc_oom_score),
3217 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3218 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3219 #ifdef CONFIG_AUDIT
3220 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3221 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3222 #endif
3223 #ifdef CONFIG_FAULT_INJECTION
3224 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3225 REG("fail-nth", 0644, proc_fail_nth_operations),
3226 #endif
3227 #ifdef CONFIG_ELF_CORE
3228 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3229 #endif
3230 #ifdef CONFIG_TASK_IO_ACCOUNTING
3231 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3232 #endif
3233 #ifdef CONFIG_USER_NS
3234 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3235 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3236 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3237 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3238 #endif
3239 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3240 REG("timers", S_IRUGO, proc_timers_operations),
3241 #endif
3242 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3243 #ifdef CONFIG_LIVEPATCH
3244 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3245 #endif
3246 #ifdef CONFIG_STACKLEAK_METRICS
3247 ONE("stack_depth", S_IRUGO, proc_stack_depth),
3248 #endif
3249 #ifdef CONFIG_PROC_PID_ARCH_STATUS
3250 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3251 #endif
3252 };
3253
3254 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3255 {
3256 return proc_pident_readdir(file, ctx,
3257 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3258 }
3259
3260 static const struct file_operations proc_tgid_base_operations = {
3261 .read = generic_read_dir,
3262 .iterate_shared = proc_tgid_base_readdir,
3263 .llseek = generic_file_llseek,
3264 };
3265
3266 struct pid *tgid_pidfd_to_pid(const struct file *file)
3267 {
3268 if (file->f_op != &proc_tgid_base_operations)
3269 return ERR_PTR(-EBADF);
3270
3271 return proc_pid(file_inode(file));
3272 }
3273
3274 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3275 {
3276 return proc_pident_lookup(dir, dentry,
3277 tgid_base_stuff,
3278 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3279 }
3280
3281 static const struct inode_operations proc_tgid_base_inode_operations = {
3282 .lookup = proc_tgid_base_lookup,
3283 .getattr = pid_getattr,
3284 .setattr = proc_setattr,
3285 .permission = proc_pid_permission,
3286 };
3287
3288 /**
3289 * proc_flush_pid - Remove dcache entries for @pid from the /proc dcache.
3290 * @pid: pid that should be flushed.
3291 *
3292 * This function walks a list of inodes (that belong to any proc
3293 * filesystem) that are attached to the pid and flushes them from
3294 * the dentry cache.
3295 *
3296 * It is safe and reasonable to cache /proc entries for a task until
3297 * that task exits. After that they just clog up the dcache with
3298 * useless entries, possibly causing useful dcache entries to be
3299 * flushed instead. This routine is provided to flush those useless
3300 * dcache entries when a process is reaped.
3301 *
3302 * NOTE: This routine is just an optimization so it does not guarantee
3303 * that no dcache entries will exist after a process is reaped
3304 * it just makes it very unlikely that any will persist.
3305 */
3306
3307 void proc_flush_pid(struct pid *pid)
3308 {
3309 proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
3310 }
3311
3312 static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3313 struct task_struct *task, const void *ptr)
3314 {
3315 struct inode *inode;
3316
3317 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3318 if (!inode)
3319 return ERR_PTR(-ENOENT);
3320
3321 inode->i_op = &proc_tgid_base_inode_operations;
3322 inode->i_fop = &proc_tgid_base_operations;
3323 inode->i_flags|=S_IMMUTABLE;
3324
3325 set_nlink(inode, nlink_tgid);
3326 pid_update_inode(task, inode);
3327
3328 d_set_d_op(dentry, &pid_dentry_operations);
3329 return d_splice_alias(inode, dentry);
3330 }
3331
3332 struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3333 {
3334 struct task_struct *task;
3335 unsigned tgid;
3336 struct proc_fs_info *fs_info;
3337 struct pid_namespace *ns;
3338 struct dentry *result = ERR_PTR(-ENOENT);
3339
3340 tgid = name_to_int(&dentry->d_name);
3341 if (tgid == ~0U)
3342 goto out;
3343
3344 fs_info = proc_sb_info(dentry->d_sb);
3345 ns = fs_info->pid_ns;
3346 rcu_read_lock();
3347 task = find_task_by_pid_ns(tgid, ns);
3348 if (task)
3349 get_task_struct(task);
3350 rcu_read_unlock();
3351 if (!task)
3352 goto out;
3353
3354 /* Limit procfs to only ptraceable tasks */
3355 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) {
3356 if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
3357 goto out_put_task;
3358 }
3359
3360 result = proc_pid_instantiate(dentry, task, NULL);
3361 out_put_task:
3362 put_task_struct(task);
3363 out:
3364 return result;
3365 }
3366
3367 /*
3368 * Find the first task with tgid >= tgid
3369 *
3370 */
3371 struct tgid_iter {
3372 unsigned int tgid;
3373 struct task_struct *task;
3374 };
3375 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3376 {
3377 struct pid *pid;
3378
3379 if (iter.task)
3380 put_task_struct(iter.task);
3381 rcu_read_lock();
3382 retry:
3383 iter.task = NULL;
3384 pid = find_ge_pid(iter.tgid, ns);
3385 if (pid) {
3386 iter.tgid = pid_nr_ns(pid, ns);
3387 iter.task = pid_task(pid, PIDTYPE_TGID);
3388 if (!iter.task) {
3389 iter.tgid += 1;
3390 goto retry;
3391 }
3392 get_task_struct(iter.task);
3393 }
3394 rcu_read_unlock();
3395 return iter;
3396 }
3397
3398 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3399
3400 /* for the /proc/ directory itself, after non-process stuff has been done */
3401 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3402 {
3403 struct tgid_iter iter;
3404 struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
3405 struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb);
3406 loff_t pos = ctx->pos;
3407
3408 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3409 return 0;
3410
3411 if (pos == TGID_OFFSET - 2) {
3412 struct inode *inode = d_inode(fs_info->proc_self);
3413 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3414 return 0;
3415 ctx->pos = pos = pos + 1;
3416 }
3417 if (pos == TGID_OFFSET - 1) {
3418 struct inode *inode = d_inode(fs_info->proc_thread_self);
3419 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3420 return 0;
3421 ctx->pos = pos = pos + 1;
3422 }
3423 iter.tgid = pos - TGID_OFFSET;
3424 iter.task = NULL;
3425 for (iter = next_tgid(ns, iter);
3426 iter.task;
3427 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3428 char name[10 + 1];
3429 unsigned int len;
3430
3431 cond_resched();
3432 if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE))
3433 continue;
3434
3435 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3436 ctx->pos = iter.tgid + TGID_OFFSET;
3437 if (!proc_fill_cache(file, ctx, name, len,
3438 proc_pid_instantiate, iter.task, NULL)) {
3439 put_task_struct(iter.task);
3440 return 0;
3441 }
3442 }
3443 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3444 return 0;
3445 }
3446
3447 /*
3448 * proc_tid_comm_permission is a special permission function exclusively
3449 * used for the node /proc/<pid>/task/<tid>/comm.
3450 * It bypasses generic permission checks in the case where a task of the same
3451 * task group attempts to access the node.
3452 * The rationale behind this is that glibc and bionic access this node for
3453 * cross thread naming (pthread_set/getname_np(!self)). However, if
3454 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3455 * which locks out the cross thread naming implementation.
3456 * This function makes sure that the node is always accessible for members of
3457 * same thread group.
3458 */
3459 static int proc_tid_comm_permission(struct inode *inode, int mask)
3460 {
3461 bool is_same_tgroup;
3462 struct task_struct *task;
3463
3464 task = get_proc_task(inode);
3465 if (!task)
3466 return -ESRCH;
3467 is_same_tgroup = same_thread_group(current, task);
3468 put_task_struct(task);
3469
3470 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3471 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3472 * read or written by the members of the corresponding
3473 * thread group.
3474 */
3475 return 0;
3476 }
3477
3478 return generic_permission(inode, mask);
3479 }
3480
3481 static const struct inode_operations proc_tid_comm_inode_operations = {
3482 .permission = proc_tid_comm_permission,
3483 };
3484
3485 /*
3486 * Tasks
3487 */
3488 static const struct pid_entry tid_base_stuff[] = {
3489 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3490 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3491 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3492 #ifdef CONFIG_NET
3493 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3494 #endif
3495 REG("environ", S_IRUSR, proc_environ_operations),
3496 REG("auxv", S_IRUSR, proc_auxv_operations),
3497 ONE("status", S_IRUGO, proc_pid_status),
3498 ONE("personality", S_IRUSR, proc_pid_personality),
3499 ONE("limits", S_IRUGO, proc_pid_limits),
3500 #ifdef CONFIG_SCHED_DEBUG
3501 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3502 #endif
3503 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3504 &proc_tid_comm_inode_operations,
3505 &proc_pid_set_comm_operations, {}),
3506 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3507 ONE("syscall", S_IRUSR, proc_pid_syscall),
3508 #endif
3509 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3510 ONE("stat", S_IRUGO, proc_tid_stat),
3511 ONE("statm", S_IRUGO, proc_pid_statm),
3512 REG("maps", S_IRUGO, proc_pid_maps_operations),
3513 #ifdef CONFIG_PROC_CHILDREN
3514 REG("children", S_IRUGO, proc_tid_children_operations),
3515 #endif
3516 #ifdef CONFIG_NUMA
3517 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3518 #endif
3519 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3520 LNK("cwd", proc_cwd_link),
3521 LNK("root", proc_root_link),
3522 LNK("exe", proc_exe_link),
3523 REG("mounts", S_IRUGO, proc_mounts_operations),
3524 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3525 #ifdef CONFIG_PROC_PAGE_MONITOR
3526 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3527 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3528 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3529 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3530 #endif
3531 #ifdef CONFIG_SECURITY
3532 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3533 #endif
3534 #ifdef CONFIG_KALLSYMS
3535 ONE("wchan", S_IRUGO, proc_pid_wchan),
3536 #endif
3537 #ifdef CONFIG_STACKTRACE
3538 ONE("stack", S_IRUSR, proc_pid_stack),
3539 #endif
3540 #ifdef CONFIG_SCHED_INFO
3541 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3542 #endif
3543 #ifdef CONFIG_LATENCYTOP
3544 REG("latency", S_IRUGO, proc_lstats_operations),
3545 #endif
3546 #ifdef CONFIG_PROC_PID_CPUSET
3547 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3548 #endif
3549 #ifdef CONFIG_CGROUPS
3550 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3551 #endif
3552 #ifdef CONFIG_PROC_CPU_RESCTRL
3553 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3554 #endif
3555 ONE("oom_score", S_IRUGO, proc_oom_score),
3556 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3557 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3558 #ifdef CONFIG_AUDIT
3559 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3560 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3561 #endif
3562 #ifdef CONFIG_FAULT_INJECTION
3563 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3564 REG("fail-nth", 0644, proc_fail_nth_operations),
3565 #endif
3566 #ifdef CONFIG_TASK_IO_ACCOUNTING
3567 ONE("io", S_IRUSR, proc_tid_io_accounting),
3568 #endif
3569 #ifdef CONFIG_USER_NS
3570 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3571 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3572 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3573 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3574 #endif
3575 #ifdef CONFIG_LIVEPATCH
3576 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3577 #endif
3578 #ifdef CONFIG_PROC_PID_ARCH_STATUS
3579 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3580 #endif
3581 };
3582
3583 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3584 {
3585 return proc_pident_readdir(file, ctx,
3586 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3587 }
3588
3589 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3590 {
3591 return proc_pident_lookup(dir, dentry,
3592 tid_base_stuff,
3593 tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3594 }
3595
3596 static const struct file_operations proc_tid_base_operations = {
3597 .read = generic_read_dir,
3598 .iterate_shared = proc_tid_base_readdir,
3599 .llseek = generic_file_llseek,
3600 };
3601
3602 static const struct inode_operations proc_tid_base_inode_operations = {
3603 .lookup = proc_tid_base_lookup,
3604 .getattr = pid_getattr,
3605 .setattr = proc_setattr,
3606 };
3607
3608 static struct dentry *proc_task_instantiate(struct dentry *dentry,
3609 struct task_struct *task, const void *ptr)
3610 {
3611 struct inode *inode;
3612 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3613 if (!inode)
3614 return ERR_PTR(-ENOENT);
3615
3616 inode->i_op = &proc_tid_base_inode_operations;
3617 inode->i_fop = &proc_tid_base_operations;
3618 inode->i_flags |= S_IMMUTABLE;
3619
3620 set_nlink(inode, nlink_tid);
3621 pid_update_inode(task, inode);
3622
3623 d_set_d_op(dentry, &pid_dentry_operations);
3624 return d_splice_alias(inode, dentry);
3625 }
3626
3627 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3628 {
3629 struct task_struct *task;
3630 struct task_struct *leader = get_proc_task(dir);
3631 unsigned tid;
3632 struct proc_fs_info *fs_info;
3633 struct pid_namespace *ns;
3634 struct dentry *result = ERR_PTR(-ENOENT);
3635
3636 if (!leader)
3637 goto out_no_task;
3638
3639 tid = name_to_int(&dentry->d_name);
3640 if (tid == ~0U)
3641 goto out;
3642
3643 fs_info = proc_sb_info(dentry->d_sb);
3644 ns = fs_info->pid_ns;
3645 rcu_read_lock();
3646 task = find_task_by_pid_ns(tid, ns);
3647 if (task)
3648 get_task_struct(task);
3649 rcu_read_unlock();
3650 if (!task)
3651 goto out;
3652 if (!same_thread_group(leader, task))
3653 goto out_drop_task;
3654
3655 result = proc_task_instantiate(dentry, task, NULL);
3656 out_drop_task:
3657 put_task_struct(task);
3658 out:
3659 put_task_struct(leader);
3660 out_no_task:
3661 return result;
3662 }
3663
3664 /*
3665 * Find the first tid of a thread group to return to user space.
3666 *
3667 * Usually this is just the thread group leader, but if the users
3668 * buffer was too small or there was a seek into the middle of the
3669 * directory we have more work todo.
3670 *
3671 * In the case of a short read we start with find_task_by_pid.
3672 *
3673 * In the case of a seek we start with the leader and walk nr
3674 * threads past it.
3675 */
3676 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3677 struct pid_namespace *ns)
3678 {
3679 struct task_struct *pos, *task;
3680 unsigned long nr = f_pos;
3681
3682 if (nr != f_pos) /* 32bit overflow? */
3683 return NULL;
3684
3685 rcu_read_lock();
3686 task = pid_task(pid, PIDTYPE_PID);
3687 if (!task)
3688 goto fail;
3689
3690 /* Attempt to start with the tid of a thread */
3691 if (tid && nr) {
3692 pos = find_task_by_pid_ns(tid, ns);
3693 if (pos && same_thread_group(pos, task))
3694 goto found;
3695 }
3696
3697 /* If nr exceeds the number of threads there is nothing todo */
3698 if (nr >= get_nr_threads(task))
3699 goto fail;
3700
3701 /* If we haven't found our starting place yet start
3702 * with the leader and walk nr threads forward.
3703 */
3704 pos = task = task->group_leader;
3705 do {
3706 if (!nr--)
3707 goto found;
3708 } while_each_thread(task, pos);
3709 fail:
3710 pos = NULL;
3711 goto out;
3712 found:
3713 get_task_struct(pos);
3714 out:
3715 rcu_read_unlock();
3716 return pos;
3717 }
3718
3719 /*
3720 * Find the next thread in the thread list.
3721 * Return NULL if there is an error or no next thread.
3722 *
3723 * The reference to the input task_struct is released.
3724 */
3725 static struct task_struct *next_tid(struct task_struct *start)
3726 {
3727 struct task_struct *pos = NULL;
3728 rcu_read_lock();
3729 if (pid_alive(start)) {
3730 pos = next_thread(start);
3731 if (thread_group_leader(pos))
3732 pos = NULL;
3733 else
3734 get_task_struct(pos);
3735 }
3736 rcu_read_unlock();
3737 put_task_struct(start);
3738 return pos;
3739 }
3740
3741 /* for the /proc/TGID/task/ directories */
3742 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3743 {
3744 struct inode *inode = file_inode(file);
3745 struct task_struct *task;
3746 struct pid_namespace *ns;
3747 int tid;
3748
3749 if (proc_inode_is_dead(inode))
3750 return -ENOENT;
3751
3752 if (!dir_emit_dots(file, ctx))
3753 return 0;
3754
3755 /* f_version caches the tgid value that the last readdir call couldn't
3756 * return. lseek aka telldir automagically resets f_version to 0.
3757 */
3758 ns = proc_pid_ns(inode->i_sb);
3759 tid = (int)file->f_version;
3760 file->f_version = 0;
3761 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3762 task;
3763 task = next_tid(task), ctx->pos++) {
3764 char name[10 + 1];
3765 unsigned int len;
3766 tid = task_pid_nr_ns(task, ns);
3767 len = snprintf(name, sizeof(name), "%u", tid);
3768 if (!proc_fill_cache(file, ctx, name, len,
3769 proc_task_instantiate, task, NULL)) {
3770 /* returning this tgid failed, save it as the first
3771 * pid for the next readir call */
3772 file->f_version = (u64)tid;
3773 put_task_struct(task);
3774 break;
3775 }
3776 }
3777
3778 return 0;
3779 }
3780
3781 static int proc_task_getattr(const struct path *path, struct kstat *stat,
3782 u32 request_mask, unsigned int query_flags)
3783 {
3784 struct inode *inode = d_inode(path->dentry);
3785 struct task_struct *p = get_proc_task(inode);
3786 generic_fillattr(inode, stat);
3787
3788 if (p) {
3789 stat->nlink += get_nr_threads(p);
3790 put_task_struct(p);
3791 }
3792
3793 return 0;
3794 }
3795
3796 static const struct inode_operations proc_task_inode_operations = {
3797 .lookup = proc_task_lookup,
3798 .getattr = proc_task_getattr,
3799 .setattr = proc_setattr,
3800 .permission = proc_pid_permission,
3801 };
3802
3803 static const struct file_operations proc_task_operations = {
3804 .read = generic_read_dir,
3805 .iterate_shared = proc_task_readdir,
3806 .llseek = generic_file_llseek,
3807 };
3808
3809 void __init set_proc_pid_nlink(void)
3810 {
3811 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3812 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3813 }
Linux with added FPC-III support