1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/proc/base.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * proc base directory handling functions
8 *
9 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
10 * Instead of using magical inumbers to determine the kind of object
11 * we allocate and fill in-core inodes upon lookup. They don't even
12 * go into icache. We cache the reference to task_struct upon lookup too.
13 * Eventually it should become a filesystem in its own. We don't use the
14 * rest of procfs anymore.
15 *
16 *
17 * Changelog:
18 * 17-Jan-2005
19 * Allan Bezerra
20 * Bruna Moreira <bruna.moreira@indt.org.br>
21 * Edjard Mota <edjard.mota@indt.org.br>
22 * Ilias Biris <ilias.biris@indt.org.br>
23 * Mauricio Lin <mauricio.lin@indt.org.br>
24 *
25 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
26 *
27 * A new process specific entry (smaps) included in /proc. It shows the
28 * size of rss for each memory area. The maps entry lacks information
29 * about physical memory size (rss) for each mapped file, i.e.,
30 * rss information for executables and library files.
31 * This additional information is useful for any tools that need to know
32 * about physical memory consumption for a process specific library.
33 *
34 * Changelog:
35 * 21-Feb-2005
36 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
37 * Pud inclusion in the page table walking.
38 *
39 * ChangeLog:
40 * 10-Mar-2005
41 * 10LE Instituto Nokia de Tecnologia - INdT:
42 * A better way to walks through the page table as suggested by Hugh Dickins.
43 *
44 * Simo Piiroinen <simo.piiroinen@nokia.com>:
45 * Smaps information related to shared, private, clean and dirty pages.
46 *
47 * Paul Mundt <paul.mundt@nokia.com>:
48 * Overall revision about smaps.
49 */
50
51 #include <linux/uaccess.h>
52
53 #include <linux/errno.h>
54 #include <linux/time.h>
55 #include <linux/proc_fs.h>
56 #include <linux/stat.h>
57 #include <linux/task_io_accounting_ops.h>
58 #include <linux/init.h>
59 #include <linux/capability.h>
60 #include <linux/file.h>
61 #include <linux/fdtable.h>
62 #include <linux/generic-radix-tree.h>
63 #include <linux/string.h>
64 #include <linux/seq_file.h>
65 #include <linux/namei.h>
66 #include <linux/mnt_namespace.h>
67 #include <linux/mm.h>
68 #include <linux/swap.h>
69 #include <linux/rcupdate.h>
70 #include <linux/kallsyms.h>
71 #include <linux/stacktrace.h>
72 #include <linux/resource.h>
73 #include <linux/module.h>
74 #include <linux/mount.h>
75 #include <linux/security.h>
76 #include <linux/ptrace.h>
77 #include <linux/tracehook.h>
78 #include <linux/printk.h>
79 #include <linux/cache.h>
80 #include <linux/cgroup.h>
81 #include <linux/cpuset.h>
82 #include <linux/audit.h>
83 #include <linux/poll.h>
84 #include <linux/nsproxy.h>
85 #include <linux/oom.h>
86 #include <linux/elf.h>
87 #include <linux/pid_namespace.h>
88 #include <linux/user_namespace.h>
89 #include <linux/fs_struct.h>
90 #include <linux/slab.h>
91 #include <linux/sched/autogroup.h>
92 #include <linux/sched/mm.h>
93 #include <linux/sched/coredump.h>
94 #include <linux/sched/debug.h>
95 #include <linux/sched/stat.h>
96 #include <linux/posix-timers.h>
97 #include <linux/time_namespace.h>
98 #include <linux/resctrl.h>
99 #include <linux/cn_proc.h>
100 #include <linux/cpufreq_times.h>
101 #include <trace/events/oom.h>
102 #include <trace/hooks/sched.h>
103 #include "internal.h"
104 #include "fd.h"
105
106 #include "../../lib/kstrtox.h"
107
108 /* NOTE:
109 * Implementing inode permission operations in /proc is almost
110 * certainly an error. Permission checks need to happen during
111 * each system call not at open time. The reason is that most of
112 * what we wish to check for permissions in /proc varies at runtime.
113 *
114 * The classic example of a problem is opening file descriptors
115 * in /proc for a task before it execs a suid executable.
116 */
117
118 static u8 nlink_tid __ro_after_init;
119 static u8 nlink_tgid __ro_after_init;
120
121 struct pid_entry {
122 const char *name;
123 unsigned int len;
124 umode_t mode;
125 const struct inode_operations *iop;
126 const struct file_operations *fop;
127 union proc_op op;
128 };
129
130 #define NOD(NAME, MODE, IOP, FOP, OP) { \
131 .name = (NAME), \
132 .len = sizeof(NAME) - 1, \
133 .mode = MODE, \
134 .iop = IOP, \
135 .fop = FOP, \
136 .op = OP, \
137 }
138
139 #define DIR(NAME, MODE, iops, fops) \
140 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
141 #define LNK(NAME, get_link) \
142 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
143 &proc_pid_link_inode_operations, NULL, \
144 { .proc_get_link = get_link } )
145 #define REG(NAME, MODE, fops) \
146 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
147 #define ONE(NAME, MODE, show) \
148 NOD(NAME, (S_IFREG|(MODE)), \
149 NULL, &proc_single_file_operations, \
150 { .proc_show = show } )
151 #define ATTR(LSM, NAME, MODE) \
152 NOD(NAME, (S_IFREG|(MODE)), \
153 NULL, &proc_pid_attr_operations, \
154 { .lsm = LSM })
155
156 /*
157 * Count the number of hardlinks for the pid_entry table, excluding the .
158 * and .. links.
159 */
pid_entry_nlink(const struct pid_entry * entries,unsigned int n)160 static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
161 unsigned int n)
162 {
163 unsigned int i;
164 unsigned int count;
165
166 count = 2;
167 for (i = 0; i < n; ++i) {
168 if (S_ISDIR(entries[i].mode))
169 ++count;
170 }
171
172 return count;
173 }
174
get_task_root(struct task_struct * task,struct path * root)175 static int get_task_root(struct task_struct *task, struct path *root)
176 {
177 int result = -ENOENT;
178
179 task_lock(task);
180 if (task->fs) {
181 get_fs_root(task->fs, root);
182 result = 0;
183 }
184 task_unlock(task);
185 return result;
186 }
187
proc_cwd_link(struct dentry * dentry,struct path * path)188 static int proc_cwd_link(struct dentry *dentry, struct path *path)
189 {
190 struct task_struct *task = get_proc_task(d_inode(dentry));
191 int result = -ENOENT;
192
193 if (task) {
194 task_lock(task);
195 if (task->fs) {
196 get_fs_pwd(task->fs, path);
197 result = 0;
198 }
199 task_unlock(task);
200 put_task_struct(task);
201 }
202 return result;
203 }
204
proc_root_link(struct dentry * dentry,struct path * path)205 static int proc_root_link(struct dentry *dentry, struct path *path)
206 {
207 struct task_struct *task = get_proc_task(d_inode(dentry));
208 int result = -ENOENT;
209
210 if (task) {
211 result = get_task_root(task, path);
212 put_task_struct(task);
213 }
214 return result;
215 }
216
217 /*
218 * If the user used setproctitle(), we just get the string from
219 * user space at arg_start, and limit it to a maximum of one page.
220 */
get_mm_proctitle(struct mm_struct * mm,char __user * buf,size_t count,unsigned long pos,unsigned long arg_start)221 static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
222 size_t count, unsigned long pos,
223 unsigned long arg_start)
224 {
225 char *page;
226 int ret, got;
227
228 if (pos >= PAGE_SIZE)
229 return 0;
230
231 page = (char *)__get_free_page(GFP_KERNEL);
232 if (!page)
233 return -ENOMEM;
234
235 ret = 0;
236 got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
237 if (got > 0) {
238 int len = strnlen(page, got);
239
240 /* Include the NUL character if it was found */
241 if (len < got)
242 len++;
243
244 if (len > pos) {
245 len -= pos;
246 if (len > count)
247 len = count;
248 len -= copy_to_user(buf, page+pos, len);
249 if (!len)
250 len = -EFAULT;
251 ret = len;
252 }
253 }
254 free_page((unsigned long)page);
255 return ret;
256 }
257
get_mm_cmdline(struct mm_struct * mm,char __user * buf,size_t count,loff_t * ppos)258 static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
259 size_t count, loff_t *ppos)
260 {
261 unsigned long arg_start, arg_end, env_start, env_end;
262 unsigned long pos, len;
263 char *page, c;
264
265 /* Check if process spawned far enough to have cmdline. */
266 if (!mm->env_end)
267 return 0;
268
269 spin_lock(&mm->arg_lock);
270 arg_start = mm->arg_start;
271 arg_end = mm->arg_end;
272 env_start = mm->env_start;
273 env_end = mm->env_end;
274 spin_unlock(&mm->arg_lock);
275
276 if (arg_start >= arg_end)
277 return 0;
278
279 /*
280 * We allow setproctitle() to overwrite the argument
281 * strings, and overflow past the original end. But
282 * only when it overflows into the environment area.
283 */
284 if (env_start != arg_end || env_end < env_start)
285 env_start = env_end = arg_end;
286 len = env_end - arg_start;
287
288 /* We're not going to care if "*ppos" has high bits set */
289 pos = *ppos;
290 if (pos >= len)
291 return 0;
292 if (count > len - pos)
293 count = len - pos;
294 if (!count)
295 return 0;
296
297 /*
298 * Magical special case: if the argv[] end byte is not
299 * zero, the user has overwritten it with setproctitle(3).
300 *
301 * Possible future enhancement: do this only once when
302 * pos is 0, and set a flag in the 'struct file'.
303 */
304 if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
305 return get_mm_proctitle(mm, buf, count, pos, arg_start);
306
307 /*
308 * For the non-setproctitle() case we limit things strictly
309 * to the [arg_start, arg_end[ range.
310 */
311 pos += arg_start;
312 if (pos < arg_start || pos >= arg_end)
313 return 0;
314 if (count > arg_end - pos)
315 count = arg_end - pos;
316
317 page = (char *)__get_free_page(GFP_KERNEL);
318 if (!page)
319 return -ENOMEM;
320
321 len = 0;
322 while (count) {
323 int got;
324 size_t size = min_t(size_t, PAGE_SIZE, count);
325
326 got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
327 if (got <= 0)
328 break;
329 got -= copy_to_user(buf, page, got);
330 if (unlikely(!got)) {
331 if (!len)
332 len = -EFAULT;
333 break;
334 }
335 pos += got;
336 buf += got;
337 len += got;
338 count -= got;
339 }
340
341 free_page((unsigned long)page);
342 return len;
343 }
344
get_task_cmdline(struct task_struct * tsk,char __user * buf,size_t count,loff_t * pos)345 static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
346 size_t count, loff_t *pos)
347 {
348 struct mm_struct *mm;
349 bool prio_inherited = false;
350 int saved_prio;
351 ssize_t ret;
352
353 mm = get_task_mm(tsk);
354 if (!mm)
355 return 0;
356
357 /*
358 * access_remote_vm() holds the hot mmap_sem lock which can cause the
359 * task for which we read cmdline etc for by some debug deamon to slow
360 * down and suffer a performance hit. Especially if the reader task has
361 * a low nice value.
362 */
363 trace_android_vh_prio_inheritance(tsk, &saved_prio, &prio_inherited);
364 ret = get_mm_cmdline(mm, buf, count, pos);
365 if (prio_inherited)
366 trace_android_vh_prio_restore(saved_prio);
367 mmput(mm);
368 return ret;
369 }
370
proc_pid_cmdline_read(struct file * file,char __user * buf,size_t count,loff_t * pos)371 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
372 size_t count, loff_t *pos)
373 {
374 struct task_struct *tsk;
375 ssize_t ret;
376
377 BUG_ON(*pos < 0);
378
379 tsk = get_proc_task(file_inode(file));
380 if (!tsk)
381 return -ESRCH;
382 ret = get_task_cmdline(tsk, buf, count, pos);
383 put_task_struct(tsk);
384 if (ret > 0)
385 *pos += ret;
386 return ret;
387 }
388
389 static const struct file_operations proc_pid_cmdline_ops = {
390 .read = proc_pid_cmdline_read,
391 .llseek = generic_file_llseek,
392 };
393
394 #ifdef CONFIG_KALLSYMS
395 /*
396 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
397 * Returns the resolved symbol. If that fails, simply return the address.
398 */
proc_pid_wchan(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)399 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
400 struct pid *pid, struct task_struct *task)
401 {
402 unsigned long wchan;
403 char symname[KSYM_NAME_LEN];
404
405 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
406 goto print0;
407
408 wchan = get_wchan(task);
409 if (wchan && !lookup_symbol_name(wchan, symname)) {
410 seq_puts(m, symname);
411 return 0;
412 }
413
414 print0:
415 seq_putc(m, '0');
416 return 0;
417 }
418 #endif /* CONFIG_KALLSYMS */
419
lock_trace(struct task_struct * task)420 static int lock_trace(struct task_struct *task)
421 {
422 int err = down_read_killable(&task->signal->exec_update_lock);
423 if (err)
424 return err;
425 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
426 up_read(&task->signal->exec_update_lock);
427 return -EPERM;
428 }
429 return 0;
430 }
431
unlock_trace(struct task_struct * task)432 static void unlock_trace(struct task_struct *task)
433 {
434 up_read(&task->signal->exec_update_lock);
435 }
436
437 #ifdef CONFIG_STACKTRACE
438
439 #define MAX_STACK_TRACE_DEPTH 64
440
proc_pid_stack(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)441 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
442 struct pid *pid, struct task_struct *task)
443 {
444 unsigned long *entries;
445 int err;
446
447 /*
448 * The ability to racily run the kernel stack unwinder on a running task
449 * and then observe the unwinder output is scary; while it is useful for
450 * debugging kernel issues, it can also allow an attacker to leak kernel
451 * stack contents.
452 * Doing this in a manner that is at least safe from races would require
453 * some work to ensure that the remote task can not be scheduled; and
454 * even then, this would still expose the unwinder as local attack
455 * surface.
456 * Therefore, this interface is restricted to root.
457 */
458 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
459 return -EACCES;
460
461 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
462 GFP_KERNEL);
463 if (!entries)
464 return -ENOMEM;
465
466 err = lock_trace(task);
467 if (!err) {
468 unsigned int i, nr_entries;
469
470 nr_entries = stack_trace_save_tsk(task, entries,
471 MAX_STACK_TRACE_DEPTH, 0);
472
473 for (i = 0; i < nr_entries; i++) {
474 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
475 }
476
477 unlock_trace(task);
478 }
479 kfree(entries);
480
481 return err;
482 }
483 #endif
484
485 #ifdef CONFIG_SCHED_INFO
486 /*
487 * Provides /proc/PID/schedstat
488 */
proc_pid_schedstat(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)489 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
490 struct pid *pid, struct task_struct *task)
491 {
492 if (unlikely(!sched_info_on()))
493 seq_puts(m, "0 0 0\n");
494 else
495 seq_printf(m, "%llu %llu %lu\n",
496 (unsigned long long)task->se.sum_exec_runtime,
497 (unsigned long long)task->sched_info.run_delay,
498 task->sched_info.pcount);
499
500 return 0;
501 }
502 #endif
503
504 #ifdef CONFIG_LATENCYTOP
lstats_show_proc(struct seq_file * m,void * v)505 static int lstats_show_proc(struct seq_file *m, void *v)
506 {
507 int i;
508 struct inode *inode = m->private;
509 struct task_struct *task = get_proc_task(inode);
510
511 if (!task)
512 return -ESRCH;
513 seq_puts(m, "Latency Top version : v0.1\n");
514 for (i = 0; i < LT_SAVECOUNT; i++) {
515 struct latency_record *lr = &task->latency_record[i];
516 if (lr->backtrace[0]) {
517 int q;
518 seq_printf(m, "%i %li %li",
519 lr->count, lr->time, lr->max);
520 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
521 unsigned long bt = lr->backtrace[q];
522
523 if (!bt)
524 break;
525 seq_printf(m, " %ps", (void *)bt);
526 }
527 seq_putc(m, '\n');
528 }
529
530 }
531 put_task_struct(task);
532 return 0;
533 }
534
lstats_open(struct inode * inode,struct file * file)535 static int lstats_open(struct inode *inode, struct file *file)
536 {
537 return single_open(file, lstats_show_proc, inode);
538 }
539
lstats_write(struct file * file,const char __user * buf,size_t count,loff_t * offs)540 static ssize_t lstats_write(struct file *file, const char __user *buf,
541 size_t count, loff_t *offs)
542 {
543 struct task_struct *task = get_proc_task(file_inode(file));
544
545 if (!task)
546 return -ESRCH;
547 clear_tsk_latency_tracing(task);
548 put_task_struct(task);
549
550 return count;
551 }
552
553 static const struct file_operations proc_lstats_operations = {
554 .open = lstats_open,
555 .read = seq_read,
556 .write = lstats_write,
557 .llseek = seq_lseek,
558 .release = single_release,
559 };
560
561 #endif
562
proc_oom_score(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)563 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
564 struct pid *pid, struct task_struct *task)
565 {
566 unsigned long totalpages = totalram_pages() + total_swap_pages;
567 unsigned long points = 0;
568 long badness;
569
570 badness = oom_badness(task, totalpages);
571 /*
572 * Special case OOM_SCORE_ADJ_MIN for all others scale the
573 * badness value into [0, 2000] range which we have been
574 * exporting for a long time so userspace might depend on it.
575 */
576 if (badness != LONG_MIN)
577 points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
578
579 seq_printf(m, "%lu\n", points);
580
581 return 0;
582 }
583
584 struct limit_names {
585 const char *name;
586 const char *unit;
587 };
588
589 static const struct limit_names lnames[RLIM_NLIMITS] = {
590 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
591 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
592 [RLIMIT_DATA] = {"Max data size", "bytes"},
593 [RLIMIT_STACK] = {"Max stack size", "bytes"},
594 [RLIMIT_CORE] = {"Max core file size", "bytes"},
595 [RLIMIT_RSS] = {"Max resident set", "bytes"},
596 [RLIMIT_NPROC] = {"Max processes", "processes"},
597 [RLIMIT_NOFILE] = {"Max open files", "files"},
598 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
599 [RLIMIT_AS] = {"Max address space", "bytes"},
600 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
601 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
602 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
603 [RLIMIT_NICE] = {"Max nice priority", NULL},
604 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
605 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
606 };
607
608 /* Display limits for a process */
proc_pid_limits(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)609 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
610 struct pid *pid, struct task_struct *task)
611 {
612 unsigned int i;
613 unsigned long flags;
614
615 struct rlimit rlim[RLIM_NLIMITS];
616
617 if (!lock_task_sighand(task, &flags))
618 return 0;
619 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
620 unlock_task_sighand(task, &flags);
621
622 /*
623 * print the file header
624 */
625 seq_puts(m, "Limit "
626 "Soft Limit "
627 "Hard Limit "
628 "Units \n");
629
630 for (i = 0; i < RLIM_NLIMITS; i++) {
631 if (rlim[i].rlim_cur == RLIM_INFINITY)
632 seq_printf(m, "%-25s %-20s ",
633 lnames[i].name, "unlimited");
634 else
635 seq_printf(m, "%-25s %-20lu ",
636 lnames[i].name, rlim[i].rlim_cur);
637
638 if (rlim[i].rlim_max == RLIM_INFINITY)
639 seq_printf(m, "%-20s ", "unlimited");
640 else
641 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
642
643 if (lnames[i].unit)
644 seq_printf(m, "%-10s\n", lnames[i].unit);
645 else
646 seq_putc(m, '\n');
647 }
648
649 return 0;
650 }
651
652 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
proc_pid_syscall(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)653 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
654 struct pid *pid, struct task_struct *task)
655 {
656 struct syscall_info info;
657 u64 *args = &info.data.args[0];
658 int res;
659
660 res = lock_trace(task);
661 if (res)
662 return res;
663
664 if (task_current_syscall(task, &info))
665 seq_puts(m, "running\n");
666 else if (info.data.nr < 0)
667 seq_printf(m, "%d 0x%llx 0x%llx\n",
668 info.data.nr, info.sp, info.data.instruction_pointer);
669 else
670 seq_printf(m,
671 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
672 info.data.nr,
673 args[0], args[1], args[2], args[3], args[4], args[5],
674 info.sp, info.data.instruction_pointer);
675 unlock_trace(task);
676
677 return 0;
678 }
679 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
680
681 /************************************************************************/
682 /* Here the fs part begins */
683 /************************************************************************/
684
685 /* permission checks */
proc_fd_access_allowed(struct inode * inode)686 static int proc_fd_access_allowed(struct inode *inode)
687 {
688 struct task_struct *task;
689 int allowed = 0;
690 /* Allow access to a task's file descriptors if it is us or we
691 * may use ptrace attach to the process and find out that
692 * information.
693 */
694 task = get_proc_task(inode);
695 if (task) {
696 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
697 put_task_struct(task);
698 }
699 return allowed;
700 }
701
proc_setattr(struct user_namespace * mnt_userns,struct dentry * dentry,struct iattr * attr)702 int proc_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
703 struct iattr *attr)
704 {
705 int error;
706 struct inode *inode = d_inode(dentry);
707
708 if (attr->ia_valid & ATTR_MODE)
709 return -EPERM;
710
711 error = setattr_prepare(&init_user_ns, dentry, attr);
712 if (error)
713 return error;
714
715 setattr_copy(&init_user_ns, inode, attr);
716 mark_inode_dirty(inode);
717 return 0;
718 }
719
720 /*
721 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
722 * or euid/egid (for hide_pid_min=2)?
723 */
has_pid_permissions(struct proc_fs_info * fs_info,struct task_struct * task,enum proc_hidepid hide_pid_min)724 static bool has_pid_permissions(struct proc_fs_info *fs_info,
725 struct task_struct *task,
726 enum proc_hidepid hide_pid_min)
727 {
728 /*
729 * If 'hidpid' mount option is set force a ptrace check,
730 * we indicate that we are using a filesystem syscall
731 * by passing PTRACE_MODE_READ_FSCREDS
732 */
733 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE)
734 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
735
736 if (fs_info->hide_pid < hide_pid_min)
737 return true;
738 if (in_group_p(fs_info->pid_gid))
739 return true;
740 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
741 }
742
743
proc_pid_permission(struct user_namespace * mnt_userns,struct inode * inode,int mask)744 static int proc_pid_permission(struct user_namespace *mnt_userns,
745 struct inode *inode, int mask)
746 {
747 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
748 struct task_struct *task;
749 bool has_perms;
750
751 task = get_proc_task(inode);
752 if (!task)
753 return -ESRCH;
754 has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS);
755 put_task_struct(task);
756
757 if (!has_perms) {
758 if (fs_info->hide_pid == HIDEPID_INVISIBLE) {
759 /*
760 * Let's make getdents(), stat(), and open()
761 * consistent with each other. If a process
762 * may not stat() a file, it shouldn't be seen
763 * in procfs at all.
764 */
765 return -ENOENT;
766 }
767
768 return -EPERM;
769 }
770 return generic_permission(&init_user_ns, inode, mask);
771 }
772
773
774
775 static const struct inode_operations proc_def_inode_operations = {
776 .setattr = proc_setattr,
777 };
778
proc_single_show(struct seq_file * m,void * v)779 static int proc_single_show(struct seq_file *m, void *v)
780 {
781 struct inode *inode = m->private;
782 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
783 struct pid *pid = proc_pid(inode);
784 struct task_struct *task;
785 int ret;
786
787 task = get_pid_task(pid, PIDTYPE_PID);
788 if (!task)
789 return -ESRCH;
790
791 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
792
793 put_task_struct(task);
794 return ret;
795 }
796
proc_single_open(struct inode * inode,struct file * filp)797 static int proc_single_open(struct inode *inode, struct file *filp)
798 {
799 return single_open(filp, proc_single_show, inode);
800 }
801
802 static const struct file_operations proc_single_file_operations = {
803 .open = proc_single_open,
804 .read = seq_read,
805 .llseek = seq_lseek,
806 .release = single_release,
807 };
808
809
proc_mem_open(struct inode * inode,unsigned int mode)810 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
811 {
812 struct task_struct *task = get_proc_task(inode);
813 struct mm_struct *mm = ERR_PTR(-ESRCH);
814
815 if (task) {
816 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
817 put_task_struct(task);
818
819 if (!IS_ERR_OR_NULL(mm)) {
820 /* ensure this mm_struct can't be freed */
821 mmgrab(mm);
822 /* but do not pin its memory */
823 mmput(mm);
824 }
825 }
826
827 return mm;
828 }
829
__mem_open(struct inode * inode,struct file * file,unsigned int mode)830 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
831 {
832 struct mm_struct *mm = proc_mem_open(inode, mode);
833
834 if (IS_ERR(mm))
835 return PTR_ERR(mm);
836
837 file->private_data = mm;
838 return 0;
839 }
840
mem_open(struct inode * inode,struct file * file)841 static int mem_open(struct inode *inode, struct file *file)
842 {
843 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
844
845 /* OK to pass negative loff_t, we can catch out-of-range */
846 file->f_mode |= FMODE_UNSIGNED_OFFSET;
847
848 return ret;
849 }
850
mem_rw(struct file * file,char __user * buf,size_t count,loff_t * ppos,int write)851 static ssize_t mem_rw(struct file *file, char __user *buf,
852 size_t count, loff_t *ppos, int write)
853 {
854 struct mm_struct *mm = file->private_data;
855 unsigned long addr = *ppos;
856 ssize_t copied;
857 char *page;
858 unsigned int flags;
859
860 if (!mm)
861 return 0;
862
863 page = (char *)__get_free_page(GFP_KERNEL);
864 if (!page)
865 return -ENOMEM;
866
867 copied = 0;
868 if (!mmget_not_zero(mm))
869 goto free;
870
871 flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
872
873 while (count > 0) {
874 size_t this_len = min_t(size_t, count, PAGE_SIZE);
875
876 if (write && copy_from_user(page, buf, this_len)) {
877 copied = -EFAULT;
878 break;
879 }
880
881 this_len = access_remote_vm(mm, addr, page, this_len, flags);
882 if (!this_len) {
883 if (!copied)
884 copied = -EIO;
885 break;
886 }
887
888 if (!write && copy_to_user(buf, page, this_len)) {
889 copied = -EFAULT;
890 break;
891 }
892
893 buf += this_len;
894 addr += this_len;
895 copied += this_len;
896 count -= this_len;
897 }
898 *ppos = addr;
899
900 mmput(mm);
901 free:
902 free_page((unsigned long) page);
903 return copied;
904 }
905
mem_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)906 static ssize_t mem_read(struct file *file, char __user *buf,
907 size_t count, loff_t *ppos)
908 {
909 return mem_rw(file, buf, count, ppos, 0);
910 }
911
mem_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)912 static ssize_t mem_write(struct file *file, const char __user *buf,
913 size_t count, loff_t *ppos)
914 {
915 return mem_rw(file, (char __user*)buf, count, ppos, 1);
916 }
917
mem_lseek(struct file * file,loff_t offset,int orig)918 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
919 {
920 switch (orig) {
921 case 0:
922 file->f_pos = offset;
923 break;
924 case 1:
925 file->f_pos += offset;
926 break;
927 default:
928 return -EINVAL;
929 }
930 force_successful_syscall_return();
931 return file->f_pos;
932 }
933
mem_release(struct inode * inode,struct file * file)934 static int mem_release(struct inode *inode, struct file *file)
935 {
936 struct mm_struct *mm = file->private_data;
937 if (mm)
938 mmdrop(mm);
939 return 0;
940 }
941
942 static const struct file_operations proc_mem_operations = {
943 .llseek = mem_lseek,
944 .read = mem_read,
945 .write = mem_write,
946 .open = mem_open,
947 .release = mem_release,
948 };
949
environ_open(struct inode * inode,struct file * file)950 static int environ_open(struct inode *inode, struct file *file)
951 {
952 return __mem_open(inode, file, PTRACE_MODE_READ);
953 }
954
environ_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)955 static ssize_t environ_read(struct file *file, char __user *buf,
956 size_t count, loff_t *ppos)
957 {
958 char *page;
959 unsigned long src = *ppos;
960 int ret = 0;
961 struct mm_struct *mm = file->private_data;
962 unsigned long env_start, env_end;
963
964 /* Ensure the process spawned far enough to have an environment. */
965 if (!mm || !mm->env_end)
966 return 0;
967
968 page = (char *)__get_free_page(GFP_KERNEL);
969 if (!page)
970 return -ENOMEM;
971
972 ret = 0;
973 if (!mmget_not_zero(mm))
974 goto free;
975
976 spin_lock(&mm->arg_lock);
977 env_start = mm->env_start;
978 env_end = mm->env_end;
979 spin_unlock(&mm->arg_lock);
980
981 while (count > 0) {
982 size_t this_len, max_len;
983 int retval;
984
985 if (src >= (env_end - env_start))
986 break;
987
988 this_len = env_end - (env_start + src);
989
990 max_len = min_t(size_t, PAGE_SIZE, count);
991 this_len = min(max_len, this_len);
992
993 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
994
995 if (retval <= 0) {
996 ret = retval;
997 break;
998 }
999
1000 if (copy_to_user(buf, page, retval)) {
1001 ret = -EFAULT;
1002 break;
1003 }
1004
1005 ret += retval;
1006 src += retval;
1007 buf += retval;
1008 count -= retval;
1009 }
1010 *ppos = src;
1011 mmput(mm);
1012
1013 free:
1014 free_page((unsigned long) page);
1015 return ret;
1016 }
1017
1018 static const struct file_operations proc_environ_operations = {
1019 .open = environ_open,
1020 .read = environ_read,
1021 .llseek = generic_file_llseek,
1022 .release = mem_release,
1023 };
1024
auxv_open(struct inode * inode,struct file * file)1025 static int auxv_open(struct inode *inode, struct file *file)
1026 {
1027 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1028 }
1029
auxv_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1030 static ssize_t auxv_read(struct file *file, char __user *buf,
1031 size_t count, loff_t *ppos)
1032 {
1033 struct mm_struct *mm = file->private_data;
1034 unsigned int nwords = 0;
1035
1036 if (!mm)
1037 return 0;
1038 do {
1039 nwords += 2;
1040 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1041 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1042 nwords * sizeof(mm->saved_auxv[0]));
1043 }
1044
1045 static const struct file_operations proc_auxv_operations = {
1046 .open = auxv_open,
1047 .read = auxv_read,
1048 .llseek = generic_file_llseek,
1049 .release = mem_release,
1050 };
1051
oom_adj_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1052 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1053 loff_t *ppos)
1054 {
1055 struct task_struct *task = get_proc_task(file_inode(file));
1056 char buffer[PROC_NUMBUF];
1057 int oom_adj = OOM_ADJUST_MIN;
1058 size_t len;
1059
1060 if (!task)
1061 return -ESRCH;
1062 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1063 oom_adj = OOM_ADJUST_MAX;
1064 else
1065 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1066 OOM_SCORE_ADJ_MAX;
1067 put_task_struct(task);
1068 if (oom_adj > OOM_ADJUST_MAX)
1069 oom_adj = OOM_ADJUST_MAX;
1070 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1071 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1072 }
1073
__set_oom_adj(struct file * file,int oom_adj,bool legacy)1074 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1075 {
1076 struct mm_struct *mm = NULL;
1077 struct task_struct *task;
1078 int err = 0;
1079
1080 task = get_proc_task(file_inode(file));
1081 if (!task)
1082 return -ESRCH;
1083
1084 mutex_lock(&oom_adj_mutex);
1085 if (legacy) {
1086 if (oom_adj < task->signal->oom_score_adj &&
1087 !capable(CAP_SYS_RESOURCE)) {
1088 err = -EACCES;
1089 goto err_unlock;
1090 }
1091 /*
1092 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1093 * /proc/pid/oom_score_adj instead.
1094 */
1095 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1096 current->comm, task_pid_nr(current), task_pid_nr(task),
1097 task_pid_nr(task));
1098 } else {
1099 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1100 !capable(CAP_SYS_RESOURCE)) {
1101 err = -EACCES;
1102 goto err_unlock;
1103 }
1104 }
1105
1106 /*
1107 * Make sure we will check other processes sharing the mm if this is
1108 * not vfrok which wants its own oom_score_adj.
1109 * pin the mm so it doesn't go away and get reused after task_unlock
1110 */
1111 if (!task->vfork_done) {
1112 struct task_struct *p = find_lock_task_mm(task);
1113
1114 if (p) {
1115 if (test_bit(MMF_MULTIPROCESS, &p->mm->flags)) {
1116 mm = p->mm;
1117 mmgrab(mm);
1118 }
1119 task_unlock(p);
1120 }
1121 }
1122
1123 task->signal->oom_score_adj = oom_adj;
1124 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1125 task->signal->oom_score_adj_min = (short)oom_adj;
1126 trace_oom_score_adj_update(task);
1127
1128 if (mm) {
1129 struct task_struct *p;
1130
1131 rcu_read_lock();
1132 for_each_process(p) {
1133 if (same_thread_group(task, p))
1134 continue;
1135
1136 /* do not touch kernel threads or the global init */
1137 if (p->flags & PF_KTHREAD || is_global_init(p))
1138 continue;
1139
1140 task_lock(p);
1141 if (!p->vfork_done && process_shares_mm(p, mm)) {
1142 p->signal->oom_score_adj = oom_adj;
1143 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1144 p->signal->oom_score_adj_min = (short)oom_adj;
1145 }
1146 task_unlock(p);
1147 }
1148 rcu_read_unlock();
1149 mmdrop(mm);
1150 }
1151 err_unlock:
1152 mutex_unlock(&oom_adj_mutex);
1153 put_task_struct(task);
1154 return err;
1155 }
1156
1157 /*
1158 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1159 * kernels. The effective policy is defined by oom_score_adj, which has a
1160 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1161 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1162 * Processes that become oom disabled via oom_adj will still be oom disabled
1163 * with this implementation.
1164 *
1165 * oom_adj cannot be removed since existing userspace binaries use it.
1166 */
oom_adj_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1167 static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1168 size_t count, loff_t *ppos)
1169 {
1170 char buffer[PROC_NUMBUF];
1171 int oom_adj;
1172 int err;
1173
1174 memset(buffer, 0, sizeof(buffer));
1175 if (count > sizeof(buffer) - 1)
1176 count = sizeof(buffer) - 1;
1177 if (copy_from_user(buffer, buf, count)) {
1178 err = -EFAULT;
1179 goto out;
1180 }
1181
1182 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1183 if (err)
1184 goto out;
1185 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1186 oom_adj != OOM_DISABLE) {
1187 err = -EINVAL;
1188 goto out;
1189 }
1190
1191 /*
1192 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1193 * value is always attainable.
1194 */
1195 if (oom_adj == OOM_ADJUST_MAX)
1196 oom_adj = OOM_SCORE_ADJ_MAX;
1197 else
1198 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1199
1200 err = __set_oom_adj(file, oom_adj, true);
1201 out:
1202 return err < 0 ? err : count;
1203 }
1204
1205 static const struct file_operations proc_oom_adj_operations = {
1206 .read = oom_adj_read,
1207 .write = oom_adj_write,
1208 .llseek = generic_file_llseek,
1209 };
1210
oom_score_adj_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1211 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1212 size_t count, loff_t *ppos)
1213 {
1214 struct task_struct *task = get_proc_task(file_inode(file));
1215 char buffer[PROC_NUMBUF];
1216 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1217 size_t len;
1218
1219 if (!task)
1220 return -ESRCH;
1221 oom_score_adj = task->signal->oom_score_adj;
1222 put_task_struct(task);
1223 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1224 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1225 }
1226
oom_score_adj_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1227 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1228 size_t count, loff_t *ppos)
1229 {
1230 char buffer[PROC_NUMBUF];
1231 int oom_score_adj;
1232 int err;
1233
1234 memset(buffer, 0, sizeof(buffer));
1235 if (count > sizeof(buffer) - 1)
1236 count = sizeof(buffer) - 1;
1237 if (copy_from_user(buffer, buf, count)) {
1238 err = -EFAULT;
1239 goto out;
1240 }
1241
1242 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1243 if (err)
1244 goto out;
1245 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1246 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1247 err = -EINVAL;
1248 goto out;
1249 }
1250
1251 err = __set_oom_adj(file, oom_score_adj, false);
1252 out:
1253 return err < 0 ? err : count;
1254 }
1255
1256 static const struct file_operations proc_oom_score_adj_operations = {
1257 .read = oom_score_adj_read,
1258 .write = oom_score_adj_write,
1259 .llseek = default_llseek,
1260 };
1261
1262 #ifdef CONFIG_AUDIT
1263 #define TMPBUFLEN 11
proc_loginuid_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1264 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1265 size_t count, loff_t *ppos)
1266 {
1267 struct inode * inode = file_inode(file);
1268 struct task_struct *task = get_proc_task(inode);
1269 ssize_t length;
1270 char tmpbuf[TMPBUFLEN];
1271
1272 if (!task)
1273 return -ESRCH;
1274 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1275 from_kuid(file->f_cred->user_ns,
1276 audit_get_loginuid(task)));
1277 put_task_struct(task);
1278 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1279 }
1280
proc_loginuid_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1281 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1282 size_t count, loff_t *ppos)
1283 {
1284 struct inode * inode = file_inode(file);
1285 uid_t loginuid;
1286 kuid_t kloginuid;
1287 int rv;
1288
1289 /* Don't let kthreads write their own loginuid */
1290 if (current->flags & PF_KTHREAD)
1291 return -EPERM;
1292
1293 rcu_read_lock();
1294 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1295 rcu_read_unlock();
1296 return -EPERM;
1297 }
1298 rcu_read_unlock();
1299
1300 if (*ppos != 0) {
1301 /* No partial writes. */
1302 return -EINVAL;
1303 }
1304
1305 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1306 if (rv < 0)
1307 return rv;
1308
1309 /* is userspace tring to explicitly UNSET the loginuid? */
1310 if (loginuid == AUDIT_UID_UNSET) {
1311 kloginuid = INVALID_UID;
1312 } else {
1313 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1314 if (!uid_valid(kloginuid))
1315 return -EINVAL;
1316 }
1317
1318 rv = audit_set_loginuid(kloginuid);
1319 if (rv < 0)
1320 return rv;
1321 return count;
1322 }
1323
1324 static const struct file_operations proc_loginuid_operations = {
1325 .read = proc_loginuid_read,
1326 .write = proc_loginuid_write,
1327 .llseek = generic_file_llseek,
1328 };
1329
proc_sessionid_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1330 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1331 size_t count, loff_t *ppos)
1332 {
1333 struct inode * inode = file_inode(file);
1334 struct task_struct *task = get_proc_task(inode);
1335 ssize_t length;
1336 char tmpbuf[TMPBUFLEN];
1337
1338 if (!task)
1339 return -ESRCH;
1340 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1341 audit_get_sessionid(task));
1342 put_task_struct(task);
1343 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1344 }
1345
1346 static const struct file_operations proc_sessionid_operations = {
1347 .read = proc_sessionid_read,
1348 .llseek = generic_file_llseek,
1349 };
1350 #endif
1351
1352 #ifdef CONFIG_FAULT_INJECTION
proc_fault_inject_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1353 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1354 size_t count, loff_t *ppos)
1355 {
1356 struct task_struct *task = get_proc_task(file_inode(file));
1357 char buffer[PROC_NUMBUF];
1358 size_t len;
1359 int make_it_fail;
1360
1361 if (!task)
1362 return -ESRCH;
1363 make_it_fail = task->make_it_fail;
1364 put_task_struct(task);
1365
1366 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1367
1368 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1369 }
1370
proc_fault_inject_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1371 static ssize_t proc_fault_inject_write(struct file * file,
1372 const char __user * buf, size_t count, loff_t *ppos)
1373 {
1374 struct task_struct *task;
1375 char buffer[PROC_NUMBUF];
1376 int make_it_fail;
1377 int rv;
1378
1379 if (!capable(CAP_SYS_RESOURCE))
1380 return -EPERM;
1381 memset(buffer, 0, sizeof(buffer));
1382 if (count > sizeof(buffer) - 1)
1383 count = sizeof(buffer) - 1;
1384 if (copy_from_user(buffer, buf, count))
1385 return -EFAULT;
1386 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1387 if (rv < 0)
1388 return rv;
1389 if (make_it_fail < 0 || make_it_fail > 1)
1390 return -EINVAL;
1391
1392 task = get_proc_task(file_inode(file));
1393 if (!task)
1394 return -ESRCH;
1395 task->make_it_fail = make_it_fail;
1396 put_task_struct(task);
1397
1398 return count;
1399 }
1400
1401 static const struct file_operations proc_fault_inject_operations = {
1402 .read = proc_fault_inject_read,
1403 .write = proc_fault_inject_write,
1404 .llseek = generic_file_llseek,
1405 };
1406
proc_fail_nth_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1407 static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1408 size_t count, loff_t *ppos)
1409 {
1410 struct task_struct *task;
1411 int err;
1412 unsigned int n;
1413
1414 err = kstrtouint_from_user(buf, count, 0, &n);
1415 if (err)
1416 return err;
1417
1418 task = get_proc_task(file_inode(file));
1419 if (!task)
1420 return -ESRCH;
1421 task->fail_nth = n;
1422 put_task_struct(task);
1423
1424 return count;
1425 }
1426
proc_fail_nth_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1427 static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1428 size_t count, loff_t *ppos)
1429 {
1430 struct task_struct *task;
1431 char numbuf[PROC_NUMBUF];
1432 ssize_t len;
1433
1434 task = get_proc_task(file_inode(file));
1435 if (!task)
1436 return -ESRCH;
1437 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1438 put_task_struct(task);
1439 return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1440 }
1441
1442 static const struct file_operations proc_fail_nth_operations = {
1443 .read = proc_fail_nth_read,
1444 .write = proc_fail_nth_write,
1445 };
1446 #endif
1447
1448
1449 #ifdef CONFIG_SCHED_DEBUG
1450 /*
1451 * Print out various scheduling related per-task fields:
1452 */
sched_show(struct seq_file * m,void * v)1453 static int sched_show(struct seq_file *m, void *v)
1454 {
1455 struct inode *inode = m->private;
1456 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
1457 struct task_struct *p;
1458
1459 p = get_proc_task(inode);
1460 if (!p)
1461 return -ESRCH;
1462 proc_sched_show_task(p, ns, m);
1463
1464 put_task_struct(p);
1465
1466 return 0;
1467 }
1468
1469 static ssize_t
sched_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)1470 sched_write(struct file *file, const char __user *buf,
1471 size_t count, loff_t *offset)
1472 {
1473 struct inode *inode = file_inode(file);
1474 struct task_struct *p;
1475
1476 p = get_proc_task(inode);
1477 if (!p)
1478 return -ESRCH;
1479 proc_sched_set_task(p);
1480
1481 put_task_struct(p);
1482
1483 return count;
1484 }
1485
sched_open(struct inode * inode,struct file * filp)1486 static int sched_open(struct inode *inode, struct file *filp)
1487 {
1488 return single_open(filp, sched_show, inode);
1489 }
1490
1491 static const struct file_operations proc_pid_sched_operations = {
1492 .open = sched_open,
1493 .read = seq_read,
1494 .write = sched_write,
1495 .llseek = seq_lseek,
1496 .release = single_release,
1497 };
1498
1499 #endif
1500
1501 #ifdef CONFIG_SCHED_AUTOGROUP
1502 /*
1503 * Print out autogroup related information:
1504 */
sched_autogroup_show(struct seq_file * m,void * v)1505 static int sched_autogroup_show(struct seq_file *m, void *v)
1506 {
1507 struct inode *inode = m->private;
1508 struct task_struct *p;
1509
1510 p = get_proc_task(inode);
1511 if (!p)
1512 return -ESRCH;
1513 proc_sched_autogroup_show_task(p, m);
1514
1515 put_task_struct(p);
1516
1517 return 0;
1518 }
1519
1520 static ssize_t
sched_autogroup_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)1521 sched_autogroup_write(struct file *file, const char __user *buf,
1522 size_t count, loff_t *offset)
1523 {
1524 struct inode *inode = file_inode(file);
1525 struct task_struct *p;
1526 char buffer[PROC_NUMBUF];
1527 int nice;
1528 int err;
1529
1530 memset(buffer, 0, sizeof(buffer));
1531 if (count > sizeof(buffer) - 1)
1532 count = sizeof(buffer) - 1;
1533 if (copy_from_user(buffer, buf, count))
1534 return -EFAULT;
1535
1536 err = kstrtoint(strstrip(buffer), 0, &nice);
1537 if (err < 0)
1538 return err;
1539
1540 p = get_proc_task(inode);
1541 if (!p)
1542 return -ESRCH;
1543
1544 err = proc_sched_autogroup_set_nice(p, nice);
1545 if (err)
1546 count = err;
1547
1548 put_task_struct(p);
1549
1550 return count;
1551 }
1552
sched_autogroup_open(struct inode * inode,struct file * filp)1553 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1554 {
1555 int ret;
1556
1557 ret = single_open(filp, sched_autogroup_show, NULL);
1558 if (!ret) {
1559 struct seq_file *m = filp->private_data;
1560
1561 m->private = inode;
1562 }
1563 return ret;
1564 }
1565
1566 static const struct file_operations proc_pid_sched_autogroup_operations = {
1567 .open = sched_autogroup_open,
1568 .read = seq_read,
1569 .write = sched_autogroup_write,
1570 .llseek = seq_lseek,
1571 .release = single_release,
1572 };
1573
1574 #endif /* CONFIG_SCHED_AUTOGROUP */
1575
1576 #ifdef CONFIG_TIME_NS
timens_offsets_show(struct seq_file * m,void * v)1577 static int timens_offsets_show(struct seq_file *m, void *v)
1578 {
1579 struct task_struct *p;
1580
1581 p = get_proc_task(file_inode(m->file));
1582 if (!p)
1583 return -ESRCH;
1584 proc_timens_show_offsets(p, m);
1585
1586 put_task_struct(p);
1587
1588 return 0;
1589 }
1590
timens_offsets_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1591 static ssize_t timens_offsets_write(struct file *file, const char __user *buf,
1592 size_t count, loff_t *ppos)
1593 {
1594 struct inode *inode = file_inode(file);
1595 struct proc_timens_offset offsets[2];
1596 char *kbuf = NULL, *pos, *next_line;
1597 struct task_struct *p;
1598 int ret, noffsets;
1599
1600 /* Only allow < page size writes at the beginning of the file */
1601 if ((*ppos != 0) || (count >= PAGE_SIZE))
1602 return -EINVAL;
1603
1604 /* Slurp in the user data */
1605 kbuf = memdup_user_nul(buf, count);
1606 if (IS_ERR(kbuf))
1607 return PTR_ERR(kbuf);
1608
1609 /* Parse the user data */
1610 ret = -EINVAL;
1611 noffsets = 0;
1612 for (pos = kbuf; pos; pos = next_line) {
1613 struct proc_timens_offset *off = &offsets[noffsets];
1614 char clock[10];
1615 int err;
1616
1617 /* Find the end of line and ensure we don't look past it */
1618 next_line = strchr(pos, '\n');
1619 if (next_line) {
1620 *next_line = '\0';
1621 next_line++;
1622 if (*next_line == '\0')
1623 next_line = NULL;
1624 }
1625
1626 err = sscanf(pos, "%9s %lld %lu", clock,
1627 &off->val.tv_sec, &off->val.tv_nsec);
1628 if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
1629 goto out;
1630
1631 clock[sizeof(clock) - 1] = 0;
1632 if (strcmp(clock, "monotonic") == 0 ||
1633 strcmp(clock, __stringify(CLOCK_MONOTONIC)) == 0)
1634 off->clockid = CLOCK_MONOTONIC;
1635 else if (strcmp(clock, "boottime") == 0 ||
1636 strcmp(clock, __stringify(CLOCK_BOOTTIME)) == 0)
1637 off->clockid = CLOCK_BOOTTIME;
1638 else
1639 goto out;
1640
1641 noffsets++;
1642 if (noffsets == ARRAY_SIZE(offsets)) {
1643 if (next_line)
1644 count = next_line - kbuf;
1645 break;
1646 }
1647 }
1648
1649 ret = -ESRCH;
1650 p = get_proc_task(inode);
1651 if (!p)
1652 goto out;
1653 ret = proc_timens_set_offset(file, p, offsets, noffsets);
1654 put_task_struct(p);
1655 if (ret)
1656 goto out;
1657
1658 ret = count;
1659 out:
1660 kfree(kbuf);
1661 return ret;
1662 }
1663
timens_offsets_open(struct inode * inode,struct file * filp)1664 static int timens_offsets_open(struct inode *inode, struct file *filp)
1665 {
1666 return single_open(filp, timens_offsets_show, inode);
1667 }
1668
1669 static const struct file_operations proc_timens_offsets_operations = {
1670 .open = timens_offsets_open,
1671 .read = seq_read,
1672 .write = timens_offsets_write,
1673 .llseek = seq_lseek,
1674 .release = single_release,
1675 };
1676 #endif /* CONFIG_TIME_NS */
1677
comm_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)1678 static ssize_t comm_write(struct file *file, const char __user *buf,
1679 size_t count, loff_t *offset)
1680 {
1681 struct inode *inode = file_inode(file);
1682 struct task_struct *p;
1683 char buffer[TASK_COMM_LEN];
1684 const size_t maxlen = sizeof(buffer) - 1;
1685
1686 memset(buffer, 0, sizeof(buffer));
1687 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1688 return -EFAULT;
1689
1690 p = get_proc_task(inode);
1691 if (!p)
1692 return -ESRCH;
1693
1694 if (same_thread_group(current, p)) {
1695 set_task_comm(p, buffer);
1696 proc_comm_connector(p);
1697 }
1698 else
1699 count = -EINVAL;
1700
1701 put_task_struct(p);
1702
1703 return count;
1704 }
1705
comm_show(struct seq_file * m,void * v)1706 static int comm_show(struct seq_file *m, void *v)
1707 {
1708 struct inode *inode = m->private;
1709 struct task_struct *p;
1710
1711 p = get_proc_task(inode);
1712 if (!p)
1713 return -ESRCH;
1714
1715 proc_task_name(m, p, false);
1716 seq_putc(m, '\n');
1717
1718 put_task_struct(p);
1719
1720 return 0;
1721 }
1722
comm_open(struct inode * inode,struct file * filp)1723 static int comm_open(struct inode *inode, struct file *filp)
1724 {
1725 return single_open(filp, comm_show, inode);
1726 }
1727
1728 static const struct file_operations proc_pid_set_comm_operations = {
1729 .open = comm_open,
1730 .read = seq_read,
1731 .write = comm_write,
1732 .llseek = seq_lseek,
1733 .release = single_release,
1734 };
1735
proc_exe_link(struct dentry * dentry,struct path * exe_path)1736 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1737 {
1738 struct task_struct *task;
1739 struct file *exe_file;
1740
1741 task = get_proc_task(d_inode(dentry));
1742 if (!task)
1743 return -ENOENT;
1744 exe_file = get_task_exe_file(task);
1745 put_task_struct(task);
1746 if (exe_file) {
1747 *exe_path = exe_file->f_path;
1748 path_get(&exe_file->f_path);
1749 fput(exe_file);
1750 return 0;
1751 } else
1752 return -ENOENT;
1753 }
1754
proc_pid_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)1755 static const char *proc_pid_get_link(struct dentry *dentry,
1756 struct inode *inode,
1757 struct delayed_call *done)
1758 {
1759 struct path path;
1760 int error = -EACCES;
1761
1762 if (!dentry)
1763 return ERR_PTR(-ECHILD);
1764
1765 /* Are we allowed to snoop on the tasks file descriptors? */
1766 if (!proc_fd_access_allowed(inode))
1767 goto out;
1768
1769 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1770 if (error)
1771 goto out;
1772
1773 error = nd_jump_link(&path);
1774 out:
1775 return ERR_PTR(error);
1776 }
1777
do_proc_readlink(struct path * path,char __user * buffer,int buflen)1778 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1779 {
1780 char *tmp = (char *)__get_free_page(GFP_KERNEL);
1781 char *pathname;
1782 int len;
1783
1784 if (!tmp)
1785 return -ENOMEM;
1786
1787 pathname = d_path(path, tmp, PAGE_SIZE);
1788 len = PTR_ERR(pathname);
1789 if (IS_ERR(pathname))
1790 goto out;
1791 len = tmp + PAGE_SIZE - 1 - pathname;
1792
1793 if (len > buflen)
1794 len = buflen;
1795 if (copy_to_user(buffer, pathname, len))
1796 len = -EFAULT;
1797 out:
1798 free_page((unsigned long)tmp);
1799 return len;
1800 }
1801
proc_pid_readlink(struct dentry * dentry,char __user * buffer,int buflen)1802 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1803 {
1804 int error = -EACCES;
1805 struct inode *inode = d_inode(dentry);
1806 struct path path;
1807
1808 /* Are we allowed to snoop on the tasks file descriptors? */
1809 if (!proc_fd_access_allowed(inode))
1810 goto out;
1811
1812 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1813 if (error)
1814 goto out;
1815
1816 error = do_proc_readlink(&path, buffer, buflen);
1817 path_put(&path);
1818 out:
1819 return error;
1820 }
1821
1822 const struct inode_operations proc_pid_link_inode_operations = {
1823 .readlink = proc_pid_readlink,
1824 .get_link = proc_pid_get_link,
1825 .setattr = proc_setattr,
1826 };
1827
1828
1829 /* building an inode */
1830
task_dump_owner(struct task_struct * task,umode_t mode,kuid_t * ruid,kgid_t * rgid)1831 void task_dump_owner(struct task_struct *task, umode_t mode,
1832 kuid_t *ruid, kgid_t *rgid)
1833 {
1834 /* Depending on the state of dumpable compute who should own a
1835 * proc file for a task.
1836 */
1837 const struct cred *cred;
1838 kuid_t uid;
1839 kgid_t gid;
1840
1841 if (unlikely(task->flags & PF_KTHREAD)) {
1842 *ruid = GLOBAL_ROOT_UID;
1843 *rgid = GLOBAL_ROOT_GID;
1844 return;
1845 }
1846
1847 /* Default to the tasks effective ownership */
1848 rcu_read_lock();
1849 cred = __task_cred(task);
1850 uid = cred->euid;
1851 gid = cred->egid;
1852 rcu_read_unlock();
1853
1854 /*
1855 * Before the /proc/pid/status file was created the only way to read
1856 * the effective uid of a /process was to stat /proc/pid. Reading
1857 * /proc/pid/status is slow enough that procps and other packages
1858 * kept stating /proc/pid. To keep the rules in /proc simple I have
1859 * made this apply to all per process world readable and executable
1860 * directories.
1861 */
1862 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1863 struct mm_struct *mm;
1864 task_lock(task);
1865 mm = task->mm;
1866 /* Make non-dumpable tasks owned by some root */
1867 if (mm) {
1868 if (get_dumpable(mm) != SUID_DUMP_USER) {
1869 struct user_namespace *user_ns = mm->user_ns;
1870
1871 uid = make_kuid(user_ns, 0);
1872 if (!uid_valid(uid))
1873 uid = GLOBAL_ROOT_UID;
1874
1875 gid = make_kgid(user_ns, 0);
1876 if (!gid_valid(gid))
1877 gid = GLOBAL_ROOT_GID;
1878 }
1879 } else {
1880 uid = GLOBAL_ROOT_UID;
1881 gid = GLOBAL_ROOT_GID;
1882 }
1883 task_unlock(task);
1884 }
1885 *ruid = uid;
1886 *rgid = gid;
1887 }
1888
proc_pid_evict_inode(struct proc_inode * ei)1889 void proc_pid_evict_inode(struct proc_inode *ei)
1890 {
1891 struct pid *pid = ei->pid;
1892
1893 if (S_ISDIR(ei->vfs_inode.i_mode)) {
1894 spin_lock(&pid->lock);
1895 hlist_del_init_rcu(&ei->sibling_inodes);
1896 spin_unlock(&pid->lock);
1897 }
1898
1899 put_pid(pid);
1900 }
1901
proc_pid_make_inode(struct super_block * sb,struct task_struct * task,umode_t mode)1902 struct inode *proc_pid_make_inode(struct super_block *sb,
1903 struct task_struct *task, umode_t mode)
1904 {
1905 struct inode * inode;
1906 struct proc_inode *ei;
1907 struct pid *pid;
1908
1909 /* We need a new inode */
1910
1911 inode = new_inode(sb);
1912 if (!inode)
1913 goto out;
1914
1915 /* Common stuff */
1916 ei = PROC_I(inode);
1917 inode->i_mode = mode;
1918 inode->i_ino = get_next_ino();
1919 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1920 inode->i_op = &proc_def_inode_operations;
1921
1922 /*
1923 * grab the reference to task.
1924 */
1925 pid = get_task_pid(task, PIDTYPE_PID);
1926 if (!pid)
1927 goto out_unlock;
1928
1929 /* Let the pid remember us for quick removal */
1930 ei->pid = pid;
1931
1932 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1933 security_task_to_inode(task, inode);
1934
1935 out:
1936 return inode;
1937
1938 out_unlock:
1939 iput(inode);
1940 return NULL;
1941 }
1942
1943 /*
1944 * Generating an inode and adding it into @pid->inodes, so that task will
1945 * invalidate inode's dentry before being released.
1946 *
1947 * This helper is used for creating dir-type entries under '/proc' and
1948 * '/proc/<tgid>/task'. Other entries(eg. fd, stat) under '/proc/<tgid>'
1949 * can be released by invalidating '/proc/<tgid>' dentry.
1950 * In theory, dentries under '/proc/<tgid>/task' can also be released by
1951 * invalidating '/proc/<tgid>' dentry, we reserve it to handle single
1952 * thread exiting situation: Any one of threads should invalidate its
1953 * '/proc/<tgid>/task/<pid>' dentry before released.
1954 */
proc_pid_make_base_inode(struct super_block * sb,struct task_struct * task,umode_t mode)1955 static struct inode *proc_pid_make_base_inode(struct super_block *sb,
1956 struct task_struct *task, umode_t mode)
1957 {
1958 struct inode *inode;
1959 struct proc_inode *ei;
1960 struct pid *pid;
1961
1962 inode = proc_pid_make_inode(sb, task, mode);
1963 if (!inode)
1964 return NULL;
1965
1966 /* Let proc_flush_pid find this directory inode */
1967 ei = PROC_I(inode);
1968 pid = ei->pid;
1969 spin_lock(&pid->lock);
1970 hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
1971 spin_unlock(&pid->lock);
1972
1973 return inode;
1974 }
1975
pid_getattr(struct user_namespace * mnt_userns,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)1976 int pid_getattr(struct user_namespace *mnt_userns, const struct path *path,
1977 struct kstat *stat, u32 request_mask, unsigned int query_flags)
1978 {
1979 struct inode *inode = d_inode(path->dentry);
1980 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
1981 struct task_struct *task;
1982
1983 generic_fillattr(&init_user_ns, inode, stat);
1984
1985 stat->uid = GLOBAL_ROOT_UID;
1986 stat->gid = GLOBAL_ROOT_GID;
1987 rcu_read_lock();
1988 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1989 if (task) {
1990 if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) {
1991 rcu_read_unlock();
1992 /*
1993 * This doesn't prevent learning whether PID exists,
1994 * it only makes getattr() consistent with readdir().
1995 */
1996 return -ENOENT;
1997 }
1998 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1999 }
2000 rcu_read_unlock();
2001 return 0;
2002 }
2003
2004 /* dentry stuff */
2005
2006 /*
2007 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
2008 */
pid_update_inode(struct task_struct * task,struct inode * inode)2009 void pid_update_inode(struct task_struct *task, struct inode *inode)
2010 {
2011 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
2012
2013 inode->i_mode &= ~(S_ISUID | S_ISGID);
2014 security_task_to_inode(task, inode);
2015 }
2016
2017 /*
2018 * Rewrite the inode's ownerships here because the owning task may have
2019 * performed a setuid(), etc.
2020 *
2021 */
pid_revalidate(struct dentry * dentry,unsigned int flags)2022 static int pid_revalidate(struct dentry *dentry, unsigned int flags)
2023 {
2024 struct inode *inode;
2025 struct task_struct *task;
2026
2027 if (flags & LOOKUP_RCU)
2028 return -ECHILD;
2029
2030 inode = d_inode(dentry);
2031 task = get_proc_task(inode);
2032
2033 if (task) {
2034 pid_update_inode(task, inode);
2035 put_task_struct(task);
2036 return 1;
2037 }
2038 return 0;
2039 }
2040
proc_inode_is_dead(struct inode * inode)2041 static inline bool proc_inode_is_dead(struct inode *inode)
2042 {
2043 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
2044 }
2045
pid_delete_dentry(const struct dentry * dentry)2046 int pid_delete_dentry(const struct dentry *dentry)
2047 {
2048 /* Is the task we represent dead?
2049 * If so, then don't put the dentry on the lru list,
2050 * kill it immediately.
2051 */
2052 return proc_inode_is_dead(d_inode(dentry));
2053 }
2054
2055 const struct dentry_operations pid_dentry_operations =
2056 {
2057 .d_revalidate = pid_revalidate,
2058 .d_delete = pid_delete_dentry,
2059 };
2060
2061 /* Lookups */
2062
2063 /*
2064 * Fill a directory entry.
2065 *
2066 * If possible create the dcache entry and derive our inode number and
2067 * file type from dcache entry.
2068 *
2069 * Since all of the proc inode numbers are dynamically generated, the inode
2070 * numbers do not exist until the inode is cache. This means creating
2071 * the dcache entry in readdir is necessary to keep the inode numbers
2072 * reported by readdir in sync with the inode numbers reported
2073 * by stat.
2074 */
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)2075 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
2076 const char *name, unsigned int len,
2077 instantiate_t instantiate, struct task_struct *task, const void *ptr)
2078 {
2079 struct dentry *child, *dir = file->f_path.dentry;
2080 struct qstr qname = QSTR_INIT(name, len);
2081 struct inode *inode;
2082 unsigned type = DT_UNKNOWN;
2083 ino_t ino = 1;
2084
2085 child = d_hash_and_lookup(dir, &qname);
2086 if (!child) {
2087 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
2088 child = d_alloc_parallel(dir, &qname, &wq);
2089 if (IS_ERR(child))
2090 goto end_instantiate;
2091 if (d_in_lookup(child)) {
2092 struct dentry *res;
2093 res = instantiate(child, task, ptr);
2094 d_lookup_done(child);
2095 if (unlikely(res)) {
2096 dput(child);
2097 child = res;
2098 if (IS_ERR(child))
2099 goto end_instantiate;
2100 }
2101 }
2102 }
2103 inode = d_inode(child);
2104 ino = inode->i_ino;
2105 type = inode->i_mode >> 12;
2106 dput(child);
2107 end_instantiate:
2108 return dir_emit(ctx, name, len, ino, type);
2109 }
2110
2111 /*
2112 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2113 * which represent vma start and end addresses.
2114 */
dname_to_vma_addr(struct dentry * dentry,unsigned long * start,unsigned long * end)2115 static int dname_to_vma_addr(struct dentry *dentry,
2116 unsigned long *start, unsigned long *end)
2117 {
2118 const char *str = dentry->d_name.name;
2119 unsigned long long sval, eval;
2120 unsigned int len;
2121
2122 if (str[0] == '0' && str[1] != '-')
2123 return -EINVAL;
2124 len = _parse_integer(str, 16, &sval);
2125 if (len & KSTRTOX_OVERFLOW)
2126 return -EINVAL;
2127 if (sval != (unsigned long)sval)
2128 return -EINVAL;
2129 str += len;
2130
2131 if (*str != '-')
2132 return -EINVAL;
2133 str++;
2134
2135 if (str[0] == '0' && str[1])
2136 return -EINVAL;
2137 len = _parse_integer(str, 16, &eval);
2138 if (len & KSTRTOX_OVERFLOW)
2139 return -EINVAL;
2140 if (eval != (unsigned long)eval)
2141 return -EINVAL;
2142 str += len;
2143
2144 if (*str != '\0')
2145 return -EINVAL;
2146
2147 *start = sval;
2148 *end = eval;
2149
2150 return 0;
2151 }
2152
map_files_d_revalidate(struct dentry * dentry,unsigned int flags)2153 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
2154 {
2155 unsigned long vm_start, vm_end;
2156 bool exact_vma_exists = false;
2157 struct mm_struct *mm = NULL;
2158 struct task_struct *task;
2159 struct inode *inode;
2160 int status = 0;
2161
2162 if (flags & LOOKUP_RCU)
2163 return -ECHILD;
2164
2165 inode = d_inode(dentry);
2166 task = get_proc_task(inode);
2167 if (!task)
2168 goto out_notask;
2169
2170 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2171 if (IS_ERR_OR_NULL(mm))
2172 goto out;
2173
2174 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2175 status = mmap_read_lock_killable(mm);
2176 if (!status) {
2177 exact_vma_exists = !!find_exact_vma(mm, vm_start,
2178 vm_end);
2179 mmap_read_unlock(mm);
2180 }
2181 }
2182
2183 mmput(mm);
2184
2185 if (exact_vma_exists) {
2186 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
2187
2188 security_task_to_inode(task, inode);
2189 status = 1;
2190 }
2191
2192 out:
2193 put_task_struct(task);
2194
2195 out_notask:
2196 return status;
2197 }
2198
2199 static const struct dentry_operations tid_map_files_dentry_operations = {
2200 .d_revalidate = map_files_d_revalidate,
2201 .d_delete = pid_delete_dentry,
2202 };
2203
map_files_get_link(struct dentry * dentry,struct path * path)2204 static int map_files_get_link(struct dentry *dentry, struct path *path)
2205 {
2206 unsigned long vm_start, vm_end;
2207 struct vm_area_struct *vma;
2208 struct task_struct *task;
2209 struct mm_struct *mm;
2210 int rc;
2211
2212 rc = -ENOENT;
2213 task = get_proc_task(d_inode(dentry));
2214 if (!task)
2215 goto out;
2216
2217 mm = get_task_mm(task);
2218 put_task_struct(task);
2219 if (!mm)
2220 goto out;
2221
2222 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2223 if (rc)
2224 goto out_mmput;
2225
2226 rc = mmap_read_lock_killable(mm);
2227 if (rc)
2228 goto out_mmput;
2229
2230 rc = -ENOENT;
2231 vma = find_exact_vma(mm, vm_start, vm_end);
2232 if (vma && vma->vm_file) {
2233 *path = vma->vm_file->f_path;
2234 path_get(path);
2235 rc = 0;
2236 }
2237 mmap_read_unlock(mm);
2238
2239 out_mmput:
2240 mmput(mm);
2241 out:
2242 return rc;
2243 }
2244
2245 struct map_files_info {
2246 unsigned long start;
2247 unsigned long end;
2248 fmode_t mode;
2249 };
2250
2251 /*
2252 * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
2253 * to concerns about how the symlinks may be used to bypass permissions on
2254 * ancestor directories in the path to the file in question.
2255 */
2256 static const char *
proc_map_files_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)2257 proc_map_files_get_link(struct dentry *dentry,
2258 struct inode *inode,
2259 struct delayed_call *done)
2260 {
2261 if (!checkpoint_restore_ns_capable(&init_user_ns))
2262 return ERR_PTR(-EPERM);
2263
2264 return proc_pid_get_link(dentry, inode, done);
2265 }
2266
2267 /*
2268 * Identical to proc_pid_link_inode_operations except for get_link()
2269 */
2270 static const struct inode_operations proc_map_files_link_inode_operations = {
2271 .readlink = proc_pid_readlink,
2272 .get_link = proc_map_files_get_link,
2273 .setattr = proc_setattr,
2274 };
2275
2276 static struct dentry *
proc_map_files_instantiate(struct dentry * dentry,struct task_struct * task,const void * ptr)2277 proc_map_files_instantiate(struct dentry *dentry,
2278 struct task_struct *task, const void *ptr)
2279 {
2280 fmode_t mode = (fmode_t)(unsigned long)ptr;
2281 struct proc_inode *ei;
2282 struct inode *inode;
2283
2284 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2285 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2286 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2287 if (!inode)
2288 return ERR_PTR(-ENOENT);
2289
2290 ei = PROC_I(inode);
2291 ei->op.proc_get_link = map_files_get_link;
2292
2293 inode->i_op = &proc_map_files_link_inode_operations;
2294 inode->i_size = 64;
2295
2296 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2297 return d_splice_alias(inode, dentry);
2298 }
2299
proc_map_files_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)2300 static struct dentry *proc_map_files_lookup(struct inode *dir,
2301 struct dentry *dentry, unsigned int flags)
2302 {
2303 unsigned long vm_start, vm_end;
2304 struct vm_area_struct *vma;
2305 struct task_struct *task;
2306 struct dentry *result;
2307 struct mm_struct *mm;
2308
2309 result = ERR_PTR(-ENOENT);
2310 task = get_proc_task(dir);
2311 if (!task)
2312 goto out;
2313
2314 result = ERR_PTR(-EACCES);
2315 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2316 goto out_put_task;
2317
2318 result = ERR_PTR(-ENOENT);
2319 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2320 goto out_put_task;
2321
2322 mm = get_task_mm(task);
2323 if (!mm)
2324 goto out_put_task;
2325
2326 result = ERR_PTR(-EINTR);
2327 if (mmap_read_lock_killable(mm))
2328 goto out_put_mm;
2329
2330 result = ERR_PTR(-ENOENT);
2331 vma = find_exact_vma(mm, vm_start, vm_end);
2332 if (!vma)
2333 goto out_no_vma;
2334
2335 if (vma->vm_file)
2336 result = proc_map_files_instantiate(dentry, task,
2337 (void *)(unsigned long)vma->vm_file->f_mode);
2338
2339 out_no_vma:
2340 mmap_read_unlock(mm);
2341 out_put_mm:
2342 mmput(mm);
2343 out_put_task:
2344 put_task_struct(task);
2345 out:
2346 return result;
2347 }
2348
2349 static const struct inode_operations proc_map_files_inode_operations = {
2350 .lookup = proc_map_files_lookup,
2351 .permission = proc_fd_permission,
2352 .setattr = proc_setattr,
2353 };
2354
2355 static int
proc_map_files_readdir(struct file * file,struct dir_context * ctx)2356 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2357 {
2358 struct vm_area_struct *vma;
2359 struct task_struct *task;
2360 struct mm_struct *mm;
2361 unsigned long nr_files, pos, i;
2362 GENRADIX(struct map_files_info) fa;
2363 struct map_files_info *p;
2364 int ret;
2365
2366 genradix_init(&fa);
2367
2368 ret = -ENOENT;
2369 task = get_proc_task(file_inode(file));
2370 if (!task)
2371 goto out;
2372
2373 ret = -EACCES;
2374 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2375 goto out_put_task;
2376
2377 ret = 0;
2378 if (!dir_emit_dots(file, ctx))
2379 goto out_put_task;
2380
2381 mm = get_task_mm(task);
2382 if (!mm)
2383 goto out_put_task;
2384
2385 ret = mmap_read_lock_killable(mm);
2386 if (ret) {
2387 mmput(mm);
2388 goto out_put_task;
2389 }
2390
2391 nr_files = 0;
2392
2393 /*
2394 * We need two passes here:
2395 *
2396 * 1) Collect vmas of mapped files with mmap_lock taken
2397 * 2) Release mmap_lock and instantiate entries
2398 *
2399 * otherwise we get lockdep complained, since filldir()
2400 * routine might require mmap_lock taken in might_fault().
2401 */
2402
2403 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2404 if (!vma->vm_file)
2405 continue;
2406 if (++pos <= ctx->pos)
2407 continue;
2408
2409 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2410 if (!p) {
2411 ret = -ENOMEM;
2412 mmap_read_unlock(mm);
2413 mmput(mm);
2414 goto out_put_task;
2415 }
2416
2417 p->start = vma->vm_start;
2418 p->end = vma->vm_end;
2419 p->mode = vma->vm_file->f_mode;
2420 }
2421 mmap_read_unlock(mm);
2422 mmput(mm);
2423
2424 for (i = 0; i < nr_files; i++) {
2425 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2426 unsigned int len;
2427
2428 p = genradix_ptr(&fa, i);
2429 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2430 if (!proc_fill_cache(file, ctx,
2431 buf, len,
2432 proc_map_files_instantiate,
2433 task,
2434 (void *)(unsigned long)p->mode))
2435 break;
2436 ctx->pos++;
2437 }
2438
2439 out_put_task:
2440 put_task_struct(task);
2441 out:
2442 genradix_free(&fa);
2443 return ret;
2444 }
2445
2446 static const struct file_operations proc_map_files_operations = {
2447 .read = generic_read_dir,
2448 .iterate_shared = proc_map_files_readdir,
2449 .llseek = generic_file_llseek,
2450 };
2451
2452 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2453 struct timers_private {
2454 struct pid *pid;
2455 struct task_struct *task;
2456 struct sighand_struct *sighand;
2457 struct pid_namespace *ns;
2458 unsigned long flags;
2459 };
2460
timers_start(struct seq_file * m,loff_t * pos)2461 static void *timers_start(struct seq_file *m, loff_t *pos)
2462 {
2463 struct timers_private *tp = m->private;
2464
2465 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2466 if (!tp->task)
2467 return ERR_PTR(-ESRCH);
2468
2469 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2470 if (!tp->sighand)
2471 return ERR_PTR(-ESRCH);
2472
2473 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2474 }
2475
timers_next(struct seq_file * m,void * v,loff_t * pos)2476 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2477 {
2478 struct timers_private *tp = m->private;
2479 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2480 }
2481
timers_stop(struct seq_file * m,void * v)2482 static void timers_stop(struct seq_file *m, void *v)
2483 {
2484 struct timers_private *tp = m->private;
2485
2486 if (tp->sighand) {
2487 unlock_task_sighand(tp->task, &tp->flags);
2488 tp->sighand = NULL;
2489 }
2490
2491 if (tp->task) {
2492 put_task_struct(tp->task);
2493 tp->task = NULL;
2494 }
2495 }
2496
show_timer(struct seq_file * m,void * v)2497 static int show_timer(struct seq_file *m, void *v)
2498 {
2499 struct k_itimer *timer;
2500 struct timers_private *tp = m->private;
2501 int notify;
2502 static const char * const nstr[] = {
2503 [SIGEV_SIGNAL] = "signal",
2504 [SIGEV_NONE] = "none",
2505 [SIGEV_THREAD] = "thread",
2506 };
2507
2508 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2509 notify = timer->it_sigev_notify;
2510
2511 seq_printf(m, "ID: %d\n", timer->it_id);
2512 seq_printf(m, "signal: %d/%px\n",
2513 timer->sigq->info.si_signo,
2514 timer->sigq->info.si_value.sival_ptr);
2515 seq_printf(m, "notify: %s/%s.%d\n",
2516 nstr[notify & ~SIGEV_THREAD_ID],
2517 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2518 pid_nr_ns(timer->it_pid, tp->ns));
2519 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2520
2521 return 0;
2522 }
2523
2524 static const struct seq_operations proc_timers_seq_ops = {
2525 .start = timers_start,
2526 .next = timers_next,
2527 .stop = timers_stop,
2528 .show = show_timer,
2529 };
2530
proc_timers_open(struct inode * inode,struct file * file)2531 static int proc_timers_open(struct inode *inode, struct file *file)
2532 {
2533 struct timers_private *tp;
2534
2535 tp = __seq_open_private(file, &proc_timers_seq_ops,
2536 sizeof(struct timers_private));
2537 if (!tp)
2538 return -ENOMEM;
2539
2540 tp->pid = proc_pid(inode);
2541 tp->ns = proc_pid_ns(inode->i_sb);
2542 return 0;
2543 }
2544
2545 static const struct file_operations proc_timers_operations = {
2546 .open = proc_timers_open,
2547 .read = seq_read,
2548 .llseek = seq_lseek,
2549 .release = seq_release_private,
2550 };
2551 #endif
2552
timerslack_ns_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)2553 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2554 size_t count, loff_t *offset)
2555 {
2556 struct inode *inode = file_inode(file);
2557 struct task_struct *p;
2558 u64 slack_ns;
2559 int err;
2560
2561 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2562 if (err < 0)
2563 return err;
2564
2565 p = get_proc_task(inode);
2566 if (!p)
2567 return -ESRCH;
2568
2569 if (p != current) {
2570 rcu_read_lock();
2571 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2572 rcu_read_unlock();
2573 count = -EPERM;
2574 goto out;
2575 }
2576 rcu_read_unlock();
2577
2578 err = security_task_setscheduler(p);
2579 if (err) {
2580 count = err;
2581 goto out;
2582 }
2583 }
2584
2585 task_lock(p);
2586 if (slack_ns == 0)
2587 p->timer_slack_ns = p->default_timer_slack_ns;
2588 else
2589 p->timer_slack_ns = slack_ns;
2590 task_unlock(p);
2591
2592 out:
2593 put_task_struct(p);
2594
2595 return count;
2596 }
2597
timerslack_ns_show(struct seq_file * m,void * v)2598 static int timerslack_ns_show(struct seq_file *m, void *v)
2599 {
2600 struct inode *inode = m->private;
2601 struct task_struct *p;
2602 int err = 0;
2603
2604 p = get_proc_task(inode);
2605 if (!p)
2606 return -ESRCH;
2607
2608 if (p != current) {
2609 rcu_read_lock();
2610 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2611 rcu_read_unlock();
2612 err = -EPERM;
2613 goto out;
2614 }
2615 rcu_read_unlock();
2616
2617 err = security_task_getscheduler(p);
2618 if (err)
2619 goto out;
2620 }
2621
2622 task_lock(p);
2623 seq_printf(m, "%llu\n", p->timer_slack_ns);
2624 task_unlock(p);
2625
2626 out:
2627 put_task_struct(p);
2628
2629 return err;
2630 }
2631
timerslack_ns_open(struct inode * inode,struct file * filp)2632 static int timerslack_ns_open(struct inode *inode, struct file *filp)
2633 {
2634 return single_open(filp, timerslack_ns_show, inode);
2635 }
2636
2637 static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2638 .open = timerslack_ns_open,
2639 .read = seq_read,
2640 .write = timerslack_ns_write,
2641 .llseek = seq_lseek,
2642 .release = single_release,
2643 };
2644
proc_pident_instantiate(struct dentry * dentry,struct task_struct * task,const void * ptr)2645 static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2646 struct task_struct *task, const void *ptr)
2647 {
2648 const struct pid_entry *p = ptr;
2649 struct inode *inode;
2650 struct proc_inode *ei;
2651
2652 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2653 if (!inode)
2654 return ERR_PTR(-ENOENT);
2655
2656 ei = PROC_I(inode);
2657 if (S_ISDIR(inode->i_mode))
2658 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2659 if (p->iop)
2660 inode->i_op = p->iop;
2661 if (p->fop)
2662 inode->i_fop = p->fop;
2663 ei->op = p->op;
2664 pid_update_inode(task, inode);
2665 d_set_d_op(dentry, &pid_dentry_operations);
2666 return d_splice_alias(inode, dentry);
2667 }
2668
proc_pident_lookup(struct inode * dir,struct dentry * dentry,const struct pid_entry * p,const struct pid_entry * end)2669 static struct dentry *proc_pident_lookup(struct inode *dir,
2670 struct dentry *dentry,
2671 const struct pid_entry *p,
2672 const struct pid_entry *end)
2673 {
2674 struct task_struct *task = get_proc_task(dir);
2675 struct dentry *res = ERR_PTR(-ENOENT);
2676
2677 if (!task)
2678 goto out_no_task;
2679
2680 /*
2681 * Yes, it does not scale. And it should not. Don't add
2682 * new entries into /proc/<tgid>/ without very good reasons.
2683 */
2684 for (; p < end; p++) {
2685 if (p->len != dentry->d_name.len)
2686 continue;
2687 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2688 res = proc_pident_instantiate(dentry, task, p);
2689 break;
2690 }
2691 }
2692 put_task_struct(task);
2693 out_no_task:
2694 return res;
2695 }
2696
proc_pident_readdir(struct file * file,struct dir_context * ctx,const struct pid_entry * ents,unsigned int nents)2697 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2698 const struct pid_entry *ents, unsigned int nents)
2699 {
2700 struct task_struct *task = get_proc_task(file_inode(file));
2701 const struct pid_entry *p;
2702
2703 if (!task)
2704 return -ENOENT;
2705
2706 if (!dir_emit_dots(file, ctx))
2707 goto out;
2708
2709 if (ctx->pos >= nents + 2)
2710 goto out;
2711
2712 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2713 if (!proc_fill_cache(file, ctx, p->name, p->len,
2714 proc_pident_instantiate, task, p))
2715 break;
2716 ctx->pos++;
2717 }
2718 out:
2719 put_task_struct(task);
2720 return 0;
2721 }
2722
2723 #ifdef CONFIG_SECURITY
proc_pid_attr_open(struct inode * inode,struct file * file)2724 static int proc_pid_attr_open(struct inode *inode, struct file *file)
2725 {
2726 file->private_data = NULL;
2727 __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
2728 return 0;
2729 }
2730
proc_pid_attr_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)2731 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2732 size_t count, loff_t *ppos)
2733 {
2734 struct inode * inode = file_inode(file);
2735 char *p = NULL;
2736 ssize_t length;
2737 struct task_struct *task = get_proc_task(inode);
2738
2739 if (!task)
2740 return -ESRCH;
2741
2742 length = security_getprocattr(task, PROC_I(inode)->op.lsm,
2743 (char*)file->f_path.dentry->d_name.name,
2744 &p);
2745 put_task_struct(task);
2746 if (length > 0)
2747 length = simple_read_from_buffer(buf, count, ppos, p, length);
2748 kfree(p);
2749 return length;
2750 }
2751
proc_pid_attr_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2752 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2753 size_t count, loff_t *ppos)
2754 {
2755 struct inode * inode = file_inode(file);
2756 struct task_struct *task;
2757 void *page;
2758 int rv;
2759
2760 /* A task may only write when it was the opener. */
2761 if (file->private_data != current->mm)
2762 return -EPERM;
2763
2764 rcu_read_lock();
2765 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2766 if (!task) {
2767 rcu_read_unlock();
2768 return -ESRCH;
2769 }
2770 /* A task may only write its own attributes. */
2771 if (current != task) {
2772 rcu_read_unlock();
2773 return -EACCES;
2774 }
2775 /* Prevent changes to overridden credentials. */
2776 if (current_cred() != current_real_cred()) {
2777 rcu_read_unlock();
2778 return -EBUSY;
2779 }
2780 rcu_read_unlock();
2781
2782 if (count > PAGE_SIZE)
2783 count = PAGE_SIZE;
2784
2785 /* No partial writes. */
2786 if (*ppos != 0)
2787 return -EINVAL;
2788
2789 page = memdup_user(buf, count);
2790 if (IS_ERR(page)) {
2791 rv = PTR_ERR(page);
2792 goto out;
2793 }
2794
2795 /* Guard against adverse ptrace interaction */
2796 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex);
2797 if (rv < 0)
2798 goto out_free;
2799
2800 rv = security_setprocattr(PROC_I(inode)->op.lsm,
2801 file->f_path.dentry->d_name.name, page,
2802 count);
2803 mutex_unlock(¤t->signal->cred_guard_mutex);
2804 out_free:
2805 kfree(page);
2806 out:
2807 return rv;
2808 }
2809
2810 static const struct file_operations proc_pid_attr_operations = {
2811 .open = proc_pid_attr_open,
2812 .read = proc_pid_attr_read,
2813 .write = proc_pid_attr_write,
2814 .llseek = generic_file_llseek,
2815 .release = mem_release,
2816 };
2817
2818 #define LSM_DIR_OPS(LSM) \
2819 static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2820 struct dir_context *ctx) \
2821 { \
2822 return proc_pident_readdir(filp, ctx, \
2823 LSM##_attr_dir_stuff, \
2824 ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2825 } \
2826 \
2827 static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2828 .read = generic_read_dir, \
2829 .iterate = proc_##LSM##_attr_dir_iterate, \
2830 .llseek = default_llseek, \
2831 }; \
2832 \
2833 static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2834 struct dentry *dentry, unsigned int flags) \
2835 { \
2836 return proc_pident_lookup(dir, dentry, \
2837 LSM##_attr_dir_stuff, \
2838 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2839 } \
2840 \
2841 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2842 .lookup = proc_##LSM##_attr_dir_lookup, \
2843 .getattr = pid_getattr, \
2844 .setattr = proc_setattr, \
2845 }
2846
2847 #ifdef CONFIG_SECURITY_SMACK
2848 static const struct pid_entry smack_attr_dir_stuff[] = {
2849 ATTR("smack", "current", 0666),
2850 };
2851 LSM_DIR_OPS(smack);
2852 #endif
2853
2854 #ifdef CONFIG_SECURITY_APPARMOR
2855 static const struct pid_entry apparmor_attr_dir_stuff[] = {
2856 ATTR("apparmor", "current", 0666),
2857 ATTR("apparmor", "prev", 0444),
2858 ATTR("apparmor", "exec", 0666),
2859 };
2860 LSM_DIR_OPS(apparmor);
2861 #endif
2862
2863 static const struct pid_entry attr_dir_stuff[] = {
2864 ATTR(NULL, "current", 0666),
2865 ATTR(NULL, "prev", 0444),
2866 ATTR(NULL, "exec", 0666),
2867 ATTR(NULL, "fscreate", 0666),
2868 ATTR(NULL, "keycreate", 0666),
2869 ATTR(NULL, "sockcreate", 0666),
2870 #ifdef CONFIG_SECURITY_SMACK
2871 DIR("smack", 0555,
2872 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2873 #endif
2874 #ifdef CONFIG_SECURITY_APPARMOR
2875 DIR("apparmor", 0555,
2876 proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
2877 #endif
2878 };
2879
proc_attr_dir_readdir(struct file * file,struct dir_context * ctx)2880 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2881 {
2882 return proc_pident_readdir(file, ctx,
2883 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2884 }
2885
2886 static const struct file_operations proc_attr_dir_operations = {
2887 .read = generic_read_dir,
2888 .iterate_shared = proc_attr_dir_readdir,
2889 .llseek = generic_file_llseek,
2890 };
2891
proc_attr_dir_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)2892 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2893 struct dentry *dentry, unsigned int flags)
2894 {
2895 return proc_pident_lookup(dir, dentry,
2896 attr_dir_stuff,
2897 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2898 }
2899
2900 static const struct inode_operations proc_attr_dir_inode_operations = {
2901 .lookup = proc_attr_dir_lookup,
2902 .getattr = pid_getattr,
2903 .setattr = proc_setattr,
2904 };
2905
2906 #endif
2907
2908 #ifdef CONFIG_ELF_CORE
proc_coredump_filter_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)2909 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2910 size_t count, loff_t *ppos)
2911 {
2912 struct task_struct *task = get_proc_task(file_inode(file));
2913 struct mm_struct *mm;
2914 char buffer[PROC_NUMBUF];
2915 size_t len;
2916 int ret;
2917
2918 if (!task)
2919 return -ESRCH;
2920
2921 ret = 0;
2922 mm = get_task_mm(task);
2923 if (mm) {
2924 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2925 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2926 MMF_DUMP_FILTER_SHIFT));
2927 mmput(mm);
2928 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2929 }
2930
2931 put_task_struct(task);
2932
2933 return ret;
2934 }
2935
proc_coredump_filter_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2936 static ssize_t proc_coredump_filter_write(struct file *file,
2937 const char __user *buf,
2938 size_t count,
2939 loff_t *ppos)
2940 {
2941 struct task_struct *task;
2942 struct mm_struct *mm;
2943 unsigned int val;
2944 int ret;
2945 int i;
2946 unsigned long mask;
2947
2948 ret = kstrtouint_from_user(buf, count, 0, &val);
2949 if (ret < 0)
2950 return ret;
2951
2952 ret = -ESRCH;
2953 task = get_proc_task(file_inode(file));
2954 if (!task)
2955 goto out_no_task;
2956
2957 mm = get_task_mm(task);
2958 if (!mm)
2959 goto out_no_mm;
2960 ret = 0;
2961
2962 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2963 if (val & mask)
2964 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2965 else
2966 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2967 }
2968
2969 mmput(mm);
2970 out_no_mm:
2971 put_task_struct(task);
2972 out_no_task:
2973 if (ret < 0)
2974 return ret;
2975 return count;
2976 }
2977
2978 static const struct file_operations proc_coredump_filter_operations = {
2979 .read = proc_coredump_filter_read,
2980 .write = proc_coredump_filter_write,
2981 .llseek = generic_file_llseek,
2982 };
2983 #endif
2984
2985 #ifdef CONFIG_TASK_IO_ACCOUNTING
do_io_accounting(struct task_struct * task,struct seq_file * m,int whole)2986 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
2987 {
2988 struct task_io_accounting acct = task->ioac;
2989 unsigned long flags;
2990 int result;
2991
2992 result = down_read_killable(&task->signal->exec_update_lock);
2993 if (result)
2994 return result;
2995
2996 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2997 result = -EACCES;
2998 goto out_unlock;
2999 }
3000
3001 if (whole && lock_task_sighand(task, &flags)) {
3002 struct task_struct *t = task;
3003
3004 task_io_accounting_add(&acct, &task->signal->ioac);
3005 while_each_thread(task, t)
3006 task_io_accounting_add(&acct, &t->ioac);
3007
3008 unlock_task_sighand(task, &flags);
3009 }
3010 seq_printf(m,
3011 "rchar: %llu\n"
3012 "wchar: %llu\n"
3013 "syscr: %llu\n"
3014 "syscw: %llu\n"
3015 "read_bytes: %llu\n"
3016 "write_bytes: %llu\n"
3017 "cancelled_write_bytes: %llu\n",
3018 (unsigned long long)acct.rchar,
3019 (unsigned long long)acct.wchar,
3020 (unsigned long long)acct.syscr,
3021 (unsigned long long)acct.syscw,
3022 (unsigned long long)acct.read_bytes,
3023 (unsigned long long)acct.write_bytes,
3024 (unsigned long long)acct.cancelled_write_bytes);
3025 result = 0;
3026
3027 out_unlock:
3028 up_read(&task->signal->exec_update_lock);
3029 return result;
3030 }
3031
proc_tid_io_accounting(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3032 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
3033 struct pid *pid, struct task_struct *task)
3034 {
3035 return do_io_accounting(task, m, 0);
3036 }
3037
proc_tgid_io_accounting(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3038 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
3039 struct pid *pid, struct task_struct *task)
3040 {
3041 return do_io_accounting(task, m, 1);
3042 }
3043 #endif /* CONFIG_TASK_IO_ACCOUNTING */
3044
3045 #ifdef CONFIG_USER_NS
proc_id_map_open(struct inode * inode,struct file * file,const struct seq_operations * seq_ops)3046 static int proc_id_map_open(struct inode *inode, struct file *file,
3047 const struct seq_operations *seq_ops)
3048 {
3049 struct user_namespace *ns = NULL;
3050 struct task_struct *task;
3051 struct seq_file *seq;
3052 int ret = -EINVAL;
3053
3054 task = get_proc_task(inode);
3055 if (task) {
3056 rcu_read_lock();
3057 ns = get_user_ns(task_cred_xxx(task, user_ns));
3058 rcu_read_unlock();
3059 put_task_struct(task);
3060 }
3061 if (!ns)
3062 goto err;
3063
3064 ret = seq_open(file, seq_ops);
3065 if (ret)
3066 goto err_put_ns;
3067
3068 seq = file->private_data;
3069 seq->private = ns;
3070
3071 return 0;
3072 err_put_ns:
3073 put_user_ns(ns);
3074 err:
3075 return ret;
3076 }
3077
proc_id_map_release(struct inode * inode,struct file * file)3078 static int proc_id_map_release(struct inode *inode, struct file *file)
3079 {
3080 struct seq_file *seq = file->private_data;
3081 struct user_namespace *ns = seq->private;
3082 put_user_ns(ns);
3083 return seq_release(inode, file);
3084 }
3085
proc_uid_map_open(struct inode * inode,struct file * file)3086 static int proc_uid_map_open(struct inode *inode, struct file *file)
3087 {
3088 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
3089 }
3090
proc_gid_map_open(struct inode * inode,struct file * file)3091 static int proc_gid_map_open(struct inode *inode, struct file *file)
3092 {
3093 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
3094 }
3095
proc_projid_map_open(struct inode * inode,struct file * file)3096 static int proc_projid_map_open(struct inode *inode, struct file *file)
3097 {
3098 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
3099 }
3100
3101 static const struct file_operations proc_uid_map_operations = {
3102 .open = proc_uid_map_open,
3103 .write = proc_uid_map_write,
3104 .read = seq_read,
3105 .llseek = seq_lseek,
3106 .release = proc_id_map_release,
3107 };
3108
3109 static const struct file_operations proc_gid_map_operations = {
3110 .open = proc_gid_map_open,
3111 .write = proc_gid_map_write,
3112 .read = seq_read,
3113 .llseek = seq_lseek,
3114 .release = proc_id_map_release,
3115 };
3116
3117 static const struct file_operations proc_projid_map_operations = {
3118 .open = proc_projid_map_open,
3119 .write = proc_projid_map_write,
3120 .read = seq_read,
3121 .llseek = seq_lseek,
3122 .release = proc_id_map_release,
3123 };
3124
proc_setgroups_open(struct inode * inode,struct file * file)3125 static int proc_setgroups_open(struct inode *inode, struct file *file)
3126 {
3127 struct user_namespace *ns = NULL;
3128 struct task_struct *task;
3129 int ret;
3130
3131 ret = -ESRCH;
3132 task = get_proc_task(inode);
3133 if (task) {
3134 rcu_read_lock();
3135 ns = get_user_ns(task_cred_xxx(task, user_ns));
3136 rcu_read_unlock();
3137 put_task_struct(task);
3138 }
3139 if (!ns)
3140 goto err;
3141
3142 if (file->f_mode & FMODE_WRITE) {
3143 ret = -EACCES;
3144 if (!ns_capable(ns, CAP_SYS_ADMIN))
3145 goto err_put_ns;
3146 }
3147
3148 ret = single_open(file, &proc_setgroups_show, ns);
3149 if (ret)
3150 goto err_put_ns;
3151
3152 return 0;
3153 err_put_ns:
3154 put_user_ns(ns);
3155 err:
3156 return ret;
3157 }
3158
proc_setgroups_release(struct inode * inode,struct file * file)3159 static int proc_setgroups_release(struct inode *inode, struct file *file)
3160 {
3161 struct seq_file *seq = file->private_data;
3162 struct user_namespace *ns = seq->private;
3163 int ret = single_release(inode, file);
3164 put_user_ns(ns);
3165 return ret;
3166 }
3167
3168 static const struct file_operations proc_setgroups_operations = {
3169 .open = proc_setgroups_open,
3170 .write = proc_setgroups_write,
3171 .read = seq_read,
3172 .llseek = seq_lseek,
3173 .release = proc_setgroups_release,
3174 };
3175 #endif /* CONFIG_USER_NS */
3176
proc_pid_personality(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3177 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3178 struct pid *pid, struct task_struct *task)
3179 {
3180 int err = lock_trace(task);
3181 if (!err) {
3182 seq_printf(m, "%08x\n", task->personality);
3183 unlock_trace(task);
3184 }
3185 return err;
3186 }
3187
3188 #ifdef CONFIG_LIVEPATCH
proc_pid_patch_state(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3189 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
3190 struct pid *pid, struct task_struct *task)
3191 {
3192 seq_printf(m, "%d\n", task->patch_state);
3193 return 0;
3194 }
3195 #endif /* CONFIG_LIVEPATCH */
3196
3197 #ifdef CONFIG_STACKLEAK_METRICS
proc_stack_depth(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3198 static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
3199 struct pid *pid, struct task_struct *task)
3200 {
3201 unsigned long prev_depth = THREAD_SIZE -
3202 (task->prev_lowest_stack & (THREAD_SIZE - 1));
3203 unsigned long depth = THREAD_SIZE -
3204 (task->lowest_stack & (THREAD_SIZE - 1));
3205
3206 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
3207 prev_depth, depth);
3208 return 0;
3209 }
3210 #endif /* CONFIG_STACKLEAK_METRICS */
3211
3212 /*
3213 * Thread groups
3214 */
3215 static const struct file_operations proc_task_operations;
3216 static const struct inode_operations proc_task_inode_operations;
3217
3218 static const struct pid_entry tgid_base_stuff[] = {
3219 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3220 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3221 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3222 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3223 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3224 #ifdef CONFIG_NET
3225 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3226 #endif
3227 REG("environ", S_IRUSR, proc_environ_operations),
3228 REG("auxv", S_IRUSR, proc_auxv_operations),
3229 ONE("status", S_IRUGO, proc_pid_status),
3230 ONE("personality", S_IRUSR, proc_pid_personality),
3231 ONE("limits", S_IRUGO, proc_pid_limits),
3232 #ifdef CONFIG_SCHED_DEBUG
3233 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3234 #endif
3235 #ifdef CONFIG_SCHED_AUTOGROUP
3236 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3237 #endif
3238 #ifdef CONFIG_TIME_NS
3239 REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
3240 #endif
3241 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3242 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3243 ONE("syscall", S_IRUSR, proc_pid_syscall),
3244 #endif
3245 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3246 ONE("stat", S_IRUGO, proc_tgid_stat),
3247 ONE("statm", S_IRUGO, proc_pid_statm),
3248 REG("maps", S_IRUGO, proc_pid_maps_operations),
3249 #ifdef CONFIG_NUMA
3250 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3251 #endif
3252 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3253 LNK("cwd", proc_cwd_link),
3254 LNK("root", proc_root_link),
3255 LNK("exe", proc_exe_link),
3256 REG("mounts", S_IRUGO, proc_mounts_operations),
3257 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3258 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3259 #ifdef CONFIG_PROC_PAGE_MONITOR
3260 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3261 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3262 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3263 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3264 #endif
3265 #ifdef CONFIG_SECURITY
3266 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3267 #endif
3268 #ifdef CONFIG_KALLSYMS
3269 ONE("wchan", S_IRUGO, proc_pid_wchan),
3270 #endif
3271 #ifdef CONFIG_STACKTRACE
3272 ONE("stack", S_IRUSR, proc_pid_stack),
3273 #endif
3274 #ifdef CONFIG_SCHED_INFO
3275 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3276 #endif
3277 #ifdef CONFIG_LATENCYTOP
3278 REG("latency", S_IRUGO, proc_lstats_operations),
3279 #endif
3280 #ifdef CONFIG_PROC_PID_CPUSET
3281 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3282 #endif
3283 #ifdef CONFIG_CGROUPS
3284 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3285 #endif
3286 #ifdef CONFIG_PROC_CPU_RESCTRL
3287 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3288 #endif
3289 ONE("oom_score", S_IRUGO, proc_oom_score),
3290 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3291 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3292 #ifdef CONFIG_AUDIT
3293 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3294 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3295 #endif
3296 #ifdef CONFIG_FAULT_INJECTION
3297 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3298 REG("fail-nth", 0644, proc_fail_nth_operations),
3299 #endif
3300 #ifdef CONFIG_ELF_CORE
3301 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3302 #endif
3303 #ifdef CONFIG_TASK_IO_ACCOUNTING
3304 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3305 #endif
3306 #ifdef CONFIG_USER_NS
3307 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3308 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3309 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3310 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3311 #endif
3312 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3313 REG("timers", S_IRUGO, proc_timers_operations),
3314 #endif
3315 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3316 #ifdef CONFIG_LIVEPATCH
3317 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3318 #endif
3319 #ifdef CONFIG_CPU_FREQ_TIMES
3320 ONE("time_in_state", 0444, proc_time_in_state_show),
3321 #endif
3322 #ifdef CONFIG_STACKLEAK_METRICS
3323 ONE("stack_depth", S_IRUGO, proc_stack_depth),
3324 #endif
3325 #ifdef CONFIG_PROC_PID_ARCH_STATUS
3326 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3327 #endif
3328 #ifdef CONFIG_SECCOMP_CACHE_DEBUG
3329 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3330 #endif
3331 };
3332
proc_tgid_base_readdir(struct file * file,struct dir_context * ctx)3333 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3334 {
3335 return proc_pident_readdir(file, ctx,
3336 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3337 }
3338
3339 static const struct file_operations proc_tgid_base_operations = {
3340 .read = generic_read_dir,
3341 .iterate_shared = proc_tgid_base_readdir,
3342 .llseek = generic_file_llseek,
3343 };
3344
tgid_pidfd_to_pid(const struct file * file)3345 struct pid *tgid_pidfd_to_pid(const struct file *file)
3346 {
3347 if (file->f_op != &proc_tgid_base_operations)
3348 return ERR_PTR(-EBADF);
3349
3350 return proc_pid(file_inode(file));
3351 }
3352
proc_tgid_base_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)3353 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3354 {
3355 return proc_pident_lookup(dir, dentry,
3356 tgid_base_stuff,
3357 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3358 }
3359
3360 static const struct inode_operations proc_tgid_base_inode_operations = {
3361 .lookup = proc_tgid_base_lookup,
3362 .getattr = pid_getattr,
3363 .setattr = proc_setattr,
3364 .permission = proc_pid_permission,
3365 };
3366
3367 /**
3368 * proc_flush_pid - Remove dcache entries for @pid from the /proc dcache.
3369 * @pid: pid that should be flushed.
3370 *
3371 * This function walks a list of inodes (that belong to any proc
3372 * filesystem) that are attached to the pid and flushes them from
3373 * the dentry cache.
3374 *
3375 * It is safe and reasonable to cache /proc entries for a task until
3376 * that task exits. After that they just clog up the dcache with
3377 * useless entries, possibly causing useful dcache entries to be
3378 * flushed instead. This routine is provided to flush those useless
3379 * dcache entries when a process is reaped.
3380 *
3381 * NOTE: This routine is just an optimization so it does not guarantee
3382 * that no dcache entries will exist after a process is reaped
3383 * it just makes it very unlikely that any will persist.
3384 */
3385
proc_flush_pid(struct pid * pid)3386 void proc_flush_pid(struct pid *pid)
3387 {
3388 proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
3389 }
3390
proc_pid_instantiate(struct dentry * dentry,struct task_struct * task,const void * ptr)3391 static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3392 struct task_struct *task, const void *ptr)
3393 {
3394 struct inode *inode;
3395
3396 inode = proc_pid_make_base_inode(dentry->d_sb, task,
3397 S_IFDIR | S_IRUGO | S_IXUGO);
3398 if (!inode)
3399 return ERR_PTR(-ENOENT);
3400
3401 inode->i_op = &proc_tgid_base_inode_operations;
3402 inode->i_fop = &proc_tgid_base_operations;
3403 inode->i_flags|=S_IMMUTABLE;
3404
3405 set_nlink(inode, nlink_tgid);
3406 pid_update_inode(task, inode);
3407
3408 d_set_d_op(dentry, &pid_dentry_operations);
3409 return d_splice_alias(inode, dentry);
3410 }
3411
proc_pid_lookup(struct dentry * dentry,unsigned int flags)3412 struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3413 {
3414 struct task_struct *task;
3415 unsigned tgid;
3416 struct proc_fs_info *fs_info;
3417 struct pid_namespace *ns;
3418 struct dentry *result = ERR_PTR(-ENOENT);
3419
3420 tgid = name_to_int(&dentry->d_name);
3421 if (tgid == ~0U)
3422 goto out;
3423
3424 fs_info = proc_sb_info(dentry->d_sb);
3425 ns = fs_info->pid_ns;
3426 rcu_read_lock();
3427 task = find_task_by_pid_ns(tgid, ns);
3428 if (task)
3429 get_task_struct(task);
3430 rcu_read_unlock();
3431 if (!task)
3432 goto out;
3433
3434 /* Limit procfs to only ptraceable tasks */
3435 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) {
3436 if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
3437 goto out_put_task;
3438 }
3439
3440 result = proc_pid_instantiate(dentry, task, NULL);
3441 out_put_task:
3442 put_task_struct(task);
3443 out:
3444 return result;
3445 }
3446
3447 /*
3448 * Find the first task with tgid >= tgid
3449 *
3450 */
3451 struct tgid_iter {
3452 unsigned int tgid;
3453 struct task_struct *task;
3454 };
next_tgid(struct pid_namespace * ns,struct tgid_iter iter)3455 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3456 {
3457 struct pid *pid;
3458
3459 if (iter.task)
3460 put_task_struct(iter.task);
3461 rcu_read_lock();
3462 retry:
3463 iter.task = NULL;
3464 pid = find_ge_pid(iter.tgid, ns);
3465 if (pid) {
3466 iter.tgid = pid_nr_ns(pid, ns);
3467 iter.task = pid_task(pid, PIDTYPE_TGID);
3468 if (!iter.task) {
3469 iter.tgid += 1;
3470 goto retry;
3471 }
3472 get_task_struct(iter.task);
3473 }
3474 rcu_read_unlock();
3475 return iter;
3476 }
3477
3478 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3479
3480 /* for the /proc/ directory itself, after non-process stuff has been done */
proc_pid_readdir(struct file * file,struct dir_context * ctx)3481 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3482 {
3483 struct tgid_iter iter;
3484 struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
3485 struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb);
3486 loff_t pos = ctx->pos;
3487
3488 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3489 return 0;
3490
3491 if (pos == TGID_OFFSET - 2) {
3492 struct inode *inode = d_inode(fs_info->proc_self);
3493 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3494 return 0;
3495 ctx->pos = pos = pos + 1;
3496 }
3497 if (pos == TGID_OFFSET - 1) {
3498 struct inode *inode = d_inode(fs_info->proc_thread_self);
3499 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3500 return 0;
3501 ctx->pos = pos = pos + 1;
3502 }
3503 iter.tgid = pos - TGID_OFFSET;
3504 iter.task = NULL;
3505 for (iter = next_tgid(ns, iter);
3506 iter.task;
3507 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3508 char name[10 + 1];
3509 unsigned int len;
3510
3511 cond_resched();
3512 if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE))
3513 continue;
3514
3515 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3516 ctx->pos = iter.tgid + TGID_OFFSET;
3517 if (!proc_fill_cache(file, ctx, name, len,
3518 proc_pid_instantiate, iter.task, NULL)) {
3519 put_task_struct(iter.task);
3520 return 0;
3521 }
3522 }
3523 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3524 return 0;
3525 }
3526
3527 /*
3528 * proc_tid_comm_permission is a special permission function exclusively
3529 * used for the node /proc/<pid>/task/<tid>/comm.
3530 * It bypasses generic permission checks in the case where a task of the same
3531 * task group attempts to access the node.
3532 * The rationale behind this is that glibc and bionic access this node for
3533 * cross thread naming (pthread_set/getname_np(!self)). However, if
3534 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3535 * which locks out the cross thread naming implementation.
3536 * This function makes sure that the node is always accessible for members of
3537 * same thread group.
3538 */
proc_tid_comm_permission(struct user_namespace * mnt_userns,struct inode * inode,int mask)3539 static int proc_tid_comm_permission(struct user_namespace *mnt_userns,
3540 struct inode *inode, int mask)
3541 {
3542 bool is_same_tgroup;
3543 struct task_struct *task;
3544
3545 task = get_proc_task(inode);
3546 if (!task)
3547 return -ESRCH;
3548 is_same_tgroup = same_thread_group(current, task);
3549 put_task_struct(task);
3550
3551 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3552 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3553 * read or written by the members of the corresponding
3554 * thread group.
3555 */
3556 return 0;
3557 }
3558
3559 return generic_permission(&init_user_ns, inode, mask);
3560 }
3561
3562 static const struct inode_operations proc_tid_comm_inode_operations = {
3563 .setattr = proc_setattr,
3564 .permission = proc_tid_comm_permission,
3565 };
3566
3567 /*
3568 * Tasks
3569 */
3570 static const struct pid_entry tid_base_stuff[] = {
3571 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3572 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3573 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3574 #ifdef CONFIG_NET
3575 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3576 #endif
3577 REG("environ", S_IRUSR, proc_environ_operations),
3578 REG("auxv", S_IRUSR, proc_auxv_operations),
3579 ONE("status", S_IRUGO, proc_pid_status),
3580 ONE("personality", S_IRUSR, proc_pid_personality),
3581 ONE("limits", S_IRUGO, proc_pid_limits),
3582 #ifdef CONFIG_SCHED_DEBUG
3583 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3584 #endif
3585 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3586 &proc_tid_comm_inode_operations,
3587 &proc_pid_set_comm_operations, {}),
3588 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3589 ONE("syscall", S_IRUSR, proc_pid_syscall),
3590 #endif
3591 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3592 ONE("stat", S_IRUGO, proc_tid_stat),
3593 ONE("statm", S_IRUGO, proc_pid_statm),
3594 REG("maps", S_IRUGO, proc_pid_maps_operations),
3595 #ifdef CONFIG_PROC_CHILDREN
3596 REG("children", S_IRUGO, proc_tid_children_operations),
3597 #endif
3598 #ifdef CONFIG_NUMA
3599 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3600 #endif
3601 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3602 LNK("cwd", proc_cwd_link),
3603 LNK("root", proc_root_link),
3604 LNK("exe", proc_exe_link),
3605 REG("mounts", S_IRUGO, proc_mounts_operations),
3606 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3607 #ifdef CONFIG_PROC_PAGE_MONITOR
3608 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3609 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3610 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3611 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3612 #endif
3613 #ifdef CONFIG_SECURITY
3614 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3615 #endif
3616 #ifdef CONFIG_KALLSYMS
3617 ONE("wchan", S_IRUGO, proc_pid_wchan),
3618 #endif
3619 #ifdef CONFIG_STACKTRACE
3620 ONE("stack", S_IRUSR, proc_pid_stack),
3621 #endif
3622 #ifdef CONFIG_SCHED_INFO
3623 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3624 #endif
3625 #ifdef CONFIG_LATENCYTOP
3626 REG("latency", S_IRUGO, proc_lstats_operations),
3627 #endif
3628 #ifdef CONFIG_PROC_PID_CPUSET
3629 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3630 #endif
3631 #ifdef CONFIG_CGROUPS
3632 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3633 #endif
3634 #ifdef CONFIG_PROC_CPU_RESCTRL
3635 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3636 #endif
3637 ONE("oom_score", S_IRUGO, proc_oom_score),
3638 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3639 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3640 #ifdef CONFIG_AUDIT
3641 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3642 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3643 #endif
3644 #ifdef CONFIG_FAULT_INJECTION
3645 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3646 REG("fail-nth", 0644, proc_fail_nth_operations),
3647 #endif
3648 #ifdef CONFIG_TASK_IO_ACCOUNTING
3649 ONE("io", S_IRUSR, proc_tid_io_accounting),
3650 #endif
3651 #ifdef CONFIG_USER_NS
3652 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3653 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3654 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3655 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3656 #endif
3657 #ifdef CONFIG_LIVEPATCH
3658 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3659 #endif
3660 #ifdef CONFIG_PROC_PID_ARCH_STATUS
3661 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3662 #endif
3663 #ifdef CONFIG_SECCOMP_CACHE_DEBUG
3664 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3665 #endif
3666 #ifdef CONFIG_CPU_FREQ_TIMES
3667 ONE("time_in_state", 0444, proc_time_in_state_show),
3668 #endif
3669 };
3670
proc_tid_base_readdir(struct file * file,struct dir_context * ctx)3671 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3672 {
3673 return proc_pident_readdir(file, ctx,
3674 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3675 }
3676
proc_tid_base_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)3677 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3678 {
3679 return proc_pident_lookup(dir, dentry,
3680 tid_base_stuff,
3681 tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3682 }
3683
3684 static const struct file_operations proc_tid_base_operations = {
3685 .read = generic_read_dir,
3686 .iterate_shared = proc_tid_base_readdir,
3687 .llseek = generic_file_llseek,
3688 };
3689
3690 static const struct inode_operations proc_tid_base_inode_operations = {
3691 .lookup = proc_tid_base_lookup,
3692 .getattr = pid_getattr,
3693 .setattr = proc_setattr,
3694 };
3695
proc_task_instantiate(struct dentry * dentry,struct task_struct * task,const void * ptr)3696 static struct dentry *proc_task_instantiate(struct dentry *dentry,
3697 struct task_struct *task, const void *ptr)
3698 {
3699 struct inode *inode;
3700 inode = proc_pid_make_base_inode(dentry->d_sb, task,
3701 S_IFDIR | S_IRUGO | S_IXUGO);
3702 if (!inode)
3703 return ERR_PTR(-ENOENT);
3704
3705 inode->i_op = &proc_tid_base_inode_operations;
3706 inode->i_fop = &proc_tid_base_operations;
3707 inode->i_flags |= S_IMMUTABLE;
3708
3709 set_nlink(inode, nlink_tid);
3710 pid_update_inode(task, inode);
3711
3712 d_set_d_op(dentry, &pid_dentry_operations);
3713 return d_splice_alias(inode, dentry);
3714 }
3715
proc_task_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)3716 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3717 {
3718 struct task_struct *task;
3719 struct task_struct *leader = get_proc_task(dir);
3720 unsigned tid;
3721 struct proc_fs_info *fs_info;
3722 struct pid_namespace *ns;
3723 struct dentry *result = ERR_PTR(-ENOENT);
3724
3725 if (!leader)
3726 goto out_no_task;
3727
3728 tid = name_to_int(&dentry->d_name);
3729 if (tid == ~0U)
3730 goto out;
3731
3732 fs_info = proc_sb_info(dentry->d_sb);
3733 ns = fs_info->pid_ns;
3734 rcu_read_lock();
3735 task = find_task_by_pid_ns(tid, ns);
3736 if (task)
3737 get_task_struct(task);
3738 rcu_read_unlock();
3739 if (!task)
3740 goto out;
3741 if (!same_thread_group(leader, task))
3742 goto out_drop_task;
3743
3744 result = proc_task_instantiate(dentry, task, NULL);
3745 out_drop_task:
3746 put_task_struct(task);
3747 out:
3748 put_task_struct(leader);
3749 out_no_task:
3750 return result;
3751 }
3752
3753 /*
3754 * Find the first tid of a thread group to return to user space.
3755 *
3756 * Usually this is just the thread group leader, but if the users
3757 * buffer was too small or there was a seek into the middle of the
3758 * directory we have more work todo.
3759 *
3760 * In the case of a short read we start with find_task_by_pid.
3761 *
3762 * In the case of a seek we start with the leader and walk nr
3763 * threads past it.
3764 */
first_tid(struct pid * pid,int tid,loff_t f_pos,struct pid_namespace * ns)3765 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3766 struct pid_namespace *ns)
3767 {
3768 struct task_struct *pos, *task;
3769 unsigned long nr = f_pos;
3770
3771 if (nr != f_pos) /* 32bit overflow? */
3772 return NULL;
3773
3774 rcu_read_lock();
3775 task = pid_task(pid, PIDTYPE_PID);
3776 if (!task)
3777 goto fail;
3778
3779 /* Attempt to start with the tid of a thread */
3780 if (tid && nr) {
3781 pos = find_task_by_pid_ns(tid, ns);
3782 if (pos && same_thread_group(pos, task))
3783 goto found;
3784 }
3785
3786 /* If nr exceeds the number of threads there is nothing todo */
3787 if (nr >= get_nr_threads(task))
3788 goto fail;
3789
3790 /* If we haven't found our starting place yet start
3791 * with the leader and walk nr threads forward.
3792 */
3793 pos = task = task->group_leader;
3794 do {
3795 if (!nr--)
3796 goto found;
3797 } while_each_thread(task, pos);
3798 fail:
3799 pos = NULL;
3800 goto out;
3801 found:
3802 get_task_struct(pos);
3803 out:
3804 rcu_read_unlock();
3805 return pos;
3806 }
3807
3808 /*
3809 * Find the next thread in the thread list.
3810 * Return NULL if there is an error or no next thread.
3811 *
3812 * The reference to the input task_struct is released.
3813 */
next_tid(struct task_struct * start)3814 static struct task_struct *next_tid(struct task_struct *start)
3815 {
3816 struct task_struct *pos = NULL;
3817 rcu_read_lock();
3818 if (pid_alive(start)) {
3819 pos = next_thread(start);
3820 if (thread_group_leader(pos))
3821 pos = NULL;
3822 else
3823 get_task_struct(pos);
3824 }
3825 rcu_read_unlock();
3826 put_task_struct(start);
3827 return pos;
3828 }
3829
3830 /* for the /proc/TGID/task/ directories */
proc_task_readdir(struct file * file,struct dir_context * ctx)3831 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3832 {
3833 struct inode *inode = file_inode(file);
3834 struct task_struct *task;
3835 struct pid_namespace *ns;
3836 int tid;
3837
3838 if (proc_inode_is_dead(inode))
3839 return -ENOENT;
3840
3841 if (!dir_emit_dots(file, ctx))
3842 return 0;
3843
3844 /* f_version caches the tgid value that the last readdir call couldn't
3845 * return. lseek aka telldir automagically resets f_version to 0.
3846 */
3847 ns = proc_pid_ns(inode->i_sb);
3848 tid = (int)file->f_version;
3849 file->f_version = 0;
3850 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3851 task;
3852 task = next_tid(task), ctx->pos++) {
3853 char name[10 + 1];
3854 unsigned int len;
3855 tid = task_pid_nr_ns(task, ns);
3856 len = snprintf(name, sizeof(name), "%u", tid);
3857 if (!proc_fill_cache(file, ctx, name, len,
3858 proc_task_instantiate, task, NULL)) {
3859 /* returning this tgid failed, save it as the first
3860 * pid for the next readir call */
3861 file->f_version = (u64)tid;
3862 put_task_struct(task);
3863 break;
3864 }
3865 }
3866
3867 return 0;
3868 }
3869
proc_task_getattr(struct user_namespace * mnt_userns,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)3870 static int proc_task_getattr(struct user_namespace *mnt_userns,
3871 const struct path *path, struct kstat *stat,
3872 u32 request_mask, unsigned int query_flags)
3873 {
3874 struct inode *inode = d_inode(path->dentry);
3875 struct task_struct *p = get_proc_task(inode);
3876 generic_fillattr(&init_user_ns, inode, stat);
3877
3878 if (p) {
3879 stat->nlink += get_nr_threads(p);
3880 put_task_struct(p);
3881 }
3882
3883 return 0;
3884 }
3885
3886 static const struct inode_operations proc_task_inode_operations = {
3887 .lookup = proc_task_lookup,
3888 .getattr = proc_task_getattr,
3889 .setattr = proc_setattr,
3890 .permission = proc_pid_permission,
3891 };
3892
3893 static const struct file_operations proc_task_operations = {
3894 .read = generic_read_dir,
3895 .iterate_shared = proc_task_readdir,
3896 .llseek = generic_file_llseek,
3897 };
3898
set_proc_pid_nlink(void)3899 void __init set_proc_pid_nlink(void)
3900 {
3901 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3902 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3903 }
3904