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/stacktrace.h>
71 #include <linux/resource.h>
72 #include <linux/module.h>
73 #include <linux/mount.h>
74 #include <linux/security.h>
75 #include <linux/ptrace.h>
76 #include <linux/tracehook.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 <trace/events/oom.h>
99 #include "internal.h"
100 #include "fd.h"
101
102 #include "../../lib/kstrtox.h"
103
104 /* NOTE:
105 * Implementing inode permission operations in /proc is almost
106 * certainly an error. Permission checks need to happen during
107 * each system call not at open time. The reason is that most of
108 * what we wish to check for permissions in /proc varies at runtime.
109 *
110 * The classic example of a problem is opening file descriptors
111 * in /proc for a task before it execs a suid executable.
112 */
113
114 static u8 nlink_tid __ro_after_init;
115 static u8 nlink_tgid __ro_after_init;
116
117 struct pid_entry {
118 const char *name;
119 unsigned int len;
120 umode_t mode;
121 const struct inode_operations *iop;
122 const struct file_operations *fop;
123 union proc_op op;
124 };
125
126 #define NOD(NAME, MODE, IOP, FOP, OP) { \
127 .name = (NAME), \
128 .len = sizeof(NAME) - 1, \
129 .mode = MODE, \
130 .iop = IOP, \
131 .fop = FOP, \
132 .op = OP, \
133 }
134
135 #define DIR(NAME, MODE, iops, fops) \
136 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
137 #define LNK(NAME, get_link) \
138 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
139 &proc_pid_link_inode_operations, NULL, \
140 { .proc_get_link = get_link } )
141 #define REG(NAME, MODE, fops) \
142 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
143 #define ONE(NAME, MODE, show) \
144 NOD(NAME, (S_IFREG|(MODE)), \
145 NULL, &proc_single_file_operations, \
146 { .proc_show = show } )
147 #define ATTR(LSM, NAME, MODE) \
148 NOD(NAME, (S_IFREG|(MODE)), \
149 NULL, &proc_pid_attr_operations, \
150 { .lsm = LSM })
151
152 /*
153 * Count the number of hardlinks for the pid_entry table, excluding the .
154 * and .. links.
155 */
pid_entry_nlink(const struct pid_entry * entries,unsigned int n)156 static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
157 unsigned int n)
158 {
159 unsigned int i;
160 unsigned int count;
161
162 count = 2;
163 for (i = 0; i < n; ++i) {
164 if (S_ISDIR(entries[i].mode))
165 ++count;
166 }
167
168 return count;
169 }
170
get_task_root(struct task_struct * task,struct path * root)171 static int get_task_root(struct task_struct *task, struct path *root)
172 {
173 int result = -ENOENT;
174
175 task_lock(task);
176 if (task->fs) {
177 get_fs_root(task->fs, root);
178 result = 0;
179 }
180 task_unlock(task);
181 return result;
182 }
183
proc_cwd_link(struct dentry * dentry,struct path * path)184 static int proc_cwd_link(struct dentry *dentry, struct path *path)
185 {
186 struct task_struct *task = get_proc_task(d_inode(dentry));
187 int result = -ENOENT;
188
189 if (task) {
190 task_lock(task);
191 if (task->fs) {
192 get_fs_pwd(task->fs, path);
193 result = 0;
194 }
195 task_unlock(task);
196 put_task_struct(task);
197 }
198 return result;
199 }
200
proc_root_link(struct dentry * dentry,struct path * path)201 static int proc_root_link(struct dentry *dentry, struct path *path)
202 {
203 struct task_struct *task = get_proc_task(d_inode(dentry));
204 int result = -ENOENT;
205
206 if (task) {
207 result = get_task_root(task, path);
208 put_task_struct(task);
209 }
210 return result;
211 }
212
213 /*
214 * If the user used setproctitle(), we just get the string from
215 * user space at arg_start, and limit it to a maximum of one page.
216 */
get_mm_proctitle(struct mm_struct * mm,char __user * buf,size_t count,unsigned long pos,unsigned long arg_start)217 static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
218 size_t count, unsigned long pos,
219 unsigned long arg_start)
220 {
221 char *page;
222 int ret, got;
223
224 if (pos >= PAGE_SIZE)
225 return 0;
226
227 page = (char *)__get_free_page(GFP_KERNEL);
228 if (!page)
229 return -ENOMEM;
230
231 ret = 0;
232 got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
233 if (got > 0) {
234 int len = strnlen(page, got);
235
236 /* Include the NUL character if it was found */
237 if (len < got)
238 len++;
239
240 if (len > pos) {
241 len -= pos;
242 if (len > count)
243 len = count;
244 len -= copy_to_user(buf, page+pos, len);
245 if (!len)
246 len = -EFAULT;
247 ret = len;
248 }
249 }
250 free_page((unsigned long)page);
251 return ret;
252 }
253
get_mm_cmdline(struct mm_struct * mm,char __user * buf,size_t count,loff_t * ppos)254 static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
255 size_t count, loff_t *ppos)
256 {
257 unsigned long arg_start, arg_end, env_start, env_end;
258 unsigned long pos, len;
259 char *page, c;
260
261 /* Check if process spawned far enough to have cmdline. */
262 if (!mm->env_end)
263 return 0;
264
265 spin_lock(&mm->arg_lock);
266 arg_start = mm->arg_start;
267 arg_end = mm->arg_end;
268 env_start = mm->env_start;
269 env_end = mm->env_end;
270 spin_unlock(&mm->arg_lock);
271
272 if (arg_start >= arg_end)
273 return 0;
274
275 /*
276 * We allow setproctitle() to overwrite the argument
277 * strings, and overflow past the original end. But
278 * only when it overflows into the environment area.
279 */
280 if (env_start != arg_end || env_end < env_start)
281 env_start = env_end = arg_end;
282 len = env_end - arg_start;
283
284 /* We're not going to care if "*ppos" has high bits set */
285 pos = *ppos;
286 if (pos >= len)
287 return 0;
288 if (count > len - pos)
289 count = len - pos;
290 if (!count)
291 return 0;
292
293 /*
294 * Magical special case: if the argv[] end byte is not
295 * zero, the user has overwritten it with setproctitle(3).
296 *
297 * Possible future enhancement: do this only once when
298 * pos is 0, and set a flag in the 'struct file'.
299 */
300 if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
301 return get_mm_proctitle(mm, buf, count, pos, arg_start);
302
303 /*
304 * For the non-setproctitle() case we limit things strictly
305 * to the [arg_start, arg_end[ range.
306 */
307 pos += arg_start;
308 if (pos < arg_start || pos >= arg_end)
309 return 0;
310 if (count > arg_end - pos)
311 count = arg_end - pos;
312
313 page = (char *)__get_free_page(GFP_KERNEL);
314 if (!page)
315 return -ENOMEM;
316
317 len = 0;
318 while (count) {
319 int got;
320 size_t size = min_t(size_t, PAGE_SIZE, count);
321
322 got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
323 if (got <= 0)
324 break;
325 got -= copy_to_user(buf, page, got);
326 if (unlikely(!got)) {
327 if (!len)
328 len = -EFAULT;
329 break;
330 }
331 pos += got;
332 buf += got;
333 len += got;
334 count -= got;
335 }
336
337 free_page((unsigned long)page);
338 return len;
339 }
340
get_task_cmdline(struct task_struct * tsk,char __user * buf,size_t count,loff_t * pos)341 static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
342 size_t count, loff_t *pos)
343 {
344 struct mm_struct *mm;
345 ssize_t ret;
346
347 mm = get_task_mm(tsk);
348 if (!mm)
349 return 0;
350
351 ret = get_mm_cmdline(mm, buf, count, pos);
352 mmput(mm);
353 return ret;
354 }
355
proc_pid_cmdline_read(struct file * file,char __user * buf,size_t count,loff_t * pos)356 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
357 size_t count, loff_t *pos)
358 {
359 struct task_struct *tsk;
360 ssize_t ret;
361
362 BUG_ON(*pos < 0);
363
364 tsk = get_proc_task(file_inode(file));
365 if (!tsk)
366 return -ESRCH;
367 ret = get_task_cmdline(tsk, buf, count, pos);
368 put_task_struct(tsk);
369 if (ret > 0)
370 *pos += ret;
371 return ret;
372 }
373
374 static const struct file_operations proc_pid_cmdline_ops = {
375 .read = proc_pid_cmdline_read,
376 .llseek = generic_file_llseek,
377 };
378
379 #ifdef CONFIG_KALLSYMS
380 /*
381 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
382 * Returns the resolved symbol. If that fails, simply return the address.
383 */
proc_pid_wchan(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)384 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
385 struct pid *pid, struct task_struct *task)
386 {
387 unsigned long wchan;
388
389 if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
390 wchan = get_wchan(task);
391 else
392 wchan = 0;
393
394 if (wchan)
395 seq_printf(m, "%ps", (void *) wchan);
396 else
397 seq_putc(m, '0');
398
399 return 0;
400 }
401 #endif /* CONFIG_KALLSYMS */
402
lock_trace(struct task_struct * task)403 static int lock_trace(struct task_struct *task)
404 {
405 int err = down_read_killable(&task->signal->exec_update_lock);
406 if (err)
407 return err;
408 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
409 up_read(&task->signal->exec_update_lock);
410 return -EPERM;
411 }
412 return 0;
413 }
414
unlock_trace(struct task_struct * task)415 static void unlock_trace(struct task_struct *task)
416 {
417 up_read(&task->signal->exec_update_lock);
418 }
419
420 #ifdef CONFIG_STACKTRACE
421
422 #define MAX_STACK_TRACE_DEPTH 64
423
proc_pid_stack(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)424 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
425 struct pid *pid, struct task_struct *task)
426 {
427 unsigned long *entries;
428 int err;
429
430 /*
431 * The ability to racily run the kernel stack unwinder on a running task
432 * and then observe the unwinder output is scary; while it is useful for
433 * debugging kernel issues, it can also allow an attacker to leak kernel
434 * stack contents.
435 * Doing this in a manner that is at least safe from races would require
436 * some work to ensure that the remote task can not be scheduled; and
437 * even then, this would still expose the unwinder as local attack
438 * surface.
439 * Therefore, this interface is restricted to root.
440 */
441 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
442 return -EACCES;
443
444 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
445 GFP_KERNEL);
446 if (!entries)
447 return -ENOMEM;
448
449 err = lock_trace(task);
450 if (!err) {
451 unsigned int i, nr_entries;
452
453 nr_entries = stack_trace_save_tsk(task, entries,
454 MAX_STACK_TRACE_DEPTH, 0);
455
456 for (i = 0; i < nr_entries; i++) {
457 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
458 }
459
460 unlock_trace(task);
461 }
462 kfree(entries);
463
464 return err;
465 }
466 #endif
467
468 #ifdef CONFIG_SCHED_INFO
469 /*
470 * Provides /proc/PID/schedstat
471 */
proc_pid_schedstat(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)472 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
473 struct pid *pid, struct task_struct *task)
474 {
475 if (unlikely(!sched_info_on()))
476 seq_puts(m, "0 0 0\n");
477 else
478 seq_printf(m, "%llu %llu %lu\n",
479 (unsigned long long)task->se.sum_exec_runtime,
480 (unsigned long long)task->sched_info.run_delay,
481 task->sched_info.pcount);
482
483 return 0;
484 }
485 #endif
486
487 #ifdef CONFIG_LATENCYTOP
lstats_show_proc(struct seq_file * m,void * v)488 static int lstats_show_proc(struct seq_file *m, void *v)
489 {
490 int i;
491 struct inode *inode = m->private;
492 struct task_struct *task = get_proc_task(inode);
493
494 if (!task)
495 return -ESRCH;
496 seq_puts(m, "Latency Top version : v0.1\n");
497 for (i = 0; i < LT_SAVECOUNT; i++) {
498 struct latency_record *lr = &task->latency_record[i];
499 if (lr->backtrace[0]) {
500 int q;
501 seq_printf(m, "%i %li %li",
502 lr->count, lr->time, lr->max);
503 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
504 unsigned long bt = lr->backtrace[q];
505
506 if (!bt)
507 break;
508 seq_printf(m, " %ps", (void *)bt);
509 }
510 seq_putc(m, '\n');
511 }
512
513 }
514 put_task_struct(task);
515 return 0;
516 }
517
lstats_open(struct inode * inode,struct file * file)518 static int lstats_open(struct inode *inode, struct file *file)
519 {
520 return single_open(file, lstats_show_proc, inode);
521 }
522
lstats_write(struct file * file,const char __user * buf,size_t count,loff_t * offs)523 static ssize_t lstats_write(struct file *file, const char __user *buf,
524 size_t count, loff_t *offs)
525 {
526 struct task_struct *task = get_proc_task(file_inode(file));
527
528 if (!task)
529 return -ESRCH;
530 clear_tsk_latency_tracing(task);
531 put_task_struct(task);
532
533 return count;
534 }
535
536 static const struct file_operations proc_lstats_operations = {
537 .open = lstats_open,
538 .read = seq_read,
539 .write = lstats_write,
540 .llseek = seq_lseek,
541 .release = single_release,
542 };
543
544 #endif
545
proc_oom_score(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)546 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
547 struct pid *pid, struct task_struct *task)
548 {
549 unsigned long totalpages = totalram_pages() + total_swap_pages;
550 unsigned long points = 0;
551 long badness;
552
553 badness = oom_badness(task, totalpages);
554 /*
555 * Special case OOM_SCORE_ADJ_MIN for all others scale the
556 * badness value into [0, 2000] range which we have been
557 * exporting for a long time so userspace might depend on it.
558 */
559 if (badness != LONG_MIN)
560 points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
561
562 seq_printf(m, "%lu\n", points);
563
564 return 0;
565 }
566
567 struct limit_names {
568 const char *name;
569 const char *unit;
570 };
571
572 static const struct limit_names lnames[RLIM_NLIMITS] = {
573 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
574 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
575 [RLIMIT_DATA] = {"Max data size", "bytes"},
576 [RLIMIT_STACK] = {"Max stack size", "bytes"},
577 [RLIMIT_CORE] = {"Max core file size", "bytes"},
578 [RLIMIT_RSS] = {"Max resident set", "bytes"},
579 [RLIMIT_NPROC] = {"Max processes", "processes"},
580 [RLIMIT_NOFILE] = {"Max open files", "files"},
581 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
582 [RLIMIT_AS] = {"Max address space", "bytes"},
583 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
584 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
585 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
586 [RLIMIT_NICE] = {"Max nice priority", NULL},
587 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
588 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
589 };
590
591 /* Display limits for a process */
proc_pid_limits(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)592 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
593 struct pid *pid, struct task_struct *task)
594 {
595 unsigned int i;
596 unsigned long flags;
597
598 struct rlimit rlim[RLIM_NLIMITS];
599
600 if (!lock_task_sighand(task, &flags))
601 return 0;
602 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
603 unlock_task_sighand(task, &flags);
604
605 /*
606 * print the file header
607 */
608 seq_puts(m, "Limit "
609 "Soft Limit "
610 "Hard Limit "
611 "Units \n");
612
613 for (i = 0; i < RLIM_NLIMITS; i++) {
614 if (rlim[i].rlim_cur == RLIM_INFINITY)
615 seq_printf(m, "%-25s %-20s ",
616 lnames[i].name, "unlimited");
617 else
618 seq_printf(m, "%-25s %-20lu ",
619 lnames[i].name, rlim[i].rlim_cur);
620
621 if (rlim[i].rlim_max == RLIM_INFINITY)
622 seq_printf(m, "%-20s ", "unlimited");
623 else
624 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
625
626 if (lnames[i].unit)
627 seq_printf(m, "%-10s\n", lnames[i].unit);
628 else
629 seq_putc(m, '\n');
630 }
631
632 return 0;
633 }
634
635 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
proc_pid_syscall(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)636 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
637 struct pid *pid, struct task_struct *task)
638 {
639 struct syscall_info info;
640 u64 *args = &info.data.args[0];
641 int res;
642
643 res = lock_trace(task);
644 if (res)
645 return res;
646
647 if (task_current_syscall(task, &info))
648 seq_puts(m, "running\n");
649 else if (info.data.nr < 0)
650 seq_printf(m, "%d 0x%llx 0x%llx\n",
651 info.data.nr, info.sp, info.data.instruction_pointer);
652 else
653 seq_printf(m,
654 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
655 info.data.nr,
656 args[0], args[1], args[2], args[3], args[4], args[5],
657 info.sp, info.data.instruction_pointer);
658 unlock_trace(task);
659
660 return 0;
661 }
662 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
663
664 /************************************************************************/
665 /* Here the fs part begins */
666 /************************************************************************/
667
668 /* permission checks */
proc_fd_access_allowed(struct inode * inode)669 static int proc_fd_access_allowed(struct inode *inode)
670 {
671 struct task_struct *task;
672 int allowed = 0;
673 /* Allow access to a task's file descriptors if it is us or we
674 * may use ptrace attach to the process and find out that
675 * information.
676 */
677 task = get_proc_task(inode);
678 if (task) {
679 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
680 put_task_struct(task);
681 }
682 return allowed;
683 }
684
proc_setattr(struct user_namespace * mnt_userns,struct dentry * dentry,struct iattr * attr)685 int proc_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
686 struct iattr *attr)
687 {
688 int error;
689 struct inode *inode = d_inode(dentry);
690
691 if (attr->ia_valid & ATTR_MODE)
692 return -EPERM;
693
694 error = setattr_prepare(&init_user_ns, dentry, attr);
695 if (error)
696 return error;
697
698 setattr_copy(&init_user_ns, inode, attr);
699 mark_inode_dirty(inode);
700 return 0;
701 }
702
703 /*
704 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
705 * or euid/egid (for hide_pid_min=2)?
706 */
has_pid_permissions(struct proc_fs_info * fs_info,struct task_struct * task,enum proc_hidepid hide_pid_min)707 static bool has_pid_permissions(struct proc_fs_info *fs_info,
708 struct task_struct *task,
709 enum proc_hidepid hide_pid_min)
710 {
711 /*
712 * If 'hidpid' mount option is set force a ptrace check,
713 * we indicate that we are using a filesystem syscall
714 * by passing PTRACE_MODE_READ_FSCREDS
715 */
716 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE)
717 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
718
719 if (fs_info->hide_pid < hide_pid_min)
720 return true;
721 if (in_group_p(fs_info->pid_gid))
722 return true;
723 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
724 }
725
726
proc_pid_permission(struct user_namespace * mnt_userns,struct inode * inode,int mask)727 static int proc_pid_permission(struct user_namespace *mnt_userns,
728 struct inode *inode, int mask)
729 {
730 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
731 struct task_struct *task;
732 bool has_perms;
733
734 task = get_proc_task(inode);
735 if (!task)
736 return -ESRCH;
737 has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS);
738 put_task_struct(task);
739
740 if (!has_perms) {
741 if (fs_info->hide_pid == HIDEPID_INVISIBLE) {
742 /*
743 * Let's make getdents(), stat(), and open()
744 * consistent with each other. If a process
745 * may not stat() a file, it shouldn't be seen
746 * in procfs at all.
747 */
748 return -ENOENT;
749 }
750
751 return -EPERM;
752 }
753 return generic_permission(&init_user_ns, inode, mask);
754 }
755
756
757
758 static const struct inode_operations proc_def_inode_operations = {
759 .setattr = proc_setattr,
760 };
761
proc_single_show(struct seq_file * m,void * v)762 static int proc_single_show(struct seq_file *m, void *v)
763 {
764 struct inode *inode = m->private;
765 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
766 struct pid *pid = proc_pid(inode);
767 struct task_struct *task;
768 int ret;
769
770 task = get_pid_task(pid, PIDTYPE_PID);
771 if (!task)
772 return -ESRCH;
773
774 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
775
776 put_task_struct(task);
777 return ret;
778 }
779
proc_single_open(struct inode * inode,struct file * filp)780 static int proc_single_open(struct inode *inode, struct file *filp)
781 {
782 return single_open(filp, proc_single_show, inode);
783 }
784
785 static const struct file_operations proc_single_file_operations = {
786 .open = proc_single_open,
787 .read = seq_read,
788 .llseek = seq_lseek,
789 .release = single_release,
790 };
791
792
proc_mem_open(struct inode * inode,unsigned int mode)793 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
794 {
795 struct task_struct *task = get_proc_task(inode);
796 struct mm_struct *mm = ERR_PTR(-ESRCH);
797
798 if (task) {
799 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
800 put_task_struct(task);
801
802 if (!IS_ERR_OR_NULL(mm)) {
803 /* ensure this mm_struct can't be freed */
804 mmgrab(mm);
805 /* but do not pin its memory */
806 mmput(mm);
807 }
808 }
809
810 return mm;
811 }
812
__mem_open(struct inode * inode,struct file * file,unsigned int mode)813 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
814 {
815 struct mm_struct *mm = proc_mem_open(inode, mode);
816
817 if (IS_ERR(mm))
818 return PTR_ERR(mm);
819
820 file->private_data = mm;
821 return 0;
822 }
823
mem_open(struct inode * inode,struct file * file)824 static int mem_open(struct inode *inode, struct file *file)
825 {
826 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
827
828 /* OK to pass negative loff_t, we can catch out-of-range */
829 file->f_mode |= FMODE_UNSIGNED_OFFSET;
830
831 return ret;
832 }
833
mem_rw(struct file * file,char __user * buf,size_t count,loff_t * ppos,int write)834 static ssize_t mem_rw(struct file *file, char __user *buf,
835 size_t count, loff_t *ppos, int write)
836 {
837 struct mm_struct *mm = file->private_data;
838 unsigned long addr = *ppos;
839 ssize_t copied;
840 char *page;
841 unsigned int flags;
842
843 if (!mm)
844 return 0;
845
846 page = (char *)__get_free_page(GFP_KERNEL);
847 if (!page)
848 return -ENOMEM;
849
850 copied = 0;
851 if (!mmget_not_zero(mm))
852 goto free;
853
854 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
855
856 while (count > 0) {
857 int this_len = min_t(int, count, PAGE_SIZE);
858
859 if (write && copy_from_user(page, buf, this_len)) {
860 copied = -EFAULT;
861 break;
862 }
863
864 this_len = access_remote_vm(mm, addr, page, this_len, flags);
865 if (!this_len) {
866 if (!copied)
867 copied = -EIO;
868 break;
869 }
870
871 if (!write && copy_to_user(buf, page, this_len)) {
872 copied = -EFAULT;
873 break;
874 }
875
876 buf += this_len;
877 addr += this_len;
878 copied += this_len;
879 count -= this_len;
880 }
881 *ppos = addr;
882
883 mmput(mm);
884 free:
885 free_page((unsigned long) page);
886 return copied;
887 }
888
mem_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)889 static ssize_t mem_read(struct file *file, char __user *buf,
890 size_t count, loff_t *ppos)
891 {
892 return mem_rw(file, buf, count, ppos, 0);
893 }
894
mem_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)895 static ssize_t mem_write(struct file *file, const char __user *buf,
896 size_t count, loff_t *ppos)
897 {
898 return mem_rw(file, (char __user*)buf, count, ppos, 1);
899 }
900
mem_lseek(struct file * file,loff_t offset,int orig)901 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
902 {
903 switch (orig) {
904 case 0:
905 file->f_pos = offset;
906 break;
907 case 1:
908 file->f_pos += offset;
909 break;
910 default:
911 return -EINVAL;
912 }
913 force_successful_syscall_return();
914 return file->f_pos;
915 }
916
mem_release(struct inode * inode,struct file * file)917 static int mem_release(struct inode *inode, struct file *file)
918 {
919 struct mm_struct *mm = file->private_data;
920 if (mm)
921 mmdrop(mm);
922 return 0;
923 }
924
925 static const struct file_operations proc_mem_operations = {
926 .llseek = mem_lseek,
927 .read = mem_read,
928 .write = mem_write,
929 .open = mem_open,
930 .release = mem_release,
931 };
932
environ_open(struct inode * inode,struct file * file)933 static int environ_open(struct inode *inode, struct file *file)
934 {
935 return __mem_open(inode, file, PTRACE_MODE_READ);
936 }
937
environ_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)938 static ssize_t environ_read(struct file *file, char __user *buf,
939 size_t count, loff_t *ppos)
940 {
941 char *page;
942 unsigned long src = *ppos;
943 int ret = 0;
944 struct mm_struct *mm = file->private_data;
945 unsigned long env_start, env_end;
946
947 /* Ensure the process spawned far enough to have an environment. */
948 if (!mm || !mm->env_end)
949 return 0;
950
951 page = (char *)__get_free_page(GFP_KERNEL);
952 if (!page)
953 return -ENOMEM;
954
955 ret = 0;
956 if (!mmget_not_zero(mm))
957 goto free;
958
959 spin_lock(&mm->arg_lock);
960 env_start = mm->env_start;
961 env_end = mm->env_end;
962 spin_unlock(&mm->arg_lock);
963
964 while (count > 0) {
965 size_t this_len, max_len;
966 int retval;
967
968 if (src >= (env_end - env_start))
969 break;
970
971 this_len = env_end - (env_start + src);
972
973 max_len = min_t(size_t, PAGE_SIZE, count);
974 this_len = min(max_len, this_len);
975
976 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
977
978 if (retval <= 0) {
979 ret = retval;
980 break;
981 }
982
983 if (copy_to_user(buf, page, retval)) {
984 ret = -EFAULT;
985 break;
986 }
987
988 ret += retval;
989 src += retval;
990 buf += retval;
991 count -= retval;
992 }
993 *ppos = src;
994 mmput(mm);
995
996 free:
997 free_page((unsigned long) page);
998 return ret;
999 }
1000
1001 static const struct file_operations proc_environ_operations = {
1002 .open = environ_open,
1003 .read = environ_read,
1004 .llseek = generic_file_llseek,
1005 .release = mem_release,
1006 };
1007
auxv_open(struct inode * inode,struct file * file)1008 static int auxv_open(struct inode *inode, struct file *file)
1009 {
1010 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1011 }
1012
auxv_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1013 static ssize_t auxv_read(struct file *file, char __user *buf,
1014 size_t count, loff_t *ppos)
1015 {
1016 struct mm_struct *mm = file->private_data;
1017 unsigned int nwords = 0;
1018
1019 if (!mm)
1020 return 0;
1021 do {
1022 nwords += 2;
1023 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1024 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1025 nwords * sizeof(mm->saved_auxv[0]));
1026 }
1027
1028 static const struct file_operations proc_auxv_operations = {
1029 .open = auxv_open,
1030 .read = auxv_read,
1031 .llseek = generic_file_llseek,
1032 .release = mem_release,
1033 };
1034
oom_adj_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1035 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1036 loff_t *ppos)
1037 {
1038 struct task_struct *task = get_proc_task(file_inode(file));
1039 char buffer[PROC_NUMBUF];
1040 int oom_adj = OOM_ADJUST_MIN;
1041 size_t len;
1042
1043 if (!task)
1044 return -ESRCH;
1045 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1046 oom_adj = OOM_ADJUST_MAX;
1047 else
1048 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1049 OOM_SCORE_ADJ_MAX;
1050 put_task_struct(task);
1051 if (oom_adj > OOM_ADJUST_MAX)
1052 oom_adj = OOM_ADJUST_MAX;
1053 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1054 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1055 }
1056
__set_oom_adj(struct file * file,int oom_adj,bool legacy)1057 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1058 {
1059 struct mm_struct *mm = NULL;
1060 struct task_struct *task;
1061 int err = 0;
1062
1063 task = get_proc_task(file_inode(file));
1064 if (!task)
1065 return -ESRCH;
1066
1067 mutex_lock(&oom_adj_mutex);
1068 if (legacy) {
1069 if (oom_adj < task->signal->oom_score_adj &&
1070 !capable(CAP_SYS_RESOURCE)) {
1071 err = -EACCES;
1072 goto err_unlock;
1073 }
1074 /*
1075 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1076 * /proc/pid/oom_score_adj instead.
1077 */
1078 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1079 current->comm, task_pid_nr(current), task_pid_nr(task),
1080 task_pid_nr(task));
1081 } else {
1082 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1083 !capable(CAP_SYS_RESOURCE)) {
1084 err = -EACCES;
1085 goto err_unlock;
1086 }
1087 }
1088
1089 /*
1090 * Make sure we will check other processes sharing the mm if this is
1091 * not vfrok which wants its own oom_score_adj.
1092 * pin the mm so it doesn't go away and get reused after task_unlock
1093 */
1094 if (!task->vfork_done) {
1095 struct task_struct *p = find_lock_task_mm(task);
1096
1097 if (p) {
1098 if (test_bit(MMF_MULTIPROCESS, &p->mm->flags)) {
1099 mm = p->mm;
1100 mmgrab(mm);
1101 }
1102 task_unlock(p);
1103 }
1104 }
1105
1106 task->signal->oom_score_adj = oom_adj;
1107 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1108 task->signal->oom_score_adj_min = (short)oom_adj;
1109 trace_oom_score_adj_update(task);
1110
1111 if (mm) {
1112 struct task_struct *p;
1113
1114 rcu_read_lock();
1115 for_each_process(p) {
1116 if (same_thread_group(task, p))
1117 continue;
1118
1119 /* do not touch kernel threads or the global init */
1120 if (p->flags & PF_KTHREAD || is_global_init(p))
1121 continue;
1122
1123 task_lock(p);
1124 if (!p->vfork_done && process_shares_mm(p, mm)) {
1125 p->signal->oom_score_adj = oom_adj;
1126 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1127 p->signal->oom_score_adj_min = (short)oom_adj;
1128 }
1129 task_unlock(p);
1130 }
1131 rcu_read_unlock();
1132 mmdrop(mm);
1133 }
1134 err_unlock:
1135 mutex_unlock(&oom_adj_mutex);
1136 put_task_struct(task);
1137 return err;
1138 }
1139
1140 /*
1141 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1142 * kernels. The effective policy is defined by oom_score_adj, which has a
1143 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1144 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1145 * Processes that become oom disabled via oom_adj will still be oom disabled
1146 * with this implementation.
1147 *
1148 * oom_adj cannot be removed since existing userspace binaries use it.
1149 */
oom_adj_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1150 static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1151 size_t count, loff_t *ppos)
1152 {
1153 char buffer[PROC_NUMBUF];
1154 int oom_adj;
1155 int err;
1156
1157 memset(buffer, 0, sizeof(buffer));
1158 if (count > sizeof(buffer) - 1)
1159 count = sizeof(buffer) - 1;
1160 if (copy_from_user(buffer, buf, count)) {
1161 err = -EFAULT;
1162 goto out;
1163 }
1164
1165 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1166 if (err)
1167 goto out;
1168 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1169 oom_adj != OOM_DISABLE) {
1170 err = -EINVAL;
1171 goto out;
1172 }
1173
1174 /*
1175 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1176 * value is always attainable.
1177 */
1178 if (oom_adj == OOM_ADJUST_MAX)
1179 oom_adj = OOM_SCORE_ADJ_MAX;
1180 else
1181 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1182
1183 err = __set_oom_adj(file, oom_adj, true);
1184 out:
1185 return err < 0 ? err : count;
1186 }
1187
1188 static const struct file_operations proc_oom_adj_operations = {
1189 .read = oom_adj_read,
1190 .write = oom_adj_write,
1191 .llseek = generic_file_llseek,
1192 };
1193
oom_score_adj_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1194 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1195 size_t count, loff_t *ppos)
1196 {
1197 struct task_struct *task = get_proc_task(file_inode(file));
1198 char buffer[PROC_NUMBUF];
1199 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1200 size_t len;
1201
1202 if (!task)
1203 return -ESRCH;
1204 oom_score_adj = task->signal->oom_score_adj;
1205 put_task_struct(task);
1206 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1207 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1208 }
1209
oom_score_adj_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1210 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1211 size_t count, loff_t *ppos)
1212 {
1213 char buffer[PROC_NUMBUF];
1214 int oom_score_adj;
1215 int err;
1216
1217 memset(buffer, 0, sizeof(buffer));
1218 if (count > sizeof(buffer) - 1)
1219 count = sizeof(buffer) - 1;
1220 if (copy_from_user(buffer, buf, count)) {
1221 err = -EFAULT;
1222 goto out;
1223 }
1224
1225 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1226 if (err)
1227 goto out;
1228 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1229 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1230 err = -EINVAL;
1231 goto out;
1232 }
1233
1234 err = __set_oom_adj(file, oom_score_adj, false);
1235 out:
1236 return err < 0 ? err : count;
1237 }
1238
1239 static const struct file_operations proc_oom_score_adj_operations = {
1240 .read = oom_score_adj_read,
1241 .write = oom_score_adj_write,
1242 .llseek = default_llseek,
1243 };
1244
1245 #ifdef CONFIG_AUDIT
1246 #define TMPBUFLEN 11
proc_loginuid_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1247 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1248 size_t count, loff_t *ppos)
1249 {
1250 struct inode * inode = file_inode(file);
1251 struct task_struct *task = get_proc_task(inode);
1252 ssize_t length;
1253 char tmpbuf[TMPBUFLEN];
1254
1255 if (!task)
1256 return -ESRCH;
1257 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1258 from_kuid(file->f_cred->user_ns,
1259 audit_get_loginuid(task)));
1260 put_task_struct(task);
1261 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1262 }
1263
proc_loginuid_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1264 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1265 size_t count, loff_t *ppos)
1266 {
1267 struct inode * inode = file_inode(file);
1268 uid_t loginuid;
1269 kuid_t kloginuid;
1270 int rv;
1271
1272 /* Don't let kthreads write their own loginuid */
1273 if (current->flags & PF_KTHREAD)
1274 return -EPERM;
1275
1276 rcu_read_lock();
1277 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1278 rcu_read_unlock();
1279 return -EPERM;
1280 }
1281 rcu_read_unlock();
1282
1283 if (*ppos != 0) {
1284 /* No partial writes. */
1285 return -EINVAL;
1286 }
1287
1288 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1289 if (rv < 0)
1290 return rv;
1291
1292 /* is userspace tring to explicitly UNSET the loginuid? */
1293 if (loginuid == AUDIT_UID_UNSET) {
1294 kloginuid = INVALID_UID;
1295 } else {
1296 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1297 if (!uid_valid(kloginuid))
1298 return -EINVAL;
1299 }
1300
1301 rv = audit_set_loginuid(kloginuid);
1302 if (rv < 0)
1303 return rv;
1304 return count;
1305 }
1306
1307 static const struct file_operations proc_loginuid_operations = {
1308 .read = proc_loginuid_read,
1309 .write = proc_loginuid_write,
1310 .llseek = generic_file_llseek,
1311 };
1312
proc_sessionid_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1313 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1314 size_t count, loff_t *ppos)
1315 {
1316 struct inode * inode = file_inode(file);
1317 struct task_struct *task = get_proc_task(inode);
1318 ssize_t length;
1319 char tmpbuf[TMPBUFLEN];
1320
1321 if (!task)
1322 return -ESRCH;
1323 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1324 audit_get_sessionid(task));
1325 put_task_struct(task);
1326 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1327 }
1328
1329 static const struct file_operations proc_sessionid_operations = {
1330 .read = proc_sessionid_read,
1331 .llseek = generic_file_llseek,
1332 };
1333 #endif
1334
1335 #ifdef CONFIG_FAULT_INJECTION
proc_fault_inject_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1336 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1337 size_t count, loff_t *ppos)
1338 {
1339 struct task_struct *task = get_proc_task(file_inode(file));
1340 char buffer[PROC_NUMBUF];
1341 size_t len;
1342 int make_it_fail;
1343
1344 if (!task)
1345 return -ESRCH;
1346 make_it_fail = task->make_it_fail;
1347 put_task_struct(task);
1348
1349 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1350
1351 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1352 }
1353
proc_fault_inject_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1354 static ssize_t proc_fault_inject_write(struct file * file,
1355 const char __user * buf, size_t count, loff_t *ppos)
1356 {
1357 struct task_struct *task;
1358 char buffer[PROC_NUMBUF];
1359 int make_it_fail;
1360 int rv;
1361
1362 if (!capable(CAP_SYS_RESOURCE))
1363 return -EPERM;
1364 memset(buffer, 0, sizeof(buffer));
1365 if (count > sizeof(buffer) - 1)
1366 count = sizeof(buffer) - 1;
1367 if (copy_from_user(buffer, buf, count))
1368 return -EFAULT;
1369 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1370 if (rv < 0)
1371 return rv;
1372 if (make_it_fail < 0 || make_it_fail > 1)
1373 return -EINVAL;
1374
1375 task = get_proc_task(file_inode(file));
1376 if (!task)
1377 return -ESRCH;
1378 task->make_it_fail = make_it_fail;
1379 put_task_struct(task);
1380
1381 return count;
1382 }
1383
1384 static const struct file_operations proc_fault_inject_operations = {
1385 .read = proc_fault_inject_read,
1386 .write = proc_fault_inject_write,
1387 .llseek = generic_file_llseek,
1388 };
1389
proc_fail_nth_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1390 static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1391 size_t count, loff_t *ppos)
1392 {
1393 struct task_struct *task;
1394 int err;
1395 unsigned int n;
1396
1397 err = kstrtouint_from_user(buf, count, 0, &n);
1398 if (err)
1399 return err;
1400
1401 task = get_proc_task(file_inode(file));
1402 if (!task)
1403 return -ESRCH;
1404 task->fail_nth = n;
1405 put_task_struct(task);
1406
1407 return count;
1408 }
1409
proc_fail_nth_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1410 static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1411 size_t count, loff_t *ppos)
1412 {
1413 struct task_struct *task;
1414 char numbuf[PROC_NUMBUF];
1415 ssize_t len;
1416
1417 task = get_proc_task(file_inode(file));
1418 if (!task)
1419 return -ESRCH;
1420 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1421 put_task_struct(task);
1422 return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1423 }
1424
1425 static const struct file_operations proc_fail_nth_operations = {
1426 .read = proc_fail_nth_read,
1427 .write = proc_fail_nth_write,
1428 };
1429 #endif
1430
1431
1432 #ifdef CONFIG_SCHED_DEBUG
1433 /*
1434 * Print out various scheduling related per-task fields:
1435 */
sched_show(struct seq_file * m,void * v)1436 static int sched_show(struct seq_file *m, void *v)
1437 {
1438 struct inode *inode = m->private;
1439 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
1440 struct task_struct *p;
1441
1442 p = get_proc_task(inode);
1443 if (!p)
1444 return -ESRCH;
1445 proc_sched_show_task(p, ns, m);
1446
1447 put_task_struct(p);
1448
1449 return 0;
1450 }
1451
1452 static ssize_t
sched_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)1453 sched_write(struct file *file, const char __user *buf,
1454 size_t count, loff_t *offset)
1455 {
1456 struct inode *inode = file_inode(file);
1457 struct task_struct *p;
1458
1459 p = get_proc_task(inode);
1460 if (!p)
1461 return -ESRCH;
1462 proc_sched_set_task(p);
1463
1464 put_task_struct(p);
1465
1466 return count;
1467 }
1468
sched_open(struct inode * inode,struct file * filp)1469 static int sched_open(struct inode *inode, struct file *filp)
1470 {
1471 return single_open(filp, sched_show, inode);
1472 }
1473
1474 static const struct file_operations proc_pid_sched_operations = {
1475 .open = sched_open,
1476 .read = seq_read,
1477 .write = sched_write,
1478 .llseek = seq_lseek,
1479 .release = single_release,
1480 };
1481
1482 #endif
1483
1484 #ifdef CONFIG_SCHED_AUTOGROUP
1485 /*
1486 * Print out autogroup related information:
1487 */
sched_autogroup_show(struct seq_file * m,void * v)1488 static int sched_autogroup_show(struct seq_file *m, void *v)
1489 {
1490 struct inode *inode = m->private;
1491 struct task_struct *p;
1492
1493 p = get_proc_task(inode);
1494 if (!p)
1495 return -ESRCH;
1496 proc_sched_autogroup_show_task(p, m);
1497
1498 put_task_struct(p);
1499
1500 return 0;
1501 }
1502
1503 static ssize_t
sched_autogroup_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)1504 sched_autogroup_write(struct file *file, const char __user *buf,
1505 size_t count, loff_t *offset)
1506 {
1507 struct inode *inode = file_inode(file);
1508 struct task_struct *p;
1509 char buffer[PROC_NUMBUF];
1510 int nice;
1511 int err;
1512
1513 memset(buffer, 0, sizeof(buffer));
1514 if (count > sizeof(buffer) - 1)
1515 count = sizeof(buffer) - 1;
1516 if (copy_from_user(buffer, buf, count))
1517 return -EFAULT;
1518
1519 err = kstrtoint(strstrip(buffer), 0, &nice);
1520 if (err < 0)
1521 return err;
1522
1523 p = get_proc_task(inode);
1524 if (!p)
1525 return -ESRCH;
1526
1527 err = proc_sched_autogroup_set_nice(p, nice);
1528 if (err)
1529 count = err;
1530
1531 put_task_struct(p);
1532
1533 return count;
1534 }
1535
sched_autogroup_open(struct inode * inode,struct file * filp)1536 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1537 {
1538 int ret;
1539
1540 ret = single_open(filp, sched_autogroup_show, NULL);
1541 if (!ret) {
1542 struct seq_file *m = filp->private_data;
1543
1544 m->private = inode;
1545 }
1546 return ret;
1547 }
1548
1549 static const struct file_operations proc_pid_sched_autogroup_operations = {
1550 .open = sched_autogroup_open,
1551 .read = seq_read,
1552 .write = sched_autogroup_write,
1553 .llseek = seq_lseek,
1554 .release = single_release,
1555 };
1556
1557 #endif /* CONFIG_SCHED_AUTOGROUP */
1558
1559 #ifdef CONFIG_TIME_NS
timens_offsets_show(struct seq_file * m,void * v)1560 static int timens_offsets_show(struct seq_file *m, void *v)
1561 {
1562 struct task_struct *p;
1563
1564 p = get_proc_task(file_inode(m->file));
1565 if (!p)
1566 return -ESRCH;
1567 proc_timens_show_offsets(p, m);
1568
1569 put_task_struct(p);
1570
1571 return 0;
1572 }
1573
timens_offsets_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1574 static ssize_t timens_offsets_write(struct file *file, const char __user *buf,
1575 size_t count, loff_t *ppos)
1576 {
1577 struct inode *inode = file_inode(file);
1578 struct proc_timens_offset offsets[2];
1579 char *kbuf = NULL, *pos, *next_line;
1580 struct task_struct *p;
1581 int ret, noffsets;
1582
1583 /* Only allow < page size writes at the beginning of the file */
1584 if ((*ppos != 0) || (count >= PAGE_SIZE))
1585 return -EINVAL;
1586
1587 /* Slurp in the user data */
1588 kbuf = memdup_user_nul(buf, count);
1589 if (IS_ERR(kbuf))
1590 return PTR_ERR(kbuf);
1591
1592 /* Parse the user data */
1593 ret = -EINVAL;
1594 noffsets = 0;
1595 for (pos = kbuf; pos; pos = next_line) {
1596 struct proc_timens_offset *off = &offsets[noffsets];
1597 char clock[10];
1598 int err;
1599
1600 /* Find the end of line and ensure we don't look past it */
1601 next_line = strchr(pos, '\n');
1602 if (next_line) {
1603 *next_line = '\0';
1604 next_line++;
1605 if (*next_line == '\0')
1606 next_line = NULL;
1607 }
1608
1609 err = sscanf(pos, "%9s %lld %lu", clock,
1610 &off->val.tv_sec, &off->val.tv_nsec);
1611 if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
1612 goto out;
1613
1614 clock[sizeof(clock) - 1] = 0;
1615 if (strcmp(clock, "monotonic") == 0 ||
1616 strcmp(clock, __stringify(CLOCK_MONOTONIC)) == 0)
1617 off->clockid = CLOCK_MONOTONIC;
1618 else if (strcmp(clock, "boottime") == 0 ||
1619 strcmp(clock, __stringify(CLOCK_BOOTTIME)) == 0)
1620 off->clockid = CLOCK_BOOTTIME;
1621 else
1622 goto out;
1623
1624 noffsets++;
1625 if (noffsets == ARRAY_SIZE(offsets)) {
1626 if (next_line)
1627 count = next_line - kbuf;
1628 break;
1629 }
1630 }
1631
1632 ret = -ESRCH;
1633 p = get_proc_task(inode);
1634 if (!p)
1635 goto out;
1636 ret = proc_timens_set_offset(file, p, offsets, noffsets);
1637 put_task_struct(p);
1638 if (ret)
1639 goto out;
1640
1641 ret = count;
1642 out:
1643 kfree(kbuf);
1644 return ret;
1645 }
1646
timens_offsets_open(struct inode * inode,struct file * filp)1647 static int timens_offsets_open(struct inode *inode, struct file *filp)
1648 {
1649 return single_open(filp, timens_offsets_show, inode);
1650 }
1651
1652 static const struct file_operations proc_timens_offsets_operations = {
1653 .open = timens_offsets_open,
1654 .read = seq_read,
1655 .write = timens_offsets_write,
1656 .llseek = seq_lseek,
1657 .release = single_release,
1658 };
1659 #endif /* CONFIG_TIME_NS */
1660
comm_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)1661 static ssize_t comm_write(struct file *file, const char __user *buf,
1662 size_t count, loff_t *offset)
1663 {
1664 struct inode *inode = file_inode(file);
1665 struct task_struct *p;
1666 char buffer[TASK_COMM_LEN];
1667 const size_t maxlen = sizeof(buffer) - 1;
1668
1669 memset(buffer, 0, sizeof(buffer));
1670 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1671 return -EFAULT;
1672
1673 p = get_proc_task(inode);
1674 if (!p)
1675 return -ESRCH;
1676
1677 if (same_thread_group(current, p))
1678 set_task_comm(p, buffer);
1679 else
1680 count = -EINVAL;
1681
1682 put_task_struct(p);
1683
1684 return count;
1685 }
1686
comm_show(struct seq_file * m,void * v)1687 static int comm_show(struct seq_file *m, void *v)
1688 {
1689 struct inode *inode = m->private;
1690 struct task_struct *p;
1691
1692 p = get_proc_task(inode);
1693 if (!p)
1694 return -ESRCH;
1695
1696 proc_task_name(m, p, false);
1697 seq_putc(m, '\n');
1698
1699 put_task_struct(p);
1700
1701 return 0;
1702 }
1703
comm_open(struct inode * inode,struct file * filp)1704 static int comm_open(struct inode *inode, struct file *filp)
1705 {
1706 return single_open(filp, comm_show, inode);
1707 }
1708
1709 static const struct file_operations proc_pid_set_comm_operations = {
1710 .open = comm_open,
1711 .read = seq_read,
1712 .write = comm_write,
1713 .llseek = seq_lseek,
1714 .release = single_release,
1715 };
1716
proc_exe_link(struct dentry * dentry,struct path * exe_path)1717 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1718 {
1719 struct task_struct *task;
1720 struct file *exe_file;
1721
1722 task = get_proc_task(d_inode(dentry));
1723 if (!task)
1724 return -ENOENT;
1725 exe_file = get_task_exe_file(task);
1726 put_task_struct(task);
1727 if (exe_file) {
1728 *exe_path = exe_file->f_path;
1729 path_get(&exe_file->f_path);
1730 fput(exe_file);
1731 return 0;
1732 } else
1733 return -ENOENT;
1734 }
1735
proc_pid_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)1736 static const char *proc_pid_get_link(struct dentry *dentry,
1737 struct inode *inode,
1738 struct delayed_call *done)
1739 {
1740 struct path path;
1741 int error = -EACCES;
1742
1743 if (!dentry)
1744 return ERR_PTR(-ECHILD);
1745
1746 /* Are we allowed to snoop on the tasks file descriptors? */
1747 if (!proc_fd_access_allowed(inode))
1748 goto out;
1749
1750 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1751 if (error)
1752 goto out;
1753
1754 error = nd_jump_link(&path);
1755 out:
1756 return ERR_PTR(error);
1757 }
1758
do_proc_readlink(struct path * path,char __user * buffer,int buflen)1759 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1760 {
1761 char *tmp = (char *)__get_free_page(GFP_KERNEL);
1762 char *pathname;
1763 int len;
1764
1765 if (!tmp)
1766 return -ENOMEM;
1767
1768 pathname = d_path(path, tmp, PAGE_SIZE);
1769 len = PTR_ERR(pathname);
1770 if (IS_ERR(pathname))
1771 goto out;
1772 len = tmp + PAGE_SIZE - 1 - pathname;
1773
1774 if (len > buflen)
1775 len = buflen;
1776 if (copy_to_user(buffer, pathname, len))
1777 len = -EFAULT;
1778 out:
1779 free_page((unsigned long)tmp);
1780 return len;
1781 }
1782
proc_pid_readlink(struct dentry * dentry,char __user * buffer,int buflen)1783 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1784 {
1785 int error = -EACCES;
1786 struct inode *inode = d_inode(dentry);
1787 struct path path;
1788
1789 /* Are we allowed to snoop on the tasks file descriptors? */
1790 if (!proc_fd_access_allowed(inode))
1791 goto out;
1792
1793 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1794 if (error)
1795 goto out;
1796
1797 error = do_proc_readlink(&path, buffer, buflen);
1798 path_put(&path);
1799 out:
1800 return error;
1801 }
1802
1803 const struct inode_operations proc_pid_link_inode_operations = {
1804 .readlink = proc_pid_readlink,
1805 .get_link = proc_pid_get_link,
1806 .setattr = proc_setattr,
1807 };
1808
1809
1810 /* building an inode */
1811
task_dump_owner(struct task_struct * task,umode_t mode,kuid_t * ruid,kgid_t * rgid)1812 void task_dump_owner(struct task_struct *task, umode_t mode,
1813 kuid_t *ruid, kgid_t *rgid)
1814 {
1815 /* Depending on the state of dumpable compute who should own a
1816 * proc file for a task.
1817 */
1818 const struct cred *cred;
1819 kuid_t uid;
1820 kgid_t gid;
1821
1822 if (unlikely(task->flags & PF_KTHREAD)) {
1823 *ruid = GLOBAL_ROOT_UID;
1824 *rgid = GLOBAL_ROOT_GID;
1825 return;
1826 }
1827
1828 /* Default to the tasks effective ownership */
1829 rcu_read_lock();
1830 cred = __task_cred(task);
1831 uid = cred->euid;
1832 gid = cred->egid;
1833 rcu_read_unlock();
1834
1835 /*
1836 * Before the /proc/pid/status file was created the only way to read
1837 * the effective uid of a /process was to stat /proc/pid. Reading
1838 * /proc/pid/status is slow enough that procps and other packages
1839 * kept stating /proc/pid. To keep the rules in /proc simple I have
1840 * made this apply to all per process world readable and executable
1841 * directories.
1842 */
1843 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1844 struct mm_struct *mm;
1845 task_lock(task);
1846 mm = task->mm;
1847 /* Make non-dumpable tasks owned by some root */
1848 if (mm) {
1849 if (get_dumpable(mm) != SUID_DUMP_USER) {
1850 struct user_namespace *user_ns = mm->user_ns;
1851
1852 uid = make_kuid(user_ns, 0);
1853 if (!uid_valid(uid))
1854 uid = GLOBAL_ROOT_UID;
1855
1856 gid = make_kgid(user_ns, 0);
1857 if (!gid_valid(gid))
1858 gid = GLOBAL_ROOT_GID;
1859 }
1860 } else {
1861 uid = GLOBAL_ROOT_UID;
1862 gid = GLOBAL_ROOT_GID;
1863 }
1864 task_unlock(task);
1865 }
1866 *ruid = uid;
1867 *rgid = gid;
1868 }
1869
proc_pid_evict_inode(struct proc_inode * ei)1870 void proc_pid_evict_inode(struct proc_inode *ei)
1871 {
1872 struct pid *pid = ei->pid;
1873
1874 if (S_ISDIR(ei->vfs_inode.i_mode)) {
1875 spin_lock(&pid->lock);
1876 hlist_del_init_rcu(&ei->sibling_inodes);
1877 spin_unlock(&pid->lock);
1878 }
1879
1880 put_pid(pid);
1881 }
1882
proc_pid_make_inode(struct super_block * sb,struct task_struct * task,umode_t mode)1883 struct inode *proc_pid_make_inode(struct super_block * sb,
1884 struct task_struct *task, umode_t mode)
1885 {
1886 struct inode * inode;
1887 struct proc_inode *ei;
1888 struct pid *pid;
1889
1890 /* We need a new inode */
1891
1892 inode = new_inode(sb);
1893 if (!inode)
1894 goto out;
1895
1896 /* Common stuff */
1897 ei = PROC_I(inode);
1898 inode->i_mode = mode;
1899 inode->i_ino = get_next_ino();
1900 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1901 inode->i_op = &proc_def_inode_operations;
1902
1903 /*
1904 * grab the reference to task.
1905 */
1906 pid = get_task_pid(task, PIDTYPE_PID);
1907 if (!pid)
1908 goto out_unlock;
1909
1910 /* Let the pid remember us for quick removal */
1911 ei->pid = pid;
1912 if (S_ISDIR(mode)) {
1913 spin_lock(&pid->lock);
1914 hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
1915 spin_unlock(&pid->lock);
1916 }
1917
1918 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 iput(inode);
1926 return NULL;
1927 }
1928
pid_getattr(struct user_namespace * mnt_userns,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)1929 int pid_getattr(struct user_namespace *mnt_userns, const struct path *path,
1930 struct kstat *stat, u32 request_mask, unsigned int query_flags)
1931 {
1932 struct inode *inode = d_inode(path->dentry);
1933 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
1934 struct task_struct *task;
1935
1936 generic_fillattr(&init_user_ns, inode, stat);
1937
1938 stat->uid = GLOBAL_ROOT_UID;
1939 stat->gid = GLOBAL_ROOT_GID;
1940 rcu_read_lock();
1941 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1942 if (task) {
1943 if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) {
1944 rcu_read_unlock();
1945 /*
1946 * This doesn't prevent learning whether PID exists,
1947 * it only makes getattr() consistent with readdir().
1948 */
1949 return -ENOENT;
1950 }
1951 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1952 }
1953 rcu_read_unlock();
1954 return 0;
1955 }
1956
1957 /* dentry stuff */
1958
1959 /*
1960 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1961 */
pid_update_inode(struct task_struct * task,struct inode * inode)1962 void pid_update_inode(struct task_struct *task, struct inode *inode)
1963 {
1964 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1965
1966 inode->i_mode &= ~(S_ISUID | S_ISGID);
1967 security_task_to_inode(task, inode);
1968 }
1969
1970 /*
1971 * Rewrite the inode's ownerships here because the owning task may have
1972 * performed a setuid(), etc.
1973 *
1974 */
pid_revalidate(struct dentry * dentry,unsigned int flags)1975 static int pid_revalidate(struct dentry *dentry, unsigned int flags)
1976 {
1977 struct inode *inode;
1978 struct task_struct *task;
1979
1980 if (flags & LOOKUP_RCU)
1981 return -ECHILD;
1982
1983 inode = d_inode(dentry);
1984 task = get_proc_task(inode);
1985
1986 if (task) {
1987 pid_update_inode(task, inode);
1988 put_task_struct(task);
1989 return 1;
1990 }
1991 return 0;
1992 }
1993
proc_inode_is_dead(struct inode * inode)1994 static inline bool proc_inode_is_dead(struct inode *inode)
1995 {
1996 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1997 }
1998
pid_delete_dentry(const struct dentry * dentry)1999 int pid_delete_dentry(const struct dentry *dentry)
2000 {
2001 /* Is the task we represent dead?
2002 * If so, then don't put the dentry on the lru list,
2003 * kill it immediately.
2004 */
2005 return proc_inode_is_dead(d_inode(dentry));
2006 }
2007
2008 const struct dentry_operations pid_dentry_operations =
2009 {
2010 .d_revalidate = pid_revalidate,
2011 .d_delete = pid_delete_dentry,
2012 };
2013
2014 /* Lookups */
2015
2016 /*
2017 * Fill a directory entry.
2018 *
2019 * If possible create the dcache entry and derive our inode number and
2020 * file type from dcache entry.
2021 *
2022 * Since all of the proc inode numbers are dynamically generated, the inode
2023 * numbers do not exist until the inode is cache. This means creating
2024 * the dcache entry in readdir is necessary to keep the inode numbers
2025 * reported by readdir in sync with the inode numbers reported
2026 * by stat.
2027 */
proc_fill_cache(struct file * file,struct dir_context * ctx,const char * name,unsigned int len,instantiate_t instantiate,struct task_struct * task,const void * ptr)2028 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
2029 const char *name, unsigned int len,
2030 instantiate_t instantiate, struct task_struct *task, const void *ptr)
2031 {
2032 struct dentry *child, *dir = file->f_path.dentry;
2033 struct qstr qname = QSTR_INIT(name, len);
2034 struct inode *inode;
2035 unsigned type = DT_UNKNOWN;
2036 ino_t ino = 1;
2037
2038 child = d_hash_and_lookup(dir, &qname);
2039 if (!child) {
2040 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
2041 child = d_alloc_parallel(dir, &qname, &wq);
2042 if (IS_ERR(child))
2043 goto end_instantiate;
2044 if (d_in_lookup(child)) {
2045 struct dentry *res;
2046 res = instantiate(child, task, ptr);
2047 d_lookup_done(child);
2048 if (unlikely(res)) {
2049 dput(child);
2050 child = res;
2051 if (IS_ERR(child))
2052 goto end_instantiate;
2053 }
2054 }
2055 }
2056 inode = d_inode(child);
2057 ino = inode->i_ino;
2058 type = inode->i_mode >> 12;
2059 dput(child);
2060 end_instantiate:
2061 return dir_emit(ctx, name, len, ino, type);
2062 }
2063
2064 /*
2065 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2066 * which represent vma start and end addresses.
2067 */
dname_to_vma_addr(struct dentry * dentry,unsigned long * start,unsigned long * end)2068 static int dname_to_vma_addr(struct dentry *dentry,
2069 unsigned long *start, unsigned long *end)
2070 {
2071 const char *str = dentry->d_name.name;
2072 unsigned long long sval, eval;
2073 unsigned int len;
2074
2075 if (str[0] == '0' && str[1] != '-')
2076 return -EINVAL;
2077 len = _parse_integer(str, 16, &sval);
2078 if (len & KSTRTOX_OVERFLOW)
2079 return -EINVAL;
2080 if (sval != (unsigned long)sval)
2081 return -EINVAL;
2082 str += len;
2083
2084 if (*str != '-')
2085 return -EINVAL;
2086 str++;
2087
2088 if (str[0] == '0' && str[1])
2089 return -EINVAL;
2090 len = _parse_integer(str, 16, &eval);
2091 if (len & KSTRTOX_OVERFLOW)
2092 return -EINVAL;
2093 if (eval != (unsigned long)eval)
2094 return -EINVAL;
2095 str += len;
2096
2097 if (*str != '\0')
2098 return -EINVAL;
2099
2100 *start = sval;
2101 *end = eval;
2102
2103 return 0;
2104 }
2105
map_files_d_revalidate(struct dentry * dentry,unsigned int flags)2106 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
2107 {
2108 unsigned long vm_start, vm_end;
2109 bool exact_vma_exists = false;
2110 struct mm_struct *mm = NULL;
2111 struct task_struct *task;
2112 struct inode *inode;
2113 int status = 0;
2114
2115 if (flags & LOOKUP_RCU)
2116 return -ECHILD;
2117
2118 inode = d_inode(dentry);
2119 task = get_proc_task(inode);
2120 if (!task)
2121 goto out_notask;
2122
2123 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2124 if (IS_ERR_OR_NULL(mm))
2125 goto out;
2126
2127 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2128 status = mmap_read_lock_killable(mm);
2129 if (!status) {
2130 exact_vma_exists = !!find_exact_vma(mm, vm_start,
2131 vm_end);
2132 mmap_read_unlock(mm);
2133 }
2134 }
2135
2136 mmput(mm);
2137
2138 if (exact_vma_exists) {
2139 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
2140
2141 security_task_to_inode(task, inode);
2142 status = 1;
2143 }
2144
2145 out:
2146 put_task_struct(task);
2147
2148 out_notask:
2149 return status;
2150 }
2151
2152 static const struct dentry_operations tid_map_files_dentry_operations = {
2153 .d_revalidate = map_files_d_revalidate,
2154 .d_delete = pid_delete_dentry,
2155 };
2156
map_files_get_link(struct dentry * dentry,struct path * path)2157 static int map_files_get_link(struct dentry *dentry, struct path *path)
2158 {
2159 unsigned long vm_start, vm_end;
2160 struct vm_area_struct *vma;
2161 struct task_struct *task;
2162 struct mm_struct *mm;
2163 int rc;
2164
2165 rc = -ENOENT;
2166 task = get_proc_task(d_inode(dentry));
2167 if (!task)
2168 goto out;
2169
2170 mm = get_task_mm(task);
2171 put_task_struct(task);
2172 if (!mm)
2173 goto out;
2174
2175 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2176 if (rc)
2177 goto out_mmput;
2178
2179 rc = mmap_read_lock_killable(mm);
2180 if (rc)
2181 goto out_mmput;
2182
2183 rc = -ENOENT;
2184 vma = find_exact_vma(mm, vm_start, vm_end);
2185 if (vma && vma->vm_file) {
2186 *path = vma->vm_file->f_path;
2187 path_get(path);
2188 rc = 0;
2189 }
2190 mmap_read_unlock(mm);
2191
2192 out_mmput:
2193 mmput(mm);
2194 out:
2195 return rc;
2196 }
2197
2198 struct map_files_info {
2199 unsigned long start;
2200 unsigned long end;
2201 fmode_t mode;
2202 };
2203
2204 /*
2205 * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
2206 * to concerns about how the symlinks may be used to bypass permissions on
2207 * ancestor directories in the path to the file in question.
2208 */
2209 static const char *
proc_map_files_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)2210 proc_map_files_get_link(struct dentry *dentry,
2211 struct inode *inode,
2212 struct delayed_call *done)
2213 {
2214 if (!checkpoint_restore_ns_capable(&init_user_ns))
2215 return ERR_PTR(-EPERM);
2216
2217 return proc_pid_get_link(dentry, inode, done);
2218 }
2219
2220 /*
2221 * Identical to proc_pid_link_inode_operations except for get_link()
2222 */
2223 static const struct inode_operations proc_map_files_link_inode_operations = {
2224 .readlink = proc_pid_readlink,
2225 .get_link = proc_map_files_get_link,
2226 .setattr = proc_setattr,
2227 };
2228
2229 static struct dentry *
proc_map_files_instantiate(struct dentry * dentry,struct task_struct * task,const void * ptr)2230 proc_map_files_instantiate(struct dentry *dentry,
2231 struct task_struct *task, const void *ptr)
2232 {
2233 fmode_t mode = (fmode_t)(unsigned long)ptr;
2234 struct proc_inode *ei;
2235 struct inode *inode;
2236
2237 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2238 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2239 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2240 if (!inode)
2241 return ERR_PTR(-ENOENT);
2242
2243 ei = PROC_I(inode);
2244 ei->op.proc_get_link = map_files_get_link;
2245
2246 inode->i_op = &proc_map_files_link_inode_operations;
2247 inode->i_size = 64;
2248
2249 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2250 return d_splice_alias(inode, dentry);
2251 }
2252
proc_map_files_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)2253 static struct dentry *proc_map_files_lookup(struct inode *dir,
2254 struct dentry *dentry, unsigned int flags)
2255 {
2256 unsigned long vm_start, vm_end;
2257 struct vm_area_struct *vma;
2258 struct task_struct *task;
2259 struct dentry *result;
2260 struct mm_struct *mm;
2261
2262 result = ERR_PTR(-ENOENT);
2263 task = get_proc_task(dir);
2264 if (!task)
2265 goto out;
2266
2267 result = ERR_PTR(-EACCES);
2268 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2269 goto out_put_task;
2270
2271 result = ERR_PTR(-ENOENT);
2272 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2273 goto out_put_task;
2274
2275 mm = get_task_mm(task);
2276 if (!mm)
2277 goto out_put_task;
2278
2279 result = ERR_PTR(-EINTR);
2280 if (mmap_read_lock_killable(mm))
2281 goto out_put_mm;
2282
2283 result = ERR_PTR(-ENOENT);
2284 vma = find_exact_vma(mm, vm_start, vm_end);
2285 if (!vma)
2286 goto out_no_vma;
2287
2288 if (vma->vm_file)
2289 result = proc_map_files_instantiate(dentry, task,
2290 (void *)(unsigned long)vma->vm_file->f_mode);
2291
2292 out_no_vma:
2293 mmap_read_unlock(mm);
2294 out_put_mm:
2295 mmput(mm);
2296 out_put_task:
2297 put_task_struct(task);
2298 out:
2299 return result;
2300 }
2301
2302 static const struct inode_operations proc_map_files_inode_operations = {
2303 .lookup = proc_map_files_lookup,
2304 .permission = proc_fd_permission,
2305 .setattr = proc_setattr,
2306 };
2307
2308 static int
proc_map_files_readdir(struct file * file,struct dir_context * ctx)2309 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2310 {
2311 struct vm_area_struct *vma;
2312 struct task_struct *task;
2313 struct mm_struct *mm;
2314 unsigned long nr_files, pos, i;
2315 GENRADIX(struct map_files_info) fa;
2316 struct map_files_info *p;
2317 int ret;
2318
2319 genradix_init(&fa);
2320
2321 ret = -ENOENT;
2322 task = get_proc_task(file_inode(file));
2323 if (!task)
2324 goto out;
2325
2326 ret = -EACCES;
2327 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2328 goto out_put_task;
2329
2330 ret = 0;
2331 if (!dir_emit_dots(file, ctx))
2332 goto out_put_task;
2333
2334 mm = get_task_mm(task);
2335 if (!mm)
2336 goto out_put_task;
2337
2338 ret = mmap_read_lock_killable(mm);
2339 if (ret) {
2340 mmput(mm);
2341 goto out_put_task;
2342 }
2343
2344 nr_files = 0;
2345
2346 /*
2347 * We need two passes here:
2348 *
2349 * 1) Collect vmas of mapped files with mmap_lock taken
2350 * 2) Release mmap_lock and instantiate entries
2351 *
2352 * otherwise we get lockdep complained, since filldir()
2353 * routine might require mmap_lock taken in might_fault().
2354 */
2355
2356 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2357 if (!vma->vm_file)
2358 continue;
2359 if (++pos <= ctx->pos)
2360 continue;
2361
2362 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2363 if (!p) {
2364 ret = -ENOMEM;
2365 mmap_read_unlock(mm);
2366 mmput(mm);
2367 goto out_put_task;
2368 }
2369
2370 p->start = vma->vm_start;
2371 p->end = vma->vm_end;
2372 p->mode = vma->vm_file->f_mode;
2373 }
2374 mmap_read_unlock(mm);
2375 mmput(mm);
2376
2377 for (i = 0; i < nr_files; i++) {
2378 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2379 unsigned int len;
2380
2381 p = genradix_ptr(&fa, i);
2382 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2383 if (!proc_fill_cache(file, ctx,
2384 buf, len,
2385 proc_map_files_instantiate,
2386 task,
2387 (void *)(unsigned long)p->mode))
2388 break;
2389 ctx->pos++;
2390 }
2391
2392 out_put_task:
2393 put_task_struct(task);
2394 out:
2395 genradix_free(&fa);
2396 return ret;
2397 }
2398
2399 static const struct file_operations proc_map_files_operations = {
2400 .read = generic_read_dir,
2401 .iterate_shared = proc_map_files_readdir,
2402 .llseek = generic_file_llseek,
2403 };
2404
2405 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2406 struct timers_private {
2407 struct pid *pid;
2408 struct task_struct *task;
2409 struct sighand_struct *sighand;
2410 struct pid_namespace *ns;
2411 unsigned long flags;
2412 };
2413
timers_start(struct seq_file * m,loff_t * pos)2414 static void *timers_start(struct seq_file *m, loff_t *pos)
2415 {
2416 struct timers_private *tp = m->private;
2417
2418 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2419 if (!tp->task)
2420 return ERR_PTR(-ESRCH);
2421
2422 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2423 if (!tp->sighand)
2424 return ERR_PTR(-ESRCH);
2425
2426 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2427 }
2428
timers_next(struct seq_file * m,void * v,loff_t * pos)2429 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2430 {
2431 struct timers_private *tp = m->private;
2432 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2433 }
2434
timers_stop(struct seq_file * m,void * v)2435 static void timers_stop(struct seq_file *m, void *v)
2436 {
2437 struct timers_private *tp = m->private;
2438
2439 if (tp->sighand) {
2440 unlock_task_sighand(tp->task, &tp->flags);
2441 tp->sighand = NULL;
2442 }
2443
2444 if (tp->task) {
2445 put_task_struct(tp->task);
2446 tp->task = NULL;
2447 }
2448 }
2449
show_timer(struct seq_file * m,void * v)2450 static int show_timer(struct seq_file *m, void *v)
2451 {
2452 struct k_itimer *timer;
2453 struct timers_private *tp = m->private;
2454 int notify;
2455 static const char * const nstr[] = {
2456 [SIGEV_SIGNAL] = "signal",
2457 [SIGEV_NONE] = "none",
2458 [SIGEV_THREAD] = "thread",
2459 };
2460
2461 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2462 notify = timer->it_sigev_notify;
2463
2464 seq_printf(m, "ID: %d\n", timer->it_id);
2465 seq_printf(m, "signal: %d/%px\n",
2466 timer->sigq->info.si_signo,
2467 timer->sigq->info.si_value.sival_ptr);
2468 seq_printf(m, "notify: %s/%s.%d\n",
2469 nstr[notify & ~SIGEV_THREAD_ID],
2470 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2471 pid_nr_ns(timer->it_pid, tp->ns));
2472 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2473
2474 return 0;
2475 }
2476
2477 static const struct seq_operations proc_timers_seq_ops = {
2478 .start = timers_start,
2479 .next = timers_next,
2480 .stop = timers_stop,
2481 .show = show_timer,
2482 };
2483
proc_timers_open(struct inode * inode,struct file * file)2484 static int proc_timers_open(struct inode *inode, struct file *file)
2485 {
2486 struct timers_private *tp;
2487
2488 tp = __seq_open_private(file, &proc_timers_seq_ops,
2489 sizeof(struct timers_private));
2490 if (!tp)
2491 return -ENOMEM;
2492
2493 tp->pid = proc_pid(inode);
2494 tp->ns = proc_pid_ns(inode->i_sb);
2495 return 0;
2496 }
2497
2498 static const struct file_operations proc_timers_operations = {
2499 .open = proc_timers_open,
2500 .read = seq_read,
2501 .llseek = seq_lseek,
2502 .release = seq_release_private,
2503 };
2504 #endif
2505
timerslack_ns_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)2506 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2507 size_t count, loff_t *offset)
2508 {
2509 struct inode *inode = file_inode(file);
2510 struct task_struct *p;
2511 u64 slack_ns;
2512 int err;
2513
2514 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2515 if (err < 0)
2516 return err;
2517
2518 p = get_proc_task(inode);
2519 if (!p)
2520 return -ESRCH;
2521
2522 if (p != current) {
2523 rcu_read_lock();
2524 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2525 rcu_read_unlock();
2526 count = -EPERM;
2527 goto out;
2528 }
2529 rcu_read_unlock();
2530
2531 err = security_task_setscheduler(p);
2532 if (err) {
2533 count = err;
2534 goto out;
2535 }
2536 }
2537
2538 task_lock(p);
2539 if (slack_ns == 0)
2540 p->timer_slack_ns = p->default_timer_slack_ns;
2541 else
2542 p->timer_slack_ns = slack_ns;
2543 task_unlock(p);
2544
2545 out:
2546 put_task_struct(p);
2547
2548 return count;
2549 }
2550
timerslack_ns_show(struct seq_file * m,void * v)2551 static int timerslack_ns_show(struct seq_file *m, void *v)
2552 {
2553 struct inode *inode = m->private;
2554 struct task_struct *p;
2555 int err = 0;
2556
2557 p = get_proc_task(inode);
2558 if (!p)
2559 return -ESRCH;
2560
2561 if (p != current) {
2562 rcu_read_lock();
2563 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2564 rcu_read_unlock();
2565 err = -EPERM;
2566 goto out;
2567 }
2568 rcu_read_unlock();
2569
2570 err = security_task_getscheduler(p);
2571 if (err)
2572 goto out;
2573 }
2574
2575 task_lock(p);
2576 seq_printf(m, "%llu\n", p->timer_slack_ns);
2577 task_unlock(p);
2578
2579 out:
2580 put_task_struct(p);
2581
2582 return err;
2583 }
2584
timerslack_ns_open(struct inode * inode,struct file * filp)2585 static int timerslack_ns_open(struct inode *inode, struct file *filp)
2586 {
2587 return single_open(filp, timerslack_ns_show, inode);
2588 }
2589
2590 static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2591 .open = timerslack_ns_open,
2592 .read = seq_read,
2593 .write = timerslack_ns_write,
2594 .llseek = seq_lseek,
2595 .release = single_release,
2596 };
2597
proc_pident_instantiate(struct dentry * dentry,struct task_struct * task,const void * ptr)2598 static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2599 struct task_struct *task, const void *ptr)
2600 {
2601 const struct pid_entry *p = ptr;
2602 struct inode *inode;
2603 struct proc_inode *ei;
2604
2605 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2606 if (!inode)
2607 return ERR_PTR(-ENOENT);
2608
2609 ei = PROC_I(inode);
2610 if (S_ISDIR(inode->i_mode))
2611 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2612 if (p->iop)
2613 inode->i_op = p->iop;
2614 if (p->fop)
2615 inode->i_fop = p->fop;
2616 ei->op = p->op;
2617 pid_update_inode(task, inode);
2618 d_set_d_op(dentry, &pid_dentry_operations);
2619 return d_splice_alias(inode, dentry);
2620 }
2621
proc_pident_lookup(struct inode * dir,struct dentry * dentry,const struct pid_entry * p,const struct pid_entry * end)2622 static struct dentry *proc_pident_lookup(struct inode *dir,
2623 struct dentry *dentry,
2624 const struct pid_entry *p,
2625 const struct pid_entry *end)
2626 {
2627 struct task_struct *task = get_proc_task(dir);
2628 struct dentry *res = ERR_PTR(-ENOENT);
2629
2630 if (!task)
2631 goto out_no_task;
2632
2633 /*
2634 * Yes, it does not scale. And it should not. Don't add
2635 * new entries into /proc/<tgid>/ without very good reasons.
2636 */
2637 for (; p < end; p++) {
2638 if (p->len != dentry->d_name.len)
2639 continue;
2640 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2641 res = proc_pident_instantiate(dentry, task, p);
2642 break;
2643 }
2644 }
2645 put_task_struct(task);
2646 out_no_task:
2647 return res;
2648 }
2649
proc_pident_readdir(struct file * file,struct dir_context * ctx,const struct pid_entry * ents,unsigned int nents)2650 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2651 const struct pid_entry *ents, unsigned int nents)
2652 {
2653 struct task_struct *task = get_proc_task(file_inode(file));
2654 const struct pid_entry *p;
2655
2656 if (!task)
2657 return -ENOENT;
2658
2659 if (!dir_emit_dots(file, ctx))
2660 goto out;
2661
2662 if (ctx->pos >= nents + 2)
2663 goto out;
2664
2665 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2666 if (!proc_fill_cache(file, ctx, p->name, p->len,
2667 proc_pident_instantiate, task, p))
2668 break;
2669 ctx->pos++;
2670 }
2671 out:
2672 put_task_struct(task);
2673 return 0;
2674 }
2675
2676 #ifdef CONFIG_SECURITY
proc_pid_attr_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)2677 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2678 size_t count, loff_t *ppos)
2679 {
2680 struct inode * inode = file_inode(file);
2681 char *p = NULL;
2682 ssize_t length;
2683 struct task_struct *task = get_proc_task(inode);
2684
2685 if (!task)
2686 return -ESRCH;
2687
2688 length = security_getprocattr(task, PROC_I(inode)->op.lsm,
2689 (char*)file->f_path.dentry->d_name.name,
2690 &p);
2691 put_task_struct(task);
2692 if (length > 0)
2693 length = simple_read_from_buffer(buf, count, ppos, p, length);
2694 kfree(p);
2695 return length;
2696 }
2697
proc_pid_attr_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2698 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2699 size_t count, loff_t *ppos)
2700 {
2701 struct inode * inode = file_inode(file);
2702 struct task_struct *task;
2703 void *page;
2704 int rv;
2705
2706 rcu_read_lock();
2707 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2708 if (!task) {
2709 rcu_read_unlock();
2710 return -ESRCH;
2711 }
2712 /* A task may only write its own attributes. */
2713 if (current != task) {
2714 rcu_read_unlock();
2715 return -EACCES;
2716 }
2717 /* Prevent changes to overridden credentials. */
2718 if (current_cred() != current_real_cred()) {
2719 rcu_read_unlock();
2720 return -EBUSY;
2721 }
2722 rcu_read_unlock();
2723
2724 if (count > PAGE_SIZE)
2725 count = PAGE_SIZE;
2726
2727 /* No partial writes. */
2728 if (*ppos != 0)
2729 return -EINVAL;
2730
2731 page = memdup_user(buf, count);
2732 if (IS_ERR(page)) {
2733 rv = PTR_ERR(page);
2734 goto out;
2735 }
2736
2737 /* Guard against adverse ptrace interaction */
2738 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex);
2739 if (rv < 0)
2740 goto out_free;
2741
2742 rv = security_setprocattr(PROC_I(inode)->op.lsm,
2743 file->f_path.dentry->d_name.name, page,
2744 count);
2745 mutex_unlock(¤t->signal->cred_guard_mutex);
2746 out_free:
2747 kfree(page);
2748 out:
2749 return rv;
2750 }
2751
2752 static const struct file_operations proc_pid_attr_operations = {
2753 .read = proc_pid_attr_read,
2754 .write = proc_pid_attr_write,
2755 .llseek = generic_file_llseek,
2756 };
2757
2758 #define LSM_DIR_OPS(LSM) \
2759 static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2760 struct dir_context *ctx) \
2761 { \
2762 return proc_pident_readdir(filp, ctx, \
2763 LSM##_attr_dir_stuff, \
2764 ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2765 } \
2766 \
2767 static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2768 .read = generic_read_dir, \
2769 .iterate = proc_##LSM##_attr_dir_iterate, \
2770 .llseek = default_llseek, \
2771 }; \
2772 \
2773 static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2774 struct dentry *dentry, unsigned int flags) \
2775 { \
2776 return proc_pident_lookup(dir, dentry, \
2777 LSM##_attr_dir_stuff, \
2778 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2779 } \
2780 \
2781 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2782 .lookup = proc_##LSM##_attr_dir_lookup, \
2783 .getattr = pid_getattr, \
2784 .setattr = proc_setattr, \
2785 }
2786
2787 #ifdef CONFIG_SECURITY_SMACK
2788 static const struct pid_entry smack_attr_dir_stuff[] = {
2789 ATTR("smack", "current", 0666),
2790 };
2791 LSM_DIR_OPS(smack);
2792 #endif
2793
2794 #ifdef CONFIG_SECURITY_APPARMOR
2795 static const struct pid_entry apparmor_attr_dir_stuff[] = {
2796 ATTR("apparmor", "current", 0666),
2797 ATTR("apparmor", "prev", 0444),
2798 ATTR("apparmor", "exec", 0666),
2799 };
2800 LSM_DIR_OPS(apparmor);
2801 #endif
2802
2803 static const struct pid_entry attr_dir_stuff[] = {
2804 ATTR(NULL, "current", 0666),
2805 ATTR(NULL, "prev", 0444),
2806 ATTR(NULL, "exec", 0666),
2807 ATTR(NULL, "fscreate", 0666),
2808 ATTR(NULL, "keycreate", 0666),
2809 ATTR(NULL, "sockcreate", 0666),
2810 #ifdef CONFIG_SECURITY_SMACK
2811 DIR("smack", 0555,
2812 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2813 #endif
2814 #ifdef CONFIG_SECURITY_APPARMOR
2815 DIR("apparmor", 0555,
2816 proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
2817 #endif
2818 };
2819
proc_attr_dir_readdir(struct file * file,struct dir_context * ctx)2820 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2821 {
2822 return proc_pident_readdir(file, ctx,
2823 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2824 }
2825
2826 static const struct file_operations proc_attr_dir_operations = {
2827 .read = generic_read_dir,
2828 .iterate_shared = proc_attr_dir_readdir,
2829 .llseek = generic_file_llseek,
2830 };
2831
proc_attr_dir_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)2832 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2833 struct dentry *dentry, unsigned int flags)
2834 {
2835 return proc_pident_lookup(dir, dentry,
2836 attr_dir_stuff,
2837 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2838 }
2839
2840 static const struct inode_operations proc_attr_dir_inode_operations = {
2841 .lookup = proc_attr_dir_lookup,
2842 .getattr = pid_getattr,
2843 .setattr = proc_setattr,
2844 };
2845
2846 #endif
2847
2848 #ifdef CONFIG_ELF_CORE
proc_coredump_filter_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)2849 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2850 size_t count, loff_t *ppos)
2851 {
2852 struct task_struct *task = get_proc_task(file_inode(file));
2853 struct mm_struct *mm;
2854 char buffer[PROC_NUMBUF];
2855 size_t len;
2856 int ret;
2857
2858 if (!task)
2859 return -ESRCH;
2860
2861 ret = 0;
2862 mm = get_task_mm(task);
2863 if (mm) {
2864 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2865 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2866 MMF_DUMP_FILTER_SHIFT));
2867 mmput(mm);
2868 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2869 }
2870
2871 put_task_struct(task);
2872
2873 return ret;
2874 }
2875
proc_coredump_filter_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2876 static ssize_t proc_coredump_filter_write(struct file *file,
2877 const char __user *buf,
2878 size_t count,
2879 loff_t *ppos)
2880 {
2881 struct task_struct *task;
2882 struct mm_struct *mm;
2883 unsigned int val;
2884 int ret;
2885 int i;
2886 unsigned long mask;
2887
2888 ret = kstrtouint_from_user(buf, count, 0, &val);
2889 if (ret < 0)
2890 return ret;
2891
2892 ret = -ESRCH;
2893 task = get_proc_task(file_inode(file));
2894 if (!task)
2895 goto out_no_task;
2896
2897 mm = get_task_mm(task);
2898 if (!mm)
2899 goto out_no_mm;
2900 ret = 0;
2901
2902 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2903 if (val & mask)
2904 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2905 else
2906 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2907 }
2908
2909 mmput(mm);
2910 out_no_mm:
2911 put_task_struct(task);
2912 out_no_task:
2913 if (ret < 0)
2914 return ret;
2915 return count;
2916 }
2917
2918 static const struct file_operations proc_coredump_filter_operations = {
2919 .read = proc_coredump_filter_read,
2920 .write = proc_coredump_filter_write,
2921 .llseek = generic_file_llseek,
2922 };
2923 #endif
2924
2925 #ifdef CONFIG_TASK_IO_ACCOUNTING
do_io_accounting(struct task_struct * task,struct seq_file * m,int whole)2926 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2927 {
2928 struct task_io_accounting acct = task->ioac;
2929 unsigned long flags;
2930 int result;
2931
2932 result = down_read_killable(&task->signal->exec_update_lock);
2933 if (result)
2934 return result;
2935
2936 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2937 result = -EACCES;
2938 goto out_unlock;
2939 }
2940
2941 if (whole && lock_task_sighand(task, &flags)) {
2942 struct task_struct *t = task;
2943
2944 task_io_accounting_add(&acct, &task->signal->ioac);
2945 while_each_thread(task, t)
2946 task_io_accounting_add(&acct, &t->ioac);
2947
2948 unlock_task_sighand(task, &flags);
2949 }
2950 seq_printf(m,
2951 "rchar: %llu\n"
2952 "wchar: %llu\n"
2953 "syscr: %llu\n"
2954 "syscw: %llu\n"
2955 "read_bytes: %llu\n"
2956 "write_bytes: %llu\n"
2957 "cancelled_write_bytes: %llu\n",
2958 (unsigned long long)acct.rchar,
2959 (unsigned long long)acct.wchar,
2960 (unsigned long long)acct.syscr,
2961 (unsigned long long)acct.syscw,
2962 (unsigned long long)acct.read_bytes,
2963 (unsigned long long)acct.write_bytes,
2964 (unsigned long long)acct.cancelled_write_bytes);
2965 result = 0;
2966
2967 out_unlock:
2968 up_read(&task->signal->exec_update_lock);
2969 return result;
2970 }
2971
proc_tid_io_accounting(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)2972 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2973 struct pid *pid, struct task_struct *task)
2974 {
2975 return do_io_accounting(task, m, 0);
2976 }
2977
proc_tgid_io_accounting(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)2978 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2979 struct pid *pid, struct task_struct *task)
2980 {
2981 return do_io_accounting(task, m, 1);
2982 }
2983 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2984
2985 #ifdef CONFIG_USER_NS
proc_id_map_open(struct inode * inode,struct file * file,const struct seq_operations * seq_ops)2986 static int proc_id_map_open(struct inode *inode, struct file *file,
2987 const struct seq_operations *seq_ops)
2988 {
2989 struct user_namespace *ns = NULL;
2990 struct task_struct *task;
2991 struct seq_file *seq;
2992 int ret = -EINVAL;
2993
2994 task = get_proc_task(inode);
2995 if (task) {
2996 rcu_read_lock();
2997 ns = get_user_ns(task_cred_xxx(task, user_ns));
2998 rcu_read_unlock();
2999 put_task_struct(task);
3000 }
3001 if (!ns)
3002 goto err;
3003
3004 ret = seq_open(file, seq_ops);
3005 if (ret)
3006 goto err_put_ns;
3007
3008 seq = file->private_data;
3009 seq->private = ns;
3010
3011 return 0;
3012 err_put_ns:
3013 put_user_ns(ns);
3014 err:
3015 return ret;
3016 }
3017
proc_id_map_release(struct inode * inode,struct file * file)3018 static int proc_id_map_release(struct inode *inode, struct file *file)
3019 {
3020 struct seq_file *seq = file->private_data;
3021 struct user_namespace *ns = seq->private;
3022 put_user_ns(ns);
3023 return seq_release(inode, file);
3024 }
3025
proc_uid_map_open(struct inode * inode,struct file * file)3026 static int proc_uid_map_open(struct inode *inode, struct file *file)
3027 {
3028 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
3029 }
3030
proc_gid_map_open(struct inode * inode,struct file * file)3031 static int proc_gid_map_open(struct inode *inode, struct file *file)
3032 {
3033 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
3034 }
3035
proc_projid_map_open(struct inode * inode,struct file * file)3036 static int proc_projid_map_open(struct inode *inode, struct file *file)
3037 {
3038 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
3039 }
3040
3041 static const struct file_operations proc_uid_map_operations = {
3042 .open = proc_uid_map_open,
3043 .write = proc_uid_map_write,
3044 .read = seq_read,
3045 .llseek = seq_lseek,
3046 .release = proc_id_map_release,
3047 };
3048
3049 static const struct file_operations proc_gid_map_operations = {
3050 .open = proc_gid_map_open,
3051 .write = proc_gid_map_write,
3052 .read = seq_read,
3053 .llseek = seq_lseek,
3054 .release = proc_id_map_release,
3055 };
3056
3057 static const struct file_operations proc_projid_map_operations = {
3058 .open = proc_projid_map_open,
3059 .write = proc_projid_map_write,
3060 .read = seq_read,
3061 .llseek = seq_lseek,
3062 .release = proc_id_map_release,
3063 };
3064
proc_setgroups_open(struct inode * inode,struct file * file)3065 static int proc_setgroups_open(struct inode *inode, struct file *file)
3066 {
3067 struct user_namespace *ns = NULL;
3068 struct task_struct *task;
3069 int ret;
3070
3071 ret = -ESRCH;
3072 task = get_proc_task(inode);
3073 if (task) {
3074 rcu_read_lock();
3075 ns = get_user_ns(task_cred_xxx(task, user_ns));
3076 rcu_read_unlock();
3077 put_task_struct(task);
3078 }
3079 if (!ns)
3080 goto err;
3081
3082 if (file->f_mode & FMODE_WRITE) {
3083 ret = -EACCES;
3084 if (!ns_capable(ns, CAP_SYS_ADMIN))
3085 goto err_put_ns;
3086 }
3087
3088 ret = single_open(file, &proc_setgroups_show, ns);
3089 if (ret)
3090 goto err_put_ns;
3091
3092 return 0;
3093 err_put_ns:
3094 put_user_ns(ns);
3095 err:
3096 return ret;
3097 }
3098
proc_setgroups_release(struct inode * inode,struct file * file)3099 static int proc_setgroups_release(struct inode *inode, struct file *file)
3100 {
3101 struct seq_file *seq = file->private_data;
3102 struct user_namespace *ns = seq->private;
3103 int ret = single_release(inode, file);
3104 put_user_ns(ns);
3105 return ret;
3106 }
3107
3108 static const struct file_operations proc_setgroups_operations = {
3109 .open = proc_setgroups_open,
3110 .write = proc_setgroups_write,
3111 .read = seq_read,
3112 .llseek = seq_lseek,
3113 .release = proc_setgroups_release,
3114 };
3115 #endif /* CONFIG_USER_NS */
3116
proc_pid_personality(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3117 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3118 struct pid *pid, struct task_struct *task)
3119 {
3120 int err = lock_trace(task);
3121 if (!err) {
3122 seq_printf(m, "%08x\n", task->personality);
3123 unlock_trace(task);
3124 }
3125 return err;
3126 }
3127
3128 #ifdef CONFIG_LIVEPATCH
proc_pid_patch_state(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3129 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
3130 struct pid *pid, struct task_struct *task)
3131 {
3132 seq_printf(m, "%d\n", task->patch_state);
3133 return 0;
3134 }
3135 #endif /* CONFIG_LIVEPATCH */
3136
3137 #ifdef CONFIG_STACKLEAK_METRICS
proc_stack_depth(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3138 static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
3139 struct pid *pid, struct task_struct *task)
3140 {
3141 unsigned long prev_depth = THREAD_SIZE -
3142 (task->prev_lowest_stack & (THREAD_SIZE - 1));
3143 unsigned long depth = THREAD_SIZE -
3144 (task->lowest_stack & (THREAD_SIZE - 1));
3145
3146 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
3147 prev_depth, depth);
3148 return 0;
3149 }
3150 #endif /* CONFIG_STACKLEAK_METRICS */
3151
3152 /*
3153 * Thread groups
3154 */
3155 static const struct file_operations proc_task_operations;
3156 static const struct inode_operations proc_task_inode_operations;
3157
3158 static const struct pid_entry tgid_base_stuff[] = {
3159 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3160 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3161 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3162 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3163 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3164 #ifdef CONFIG_NET
3165 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3166 #endif
3167 REG("environ", S_IRUSR, proc_environ_operations),
3168 REG("auxv", S_IRUSR, proc_auxv_operations),
3169 ONE("status", S_IRUGO, proc_pid_status),
3170 ONE("personality", S_IRUSR, proc_pid_personality),
3171 ONE("limits", S_IRUGO, proc_pid_limits),
3172 #ifdef CONFIG_SCHED_DEBUG
3173 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3174 #endif
3175 #ifdef CONFIG_SCHED_AUTOGROUP
3176 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3177 #endif
3178 #ifdef CONFIG_TIME_NS
3179 REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
3180 #endif
3181 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3182 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3183 ONE("syscall", S_IRUSR, proc_pid_syscall),
3184 #endif
3185 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3186 ONE("stat", S_IRUGO, proc_tgid_stat),
3187 ONE("statm", S_IRUGO, proc_pid_statm),
3188 REG("maps", S_IRUGO, proc_pid_maps_operations),
3189 #ifdef CONFIG_NUMA
3190 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3191 #endif
3192 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3193 LNK("cwd", proc_cwd_link),
3194 LNK("root", proc_root_link),
3195 LNK("exe", proc_exe_link),
3196 REG("mounts", S_IRUGO, proc_mounts_operations),
3197 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3198 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3199 #ifdef CONFIG_PROC_PAGE_MONITOR
3200 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3201 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3202 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3203 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3204 #endif
3205 #ifdef CONFIG_SECURITY
3206 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3207 #endif
3208 #ifdef CONFIG_KALLSYMS
3209 ONE("wchan", S_IRUGO, proc_pid_wchan),
3210 #endif
3211 #ifdef CONFIG_STACKTRACE
3212 ONE("stack", S_IRUSR, proc_pid_stack),
3213 #endif
3214 #ifdef CONFIG_SCHED_INFO
3215 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3216 #endif
3217 #ifdef CONFIG_LATENCYTOP
3218 REG("latency", S_IRUGO, proc_lstats_operations),
3219 #endif
3220 #ifdef CONFIG_PROC_PID_CPUSET
3221 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3222 #endif
3223 #ifdef CONFIG_CGROUPS
3224 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3225 #endif
3226 #ifdef CONFIG_PROC_CPU_RESCTRL
3227 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3228 #endif
3229 ONE("oom_score", S_IRUGO, proc_oom_score),
3230 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3231 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3232 #ifdef CONFIG_AUDIT
3233 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3234 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3235 #endif
3236 #ifdef CONFIG_FAULT_INJECTION
3237 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3238 REG("fail-nth", 0644, proc_fail_nth_operations),
3239 #endif
3240 #ifdef CONFIG_ELF_CORE
3241 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3242 #endif
3243 #ifdef CONFIG_TASK_IO_ACCOUNTING
3244 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3245 #endif
3246 #ifdef CONFIG_USER_NS
3247 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3248 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3249 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3250 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3251 #endif
3252 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3253 REG("timers", S_IRUGO, proc_timers_operations),
3254 #endif
3255 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3256 #ifdef CONFIG_LIVEPATCH
3257 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3258 #endif
3259 #ifdef CONFIG_STACKLEAK_METRICS
3260 ONE("stack_depth", S_IRUGO, proc_stack_depth),
3261 #endif
3262 #ifdef CONFIG_PROC_PID_ARCH_STATUS
3263 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3264 #endif
3265 #ifdef CONFIG_SECCOMP_CACHE_DEBUG
3266 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3267 #endif
3268 };
3269
proc_tgid_base_readdir(struct file * file,struct dir_context * ctx)3270 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3271 {
3272 return proc_pident_readdir(file, ctx,
3273 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3274 }
3275
3276 static const struct file_operations proc_tgid_base_operations = {
3277 .read = generic_read_dir,
3278 .iterate_shared = proc_tgid_base_readdir,
3279 .llseek = generic_file_llseek,
3280 };
3281
tgid_pidfd_to_pid(const struct file * file)3282 struct pid *tgid_pidfd_to_pid(const struct file *file)
3283 {
3284 if (file->f_op != &proc_tgid_base_operations)
3285 return ERR_PTR(-EBADF);
3286
3287 return proc_pid(file_inode(file));
3288 }
3289
proc_tgid_base_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)3290 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3291 {
3292 return proc_pident_lookup(dir, dentry,
3293 tgid_base_stuff,
3294 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3295 }
3296
3297 static const struct inode_operations proc_tgid_base_inode_operations = {
3298 .lookup = proc_tgid_base_lookup,
3299 .getattr = pid_getattr,
3300 .setattr = proc_setattr,
3301 .permission = proc_pid_permission,
3302 };
3303
3304 /**
3305 * proc_flush_pid - Remove dcache entries for @pid from the /proc dcache.
3306 * @pid: pid that should be flushed.
3307 *
3308 * This function walks a list of inodes (that belong to any proc
3309 * filesystem) that are attached to the pid and flushes them from
3310 * the dentry cache.
3311 *
3312 * It is safe and reasonable to cache /proc entries for a task until
3313 * that task exits. After that they just clog up the dcache with
3314 * useless entries, possibly causing useful dcache entries to be
3315 * flushed instead. This routine is provided to flush those useless
3316 * dcache entries when a process is reaped.
3317 *
3318 * NOTE: This routine is just an optimization so it does not guarantee
3319 * that no dcache entries will exist after a process is reaped
3320 * it just makes it very unlikely that any will persist.
3321 */
3322
proc_flush_pid(struct pid * pid)3323 void proc_flush_pid(struct pid *pid)
3324 {
3325 proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
3326 }
3327
proc_pid_instantiate(struct dentry * dentry,struct task_struct * task,const void * ptr)3328 static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3329 struct task_struct *task, const void *ptr)
3330 {
3331 struct inode *inode;
3332
3333 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3334 if (!inode)
3335 return ERR_PTR(-ENOENT);
3336
3337 inode->i_op = &proc_tgid_base_inode_operations;
3338 inode->i_fop = &proc_tgid_base_operations;
3339 inode->i_flags|=S_IMMUTABLE;
3340
3341 set_nlink(inode, nlink_tgid);
3342 pid_update_inode(task, inode);
3343
3344 d_set_d_op(dentry, &pid_dentry_operations);
3345 return d_splice_alias(inode, dentry);
3346 }
3347
proc_pid_lookup(struct dentry * dentry,unsigned int flags)3348 struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3349 {
3350 struct task_struct *task;
3351 unsigned tgid;
3352 struct proc_fs_info *fs_info;
3353 struct pid_namespace *ns;
3354 struct dentry *result = ERR_PTR(-ENOENT);
3355
3356 tgid = name_to_int(&dentry->d_name);
3357 if (tgid == ~0U)
3358 goto out;
3359
3360 fs_info = proc_sb_info(dentry->d_sb);
3361 ns = fs_info->pid_ns;
3362 rcu_read_lock();
3363 task = find_task_by_pid_ns(tgid, ns);
3364 if (task)
3365 get_task_struct(task);
3366 rcu_read_unlock();
3367 if (!task)
3368 goto out;
3369
3370 /* Limit procfs to only ptraceable tasks */
3371 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) {
3372 if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
3373 goto out_put_task;
3374 }
3375
3376 result = proc_pid_instantiate(dentry, task, NULL);
3377 out_put_task:
3378 put_task_struct(task);
3379 out:
3380 return result;
3381 }
3382
3383 /*
3384 * Find the first task with tgid >= tgid
3385 *
3386 */
3387 struct tgid_iter {
3388 unsigned int tgid;
3389 struct task_struct *task;
3390 };
next_tgid(struct pid_namespace * ns,struct tgid_iter iter)3391 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3392 {
3393 struct pid *pid;
3394
3395 if (iter.task)
3396 put_task_struct(iter.task);
3397 rcu_read_lock();
3398 retry:
3399 iter.task = NULL;
3400 pid = find_ge_pid(iter.tgid, ns);
3401 if (pid) {
3402 iter.tgid = pid_nr_ns(pid, ns);
3403 iter.task = pid_task(pid, PIDTYPE_TGID);
3404 if (!iter.task) {
3405 iter.tgid += 1;
3406 goto retry;
3407 }
3408 get_task_struct(iter.task);
3409 }
3410 rcu_read_unlock();
3411 return iter;
3412 }
3413
3414 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3415
3416 /* for the /proc/ directory itself, after non-process stuff has been done */
proc_pid_readdir(struct file * file,struct dir_context * ctx)3417 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3418 {
3419 struct tgid_iter iter;
3420 struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
3421 struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb);
3422 loff_t pos = ctx->pos;
3423
3424 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3425 return 0;
3426
3427 if (pos == TGID_OFFSET - 2) {
3428 struct inode *inode = d_inode(fs_info->proc_self);
3429 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3430 return 0;
3431 ctx->pos = pos = pos + 1;
3432 }
3433 if (pos == TGID_OFFSET - 1) {
3434 struct inode *inode = d_inode(fs_info->proc_thread_self);
3435 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3436 return 0;
3437 ctx->pos = pos = pos + 1;
3438 }
3439 iter.tgid = pos - TGID_OFFSET;
3440 iter.task = NULL;
3441 for (iter = next_tgid(ns, iter);
3442 iter.task;
3443 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3444 char name[10 + 1];
3445 unsigned int len;
3446
3447 cond_resched();
3448 if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE))
3449 continue;
3450
3451 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3452 ctx->pos = iter.tgid + TGID_OFFSET;
3453 if (!proc_fill_cache(file, ctx, name, len,
3454 proc_pid_instantiate, iter.task, NULL)) {
3455 put_task_struct(iter.task);
3456 return 0;
3457 }
3458 }
3459 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3460 return 0;
3461 }
3462
3463 /*
3464 * proc_tid_comm_permission is a special permission function exclusively
3465 * used for the node /proc/<pid>/task/<tid>/comm.
3466 * It bypasses generic permission checks in the case where a task of the same
3467 * task group attempts to access the node.
3468 * The rationale behind this is that glibc and bionic access this node for
3469 * cross thread naming (pthread_set/getname_np(!self)). However, if
3470 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3471 * which locks out the cross thread naming implementation.
3472 * This function makes sure that the node is always accessible for members of
3473 * same thread group.
3474 */
proc_tid_comm_permission(struct user_namespace * mnt_userns,struct inode * inode,int mask)3475 static int proc_tid_comm_permission(struct user_namespace *mnt_userns,
3476 struct inode *inode, int mask)
3477 {
3478 bool is_same_tgroup;
3479 struct task_struct *task;
3480
3481 task = get_proc_task(inode);
3482 if (!task)
3483 return -ESRCH;
3484 is_same_tgroup = same_thread_group(current, task);
3485 put_task_struct(task);
3486
3487 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3488 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3489 * read or written by the members of the corresponding
3490 * thread group.
3491 */
3492 return 0;
3493 }
3494
3495 return generic_permission(&init_user_ns, inode, mask);
3496 }
3497
3498 static const struct inode_operations proc_tid_comm_inode_operations = {
3499 .permission = proc_tid_comm_permission,
3500 };
3501
3502 /*
3503 * Tasks
3504 */
3505 static const struct pid_entry tid_base_stuff[] = {
3506 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3507 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3508 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3509 #ifdef CONFIG_NET
3510 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3511 #endif
3512 REG("environ", S_IRUSR, proc_environ_operations),
3513 REG("auxv", S_IRUSR, proc_auxv_operations),
3514 ONE("status", S_IRUGO, proc_pid_status),
3515 ONE("personality", S_IRUSR, proc_pid_personality),
3516 ONE("limits", S_IRUGO, proc_pid_limits),
3517 #ifdef CONFIG_SCHED_DEBUG
3518 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3519 #endif
3520 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3521 &proc_tid_comm_inode_operations,
3522 &proc_pid_set_comm_operations, {}),
3523 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3524 ONE("syscall", S_IRUSR, proc_pid_syscall),
3525 #endif
3526 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3527 ONE("stat", S_IRUGO, proc_tid_stat),
3528 ONE("statm", S_IRUGO, proc_pid_statm),
3529 REG("maps", S_IRUGO, proc_pid_maps_operations),
3530 #ifdef CONFIG_PROC_CHILDREN
3531 REG("children", S_IRUGO, proc_tid_children_operations),
3532 #endif
3533 #ifdef CONFIG_NUMA
3534 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3535 #endif
3536 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3537 LNK("cwd", proc_cwd_link),
3538 LNK("root", proc_root_link),
3539 LNK("exe", proc_exe_link),
3540 REG("mounts", S_IRUGO, proc_mounts_operations),
3541 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3542 #ifdef CONFIG_PROC_PAGE_MONITOR
3543 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3544 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3545 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3546 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3547 #endif
3548 #ifdef CONFIG_SECURITY
3549 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3550 #endif
3551 #ifdef CONFIG_KALLSYMS
3552 ONE("wchan", S_IRUGO, proc_pid_wchan),
3553 #endif
3554 #ifdef CONFIG_STACKTRACE
3555 ONE("stack", S_IRUSR, proc_pid_stack),
3556 #endif
3557 #ifdef CONFIG_SCHED_INFO
3558 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3559 #endif
3560 #ifdef CONFIG_LATENCYTOP
3561 REG("latency", S_IRUGO, proc_lstats_operations),
3562 #endif
3563 #ifdef CONFIG_PROC_PID_CPUSET
3564 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3565 #endif
3566 #ifdef CONFIG_CGROUPS
3567 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3568 #endif
3569 #ifdef CONFIG_PROC_CPU_RESCTRL
3570 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3571 #endif
3572 ONE("oom_score", S_IRUGO, proc_oom_score),
3573 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3574 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3575 #ifdef CONFIG_AUDIT
3576 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3577 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3578 #endif
3579 #ifdef CONFIG_FAULT_INJECTION
3580 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3581 REG("fail-nth", 0644, proc_fail_nth_operations),
3582 #endif
3583 #ifdef CONFIG_TASK_IO_ACCOUNTING
3584 ONE("io", S_IRUSR, proc_tid_io_accounting),
3585 #endif
3586 #ifdef CONFIG_USER_NS
3587 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3588 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3589 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3590 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3591 #endif
3592 #ifdef CONFIG_LIVEPATCH
3593 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3594 #endif
3595 #ifdef CONFIG_PROC_PID_ARCH_STATUS
3596 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3597 #endif
3598 #ifdef CONFIG_SECCOMP_CACHE_DEBUG
3599 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3600 #endif
3601 };
3602
proc_tid_base_readdir(struct file * file,struct dir_context * ctx)3603 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3604 {
3605 return proc_pident_readdir(file, ctx,
3606 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3607 }
3608
proc_tid_base_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)3609 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3610 {
3611 return proc_pident_lookup(dir, dentry,
3612 tid_base_stuff,
3613 tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3614 }
3615
3616 static const struct file_operations proc_tid_base_operations = {
3617 .read = generic_read_dir,
3618 .iterate_shared = proc_tid_base_readdir,
3619 .llseek = generic_file_llseek,
3620 };
3621
3622 static const struct inode_operations proc_tid_base_inode_operations = {
3623 .lookup = proc_tid_base_lookup,
3624 .getattr = pid_getattr,
3625 .setattr = proc_setattr,
3626 };
3627
proc_task_instantiate(struct dentry * dentry,struct task_struct * task,const void * ptr)3628 static struct dentry *proc_task_instantiate(struct dentry *dentry,
3629 struct task_struct *task, const void *ptr)
3630 {
3631 struct inode *inode;
3632 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3633 if (!inode)
3634 return ERR_PTR(-ENOENT);
3635
3636 inode->i_op = &proc_tid_base_inode_operations;
3637 inode->i_fop = &proc_tid_base_operations;
3638 inode->i_flags |= S_IMMUTABLE;
3639
3640 set_nlink(inode, nlink_tid);
3641 pid_update_inode(task, inode);
3642
3643 d_set_d_op(dentry, &pid_dentry_operations);
3644 return d_splice_alias(inode, dentry);
3645 }
3646
proc_task_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)3647 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3648 {
3649 struct task_struct *task;
3650 struct task_struct *leader = get_proc_task(dir);
3651 unsigned tid;
3652 struct proc_fs_info *fs_info;
3653 struct pid_namespace *ns;
3654 struct dentry *result = ERR_PTR(-ENOENT);
3655
3656 if (!leader)
3657 goto out_no_task;
3658
3659 tid = name_to_int(&dentry->d_name);
3660 if (tid == ~0U)
3661 goto out;
3662
3663 fs_info = proc_sb_info(dentry->d_sb);
3664 ns = fs_info->pid_ns;
3665 rcu_read_lock();
3666 task = find_task_by_pid_ns(tid, ns);
3667 if (task)
3668 get_task_struct(task);
3669 rcu_read_unlock();
3670 if (!task)
3671 goto out;
3672 if (!same_thread_group(leader, task))
3673 goto out_drop_task;
3674
3675 result = proc_task_instantiate(dentry, task, NULL);
3676 out_drop_task:
3677 put_task_struct(task);
3678 out:
3679 put_task_struct(leader);
3680 out_no_task:
3681 return result;
3682 }
3683
3684 /*
3685 * Find the first tid of a thread group to return to user space.
3686 *
3687 * Usually this is just the thread group leader, but if the users
3688 * buffer was too small or there was a seek into the middle of the
3689 * directory we have more work todo.
3690 *
3691 * In the case of a short read we start with find_task_by_pid.
3692 *
3693 * In the case of a seek we start with the leader and walk nr
3694 * threads past it.
3695 */
first_tid(struct pid * pid,int tid,loff_t f_pos,struct pid_namespace * ns)3696 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3697 struct pid_namespace *ns)
3698 {
3699 struct task_struct *pos, *task;
3700 unsigned long nr = f_pos;
3701
3702 if (nr != f_pos) /* 32bit overflow? */
3703 return NULL;
3704
3705 rcu_read_lock();
3706 task = pid_task(pid, PIDTYPE_PID);
3707 if (!task)
3708 goto fail;
3709
3710 /* Attempt to start with the tid of a thread */
3711 if (tid && nr) {
3712 pos = find_task_by_pid_ns(tid, ns);
3713 if (pos && same_thread_group(pos, task))
3714 goto found;
3715 }
3716
3717 /* If nr exceeds the number of threads there is nothing todo */
3718 if (nr >= get_nr_threads(task))
3719 goto fail;
3720
3721 /* If we haven't found our starting place yet start
3722 * with the leader and walk nr threads forward.
3723 */
3724 pos = task = task->group_leader;
3725 do {
3726 if (!nr--)
3727 goto found;
3728 } while_each_thread(task, pos);
3729 fail:
3730 pos = NULL;
3731 goto out;
3732 found:
3733 get_task_struct(pos);
3734 out:
3735 rcu_read_unlock();
3736 return pos;
3737 }
3738
3739 /*
3740 * Find the next thread in the thread list.
3741 * Return NULL if there is an error or no next thread.
3742 *
3743 * The reference to the input task_struct is released.
3744 */
next_tid(struct task_struct * start)3745 static struct task_struct *next_tid(struct task_struct *start)
3746 {
3747 struct task_struct *pos = NULL;
3748 rcu_read_lock();
3749 if (pid_alive(start)) {
3750 pos = next_thread(start);
3751 if (thread_group_leader(pos))
3752 pos = NULL;
3753 else
3754 get_task_struct(pos);
3755 }
3756 rcu_read_unlock();
3757 put_task_struct(start);
3758 return pos;
3759 }
3760
3761 /* for the /proc/TGID/task/ directories */
proc_task_readdir(struct file * file,struct dir_context * ctx)3762 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3763 {
3764 struct inode *inode = file_inode(file);
3765 struct task_struct *task;
3766 struct pid_namespace *ns;
3767 int tid;
3768
3769 if (proc_inode_is_dead(inode))
3770 return -ENOENT;
3771
3772 if (!dir_emit_dots(file, ctx))
3773 return 0;
3774
3775 /* f_version caches the tgid value that the last readdir call couldn't
3776 * return. lseek aka telldir automagically resets f_version to 0.
3777 */
3778 ns = proc_pid_ns(inode->i_sb);
3779 tid = (int)file->f_version;
3780 file->f_version = 0;
3781 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3782 task;
3783 task = next_tid(task), ctx->pos++) {
3784 char name[10 + 1];
3785 unsigned int len;
3786 tid = task_pid_nr_ns(task, ns);
3787 len = snprintf(name, sizeof(name), "%u", tid);
3788 if (!proc_fill_cache(file, ctx, name, len,
3789 proc_task_instantiate, task, NULL)) {
3790 /* returning this tgid failed, save it as the first
3791 * pid for the next readir call */
3792 file->f_version = (u64)tid;
3793 put_task_struct(task);
3794 break;
3795 }
3796 }
3797
3798 return 0;
3799 }
3800
proc_task_getattr(struct user_namespace * mnt_userns,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)3801 static int proc_task_getattr(struct user_namespace *mnt_userns,
3802 const struct path *path, struct kstat *stat,
3803 u32 request_mask, unsigned int query_flags)
3804 {
3805 struct inode *inode = d_inode(path->dentry);
3806 struct task_struct *p = get_proc_task(inode);
3807 generic_fillattr(&init_user_ns, inode, stat);
3808
3809 if (p) {
3810 stat->nlink += get_nr_threads(p);
3811 put_task_struct(p);
3812 }
3813
3814 return 0;
3815 }
3816
3817 static const struct inode_operations proc_task_inode_operations = {
3818 .lookup = proc_task_lookup,
3819 .getattr = proc_task_getattr,
3820 .setattr = proc_setattr,
3821 .permission = proc_pid_permission,
3822 };
3823
3824 static const struct file_operations proc_task_operations = {
3825 .read = generic_read_dir,
3826 .iterate_shared = proc_task_readdir,
3827 .llseek = generic_file_llseek,
3828 };
3829
set_proc_pid_nlink(void)3830 void __init set_proc_pid_nlink(void)
3831 {
3832 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3833 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3834 }
3835