Line data Source code
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/printk.h>
78 : #include <linux/cache.h>
79 : #include <linux/cgroup.h>
80 : #include <linux/cpuset.h>
81 : #include <linux/audit.h>
82 : #include <linux/poll.h>
83 : #include <linux/nsproxy.h>
84 : #include <linux/oom.h>
85 : #include <linux/elf.h>
86 : #include <linux/pid_namespace.h>
87 : #include <linux/user_namespace.h>
88 : #include <linux/fs_struct.h>
89 : #include <linux/slab.h>
90 : #include <linux/sched/autogroup.h>
91 : #include <linux/sched/mm.h>
92 : #include <linux/sched/coredump.h>
93 : #include <linux/sched/debug.h>
94 : #include <linux/sched/stat.h>
95 : #include <linux/posix-timers.h>
96 : #include <linux/time_namespace.h>
97 : #include <linux/resctrl.h>
98 : #include <linux/cn_proc.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 2 : 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 2 : count = 2;
164 65 : for (i = 0; i < n; ++i) {
165 63 : if (S_ISDIR(entries[i].mode))
166 8 : ++count;
167 : }
168 :
169 2 : return count;
170 : }
171 :
172 : static int get_task_root(struct task_struct *task, struct path *root)
173 : {
174 0 : int result = -ENOENT;
175 :
176 0 : task_lock(task);
177 : if (task->fs) {
178 0 : get_fs_root(task->fs, root);
179 0 : result = 0;
180 : }
181 0 : task_unlock(task);
182 : return result;
183 : }
184 :
185 0 : static int proc_cwd_link(struct dentry *dentry, struct path *path)
186 : {
187 0 : struct task_struct *task = get_proc_task(d_inode(dentry));
188 0 : int result = -ENOENT;
189 :
190 0 : if (task) {
191 : task_lock(task);
192 0 : if (task->fs) {
193 0 : get_fs_pwd(task->fs, path);
194 0 : result = 0;
195 : }
196 : task_unlock(task);
197 0 : put_task_struct(task);
198 : }
199 0 : return result;
200 : }
201 :
202 0 : static int proc_root_link(struct dentry *dentry, struct path *path)
203 : {
204 0 : struct task_struct *task = get_proc_task(d_inode(dentry));
205 0 : int result = -ENOENT;
206 :
207 0 : if (task) {
208 0 : result = get_task_root(task, path);
209 0 : put_task_struct(task);
210 : }
211 0 : 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 0 : 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 0 : if (pos >= PAGE_SIZE)
226 : return 0;
227 :
228 0 : page = (char *)__get_free_page(GFP_KERNEL);
229 0 : if (!page)
230 : return -ENOMEM;
231 :
232 0 : ret = 0;
233 0 : got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
234 0 : if (got > 0) {
235 0 : int len = strnlen(page, got);
236 :
237 : /* Include the NUL character if it was found */
238 0 : if (len < got)
239 0 : len++;
240 :
241 0 : if (len > pos) {
242 0 : len -= pos;
243 0 : if (len > count)
244 0 : len = count;
245 0 : len -= copy_to_user(buf, page+pos, len);
246 0 : if (!len)
247 0 : len = -EFAULT;
248 : ret = len;
249 : }
250 : }
251 0 : free_page((unsigned long)page);
252 0 : return ret;
253 : }
254 :
255 0 : 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 0 : if (!mm->env_end)
264 : return 0;
265 :
266 0 : spin_lock(&mm->arg_lock);
267 0 : arg_start = mm->arg_start;
268 0 : arg_end = mm->arg_end;
269 0 : env_start = mm->env_start;
270 0 : env_end = mm->env_end;
271 0 : spin_unlock(&mm->arg_lock);
272 :
273 0 : 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 0 : if (env_start != arg_end || env_end < env_start)
282 0 : env_start = env_end = arg_end;
283 0 : len = env_end - arg_start;
284 :
285 : /* We're not going to care if "*ppos" has high bits set */
286 0 : pos = *ppos;
287 0 : if (pos >= len)
288 : return 0;
289 0 : if (count > len - pos)
290 0 : count = len - pos;
291 0 : 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 0 : if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
302 0 : 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 0 : pos += arg_start;
309 0 : if (pos < arg_start || pos >= arg_end)
310 : return 0;
311 0 : if (count > arg_end - pos)
312 0 : count = arg_end - pos;
313 :
314 0 : page = (char *)__get_free_page(GFP_KERNEL);
315 0 : if (!page)
316 : return -ENOMEM;
317 :
318 : len = 0;
319 0 : while (count) {
320 : int got;
321 0 : size_t size = min_t(size_t, PAGE_SIZE, count);
322 :
323 0 : got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
324 0 : if (got <= 0)
325 : break;
326 0 : got -= copy_to_user(buf, page, got);
327 0 : if (unlikely(!got)) {
328 0 : if (!len)
329 0 : len = -EFAULT;
330 : break;
331 : }
332 0 : pos += got;
333 0 : buf += got;
334 0 : len += got;
335 0 : count -= got;
336 : }
337 :
338 0 : free_page((unsigned long)page);
339 0 : return len;
340 : }
341 :
342 0 : 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 0 : mm = get_task_mm(tsk);
349 0 : if (!mm)
350 : return 0;
351 :
352 0 : ret = get_mm_cmdline(mm, buf, count, pos);
353 0 : mmput(mm);
354 0 : return ret;
355 : }
356 :
357 0 : 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 0 : BUG_ON(*pos < 0);
364 :
365 0 : tsk = get_proc_task(file_inode(file));
366 0 : if (!tsk)
367 : return -ESRCH;
368 0 : ret = get_task_cmdline(tsk, buf, count, pos);
369 0 : put_task_struct(tsk);
370 0 : if (ret > 0)
371 0 : *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 0 : 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 0 : if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
392 : goto print0;
393 :
394 0 : wchan = get_wchan(task);
395 0 : if (wchan && !lookup_symbol_name(wchan, symname)) {
396 0 : seq_puts(m, symname);
397 0 : return 0;
398 : }
399 :
400 : print0:
401 0 : seq_putc(m, '0');
402 0 : return 0;
403 : }
404 : #endif /* CONFIG_KALLSYMS */
405 :
406 0 : static int lock_trace(struct task_struct *task)
407 : {
408 0 : int err = down_read_killable(&task->signal->exec_update_lock);
409 0 : if (err)
410 : return err;
411 0 : if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
412 0 : up_read(&task->signal->exec_update_lock);
413 0 : return -EPERM;
414 : }
415 : return 0;
416 : }
417 :
418 : static void unlock_trace(struct task_struct *task)
419 : {
420 0 : up_read(&task->signal->exec_update_lock);
421 : }
422 :
423 : #ifdef CONFIG_STACKTRACE
424 :
425 : #define MAX_STACK_TRACE_DEPTH 64
426 :
427 0 : 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 0 : if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
445 : return -EACCES;
446 :
447 0 : entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
448 : GFP_KERNEL);
449 0 : if (!entries)
450 : return -ENOMEM;
451 :
452 0 : err = lock_trace(task);
453 0 : if (!err) {
454 : unsigned int i, nr_entries;
455 :
456 0 : nr_entries = stack_trace_save_tsk(task, entries,
457 : MAX_STACK_TRACE_DEPTH, 0);
458 :
459 0 : for (i = 0; i < nr_entries; i++) {
460 0 : seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
461 : }
462 :
463 0 : unlock_trace(task);
464 : }
465 0 : kfree(entries);
466 :
467 0 : 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 0 : static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
550 : struct pid *pid, struct task_struct *task)
551 : {
552 0 : unsigned long totalpages = totalram_pages() + total_swap_pages;
553 0 : unsigned long points = 0;
554 : long badness;
555 :
556 0 : badness = oom_badness(task, totalpages);
557 : /*
558 : * Special case OOM_SCORE_ADJ_MIN for all others scale the
559 : * badness value into [0, 2000] range which we have been
560 : * exporting for a long time so userspace might depend on it.
561 : */
562 0 : if (badness != LONG_MIN)
563 0 : points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
564 :
565 0 : seq_printf(m, "%lu\n", points);
566 :
567 0 : return 0;
568 : }
569 :
570 : struct limit_names {
571 : const char *name;
572 : const char *unit;
573 : };
574 :
575 : static const struct limit_names lnames[RLIM_NLIMITS] = {
576 : [RLIMIT_CPU] = {"Max cpu time", "seconds"},
577 : [RLIMIT_FSIZE] = {"Max file size", "bytes"},
578 : [RLIMIT_DATA] = {"Max data size", "bytes"},
579 : [RLIMIT_STACK] = {"Max stack size", "bytes"},
580 : [RLIMIT_CORE] = {"Max core file size", "bytes"},
581 : [RLIMIT_RSS] = {"Max resident set", "bytes"},
582 : [RLIMIT_NPROC] = {"Max processes", "processes"},
583 : [RLIMIT_NOFILE] = {"Max open files", "files"},
584 : [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
585 : [RLIMIT_AS] = {"Max address space", "bytes"},
586 : [RLIMIT_LOCKS] = {"Max file locks", "locks"},
587 : [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
588 : [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
589 : [RLIMIT_NICE] = {"Max nice priority", NULL},
590 : [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
591 : [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
592 : };
593 :
594 : /* Display limits for a process */
595 0 : static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
596 : struct pid *pid, struct task_struct *task)
597 : {
598 : unsigned int i;
599 : unsigned long flags;
600 :
601 : struct rlimit rlim[RLIM_NLIMITS];
602 :
603 0 : if (!lock_task_sighand(task, &flags))
604 : return 0;
605 0 : memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
606 0 : unlock_task_sighand(task, &flags);
607 :
608 : /*
609 : * print the file header
610 : */
611 0 : seq_puts(m, "Limit "
612 : "Soft Limit "
613 : "Hard Limit "
614 : "Units \n");
615 :
616 0 : for (i = 0; i < RLIM_NLIMITS; i++) {
617 0 : if (rlim[i].rlim_cur == RLIM_INFINITY)
618 0 : seq_printf(m, "%-25s %-20s ",
619 : lnames[i].name, "unlimited");
620 : else
621 0 : seq_printf(m, "%-25s %-20lu ",
622 : lnames[i].name, rlim[i].rlim_cur);
623 :
624 0 : if (rlim[i].rlim_max == RLIM_INFINITY)
625 0 : seq_printf(m, "%-20s ", "unlimited");
626 : else
627 0 : seq_printf(m, "%-20lu ", rlim[i].rlim_max);
628 :
629 0 : if (lnames[i].unit)
630 0 : seq_printf(m, "%-10s\n", lnames[i].unit);
631 : else
632 0 : seq_putc(m, '\n');
633 : }
634 :
635 : return 0;
636 : }
637 :
638 : #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
639 : static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
640 : struct pid *pid, struct task_struct *task)
641 : {
642 : struct syscall_info info;
643 : u64 *args = &info.data.args[0];
644 : int res;
645 :
646 : res = lock_trace(task);
647 : if (res)
648 : return res;
649 :
650 : if (task_current_syscall(task, &info))
651 : seq_puts(m, "running\n");
652 : else if (info.data.nr < 0)
653 : seq_printf(m, "%d 0x%llx 0x%llx\n",
654 : info.data.nr, info.sp, info.data.instruction_pointer);
655 : else
656 : seq_printf(m,
657 : "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
658 : info.data.nr,
659 : args[0], args[1], args[2], args[3], args[4], args[5],
660 : info.sp, info.data.instruction_pointer);
661 : unlock_trace(task);
662 :
663 : return 0;
664 : }
665 : #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
666 :
667 : /************************************************************************/
668 : /* Here the fs part begins */
669 : /************************************************************************/
670 :
671 : /* permission checks */
672 0 : static bool proc_fd_access_allowed(struct inode *inode)
673 : {
674 : struct task_struct *task;
675 0 : bool allowed = false;
676 : /* Allow access to a task's file descriptors if it is us or we
677 : * may use ptrace attach to the process and find out that
678 : * information.
679 : */
680 0 : task = get_proc_task(inode);
681 0 : if (task) {
682 0 : allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
683 0 : put_task_struct(task);
684 : }
685 0 : return allowed;
686 : }
687 :
688 0 : int proc_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
689 : struct iattr *attr)
690 : {
691 : int error;
692 0 : struct inode *inode = d_inode(dentry);
693 :
694 0 : if (attr->ia_valid & ATTR_MODE)
695 : return -EPERM;
696 :
697 0 : error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
698 0 : if (error)
699 : return error;
700 :
701 0 : setattr_copy(&nop_mnt_idmap, inode, attr);
702 0 : mark_inode_dirty(inode);
703 0 : return 0;
704 : }
705 :
706 : /*
707 : * May current process learn task's sched/cmdline info (for hide_pid_min=1)
708 : * or euid/egid (for hide_pid_min=2)?
709 : */
710 0 : static bool has_pid_permissions(struct proc_fs_info *fs_info,
711 : struct task_struct *task,
712 : enum proc_hidepid hide_pid_min)
713 : {
714 : /*
715 : * If 'hidpid' mount option is set force a ptrace check,
716 : * we indicate that we are using a filesystem syscall
717 : * by passing PTRACE_MODE_READ_FSCREDS
718 : */
719 0 : if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE)
720 0 : return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
721 :
722 0 : if (fs_info->hide_pid < hide_pid_min)
723 : return true;
724 0 : if (in_group_p(fs_info->pid_gid))
725 : return true;
726 0 : return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
727 : }
728 :
729 :
730 0 : static int proc_pid_permission(struct mnt_idmap *idmap,
731 : struct inode *inode, int mask)
732 : {
733 0 : struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
734 : struct task_struct *task;
735 : bool has_perms;
736 :
737 0 : task = get_proc_task(inode);
738 0 : if (!task)
739 : return -ESRCH;
740 0 : has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS);
741 0 : put_task_struct(task);
742 :
743 0 : if (!has_perms) {
744 0 : if (fs_info->hide_pid == HIDEPID_INVISIBLE) {
745 : /*
746 : * Let's make getdents(), stat(), and open()
747 : * consistent with each other. If a process
748 : * may not stat() a file, it shouldn't be seen
749 : * in procfs at all.
750 : */
751 : return -ENOENT;
752 : }
753 :
754 0 : return -EPERM;
755 : }
756 0 : return generic_permission(&nop_mnt_idmap, inode, mask);
757 : }
758 :
759 :
760 :
761 : static const struct inode_operations proc_def_inode_operations = {
762 : .setattr = proc_setattr,
763 : };
764 :
765 0 : static int proc_single_show(struct seq_file *m, void *v)
766 : {
767 0 : struct inode *inode = m->private;
768 0 : struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
769 0 : struct pid *pid = proc_pid(inode);
770 : struct task_struct *task;
771 : int ret;
772 :
773 0 : task = get_pid_task(pid, PIDTYPE_PID);
774 0 : if (!task)
775 : return -ESRCH;
776 :
777 0 : ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
778 :
779 0 : put_task_struct(task);
780 0 : return ret;
781 : }
782 :
783 0 : static int proc_single_open(struct inode *inode, struct file *filp)
784 : {
785 0 : return single_open(filp, proc_single_show, inode);
786 : }
787 :
788 : static const struct file_operations proc_single_file_operations = {
789 : .open = proc_single_open,
790 : .read = seq_read,
791 : .llseek = seq_lseek,
792 : .release = single_release,
793 : };
794 :
795 :
796 0 : struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
797 : {
798 0 : struct task_struct *task = get_proc_task(inode);
799 0 : struct mm_struct *mm = ERR_PTR(-ESRCH);
800 :
801 0 : if (task) {
802 0 : mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
803 0 : put_task_struct(task);
804 :
805 0 : if (!IS_ERR_OR_NULL(mm)) {
806 : /* ensure this mm_struct can't be freed */
807 0 : mmgrab(mm);
808 : /* but do not pin its memory */
809 0 : mmput(mm);
810 : }
811 : }
812 :
813 0 : return mm;
814 : }
815 :
816 : static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
817 : {
818 0 : struct mm_struct *mm = proc_mem_open(inode, mode);
819 :
820 0 : if (IS_ERR(mm))
821 0 : return PTR_ERR(mm);
822 :
823 0 : file->private_data = mm;
824 : return 0;
825 : }
826 :
827 0 : static int mem_open(struct inode *inode, struct file *file)
828 : {
829 0 : int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
830 :
831 : /* OK to pass negative loff_t, we can catch out-of-range */
832 0 : file->f_mode |= FMODE_UNSIGNED_OFFSET;
833 :
834 0 : return ret;
835 : }
836 :
837 0 : static ssize_t mem_rw(struct file *file, char __user *buf,
838 : size_t count, loff_t *ppos, int write)
839 : {
840 0 : struct mm_struct *mm = file->private_data;
841 0 : unsigned long addr = *ppos;
842 : ssize_t copied;
843 : char *page;
844 : unsigned int flags;
845 :
846 0 : if (!mm)
847 : return 0;
848 :
849 0 : page = (char *)__get_free_page(GFP_KERNEL);
850 0 : if (!page)
851 : return -ENOMEM;
852 :
853 0 : copied = 0;
854 0 : if (!mmget_not_zero(mm))
855 : goto free;
856 :
857 0 : flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
858 :
859 0 : while (count > 0) {
860 0 : size_t this_len = min_t(size_t, count, PAGE_SIZE);
861 :
862 0 : if (write && copy_from_user(page, buf, this_len)) {
863 : copied = -EFAULT;
864 : break;
865 : }
866 :
867 0 : this_len = access_remote_vm(mm, addr, page, this_len, flags);
868 0 : if (!this_len) {
869 0 : if (!copied)
870 0 : copied = -EIO;
871 : break;
872 : }
873 :
874 0 : if (!write && copy_to_user(buf, page, this_len)) {
875 : copied = -EFAULT;
876 : break;
877 : }
878 :
879 0 : buf += this_len;
880 0 : addr += this_len;
881 0 : copied += this_len;
882 0 : count -= this_len;
883 : }
884 0 : *ppos = addr;
885 :
886 0 : mmput(mm);
887 : free:
888 0 : free_page((unsigned long) page);
889 : return copied;
890 : }
891 :
892 0 : static ssize_t mem_read(struct file *file, char __user *buf,
893 : size_t count, loff_t *ppos)
894 : {
895 0 : return mem_rw(file, buf, count, ppos, 0);
896 : }
897 :
898 0 : static ssize_t mem_write(struct file *file, const char __user *buf,
899 : size_t count, loff_t *ppos)
900 : {
901 0 : return mem_rw(file, (char __user*)buf, count, ppos, 1);
902 : }
903 :
904 0 : loff_t mem_lseek(struct file *file, loff_t offset, int orig)
905 : {
906 0 : switch (orig) {
907 : case 0:
908 0 : file->f_pos = offset;
909 0 : break;
910 : case 1:
911 0 : file->f_pos += offset;
912 0 : break;
913 : default:
914 : return -EINVAL;
915 : }
916 : force_successful_syscall_return();
917 0 : return file->f_pos;
918 : }
919 :
920 0 : static int mem_release(struct inode *inode, struct file *file)
921 : {
922 0 : struct mm_struct *mm = file->private_data;
923 0 : if (mm)
924 : mmdrop(mm);
925 0 : return 0;
926 : }
927 :
928 : static const struct file_operations proc_mem_operations = {
929 : .llseek = mem_lseek,
930 : .read = mem_read,
931 : .write = mem_write,
932 : .open = mem_open,
933 : .release = mem_release,
934 : };
935 :
936 0 : static int environ_open(struct inode *inode, struct file *file)
937 : {
938 0 : return __mem_open(inode, file, PTRACE_MODE_READ);
939 : }
940 :
941 0 : static ssize_t environ_read(struct file *file, char __user *buf,
942 : size_t count, loff_t *ppos)
943 : {
944 : char *page;
945 0 : unsigned long src = *ppos;
946 0 : int ret = 0;
947 0 : struct mm_struct *mm = file->private_data;
948 : unsigned long env_start, env_end;
949 :
950 : /* Ensure the process spawned far enough to have an environment. */
951 0 : if (!mm || !mm->env_end)
952 : return 0;
953 :
954 0 : page = (char *)__get_free_page(GFP_KERNEL);
955 0 : if (!page)
956 : return -ENOMEM;
957 :
958 0 : ret = 0;
959 0 : if (!mmget_not_zero(mm))
960 : goto free;
961 :
962 0 : spin_lock(&mm->arg_lock);
963 0 : env_start = mm->env_start;
964 0 : env_end = mm->env_end;
965 0 : spin_unlock(&mm->arg_lock);
966 :
967 0 : while (count > 0) {
968 : size_t this_len, max_len;
969 : int retval;
970 :
971 0 : if (src >= (env_end - env_start))
972 : break;
973 :
974 0 : this_len = env_end - (env_start + src);
975 :
976 0 : max_len = min_t(size_t, PAGE_SIZE, count);
977 0 : this_len = min(max_len, this_len);
978 :
979 0 : retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
980 :
981 0 : if (retval <= 0) {
982 : ret = retval;
983 : break;
984 : }
985 :
986 0 : if (copy_to_user(buf, page, retval)) {
987 : ret = -EFAULT;
988 : break;
989 : }
990 :
991 0 : ret += retval;
992 0 : src += retval;
993 0 : buf += retval;
994 0 : count -= retval;
995 : }
996 0 : *ppos = src;
997 0 : mmput(mm);
998 :
999 : free:
1000 0 : free_page((unsigned long) page);
1001 0 : return ret;
1002 : }
1003 :
1004 : static const struct file_operations proc_environ_operations = {
1005 : .open = environ_open,
1006 : .read = environ_read,
1007 : .llseek = generic_file_llseek,
1008 : .release = mem_release,
1009 : };
1010 :
1011 0 : static int auxv_open(struct inode *inode, struct file *file)
1012 : {
1013 0 : return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1014 : }
1015 :
1016 0 : static ssize_t auxv_read(struct file *file, char __user *buf,
1017 : size_t count, loff_t *ppos)
1018 : {
1019 0 : struct mm_struct *mm = file->private_data;
1020 0 : unsigned int nwords = 0;
1021 :
1022 0 : if (!mm)
1023 : return 0;
1024 : do {
1025 0 : nwords += 2;
1026 0 : } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1027 0 : return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1028 : nwords * sizeof(mm->saved_auxv[0]));
1029 : }
1030 :
1031 : static const struct file_operations proc_auxv_operations = {
1032 : .open = auxv_open,
1033 : .read = auxv_read,
1034 : .llseek = generic_file_llseek,
1035 : .release = mem_release,
1036 : };
1037 :
1038 0 : static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1039 : loff_t *ppos)
1040 : {
1041 0 : struct task_struct *task = get_proc_task(file_inode(file));
1042 : char buffer[PROC_NUMBUF];
1043 0 : int oom_adj = OOM_ADJUST_MIN;
1044 : size_t len;
1045 :
1046 0 : if (!task)
1047 : return -ESRCH;
1048 0 : if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1049 : oom_adj = OOM_ADJUST_MAX;
1050 : else
1051 0 : oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1052 : OOM_SCORE_ADJ_MAX;
1053 0 : put_task_struct(task);
1054 0 : if (oom_adj > OOM_ADJUST_MAX)
1055 0 : oom_adj = OOM_ADJUST_MAX;
1056 0 : len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1057 0 : return simple_read_from_buffer(buf, count, ppos, buffer, len);
1058 : }
1059 :
1060 0 : static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1061 : {
1062 0 : struct mm_struct *mm = NULL;
1063 : struct task_struct *task;
1064 0 : int err = 0;
1065 :
1066 0 : task = get_proc_task(file_inode(file));
1067 0 : if (!task)
1068 : return -ESRCH;
1069 :
1070 0 : mutex_lock(&oom_adj_mutex);
1071 0 : if (legacy) {
1072 0 : if (oom_adj < task->signal->oom_score_adj &&
1073 0 : !capable(CAP_SYS_RESOURCE)) {
1074 : err = -EACCES;
1075 : goto err_unlock;
1076 : }
1077 : /*
1078 : * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1079 : * /proc/pid/oom_score_adj instead.
1080 : */
1081 0 : pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1082 : current->comm, task_pid_nr(current), task_pid_nr(task),
1083 : task_pid_nr(task));
1084 : } else {
1085 0 : if ((short)oom_adj < task->signal->oom_score_adj_min &&
1086 0 : !capable(CAP_SYS_RESOURCE)) {
1087 : err = -EACCES;
1088 : goto err_unlock;
1089 : }
1090 : }
1091 :
1092 : /*
1093 : * Make sure we will check other processes sharing the mm if this is
1094 : * not vfrok which wants its own oom_score_adj.
1095 : * pin the mm so it doesn't go away and get reused after task_unlock
1096 : */
1097 0 : if (!task->vfork_done) {
1098 0 : struct task_struct *p = find_lock_task_mm(task);
1099 :
1100 0 : if (p) {
1101 0 : if (test_bit(MMF_MULTIPROCESS, &p->mm->flags)) {
1102 0 : mm = p->mm;
1103 : mmgrab(mm);
1104 : }
1105 0 : task_unlock(p);
1106 : }
1107 : }
1108 :
1109 0 : task->signal->oom_score_adj = oom_adj;
1110 0 : if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1111 0 : task->signal->oom_score_adj_min = (short)oom_adj;
1112 : trace_oom_score_adj_update(task);
1113 :
1114 0 : if (mm) {
1115 : struct task_struct *p;
1116 :
1117 : rcu_read_lock();
1118 0 : for_each_process(p) {
1119 0 : if (same_thread_group(task, p))
1120 0 : continue;
1121 :
1122 : /* do not touch kernel threads or the global init */
1123 0 : if (p->flags & PF_KTHREAD || is_global_init(p))
1124 0 : continue;
1125 :
1126 0 : task_lock(p);
1127 0 : if (!p->vfork_done && process_shares_mm(p, mm)) {
1128 0 : p->signal->oom_score_adj = oom_adj;
1129 0 : if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1130 0 : p->signal->oom_score_adj_min = (short)oom_adj;
1131 : }
1132 0 : task_unlock(p);
1133 : }
1134 0 : rcu_read_unlock();
1135 : mmdrop(mm);
1136 : }
1137 : err_unlock:
1138 0 : mutex_unlock(&oom_adj_mutex);
1139 0 : put_task_struct(task);
1140 0 : return err;
1141 : }
1142 :
1143 : /*
1144 : * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1145 : * kernels. The effective policy is defined by oom_score_adj, which has a
1146 : * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1147 : * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1148 : * Processes that become oom disabled via oom_adj will still be oom disabled
1149 : * with this implementation.
1150 : *
1151 : * oom_adj cannot be removed since existing userspace binaries use it.
1152 : */
1153 0 : static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1154 : size_t count, loff_t *ppos)
1155 : {
1156 : char buffer[PROC_NUMBUF];
1157 : int oom_adj;
1158 : int err;
1159 :
1160 0 : memset(buffer, 0, sizeof(buffer));
1161 0 : if (count > sizeof(buffer) - 1)
1162 0 : count = sizeof(buffer) - 1;
1163 0 : if (copy_from_user(buffer, buf, count)) {
1164 : err = -EFAULT;
1165 : goto out;
1166 : }
1167 :
1168 0 : err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1169 0 : if (err)
1170 : goto out;
1171 0 : if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1172 : oom_adj != OOM_DISABLE) {
1173 : err = -EINVAL;
1174 : goto out;
1175 : }
1176 :
1177 : /*
1178 : * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1179 : * value is always attainable.
1180 : */
1181 0 : if (oom_adj == OOM_ADJUST_MAX)
1182 0 : oom_adj = OOM_SCORE_ADJ_MAX;
1183 : else
1184 0 : oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1185 :
1186 0 : err = __set_oom_adj(file, oom_adj, true);
1187 : out:
1188 0 : return err < 0 ? err : count;
1189 : }
1190 :
1191 : static const struct file_operations proc_oom_adj_operations = {
1192 : .read = oom_adj_read,
1193 : .write = oom_adj_write,
1194 : .llseek = generic_file_llseek,
1195 : };
1196 :
1197 0 : static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1198 : size_t count, loff_t *ppos)
1199 : {
1200 0 : struct task_struct *task = get_proc_task(file_inode(file));
1201 : char buffer[PROC_NUMBUF];
1202 0 : short oom_score_adj = OOM_SCORE_ADJ_MIN;
1203 : size_t len;
1204 :
1205 0 : if (!task)
1206 : return -ESRCH;
1207 0 : oom_score_adj = task->signal->oom_score_adj;
1208 0 : put_task_struct(task);
1209 0 : len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1210 0 : return simple_read_from_buffer(buf, count, ppos, buffer, len);
1211 : }
1212 :
1213 0 : static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1214 : size_t count, loff_t *ppos)
1215 : {
1216 : char buffer[PROC_NUMBUF];
1217 : int oom_score_adj;
1218 : int err;
1219 :
1220 0 : memset(buffer, 0, sizeof(buffer));
1221 0 : if (count > sizeof(buffer) - 1)
1222 0 : count = sizeof(buffer) - 1;
1223 0 : if (copy_from_user(buffer, buf, count)) {
1224 : err = -EFAULT;
1225 : goto out;
1226 : }
1227 :
1228 0 : err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1229 0 : if (err)
1230 : goto out;
1231 0 : if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1232 : oom_score_adj > OOM_SCORE_ADJ_MAX) {
1233 : err = -EINVAL;
1234 : goto out;
1235 : }
1236 :
1237 0 : err = __set_oom_adj(file, oom_score_adj, false);
1238 : out:
1239 0 : return err < 0 ? err : count;
1240 : }
1241 :
1242 : static const struct file_operations proc_oom_score_adj_operations = {
1243 : .read = oom_score_adj_read,
1244 : .write = oom_score_adj_write,
1245 : .llseek = default_llseek,
1246 : };
1247 :
1248 : #ifdef CONFIG_AUDIT
1249 : #define TMPBUFLEN 11
1250 : static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1251 : size_t count, loff_t *ppos)
1252 : {
1253 : struct inode * inode = file_inode(file);
1254 : struct task_struct *task = get_proc_task(inode);
1255 : ssize_t length;
1256 : char tmpbuf[TMPBUFLEN];
1257 :
1258 : if (!task)
1259 : return -ESRCH;
1260 : length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1261 : from_kuid(file->f_cred->user_ns,
1262 : audit_get_loginuid(task)));
1263 : put_task_struct(task);
1264 : return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1265 : }
1266 :
1267 : static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1268 : size_t count, loff_t *ppos)
1269 : {
1270 : struct inode * inode = file_inode(file);
1271 : uid_t loginuid;
1272 : kuid_t kloginuid;
1273 : int rv;
1274 :
1275 : /* Don't let kthreads write their own loginuid */
1276 : if (current->flags & PF_KTHREAD)
1277 : return -EPERM;
1278 :
1279 : rcu_read_lock();
1280 : if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1281 : rcu_read_unlock();
1282 : return -EPERM;
1283 : }
1284 : rcu_read_unlock();
1285 :
1286 : if (*ppos != 0) {
1287 : /* No partial writes. */
1288 : return -EINVAL;
1289 : }
1290 :
1291 : rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1292 : if (rv < 0)
1293 : return rv;
1294 :
1295 : /* is userspace tring to explicitly UNSET the loginuid? */
1296 : if (loginuid == AUDIT_UID_UNSET) {
1297 : kloginuid = INVALID_UID;
1298 : } else {
1299 : kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1300 : if (!uid_valid(kloginuid))
1301 : return -EINVAL;
1302 : }
1303 :
1304 : rv = audit_set_loginuid(kloginuid);
1305 : if (rv < 0)
1306 : return rv;
1307 : return count;
1308 : }
1309 :
1310 : static const struct file_operations proc_loginuid_operations = {
1311 : .read = proc_loginuid_read,
1312 : .write = proc_loginuid_write,
1313 : .llseek = generic_file_llseek,
1314 : };
1315 :
1316 : static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1317 : size_t count, loff_t *ppos)
1318 : {
1319 : struct inode * inode = file_inode(file);
1320 : struct task_struct *task = get_proc_task(inode);
1321 : ssize_t length;
1322 : char tmpbuf[TMPBUFLEN];
1323 :
1324 : if (!task)
1325 : return -ESRCH;
1326 : length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1327 : audit_get_sessionid(task));
1328 : put_task_struct(task);
1329 : return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1330 : }
1331 :
1332 : static const struct file_operations proc_sessionid_operations = {
1333 : .read = proc_sessionid_read,
1334 : .llseek = generic_file_llseek,
1335 : };
1336 : #endif
1337 :
1338 : #ifdef CONFIG_FAULT_INJECTION
1339 : static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1340 : size_t count, loff_t *ppos)
1341 : {
1342 : struct task_struct *task = get_proc_task(file_inode(file));
1343 : char buffer[PROC_NUMBUF];
1344 : size_t len;
1345 : int make_it_fail;
1346 :
1347 : if (!task)
1348 : return -ESRCH;
1349 : make_it_fail = task->make_it_fail;
1350 : put_task_struct(task);
1351 :
1352 : len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1353 :
1354 : return simple_read_from_buffer(buf, count, ppos, buffer, len);
1355 : }
1356 :
1357 : static ssize_t proc_fault_inject_write(struct file * file,
1358 : const char __user * buf, size_t count, loff_t *ppos)
1359 : {
1360 : struct task_struct *task;
1361 : char buffer[PROC_NUMBUF];
1362 : int make_it_fail;
1363 : int rv;
1364 :
1365 : if (!capable(CAP_SYS_RESOURCE))
1366 : return -EPERM;
1367 : memset(buffer, 0, sizeof(buffer));
1368 : if (count > sizeof(buffer) - 1)
1369 : count = sizeof(buffer) - 1;
1370 : if (copy_from_user(buffer, buf, count))
1371 : return -EFAULT;
1372 : rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1373 : if (rv < 0)
1374 : return rv;
1375 : if (make_it_fail < 0 || make_it_fail > 1)
1376 : return -EINVAL;
1377 :
1378 : task = get_proc_task(file_inode(file));
1379 : if (!task)
1380 : return -ESRCH;
1381 : task->make_it_fail = make_it_fail;
1382 : put_task_struct(task);
1383 :
1384 : return count;
1385 : }
1386 :
1387 : static const struct file_operations proc_fault_inject_operations = {
1388 : .read = proc_fault_inject_read,
1389 : .write = proc_fault_inject_write,
1390 : .llseek = generic_file_llseek,
1391 : };
1392 :
1393 : static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1394 : size_t count, loff_t *ppos)
1395 : {
1396 : struct task_struct *task;
1397 : int err;
1398 : unsigned int n;
1399 :
1400 : err = kstrtouint_from_user(buf, count, 0, &n);
1401 : if (err)
1402 : return err;
1403 :
1404 : task = get_proc_task(file_inode(file));
1405 : if (!task)
1406 : return -ESRCH;
1407 : task->fail_nth = n;
1408 : put_task_struct(task);
1409 :
1410 : return count;
1411 : }
1412 :
1413 : static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1414 : size_t count, loff_t *ppos)
1415 : {
1416 : struct task_struct *task;
1417 : char numbuf[PROC_NUMBUF];
1418 : ssize_t len;
1419 :
1420 : task = get_proc_task(file_inode(file));
1421 : if (!task)
1422 : return -ESRCH;
1423 : len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1424 : put_task_struct(task);
1425 : return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1426 : }
1427 :
1428 : static const struct file_operations proc_fail_nth_operations = {
1429 : .read = proc_fail_nth_read,
1430 : .write = proc_fail_nth_write,
1431 : };
1432 : #endif
1433 :
1434 :
1435 : #ifdef CONFIG_SCHED_DEBUG
1436 : /*
1437 : * Print out various scheduling related per-task fields:
1438 : */
1439 0 : static int sched_show(struct seq_file *m, void *v)
1440 : {
1441 0 : struct inode *inode = m->private;
1442 0 : struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
1443 : struct task_struct *p;
1444 :
1445 0 : p = get_proc_task(inode);
1446 0 : if (!p)
1447 : return -ESRCH;
1448 0 : proc_sched_show_task(p, ns, m);
1449 :
1450 0 : put_task_struct(p);
1451 :
1452 0 : return 0;
1453 : }
1454 :
1455 : static ssize_t
1456 0 : sched_write(struct file *file, const char __user *buf,
1457 : size_t count, loff_t *offset)
1458 : {
1459 0 : struct inode *inode = file_inode(file);
1460 : struct task_struct *p;
1461 :
1462 0 : p = get_proc_task(inode);
1463 0 : if (!p)
1464 : return -ESRCH;
1465 0 : proc_sched_set_task(p);
1466 :
1467 0 : put_task_struct(p);
1468 :
1469 0 : return count;
1470 : }
1471 :
1472 0 : static int sched_open(struct inode *inode, struct file *filp)
1473 : {
1474 0 : return single_open(filp, sched_show, inode);
1475 : }
1476 :
1477 : static const struct file_operations proc_pid_sched_operations = {
1478 : .open = sched_open,
1479 : .read = seq_read,
1480 : .write = sched_write,
1481 : .llseek = seq_lseek,
1482 : .release = single_release,
1483 : };
1484 :
1485 : #endif
1486 :
1487 : #ifdef CONFIG_SCHED_AUTOGROUP
1488 : /*
1489 : * Print out autogroup related information:
1490 : */
1491 : static int sched_autogroup_show(struct seq_file *m, void *v)
1492 : {
1493 : struct inode *inode = m->private;
1494 : struct task_struct *p;
1495 :
1496 : p = get_proc_task(inode);
1497 : if (!p)
1498 : return -ESRCH;
1499 : proc_sched_autogroup_show_task(p, m);
1500 :
1501 : put_task_struct(p);
1502 :
1503 : return 0;
1504 : }
1505 :
1506 : static ssize_t
1507 : sched_autogroup_write(struct file *file, const char __user *buf,
1508 : size_t count, loff_t *offset)
1509 : {
1510 : struct inode *inode = file_inode(file);
1511 : struct task_struct *p;
1512 : char buffer[PROC_NUMBUF];
1513 : int nice;
1514 : int err;
1515 :
1516 : memset(buffer, 0, sizeof(buffer));
1517 : if (count > sizeof(buffer) - 1)
1518 : count = sizeof(buffer) - 1;
1519 : if (copy_from_user(buffer, buf, count))
1520 : return -EFAULT;
1521 :
1522 : err = kstrtoint(strstrip(buffer), 0, &nice);
1523 : if (err < 0)
1524 : return err;
1525 :
1526 : p = get_proc_task(inode);
1527 : if (!p)
1528 : return -ESRCH;
1529 :
1530 : err = proc_sched_autogroup_set_nice(p, nice);
1531 : if (err)
1532 : count = err;
1533 :
1534 : put_task_struct(p);
1535 :
1536 : return count;
1537 : }
1538 :
1539 : static int sched_autogroup_open(struct inode *inode, struct file *filp)
1540 : {
1541 : int ret;
1542 :
1543 : ret = single_open(filp, sched_autogroup_show, NULL);
1544 : if (!ret) {
1545 : struct seq_file *m = filp->private_data;
1546 :
1547 : m->private = inode;
1548 : }
1549 : return ret;
1550 : }
1551 :
1552 : static const struct file_operations proc_pid_sched_autogroup_operations = {
1553 : .open = sched_autogroup_open,
1554 : .read = seq_read,
1555 : .write = sched_autogroup_write,
1556 : .llseek = seq_lseek,
1557 : .release = single_release,
1558 : };
1559 :
1560 : #endif /* CONFIG_SCHED_AUTOGROUP */
1561 :
1562 : #ifdef CONFIG_TIME_NS
1563 : static int timens_offsets_show(struct seq_file *m, void *v)
1564 : {
1565 : struct task_struct *p;
1566 :
1567 : p = get_proc_task(file_inode(m->file));
1568 : if (!p)
1569 : return -ESRCH;
1570 : proc_timens_show_offsets(p, m);
1571 :
1572 : put_task_struct(p);
1573 :
1574 : return 0;
1575 : }
1576 :
1577 : static ssize_t timens_offsets_write(struct file *file, const char __user *buf,
1578 : size_t count, loff_t *ppos)
1579 : {
1580 : struct inode *inode = file_inode(file);
1581 : struct proc_timens_offset offsets[2];
1582 : char *kbuf = NULL, *pos, *next_line;
1583 : struct task_struct *p;
1584 : int ret, noffsets;
1585 :
1586 : /* Only allow < page size writes at the beginning of the file */
1587 : if ((*ppos != 0) || (count >= PAGE_SIZE))
1588 : return -EINVAL;
1589 :
1590 : /* Slurp in the user data */
1591 : kbuf = memdup_user_nul(buf, count);
1592 : if (IS_ERR(kbuf))
1593 : return PTR_ERR(kbuf);
1594 :
1595 : /* Parse the user data */
1596 : ret = -EINVAL;
1597 : noffsets = 0;
1598 : for (pos = kbuf; pos; pos = next_line) {
1599 : struct proc_timens_offset *off = &offsets[noffsets];
1600 : char clock[10];
1601 : int err;
1602 :
1603 : /* Find the end of line and ensure we don't look past it */
1604 : next_line = strchr(pos, '\n');
1605 : if (next_line) {
1606 : *next_line = '\0';
1607 : next_line++;
1608 : if (*next_line == '\0')
1609 : next_line = NULL;
1610 : }
1611 :
1612 : err = sscanf(pos, "%9s %lld %lu", clock,
1613 : &off->val.tv_sec, &off->val.tv_nsec);
1614 : if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
1615 : goto out;
1616 :
1617 : clock[sizeof(clock) - 1] = 0;
1618 : if (strcmp(clock, "monotonic") == 0 ||
1619 : strcmp(clock, __stringify(CLOCK_MONOTONIC)) == 0)
1620 : off->clockid = CLOCK_MONOTONIC;
1621 : else if (strcmp(clock, "boottime") == 0 ||
1622 : strcmp(clock, __stringify(CLOCK_BOOTTIME)) == 0)
1623 : off->clockid = CLOCK_BOOTTIME;
1624 : else
1625 : goto out;
1626 :
1627 : noffsets++;
1628 : if (noffsets == ARRAY_SIZE(offsets)) {
1629 : if (next_line)
1630 : count = next_line - kbuf;
1631 : break;
1632 : }
1633 : }
1634 :
1635 : ret = -ESRCH;
1636 : p = get_proc_task(inode);
1637 : if (!p)
1638 : goto out;
1639 : ret = proc_timens_set_offset(file, p, offsets, noffsets);
1640 : put_task_struct(p);
1641 : if (ret)
1642 : goto out;
1643 :
1644 : ret = count;
1645 : out:
1646 : kfree(kbuf);
1647 : return ret;
1648 : }
1649 :
1650 : static int timens_offsets_open(struct inode *inode, struct file *filp)
1651 : {
1652 : return single_open(filp, timens_offsets_show, inode);
1653 : }
1654 :
1655 : static const struct file_operations proc_timens_offsets_operations = {
1656 : .open = timens_offsets_open,
1657 : .read = seq_read,
1658 : .write = timens_offsets_write,
1659 : .llseek = seq_lseek,
1660 : .release = single_release,
1661 : };
1662 : #endif /* CONFIG_TIME_NS */
1663 :
1664 0 : static ssize_t comm_write(struct file *file, const char __user *buf,
1665 : size_t count, loff_t *offset)
1666 : {
1667 0 : struct inode *inode = file_inode(file);
1668 : struct task_struct *p;
1669 : char buffer[TASK_COMM_LEN];
1670 0 : const size_t maxlen = sizeof(buffer) - 1;
1671 :
1672 0 : memset(buffer, 0, sizeof(buffer));
1673 0 : if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1674 : return -EFAULT;
1675 :
1676 0 : p = get_proc_task(inode);
1677 0 : if (!p)
1678 : return -ESRCH;
1679 :
1680 0 : if (same_thread_group(current, p)) {
1681 : set_task_comm(p, buffer);
1682 : proc_comm_connector(p);
1683 : }
1684 : else
1685 : count = -EINVAL;
1686 :
1687 0 : put_task_struct(p);
1688 :
1689 0 : return count;
1690 : }
1691 :
1692 0 : static int comm_show(struct seq_file *m, void *v)
1693 : {
1694 0 : struct inode *inode = m->private;
1695 : struct task_struct *p;
1696 :
1697 0 : p = get_proc_task(inode);
1698 0 : if (!p)
1699 : return -ESRCH;
1700 :
1701 0 : proc_task_name(m, p, false);
1702 0 : seq_putc(m, '\n');
1703 :
1704 0 : put_task_struct(p);
1705 :
1706 0 : return 0;
1707 : }
1708 :
1709 0 : static int comm_open(struct inode *inode, struct file *filp)
1710 : {
1711 0 : return single_open(filp, comm_show, inode);
1712 : }
1713 :
1714 : static const struct file_operations proc_pid_set_comm_operations = {
1715 : .open = comm_open,
1716 : .read = seq_read,
1717 : .write = comm_write,
1718 : .llseek = seq_lseek,
1719 : .release = single_release,
1720 : };
1721 :
1722 0 : static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1723 : {
1724 : struct task_struct *task;
1725 : struct file *exe_file;
1726 :
1727 0 : task = get_proc_task(d_inode(dentry));
1728 0 : if (!task)
1729 : return -ENOENT;
1730 0 : exe_file = get_task_exe_file(task);
1731 0 : put_task_struct(task);
1732 0 : if (exe_file) {
1733 0 : *exe_path = exe_file->f_path;
1734 0 : path_get(&exe_file->f_path);
1735 0 : fput(exe_file);
1736 0 : return 0;
1737 : } else
1738 : return -ENOENT;
1739 : }
1740 :
1741 0 : static const char *proc_pid_get_link(struct dentry *dentry,
1742 : struct inode *inode,
1743 : struct delayed_call *done)
1744 : {
1745 : struct path path;
1746 0 : int error = -EACCES;
1747 :
1748 0 : if (!dentry)
1749 : return ERR_PTR(-ECHILD);
1750 :
1751 : /* Are we allowed to snoop on the tasks file descriptors? */
1752 0 : if (!proc_fd_access_allowed(inode))
1753 : goto out;
1754 :
1755 0 : error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1756 0 : if (error)
1757 : goto out;
1758 :
1759 0 : error = nd_jump_link(&path);
1760 : out:
1761 0 : return ERR_PTR(error);
1762 : }
1763 :
1764 0 : static int do_proc_readlink(const struct path *path, char __user *buffer, int buflen)
1765 : {
1766 0 : char *tmp = kmalloc(PATH_MAX, GFP_KERNEL);
1767 : char *pathname;
1768 : int len;
1769 :
1770 0 : if (!tmp)
1771 : return -ENOMEM;
1772 :
1773 0 : pathname = d_path(path, tmp, PATH_MAX);
1774 0 : len = PTR_ERR(pathname);
1775 0 : if (IS_ERR(pathname))
1776 : goto out;
1777 0 : len = tmp + PATH_MAX - 1 - pathname;
1778 :
1779 0 : if (len > buflen)
1780 0 : len = buflen;
1781 0 : if (copy_to_user(buffer, pathname, len))
1782 0 : len = -EFAULT;
1783 : out:
1784 0 : kfree(tmp);
1785 0 : return len;
1786 : }
1787 :
1788 0 : static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1789 : {
1790 0 : int error = -EACCES;
1791 0 : struct inode *inode = d_inode(dentry);
1792 : struct path path;
1793 :
1794 : /* Are we allowed to snoop on the tasks file descriptors? */
1795 0 : if (!proc_fd_access_allowed(inode))
1796 : goto out;
1797 :
1798 0 : error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1799 0 : if (error)
1800 : goto out;
1801 :
1802 0 : error = do_proc_readlink(&path, buffer, buflen);
1803 0 : path_put(&path);
1804 : out:
1805 0 : return error;
1806 : }
1807 :
1808 : const struct inode_operations proc_pid_link_inode_operations = {
1809 : .readlink = proc_pid_readlink,
1810 : .get_link = proc_pid_get_link,
1811 : .setattr = proc_setattr,
1812 : };
1813 :
1814 :
1815 : /* building an inode */
1816 :
1817 0 : void task_dump_owner(struct task_struct *task, umode_t mode,
1818 : kuid_t *ruid, kgid_t *rgid)
1819 : {
1820 : /* Depending on the state of dumpable compute who should own a
1821 : * proc file for a task.
1822 : */
1823 : const struct cred *cred;
1824 : kuid_t uid;
1825 : kgid_t gid;
1826 :
1827 0 : if (unlikely(task->flags & PF_KTHREAD)) {
1828 0 : *ruid = GLOBAL_ROOT_UID;
1829 0 : *rgid = GLOBAL_ROOT_GID;
1830 0 : return;
1831 : }
1832 :
1833 : /* Default to the tasks effective ownership */
1834 : rcu_read_lock();
1835 0 : cred = __task_cred(task);
1836 0 : uid = cred->euid;
1837 0 : gid = cred->egid;
1838 : rcu_read_unlock();
1839 :
1840 : /*
1841 : * Before the /proc/pid/status file was created the only way to read
1842 : * the effective uid of a /process was to stat /proc/pid. Reading
1843 : * /proc/pid/status is slow enough that procps and other packages
1844 : * kept stating /proc/pid. To keep the rules in /proc simple I have
1845 : * made this apply to all per process world readable and executable
1846 : * directories.
1847 : */
1848 0 : if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1849 : struct mm_struct *mm;
1850 0 : task_lock(task);
1851 0 : mm = task->mm;
1852 : /* Make non-dumpable tasks owned by some root */
1853 0 : if (mm) {
1854 0 : if (get_dumpable(mm) != SUID_DUMP_USER) {
1855 0 : struct user_namespace *user_ns = mm->user_ns;
1856 :
1857 0 : uid = make_kuid(user_ns, 0);
1858 0 : if (!uid_valid(uid))
1859 : uid = GLOBAL_ROOT_UID;
1860 :
1861 0 : gid = make_kgid(user_ns, 0);
1862 0 : if (!gid_valid(gid))
1863 : gid = GLOBAL_ROOT_GID;
1864 : }
1865 : } else {
1866 : uid = GLOBAL_ROOT_UID;
1867 : gid = GLOBAL_ROOT_GID;
1868 : }
1869 0 : task_unlock(task);
1870 : }
1871 0 : *ruid = uid;
1872 0 : *rgid = gid;
1873 : }
1874 :
1875 0 : void proc_pid_evict_inode(struct proc_inode *ei)
1876 : {
1877 0 : struct pid *pid = ei->pid;
1878 :
1879 0 : if (S_ISDIR(ei->vfs_inode.i_mode)) {
1880 0 : spin_lock(&pid->lock);
1881 0 : hlist_del_init_rcu(&ei->sibling_inodes);
1882 0 : spin_unlock(&pid->lock);
1883 : }
1884 :
1885 0 : put_pid(pid);
1886 0 : }
1887 :
1888 0 : struct inode *proc_pid_make_inode(struct super_block *sb,
1889 : struct task_struct *task, umode_t mode)
1890 : {
1891 : struct inode * inode;
1892 : struct proc_inode *ei;
1893 : struct pid *pid;
1894 :
1895 : /* We need a new inode */
1896 :
1897 0 : inode = new_inode(sb);
1898 0 : if (!inode)
1899 : goto out;
1900 :
1901 : /* Common stuff */
1902 0 : ei = PROC_I(inode);
1903 0 : inode->i_mode = mode;
1904 0 : inode->i_ino = get_next_ino();
1905 0 : inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1906 0 : inode->i_op = &proc_def_inode_operations;
1907 :
1908 : /*
1909 : * grab the reference to task.
1910 : */
1911 0 : pid = get_task_pid(task, PIDTYPE_PID);
1912 0 : if (!pid)
1913 : goto out_unlock;
1914 :
1915 : /* Let the pid remember us for quick removal */
1916 0 : ei->pid = pid;
1917 :
1918 0 : task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1919 : security_task_to_inode(task, inode);
1920 :
1921 : out:
1922 : return inode;
1923 :
1924 : out_unlock:
1925 0 : iput(inode);
1926 0 : return NULL;
1927 : }
1928 :
1929 : /*
1930 : * Generating an inode and adding it into @pid->inodes, so that task will
1931 : * invalidate inode's dentry before being released.
1932 : *
1933 : * This helper is used for creating dir-type entries under '/proc' and
1934 : * '/proc/<tgid>/task'. Other entries(eg. fd, stat) under '/proc/<tgid>'
1935 : * can be released by invalidating '/proc/<tgid>' dentry.
1936 : * In theory, dentries under '/proc/<tgid>/task' can also be released by
1937 : * invalidating '/proc/<tgid>' dentry, we reserve it to handle single
1938 : * thread exiting situation: Any one of threads should invalidate its
1939 : * '/proc/<tgid>/task/<pid>' dentry before released.
1940 : */
1941 0 : static struct inode *proc_pid_make_base_inode(struct super_block *sb,
1942 : struct task_struct *task, umode_t mode)
1943 : {
1944 : struct inode *inode;
1945 : struct proc_inode *ei;
1946 : struct pid *pid;
1947 :
1948 0 : inode = proc_pid_make_inode(sb, task, mode);
1949 0 : if (!inode)
1950 : return NULL;
1951 :
1952 : /* Let proc_flush_pid find this directory inode */
1953 0 : ei = PROC_I(inode);
1954 0 : pid = ei->pid;
1955 0 : spin_lock(&pid->lock);
1956 0 : hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
1957 0 : spin_unlock(&pid->lock);
1958 :
1959 0 : return inode;
1960 : }
1961 :
1962 0 : int pid_getattr(struct mnt_idmap *idmap, const struct path *path,
1963 : struct kstat *stat, u32 request_mask, unsigned int query_flags)
1964 : {
1965 0 : struct inode *inode = d_inode(path->dentry);
1966 0 : struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
1967 : struct task_struct *task;
1968 :
1969 0 : generic_fillattr(&nop_mnt_idmap, inode, stat);
1970 :
1971 0 : stat->uid = GLOBAL_ROOT_UID;
1972 0 : stat->gid = GLOBAL_ROOT_GID;
1973 : rcu_read_lock();
1974 0 : task = pid_task(proc_pid(inode), PIDTYPE_PID);
1975 0 : if (task) {
1976 0 : if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) {
1977 : rcu_read_unlock();
1978 : /*
1979 : * This doesn't prevent learning whether PID exists,
1980 : * it only makes getattr() consistent with readdir().
1981 : */
1982 0 : return -ENOENT;
1983 : }
1984 0 : task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1985 : }
1986 : rcu_read_unlock();
1987 0 : return 0;
1988 : }
1989 :
1990 : /* dentry stuff */
1991 :
1992 : /*
1993 : * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1994 : */
1995 0 : void pid_update_inode(struct task_struct *task, struct inode *inode)
1996 : {
1997 0 : task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1998 :
1999 0 : inode->i_mode &= ~(S_ISUID | S_ISGID);
2000 0 : security_task_to_inode(task, inode);
2001 0 : }
2002 :
2003 : /*
2004 : * Rewrite the inode's ownerships here because the owning task may have
2005 : * performed a setuid(), etc.
2006 : *
2007 : */
2008 0 : static int pid_revalidate(struct dentry *dentry, unsigned int flags)
2009 : {
2010 : struct inode *inode;
2011 : struct task_struct *task;
2012 0 : int ret = 0;
2013 :
2014 : rcu_read_lock();
2015 0 : inode = d_inode_rcu(dentry);
2016 0 : if (!inode)
2017 : goto out;
2018 0 : task = pid_task(proc_pid(inode), PIDTYPE_PID);
2019 :
2020 0 : if (task) {
2021 0 : pid_update_inode(task, inode);
2022 0 : ret = 1;
2023 : }
2024 : out:
2025 : rcu_read_unlock();
2026 0 : return ret;
2027 : }
2028 :
2029 : static inline bool proc_inode_is_dead(struct inode *inode)
2030 : {
2031 0 : return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
2032 : }
2033 :
2034 0 : int pid_delete_dentry(const struct dentry *dentry)
2035 : {
2036 : /* Is the task we represent dead?
2037 : * If so, then don't put the dentry on the lru list,
2038 : * kill it immediately.
2039 : */
2040 0 : return proc_inode_is_dead(d_inode(dentry));
2041 : }
2042 :
2043 : const struct dentry_operations pid_dentry_operations =
2044 : {
2045 : .d_revalidate = pid_revalidate,
2046 : .d_delete = pid_delete_dentry,
2047 : };
2048 :
2049 : /* Lookups */
2050 :
2051 : /*
2052 : * Fill a directory entry.
2053 : *
2054 : * If possible create the dcache entry and derive our inode number and
2055 : * file type from dcache entry.
2056 : *
2057 : * Since all of the proc inode numbers are dynamically generated, the inode
2058 : * numbers do not exist until the inode is cache. This means creating
2059 : * the dcache entry in readdir is necessary to keep the inode numbers
2060 : * reported by readdir in sync with the inode numbers reported
2061 : * by stat.
2062 : */
2063 0 : bool proc_fill_cache(struct file *file, struct dir_context *ctx,
2064 : const char *name, unsigned int len,
2065 : instantiate_t instantiate, struct task_struct *task, const void *ptr)
2066 : {
2067 0 : struct dentry *child, *dir = file->f_path.dentry;
2068 0 : struct qstr qname = QSTR_INIT(name, len);
2069 : struct inode *inode;
2070 0 : unsigned type = DT_UNKNOWN;
2071 0 : ino_t ino = 1;
2072 :
2073 0 : child = d_hash_and_lookup(dir, &qname);
2074 0 : if (!child) {
2075 0 : DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
2076 0 : child = d_alloc_parallel(dir, &qname, &wq);
2077 0 : if (IS_ERR(child))
2078 : goto end_instantiate;
2079 0 : if (d_in_lookup(child)) {
2080 : struct dentry *res;
2081 0 : res = instantiate(child, task, ptr);
2082 0 : d_lookup_done(child);
2083 0 : if (unlikely(res)) {
2084 0 : dput(child);
2085 0 : child = res;
2086 0 : if (IS_ERR(child))
2087 : goto end_instantiate;
2088 : }
2089 : }
2090 : }
2091 0 : inode = d_inode(child);
2092 0 : ino = inode->i_ino;
2093 0 : type = inode->i_mode >> 12;
2094 0 : dput(child);
2095 : end_instantiate:
2096 0 : return dir_emit(ctx, name, len, ino, type);
2097 : }
2098 :
2099 : /*
2100 : * dname_to_vma_addr - maps a dentry name into two unsigned longs
2101 : * which represent vma start and end addresses.
2102 : */
2103 0 : static int dname_to_vma_addr(struct dentry *dentry,
2104 : unsigned long *start, unsigned long *end)
2105 : {
2106 0 : const char *str = dentry->d_name.name;
2107 : unsigned long long sval, eval;
2108 : unsigned int len;
2109 :
2110 0 : if (str[0] == '0' && str[1] != '-')
2111 : return -EINVAL;
2112 0 : len = _parse_integer(str, 16, &sval);
2113 0 : if (len & KSTRTOX_OVERFLOW)
2114 : return -EINVAL;
2115 : if (sval != (unsigned long)sval)
2116 : return -EINVAL;
2117 0 : str += len;
2118 :
2119 0 : if (*str != '-')
2120 : return -EINVAL;
2121 0 : str++;
2122 :
2123 0 : if (str[0] == '0' && str[1])
2124 : return -EINVAL;
2125 0 : len = _parse_integer(str, 16, &eval);
2126 0 : if (len & KSTRTOX_OVERFLOW)
2127 : return -EINVAL;
2128 : if (eval != (unsigned long)eval)
2129 : return -EINVAL;
2130 0 : str += len;
2131 :
2132 0 : if (*str != '\0')
2133 : return -EINVAL;
2134 :
2135 0 : *start = sval;
2136 0 : *end = eval;
2137 :
2138 : return 0;
2139 : }
2140 :
2141 0 : static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
2142 : {
2143 : unsigned long vm_start, vm_end;
2144 0 : bool exact_vma_exists = false;
2145 0 : struct mm_struct *mm = NULL;
2146 : struct task_struct *task;
2147 : struct inode *inode;
2148 0 : int status = 0;
2149 :
2150 0 : if (flags & LOOKUP_RCU)
2151 : return -ECHILD;
2152 :
2153 0 : inode = d_inode(dentry);
2154 0 : task = get_proc_task(inode);
2155 0 : if (!task)
2156 : goto out_notask;
2157 :
2158 0 : mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2159 0 : if (IS_ERR_OR_NULL(mm))
2160 : goto out;
2161 :
2162 0 : if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2163 0 : status = mmap_read_lock_killable(mm);
2164 0 : if (!status) {
2165 0 : exact_vma_exists = !!find_exact_vma(mm, vm_start,
2166 : vm_end);
2167 : mmap_read_unlock(mm);
2168 : }
2169 : }
2170 :
2171 0 : mmput(mm);
2172 :
2173 0 : if (exact_vma_exists) {
2174 0 : task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
2175 :
2176 : security_task_to_inode(task, inode);
2177 : status = 1;
2178 : }
2179 :
2180 : out:
2181 0 : put_task_struct(task);
2182 :
2183 : out_notask:
2184 : return status;
2185 : }
2186 :
2187 : static const struct dentry_operations tid_map_files_dentry_operations = {
2188 : .d_revalidate = map_files_d_revalidate,
2189 : .d_delete = pid_delete_dentry,
2190 : };
2191 :
2192 0 : static int map_files_get_link(struct dentry *dentry, struct path *path)
2193 : {
2194 : unsigned long vm_start, vm_end;
2195 : struct vm_area_struct *vma;
2196 : struct task_struct *task;
2197 : struct mm_struct *mm;
2198 : int rc;
2199 :
2200 0 : rc = -ENOENT;
2201 0 : task = get_proc_task(d_inode(dentry));
2202 0 : if (!task)
2203 : goto out;
2204 :
2205 0 : mm = get_task_mm(task);
2206 0 : put_task_struct(task);
2207 0 : if (!mm)
2208 : goto out;
2209 :
2210 0 : rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2211 0 : if (rc)
2212 : goto out_mmput;
2213 :
2214 0 : rc = mmap_read_lock_killable(mm);
2215 0 : if (rc)
2216 : goto out_mmput;
2217 :
2218 0 : rc = -ENOENT;
2219 0 : vma = find_exact_vma(mm, vm_start, vm_end);
2220 0 : if (vma && vma->vm_file) {
2221 0 : *path = vma->vm_file->f_path;
2222 0 : path_get(path);
2223 0 : rc = 0;
2224 : }
2225 : mmap_read_unlock(mm);
2226 :
2227 : out_mmput:
2228 0 : mmput(mm);
2229 : out:
2230 0 : return rc;
2231 : }
2232 :
2233 : struct map_files_info {
2234 : unsigned long start;
2235 : unsigned long end;
2236 : fmode_t mode;
2237 : };
2238 :
2239 : /*
2240 : * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
2241 : * to concerns about how the symlinks may be used to bypass permissions on
2242 : * ancestor directories in the path to the file in question.
2243 : */
2244 : static const char *
2245 0 : proc_map_files_get_link(struct dentry *dentry,
2246 : struct inode *inode,
2247 : struct delayed_call *done)
2248 : {
2249 0 : if (!checkpoint_restore_ns_capable(&init_user_ns))
2250 : return ERR_PTR(-EPERM);
2251 :
2252 0 : return proc_pid_get_link(dentry, inode, done);
2253 : }
2254 :
2255 : /*
2256 : * Identical to proc_pid_link_inode_operations except for get_link()
2257 : */
2258 : static const struct inode_operations proc_map_files_link_inode_operations = {
2259 : .readlink = proc_pid_readlink,
2260 : .get_link = proc_map_files_get_link,
2261 : .setattr = proc_setattr,
2262 : };
2263 :
2264 : static struct dentry *
2265 0 : proc_map_files_instantiate(struct dentry *dentry,
2266 : struct task_struct *task, const void *ptr)
2267 : {
2268 0 : fmode_t mode = (fmode_t)(unsigned long)ptr;
2269 : struct proc_inode *ei;
2270 : struct inode *inode;
2271 :
2272 0 : inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2273 0 : ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2274 0 : ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2275 0 : if (!inode)
2276 : return ERR_PTR(-ENOENT);
2277 :
2278 0 : ei = PROC_I(inode);
2279 0 : ei->op.proc_get_link = map_files_get_link;
2280 :
2281 0 : inode->i_op = &proc_map_files_link_inode_operations;
2282 0 : inode->i_size = 64;
2283 :
2284 0 : d_set_d_op(dentry, &tid_map_files_dentry_operations);
2285 0 : return d_splice_alias(inode, dentry);
2286 : }
2287 :
2288 0 : static struct dentry *proc_map_files_lookup(struct inode *dir,
2289 : struct dentry *dentry, unsigned int flags)
2290 : {
2291 : unsigned long vm_start, vm_end;
2292 : struct vm_area_struct *vma;
2293 : struct task_struct *task;
2294 : struct dentry *result;
2295 : struct mm_struct *mm;
2296 :
2297 0 : result = ERR_PTR(-ENOENT);
2298 0 : task = get_proc_task(dir);
2299 0 : if (!task)
2300 : goto out;
2301 :
2302 0 : result = ERR_PTR(-EACCES);
2303 0 : if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2304 : goto out_put_task;
2305 :
2306 0 : result = ERR_PTR(-ENOENT);
2307 0 : if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2308 : goto out_put_task;
2309 :
2310 0 : mm = get_task_mm(task);
2311 0 : if (!mm)
2312 : goto out_put_task;
2313 :
2314 0 : result = ERR_PTR(-EINTR);
2315 0 : if (mmap_read_lock_killable(mm))
2316 : goto out_put_mm;
2317 :
2318 0 : result = ERR_PTR(-ENOENT);
2319 0 : vma = find_exact_vma(mm, vm_start, vm_end);
2320 0 : if (!vma)
2321 : goto out_no_vma;
2322 :
2323 0 : if (vma->vm_file)
2324 0 : result = proc_map_files_instantiate(dentry, task,
2325 0 : (void *)(unsigned long)vma->vm_file->f_mode);
2326 :
2327 : out_no_vma:
2328 : mmap_read_unlock(mm);
2329 : out_put_mm:
2330 0 : mmput(mm);
2331 : out_put_task:
2332 0 : put_task_struct(task);
2333 : out:
2334 0 : return result;
2335 : }
2336 :
2337 : static const struct inode_operations proc_map_files_inode_operations = {
2338 : .lookup = proc_map_files_lookup,
2339 : .permission = proc_fd_permission,
2340 : .setattr = proc_setattr,
2341 : };
2342 :
2343 : static int
2344 0 : proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2345 : {
2346 : struct vm_area_struct *vma;
2347 : struct task_struct *task;
2348 : struct mm_struct *mm;
2349 : unsigned long nr_files, pos, i;
2350 : GENRADIX(struct map_files_info) fa;
2351 : struct map_files_info *p;
2352 : int ret;
2353 : struct vma_iterator vmi;
2354 :
2355 0 : genradix_init(&fa);
2356 :
2357 0 : ret = -ENOENT;
2358 0 : task = get_proc_task(file_inode(file));
2359 0 : if (!task)
2360 : goto out;
2361 :
2362 0 : ret = -EACCES;
2363 0 : if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2364 : goto out_put_task;
2365 :
2366 0 : ret = 0;
2367 0 : if (!dir_emit_dots(file, ctx))
2368 : goto out_put_task;
2369 :
2370 0 : mm = get_task_mm(task);
2371 0 : if (!mm)
2372 : goto out_put_task;
2373 :
2374 0 : ret = mmap_read_lock_killable(mm);
2375 0 : if (ret) {
2376 0 : mmput(mm);
2377 0 : goto out_put_task;
2378 : }
2379 :
2380 0 : nr_files = 0;
2381 :
2382 : /*
2383 : * We need two passes here:
2384 : *
2385 : * 1) Collect vmas of mapped files with mmap_lock taken
2386 : * 2) Release mmap_lock and instantiate entries
2387 : *
2388 : * otherwise we get lockdep complained, since filldir()
2389 : * routine might require mmap_lock taken in might_fault().
2390 : */
2391 :
2392 0 : pos = 2;
2393 : vma_iter_init(&vmi, mm, 0);
2394 0 : for_each_vma(vmi, vma) {
2395 0 : if (!vma->vm_file)
2396 0 : continue;
2397 0 : if (++pos <= ctx->pos)
2398 0 : continue;
2399 :
2400 0 : p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2401 0 : if (!p) {
2402 0 : ret = -ENOMEM;
2403 0 : mmap_read_unlock(mm);
2404 0 : mmput(mm);
2405 0 : goto out_put_task;
2406 : }
2407 :
2408 0 : p->start = vma->vm_start;
2409 0 : p->end = vma->vm_end;
2410 0 : p->mode = vma->vm_file->f_mode;
2411 : }
2412 0 : mmap_read_unlock(mm);
2413 0 : mmput(mm);
2414 :
2415 0 : for (i = 0; i < nr_files; i++) {
2416 : char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2417 : unsigned int len;
2418 :
2419 0 : p = genradix_ptr(&fa, i);
2420 0 : len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2421 0 : if (!proc_fill_cache(file, ctx,
2422 : buf, len,
2423 : proc_map_files_instantiate,
2424 : task,
2425 0 : (void *)(unsigned long)p->mode))
2426 : break;
2427 0 : ctx->pos++;
2428 : }
2429 :
2430 : out_put_task:
2431 0 : put_task_struct(task);
2432 : out:
2433 0 : genradix_free(&fa);
2434 0 : return ret;
2435 : }
2436 :
2437 : static const struct file_operations proc_map_files_operations = {
2438 : .read = generic_read_dir,
2439 : .iterate_shared = proc_map_files_readdir,
2440 : .llseek = generic_file_llseek,
2441 : };
2442 :
2443 : #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2444 : struct timers_private {
2445 : struct pid *pid;
2446 : struct task_struct *task;
2447 : struct sighand_struct *sighand;
2448 : struct pid_namespace *ns;
2449 : unsigned long flags;
2450 : };
2451 :
2452 : static void *timers_start(struct seq_file *m, loff_t *pos)
2453 : {
2454 : struct timers_private *tp = m->private;
2455 :
2456 : tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2457 : if (!tp->task)
2458 : return ERR_PTR(-ESRCH);
2459 :
2460 : tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2461 : if (!tp->sighand)
2462 : return ERR_PTR(-ESRCH);
2463 :
2464 : return seq_list_start(&tp->task->signal->posix_timers, *pos);
2465 : }
2466 :
2467 : static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2468 : {
2469 : struct timers_private *tp = m->private;
2470 : return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2471 : }
2472 :
2473 : static void timers_stop(struct seq_file *m, void *v)
2474 : {
2475 : struct timers_private *tp = m->private;
2476 :
2477 : if (tp->sighand) {
2478 : unlock_task_sighand(tp->task, &tp->flags);
2479 : tp->sighand = NULL;
2480 : }
2481 :
2482 : if (tp->task) {
2483 : put_task_struct(tp->task);
2484 : tp->task = NULL;
2485 : }
2486 : }
2487 :
2488 : static int show_timer(struct seq_file *m, void *v)
2489 : {
2490 : struct k_itimer *timer;
2491 : struct timers_private *tp = m->private;
2492 : int notify;
2493 : static const char * const nstr[] = {
2494 : [SIGEV_SIGNAL] = "signal",
2495 : [SIGEV_NONE] = "none",
2496 : [SIGEV_THREAD] = "thread",
2497 : };
2498 :
2499 : timer = list_entry((struct list_head *)v, struct k_itimer, list);
2500 : notify = timer->it_sigev_notify;
2501 :
2502 : seq_printf(m, "ID: %d\n", timer->it_id);
2503 : seq_printf(m, "signal: %d/%px\n",
2504 : timer->sigq->info.si_signo,
2505 : timer->sigq->info.si_value.sival_ptr);
2506 : seq_printf(m, "notify: %s/%s.%d\n",
2507 : nstr[notify & ~SIGEV_THREAD_ID],
2508 : (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2509 : pid_nr_ns(timer->it_pid, tp->ns));
2510 : seq_printf(m, "ClockID: %d\n", timer->it_clock);
2511 :
2512 : return 0;
2513 : }
2514 :
2515 : static const struct seq_operations proc_timers_seq_ops = {
2516 : .start = timers_start,
2517 : .next = timers_next,
2518 : .stop = timers_stop,
2519 : .show = show_timer,
2520 : };
2521 :
2522 : static int proc_timers_open(struct inode *inode, struct file *file)
2523 : {
2524 : struct timers_private *tp;
2525 :
2526 : tp = __seq_open_private(file, &proc_timers_seq_ops,
2527 : sizeof(struct timers_private));
2528 : if (!tp)
2529 : return -ENOMEM;
2530 :
2531 : tp->pid = proc_pid(inode);
2532 : tp->ns = proc_pid_ns(inode->i_sb);
2533 : return 0;
2534 : }
2535 :
2536 : static const struct file_operations proc_timers_operations = {
2537 : .open = proc_timers_open,
2538 : .read = seq_read,
2539 : .llseek = seq_lseek,
2540 : .release = seq_release_private,
2541 : };
2542 : #endif
2543 :
2544 0 : static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2545 : size_t count, loff_t *offset)
2546 : {
2547 0 : struct inode *inode = file_inode(file);
2548 : struct task_struct *p;
2549 : u64 slack_ns;
2550 : int err;
2551 :
2552 0 : err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2553 0 : if (err < 0)
2554 0 : return err;
2555 :
2556 0 : p = get_proc_task(inode);
2557 0 : if (!p)
2558 : return -ESRCH;
2559 :
2560 0 : if (p != current) {
2561 : rcu_read_lock();
2562 0 : if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2563 : rcu_read_unlock();
2564 0 : count = -EPERM;
2565 0 : goto out;
2566 : }
2567 0 : rcu_read_unlock();
2568 :
2569 0 : err = security_task_setscheduler(p);
2570 0 : if (err) {
2571 0 : count = err;
2572 0 : goto out;
2573 : }
2574 : }
2575 :
2576 : task_lock(p);
2577 0 : if (slack_ns == 0)
2578 0 : p->timer_slack_ns = p->default_timer_slack_ns;
2579 : else
2580 0 : p->timer_slack_ns = slack_ns;
2581 : task_unlock(p);
2582 :
2583 : out:
2584 0 : put_task_struct(p);
2585 :
2586 0 : return count;
2587 : }
2588 :
2589 0 : static int timerslack_ns_show(struct seq_file *m, void *v)
2590 : {
2591 0 : struct inode *inode = m->private;
2592 : struct task_struct *p;
2593 0 : int err = 0;
2594 :
2595 0 : p = get_proc_task(inode);
2596 0 : if (!p)
2597 : return -ESRCH;
2598 :
2599 0 : if (p != current) {
2600 : rcu_read_lock();
2601 0 : if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2602 : rcu_read_unlock();
2603 0 : err = -EPERM;
2604 0 : goto out;
2605 : }
2606 : rcu_read_unlock();
2607 :
2608 0 : err = security_task_getscheduler(p);
2609 : if (err)
2610 : goto out;
2611 : }
2612 :
2613 : task_lock(p);
2614 0 : seq_printf(m, "%llu\n", p->timer_slack_ns);
2615 : task_unlock(p);
2616 :
2617 : out:
2618 0 : put_task_struct(p);
2619 :
2620 0 : return err;
2621 : }
2622 :
2623 0 : static int timerslack_ns_open(struct inode *inode, struct file *filp)
2624 : {
2625 0 : return single_open(filp, timerslack_ns_show, inode);
2626 : }
2627 :
2628 : static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2629 : .open = timerslack_ns_open,
2630 : .read = seq_read,
2631 : .write = timerslack_ns_write,
2632 : .llseek = seq_lseek,
2633 : .release = single_release,
2634 : };
2635 :
2636 0 : static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2637 : struct task_struct *task, const void *ptr)
2638 : {
2639 0 : const struct pid_entry *p = ptr;
2640 : struct inode *inode;
2641 : struct proc_inode *ei;
2642 :
2643 0 : inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2644 0 : if (!inode)
2645 : return ERR_PTR(-ENOENT);
2646 :
2647 0 : ei = PROC_I(inode);
2648 0 : if (S_ISDIR(inode->i_mode))
2649 0 : set_nlink(inode, 2); /* Use getattr to fix if necessary */
2650 0 : if (p->iop)
2651 0 : inode->i_op = p->iop;
2652 0 : if (p->fop)
2653 0 : inode->i_fop = p->fop;
2654 0 : ei->op = p->op;
2655 0 : pid_update_inode(task, inode);
2656 0 : d_set_d_op(dentry, &pid_dentry_operations);
2657 0 : return d_splice_alias(inode, dentry);
2658 : }
2659 :
2660 0 : static struct dentry *proc_pident_lookup(struct inode *dir,
2661 : struct dentry *dentry,
2662 : const struct pid_entry *p,
2663 : const struct pid_entry *end)
2664 : {
2665 0 : struct task_struct *task = get_proc_task(dir);
2666 0 : struct dentry *res = ERR_PTR(-ENOENT);
2667 :
2668 0 : if (!task)
2669 : goto out_no_task;
2670 :
2671 : /*
2672 : * Yes, it does not scale. And it should not. Don't add
2673 : * new entries into /proc/<tgid>/ without very good reasons.
2674 : */
2675 0 : for (; p < end; p++) {
2676 0 : if (p->len != dentry->d_name.len)
2677 0 : continue;
2678 0 : if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2679 0 : res = proc_pident_instantiate(dentry, task, p);
2680 0 : break;
2681 : }
2682 : }
2683 0 : put_task_struct(task);
2684 : out_no_task:
2685 0 : return res;
2686 : }
2687 :
2688 0 : static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2689 : const struct pid_entry *ents, unsigned int nents)
2690 : {
2691 0 : struct task_struct *task = get_proc_task(file_inode(file));
2692 : const struct pid_entry *p;
2693 :
2694 0 : if (!task)
2695 : return -ENOENT;
2696 :
2697 0 : if (!dir_emit_dots(file, ctx))
2698 : goto out;
2699 :
2700 0 : if (ctx->pos >= nents + 2)
2701 : goto out;
2702 :
2703 0 : for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2704 0 : if (!proc_fill_cache(file, ctx, p->name, p->len,
2705 : proc_pident_instantiate, task, p))
2706 : break;
2707 0 : ctx->pos++;
2708 : }
2709 : out:
2710 0 : put_task_struct(task);
2711 0 : return 0;
2712 : }
2713 :
2714 : #ifdef CONFIG_SECURITY
2715 : static int proc_pid_attr_open(struct inode *inode, struct file *file)
2716 : {
2717 : file->private_data = NULL;
2718 : __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
2719 : return 0;
2720 : }
2721 :
2722 : static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2723 : size_t count, loff_t *ppos)
2724 : {
2725 : struct inode * inode = file_inode(file);
2726 : char *p = NULL;
2727 : ssize_t length;
2728 : struct task_struct *task = get_proc_task(inode);
2729 :
2730 : if (!task)
2731 : return -ESRCH;
2732 :
2733 : length = security_getprocattr(task, PROC_I(inode)->op.lsm,
2734 : file->f_path.dentry->d_name.name,
2735 : &p);
2736 : put_task_struct(task);
2737 : if (length > 0)
2738 : length = simple_read_from_buffer(buf, count, ppos, p, length);
2739 : kfree(p);
2740 : return length;
2741 : }
2742 :
2743 : static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2744 : size_t count, loff_t *ppos)
2745 : {
2746 : struct inode * inode = file_inode(file);
2747 : struct task_struct *task;
2748 : void *page;
2749 : int rv;
2750 :
2751 : /* A task may only write when it was the opener. */
2752 : if (file->private_data != current->mm)
2753 : return -EPERM;
2754 :
2755 : rcu_read_lock();
2756 : task = pid_task(proc_pid(inode), PIDTYPE_PID);
2757 : if (!task) {
2758 : rcu_read_unlock();
2759 : return -ESRCH;
2760 : }
2761 : /* A task may only write its own attributes. */
2762 : if (current != task) {
2763 : rcu_read_unlock();
2764 : return -EACCES;
2765 : }
2766 : /* Prevent changes to overridden credentials. */
2767 : if (current_cred() != current_real_cred()) {
2768 : rcu_read_unlock();
2769 : return -EBUSY;
2770 : }
2771 : rcu_read_unlock();
2772 :
2773 : if (count > PAGE_SIZE)
2774 : count = PAGE_SIZE;
2775 :
2776 : /* No partial writes. */
2777 : if (*ppos != 0)
2778 : return -EINVAL;
2779 :
2780 : page = memdup_user(buf, count);
2781 : if (IS_ERR(page)) {
2782 : rv = PTR_ERR(page);
2783 : goto out;
2784 : }
2785 :
2786 : /* Guard against adverse ptrace interaction */
2787 : rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex);
2788 : if (rv < 0)
2789 : goto out_free;
2790 :
2791 : rv = security_setprocattr(PROC_I(inode)->op.lsm,
2792 : file->f_path.dentry->d_name.name, page,
2793 : count);
2794 : mutex_unlock(¤t->signal->cred_guard_mutex);
2795 : out_free:
2796 : kfree(page);
2797 : out:
2798 : return rv;
2799 : }
2800 :
2801 : static const struct file_operations proc_pid_attr_operations = {
2802 : .open = proc_pid_attr_open,
2803 : .read = proc_pid_attr_read,
2804 : .write = proc_pid_attr_write,
2805 : .llseek = generic_file_llseek,
2806 : .release = mem_release,
2807 : };
2808 :
2809 : #define LSM_DIR_OPS(LSM) \
2810 : static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2811 : struct dir_context *ctx) \
2812 : { \
2813 : return proc_pident_readdir(filp, ctx, \
2814 : LSM##_attr_dir_stuff, \
2815 : ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2816 : } \
2817 : \
2818 : static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2819 : .read = generic_read_dir, \
2820 : .iterate = proc_##LSM##_attr_dir_iterate, \
2821 : .llseek = default_llseek, \
2822 : }; \
2823 : \
2824 : static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2825 : struct dentry *dentry, unsigned int flags) \
2826 : { \
2827 : return proc_pident_lookup(dir, dentry, \
2828 : LSM##_attr_dir_stuff, \
2829 : LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2830 : } \
2831 : \
2832 : static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2833 : .lookup = proc_##LSM##_attr_dir_lookup, \
2834 : .getattr = pid_getattr, \
2835 : .setattr = proc_setattr, \
2836 : }
2837 :
2838 : #ifdef CONFIG_SECURITY_SMACK
2839 : static const struct pid_entry smack_attr_dir_stuff[] = {
2840 : ATTR("smack", "current", 0666),
2841 : };
2842 : LSM_DIR_OPS(smack);
2843 : #endif
2844 :
2845 : #ifdef CONFIG_SECURITY_APPARMOR
2846 : static const struct pid_entry apparmor_attr_dir_stuff[] = {
2847 : ATTR("apparmor", "current", 0666),
2848 : ATTR("apparmor", "prev", 0444),
2849 : ATTR("apparmor", "exec", 0666),
2850 : };
2851 : LSM_DIR_OPS(apparmor);
2852 : #endif
2853 :
2854 : static const struct pid_entry attr_dir_stuff[] = {
2855 : ATTR(NULL, "current", 0666),
2856 : ATTR(NULL, "prev", 0444),
2857 : ATTR(NULL, "exec", 0666),
2858 : ATTR(NULL, "fscreate", 0666),
2859 : ATTR(NULL, "keycreate", 0666),
2860 : ATTR(NULL, "sockcreate", 0666),
2861 : #ifdef CONFIG_SECURITY_SMACK
2862 : DIR("smack", 0555,
2863 : proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2864 : #endif
2865 : #ifdef CONFIG_SECURITY_APPARMOR
2866 : DIR("apparmor", 0555,
2867 : proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
2868 : #endif
2869 : };
2870 :
2871 : static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2872 : {
2873 : return proc_pident_readdir(file, ctx,
2874 : attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2875 : }
2876 :
2877 : static const struct file_operations proc_attr_dir_operations = {
2878 : .read = generic_read_dir,
2879 : .iterate_shared = proc_attr_dir_readdir,
2880 : .llseek = generic_file_llseek,
2881 : };
2882 :
2883 : static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2884 : struct dentry *dentry, unsigned int flags)
2885 : {
2886 : return proc_pident_lookup(dir, dentry,
2887 : attr_dir_stuff,
2888 : attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2889 : }
2890 :
2891 : static const struct inode_operations proc_attr_dir_inode_operations = {
2892 : .lookup = proc_attr_dir_lookup,
2893 : .getattr = pid_getattr,
2894 : .setattr = proc_setattr,
2895 : };
2896 :
2897 : #endif
2898 :
2899 : #ifdef CONFIG_ELF_CORE
2900 0 : static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2901 : size_t count, loff_t *ppos)
2902 : {
2903 0 : struct task_struct *task = get_proc_task(file_inode(file));
2904 : struct mm_struct *mm;
2905 : char buffer[PROC_NUMBUF];
2906 : size_t len;
2907 : int ret;
2908 :
2909 0 : if (!task)
2910 : return -ESRCH;
2911 :
2912 0 : ret = 0;
2913 0 : mm = get_task_mm(task);
2914 0 : if (mm) {
2915 0 : len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2916 0 : ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2917 : MMF_DUMP_FILTER_SHIFT));
2918 0 : mmput(mm);
2919 0 : ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2920 : }
2921 :
2922 0 : put_task_struct(task);
2923 :
2924 0 : return ret;
2925 : }
2926 :
2927 0 : static ssize_t proc_coredump_filter_write(struct file *file,
2928 : const char __user *buf,
2929 : size_t count,
2930 : loff_t *ppos)
2931 : {
2932 : struct task_struct *task;
2933 : struct mm_struct *mm;
2934 : unsigned int val;
2935 : int ret;
2936 : int i;
2937 : unsigned long mask;
2938 :
2939 0 : ret = kstrtouint_from_user(buf, count, 0, &val);
2940 0 : if (ret < 0)
2941 0 : return ret;
2942 :
2943 0 : ret = -ESRCH;
2944 0 : task = get_proc_task(file_inode(file));
2945 0 : if (!task)
2946 : goto out_no_task;
2947 :
2948 0 : mm = get_task_mm(task);
2949 0 : if (!mm)
2950 : goto out_no_mm;
2951 : ret = 0;
2952 :
2953 0 : for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2954 0 : if (val & mask)
2955 0 : set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2956 : else
2957 0 : clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2958 : }
2959 :
2960 0 : mmput(mm);
2961 : out_no_mm:
2962 0 : put_task_struct(task);
2963 : out_no_task:
2964 0 : if (ret < 0)
2965 0 : return ret;
2966 0 : return count;
2967 : }
2968 :
2969 : static const struct file_operations proc_coredump_filter_operations = {
2970 : .read = proc_coredump_filter_read,
2971 : .write = proc_coredump_filter_write,
2972 : .llseek = generic_file_llseek,
2973 : };
2974 : #endif
2975 :
2976 : #ifdef CONFIG_TASK_IO_ACCOUNTING
2977 : static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2978 : {
2979 : struct task_io_accounting acct = task->ioac;
2980 : unsigned long flags;
2981 : int result;
2982 :
2983 : result = down_read_killable(&task->signal->exec_update_lock);
2984 : if (result)
2985 : return result;
2986 :
2987 : if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2988 : result = -EACCES;
2989 : goto out_unlock;
2990 : }
2991 :
2992 : if (whole && lock_task_sighand(task, &flags)) {
2993 : struct task_struct *t = task;
2994 :
2995 : task_io_accounting_add(&acct, &task->signal->ioac);
2996 : while_each_thread(task, t)
2997 : task_io_accounting_add(&acct, &t->ioac);
2998 :
2999 : unlock_task_sighand(task, &flags);
3000 : }
3001 : seq_printf(m,
3002 : "rchar: %llu\n"
3003 : "wchar: %llu\n"
3004 : "syscr: %llu\n"
3005 : "syscw: %llu\n"
3006 : "read_bytes: %llu\n"
3007 : "write_bytes: %llu\n"
3008 : "cancelled_write_bytes: %llu\n",
3009 : (unsigned long long)acct.rchar,
3010 : (unsigned long long)acct.wchar,
3011 : (unsigned long long)acct.syscr,
3012 : (unsigned long long)acct.syscw,
3013 : (unsigned long long)acct.read_bytes,
3014 : (unsigned long long)acct.write_bytes,
3015 : (unsigned long long)acct.cancelled_write_bytes);
3016 : result = 0;
3017 :
3018 : out_unlock:
3019 : up_read(&task->signal->exec_update_lock);
3020 : return result;
3021 : }
3022 :
3023 : static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
3024 : struct pid *pid, struct task_struct *task)
3025 : {
3026 : return do_io_accounting(task, m, 0);
3027 : }
3028 :
3029 : static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
3030 : struct pid *pid, struct task_struct *task)
3031 : {
3032 : return do_io_accounting(task, m, 1);
3033 : }
3034 : #endif /* CONFIG_TASK_IO_ACCOUNTING */
3035 :
3036 : #ifdef CONFIG_USER_NS
3037 : static int proc_id_map_open(struct inode *inode, struct file *file,
3038 : const struct seq_operations *seq_ops)
3039 : {
3040 : struct user_namespace *ns = NULL;
3041 : struct task_struct *task;
3042 : struct seq_file *seq;
3043 : int ret = -EINVAL;
3044 :
3045 : task = get_proc_task(inode);
3046 : if (task) {
3047 : rcu_read_lock();
3048 : ns = get_user_ns(task_cred_xxx(task, user_ns));
3049 : rcu_read_unlock();
3050 : put_task_struct(task);
3051 : }
3052 : if (!ns)
3053 : goto err;
3054 :
3055 : ret = seq_open(file, seq_ops);
3056 : if (ret)
3057 : goto err_put_ns;
3058 :
3059 : seq = file->private_data;
3060 : seq->private = ns;
3061 :
3062 : return 0;
3063 : err_put_ns:
3064 : put_user_ns(ns);
3065 : err:
3066 : return ret;
3067 : }
3068 :
3069 : static int proc_id_map_release(struct inode *inode, struct file *file)
3070 : {
3071 : struct seq_file *seq = file->private_data;
3072 : struct user_namespace *ns = seq->private;
3073 : put_user_ns(ns);
3074 : return seq_release(inode, file);
3075 : }
3076 :
3077 : static int proc_uid_map_open(struct inode *inode, struct file *file)
3078 : {
3079 : return proc_id_map_open(inode, file, &proc_uid_seq_operations);
3080 : }
3081 :
3082 : static int proc_gid_map_open(struct inode *inode, struct file *file)
3083 : {
3084 : return proc_id_map_open(inode, file, &proc_gid_seq_operations);
3085 : }
3086 :
3087 : static int proc_projid_map_open(struct inode *inode, struct file *file)
3088 : {
3089 : return proc_id_map_open(inode, file, &proc_projid_seq_operations);
3090 : }
3091 :
3092 : static const struct file_operations proc_uid_map_operations = {
3093 : .open = proc_uid_map_open,
3094 : .write = proc_uid_map_write,
3095 : .read = seq_read,
3096 : .llseek = seq_lseek,
3097 : .release = proc_id_map_release,
3098 : };
3099 :
3100 : static const struct file_operations proc_gid_map_operations = {
3101 : .open = proc_gid_map_open,
3102 : .write = proc_gid_map_write,
3103 : .read = seq_read,
3104 : .llseek = seq_lseek,
3105 : .release = proc_id_map_release,
3106 : };
3107 :
3108 : static const struct file_operations proc_projid_map_operations = {
3109 : .open = proc_projid_map_open,
3110 : .write = proc_projid_map_write,
3111 : .read = seq_read,
3112 : .llseek = seq_lseek,
3113 : .release = proc_id_map_release,
3114 : };
3115 :
3116 : static int proc_setgroups_open(struct inode *inode, struct file *file)
3117 : {
3118 : struct user_namespace *ns = NULL;
3119 : struct task_struct *task;
3120 : int ret;
3121 :
3122 : ret = -ESRCH;
3123 : task = get_proc_task(inode);
3124 : if (task) {
3125 : rcu_read_lock();
3126 : ns = get_user_ns(task_cred_xxx(task, user_ns));
3127 : rcu_read_unlock();
3128 : put_task_struct(task);
3129 : }
3130 : if (!ns)
3131 : goto err;
3132 :
3133 : if (file->f_mode & FMODE_WRITE) {
3134 : ret = -EACCES;
3135 : if (!ns_capable(ns, CAP_SYS_ADMIN))
3136 : goto err_put_ns;
3137 : }
3138 :
3139 : ret = single_open(file, &proc_setgroups_show, ns);
3140 : if (ret)
3141 : goto err_put_ns;
3142 :
3143 : return 0;
3144 : err_put_ns:
3145 : put_user_ns(ns);
3146 : err:
3147 : return ret;
3148 : }
3149 :
3150 : static int proc_setgroups_release(struct inode *inode, struct file *file)
3151 : {
3152 : struct seq_file *seq = file->private_data;
3153 : struct user_namespace *ns = seq->private;
3154 : int ret = single_release(inode, file);
3155 : put_user_ns(ns);
3156 : return ret;
3157 : }
3158 :
3159 : static const struct file_operations proc_setgroups_operations = {
3160 : .open = proc_setgroups_open,
3161 : .write = proc_setgroups_write,
3162 : .read = seq_read,
3163 : .llseek = seq_lseek,
3164 : .release = proc_setgroups_release,
3165 : };
3166 : #endif /* CONFIG_USER_NS */
3167 :
3168 0 : static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3169 : struct pid *pid, struct task_struct *task)
3170 : {
3171 0 : int err = lock_trace(task);
3172 0 : if (!err) {
3173 0 : seq_printf(m, "%08x\n", task->personality);
3174 0 : unlock_trace(task);
3175 : }
3176 0 : return err;
3177 : }
3178 :
3179 : #ifdef CONFIG_LIVEPATCH
3180 : static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
3181 : struct pid *pid, struct task_struct *task)
3182 : {
3183 : seq_printf(m, "%d\n", task->patch_state);
3184 : return 0;
3185 : }
3186 : #endif /* CONFIG_LIVEPATCH */
3187 :
3188 : #ifdef CONFIG_KSM
3189 : static int proc_pid_ksm_merging_pages(struct seq_file *m, struct pid_namespace *ns,
3190 : struct pid *pid, struct task_struct *task)
3191 : {
3192 : struct mm_struct *mm;
3193 :
3194 : mm = get_task_mm(task);
3195 : if (mm) {
3196 : seq_printf(m, "%lu\n", mm->ksm_merging_pages);
3197 : mmput(mm);
3198 : }
3199 :
3200 : return 0;
3201 : }
3202 : static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns,
3203 : struct pid *pid, struct task_struct *task)
3204 : {
3205 : struct mm_struct *mm;
3206 :
3207 : mm = get_task_mm(task);
3208 : if (mm) {
3209 : seq_printf(m, "ksm_rmap_items %lu\n", mm->ksm_rmap_items);
3210 : mmput(mm);
3211 : }
3212 :
3213 : return 0;
3214 : }
3215 : #endif /* CONFIG_KSM */
3216 :
3217 : #ifdef CONFIG_STACKLEAK_METRICS
3218 : static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
3219 : struct pid *pid, struct task_struct *task)
3220 : {
3221 : unsigned long prev_depth = THREAD_SIZE -
3222 : (task->prev_lowest_stack & (THREAD_SIZE - 1));
3223 : unsigned long depth = THREAD_SIZE -
3224 : (task->lowest_stack & (THREAD_SIZE - 1));
3225 :
3226 : seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
3227 : prev_depth, depth);
3228 : return 0;
3229 : }
3230 : #endif /* CONFIG_STACKLEAK_METRICS */
3231 :
3232 : /*
3233 : * Thread groups
3234 : */
3235 : static const struct file_operations proc_task_operations;
3236 : static const struct inode_operations proc_task_inode_operations;
3237 :
3238 : static const struct pid_entry tgid_base_stuff[] = {
3239 : DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3240 : DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3241 : DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3242 : DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3243 : DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3244 : #ifdef CONFIG_NET
3245 : DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3246 : #endif
3247 : REG("environ", S_IRUSR, proc_environ_operations),
3248 : REG("auxv", S_IRUSR, proc_auxv_operations),
3249 : ONE("status", S_IRUGO, proc_pid_status),
3250 : ONE("personality", S_IRUSR, proc_pid_personality),
3251 : ONE("limits", S_IRUGO, proc_pid_limits),
3252 : #ifdef CONFIG_SCHED_DEBUG
3253 : REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3254 : #endif
3255 : #ifdef CONFIG_SCHED_AUTOGROUP
3256 : REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3257 : #endif
3258 : #ifdef CONFIG_TIME_NS
3259 : REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
3260 : #endif
3261 : REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3262 : #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3263 : ONE("syscall", S_IRUSR, proc_pid_syscall),
3264 : #endif
3265 : REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3266 : ONE("stat", S_IRUGO, proc_tgid_stat),
3267 : ONE("statm", S_IRUGO, proc_pid_statm),
3268 : REG("maps", S_IRUGO, proc_pid_maps_operations),
3269 : #ifdef CONFIG_NUMA
3270 : REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3271 : #endif
3272 : REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3273 : LNK("cwd", proc_cwd_link),
3274 : LNK("root", proc_root_link),
3275 : LNK("exe", proc_exe_link),
3276 : REG("mounts", S_IRUGO, proc_mounts_operations),
3277 : REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3278 : REG("mountstats", S_IRUSR, proc_mountstats_operations),
3279 : #ifdef CONFIG_PROC_PAGE_MONITOR
3280 : REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3281 : REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3282 : REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3283 : REG("pagemap", S_IRUSR, proc_pagemap_operations),
3284 : #endif
3285 : #ifdef CONFIG_SECURITY
3286 : DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3287 : #endif
3288 : #ifdef CONFIG_KALLSYMS
3289 : ONE("wchan", S_IRUGO, proc_pid_wchan),
3290 : #endif
3291 : #ifdef CONFIG_STACKTRACE
3292 : ONE("stack", S_IRUSR, proc_pid_stack),
3293 : #endif
3294 : #ifdef CONFIG_SCHED_INFO
3295 : ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3296 : #endif
3297 : #ifdef CONFIG_LATENCYTOP
3298 : REG("latency", S_IRUGO, proc_lstats_operations),
3299 : #endif
3300 : #ifdef CONFIG_PROC_PID_CPUSET
3301 : ONE("cpuset", S_IRUGO, proc_cpuset_show),
3302 : #endif
3303 : #ifdef CONFIG_CGROUPS
3304 : ONE("cgroup", S_IRUGO, proc_cgroup_show),
3305 : #endif
3306 : #ifdef CONFIG_PROC_CPU_RESCTRL
3307 : ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3308 : #endif
3309 : ONE("oom_score", S_IRUGO, proc_oom_score),
3310 : REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3311 : REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3312 : #ifdef CONFIG_AUDIT
3313 : REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3314 : REG("sessionid", S_IRUGO, proc_sessionid_operations),
3315 : #endif
3316 : #ifdef CONFIG_FAULT_INJECTION
3317 : REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3318 : REG("fail-nth", 0644, proc_fail_nth_operations),
3319 : #endif
3320 : #ifdef CONFIG_ELF_CORE
3321 : REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3322 : #endif
3323 : #ifdef CONFIG_TASK_IO_ACCOUNTING
3324 : ONE("io", S_IRUSR, proc_tgid_io_accounting),
3325 : #endif
3326 : #ifdef CONFIG_USER_NS
3327 : REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3328 : REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3329 : REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3330 : REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3331 : #endif
3332 : #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3333 : REG("timers", S_IRUGO, proc_timers_operations),
3334 : #endif
3335 : REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3336 : #ifdef CONFIG_LIVEPATCH
3337 : ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3338 : #endif
3339 : #ifdef CONFIG_STACKLEAK_METRICS
3340 : ONE("stack_depth", S_IRUGO, proc_stack_depth),
3341 : #endif
3342 : #ifdef CONFIG_PROC_PID_ARCH_STATUS
3343 : ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3344 : #endif
3345 : #ifdef CONFIG_SECCOMP_CACHE_DEBUG
3346 : ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3347 : #endif
3348 : #ifdef CONFIG_KSM
3349 : ONE("ksm_merging_pages", S_IRUSR, proc_pid_ksm_merging_pages),
3350 : ONE("ksm_stat", S_IRUSR, proc_pid_ksm_stat),
3351 : #endif
3352 : };
3353 :
3354 0 : static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3355 : {
3356 0 : return proc_pident_readdir(file, ctx,
3357 : tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3358 : }
3359 :
3360 : static const struct file_operations proc_tgid_base_operations = {
3361 : .read = generic_read_dir,
3362 : .iterate_shared = proc_tgid_base_readdir,
3363 : .llseek = generic_file_llseek,
3364 : };
3365 :
3366 0 : struct pid *tgid_pidfd_to_pid(const struct file *file)
3367 : {
3368 0 : if (file->f_op != &proc_tgid_base_operations)
3369 : return ERR_PTR(-EBADF);
3370 :
3371 0 : return proc_pid(file_inode(file));
3372 : }
3373 :
3374 0 : static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3375 : {
3376 0 : return proc_pident_lookup(dir, dentry,
3377 : tgid_base_stuff,
3378 : tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3379 : }
3380 :
3381 : static const struct inode_operations proc_tgid_base_inode_operations = {
3382 : .lookup = proc_tgid_base_lookup,
3383 : .getattr = pid_getattr,
3384 : .setattr = proc_setattr,
3385 : .permission = proc_pid_permission,
3386 : };
3387 :
3388 : /**
3389 : * proc_flush_pid - Remove dcache entries for @pid from the /proc dcache.
3390 : * @pid: pid that should be flushed.
3391 : *
3392 : * This function walks a list of inodes (that belong to any proc
3393 : * filesystem) that are attached to the pid and flushes them from
3394 : * the dentry cache.
3395 : *
3396 : * It is safe and reasonable to cache /proc entries for a task until
3397 : * that task exits. After that they just clog up the dcache with
3398 : * useless entries, possibly causing useful dcache entries to be
3399 : * flushed instead. This routine is provided to flush those useless
3400 : * dcache entries when a process is reaped.
3401 : *
3402 : * NOTE: This routine is just an optimization so it does not guarantee
3403 : * that no dcache entries will exist after a process is reaped
3404 : * it just makes it very unlikely that any will persist.
3405 : */
3406 :
3407 333 : void proc_flush_pid(struct pid *pid)
3408 : {
3409 333 : proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
3410 333 : }
3411 :
3412 0 : static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3413 : struct task_struct *task, const void *ptr)
3414 : {
3415 : struct inode *inode;
3416 :
3417 0 : inode = proc_pid_make_base_inode(dentry->d_sb, task,
3418 : S_IFDIR | S_IRUGO | S_IXUGO);
3419 0 : if (!inode)
3420 : return ERR_PTR(-ENOENT);
3421 :
3422 0 : inode->i_op = &proc_tgid_base_inode_operations;
3423 0 : inode->i_fop = &proc_tgid_base_operations;
3424 0 : inode->i_flags|=S_IMMUTABLE;
3425 :
3426 0 : set_nlink(inode, nlink_tgid);
3427 0 : pid_update_inode(task, inode);
3428 :
3429 0 : d_set_d_op(dentry, &pid_dentry_operations);
3430 0 : return d_splice_alias(inode, dentry);
3431 : }
3432 :
3433 0 : struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3434 : {
3435 : struct task_struct *task;
3436 : unsigned tgid;
3437 : struct proc_fs_info *fs_info;
3438 : struct pid_namespace *ns;
3439 0 : struct dentry *result = ERR_PTR(-ENOENT);
3440 :
3441 0 : tgid = name_to_int(&dentry->d_name);
3442 0 : if (tgid == ~0U)
3443 : goto out;
3444 :
3445 0 : fs_info = proc_sb_info(dentry->d_sb);
3446 0 : ns = fs_info->pid_ns;
3447 : rcu_read_lock();
3448 0 : task = find_task_by_pid_ns(tgid, ns);
3449 0 : if (task)
3450 : get_task_struct(task);
3451 : rcu_read_unlock();
3452 0 : if (!task)
3453 : goto out;
3454 :
3455 : /* Limit procfs to only ptraceable tasks */
3456 0 : if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) {
3457 0 : if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
3458 : goto out_put_task;
3459 : }
3460 :
3461 0 : result = proc_pid_instantiate(dentry, task, NULL);
3462 : out_put_task:
3463 0 : put_task_struct(task);
3464 : out:
3465 0 : return result;
3466 : }
3467 :
3468 : /*
3469 : * Find the first task with tgid >= tgid
3470 : *
3471 : */
3472 : struct tgid_iter {
3473 : unsigned int tgid;
3474 : struct task_struct *task;
3475 : };
3476 0 : static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3477 : {
3478 : struct pid *pid;
3479 :
3480 0 : if (iter.task)
3481 0 : put_task_struct(iter.task);
3482 : rcu_read_lock();
3483 : retry:
3484 0 : iter.task = NULL;
3485 0 : pid = find_ge_pid(iter.tgid, ns);
3486 0 : if (pid) {
3487 0 : iter.tgid = pid_nr_ns(pid, ns);
3488 0 : iter.task = pid_task(pid, PIDTYPE_TGID);
3489 0 : if (!iter.task) {
3490 0 : iter.tgid += 1;
3491 0 : goto retry;
3492 : }
3493 0 : get_task_struct(iter.task);
3494 : }
3495 : rcu_read_unlock();
3496 0 : return iter;
3497 : }
3498 :
3499 : #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3500 :
3501 : /* for the /proc/ directory itself, after non-process stuff has been done */
3502 0 : int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3503 : {
3504 : struct tgid_iter iter;
3505 0 : struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
3506 0 : struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb);
3507 0 : loff_t pos = ctx->pos;
3508 :
3509 0 : if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3510 : return 0;
3511 :
3512 0 : if (pos == TGID_OFFSET - 2) {
3513 0 : struct inode *inode = d_inode(fs_info->proc_self);
3514 0 : if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3515 : return 0;
3516 0 : ctx->pos = pos = pos + 1;
3517 : }
3518 0 : if (pos == TGID_OFFSET - 1) {
3519 0 : struct inode *inode = d_inode(fs_info->proc_thread_self);
3520 0 : if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3521 : return 0;
3522 0 : ctx->pos = pos = pos + 1;
3523 : }
3524 0 : iter.tgid = pos - TGID_OFFSET;
3525 0 : iter.task = NULL;
3526 0 : for (iter = next_tgid(ns, iter);
3527 : iter.task;
3528 0 : iter.tgid += 1, iter = next_tgid(ns, iter)) {
3529 : char name[10 + 1];
3530 : unsigned int len;
3531 :
3532 0 : cond_resched();
3533 0 : if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE))
3534 0 : continue;
3535 :
3536 0 : len = snprintf(name, sizeof(name), "%u", iter.tgid);
3537 0 : ctx->pos = iter.tgid + TGID_OFFSET;
3538 0 : if (!proc_fill_cache(file, ctx, name, len,
3539 : proc_pid_instantiate, iter.task, NULL)) {
3540 0 : put_task_struct(iter.task);
3541 0 : return 0;
3542 : }
3543 : }
3544 0 : ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3545 0 : return 0;
3546 : }
3547 :
3548 : /*
3549 : * proc_tid_comm_permission is a special permission function exclusively
3550 : * used for the node /proc/<pid>/task/<tid>/comm.
3551 : * It bypasses generic permission checks in the case where a task of the same
3552 : * task group attempts to access the node.
3553 : * The rationale behind this is that glibc and bionic access this node for
3554 : * cross thread naming (pthread_set/getname_np(!self)). However, if
3555 : * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3556 : * which locks out the cross thread naming implementation.
3557 : * This function makes sure that the node is always accessible for members of
3558 : * same thread group.
3559 : */
3560 0 : static int proc_tid_comm_permission(struct mnt_idmap *idmap,
3561 : struct inode *inode, int mask)
3562 : {
3563 : bool is_same_tgroup;
3564 : struct task_struct *task;
3565 :
3566 0 : task = get_proc_task(inode);
3567 0 : if (!task)
3568 : return -ESRCH;
3569 0 : is_same_tgroup = same_thread_group(current, task);
3570 0 : put_task_struct(task);
3571 :
3572 0 : if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3573 : /* This file (/proc/<pid>/task/<tid>/comm) can always be
3574 : * read or written by the members of the corresponding
3575 : * thread group.
3576 : */
3577 : return 0;
3578 : }
3579 :
3580 0 : return generic_permission(&nop_mnt_idmap, inode, mask);
3581 : }
3582 :
3583 : static const struct inode_operations proc_tid_comm_inode_operations = {
3584 : .permission = proc_tid_comm_permission,
3585 : };
3586 :
3587 : /*
3588 : * Tasks
3589 : */
3590 : static const struct pid_entry tid_base_stuff[] = {
3591 : DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3592 : DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3593 : DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3594 : #ifdef CONFIG_NET
3595 : DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3596 : #endif
3597 : REG("environ", S_IRUSR, proc_environ_operations),
3598 : REG("auxv", S_IRUSR, proc_auxv_operations),
3599 : ONE("status", S_IRUGO, proc_pid_status),
3600 : ONE("personality", S_IRUSR, proc_pid_personality),
3601 : ONE("limits", S_IRUGO, proc_pid_limits),
3602 : #ifdef CONFIG_SCHED_DEBUG
3603 : REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3604 : #endif
3605 : NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3606 : &proc_tid_comm_inode_operations,
3607 : &proc_pid_set_comm_operations, {}),
3608 : #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3609 : ONE("syscall", S_IRUSR, proc_pid_syscall),
3610 : #endif
3611 : REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3612 : ONE("stat", S_IRUGO, proc_tid_stat),
3613 : ONE("statm", S_IRUGO, proc_pid_statm),
3614 : REG("maps", S_IRUGO, proc_pid_maps_operations),
3615 : #ifdef CONFIG_PROC_CHILDREN
3616 : REG("children", S_IRUGO, proc_tid_children_operations),
3617 : #endif
3618 : #ifdef CONFIG_NUMA
3619 : REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3620 : #endif
3621 : REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3622 : LNK("cwd", proc_cwd_link),
3623 : LNK("root", proc_root_link),
3624 : LNK("exe", proc_exe_link),
3625 : REG("mounts", S_IRUGO, proc_mounts_operations),
3626 : REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3627 : #ifdef CONFIG_PROC_PAGE_MONITOR
3628 : REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3629 : REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3630 : REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3631 : REG("pagemap", S_IRUSR, proc_pagemap_operations),
3632 : #endif
3633 : #ifdef CONFIG_SECURITY
3634 : DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3635 : #endif
3636 : #ifdef CONFIG_KALLSYMS
3637 : ONE("wchan", S_IRUGO, proc_pid_wchan),
3638 : #endif
3639 : #ifdef CONFIG_STACKTRACE
3640 : ONE("stack", S_IRUSR, proc_pid_stack),
3641 : #endif
3642 : #ifdef CONFIG_SCHED_INFO
3643 : ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3644 : #endif
3645 : #ifdef CONFIG_LATENCYTOP
3646 : REG("latency", S_IRUGO, proc_lstats_operations),
3647 : #endif
3648 : #ifdef CONFIG_PROC_PID_CPUSET
3649 : ONE("cpuset", S_IRUGO, proc_cpuset_show),
3650 : #endif
3651 : #ifdef CONFIG_CGROUPS
3652 : ONE("cgroup", S_IRUGO, proc_cgroup_show),
3653 : #endif
3654 : #ifdef CONFIG_PROC_CPU_RESCTRL
3655 : ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3656 : #endif
3657 : ONE("oom_score", S_IRUGO, proc_oom_score),
3658 : REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3659 : REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3660 : #ifdef CONFIG_AUDIT
3661 : REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3662 : REG("sessionid", S_IRUGO, proc_sessionid_operations),
3663 : #endif
3664 : #ifdef CONFIG_FAULT_INJECTION
3665 : REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3666 : REG("fail-nth", 0644, proc_fail_nth_operations),
3667 : #endif
3668 : #ifdef CONFIG_TASK_IO_ACCOUNTING
3669 : ONE("io", S_IRUSR, proc_tid_io_accounting),
3670 : #endif
3671 : #ifdef CONFIG_USER_NS
3672 : REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3673 : REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3674 : REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3675 : REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3676 : #endif
3677 : #ifdef CONFIG_LIVEPATCH
3678 : ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3679 : #endif
3680 : #ifdef CONFIG_PROC_PID_ARCH_STATUS
3681 : ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3682 : #endif
3683 : #ifdef CONFIG_SECCOMP_CACHE_DEBUG
3684 : ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3685 : #endif
3686 : #ifdef CONFIG_KSM
3687 : ONE("ksm_merging_pages", S_IRUSR, proc_pid_ksm_merging_pages),
3688 : ONE("ksm_stat", S_IRUSR, proc_pid_ksm_stat),
3689 : #endif
3690 : };
3691 :
3692 0 : static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3693 : {
3694 0 : return proc_pident_readdir(file, ctx,
3695 : tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3696 : }
3697 :
3698 0 : static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3699 : {
3700 0 : return proc_pident_lookup(dir, dentry,
3701 : tid_base_stuff,
3702 : tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3703 : }
3704 :
3705 : static const struct file_operations proc_tid_base_operations = {
3706 : .read = generic_read_dir,
3707 : .iterate_shared = proc_tid_base_readdir,
3708 : .llseek = generic_file_llseek,
3709 : };
3710 :
3711 : static const struct inode_operations proc_tid_base_inode_operations = {
3712 : .lookup = proc_tid_base_lookup,
3713 : .getattr = pid_getattr,
3714 : .setattr = proc_setattr,
3715 : };
3716 :
3717 0 : static struct dentry *proc_task_instantiate(struct dentry *dentry,
3718 : struct task_struct *task, const void *ptr)
3719 : {
3720 : struct inode *inode;
3721 0 : inode = proc_pid_make_base_inode(dentry->d_sb, task,
3722 : S_IFDIR | S_IRUGO | S_IXUGO);
3723 0 : if (!inode)
3724 : return ERR_PTR(-ENOENT);
3725 :
3726 0 : inode->i_op = &proc_tid_base_inode_operations;
3727 0 : inode->i_fop = &proc_tid_base_operations;
3728 0 : inode->i_flags |= S_IMMUTABLE;
3729 :
3730 0 : set_nlink(inode, nlink_tid);
3731 0 : pid_update_inode(task, inode);
3732 :
3733 0 : d_set_d_op(dentry, &pid_dentry_operations);
3734 0 : return d_splice_alias(inode, dentry);
3735 : }
3736 :
3737 0 : static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3738 : {
3739 : struct task_struct *task;
3740 0 : struct task_struct *leader = get_proc_task(dir);
3741 : unsigned tid;
3742 : struct proc_fs_info *fs_info;
3743 : struct pid_namespace *ns;
3744 0 : struct dentry *result = ERR_PTR(-ENOENT);
3745 :
3746 0 : if (!leader)
3747 : goto out_no_task;
3748 :
3749 0 : tid = name_to_int(&dentry->d_name);
3750 0 : if (tid == ~0U)
3751 : goto out;
3752 :
3753 0 : fs_info = proc_sb_info(dentry->d_sb);
3754 0 : ns = fs_info->pid_ns;
3755 : rcu_read_lock();
3756 0 : task = find_task_by_pid_ns(tid, ns);
3757 0 : if (task)
3758 : get_task_struct(task);
3759 : rcu_read_unlock();
3760 0 : if (!task)
3761 : goto out;
3762 0 : if (!same_thread_group(leader, task))
3763 : goto out_drop_task;
3764 :
3765 0 : result = proc_task_instantiate(dentry, task, NULL);
3766 : out_drop_task:
3767 0 : put_task_struct(task);
3768 : out:
3769 0 : put_task_struct(leader);
3770 : out_no_task:
3771 0 : return result;
3772 : }
3773 :
3774 : /*
3775 : * Find the first tid of a thread group to return to user space.
3776 : *
3777 : * Usually this is just the thread group leader, but if the users
3778 : * buffer was too small or there was a seek into the middle of the
3779 : * directory we have more work todo.
3780 : *
3781 : * In the case of a short read we start with find_task_by_pid.
3782 : *
3783 : * In the case of a seek we start with the leader and walk nr
3784 : * threads past it.
3785 : */
3786 0 : static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3787 : struct pid_namespace *ns)
3788 : {
3789 : struct task_struct *pos, *task;
3790 0 : unsigned long nr = f_pos;
3791 :
3792 : if (nr != f_pos) /* 32bit overflow? */
3793 : return NULL;
3794 :
3795 : rcu_read_lock();
3796 0 : task = pid_task(pid, PIDTYPE_PID);
3797 0 : if (!task)
3798 : goto fail;
3799 :
3800 : /* Attempt to start with the tid of a thread */
3801 0 : if (tid && nr) {
3802 0 : pos = find_task_by_pid_ns(tid, ns);
3803 0 : if (pos && same_thread_group(pos, task))
3804 : goto found;
3805 : }
3806 :
3807 : /* If nr exceeds the number of threads there is nothing todo */
3808 0 : if (nr >= get_nr_threads(task))
3809 : goto fail;
3810 :
3811 : /* If we haven't found our starting place yet start
3812 : * with the leader and walk nr threads forward.
3813 : */
3814 0 : pos = task = task->group_leader;
3815 : do {
3816 0 : if (!nr--)
3817 : goto found;
3818 0 : } while_each_thread(task, pos);
3819 : fail:
3820 : pos = NULL;
3821 : goto out;
3822 : found:
3823 : get_task_struct(pos);
3824 : out:
3825 : rcu_read_unlock();
3826 : return pos;
3827 : }
3828 :
3829 : /*
3830 : * Find the next thread in the thread list.
3831 : * Return NULL if there is an error or no next thread.
3832 : *
3833 : * The reference to the input task_struct is released.
3834 : */
3835 0 : static struct task_struct *next_tid(struct task_struct *start)
3836 : {
3837 0 : struct task_struct *pos = NULL;
3838 : rcu_read_lock();
3839 0 : if (pid_alive(start)) {
3840 0 : pos = next_thread(start);
3841 0 : if (thread_group_leader(pos))
3842 : pos = NULL;
3843 : else
3844 : get_task_struct(pos);
3845 : }
3846 : rcu_read_unlock();
3847 0 : put_task_struct(start);
3848 0 : return pos;
3849 : }
3850 :
3851 : /* for the /proc/TGID/task/ directories */
3852 0 : static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3853 : {
3854 0 : struct inode *inode = file_inode(file);
3855 : struct task_struct *task;
3856 : struct pid_namespace *ns;
3857 : int tid;
3858 :
3859 0 : if (proc_inode_is_dead(inode))
3860 : return -ENOENT;
3861 :
3862 0 : if (!dir_emit_dots(file, ctx))
3863 : return 0;
3864 :
3865 : /* f_version caches the tgid value that the last readdir call couldn't
3866 : * return. lseek aka telldir automagically resets f_version to 0.
3867 : */
3868 0 : ns = proc_pid_ns(inode->i_sb);
3869 0 : tid = (int)file->f_version;
3870 0 : file->f_version = 0;
3871 0 : for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3872 : task;
3873 0 : task = next_tid(task), ctx->pos++) {
3874 : char name[10 + 1];
3875 : unsigned int len;
3876 :
3877 0 : tid = task_pid_nr_ns(task, ns);
3878 0 : if (!tid)
3879 0 : continue; /* The task has just exited. */
3880 0 : len = snprintf(name, sizeof(name), "%u", tid);
3881 0 : if (!proc_fill_cache(file, ctx, name, len,
3882 : proc_task_instantiate, task, NULL)) {
3883 : /* returning this tgid failed, save it as the first
3884 : * pid for the next readir call */
3885 0 : file->f_version = (u64)tid;
3886 0 : put_task_struct(task);
3887 0 : break;
3888 : }
3889 : }
3890 :
3891 : return 0;
3892 : }
3893 :
3894 0 : static int proc_task_getattr(struct mnt_idmap *idmap,
3895 : const struct path *path, struct kstat *stat,
3896 : u32 request_mask, unsigned int query_flags)
3897 : {
3898 0 : struct inode *inode = d_inode(path->dentry);
3899 0 : struct task_struct *p = get_proc_task(inode);
3900 0 : generic_fillattr(&nop_mnt_idmap, inode, stat);
3901 :
3902 0 : if (p) {
3903 0 : stat->nlink += get_nr_threads(p);
3904 0 : put_task_struct(p);
3905 : }
3906 :
3907 0 : return 0;
3908 : }
3909 :
3910 : static const struct inode_operations proc_task_inode_operations = {
3911 : .lookup = proc_task_lookup,
3912 : .getattr = proc_task_getattr,
3913 : .setattr = proc_setattr,
3914 : .permission = proc_pid_permission,
3915 : };
3916 :
3917 : static const struct file_operations proc_task_operations = {
3918 : .read = generic_read_dir,
3919 : .iterate_shared = proc_task_readdir,
3920 : .llseek = generic_file_llseek,
3921 : };
3922 :
3923 1 : void __init set_proc_pid_nlink(void)
3924 : {
3925 1 : nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3926 1 : nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3927 1 : }
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