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ARM: tegra: Rename tegra20 clock file
[linux-2.6.git] / fs / proc / base.c
blob1b6c84cbdb732e5684ccaa823548b8780cf1c16d
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/user_namespace.h>
85 #include <linux/fs_struct.h>
86 #include <linux/slab.h>
87 #include <linux/flex_array.h>
88 #ifdef CONFIG_HARDWALL
89 #include <asm/hardwall.h>
90 #endif
91 #include <trace/events/oom.h>
92 #include "internal.h"
93
94 /* NOTE:
95 * Implementing inode permission operations in /proc is almost
96 * certainly an error. Permission checks need to happen during
97 * each system call not at open time. The reason is that most of
98 * what we wish to check for permissions in /proc varies at runtime.
99 *
100 * The classic example of a problem is opening file descriptors
101 * in /proc for a task before it execs a suid executable.
102 */
103
104 struct pid_entry {
105 char *name;
106 int len;
107 umode_t mode;
108 const struct inode_operations *iop;
109 const struct file_operations *fop;
110 union proc_op op;
111 };
112
113 #define NOD(NAME, MODE, IOP, FOP, OP) { \
114 .name = (NAME), \
115 .len = sizeof(NAME) - 1, \
116 .mode = MODE, \
117 .iop = IOP, \
118 .fop = FOP, \
119 .op = OP, \
120 }
121
122 #define DIR(NAME, MODE, iops, fops) \
123 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
124 #define LNK(NAME, get_link) \
125 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
126 &proc_pid_link_inode_operations, NULL, \
127 { .proc_get_link = get_link } )
128 #define REG(NAME, MODE, fops) \
129 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
130 #define INF(NAME, MODE, read) \
131 NOD(NAME, (S_IFREG|(MODE)), \
132 NULL, &proc_info_file_operations, \
133 { .proc_read = read } )
134 #define ONE(NAME, MODE, show) \
135 NOD(NAME, (S_IFREG|(MODE)), \
136 NULL, &proc_single_file_operations, \
137 { .proc_show = show } )
138
139 static int proc_fd_permission(struct inode *inode, int mask);
140
141 /*
142 * Count the number of hardlinks for the pid_entry table, excluding the .
143 * and .. links.
144 */
145 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
146 unsigned int n)
147 {
148 unsigned int i;
149 unsigned int count;
150
151 count = 0;
152 for (i = 0; i < n; ++i) {
153 if (S_ISDIR(entries[i].mode))
154 ++count;
155 }
156
157 return count;
158 }
159
160 static int get_task_root(struct task_struct *task, struct path *root)
161 {
162 int result = -ENOENT;
163
164 task_lock(task);
165 if (task->fs) {
166 get_fs_root(task->fs, root);
167 result = 0;
168 }
169 task_unlock(task);
170 return result;
171 }
172
173 static int proc_cwd_link(struct dentry *dentry, struct path *path)
174 {
175 struct task_struct *task = get_proc_task(dentry->d_inode);
176 int result = -ENOENT;
177
178 if (task) {
179 task_lock(task);
180 if (task->fs) {
181 get_fs_pwd(task->fs, path);
182 result = 0;
183 }
184 task_unlock(task);
185 put_task_struct(task);
186 }
187 return result;
188 }
189
190 static int proc_root_link(struct dentry *dentry, struct path *path)
191 {
192 struct task_struct *task = get_proc_task(dentry->d_inode);
193 int result = -ENOENT;
194
195 if (task) {
196 result = get_task_root(task, path);
197 put_task_struct(task);
198 }
199 return result;
200 }
201
202 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
203 {
204 int res = 0;
205 unsigned int len;
206 struct mm_struct *mm = get_task_mm(task);
207 if (!mm)
208 goto out;
209 if (!mm->arg_end)
210 goto out_mm; /* Shh! No looking before we're done */
211
212 len = mm->arg_end - mm->arg_start;
213
214 if (len > PAGE_SIZE)
215 len = PAGE_SIZE;
216
217 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
218
219 // If the nul at the end of args has been overwritten, then
220 // assume application is using setproctitle(3).
221 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
222 len = strnlen(buffer, res);
223 if (len < res) {
224 res = len;
225 } else {
226 len = mm->env_end - mm->env_start;
227 if (len > PAGE_SIZE - res)
228 len = PAGE_SIZE - res;
229 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
230 res = strnlen(buffer, res);
231 }
232 }
233 out_mm:
234 mmput(mm);
235 out:
236 return res;
237 }
238
239 static int proc_pid_auxv(struct task_struct *task, char *buffer)
240 {
241 struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ);
242 int res = PTR_ERR(mm);
243 if (mm && !IS_ERR(mm)) {
244 unsigned int nwords = 0;
245 do {
246 nwords += 2;
247 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
248 res = nwords * sizeof(mm->saved_auxv[0]);
249 if (res > PAGE_SIZE)
250 res = PAGE_SIZE;
251 memcpy(buffer, mm->saved_auxv, res);
252 mmput(mm);
253 }
254 return res;
255 }
256
257
258 #ifdef CONFIG_KALLSYMS
259 /*
260 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
261 * Returns the resolved symbol. If that fails, simply return the address.
262 */
263 static int proc_pid_wchan(struct task_struct *task, char *buffer)
264 {
265 unsigned long wchan;
266 char symname[KSYM_NAME_LEN];
267
268 wchan = get_wchan(task);
269
270 if (lookup_symbol_name(wchan, symname) < 0)
271 if (!ptrace_may_access(task, PTRACE_MODE_READ))
272 return 0;
273 else
274 return sprintf(buffer, "%lu", wchan);
275 else
276 return sprintf(buffer, "%s", symname);
277 }
278 #endif /* CONFIG_KALLSYMS */
279
280 static int lock_trace(struct task_struct *task)
281 {
282 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
283 if (err)
284 return err;
285 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
286 mutex_unlock(&task->signal->cred_guard_mutex);
287 return -EPERM;
288 }
289 return 0;
290 }
291
292 static void unlock_trace(struct task_struct *task)
293 {
294 mutex_unlock(&task->signal->cred_guard_mutex);
295 }
296
297 #ifdef CONFIG_STACKTRACE
298
299 #define MAX_STACK_TRACE_DEPTH 64
300
301 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
302 struct pid *pid, struct task_struct *task)
303 {
304 struct stack_trace trace;
305 unsigned long *entries;
306 int err;
307 int i;
308
309 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
310 if (!entries)
311 return -ENOMEM;
312
313 trace.nr_entries = 0;
314 trace.max_entries = MAX_STACK_TRACE_DEPTH;
315 trace.entries = entries;
316 trace.skip = 0;
317
318 err = lock_trace(task);
319 if (!err) {
320 save_stack_trace_tsk(task, &trace);
321
322 for (i = 0; i < trace.nr_entries; i++) {
323 seq_printf(m, "[<%pK>] %pS\n",
324 (void *)entries[i], (void *)entries[i]);
325 }
326 unlock_trace(task);
327 }
328 kfree(entries);
329
330 return err;
331 }
332 #endif
333
334 #ifdef CONFIG_SCHEDSTATS
335 /*
336 * Provides /proc/PID/schedstat
337 */
338 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
339 {
340 return sprintf(buffer, "%llu %llu %lu\n",
341 (unsigned long long)task->se.sum_exec_runtime,
342 (unsigned long long)task->sched_info.run_delay,
343 task->sched_info.pcount);
344 }
345 #endif
346
347 #ifdef CONFIG_LATENCYTOP
348 static int lstats_show_proc(struct seq_file *m, void *v)
349 {
350 int i;
351 struct inode *inode = m->private;
352 struct task_struct *task = get_proc_task(inode);
353
354 if (!task)
355 return -ESRCH;
356 seq_puts(m, "Latency Top version : v0.1\n");
357 for (i = 0; i < 32; i++) {
358 struct latency_record *lr = &task->latency_record[i];
359 if (lr->backtrace[0]) {
360 int q;
361 seq_printf(m, "%i %li %li",
362 lr->count, lr->time, lr->max);
363 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
364 unsigned long bt = lr->backtrace[q];
365 if (!bt)
366 break;
367 if (bt == ULONG_MAX)
368 break;
369 seq_printf(m, " %ps", (void *)bt);
370 }
371 seq_putc(m, '\n');
372 }
373
374 }
375 put_task_struct(task);
376 return 0;
377 }
378
379 static int lstats_open(struct inode *inode, struct file *file)
380 {
381 return single_open(file, lstats_show_proc, inode);
382 }
383
384 static ssize_t lstats_write(struct file *file, const char __user *buf,
385 size_t count, loff_t *offs)
386 {
387 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
388
389 if (!task)
390 return -ESRCH;
391 clear_all_latency_tracing(task);
392 put_task_struct(task);
393
394 return count;
395 }
396
397 static const struct file_operations proc_lstats_operations = {
398 .open = lstats_open,
399 .read = seq_read,
400 .write = lstats_write,
401 .llseek = seq_lseek,
402 .release = single_release,
403 };
404
405 #endif
406
407 static 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
420 struct limit_names {
421 char *name;
422 char *unit;
423 };
424
425 static 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 */
445 static 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
490 static 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 */
518 static 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
534 int 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 if ((attr->ia_valid & ATTR_SIZE) &&
547 attr->ia_size != i_size_read(inode)) {
548 error = vmtruncate(inode, attr->ia_size);
549 if (error)
550 return error;
551 }
552
553 setattr_copy(inode, attr);
554 mark_inode_dirty(inode);
555 return 0;
556 }
557
558 /*
559 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
560 * or euid/egid (for hide_pid_min=2)?
561 */
562 static bool has_pid_permissions(struct pid_namespace *pid,
563 struct task_struct *task,
564 int hide_pid_min)
565 {
566 if (pid->hide_pid < hide_pid_min)
567 return true;
568 if (in_group_p(pid->pid_gid))
569 return true;
570 return ptrace_may_access(task, PTRACE_MODE_READ);
571 }
572
573
574 static int proc_pid_permission(struct inode *inode, int mask)
575 {
576 struct pid_namespace *pid = inode->i_sb->s_fs_info;
577 struct task_struct *task;
578 bool has_perms;
579
580 task = get_proc_task(inode);
581 if (!task)
582 return -ESRCH;
583 has_perms = has_pid_permissions(pid, task, 1);
584 put_task_struct(task);
585
586 if (!has_perms) {
587 if (pid->hide_pid == 2) {
588 /*
589 * Let's make getdents(), stat(), and open()
590 * consistent with each other. If a process
591 * may not stat() a file, it shouldn't be seen
592 * in procfs at all.
593 */
594 return -ENOENT;
595 }
596
597 return -EPERM;
598 }
599 return generic_permission(inode, mask);
600 }
601
602
603
604 static const struct inode_operations proc_def_inode_operations = {
605 .setattr = proc_setattr,
606 };
607
608 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
609
610 static ssize_t proc_info_read(struct file * file, char __user * buf,
611 size_t count, loff_t *ppos)
612 {
613 struct inode * inode = file->f_path.dentry->d_inode;
614 unsigned long page;
615 ssize_t length;
616 struct task_struct *task = get_proc_task(inode);
617
618 length = -ESRCH;
619 if (!task)
620 goto out_no_task;
621
622 if (count > PROC_BLOCK_SIZE)
623 count = PROC_BLOCK_SIZE;
624
625 length = -ENOMEM;
626 if (!(page = __get_free_page(GFP_TEMPORARY)))
627 goto out;
628
629 length = PROC_I(inode)->op.proc_read(task, (char*)page);
630
631 if (length >= 0)
632 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
633 free_page(page);
634 out:
635 put_task_struct(task);
636 out_no_task:
637 return length;
638 }
639
640 static const struct file_operations proc_info_file_operations = {
641 .read = proc_info_read,
642 .llseek = generic_file_llseek,
643 };
644
645 static int proc_single_show(struct seq_file *m, void *v)
646 {
647 struct inode *inode = m->private;
648 struct pid_namespace *ns;
649 struct pid *pid;
650 struct task_struct *task;
651 int ret;
652
653 ns = inode->i_sb->s_fs_info;
654 pid = proc_pid(inode);
655 task = get_pid_task(pid, PIDTYPE_PID);
656 if (!task)
657 return -ESRCH;
658
659 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
660
661 put_task_struct(task);
662 return ret;
663 }
664
665 static int proc_single_open(struct inode *inode, struct file *filp)
666 {
667 return single_open(filp, proc_single_show, inode);
668 }
669
670 static const struct file_operations proc_single_file_operations = {
671 .open = proc_single_open,
672 .read = seq_read,
673 .llseek = seq_lseek,
674 .release = single_release,
675 };
676
677 static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
678 {
679 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
680 struct mm_struct *mm;
681
682 if (!task)
683 return -ESRCH;
684
685 mm = mm_access(task, mode);
686 put_task_struct(task);
687
688 if (IS_ERR(mm))
689 return PTR_ERR(mm);
690
691 if (mm) {
692 /* ensure this mm_struct can't be freed */
693 atomic_inc(&mm->mm_count);
694 /* but do not pin its memory */
695 mmput(mm);
696 }
697
698 file->private_data = mm;
699
700 return 0;
701 }
702
703 static int mem_open(struct inode *inode, struct file *file)
704 {
705 int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
706
707 /* OK to pass negative loff_t, we can catch out-of-range */
708 file->f_mode |= FMODE_UNSIGNED_OFFSET;
709
710 return ret;
711 }
712
713 static ssize_t mem_rw(struct file *file, char __user *buf,
714 size_t count, loff_t *ppos, int write)
715 {
716 struct mm_struct *mm = file->private_data;
717 unsigned long addr = *ppos;
718 ssize_t copied;
719 char *page;
720
721 if (!mm)
722 return 0;
723
724 page = (char *)__get_free_page(GFP_TEMPORARY);
725 if (!page)
726 return -ENOMEM;
727
728 copied = 0;
729 if (!atomic_inc_not_zero(&mm->mm_users))
730 goto free;
731
732 while (count > 0) {
733 int this_len = min_t(int, count, PAGE_SIZE);
734
735 if (write && copy_from_user(page, buf, this_len)) {
736 copied = -EFAULT;
737 break;
738 }
739
740 this_len = access_remote_vm(mm, addr, page, this_len, write);
741 if (!this_len) {
742 if (!copied)
743 copied = -EIO;
744 break;
745 }
746
747 if (!write && copy_to_user(buf, page, this_len)) {
748 copied = -EFAULT;
749 break;
750 }
751
752 buf += this_len;
753 addr += this_len;
754 copied += this_len;
755 count -= this_len;
756 }
757 *ppos = addr;
758
759 mmput(mm);
760 free:
761 free_page((unsigned long) page);
762 return copied;
763 }
764
765 static ssize_t mem_read(struct file *file, char __user *buf,
766 size_t count, loff_t *ppos)
767 {
768 return mem_rw(file, buf, count, ppos, 0);
769 }
770
771 static ssize_t mem_write(struct file *file, const char __user *buf,
772 size_t count, loff_t *ppos)
773 {
774 return mem_rw(file, (char __user*)buf, count, ppos, 1);
775 }
776
777 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
778 {
779 switch (orig) {
780 case 0:
781 file->f_pos = offset;
782 break;
783 case 1:
784 file->f_pos += offset;
785 break;
786 default:
787 return -EINVAL;
788 }
789 force_successful_syscall_return();
790 return file->f_pos;
791 }
792
793 static int mem_release(struct inode *inode, struct file *file)
794 {
795 struct mm_struct *mm = file->private_data;
796 if (mm)
797 mmdrop(mm);
798 return 0;
799 }
800
801 static const struct file_operations proc_mem_operations = {
802 .llseek = mem_lseek,
803 .read = mem_read,
804 .write = mem_write,
805 .open = mem_open,
806 .release = mem_release,
807 };
808
809 static int environ_open(struct inode *inode, struct file *file)
810 {
811 return __mem_open(inode, file, PTRACE_MODE_READ);
812 }
813
814 static ssize_t environ_read(struct file *file, char __user *buf,
815 size_t count, loff_t *ppos)
816 {
817 char *page;
818 unsigned long src = *ppos;
819 int ret = 0;
820 struct mm_struct *mm = file->private_data;
821
822 if (!mm)
823 return 0;
824
825 page = (char *)__get_free_page(GFP_TEMPORARY);
826 if (!page)
827 return -ENOMEM;
828
829 ret = 0;
830 if (!atomic_inc_not_zero(&mm->mm_users))
831 goto free;
832 while (count > 0) {
833 size_t this_len, max_len;
834 int retval;
835
836 if (src >= (mm->env_end - mm->env_start))
837 break;
838
839 this_len = mm->env_end - (mm->env_start + src);
840
841 max_len = min_t(size_t, PAGE_SIZE, count);
842 this_len = min(max_len, this_len);
843
844 retval = access_remote_vm(mm, (mm->env_start + src),
845 page, this_len, 0);
846
847 if (retval <= 0) {
848 ret = retval;
849 break;
850 }
851
852 if (copy_to_user(buf, page, retval)) {
853 ret = -EFAULT;
854 break;
855 }
856
857 ret += retval;
858 src += retval;
859 buf += retval;
860 count -= retval;
861 }
862 *ppos = src;
863 mmput(mm);
864
865 free:
866 free_page((unsigned long) page);
867 return ret;
868 }
869
870 static const struct file_operations proc_environ_operations = {
871 .open = environ_open,
872 .read = environ_read,
873 .llseek = generic_file_llseek,
874 .release = mem_release,
875 };
876
877 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
878 size_t count, loff_t *ppos)
879 {
880 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
881 char buffer[PROC_NUMBUF];
882 size_t len;
883 int oom_adjust = OOM_DISABLE;
884 unsigned long flags;
885
886 if (!task)
887 return -ESRCH;
888
889 if (lock_task_sighand(task, &flags)) {
890 oom_adjust = task->signal->oom_adj;
891 unlock_task_sighand(task, &flags);
892 }
893
894 put_task_struct(task);
895
896 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
897
898 return simple_read_from_buffer(buf, count, ppos, buffer, len);
899 }
900
901 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
902 size_t count, loff_t *ppos)
903 {
904 struct task_struct *task;
905 char buffer[PROC_NUMBUF];
906 int oom_adjust;
907 unsigned long flags;
908 int err;
909
910 memset(buffer, 0, sizeof(buffer));
911 if (count > sizeof(buffer) - 1)
912 count = sizeof(buffer) - 1;
913 if (copy_from_user(buffer, buf, count)) {
914 err = -EFAULT;
915 goto out;
916 }
917
918 err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
919 if (err)
920 goto out;
921 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
922 oom_adjust != OOM_DISABLE) {
923 err = -EINVAL;
924 goto out;
925 }
926
927 task = get_proc_task(file->f_path.dentry->d_inode);
928 if (!task) {
929 err = -ESRCH;
930 goto out;
931 }
932
933 task_lock(task);
934 if (!task->mm) {
935 err = -EINVAL;
936 goto err_task_lock;
937 }
938
939 if (!lock_task_sighand(task, &flags)) {
940 err = -ESRCH;
941 goto err_task_lock;
942 }
943
944 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
945 err = -EACCES;
946 goto err_sighand;
947 }
948
949 /*
950 * Warn that /proc/pid/oom_adj is deprecated, see
951 * Documentation/feature-removal-schedule.txt.
952 */
953 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
954 current->comm, task_pid_nr(current), task_pid_nr(task),
955 task_pid_nr(task));
956 task->signal->oom_adj = oom_adjust;
957 /*
958 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
959 * value is always attainable.
960 */
961 if (task->signal->oom_adj == OOM_ADJUST_MAX)
962 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
963 else
964 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
965 -OOM_DISABLE;
966 trace_oom_score_adj_update(task);
967 err_sighand:
968 unlock_task_sighand(task, &flags);
969 err_task_lock:
970 task_unlock(task);
971 put_task_struct(task);
972 out:
973 return err < 0 ? err : count;
974 }
975
976 static const struct file_operations proc_oom_adjust_operations = {
977 .read = oom_adjust_read,
978 .write = oom_adjust_write,
979 .llseek = generic_file_llseek,
980 };
981
982 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
983 size_t count, loff_t *ppos)
984 {
985 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
986 char buffer[PROC_NUMBUF];
987 int oom_score_adj = OOM_SCORE_ADJ_MIN;
988 unsigned long flags;
989 size_t len;
990
991 if (!task)
992 return -ESRCH;
993 if (lock_task_sighand(task, &flags)) {
994 oom_score_adj = task->signal->oom_score_adj;
995 unlock_task_sighand(task, &flags);
996 }
997 put_task_struct(task);
998 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
999 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1000 }
1001
1002 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1003 size_t count, loff_t *ppos)
1004 {
1005 struct task_struct *task;
1006 char buffer[PROC_NUMBUF];
1007 unsigned long flags;
1008 int oom_score_adj;
1009 int err;
1010
1011 memset(buffer, 0, sizeof(buffer));
1012 if (count > sizeof(buffer) - 1)
1013 count = sizeof(buffer) - 1;
1014 if (copy_from_user(buffer, buf, count)) {
1015 err = -EFAULT;
1016 goto out;
1017 }
1018
1019 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1020 if (err)
1021 goto out;
1022 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1023 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1024 err = -EINVAL;
1025 goto out;
1026 }
1027
1028 task = get_proc_task(file->f_path.dentry->d_inode);
1029 if (!task) {
1030 err = -ESRCH;
1031 goto out;
1032 }
1033
1034 task_lock(task);
1035 if (!task->mm) {
1036 err = -EINVAL;
1037 goto err_task_lock;
1038 }
1039
1040 if (!lock_task_sighand(task, &flags)) {
1041 err = -ESRCH;
1042 goto err_task_lock;
1043 }
1044
1045 if (oom_score_adj < task->signal->oom_score_adj_min &&
1046 !capable(CAP_SYS_RESOURCE)) {
1047 err = -EACCES;
1048 goto err_sighand;
1049 }
1050
1051 task->signal->oom_score_adj = oom_score_adj;
1052 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1053 task->signal->oom_score_adj_min = oom_score_adj;
1054 trace_oom_score_adj_update(task);
1055 /*
1056 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1057 * always attainable.
1058 */
1059 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1060 task->signal->oom_adj = OOM_DISABLE;
1061 else
1062 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1063 OOM_SCORE_ADJ_MAX;
1064 err_sighand:
1065 unlock_task_sighand(task, &flags);
1066 err_task_lock:
1067 task_unlock(task);
1068 put_task_struct(task);
1069 out:
1070 return err < 0 ? err : count;
1071 }
1072
1073 static const struct file_operations proc_oom_score_adj_operations = {
1074 .read = oom_score_adj_read,
1075 .write = oom_score_adj_write,
1076 .llseek = default_llseek,
1077 };
1078
1079 #ifdef CONFIG_AUDITSYSCALL
1080 #define TMPBUFLEN 21
1081 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1082 size_t count, loff_t *ppos)
1083 {
1084 struct inode * inode = file->f_path.dentry->d_inode;
1085 struct task_struct *task = get_proc_task(inode);
1086 ssize_t length;
1087 char tmpbuf[TMPBUFLEN];
1088
1089 if (!task)
1090 return -ESRCH;
1091 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1092 audit_get_loginuid(task));
1093 put_task_struct(task);
1094 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1095 }
1096
1097 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1098 size_t count, loff_t *ppos)
1099 {
1100 struct inode * inode = file->f_path.dentry->d_inode;
1101 char *page, *tmp;
1102 ssize_t length;
1103 uid_t loginuid;
1104
1105 rcu_read_lock();
1106 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1107 rcu_read_unlock();
1108 return -EPERM;
1109 }
1110 rcu_read_unlock();
1111
1112 if (count >= PAGE_SIZE)
1113 count = PAGE_SIZE - 1;
1114
1115 if (*ppos != 0) {
1116 /* No partial writes. */
1117 return -EINVAL;
1118 }
1119 page = (char*)__get_free_page(GFP_TEMPORARY);
1120 if (!page)
1121 return -ENOMEM;
1122 length = -EFAULT;
1123 if (copy_from_user(page, buf, count))
1124 goto out_free_page;
1125
1126 page[count] = '\0';
1127 loginuid = simple_strtoul(page, &tmp, 10);
1128 if (tmp == page) {
1129 length = -EINVAL;
1130 goto out_free_page;
1131
1132 }
1133 length = audit_set_loginuid(loginuid);
1134 if (likely(length == 0))
1135 length = count;
1136
1137 out_free_page:
1138 free_page((unsigned long) page);
1139 return length;
1140 }
1141
1142 static const struct file_operations proc_loginuid_operations = {
1143 .read = proc_loginuid_read,
1144 .write = proc_loginuid_write,
1145 .llseek = generic_file_llseek,
1146 };
1147
1148 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1149 size_t count, loff_t *ppos)
1150 {
1151 struct inode * inode = file->f_path.dentry->d_inode;
1152 struct task_struct *task = get_proc_task(inode);
1153 ssize_t length;
1154 char tmpbuf[TMPBUFLEN];
1155
1156 if (!task)
1157 return -ESRCH;
1158 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1159 audit_get_sessionid(task));
1160 put_task_struct(task);
1161 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1162 }
1163
1164 static const struct file_operations proc_sessionid_operations = {
1165 .read = proc_sessionid_read,
1166 .llseek = generic_file_llseek,
1167 };
1168 #endif
1169
1170 #ifdef CONFIG_FAULT_INJECTION
1171 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1172 size_t count, loff_t *ppos)
1173 {
1174 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1175 char buffer[PROC_NUMBUF];
1176 size_t len;
1177 int make_it_fail;
1178
1179 if (!task)
1180 return -ESRCH;
1181 make_it_fail = task->make_it_fail;
1182 put_task_struct(task);
1183
1184 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1185
1186 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1187 }
1188
1189 static ssize_t proc_fault_inject_write(struct file * file,
1190 const char __user * buf, size_t count, loff_t *ppos)
1191 {
1192 struct task_struct *task;
1193 char buffer[PROC_NUMBUF], *end;
1194 int make_it_fail;
1195
1196 if (!capable(CAP_SYS_RESOURCE))
1197 return -EPERM;
1198 memset(buffer, 0, sizeof(buffer));
1199 if (count > sizeof(buffer) - 1)
1200 count = sizeof(buffer) - 1;
1201 if (copy_from_user(buffer, buf, count))
1202 return -EFAULT;
1203 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1204 if (*end)
1205 return -EINVAL;
1206 task = get_proc_task(file->f_dentry->d_inode);
1207 if (!task)
1208 return -ESRCH;
1209 task->make_it_fail = make_it_fail;
1210 put_task_struct(task);
1211
1212 return count;
1213 }
1214
1215 static const struct file_operations proc_fault_inject_operations = {
1216 .read = proc_fault_inject_read,
1217 .write = proc_fault_inject_write,
1218 .llseek = generic_file_llseek,
1219 };
1220 #endif
1221
1222
1223 #ifdef CONFIG_SCHED_DEBUG
1224 /*
1225 * Print out various scheduling related per-task fields:
1226 */
1227 static int sched_show(struct seq_file *m, void *v)
1228 {
1229 struct inode *inode = m->private;
1230 struct task_struct *p;
1231
1232 p = get_proc_task(inode);
1233 if (!p)
1234 return -ESRCH;
1235 proc_sched_show_task(p, m);
1236
1237 put_task_struct(p);
1238
1239 return 0;
1240 }
1241
1242 static ssize_t
1243 sched_write(struct file *file, const char __user *buf,
1244 size_t count, loff_t *offset)
1245 {
1246 struct inode *inode = file->f_path.dentry->d_inode;
1247 struct task_struct *p;
1248
1249 p = get_proc_task(inode);
1250 if (!p)
1251 return -ESRCH;
1252 proc_sched_set_task(p);
1253
1254 put_task_struct(p);
1255
1256 return count;
1257 }
1258
1259 static int sched_open(struct inode *inode, struct file *filp)
1260 {
1261 return single_open(filp, sched_show, inode);
1262 }
1263
1264 static const struct file_operations proc_pid_sched_operations = {
1265 .open = sched_open,
1266 .read = seq_read,
1267 .write = sched_write,
1268 .llseek = seq_lseek,
1269 .release = single_release,
1270 };
1271
1272 #endif
1273
1274 #ifdef CONFIG_SCHED_AUTOGROUP
1275 /*
1276 * Print out autogroup related information:
1277 */
1278 static int sched_autogroup_show(struct seq_file *m, void *v)
1279 {
1280 struct inode *inode = m->private;
1281 struct task_struct *p;
1282
1283 p = get_proc_task(inode);
1284 if (!p)
1285 return -ESRCH;
1286 proc_sched_autogroup_show_task(p, m);
1287
1288 put_task_struct(p);
1289
1290 return 0;
1291 }
1292
1293 static ssize_t
1294 sched_autogroup_write(struct file *file, const char __user *buf,
1295 size_t count, loff_t *offset)
1296 {
1297 struct inode *inode = file->f_path.dentry->d_inode;
1298 struct task_struct *p;
1299 char buffer[PROC_NUMBUF];
1300 int nice;
1301 int err;
1302
1303 memset(buffer, 0, sizeof(buffer));
1304 if (count > sizeof(buffer) - 1)
1305 count = sizeof(buffer) - 1;
1306 if (copy_from_user(buffer, buf, count))
1307 return -EFAULT;
1308
1309 err = kstrtoint(strstrip(buffer), 0, &nice);
1310 if (err < 0)
1311 return err;
1312
1313 p = get_proc_task(inode);
1314 if (!p)
1315 return -ESRCH;
1316
1317 err = proc_sched_autogroup_set_nice(p, nice);
1318 if (err)
1319 count = err;
1320
1321 put_task_struct(p);
1322
1323 return count;
1324 }
1325
1326 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1327 {
1328 int ret;
1329
1330 ret = single_open(filp, sched_autogroup_show, NULL);
1331 if (!ret) {
1332 struct seq_file *m = filp->private_data;
1333
1334 m->private = inode;
1335 }
1336 return ret;
1337 }
1338
1339 static const struct file_operations proc_pid_sched_autogroup_operations = {
1340 .open = sched_autogroup_open,
1341 .read = seq_read,
1342 .write = sched_autogroup_write,
1343 .llseek = seq_lseek,
1344 .release = single_release,
1345 };
1346
1347 #endif /* CONFIG_SCHED_AUTOGROUP */
1348
1349 static ssize_t comm_write(struct file *file, const char __user *buf,
1350 size_t count, loff_t *offset)
1351 {
1352 struct inode *inode = file->f_path.dentry->d_inode;
1353 struct task_struct *p;
1354 char buffer[TASK_COMM_LEN];
1355
1356 memset(buffer, 0, sizeof(buffer));
1357 if (count > sizeof(buffer) - 1)
1358 count = sizeof(buffer) - 1;
1359 if (copy_from_user(buffer, buf, count))
1360 return -EFAULT;
1361
1362 p = get_proc_task(inode);
1363 if (!p)
1364 return -ESRCH;
1365
1366 if (same_thread_group(current, p))
1367 set_task_comm(p, buffer);
1368 else
1369 count = -EINVAL;
1370
1371 put_task_struct(p);
1372
1373 return count;
1374 }
1375
1376 static int comm_show(struct seq_file *m, void *v)
1377 {
1378 struct inode *inode = m->private;
1379 struct task_struct *p;
1380
1381 p = get_proc_task(inode);
1382 if (!p)
1383 return -ESRCH;
1384
1385 task_lock(p);
1386 seq_printf(m, "%s\n", p->comm);
1387 task_unlock(p);
1388
1389 put_task_struct(p);
1390
1391 return 0;
1392 }
1393
1394 static int comm_open(struct inode *inode, struct file *filp)
1395 {
1396 return single_open(filp, comm_show, inode);
1397 }
1398
1399 static const struct file_operations proc_pid_set_comm_operations = {
1400 .open = comm_open,
1401 .read = seq_read,
1402 .write = comm_write,
1403 .llseek = seq_lseek,
1404 .release = single_release,
1405 };
1406
1407 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1408 {
1409 struct task_struct *task;
1410 struct mm_struct *mm;
1411 struct file *exe_file;
1412
1413 task = get_proc_task(dentry->d_inode);
1414 if (!task)
1415 return -ENOENT;
1416 mm = get_task_mm(task);
1417 put_task_struct(task);
1418 if (!mm)
1419 return -ENOENT;
1420 exe_file = get_mm_exe_file(mm);
1421 mmput(mm);
1422 if (exe_file) {
1423 *exe_path = exe_file->f_path;
1424 path_get(&exe_file->f_path);
1425 fput(exe_file);
1426 return 0;
1427 } else
1428 return -ENOENT;
1429 }
1430
1431 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1432 {
1433 struct inode *inode = dentry->d_inode;
1434 struct path path;
1435 int error = -EACCES;
1436
1437 /* Are we allowed to snoop on the tasks file descriptors? */
1438 if (!proc_fd_access_allowed(inode))
1439 goto out;
1440
1441 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1442 if (error)
1443 goto out;
1444
1445 nd_jump_link(nd, &path);
1446 return NULL;
1447 out:
1448 return ERR_PTR(error);
1449 }
1450
1451 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1452 {
1453 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1454 char *pathname;
1455 int len;
1456
1457 if (!tmp)
1458 return -ENOMEM;
1459
1460 pathname = d_path(path, tmp, PAGE_SIZE);
1461 len = PTR_ERR(pathname);
1462 if (IS_ERR(pathname))
1463 goto out;
1464 len = tmp + PAGE_SIZE - 1 - pathname;
1465
1466 if (len > buflen)
1467 len = buflen;
1468 if (copy_to_user(buffer, pathname, len))
1469 len = -EFAULT;
1470 out:
1471 free_page((unsigned long)tmp);
1472 return len;
1473 }
1474
1475 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1476 {
1477 int error = -EACCES;
1478 struct inode *inode = dentry->d_inode;
1479 struct path path;
1480
1481 /* Are we allowed to snoop on the tasks file descriptors? */
1482 if (!proc_fd_access_allowed(inode))
1483 goto out;
1484
1485 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1486 if (error)
1487 goto out;
1488
1489 error = do_proc_readlink(&path, buffer, buflen);
1490 path_put(&path);
1491 out:
1492 return error;
1493 }
1494
1495 static const struct inode_operations proc_pid_link_inode_operations = {
1496 .readlink = proc_pid_readlink,
1497 .follow_link = proc_pid_follow_link,
1498 .setattr = proc_setattr,
1499 };
1500
1501
1502 /* building an inode */
1503
1504 static int task_dumpable(struct task_struct *task)
1505 {
1506 int dumpable = 0;
1507 struct mm_struct *mm;
1508
1509 task_lock(task);
1510 mm = task->mm;
1511 if (mm)
1512 dumpable = get_dumpable(mm);
1513 task_unlock(task);
1514 if(dumpable == 1)
1515 return 1;
1516 return 0;
1517 }
1518
1519 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1520 {
1521 struct inode * inode;
1522 struct proc_inode *ei;
1523 const struct cred *cred;
1524
1525 /* We need a new inode */
1526
1527 inode = new_inode(sb);
1528 if (!inode)
1529 goto out;
1530
1531 /* Common stuff */
1532 ei = PROC_I(inode);
1533 inode->i_ino = get_next_ino();
1534 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1535 inode->i_op = &proc_def_inode_operations;
1536
1537 /*
1538 * grab the reference to task.
1539 */
1540 ei->pid = get_task_pid(task, PIDTYPE_PID);
1541 if (!ei->pid)
1542 goto out_unlock;
1543
1544 if (task_dumpable(task)) {
1545 rcu_read_lock();
1546 cred = __task_cred(task);
1547 inode->i_uid = cred->euid;
1548 inode->i_gid = cred->egid;
1549 rcu_read_unlock();
1550 }
1551 security_task_to_inode(task, inode);
1552
1553 out:
1554 return inode;
1555
1556 out_unlock:
1557 iput(inode);
1558 return NULL;
1559 }
1560
1561 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1562 {
1563 struct inode *inode = dentry->d_inode;
1564 struct task_struct *task;
1565 const struct cred *cred;
1566 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1567
1568 generic_fillattr(inode, stat);
1569
1570 rcu_read_lock();
1571 stat->uid = GLOBAL_ROOT_UID;
1572 stat->gid = GLOBAL_ROOT_GID;
1573 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1574 if (task) {
1575 if (!has_pid_permissions(pid, task, 2)) {
1576 rcu_read_unlock();
1577 /*
1578 * This doesn't prevent learning whether PID exists,
1579 * it only makes getattr() consistent with readdir().
1580 */
1581 return -ENOENT;
1582 }
1583 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1584 task_dumpable(task)) {
1585 cred = __task_cred(task);
1586 stat->uid = cred->euid;
1587 stat->gid = cred->egid;
1588 }
1589 }
1590 rcu_read_unlock();
1591 return 0;
1592 }
1593
1594 /* dentry stuff */
1595
1596 /*
1597 * Exceptional case: normally we are not allowed to unhash a busy
1598 * directory. In this case, however, we can do it - no aliasing problems
1599 * due to the way we treat inodes.
1600 *
1601 * Rewrite the inode's ownerships here because the owning task may have
1602 * performed a setuid(), etc.
1603 *
1604 * Before the /proc/pid/status file was created the only way to read
1605 * the effective uid of a /process was to stat /proc/pid. Reading
1606 * /proc/pid/status is slow enough that procps and other packages
1607 * kept stating /proc/pid. To keep the rules in /proc simple I have
1608 * made this apply to all per process world readable and executable
1609 * directories.
1610 */
1611 int pid_revalidate(struct dentry *dentry, unsigned int flags)
1612 {
1613 struct inode *inode;
1614 struct task_struct *task;
1615 const struct cred *cred;
1616
1617 if (flags & LOOKUP_RCU)
1618 return -ECHILD;
1619
1620 inode = dentry->d_inode;
1621 task = get_proc_task(inode);
1622
1623 if (task) {
1624 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1625 task_dumpable(task)) {
1626 rcu_read_lock();
1627 cred = __task_cred(task);
1628 inode->i_uid = cred->euid;
1629 inode->i_gid = cred->egid;
1630 rcu_read_unlock();
1631 } else {
1632 inode->i_uid = GLOBAL_ROOT_UID;
1633 inode->i_gid = GLOBAL_ROOT_GID;
1634 }
1635 inode->i_mode &= ~(S_ISUID | S_ISGID);
1636 security_task_to_inode(task, inode);
1637 put_task_struct(task);
1638 return 1;
1639 }
1640 d_drop(dentry);
1641 return 0;
1642 }
1643
1644 static int pid_delete_dentry(const struct dentry * dentry)
1645 {
1646 /* Is the task we represent dead?
1647 * If so, then don't put the dentry on the lru list,
1648 * kill it immediately.
1649 */
1650 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1651 }
1652
1653 const struct dentry_operations pid_dentry_operations =
1654 {
1655 .d_revalidate = pid_revalidate,
1656 .d_delete = pid_delete_dentry,
1657 };
1658
1659 /* Lookups */
1660
1661 /*
1662 * Fill a directory entry.
1663 *
1664 * If possible create the dcache entry and derive our inode number and
1665 * file type from dcache entry.
1666 *
1667 * Since all of the proc inode numbers are dynamically generated, the inode
1668 * numbers do not exist until the inode is cache. This means creating the
1669 * the dcache entry in readdir is necessary to keep the inode numbers
1670 * reported by readdir in sync with the inode numbers reported
1671 * by stat.
1672 */
1673 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1674 const char *name, int len,
1675 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1676 {
1677 struct dentry *child, *dir = filp->f_path.dentry;
1678 struct inode *inode;
1679 struct qstr qname;
1680 ino_t ino = 0;
1681 unsigned type = DT_UNKNOWN;
1682
1683 qname.name = name;
1684 qname.len = len;
1685 qname.hash = full_name_hash(name, len);
1686
1687 child = d_lookup(dir, &qname);
1688 if (!child) {
1689 struct dentry *new;
1690 new = d_alloc(dir, &qname);
1691 if (new) {
1692 child = instantiate(dir->d_inode, new, task, ptr);
1693 if (child)
1694 dput(new);
1695 else
1696 child = new;
1697 }
1698 }
1699 if (!child || IS_ERR(child) || !child->d_inode)
1700 goto end_instantiate;
1701 inode = child->d_inode;
1702 if (inode) {
1703 ino = inode->i_ino;
1704 type = inode->i_mode >> 12;
1705 }
1706 dput(child);
1707 end_instantiate:
1708 if (!ino)
1709 ino = find_inode_number(dir, &qname);
1710 if (!ino)
1711 ino = 1;
1712 return filldir(dirent, name, len, filp->f_pos, ino, type);
1713 }
1714
1715 static unsigned name_to_int(struct dentry *dentry)
1716 {
1717 const char *name = dentry->d_name.name;
1718 int len = dentry->d_name.len;
1719 unsigned n = 0;
1720
1721 if (len > 1 && *name == '0')
1722 goto out;
1723 while (len-- > 0) {
1724 unsigned c = *name++ - '0';
1725 if (c > 9)
1726 goto out;
1727 if (n >= (~0U-9)/10)
1728 goto out;
1729 n *= 10;
1730 n += c;
1731 }
1732 return n;
1733 out:
1734 return ~0U;
1735 }
1736
1737 #define PROC_FDINFO_MAX 64
1738
1739 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1740 {
1741 struct task_struct *task = get_proc_task(inode);
1742 struct files_struct *files = NULL;
1743 struct file *file;
1744 int fd = proc_fd(inode);
1745
1746 if (task) {
1747 files = get_files_struct(task);
1748 put_task_struct(task);
1749 }
1750 if (files) {
1751 /*
1752 * We are not taking a ref to the file structure, so we must
1753 * hold ->file_lock.
1754 */
1755 spin_lock(&files->file_lock);
1756 file = fcheck_files(files, fd);
1757 if (file) {
1758 unsigned int f_flags;
1759 struct fdtable *fdt;
1760
1761 fdt = files_fdtable(files);
1762 f_flags = file->f_flags & ~O_CLOEXEC;
1763 if (close_on_exec(fd, fdt))
1764 f_flags |= O_CLOEXEC;
1765
1766 if (path) {
1767 *path = file->f_path;
1768 path_get(&file->f_path);
1769 }
1770 if (info)
1771 snprintf(info, PROC_FDINFO_MAX,
1772 "pos:\t%lli\n"
1773 "flags:\t0%o\n",
1774 (long long) file->f_pos,
1775 f_flags);
1776 spin_unlock(&files->file_lock);
1777 put_files_struct(files);
1778 return 0;
1779 }
1780 spin_unlock(&files->file_lock);
1781 put_files_struct(files);
1782 }
1783 return -ENOENT;
1784 }
1785
1786 static int proc_fd_link(struct dentry *dentry, struct path *path)
1787 {
1788 return proc_fd_info(dentry->d_inode, path, NULL);
1789 }
1790
1791 static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
1792 {
1793 struct inode *inode;
1794 struct task_struct *task;
1795 int fd;
1796 struct files_struct *files;
1797 const struct cred *cred;
1798
1799 if (flags & LOOKUP_RCU)
1800 return -ECHILD;
1801
1802 inode = dentry->d_inode;
1803 task = get_proc_task(inode);
1804 fd = proc_fd(inode);
1805
1806 if (task) {
1807 files = get_files_struct(task);
1808 if (files) {
1809 struct file *file;
1810 rcu_read_lock();
1811 file = fcheck_files(files, fd);
1812 if (file) {
1813 unsigned f_mode = file->f_mode;
1814
1815 rcu_read_unlock();
1816 put_files_struct(files);
1817
1818 if (task_dumpable(task)) {
1819 rcu_read_lock();
1820 cred = __task_cred(task);
1821 inode->i_uid = cred->euid;
1822 inode->i_gid = cred->egid;
1823 rcu_read_unlock();
1824 } else {
1825 inode->i_uid = GLOBAL_ROOT_UID;
1826 inode->i_gid = GLOBAL_ROOT_GID;
1827 }
1828
1829 if (S_ISLNK(inode->i_mode)) {
1830 unsigned i_mode = S_IFLNK;
1831 if (f_mode & FMODE_READ)
1832 i_mode |= S_IRUSR | S_IXUSR;
1833 if (f_mode & FMODE_WRITE)
1834 i_mode |= S_IWUSR | S_IXUSR;
1835 inode->i_mode = i_mode;
1836 }
1837
1838 security_task_to_inode(task, inode);
1839 put_task_struct(task);
1840 return 1;
1841 }
1842 rcu_read_unlock();
1843 put_files_struct(files);
1844 }
1845 put_task_struct(task);
1846 }
1847 d_drop(dentry);
1848 return 0;
1849 }
1850
1851 static const struct dentry_operations tid_fd_dentry_operations =
1852 {
1853 .d_revalidate = tid_fd_revalidate,
1854 .d_delete = pid_delete_dentry,
1855 };
1856
1857 static struct dentry *proc_fd_instantiate(struct inode *dir,
1858 struct dentry *dentry, struct task_struct *task, const void *ptr)
1859 {
1860 unsigned fd = (unsigned long)ptr;
1861 struct inode *inode;
1862 struct proc_inode *ei;
1863 struct dentry *error = ERR_PTR(-ENOENT);
1864
1865 inode = proc_pid_make_inode(dir->i_sb, task);
1866 if (!inode)
1867 goto out;
1868 ei = PROC_I(inode);
1869 ei->fd = fd;
1870
1871 inode->i_mode = S_IFLNK;
1872 inode->i_op = &proc_pid_link_inode_operations;
1873 inode->i_size = 64;
1874 ei->op.proc_get_link = proc_fd_link;
1875 d_set_d_op(dentry, &tid_fd_dentry_operations);
1876 d_add(dentry, inode);
1877 /* Close the race of the process dying before we return the dentry */
1878 if (tid_fd_revalidate(dentry, 0))
1879 error = NULL;
1880
1881 out:
1882 return error;
1883 }
1884
1885 static struct dentry *proc_lookupfd_common(struct inode *dir,
1886 struct dentry *dentry,
1887 instantiate_t instantiate)
1888 {
1889 struct task_struct *task = get_proc_task(dir);
1890 unsigned fd = name_to_int(dentry);
1891 struct dentry *result = ERR_PTR(-ENOENT);
1892
1893 if (!task)
1894 goto out_no_task;
1895 if (fd == ~0U)
1896 goto out;
1897
1898 result = instantiate(dir, dentry, task, (void *)(unsigned long)fd);
1899 out:
1900 put_task_struct(task);
1901 out_no_task:
1902 return result;
1903 }
1904
1905 static int proc_readfd_common(struct file * filp, void * dirent,
1906 filldir_t filldir, instantiate_t instantiate)
1907 {
1908 struct dentry *dentry = filp->f_path.dentry;
1909 struct inode *inode = dentry->d_inode;
1910 struct task_struct *p = get_proc_task(inode);
1911 unsigned int fd, ino;
1912 int retval;
1913 struct files_struct * files;
1914
1915 retval = -ENOENT;
1916 if (!p)
1917 goto out_no_task;
1918 retval = 0;
1919
1920 fd = filp->f_pos;
1921 switch (fd) {
1922 case 0:
1923 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1924 goto out;
1925 filp->f_pos++;
1926 case 1:
1927 ino = parent_ino(dentry);
1928 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1929 goto out;
1930 filp->f_pos++;
1931 default:
1932 files = get_files_struct(p);
1933 if (!files)
1934 goto out;
1935 rcu_read_lock();
1936 for (fd = filp->f_pos-2;
1937 fd < files_fdtable(files)->max_fds;
1938 fd++, filp->f_pos++) {
1939 char name[PROC_NUMBUF];
1940 int len;
1941 int rv;
1942
1943 if (!fcheck_files(files, fd))
1944 continue;
1945 rcu_read_unlock();
1946
1947 len = snprintf(name, sizeof(name), "%d", fd);
1948 rv = proc_fill_cache(filp, dirent, filldir,
1949 name, len, instantiate, p,
1950 (void *)(unsigned long)fd);
1951 if (rv < 0)
1952 goto out_fd_loop;
1953 rcu_read_lock();
1954 }
1955 rcu_read_unlock();
1956 out_fd_loop:
1957 put_files_struct(files);
1958 }
1959 out:
1960 put_task_struct(p);
1961 out_no_task:
1962 return retval;
1963 }
1964
1965 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1966 unsigned int flags)
1967 {
1968 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1969 }
1970
1971 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1972 {
1973 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1974 }
1975
1976 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1977 size_t len, loff_t *ppos)
1978 {
1979 char tmp[PROC_FDINFO_MAX];
1980 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
1981 if (!err)
1982 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1983 return err;
1984 }
1985
1986 static const struct file_operations proc_fdinfo_file_operations = {
1987 .open = nonseekable_open,
1988 .read = proc_fdinfo_read,
1989 .llseek = no_llseek,
1990 };
1991
1992 static const struct file_operations proc_fd_operations = {
1993 .read = generic_read_dir,
1994 .readdir = proc_readfd,
1995 .llseek = default_llseek,
1996 };
1997
1998 #ifdef CONFIG_CHECKPOINT_RESTORE
1999
2000 /*
2001 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2002 * which represent vma start and end addresses.
2003 */
2004 static int dname_to_vma_addr(struct dentry *dentry,
2005 unsigned long *start, unsigned long *end)
2006 {
2007 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
2008 return -EINVAL;
2009
2010 return 0;
2011 }
2012
2013 static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
2014 {
2015 unsigned long vm_start, vm_end;
2016 bool exact_vma_exists = false;
2017 struct mm_struct *mm = NULL;
2018 struct task_struct *task;
2019 const struct cred *cred;
2020 struct inode *inode;
2021 int status = 0;
2022
2023 if (flags & LOOKUP_RCU)
2024 return -ECHILD;
2025
2026 if (!capable(CAP_SYS_ADMIN)) {
2027 status = -EACCES;
2028 goto out_notask;
2029 }
2030
2031 inode = dentry->d_inode;
2032 task = get_proc_task(inode);
2033 if (!task)
2034 goto out_notask;
2035
2036 mm = mm_access(task, PTRACE_MODE_READ);
2037 if (IS_ERR_OR_NULL(mm))
2038 goto out;
2039
2040 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2041 down_read(&mm->mmap_sem);
2042 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
2043 up_read(&mm->mmap_sem);
2044 }
2045
2046 mmput(mm);
2047
2048 if (exact_vma_exists) {
2049 if (task_dumpable(task)) {
2050 rcu_read_lock();
2051 cred = __task_cred(task);
2052 inode->i_uid = cred->euid;
2053 inode->i_gid = cred->egid;
2054 rcu_read_unlock();
2055 } else {
2056 inode->i_uid = GLOBAL_ROOT_UID;
2057 inode->i_gid = GLOBAL_ROOT_GID;
2058 }
2059 security_task_to_inode(task, inode);
2060 status = 1;
2061 }
2062
2063 out:
2064 put_task_struct(task);
2065
2066 out_notask:
2067 if (status <= 0)
2068 d_drop(dentry);
2069
2070 return status;
2071 }
2072
2073 static const struct dentry_operations tid_map_files_dentry_operations = {
2074 .d_revalidate = map_files_d_revalidate,
2075 .d_delete = pid_delete_dentry,
2076 };
2077
2078 static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
2079 {
2080 unsigned long vm_start, vm_end;
2081 struct vm_area_struct *vma;
2082 struct task_struct *task;
2083 struct mm_struct *mm;
2084 int rc;
2085
2086 rc = -ENOENT;
2087 task = get_proc_task(dentry->d_inode);
2088 if (!task)
2089 goto out;
2090
2091 mm = get_task_mm(task);
2092 put_task_struct(task);
2093 if (!mm)
2094 goto out;
2095
2096 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2097 if (rc)
2098 goto out_mmput;
2099
2100 down_read(&mm->mmap_sem);
2101 vma = find_exact_vma(mm, vm_start, vm_end);
2102 if (vma && vma->vm_file) {
2103 *path = vma->vm_file->f_path;
2104 path_get(path);
2105 rc = 0;
2106 }
2107 up_read(&mm->mmap_sem);
2108
2109 out_mmput:
2110 mmput(mm);
2111 out:
2112 return rc;
2113 }
2114
2115 struct map_files_info {
2116 struct file *file;
2117 unsigned long len;
2118 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
2119 };
2120
2121 static struct dentry *
2122 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
2123 struct task_struct *task, const void *ptr)
2124 {
2125 const struct file *file = ptr;
2126 struct proc_inode *ei;
2127 struct inode *inode;
2128
2129 if (!file)
2130 return ERR_PTR(-ENOENT);
2131
2132 inode = proc_pid_make_inode(dir->i_sb, task);
2133 if (!inode)
2134 return ERR_PTR(-ENOENT);
2135
2136 ei = PROC_I(inode);
2137 ei->op.proc_get_link = proc_map_files_get_link;
2138
2139 inode->i_op = &proc_pid_link_inode_operations;
2140 inode->i_size = 64;
2141 inode->i_mode = S_IFLNK;
2142
2143 if (file->f_mode & FMODE_READ)
2144 inode->i_mode |= S_IRUSR;
2145 if (file->f_mode & FMODE_WRITE)
2146 inode->i_mode |= S_IWUSR;
2147
2148 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2149 d_add(dentry, inode);
2150
2151 return NULL;
2152 }
2153
2154 static struct dentry *proc_map_files_lookup(struct inode *dir,
2155 struct dentry *dentry, unsigned int flags)
2156 {
2157 unsigned long vm_start, vm_end;
2158 struct vm_area_struct *vma;
2159 struct task_struct *task;
2160 struct dentry *result;
2161 struct mm_struct *mm;
2162
2163 result = ERR_PTR(-EACCES);
2164 if (!capable(CAP_SYS_ADMIN))
2165 goto out;
2166
2167 result = ERR_PTR(-ENOENT);
2168 task = get_proc_task(dir);
2169 if (!task)
2170 goto out;
2171
2172 result = ERR_PTR(-EACCES);
2173 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2174 goto out_put_task;
2175
2176 result = ERR_PTR(-ENOENT);
2177 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2178 goto out_put_task;
2179
2180 mm = get_task_mm(task);
2181 if (!mm)
2182 goto out_put_task;
2183
2184 down_read(&mm->mmap_sem);
2185 vma = find_exact_vma(mm, vm_start, vm_end);
2186 if (!vma)
2187 goto out_no_vma;
2188
2189 result = proc_map_files_instantiate(dir, dentry, task, vma->vm_file);
2190
2191 out_no_vma:
2192 up_read(&mm->mmap_sem);
2193 mmput(mm);
2194 out_put_task:
2195 put_task_struct(task);
2196 out:
2197 return result;
2198 }
2199
2200 static const struct inode_operations proc_map_files_inode_operations = {
2201 .lookup = proc_map_files_lookup,
2202 .permission = proc_fd_permission,
2203 .setattr = proc_setattr,
2204 };
2205
2206 static int
2207 proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
2208 {
2209 struct dentry *dentry = filp->f_path.dentry;
2210 struct inode *inode = dentry->d_inode;
2211 struct vm_area_struct *vma;
2212 struct task_struct *task;
2213 struct mm_struct *mm;
2214 ino_t ino;
2215 int ret;
2216
2217 ret = -EACCES;
2218 if (!capable(CAP_SYS_ADMIN))
2219 goto out;
2220
2221 ret = -ENOENT;
2222 task = get_proc_task(inode);
2223 if (!task)
2224 goto out;
2225
2226 ret = -EACCES;
2227 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2228 goto out_put_task;
2229
2230 ret = 0;
2231 switch (filp->f_pos) {
2232 case 0:
2233 ino = inode->i_ino;
2234 if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0)
2235 goto out_put_task;
2236 filp->f_pos++;
2237 case 1:
2238 ino = parent_ino(dentry);
2239 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2240 goto out_put_task;
2241 filp->f_pos++;
2242 default:
2243 {
2244 unsigned long nr_files, pos, i;
2245 struct flex_array *fa = NULL;
2246 struct map_files_info info;
2247 struct map_files_info *p;
2248
2249 mm = get_task_mm(task);
2250 if (!mm)
2251 goto out_put_task;
2252 down_read(&mm->mmap_sem);
2253
2254 nr_files = 0;
2255
2256 /*
2257 * We need two passes here:
2258 *
2259 * 1) Collect vmas of mapped files with mmap_sem taken
2260 * 2) Release mmap_sem and instantiate entries
2261 *
2262 * otherwise we get lockdep complained, since filldir()
2263 * routine might require mmap_sem taken in might_fault().
2264 */
2265
2266 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2267 if (vma->vm_file && ++pos > filp->f_pos)
2268 nr_files++;
2269 }
2270
2271 if (nr_files) {
2272 fa = flex_array_alloc(sizeof(info), nr_files,
2273 GFP_KERNEL);
2274 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2275 GFP_KERNEL)) {
2276 ret = -ENOMEM;
2277 if (fa)
2278 flex_array_free(fa);
2279 up_read(&mm->mmap_sem);
2280 mmput(mm);
2281 goto out_put_task;
2282 }
2283 for (i = 0, vma = mm->mmap, pos = 2; vma;
2284 vma = vma->vm_next) {
2285 if (!vma->vm_file)
2286 continue;
2287 if (++pos <= filp->f_pos)
2288 continue;
2289
2290 get_file(vma->vm_file);
2291 info.file = vma->vm_file;
2292 info.len = snprintf(info.name,
2293 sizeof(info.name), "%lx-%lx",
2294 vma->vm_start, vma->vm_end);
2295 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2296 BUG();
2297 }
2298 }
2299 up_read(&mm->mmap_sem);
2300
2301 for (i = 0; i < nr_files; i++) {
2302 p = flex_array_get(fa, i);
2303 ret = proc_fill_cache(filp, dirent, filldir,
2304 p->name, p->len,
2305 proc_map_files_instantiate,
2306 task, p->file);
2307 if (ret)
2308 break;
2309 filp->f_pos++;
2310 fput(p->file);
2311 }
2312 for (; i < nr_files; i++) {
2313 /*
2314 * In case of error don't forget
2315 * to put rest of file refs.
2316 */
2317 p = flex_array_get(fa, i);
2318 fput(p->file);
2319 }
2320 if (fa)
2321 flex_array_free(fa);
2322 mmput(mm);
2323 }
2324 }
2325
2326 out_put_task:
2327 put_task_struct(task);
2328 out:
2329 return ret;
2330 }
2331
2332 static const struct file_operations proc_map_files_operations = {
2333 .read = generic_read_dir,
2334 .readdir = proc_map_files_readdir,
2335 .llseek = default_llseek,
2336 };
2337
2338 #endif /* CONFIG_CHECKPOINT_RESTORE */
2339
2340 /*
2341 * /proc/pid/fd needs a special permission handler so that a process can still
2342 * access /proc/self/fd after it has executed a setuid().
2343 */
2344 static int proc_fd_permission(struct inode *inode, int mask)
2345 {
2346 int rv = generic_permission(inode, mask);
2347 if (rv == 0)
2348 return 0;
2349 if (task_pid(current) == proc_pid(inode))
2350 rv = 0;
2351 return rv;
2352 }
2353
2354 /*
2355 * proc directories can do almost nothing..
2356 */
2357 static const struct inode_operations proc_fd_inode_operations = {
2358 .lookup = proc_lookupfd,
2359 .permission = proc_fd_permission,
2360 .setattr = proc_setattr,
2361 };
2362
2363 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2364 struct dentry *dentry, struct task_struct *task, const void *ptr)
2365 {
2366 unsigned fd = (unsigned long)ptr;
2367 struct inode *inode;
2368 struct proc_inode *ei;
2369 struct dentry *error = ERR_PTR(-ENOENT);
2370
2371 inode = proc_pid_make_inode(dir->i_sb, task);
2372 if (!inode)
2373 goto out;
2374 ei = PROC_I(inode);
2375 ei->fd = fd;
2376 inode->i_mode = S_IFREG | S_IRUSR;
2377 inode->i_fop = &proc_fdinfo_file_operations;
2378 d_set_d_op(dentry, &tid_fd_dentry_operations);
2379 d_add(dentry, inode);
2380 /* Close the race of the process dying before we return the dentry */
2381 if (tid_fd_revalidate(dentry, 0))
2382 error = NULL;
2383
2384 out:
2385 return error;
2386 }
2387
2388 static struct dentry *proc_lookupfdinfo(struct inode *dir,
2389 struct dentry *dentry,
2390 unsigned int flags)
2391 {
2392 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2393 }
2394
2395 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2396 {
2397 return proc_readfd_common(filp, dirent, filldir,
2398 proc_fdinfo_instantiate);
2399 }
2400
2401 static const struct file_operations proc_fdinfo_operations = {
2402 .read = generic_read_dir,
2403 .readdir = proc_readfdinfo,
2404 .llseek = default_llseek,
2405 };
2406
2407 /*
2408 * proc directories can do almost nothing..
2409 */
2410 static const struct inode_operations proc_fdinfo_inode_operations = {
2411 .lookup = proc_lookupfdinfo,
2412 .setattr = proc_setattr,
2413 };
2414
2415
2416 static struct dentry *proc_pident_instantiate(struct inode *dir,
2417 struct dentry *dentry, struct task_struct *task, const void *ptr)
2418 {
2419 const struct pid_entry *p = ptr;
2420 struct inode *inode;
2421 struct proc_inode *ei;
2422 struct dentry *error = ERR_PTR(-ENOENT);
2423
2424 inode = proc_pid_make_inode(dir->i_sb, task);
2425 if (!inode)
2426 goto out;
2427
2428 ei = PROC_I(inode);
2429 inode->i_mode = p->mode;
2430 if (S_ISDIR(inode->i_mode))
2431 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2432 if (p->iop)
2433 inode->i_op = p->iop;
2434 if (p->fop)
2435 inode->i_fop = p->fop;
2436 ei->op = p->op;
2437 d_set_d_op(dentry, &pid_dentry_operations);
2438 d_add(dentry, inode);
2439 /* Close the race of the process dying before we return the dentry */
2440 if (pid_revalidate(dentry, 0))
2441 error = NULL;
2442 out:
2443 return error;
2444 }
2445
2446 static struct dentry *proc_pident_lookup(struct inode *dir,
2447 struct dentry *dentry,
2448 const struct pid_entry *ents,
2449 unsigned int nents)
2450 {
2451 struct dentry *error;
2452 struct task_struct *task = get_proc_task(dir);
2453 const struct pid_entry *p, *last;
2454
2455 error = ERR_PTR(-ENOENT);
2456
2457 if (!task)
2458 goto out_no_task;
2459
2460 /*
2461 * Yes, it does not scale. And it should not. Don't add
2462 * new entries into /proc/<tgid>/ without very good reasons.
2463 */
2464 last = &ents[nents - 1];
2465 for (p = ents; p <= last; p++) {
2466 if (p->len != dentry->d_name.len)
2467 continue;
2468 if (!memcmp(dentry->d_name.name, p->name, p->len))
2469 break;
2470 }
2471 if (p > last)
2472 goto out;
2473
2474 error = proc_pident_instantiate(dir, dentry, task, p);
2475 out:
2476 put_task_struct(task);
2477 out_no_task:
2478 return error;
2479 }
2480
2481 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2482 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2483 {
2484 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2485 proc_pident_instantiate, task, p);
2486 }
2487
2488 static int proc_pident_readdir(struct file *filp,
2489 void *dirent, filldir_t filldir,
2490 const struct pid_entry *ents, unsigned int nents)
2491 {
2492 int i;
2493 struct dentry *dentry = filp->f_path.dentry;
2494 struct inode *inode = dentry->d_inode;
2495 struct task_struct *task = get_proc_task(inode);
2496 const struct pid_entry *p, *last;
2497 ino_t ino;
2498 int ret;
2499
2500 ret = -ENOENT;
2501 if (!task)
2502 goto out_no_task;
2503
2504 ret = 0;
2505 i = filp->f_pos;
2506 switch (i) {
2507 case 0:
2508 ino = inode->i_ino;
2509 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2510 goto out;
2511 i++;
2512 filp->f_pos++;
2513 /* fall through */
2514 case 1:
2515 ino = parent_ino(dentry);
2516 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2517 goto out;
2518 i++;
2519 filp->f_pos++;
2520 /* fall through */
2521 default:
2522 i -= 2;
2523 if (i >= nents) {
2524 ret = 1;
2525 goto out;
2526 }
2527 p = ents + i;
2528 last = &ents[nents - 1];
2529 while (p <= last) {
2530 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2531 goto out;
2532 filp->f_pos++;
2533 p++;
2534 }
2535 }
2536
2537 ret = 1;
2538 out:
2539 put_task_struct(task);
2540 out_no_task:
2541 return ret;
2542 }
2543
2544 #ifdef CONFIG_SECURITY
2545 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2546 size_t count, loff_t *ppos)
2547 {
2548 struct inode * inode = file->f_path.dentry->d_inode;
2549 char *p = NULL;
2550 ssize_t length;
2551 struct task_struct *task = get_proc_task(inode);
2552
2553 if (!task)
2554 return -ESRCH;
2555
2556 length = security_getprocattr(task,
2557 (char*)file->f_path.dentry->d_name.name,
2558 &p);
2559 put_task_struct(task);
2560 if (length > 0)
2561 length = simple_read_from_buffer(buf, count, ppos, p, length);
2562 kfree(p);
2563 return length;
2564 }
2565
2566 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2567 size_t count, loff_t *ppos)
2568 {
2569 struct inode * inode = file->f_path.dentry->d_inode;
2570 char *page;
2571 ssize_t length;
2572 struct task_struct *task = get_proc_task(inode);
2573
2574 length = -ESRCH;
2575 if (!task)
2576 goto out_no_task;
2577 if (count > PAGE_SIZE)
2578 count = PAGE_SIZE;
2579
2580 /* No partial writes. */
2581 length = -EINVAL;
2582 if (*ppos != 0)
2583 goto out;
2584
2585 length = -ENOMEM;
2586 page = (char*)__get_free_page(GFP_TEMPORARY);
2587 if (!page)
2588 goto out;
2589
2590 length = -EFAULT;
2591 if (copy_from_user(page, buf, count))
2592 goto out_free;
2593
2594 /* Guard against adverse ptrace interaction */
2595 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2596 if (length < 0)
2597 goto out_free;
2598
2599 length = security_setprocattr(task,
2600 (char*)file->f_path.dentry->d_name.name,
2601 (void*)page, count);
2602 mutex_unlock(&task->signal->cred_guard_mutex);
2603 out_free:
2604 free_page((unsigned long) page);
2605 out:
2606 put_task_struct(task);
2607 out_no_task:
2608 return length;
2609 }
2610
2611 static const struct file_operations proc_pid_attr_operations = {
2612 .read = proc_pid_attr_read,
2613 .write = proc_pid_attr_write,
2614 .llseek = generic_file_llseek,
2615 };
2616
2617 static const struct pid_entry attr_dir_stuff[] = {
2618 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2619 REG("prev", S_IRUGO, proc_pid_attr_operations),
2620 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2621 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2622 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2623 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2624 };
2625
2626 static int proc_attr_dir_readdir(struct file * filp,
2627 void * dirent, filldir_t filldir)
2628 {
2629 return proc_pident_readdir(filp,dirent,filldir,
2630 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2631 }
2632
2633 static const struct file_operations proc_attr_dir_operations = {
2634 .read = generic_read_dir,
2635 .readdir = proc_attr_dir_readdir,
2636 .llseek = default_llseek,
2637 };
2638
2639 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2640 struct dentry *dentry, unsigned int flags)
2641 {
2642 return proc_pident_lookup(dir, dentry,
2643 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2644 }
2645
2646 static const struct inode_operations proc_attr_dir_inode_operations = {
2647 .lookup = proc_attr_dir_lookup,
2648 .getattr = pid_getattr,
2649 .setattr = proc_setattr,
2650 };
2651
2652 #endif
2653
2654 #ifdef CONFIG_ELF_CORE
2655 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2656 size_t count, loff_t *ppos)
2657 {
2658 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2659 struct mm_struct *mm;
2660 char buffer[PROC_NUMBUF];
2661 size_t len;
2662 int ret;
2663
2664 if (!task)
2665 return -ESRCH;
2666
2667 ret = 0;
2668 mm = get_task_mm(task);
2669 if (mm) {
2670 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2671 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2672 MMF_DUMP_FILTER_SHIFT));
2673 mmput(mm);
2674 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2675 }
2676
2677 put_task_struct(task);
2678
2679 return ret;
2680 }
2681
2682 static ssize_t proc_coredump_filter_write(struct file *file,
2683 const char __user *buf,
2684 size_t count,
2685 loff_t *ppos)
2686 {
2687 struct task_struct *task;
2688 struct mm_struct *mm;
2689 char buffer[PROC_NUMBUF], *end;
2690 unsigned int val;
2691 int ret;
2692 int i;
2693 unsigned long mask;
2694
2695 ret = -EFAULT;
2696 memset(buffer, 0, sizeof(buffer));
2697 if (count > sizeof(buffer) - 1)
2698 count = sizeof(buffer) - 1;
2699 if (copy_from_user(buffer, buf, count))
2700 goto out_no_task;
2701
2702 ret = -EINVAL;
2703 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2704 if (*end == '\n')
2705 end++;
2706 if (end - buffer == 0)
2707 goto out_no_task;
2708
2709 ret = -ESRCH;
2710 task = get_proc_task(file->f_dentry->d_inode);
2711 if (!task)
2712 goto out_no_task;
2713
2714 ret = end - buffer;
2715 mm = get_task_mm(task);
2716 if (!mm)
2717 goto out_no_mm;
2718
2719 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2720 if (val & mask)
2721 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2722 else
2723 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2724 }
2725
2726 mmput(mm);
2727 out_no_mm:
2728 put_task_struct(task);
2729 out_no_task:
2730 return ret;
2731 }
2732
2733 static const struct file_operations proc_coredump_filter_operations = {
2734 .read = proc_coredump_filter_read,
2735 .write = proc_coredump_filter_write,
2736 .llseek = generic_file_llseek,
2737 };
2738 #endif
2739
2740 /*
2741 * /proc/self:
2742 */
2743 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2744 int buflen)
2745 {
2746 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2747 pid_t tgid = task_tgid_nr_ns(current, ns);
2748 char tmp[PROC_NUMBUF];
2749 if (!tgid)
2750 return -ENOENT;
2751 sprintf(tmp, "%d", tgid);
2752 return vfs_readlink(dentry,buffer,buflen,tmp);
2753 }
2754
2755 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2756 {
2757 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2758 pid_t tgid = task_tgid_nr_ns(current, ns);
2759 char *name = ERR_PTR(-ENOENT);
2760 if (tgid) {
2761 name = __getname();
2762 if (!name)
2763 name = ERR_PTR(-ENOMEM);
2764 else
2765 sprintf(name, "%d", tgid);
2766 }
2767 nd_set_link(nd, name);
2768 return NULL;
2769 }
2770
2771 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2772 void *cookie)
2773 {
2774 char *s = nd_get_link(nd);
2775 if (!IS_ERR(s))
2776 __putname(s);
2777 }
2778
2779 static const struct inode_operations proc_self_inode_operations = {
2780 .readlink = proc_self_readlink,
2781 .follow_link = proc_self_follow_link,
2782 .put_link = proc_self_put_link,
2783 };
2784
2785 /*
2786 * proc base
2787 *
2788 * These are the directory entries in the root directory of /proc
2789 * that properly belong to the /proc filesystem, as they describe
2790 * describe something that is process related.
2791 */
2792 static const struct pid_entry proc_base_stuff[] = {
2793 NOD("self", S_IFLNK|S_IRWXUGO,
2794 &proc_self_inode_operations, NULL, {}),
2795 };
2796
2797 static struct dentry *proc_base_instantiate(struct inode *dir,
2798 struct dentry *dentry, struct task_struct *task, const void *ptr)
2799 {
2800 const struct pid_entry *p = ptr;
2801 struct inode *inode;
2802 struct proc_inode *ei;
2803 struct dentry *error;
2804
2805 /* Allocate the inode */
2806 error = ERR_PTR(-ENOMEM);
2807 inode = new_inode(dir->i_sb);
2808 if (!inode)
2809 goto out;
2810
2811 /* Initialize the inode */
2812 ei = PROC_I(inode);
2813 inode->i_ino = get_next_ino();
2814 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2815
2816 /*
2817 * grab the reference to the task.
2818 */
2819 ei->pid = get_task_pid(task, PIDTYPE_PID);
2820 if (!ei->pid)
2821 goto out_iput;
2822
2823 inode->i_mode = p->mode;
2824 if (S_ISDIR(inode->i_mode))
2825 set_nlink(inode, 2);
2826 if (S_ISLNK(inode->i_mode))
2827 inode->i_size = 64;
2828 if (p->iop)
2829 inode->i_op = p->iop;
2830 if (p->fop)
2831 inode->i_fop = p->fop;
2832 ei->op = p->op;
2833 d_add(dentry, inode);
2834 error = NULL;
2835 out:
2836 return error;
2837 out_iput:
2838 iput(inode);
2839 goto out;
2840 }
2841
2842 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2843 {
2844 struct dentry *error;
2845 struct task_struct *task = get_proc_task(dir);
2846 const struct pid_entry *p, *last;
2847
2848 error = ERR_PTR(-ENOENT);
2849
2850 if (!task)
2851 goto out_no_task;
2852
2853 /* Lookup the directory entry */
2854 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2855 for (p = proc_base_stuff; p <= last; p++) {
2856 if (p->len != dentry->d_name.len)
2857 continue;
2858 if (!memcmp(dentry->d_name.name, p->name, p->len))
2859 break;
2860 }
2861 if (p > last)
2862 goto out;
2863
2864 error = proc_base_instantiate(dir, dentry, task, p);
2865
2866 out:
2867 put_task_struct(task);
2868 out_no_task:
2869 return error;
2870 }
2871
2872 static int proc_base_fill_cache(struct file *filp, void *dirent,
2873 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2874 {
2875 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2876 proc_base_instantiate, task, p);
2877 }
2878
2879 #ifdef CONFIG_TASK_IO_ACCOUNTING
2880 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2881 {
2882 struct task_io_accounting acct = task->ioac;
2883 unsigned long flags;
2884 int result;
2885
2886 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2887 if (result)
2888 return result;
2889
2890 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2891 result = -EACCES;
2892 goto out_unlock;
2893 }
2894
2895 if (whole && lock_task_sighand(task, &flags)) {
2896 struct task_struct *t = task;
2897
2898 task_io_accounting_add(&acct, &task->signal->ioac);
2899 while_each_thread(task, t)
2900 task_io_accounting_add(&acct, &t->ioac);
2901
2902 unlock_task_sighand(task, &flags);
2903 }
2904 result = sprintf(buffer,
2905 "rchar: %llu\n"
2906 "wchar: %llu\n"
2907 "syscr: %llu\n"
2908 "syscw: %llu\n"
2909 "read_bytes: %llu\n"
2910 "write_bytes: %llu\n"
2911 "cancelled_write_bytes: %llu\n",
2912 (unsigned long long)acct.rchar,
2913 (unsigned long long)acct.wchar,
2914 (unsigned long long)acct.syscr,
2915 (unsigned long long)acct.syscw,
2916 (unsigned long long)acct.read_bytes,
2917 (unsigned long long)acct.write_bytes,
2918 (unsigned long long)acct.cancelled_write_bytes);
2919 out_unlock:
2920 mutex_unlock(&task->signal->cred_guard_mutex);
2921 return result;
2922 }
2923
2924 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2925 {
2926 return do_io_accounting(task, buffer, 0);
2927 }
2928
2929 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2930 {
2931 return do_io_accounting(task, buffer, 1);
2932 }
2933 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2934
2935 #ifdef CONFIG_USER_NS
2936 static int proc_id_map_open(struct inode *inode, struct file *file,
2937 struct seq_operations *seq_ops)
2938 {
2939 struct user_namespace *ns = NULL;
2940 struct task_struct *task;
2941 struct seq_file *seq;
2942 int ret = -EINVAL;
2943
2944 task = get_proc_task(inode);
2945 if (task) {
2946 rcu_read_lock();
2947 ns = get_user_ns(task_cred_xxx(task, user_ns));
2948 rcu_read_unlock();
2949 put_task_struct(task);
2950 }
2951 if (!ns)
2952 goto err;
2953
2954 ret = seq_open(file, seq_ops);
2955 if (ret)
2956 goto err_put_ns;
2957
2958 seq = file->private_data;
2959 seq->private = ns;
2960
2961 return 0;
2962 err_put_ns:
2963 put_user_ns(ns);
2964 err:
2965 return ret;
2966 }
2967
2968 static int proc_id_map_release(struct inode *inode, struct file *file)
2969 {
2970 struct seq_file *seq = file->private_data;
2971 struct user_namespace *ns = seq->private;
2972 put_user_ns(ns);
2973 return seq_release(inode, file);
2974 }
2975
2976 static int proc_uid_map_open(struct inode *inode, struct file *file)
2977 {
2978 return proc_id_map_open(inode, file, &proc_uid_seq_operations);
2979 }
2980
2981 static int proc_gid_map_open(struct inode *inode, struct file *file)
2982 {
2983 return proc_id_map_open(inode, file, &proc_gid_seq_operations);
2984 }
2985
2986 static const struct file_operations proc_uid_map_operations = {
2987 .open = proc_uid_map_open,
2988 .write = proc_uid_map_write,
2989 .read = seq_read,
2990 .llseek = seq_lseek,
2991 .release = proc_id_map_release,
2992 };
2993
2994 static const struct file_operations proc_gid_map_operations = {
2995 .open = proc_gid_map_open,
2996 .write = proc_gid_map_write,
2997 .read = seq_read,
2998 .llseek = seq_lseek,
2999 .release = proc_id_map_release,
3000 };
3001 #endif /* CONFIG_USER_NS */
3002
3003 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3004 struct pid *pid, struct task_struct *task)
3005 {
3006 int err = lock_trace(task);
3007 if (!err) {
3008 seq_printf(m, "%08x\n", task->personality);
3009 unlock_trace(task);
3010 }
3011 return err;
3012 }
3013
3014 /*
3015 * Thread groups
3016 */
3017 static const struct file_operations proc_task_operations;
3018 static const struct inode_operations proc_task_inode_operations;
3019
3020 static const struct pid_entry tgid_base_stuff[] = {
3021 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3022 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3023 #ifdef CONFIG_CHECKPOINT_RESTORE
3024 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3025 #endif
3026 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3027 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3028 #ifdef CONFIG_NET
3029 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3030 #endif
3031 REG("environ", S_IRUSR, proc_environ_operations),
3032 INF("auxv", S_IRUSR, proc_pid_auxv),
3033 ONE("status", S_IRUGO, proc_pid_status),
3034 ONE("personality", S_IRUGO, proc_pid_personality),
3035 INF("limits", S_IRUGO, proc_pid_limits),
3036 #ifdef CONFIG_SCHED_DEBUG
3037 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3038 #endif
3039 #ifdef CONFIG_SCHED_AUTOGROUP
3040 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3041 #endif
3042 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3043 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3044 INF("syscall", S_IRUGO, proc_pid_syscall),
3045 #endif
3046 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3047 ONE("stat", S_IRUGO, proc_tgid_stat),
3048 ONE("statm", S_IRUGO, proc_pid_statm),
3049 REG("maps", S_IRUGO, proc_pid_maps_operations),
3050 #ifdef CONFIG_NUMA
3051 REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3052 #endif
3053 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3054 LNK("cwd", proc_cwd_link),
3055 LNK("root", proc_root_link),
3056 LNK("exe", proc_exe_link),
3057 REG("mounts", S_IRUGO, proc_mounts_operations),
3058 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3059 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3060 #ifdef CONFIG_PROC_PAGE_MONITOR
3061 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3062 REG("smaps", S_IRUGO, proc_pid_smaps_operations),
3063 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3064 #endif
3065 #ifdef CONFIG_SECURITY
3066 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3067 #endif
3068 #ifdef CONFIG_KALLSYMS
3069 INF("wchan", S_IRUGO, proc_pid_wchan),
3070 #endif
3071 #ifdef CONFIG_STACKTRACE
3072 ONE("stack", S_IRUGO, proc_pid_stack),
3073 #endif
3074 #ifdef CONFIG_SCHEDSTATS
3075 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3076 #endif
3077 #ifdef CONFIG_LATENCYTOP
3078 REG("latency", S_IRUGO, proc_lstats_operations),
3079 #endif
3080 #ifdef CONFIG_PROC_PID_CPUSET
3081 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3082 #endif
3083 #ifdef CONFIG_CGROUPS
3084 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3085 #endif
3086 INF("oom_score", S_IRUGO, proc_oom_score),
3087 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3088 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3089 #ifdef CONFIG_AUDITSYSCALL
3090 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3091 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3092 #endif
3093 #ifdef CONFIG_FAULT_INJECTION
3094 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3095 #endif
3096 #ifdef CONFIG_ELF_CORE
3097 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3098 #endif
3099 #ifdef CONFIG_TASK_IO_ACCOUNTING
3100 INF("io", S_IRUSR, proc_tgid_io_accounting),
3101 #endif
3102 #ifdef CONFIG_HARDWALL
3103 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3104 #endif
3105 #ifdef CONFIG_USER_NS
3106 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3107 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3108 #endif
3109 };
3110
3111 static int proc_tgid_base_readdir(struct file * filp,
3112 void * dirent, filldir_t filldir)
3113 {
3114 return proc_pident_readdir(filp,dirent,filldir,
3115 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
3116 }
3117
3118 static const struct file_operations proc_tgid_base_operations = {
3119 .read = generic_read_dir,
3120 .readdir = proc_tgid_base_readdir,
3121 .llseek = default_llseek,
3122 };
3123
3124 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3125 {
3126 return proc_pident_lookup(dir, dentry,
3127 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3128 }
3129
3130 static const struct inode_operations proc_tgid_base_inode_operations = {
3131 .lookup = proc_tgid_base_lookup,
3132 .getattr = pid_getattr,
3133 .setattr = proc_setattr,
3134 .permission = proc_pid_permission,
3135 };
3136
3137 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
3138 {
3139 struct dentry *dentry, *leader, *dir;
3140 char buf[PROC_NUMBUF];
3141 struct qstr name;
3142
3143 name.name = buf;
3144 name.len = snprintf(buf, sizeof(buf), "%d", pid);
3145 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
3146 if (dentry) {
3147 shrink_dcache_parent(dentry);
3148 d_drop(dentry);
3149 dput(dentry);
3150 }
3151
3152 name.name = buf;
3153 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
3154 leader = d_hash_and_lookup(mnt->mnt_root, &name);
3155 if (!leader)
3156 goto out;
3157
3158 name.name = "task";
3159 name.len = strlen(name.name);
3160 dir = d_hash_and_lookup(leader, &name);
3161 if (!dir)
3162 goto out_put_leader;
3163
3164 name.name = buf;
3165 name.len = snprintf(buf, sizeof(buf), "%d", pid);
3166 dentry = d_hash_and_lookup(dir, &name);
3167 if (dentry) {
3168 shrink_dcache_parent(dentry);
3169 d_drop(dentry);
3170 dput(dentry);
3171 }
3172
3173 dput(dir);
3174 out_put_leader:
3175 dput(leader);
3176 out:
3177 return;
3178 }
3179
3180 /**
3181 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3182 * @task: task that should be flushed.
3183 *
3184 * When flushing dentries from proc, one needs to flush them from global
3185 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3186 * in. This call is supposed to do all of this job.
3187 *
3188 * Looks in the dcache for
3189 * /proc/@pid
3190 * /proc/@tgid/task/@pid
3191 * if either directory is present flushes it and all of it'ts children
3192 * from the dcache.
3193 *
3194 * It is safe and reasonable to cache /proc entries for a task until
3195 * that task exits. After that they just clog up the dcache with
3196 * useless entries, possibly causing useful dcache entries to be
3197 * flushed instead. This routine is proved to flush those useless
3198 * dcache entries at process exit time.
3199 *
3200 * NOTE: This routine is just an optimization so it does not guarantee
3201 * that no dcache entries will exist at process exit time it
3202 * just makes it very unlikely that any will persist.
3203 */
3204
3205 void proc_flush_task(struct task_struct *task)
3206 {
3207 int i;
3208 struct pid *pid, *tgid;
3209 struct upid *upid;
3210
3211 pid = task_pid(task);
3212 tgid = task_tgid(task);
3213
3214 for (i = 0; i <= pid->level; i++) {
3215 upid = &pid->numbers[i];
3216 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3217 tgid->numbers[i].nr);
3218 }
3219
3220 upid = &pid->numbers[pid->level];
3221 if (upid->nr == 1)
3222 pid_ns_release_proc(upid->ns);
3223 }
3224
3225 static struct dentry *proc_pid_instantiate(struct inode *dir,
3226 struct dentry * dentry,
3227 struct task_struct *task, const void *ptr)
3228 {
3229 struct dentry *error = ERR_PTR(-ENOENT);
3230 struct inode *inode;
3231
3232 inode = proc_pid_make_inode(dir->i_sb, task);
3233 if (!inode)
3234 goto out;
3235
3236 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3237 inode->i_op = &proc_tgid_base_inode_operations;
3238 inode->i_fop = &proc_tgid_base_operations;
3239 inode->i_flags|=S_IMMUTABLE;
3240
3241 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
3242 ARRAY_SIZE(tgid_base_stuff)));
3243
3244 d_set_d_op(dentry, &pid_dentry_operations);
3245
3246 d_add(dentry, inode);
3247 /* Close the race of the process dying before we return the dentry */
3248 if (pid_revalidate(dentry, 0))
3249 error = NULL;
3250 out:
3251 return error;
3252 }
3253
3254 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3255 {
3256 struct dentry *result;
3257 struct task_struct *task;
3258 unsigned tgid;
3259 struct pid_namespace *ns;
3260
3261 result = proc_base_lookup(dir, dentry);
3262 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
3263 goto out;
3264
3265 tgid = name_to_int(dentry);
3266 if (tgid == ~0U)
3267 goto out;
3268
3269 ns = dentry->d_sb->s_fs_info;
3270 rcu_read_lock();
3271 task = find_task_by_pid_ns(tgid, ns);
3272 if (task)
3273 get_task_struct(task);
3274 rcu_read_unlock();
3275 if (!task)
3276 goto out;
3277
3278 result = proc_pid_instantiate(dir, dentry, task, NULL);
3279 put_task_struct(task);
3280 out:
3281 return result;
3282 }
3283
3284 /*
3285 * Find the first task with tgid >= tgid
3286 *
3287 */
3288 struct tgid_iter {
3289 unsigned int tgid;
3290 struct task_struct *task;
3291 };
3292 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3293 {
3294 struct pid *pid;
3295
3296 if (iter.task)
3297 put_task_struct(iter.task);
3298 rcu_read_lock();
3299 retry:
3300 iter.task = NULL;
3301 pid = find_ge_pid(iter.tgid, ns);
3302 if (pid) {
3303 iter.tgid = pid_nr_ns(pid, ns);
3304 iter.task = pid_task(pid, PIDTYPE_PID);
3305 /* What we to know is if the pid we have find is the
3306 * pid of a thread_group_leader. Testing for task
3307 * being a thread_group_leader is the obvious thing
3308 * todo but there is a window when it fails, due to
3309 * the pid transfer logic in de_thread.
3310 *
3311 * So we perform the straight forward test of seeing
3312 * if the pid we have found is the pid of a thread
3313 * group leader, and don't worry if the task we have
3314 * found doesn't happen to be a thread group leader.
3315 * As we don't care in the case of readdir.
3316 */
3317 if (!iter.task || !has_group_leader_pid(iter.task)) {
3318 iter.tgid += 1;
3319 goto retry;
3320 }
3321 get_task_struct(iter.task);
3322 }
3323 rcu_read_unlock();
3324 return iter;
3325 }
3326
3327 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3328
3329 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3330 struct tgid_iter iter)
3331 {
3332 char name[PROC_NUMBUF];
3333 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3334 return proc_fill_cache(filp, dirent, filldir, name, len,
3335 proc_pid_instantiate, iter.task, NULL);
3336 }
3337
3338 static int fake_filldir(void *buf, const char *name, int namelen,
3339 loff_t offset, u64 ino, unsigned d_type)
3340 {
3341 return 0;
3342 }
3343
3344 /* for the /proc/ directory itself, after non-process stuff has been done */
3345 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3346 {
3347 unsigned int nr;
3348 struct task_struct *reaper;
3349 struct tgid_iter iter;
3350 struct pid_namespace *ns;
3351 filldir_t __filldir;
3352
3353 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3354 goto out_no_task;
3355 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3356
3357 reaper = get_proc_task(filp->f_path.dentry->d_inode);
3358 if (!reaper)
3359 goto out_no_task;
3360
3361 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3362 const struct pid_entry *p = &proc_base_stuff[nr];
3363 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3364 goto out;
3365 }
3366
3367 ns = filp->f_dentry->d_sb->s_fs_info;
3368 iter.task = NULL;
3369 iter.tgid = filp->f_pos - TGID_OFFSET;
3370 for (iter = next_tgid(ns, iter);
3371 iter.task;
3372 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3373 if (has_pid_permissions(ns, iter.task, 2))
3374 __filldir = filldir;
3375 else
3376 __filldir = fake_filldir;
3377
3378 filp->f_pos = iter.tgid + TGID_OFFSET;
3379 if (proc_pid_fill_cache(filp, dirent, __filldir, iter) < 0) {
3380 put_task_struct(iter.task);
3381 goto out;
3382 }
3383 }
3384 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3385 out:
3386 put_task_struct(reaper);
3387 out_no_task:
3388 return 0;
3389 }
3390
3391 /*
3392 * Tasks
3393 */
3394 static const struct pid_entry tid_base_stuff[] = {
3395 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3396 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3397 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3398 REG("environ", S_IRUSR, proc_environ_operations),
3399 INF("auxv", S_IRUSR, proc_pid_auxv),
3400 ONE("status", S_IRUGO, proc_pid_status),
3401 ONE("personality", S_IRUGO, proc_pid_personality),
3402 INF("limits", S_IRUGO, proc_pid_limits),
3403 #ifdef CONFIG_SCHED_DEBUG
3404 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3405 #endif
3406 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3407 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3408 INF("syscall", S_IRUGO, proc_pid_syscall),
3409 #endif
3410 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3411 ONE("stat", S_IRUGO, proc_tid_stat),
3412 ONE("statm", S_IRUGO, proc_pid_statm),
3413 REG("maps", S_IRUGO, proc_tid_maps_operations),
3414 #ifdef CONFIG_CHECKPOINT_RESTORE
3415 REG("children", S_IRUGO, proc_tid_children_operations),
3416 #endif
3417 #ifdef CONFIG_NUMA
3418 REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
3419 #endif
3420 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3421 LNK("cwd", proc_cwd_link),
3422 LNK("root", proc_root_link),
3423 LNK("exe", proc_exe_link),
3424 REG("mounts", S_IRUGO, proc_mounts_operations),
3425 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3426 #ifdef CONFIG_PROC_PAGE_MONITOR
3427 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3428 REG("smaps", S_IRUGO, proc_tid_smaps_operations),
3429 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3430 #endif
3431 #ifdef CONFIG_SECURITY
3432 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3433 #endif
3434 #ifdef CONFIG_KALLSYMS
3435 INF("wchan", S_IRUGO, proc_pid_wchan),
3436 #endif
3437 #ifdef CONFIG_STACKTRACE
3438 ONE("stack", S_IRUGO, proc_pid_stack),
3439 #endif
3440 #ifdef CONFIG_SCHEDSTATS
3441 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3442 #endif
3443 #ifdef CONFIG_LATENCYTOP
3444 REG("latency", S_IRUGO, proc_lstats_operations),
3445 #endif
3446 #ifdef CONFIG_PROC_PID_CPUSET
3447 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3448 #endif
3449 #ifdef CONFIG_CGROUPS
3450 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3451 #endif
3452 INF("oom_score", S_IRUGO, proc_oom_score),
3453 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3454 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3455 #ifdef CONFIG_AUDITSYSCALL
3456 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3457 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3458 #endif
3459 #ifdef CONFIG_FAULT_INJECTION
3460 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3461 #endif
3462 #ifdef CONFIG_TASK_IO_ACCOUNTING
3463 INF("io", S_IRUSR, proc_tid_io_accounting),
3464 #endif
3465 #ifdef CONFIG_HARDWALL
3466 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3467 #endif
3468 #ifdef CONFIG_USER_NS
3469 REG("uid_map", S_IRUGO|S_IWUSR, proc_uid_map_operations),
3470 REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations),
3471 #endif
3472 };
3473
3474 static int proc_tid_base_readdir(struct file * filp,
3475 void * dirent, filldir_t filldir)
3476 {
3477 return proc_pident_readdir(filp,dirent,filldir,
3478 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3479 }
3480
3481 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3482 {
3483 return proc_pident_lookup(dir, dentry,
3484 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3485 }
3486
3487 static const struct file_operations proc_tid_base_operations = {
3488 .read = generic_read_dir,
3489 .readdir = proc_tid_base_readdir,
3490 .llseek = default_llseek,
3491 };
3492
3493 static const struct inode_operations proc_tid_base_inode_operations = {
3494 .lookup = proc_tid_base_lookup,
3495 .getattr = pid_getattr,
3496 .setattr = proc_setattr,
3497 };
3498
3499 static struct dentry *proc_task_instantiate(struct inode *dir,
3500 struct dentry *dentry, struct task_struct *task, const void *ptr)
3501 {
3502 struct dentry *error = ERR_PTR(-ENOENT);
3503 struct inode *inode;
3504 inode = proc_pid_make_inode(dir->i_sb, task);
3505
3506 if (!inode)
3507 goto out;
3508 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3509 inode->i_op = &proc_tid_base_inode_operations;
3510 inode->i_fop = &proc_tid_base_operations;
3511 inode->i_flags|=S_IMMUTABLE;
3512
3513 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3514 ARRAY_SIZE(tid_base_stuff)));
3515
3516 d_set_d_op(dentry, &pid_dentry_operations);
3517
3518 d_add(dentry, inode);
3519 /* Close the race of the process dying before we return the dentry */
3520 if (pid_revalidate(dentry, 0))
3521 error = NULL;
3522 out:
3523 return error;
3524 }
3525
3526 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3527 {
3528 struct dentry *result = ERR_PTR(-ENOENT);
3529 struct task_struct *task;
3530 struct task_struct *leader = get_proc_task(dir);
3531 unsigned tid;
3532 struct pid_namespace *ns;
3533
3534 if (!leader)
3535 goto out_no_task;
3536
3537 tid = name_to_int(dentry);
3538 if (tid == ~0U)
3539 goto out;
3540
3541 ns = dentry->d_sb->s_fs_info;
3542 rcu_read_lock();
3543 task = find_task_by_pid_ns(tid, ns);
3544 if (task)
3545 get_task_struct(task);
3546 rcu_read_unlock();
3547 if (!task)
3548 goto out;
3549 if (!same_thread_group(leader, task))
3550 goto out_drop_task;
3551
3552 result = proc_task_instantiate(dir, dentry, task, NULL);
3553 out_drop_task:
3554 put_task_struct(task);
3555 out:
3556 put_task_struct(leader);
3557 out_no_task:
3558 return result;
3559 }
3560
3561 /*
3562 * Find the first tid of a thread group to return to user space.
3563 *
3564 * Usually this is just the thread group leader, but if the users
3565 * buffer was too small or there was a seek into the middle of the
3566 * directory we have more work todo.
3567 *
3568 * In the case of a short read we start with find_task_by_pid.
3569 *
3570 * In the case of a seek we start with the leader and walk nr
3571 * threads past it.
3572 */
3573 static struct task_struct *first_tid(struct task_struct *leader,
3574 int tid, int nr, struct pid_namespace *ns)
3575 {
3576 struct task_struct *pos;
3577
3578 rcu_read_lock();
3579 /* Attempt to start with the pid of a thread */
3580 if (tid && (nr > 0)) {
3581 pos = find_task_by_pid_ns(tid, ns);
3582 if (pos && (pos->group_leader == leader))
3583 goto found;
3584 }
3585
3586 /* If nr exceeds the number of threads there is nothing todo */
3587 pos = NULL;
3588 if (nr && nr >= get_nr_threads(leader))
3589 goto out;
3590
3591 /* If we haven't found our starting place yet start
3592 * with the leader and walk nr threads forward.
3593 */
3594 for (pos = leader; nr > 0; --nr) {
3595 pos = next_thread(pos);
3596 if (pos == leader) {
3597 pos = NULL;
3598 goto out;
3599 }
3600 }
3601 found:
3602 get_task_struct(pos);
3603 out:
3604 rcu_read_unlock();
3605 return pos;
3606 }
3607
3608 /*
3609 * Find the next thread in the thread list.
3610 * Return NULL if there is an error or no next thread.
3611 *
3612 * The reference to the input task_struct is released.
3613 */
3614 static struct task_struct *next_tid(struct task_struct *start)
3615 {
3616 struct task_struct *pos = NULL;
3617 rcu_read_lock();
3618 if (pid_alive(start)) {
3619 pos = next_thread(start);
3620 if (thread_group_leader(pos))
3621 pos = NULL;
3622 else
3623 get_task_struct(pos);
3624 }
3625 rcu_read_unlock();
3626 put_task_struct(start);
3627 return pos;
3628 }
3629
3630 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3631 struct task_struct *task, int tid)
3632 {
3633 char name[PROC_NUMBUF];
3634 int len = snprintf(name, sizeof(name), "%d", tid);
3635 return proc_fill_cache(filp, dirent, filldir, name, len,
3636 proc_task_instantiate, task, NULL);
3637 }
3638
3639 /* for the /proc/TGID/task/ directories */
3640 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3641 {
3642 struct dentry *dentry = filp->f_path.dentry;
3643 struct inode *inode = dentry->d_inode;
3644 struct task_struct *leader = NULL;
3645 struct task_struct *task;
3646 int retval = -ENOENT;
3647 ino_t ino;
3648 int tid;
3649 struct pid_namespace *ns;
3650
3651 task = get_proc_task(inode);
3652 if (!task)
3653 goto out_no_task;
3654 rcu_read_lock();
3655 if (pid_alive(task)) {
3656 leader = task->group_leader;
3657 get_task_struct(leader);
3658 }
3659 rcu_read_unlock();
3660 put_task_struct(task);
3661 if (!leader)
3662 goto out_no_task;
3663 retval = 0;
3664
3665 switch ((unsigned long)filp->f_pos) {
3666 case 0:
3667 ino = inode->i_ino;
3668 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3669 goto out;
3670 filp->f_pos++;
3671 /* fall through */
3672 case 1:
3673 ino = parent_ino(dentry);
3674 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3675 goto out;
3676 filp->f_pos++;
3677 /* fall through */
3678 }
3679
3680 /* f_version caches the tgid value that the last readdir call couldn't
3681 * return. lseek aka telldir automagically resets f_version to 0.
3682 */
3683 ns = filp->f_dentry->d_sb->s_fs_info;
3684 tid = (int)filp->f_version;
3685 filp->f_version = 0;
3686 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3687 task;
3688 task = next_tid(task), filp->f_pos++) {
3689 tid = task_pid_nr_ns(task, ns);
3690 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3691 /* returning this tgid failed, save it as the first
3692 * pid for the next readir call */
3693 filp->f_version = (u64)tid;
3694 put_task_struct(task);
3695 break;
3696 }
3697 }
3698 out:
3699 put_task_struct(leader);
3700 out_no_task:
3701 return retval;
3702 }
3703
3704 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3705 {
3706 struct inode *inode = dentry->d_inode;
3707 struct task_struct *p = get_proc_task(inode);
3708 generic_fillattr(inode, stat);
3709
3710 if (p) {
3711 stat->nlink += get_nr_threads(p);
3712 put_task_struct(p);
3713 }
3714
3715 return 0;
3716 }
3717
3718 static const struct inode_operations proc_task_inode_operations = {
3719 .lookup = proc_task_lookup,
3720 .getattr = proc_task_getattr,
3721 .setattr = proc_setattr,
3722 .permission = proc_pid_permission,
3723 };
3724
3725 static const struct file_operations proc_task_operations = {
3726 .read = generic_read_dir,
3727 .readdir = proc_task_readdir,
3728 .llseek = default_llseek,
3729 };
Linus' kernel tree