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/generic-radix-tree.h>
62 #include <linux/string.h>
63 #include <linux/seq_file.h>
64 #include <linux/namei.h>
65 #include <linux/mnt_namespace.h>
66 #include <linux/mm.h>
67 #include <linux/swap.h>
68 #include <linux/rcupdate.h>
69 #include <linux/kallsyms.h>
70 #include <linux/stacktrace.h>
71 #include <linux/resource.h>
72 #include <linux/module.h>
73 #include <linux/mount.h>
74 #include <linux/security.h>
75 #include <linux/ptrace.h>
76 #include <linux/printk.h>
77 #include <linux/cache.h>
78 #include <linux/cgroup.h>
79 #include <linux/cpuset.h>
80 #include <linux/audit.h>
81 #include <linux/poll.h>
82 #include <linux/nsproxy.h>
83 #include <linux/oom.h>
84 #include <linux/elf.h>
85 #include <linux/pid_namespace.h>
86 #include <linux/user_namespace.h>
87 #include <linux/fs_parser.h>
88 #include <linux/fs_struct.h>
89 #include <linux/slab.h>
90 #include <linux/sched/autogroup.h>
91 #include <linux/sched/mm.h>
92 #include <linux/sched/coredump.h>
93 #include <linux/sched/debug.h>
94 #include <linux/sched/stat.h>
95 #include <linux/posix-timers.h>
96 #include <linux/time_namespace.h>
97 #include <linux/resctrl.h>
98 #include <linux/cn_proc.h>
99 #include <linux/ksm.h>
100 #include <uapi/linux/lsm.h>
101 #include <trace/events/oom.h>
102 #include "internal.h"
103 #include "fd.h"
104
105 #include "../../lib/kstrtox.h"
106
107 /* NOTE:
108 * Implementing inode permission operations in /proc is almost
109 * certainly an error. Permission checks need to happen during
110 * each system call not at open time. The reason is that most of
111 * what we wish to check for permissions in /proc varies at runtime.
112 *
113 * The classic example of a problem is opening file descriptors
114 * in /proc for a task before it execs a suid executable.
115 */
116
117 static u8 nlink_tid __ro_after_init;
118 static u8 nlink_tgid __ro_after_init;
119
120 enum proc_mem_force {
121 PROC_MEM_FORCE_ALWAYS,
122 PROC_MEM_FORCE_PTRACE,
123 PROC_MEM_FORCE_NEVER
124 };
125
126 static enum proc_mem_force proc_mem_force_override __ro_after_init =
127 IS_ENABLED(CONFIG_PROC_MEM_NO_FORCE) ? PROC_MEM_FORCE_NEVER :
128 IS_ENABLED(CONFIG_PROC_MEM_FORCE_PTRACE) ? PROC_MEM_FORCE_PTRACE :
129 PROC_MEM_FORCE_ALWAYS;
130
131 static const struct constant_table proc_mem_force_table[] __initconst = {
132 { "always", PROC_MEM_FORCE_ALWAYS },
133 { "ptrace", PROC_MEM_FORCE_PTRACE },
134 { "never", PROC_MEM_FORCE_NEVER },
135 { }
136 };
137
early_proc_mem_force_override(char * buf)138 static int __init early_proc_mem_force_override(char *buf)
139 {
140 if (!buf)
141 return -EINVAL;
142
143 /*
144 * lookup_constant() defaults to proc_mem_force_override to preseve
145 * the initial Kconfig choice in case an invalid param gets passed.
146 */
147 proc_mem_force_override = lookup_constant(proc_mem_force_table,
148 buf, proc_mem_force_override);
149
150 return 0;
151 }
152 early_param("proc_mem.force_override", early_proc_mem_force_override);
153
154 struct pid_entry {
155 const char *name;
156 unsigned int len;
157 umode_t mode;
158 const struct inode_operations *iop;
159 const struct file_operations *fop;
160 union proc_op op;
161 };
162
163 #define NOD(NAME, MODE, IOP, FOP, OP) { \
164 .name = (NAME), \
165 .len = sizeof(NAME) - 1, \
166 .mode = MODE, \
167 .iop = IOP, \
168 .fop = FOP, \
169 .op = OP, \
170 }
171
172 #define DIR(NAME, MODE, iops, fops) \
173 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
174 #define LNK(NAME, get_link) \
175 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
176 &proc_pid_link_inode_operations, NULL, \
177 { .proc_get_link = get_link } )
178 #define REG(NAME, MODE, fops) \
179 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
180 #define ONE(NAME, MODE, show) \
181 NOD(NAME, (S_IFREG|(MODE)), \
182 NULL, &proc_single_file_operations, \
183 { .proc_show = show } )
184 #define ATTR(LSMID, NAME, MODE) \
185 NOD(NAME, (S_IFREG|(MODE)), \
186 NULL, &proc_pid_attr_operations, \
187 { .lsmid = LSMID })
188
189 /*
190 * Count the number of hardlinks for the pid_entry table, excluding the .
191 * and .. links.
192 */
pid_entry_nlink(const struct pid_entry * entries,unsigned int n)193 static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
194 unsigned int n)
195 {
196 unsigned int i;
197 unsigned int count;
198
199 count = 2;
200 for (i = 0; i < n; ++i) {
201 if (S_ISDIR(entries[i].mode))
202 ++count;
203 }
204
205 return count;
206 }
207
get_task_root(struct task_struct * task,struct path * root)208 static int get_task_root(struct task_struct *task, struct path *root)
209 {
210 int result = -ENOENT;
211
212 task_lock(task);
213 if (task->fs) {
214 get_fs_root(task->fs, root);
215 result = 0;
216 }
217 task_unlock(task);
218 return result;
219 }
220
proc_cwd_link(struct dentry * dentry,struct path * path)221 static int proc_cwd_link(struct dentry *dentry, struct path *path)
222 {
223 struct task_struct *task = get_proc_task(d_inode(dentry));
224 int result = -ENOENT;
225
226 if (task) {
227 task_lock(task);
228 if (task->fs) {
229 get_fs_pwd(task->fs, path);
230 result = 0;
231 }
232 task_unlock(task);
233 put_task_struct(task);
234 }
235 return result;
236 }
237
proc_root_link(struct dentry * dentry,struct path * path)238 static int proc_root_link(struct dentry *dentry, struct path *path)
239 {
240 struct task_struct *task = get_proc_task(d_inode(dentry));
241 int result = -ENOENT;
242
243 if (task) {
244 result = get_task_root(task, path);
245 put_task_struct(task);
246 }
247 return result;
248 }
249
250 /*
251 * If the user used setproctitle(), we just get the string from
252 * user space at arg_start, and limit it to a maximum of one page.
253 */
get_mm_proctitle(struct mm_struct * mm,char __user * buf,size_t count,unsigned long pos,unsigned long arg_start)254 static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
255 size_t count, unsigned long pos,
256 unsigned long arg_start)
257 {
258 char *page;
259 int ret, got;
260
261 if (pos >= PAGE_SIZE)
262 return 0;
263
264 page = (char *)__get_free_page(GFP_KERNEL);
265 if (!page)
266 return -ENOMEM;
267
268 ret = 0;
269 got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
270 if (got > 0) {
271 int len = strnlen(page, got);
272
273 /* Include the NUL character if it was found */
274 if (len < got)
275 len++;
276
277 if (len > pos) {
278 len -= pos;
279 if (len > count)
280 len = count;
281 len -= copy_to_user(buf, page+pos, len);
282 if (!len)
283 len = -EFAULT;
284 ret = len;
285 }
286 }
287 free_page((unsigned long)page);
288 return ret;
289 }
290
get_mm_cmdline(struct mm_struct * mm,char __user * buf,size_t count,loff_t * ppos)291 static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
292 size_t count, loff_t *ppos)
293 {
294 unsigned long arg_start, arg_end, env_start, env_end;
295 unsigned long pos, len;
296 char *page, c;
297
298 /* Check if process spawned far enough to have cmdline. */
299 if (!mm->env_end)
300 return 0;
301
302 spin_lock(&mm->arg_lock);
303 arg_start = mm->arg_start;
304 arg_end = mm->arg_end;
305 env_start = mm->env_start;
306 env_end = mm->env_end;
307 spin_unlock(&mm->arg_lock);
308
309 if (arg_start >= arg_end)
310 return 0;
311
312 /*
313 * We allow setproctitle() to overwrite the argument
314 * strings, and overflow past the original end. But
315 * only when it overflows into the environment area.
316 */
317 if (env_start != arg_end || env_end < env_start)
318 env_start = env_end = arg_end;
319 len = env_end - arg_start;
320
321 /* We're not going to care if "*ppos" has high bits set */
322 pos = *ppos;
323 if (pos >= len)
324 return 0;
325 if (count > len - pos)
326 count = len - pos;
327 if (!count)
328 return 0;
329
330 /*
331 * Magical special case: if the argv[] end byte is not
332 * zero, the user has overwritten it with setproctitle(3).
333 *
334 * Possible future enhancement: do this only once when
335 * pos is 0, and set a flag in the 'struct file'.
336 */
337 if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
338 return get_mm_proctitle(mm, buf, count, pos, arg_start);
339
340 /*
341 * For the non-setproctitle() case we limit things strictly
342 * to the [arg_start, arg_end[ range.
343 */
344 pos += arg_start;
345 if (pos < arg_start || pos >= arg_end)
346 return 0;
347 if (count > arg_end - pos)
348 count = arg_end - pos;
349
350 page = (char *)__get_free_page(GFP_KERNEL);
351 if (!page)
352 return -ENOMEM;
353
354 len = 0;
355 while (count) {
356 int got;
357 size_t size = min_t(size_t, PAGE_SIZE, count);
358
359 got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
360 if (got <= 0)
361 break;
362 got -= copy_to_user(buf, page, got);
363 if (unlikely(!got)) {
364 if (!len)
365 len = -EFAULT;
366 break;
367 }
368 pos += got;
369 buf += got;
370 len += got;
371 count -= got;
372 }
373
374 free_page((unsigned long)page);
375 return len;
376 }
377
get_task_cmdline(struct task_struct * tsk,char __user * buf,size_t count,loff_t * pos)378 static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
379 size_t count, loff_t *pos)
380 {
381 struct mm_struct *mm;
382 ssize_t ret;
383
384 mm = get_task_mm(tsk);
385 if (!mm)
386 return 0;
387
388 ret = get_mm_cmdline(mm, buf, count, pos);
389 mmput(mm);
390 return ret;
391 }
392
proc_pid_cmdline_read(struct file * file,char __user * buf,size_t count,loff_t * pos)393 static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
394 size_t count, loff_t *pos)
395 {
396 struct task_struct *tsk;
397 ssize_t ret;
398
399 BUG_ON(*pos < 0);
400
401 tsk = get_proc_task(file_inode(file));
402 if (!tsk)
403 return -ESRCH;
404 ret = get_task_cmdline(tsk, buf, count, pos);
405 put_task_struct(tsk);
406 if (ret > 0)
407 *pos += ret;
408 return ret;
409 }
410
411 static const struct file_operations proc_pid_cmdline_ops = {
412 .read = proc_pid_cmdline_read,
413 .llseek = generic_file_llseek,
414 };
415
416 #ifdef CONFIG_KALLSYMS
417 /*
418 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
419 * Returns the resolved symbol to user space.
420 */
proc_pid_wchan(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)421 static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
422 struct pid *pid, struct task_struct *task)
423 {
424 unsigned long wchan;
425 char symname[KSYM_NAME_LEN];
426
427 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
428 goto print0;
429
430 wchan = get_wchan(task);
431 if (wchan && !lookup_symbol_name(wchan, symname)) {
432 seq_puts(m, symname);
433 return 0;
434 }
435
436 print0:
437 seq_putc(m, '0');
438 return 0;
439 }
440 #endif /* CONFIG_KALLSYMS */
441
lock_trace(struct task_struct * task)442 static int lock_trace(struct task_struct *task)
443 {
444 int err = down_read_killable(&task->signal->exec_update_lock);
445 if (err)
446 return err;
447 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
448 up_read(&task->signal->exec_update_lock);
449 return -EPERM;
450 }
451 return 0;
452 }
453
unlock_trace(struct task_struct * task)454 static void unlock_trace(struct task_struct *task)
455 {
456 up_read(&task->signal->exec_update_lock);
457 }
458
459 #ifdef CONFIG_STACKTRACE
460
461 #define MAX_STACK_TRACE_DEPTH 64
462
proc_pid_stack(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)463 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
464 struct pid *pid, struct task_struct *task)
465 {
466 unsigned long *entries;
467 int err;
468
469 /*
470 * The ability to racily run the kernel stack unwinder on a running task
471 * and then observe the unwinder output is scary; while it is useful for
472 * debugging kernel issues, it can also allow an attacker to leak kernel
473 * stack contents.
474 * Doing this in a manner that is at least safe from races would require
475 * some work to ensure that the remote task can not be scheduled; and
476 * even then, this would still expose the unwinder as local attack
477 * surface.
478 * Therefore, this interface is restricted to root.
479 */
480 if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
481 return -EACCES;
482
483 entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
484 GFP_KERNEL);
485 if (!entries)
486 return -ENOMEM;
487
488 err = lock_trace(task);
489 if (!err) {
490 unsigned int i, nr_entries;
491
492 nr_entries = stack_trace_save_tsk(task, entries,
493 MAX_STACK_TRACE_DEPTH, 0);
494
495 for (i = 0; i < nr_entries; i++) {
496 seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
497 }
498
499 unlock_trace(task);
500 }
501 kfree(entries);
502
503 return err;
504 }
505 #endif
506
507 #ifdef CONFIG_SCHED_INFO
508 /*
509 * Provides /proc/PID/schedstat
510 */
proc_pid_schedstat(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)511 static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
512 struct pid *pid, struct task_struct *task)
513 {
514 if (unlikely(!sched_info_on()))
515 seq_puts(m, "0 0 0\n");
516 else
517 seq_printf(m, "%llu %llu %lu\n",
518 (unsigned long long)task->se.sum_exec_runtime,
519 (unsigned long long)task->sched_info.run_delay,
520 task->sched_info.pcount);
521
522 return 0;
523 }
524 #endif
525
526 #ifdef CONFIG_LATENCYTOP
lstats_show_proc(struct seq_file * m,void * v)527 static int lstats_show_proc(struct seq_file *m, void *v)
528 {
529 int i;
530 struct inode *inode = m->private;
531 struct task_struct *task = get_proc_task(inode);
532
533 if (!task)
534 return -ESRCH;
535 seq_puts(m, "Latency Top version : v0.1\n");
536 for (i = 0; i < LT_SAVECOUNT; i++) {
537 struct latency_record *lr = &task->latency_record[i];
538 if (lr->backtrace[0]) {
539 int q;
540 seq_printf(m, "%i %li %li",
541 lr->count, lr->time, lr->max);
542 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
543 unsigned long bt = lr->backtrace[q];
544
545 if (!bt)
546 break;
547 seq_printf(m, " %ps", (void *)bt);
548 }
549 seq_putc(m, '\n');
550 }
551
552 }
553 put_task_struct(task);
554 return 0;
555 }
556
lstats_open(struct inode * inode,struct file * file)557 static int lstats_open(struct inode *inode, struct file *file)
558 {
559 return single_open(file, lstats_show_proc, inode);
560 }
561
lstats_write(struct file * file,const char __user * buf,size_t count,loff_t * offs)562 static ssize_t lstats_write(struct file *file, const char __user *buf,
563 size_t count, loff_t *offs)
564 {
565 struct task_struct *task = get_proc_task(file_inode(file));
566
567 if (!task)
568 return -ESRCH;
569 clear_tsk_latency_tracing(task);
570 put_task_struct(task);
571
572 return count;
573 }
574
575 static const struct file_operations proc_lstats_operations = {
576 .open = lstats_open,
577 .read = seq_read,
578 .write = lstats_write,
579 .llseek = seq_lseek,
580 .release = single_release,
581 };
582
583 #endif
584
proc_oom_score(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)585 static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
586 struct pid *pid, struct task_struct *task)
587 {
588 unsigned long totalpages = totalram_pages() + total_swap_pages;
589 unsigned long points = 0;
590 long badness;
591
592 badness = oom_badness(task, totalpages);
593 /*
594 * Special case OOM_SCORE_ADJ_MIN for all others scale the
595 * badness value into [0, 2000] range which we have been
596 * exporting for a long time so userspace might depend on it.
597 */
598 if (badness != LONG_MIN)
599 points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
600
601 seq_printf(m, "%lu\n", points);
602
603 return 0;
604 }
605
606 struct limit_names {
607 const char *name;
608 const char *unit;
609 };
610
611 static const struct limit_names lnames[RLIM_NLIMITS] = {
612 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
613 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
614 [RLIMIT_DATA] = {"Max data size", "bytes"},
615 [RLIMIT_STACK] = {"Max stack size", "bytes"},
616 [RLIMIT_CORE] = {"Max core file size", "bytes"},
617 [RLIMIT_RSS] = {"Max resident set", "bytes"},
618 [RLIMIT_NPROC] = {"Max processes", "processes"},
619 [RLIMIT_NOFILE] = {"Max open files", "files"},
620 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
621 [RLIMIT_AS] = {"Max address space", "bytes"},
622 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
623 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
624 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
625 [RLIMIT_NICE] = {"Max nice priority", NULL},
626 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
627 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
628 };
629
630 /* Display limits for a process */
proc_pid_limits(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)631 static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
632 struct pid *pid, struct task_struct *task)
633 {
634 unsigned int i;
635 unsigned long flags;
636
637 struct rlimit rlim[RLIM_NLIMITS];
638
639 if (!lock_task_sighand(task, &flags))
640 return 0;
641 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
642 unlock_task_sighand(task, &flags);
643
644 /*
645 * print the file header
646 */
647 seq_puts(m, "Limit "
648 "Soft Limit "
649 "Hard Limit "
650 "Units \n");
651
652 for (i = 0; i < RLIM_NLIMITS; i++) {
653 if (rlim[i].rlim_cur == RLIM_INFINITY)
654 seq_printf(m, "%-25s %-20s ",
655 lnames[i].name, "unlimited");
656 else
657 seq_printf(m, "%-25s %-20lu ",
658 lnames[i].name, rlim[i].rlim_cur);
659
660 if (rlim[i].rlim_max == RLIM_INFINITY)
661 seq_printf(m, "%-20s ", "unlimited");
662 else
663 seq_printf(m, "%-20lu ", rlim[i].rlim_max);
664
665 if (lnames[i].unit)
666 seq_printf(m, "%-10s\n", lnames[i].unit);
667 else
668 seq_putc(m, '\n');
669 }
670
671 return 0;
672 }
673
674 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
proc_pid_syscall(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)675 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
676 struct pid *pid, struct task_struct *task)
677 {
678 struct syscall_info info;
679 u64 *args = &info.data.args[0];
680 int res;
681
682 res = lock_trace(task);
683 if (res)
684 return res;
685
686 if (task_current_syscall(task, &info))
687 seq_puts(m, "running\n");
688 else if (info.data.nr < 0)
689 seq_printf(m, "%d 0x%llx 0x%llx\n",
690 info.data.nr, info.sp, info.data.instruction_pointer);
691 else
692 seq_printf(m,
693 "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
694 info.data.nr,
695 args[0], args[1], args[2], args[3], args[4], args[5],
696 info.sp, info.data.instruction_pointer);
697 unlock_trace(task);
698
699 return 0;
700 }
701 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
702
703 /************************************************************************/
704 /* Here the fs part begins */
705 /************************************************************************/
706
707 /* permission checks */
proc_fd_access_allowed(struct inode * inode)708 static bool proc_fd_access_allowed(struct inode *inode)
709 {
710 struct task_struct *task;
711 bool allowed = false;
712 /* Allow access to a task's file descriptors if it is us or we
713 * may use ptrace attach to the process and find out that
714 * information.
715 */
716 task = get_proc_task(inode);
717 if (task) {
718 allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
719 put_task_struct(task);
720 }
721 return allowed;
722 }
723
proc_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * attr)724 int proc_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
725 struct iattr *attr)
726 {
727 int error;
728 struct inode *inode = d_inode(dentry);
729
730 if (attr->ia_valid & ATTR_MODE)
731 return -EPERM;
732
733 error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
734 if (error)
735 return error;
736
737 setattr_copy(&nop_mnt_idmap, inode, attr);
738 return 0;
739 }
740
741 /*
742 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
743 * or euid/egid (for hide_pid_min=2)?
744 */
has_pid_permissions(struct proc_fs_info * fs_info,struct task_struct * task,enum proc_hidepid hide_pid_min)745 static bool has_pid_permissions(struct proc_fs_info *fs_info,
746 struct task_struct *task,
747 enum proc_hidepid hide_pid_min)
748 {
749 /*
750 * If 'hidpid' mount option is set force a ptrace check,
751 * we indicate that we are using a filesystem syscall
752 * by passing PTRACE_MODE_READ_FSCREDS
753 */
754 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE)
755 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
756
757 if (fs_info->hide_pid < hide_pid_min)
758 return true;
759 if (in_group_p(fs_info->pid_gid))
760 return true;
761 return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
762 }
763
764
proc_pid_permission(struct mnt_idmap * idmap,struct inode * inode,int mask)765 static int proc_pid_permission(struct mnt_idmap *idmap,
766 struct inode *inode, int mask)
767 {
768 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
769 struct task_struct *task;
770 bool has_perms;
771
772 task = get_proc_task(inode);
773 if (!task)
774 return -ESRCH;
775 has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS);
776 put_task_struct(task);
777
778 if (!has_perms) {
779 if (fs_info->hide_pid == HIDEPID_INVISIBLE) {
780 /*
781 * Let's make getdents(), stat(), and open()
782 * consistent with each other. If a process
783 * may not stat() a file, it shouldn't be seen
784 * in procfs at all.
785 */
786 return -ENOENT;
787 }
788
789 return -EPERM;
790 }
791 return generic_permission(&nop_mnt_idmap, inode, mask);
792 }
793
794
795
796 static const struct inode_operations proc_def_inode_operations = {
797 .setattr = proc_setattr,
798 };
799
proc_single_show(struct seq_file * m,void * v)800 static int proc_single_show(struct seq_file *m, void *v)
801 {
802 struct inode *inode = m->private;
803 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
804 struct pid *pid = proc_pid(inode);
805 struct task_struct *task;
806 int ret;
807
808 task = get_pid_task(pid, PIDTYPE_PID);
809 if (!task)
810 return -ESRCH;
811
812 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
813
814 put_task_struct(task);
815 return ret;
816 }
817
proc_single_open(struct inode * inode,struct file * filp)818 static int proc_single_open(struct inode *inode, struct file *filp)
819 {
820 return single_open(filp, proc_single_show, inode);
821 }
822
823 static const struct file_operations proc_single_file_operations = {
824 .open = proc_single_open,
825 .read = seq_read,
826 .llseek = seq_lseek,
827 .release = single_release,
828 };
829
830
proc_mem_open(struct inode * inode,unsigned int mode)831 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
832 {
833 struct task_struct *task = get_proc_task(inode);
834 struct mm_struct *mm;
835
836 if (!task)
837 return ERR_PTR(-ESRCH);
838
839 mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
840 put_task_struct(task);
841
842 if (IS_ERR(mm))
843 return mm == ERR_PTR(-ESRCH) ? NULL : mm;
844
845 /* ensure this mm_struct can't be freed */
846 mmgrab(mm);
847 /* but do not pin its memory */
848 mmput(mm);
849
850 return mm;
851 }
852
__mem_open(struct inode * inode,struct file * file,unsigned int mode)853 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
854 {
855 struct mm_struct *mm = proc_mem_open(inode, mode);
856
857 if (IS_ERR(mm))
858 return PTR_ERR(mm);
859
860 file->private_data = mm;
861 return 0;
862 }
863
mem_open(struct inode * inode,struct file * file)864 static int mem_open(struct inode *inode, struct file *file)
865 {
866 if (WARN_ON_ONCE(!(file->f_op->fop_flags & FOP_UNSIGNED_OFFSET)))
867 return -EINVAL;
868 return __mem_open(inode, file, PTRACE_MODE_ATTACH);
869 }
870
proc_mem_foll_force(struct file * file,struct mm_struct * mm)871 static bool proc_mem_foll_force(struct file *file, struct mm_struct *mm)
872 {
873 struct task_struct *task;
874 bool ptrace_active = false;
875
876 switch (proc_mem_force_override) {
877 case PROC_MEM_FORCE_NEVER:
878 return false;
879 case PROC_MEM_FORCE_PTRACE:
880 task = get_proc_task(file_inode(file));
881 if (task) {
882 ptrace_active = READ_ONCE(task->ptrace) &&
883 READ_ONCE(task->mm) == mm &&
884 READ_ONCE(task->parent) == current;
885 put_task_struct(task);
886 }
887 return ptrace_active;
888 default:
889 return true;
890 }
891 }
892
mem_rw(struct file * file,char __user * buf,size_t count,loff_t * ppos,int write)893 static ssize_t mem_rw(struct file *file, char __user *buf,
894 size_t count, loff_t *ppos, int write)
895 {
896 struct mm_struct *mm = file->private_data;
897 unsigned long addr = *ppos;
898 ssize_t copied;
899 char *page;
900 unsigned int flags;
901
902 if (!mm)
903 return 0;
904
905 page = (char *)__get_free_page(GFP_KERNEL);
906 if (!page)
907 return -ENOMEM;
908
909 copied = 0;
910 if (!mmget_not_zero(mm))
911 goto free;
912
913 flags = write ? FOLL_WRITE : 0;
914 if (proc_mem_foll_force(file, mm))
915 flags |= FOLL_FORCE;
916
917 while (count > 0) {
918 size_t this_len = min_t(size_t, count, PAGE_SIZE);
919
920 if (write && copy_from_user(page, buf, this_len)) {
921 copied = -EFAULT;
922 break;
923 }
924
925 this_len = access_remote_vm(mm, addr, page, this_len, flags);
926 if (!this_len) {
927 if (!copied)
928 copied = -EIO;
929 break;
930 }
931
932 if (!write && copy_to_user(buf, page, this_len)) {
933 copied = -EFAULT;
934 break;
935 }
936
937 buf += this_len;
938 addr += this_len;
939 copied += this_len;
940 count -= this_len;
941 }
942 *ppos = addr;
943
944 mmput(mm);
945 free:
946 free_page((unsigned long) page);
947 return copied;
948 }
949
mem_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)950 static ssize_t mem_read(struct file *file, char __user *buf,
951 size_t count, loff_t *ppos)
952 {
953 return mem_rw(file, buf, count, ppos, 0);
954 }
955
mem_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)956 static ssize_t mem_write(struct file *file, const char __user *buf,
957 size_t count, loff_t *ppos)
958 {
959 return mem_rw(file, (char __user*)buf, count, ppos, 1);
960 }
961
mem_lseek(struct file * file,loff_t offset,int orig)962 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
963 {
964 switch (orig) {
965 case 0:
966 file->f_pos = offset;
967 break;
968 case 1:
969 file->f_pos += offset;
970 break;
971 default:
972 return -EINVAL;
973 }
974 force_successful_syscall_return();
975 return file->f_pos;
976 }
977
mem_release(struct inode * inode,struct file * file)978 static int mem_release(struct inode *inode, struct file *file)
979 {
980 struct mm_struct *mm = file->private_data;
981 if (mm)
982 mmdrop(mm);
983 return 0;
984 }
985
986 static const struct file_operations proc_mem_operations = {
987 .llseek = mem_lseek,
988 .read = mem_read,
989 .write = mem_write,
990 .open = mem_open,
991 .release = mem_release,
992 .fop_flags = FOP_UNSIGNED_OFFSET,
993 };
994
environ_open(struct inode * inode,struct file * file)995 static int environ_open(struct inode *inode, struct file *file)
996 {
997 return __mem_open(inode, file, PTRACE_MODE_READ);
998 }
999
environ_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1000 static ssize_t environ_read(struct file *file, char __user *buf,
1001 size_t count, loff_t *ppos)
1002 {
1003 char *page;
1004 unsigned long src = *ppos;
1005 int ret = 0;
1006 struct mm_struct *mm = file->private_data;
1007 unsigned long env_start, env_end;
1008
1009 /* Ensure the process spawned far enough to have an environment. */
1010 if (!mm || !mm->env_end)
1011 return 0;
1012
1013 page = (char *)__get_free_page(GFP_KERNEL);
1014 if (!page)
1015 return -ENOMEM;
1016
1017 ret = 0;
1018 if (!mmget_not_zero(mm))
1019 goto free;
1020
1021 spin_lock(&mm->arg_lock);
1022 env_start = mm->env_start;
1023 env_end = mm->env_end;
1024 spin_unlock(&mm->arg_lock);
1025
1026 while (count > 0) {
1027 size_t this_len, max_len;
1028 int retval;
1029
1030 if (src >= (env_end - env_start))
1031 break;
1032
1033 this_len = env_end - (env_start + src);
1034
1035 max_len = min_t(size_t, PAGE_SIZE, count);
1036 this_len = min(max_len, this_len);
1037
1038 retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
1039
1040 if (retval <= 0) {
1041 ret = retval;
1042 break;
1043 }
1044
1045 if (copy_to_user(buf, page, retval)) {
1046 ret = -EFAULT;
1047 break;
1048 }
1049
1050 ret += retval;
1051 src += retval;
1052 buf += retval;
1053 count -= retval;
1054 }
1055 *ppos = src;
1056 mmput(mm);
1057
1058 free:
1059 free_page((unsigned long) page);
1060 return ret;
1061 }
1062
1063 static const struct file_operations proc_environ_operations = {
1064 .open = environ_open,
1065 .read = environ_read,
1066 .llseek = generic_file_llseek,
1067 .release = mem_release,
1068 };
1069
auxv_open(struct inode * inode,struct file * file)1070 static int auxv_open(struct inode *inode, struct file *file)
1071 {
1072 return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1073 }
1074
auxv_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1075 static ssize_t auxv_read(struct file *file, char __user *buf,
1076 size_t count, loff_t *ppos)
1077 {
1078 struct mm_struct *mm = file->private_data;
1079 unsigned int nwords = 0;
1080
1081 if (!mm)
1082 return 0;
1083 do {
1084 nwords += 2;
1085 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1086 return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1087 nwords * sizeof(mm->saved_auxv[0]));
1088 }
1089
1090 static const struct file_operations proc_auxv_operations = {
1091 .open = auxv_open,
1092 .read = auxv_read,
1093 .llseek = generic_file_llseek,
1094 .release = mem_release,
1095 };
1096
oom_adj_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1097 static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1098 loff_t *ppos)
1099 {
1100 struct task_struct *task = get_proc_task(file_inode(file));
1101 char buffer[PROC_NUMBUF];
1102 int oom_adj = OOM_ADJUST_MIN;
1103 size_t len;
1104
1105 if (!task)
1106 return -ESRCH;
1107 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1108 oom_adj = OOM_ADJUST_MAX;
1109 else
1110 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1111 OOM_SCORE_ADJ_MAX;
1112 put_task_struct(task);
1113 if (oom_adj > OOM_ADJUST_MAX)
1114 oom_adj = OOM_ADJUST_MAX;
1115 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1116 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1117 }
1118
__set_oom_adj(struct file * file,int oom_adj,bool legacy)1119 static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1120 {
1121 struct mm_struct *mm = NULL;
1122 struct task_struct *task;
1123 int err = 0;
1124
1125 task = get_proc_task(file_inode(file));
1126 if (!task)
1127 return -ESRCH;
1128
1129 mutex_lock(&oom_adj_mutex);
1130 if (legacy) {
1131 if (oom_adj < task->signal->oom_score_adj &&
1132 !capable(CAP_SYS_RESOURCE)) {
1133 err = -EACCES;
1134 goto err_unlock;
1135 }
1136 /*
1137 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1138 * /proc/pid/oom_score_adj instead.
1139 */
1140 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1141 current->comm, task_pid_nr(current), task_pid_nr(task),
1142 task_pid_nr(task));
1143 } else {
1144 if ((short)oom_adj < task->signal->oom_score_adj_min &&
1145 !capable(CAP_SYS_RESOURCE)) {
1146 err = -EACCES;
1147 goto err_unlock;
1148 }
1149 }
1150
1151 /*
1152 * Make sure we will check other processes sharing the mm if this is
1153 * not vfrok which wants its own oom_score_adj.
1154 * pin the mm so it doesn't go away and get reused after task_unlock
1155 */
1156 if (!task->vfork_done) {
1157 struct task_struct *p = find_lock_task_mm(task);
1158
1159 if (p) {
1160 if (test_bit(MMF_MULTIPROCESS, &p->mm->flags)) {
1161 mm = p->mm;
1162 mmgrab(mm);
1163 }
1164 task_unlock(p);
1165 }
1166 }
1167
1168 task->signal->oom_score_adj = oom_adj;
1169 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1170 task->signal->oom_score_adj_min = (short)oom_adj;
1171 trace_oom_score_adj_update(task);
1172
1173 if (mm) {
1174 struct task_struct *p;
1175
1176 rcu_read_lock();
1177 for_each_process(p) {
1178 if (same_thread_group(task, p))
1179 continue;
1180
1181 /* do not touch kernel threads or the global init */
1182 if (p->flags & PF_KTHREAD || is_global_init(p))
1183 continue;
1184
1185 task_lock(p);
1186 if (!p->vfork_done && process_shares_mm(p, mm)) {
1187 p->signal->oom_score_adj = oom_adj;
1188 if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1189 p->signal->oom_score_adj_min = (short)oom_adj;
1190 }
1191 task_unlock(p);
1192 }
1193 rcu_read_unlock();
1194 mmdrop(mm);
1195 }
1196 err_unlock:
1197 mutex_unlock(&oom_adj_mutex);
1198 put_task_struct(task);
1199 return err;
1200 }
1201
1202 /*
1203 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1204 * kernels. The effective policy is defined by oom_score_adj, which has a
1205 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1206 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1207 * Processes that become oom disabled via oom_adj will still be oom disabled
1208 * with this implementation.
1209 *
1210 * oom_adj cannot be removed since existing userspace binaries use it.
1211 */
oom_adj_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1212 static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1213 size_t count, loff_t *ppos)
1214 {
1215 char buffer[PROC_NUMBUF] = {};
1216 int oom_adj;
1217 int err;
1218
1219 if (count > sizeof(buffer) - 1)
1220 count = sizeof(buffer) - 1;
1221 if (copy_from_user(buffer, buf, count)) {
1222 err = -EFAULT;
1223 goto out;
1224 }
1225
1226 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1227 if (err)
1228 goto out;
1229 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1230 oom_adj != OOM_DISABLE) {
1231 err = -EINVAL;
1232 goto out;
1233 }
1234
1235 /*
1236 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1237 * value is always attainable.
1238 */
1239 if (oom_adj == OOM_ADJUST_MAX)
1240 oom_adj = OOM_SCORE_ADJ_MAX;
1241 else
1242 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1243
1244 err = __set_oom_adj(file, oom_adj, true);
1245 out:
1246 return err < 0 ? err : count;
1247 }
1248
1249 static const struct file_operations proc_oom_adj_operations = {
1250 .read = oom_adj_read,
1251 .write = oom_adj_write,
1252 .llseek = generic_file_llseek,
1253 };
1254
oom_score_adj_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1255 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1256 size_t count, loff_t *ppos)
1257 {
1258 struct task_struct *task = get_proc_task(file_inode(file));
1259 char buffer[PROC_NUMBUF];
1260 short oom_score_adj = OOM_SCORE_ADJ_MIN;
1261 size_t len;
1262
1263 if (!task)
1264 return -ESRCH;
1265 oom_score_adj = task->signal->oom_score_adj;
1266 put_task_struct(task);
1267 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1268 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1269 }
1270
oom_score_adj_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1271 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1272 size_t count, loff_t *ppos)
1273 {
1274 char buffer[PROC_NUMBUF] = {};
1275 int oom_score_adj;
1276 int err;
1277
1278 if (count > sizeof(buffer) - 1)
1279 count = sizeof(buffer) - 1;
1280 if (copy_from_user(buffer, buf, count)) {
1281 err = -EFAULT;
1282 goto out;
1283 }
1284
1285 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1286 if (err)
1287 goto out;
1288 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1289 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1290 err = -EINVAL;
1291 goto out;
1292 }
1293
1294 err = __set_oom_adj(file, oom_score_adj, false);
1295 out:
1296 return err < 0 ? err : count;
1297 }
1298
1299 static const struct file_operations proc_oom_score_adj_operations = {
1300 .read = oom_score_adj_read,
1301 .write = oom_score_adj_write,
1302 .llseek = default_llseek,
1303 };
1304
1305 #ifdef CONFIG_AUDIT
1306 #define TMPBUFLEN 11
proc_loginuid_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1307 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1308 size_t count, loff_t *ppos)
1309 {
1310 struct inode * inode = file_inode(file);
1311 struct task_struct *task = get_proc_task(inode);
1312 ssize_t length;
1313 char tmpbuf[TMPBUFLEN];
1314
1315 if (!task)
1316 return -ESRCH;
1317 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1318 from_kuid(file->f_cred->user_ns,
1319 audit_get_loginuid(task)));
1320 put_task_struct(task);
1321 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1322 }
1323
proc_loginuid_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1324 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1325 size_t count, loff_t *ppos)
1326 {
1327 struct inode * inode = file_inode(file);
1328 uid_t loginuid;
1329 kuid_t kloginuid;
1330 int rv;
1331
1332 /* Don't let kthreads write their own loginuid */
1333 if (current->flags & PF_KTHREAD)
1334 return -EPERM;
1335
1336 rcu_read_lock();
1337 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1338 rcu_read_unlock();
1339 return -EPERM;
1340 }
1341 rcu_read_unlock();
1342
1343 if (*ppos != 0) {
1344 /* No partial writes. */
1345 return -EINVAL;
1346 }
1347
1348 rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1349 if (rv < 0)
1350 return rv;
1351
1352 /* is userspace tring to explicitly UNSET the loginuid? */
1353 if (loginuid == AUDIT_UID_UNSET) {
1354 kloginuid = INVALID_UID;
1355 } else {
1356 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1357 if (!uid_valid(kloginuid))
1358 return -EINVAL;
1359 }
1360
1361 rv = audit_set_loginuid(kloginuid);
1362 if (rv < 0)
1363 return rv;
1364 return count;
1365 }
1366
1367 static const struct file_operations proc_loginuid_operations = {
1368 .read = proc_loginuid_read,
1369 .write = proc_loginuid_write,
1370 .llseek = generic_file_llseek,
1371 };
1372
proc_sessionid_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1373 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1374 size_t count, loff_t *ppos)
1375 {
1376 struct inode * inode = file_inode(file);
1377 struct task_struct *task = get_proc_task(inode);
1378 ssize_t length;
1379 char tmpbuf[TMPBUFLEN];
1380
1381 if (!task)
1382 return -ESRCH;
1383 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1384 audit_get_sessionid(task));
1385 put_task_struct(task);
1386 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1387 }
1388
1389 static const struct file_operations proc_sessionid_operations = {
1390 .read = proc_sessionid_read,
1391 .llseek = generic_file_llseek,
1392 };
1393 #endif
1394
1395 #ifdef CONFIG_FAULT_INJECTION
proc_fault_inject_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1396 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1397 size_t count, loff_t *ppos)
1398 {
1399 struct task_struct *task = get_proc_task(file_inode(file));
1400 char buffer[PROC_NUMBUF];
1401 size_t len;
1402 int make_it_fail;
1403
1404 if (!task)
1405 return -ESRCH;
1406 make_it_fail = task->make_it_fail;
1407 put_task_struct(task);
1408
1409 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1410
1411 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1412 }
1413
proc_fault_inject_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1414 static ssize_t proc_fault_inject_write(struct file * file,
1415 const char __user * buf, size_t count, loff_t *ppos)
1416 {
1417 struct task_struct *task;
1418 char buffer[PROC_NUMBUF] = {};
1419 int make_it_fail;
1420 int rv;
1421
1422 if (!capable(CAP_SYS_RESOURCE))
1423 return -EPERM;
1424
1425 if (count > sizeof(buffer) - 1)
1426 count = sizeof(buffer) - 1;
1427 if (copy_from_user(buffer, buf, count))
1428 return -EFAULT;
1429 rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1430 if (rv < 0)
1431 return rv;
1432 if (make_it_fail < 0 || make_it_fail > 1)
1433 return -EINVAL;
1434
1435 task = get_proc_task(file_inode(file));
1436 if (!task)
1437 return -ESRCH;
1438 task->make_it_fail = make_it_fail;
1439 put_task_struct(task);
1440
1441 return count;
1442 }
1443
1444 static const struct file_operations proc_fault_inject_operations = {
1445 .read = proc_fault_inject_read,
1446 .write = proc_fault_inject_write,
1447 .llseek = generic_file_llseek,
1448 };
1449
proc_fail_nth_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1450 static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1451 size_t count, loff_t *ppos)
1452 {
1453 struct task_struct *task;
1454 int err;
1455 unsigned int n;
1456
1457 err = kstrtouint_from_user(buf, count, 0, &n);
1458 if (err)
1459 return err;
1460
1461 task = get_proc_task(file_inode(file));
1462 if (!task)
1463 return -ESRCH;
1464 task->fail_nth = n;
1465 put_task_struct(task);
1466
1467 return count;
1468 }
1469
proc_fail_nth_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1470 static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1471 size_t count, loff_t *ppos)
1472 {
1473 struct task_struct *task;
1474 char numbuf[PROC_NUMBUF];
1475 ssize_t len;
1476
1477 task = get_proc_task(file_inode(file));
1478 if (!task)
1479 return -ESRCH;
1480 len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1481 put_task_struct(task);
1482 return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1483 }
1484
1485 static const struct file_operations proc_fail_nth_operations = {
1486 .read = proc_fail_nth_read,
1487 .write = proc_fail_nth_write,
1488 };
1489 #endif
1490
1491
1492 /*
1493 * Print out various scheduling related per-task fields:
1494 */
sched_show(struct seq_file * m,void * v)1495 static int sched_show(struct seq_file *m, void *v)
1496 {
1497 struct inode *inode = m->private;
1498 struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
1499 struct task_struct *p;
1500
1501 p = get_proc_task(inode);
1502 if (!p)
1503 return -ESRCH;
1504 proc_sched_show_task(p, ns, m);
1505
1506 put_task_struct(p);
1507
1508 return 0;
1509 }
1510
1511 static ssize_t
sched_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)1512 sched_write(struct file *file, const char __user *buf,
1513 size_t count, loff_t *offset)
1514 {
1515 struct inode *inode = file_inode(file);
1516 struct task_struct *p;
1517
1518 p = get_proc_task(inode);
1519 if (!p)
1520 return -ESRCH;
1521 proc_sched_set_task(p);
1522
1523 put_task_struct(p);
1524
1525 return count;
1526 }
1527
sched_open(struct inode * inode,struct file * filp)1528 static int sched_open(struct inode *inode, struct file *filp)
1529 {
1530 return single_open(filp, sched_show, inode);
1531 }
1532
1533 static const struct file_operations proc_pid_sched_operations = {
1534 .open = sched_open,
1535 .read = seq_read,
1536 .write = sched_write,
1537 .llseek = seq_lseek,
1538 .release = single_release,
1539 };
1540
1541 #ifdef CONFIG_SCHED_AUTOGROUP
1542 /*
1543 * Print out autogroup related information:
1544 */
sched_autogroup_show(struct seq_file * m,void * v)1545 static int sched_autogroup_show(struct seq_file *m, void *v)
1546 {
1547 struct inode *inode = m->private;
1548 struct task_struct *p;
1549
1550 p = get_proc_task(inode);
1551 if (!p)
1552 return -ESRCH;
1553 proc_sched_autogroup_show_task(p, m);
1554
1555 put_task_struct(p);
1556
1557 return 0;
1558 }
1559
1560 static ssize_t
sched_autogroup_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)1561 sched_autogroup_write(struct file *file, const char __user *buf,
1562 size_t count, loff_t *offset)
1563 {
1564 struct inode *inode = file_inode(file);
1565 struct task_struct *p;
1566 char buffer[PROC_NUMBUF] = {};
1567 int nice;
1568 int err;
1569
1570 if (count > sizeof(buffer) - 1)
1571 count = sizeof(buffer) - 1;
1572 if (copy_from_user(buffer, buf, count))
1573 return -EFAULT;
1574
1575 err = kstrtoint(strstrip(buffer), 0, &nice);
1576 if (err < 0)
1577 return err;
1578
1579 p = get_proc_task(inode);
1580 if (!p)
1581 return -ESRCH;
1582
1583 err = proc_sched_autogroup_set_nice(p, nice);
1584 if (err)
1585 count = err;
1586
1587 put_task_struct(p);
1588
1589 return count;
1590 }
1591
sched_autogroup_open(struct inode * inode,struct file * filp)1592 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1593 {
1594 int ret;
1595
1596 ret = single_open(filp, sched_autogroup_show, NULL);
1597 if (!ret) {
1598 struct seq_file *m = filp->private_data;
1599
1600 m->private = inode;
1601 }
1602 return ret;
1603 }
1604
1605 static const struct file_operations proc_pid_sched_autogroup_operations = {
1606 .open = sched_autogroup_open,
1607 .read = seq_read,
1608 .write = sched_autogroup_write,
1609 .llseek = seq_lseek,
1610 .release = single_release,
1611 };
1612
1613 #endif /* CONFIG_SCHED_AUTOGROUP */
1614
1615 #ifdef CONFIG_TIME_NS
timens_offsets_show(struct seq_file * m,void * v)1616 static int timens_offsets_show(struct seq_file *m, void *v)
1617 {
1618 struct task_struct *p;
1619
1620 p = get_proc_task(file_inode(m->file));
1621 if (!p)
1622 return -ESRCH;
1623 proc_timens_show_offsets(p, m);
1624
1625 put_task_struct(p);
1626
1627 return 0;
1628 }
1629
timens_offsets_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1630 static ssize_t timens_offsets_write(struct file *file, const char __user *buf,
1631 size_t count, loff_t *ppos)
1632 {
1633 struct inode *inode = file_inode(file);
1634 struct proc_timens_offset offsets[2];
1635 char *kbuf = NULL, *pos, *next_line;
1636 struct task_struct *p;
1637 int ret, noffsets;
1638
1639 /* Only allow < page size writes at the beginning of the file */
1640 if ((*ppos != 0) || (count >= PAGE_SIZE))
1641 return -EINVAL;
1642
1643 /* Slurp in the user data */
1644 kbuf = memdup_user_nul(buf, count);
1645 if (IS_ERR(kbuf))
1646 return PTR_ERR(kbuf);
1647
1648 /* Parse the user data */
1649 ret = -EINVAL;
1650 noffsets = 0;
1651 for (pos = kbuf; pos; pos = next_line) {
1652 struct proc_timens_offset *off = &offsets[noffsets];
1653 char clock[10];
1654 int err;
1655
1656 /* Find the end of line and ensure we don't look past it */
1657 next_line = strchr(pos, '\n');
1658 if (next_line) {
1659 *next_line = '\0';
1660 next_line++;
1661 if (*next_line == '\0')
1662 next_line = NULL;
1663 }
1664
1665 err = sscanf(pos, "%9s %lld %lu", clock,
1666 &off->val.tv_sec, &off->val.tv_nsec);
1667 if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
1668 goto out;
1669
1670 clock[sizeof(clock) - 1] = 0;
1671 if (strcmp(clock, "monotonic") == 0 ||
1672 strcmp(clock, __stringify(CLOCK_MONOTONIC)) == 0)
1673 off->clockid = CLOCK_MONOTONIC;
1674 else if (strcmp(clock, "boottime") == 0 ||
1675 strcmp(clock, __stringify(CLOCK_BOOTTIME)) == 0)
1676 off->clockid = CLOCK_BOOTTIME;
1677 else
1678 goto out;
1679
1680 noffsets++;
1681 if (noffsets == ARRAY_SIZE(offsets)) {
1682 if (next_line)
1683 count = next_line - kbuf;
1684 break;
1685 }
1686 }
1687
1688 ret = -ESRCH;
1689 p = get_proc_task(inode);
1690 if (!p)
1691 goto out;
1692 ret = proc_timens_set_offset(file, p, offsets, noffsets);
1693 put_task_struct(p);
1694 if (ret)
1695 goto out;
1696
1697 ret = count;
1698 out:
1699 kfree(kbuf);
1700 return ret;
1701 }
1702
timens_offsets_open(struct inode * inode,struct file * filp)1703 static int timens_offsets_open(struct inode *inode, struct file *filp)
1704 {
1705 return single_open(filp, timens_offsets_show, inode);
1706 }
1707
1708 static const struct file_operations proc_timens_offsets_operations = {
1709 .open = timens_offsets_open,
1710 .read = seq_read,
1711 .write = timens_offsets_write,
1712 .llseek = seq_lseek,
1713 .release = single_release,
1714 };
1715 #endif /* CONFIG_TIME_NS */
1716
comm_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)1717 static ssize_t comm_write(struct file *file, const char __user *buf,
1718 size_t count, loff_t *offset)
1719 {
1720 struct inode *inode = file_inode(file);
1721 struct task_struct *p;
1722 char buffer[TASK_COMM_LEN] = {};
1723 const size_t maxlen = sizeof(buffer) - 1;
1724
1725 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1726 return -EFAULT;
1727
1728 p = get_proc_task(inode);
1729 if (!p)
1730 return -ESRCH;
1731
1732 if (same_thread_group(current, p)) {
1733 set_task_comm(p, buffer);
1734 proc_comm_connector(p);
1735 }
1736 else
1737 count = -EINVAL;
1738
1739 put_task_struct(p);
1740
1741 return count;
1742 }
1743
comm_show(struct seq_file * m,void * v)1744 static int comm_show(struct seq_file *m, void *v)
1745 {
1746 struct inode *inode = m->private;
1747 struct task_struct *p;
1748
1749 p = get_proc_task(inode);
1750 if (!p)
1751 return -ESRCH;
1752
1753 proc_task_name(m, p, false);
1754 seq_putc(m, '\n');
1755
1756 put_task_struct(p);
1757
1758 return 0;
1759 }
1760
comm_open(struct inode * inode,struct file * filp)1761 static int comm_open(struct inode *inode, struct file *filp)
1762 {
1763 return single_open(filp, comm_show, inode);
1764 }
1765
1766 static const struct file_operations proc_pid_set_comm_operations = {
1767 .open = comm_open,
1768 .read = seq_read,
1769 .write = comm_write,
1770 .llseek = seq_lseek,
1771 .release = single_release,
1772 };
1773
proc_exe_link(struct dentry * dentry,struct path * exe_path)1774 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1775 {
1776 struct task_struct *task;
1777 struct file *exe_file;
1778
1779 task = get_proc_task(d_inode(dentry));
1780 if (!task)
1781 return -ENOENT;
1782 exe_file = get_task_exe_file(task);
1783 put_task_struct(task);
1784 if (exe_file) {
1785 *exe_path = exe_file->f_path;
1786 path_get(&exe_file->f_path);
1787 fput(exe_file);
1788 return 0;
1789 } else
1790 return -ENOENT;
1791 }
1792
proc_pid_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)1793 static const char *proc_pid_get_link(struct dentry *dentry,
1794 struct inode *inode,
1795 struct delayed_call *done)
1796 {
1797 struct path path;
1798 int error = -EACCES;
1799
1800 if (!dentry)
1801 return ERR_PTR(-ECHILD);
1802
1803 /* Are we allowed to snoop on the tasks file descriptors? */
1804 if (!proc_fd_access_allowed(inode))
1805 goto out;
1806
1807 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1808 if (error)
1809 goto out;
1810
1811 error = nd_jump_link(&path);
1812 out:
1813 return ERR_PTR(error);
1814 }
1815
do_proc_readlink(const struct path * path,char __user * buffer,int buflen)1816 static int do_proc_readlink(const struct path *path, char __user *buffer, int buflen)
1817 {
1818 char *tmp = kmalloc(PATH_MAX, GFP_KERNEL);
1819 char *pathname;
1820 int len;
1821
1822 if (!tmp)
1823 return -ENOMEM;
1824
1825 pathname = d_path(path, tmp, PATH_MAX);
1826 len = PTR_ERR(pathname);
1827 if (IS_ERR(pathname))
1828 goto out;
1829 len = tmp + PATH_MAX - 1 - pathname;
1830
1831 if (len > buflen)
1832 len = buflen;
1833 if (copy_to_user(buffer, pathname, len))
1834 len = -EFAULT;
1835 out:
1836 kfree(tmp);
1837 return len;
1838 }
1839
proc_pid_readlink(struct dentry * dentry,char __user * buffer,int buflen)1840 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1841 {
1842 int error = -EACCES;
1843 struct inode *inode = d_inode(dentry);
1844 struct path path;
1845
1846 /* Are we allowed to snoop on the tasks file descriptors? */
1847 if (!proc_fd_access_allowed(inode))
1848 goto out;
1849
1850 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1851 if (error)
1852 goto out;
1853
1854 error = do_proc_readlink(&path, buffer, buflen);
1855 path_put(&path);
1856 out:
1857 return error;
1858 }
1859
1860 const struct inode_operations proc_pid_link_inode_operations = {
1861 .readlink = proc_pid_readlink,
1862 .get_link = proc_pid_get_link,
1863 .setattr = proc_setattr,
1864 };
1865
1866
1867 /* building an inode */
1868
task_dump_owner(struct task_struct * task,umode_t mode,kuid_t * ruid,kgid_t * rgid)1869 void task_dump_owner(struct task_struct *task, umode_t mode,
1870 kuid_t *ruid, kgid_t *rgid)
1871 {
1872 /* Depending on the state of dumpable compute who should own a
1873 * proc file for a task.
1874 */
1875 const struct cred *cred;
1876 kuid_t uid;
1877 kgid_t gid;
1878
1879 if (unlikely(task->flags & PF_KTHREAD)) {
1880 *ruid = GLOBAL_ROOT_UID;
1881 *rgid = GLOBAL_ROOT_GID;
1882 return;
1883 }
1884
1885 /* Default to the tasks effective ownership */
1886 rcu_read_lock();
1887 cred = __task_cred(task);
1888 uid = cred->euid;
1889 gid = cred->egid;
1890 rcu_read_unlock();
1891
1892 /*
1893 * Before the /proc/pid/status file was created the only way to read
1894 * the effective uid of a /process was to stat /proc/pid. Reading
1895 * /proc/pid/status is slow enough that procps and other packages
1896 * kept stating /proc/pid. To keep the rules in /proc simple I have
1897 * made this apply to all per process world readable and executable
1898 * directories.
1899 */
1900 if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1901 struct mm_struct *mm;
1902 task_lock(task);
1903 mm = task->mm;
1904 /* Make non-dumpable tasks owned by some root */
1905 if (mm) {
1906 if (get_dumpable(mm) != SUID_DUMP_USER) {
1907 struct user_namespace *user_ns = mm->user_ns;
1908
1909 uid = make_kuid(user_ns, 0);
1910 if (!uid_valid(uid))
1911 uid = GLOBAL_ROOT_UID;
1912
1913 gid = make_kgid(user_ns, 0);
1914 if (!gid_valid(gid))
1915 gid = GLOBAL_ROOT_GID;
1916 }
1917 } else {
1918 uid = GLOBAL_ROOT_UID;
1919 gid = GLOBAL_ROOT_GID;
1920 }
1921 task_unlock(task);
1922 }
1923 *ruid = uid;
1924 *rgid = gid;
1925 }
1926
proc_pid_evict_inode(struct proc_inode * ei)1927 void proc_pid_evict_inode(struct proc_inode *ei)
1928 {
1929 struct pid *pid = ei->pid;
1930
1931 if (S_ISDIR(ei->vfs_inode.i_mode)) {
1932 spin_lock(&pid->lock);
1933 hlist_del_init_rcu(&ei->sibling_inodes);
1934 spin_unlock(&pid->lock);
1935 }
1936 }
1937
proc_pid_make_inode(struct super_block * sb,struct task_struct * task,umode_t mode)1938 struct inode *proc_pid_make_inode(struct super_block *sb,
1939 struct task_struct *task, umode_t mode)
1940 {
1941 struct inode * inode;
1942 struct proc_inode *ei;
1943 struct pid *pid;
1944
1945 /* We need a new inode */
1946
1947 inode = new_inode(sb);
1948 if (!inode)
1949 goto out;
1950
1951 /* Common stuff */
1952 ei = PROC_I(inode);
1953 inode->i_mode = mode;
1954 inode->i_ino = get_next_ino();
1955 simple_inode_init_ts(inode);
1956 inode->i_op = &proc_def_inode_operations;
1957
1958 /*
1959 * grab the reference to task.
1960 */
1961 pid = get_task_pid(task, PIDTYPE_PID);
1962 if (!pid)
1963 goto out_unlock;
1964
1965 /* Let the pid remember us for quick removal */
1966 ei->pid = pid;
1967
1968 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1969 security_task_to_inode(task, inode);
1970
1971 out:
1972 return inode;
1973
1974 out_unlock:
1975 iput(inode);
1976 return NULL;
1977 }
1978
1979 /*
1980 * Generating an inode and adding it into @pid->inodes, so that task will
1981 * invalidate inode's dentry before being released.
1982 *
1983 * This helper is used for creating dir-type entries under '/proc' and
1984 * '/proc/<tgid>/task'. Other entries(eg. fd, stat) under '/proc/<tgid>'
1985 * can be released by invalidating '/proc/<tgid>' dentry.
1986 * In theory, dentries under '/proc/<tgid>/task' can also be released by
1987 * invalidating '/proc/<tgid>' dentry, we reserve it to handle single
1988 * thread exiting situation: Any one of threads should invalidate its
1989 * '/proc/<tgid>/task/<pid>' dentry before released.
1990 */
proc_pid_make_base_inode(struct super_block * sb,struct task_struct * task,umode_t mode)1991 static struct inode *proc_pid_make_base_inode(struct super_block *sb,
1992 struct task_struct *task, umode_t mode)
1993 {
1994 struct inode *inode;
1995 struct proc_inode *ei;
1996 struct pid *pid;
1997
1998 inode = proc_pid_make_inode(sb, task, mode);
1999 if (!inode)
2000 return NULL;
2001
2002 /* Let proc_flush_pid find this directory inode */
2003 ei = PROC_I(inode);
2004 pid = ei->pid;
2005 spin_lock(&pid->lock);
2006 hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
2007 spin_unlock(&pid->lock);
2008
2009 return inode;
2010 }
2011
pid_getattr(struct mnt_idmap * idmap,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)2012 int pid_getattr(struct mnt_idmap *idmap, const struct path *path,
2013 struct kstat *stat, u32 request_mask, unsigned int query_flags)
2014 {
2015 struct inode *inode = d_inode(path->dentry);
2016 struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
2017 struct task_struct *task;
2018
2019 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
2020
2021 stat->uid = GLOBAL_ROOT_UID;
2022 stat->gid = GLOBAL_ROOT_GID;
2023 rcu_read_lock();
2024 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2025 if (task) {
2026 if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) {
2027 rcu_read_unlock();
2028 /*
2029 * This doesn't prevent learning whether PID exists,
2030 * it only makes getattr() consistent with readdir().
2031 */
2032 return -ENOENT;
2033 }
2034 task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
2035 }
2036 rcu_read_unlock();
2037 return 0;
2038 }
2039
2040 /* dentry stuff */
2041
2042 /*
2043 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
2044 */
pid_update_inode(struct task_struct * task,struct inode * inode)2045 void pid_update_inode(struct task_struct *task, struct inode *inode)
2046 {
2047 task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
2048
2049 inode->i_mode &= ~(S_ISUID | S_ISGID);
2050 security_task_to_inode(task, inode);
2051 }
2052
2053 /*
2054 * Rewrite the inode's ownerships here because the owning task may have
2055 * performed a setuid(), etc.
2056 *
2057 */
pid_revalidate(struct inode * dir,const struct qstr * name,struct dentry * dentry,unsigned int flags)2058 static int pid_revalidate(struct inode *dir, const struct qstr *name,
2059 struct dentry *dentry, unsigned int flags)
2060 {
2061 struct inode *inode;
2062 struct task_struct *task;
2063 int ret = 0;
2064
2065 rcu_read_lock();
2066 inode = d_inode_rcu(dentry);
2067 if (!inode)
2068 goto out;
2069 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2070
2071 if (task) {
2072 pid_update_inode(task, inode);
2073 ret = 1;
2074 }
2075 out:
2076 rcu_read_unlock();
2077 return ret;
2078 }
2079
proc_inode_is_dead(struct inode * inode)2080 static inline bool proc_inode_is_dead(struct inode *inode)
2081 {
2082 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
2083 }
2084
pid_delete_dentry(const struct dentry * dentry)2085 int pid_delete_dentry(const struct dentry *dentry)
2086 {
2087 /* Is the task we represent dead?
2088 * If so, then don't put the dentry on the lru list,
2089 * kill it immediately.
2090 */
2091 return proc_inode_is_dead(d_inode(dentry));
2092 }
2093
2094 const struct dentry_operations pid_dentry_operations =
2095 {
2096 .d_revalidate = pid_revalidate,
2097 .d_delete = pid_delete_dentry,
2098 };
2099
2100 /* Lookups */
2101
2102 /*
2103 * Fill a directory entry.
2104 *
2105 * If possible create the dcache entry and derive our inode number and
2106 * file type from dcache entry.
2107 *
2108 * Since all of the proc inode numbers are dynamically generated, the inode
2109 * numbers do not exist until the inode is cache. This means creating
2110 * the dcache entry in readdir is necessary to keep the inode numbers
2111 * reported by readdir in sync with the inode numbers reported
2112 * by stat.
2113 */
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)2114 bool proc_fill_cache(struct file *file, struct dir_context *ctx,
2115 const char *name, unsigned int len,
2116 instantiate_t instantiate, struct task_struct *task, const void *ptr)
2117 {
2118 struct dentry *child, *dir = file->f_path.dentry;
2119 struct qstr qname = QSTR_INIT(name, len);
2120 struct inode *inode;
2121 unsigned type = DT_UNKNOWN;
2122 ino_t ino = 1;
2123
2124 child = d_hash_and_lookup(dir, &qname);
2125 if (!child) {
2126 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
2127 child = d_alloc_parallel(dir, &qname, &wq);
2128 if (IS_ERR(child))
2129 goto end_instantiate;
2130 if (d_in_lookup(child)) {
2131 struct dentry *res;
2132 res = instantiate(child, task, ptr);
2133 d_lookup_done(child);
2134 if (unlikely(res)) {
2135 dput(child);
2136 child = res;
2137 if (IS_ERR(child))
2138 goto end_instantiate;
2139 }
2140 }
2141 }
2142 inode = d_inode(child);
2143 ino = inode->i_ino;
2144 type = inode->i_mode >> 12;
2145 dput(child);
2146 end_instantiate:
2147 return dir_emit(ctx, name, len, ino, type);
2148 }
2149
2150 /*
2151 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2152 * which represent vma start and end addresses.
2153 */
dname_to_vma_addr(struct dentry * dentry,unsigned long * start,unsigned long * end)2154 static int dname_to_vma_addr(struct dentry *dentry,
2155 unsigned long *start, unsigned long *end)
2156 {
2157 const char *str = dentry->d_name.name;
2158 unsigned long long sval, eval;
2159 unsigned int len;
2160
2161 if (str[0] == '0' && str[1] != '-')
2162 return -EINVAL;
2163 len = _parse_integer(str, 16, &sval);
2164 if (len & KSTRTOX_OVERFLOW)
2165 return -EINVAL;
2166 if (sval != (unsigned long)sval)
2167 return -EINVAL;
2168 str += len;
2169
2170 if (*str != '-')
2171 return -EINVAL;
2172 str++;
2173
2174 if (str[0] == '0' && str[1])
2175 return -EINVAL;
2176 len = _parse_integer(str, 16, &eval);
2177 if (len & KSTRTOX_OVERFLOW)
2178 return -EINVAL;
2179 if (eval != (unsigned long)eval)
2180 return -EINVAL;
2181 str += len;
2182
2183 if (*str != '\0')
2184 return -EINVAL;
2185
2186 *start = sval;
2187 *end = eval;
2188
2189 return 0;
2190 }
2191
map_files_d_revalidate(struct inode * dir,const struct qstr * name,struct dentry * dentry,unsigned int flags)2192 static int map_files_d_revalidate(struct inode *dir, const struct qstr *name,
2193 struct dentry *dentry, unsigned int flags)
2194 {
2195 unsigned long vm_start, vm_end;
2196 bool exact_vma_exists = false;
2197 struct mm_struct *mm = NULL;
2198 struct task_struct *task;
2199 struct inode *inode;
2200 int status = 0;
2201
2202 if (flags & LOOKUP_RCU)
2203 return -ECHILD;
2204
2205 inode = d_inode(dentry);
2206 task = get_proc_task(inode);
2207 if (!task)
2208 goto out_notask;
2209
2210 mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2211 if (IS_ERR(mm))
2212 goto out;
2213
2214 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2215 status = mmap_read_lock_killable(mm);
2216 if (!status) {
2217 exact_vma_exists = !!find_exact_vma(mm, vm_start,
2218 vm_end);
2219 mmap_read_unlock(mm);
2220 }
2221 }
2222
2223 mmput(mm);
2224
2225 if (exact_vma_exists) {
2226 task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
2227
2228 security_task_to_inode(task, inode);
2229 status = 1;
2230 }
2231
2232 out:
2233 put_task_struct(task);
2234
2235 out_notask:
2236 return status;
2237 }
2238
2239 static const struct dentry_operations tid_map_files_dentry_operations = {
2240 .d_revalidate = map_files_d_revalidate,
2241 .d_delete = pid_delete_dentry,
2242 };
2243
map_files_get_link(struct dentry * dentry,struct path * path)2244 static int map_files_get_link(struct dentry *dentry, struct path *path)
2245 {
2246 unsigned long vm_start, vm_end;
2247 struct vm_area_struct *vma;
2248 struct task_struct *task;
2249 struct mm_struct *mm;
2250 int rc;
2251
2252 rc = -ENOENT;
2253 task = get_proc_task(d_inode(dentry));
2254 if (!task)
2255 goto out;
2256
2257 mm = get_task_mm(task);
2258 put_task_struct(task);
2259 if (!mm)
2260 goto out;
2261
2262 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2263 if (rc)
2264 goto out_mmput;
2265
2266 rc = mmap_read_lock_killable(mm);
2267 if (rc)
2268 goto out_mmput;
2269
2270 rc = -ENOENT;
2271 vma = find_exact_vma(mm, vm_start, vm_end);
2272 if (vma && vma->vm_file) {
2273 *path = *file_user_path(vma->vm_file);
2274 path_get(path);
2275 rc = 0;
2276 }
2277 mmap_read_unlock(mm);
2278
2279 out_mmput:
2280 mmput(mm);
2281 out:
2282 return rc;
2283 }
2284
2285 struct map_files_info {
2286 unsigned long start;
2287 unsigned long end;
2288 fmode_t mode;
2289 };
2290
2291 /*
2292 * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
2293 * to concerns about how the symlinks may be used to bypass permissions on
2294 * ancestor directories in the path to the file in question.
2295 */
2296 static const char *
proc_map_files_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)2297 proc_map_files_get_link(struct dentry *dentry,
2298 struct inode *inode,
2299 struct delayed_call *done)
2300 {
2301 if (!checkpoint_restore_ns_capable(&init_user_ns))
2302 return ERR_PTR(-EPERM);
2303
2304 return proc_pid_get_link(dentry, inode, done);
2305 }
2306
2307 /*
2308 * Identical to proc_pid_link_inode_operations except for get_link()
2309 */
2310 static const struct inode_operations proc_map_files_link_inode_operations = {
2311 .readlink = proc_pid_readlink,
2312 .get_link = proc_map_files_get_link,
2313 .setattr = proc_setattr,
2314 };
2315
2316 static struct dentry *
proc_map_files_instantiate(struct dentry * dentry,struct task_struct * task,const void * ptr)2317 proc_map_files_instantiate(struct dentry *dentry,
2318 struct task_struct *task, const void *ptr)
2319 {
2320 fmode_t mode = (fmode_t)(unsigned long)ptr;
2321 struct proc_inode *ei;
2322 struct inode *inode;
2323
2324 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2325 ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2326 ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2327 if (!inode)
2328 return ERR_PTR(-ENOENT);
2329
2330 ei = PROC_I(inode);
2331 ei->op.proc_get_link = map_files_get_link;
2332
2333 inode->i_op = &proc_map_files_link_inode_operations;
2334 inode->i_size = 64;
2335
2336 return proc_splice_unmountable(inode, dentry,
2337 &tid_map_files_dentry_operations);
2338 }
2339
proc_map_files_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)2340 static struct dentry *proc_map_files_lookup(struct inode *dir,
2341 struct dentry *dentry, unsigned int flags)
2342 {
2343 unsigned long vm_start, vm_end;
2344 struct vm_area_struct *vma;
2345 struct task_struct *task;
2346 struct dentry *result;
2347 struct mm_struct *mm;
2348
2349 result = ERR_PTR(-ENOENT);
2350 task = get_proc_task(dir);
2351 if (!task)
2352 goto out;
2353
2354 result = ERR_PTR(-EACCES);
2355 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2356 goto out_put_task;
2357
2358 result = ERR_PTR(-ENOENT);
2359 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2360 goto out_put_task;
2361
2362 mm = get_task_mm(task);
2363 if (!mm)
2364 goto out_put_task;
2365
2366 result = ERR_PTR(-EINTR);
2367 if (mmap_read_lock_killable(mm))
2368 goto out_put_mm;
2369
2370 result = ERR_PTR(-ENOENT);
2371 vma = find_exact_vma(mm, vm_start, vm_end);
2372 if (!vma)
2373 goto out_no_vma;
2374
2375 if (vma->vm_file)
2376 result = proc_map_files_instantiate(dentry, task,
2377 (void *)(unsigned long)vma->vm_file->f_mode);
2378
2379 out_no_vma:
2380 mmap_read_unlock(mm);
2381 out_put_mm:
2382 mmput(mm);
2383 out_put_task:
2384 put_task_struct(task);
2385 out:
2386 return result;
2387 }
2388
2389 static const struct inode_operations proc_map_files_inode_operations = {
2390 .lookup = proc_map_files_lookup,
2391 .permission = proc_fd_permission,
2392 .setattr = proc_setattr,
2393 };
2394
2395 static int
proc_map_files_readdir(struct file * file,struct dir_context * ctx)2396 proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2397 {
2398 struct vm_area_struct *vma;
2399 struct task_struct *task;
2400 struct mm_struct *mm;
2401 unsigned long nr_files, pos, i;
2402 GENRADIX(struct map_files_info) fa;
2403 struct map_files_info *p;
2404 int ret;
2405 struct vma_iterator vmi;
2406
2407 genradix_init(&fa);
2408
2409 ret = -ENOENT;
2410 task = get_proc_task(file_inode(file));
2411 if (!task)
2412 goto out;
2413
2414 ret = -EACCES;
2415 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2416 goto out_put_task;
2417
2418 ret = 0;
2419 if (!dir_emit_dots(file, ctx))
2420 goto out_put_task;
2421
2422 mm = get_task_mm(task);
2423 if (!mm)
2424 goto out_put_task;
2425
2426 ret = mmap_read_lock_killable(mm);
2427 if (ret) {
2428 mmput(mm);
2429 goto out_put_task;
2430 }
2431
2432 nr_files = 0;
2433
2434 /*
2435 * We need two passes here:
2436 *
2437 * 1) Collect vmas of mapped files with mmap_lock taken
2438 * 2) Release mmap_lock and instantiate entries
2439 *
2440 * otherwise we get lockdep complained, since filldir()
2441 * routine might require mmap_lock taken in might_fault().
2442 */
2443
2444 pos = 2;
2445 vma_iter_init(&vmi, mm, 0);
2446 for_each_vma(vmi, vma) {
2447 if (!vma->vm_file)
2448 continue;
2449 if (++pos <= ctx->pos)
2450 continue;
2451
2452 p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2453 if (!p) {
2454 ret = -ENOMEM;
2455 mmap_read_unlock(mm);
2456 mmput(mm);
2457 goto out_put_task;
2458 }
2459
2460 p->start = vma->vm_start;
2461 p->end = vma->vm_end;
2462 p->mode = vma->vm_file->f_mode;
2463 }
2464 mmap_read_unlock(mm);
2465 mmput(mm);
2466
2467 for (i = 0; i < nr_files; i++) {
2468 char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
2469 unsigned int len;
2470
2471 p = genradix_ptr(&fa, i);
2472 len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2473 if (!proc_fill_cache(file, ctx,
2474 buf, len,
2475 proc_map_files_instantiate,
2476 task,
2477 (void *)(unsigned long)p->mode))
2478 break;
2479 ctx->pos++;
2480 }
2481
2482 out_put_task:
2483 put_task_struct(task);
2484 out:
2485 genradix_free(&fa);
2486 return ret;
2487 }
2488
2489 static const struct file_operations proc_map_files_operations = {
2490 .read = generic_read_dir,
2491 .iterate_shared = proc_map_files_readdir,
2492 .llseek = generic_file_llseek,
2493 };
2494
2495 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2496 struct timers_private {
2497 struct pid *pid;
2498 struct task_struct *task;
2499 struct pid_namespace *ns;
2500 };
2501
timers_start(struct seq_file * m,loff_t * pos)2502 static void *timers_start(struct seq_file *m, loff_t *pos)
2503 {
2504 struct timers_private *tp = m->private;
2505
2506 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2507 if (!tp->task)
2508 return ERR_PTR(-ESRCH);
2509
2510 rcu_read_lock();
2511 return seq_hlist_start_rcu(&tp->task->signal->posix_timers, *pos);
2512 }
2513
timers_next(struct seq_file * m,void * v,loff_t * pos)2514 static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2515 {
2516 struct timers_private *tp = m->private;
2517
2518 return seq_hlist_next_rcu(v, &tp->task->signal->posix_timers, pos);
2519 }
2520
timers_stop(struct seq_file * m,void * v)2521 static void timers_stop(struct seq_file *m, void *v)
2522 {
2523 struct timers_private *tp = m->private;
2524
2525 if (tp->task) {
2526 put_task_struct(tp->task);
2527 tp->task = NULL;
2528 rcu_read_unlock();
2529 }
2530 }
2531
show_timer(struct seq_file * m,void * v)2532 static int show_timer(struct seq_file *m, void *v)
2533 {
2534 static const char * const nstr[] = {
2535 [SIGEV_SIGNAL] = "signal",
2536 [SIGEV_NONE] = "none",
2537 [SIGEV_THREAD] = "thread",
2538 };
2539
2540 struct k_itimer *timer = hlist_entry((struct hlist_node *)v, struct k_itimer, list);
2541 struct timers_private *tp = m->private;
2542 int notify = timer->it_sigev_notify;
2543
2544 guard(spinlock_irq)(&timer->it_lock);
2545 if (!posixtimer_valid(timer))
2546 return 0;
2547
2548 seq_printf(m, "ID: %d\n", timer->it_id);
2549 seq_printf(m, "signal: %d/%px\n", timer->sigq.info.si_signo,
2550 timer->sigq.info.si_value.sival_ptr);
2551 seq_printf(m, "notify: %s/%s.%d\n", nstr[notify & ~SIGEV_THREAD_ID],
2552 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2553 pid_nr_ns(timer->it_pid, tp->ns));
2554 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2555
2556 return 0;
2557 }
2558
2559 static const struct seq_operations proc_timers_seq_ops = {
2560 .start = timers_start,
2561 .next = timers_next,
2562 .stop = timers_stop,
2563 .show = show_timer,
2564 };
2565
proc_timers_open(struct inode * inode,struct file * file)2566 static int proc_timers_open(struct inode *inode, struct file *file)
2567 {
2568 struct timers_private *tp;
2569
2570 tp = __seq_open_private(file, &proc_timers_seq_ops,
2571 sizeof(struct timers_private));
2572 if (!tp)
2573 return -ENOMEM;
2574
2575 tp->pid = proc_pid(inode);
2576 tp->ns = proc_pid_ns(inode->i_sb);
2577 return 0;
2578 }
2579
2580 static const struct file_operations proc_timers_operations = {
2581 .open = proc_timers_open,
2582 .read = seq_read,
2583 .llseek = seq_lseek,
2584 .release = seq_release_private,
2585 };
2586 #endif
2587
timerslack_ns_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)2588 static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2589 size_t count, loff_t *offset)
2590 {
2591 struct inode *inode = file_inode(file);
2592 struct task_struct *p;
2593 u64 slack_ns;
2594 int err;
2595
2596 err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2597 if (err < 0)
2598 return err;
2599
2600 p = get_proc_task(inode);
2601 if (!p)
2602 return -ESRCH;
2603
2604 if (p != current) {
2605 rcu_read_lock();
2606 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2607 rcu_read_unlock();
2608 count = -EPERM;
2609 goto out;
2610 }
2611 rcu_read_unlock();
2612
2613 err = security_task_setscheduler(p);
2614 if (err) {
2615 count = err;
2616 goto out;
2617 }
2618 }
2619
2620 task_lock(p);
2621 if (rt_or_dl_task_policy(p))
2622 slack_ns = 0;
2623 else if (slack_ns == 0)
2624 slack_ns = p->default_timer_slack_ns;
2625 p->timer_slack_ns = slack_ns;
2626 task_unlock(p);
2627
2628 out:
2629 put_task_struct(p);
2630
2631 return count;
2632 }
2633
timerslack_ns_show(struct seq_file * m,void * v)2634 static int timerslack_ns_show(struct seq_file *m, void *v)
2635 {
2636 struct inode *inode = m->private;
2637 struct task_struct *p;
2638 int err = 0;
2639
2640 p = get_proc_task(inode);
2641 if (!p)
2642 return -ESRCH;
2643
2644 if (p != current) {
2645 rcu_read_lock();
2646 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2647 rcu_read_unlock();
2648 err = -EPERM;
2649 goto out;
2650 }
2651 rcu_read_unlock();
2652
2653 err = security_task_getscheduler(p);
2654 if (err)
2655 goto out;
2656 }
2657
2658 task_lock(p);
2659 seq_printf(m, "%llu\n", p->timer_slack_ns);
2660 task_unlock(p);
2661
2662 out:
2663 put_task_struct(p);
2664
2665 return err;
2666 }
2667
timerslack_ns_open(struct inode * inode,struct file * filp)2668 static int timerslack_ns_open(struct inode *inode, struct file *filp)
2669 {
2670 return single_open(filp, timerslack_ns_show, inode);
2671 }
2672
2673 static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2674 .open = timerslack_ns_open,
2675 .read = seq_read,
2676 .write = timerslack_ns_write,
2677 .llseek = seq_lseek,
2678 .release = single_release,
2679 };
2680
proc_pident_instantiate(struct dentry * dentry,struct task_struct * task,const void * ptr)2681 static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2682 struct task_struct *task, const void *ptr)
2683 {
2684 const struct pid_entry *p = ptr;
2685 struct inode *inode;
2686 struct proc_inode *ei;
2687
2688 inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2689 if (!inode)
2690 return ERR_PTR(-ENOENT);
2691
2692 ei = PROC_I(inode);
2693 if (S_ISDIR(inode->i_mode))
2694 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2695 if (p->iop)
2696 inode->i_op = p->iop;
2697 if (p->fop)
2698 inode->i_fop = p->fop;
2699 ei->op = p->op;
2700 pid_update_inode(task, inode);
2701 d_set_d_op(dentry, &pid_dentry_operations);
2702 return d_splice_alias(inode, dentry);
2703 }
2704
proc_pident_lookup(struct inode * dir,struct dentry * dentry,const struct pid_entry * p,const struct pid_entry * end)2705 static struct dentry *proc_pident_lookup(struct inode *dir,
2706 struct dentry *dentry,
2707 const struct pid_entry *p,
2708 const struct pid_entry *end)
2709 {
2710 struct task_struct *task = get_proc_task(dir);
2711 struct dentry *res = ERR_PTR(-ENOENT);
2712
2713 if (!task)
2714 goto out_no_task;
2715
2716 /*
2717 * Yes, it does not scale. And it should not. Don't add
2718 * new entries into /proc/<tgid>/ without very good reasons.
2719 */
2720 for (; p < end; p++) {
2721 if (p->len != dentry->d_name.len)
2722 continue;
2723 if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2724 res = proc_pident_instantiate(dentry, task, p);
2725 break;
2726 }
2727 }
2728 put_task_struct(task);
2729 out_no_task:
2730 return res;
2731 }
2732
proc_pident_readdir(struct file * file,struct dir_context * ctx,const struct pid_entry * ents,unsigned int nents)2733 static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2734 const struct pid_entry *ents, unsigned int nents)
2735 {
2736 struct task_struct *task = get_proc_task(file_inode(file));
2737 const struct pid_entry *p;
2738
2739 if (!task)
2740 return -ENOENT;
2741
2742 if (!dir_emit_dots(file, ctx))
2743 goto out;
2744
2745 if (ctx->pos >= nents + 2)
2746 goto out;
2747
2748 for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2749 if (!proc_fill_cache(file, ctx, p->name, p->len,
2750 proc_pident_instantiate, task, p))
2751 break;
2752 ctx->pos++;
2753 }
2754 out:
2755 put_task_struct(task);
2756 return 0;
2757 }
2758
2759 #ifdef CONFIG_SECURITY
proc_pid_attr_open(struct inode * inode,struct file * file)2760 static int proc_pid_attr_open(struct inode *inode, struct file *file)
2761 {
2762 file->private_data = NULL;
2763 __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
2764 return 0;
2765 }
2766
proc_pid_attr_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)2767 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2768 size_t count, loff_t *ppos)
2769 {
2770 struct inode * inode = file_inode(file);
2771 char *p = NULL;
2772 ssize_t length;
2773 struct task_struct *task = get_proc_task(inode);
2774
2775 if (!task)
2776 return -ESRCH;
2777
2778 length = security_getprocattr(task, PROC_I(inode)->op.lsmid,
2779 file->f_path.dentry->d_name.name,
2780 &p);
2781 put_task_struct(task);
2782 if (length > 0)
2783 length = simple_read_from_buffer(buf, count, ppos, p, length);
2784 kfree(p);
2785 return length;
2786 }
2787
proc_pid_attr_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2788 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2789 size_t count, loff_t *ppos)
2790 {
2791 struct inode * inode = file_inode(file);
2792 struct task_struct *task;
2793 void *page;
2794 int rv;
2795
2796 /* A task may only write when it was the opener. */
2797 if (file->private_data != current->mm)
2798 return -EPERM;
2799
2800 rcu_read_lock();
2801 task = pid_task(proc_pid(inode), PIDTYPE_PID);
2802 if (!task) {
2803 rcu_read_unlock();
2804 return -ESRCH;
2805 }
2806 /* A task may only write its own attributes. */
2807 if (current != task) {
2808 rcu_read_unlock();
2809 return -EACCES;
2810 }
2811 /* Prevent changes to overridden credentials. */
2812 if (current_cred() != current_real_cred()) {
2813 rcu_read_unlock();
2814 return -EBUSY;
2815 }
2816 rcu_read_unlock();
2817
2818 if (count > PAGE_SIZE)
2819 count = PAGE_SIZE;
2820
2821 /* No partial writes. */
2822 if (*ppos != 0)
2823 return -EINVAL;
2824
2825 page = memdup_user(buf, count);
2826 if (IS_ERR(page)) {
2827 rv = PTR_ERR(page);
2828 goto out;
2829 }
2830
2831 /* Guard against adverse ptrace interaction */
2832 rv = mutex_lock_interruptible(¤t->signal->cred_guard_mutex);
2833 if (rv < 0)
2834 goto out_free;
2835
2836 rv = security_setprocattr(PROC_I(inode)->op.lsmid,
2837 file->f_path.dentry->d_name.name, page,
2838 count);
2839 mutex_unlock(¤t->signal->cred_guard_mutex);
2840 out_free:
2841 kfree(page);
2842 out:
2843 return rv;
2844 }
2845
2846 static const struct file_operations proc_pid_attr_operations = {
2847 .open = proc_pid_attr_open,
2848 .read = proc_pid_attr_read,
2849 .write = proc_pid_attr_write,
2850 .llseek = generic_file_llseek,
2851 .release = mem_release,
2852 };
2853
2854 #define LSM_DIR_OPS(LSM) \
2855 static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2856 struct dir_context *ctx) \
2857 { \
2858 return proc_pident_readdir(filp, ctx, \
2859 LSM##_attr_dir_stuff, \
2860 ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2861 } \
2862 \
2863 static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2864 .read = generic_read_dir, \
2865 .iterate_shared = proc_##LSM##_attr_dir_iterate, \
2866 .llseek = default_llseek, \
2867 }; \
2868 \
2869 static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2870 struct dentry *dentry, unsigned int flags) \
2871 { \
2872 return proc_pident_lookup(dir, dentry, \
2873 LSM##_attr_dir_stuff, \
2874 LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2875 } \
2876 \
2877 static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2878 .lookup = proc_##LSM##_attr_dir_lookup, \
2879 .getattr = pid_getattr, \
2880 .setattr = proc_setattr, \
2881 }
2882
2883 #ifdef CONFIG_SECURITY_SMACK
2884 static const struct pid_entry smack_attr_dir_stuff[] = {
2885 ATTR(LSM_ID_SMACK, "current", 0666),
2886 };
2887 LSM_DIR_OPS(smack);
2888 #endif
2889
2890 #ifdef CONFIG_SECURITY_APPARMOR
2891 static const struct pid_entry apparmor_attr_dir_stuff[] = {
2892 ATTR(LSM_ID_APPARMOR, "current", 0666),
2893 ATTR(LSM_ID_APPARMOR, "prev", 0444),
2894 ATTR(LSM_ID_APPARMOR, "exec", 0666),
2895 };
2896 LSM_DIR_OPS(apparmor);
2897 #endif
2898
2899 static const struct pid_entry attr_dir_stuff[] = {
2900 ATTR(LSM_ID_UNDEF, "current", 0666),
2901 ATTR(LSM_ID_UNDEF, "prev", 0444),
2902 ATTR(LSM_ID_UNDEF, "exec", 0666),
2903 ATTR(LSM_ID_UNDEF, "fscreate", 0666),
2904 ATTR(LSM_ID_UNDEF, "keycreate", 0666),
2905 ATTR(LSM_ID_UNDEF, "sockcreate", 0666),
2906 #ifdef CONFIG_SECURITY_SMACK
2907 DIR("smack", 0555,
2908 proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2909 #endif
2910 #ifdef CONFIG_SECURITY_APPARMOR
2911 DIR("apparmor", 0555,
2912 proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
2913 #endif
2914 };
2915
proc_attr_dir_readdir(struct file * file,struct dir_context * ctx)2916 static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2917 {
2918 return proc_pident_readdir(file, ctx,
2919 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2920 }
2921
2922 static const struct file_operations proc_attr_dir_operations = {
2923 .read = generic_read_dir,
2924 .iterate_shared = proc_attr_dir_readdir,
2925 .llseek = generic_file_llseek,
2926 };
2927
proc_attr_dir_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)2928 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2929 struct dentry *dentry, unsigned int flags)
2930 {
2931 return proc_pident_lookup(dir, dentry,
2932 attr_dir_stuff,
2933 attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2934 }
2935
2936 static const struct inode_operations proc_attr_dir_inode_operations = {
2937 .lookup = proc_attr_dir_lookup,
2938 .getattr = pid_getattr,
2939 .setattr = proc_setattr,
2940 };
2941
2942 #endif
2943
2944 #ifdef CONFIG_ELF_CORE
proc_coredump_filter_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)2945 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2946 size_t count, loff_t *ppos)
2947 {
2948 struct task_struct *task = get_proc_task(file_inode(file));
2949 struct mm_struct *mm;
2950 char buffer[PROC_NUMBUF];
2951 size_t len;
2952 int ret;
2953
2954 if (!task)
2955 return -ESRCH;
2956
2957 ret = 0;
2958 mm = get_task_mm(task);
2959 if (mm) {
2960 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2961 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2962 MMF_DUMP_FILTER_SHIFT));
2963 mmput(mm);
2964 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2965 }
2966
2967 put_task_struct(task);
2968
2969 return ret;
2970 }
2971
proc_coredump_filter_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2972 static ssize_t proc_coredump_filter_write(struct file *file,
2973 const char __user *buf,
2974 size_t count,
2975 loff_t *ppos)
2976 {
2977 struct task_struct *task;
2978 struct mm_struct *mm;
2979 unsigned int val;
2980 int ret;
2981 int i;
2982 unsigned long mask;
2983
2984 ret = kstrtouint_from_user(buf, count, 0, &val);
2985 if (ret < 0)
2986 return ret;
2987
2988 ret = -ESRCH;
2989 task = get_proc_task(file_inode(file));
2990 if (!task)
2991 goto out_no_task;
2992
2993 mm = get_task_mm(task);
2994 if (!mm)
2995 goto out_no_mm;
2996 ret = 0;
2997
2998 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2999 if (val & mask)
3000 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
3001 else
3002 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
3003 }
3004
3005 mmput(mm);
3006 out_no_mm:
3007 put_task_struct(task);
3008 out_no_task:
3009 if (ret < 0)
3010 return ret;
3011 return count;
3012 }
3013
3014 static const struct file_operations proc_coredump_filter_operations = {
3015 .read = proc_coredump_filter_read,
3016 .write = proc_coredump_filter_write,
3017 .llseek = generic_file_llseek,
3018 };
3019 #endif
3020
3021 #ifdef CONFIG_TASK_IO_ACCOUNTING
do_io_accounting(struct task_struct * task,struct seq_file * m,int whole)3022 static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
3023 {
3024 struct task_io_accounting acct;
3025 int result;
3026
3027 result = down_read_killable(&task->signal->exec_update_lock);
3028 if (result)
3029 return result;
3030
3031 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
3032 result = -EACCES;
3033 goto out_unlock;
3034 }
3035
3036 if (whole) {
3037 struct signal_struct *sig = task->signal;
3038 struct task_struct *t;
3039 unsigned int seq = 1;
3040 unsigned long flags;
3041
3042 rcu_read_lock();
3043 do {
3044 seq++; /* 2 on the 1st/lockless path, otherwise odd */
3045 flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq);
3046
3047 acct = sig->ioac;
3048 __for_each_thread(sig, t)
3049 task_io_accounting_add(&acct, &t->ioac);
3050
3051 } while (need_seqretry(&sig->stats_lock, seq));
3052 done_seqretry_irqrestore(&sig->stats_lock, seq, flags);
3053 rcu_read_unlock();
3054 } else {
3055 acct = task->ioac;
3056 }
3057
3058 seq_printf(m,
3059 "rchar: %llu\n"
3060 "wchar: %llu\n"
3061 "syscr: %llu\n"
3062 "syscw: %llu\n"
3063 "read_bytes: %llu\n"
3064 "write_bytes: %llu\n"
3065 "cancelled_write_bytes: %llu\n",
3066 (unsigned long long)acct.rchar,
3067 (unsigned long long)acct.wchar,
3068 (unsigned long long)acct.syscr,
3069 (unsigned long long)acct.syscw,
3070 (unsigned long long)acct.read_bytes,
3071 (unsigned long long)acct.write_bytes,
3072 (unsigned long long)acct.cancelled_write_bytes);
3073 result = 0;
3074
3075 out_unlock:
3076 up_read(&task->signal->exec_update_lock);
3077 return result;
3078 }
3079
proc_tid_io_accounting(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3080 static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
3081 struct pid *pid, struct task_struct *task)
3082 {
3083 return do_io_accounting(task, m, 0);
3084 }
3085
proc_tgid_io_accounting(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3086 static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
3087 struct pid *pid, struct task_struct *task)
3088 {
3089 return do_io_accounting(task, m, 1);
3090 }
3091 #endif /* CONFIG_TASK_IO_ACCOUNTING */
3092
3093 #ifdef CONFIG_USER_NS
proc_id_map_open(struct inode * inode,struct file * file,const struct seq_operations * seq_ops)3094 static int proc_id_map_open(struct inode *inode, struct file *file,
3095 const struct seq_operations *seq_ops)
3096 {
3097 struct user_namespace *ns = NULL;
3098 struct task_struct *task;
3099 struct seq_file *seq;
3100 int ret = -EINVAL;
3101
3102 task = get_proc_task(inode);
3103 if (task) {
3104 rcu_read_lock();
3105 ns = get_user_ns(task_cred_xxx(task, user_ns));
3106 rcu_read_unlock();
3107 put_task_struct(task);
3108 }
3109 if (!ns)
3110 goto err;
3111
3112 ret = seq_open(file, seq_ops);
3113 if (ret)
3114 goto err_put_ns;
3115
3116 seq = file->private_data;
3117 seq->private = ns;
3118
3119 return 0;
3120 err_put_ns:
3121 put_user_ns(ns);
3122 err:
3123 return ret;
3124 }
3125
proc_id_map_release(struct inode * inode,struct file * file)3126 static int proc_id_map_release(struct inode *inode, struct file *file)
3127 {
3128 struct seq_file *seq = file->private_data;
3129 struct user_namespace *ns = seq->private;
3130 put_user_ns(ns);
3131 return seq_release(inode, file);
3132 }
3133
proc_uid_map_open(struct inode * inode,struct file * file)3134 static int proc_uid_map_open(struct inode *inode, struct file *file)
3135 {
3136 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
3137 }
3138
proc_gid_map_open(struct inode * inode,struct file * file)3139 static int proc_gid_map_open(struct inode *inode, struct file *file)
3140 {
3141 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
3142 }
3143
proc_projid_map_open(struct inode * inode,struct file * file)3144 static int proc_projid_map_open(struct inode *inode, struct file *file)
3145 {
3146 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
3147 }
3148
3149 static const struct file_operations proc_uid_map_operations = {
3150 .open = proc_uid_map_open,
3151 .write = proc_uid_map_write,
3152 .read = seq_read,
3153 .llseek = seq_lseek,
3154 .release = proc_id_map_release,
3155 };
3156
3157 static const struct file_operations proc_gid_map_operations = {
3158 .open = proc_gid_map_open,
3159 .write = proc_gid_map_write,
3160 .read = seq_read,
3161 .llseek = seq_lseek,
3162 .release = proc_id_map_release,
3163 };
3164
3165 static const struct file_operations proc_projid_map_operations = {
3166 .open = proc_projid_map_open,
3167 .write = proc_projid_map_write,
3168 .read = seq_read,
3169 .llseek = seq_lseek,
3170 .release = proc_id_map_release,
3171 };
3172
proc_setgroups_open(struct inode * inode,struct file * file)3173 static int proc_setgroups_open(struct inode *inode, struct file *file)
3174 {
3175 struct user_namespace *ns = NULL;
3176 struct task_struct *task;
3177 int ret;
3178
3179 ret = -ESRCH;
3180 task = get_proc_task(inode);
3181 if (task) {
3182 rcu_read_lock();
3183 ns = get_user_ns(task_cred_xxx(task, user_ns));
3184 rcu_read_unlock();
3185 put_task_struct(task);
3186 }
3187 if (!ns)
3188 goto err;
3189
3190 if (file->f_mode & FMODE_WRITE) {
3191 ret = -EACCES;
3192 if (!ns_capable(ns, CAP_SYS_ADMIN))
3193 goto err_put_ns;
3194 }
3195
3196 ret = single_open(file, &proc_setgroups_show, ns);
3197 if (ret)
3198 goto err_put_ns;
3199
3200 return 0;
3201 err_put_ns:
3202 put_user_ns(ns);
3203 err:
3204 return ret;
3205 }
3206
proc_setgroups_release(struct inode * inode,struct file * file)3207 static int proc_setgroups_release(struct inode *inode, struct file *file)
3208 {
3209 struct seq_file *seq = file->private_data;
3210 struct user_namespace *ns = seq->private;
3211 int ret = single_release(inode, file);
3212 put_user_ns(ns);
3213 return ret;
3214 }
3215
3216 static const struct file_operations proc_setgroups_operations = {
3217 .open = proc_setgroups_open,
3218 .write = proc_setgroups_write,
3219 .read = seq_read,
3220 .llseek = seq_lseek,
3221 .release = proc_setgroups_release,
3222 };
3223 #endif /* CONFIG_USER_NS */
3224
proc_pid_personality(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3225 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3226 struct pid *pid, struct task_struct *task)
3227 {
3228 int err = lock_trace(task);
3229 if (!err) {
3230 seq_printf(m, "%08x\n", task->personality);
3231 unlock_trace(task);
3232 }
3233 return err;
3234 }
3235
3236 #ifdef CONFIG_LIVEPATCH
proc_pid_patch_state(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3237 static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
3238 struct pid *pid, struct task_struct *task)
3239 {
3240 seq_printf(m, "%d\n", task->patch_state);
3241 return 0;
3242 }
3243 #endif /* CONFIG_LIVEPATCH */
3244
3245 #ifdef CONFIG_KSM
proc_pid_ksm_merging_pages(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3246 static int proc_pid_ksm_merging_pages(struct seq_file *m, struct pid_namespace *ns,
3247 struct pid *pid, struct task_struct *task)
3248 {
3249 struct mm_struct *mm;
3250
3251 mm = get_task_mm(task);
3252 if (mm) {
3253 seq_printf(m, "%lu\n", mm->ksm_merging_pages);
3254 mmput(mm);
3255 }
3256
3257 return 0;
3258 }
proc_pid_ksm_stat(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3259 static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns,
3260 struct pid *pid, struct task_struct *task)
3261 {
3262 struct mm_struct *mm;
3263 int ret = 0;
3264
3265 mm = get_task_mm(task);
3266 if (mm) {
3267 seq_printf(m, "ksm_rmap_items %lu\n", mm->ksm_rmap_items);
3268 seq_printf(m, "ksm_zero_pages %ld\n", mm_ksm_zero_pages(mm));
3269 seq_printf(m, "ksm_merging_pages %lu\n", mm->ksm_merging_pages);
3270 seq_printf(m, "ksm_process_profit %ld\n", ksm_process_profit(mm));
3271 seq_printf(m, "ksm_merge_any: %s\n",
3272 test_bit(MMF_VM_MERGE_ANY, &mm->flags) ? "yes" : "no");
3273 ret = mmap_read_lock_killable(mm);
3274 if (ret) {
3275 mmput(mm);
3276 return ret;
3277 }
3278 seq_printf(m, "ksm_mergeable: %s\n",
3279 ksm_process_mergeable(mm) ? "yes" : "no");
3280 mmap_read_unlock(mm);
3281 mmput(mm);
3282 }
3283
3284 return 0;
3285 }
3286 #endif /* CONFIG_KSM */
3287
3288 #ifdef CONFIG_STACKLEAK_METRICS
proc_stack_depth(struct seq_file * m,struct pid_namespace * ns,struct pid * pid,struct task_struct * task)3289 static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
3290 struct pid *pid, struct task_struct *task)
3291 {
3292 unsigned long prev_depth = THREAD_SIZE -
3293 (task->prev_lowest_stack & (THREAD_SIZE - 1));
3294 unsigned long depth = THREAD_SIZE -
3295 (task->lowest_stack & (THREAD_SIZE - 1));
3296
3297 seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
3298 prev_depth, depth);
3299 return 0;
3300 }
3301 #endif /* CONFIG_STACKLEAK_METRICS */
3302
3303 /*
3304 * Thread groups
3305 */
3306 static const struct file_operations proc_task_operations;
3307 static const struct inode_operations proc_task_inode_operations;
3308
3309 static const struct pid_entry tgid_base_stuff[] = {
3310 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3311 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3312 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3313 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3314 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3315 #ifdef CONFIG_NET
3316 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3317 #endif
3318 REG("environ", S_IRUSR, proc_environ_operations),
3319 REG("auxv", S_IRUSR, proc_auxv_operations),
3320 ONE("status", S_IRUGO, proc_pid_status),
3321 ONE("personality", S_IRUSR, proc_pid_personality),
3322 ONE("limits", S_IRUGO, proc_pid_limits),
3323 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3324 #ifdef CONFIG_SCHED_AUTOGROUP
3325 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3326 #endif
3327 #ifdef CONFIG_TIME_NS
3328 REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
3329 #endif
3330 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3331 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3332 ONE("syscall", S_IRUSR, proc_pid_syscall),
3333 #endif
3334 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3335 ONE("stat", S_IRUGO, proc_tgid_stat),
3336 ONE("statm", S_IRUGO, proc_pid_statm),
3337 REG("maps", S_IRUGO, proc_pid_maps_operations),
3338 #ifdef CONFIG_NUMA
3339 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3340 #endif
3341 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3342 LNK("cwd", proc_cwd_link),
3343 LNK("root", proc_root_link),
3344 LNK("exe", proc_exe_link),
3345 REG("mounts", S_IRUGO, proc_mounts_operations),
3346 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3347 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3348 #ifdef CONFIG_PROC_PAGE_MONITOR
3349 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3350 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3351 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3352 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3353 #endif
3354 #ifdef CONFIG_SECURITY
3355 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3356 #endif
3357 #ifdef CONFIG_KALLSYMS
3358 ONE("wchan", S_IRUGO, proc_pid_wchan),
3359 #endif
3360 #ifdef CONFIG_STACKTRACE
3361 ONE("stack", S_IRUSR, proc_pid_stack),
3362 #endif
3363 #ifdef CONFIG_SCHED_INFO
3364 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3365 #endif
3366 #ifdef CONFIG_LATENCYTOP
3367 REG("latency", S_IRUGO, proc_lstats_operations),
3368 #endif
3369 #ifdef CONFIG_PROC_PID_CPUSET
3370 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3371 #endif
3372 #ifdef CONFIG_CGROUPS
3373 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3374 #endif
3375 #ifdef CONFIG_PROC_CPU_RESCTRL
3376 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3377 #endif
3378 ONE("oom_score", S_IRUGO, proc_oom_score),
3379 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3380 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3381 #ifdef CONFIG_AUDIT
3382 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3383 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3384 #endif
3385 #ifdef CONFIG_FAULT_INJECTION
3386 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3387 REG("fail-nth", 0644, proc_fail_nth_operations),
3388 #endif
3389 #ifdef CONFIG_ELF_CORE
3390 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3391 #endif
3392 #ifdef CONFIG_TASK_IO_ACCOUNTING
3393 ONE("io", S_IRUSR, proc_tgid_io_accounting),
3394 #endif
3395 #ifdef CONFIG_USER_NS
3396 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3397 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3398 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3399 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3400 #endif
3401 #if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3402 REG("timers", S_IRUGO, proc_timers_operations),
3403 #endif
3404 REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3405 #ifdef CONFIG_LIVEPATCH
3406 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3407 #endif
3408 #ifdef CONFIG_STACKLEAK_METRICS
3409 ONE("stack_depth", S_IRUGO, proc_stack_depth),
3410 #endif
3411 #ifdef CONFIG_PROC_PID_ARCH_STATUS
3412 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3413 #endif
3414 #ifdef CONFIG_SECCOMP_CACHE_DEBUG
3415 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3416 #endif
3417 #ifdef CONFIG_KSM
3418 ONE("ksm_merging_pages", S_IRUSR, proc_pid_ksm_merging_pages),
3419 ONE("ksm_stat", S_IRUSR, proc_pid_ksm_stat),
3420 #endif
3421 };
3422
proc_tgid_base_readdir(struct file * file,struct dir_context * ctx)3423 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
3424 {
3425 return proc_pident_readdir(file, ctx,
3426 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3427 }
3428
3429 static const struct file_operations proc_tgid_base_operations = {
3430 .read = generic_read_dir,
3431 .iterate_shared = proc_tgid_base_readdir,
3432 .llseek = generic_file_llseek,
3433 };
3434
tgid_pidfd_to_pid(const struct file * file)3435 struct pid *tgid_pidfd_to_pid(const struct file *file)
3436 {
3437 if (file->f_op != &proc_tgid_base_operations)
3438 return ERR_PTR(-EBADF);
3439
3440 return proc_pid(file_inode(file));
3441 }
3442
proc_tgid_base_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)3443 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3444 {
3445 return proc_pident_lookup(dir, dentry,
3446 tgid_base_stuff,
3447 tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3448 }
3449
3450 static const struct inode_operations proc_tgid_base_inode_operations = {
3451 .lookup = proc_tgid_base_lookup,
3452 .getattr = pid_getattr,
3453 .setattr = proc_setattr,
3454 .permission = proc_pid_permission,
3455 };
3456
3457 /**
3458 * proc_flush_pid - Remove dcache entries for @pid from the /proc dcache.
3459 * @pid: pid that should be flushed.
3460 *
3461 * This function walks a list of inodes (that belong to any proc
3462 * filesystem) that are attached to the pid and flushes them from
3463 * the dentry cache.
3464 *
3465 * It is safe and reasonable to cache /proc entries for a task until
3466 * that task exits. After that they just clog up the dcache with
3467 * useless entries, possibly causing useful dcache entries to be
3468 * flushed instead. This routine is provided to flush those useless
3469 * dcache entries when a process is reaped.
3470 *
3471 * NOTE: This routine is just an optimization so it does not guarantee
3472 * that no dcache entries will exist after a process is reaped
3473 * it just makes it very unlikely that any will persist.
3474 */
3475
proc_flush_pid(struct pid * pid)3476 void proc_flush_pid(struct pid *pid)
3477 {
3478 proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
3479 }
3480
proc_pid_instantiate(struct dentry * dentry,struct task_struct * task,const void * ptr)3481 static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3482 struct task_struct *task, const void *ptr)
3483 {
3484 struct inode *inode;
3485
3486 inode = proc_pid_make_base_inode(dentry->d_sb, task,
3487 S_IFDIR | S_IRUGO | S_IXUGO);
3488 if (!inode)
3489 return ERR_PTR(-ENOENT);
3490
3491 inode->i_op = &proc_tgid_base_inode_operations;
3492 inode->i_fop = &proc_tgid_base_operations;
3493 inode->i_flags|=S_IMMUTABLE;
3494
3495 set_nlink(inode, nlink_tgid);
3496 pid_update_inode(task, inode);
3497
3498 d_set_d_op(dentry, &pid_dentry_operations);
3499 return d_splice_alias(inode, dentry);
3500 }
3501
proc_pid_lookup(struct dentry * dentry,unsigned int flags)3502 struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3503 {
3504 struct task_struct *task;
3505 unsigned tgid;
3506 struct proc_fs_info *fs_info;
3507 struct pid_namespace *ns;
3508 struct dentry *result = ERR_PTR(-ENOENT);
3509
3510 tgid = name_to_int(&dentry->d_name);
3511 if (tgid == ~0U)
3512 goto out;
3513
3514 fs_info = proc_sb_info(dentry->d_sb);
3515 ns = fs_info->pid_ns;
3516 rcu_read_lock();
3517 task = find_task_by_pid_ns(tgid, ns);
3518 if (task)
3519 get_task_struct(task);
3520 rcu_read_unlock();
3521 if (!task)
3522 goto out;
3523
3524 /* Limit procfs to only ptraceable tasks */
3525 if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) {
3526 if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
3527 goto out_put_task;
3528 }
3529
3530 result = proc_pid_instantiate(dentry, task, NULL);
3531 out_put_task:
3532 put_task_struct(task);
3533 out:
3534 return result;
3535 }
3536
3537 /*
3538 * Find the first task with tgid >= tgid
3539 *
3540 */
3541 struct tgid_iter {
3542 unsigned int tgid;
3543 struct task_struct *task;
3544 };
next_tgid(struct pid_namespace * ns,struct tgid_iter iter)3545 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3546 {
3547 struct pid *pid;
3548
3549 if (iter.task)
3550 put_task_struct(iter.task);
3551 rcu_read_lock();
3552 retry:
3553 iter.task = NULL;
3554 pid = find_ge_pid(iter.tgid, ns);
3555 if (pid) {
3556 iter.tgid = pid_nr_ns(pid, ns);
3557 iter.task = pid_task(pid, PIDTYPE_TGID);
3558 if (!iter.task) {
3559 iter.tgid += 1;
3560 goto retry;
3561 }
3562 get_task_struct(iter.task);
3563 }
3564 rcu_read_unlock();
3565 return iter;
3566 }
3567
3568 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
3569
3570 /* for the /proc/ directory itself, after non-process stuff has been done */
proc_pid_readdir(struct file * file,struct dir_context * ctx)3571 int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3572 {
3573 struct tgid_iter iter;
3574 struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
3575 struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb);
3576 loff_t pos = ctx->pos;
3577
3578 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3579 return 0;
3580
3581 if (pos == TGID_OFFSET - 2) {
3582 struct inode *inode = d_inode(fs_info->proc_self);
3583 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3584 return 0;
3585 ctx->pos = pos = pos + 1;
3586 }
3587 if (pos == TGID_OFFSET - 1) {
3588 struct inode *inode = d_inode(fs_info->proc_thread_self);
3589 if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3590 return 0;
3591 ctx->pos = pos = pos + 1;
3592 }
3593 iter.tgid = pos - TGID_OFFSET;
3594 iter.task = NULL;
3595 for (iter = next_tgid(ns, iter);
3596 iter.task;
3597 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3598 char name[10 + 1];
3599 unsigned int len;
3600
3601 cond_resched();
3602 if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE))
3603 continue;
3604
3605 len = snprintf(name, sizeof(name), "%u", iter.tgid);
3606 ctx->pos = iter.tgid + TGID_OFFSET;
3607 if (!proc_fill_cache(file, ctx, name, len,
3608 proc_pid_instantiate, iter.task, NULL)) {
3609 put_task_struct(iter.task);
3610 return 0;
3611 }
3612 }
3613 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
3614 return 0;
3615 }
3616
3617 /*
3618 * proc_tid_comm_permission is a special permission function exclusively
3619 * used for the node /proc/<pid>/task/<tid>/comm.
3620 * It bypasses generic permission checks in the case where a task of the same
3621 * task group attempts to access the node.
3622 * The rationale behind this is that glibc and bionic access this node for
3623 * cross thread naming (pthread_set/getname_np(!self)). However, if
3624 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3625 * which locks out the cross thread naming implementation.
3626 * This function makes sure that the node is always accessible for members of
3627 * same thread group.
3628 */
proc_tid_comm_permission(struct mnt_idmap * idmap,struct inode * inode,int mask)3629 static int proc_tid_comm_permission(struct mnt_idmap *idmap,
3630 struct inode *inode, int mask)
3631 {
3632 bool is_same_tgroup;
3633 struct task_struct *task;
3634
3635 task = get_proc_task(inode);
3636 if (!task)
3637 return -ESRCH;
3638 is_same_tgroup = same_thread_group(current, task);
3639 put_task_struct(task);
3640
3641 if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3642 /* This file (/proc/<pid>/task/<tid>/comm) can always be
3643 * read or written by the members of the corresponding
3644 * thread group.
3645 */
3646 return 0;
3647 }
3648
3649 return generic_permission(&nop_mnt_idmap, inode, mask);
3650 }
3651
3652 static const struct inode_operations proc_tid_comm_inode_operations = {
3653 .setattr = proc_setattr,
3654 .permission = proc_tid_comm_permission,
3655 };
3656
3657 /*
3658 * Tasks
3659 */
3660 static const struct pid_entry tid_base_stuff[] = {
3661 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3662 DIR("fdinfo", S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3663 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3664 #ifdef CONFIG_NET
3665 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3666 #endif
3667 REG("environ", S_IRUSR, proc_environ_operations),
3668 REG("auxv", S_IRUSR, proc_auxv_operations),
3669 ONE("status", S_IRUGO, proc_pid_status),
3670 ONE("personality", S_IRUSR, proc_pid_personality),
3671 ONE("limits", S_IRUGO, proc_pid_limits),
3672 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3673 NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
3674 &proc_tid_comm_inode_operations,
3675 &proc_pid_set_comm_operations, {}),
3676 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3677 ONE("syscall", S_IRUSR, proc_pid_syscall),
3678 #endif
3679 REG("cmdline", S_IRUGO, proc_pid_cmdline_ops),
3680 ONE("stat", S_IRUGO, proc_tid_stat),
3681 ONE("statm", S_IRUGO, proc_pid_statm),
3682 REG("maps", S_IRUGO, proc_pid_maps_operations),
3683 #ifdef CONFIG_PROC_CHILDREN
3684 REG("children", S_IRUGO, proc_tid_children_operations),
3685 #endif
3686 #ifdef CONFIG_NUMA
3687 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3688 #endif
3689 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3690 LNK("cwd", proc_cwd_link),
3691 LNK("root", proc_root_link),
3692 LNK("exe", proc_exe_link),
3693 REG("mounts", S_IRUGO, proc_mounts_operations),
3694 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3695 #ifdef CONFIG_PROC_PAGE_MONITOR
3696 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3697 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3698 REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3699 REG("pagemap", S_IRUSR, proc_pagemap_operations),
3700 #endif
3701 #ifdef CONFIG_SECURITY
3702 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3703 #endif
3704 #ifdef CONFIG_KALLSYMS
3705 ONE("wchan", S_IRUGO, proc_pid_wchan),
3706 #endif
3707 #ifdef CONFIG_STACKTRACE
3708 ONE("stack", S_IRUSR, proc_pid_stack),
3709 #endif
3710 #ifdef CONFIG_SCHED_INFO
3711 ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3712 #endif
3713 #ifdef CONFIG_LATENCYTOP
3714 REG("latency", S_IRUGO, proc_lstats_operations),
3715 #endif
3716 #ifdef CONFIG_PROC_PID_CPUSET
3717 ONE("cpuset", S_IRUGO, proc_cpuset_show),
3718 #endif
3719 #ifdef CONFIG_CGROUPS
3720 ONE("cgroup", S_IRUGO, proc_cgroup_show),
3721 #endif
3722 #ifdef CONFIG_PROC_CPU_RESCTRL
3723 ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3724 #endif
3725 ONE("oom_score", S_IRUGO, proc_oom_score),
3726 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3727 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3728 #ifdef CONFIG_AUDIT
3729 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3730 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3731 #endif
3732 #ifdef CONFIG_FAULT_INJECTION
3733 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3734 REG("fail-nth", 0644, proc_fail_nth_operations),
3735 #endif
3736 #ifdef CONFIG_TASK_IO_ACCOUNTING
3737 ONE("io", S_IRUSR, proc_tid_io_accounting),
3738 #endif
3739 #ifdef CONFIG_USER_NS
3740 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3741 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3742 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3743 REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
3744 #endif
3745 #ifdef CONFIG_LIVEPATCH
3746 ONE("patch_state", S_IRUSR, proc_pid_patch_state),
3747 #endif
3748 #ifdef CONFIG_PROC_PID_ARCH_STATUS
3749 ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3750 #endif
3751 #ifdef CONFIG_SECCOMP_CACHE_DEBUG
3752 ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
3753 #endif
3754 #ifdef CONFIG_KSM
3755 ONE("ksm_merging_pages", S_IRUSR, proc_pid_ksm_merging_pages),
3756 ONE("ksm_stat", S_IRUSR, proc_pid_ksm_stat),
3757 #endif
3758 };
3759
proc_tid_base_readdir(struct file * file,struct dir_context * ctx)3760 static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
3761 {
3762 return proc_pident_readdir(file, ctx,
3763 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3764 }
3765
proc_tid_base_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)3766 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3767 {
3768 return proc_pident_lookup(dir, dentry,
3769 tid_base_stuff,
3770 tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3771 }
3772
3773 static const struct file_operations proc_tid_base_operations = {
3774 .read = generic_read_dir,
3775 .iterate_shared = proc_tid_base_readdir,
3776 .llseek = generic_file_llseek,
3777 };
3778
3779 static const struct inode_operations proc_tid_base_inode_operations = {
3780 .lookup = proc_tid_base_lookup,
3781 .getattr = pid_getattr,
3782 .setattr = proc_setattr,
3783 };
3784
proc_task_instantiate(struct dentry * dentry,struct task_struct * task,const void * ptr)3785 static struct dentry *proc_task_instantiate(struct dentry *dentry,
3786 struct task_struct *task, const void *ptr)
3787 {
3788 struct inode *inode;
3789 inode = proc_pid_make_base_inode(dentry->d_sb, task,
3790 S_IFDIR | S_IRUGO | S_IXUGO);
3791 if (!inode)
3792 return ERR_PTR(-ENOENT);
3793
3794 inode->i_op = &proc_tid_base_inode_operations;
3795 inode->i_fop = &proc_tid_base_operations;
3796 inode->i_flags |= S_IMMUTABLE;
3797
3798 set_nlink(inode, nlink_tid);
3799 pid_update_inode(task, inode);
3800
3801 d_set_d_op(dentry, &pid_dentry_operations);
3802 return d_splice_alias(inode, dentry);
3803 }
3804
proc_task_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)3805 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3806 {
3807 struct task_struct *task;
3808 struct task_struct *leader = get_proc_task(dir);
3809 unsigned tid;
3810 struct proc_fs_info *fs_info;
3811 struct pid_namespace *ns;
3812 struct dentry *result = ERR_PTR(-ENOENT);
3813
3814 if (!leader)
3815 goto out_no_task;
3816
3817 tid = name_to_int(&dentry->d_name);
3818 if (tid == ~0U)
3819 goto out;
3820
3821 fs_info = proc_sb_info(dentry->d_sb);
3822 ns = fs_info->pid_ns;
3823 rcu_read_lock();
3824 task = find_task_by_pid_ns(tid, ns);
3825 if (task)
3826 get_task_struct(task);
3827 rcu_read_unlock();
3828 if (!task)
3829 goto out;
3830 if (!same_thread_group(leader, task))
3831 goto out_drop_task;
3832
3833 result = proc_task_instantiate(dentry, task, NULL);
3834 out_drop_task:
3835 put_task_struct(task);
3836 out:
3837 put_task_struct(leader);
3838 out_no_task:
3839 return result;
3840 }
3841
3842 /*
3843 * Find the first tid of a thread group to return to user space.
3844 *
3845 * Usually this is just the thread group leader, but if the users
3846 * buffer was too small or there was a seek into the middle of the
3847 * directory we have more work todo.
3848 *
3849 * In the case of a short read we start with find_task_by_pid.
3850 *
3851 * In the case of a seek we start with the leader and walk nr
3852 * threads past it.
3853 */
first_tid(struct pid * pid,int tid,loff_t f_pos,struct pid_namespace * ns)3854 static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3855 struct pid_namespace *ns)
3856 {
3857 struct task_struct *pos, *task;
3858 unsigned long nr = f_pos;
3859
3860 if (nr != f_pos) /* 32bit overflow? */
3861 return NULL;
3862
3863 rcu_read_lock();
3864 task = pid_task(pid, PIDTYPE_PID);
3865 if (!task)
3866 goto fail;
3867
3868 /* Attempt to start with the tid of a thread */
3869 if (tid && nr) {
3870 pos = find_task_by_pid_ns(tid, ns);
3871 if (pos && same_thread_group(pos, task))
3872 goto found;
3873 }
3874
3875 /* If nr exceeds the number of threads there is nothing todo */
3876 if (nr >= get_nr_threads(task))
3877 goto fail;
3878
3879 /* If we haven't found our starting place yet start
3880 * with the leader and walk nr threads forward.
3881 */
3882 for_each_thread(task, pos) {
3883 if (!nr--)
3884 goto found;
3885 }
3886 fail:
3887 pos = NULL;
3888 goto out;
3889 found:
3890 get_task_struct(pos);
3891 out:
3892 rcu_read_unlock();
3893 return pos;
3894 }
3895
3896 /*
3897 * Find the next thread in the thread list.
3898 * Return NULL if there is an error or no next thread.
3899 *
3900 * The reference to the input task_struct is released.
3901 */
next_tid(struct task_struct * start)3902 static struct task_struct *next_tid(struct task_struct *start)
3903 {
3904 struct task_struct *pos = NULL;
3905 rcu_read_lock();
3906 if (pid_alive(start)) {
3907 pos = __next_thread(start);
3908 if (pos)
3909 get_task_struct(pos);
3910 }
3911 rcu_read_unlock();
3912 put_task_struct(start);
3913 return pos;
3914 }
3915
3916 /* for the /proc/TGID/task/ directories */
proc_task_readdir(struct file * file,struct dir_context * ctx)3917 static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3918 {
3919 struct inode *inode = file_inode(file);
3920 struct task_struct *task;
3921 struct pid_namespace *ns;
3922 int tid;
3923
3924 if (proc_inode_is_dead(inode))
3925 return -ENOENT;
3926
3927 if (!dir_emit_dots(file, ctx))
3928 return 0;
3929
3930 /* We cache the tgid value that the last readdir call couldn't
3931 * return and lseek resets it to 0.
3932 */
3933 ns = proc_pid_ns(inode->i_sb);
3934 tid = (int)(intptr_t)file->private_data;
3935 file->private_data = NULL;
3936 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3937 task;
3938 task = next_tid(task), ctx->pos++) {
3939 char name[10 + 1];
3940 unsigned int len;
3941
3942 tid = task_pid_nr_ns(task, ns);
3943 if (!tid)
3944 continue; /* The task has just exited. */
3945 len = snprintf(name, sizeof(name), "%u", tid);
3946 if (!proc_fill_cache(file, ctx, name, len,
3947 proc_task_instantiate, task, NULL)) {
3948 /* returning this tgid failed, save it as the first
3949 * pid for the next readir call */
3950 file->private_data = (void *)(intptr_t)tid;
3951 put_task_struct(task);
3952 break;
3953 }
3954 }
3955
3956 return 0;
3957 }
3958
proc_task_getattr(struct mnt_idmap * idmap,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)3959 static int proc_task_getattr(struct mnt_idmap *idmap,
3960 const struct path *path, struct kstat *stat,
3961 u32 request_mask, unsigned int query_flags)
3962 {
3963 struct inode *inode = d_inode(path->dentry);
3964 struct task_struct *p = get_proc_task(inode);
3965 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
3966
3967 if (p) {
3968 stat->nlink += get_nr_threads(p);
3969 put_task_struct(p);
3970 }
3971
3972 return 0;
3973 }
3974
3975 /*
3976 * proc_task_readdir() set @file->private_data to a positive integer
3977 * value, so casting that to u64 is safe. generic_llseek_cookie() will
3978 * set @cookie to 0, so casting to an int is safe. The WARN_ON_ONCE() is
3979 * here to catch any unexpected change in behavior either in
3980 * proc_task_readdir() or generic_llseek_cookie().
3981 */
proc_dir_llseek(struct file * file,loff_t offset,int whence)3982 static loff_t proc_dir_llseek(struct file *file, loff_t offset, int whence)
3983 {
3984 u64 cookie = (u64)(intptr_t)file->private_data;
3985 loff_t off;
3986
3987 off = generic_llseek_cookie(file, offset, whence, &cookie);
3988 WARN_ON_ONCE(cookie > INT_MAX);
3989 file->private_data = (void *)(intptr_t)cookie; /* serialized by f_pos_lock */
3990 return off;
3991 }
3992
3993 static const struct inode_operations proc_task_inode_operations = {
3994 .lookup = proc_task_lookup,
3995 .getattr = proc_task_getattr,
3996 .setattr = proc_setattr,
3997 .permission = proc_pid_permission,
3998 };
3999
4000 static const struct file_operations proc_task_operations = {
4001 .read = generic_read_dir,
4002 .iterate_shared = proc_task_readdir,
4003 .llseek = proc_dir_llseek,
4004 };
4005
set_proc_pid_nlink(void)4006 void __init set_proc_pid_nlink(void)
4007 {
4008 nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
4009 nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
4010 }
4011