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1/*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50#include <asm/uaccess.h>
51
52#include <linux/errno.h>
53#include <linux/time.h>
54#include <linux/proc_fs.h>
55#include <linux/stat.h>
56#include <linux/task_io_accounting_ops.h>
57#include <linux/init.h>
58#include <linux/capability.h>
59#include <linux/file.h>
60#include <linux/fdtable.h>
61#include <linux/string.h>
62#include <linux/seq_file.h>
63#include <linux/namei.h>
64#include <linux/mnt_namespace.h>
65#include <linux/mm.h>
66#include <linux/swap.h>
67#include <linux/rcupdate.h>
68#include <linux/kallsyms.h>
69#include <linux/stacktrace.h>
70#include <linux/resource.h>
71#include <linux/module.h>
72#include <linux/mount.h>
73#include <linux/security.h>
74#include <linux/ptrace.h>
75#include <linux/tracehook.h>
76#include <linux/cgroup.h>
77#include <linux/cpuset.h>
78#include <linux/audit.h>
79#include <linux/poll.h>
80#include <linux/nsproxy.h>
81#include <linux/oom.h>
82#include <linux/elf.h>
83#include <linux/pid_namespace.h>
84#include <linux/fs_struct.h>
85#include <linux/slab.h>
86#ifdef CONFIG_HARDWALL
87#include <asm/hardwall.h>
88#endif
89#include "internal.h"
90
91/* NOTE:
92 * Implementing inode permission operations in /proc is almost
93 * certainly an error. Permission checks need to happen during
94 * each system call not at open time. The reason is that most of
95 * what we wish to check for permissions in /proc varies at runtime.
96 *
97 * The classic example of a problem is opening file descriptors
98 * in /proc for a task before it execs a suid executable.
99 */
100
101struct pid_entry {
102 char *name;
103 int len;
104 mode_t mode;
105 const struct inode_operations *iop;
106 const struct file_operations *fop;
107 union proc_op op;
108};
109
110#define NOD(NAME, MODE, IOP, FOP, OP) { \
111 .name = (NAME), \
112 .len = sizeof(NAME) - 1, \
113 .mode = MODE, \
114 .iop = IOP, \
115 .fop = FOP, \
116 .op = OP, \
117}
118
119#define DIR(NAME, MODE, iops, fops) \
120 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
121#define LNK(NAME, get_link) \
122 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
123 &proc_pid_link_inode_operations, NULL, \
124 { .proc_get_link = get_link } )
125#define REG(NAME, MODE, fops) \
126 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
127#define INF(NAME, MODE, read) \
128 NOD(NAME, (S_IFREG|(MODE)), \
129 NULL, &proc_info_file_operations, \
130 { .proc_read = read } )
131#define ONE(NAME, MODE, show) \
132 NOD(NAME, (S_IFREG|(MODE)), \
133 NULL, &proc_single_file_operations, \
134 { .proc_show = show } )
135
136/*
137 * Count the number of hardlinks for the pid_entry table, excluding the .
138 * and .. links.
139 */
140static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
141 unsigned int n)
142{
143 unsigned int i;
144 unsigned int count;
145
146 count = 0;
147 for (i = 0; i < n; ++i) {
148 if (S_ISDIR(entries[i].mode))
149 ++count;
150 }
151
152 return count;
153}
154
155static int get_task_root(struct task_struct *task, struct path *root)
156{
157 int result = -ENOENT;
158
159 task_lock(task);
160 if (task->fs) {
161 get_fs_root(task->fs, root);
162 result = 0;
163 }
164 task_unlock(task);
165 return result;
166}
167
168static int proc_cwd_link(struct inode *inode, struct path *path)
169{
170 struct task_struct *task = get_proc_task(inode);
171 int result = -ENOENT;
172
173 if (task) {
174 task_lock(task);
175 if (task->fs) {
176 get_fs_pwd(task->fs, path);
177 result = 0;
178 }
179 task_unlock(task);
180 put_task_struct(task);
181 }
182 return result;
183}
184
185static int proc_root_link(struct inode *inode, struct path *path)
186{
187 struct task_struct *task = get_proc_task(inode);
188 int result = -ENOENT;
189
190 if (task) {
191 result = get_task_root(task, path);
192 put_task_struct(task);
193 }
194 return result;
195}
196
197static struct mm_struct *__check_mem_permission(struct task_struct *task)
198{
199 struct mm_struct *mm;
200
201 mm = get_task_mm(task);
202 if (!mm)
203 return ERR_PTR(-EINVAL);
204
205 /*
206 * A task can always look at itself, in case it chooses
207 * to use system calls instead of load instructions.
208 */
209 if (task == current)
210 return mm;
211
212 /*
213 * If current is actively ptrace'ing, and would also be
214 * permitted to freshly attach with ptrace now, permit it.
215 */
216 if (task_is_stopped_or_traced(task)) {
217 int match;
218 rcu_read_lock();
219 match = (ptrace_parent(task) == current);
220 rcu_read_unlock();
221 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
222 return mm;
223 }
224
225 /*
226 * No one else is allowed.
227 */
228 mmput(mm);
229 return ERR_PTR(-EPERM);
230}
231
232/*
233 * If current may access user memory in @task return a reference to the
234 * corresponding mm, otherwise ERR_PTR.
235 */
236static struct mm_struct *check_mem_permission(struct task_struct *task)
237{
238 struct mm_struct *mm;
239 int err;
240
241 /*
242 * Avoid racing if task exec's as we might get a new mm but validate
243 * against old credentials.
244 */
245 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
246 if (err)
247 return ERR_PTR(err);
248
249 mm = __check_mem_permission(task);
250 mutex_unlock(&task->signal->cred_guard_mutex);
251
252 return mm;
253}
254
255struct mm_struct *mm_for_maps(struct task_struct *task)
256{
257 struct mm_struct *mm;
258 int err;
259
260 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
261 if (err)
262 return ERR_PTR(err);
263
264 mm = get_task_mm(task);
265 if (mm && mm != current->mm &&
266 !ptrace_may_access(task, PTRACE_MODE_READ)) {
267 mmput(mm);
268 mm = ERR_PTR(-EACCES);
269 }
270 mutex_unlock(&task->signal->cred_guard_mutex);
271
272 return mm;
273}
274
275static int proc_pid_cmdline(struct task_struct *task, char * buffer)
276{
277 int res = 0;
278 unsigned int len;
279 struct mm_struct *mm = get_task_mm(task);
280 if (!mm)
281 goto out;
282 if (!mm->arg_end)
283 goto out_mm; /* Shh! No looking before we're done */
284
285 len = mm->arg_end - mm->arg_start;
286
287 if (len > PAGE_SIZE)
288 len = PAGE_SIZE;
289
290 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
291
292 // If the nul at the end of args has been overwritten, then
293 // assume application is using setproctitle(3).
294 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
295 len = strnlen(buffer, res);
296 if (len < res) {
297 res = len;
298 } else {
299 len = mm->env_end - mm->env_start;
300 if (len > PAGE_SIZE - res)
301 len = PAGE_SIZE - res;
302 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
303 res = strnlen(buffer, res);
304 }
305 }
306out_mm:
307 mmput(mm);
308out:
309 return res;
310}
311
312static int proc_pid_auxv(struct task_struct *task, char *buffer)
313{
314 struct mm_struct *mm = mm_for_maps(task);
315 int res = PTR_ERR(mm);
316 if (mm && !IS_ERR(mm)) {
317 unsigned int nwords = 0;
318 do {
319 nwords += 2;
320 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
321 res = nwords * sizeof(mm->saved_auxv[0]);
322 if (res > PAGE_SIZE)
323 res = PAGE_SIZE;
324 memcpy(buffer, mm->saved_auxv, res);
325 mmput(mm);
326 }
327 return res;
328}
329
330
331#ifdef CONFIG_KALLSYMS
332/*
333 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
334 * Returns the resolved symbol. If that fails, simply return the address.
335 */
336static int proc_pid_wchan(struct task_struct *task, char *buffer)
337{
338 unsigned long wchan;
339 char symname[KSYM_NAME_LEN];
340
341 wchan = get_wchan(task);
342
343 if (lookup_symbol_name(wchan, symname) < 0)
344 if (!ptrace_may_access(task, PTRACE_MODE_READ))
345 return 0;
346 else
347 return sprintf(buffer, "%lu", wchan);
348 else
349 return sprintf(buffer, "%s", symname);
350}
351#endif /* CONFIG_KALLSYMS */
352
353static int lock_trace(struct task_struct *task)
354{
355 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
356 if (err)
357 return err;
358 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
359 mutex_unlock(&task->signal->cred_guard_mutex);
360 return -EPERM;
361 }
362 return 0;
363}
364
365static void unlock_trace(struct task_struct *task)
366{
367 mutex_unlock(&task->signal->cred_guard_mutex);
368}
369
370#ifdef CONFIG_STACKTRACE
371
372#define MAX_STACK_TRACE_DEPTH 64
373
374static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
375 struct pid *pid, struct task_struct *task)
376{
377 struct stack_trace trace;
378 unsigned long *entries;
379 int err;
380 int i;
381
382 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
383 if (!entries)
384 return -ENOMEM;
385
386 trace.nr_entries = 0;
387 trace.max_entries = MAX_STACK_TRACE_DEPTH;
388 trace.entries = entries;
389 trace.skip = 0;
390
391 err = lock_trace(task);
392 if (!err) {
393 save_stack_trace_tsk(task, &trace);
394
395 for (i = 0; i < trace.nr_entries; i++) {
396 seq_printf(m, "[<%pK>] %pS\n",
397 (void *)entries[i], (void *)entries[i]);
398 }
399 unlock_trace(task);
400 }
401 kfree(entries);
402
403 return err;
404}
405#endif
406
407#ifdef CONFIG_SCHEDSTATS
408/*
409 * Provides /proc/PID/schedstat
410 */
411static int proc_pid_schedstat(struct task_struct *task, char *buffer)
412{
413 return sprintf(buffer, "%llu %llu %lu\n",
414 (unsigned long long)task->se.sum_exec_runtime,
415 (unsigned long long)task->sched_info.run_delay,
416 task->sched_info.pcount);
417}
418#endif
419
420#ifdef CONFIG_LATENCYTOP
421static int lstats_show_proc(struct seq_file *m, void *v)
422{
423 int i;
424 struct inode *inode = m->private;
425 struct task_struct *task = get_proc_task(inode);
426
427 if (!task)
428 return -ESRCH;
429 seq_puts(m, "Latency Top version : v0.1\n");
430 for (i = 0; i < 32; i++) {
431 struct latency_record *lr = &task->latency_record[i];
432 if (lr->backtrace[0]) {
433 int q;
434 seq_printf(m, "%i %li %li",
435 lr->count, lr->time, lr->max);
436 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
437 unsigned long bt = lr->backtrace[q];
438 if (!bt)
439 break;
440 if (bt == ULONG_MAX)
441 break;
442 seq_printf(m, " %ps", (void *)bt);
443 }
444 seq_putc(m, '\n');
445 }
446
447 }
448 put_task_struct(task);
449 return 0;
450}
451
452static int lstats_open(struct inode *inode, struct file *file)
453{
454 return single_open(file, lstats_show_proc, inode);
455}
456
457static ssize_t lstats_write(struct file *file, const char __user *buf,
458 size_t count, loff_t *offs)
459{
460 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
461
462 if (!task)
463 return -ESRCH;
464 clear_all_latency_tracing(task);
465 put_task_struct(task);
466
467 return count;
468}
469
470static const struct file_operations proc_lstats_operations = {
471 .open = lstats_open,
472 .read = seq_read,
473 .write = lstats_write,
474 .llseek = seq_lseek,
475 .release = single_release,
476};
477
478#endif
479
480static int proc_oom_score(struct task_struct *task, char *buffer)
481{
482 unsigned long points = 0;
483
484 read_lock(&tasklist_lock);
485 if (pid_alive(task))
486 points = oom_badness(task, NULL, NULL,
487 totalram_pages + total_swap_pages);
488 read_unlock(&tasklist_lock);
489 return sprintf(buffer, "%lu\n", points);
490}
491
492struct limit_names {
493 char *name;
494 char *unit;
495};
496
497static const struct limit_names lnames[RLIM_NLIMITS] = {
498 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
499 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
500 [RLIMIT_DATA] = {"Max data size", "bytes"},
501 [RLIMIT_STACK] = {"Max stack size", "bytes"},
502 [RLIMIT_CORE] = {"Max core file size", "bytes"},
503 [RLIMIT_RSS] = {"Max resident set", "bytes"},
504 [RLIMIT_NPROC] = {"Max processes", "processes"},
505 [RLIMIT_NOFILE] = {"Max open files", "files"},
506 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
507 [RLIMIT_AS] = {"Max address space", "bytes"},
508 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
509 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
510 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
511 [RLIMIT_NICE] = {"Max nice priority", NULL},
512 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
513 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
514};
515
516/* Display limits for a process */
517static int proc_pid_limits(struct task_struct *task, char *buffer)
518{
519 unsigned int i;
520 int count = 0;
521 unsigned long flags;
522 char *bufptr = buffer;
523
524 struct rlimit rlim[RLIM_NLIMITS];
525
526 if (!lock_task_sighand(task, &flags))
527 return 0;
528 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
529 unlock_task_sighand(task, &flags);
530
531 /*
532 * print the file header
533 */
534 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
535 "Limit", "Soft Limit", "Hard Limit", "Units");
536
537 for (i = 0; i < RLIM_NLIMITS; i++) {
538 if (rlim[i].rlim_cur == RLIM_INFINITY)
539 count += sprintf(&bufptr[count], "%-25s %-20s ",
540 lnames[i].name, "unlimited");
541 else
542 count += sprintf(&bufptr[count], "%-25s %-20lu ",
543 lnames[i].name, rlim[i].rlim_cur);
544
545 if (rlim[i].rlim_max == RLIM_INFINITY)
546 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
547 else
548 count += sprintf(&bufptr[count], "%-20lu ",
549 rlim[i].rlim_max);
550
551 if (lnames[i].unit)
552 count += sprintf(&bufptr[count], "%-10s\n",
553 lnames[i].unit);
554 else
555 count += sprintf(&bufptr[count], "\n");
556 }
557
558 return count;
559}
560
561#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
562static int proc_pid_syscall(struct task_struct *task, char *buffer)
563{
564 long nr;
565 unsigned long args[6], sp, pc;
566 int res = lock_trace(task);
567 if (res)
568 return res;
569
570 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
571 res = sprintf(buffer, "running\n");
572 else if (nr < 0)
573 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
574 else
575 res = sprintf(buffer,
576 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
577 nr,
578 args[0], args[1], args[2], args[3], args[4], args[5],
579 sp, pc);
580 unlock_trace(task);
581 return res;
582}
583#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
584
585/************************************************************************/
586/* Here the fs part begins */
587/************************************************************************/
588
589/* permission checks */
590static int proc_fd_access_allowed(struct inode *inode)
591{
592 struct task_struct *task;
593 int allowed = 0;
594 /* Allow access to a task's file descriptors if it is us or we
595 * may use ptrace attach to the process and find out that
596 * information.
597 */
598 task = get_proc_task(inode);
599 if (task) {
600 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
601 put_task_struct(task);
602 }
603 return allowed;
604}
605
606int proc_setattr(struct dentry *dentry, struct iattr *attr)
607{
608 int error;
609 struct inode *inode = dentry->d_inode;
610
611 if (attr->ia_valid & ATTR_MODE)
612 return -EPERM;
613
614 error = inode_change_ok(inode, attr);
615 if (error)
616 return error;
617
618 if ((attr->ia_valid & ATTR_SIZE) &&
619 attr->ia_size != i_size_read(inode)) {
620 error = vmtruncate(inode, attr->ia_size);
621 if (error)
622 return error;
623 }
624
625 setattr_copy(inode, attr);
626 mark_inode_dirty(inode);
627 return 0;
628}
629
630static const struct inode_operations proc_def_inode_operations = {
631 .setattr = proc_setattr,
632};
633
634static int mounts_open_common(struct inode *inode, struct file *file,
635 const struct seq_operations *op)
636{
637 struct task_struct *task = get_proc_task(inode);
638 struct nsproxy *nsp;
639 struct mnt_namespace *ns = NULL;
640 struct path root;
641 struct proc_mounts *p;
642 int ret = -EINVAL;
643
644 if (task) {
645 rcu_read_lock();
646 nsp = task_nsproxy(task);
647 if (nsp) {
648 ns = nsp->mnt_ns;
649 if (ns)
650 get_mnt_ns(ns);
651 }
652 rcu_read_unlock();
653 if (ns && get_task_root(task, &root) == 0)
654 ret = 0;
655 put_task_struct(task);
656 }
657
658 if (!ns)
659 goto err;
660 if (ret)
661 goto err_put_ns;
662
663 ret = -ENOMEM;
664 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
665 if (!p)
666 goto err_put_path;
667
668 file->private_data = &p->m;
669 ret = seq_open(file, op);
670 if (ret)
671 goto err_free;
672
673 p->m.private = p;
674 p->ns = ns;
675 p->root = root;
676 p->m.poll_event = ns->event;
677
678 return 0;
679
680 err_free:
681 kfree(p);
682 err_put_path:
683 path_put(&root);
684 err_put_ns:
685 put_mnt_ns(ns);
686 err:
687 return ret;
688}
689
690static int mounts_release(struct inode *inode, struct file *file)
691{
692 struct proc_mounts *p = file->private_data;
693 path_put(&p->root);
694 put_mnt_ns(p->ns);
695 return seq_release(inode, file);
696}
697
698static unsigned mounts_poll(struct file *file, poll_table *wait)
699{
700 struct proc_mounts *p = file->private_data;
701 unsigned res = POLLIN | POLLRDNORM;
702
703 poll_wait(file, &p->ns->poll, wait);
704 if (mnt_had_events(p))
705 res |= POLLERR | POLLPRI;
706
707 return res;
708}
709
710static int mounts_open(struct inode *inode, struct file *file)
711{
712 return mounts_open_common(inode, file, &mounts_op);
713}
714
715static const struct file_operations proc_mounts_operations = {
716 .open = mounts_open,
717 .read = seq_read,
718 .llseek = seq_lseek,
719 .release = mounts_release,
720 .poll = mounts_poll,
721};
722
723static int mountinfo_open(struct inode *inode, struct file *file)
724{
725 return mounts_open_common(inode, file, &mountinfo_op);
726}
727
728static const struct file_operations proc_mountinfo_operations = {
729 .open = mountinfo_open,
730 .read = seq_read,
731 .llseek = seq_lseek,
732 .release = mounts_release,
733 .poll = mounts_poll,
734};
735
736static int mountstats_open(struct inode *inode, struct file *file)
737{
738 return mounts_open_common(inode, file, &mountstats_op);
739}
740
741static const struct file_operations proc_mountstats_operations = {
742 .open = mountstats_open,
743 .read = seq_read,
744 .llseek = seq_lseek,
745 .release = mounts_release,
746};
747
748#define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
749
750static ssize_t proc_info_read(struct file * file, char __user * buf,
751 size_t count, loff_t *ppos)
752{
753 struct inode * inode = file->f_path.dentry->d_inode;
754 unsigned long page;
755 ssize_t length;
756 struct task_struct *task = get_proc_task(inode);
757
758 length = -ESRCH;
759 if (!task)
760 goto out_no_task;
761
762 if (count > PROC_BLOCK_SIZE)
763 count = PROC_BLOCK_SIZE;
764
765 length = -ENOMEM;
766 if (!(page = __get_free_page(GFP_TEMPORARY)))
767 goto out;
768
769 length = PROC_I(inode)->op.proc_read(task, (char*)page);
770
771 if (length >= 0)
772 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
773 free_page(page);
774out:
775 put_task_struct(task);
776out_no_task:
777 return length;
778}
779
780static const struct file_operations proc_info_file_operations = {
781 .read = proc_info_read,
782 .llseek = generic_file_llseek,
783};
784
785static int proc_single_show(struct seq_file *m, void *v)
786{
787 struct inode *inode = m->private;
788 struct pid_namespace *ns;
789 struct pid *pid;
790 struct task_struct *task;
791 int ret;
792
793 ns = inode->i_sb->s_fs_info;
794 pid = proc_pid(inode);
795 task = get_pid_task(pid, PIDTYPE_PID);
796 if (!task)
797 return -ESRCH;
798
799 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
800
801 put_task_struct(task);
802 return ret;
803}
804
805static int proc_single_open(struct inode *inode, struct file *filp)
806{
807 return single_open(filp, proc_single_show, inode);
808}
809
810static const struct file_operations proc_single_file_operations = {
811 .open = proc_single_open,
812 .read = seq_read,
813 .llseek = seq_lseek,
814 .release = single_release,
815};
816
817static int mem_open(struct inode* inode, struct file* file)
818{
819 file->private_data = (void*)((long)current->self_exec_id);
820 /* OK to pass negative loff_t, we can catch out-of-range */
821 file->f_mode |= FMODE_UNSIGNED_OFFSET;
822 return 0;
823}
824
825static ssize_t mem_read(struct file * file, char __user * buf,
826 size_t count, loff_t *ppos)
827{
828 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
829 char *page;
830 unsigned long src = *ppos;
831 int ret = -ESRCH;
832 struct mm_struct *mm;
833
834 if (!task)
835 goto out_no_task;
836
837 ret = -ENOMEM;
838 page = (char *)__get_free_page(GFP_TEMPORARY);
839 if (!page)
840 goto out;
841
842 mm = check_mem_permission(task);
843 ret = PTR_ERR(mm);
844 if (IS_ERR(mm))
845 goto out_free;
846
847 ret = -EIO;
848
849 if (file->private_data != (void*)((long)current->self_exec_id))
850 goto out_put;
851
852 ret = 0;
853
854 while (count > 0) {
855 int this_len, retval;
856
857 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
858 retval = access_remote_vm(mm, src, page, this_len, 0);
859 if (!retval) {
860 if (!ret)
861 ret = -EIO;
862 break;
863 }
864
865 if (copy_to_user(buf, page, retval)) {
866 ret = -EFAULT;
867 break;
868 }
869
870 ret += retval;
871 src += retval;
872 buf += retval;
873 count -= retval;
874 }
875 *ppos = src;
876
877out_put:
878 mmput(mm);
879out_free:
880 free_page((unsigned long) page);
881out:
882 put_task_struct(task);
883out_no_task:
884 return ret;
885}
886
887static ssize_t mem_write(struct file * file, const char __user *buf,
888 size_t count, loff_t *ppos)
889{
890 int copied;
891 char *page;
892 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
893 unsigned long dst = *ppos;
894 struct mm_struct *mm;
895
896 copied = -ESRCH;
897 if (!task)
898 goto out_no_task;
899
900 copied = -ENOMEM;
901 page = (char *)__get_free_page(GFP_TEMPORARY);
902 if (!page)
903 goto out_task;
904
905 mm = check_mem_permission(task);
906 copied = PTR_ERR(mm);
907 if (IS_ERR(mm))
908 goto out_free;
909
910 copied = -EIO;
911 if (file->private_data != (void *)((long)current->self_exec_id))
912 goto out_mm;
913
914 copied = 0;
915 while (count > 0) {
916 int this_len, retval;
917
918 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
919 if (copy_from_user(page, buf, this_len)) {
920 copied = -EFAULT;
921 break;
922 }
923 retval = access_remote_vm(mm, dst, page, this_len, 1);
924 if (!retval) {
925 if (!copied)
926 copied = -EIO;
927 break;
928 }
929 copied += retval;
930 buf += retval;
931 dst += retval;
932 count -= retval;
933 }
934 *ppos = dst;
935
936out_mm:
937 mmput(mm);
938out_free:
939 free_page((unsigned long) page);
940out_task:
941 put_task_struct(task);
942out_no_task:
943 return copied;
944}
945
946loff_t mem_lseek(struct file *file, loff_t offset, int orig)
947{
948 switch (orig) {
949 case 0:
950 file->f_pos = offset;
951 break;
952 case 1:
953 file->f_pos += offset;
954 break;
955 default:
956 return -EINVAL;
957 }
958 force_successful_syscall_return();
959 return file->f_pos;
960}
961
962static const struct file_operations proc_mem_operations = {
963 .llseek = mem_lseek,
964 .read = mem_read,
965 .write = mem_write,
966 .open = mem_open,
967};
968
969static ssize_t environ_read(struct file *file, char __user *buf,
970 size_t count, loff_t *ppos)
971{
972 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
973 char *page;
974 unsigned long src = *ppos;
975 int ret = -ESRCH;
976 struct mm_struct *mm;
977
978 if (!task)
979 goto out_no_task;
980
981 ret = -ENOMEM;
982 page = (char *)__get_free_page(GFP_TEMPORARY);
983 if (!page)
984 goto out;
985
986
987 mm = mm_for_maps(task);
988 ret = PTR_ERR(mm);
989 if (!mm || IS_ERR(mm))
990 goto out_free;
991
992 ret = 0;
993 while (count > 0) {
994 int this_len, retval, max_len;
995
996 this_len = mm->env_end - (mm->env_start + src);
997
998 if (this_len <= 0)
999 break;
1000
1001 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
1002 this_len = (this_len > max_len) ? max_len : this_len;
1003
1004 retval = access_process_vm(task, (mm->env_start + src),
1005 page, this_len, 0);
1006
1007 if (retval <= 0) {
1008 ret = retval;
1009 break;
1010 }
1011
1012 if (copy_to_user(buf, page, retval)) {
1013 ret = -EFAULT;
1014 break;
1015 }
1016
1017 ret += retval;
1018 src += retval;
1019 buf += retval;
1020 count -= retval;
1021 }
1022 *ppos = src;
1023
1024 mmput(mm);
1025out_free:
1026 free_page((unsigned long) page);
1027out:
1028 put_task_struct(task);
1029out_no_task:
1030 return ret;
1031}
1032
1033static const struct file_operations proc_environ_operations = {
1034 .read = environ_read,
1035 .llseek = generic_file_llseek,
1036};
1037
1038static ssize_t oom_adjust_read(struct file *file, char __user *buf,
1039 size_t count, loff_t *ppos)
1040{
1041 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1042 char buffer[PROC_NUMBUF];
1043 size_t len;
1044 int oom_adjust = OOM_DISABLE;
1045 unsigned long flags;
1046
1047 if (!task)
1048 return -ESRCH;
1049
1050 if (lock_task_sighand(task, &flags)) {
1051 oom_adjust = task->signal->oom_adj;
1052 unlock_task_sighand(task, &flags);
1053 }
1054
1055 put_task_struct(task);
1056
1057 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
1058
1059 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1060}
1061
1062static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1063 size_t count, loff_t *ppos)
1064{
1065 struct task_struct *task;
1066 char buffer[PROC_NUMBUF];
1067 int oom_adjust;
1068 unsigned long flags;
1069 int err;
1070
1071 memset(buffer, 0, sizeof(buffer));
1072 if (count > sizeof(buffer) - 1)
1073 count = sizeof(buffer) - 1;
1074 if (copy_from_user(buffer, buf, count)) {
1075 err = -EFAULT;
1076 goto out;
1077 }
1078
1079 err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
1080 if (err)
1081 goto out;
1082 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1083 oom_adjust != OOM_DISABLE) {
1084 err = -EINVAL;
1085 goto out;
1086 }
1087
1088 task = get_proc_task(file->f_path.dentry->d_inode);
1089 if (!task) {
1090 err = -ESRCH;
1091 goto out;
1092 }
1093
1094 task_lock(task);
1095 if (!task->mm) {
1096 err = -EINVAL;
1097 goto err_task_lock;
1098 }
1099
1100 if (!lock_task_sighand(task, &flags)) {
1101 err = -ESRCH;
1102 goto err_task_lock;
1103 }
1104
1105 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1106 err = -EACCES;
1107 goto err_sighand;
1108 }
1109
1110 if (oom_adjust != task->signal->oom_adj) {
1111 if (oom_adjust == OOM_DISABLE)
1112 atomic_inc(&task->mm->oom_disable_count);
1113 if (task->signal->oom_adj == OOM_DISABLE)
1114 atomic_dec(&task->mm->oom_disable_count);
1115 }
1116
1117 /*
1118 * Warn that /proc/pid/oom_adj is deprecated, see
1119 * Documentation/feature-removal-schedule.txt.
1120 */
1121 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1122 current->comm, task_pid_nr(current), task_pid_nr(task),
1123 task_pid_nr(task));
1124 task->signal->oom_adj = oom_adjust;
1125 /*
1126 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1127 * value is always attainable.
1128 */
1129 if (task->signal->oom_adj == OOM_ADJUST_MAX)
1130 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
1131 else
1132 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
1133 -OOM_DISABLE;
1134err_sighand:
1135 unlock_task_sighand(task, &flags);
1136err_task_lock:
1137 task_unlock(task);
1138 put_task_struct(task);
1139out:
1140 return err < 0 ? err : count;
1141}
1142
1143static const struct file_operations proc_oom_adjust_operations = {
1144 .read = oom_adjust_read,
1145 .write = oom_adjust_write,
1146 .llseek = generic_file_llseek,
1147};
1148
1149static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1150 size_t count, loff_t *ppos)
1151{
1152 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1153 char buffer[PROC_NUMBUF];
1154 int oom_score_adj = OOM_SCORE_ADJ_MIN;
1155 unsigned long flags;
1156 size_t len;
1157
1158 if (!task)
1159 return -ESRCH;
1160 if (lock_task_sighand(task, &flags)) {
1161 oom_score_adj = task->signal->oom_score_adj;
1162 unlock_task_sighand(task, &flags);
1163 }
1164 put_task_struct(task);
1165 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
1166 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1167}
1168
1169static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1170 size_t count, loff_t *ppos)
1171{
1172 struct task_struct *task;
1173 char buffer[PROC_NUMBUF];
1174 unsigned long flags;
1175 int oom_score_adj;
1176 int err;
1177
1178 memset(buffer, 0, sizeof(buffer));
1179 if (count > sizeof(buffer) - 1)
1180 count = sizeof(buffer) - 1;
1181 if (copy_from_user(buffer, buf, count)) {
1182 err = -EFAULT;
1183 goto out;
1184 }
1185
1186 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1187 if (err)
1188 goto out;
1189 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1190 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1191 err = -EINVAL;
1192 goto out;
1193 }
1194
1195 task = get_proc_task(file->f_path.dentry->d_inode);
1196 if (!task) {
1197 err = -ESRCH;
1198 goto out;
1199 }
1200
1201 task_lock(task);
1202 if (!task->mm) {
1203 err = -EINVAL;
1204 goto err_task_lock;
1205 }
1206
1207 if (!lock_task_sighand(task, &flags)) {
1208 err = -ESRCH;
1209 goto err_task_lock;
1210 }
1211
1212 if (oom_score_adj < task->signal->oom_score_adj_min &&
1213 !capable(CAP_SYS_RESOURCE)) {
1214 err = -EACCES;
1215 goto err_sighand;
1216 }
1217
1218 if (oom_score_adj != task->signal->oom_score_adj) {
1219 if (oom_score_adj == OOM_SCORE_ADJ_MIN)
1220 atomic_inc(&task->mm->oom_disable_count);
1221 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1222 atomic_dec(&task->mm->oom_disable_count);
1223 }
1224 task->signal->oom_score_adj = oom_score_adj;
1225 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1226 task->signal->oom_score_adj_min = oom_score_adj;
1227 /*
1228 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1229 * always attainable.
1230 */
1231 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1232 task->signal->oom_adj = OOM_DISABLE;
1233 else
1234 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1235 OOM_SCORE_ADJ_MAX;
1236err_sighand:
1237 unlock_task_sighand(task, &flags);
1238err_task_lock:
1239 task_unlock(task);
1240 put_task_struct(task);
1241out:
1242 return err < 0 ? err : count;
1243}
1244
1245static const struct file_operations proc_oom_score_adj_operations = {
1246 .read = oom_score_adj_read,
1247 .write = oom_score_adj_write,
1248 .llseek = default_llseek,
1249};
1250
1251#ifdef CONFIG_AUDITSYSCALL
1252#define TMPBUFLEN 21
1253static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1254 size_t count, loff_t *ppos)
1255{
1256 struct inode * inode = file->f_path.dentry->d_inode;
1257 struct task_struct *task = get_proc_task(inode);
1258 ssize_t length;
1259 char tmpbuf[TMPBUFLEN];
1260
1261 if (!task)
1262 return -ESRCH;
1263 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1264 audit_get_loginuid(task));
1265 put_task_struct(task);
1266 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1267}
1268
1269static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1270 size_t count, loff_t *ppos)
1271{
1272 struct inode * inode = file->f_path.dentry->d_inode;
1273 char *page, *tmp;
1274 ssize_t length;
1275 uid_t loginuid;
1276
1277 if (!capable(CAP_AUDIT_CONTROL))
1278 return -EPERM;
1279
1280 rcu_read_lock();
1281 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1282 rcu_read_unlock();
1283 return -EPERM;
1284 }
1285 rcu_read_unlock();
1286
1287 if (count >= PAGE_SIZE)
1288 count = PAGE_SIZE - 1;
1289
1290 if (*ppos != 0) {
1291 /* No partial writes. */
1292 return -EINVAL;
1293 }
1294 page = (char*)__get_free_page(GFP_TEMPORARY);
1295 if (!page)
1296 return -ENOMEM;
1297 length = -EFAULT;
1298 if (copy_from_user(page, buf, count))
1299 goto out_free_page;
1300
1301 page[count] = '\0';
1302 loginuid = simple_strtoul(page, &tmp, 10);
1303 if (tmp == page) {
1304 length = -EINVAL;
1305 goto out_free_page;
1306
1307 }
1308 length = audit_set_loginuid(current, loginuid);
1309 if (likely(length == 0))
1310 length = count;
1311
1312out_free_page:
1313 free_page((unsigned long) page);
1314 return length;
1315}
1316
1317static const struct file_operations proc_loginuid_operations = {
1318 .read = proc_loginuid_read,
1319 .write = proc_loginuid_write,
1320 .llseek = generic_file_llseek,
1321};
1322
1323static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1324 size_t count, loff_t *ppos)
1325{
1326 struct inode * inode = file->f_path.dentry->d_inode;
1327 struct task_struct *task = get_proc_task(inode);
1328 ssize_t length;
1329 char tmpbuf[TMPBUFLEN];
1330
1331 if (!task)
1332 return -ESRCH;
1333 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1334 audit_get_sessionid(task));
1335 put_task_struct(task);
1336 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1337}
1338
1339static const struct file_operations proc_sessionid_operations = {
1340 .read = proc_sessionid_read,
1341 .llseek = generic_file_llseek,
1342};
1343#endif
1344
1345#ifdef CONFIG_FAULT_INJECTION
1346static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1347 size_t count, loff_t *ppos)
1348{
1349 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1350 char buffer[PROC_NUMBUF];
1351 size_t len;
1352 int make_it_fail;
1353
1354 if (!task)
1355 return -ESRCH;
1356 make_it_fail = task->make_it_fail;
1357 put_task_struct(task);
1358
1359 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1360
1361 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1362}
1363
1364static ssize_t proc_fault_inject_write(struct file * file,
1365 const char __user * buf, size_t count, loff_t *ppos)
1366{
1367 struct task_struct *task;
1368 char buffer[PROC_NUMBUF], *end;
1369 int make_it_fail;
1370
1371 if (!capable(CAP_SYS_RESOURCE))
1372 return -EPERM;
1373 memset(buffer, 0, sizeof(buffer));
1374 if (count > sizeof(buffer) - 1)
1375 count = sizeof(buffer) - 1;
1376 if (copy_from_user(buffer, buf, count))
1377 return -EFAULT;
1378 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1379 if (*end)
1380 return -EINVAL;
1381 task = get_proc_task(file->f_dentry->d_inode);
1382 if (!task)
1383 return -ESRCH;
1384 task->make_it_fail = make_it_fail;
1385 put_task_struct(task);
1386
1387 return count;
1388}
1389
1390static const struct file_operations proc_fault_inject_operations = {
1391 .read = proc_fault_inject_read,
1392 .write = proc_fault_inject_write,
1393 .llseek = generic_file_llseek,
1394};
1395#endif
1396
1397
1398#ifdef CONFIG_SCHED_DEBUG
1399/*
1400 * Print out various scheduling related per-task fields:
1401 */
1402static int sched_show(struct seq_file *m, void *v)
1403{
1404 struct inode *inode = m->private;
1405 struct task_struct *p;
1406
1407 p = get_proc_task(inode);
1408 if (!p)
1409 return -ESRCH;
1410 proc_sched_show_task(p, m);
1411
1412 put_task_struct(p);
1413
1414 return 0;
1415}
1416
1417static ssize_t
1418sched_write(struct file *file, const char __user *buf,
1419 size_t count, loff_t *offset)
1420{
1421 struct inode *inode = file->f_path.dentry->d_inode;
1422 struct task_struct *p;
1423
1424 p = get_proc_task(inode);
1425 if (!p)
1426 return -ESRCH;
1427 proc_sched_set_task(p);
1428
1429 put_task_struct(p);
1430
1431 return count;
1432}
1433
1434static int sched_open(struct inode *inode, struct file *filp)
1435{
1436 return single_open(filp, sched_show, inode);
1437}
1438
1439static const struct file_operations proc_pid_sched_operations = {
1440 .open = sched_open,
1441 .read = seq_read,
1442 .write = sched_write,
1443 .llseek = seq_lseek,
1444 .release = single_release,
1445};
1446
1447#endif
1448
1449#ifdef CONFIG_SCHED_AUTOGROUP
1450/*
1451 * Print out autogroup related information:
1452 */
1453static int sched_autogroup_show(struct seq_file *m, void *v)
1454{
1455 struct inode *inode = m->private;
1456 struct task_struct *p;
1457
1458 p = get_proc_task(inode);
1459 if (!p)
1460 return -ESRCH;
1461 proc_sched_autogroup_show_task(p, m);
1462
1463 put_task_struct(p);
1464
1465 return 0;
1466}
1467
1468static ssize_t
1469sched_autogroup_write(struct file *file, const char __user *buf,
1470 size_t count, loff_t *offset)
1471{
1472 struct inode *inode = file->f_path.dentry->d_inode;
1473 struct task_struct *p;
1474 char buffer[PROC_NUMBUF];
1475 int nice;
1476 int err;
1477
1478 memset(buffer, 0, sizeof(buffer));
1479 if (count > sizeof(buffer) - 1)
1480 count = sizeof(buffer) - 1;
1481 if (copy_from_user(buffer, buf, count))
1482 return -EFAULT;
1483
1484 err = kstrtoint(strstrip(buffer), 0, &nice);
1485 if (err < 0)
1486 return err;
1487
1488 p = get_proc_task(inode);
1489 if (!p)
1490 return -ESRCH;
1491
1492 err = nice;
1493 err = proc_sched_autogroup_set_nice(p, &err);
1494 if (err)
1495 count = err;
1496
1497 put_task_struct(p);
1498
1499 return count;
1500}
1501
1502static int sched_autogroup_open(struct inode *inode, struct file *filp)
1503{
1504 int ret;
1505
1506 ret = single_open(filp, sched_autogroup_show, NULL);
1507 if (!ret) {
1508 struct seq_file *m = filp->private_data;
1509
1510 m->private = inode;
1511 }
1512 return ret;
1513}
1514
1515static const struct file_operations proc_pid_sched_autogroup_operations = {
1516 .open = sched_autogroup_open,
1517 .read = seq_read,
1518 .write = sched_autogroup_write,
1519 .llseek = seq_lseek,
1520 .release = single_release,
1521};
1522
1523#endif /* CONFIG_SCHED_AUTOGROUP */
1524
1525static ssize_t comm_write(struct file *file, const char __user *buf,
1526 size_t count, loff_t *offset)
1527{
1528 struct inode *inode = file->f_path.dentry->d_inode;
1529 struct task_struct *p;
1530 char buffer[TASK_COMM_LEN];
1531
1532 memset(buffer, 0, sizeof(buffer));
1533 if (count > sizeof(buffer) - 1)
1534 count = sizeof(buffer) - 1;
1535 if (copy_from_user(buffer, buf, count))
1536 return -EFAULT;
1537
1538 p = get_proc_task(inode);
1539 if (!p)
1540 return -ESRCH;
1541
1542 if (same_thread_group(current, p))
1543 set_task_comm(p, buffer);
1544 else
1545 count = -EINVAL;
1546
1547 put_task_struct(p);
1548
1549 return count;
1550}
1551
1552static int comm_show(struct seq_file *m, void *v)
1553{
1554 struct inode *inode = m->private;
1555 struct task_struct *p;
1556
1557 p = get_proc_task(inode);
1558 if (!p)
1559 return -ESRCH;
1560
1561 task_lock(p);
1562 seq_printf(m, "%s\n", p->comm);
1563 task_unlock(p);
1564
1565 put_task_struct(p);
1566
1567 return 0;
1568}
1569
1570static int comm_open(struct inode *inode, struct file *filp)
1571{
1572 return single_open(filp, comm_show, inode);
1573}
1574
1575static const struct file_operations proc_pid_set_comm_operations = {
1576 .open = comm_open,
1577 .read = seq_read,
1578 .write = comm_write,
1579 .llseek = seq_lseek,
1580 .release = single_release,
1581};
1582
1583static int proc_exe_link(struct inode *inode, struct path *exe_path)
1584{
1585 struct task_struct *task;
1586 struct mm_struct *mm;
1587 struct file *exe_file;
1588
1589 task = get_proc_task(inode);
1590 if (!task)
1591 return -ENOENT;
1592 mm = get_task_mm(task);
1593 put_task_struct(task);
1594 if (!mm)
1595 return -ENOENT;
1596 exe_file = get_mm_exe_file(mm);
1597 mmput(mm);
1598 if (exe_file) {
1599 *exe_path = exe_file->f_path;
1600 path_get(&exe_file->f_path);
1601 fput(exe_file);
1602 return 0;
1603 } else
1604 return -ENOENT;
1605}
1606
1607static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1608{
1609 struct inode *inode = dentry->d_inode;
1610 int error = -EACCES;
1611
1612 /* We don't need a base pointer in the /proc filesystem */
1613 path_put(&nd->path);
1614
1615 /* Are we allowed to snoop on the tasks file descriptors? */
1616 if (!proc_fd_access_allowed(inode))
1617 goto out;
1618
1619 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1620out:
1621 return ERR_PTR(error);
1622}
1623
1624static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1625{
1626 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1627 char *pathname;
1628 int len;
1629
1630 if (!tmp)
1631 return -ENOMEM;
1632
1633 pathname = d_path(path, tmp, PAGE_SIZE);
1634 len = PTR_ERR(pathname);
1635 if (IS_ERR(pathname))
1636 goto out;
1637 len = tmp + PAGE_SIZE - 1 - pathname;
1638
1639 if (len > buflen)
1640 len = buflen;
1641 if (copy_to_user(buffer, pathname, len))
1642 len = -EFAULT;
1643 out:
1644 free_page((unsigned long)tmp);
1645 return len;
1646}
1647
1648static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1649{
1650 int error = -EACCES;
1651 struct inode *inode = dentry->d_inode;
1652 struct path path;
1653
1654 /* Are we allowed to snoop on the tasks file descriptors? */
1655 if (!proc_fd_access_allowed(inode))
1656 goto out;
1657
1658 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1659 if (error)
1660 goto out;
1661
1662 error = do_proc_readlink(&path, buffer, buflen);
1663 path_put(&path);
1664out:
1665 return error;
1666}
1667
1668static const struct inode_operations proc_pid_link_inode_operations = {
1669 .readlink = proc_pid_readlink,
1670 .follow_link = proc_pid_follow_link,
1671 .setattr = proc_setattr,
1672};
1673
1674
1675/* building an inode */
1676
1677static int task_dumpable(struct task_struct *task)
1678{
1679 int dumpable = 0;
1680 struct mm_struct *mm;
1681
1682 task_lock(task);
1683 mm = task->mm;
1684 if (mm)
1685 dumpable = get_dumpable(mm);
1686 task_unlock(task);
1687 if(dumpable == 1)
1688 return 1;
1689 return 0;
1690}
1691
1692struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1693{
1694 struct inode * inode;
1695 struct proc_inode *ei;
1696 const struct cred *cred;
1697
1698 /* We need a new inode */
1699
1700 inode = new_inode(sb);
1701 if (!inode)
1702 goto out;
1703
1704 /* Common stuff */
1705 ei = PROC_I(inode);
1706 inode->i_ino = get_next_ino();
1707 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1708 inode->i_op = &proc_def_inode_operations;
1709
1710 /*
1711 * grab the reference to task.
1712 */
1713 ei->pid = get_task_pid(task, PIDTYPE_PID);
1714 if (!ei->pid)
1715 goto out_unlock;
1716
1717 if (task_dumpable(task)) {
1718 rcu_read_lock();
1719 cred = __task_cred(task);
1720 inode->i_uid = cred->euid;
1721 inode->i_gid = cred->egid;
1722 rcu_read_unlock();
1723 }
1724 security_task_to_inode(task, inode);
1725
1726out:
1727 return inode;
1728
1729out_unlock:
1730 iput(inode);
1731 return NULL;
1732}
1733
1734int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1735{
1736 struct inode *inode = dentry->d_inode;
1737 struct task_struct *task;
1738 const struct cred *cred;
1739
1740 generic_fillattr(inode, stat);
1741
1742 rcu_read_lock();
1743 stat->uid = 0;
1744 stat->gid = 0;
1745 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1746 if (task) {
1747 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1748 task_dumpable(task)) {
1749 cred = __task_cred(task);
1750 stat->uid = cred->euid;
1751 stat->gid = cred->egid;
1752 }
1753 }
1754 rcu_read_unlock();
1755 return 0;
1756}
1757
1758/* dentry stuff */
1759
1760/*
1761 * Exceptional case: normally we are not allowed to unhash a busy
1762 * directory. In this case, however, we can do it - no aliasing problems
1763 * due to the way we treat inodes.
1764 *
1765 * Rewrite the inode's ownerships here because the owning task may have
1766 * performed a setuid(), etc.
1767 *
1768 * Before the /proc/pid/status file was created the only way to read
1769 * the effective uid of a /process was to stat /proc/pid. Reading
1770 * /proc/pid/status is slow enough that procps and other packages
1771 * kept stating /proc/pid. To keep the rules in /proc simple I have
1772 * made this apply to all per process world readable and executable
1773 * directories.
1774 */
1775int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1776{
1777 struct inode *inode;
1778 struct task_struct *task;
1779 const struct cred *cred;
1780
1781 if (nd && nd->flags & LOOKUP_RCU)
1782 return -ECHILD;
1783
1784 inode = dentry->d_inode;
1785 task = get_proc_task(inode);
1786
1787 if (task) {
1788 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1789 task_dumpable(task)) {
1790 rcu_read_lock();
1791 cred = __task_cred(task);
1792 inode->i_uid = cred->euid;
1793 inode->i_gid = cred->egid;
1794 rcu_read_unlock();
1795 } else {
1796 inode->i_uid = 0;
1797 inode->i_gid = 0;
1798 }
1799 inode->i_mode &= ~(S_ISUID | S_ISGID);
1800 security_task_to_inode(task, inode);
1801 put_task_struct(task);
1802 return 1;
1803 }
1804 d_drop(dentry);
1805 return 0;
1806}
1807
1808static int pid_delete_dentry(const struct dentry * dentry)
1809{
1810 /* Is the task we represent dead?
1811 * If so, then don't put the dentry on the lru list,
1812 * kill it immediately.
1813 */
1814 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1815}
1816
1817const struct dentry_operations pid_dentry_operations =
1818{
1819 .d_revalidate = pid_revalidate,
1820 .d_delete = pid_delete_dentry,
1821};
1822
1823/* Lookups */
1824
1825/*
1826 * Fill a directory entry.
1827 *
1828 * If possible create the dcache entry and derive our inode number and
1829 * file type from dcache entry.
1830 *
1831 * Since all of the proc inode numbers are dynamically generated, the inode
1832 * numbers do not exist until the inode is cache. This means creating the
1833 * the dcache entry in readdir is necessary to keep the inode numbers
1834 * reported by readdir in sync with the inode numbers reported
1835 * by stat.
1836 */
1837int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1838 const char *name, int len,
1839 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1840{
1841 struct dentry *child, *dir = filp->f_path.dentry;
1842 struct inode *inode;
1843 struct qstr qname;
1844 ino_t ino = 0;
1845 unsigned type = DT_UNKNOWN;
1846
1847 qname.name = name;
1848 qname.len = len;
1849 qname.hash = full_name_hash(name, len);
1850
1851 child = d_lookup(dir, &qname);
1852 if (!child) {
1853 struct dentry *new;
1854 new = d_alloc(dir, &qname);
1855 if (new) {
1856 child = instantiate(dir->d_inode, new, task, ptr);
1857 if (child)
1858 dput(new);
1859 else
1860 child = new;
1861 }
1862 }
1863 if (!child || IS_ERR(child) || !child->d_inode)
1864 goto end_instantiate;
1865 inode = child->d_inode;
1866 if (inode) {
1867 ino = inode->i_ino;
1868 type = inode->i_mode >> 12;
1869 }
1870 dput(child);
1871end_instantiate:
1872 if (!ino)
1873 ino = find_inode_number(dir, &qname);
1874 if (!ino)
1875 ino = 1;
1876 return filldir(dirent, name, len, filp->f_pos, ino, type);
1877}
1878
1879static unsigned name_to_int(struct dentry *dentry)
1880{
1881 const char *name = dentry->d_name.name;
1882 int len = dentry->d_name.len;
1883 unsigned n = 0;
1884
1885 if (len > 1 && *name == '0')
1886 goto out;
1887 while (len-- > 0) {
1888 unsigned c = *name++ - '0';
1889 if (c > 9)
1890 goto out;
1891 if (n >= (~0U-9)/10)
1892 goto out;
1893 n *= 10;
1894 n += c;
1895 }
1896 return n;
1897out:
1898 return ~0U;
1899}
1900
1901#define PROC_FDINFO_MAX 64
1902
1903static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1904{
1905 struct task_struct *task = get_proc_task(inode);
1906 struct files_struct *files = NULL;
1907 struct file *file;
1908 int fd = proc_fd(inode);
1909
1910 if (task) {
1911 files = get_files_struct(task);
1912 put_task_struct(task);
1913 }
1914 if (files) {
1915 /*
1916 * We are not taking a ref to the file structure, so we must
1917 * hold ->file_lock.
1918 */
1919 spin_lock(&files->file_lock);
1920 file = fcheck_files(files, fd);
1921 if (file) {
1922 unsigned int f_flags;
1923 struct fdtable *fdt;
1924
1925 fdt = files_fdtable(files);
1926 f_flags = file->f_flags & ~O_CLOEXEC;
1927 if (FD_ISSET(fd, fdt->close_on_exec))
1928 f_flags |= O_CLOEXEC;
1929
1930 if (path) {
1931 *path = file->f_path;
1932 path_get(&file->f_path);
1933 }
1934 if (info)
1935 snprintf(info, PROC_FDINFO_MAX,
1936 "pos:\t%lli\n"
1937 "flags:\t0%o\n",
1938 (long long) file->f_pos,
1939 f_flags);
1940 spin_unlock(&files->file_lock);
1941 put_files_struct(files);
1942 return 0;
1943 }
1944 spin_unlock(&files->file_lock);
1945 put_files_struct(files);
1946 }
1947 return -ENOENT;
1948}
1949
1950static int proc_fd_link(struct inode *inode, struct path *path)
1951{
1952 return proc_fd_info(inode, path, NULL);
1953}
1954
1955static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1956{
1957 struct inode *inode;
1958 struct task_struct *task;
1959 int fd;
1960 struct files_struct *files;
1961 const struct cred *cred;
1962
1963 if (nd && nd->flags & LOOKUP_RCU)
1964 return -ECHILD;
1965
1966 inode = dentry->d_inode;
1967 task = get_proc_task(inode);
1968 fd = proc_fd(inode);
1969
1970 if (task) {
1971 files = get_files_struct(task);
1972 if (files) {
1973 rcu_read_lock();
1974 if (fcheck_files(files, fd)) {
1975 rcu_read_unlock();
1976 put_files_struct(files);
1977 if (task_dumpable(task)) {
1978 rcu_read_lock();
1979 cred = __task_cred(task);
1980 inode->i_uid = cred->euid;
1981 inode->i_gid = cred->egid;
1982 rcu_read_unlock();
1983 } else {
1984 inode->i_uid = 0;
1985 inode->i_gid = 0;
1986 }
1987 inode->i_mode &= ~(S_ISUID | S_ISGID);
1988 security_task_to_inode(task, inode);
1989 put_task_struct(task);
1990 return 1;
1991 }
1992 rcu_read_unlock();
1993 put_files_struct(files);
1994 }
1995 put_task_struct(task);
1996 }
1997 d_drop(dentry);
1998 return 0;
1999}
2000
2001static const struct dentry_operations tid_fd_dentry_operations =
2002{
2003 .d_revalidate = tid_fd_revalidate,
2004 .d_delete = pid_delete_dentry,
2005};
2006
2007static struct dentry *proc_fd_instantiate(struct inode *dir,
2008 struct dentry *dentry, struct task_struct *task, const void *ptr)
2009{
2010 unsigned fd = *(const unsigned *)ptr;
2011 struct file *file;
2012 struct files_struct *files;
2013 struct inode *inode;
2014 struct proc_inode *ei;
2015 struct dentry *error = ERR_PTR(-ENOENT);
2016
2017 inode = proc_pid_make_inode(dir->i_sb, task);
2018 if (!inode)
2019 goto out;
2020 ei = PROC_I(inode);
2021 ei->fd = fd;
2022 files = get_files_struct(task);
2023 if (!files)
2024 goto out_iput;
2025 inode->i_mode = S_IFLNK;
2026
2027 /*
2028 * We are not taking a ref to the file structure, so we must
2029 * hold ->file_lock.
2030 */
2031 spin_lock(&files->file_lock);
2032 file = fcheck_files(files, fd);
2033 if (!file)
2034 goto out_unlock;
2035 if (file->f_mode & FMODE_READ)
2036 inode->i_mode |= S_IRUSR | S_IXUSR;
2037 if (file->f_mode & FMODE_WRITE)
2038 inode->i_mode |= S_IWUSR | S_IXUSR;
2039 spin_unlock(&files->file_lock);
2040 put_files_struct(files);
2041
2042 inode->i_op = &proc_pid_link_inode_operations;
2043 inode->i_size = 64;
2044 ei->op.proc_get_link = proc_fd_link;
2045 d_set_d_op(dentry, &tid_fd_dentry_operations);
2046 d_add(dentry, inode);
2047 /* Close the race of the process dying before we return the dentry */
2048 if (tid_fd_revalidate(dentry, NULL))
2049 error = NULL;
2050
2051 out:
2052 return error;
2053out_unlock:
2054 spin_unlock(&files->file_lock);
2055 put_files_struct(files);
2056out_iput:
2057 iput(inode);
2058 goto out;
2059}
2060
2061static struct dentry *proc_lookupfd_common(struct inode *dir,
2062 struct dentry *dentry,
2063 instantiate_t instantiate)
2064{
2065 struct task_struct *task = get_proc_task(dir);
2066 unsigned fd = name_to_int(dentry);
2067 struct dentry *result = ERR_PTR(-ENOENT);
2068
2069 if (!task)
2070 goto out_no_task;
2071 if (fd == ~0U)
2072 goto out;
2073
2074 result = instantiate(dir, dentry, task, &fd);
2075out:
2076 put_task_struct(task);
2077out_no_task:
2078 return result;
2079}
2080
2081static int proc_readfd_common(struct file * filp, void * dirent,
2082 filldir_t filldir, instantiate_t instantiate)
2083{
2084 struct dentry *dentry = filp->f_path.dentry;
2085 struct inode *inode = dentry->d_inode;
2086 struct task_struct *p = get_proc_task(inode);
2087 unsigned int fd, ino;
2088 int retval;
2089 struct files_struct * files;
2090
2091 retval = -ENOENT;
2092 if (!p)
2093 goto out_no_task;
2094 retval = 0;
2095
2096 fd = filp->f_pos;
2097 switch (fd) {
2098 case 0:
2099 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
2100 goto out;
2101 filp->f_pos++;
2102 case 1:
2103 ino = parent_ino(dentry);
2104 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2105 goto out;
2106 filp->f_pos++;
2107 default:
2108 files = get_files_struct(p);
2109 if (!files)
2110 goto out;
2111 rcu_read_lock();
2112 for (fd = filp->f_pos-2;
2113 fd < files_fdtable(files)->max_fds;
2114 fd++, filp->f_pos++) {
2115 char name[PROC_NUMBUF];
2116 int len;
2117
2118 if (!fcheck_files(files, fd))
2119 continue;
2120 rcu_read_unlock();
2121
2122 len = snprintf(name, sizeof(name), "%d", fd);
2123 if (proc_fill_cache(filp, dirent, filldir,
2124 name, len, instantiate,
2125 p, &fd) < 0) {
2126 rcu_read_lock();
2127 break;
2128 }
2129 rcu_read_lock();
2130 }
2131 rcu_read_unlock();
2132 put_files_struct(files);
2133 }
2134out:
2135 put_task_struct(p);
2136out_no_task:
2137 return retval;
2138}
2139
2140static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
2141 struct nameidata *nd)
2142{
2143 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
2144}
2145
2146static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
2147{
2148 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
2149}
2150
2151static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
2152 size_t len, loff_t *ppos)
2153{
2154 char tmp[PROC_FDINFO_MAX];
2155 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
2156 if (!err)
2157 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
2158 return err;
2159}
2160
2161static const struct file_operations proc_fdinfo_file_operations = {
2162 .open = nonseekable_open,
2163 .read = proc_fdinfo_read,
2164 .llseek = no_llseek,
2165};
2166
2167static const struct file_operations proc_fd_operations = {
2168 .read = generic_read_dir,
2169 .readdir = proc_readfd,
2170 .llseek = default_llseek,
2171};
2172
2173/*
2174 * /proc/pid/fd needs a special permission handler so that a process can still
2175 * access /proc/self/fd after it has executed a setuid().
2176 */
2177static int proc_fd_permission(struct inode *inode, int mask)
2178{
2179 int rv = generic_permission(inode, mask);
2180 if (rv == 0)
2181 return 0;
2182 if (task_pid(current) == proc_pid(inode))
2183 rv = 0;
2184 return rv;
2185}
2186
2187/*
2188 * proc directories can do almost nothing..
2189 */
2190static const struct inode_operations proc_fd_inode_operations = {
2191 .lookup = proc_lookupfd,
2192 .permission = proc_fd_permission,
2193 .setattr = proc_setattr,
2194};
2195
2196static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2197 struct dentry *dentry, struct task_struct *task, const void *ptr)
2198{
2199 unsigned fd = *(unsigned *)ptr;
2200 struct inode *inode;
2201 struct proc_inode *ei;
2202 struct dentry *error = ERR_PTR(-ENOENT);
2203
2204 inode = proc_pid_make_inode(dir->i_sb, task);
2205 if (!inode)
2206 goto out;
2207 ei = PROC_I(inode);
2208 ei->fd = fd;
2209 inode->i_mode = S_IFREG | S_IRUSR;
2210 inode->i_fop = &proc_fdinfo_file_operations;
2211 d_set_d_op(dentry, &tid_fd_dentry_operations);
2212 d_add(dentry, inode);
2213 /* Close the race of the process dying before we return the dentry */
2214 if (tid_fd_revalidate(dentry, NULL))
2215 error = NULL;
2216
2217 out:
2218 return error;
2219}
2220
2221static struct dentry *proc_lookupfdinfo(struct inode *dir,
2222 struct dentry *dentry,
2223 struct nameidata *nd)
2224{
2225 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2226}
2227
2228static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2229{
2230 return proc_readfd_common(filp, dirent, filldir,
2231 proc_fdinfo_instantiate);
2232}
2233
2234static const struct file_operations proc_fdinfo_operations = {
2235 .read = generic_read_dir,
2236 .readdir = proc_readfdinfo,
2237 .llseek = default_llseek,
2238};
2239
2240/*
2241 * proc directories can do almost nothing..
2242 */
2243static const struct inode_operations proc_fdinfo_inode_operations = {
2244 .lookup = proc_lookupfdinfo,
2245 .setattr = proc_setattr,
2246};
2247
2248
2249static struct dentry *proc_pident_instantiate(struct inode *dir,
2250 struct dentry *dentry, struct task_struct *task, const void *ptr)
2251{
2252 const struct pid_entry *p = ptr;
2253 struct inode *inode;
2254 struct proc_inode *ei;
2255 struct dentry *error = ERR_PTR(-ENOENT);
2256
2257 inode = proc_pid_make_inode(dir->i_sb, task);
2258 if (!inode)
2259 goto out;
2260
2261 ei = PROC_I(inode);
2262 inode->i_mode = p->mode;
2263 if (S_ISDIR(inode->i_mode))
2264 inode->i_nlink = 2; /* Use getattr to fix if necessary */
2265 if (p->iop)
2266 inode->i_op = p->iop;
2267 if (p->fop)
2268 inode->i_fop = p->fop;
2269 ei->op = p->op;
2270 d_set_d_op(dentry, &pid_dentry_operations);
2271 d_add(dentry, inode);
2272 /* Close the race of the process dying before we return the dentry */
2273 if (pid_revalidate(dentry, NULL))
2274 error = NULL;
2275out:
2276 return error;
2277}
2278
2279static struct dentry *proc_pident_lookup(struct inode *dir,
2280 struct dentry *dentry,
2281 const struct pid_entry *ents,
2282 unsigned int nents)
2283{
2284 struct dentry *error;
2285 struct task_struct *task = get_proc_task(dir);
2286 const struct pid_entry *p, *last;
2287
2288 error = ERR_PTR(-ENOENT);
2289
2290 if (!task)
2291 goto out_no_task;
2292
2293 /*
2294 * Yes, it does not scale. And it should not. Don't add
2295 * new entries into /proc/<tgid>/ without very good reasons.
2296 */
2297 last = &ents[nents - 1];
2298 for (p = ents; p <= last; p++) {
2299 if (p->len != dentry->d_name.len)
2300 continue;
2301 if (!memcmp(dentry->d_name.name, p->name, p->len))
2302 break;
2303 }
2304 if (p > last)
2305 goto out;
2306
2307 error = proc_pident_instantiate(dir, dentry, task, p);
2308out:
2309 put_task_struct(task);
2310out_no_task:
2311 return error;
2312}
2313
2314static int proc_pident_fill_cache(struct file *filp, void *dirent,
2315 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2316{
2317 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2318 proc_pident_instantiate, task, p);
2319}
2320
2321static int proc_pident_readdir(struct file *filp,
2322 void *dirent, filldir_t filldir,
2323 const struct pid_entry *ents, unsigned int nents)
2324{
2325 int i;
2326 struct dentry *dentry = filp->f_path.dentry;
2327 struct inode *inode = dentry->d_inode;
2328 struct task_struct *task = get_proc_task(inode);
2329 const struct pid_entry *p, *last;
2330 ino_t ino;
2331 int ret;
2332
2333 ret = -ENOENT;
2334 if (!task)
2335 goto out_no_task;
2336
2337 ret = 0;
2338 i = filp->f_pos;
2339 switch (i) {
2340 case 0:
2341 ino = inode->i_ino;
2342 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2343 goto out;
2344 i++;
2345 filp->f_pos++;
2346 /* fall through */
2347 case 1:
2348 ino = parent_ino(dentry);
2349 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2350 goto out;
2351 i++;
2352 filp->f_pos++;
2353 /* fall through */
2354 default:
2355 i -= 2;
2356 if (i >= nents) {
2357 ret = 1;
2358 goto out;
2359 }
2360 p = ents + i;
2361 last = &ents[nents - 1];
2362 while (p <= last) {
2363 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2364 goto out;
2365 filp->f_pos++;
2366 p++;
2367 }
2368 }
2369
2370 ret = 1;
2371out:
2372 put_task_struct(task);
2373out_no_task:
2374 return ret;
2375}
2376
2377#ifdef CONFIG_SECURITY
2378static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2379 size_t count, loff_t *ppos)
2380{
2381 struct inode * inode = file->f_path.dentry->d_inode;
2382 char *p = NULL;
2383 ssize_t length;
2384 struct task_struct *task = get_proc_task(inode);
2385
2386 if (!task)
2387 return -ESRCH;
2388
2389 length = security_getprocattr(task,
2390 (char*)file->f_path.dentry->d_name.name,
2391 &p);
2392 put_task_struct(task);
2393 if (length > 0)
2394 length = simple_read_from_buffer(buf, count, ppos, p, length);
2395 kfree(p);
2396 return length;
2397}
2398
2399static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2400 size_t count, loff_t *ppos)
2401{
2402 struct inode * inode = file->f_path.dentry->d_inode;
2403 char *page;
2404 ssize_t length;
2405 struct task_struct *task = get_proc_task(inode);
2406
2407 length = -ESRCH;
2408 if (!task)
2409 goto out_no_task;
2410 if (count > PAGE_SIZE)
2411 count = PAGE_SIZE;
2412
2413 /* No partial writes. */
2414 length = -EINVAL;
2415 if (*ppos != 0)
2416 goto out;
2417
2418 length = -ENOMEM;
2419 page = (char*)__get_free_page(GFP_TEMPORARY);
2420 if (!page)
2421 goto out;
2422
2423 length = -EFAULT;
2424 if (copy_from_user(page, buf, count))
2425 goto out_free;
2426
2427 /* Guard against adverse ptrace interaction */
2428 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2429 if (length < 0)
2430 goto out_free;
2431
2432 length = security_setprocattr(task,
2433 (char*)file->f_path.dentry->d_name.name,
2434 (void*)page, count);
2435 mutex_unlock(&task->signal->cred_guard_mutex);
2436out_free:
2437 free_page((unsigned long) page);
2438out:
2439 put_task_struct(task);
2440out_no_task:
2441 return length;
2442}
2443
2444static const struct file_operations proc_pid_attr_operations = {
2445 .read = proc_pid_attr_read,
2446 .write = proc_pid_attr_write,
2447 .llseek = generic_file_llseek,
2448};
2449
2450static const struct pid_entry attr_dir_stuff[] = {
2451 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2452 REG("prev", S_IRUGO, proc_pid_attr_operations),
2453 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2454 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2455 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2456 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2457};
2458
2459static int proc_attr_dir_readdir(struct file * filp,
2460 void * dirent, filldir_t filldir)
2461{
2462 return proc_pident_readdir(filp,dirent,filldir,
2463 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2464}
2465
2466static const struct file_operations proc_attr_dir_operations = {
2467 .read = generic_read_dir,
2468 .readdir = proc_attr_dir_readdir,
2469 .llseek = default_llseek,
2470};
2471
2472static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2473 struct dentry *dentry, struct nameidata *nd)
2474{
2475 return proc_pident_lookup(dir, dentry,
2476 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2477}
2478
2479static const struct inode_operations proc_attr_dir_inode_operations = {
2480 .lookup = proc_attr_dir_lookup,
2481 .getattr = pid_getattr,
2482 .setattr = proc_setattr,
2483};
2484
2485#endif
2486
2487#ifdef CONFIG_ELF_CORE
2488static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2489 size_t count, loff_t *ppos)
2490{
2491 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2492 struct mm_struct *mm;
2493 char buffer[PROC_NUMBUF];
2494 size_t len;
2495 int ret;
2496
2497 if (!task)
2498 return -ESRCH;
2499
2500 ret = 0;
2501 mm = get_task_mm(task);
2502 if (mm) {
2503 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2504 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2505 MMF_DUMP_FILTER_SHIFT));
2506 mmput(mm);
2507 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2508 }
2509
2510 put_task_struct(task);
2511
2512 return ret;
2513}
2514
2515static ssize_t proc_coredump_filter_write(struct file *file,
2516 const char __user *buf,
2517 size_t count,
2518 loff_t *ppos)
2519{
2520 struct task_struct *task;
2521 struct mm_struct *mm;
2522 char buffer[PROC_NUMBUF], *end;
2523 unsigned int val;
2524 int ret;
2525 int i;
2526 unsigned long mask;
2527
2528 ret = -EFAULT;
2529 memset(buffer, 0, sizeof(buffer));
2530 if (count > sizeof(buffer) - 1)
2531 count = sizeof(buffer) - 1;
2532 if (copy_from_user(buffer, buf, count))
2533 goto out_no_task;
2534
2535 ret = -EINVAL;
2536 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2537 if (*end == '\n')
2538 end++;
2539 if (end - buffer == 0)
2540 goto out_no_task;
2541
2542 ret = -ESRCH;
2543 task = get_proc_task(file->f_dentry->d_inode);
2544 if (!task)
2545 goto out_no_task;
2546
2547 ret = end - buffer;
2548 mm = get_task_mm(task);
2549 if (!mm)
2550 goto out_no_mm;
2551
2552 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2553 if (val & mask)
2554 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2555 else
2556 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2557 }
2558
2559 mmput(mm);
2560 out_no_mm:
2561 put_task_struct(task);
2562 out_no_task:
2563 return ret;
2564}
2565
2566static const struct file_operations proc_coredump_filter_operations = {
2567 .read = proc_coredump_filter_read,
2568 .write = proc_coredump_filter_write,
2569 .llseek = generic_file_llseek,
2570};
2571#endif
2572
2573/*
2574 * /proc/self:
2575 */
2576static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2577 int buflen)
2578{
2579 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2580 pid_t tgid = task_tgid_nr_ns(current, ns);
2581 char tmp[PROC_NUMBUF];
2582 if (!tgid)
2583 return -ENOENT;
2584 sprintf(tmp, "%d", tgid);
2585 return vfs_readlink(dentry,buffer,buflen,tmp);
2586}
2587
2588static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2589{
2590 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2591 pid_t tgid = task_tgid_nr_ns(current, ns);
2592 char *name = ERR_PTR(-ENOENT);
2593 if (tgid) {
2594 name = __getname();
2595 if (!name)
2596 name = ERR_PTR(-ENOMEM);
2597 else
2598 sprintf(name, "%d", tgid);
2599 }
2600 nd_set_link(nd, name);
2601 return NULL;
2602}
2603
2604static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2605 void *cookie)
2606{
2607 char *s = nd_get_link(nd);
2608 if (!IS_ERR(s))
2609 __putname(s);
2610}
2611
2612static const struct inode_operations proc_self_inode_operations = {
2613 .readlink = proc_self_readlink,
2614 .follow_link = proc_self_follow_link,
2615 .put_link = proc_self_put_link,
2616};
2617
2618/*
2619 * proc base
2620 *
2621 * These are the directory entries in the root directory of /proc
2622 * that properly belong to the /proc filesystem, as they describe
2623 * describe something that is process related.
2624 */
2625static const struct pid_entry proc_base_stuff[] = {
2626 NOD("self", S_IFLNK|S_IRWXUGO,
2627 &proc_self_inode_operations, NULL, {}),
2628};
2629
2630static struct dentry *proc_base_instantiate(struct inode *dir,
2631 struct dentry *dentry, struct task_struct *task, const void *ptr)
2632{
2633 const struct pid_entry *p = ptr;
2634 struct inode *inode;
2635 struct proc_inode *ei;
2636 struct dentry *error;
2637
2638 /* Allocate the inode */
2639 error = ERR_PTR(-ENOMEM);
2640 inode = new_inode(dir->i_sb);
2641 if (!inode)
2642 goto out;
2643
2644 /* Initialize the inode */
2645 ei = PROC_I(inode);
2646 inode->i_ino = get_next_ino();
2647 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2648
2649 /*
2650 * grab the reference to the task.
2651 */
2652 ei->pid = get_task_pid(task, PIDTYPE_PID);
2653 if (!ei->pid)
2654 goto out_iput;
2655
2656 inode->i_mode = p->mode;
2657 if (S_ISDIR(inode->i_mode))
2658 inode->i_nlink = 2;
2659 if (S_ISLNK(inode->i_mode))
2660 inode->i_size = 64;
2661 if (p->iop)
2662 inode->i_op = p->iop;
2663 if (p->fop)
2664 inode->i_fop = p->fop;
2665 ei->op = p->op;
2666 d_add(dentry, inode);
2667 error = NULL;
2668out:
2669 return error;
2670out_iput:
2671 iput(inode);
2672 goto out;
2673}
2674
2675static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2676{
2677 struct dentry *error;
2678 struct task_struct *task = get_proc_task(dir);
2679 const struct pid_entry *p, *last;
2680
2681 error = ERR_PTR(-ENOENT);
2682
2683 if (!task)
2684 goto out_no_task;
2685
2686 /* Lookup the directory entry */
2687 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2688 for (p = proc_base_stuff; p <= last; p++) {
2689 if (p->len != dentry->d_name.len)
2690 continue;
2691 if (!memcmp(dentry->d_name.name, p->name, p->len))
2692 break;
2693 }
2694 if (p > last)
2695 goto out;
2696
2697 error = proc_base_instantiate(dir, dentry, task, p);
2698
2699out:
2700 put_task_struct(task);
2701out_no_task:
2702 return error;
2703}
2704
2705static int proc_base_fill_cache(struct file *filp, void *dirent,
2706 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2707{
2708 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2709 proc_base_instantiate, task, p);
2710}
2711
2712#ifdef CONFIG_TASK_IO_ACCOUNTING
2713static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2714{
2715 struct task_io_accounting acct = task->ioac;
2716 unsigned long flags;
2717 int result;
2718
2719 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2720 if (result)
2721 return result;
2722
2723 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2724 result = -EACCES;
2725 goto out_unlock;
2726 }
2727
2728 if (whole && lock_task_sighand(task, &flags)) {
2729 struct task_struct *t = task;
2730
2731 task_io_accounting_add(&acct, &task->signal->ioac);
2732 while_each_thread(task, t)
2733 task_io_accounting_add(&acct, &t->ioac);
2734
2735 unlock_task_sighand(task, &flags);
2736 }
2737 result = sprintf(buffer,
2738 "rchar: %llu\n"
2739 "wchar: %llu\n"
2740 "syscr: %llu\n"
2741 "syscw: %llu\n"
2742 "read_bytes: %llu\n"
2743 "write_bytes: %llu\n"
2744 "cancelled_write_bytes: %llu\n",
2745 (unsigned long long)acct.rchar,
2746 (unsigned long long)acct.wchar,
2747 (unsigned long long)acct.syscr,
2748 (unsigned long long)acct.syscw,
2749 (unsigned long long)acct.read_bytes,
2750 (unsigned long long)acct.write_bytes,
2751 (unsigned long long)acct.cancelled_write_bytes);
2752out_unlock:
2753 mutex_unlock(&task->signal->cred_guard_mutex);
2754 return result;
2755}
2756
2757static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2758{
2759 return do_io_accounting(task, buffer, 0);
2760}
2761
2762static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2763{
2764 return do_io_accounting(task, buffer, 1);
2765}
2766#endif /* CONFIG_TASK_IO_ACCOUNTING */
2767
2768static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2769 struct pid *pid, struct task_struct *task)
2770{
2771 int err = lock_trace(task);
2772 if (!err) {
2773 seq_printf(m, "%08x\n", task->personality);
2774 unlock_trace(task);
2775 }
2776 return err;
2777}
2778
2779/*
2780 * Thread groups
2781 */
2782static const struct file_operations proc_task_operations;
2783static const struct inode_operations proc_task_inode_operations;
2784
2785static const struct pid_entry tgid_base_stuff[] = {
2786 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2787 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2788 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2789 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2790#ifdef CONFIG_NET
2791 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2792#endif
2793 REG("environ", S_IRUSR, proc_environ_operations),
2794 INF("auxv", S_IRUSR, proc_pid_auxv),
2795 ONE("status", S_IRUGO, proc_pid_status),
2796 ONE("personality", S_IRUGO, proc_pid_personality),
2797 INF("limits", S_IRUGO, proc_pid_limits),
2798#ifdef CONFIG_SCHED_DEBUG
2799 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2800#endif
2801#ifdef CONFIG_SCHED_AUTOGROUP
2802 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2803#endif
2804 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2805#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2806 INF("syscall", S_IRUGO, proc_pid_syscall),
2807#endif
2808 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2809 ONE("stat", S_IRUGO, proc_tgid_stat),
2810 ONE("statm", S_IRUGO, proc_pid_statm),
2811 REG("maps", S_IRUGO, proc_maps_operations),
2812#ifdef CONFIG_NUMA
2813 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2814#endif
2815 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2816 LNK("cwd", proc_cwd_link),
2817 LNK("root", proc_root_link),
2818 LNK("exe", proc_exe_link),
2819 REG("mounts", S_IRUGO, proc_mounts_operations),
2820 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2821 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2822#ifdef CONFIG_PROC_PAGE_MONITOR
2823 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2824 REG("smaps", S_IRUGO, proc_smaps_operations),
2825 REG("pagemap", S_IRUGO, proc_pagemap_operations),
2826#endif
2827#ifdef CONFIG_SECURITY
2828 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2829#endif
2830#ifdef CONFIG_KALLSYMS
2831 INF("wchan", S_IRUGO, proc_pid_wchan),
2832#endif
2833#ifdef CONFIG_STACKTRACE
2834 ONE("stack", S_IRUGO, proc_pid_stack),
2835#endif
2836#ifdef CONFIG_SCHEDSTATS
2837 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2838#endif
2839#ifdef CONFIG_LATENCYTOP
2840 REG("latency", S_IRUGO, proc_lstats_operations),
2841#endif
2842#ifdef CONFIG_PROC_PID_CPUSET
2843 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2844#endif
2845#ifdef CONFIG_CGROUPS
2846 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2847#endif
2848 INF("oom_score", S_IRUGO, proc_oom_score),
2849 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2850 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2851#ifdef CONFIG_AUDITSYSCALL
2852 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2853 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2854#endif
2855#ifdef CONFIG_FAULT_INJECTION
2856 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2857#endif
2858#ifdef CONFIG_ELF_CORE
2859 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2860#endif
2861#ifdef CONFIG_TASK_IO_ACCOUNTING
2862 INF("io", S_IRUSR, proc_tgid_io_accounting),
2863#endif
2864#ifdef CONFIG_HARDWALL
2865 INF("hardwall", S_IRUGO, proc_pid_hardwall),
2866#endif
2867};
2868
2869static int proc_tgid_base_readdir(struct file * filp,
2870 void * dirent, filldir_t filldir)
2871{
2872 return proc_pident_readdir(filp,dirent,filldir,
2873 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2874}
2875
2876static const struct file_operations proc_tgid_base_operations = {
2877 .read = generic_read_dir,
2878 .readdir = proc_tgid_base_readdir,
2879 .llseek = default_llseek,
2880};
2881
2882static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2883 return proc_pident_lookup(dir, dentry,
2884 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2885}
2886
2887static const struct inode_operations proc_tgid_base_inode_operations = {
2888 .lookup = proc_tgid_base_lookup,
2889 .getattr = pid_getattr,
2890 .setattr = proc_setattr,
2891};
2892
2893static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2894{
2895 struct dentry *dentry, *leader, *dir;
2896 char buf[PROC_NUMBUF];
2897 struct qstr name;
2898
2899 name.name = buf;
2900 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2901 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2902 if (dentry) {
2903 shrink_dcache_parent(dentry);
2904 d_drop(dentry);
2905 dput(dentry);
2906 }
2907
2908 name.name = buf;
2909 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2910 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2911 if (!leader)
2912 goto out;
2913
2914 name.name = "task";
2915 name.len = strlen(name.name);
2916 dir = d_hash_and_lookup(leader, &name);
2917 if (!dir)
2918 goto out_put_leader;
2919
2920 name.name = buf;
2921 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2922 dentry = d_hash_and_lookup(dir, &name);
2923 if (dentry) {
2924 shrink_dcache_parent(dentry);
2925 d_drop(dentry);
2926 dput(dentry);
2927 }
2928
2929 dput(dir);
2930out_put_leader:
2931 dput(leader);
2932out:
2933 return;
2934}
2935
2936/**
2937 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2938 * @task: task that should be flushed.
2939 *
2940 * When flushing dentries from proc, one needs to flush them from global
2941 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2942 * in. This call is supposed to do all of this job.
2943 *
2944 * Looks in the dcache for
2945 * /proc/@pid
2946 * /proc/@tgid/task/@pid
2947 * if either directory is present flushes it and all of it'ts children
2948 * from the dcache.
2949 *
2950 * It is safe and reasonable to cache /proc entries for a task until
2951 * that task exits. After that they just clog up the dcache with
2952 * useless entries, possibly causing useful dcache entries to be
2953 * flushed instead. This routine is proved to flush those useless
2954 * dcache entries at process exit time.
2955 *
2956 * NOTE: This routine is just an optimization so it does not guarantee
2957 * that no dcache entries will exist at process exit time it
2958 * just makes it very unlikely that any will persist.
2959 */
2960
2961void proc_flush_task(struct task_struct *task)
2962{
2963 int i;
2964 struct pid *pid, *tgid;
2965 struct upid *upid;
2966
2967 pid = task_pid(task);
2968 tgid = task_tgid(task);
2969
2970 for (i = 0; i <= pid->level; i++) {
2971 upid = &pid->numbers[i];
2972 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2973 tgid->numbers[i].nr);
2974 }
2975
2976 upid = &pid->numbers[pid->level];
2977 if (upid->nr == 1)
2978 pid_ns_release_proc(upid->ns);
2979}
2980
2981static struct dentry *proc_pid_instantiate(struct inode *dir,
2982 struct dentry * dentry,
2983 struct task_struct *task, const void *ptr)
2984{
2985 struct dentry *error = ERR_PTR(-ENOENT);
2986 struct inode *inode;
2987
2988 inode = proc_pid_make_inode(dir->i_sb, task);
2989 if (!inode)
2990 goto out;
2991
2992 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2993 inode->i_op = &proc_tgid_base_inode_operations;
2994 inode->i_fop = &proc_tgid_base_operations;
2995 inode->i_flags|=S_IMMUTABLE;
2996
2997 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2998 ARRAY_SIZE(tgid_base_stuff));
2999
3000 d_set_d_op(dentry, &pid_dentry_operations);
3001
3002 d_add(dentry, inode);
3003 /* Close the race of the process dying before we return the dentry */
3004 if (pid_revalidate(dentry, NULL))
3005 error = NULL;
3006out:
3007 return error;
3008}
3009
3010struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3011{
3012 struct dentry *result;
3013 struct task_struct *task;
3014 unsigned tgid;
3015 struct pid_namespace *ns;
3016
3017 result = proc_base_lookup(dir, dentry);
3018 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
3019 goto out;
3020
3021 tgid = name_to_int(dentry);
3022 if (tgid == ~0U)
3023 goto out;
3024
3025 ns = dentry->d_sb->s_fs_info;
3026 rcu_read_lock();
3027 task = find_task_by_pid_ns(tgid, ns);
3028 if (task)
3029 get_task_struct(task);
3030 rcu_read_unlock();
3031 if (!task)
3032 goto out;
3033
3034 result = proc_pid_instantiate(dir, dentry, task, NULL);
3035 put_task_struct(task);
3036out:
3037 return result;
3038}
3039
3040/*
3041 * Find the first task with tgid >= tgid
3042 *
3043 */
3044struct tgid_iter {
3045 unsigned int tgid;
3046 struct task_struct *task;
3047};
3048static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3049{
3050 struct pid *pid;
3051
3052 if (iter.task)
3053 put_task_struct(iter.task);
3054 rcu_read_lock();
3055retry:
3056 iter.task = NULL;
3057 pid = find_ge_pid(iter.tgid, ns);
3058 if (pid) {
3059 iter.tgid = pid_nr_ns(pid, ns);
3060 iter.task = pid_task(pid, PIDTYPE_PID);
3061 /* What we to know is if the pid we have find is the
3062 * pid of a thread_group_leader. Testing for task
3063 * being a thread_group_leader is the obvious thing
3064 * todo but there is a window when it fails, due to
3065 * the pid transfer logic in de_thread.
3066 *
3067 * So we perform the straight forward test of seeing
3068 * if the pid we have found is the pid of a thread
3069 * group leader, and don't worry if the task we have
3070 * found doesn't happen to be a thread group leader.
3071 * As we don't care in the case of readdir.
3072 */
3073 if (!iter.task || !has_group_leader_pid(iter.task)) {
3074 iter.tgid += 1;
3075 goto retry;
3076 }
3077 get_task_struct(iter.task);
3078 }
3079 rcu_read_unlock();
3080 return iter;
3081}
3082
3083#define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3084
3085static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3086 struct tgid_iter iter)
3087{
3088 char name[PROC_NUMBUF];
3089 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3090 return proc_fill_cache(filp, dirent, filldir, name, len,
3091 proc_pid_instantiate, iter.task, NULL);
3092}
3093
3094/* for the /proc/ directory itself, after non-process stuff has been done */
3095int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3096{
3097 unsigned int nr;
3098 struct task_struct *reaper;
3099 struct tgid_iter iter;
3100 struct pid_namespace *ns;
3101
3102 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3103 goto out_no_task;
3104 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3105
3106 reaper = get_proc_task(filp->f_path.dentry->d_inode);
3107 if (!reaper)
3108 goto out_no_task;
3109
3110 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3111 const struct pid_entry *p = &proc_base_stuff[nr];
3112 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3113 goto out;
3114 }
3115
3116 ns = filp->f_dentry->d_sb->s_fs_info;
3117 iter.task = NULL;
3118 iter.tgid = filp->f_pos - TGID_OFFSET;
3119 for (iter = next_tgid(ns, iter);
3120 iter.task;
3121 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3122 filp->f_pos = iter.tgid + TGID_OFFSET;
3123 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
3124 put_task_struct(iter.task);
3125 goto out;
3126 }
3127 }
3128 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3129out:
3130 put_task_struct(reaper);
3131out_no_task:
3132 return 0;
3133}
3134
3135/*
3136 * Tasks
3137 */
3138static const struct pid_entry tid_base_stuff[] = {
3139 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3140 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3141 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3142 REG("environ", S_IRUSR, proc_environ_operations),
3143 INF("auxv", S_IRUSR, proc_pid_auxv),
3144 ONE("status", S_IRUGO, proc_pid_status),
3145 ONE("personality", S_IRUGO, proc_pid_personality),
3146 INF("limits", S_IRUGO, proc_pid_limits),
3147#ifdef CONFIG_SCHED_DEBUG
3148 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3149#endif
3150 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3151#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3152 INF("syscall", S_IRUGO, proc_pid_syscall),
3153#endif
3154 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3155 ONE("stat", S_IRUGO, proc_tid_stat),
3156 ONE("statm", S_IRUGO, proc_pid_statm),
3157 REG("maps", S_IRUGO, proc_maps_operations),
3158#ifdef CONFIG_NUMA
3159 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3160#endif
3161 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3162 LNK("cwd", proc_cwd_link),
3163 LNK("root", proc_root_link),
3164 LNK("exe", proc_exe_link),
3165 REG("mounts", S_IRUGO, proc_mounts_operations),
3166 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3167#ifdef CONFIG_PROC_PAGE_MONITOR
3168 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3169 REG("smaps", S_IRUGO, proc_smaps_operations),
3170 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3171#endif
3172#ifdef CONFIG_SECURITY
3173 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3174#endif
3175#ifdef CONFIG_KALLSYMS
3176 INF("wchan", S_IRUGO, proc_pid_wchan),
3177#endif
3178#ifdef CONFIG_STACKTRACE
3179 ONE("stack", S_IRUGO, proc_pid_stack),
3180#endif
3181#ifdef CONFIG_SCHEDSTATS
3182 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3183#endif
3184#ifdef CONFIG_LATENCYTOP
3185 REG("latency", S_IRUGO, proc_lstats_operations),
3186#endif
3187#ifdef CONFIG_PROC_PID_CPUSET
3188 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3189#endif
3190#ifdef CONFIG_CGROUPS
3191 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3192#endif
3193 INF("oom_score", S_IRUGO, proc_oom_score),
3194 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3195 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3196#ifdef CONFIG_AUDITSYSCALL
3197 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3198 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3199#endif
3200#ifdef CONFIG_FAULT_INJECTION
3201 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3202#endif
3203#ifdef CONFIG_TASK_IO_ACCOUNTING
3204 INF("io", S_IRUSR, proc_tid_io_accounting),
3205#endif
3206#ifdef CONFIG_HARDWALL
3207 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3208#endif
3209};
3210
3211static int proc_tid_base_readdir(struct file * filp,
3212 void * dirent, filldir_t filldir)
3213{
3214 return proc_pident_readdir(filp,dirent,filldir,
3215 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3216}
3217
3218static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3219 return proc_pident_lookup(dir, dentry,
3220 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3221}
3222
3223static const struct file_operations proc_tid_base_operations = {
3224 .read = generic_read_dir,
3225 .readdir = proc_tid_base_readdir,
3226 .llseek = default_llseek,
3227};
3228
3229static const struct inode_operations proc_tid_base_inode_operations = {
3230 .lookup = proc_tid_base_lookup,
3231 .getattr = pid_getattr,
3232 .setattr = proc_setattr,
3233};
3234
3235static struct dentry *proc_task_instantiate(struct inode *dir,
3236 struct dentry *dentry, struct task_struct *task, const void *ptr)
3237{
3238 struct dentry *error = ERR_PTR(-ENOENT);
3239 struct inode *inode;
3240 inode = proc_pid_make_inode(dir->i_sb, task);
3241
3242 if (!inode)
3243 goto out;
3244 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3245 inode->i_op = &proc_tid_base_inode_operations;
3246 inode->i_fop = &proc_tid_base_operations;
3247 inode->i_flags|=S_IMMUTABLE;
3248
3249 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3250 ARRAY_SIZE(tid_base_stuff));
3251
3252 d_set_d_op(dentry, &pid_dentry_operations);
3253
3254 d_add(dentry, inode);
3255 /* Close the race of the process dying before we return the dentry */
3256 if (pid_revalidate(dentry, NULL))
3257 error = NULL;
3258out:
3259 return error;
3260}
3261
3262static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3263{
3264 struct dentry *result = ERR_PTR(-ENOENT);
3265 struct task_struct *task;
3266 struct task_struct *leader = get_proc_task(dir);
3267 unsigned tid;
3268 struct pid_namespace *ns;
3269
3270 if (!leader)
3271 goto out_no_task;
3272
3273 tid = name_to_int(dentry);
3274 if (tid == ~0U)
3275 goto out;
3276
3277 ns = dentry->d_sb->s_fs_info;
3278 rcu_read_lock();
3279 task = find_task_by_pid_ns(tid, ns);
3280 if (task)
3281 get_task_struct(task);
3282 rcu_read_unlock();
3283 if (!task)
3284 goto out;
3285 if (!same_thread_group(leader, task))
3286 goto out_drop_task;
3287
3288 result = proc_task_instantiate(dir, dentry, task, NULL);
3289out_drop_task:
3290 put_task_struct(task);
3291out:
3292 put_task_struct(leader);
3293out_no_task:
3294 return result;
3295}
3296
3297/*
3298 * Find the first tid of a thread group to return to user space.
3299 *
3300 * Usually this is just the thread group leader, but if the users
3301 * buffer was too small or there was a seek into the middle of the
3302 * directory we have more work todo.
3303 *
3304 * In the case of a short read we start with find_task_by_pid.
3305 *
3306 * In the case of a seek we start with the leader and walk nr
3307 * threads past it.
3308 */
3309static struct task_struct *first_tid(struct task_struct *leader,
3310 int tid, int nr, struct pid_namespace *ns)
3311{
3312 struct task_struct *pos;
3313
3314 rcu_read_lock();
3315 /* Attempt to start with the pid of a thread */
3316 if (tid && (nr > 0)) {
3317 pos = find_task_by_pid_ns(tid, ns);
3318 if (pos && (pos->group_leader == leader))
3319 goto found;
3320 }
3321
3322 /* If nr exceeds the number of threads there is nothing todo */
3323 pos = NULL;
3324 if (nr && nr >= get_nr_threads(leader))
3325 goto out;
3326
3327 /* If we haven't found our starting place yet start
3328 * with the leader and walk nr threads forward.
3329 */
3330 for (pos = leader; nr > 0; --nr) {
3331 pos = next_thread(pos);
3332 if (pos == leader) {
3333 pos = NULL;
3334 goto out;
3335 }
3336 }
3337found:
3338 get_task_struct(pos);
3339out:
3340 rcu_read_unlock();
3341 return pos;
3342}
3343
3344/*
3345 * Find the next thread in the thread list.
3346 * Return NULL if there is an error or no next thread.
3347 *
3348 * The reference to the input task_struct is released.
3349 */
3350static struct task_struct *next_tid(struct task_struct *start)
3351{
3352 struct task_struct *pos = NULL;
3353 rcu_read_lock();
3354 if (pid_alive(start)) {
3355 pos = next_thread(start);
3356 if (thread_group_leader(pos))
3357 pos = NULL;
3358 else
3359 get_task_struct(pos);
3360 }
3361 rcu_read_unlock();
3362 put_task_struct(start);
3363 return pos;
3364}
3365
3366static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3367 struct task_struct *task, int tid)
3368{
3369 char name[PROC_NUMBUF];
3370 int len = snprintf(name, sizeof(name), "%d", tid);
3371 return proc_fill_cache(filp, dirent, filldir, name, len,
3372 proc_task_instantiate, task, NULL);
3373}
3374
3375/* for the /proc/TGID/task/ directories */
3376static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3377{
3378 struct dentry *dentry = filp->f_path.dentry;
3379 struct inode *inode = dentry->d_inode;
3380 struct task_struct *leader = NULL;
3381 struct task_struct *task;
3382 int retval = -ENOENT;
3383 ino_t ino;
3384 int tid;
3385 struct pid_namespace *ns;
3386
3387 task = get_proc_task(inode);
3388 if (!task)
3389 goto out_no_task;
3390 rcu_read_lock();
3391 if (pid_alive(task)) {
3392 leader = task->group_leader;
3393 get_task_struct(leader);
3394 }
3395 rcu_read_unlock();
3396 put_task_struct(task);
3397 if (!leader)
3398 goto out_no_task;
3399 retval = 0;
3400
3401 switch ((unsigned long)filp->f_pos) {
3402 case 0:
3403 ino = inode->i_ino;
3404 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3405 goto out;
3406 filp->f_pos++;
3407 /* fall through */
3408 case 1:
3409 ino = parent_ino(dentry);
3410 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3411 goto out;
3412 filp->f_pos++;
3413 /* fall through */
3414 }
3415
3416 /* f_version caches the tgid value that the last readdir call couldn't
3417 * return. lseek aka telldir automagically resets f_version to 0.
3418 */
3419 ns = filp->f_dentry->d_sb->s_fs_info;
3420 tid = (int)filp->f_version;
3421 filp->f_version = 0;
3422 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3423 task;
3424 task = next_tid(task), filp->f_pos++) {
3425 tid = task_pid_nr_ns(task, ns);
3426 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3427 /* returning this tgid failed, save it as the first
3428 * pid for the next readir call */
3429 filp->f_version = (u64)tid;
3430 put_task_struct(task);
3431 break;
3432 }
3433 }
3434out:
3435 put_task_struct(leader);
3436out_no_task:
3437 return retval;
3438}
3439
3440static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3441{
3442 struct inode *inode = dentry->d_inode;
3443 struct task_struct *p = get_proc_task(inode);
3444 generic_fillattr(inode, stat);
3445
3446 if (p) {
3447 stat->nlink += get_nr_threads(p);
3448 put_task_struct(p);
3449 }
3450
3451 return 0;
3452}
3453
3454static const struct inode_operations proc_task_inode_operations = {
3455 .lookup = proc_task_lookup,
3456 .getattr = proc_task_getattr,
3457 .setattr = proc_setattr,
3458};
3459
3460static const struct file_operations proc_task_operations = {
3461 .read = generic_read_dir,
3462 .readdir = proc_task_readdir,
3463 .llseek = default_llseek,
3464};
1/*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50#include <asm/uaccess.h>
51
52#include <linux/errno.h>
53#include <linux/time.h>
54#include <linux/proc_fs.h>
55#include <linux/stat.h>
56#include <linux/task_io_accounting_ops.h>
57#include <linux/init.h>
58#include <linux/capability.h>
59#include <linux/file.h>
60#include <linux/fdtable.h>
61#include <linux/string.h>
62#include <linux/seq_file.h>
63#include <linux/namei.h>
64#include <linux/mnt_namespace.h>
65#include <linux/mm.h>
66#include <linux/swap.h>
67#include <linux/rcupdate.h>
68#include <linux/kallsyms.h>
69#include <linux/stacktrace.h>
70#include <linux/resource.h>
71#include <linux/module.h>
72#include <linux/mount.h>
73#include <linux/security.h>
74#include <linux/ptrace.h>
75#include <linux/tracehook.h>
76#include <linux/printk.h>
77#include <linux/cgroup.h>
78#include <linux/cpuset.h>
79#include <linux/audit.h>
80#include <linux/poll.h>
81#include <linux/nsproxy.h>
82#include <linux/oom.h>
83#include <linux/elf.h>
84#include <linux/pid_namespace.h>
85#include <linux/user_namespace.h>
86#include <linux/fs_struct.h>
87#include <linux/slab.h>
88#include <linux/flex_array.h>
89#include <linux/posix-timers.h>
90#ifdef CONFIG_HARDWALL
91#include <asm/hardwall.h>
92#endif
93#include <trace/events/oom.h>
94#include "internal.h"
95#include "fd.h"
96
97/* NOTE:
98 * Implementing inode permission operations in /proc is almost
99 * certainly an error. Permission checks need to happen during
100 * each system call not at open time. The reason is that most of
101 * what we wish to check for permissions in /proc varies at runtime.
102 *
103 * The classic example of a problem is opening file descriptors
104 * in /proc for a task before it execs a suid executable.
105 */
106
107struct pid_entry {
108 char *name;
109 int len;
110 umode_t mode;
111 const struct inode_operations *iop;
112 const struct file_operations *fop;
113 union proc_op op;
114};
115
116#define NOD(NAME, MODE, IOP, FOP, OP) { \
117 .name = (NAME), \
118 .len = sizeof(NAME) - 1, \
119 .mode = MODE, \
120 .iop = IOP, \
121 .fop = FOP, \
122 .op = OP, \
123}
124
125#define DIR(NAME, MODE, iops, fops) \
126 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
127#define LNK(NAME, get_link) \
128 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
129 &proc_pid_link_inode_operations, NULL, \
130 { .proc_get_link = get_link } )
131#define REG(NAME, MODE, fops) \
132 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
133#define INF(NAME, MODE, read) \
134 NOD(NAME, (S_IFREG|(MODE)), \
135 NULL, &proc_info_file_operations, \
136 { .proc_read = read } )
137#define ONE(NAME, MODE, show) \
138 NOD(NAME, (S_IFREG|(MODE)), \
139 NULL, &proc_single_file_operations, \
140 { .proc_show = show } )
141
142/*
143 * Count the number of hardlinks for the pid_entry table, excluding the .
144 * and .. links.
145 */
146static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
147 unsigned int n)
148{
149 unsigned int i;
150 unsigned int count;
151
152 count = 0;
153 for (i = 0; i < n; ++i) {
154 if (S_ISDIR(entries[i].mode))
155 ++count;
156 }
157
158 return count;
159}
160
161static int get_task_root(struct task_struct *task, struct path *root)
162{
163 int result = -ENOENT;
164
165 task_lock(task);
166 if (task->fs) {
167 get_fs_root(task->fs, root);
168 result = 0;
169 }
170 task_unlock(task);
171 return result;
172}
173
174static int proc_cwd_link(struct dentry *dentry, struct path *path)
175{
176 struct task_struct *task = get_proc_task(dentry->d_inode);
177 int result = -ENOENT;
178
179 if (task) {
180 task_lock(task);
181 if (task->fs) {
182 get_fs_pwd(task->fs, path);
183 result = 0;
184 }
185 task_unlock(task);
186 put_task_struct(task);
187 }
188 return result;
189}
190
191static int proc_root_link(struct dentry *dentry, struct path *path)
192{
193 struct task_struct *task = get_proc_task(dentry->d_inode);
194 int result = -ENOENT;
195
196 if (task) {
197 result = get_task_root(task, path);
198 put_task_struct(task);
199 }
200 return result;
201}
202
203static int proc_pid_cmdline(struct task_struct *task, char *buffer)
204{
205 return get_cmdline(task, buffer, PAGE_SIZE);
206}
207
208static int proc_pid_auxv(struct task_struct *task, char *buffer)
209{
210 struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ);
211 int res = PTR_ERR(mm);
212 if (mm && !IS_ERR(mm)) {
213 unsigned int nwords = 0;
214 do {
215 nwords += 2;
216 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
217 res = nwords * sizeof(mm->saved_auxv[0]);
218 if (res > PAGE_SIZE)
219 res = PAGE_SIZE;
220 memcpy(buffer, mm->saved_auxv, res);
221 mmput(mm);
222 }
223 return res;
224}
225
226
227#ifdef CONFIG_KALLSYMS
228/*
229 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
230 * Returns the resolved symbol. If that fails, simply return the address.
231 */
232static int proc_pid_wchan(struct task_struct *task, char *buffer)
233{
234 unsigned long wchan;
235 char symname[KSYM_NAME_LEN];
236
237 wchan = get_wchan(task);
238
239 if (lookup_symbol_name(wchan, symname) < 0)
240 if (!ptrace_may_access(task, PTRACE_MODE_READ))
241 return 0;
242 else
243 return sprintf(buffer, "%lu", wchan);
244 else
245 return sprintf(buffer, "%s", symname);
246}
247#endif /* CONFIG_KALLSYMS */
248
249static int lock_trace(struct task_struct *task)
250{
251 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
252 if (err)
253 return err;
254 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
255 mutex_unlock(&task->signal->cred_guard_mutex);
256 return -EPERM;
257 }
258 return 0;
259}
260
261static void unlock_trace(struct task_struct *task)
262{
263 mutex_unlock(&task->signal->cred_guard_mutex);
264}
265
266#ifdef CONFIG_STACKTRACE
267
268#define MAX_STACK_TRACE_DEPTH 64
269
270static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
271 struct pid *pid, struct task_struct *task)
272{
273 struct stack_trace trace;
274 unsigned long *entries;
275 int err;
276 int i;
277
278 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
279 if (!entries)
280 return -ENOMEM;
281
282 trace.nr_entries = 0;
283 trace.max_entries = MAX_STACK_TRACE_DEPTH;
284 trace.entries = entries;
285 trace.skip = 0;
286
287 err = lock_trace(task);
288 if (!err) {
289 save_stack_trace_tsk(task, &trace);
290
291 for (i = 0; i < trace.nr_entries; i++) {
292 seq_printf(m, "[<%pK>] %pS\n",
293 (void *)entries[i], (void *)entries[i]);
294 }
295 unlock_trace(task);
296 }
297 kfree(entries);
298
299 return err;
300}
301#endif
302
303#ifdef CONFIG_SCHEDSTATS
304/*
305 * Provides /proc/PID/schedstat
306 */
307static int proc_pid_schedstat(struct task_struct *task, char *buffer)
308{
309 return sprintf(buffer, "%llu %llu %lu\n",
310 (unsigned long long)task->se.sum_exec_runtime,
311 (unsigned long long)task->sched_info.run_delay,
312 task->sched_info.pcount);
313}
314#endif
315
316#ifdef CONFIG_LATENCYTOP
317static int lstats_show_proc(struct seq_file *m, void *v)
318{
319 int i;
320 struct inode *inode = m->private;
321 struct task_struct *task = get_proc_task(inode);
322
323 if (!task)
324 return -ESRCH;
325 seq_puts(m, "Latency Top version : v0.1\n");
326 for (i = 0; i < 32; i++) {
327 struct latency_record *lr = &task->latency_record[i];
328 if (lr->backtrace[0]) {
329 int q;
330 seq_printf(m, "%i %li %li",
331 lr->count, lr->time, lr->max);
332 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
333 unsigned long bt = lr->backtrace[q];
334 if (!bt)
335 break;
336 if (bt == ULONG_MAX)
337 break;
338 seq_printf(m, " %ps", (void *)bt);
339 }
340 seq_putc(m, '\n');
341 }
342
343 }
344 put_task_struct(task);
345 return 0;
346}
347
348static int lstats_open(struct inode *inode, struct file *file)
349{
350 return single_open(file, lstats_show_proc, inode);
351}
352
353static ssize_t lstats_write(struct file *file, const char __user *buf,
354 size_t count, loff_t *offs)
355{
356 struct task_struct *task = get_proc_task(file_inode(file));
357
358 if (!task)
359 return -ESRCH;
360 clear_all_latency_tracing(task);
361 put_task_struct(task);
362
363 return count;
364}
365
366static const struct file_operations proc_lstats_operations = {
367 .open = lstats_open,
368 .read = seq_read,
369 .write = lstats_write,
370 .llseek = seq_lseek,
371 .release = single_release,
372};
373
374#endif
375
376#ifdef CONFIG_CGROUPS
377static int cgroup_open(struct inode *inode, struct file *file)
378{
379 struct pid *pid = PROC_I(inode)->pid;
380 return single_open(file, proc_cgroup_show, pid);
381}
382
383static const struct file_operations proc_cgroup_operations = {
384 .open = cgroup_open,
385 .read = seq_read,
386 .llseek = seq_lseek,
387 .release = single_release,
388};
389#endif
390
391#ifdef CONFIG_PROC_PID_CPUSET
392
393static int cpuset_open(struct inode *inode, struct file *file)
394{
395 struct pid *pid = PROC_I(inode)->pid;
396 return single_open(file, proc_cpuset_show, pid);
397}
398
399static const struct file_operations proc_cpuset_operations = {
400 .open = cpuset_open,
401 .read = seq_read,
402 .llseek = seq_lseek,
403 .release = single_release,
404};
405#endif
406
407static int proc_oom_score(struct task_struct *task, char *buffer)
408{
409 unsigned long totalpages = totalram_pages + total_swap_pages;
410 unsigned long points = 0;
411
412 read_lock(&tasklist_lock);
413 if (pid_alive(task))
414 points = oom_badness(task, NULL, NULL, totalpages) *
415 1000 / totalpages;
416 read_unlock(&tasklist_lock);
417 return sprintf(buffer, "%lu\n", points);
418}
419
420struct limit_names {
421 char *name;
422 char *unit;
423};
424
425static const struct limit_names lnames[RLIM_NLIMITS] = {
426 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
427 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
428 [RLIMIT_DATA] = {"Max data size", "bytes"},
429 [RLIMIT_STACK] = {"Max stack size", "bytes"},
430 [RLIMIT_CORE] = {"Max core file size", "bytes"},
431 [RLIMIT_RSS] = {"Max resident set", "bytes"},
432 [RLIMIT_NPROC] = {"Max processes", "processes"},
433 [RLIMIT_NOFILE] = {"Max open files", "files"},
434 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
435 [RLIMIT_AS] = {"Max address space", "bytes"},
436 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
437 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
438 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
439 [RLIMIT_NICE] = {"Max nice priority", NULL},
440 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
441 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
442};
443
444/* Display limits for a process */
445static int proc_pid_limits(struct task_struct *task, char *buffer)
446{
447 unsigned int i;
448 int count = 0;
449 unsigned long flags;
450 char *bufptr = buffer;
451
452 struct rlimit rlim[RLIM_NLIMITS];
453
454 if (!lock_task_sighand(task, &flags))
455 return 0;
456 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
457 unlock_task_sighand(task, &flags);
458
459 /*
460 * print the file header
461 */
462 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
463 "Limit", "Soft Limit", "Hard Limit", "Units");
464
465 for (i = 0; i < RLIM_NLIMITS; i++) {
466 if (rlim[i].rlim_cur == RLIM_INFINITY)
467 count += sprintf(&bufptr[count], "%-25s %-20s ",
468 lnames[i].name, "unlimited");
469 else
470 count += sprintf(&bufptr[count], "%-25s %-20lu ",
471 lnames[i].name, rlim[i].rlim_cur);
472
473 if (rlim[i].rlim_max == RLIM_INFINITY)
474 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
475 else
476 count += sprintf(&bufptr[count], "%-20lu ",
477 rlim[i].rlim_max);
478
479 if (lnames[i].unit)
480 count += sprintf(&bufptr[count], "%-10s\n",
481 lnames[i].unit);
482 else
483 count += sprintf(&bufptr[count], "\n");
484 }
485
486 return count;
487}
488
489#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
490static int proc_pid_syscall(struct task_struct *task, char *buffer)
491{
492 long nr;
493 unsigned long args[6], sp, pc;
494 int res = lock_trace(task);
495 if (res)
496 return res;
497
498 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
499 res = sprintf(buffer, "running\n");
500 else if (nr < 0)
501 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
502 else
503 res = sprintf(buffer,
504 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
505 nr,
506 args[0], args[1], args[2], args[3], args[4], args[5],
507 sp, pc);
508 unlock_trace(task);
509 return res;
510}
511#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
512
513/************************************************************************/
514/* Here the fs part begins */
515/************************************************************************/
516
517/* permission checks */
518static int proc_fd_access_allowed(struct inode *inode)
519{
520 struct task_struct *task;
521 int allowed = 0;
522 /* Allow access to a task's file descriptors if it is us or we
523 * may use ptrace attach to the process and find out that
524 * information.
525 */
526 task = get_proc_task(inode);
527 if (task) {
528 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
529 put_task_struct(task);
530 }
531 return allowed;
532}
533
534int proc_setattr(struct dentry *dentry, struct iattr *attr)
535{
536 int error;
537 struct inode *inode = dentry->d_inode;
538
539 if (attr->ia_valid & ATTR_MODE)
540 return -EPERM;
541
542 error = inode_change_ok(inode, attr);
543 if (error)
544 return error;
545
546 setattr_copy(inode, attr);
547 mark_inode_dirty(inode);
548 return 0;
549}
550
551/*
552 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
553 * or euid/egid (for hide_pid_min=2)?
554 */
555static bool has_pid_permissions(struct pid_namespace *pid,
556 struct task_struct *task,
557 int hide_pid_min)
558{
559 if (pid->hide_pid < hide_pid_min)
560 return true;
561 if (in_group_p(pid->pid_gid))
562 return true;
563 return ptrace_may_access(task, PTRACE_MODE_READ);
564}
565
566
567static int proc_pid_permission(struct inode *inode, int mask)
568{
569 struct pid_namespace *pid = inode->i_sb->s_fs_info;
570 struct task_struct *task;
571 bool has_perms;
572
573 task = get_proc_task(inode);
574 if (!task)
575 return -ESRCH;
576 has_perms = has_pid_permissions(pid, task, 1);
577 put_task_struct(task);
578
579 if (!has_perms) {
580 if (pid->hide_pid == 2) {
581 /*
582 * Let's make getdents(), stat(), and open()
583 * consistent with each other. If a process
584 * may not stat() a file, it shouldn't be seen
585 * in procfs at all.
586 */
587 return -ENOENT;
588 }
589
590 return -EPERM;
591 }
592 return generic_permission(inode, mask);
593}
594
595
596
597static const struct inode_operations proc_def_inode_operations = {
598 .setattr = proc_setattr,
599};
600
601#define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
602
603static ssize_t proc_info_read(struct file * file, char __user * buf,
604 size_t count, loff_t *ppos)
605{
606 struct inode * inode = file_inode(file);
607 unsigned long page;
608 ssize_t length;
609 struct task_struct *task = get_proc_task(inode);
610
611 length = -ESRCH;
612 if (!task)
613 goto out_no_task;
614
615 if (count > PROC_BLOCK_SIZE)
616 count = PROC_BLOCK_SIZE;
617
618 length = -ENOMEM;
619 if (!(page = __get_free_page(GFP_TEMPORARY)))
620 goto out;
621
622 length = PROC_I(inode)->op.proc_read(task, (char*)page);
623
624 if (length >= 0)
625 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
626 free_page(page);
627out:
628 put_task_struct(task);
629out_no_task:
630 return length;
631}
632
633static const struct file_operations proc_info_file_operations = {
634 .read = proc_info_read,
635 .llseek = generic_file_llseek,
636};
637
638static int proc_single_show(struct seq_file *m, void *v)
639{
640 struct inode *inode = m->private;
641 struct pid_namespace *ns;
642 struct pid *pid;
643 struct task_struct *task;
644 int ret;
645
646 ns = inode->i_sb->s_fs_info;
647 pid = proc_pid(inode);
648 task = get_pid_task(pid, PIDTYPE_PID);
649 if (!task)
650 return -ESRCH;
651
652 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
653
654 put_task_struct(task);
655 return ret;
656}
657
658static int proc_single_open(struct inode *inode, struct file *filp)
659{
660 return single_open(filp, proc_single_show, inode);
661}
662
663static const struct file_operations proc_single_file_operations = {
664 .open = proc_single_open,
665 .read = seq_read,
666 .llseek = seq_lseek,
667 .release = single_release,
668};
669
670static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
671{
672 struct task_struct *task = get_proc_task(file_inode(file));
673 struct mm_struct *mm;
674
675 if (!task)
676 return -ESRCH;
677
678 mm = mm_access(task, mode);
679 put_task_struct(task);
680
681 if (IS_ERR(mm))
682 return PTR_ERR(mm);
683
684 if (mm) {
685 /* ensure this mm_struct can't be freed */
686 atomic_inc(&mm->mm_count);
687 /* but do not pin its memory */
688 mmput(mm);
689 }
690
691 file->private_data = mm;
692
693 return 0;
694}
695
696static int mem_open(struct inode *inode, struct file *file)
697{
698 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
699
700 /* OK to pass negative loff_t, we can catch out-of-range */
701 file->f_mode |= FMODE_UNSIGNED_OFFSET;
702
703 return ret;
704}
705
706static ssize_t mem_rw(struct file *file, char __user *buf,
707 size_t count, loff_t *ppos, int write)
708{
709 struct mm_struct *mm = file->private_data;
710 unsigned long addr = *ppos;
711 ssize_t copied;
712 char *page;
713
714 if (!mm)
715 return 0;
716
717 page = (char *)__get_free_page(GFP_TEMPORARY);
718 if (!page)
719 return -ENOMEM;
720
721 copied = 0;
722 if (!atomic_inc_not_zero(&mm->mm_users))
723 goto free;
724
725 while (count > 0) {
726 int this_len = min_t(int, count, PAGE_SIZE);
727
728 if (write && copy_from_user(page, buf, this_len)) {
729 copied = -EFAULT;
730 break;
731 }
732
733 this_len = access_remote_vm(mm, addr, page, this_len, write);
734 if (!this_len) {
735 if (!copied)
736 copied = -EIO;
737 break;
738 }
739
740 if (!write && copy_to_user(buf, page, this_len)) {
741 copied = -EFAULT;
742 break;
743 }
744
745 buf += this_len;
746 addr += this_len;
747 copied += this_len;
748 count -= this_len;
749 }
750 *ppos = addr;
751
752 mmput(mm);
753free:
754 free_page((unsigned long) page);
755 return copied;
756}
757
758static ssize_t mem_read(struct file *file, char __user *buf,
759 size_t count, loff_t *ppos)
760{
761 return mem_rw(file, buf, count, ppos, 0);
762}
763
764static ssize_t mem_write(struct file *file, const char __user *buf,
765 size_t count, loff_t *ppos)
766{
767 return mem_rw(file, (char __user*)buf, count, ppos, 1);
768}
769
770loff_t mem_lseek(struct file *file, loff_t offset, int orig)
771{
772 switch (orig) {
773 case 0:
774 file->f_pos = offset;
775 break;
776 case 1:
777 file->f_pos += offset;
778 break;
779 default:
780 return -EINVAL;
781 }
782 force_successful_syscall_return();
783 return file->f_pos;
784}
785
786static int mem_release(struct inode *inode, struct file *file)
787{
788 struct mm_struct *mm = file->private_data;
789 if (mm)
790 mmdrop(mm);
791 return 0;
792}
793
794static const struct file_operations proc_mem_operations = {
795 .llseek = mem_lseek,
796 .read = mem_read,
797 .write = mem_write,
798 .open = mem_open,
799 .release = mem_release,
800};
801
802static int environ_open(struct inode *inode, struct file *file)
803{
804 return __mem_open(inode, file, PTRACE_MODE_READ);
805}
806
807static ssize_t environ_read(struct file *file, char __user *buf,
808 size_t count, loff_t *ppos)
809{
810 char *page;
811 unsigned long src = *ppos;
812 int ret = 0;
813 struct mm_struct *mm = file->private_data;
814
815 if (!mm)
816 return 0;
817
818 page = (char *)__get_free_page(GFP_TEMPORARY);
819 if (!page)
820 return -ENOMEM;
821
822 ret = 0;
823 if (!atomic_inc_not_zero(&mm->mm_users))
824 goto free;
825 while (count > 0) {
826 size_t this_len, max_len;
827 int retval;
828
829 if (src >= (mm->env_end - mm->env_start))
830 break;
831
832 this_len = mm->env_end - (mm->env_start + src);
833
834 max_len = min_t(size_t, PAGE_SIZE, count);
835 this_len = min(max_len, this_len);
836
837 retval = access_remote_vm(mm, (mm->env_start + src),
838 page, this_len, 0);
839
840 if (retval <= 0) {
841 ret = retval;
842 break;
843 }
844
845 if (copy_to_user(buf, page, retval)) {
846 ret = -EFAULT;
847 break;
848 }
849
850 ret += retval;
851 src += retval;
852 buf += retval;
853 count -= retval;
854 }
855 *ppos = src;
856 mmput(mm);
857
858free:
859 free_page((unsigned long) page);
860 return ret;
861}
862
863static const struct file_operations proc_environ_operations = {
864 .open = environ_open,
865 .read = environ_read,
866 .llseek = generic_file_llseek,
867 .release = mem_release,
868};
869
870static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
871 loff_t *ppos)
872{
873 struct task_struct *task = get_proc_task(file_inode(file));
874 char buffer[PROC_NUMBUF];
875 int oom_adj = OOM_ADJUST_MIN;
876 size_t len;
877 unsigned long flags;
878
879 if (!task)
880 return -ESRCH;
881 if (lock_task_sighand(task, &flags)) {
882 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
883 oom_adj = OOM_ADJUST_MAX;
884 else
885 oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
886 OOM_SCORE_ADJ_MAX;
887 unlock_task_sighand(task, &flags);
888 }
889 put_task_struct(task);
890 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
891 return simple_read_from_buffer(buf, count, ppos, buffer, len);
892}
893
894static ssize_t oom_adj_write(struct file *file, const char __user *buf,
895 size_t count, loff_t *ppos)
896{
897 struct task_struct *task;
898 char buffer[PROC_NUMBUF];
899 int oom_adj;
900 unsigned long flags;
901 int err;
902
903 memset(buffer, 0, sizeof(buffer));
904 if (count > sizeof(buffer) - 1)
905 count = sizeof(buffer) - 1;
906 if (copy_from_user(buffer, buf, count)) {
907 err = -EFAULT;
908 goto out;
909 }
910
911 err = kstrtoint(strstrip(buffer), 0, &oom_adj);
912 if (err)
913 goto out;
914 if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
915 oom_adj != OOM_DISABLE) {
916 err = -EINVAL;
917 goto out;
918 }
919
920 task = get_proc_task(file_inode(file));
921 if (!task) {
922 err = -ESRCH;
923 goto out;
924 }
925
926 task_lock(task);
927 if (!task->mm) {
928 err = -EINVAL;
929 goto err_task_lock;
930 }
931
932 if (!lock_task_sighand(task, &flags)) {
933 err = -ESRCH;
934 goto err_task_lock;
935 }
936
937 /*
938 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
939 * value is always attainable.
940 */
941 if (oom_adj == OOM_ADJUST_MAX)
942 oom_adj = OOM_SCORE_ADJ_MAX;
943 else
944 oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
945
946 if (oom_adj < task->signal->oom_score_adj &&
947 !capable(CAP_SYS_RESOURCE)) {
948 err = -EACCES;
949 goto err_sighand;
950 }
951
952 /*
953 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
954 * /proc/pid/oom_score_adj instead.
955 */
956 pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
957 current->comm, task_pid_nr(current), task_pid_nr(task),
958 task_pid_nr(task));
959
960 task->signal->oom_score_adj = oom_adj;
961 trace_oom_score_adj_update(task);
962err_sighand:
963 unlock_task_sighand(task, &flags);
964err_task_lock:
965 task_unlock(task);
966 put_task_struct(task);
967out:
968 return err < 0 ? err : count;
969}
970
971static const struct file_operations proc_oom_adj_operations = {
972 .read = oom_adj_read,
973 .write = oom_adj_write,
974 .llseek = generic_file_llseek,
975};
976
977static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
978 size_t count, loff_t *ppos)
979{
980 struct task_struct *task = get_proc_task(file_inode(file));
981 char buffer[PROC_NUMBUF];
982 short oom_score_adj = OOM_SCORE_ADJ_MIN;
983 unsigned long flags;
984 size_t len;
985
986 if (!task)
987 return -ESRCH;
988 if (lock_task_sighand(task, &flags)) {
989 oom_score_adj = task->signal->oom_score_adj;
990 unlock_task_sighand(task, &flags);
991 }
992 put_task_struct(task);
993 len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
994 return simple_read_from_buffer(buf, count, ppos, buffer, len);
995}
996
997static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
998 size_t count, loff_t *ppos)
999{
1000 struct task_struct *task;
1001 char buffer[PROC_NUMBUF];
1002 unsigned long flags;
1003 int oom_score_adj;
1004 int err;
1005
1006 memset(buffer, 0, sizeof(buffer));
1007 if (count > sizeof(buffer) - 1)
1008 count = sizeof(buffer) - 1;
1009 if (copy_from_user(buffer, buf, count)) {
1010 err = -EFAULT;
1011 goto out;
1012 }
1013
1014 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1015 if (err)
1016 goto out;
1017 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1018 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1019 err = -EINVAL;
1020 goto out;
1021 }
1022
1023 task = get_proc_task(file_inode(file));
1024 if (!task) {
1025 err = -ESRCH;
1026 goto out;
1027 }
1028
1029 task_lock(task);
1030 if (!task->mm) {
1031 err = -EINVAL;
1032 goto err_task_lock;
1033 }
1034
1035 if (!lock_task_sighand(task, &flags)) {
1036 err = -ESRCH;
1037 goto err_task_lock;
1038 }
1039
1040 if ((short)oom_score_adj < task->signal->oom_score_adj_min &&
1041 !capable(CAP_SYS_RESOURCE)) {
1042 err = -EACCES;
1043 goto err_sighand;
1044 }
1045
1046 task->signal->oom_score_adj = (short)oom_score_adj;
1047 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1048 task->signal->oom_score_adj_min = (short)oom_score_adj;
1049 trace_oom_score_adj_update(task);
1050
1051err_sighand:
1052 unlock_task_sighand(task, &flags);
1053err_task_lock:
1054 task_unlock(task);
1055 put_task_struct(task);
1056out:
1057 return err < 0 ? err : count;
1058}
1059
1060static const struct file_operations proc_oom_score_adj_operations = {
1061 .read = oom_score_adj_read,
1062 .write = oom_score_adj_write,
1063 .llseek = default_llseek,
1064};
1065
1066#ifdef CONFIG_AUDITSYSCALL
1067#define TMPBUFLEN 21
1068static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1069 size_t count, loff_t *ppos)
1070{
1071 struct inode * inode = file_inode(file);
1072 struct task_struct *task = get_proc_task(inode);
1073 ssize_t length;
1074 char tmpbuf[TMPBUFLEN];
1075
1076 if (!task)
1077 return -ESRCH;
1078 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1079 from_kuid(file->f_cred->user_ns,
1080 audit_get_loginuid(task)));
1081 put_task_struct(task);
1082 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1083}
1084
1085static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1086 size_t count, loff_t *ppos)
1087{
1088 struct inode * inode = file_inode(file);
1089 char *page, *tmp;
1090 ssize_t length;
1091 uid_t loginuid;
1092 kuid_t kloginuid;
1093
1094 rcu_read_lock();
1095 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1096 rcu_read_unlock();
1097 return -EPERM;
1098 }
1099 rcu_read_unlock();
1100
1101 if (count >= PAGE_SIZE)
1102 count = PAGE_SIZE - 1;
1103
1104 if (*ppos != 0) {
1105 /* No partial writes. */
1106 return -EINVAL;
1107 }
1108 page = (char*)__get_free_page(GFP_TEMPORARY);
1109 if (!page)
1110 return -ENOMEM;
1111 length = -EFAULT;
1112 if (copy_from_user(page, buf, count))
1113 goto out_free_page;
1114
1115 page[count] = '\0';
1116 loginuid = simple_strtoul(page, &tmp, 10);
1117 if (tmp == page) {
1118 length = -EINVAL;
1119 goto out_free_page;
1120
1121 }
1122
1123 /* is userspace tring to explicitly UNSET the loginuid? */
1124 if (loginuid == AUDIT_UID_UNSET) {
1125 kloginuid = INVALID_UID;
1126 } else {
1127 kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1128 if (!uid_valid(kloginuid)) {
1129 length = -EINVAL;
1130 goto out_free_page;
1131 }
1132 }
1133
1134 length = audit_set_loginuid(kloginuid);
1135 if (likely(length == 0))
1136 length = count;
1137
1138out_free_page:
1139 free_page((unsigned long) page);
1140 return length;
1141}
1142
1143static const struct file_operations proc_loginuid_operations = {
1144 .read = proc_loginuid_read,
1145 .write = proc_loginuid_write,
1146 .llseek = generic_file_llseek,
1147};
1148
1149static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1150 size_t count, loff_t *ppos)
1151{
1152 struct inode * inode = file_inode(file);
1153 struct task_struct *task = get_proc_task(inode);
1154 ssize_t length;
1155 char tmpbuf[TMPBUFLEN];
1156
1157 if (!task)
1158 return -ESRCH;
1159 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1160 audit_get_sessionid(task));
1161 put_task_struct(task);
1162 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1163}
1164
1165static const struct file_operations proc_sessionid_operations = {
1166 .read = proc_sessionid_read,
1167 .llseek = generic_file_llseek,
1168};
1169#endif
1170
1171#ifdef CONFIG_FAULT_INJECTION
1172static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1173 size_t count, loff_t *ppos)
1174{
1175 struct task_struct *task = get_proc_task(file_inode(file));
1176 char buffer[PROC_NUMBUF];
1177 size_t len;
1178 int make_it_fail;
1179
1180 if (!task)
1181 return -ESRCH;
1182 make_it_fail = task->make_it_fail;
1183 put_task_struct(task);
1184
1185 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1186
1187 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1188}
1189
1190static ssize_t proc_fault_inject_write(struct file * file,
1191 const char __user * buf, size_t count, loff_t *ppos)
1192{
1193 struct task_struct *task;
1194 char buffer[PROC_NUMBUF], *end;
1195 int make_it_fail;
1196
1197 if (!capable(CAP_SYS_RESOURCE))
1198 return -EPERM;
1199 memset(buffer, 0, sizeof(buffer));
1200 if (count > sizeof(buffer) - 1)
1201 count = sizeof(buffer) - 1;
1202 if (copy_from_user(buffer, buf, count))
1203 return -EFAULT;
1204 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1205 if (*end)
1206 return -EINVAL;
1207 if (make_it_fail < 0 || make_it_fail > 1)
1208 return -EINVAL;
1209
1210 task = get_proc_task(file_inode(file));
1211 if (!task)
1212 return -ESRCH;
1213 task->make_it_fail = make_it_fail;
1214 put_task_struct(task);
1215
1216 return count;
1217}
1218
1219static const struct file_operations proc_fault_inject_operations = {
1220 .read = proc_fault_inject_read,
1221 .write = proc_fault_inject_write,
1222 .llseek = generic_file_llseek,
1223};
1224#endif
1225
1226
1227#ifdef CONFIG_SCHED_DEBUG
1228/*
1229 * Print out various scheduling related per-task fields:
1230 */
1231static int sched_show(struct seq_file *m, void *v)
1232{
1233 struct inode *inode = m->private;
1234 struct task_struct *p;
1235
1236 p = get_proc_task(inode);
1237 if (!p)
1238 return -ESRCH;
1239 proc_sched_show_task(p, m);
1240
1241 put_task_struct(p);
1242
1243 return 0;
1244}
1245
1246static ssize_t
1247sched_write(struct file *file, const char __user *buf,
1248 size_t count, loff_t *offset)
1249{
1250 struct inode *inode = file_inode(file);
1251 struct task_struct *p;
1252
1253 p = get_proc_task(inode);
1254 if (!p)
1255 return -ESRCH;
1256 proc_sched_set_task(p);
1257
1258 put_task_struct(p);
1259
1260 return count;
1261}
1262
1263static int sched_open(struct inode *inode, struct file *filp)
1264{
1265 return single_open(filp, sched_show, inode);
1266}
1267
1268static const struct file_operations proc_pid_sched_operations = {
1269 .open = sched_open,
1270 .read = seq_read,
1271 .write = sched_write,
1272 .llseek = seq_lseek,
1273 .release = single_release,
1274};
1275
1276#endif
1277
1278#ifdef CONFIG_SCHED_AUTOGROUP
1279/*
1280 * Print out autogroup related information:
1281 */
1282static int sched_autogroup_show(struct seq_file *m, void *v)
1283{
1284 struct inode *inode = m->private;
1285 struct task_struct *p;
1286
1287 p = get_proc_task(inode);
1288 if (!p)
1289 return -ESRCH;
1290 proc_sched_autogroup_show_task(p, m);
1291
1292 put_task_struct(p);
1293
1294 return 0;
1295}
1296
1297static ssize_t
1298sched_autogroup_write(struct file *file, const char __user *buf,
1299 size_t count, loff_t *offset)
1300{
1301 struct inode *inode = file_inode(file);
1302 struct task_struct *p;
1303 char buffer[PROC_NUMBUF];
1304 int nice;
1305 int err;
1306
1307 memset(buffer, 0, sizeof(buffer));
1308 if (count > sizeof(buffer) - 1)
1309 count = sizeof(buffer) - 1;
1310 if (copy_from_user(buffer, buf, count))
1311 return -EFAULT;
1312
1313 err = kstrtoint(strstrip(buffer), 0, &nice);
1314 if (err < 0)
1315 return err;
1316
1317 p = get_proc_task(inode);
1318 if (!p)
1319 return -ESRCH;
1320
1321 err = proc_sched_autogroup_set_nice(p, nice);
1322 if (err)
1323 count = err;
1324
1325 put_task_struct(p);
1326
1327 return count;
1328}
1329
1330static int sched_autogroup_open(struct inode *inode, struct file *filp)
1331{
1332 int ret;
1333
1334 ret = single_open(filp, sched_autogroup_show, NULL);
1335 if (!ret) {
1336 struct seq_file *m = filp->private_data;
1337
1338 m->private = inode;
1339 }
1340 return ret;
1341}
1342
1343static const struct file_operations proc_pid_sched_autogroup_operations = {
1344 .open = sched_autogroup_open,
1345 .read = seq_read,
1346 .write = sched_autogroup_write,
1347 .llseek = seq_lseek,
1348 .release = single_release,
1349};
1350
1351#endif /* CONFIG_SCHED_AUTOGROUP */
1352
1353static ssize_t comm_write(struct file *file, const char __user *buf,
1354 size_t count, loff_t *offset)
1355{
1356 struct inode *inode = file_inode(file);
1357 struct task_struct *p;
1358 char buffer[TASK_COMM_LEN];
1359 const size_t maxlen = sizeof(buffer) - 1;
1360
1361 memset(buffer, 0, sizeof(buffer));
1362 if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
1363 return -EFAULT;
1364
1365 p = get_proc_task(inode);
1366 if (!p)
1367 return -ESRCH;
1368
1369 if (same_thread_group(current, p))
1370 set_task_comm(p, buffer);
1371 else
1372 count = -EINVAL;
1373
1374 put_task_struct(p);
1375
1376 return count;
1377}
1378
1379static int comm_show(struct seq_file *m, void *v)
1380{
1381 struct inode *inode = m->private;
1382 struct task_struct *p;
1383
1384 p = get_proc_task(inode);
1385 if (!p)
1386 return -ESRCH;
1387
1388 task_lock(p);
1389 seq_printf(m, "%s\n", p->comm);
1390 task_unlock(p);
1391
1392 put_task_struct(p);
1393
1394 return 0;
1395}
1396
1397static int comm_open(struct inode *inode, struct file *filp)
1398{
1399 return single_open(filp, comm_show, inode);
1400}
1401
1402static const struct file_operations proc_pid_set_comm_operations = {
1403 .open = comm_open,
1404 .read = seq_read,
1405 .write = comm_write,
1406 .llseek = seq_lseek,
1407 .release = single_release,
1408};
1409
1410static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1411{
1412 struct task_struct *task;
1413 struct mm_struct *mm;
1414 struct file *exe_file;
1415
1416 task = get_proc_task(dentry->d_inode);
1417 if (!task)
1418 return -ENOENT;
1419 mm = get_task_mm(task);
1420 put_task_struct(task);
1421 if (!mm)
1422 return -ENOENT;
1423 exe_file = get_mm_exe_file(mm);
1424 mmput(mm);
1425 if (exe_file) {
1426 *exe_path = exe_file->f_path;
1427 path_get(&exe_file->f_path);
1428 fput(exe_file);
1429 return 0;
1430 } else
1431 return -ENOENT;
1432}
1433
1434static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1435{
1436 struct inode *inode = dentry->d_inode;
1437 struct path path;
1438 int error = -EACCES;
1439
1440 /* Are we allowed to snoop on the tasks file descriptors? */
1441 if (!proc_fd_access_allowed(inode))
1442 goto out;
1443
1444 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1445 if (error)
1446 goto out;
1447
1448 nd_jump_link(nd, &path);
1449 return NULL;
1450out:
1451 return ERR_PTR(error);
1452}
1453
1454static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1455{
1456 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1457 char *pathname;
1458 int len;
1459
1460 if (!tmp)
1461 return -ENOMEM;
1462
1463 pathname = d_path(path, tmp, PAGE_SIZE);
1464 len = PTR_ERR(pathname);
1465 if (IS_ERR(pathname))
1466 goto out;
1467 len = tmp + PAGE_SIZE - 1 - pathname;
1468
1469 if (len > buflen)
1470 len = buflen;
1471 if (copy_to_user(buffer, pathname, len))
1472 len = -EFAULT;
1473 out:
1474 free_page((unsigned long)tmp);
1475 return len;
1476}
1477
1478static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1479{
1480 int error = -EACCES;
1481 struct inode *inode = dentry->d_inode;
1482 struct path path;
1483
1484 /* Are we allowed to snoop on the tasks file descriptors? */
1485 if (!proc_fd_access_allowed(inode))
1486 goto out;
1487
1488 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1489 if (error)
1490 goto out;
1491
1492 error = do_proc_readlink(&path, buffer, buflen);
1493 path_put(&path);
1494out:
1495 return error;
1496}
1497
1498const struct inode_operations proc_pid_link_inode_operations = {
1499 .readlink = proc_pid_readlink,
1500 .follow_link = proc_pid_follow_link,
1501 .setattr = proc_setattr,
1502};
1503
1504
1505/* building an inode */
1506
1507struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1508{
1509 struct inode * inode;
1510 struct proc_inode *ei;
1511 const struct cred *cred;
1512
1513 /* We need a new inode */
1514
1515 inode = new_inode(sb);
1516 if (!inode)
1517 goto out;
1518
1519 /* Common stuff */
1520 ei = PROC_I(inode);
1521 inode->i_ino = get_next_ino();
1522 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1523 inode->i_op = &proc_def_inode_operations;
1524
1525 /*
1526 * grab the reference to task.
1527 */
1528 ei->pid = get_task_pid(task, PIDTYPE_PID);
1529 if (!ei->pid)
1530 goto out_unlock;
1531
1532 if (task_dumpable(task)) {
1533 rcu_read_lock();
1534 cred = __task_cred(task);
1535 inode->i_uid = cred->euid;
1536 inode->i_gid = cred->egid;
1537 rcu_read_unlock();
1538 }
1539 security_task_to_inode(task, inode);
1540
1541out:
1542 return inode;
1543
1544out_unlock:
1545 iput(inode);
1546 return NULL;
1547}
1548
1549int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1550{
1551 struct inode *inode = dentry->d_inode;
1552 struct task_struct *task;
1553 const struct cred *cred;
1554 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1555
1556 generic_fillattr(inode, stat);
1557
1558 rcu_read_lock();
1559 stat->uid = GLOBAL_ROOT_UID;
1560 stat->gid = GLOBAL_ROOT_GID;
1561 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1562 if (task) {
1563 if (!has_pid_permissions(pid, task, 2)) {
1564 rcu_read_unlock();
1565 /*
1566 * This doesn't prevent learning whether PID exists,
1567 * it only makes getattr() consistent with readdir().
1568 */
1569 return -ENOENT;
1570 }
1571 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1572 task_dumpable(task)) {
1573 cred = __task_cred(task);
1574 stat->uid = cred->euid;
1575 stat->gid = cred->egid;
1576 }
1577 }
1578 rcu_read_unlock();
1579 return 0;
1580}
1581
1582/* dentry stuff */
1583
1584/*
1585 * Exceptional case: normally we are not allowed to unhash a busy
1586 * directory. In this case, however, we can do it - no aliasing problems
1587 * due to the way we treat inodes.
1588 *
1589 * Rewrite the inode's ownerships here because the owning task may have
1590 * performed a setuid(), etc.
1591 *
1592 * Before the /proc/pid/status file was created the only way to read
1593 * the effective uid of a /process was to stat /proc/pid. Reading
1594 * /proc/pid/status is slow enough that procps and other packages
1595 * kept stating /proc/pid. To keep the rules in /proc simple I have
1596 * made this apply to all per process world readable and executable
1597 * directories.
1598 */
1599int pid_revalidate(struct dentry *dentry, unsigned int flags)
1600{
1601 struct inode *inode;
1602 struct task_struct *task;
1603 const struct cred *cred;
1604
1605 if (flags & LOOKUP_RCU)
1606 return -ECHILD;
1607
1608 inode = dentry->d_inode;
1609 task = get_proc_task(inode);
1610
1611 if (task) {
1612 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1613 task_dumpable(task)) {
1614 rcu_read_lock();
1615 cred = __task_cred(task);
1616 inode->i_uid = cred->euid;
1617 inode->i_gid = cred->egid;
1618 rcu_read_unlock();
1619 } else {
1620 inode->i_uid = GLOBAL_ROOT_UID;
1621 inode->i_gid = GLOBAL_ROOT_GID;
1622 }
1623 inode->i_mode &= ~(S_ISUID | S_ISGID);
1624 security_task_to_inode(task, inode);
1625 put_task_struct(task);
1626 return 1;
1627 }
1628 d_drop(dentry);
1629 return 0;
1630}
1631
1632static inline bool proc_inode_is_dead(struct inode *inode)
1633{
1634 return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1635}
1636
1637int pid_delete_dentry(const struct dentry *dentry)
1638{
1639 /* Is the task we represent dead?
1640 * If so, then don't put the dentry on the lru list,
1641 * kill it immediately.
1642 */
1643 return proc_inode_is_dead(dentry->d_inode);
1644}
1645
1646const struct dentry_operations pid_dentry_operations =
1647{
1648 .d_revalidate = pid_revalidate,
1649 .d_delete = pid_delete_dentry,
1650};
1651
1652/* Lookups */
1653
1654/*
1655 * Fill a directory entry.
1656 *
1657 * If possible create the dcache entry and derive our inode number and
1658 * file type from dcache entry.
1659 *
1660 * Since all of the proc inode numbers are dynamically generated, the inode
1661 * numbers do not exist until the inode is cache. This means creating the
1662 * the dcache entry in readdir is necessary to keep the inode numbers
1663 * reported by readdir in sync with the inode numbers reported
1664 * by stat.
1665 */
1666bool proc_fill_cache(struct file *file, struct dir_context *ctx,
1667 const char *name, int len,
1668 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1669{
1670 struct dentry *child, *dir = file->f_path.dentry;
1671 struct qstr qname = QSTR_INIT(name, len);
1672 struct inode *inode;
1673 unsigned type;
1674 ino_t ino;
1675
1676 child = d_hash_and_lookup(dir, &qname);
1677 if (!child) {
1678 child = d_alloc(dir, &qname);
1679 if (!child)
1680 goto end_instantiate;
1681 if (instantiate(dir->d_inode, child, task, ptr) < 0) {
1682 dput(child);
1683 goto end_instantiate;
1684 }
1685 }
1686 inode = child->d_inode;
1687 ino = inode->i_ino;
1688 type = inode->i_mode >> 12;
1689 dput(child);
1690 return dir_emit(ctx, name, len, ino, type);
1691
1692end_instantiate:
1693 return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
1694}
1695
1696#ifdef CONFIG_CHECKPOINT_RESTORE
1697
1698/*
1699 * dname_to_vma_addr - maps a dentry name into two unsigned longs
1700 * which represent vma start and end addresses.
1701 */
1702static int dname_to_vma_addr(struct dentry *dentry,
1703 unsigned long *start, unsigned long *end)
1704{
1705 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
1706 return -EINVAL;
1707
1708 return 0;
1709}
1710
1711static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
1712{
1713 unsigned long vm_start, vm_end;
1714 bool exact_vma_exists = false;
1715 struct mm_struct *mm = NULL;
1716 struct task_struct *task;
1717 const struct cred *cred;
1718 struct inode *inode;
1719 int status = 0;
1720
1721 if (flags & LOOKUP_RCU)
1722 return -ECHILD;
1723
1724 if (!capable(CAP_SYS_ADMIN)) {
1725 status = -EPERM;
1726 goto out_notask;
1727 }
1728
1729 inode = dentry->d_inode;
1730 task = get_proc_task(inode);
1731 if (!task)
1732 goto out_notask;
1733
1734 mm = mm_access(task, PTRACE_MODE_READ);
1735 if (IS_ERR_OR_NULL(mm))
1736 goto out;
1737
1738 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
1739 down_read(&mm->mmap_sem);
1740 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
1741 up_read(&mm->mmap_sem);
1742 }
1743
1744 mmput(mm);
1745
1746 if (exact_vma_exists) {
1747 if (task_dumpable(task)) {
1748 rcu_read_lock();
1749 cred = __task_cred(task);
1750 inode->i_uid = cred->euid;
1751 inode->i_gid = cred->egid;
1752 rcu_read_unlock();
1753 } else {
1754 inode->i_uid = GLOBAL_ROOT_UID;
1755 inode->i_gid = GLOBAL_ROOT_GID;
1756 }
1757 security_task_to_inode(task, inode);
1758 status = 1;
1759 }
1760
1761out:
1762 put_task_struct(task);
1763
1764out_notask:
1765 if (status <= 0)
1766 d_drop(dentry);
1767
1768 return status;
1769}
1770
1771static const struct dentry_operations tid_map_files_dentry_operations = {
1772 .d_revalidate = map_files_d_revalidate,
1773 .d_delete = pid_delete_dentry,
1774};
1775
1776static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
1777{
1778 unsigned long vm_start, vm_end;
1779 struct vm_area_struct *vma;
1780 struct task_struct *task;
1781 struct mm_struct *mm;
1782 int rc;
1783
1784 rc = -ENOENT;
1785 task = get_proc_task(dentry->d_inode);
1786 if (!task)
1787 goto out;
1788
1789 mm = get_task_mm(task);
1790 put_task_struct(task);
1791 if (!mm)
1792 goto out;
1793
1794 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
1795 if (rc)
1796 goto out_mmput;
1797
1798 rc = -ENOENT;
1799 down_read(&mm->mmap_sem);
1800 vma = find_exact_vma(mm, vm_start, vm_end);
1801 if (vma && vma->vm_file) {
1802 *path = vma->vm_file->f_path;
1803 path_get(path);
1804 rc = 0;
1805 }
1806 up_read(&mm->mmap_sem);
1807
1808out_mmput:
1809 mmput(mm);
1810out:
1811 return rc;
1812}
1813
1814struct map_files_info {
1815 fmode_t mode;
1816 unsigned long len;
1817 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
1818};
1819
1820static int
1821proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
1822 struct task_struct *task, const void *ptr)
1823{
1824 fmode_t mode = (fmode_t)(unsigned long)ptr;
1825 struct proc_inode *ei;
1826 struct inode *inode;
1827
1828 inode = proc_pid_make_inode(dir->i_sb, task);
1829 if (!inode)
1830 return -ENOENT;
1831
1832 ei = PROC_I(inode);
1833 ei->op.proc_get_link = proc_map_files_get_link;
1834
1835 inode->i_op = &proc_pid_link_inode_operations;
1836 inode->i_size = 64;
1837 inode->i_mode = S_IFLNK;
1838
1839 if (mode & FMODE_READ)
1840 inode->i_mode |= S_IRUSR;
1841 if (mode & FMODE_WRITE)
1842 inode->i_mode |= S_IWUSR;
1843
1844 d_set_d_op(dentry, &tid_map_files_dentry_operations);
1845 d_add(dentry, inode);
1846
1847 return 0;
1848}
1849
1850static struct dentry *proc_map_files_lookup(struct inode *dir,
1851 struct dentry *dentry, unsigned int flags)
1852{
1853 unsigned long vm_start, vm_end;
1854 struct vm_area_struct *vma;
1855 struct task_struct *task;
1856 int result;
1857 struct mm_struct *mm;
1858
1859 result = -EPERM;
1860 if (!capable(CAP_SYS_ADMIN))
1861 goto out;
1862
1863 result = -ENOENT;
1864 task = get_proc_task(dir);
1865 if (!task)
1866 goto out;
1867
1868 result = -EACCES;
1869 if (!ptrace_may_access(task, PTRACE_MODE_READ))
1870 goto out_put_task;
1871
1872 result = -ENOENT;
1873 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
1874 goto out_put_task;
1875
1876 mm = get_task_mm(task);
1877 if (!mm)
1878 goto out_put_task;
1879
1880 down_read(&mm->mmap_sem);
1881 vma = find_exact_vma(mm, vm_start, vm_end);
1882 if (!vma)
1883 goto out_no_vma;
1884
1885 if (vma->vm_file)
1886 result = proc_map_files_instantiate(dir, dentry, task,
1887 (void *)(unsigned long)vma->vm_file->f_mode);
1888
1889out_no_vma:
1890 up_read(&mm->mmap_sem);
1891 mmput(mm);
1892out_put_task:
1893 put_task_struct(task);
1894out:
1895 return ERR_PTR(result);
1896}
1897
1898static const struct inode_operations proc_map_files_inode_operations = {
1899 .lookup = proc_map_files_lookup,
1900 .permission = proc_fd_permission,
1901 .setattr = proc_setattr,
1902};
1903
1904static int
1905proc_map_files_readdir(struct file *file, struct dir_context *ctx)
1906{
1907 struct vm_area_struct *vma;
1908 struct task_struct *task;
1909 struct mm_struct *mm;
1910 unsigned long nr_files, pos, i;
1911 struct flex_array *fa = NULL;
1912 struct map_files_info info;
1913 struct map_files_info *p;
1914 int ret;
1915
1916 ret = -EPERM;
1917 if (!capable(CAP_SYS_ADMIN))
1918 goto out;
1919
1920 ret = -ENOENT;
1921 task = get_proc_task(file_inode(file));
1922 if (!task)
1923 goto out;
1924
1925 ret = -EACCES;
1926 if (!ptrace_may_access(task, PTRACE_MODE_READ))
1927 goto out_put_task;
1928
1929 ret = 0;
1930 if (!dir_emit_dots(file, ctx))
1931 goto out_put_task;
1932
1933 mm = get_task_mm(task);
1934 if (!mm)
1935 goto out_put_task;
1936 down_read(&mm->mmap_sem);
1937
1938 nr_files = 0;
1939
1940 /*
1941 * We need two passes here:
1942 *
1943 * 1) Collect vmas of mapped files with mmap_sem taken
1944 * 2) Release mmap_sem and instantiate entries
1945 *
1946 * otherwise we get lockdep complained, since filldir()
1947 * routine might require mmap_sem taken in might_fault().
1948 */
1949
1950 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
1951 if (vma->vm_file && ++pos > ctx->pos)
1952 nr_files++;
1953 }
1954
1955 if (nr_files) {
1956 fa = flex_array_alloc(sizeof(info), nr_files,
1957 GFP_KERNEL);
1958 if (!fa || flex_array_prealloc(fa, 0, nr_files,
1959 GFP_KERNEL)) {
1960 ret = -ENOMEM;
1961 if (fa)
1962 flex_array_free(fa);
1963 up_read(&mm->mmap_sem);
1964 mmput(mm);
1965 goto out_put_task;
1966 }
1967 for (i = 0, vma = mm->mmap, pos = 2; vma;
1968 vma = vma->vm_next) {
1969 if (!vma->vm_file)
1970 continue;
1971 if (++pos <= ctx->pos)
1972 continue;
1973
1974 info.mode = vma->vm_file->f_mode;
1975 info.len = snprintf(info.name,
1976 sizeof(info.name), "%lx-%lx",
1977 vma->vm_start, vma->vm_end);
1978 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
1979 BUG();
1980 }
1981 }
1982 up_read(&mm->mmap_sem);
1983
1984 for (i = 0; i < nr_files; i++) {
1985 p = flex_array_get(fa, i);
1986 if (!proc_fill_cache(file, ctx,
1987 p->name, p->len,
1988 proc_map_files_instantiate,
1989 task,
1990 (void *)(unsigned long)p->mode))
1991 break;
1992 ctx->pos++;
1993 }
1994 if (fa)
1995 flex_array_free(fa);
1996 mmput(mm);
1997
1998out_put_task:
1999 put_task_struct(task);
2000out:
2001 return ret;
2002}
2003
2004static const struct file_operations proc_map_files_operations = {
2005 .read = generic_read_dir,
2006 .iterate = proc_map_files_readdir,
2007 .llseek = default_llseek,
2008};
2009
2010struct timers_private {
2011 struct pid *pid;
2012 struct task_struct *task;
2013 struct sighand_struct *sighand;
2014 struct pid_namespace *ns;
2015 unsigned long flags;
2016};
2017
2018static void *timers_start(struct seq_file *m, loff_t *pos)
2019{
2020 struct timers_private *tp = m->private;
2021
2022 tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2023 if (!tp->task)
2024 return ERR_PTR(-ESRCH);
2025
2026 tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2027 if (!tp->sighand)
2028 return ERR_PTR(-ESRCH);
2029
2030 return seq_list_start(&tp->task->signal->posix_timers, *pos);
2031}
2032
2033static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2034{
2035 struct timers_private *tp = m->private;
2036 return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2037}
2038
2039static void timers_stop(struct seq_file *m, void *v)
2040{
2041 struct timers_private *tp = m->private;
2042
2043 if (tp->sighand) {
2044 unlock_task_sighand(tp->task, &tp->flags);
2045 tp->sighand = NULL;
2046 }
2047
2048 if (tp->task) {
2049 put_task_struct(tp->task);
2050 tp->task = NULL;
2051 }
2052}
2053
2054static int show_timer(struct seq_file *m, void *v)
2055{
2056 struct k_itimer *timer;
2057 struct timers_private *tp = m->private;
2058 int notify;
2059 static char *nstr[] = {
2060 [SIGEV_SIGNAL] = "signal",
2061 [SIGEV_NONE] = "none",
2062 [SIGEV_THREAD] = "thread",
2063 };
2064
2065 timer = list_entry((struct list_head *)v, struct k_itimer, list);
2066 notify = timer->it_sigev_notify;
2067
2068 seq_printf(m, "ID: %d\n", timer->it_id);
2069 seq_printf(m, "signal: %d/%p\n", timer->sigq->info.si_signo,
2070 timer->sigq->info.si_value.sival_ptr);
2071 seq_printf(m, "notify: %s/%s.%d\n",
2072 nstr[notify & ~SIGEV_THREAD_ID],
2073 (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2074 pid_nr_ns(timer->it_pid, tp->ns));
2075 seq_printf(m, "ClockID: %d\n", timer->it_clock);
2076
2077 return 0;
2078}
2079
2080static const struct seq_operations proc_timers_seq_ops = {
2081 .start = timers_start,
2082 .next = timers_next,
2083 .stop = timers_stop,
2084 .show = show_timer,
2085};
2086
2087static int proc_timers_open(struct inode *inode, struct file *file)
2088{
2089 struct timers_private *tp;
2090
2091 tp = __seq_open_private(file, &proc_timers_seq_ops,
2092 sizeof(struct timers_private));
2093 if (!tp)
2094 return -ENOMEM;
2095
2096 tp->pid = proc_pid(inode);
2097 tp->ns = inode->i_sb->s_fs_info;
2098 return 0;
2099}
2100
2101static const struct file_operations proc_timers_operations = {
2102 .open = proc_timers_open,
2103 .read = seq_read,
2104 .llseek = seq_lseek,
2105 .release = seq_release_private,
2106};
2107#endif /* CONFIG_CHECKPOINT_RESTORE */
2108
2109static int proc_pident_instantiate(struct inode *dir,
2110 struct dentry *dentry, struct task_struct *task, const void *ptr)
2111{
2112 const struct pid_entry *p = ptr;
2113 struct inode *inode;
2114 struct proc_inode *ei;
2115
2116 inode = proc_pid_make_inode(dir->i_sb, task);
2117 if (!inode)
2118 goto out;
2119
2120 ei = PROC_I(inode);
2121 inode->i_mode = p->mode;
2122 if (S_ISDIR(inode->i_mode))
2123 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2124 if (p->iop)
2125 inode->i_op = p->iop;
2126 if (p->fop)
2127 inode->i_fop = p->fop;
2128 ei->op = p->op;
2129 d_set_d_op(dentry, &pid_dentry_operations);
2130 d_add(dentry, inode);
2131 /* Close the race of the process dying before we return the dentry */
2132 if (pid_revalidate(dentry, 0))
2133 return 0;
2134out:
2135 return -ENOENT;
2136}
2137
2138static struct dentry *proc_pident_lookup(struct inode *dir,
2139 struct dentry *dentry,
2140 const struct pid_entry *ents,
2141 unsigned int nents)
2142{
2143 int error;
2144 struct task_struct *task = get_proc_task(dir);
2145 const struct pid_entry *p, *last;
2146
2147 error = -ENOENT;
2148
2149 if (!task)
2150 goto out_no_task;
2151
2152 /*
2153 * Yes, it does not scale. And it should not. Don't add
2154 * new entries into /proc/<tgid>/ without very good reasons.
2155 */
2156 last = &ents[nents - 1];
2157 for (p = ents; p <= last; p++) {
2158 if (p->len != dentry->d_name.len)
2159 continue;
2160 if (!memcmp(dentry->d_name.name, p->name, p->len))
2161 break;
2162 }
2163 if (p > last)
2164 goto out;
2165
2166 error = proc_pident_instantiate(dir, dentry, task, p);
2167out:
2168 put_task_struct(task);
2169out_no_task:
2170 return ERR_PTR(error);
2171}
2172
2173static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
2174 const struct pid_entry *ents, unsigned int nents)
2175{
2176 struct task_struct *task = get_proc_task(file_inode(file));
2177 const struct pid_entry *p;
2178
2179 if (!task)
2180 return -ENOENT;
2181
2182 if (!dir_emit_dots(file, ctx))
2183 goto out;
2184
2185 if (ctx->pos >= nents + 2)
2186 goto out;
2187
2188 for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) {
2189 if (!proc_fill_cache(file, ctx, p->name, p->len,
2190 proc_pident_instantiate, task, p))
2191 break;
2192 ctx->pos++;
2193 }
2194out:
2195 put_task_struct(task);
2196 return 0;
2197}
2198
2199#ifdef CONFIG_SECURITY
2200static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2201 size_t count, loff_t *ppos)
2202{
2203 struct inode * inode = file_inode(file);
2204 char *p = NULL;
2205 ssize_t length;
2206 struct task_struct *task = get_proc_task(inode);
2207
2208 if (!task)
2209 return -ESRCH;
2210
2211 length = security_getprocattr(task,
2212 (char*)file->f_path.dentry->d_name.name,
2213 &p);
2214 put_task_struct(task);
2215 if (length > 0)
2216 length = simple_read_from_buffer(buf, count, ppos, p, length);
2217 kfree(p);
2218 return length;
2219}
2220
2221static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2222 size_t count, loff_t *ppos)
2223{
2224 struct inode * inode = file_inode(file);
2225 char *page;
2226 ssize_t length;
2227 struct task_struct *task = get_proc_task(inode);
2228
2229 length = -ESRCH;
2230 if (!task)
2231 goto out_no_task;
2232 if (count > PAGE_SIZE)
2233 count = PAGE_SIZE;
2234
2235 /* No partial writes. */
2236 length = -EINVAL;
2237 if (*ppos != 0)
2238 goto out;
2239
2240 length = -ENOMEM;
2241 page = (char*)__get_free_page(GFP_TEMPORARY);
2242 if (!page)
2243 goto out;
2244
2245 length = -EFAULT;
2246 if (copy_from_user(page, buf, count))
2247 goto out_free;
2248
2249 /* Guard against adverse ptrace interaction */
2250 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2251 if (length < 0)
2252 goto out_free;
2253
2254 length = security_setprocattr(task,
2255 (char*)file->f_path.dentry->d_name.name,
2256 (void*)page, count);
2257 mutex_unlock(&task->signal->cred_guard_mutex);
2258out_free:
2259 free_page((unsigned long) page);
2260out:
2261 put_task_struct(task);
2262out_no_task:
2263 return length;
2264}
2265
2266static const struct file_operations proc_pid_attr_operations = {
2267 .read = proc_pid_attr_read,
2268 .write = proc_pid_attr_write,
2269 .llseek = generic_file_llseek,
2270};
2271
2272static const struct pid_entry attr_dir_stuff[] = {
2273 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2274 REG("prev", S_IRUGO, proc_pid_attr_operations),
2275 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2276 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2277 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2278 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2279};
2280
2281static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
2282{
2283 return proc_pident_readdir(file, ctx,
2284 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2285}
2286
2287static const struct file_operations proc_attr_dir_operations = {
2288 .read = generic_read_dir,
2289 .iterate = proc_attr_dir_readdir,
2290 .llseek = default_llseek,
2291};
2292
2293static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2294 struct dentry *dentry, unsigned int flags)
2295{
2296 return proc_pident_lookup(dir, dentry,
2297 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2298}
2299
2300static const struct inode_operations proc_attr_dir_inode_operations = {
2301 .lookup = proc_attr_dir_lookup,
2302 .getattr = pid_getattr,
2303 .setattr = proc_setattr,
2304};
2305
2306#endif
2307
2308#ifdef CONFIG_ELF_CORE
2309static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2310 size_t count, loff_t *ppos)
2311{
2312 struct task_struct *task = get_proc_task(file_inode(file));
2313 struct mm_struct *mm;
2314 char buffer[PROC_NUMBUF];
2315 size_t len;
2316 int ret;
2317
2318 if (!task)
2319 return -ESRCH;
2320
2321 ret = 0;
2322 mm = get_task_mm(task);
2323 if (mm) {
2324 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2325 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2326 MMF_DUMP_FILTER_SHIFT));
2327 mmput(mm);
2328 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2329 }
2330
2331 put_task_struct(task);
2332
2333 return ret;
2334}
2335
2336static ssize_t proc_coredump_filter_write(struct file *file,
2337 const char __user *buf,
2338 size_t count,
2339 loff_t *ppos)
2340{
2341 struct task_struct *task;
2342 struct mm_struct *mm;
2343 char buffer[PROC_NUMBUF], *end;
2344 unsigned int val;
2345 int ret;
2346 int i;
2347 unsigned long mask;
2348
2349 ret = -EFAULT;
2350 memset(buffer, 0, sizeof(buffer));
2351 if (count > sizeof(buffer) - 1)
2352 count = sizeof(buffer) - 1;
2353 if (copy_from_user(buffer, buf, count))
2354 goto out_no_task;
2355
2356 ret = -EINVAL;
2357 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2358 if (*end == '\n')
2359 end++;
2360 if (end - buffer == 0)
2361 goto out_no_task;
2362
2363 ret = -ESRCH;
2364 task = get_proc_task(file_inode(file));
2365 if (!task)
2366 goto out_no_task;
2367
2368 ret = end - buffer;
2369 mm = get_task_mm(task);
2370 if (!mm)
2371 goto out_no_mm;
2372
2373 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2374 if (val & mask)
2375 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2376 else
2377 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2378 }
2379
2380 mmput(mm);
2381 out_no_mm:
2382 put_task_struct(task);
2383 out_no_task:
2384 return ret;
2385}
2386
2387static const struct file_operations proc_coredump_filter_operations = {
2388 .read = proc_coredump_filter_read,
2389 .write = proc_coredump_filter_write,
2390 .llseek = generic_file_llseek,
2391};
2392#endif
2393
2394#ifdef CONFIG_TASK_IO_ACCOUNTING
2395static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2396{
2397 struct task_io_accounting acct = task->ioac;
2398 unsigned long flags;
2399 int result;
2400
2401 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2402 if (result)
2403 return result;
2404
2405 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2406 result = -EACCES;
2407 goto out_unlock;
2408 }
2409
2410 if (whole && lock_task_sighand(task, &flags)) {
2411 struct task_struct *t = task;
2412
2413 task_io_accounting_add(&acct, &task->signal->ioac);
2414 while_each_thread(task, t)
2415 task_io_accounting_add(&acct, &t->ioac);
2416
2417 unlock_task_sighand(task, &flags);
2418 }
2419 result = sprintf(buffer,
2420 "rchar: %llu\n"
2421 "wchar: %llu\n"
2422 "syscr: %llu\n"
2423 "syscw: %llu\n"
2424 "read_bytes: %llu\n"
2425 "write_bytes: %llu\n"
2426 "cancelled_write_bytes: %llu\n",
2427 (unsigned long long)acct.rchar,
2428 (unsigned long long)acct.wchar,
2429 (unsigned long long)acct.syscr,
2430 (unsigned long long)acct.syscw,
2431 (unsigned long long)acct.read_bytes,
2432 (unsigned long long)acct.write_bytes,
2433 (unsigned long long)acct.cancelled_write_bytes);
2434out_unlock:
2435 mutex_unlock(&task->signal->cred_guard_mutex);
2436 return result;
2437}
2438
2439static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2440{
2441 return do_io_accounting(task, buffer, 0);
2442}
2443
2444static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2445{
2446 return do_io_accounting(task, buffer, 1);
2447}
2448#endif /* CONFIG_TASK_IO_ACCOUNTING */
2449
2450#ifdef CONFIG_USER_NS
2451static int proc_id_map_open(struct inode *inode, struct file *file,
2452 struct seq_operations *seq_ops)
2453{
2454 struct user_namespace *ns = NULL;
2455 struct task_struct *task;
2456 struct seq_file *seq;
2457 int ret = -EINVAL;
2458
2459 task = get_proc_task(inode);
2460 if (task) {
2461 rcu_read_lock();
2462 ns = get_user_ns(task_cred_xxx(task, user_ns));
2463 rcu_read_unlock();
2464 put_task_struct(task);
2465 }
2466 if (!ns)
2467 goto err;
2468
2469 ret = seq_open(file, seq_ops);
2470 if (ret)
2471 goto err_put_ns;
2472
2473 seq = file->private_data;
2474 seq->private = ns;
2475
2476 return 0;
2477err_put_ns:
2478 put_user_ns(ns);
2479err:
2480 return ret;
2481}
2482
2483static int proc_id_map_release(struct inode *inode, struct file *file)
2484{
2485 struct seq_file *seq = file->private_data;
2486 struct user_namespace *ns = seq->private;
2487 put_user_ns(ns);
2488 return seq_release(inode, file);
2489}
2490
2491static int proc_uid_map_open(struct inode *inode, struct file *file)
2492{
2493 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2494}
2495
2496static int proc_gid_map_open(struct inode *inode, struct file *file)
2497{
2498 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2499}
2500
2501static int proc_projid_map_open(struct inode *inode, struct file *file)
2502{
2503 return proc_id_map_open(inode, file, &proc_projid_seq_operations);
2504}
2505
2506static const struct file_operations proc_uid_map_operations = {
2507 .open = proc_uid_map_open,
2508 .write = proc_uid_map_write,
2509 .read = seq_read,
2510 .llseek = seq_lseek,
2511 .release = proc_id_map_release,
2512};
2513
2514static const struct file_operations proc_gid_map_operations = {
2515 .open = proc_gid_map_open,
2516 .write = proc_gid_map_write,
2517 .read = seq_read,
2518 .llseek = seq_lseek,
2519 .release = proc_id_map_release,
2520};
2521
2522static const struct file_operations proc_projid_map_operations = {
2523 .open = proc_projid_map_open,
2524 .write = proc_projid_map_write,
2525 .read = seq_read,
2526 .llseek = seq_lseek,
2527 .release = proc_id_map_release,
2528};
2529#endif /* CONFIG_USER_NS */
2530
2531static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2532 struct pid *pid, struct task_struct *task)
2533{
2534 int err = lock_trace(task);
2535 if (!err) {
2536 seq_printf(m, "%08x\n", task->personality);
2537 unlock_trace(task);
2538 }
2539 return err;
2540}
2541
2542/*
2543 * Thread groups
2544 */
2545static const struct file_operations proc_task_operations;
2546static const struct inode_operations proc_task_inode_operations;
2547
2548static const struct pid_entry tgid_base_stuff[] = {
2549 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2550 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2551#ifdef CONFIG_CHECKPOINT_RESTORE
2552 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
2553#endif
2554 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2555 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2556#ifdef CONFIG_NET
2557 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2558#endif
2559 REG("environ", S_IRUSR, proc_environ_operations),
2560 INF("auxv", S_IRUSR, proc_pid_auxv),
2561 ONE("status", S_IRUGO, proc_pid_status),
2562 ONE("personality", S_IRUSR, proc_pid_personality),
2563 INF("limits", S_IRUGO, proc_pid_limits),
2564#ifdef CONFIG_SCHED_DEBUG
2565 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2566#endif
2567#ifdef CONFIG_SCHED_AUTOGROUP
2568 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2569#endif
2570 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2571#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2572 INF("syscall", S_IRUSR, proc_pid_syscall),
2573#endif
2574 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2575 ONE("stat", S_IRUGO, proc_tgid_stat),
2576 ONE("statm", S_IRUGO, proc_pid_statm),
2577 REG("maps", S_IRUGO, proc_pid_maps_operations),
2578#ifdef CONFIG_NUMA
2579 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
2580#endif
2581 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2582 LNK("cwd", proc_cwd_link),
2583 LNK("root", proc_root_link),
2584 LNK("exe", proc_exe_link),
2585 REG("mounts", S_IRUGO, proc_mounts_operations),
2586 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2587 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2588#ifdef CONFIG_PROC_PAGE_MONITOR
2589 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2590 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
2591 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2592#endif
2593#ifdef CONFIG_SECURITY
2594 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2595#endif
2596#ifdef CONFIG_KALLSYMS
2597 INF("wchan", S_IRUGO, proc_pid_wchan),
2598#endif
2599#ifdef CONFIG_STACKTRACE
2600 ONE("stack", S_IRUSR, proc_pid_stack),
2601#endif
2602#ifdef CONFIG_SCHEDSTATS
2603 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2604#endif
2605#ifdef CONFIG_LATENCYTOP
2606 REG("latency", S_IRUGO, proc_lstats_operations),
2607#endif
2608#ifdef CONFIG_PROC_PID_CPUSET
2609 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2610#endif
2611#ifdef CONFIG_CGROUPS
2612 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2613#endif
2614 INF("oom_score", S_IRUGO, proc_oom_score),
2615 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2616 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2617#ifdef CONFIG_AUDITSYSCALL
2618 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2619 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2620#endif
2621#ifdef CONFIG_FAULT_INJECTION
2622 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2623#endif
2624#ifdef CONFIG_ELF_CORE
2625 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2626#endif
2627#ifdef CONFIG_TASK_IO_ACCOUNTING
2628 INF("io", S_IRUSR, proc_tgid_io_accounting),
2629#endif
2630#ifdef CONFIG_HARDWALL
2631 INF("hardwall", S_IRUGO, proc_pid_hardwall),
2632#endif
2633#ifdef CONFIG_USER_NS
2634 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2635 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2636 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2637#endif
2638#ifdef CONFIG_CHECKPOINT_RESTORE
2639 REG("timers", S_IRUGO, proc_timers_operations),
2640#endif
2641};
2642
2643static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
2644{
2645 return proc_pident_readdir(file, ctx,
2646 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2647}
2648
2649static const struct file_operations proc_tgid_base_operations = {
2650 .read = generic_read_dir,
2651 .iterate = proc_tgid_base_readdir,
2652 .llseek = default_llseek,
2653};
2654
2655static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2656{
2657 return proc_pident_lookup(dir, dentry,
2658 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2659}
2660
2661static const struct inode_operations proc_tgid_base_inode_operations = {
2662 .lookup = proc_tgid_base_lookup,
2663 .getattr = pid_getattr,
2664 .setattr = proc_setattr,
2665 .permission = proc_pid_permission,
2666};
2667
2668static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2669{
2670 struct dentry *dentry, *leader, *dir;
2671 char buf[PROC_NUMBUF];
2672 struct qstr name;
2673
2674 name.name = buf;
2675 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2676 /* no ->d_hash() rejects on procfs */
2677 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2678 if (dentry) {
2679 shrink_dcache_parent(dentry);
2680 d_drop(dentry);
2681 dput(dentry);
2682 }
2683
2684 name.name = buf;
2685 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2686 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2687 if (!leader)
2688 goto out;
2689
2690 name.name = "task";
2691 name.len = strlen(name.name);
2692 dir = d_hash_and_lookup(leader, &name);
2693 if (!dir)
2694 goto out_put_leader;
2695
2696 name.name = buf;
2697 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2698 dentry = d_hash_and_lookup(dir, &name);
2699 if (dentry) {
2700 shrink_dcache_parent(dentry);
2701 d_drop(dentry);
2702 dput(dentry);
2703 }
2704
2705 dput(dir);
2706out_put_leader:
2707 dput(leader);
2708out:
2709 return;
2710}
2711
2712/**
2713 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2714 * @task: task that should be flushed.
2715 *
2716 * When flushing dentries from proc, one needs to flush them from global
2717 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2718 * in. This call is supposed to do all of this job.
2719 *
2720 * Looks in the dcache for
2721 * /proc/@pid
2722 * /proc/@tgid/task/@pid
2723 * if either directory is present flushes it and all of it'ts children
2724 * from the dcache.
2725 *
2726 * It is safe and reasonable to cache /proc entries for a task until
2727 * that task exits. After that they just clog up the dcache with
2728 * useless entries, possibly causing useful dcache entries to be
2729 * flushed instead. This routine is proved to flush those useless
2730 * dcache entries at process exit time.
2731 *
2732 * NOTE: This routine is just an optimization so it does not guarantee
2733 * that no dcache entries will exist at process exit time it
2734 * just makes it very unlikely that any will persist.
2735 */
2736
2737void proc_flush_task(struct task_struct *task)
2738{
2739 int i;
2740 struct pid *pid, *tgid;
2741 struct upid *upid;
2742
2743 pid = task_pid(task);
2744 tgid = task_tgid(task);
2745
2746 for (i = 0; i <= pid->level; i++) {
2747 upid = &pid->numbers[i];
2748 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2749 tgid->numbers[i].nr);
2750 }
2751}
2752
2753static int proc_pid_instantiate(struct inode *dir,
2754 struct dentry * dentry,
2755 struct task_struct *task, const void *ptr)
2756{
2757 struct inode *inode;
2758
2759 inode = proc_pid_make_inode(dir->i_sb, task);
2760 if (!inode)
2761 goto out;
2762
2763 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2764 inode->i_op = &proc_tgid_base_inode_operations;
2765 inode->i_fop = &proc_tgid_base_operations;
2766 inode->i_flags|=S_IMMUTABLE;
2767
2768 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
2769 ARRAY_SIZE(tgid_base_stuff)));
2770
2771 d_set_d_op(dentry, &pid_dentry_operations);
2772
2773 d_add(dentry, inode);
2774 /* Close the race of the process dying before we return the dentry */
2775 if (pid_revalidate(dentry, 0))
2776 return 0;
2777out:
2778 return -ENOENT;
2779}
2780
2781struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
2782{
2783 int result = 0;
2784 struct task_struct *task;
2785 unsigned tgid;
2786 struct pid_namespace *ns;
2787
2788 tgid = name_to_int(dentry);
2789 if (tgid == ~0U)
2790 goto out;
2791
2792 ns = dentry->d_sb->s_fs_info;
2793 rcu_read_lock();
2794 task = find_task_by_pid_ns(tgid, ns);
2795 if (task)
2796 get_task_struct(task);
2797 rcu_read_unlock();
2798 if (!task)
2799 goto out;
2800
2801 result = proc_pid_instantiate(dir, dentry, task, NULL);
2802 put_task_struct(task);
2803out:
2804 return ERR_PTR(result);
2805}
2806
2807/*
2808 * Find the first task with tgid >= tgid
2809 *
2810 */
2811struct tgid_iter {
2812 unsigned int tgid;
2813 struct task_struct *task;
2814};
2815static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2816{
2817 struct pid *pid;
2818
2819 if (iter.task)
2820 put_task_struct(iter.task);
2821 rcu_read_lock();
2822retry:
2823 iter.task = NULL;
2824 pid = find_ge_pid(iter.tgid, ns);
2825 if (pid) {
2826 iter.tgid = pid_nr_ns(pid, ns);
2827 iter.task = pid_task(pid, PIDTYPE_PID);
2828 /* What we to know is if the pid we have find is the
2829 * pid of a thread_group_leader. Testing for task
2830 * being a thread_group_leader is the obvious thing
2831 * todo but there is a window when it fails, due to
2832 * the pid transfer logic in de_thread.
2833 *
2834 * So we perform the straight forward test of seeing
2835 * if the pid we have found is the pid of a thread
2836 * group leader, and don't worry if the task we have
2837 * found doesn't happen to be a thread group leader.
2838 * As we don't care in the case of readdir.
2839 */
2840 if (!iter.task || !has_group_leader_pid(iter.task)) {
2841 iter.tgid += 1;
2842 goto retry;
2843 }
2844 get_task_struct(iter.task);
2845 }
2846 rcu_read_unlock();
2847 return iter;
2848}
2849
2850#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 1)
2851
2852/* for the /proc/ directory itself, after non-process stuff has been done */
2853int proc_pid_readdir(struct file *file, struct dir_context *ctx)
2854{
2855 struct tgid_iter iter;
2856 struct pid_namespace *ns = file->f_dentry->d_sb->s_fs_info;
2857 loff_t pos = ctx->pos;
2858
2859 if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
2860 return 0;
2861
2862 if (pos == TGID_OFFSET - 1) {
2863 struct inode *inode = ns->proc_self->d_inode;
2864 if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
2865 return 0;
2866 iter.tgid = 0;
2867 } else {
2868 iter.tgid = pos - TGID_OFFSET;
2869 }
2870 iter.task = NULL;
2871 for (iter = next_tgid(ns, iter);
2872 iter.task;
2873 iter.tgid += 1, iter = next_tgid(ns, iter)) {
2874 char name[PROC_NUMBUF];
2875 int len;
2876 if (!has_pid_permissions(ns, iter.task, 2))
2877 continue;
2878
2879 len = snprintf(name, sizeof(name), "%d", iter.tgid);
2880 ctx->pos = iter.tgid + TGID_OFFSET;
2881 if (!proc_fill_cache(file, ctx, name, len,
2882 proc_pid_instantiate, iter.task, NULL)) {
2883 put_task_struct(iter.task);
2884 return 0;
2885 }
2886 }
2887 ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
2888 return 0;
2889}
2890
2891/*
2892 * Tasks
2893 */
2894static const struct pid_entry tid_base_stuff[] = {
2895 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2896 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2897 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2898 REG("environ", S_IRUSR, proc_environ_operations),
2899 INF("auxv", S_IRUSR, proc_pid_auxv),
2900 ONE("status", S_IRUGO, proc_pid_status),
2901 ONE("personality", S_IRUSR, proc_pid_personality),
2902 INF("limits", S_IRUGO, proc_pid_limits),
2903#ifdef CONFIG_SCHED_DEBUG
2904 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2905#endif
2906 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2907#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2908 INF("syscall", S_IRUSR, proc_pid_syscall),
2909#endif
2910 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2911 ONE("stat", S_IRUGO, proc_tid_stat),
2912 ONE("statm", S_IRUGO, proc_pid_statm),
2913 REG("maps", S_IRUGO, proc_tid_maps_operations),
2914#ifdef CONFIG_CHECKPOINT_RESTORE
2915 REG("children", S_IRUGO, proc_tid_children_operations),
2916#endif
2917#ifdef CONFIG_NUMA
2918 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
2919#endif
2920 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2921 LNK("cwd", proc_cwd_link),
2922 LNK("root", proc_root_link),
2923 LNK("exe", proc_exe_link),
2924 REG("mounts", S_IRUGO, proc_mounts_operations),
2925 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2926#ifdef CONFIG_PROC_PAGE_MONITOR
2927 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2928 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
2929 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2930#endif
2931#ifdef CONFIG_SECURITY
2932 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2933#endif
2934#ifdef CONFIG_KALLSYMS
2935 INF("wchan", S_IRUGO, proc_pid_wchan),
2936#endif
2937#ifdef CONFIG_STACKTRACE
2938 ONE("stack", S_IRUSR, proc_pid_stack),
2939#endif
2940#ifdef CONFIG_SCHEDSTATS
2941 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2942#endif
2943#ifdef CONFIG_LATENCYTOP
2944 REG("latency", S_IRUGO, proc_lstats_operations),
2945#endif
2946#ifdef CONFIG_PROC_PID_CPUSET
2947 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2948#endif
2949#ifdef CONFIG_CGROUPS
2950 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2951#endif
2952 INF("oom_score", S_IRUGO, proc_oom_score),
2953 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
2954 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2955#ifdef CONFIG_AUDITSYSCALL
2956 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2957 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2958#endif
2959#ifdef CONFIG_FAULT_INJECTION
2960 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2961#endif
2962#ifdef CONFIG_TASK_IO_ACCOUNTING
2963 INF("io", S_IRUSR, proc_tid_io_accounting),
2964#endif
2965#ifdef CONFIG_HARDWALL
2966 INF("hardwall", S_IRUGO, proc_pid_hardwall),
2967#endif
2968#ifdef CONFIG_USER_NS
2969 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
2970 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
2971 REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
2972#endif
2973};
2974
2975static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
2976{
2977 return proc_pident_readdir(file, ctx,
2978 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2979}
2980
2981static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
2982{
2983 return proc_pident_lookup(dir, dentry,
2984 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2985}
2986
2987static const struct file_operations proc_tid_base_operations = {
2988 .read = generic_read_dir,
2989 .iterate = proc_tid_base_readdir,
2990 .llseek = default_llseek,
2991};
2992
2993static const struct inode_operations proc_tid_base_inode_operations = {
2994 .lookup = proc_tid_base_lookup,
2995 .getattr = pid_getattr,
2996 .setattr = proc_setattr,
2997};
2998
2999static int proc_task_instantiate(struct inode *dir,
3000 struct dentry *dentry, struct task_struct *task, const void *ptr)
3001{
3002 struct inode *inode;
3003 inode = proc_pid_make_inode(dir->i_sb, task);
3004
3005 if (!inode)
3006 goto out;
3007 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3008 inode->i_op = &proc_tid_base_inode_operations;
3009 inode->i_fop = &proc_tid_base_operations;
3010 inode->i_flags|=S_IMMUTABLE;
3011
3012 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3013 ARRAY_SIZE(tid_base_stuff)));
3014
3015 d_set_d_op(dentry, &pid_dentry_operations);
3016
3017 d_add(dentry, inode);
3018 /* Close the race of the process dying before we return the dentry */
3019 if (pid_revalidate(dentry, 0))
3020 return 0;
3021out:
3022 return -ENOENT;
3023}
3024
3025static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3026{
3027 int result = -ENOENT;
3028 struct task_struct *task;
3029 struct task_struct *leader = get_proc_task(dir);
3030 unsigned tid;
3031 struct pid_namespace *ns;
3032
3033 if (!leader)
3034 goto out_no_task;
3035
3036 tid = name_to_int(dentry);
3037 if (tid == ~0U)
3038 goto out;
3039
3040 ns = dentry->d_sb->s_fs_info;
3041 rcu_read_lock();
3042 task = find_task_by_pid_ns(tid, ns);
3043 if (task)
3044 get_task_struct(task);
3045 rcu_read_unlock();
3046 if (!task)
3047 goto out;
3048 if (!same_thread_group(leader, task))
3049 goto out_drop_task;
3050
3051 result = proc_task_instantiate(dir, dentry, task, NULL);
3052out_drop_task:
3053 put_task_struct(task);
3054out:
3055 put_task_struct(leader);
3056out_no_task:
3057 return ERR_PTR(result);
3058}
3059
3060/*
3061 * Find the first tid of a thread group to return to user space.
3062 *
3063 * Usually this is just the thread group leader, but if the users
3064 * buffer was too small or there was a seek into the middle of the
3065 * directory we have more work todo.
3066 *
3067 * In the case of a short read we start with find_task_by_pid.
3068 *
3069 * In the case of a seek we start with the leader and walk nr
3070 * threads past it.
3071 */
3072static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3073 struct pid_namespace *ns)
3074{
3075 struct task_struct *pos, *task;
3076 unsigned long nr = f_pos;
3077
3078 if (nr != f_pos) /* 32bit overflow? */
3079 return NULL;
3080
3081 rcu_read_lock();
3082 task = pid_task(pid, PIDTYPE_PID);
3083 if (!task)
3084 goto fail;
3085
3086 /* Attempt to start with the tid of a thread */
3087 if (tid && nr) {
3088 pos = find_task_by_pid_ns(tid, ns);
3089 if (pos && same_thread_group(pos, task))
3090 goto found;
3091 }
3092
3093 /* If nr exceeds the number of threads there is nothing todo */
3094 if (nr >= get_nr_threads(task))
3095 goto fail;
3096
3097 /* If we haven't found our starting place yet start
3098 * with the leader and walk nr threads forward.
3099 */
3100 pos = task = task->group_leader;
3101 do {
3102 if (!nr--)
3103 goto found;
3104 } while_each_thread(task, pos);
3105fail:
3106 pos = NULL;
3107 goto out;
3108found:
3109 get_task_struct(pos);
3110out:
3111 rcu_read_unlock();
3112 return pos;
3113}
3114
3115/*
3116 * Find the next thread in the thread list.
3117 * Return NULL if there is an error or no next thread.
3118 *
3119 * The reference to the input task_struct is released.
3120 */
3121static struct task_struct *next_tid(struct task_struct *start)
3122{
3123 struct task_struct *pos = NULL;
3124 rcu_read_lock();
3125 if (pid_alive(start)) {
3126 pos = next_thread(start);
3127 if (thread_group_leader(pos))
3128 pos = NULL;
3129 else
3130 get_task_struct(pos);
3131 }
3132 rcu_read_unlock();
3133 put_task_struct(start);
3134 return pos;
3135}
3136
3137/* for the /proc/TGID/task/ directories */
3138static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3139{
3140 struct inode *inode = file_inode(file);
3141 struct task_struct *task;
3142 struct pid_namespace *ns;
3143 int tid;
3144
3145 if (proc_inode_is_dead(inode))
3146 return -ENOENT;
3147
3148 if (!dir_emit_dots(file, ctx))
3149 return 0;
3150
3151 /* f_version caches the tgid value that the last readdir call couldn't
3152 * return. lseek aka telldir automagically resets f_version to 0.
3153 */
3154 ns = file->f_dentry->d_sb->s_fs_info;
3155 tid = (int)file->f_version;
3156 file->f_version = 0;
3157 for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3158 task;
3159 task = next_tid(task), ctx->pos++) {
3160 char name[PROC_NUMBUF];
3161 int len;
3162 tid = task_pid_nr_ns(task, ns);
3163 len = snprintf(name, sizeof(name), "%d", tid);
3164 if (!proc_fill_cache(file, ctx, name, len,
3165 proc_task_instantiate, task, NULL)) {
3166 /* returning this tgid failed, save it as the first
3167 * pid for the next readir call */
3168 file->f_version = (u64)tid;
3169 put_task_struct(task);
3170 break;
3171 }
3172 }
3173
3174 return 0;
3175}
3176
3177static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3178{
3179 struct inode *inode = dentry->d_inode;
3180 struct task_struct *p = get_proc_task(inode);
3181 generic_fillattr(inode, stat);
3182
3183 if (p) {
3184 stat->nlink += get_nr_threads(p);
3185 put_task_struct(p);
3186 }
3187
3188 return 0;
3189}
3190
3191static const struct inode_operations proc_task_inode_operations = {
3192 .lookup = proc_task_lookup,
3193 .getattr = proc_task_getattr,
3194 .setattr = proc_setattr,
3195 .permission = proc_pid_permission,
3196};
3197
3198static const struct file_operations proc_task_operations = {
3199 .read = generic_read_dir,
3200 .iterate = proc_task_readdir,
3201 .llseek = default_llseek,
3202};