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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / proc / base.c
blob9cde9edf9c4d40a4a3c20e3fb1c3758518092f98
1 /*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50 #include <asm/uaccess.h>
51
52 #include <linux/errno.h>
53 #include <linux/time.h>
54 #include <linux/proc_fs.h>
55 #include <linux/stat.h>
56 #include <linux/task_io_accounting_ops.h>
57 #include <linux/init.h>
58 #include <linux/capability.h>
59 #include <linux/file.h>
60 #include <linux/fdtable.h>
61 #include <linux/string.h>
62 #include <linux/seq_file.h>
63 #include <linux/namei.h>
64 #include <linux/mnt_namespace.h>
65 #include <linux/mm.h>
66 #include <linux/swap.h>
67 #include <linux/rcupdate.h>
68 #include <linux/kallsyms.h>
69 #include <linux/stacktrace.h>
70 #include <linux/resource.h>
71 #include <linux/module.h>
72 #include <linux/mount.h>
73 #include <linux/security.h>
74 #include <linux/ptrace.h>
75 #include <linux/tracehook.h>
76 #include <linux/cgroup.h>
77 #include <linux/cpuset.h>
78 #include <linux/audit.h>
79 #include <linux/poll.h>
80 #include <linux/nsproxy.h>
81 #include <linux/oom.h>
82 #include <linux/elf.h>
83 #include <linux/pid_namespace.h>
84 #include <linux/fs_struct.h>
85 #include <linux/slab.h>
86 #include <linux/flex_array.h>
87 #ifdef CONFIG_HARDWALL
88 #include <asm/hardwall.h>
89 #endif
90 #include <trace/events/oom.h>
91 #include "internal.h"
92
93 /* NOTE:
94 * Implementing inode permission operations in /proc is almost
95 * certainly an error. Permission checks need to happen during
96 * each system call not at open time. The reason is that most of
97 * what we wish to check for permissions in /proc varies at runtime.
98 *
99 * The classic example of a problem is opening file descriptors
100 * in /proc for a task before it execs a suid executable.
101 */
102
103 struct pid_entry {
104 char *name;
105 int len;
106 umode_t mode;
107 const struct inode_operations *iop;
108 const struct file_operations *fop;
109 union proc_op op;
110 };
111
112 #define NOD(NAME, MODE, IOP, FOP, OP) { \
113 .name = (NAME), \
114 .len = sizeof(NAME) - 1, \
115 .mode = MODE, \
116 .iop = IOP, \
117 .fop = FOP, \
118 .op = OP, \
119 }
120
121 #define DIR(NAME, MODE, iops, fops) \
122 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
123 #define LNK(NAME, get_link) \
124 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
125 &proc_pid_link_inode_operations, NULL, \
126 { .proc_get_link = get_link } )
127 #define REG(NAME, MODE, fops) \
128 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
129 #define INF(NAME, MODE, read) \
130 NOD(NAME, (S_IFREG|(MODE)), \
131 NULL, &proc_info_file_operations, \
132 { .proc_read = read } )
133 #define ONE(NAME, MODE, show) \
134 NOD(NAME, (S_IFREG|(MODE)), \
135 NULL, &proc_single_file_operations, \
136 { .proc_show = show } )
137
138 static int proc_fd_permission(struct inode *inode, int mask);
139
140 /*
141 * Count the number of hardlinks for the pid_entry table, excluding the .
142 * and .. links.
143 */
144 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
145 unsigned int n)
146 {
147 unsigned int i;
148 unsigned int count;
149
150 count = 0;
151 for (i = 0; i < n; ++i) {
152 if (S_ISDIR(entries[i].mode))
153 ++count;
154 }
155
156 return count;
157 }
158
159 static int get_task_root(struct task_struct *task, struct path *root)
160 {
161 int result = -ENOENT;
162
163 task_lock(task);
164 if (task->fs) {
165 get_fs_root(task->fs, root);
166 result = 0;
167 }
168 task_unlock(task);
169 return result;
170 }
171
172 static int proc_cwd_link(struct dentry *dentry, struct path *path)
173 {
174 struct task_struct *task = get_proc_task(dentry->d_inode);
175 int result = -ENOENT;
176
177 if (task) {
178 task_lock(task);
179 if (task->fs) {
180 get_fs_pwd(task->fs, path);
181 result = 0;
182 }
183 task_unlock(task);
184 put_task_struct(task);
185 }
186 return result;
187 }
188
189 static int proc_root_link(struct dentry *dentry, struct path *path)
190 {
191 struct task_struct *task = get_proc_task(dentry->d_inode);
192 int result = -ENOENT;
193
194 if (task) {
195 result = get_task_root(task, path);
196 put_task_struct(task);
197 }
198 return result;
199 }
200
201 static struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
202 {
203 struct mm_struct *mm;
204 int err;
205
206 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
207 if (err)
208 return ERR_PTR(err);
209
210 mm = get_task_mm(task);
211 if (mm && mm != current->mm &&
212 !ptrace_may_access(task, mode)) {
213 mmput(mm);
214 mm = ERR_PTR(-EACCES);
215 }
216 mutex_unlock(&task->signal->cred_guard_mutex);
217
218 return mm;
219 }
220
221 struct mm_struct *mm_for_maps(struct task_struct *task)
222 {
223 return mm_access(task, PTRACE_MODE_READ);
224 }
225
226 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
227 {
228 int res = 0;
229 unsigned int len;
230 struct mm_struct *mm = get_task_mm(task);
231 if (!mm)
232 goto out;
233 if (!mm->arg_end)
234 goto out_mm; /* Shh! No looking before we're done */
235
236 len = mm->arg_end - mm->arg_start;
237
238 if (len > PAGE_SIZE)
239 len = PAGE_SIZE;
240
241 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
242
243 // If the nul at the end of args has been overwritten, then
244 // assume application is using setproctitle(3).
245 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
246 len = strnlen(buffer, res);
247 if (len < res) {
248 res = len;
249 } else {
250 len = mm->env_end - mm->env_start;
251 if (len > PAGE_SIZE - res)
252 len = PAGE_SIZE - res;
253 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
254 res = strnlen(buffer, res);
255 }
256 }
257 out_mm:
258 mmput(mm);
259 out:
260 return res;
261 }
262
263 static int proc_pid_auxv(struct task_struct *task, char *buffer)
264 {
265 struct mm_struct *mm = mm_for_maps(task);
266 int res = PTR_ERR(mm);
267 if (mm && !IS_ERR(mm)) {
268 unsigned int nwords = 0;
269 do {
270 nwords += 2;
271 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
272 res = nwords * sizeof(mm->saved_auxv[0]);
273 if (res > PAGE_SIZE)
274 res = PAGE_SIZE;
275 memcpy(buffer, mm->saved_auxv, res);
276 mmput(mm);
277 }
278 return res;
279 }
280
281
282 #ifdef CONFIG_KALLSYMS
283 /*
284 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
285 * Returns the resolved symbol. If that fails, simply return the address.
286 */
287 static int proc_pid_wchan(struct task_struct *task, char *buffer)
288 {
289 unsigned long wchan;
290 char symname[KSYM_NAME_LEN];
291
292 wchan = get_wchan(task);
293
294 if (lookup_symbol_name(wchan, symname) < 0)
295 if (!ptrace_may_access(task, PTRACE_MODE_READ))
296 return 0;
297 else
298 return sprintf(buffer, "%lu", wchan);
299 else
300 return sprintf(buffer, "%s", symname);
301 }
302 #endif /* CONFIG_KALLSYMS */
303
304 static int lock_trace(struct task_struct *task)
305 {
306 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
307 if (err)
308 return err;
309 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
310 mutex_unlock(&task->signal->cred_guard_mutex);
311 return -EPERM;
312 }
313 return 0;
314 }
315
316 static void unlock_trace(struct task_struct *task)
317 {
318 mutex_unlock(&task->signal->cred_guard_mutex);
319 }
320
321 #ifdef CONFIG_STACKTRACE
322
323 #define MAX_STACK_TRACE_DEPTH 64
324
325 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
326 struct pid *pid, struct task_struct *task)
327 {
328 struct stack_trace trace;
329 unsigned long *entries;
330 int err;
331 int i;
332
333 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
334 if (!entries)
335 return -ENOMEM;
336
337 trace.nr_entries = 0;
338 trace.max_entries = MAX_STACK_TRACE_DEPTH;
339 trace.entries = entries;
340 trace.skip = 0;
341
342 err = lock_trace(task);
343 if (!err) {
344 save_stack_trace_tsk(task, &trace);
345
346 for (i = 0; i < trace.nr_entries; i++) {
347 seq_printf(m, "[<%pK>] %pS\n",
348 (void *)entries[i], (void *)entries[i]);
349 }
350 unlock_trace(task);
351 }
352 kfree(entries);
353
354 return err;
355 }
356 #endif
357
358 #ifdef CONFIG_SCHEDSTATS
359 /*
360 * Provides /proc/PID/schedstat
361 */
362 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
363 {
364 return sprintf(buffer, "%llu %llu %lu\n",
365 (unsigned long long)task->se.sum_exec_runtime,
366 (unsigned long long)task->sched_info.run_delay,
367 task->sched_info.pcount);
368 }
369 #endif
370
371 #ifdef CONFIG_LATENCYTOP
372 static int lstats_show_proc(struct seq_file *m, void *v)
373 {
374 int i;
375 struct inode *inode = m->private;
376 struct task_struct *task = get_proc_task(inode);
377
378 if (!task)
379 return -ESRCH;
380 seq_puts(m, "Latency Top version : v0.1\n");
381 for (i = 0; i < 32; i++) {
382 struct latency_record *lr = &task->latency_record[i];
383 if (lr->backtrace[0]) {
384 int q;
385 seq_printf(m, "%i %li %li",
386 lr->count, lr->time, lr->max);
387 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
388 unsigned long bt = lr->backtrace[q];
389 if (!bt)
390 break;
391 if (bt == ULONG_MAX)
392 break;
393 seq_printf(m, " %ps", (void *)bt);
394 }
395 seq_putc(m, '\n');
396 }
397
398 }
399 put_task_struct(task);
400 return 0;
401 }
402
403 static int lstats_open(struct inode *inode, struct file *file)
404 {
405 return single_open(file, lstats_show_proc, inode);
406 }
407
408 static ssize_t lstats_write(struct file *file, const char __user *buf,
409 size_t count, loff_t *offs)
410 {
411 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
412
413 if (!task)
414 return -ESRCH;
415 clear_all_latency_tracing(task);
416 put_task_struct(task);
417
418 return count;
419 }
420
421 static const struct file_operations proc_lstats_operations = {
422 .open = lstats_open,
423 .read = seq_read,
424 .write = lstats_write,
425 .llseek = seq_lseek,
426 .release = single_release,
427 };
428
429 #endif
430
431 static int proc_oom_score(struct task_struct *task, char *buffer)
432 {
433 unsigned long points = 0;
434
435 read_lock(&tasklist_lock);
436 if (pid_alive(task))
437 points = oom_badness(task, NULL, NULL,
438 totalram_pages + total_swap_pages);
439 read_unlock(&tasklist_lock);
440 return sprintf(buffer, "%lu\n", points);
441 }
442
443 struct limit_names {
444 char *name;
445 char *unit;
446 };
447
448 static const struct limit_names lnames[RLIM_NLIMITS] = {
449 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
450 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
451 [RLIMIT_DATA] = {"Max data size", "bytes"},
452 [RLIMIT_STACK] = {"Max stack size", "bytes"},
453 [RLIMIT_CORE] = {"Max core file size", "bytes"},
454 [RLIMIT_RSS] = {"Max resident set", "bytes"},
455 [RLIMIT_NPROC] = {"Max processes", "processes"},
456 [RLIMIT_NOFILE] = {"Max open files", "files"},
457 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
458 [RLIMIT_AS] = {"Max address space", "bytes"},
459 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
460 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
461 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
462 [RLIMIT_NICE] = {"Max nice priority", NULL},
463 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
464 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
465 };
466
467 /* Display limits for a process */
468 static int proc_pid_limits(struct task_struct *task, char *buffer)
469 {
470 unsigned int i;
471 int count = 0;
472 unsigned long flags;
473 char *bufptr = buffer;
474
475 struct rlimit rlim[RLIM_NLIMITS];
476
477 if (!lock_task_sighand(task, &flags))
478 return 0;
479 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
480 unlock_task_sighand(task, &flags);
481
482 /*
483 * print the file header
484 */
485 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
486 "Limit", "Soft Limit", "Hard Limit", "Units");
487
488 for (i = 0; i < RLIM_NLIMITS; i++) {
489 if (rlim[i].rlim_cur == RLIM_INFINITY)
490 count += sprintf(&bufptr[count], "%-25s %-20s ",
491 lnames[i].name, "unlimited");
492 else
493 count += sprintf(&bufptr[count], "%-25s %-20lu ",
494 lnames[i].name, rlim[i].rlim_cur);
495
496 if (rlim[i].rlim_max == RLIM_INFINITY)
497 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
498 else
499 count += sprintf(&bufptr[count], "%-20lu ",
500 rlim[i].rlim_max);
501
502 if (lnames[i].unit)
503 count += sprintf(&bufptr[count], "%-10s\n",
504 lnames[i].unit);
505 else
506 count += sprintf(&bufptr[count], "\n");
507 }
508
509 return count;
510 }
511
512 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
513 static int proc_pid_syscall(struct task_struct *task, char *buffer)
514 {
515 long nr;
516 unsigned long args[6], sp, pc;
517 int res = lock_trace(task);
518 if (res)
519 return res;
520
521 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
522 res = sprintf(buffer, "running\n");
523 else if (nr < 0)
524 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
525 else
526 res = sprintf(buffer,
527 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
528 nr,
529 args[0], args[1], args[2], args[3], args[4], args[5],
530 sp, pc);
531 unlock_trace(task);
532 return res;
533 }
534 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
535
536 /************************************************************************/
537 /* Here the fs part begins */
538 /************************************************************************/
539
540 /* permission checks */
541 static int proc_fd_access_allowed(struct inode *inode)
542 {
543 struct task_struct *task;
544 int allowed = 0;
545 /* Allow access to a task's file descriptors if it is us or we
546 * may use ptrace attach to the process and find out that
547 * information.
548 */
549 task = get_proc_task(inode);
550 if (task) {
551 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
552 put_task_struct(task);
553 }
554 return allowed;
555 }
556
557 int proc_setattr(struct dentry *dentry, struct iattr *attr)
558 {
559 int error;
560 struct inode *inode = dentry->d_inode;
561
562 if (attr->ia_valid & ATTR_MODE)
563 return -EPERM;
564
565 error = inode_change_ok(inode, attr);
566 if (error)
567 return error;
568
569 if ((attr->ia_valid & ATTR_SIZE) &&
570 attr->ia_size != i_size_read(inode)) {
571 error = vmtruncate(inode, attr->ia_size);
572 if (error)
573 return error;
574 }
575
576 setattr_copy(inode, attr);
577 mark_inode_dirty(inode);
578 return 0;
579 }
580
581 /*
582 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
583 * or euid/egid (for hide_pid_min=2)?
584 */
585 static bool has_pid_permissions(struct pid_namespace *pid,
586 struct task_struct *task,
587 int hide_pid_min)
588 {
589 if (pid->hide_pid < hide_pid_min)
590 return true;
591 if (in_group_p(pid->pid_gid))
592 return true;
593 return ptrace_may_access(task, PTRACE_MODE_READ);
594 }
595
596
597 static int proc_pid_permission(struct inode *inode, int mask)
598 {
599 struct pid_namespace *pid = inode->i_sb->s_fs_info;
600 struct task_struct *task;
601 bool has_perms;
602
603 task = get_proc_task(inode);
604 if (!task)
605 return -ESRCH;
606 has_perms = has_pid_permissions(pid, task, 1);
607 put_task_struct(task);
608
609 if (!has_perms) {
610 if (pid->hide_pid == 2) {
611 /*
612 * Let's make getdents(), stat(), and open()
613 * consistent with each other. If a process
614 * may not stat() a file, it shouldn't be seen
615 * in procfs at all.
616 */
617 return -ENOENT;
618 }
619
620 return -EPERM;
621 }
622 return generic_permission(inode, mask);
623 }
624
625
626
627 static const struct inode_operations proc_def_inode_operations = {
628 .setattr = proc_setattr,
629 };
630
631 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
632
633 static ssize_t proc_info_read(struct file * file, char __user * buf,
634 size_t count, loff_t *ppos)
635 {
636 struct inode * inode = file->f_path.dentry->d_inode;
637 unsigned long page;
638 ssize_t length;
639 struct task_struct *task = get_proc_task(inode);
640
641 length = -ESRCH;
642 if (!task)
643 goto out_no_task;
644
645 if (count > PROC_BLOCK_SIZE)
646 count = PROC_BLOCK_SIZE;
647
648 length = -ENOMEM;
649 if (!(page = __get_free_page(GFP_TEMPORARY)))
650 goto out;
651
652 length = PROC_I(inode)->op.proc_read(task, (char*)page);
653
654 if (length >= 0)
655 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
656 free_page(page);
657 out:
658 put_task_struct(task);
659 out_no_task:
660 return length;
661 }
662
663 static const struct file_operations proc_info_file_operations = {
664 .read = proc_info_read,
665 .llseek = generic_file_llseek,
666 };
667
668 static int proc_single_show(struct seq_file *m, void *v)
669 {
670 struct inode *inode = m->private;
671 struct pid_namespace *ns;
672 struct pid *pid;
673 struct task_struct *task;
674 int ret;
675
676 ns = inode->i_sb->s_fs_info;
677 pid = proc_pid(inode);
678 task = get_pid_task(pid, PIDTYPE_PID);
679 if (!task)
680 return -ESRCH;
681
682 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
683
684 put_task_struct(task);
685 return ret;
686 }
687
688 static int proc_single_open(struct inode *inode, struct file *filp)
689 {
690 return single_open(filp, proc_single_show, inode);
691 }
692
693 static const struct file_operations proc_single_file_operations = {
694 .open = proc_single_open,
695 .read = seq_read,
696 .llseek = seq_lseek,
697 .release = single_release,
698 };
699
700 static int mem_open(struct inode* inode, struct file* file)
701 {
702 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
703 struct mm_struct *mm;
704
705 if (!task)
706 return -ESRCH;
707
708 mm = mm_access(task, PTRACE_MODE_ATTACH);
709 put_task_struct(task);
710
711 if (IS_ERR(mm))
712 return PTR_ERR(mm);
713
714 /* OK to pass negative loff_t, we can catch out-of-range */
715 file->f_mode |= FMODE_UNSIGNED_OFFSET;
716 file->private_data = mm;
717
718 return 0;
719 }
720
721 static ssize_t mem_read(struct file * file, char __user * buf,
722 size_t count, loff_t *ppos)
723 {
724 int ret;
725 char *page;
726 unsigned long src = *ppos;
727 struct mm_struct *mm = file->private_data;
728
729 if (!mm)
730 return 0;
731
732 page = (char *)__get_free_page(GFP_TEMPORARY);
733 if (!page)
734 return -ENOMEM;
735
736 ret = 0;
737
738 while (count > 0) {
739 int this_len, retval;
740
741 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
742 retval = access_remote_vm(mm, src, page, this_len, 0);
743 if (!retval) {
744 if (!ret)
745 ret = -EIO;
746 break;
747 }
748
749 if (copy_to_user(buf, page, retval)) {
750 ret = -EFAULT;
751 break;
752 }
753
754 ret += retval;
755 src += retval;
756 buf += retval;
757 count -= retval;
758 }
759 *ppos = src;
760
761 free_page((unsigned long) page);
762 return ret;
763 }
764
765 static ssize_t mem_write(struct file * file, const char __user *buf,
766 size_t count, loff_t *ppos)
767 {
768 int copied;
769 char *page;
770 unsigned long dst = *ppos;
771 struct mm_struct *mm = file->private_data;
772
773 if (!mm)
774 return 0;
775
776 page = (char *)__get_free_page(GFP_TEMPORARY);
777 if (!page)
778 return -ENOMEM;
779
780 copied = 0;
781 while (count > 0) {
782 int this_len, retval;
783
784 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
785 if (copy_from_user(page, buf, this_len)) {
786 copied = -EFAULT;
787 break;
788 }
789 retval = access_remote_vm(mm, dst, page, this_len, 1);
790 if (!retval) {
791 if (!copied)
792 copied = -EIO;
793 break;
794 }
795 copied += retval;
796 buf += retval;
797 dst += retval;
798 count -= retval;
799 }
800 *ppos = dst;
801
802 free_page((unsigned long) page);
803 return copied;
804 }
805
806 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
807 {
808 switch (orig) {
809 case 0:
810 file->f_pos = offset;
811 break;
812 case 1:
813 file->f_pos += offset;
814 break;
815 default:
816 return -EINVAL;
817 }
818 force_successful_syscall_return();
819 return file->f_pos;
820 }
821
822 static int mem_release(struct inode *inode, struct file *file)
823 {
824 struct mm_struct *mm = file->private_data;
825
826 mmput(mm);
827 return 0;
828 }
829
830 static const struct file_operations proc_mem_operations = {
831 .llseek = mem_lseek,
832 .read = mem_read,
833 .write = mem_write,
834 .open = mem_open,
835 .release = mem_release,
836 };
837
838 static ssize_t environ_read(struct file *file, char __user *buf,
839 size_t count, loff_t *ppos)
840 {
841 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
842 char *page;
843 unsigned long src = *ppos;
844 int ret = -ESRCH;
845 struct mm_struct *mm;
846
847 if (!task)
848 goto out_no_task;
849
850 ret = -ENOMEM;
851 page = (char *)__get_free_page(GFP_TEMPORARY);
852 if (!page)
853 goto out;
854
855
856 mm = mm_for_maps(task);
857 ret = PTR_ERR(mm);
858 if (!mm || IS_ERR(mm))
859 goto out_free;
860
861 ret = 0;
862 while (count > 0) {
863 int this_len, retval, max_len;
864
865 this_len = mm->env_end - (mm->env_start + src);
866
867 if (this_len <= 0)
868 break;
869
870 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
871 this_len = (this_len > max_len) ? max_len : this_len;
872
873 retval = access_process_vm(task, (mm->env_start + src),
874 page, this_len, 0);
875
876 if (retval <= 0) {
877 ret = retval;
878 break;
879 }
880
881 if (copy_to_user(buf, page, retval)) {
882 ret = -EFAULT;
883 break;
884 }
885
886 ret += retval;
887 src += retval;
888 buf += retval;
889 count -= retval;
890 }
891 *ppos = src;
892
893 mmput(mm);
894 out_free:
895 free_page((unsigned long) page);
896 out:
897 put_task_struct(task);
898 out_no_task:
899 return ret;
900 }
901
902 static const struct file_operations proc_environ_operations = {
903 .read = environ_read,
904 .llseek = generic_file_llseek,
905 };
906
907 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
908 size_t count, loff_t *ppos)
909 {
910 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
911 char buffer[PROC_NUMBUF];
912 size_t len;
913 int oom_adjust = OOM_DISABLE;
914 unsigned long flags;
915
916 if (!task)
917 return -ESRCH;
918
919 if (lock_task_sighand(task, &flags)) {
920 oom_adjust = task->signal->oom_adj;
921 unlock_task_sighand(task, &flags);
922 }
923
924 put_task_struct(task);
925
926 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
927
928 return simple_read_from_buffer(buf, count, ppos, buffer, len);
929 }
930
931 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
932 size_t count, loff_t *ppos)
933 {
934 struct task_struct *task;
935 char buffer[PROC_NUMBUF];
936 int oom_adjust;
937 unsigned long flags;
938 int err;
939
940 memset(buffer, 0, sizeof(buffer));
941 if (count > sizeof(buffer) - 1)
942 count = sizeof(buffer) - 1;
943 if (copy_from_user(buffer, buf, count)) {
944 err = -EFAULT;
945 goto out;
946 }
947
948 err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
949 if (err)
950 goto out;
951 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
952 oom_adjust != OOM_DISABLE) {
953 err = -EINVAL;
954 goto out;
955 }
956
957 task = get_proc_task(file->f_path.dentry->d_inode);
958 if (!task) {
959 err = -ESRCH;
960 goto out;
961 }
962
963 task_lock(task);
964 if (!task->mm) {
965 err = -EINVAL;
966 goto err_task_lock;
967 }
968
969 if (!lock_task_sighand(task, &flags)) {
970 err = -ESRCH;
971 goto err_task_lock;
972 }
973
974 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
975 err = -EACCES;
976 goto err_sighand;
977 }
978
979 /*
980 * Warn that /proc/pid/oom_adj is deprecated, see
981 * Documentation/feature-removal-schedule.txt.
982 */
983 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
984 current->comm, task_pid_nr(current), task_pid_nr(task),
985 task_pid_nr(task));
986 task->signal->oom_adj = oom_adjust;
987 /*
988 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
989 * value is always attainable.
990 */
991 if (task->signal->oom_adj == OOM_ADJUST_MAX)
992 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
993 else
994 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
995 -OOM_DISABLE;
996 trace_oom_score_adj_update(task);
997 err_sighand:
998 unlock_task_sighand(task, &flags);
999 err_task_lock:
1000 task_unlock(task);
1001 put_task_struct(task);
1002 out:
1003 return err < 0 ? err : count;
1004 }
1005
1006 static const struct file_operations proc_oom_adjust_operations = {
1007 .read = oom_adjust_read,
1008 .write = oom_adjust_write,
1009 .llseek = generic_file_llseek,
1010 };
1011
1012 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1013 size_t count, loff_t *ppos)
1014 {
1015 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1016 char buffer[PROC_NUMBUF];
1017 int oom_score_adj = OOM_SCORE_ADJ_MIN;
1018 unsigned long flags;
1019 size_t len;
1020
1021 if (!task)
1022 return -ESRCH;
1023 if (lock_task_sighand(task, &flags)) {
1024 oom_score_adj = task->signal->oom_score_adj;
1025 unlock_task_sighand(task, &flags);
1026 }
1027 put_task_struct(task);
1028 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
1029 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1030 }
1031
1032 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1033 size_t count, loff_t *ppos)
1034 {
1035 struct task_struct *task;
1036 char buffer[PROC_NUMBUF];
1037 unsigned long flags;
1038 int oom_score_adj;
1039 int err;
1040
1041 memset(buffer, 0, sizeof(buffer));
1042 if (count > sizeof(buffer) - 1)
1043 count = sizeof(buffer) - 1;
1044 if (copy_from_user(buffer, buf, count)) {
1045 err = -EFAULT;
1046 goto out;
1047 }
1048
1049 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1050 if (err)
1051 goto out;
1052 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1053 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1054 err = -EINVAL;
1055 goto out;
1056 }
1057
1058 task = get_proc_task(file->f_path.dentry->d_inode);
1059 if (!task) {
1060 err = -ESRCH;
1061 goto out;
1062 }
1063
1064 task_lock(task);
1065 if (!task->mm) {
1066 err = -EINVAL;
1067 goto err_task_lock;
1068 }
1069
1070 if (!lock_task_sighand(task, &flags)) {
1071 err = -ESRCH;
1072 goto err_task_lock;
1073 }
1074
1075 if (oom_score_adj < task->signal->oom_score_adj_min &&
1076 !capable(CAP_SYS_RESOURCE)) {
1077 err = -EACCES;
1078 goto err_sighand;
1079 }
1080
1081 task->signal->oom_score_adj = oom_score_adj;
1082 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1083 task->signal->oom_score_adj_min = oom_score_adj;
1084 trace_oom_score_adj_update(task);
1085 /*
1086 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1087 * always attainable.
1088 */
1089 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1090 task->signal->oom_adj = OOM_DISABLE;
1091 else
1092 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1093 OOM_SCORE_ADJ_MAX;
1094 err_sighand:
1095 unlock_task_sighand(task, &flags);
1096 err_task_lock:
1097 task_unlock(task);
1098 put_task_struct(task);
1099 out:
1100 return err < 0 ? err : count;
1101 }
1102
1103 static const struct file_operations proc_oom_score_adj_operations = {
1104 .read = oom_score_adj_read,
1105 .write = oom_score_adj_write,
1106 .llseek = default_llseek,
1107 };
1108
1109 #ifdef CONFIG_AUDITSYSCALL
1110 #define TMPBUFLEN 21
1111 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1112 size_t count, loff_t *ppos)
1113 {
1114 struct inode * inode = file->f_path.dentry->d_inode;
1115 struct task_struct *task = get_proc_task(inode);
1116 ssize_t length;
1117 char tmpbuf[TMPBUFLEN];
1118
1119 if (!task)
1120 return -ESRCH;
1121 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1122 audit_get_loginuid(task));
1123 put_task_struct(task);
1124 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1125 }
1126
1127 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1128 size_t count, loff_t *ppos)
1129 {
1130 struct inode * inode = file->f_path.dentry->d_inode;
1131 char *page, *tmp;
1132 ssize_t length;
1133 uid_t loginuid;
1134
1135 rcu_read_lock();
1136 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1137 rcu_read_unlock();
1138 return -EPERM;
1139 }
1140 rcu_read_unlock();
1141
1142 if (count >= PAGE_SIZE)
1143 count = PAGE_SIZE - 1;
1144
1145 if (*ppos != 0) {
1146 /* No partial writes. */
1147 return -EINVAL;
1148 }
1149 page = (char*)__get_free_page(GFP_TEMPORARY);
1150 if (!page)
1151 return -ENOMEM;
1152 length = -EFAULT;
1153 if (copy_from_user(page, buf, count))
1154 goto out_free_page;
1155
1156 page[count] = '\0';
1157 loginuid = simple_strtoul(page, &tmp, 10);
1158 if (tmp == page) {
1159 length = -EINVAL;
1160 goto out_free_page;
1161
1162 }
1163 length = audit_set_loginuid(loginuid);
1164 if (likely(length == 0))
1165 length = count;
1166
1167 out_free_page:
1168 free_page((unsigned long) page);
1169 return length;
1170 }
1171
1172 static const struct file_operations proc_loginuid_operations = {
1173 .read = proc_loginuid_read,
1174 .write = proc_loginuid_write,
1175 .llseek = generic_file_llseek,
1176 };
1177
1178 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1179 size_t count, loff_t *ppos)
1180 {
1181 struct inode * inode = file->f_path.dentry->d_inode;
1182 struct task_struct *task = get_proc_task(inode);
1183 ssize_t length;
1184 char tmpbuf[TMPBUFLEN];
1185
1186 if (!task)
1187 return -ESRCH;
1188 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1189 audit_get_sessionid(task));
1190 put_task_struct(task);
1191 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1192 }
1193
1194 static const struct file_operations proc_sessionid_operations = {
1195 .read = proc_sessionid_read,
1196 .llseek = generic_file_llseek,
1197 };
1198 #endif
1199
1200 #ifdef CONFIG_FAULT_INJECTION
1201 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1202 size_t count, loff_t *ppos)
1203 {
1204 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1205 char buffer[PROC_NUMBUF];
1206 size_t len;
1207 int make_it_fail;
1208
1209 if (!task)
1210 return -ESRCH;
1211 make_it_fail = task->make_it_fail;
1212 put_task_struct(task);
1213
1214 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1215
1216 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1217 }
1218
1219 static ssize_t proc_fault_inject_write(struct file * file,
1220 const char __user * buf, size_t count, loff_t *ppos)
1221 {
1222 struct task_struct *task;
1223 char buffer[PROC_NUMBUF], *end;
1224 int make_it_fail;
1225
1226 if (!capable(CAP_SYS_RESOURCE))
1227 return -EPERM;
1228 memset(buffer, 0, sizeof(buffer));
1229 if (count > sizeof(buffer) - 1)
1230 count = sizeof(buffer) - 1;
1231 if (copy_from_user(buffer, buf, count))
1232 return -EFAULT;
1233 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1234 if (*end)
1235 return -EINVAL;
1236 task = get_proc_task(file->f_dentry->d_inode);
1237 if (!task)
1238 return -ESRCH;
1239 task->make_it_fail = make_it_fail;
1240 put_task_struct(task);
1241
1242 return count;
1243 }
1244
1245 static const struct file_operations proc_fault_inject_operations = {
1246 .read = proc_fault_inject_read,
1247 .write = proc_fault_inject_write,
1248 .llseek = generic_file_llseek,
1249 };
1250 #endif
1251
1252
1253 #ifdef CONFIG_SCHED_DEBUG
1254 /*
1255 * Print out various scheduling related per-task fields:
1256 */
1257 static int sched_show(struct seq_file *m, void *v)
1258 {
1259 struct inode *inode = m->private;
1260 struct task_struct *p;
1261
1262 p = get_proc_task(inode);
1263 if (!p)
1264 return -ESRCH;
1265 proc_sched_show_task(p, m);
1266
1267 put_task_struct(p);
1268
1269 return 0;
1270 }
1271
1272 static ssize_t
1273 sched_write(struct file *file, const char __user *buf,
1274 size_t count, loff_t *offset)
1275 {
1276 struct inode *inode = file->f_path.dentry->d_inode;
1277 struct task_struct *p;
1278
1279 p = get_proc_task(inode);
1280 if (!p)
1281 return -ESRCH;
1282 proc_sched_set_task(p);
1283
1284 put_task_struct(p);
1285
1286 return count;
1287 }
1288
1289 static int sched_open(struct inode *inode, struct file *filp)
1290 {
1291 return single_open(filp, sched_show, inode);
1292 }
1293
1294 static const struct file_operations proc_pid_sched_operations = {
1295 .open = sched_open,
1296 .read = seq_read,
1297 .write = sched_write,
1298 .llseek = seq_lseek,
1299 .release = single_release,
1300 };
1301
1302 #endif
1303
1304 #ifdef CONFIG_SCHED_AUTOGROUP
1305 /*
1306 * Print out autogroup related information:
1307 */
1308 static int sched_autogroup_show(struct seq_file *m, void *v)
1309 {
1310 struct inode *inode = m->private;
1311 struct task_struct *p;
1312
1313 p = get_proc_task(inode);
1314 if (!p)
1315 return -ESRCH;
1316 proc_sched_autogroup_show_task(p, m);
1317
1318 put_task_struct(p);
1319
1320 return 0;
1321 }
1322
1323 static ssize_t
1324 sched_autogroup_write(struct file *file, const char __user *buf,
1325 size_t count, loff_t *offset)
1326 {
1327 struct inode *inode = file->f_path.dentry->d_inode;
1328 struct task_struct *p;
1329 char buffer[PROC_NUMBUF];
1330 int nice;
1331 int err;
1332
1333 memset(buffer, 0, sizeof(buffer));
1334 if (count > sizeof(buffer) - 1)
1335 count = sizeof(buffer) - 1;
1336 if (copy_from_user(buffer, buf, count))
1337 return -EFAULT;
1338
1339 err = kstrtoint(strstrip(buffer), 0, &nice);
1340 if (err < 0)
1341 return err;
1342
1343 p = get_proc_task(inode);
1344 if (!p)
1345 return -ESRCH;
1346
1347 err = nice;
1348 err = proc_sched_autogroup_set_nice(p, &err);
1349 if (err)
1350 count = err;
1351
1352 put_task_struct(p);
1353
1354 return count;
1355 }
1356
1357 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1358 {
1359 int ret;
1360
1361 ret = single_open(filp, sched_autogroup_show, NULL);
1362 if (!ret) {
1363 struct seq_file *m = filp->private_data;
1364
1365 m->private = inode;
1366 }
1367 return ret;
1368 }
1369
1370 static const struct file_operations proc_pid_sched_autogroup_operations = {
1371 .open = sched_autogroup_open,
1372 .read = seq_read,
1373 .write = sched_autogroup_write,
1374 .llseek = seq_lseek,
1375 .release = single_release,
1376 };
1377
1378 #endif /* CONFIG_SCHED_AUTOGROUP */
1379
1380 static ssize_t comm_write(struct file *file, const char __user *buf,
1381 size_t count, loff_t *offset)
1382 {
1383 struct inode *inode = file->f_path.dentry->d_inode;
1384 struct task_struct *p;
1385 char buffer[TASK_COMM_LEN];
1386
1387 memset(buffer, 0, sizeof(buffer));
1388 if (count > sizeof(buffer) - 1)
1389 count = sizeof(buffer) - 1;
1390 if (copy_from_user(buffer, buf, count))
1391 return -EFAULT;
1392
1393 p = get_proc_task(inode);
1394 if (!p)
1395 return -ESRCH;
1396
1397 if (same_thread_group(current, p))
1398 set_task_comm(p, buffer);
1399 else
1400 count = -EINVAL;
1401
1402 put_task_struct(p);
1403
1404 return count;
1405 }
1406
1407 static int comm_show(struct seq_file *m, void *v)
1408 {
1409 struct inode *inode = m->private;
1410 struct task_struct *p;
1411
1412 p = get_proc_task(inode);
1413 if (!p)
1414 return -ESRCH;
1415
1416 task_lock(p);
1417 seq_printf(m, "%s\n", p->comm);
1418 task_unlock(p);
1419
1420 put_task_struct(p);
1421
1422 return 0;
1423 }
1424
1425 static int comm_open(struct inode *inode, struct file *filp)
1426 {
1427 return single_open(filp, comm_show, inode);
1428 }
1429
1430 static const struct file_operations proc_pid_set_comm_operations = {
1431 .open = comm_open,
1432 .read = seq_read,
1433 .write = comm_write,
1434 .llseek = seq_lseek,
1435 .release = single_release,
1436 };
1437
1438 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1439 {
1440 struct task_struct *task;
1441 struct mm_struct *mm;
1442 struct file *exe_file;
1443
1444 task = get_proc_task(dentry->d_inode);
1445 if (!task)
1446 return -ENOENT;
1447 mm = get_task_mm(task);
1448 put_task_struct(task);
1449 if (!mm)
1450 return -ENOENT;
1451 exe_file = get_mm_exe_file(mm);
1452 mmput(mm);
1453 if (exe_file) {
1454 *exe_path = exe_file->f_path;
1455 path_get(&exe_file->f_path);
1456 fput(exe_file);
1457 return 0;
1458 } else
1459 return -ENOENT;
1460 }
1461
1462 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1463 {
1464 struct inode *inode = dentry->d_inode;
1465 int error = -EACCES;
1466
1467 /* We don't need a base pointer in the /proc filesystem */
1468 path_put(&nd->path);
1469
1470 /* Are we allowed to snoop on the tasks file descriptors? */
1471 if (!proc_fd_access_allowed(inode))
1472 goto out;
1473
1474 error = PROC_I(inode)->op.proc_get_link(dentry, &nd->path);
1475 out:
1476 return ERR_PTR(error);
1477 }
1478
1479 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1480 {
1481 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1482 char *pathname;
1483 int len;
1484
1485 if (!tmp)
1486 return -ENOMEM;
1487
1488 pathname = d_path(path, tmp, PAGE_SIZE);
1489 len = PTR_ERR(pathname);
1490 if (IS_ERR(pathname))
1491 goto out;
1492 len = tmp + PAGE_SIZE - 1 - pathname;
1493
1494 if (len > buflen)
1495 len = buflen;
1496 if (copy_to_user(buffer, pathname, len))
1497 len = -EFAULT;
1498 out:
1499 free_page((unsigned long)tmp);
1500 return len;
1501 }
1502
1503 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1504 {
1505 int error = -EACCES;
1506 struct inode *inode = dentry->d_inode;
1507 struct path path;
1508
1509 /* Are we allowed to snoop on the tasks file descriptors? */
1510 if (!proc_fd_access_allowed(inode))
1511 goto out;
1512
1513 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1514 if (error)
1515 goto out;
1516
1517 error = do_proc_readlink(&path, buffer, buflen);
1518 path_put(&path);
1519 out:
1520 return error;
1521 }
1522
1523 static const struct inode_operations proc_pid_link_inode_operations = {
1524 .readlink = proc_pid_readlink,
1525 .follow_link = proc_pid_follow_link,
1526 .setattr = proc_setattr,
1527 };
1528
1529
1530 /* building an inode */
1531
1532 static int task_dumpable(struct task_struct *task)
1533 {
1534 int dumpable = 0;
1535 struct mm_struct *mm;
1536
1537 task_lock(task);
1538 mm = task->mm;
1539 if (mm)
1540 dumpable = get_dumpable(mm);
1541 task_unlock(task);
1542 if(dumpable == 1)
1543 return 1;
1544 return 0;
1545 }
1546
1547 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1548 {
1549 struct inode * inode;
1550 struct proc_inode *ei;
1551 const struct cred *cred;
1552
1553 /* We need a new inode */
1554
1555 inode = new_inode(sb);
1556 if (!inode)
1557 goto out;
1558
1559 /* Common stuff */
1560 ei = PROC_I(inode);
1561 inode->i_ino = get_next_ino();
1562 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1563 inode->i_op = &proc_def_inode_operations;
1564
1565 /*
1566 * grab the reference to task.
1567 */
1568 ei->pid = get_task_pid(task, PIDTYPE_PID);
1569 if (!ei->pid)
1570 goto out_unlock;
1571
1572 if (task_dumpable(task)) {
1573 rcu_read_lock();
1574 cred = __task_cred(task);
1575 inode->i_uid = cred->euid;
1576 inode->i_gid = cred->egid;
1577 rcu_read_unlock();
1578 }
1579 security_task_to_inode(task, inode);
1580
1581 out:
1582 return inode;
1583
1584 out_unlock:
1585 iput(inode);
1586 return NULL;
1587 }
1588
1589 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1590 {
1591 struct inode *inode = dentry->d_inode;
1592 struct task_struct *task;
1593 const struct cred *cred;
1594 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1595
1596 generic_fillattr(inode, stat);
1597
1598 rcu_read_lock();
1599 stat->uid = 0;
1600 stat->gid = 0;
1601 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1602 if (task) {
1603 if (!has_pid_permissions(pid, task, 2)) {
1604 rcu_read_unlock();
1605 /*
1606 * This doesn't prevent learning whether PID exists,
1607 * it only makes getattr() consistent with readdir().
1608 */
1609 return -ENOENT;
1610 }
1611 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1612 task_dumpable(task)) {
1613 cred = __task_cred(task);
1614 stat->uid = cred->euid;
1615 stat->gid = cred->egid;
1616 }
1617 }
1618 rcu_read_unlock();
1619 return 0;
1620 }
1621
1622 /* dentry stuff */
1623
1624 /*
1625 * Exceptional case: normally we are not allowed to unhash a busy
1626 * directory. In this case, however, we can do it - no aliasing problems
1627 * due to the way we treat inodes.
1628 *
1629 * Rewrite the inode's ownerships here because the owning task may have
1630 * performed a setuid(), etc.
1631 *
1632 * Before the /proc/pid/status file was created the only way to read
1633 * the effective uid of a /process was to stat /proc/pid. Reading
1634 * /proc/pid/status is slow enough that procps and other packages
1635 * kept stating /proc/pid. To keep the rules in /proc simple I have
1636 * made this apply to all per process world readable and executable
1637 * directories.
1638 */
1639 int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1640 {
1641 struct inode *inode;
1642 struct task_struct *task;
1643 const struct cred *cred;
1644
1645 if (nd && nd->flags & LOOKUP_RCU)
1646 return -ECHILD;
1647
1648 inode = dentry->d_inode;
1649 task = get_proc_task(inode);
1650
1651 if (task) {
1652 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1653 task_dumpable(task)) {
1654 rcu_read_lock();
1655 cred = __task_cred(task);
1656 inode->i_uid = cred->euid;
1657 inode->i_gid = cred->egid;
1658 rcu_read_unlock();
1659 } else {
1660 inode->i_uid = 0;
1661 inode->i_gid = 0;
1662 }
1663 inode->i_mode &= ~(S_ISUID | S_ISGID);
1664 security_task_to_inode(task, inode);
1665 put_task_struct(task);
1666 return 1;
1667 }
1668 d_drop(dentry);
1669 return 0;
1670 }
1671
1672 static int pid_delete_dentry(const struct dentry * dentry)
1673 {
1674 /* Is the task we represent dead?
1675 * If so, then don't put the dentry on the lru list,
1676 * kill it immediately.
1677 */
1678 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1679 }
1680
1681 const struct dentry_operations pid_dentry_operations =
1682 {
1683 .d_revalidate = pid_revalidate,
1684 .d_delete = pid_delete_dentry,
1685 };
1686
1687 /* Lookups */
1688
1689 /*
1690 * Fill a directory entry.
1691 *
1692 * If possible create the dcache entry and derive our inode number and
1693 * file type from dcache entry.
1694 *
1695 * Since all of the proc inode numbers are dynamically generated, the inode
1696 * numbers do not exist until the inode is cache. This means creating the
1697 * the dcache entry in readdir is necessary to keep the inode numbers
1698 * reported by readdir in sync with the inode numbers reported
1699 * by stat.
1700 */
1701 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1702 const char *name, int len,
1703 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1704 {
1705 struct dentry *child, *dir = filp->f_path.dentry;
1706 struct inode *inode;
1707 struct qstr qname;
1708 ino_t ino = 0;
1709 unsigned type = DT_UNKNOWN;
1710
1711 qname.name = name;
1712 qname.len = len;
1713 qname.hash = full_name_hash(name, len);
1714
1715 child = d_lookup(dir, &qname);
1716 if (!child) {
1717 struct dentry *new;
1718 new = d_alloc(dir, &qname);
1719 if (new) {
1720 child = instantiate(dir->d_inode, new, task, ptr);
1721 if (child)
1722 dput(new);
1723 else
1724 child = new;
1725 }
1726 }
1727 if (!child || IS_ERR(child) || !child->d_inode)
1728 goto end_instantiate;
1729 inode = child->d_inode;
1730 if (inode) {
1731 ino = inode->i_ino;
1732 type = inode->i_mode >> 12;
1733 }
1734 dput(child);
1735 end_instantiate:
1736 if (!ino)
1737 ino = find_inode_number(dir, &qname);
1738 if (!ino)
1739 ino = 1;
1740 return filldir(dirent, name, len, filp->f_pos, ino, type);
1741 }
1742
1743 static unsigned name_to_int(struct dentry *dentry)
1744 {
1745 const char *name = dentry->d_name.name;
1746 int len = dentry->d_name.len;
1747 unsigned n = 0;
1748
1749 if (len > 1 && *name == '0')
1750 goto out;
1751 while (len-- > 0) {
1752 unsigned c = *name++ - '0';
1753 if (c > 9)
1754 goto out;
1755 if (n >= (~0U-9)/10)
1756 goto out;
1757 n *= 10;
1758 n += c;
1759 }
1760 return n;
1761 out:
1762 return ~0U;
1763 }
1764
1765 #define PROC_FDINFO_MAX 64
1766
1767 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1768 {
1769 struct task_struct *task = get_proc_task(inode);
1770 struct files_struct *files = NULL;
1771 struct file *file;
1772 int fd = proc_fd(inode);
1773
1774 if (task) {
1775 files = get_files_struct(task);
1776 put_task_struct(task);
1777 }
1778 if (files) {
1779 /*
1780 * We are not taking a ref to the file structure, so we must
1781 * hold ->file_lock.
1782 */
1783 spin_lock(&files->file_lock);
1784 file = fcheck_files(files, fd);
1785 if (file) {
1786 unsigned int f_flags;
1787 struct fdtable *fdt;
1788
1789 fdt = files_fdtable(files);
1790 f_flags = file->f_flags & ~O_CLOEXEC;
1791 if (FD_ISSET(fd, fdt->close_on_exec))
1792 f_flags |= O_CLOEXEC;
1793
1794 if (path) {
1795 *path = file->f_path;
1796 path_get(&file->f_path);
1797 }
1798 if (info)
1799 snprintf(info, PROC_FDINFO_MAX,
1800 "pos:\t%lli\n"
1801 "flags:\t0%o\n",
1802 (long long) file->f_pos,
1803 f_flags);
1804 spin_unlock(&files->file_lock);
1805 put_files_struct(files);
1806 return 0;
1807 }
1808 spin_unlock(&files->file_lock);
1809 put_files_struct(files);
1810 }
1811 return -ENOENT;
1812 }
1813
1814 static int proc_fd_link(struct dentry *dentry, struct path *path)
1815 {
1816 return proc_fd_info(dentry->d_inode, path, NULL);
1817 }
1818
1819 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1820 {
1821 struct inode *inode;
1822 struct task_struct *task;
1823 int fd;
1824 struct files_struct *files;
1825 const struct cred *cred;
1826
1827 if (nd && nd->flags & LOOKUP_RCU)
1828 return -ECHILD;
1829
1830 inode = dentry->d_inode;
1831 task = get_proc_task(inode);
1832 fd = proc_fd(inode);
1833
1834 if (task) {
1835 files = get_files_struct(task);
1836 if (files) {
1837 rcu_read_lock();
1838 if (fcheck_files(files, fd)) {
1839 rcu_read_unlock();
1840 put_files_struct(files);
1841 if (task_dumpable(task)) {
1842 rcu_read_lock();
1843 cred = __task_cred(task);
1844 inode->i_uid = cred->euid;
1845 inode->i_gid = cred->egid;
1846 rcu_read_unlock();
1847 } else {
1848 inode->i_uid = 0;
1849 inode->i_gid = 0;
1850 }
1851 inode->i_mode &= ~(S_ISUID | S_ISGID);
1852 security_task_to_inode(task, inode);
1853 put_task_struct(task);
1854 return 1;
1855 }
1856 rcu_read_unlock();
1857 put_files_struct(files);
1858 }
1859 put_task_struct(task);
1860 }
1861 d_drop(dentry);
1862 return 0;
1863 }
1864
1865 static const struct dentry_operations tid_fd_dentry_operations =
1866 {
1867 .d_revalidate = tid_fd_revalidate,
1868 .d_delete = pid_delete_dentry,
1869 };
1870
1871 static struct dentry *proc_fd_instantiate(struct inode *dir,
1872 struct dentry *dentry, struct task_struct *task, const void *ptr)
1873 {
1874 unsigned fd = *(const unsigned *)ptr;
1875 struct file *file;
1876 struct files_struct *files;
1877 struct inode *inode;
1878 struct proc_inode *ei;
1879 struct dentry *error = ERR_PTR(-ENOENT);
1880
1881 inode = proc_pid_make_inode(dir->i_sb, task);
1882 if (!inode)
1883 goto out;
1884 ei = PROC_I(inode);
1885 ei->fd = fd;
1886 files = get_files_struct(task);
1887 if (!files)
1888 goto out_iput;
1889 inode->i_mode = S_IFLNK;
1890
1891 /*
1892 * We are not taking a ref to the file structure, so we must
1893 * hold ->file_lock.
1894 */
1895 spin_lock(&files->file_lock);
1896 file = fcheck_files(files, fd);
1897 if (!file)
1898 goto out_unlock;
1899 if (file->f_mode & FMODE_READ)
1900 inode->i_mode |= S_IRUSR | S_IXUSR;
1901 if (file->f_mode & FMODE_WRITE)
1902 inode->i_mode |= S_IWUSR | S_IXUSR;
1903 spin_unlock(&files->file_lock);
1904 put_files_struct(files);
1905
1906 inode->i_op = &proc_pid_link_inode_operations;
1907 inode->i_size = 64;
1908 ei->op.proc_get_link = proc_fd_link;
1909 d_set_d_op(dentry, &tid_fd_dentry_operations);
1910 d_add(dentry, inode);
1911 /* Close the race of the process dying before we return the dentry */
1912 if (tid_fd_revalidate(dentry, NULL))
1913 error = NULL;
1914
1915 out:
1916 return error;
1917 out_unlock:
1918 spin_unlock(&files->file_lock);
1919 put_files_struct(files);
1920 out_iput:
1921 iput(inode);
1922 goto out;
1923 }
1924
1925 static struct dentry *proc_lookupfd_common(struct inode *dir,
1926 struct dentry *dentry,
1927 instantiate_t instantiate)
1928 {
1929 struct task_struct *task = get_proc_task(dir);
1930 unsigned fd = name_to_int(dentry);
1931 struct dentry *result = ERR_PTR(-ENOENT);
1932
1933 if (!task)
1934 goto out_no_task;
1935 if (fd == ~0U)
1936 goto out;
1937
1938 result = instantiate(dir, dentry, task, &fd);
1939 out:
1940 put_task_struct(task);
1941 out_no_task:
1942 return result;
1943 }
1944
1945 static int proc_readfd_common(struct file * filp, void * dirent,
1946 filldir_t filldir, instantiate_t instantiate)
1947 {
1948 struct dentry *dentry = filp->f_path.dentry;
1949 struct inode *inode = dentry->d_inode;
1950 struct task_struct *p = get_proc_task(inode);
1951 unsigned int fd, ino;
1952 int retval;
1953 struct files_struct * files;
1954
1955 retval = -ENOENT;
1956 if (!p)
1957 goto out_no_task;
1958 retval = 0;
1959
1960 fd = filp->f_pos;
1961 switch (fd) {
1962 case 0:
1963 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1964 goto out;
1965 filp->f_pos++;
1966 case 1:
1967 ino = parent_ino(dentry);
1968 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1969 goto out;
1970 filp->f_pos++;
1971 default:
1972 files = get_files_struct(p);
1973 if (!files)
1974 goto out;
1975 rcu_read_lock();
1976 for (fd = filp->f_pos-2;
1977 fd < files_fdtable(files)->max_fds;
1978 fd++, filp->f_pos++) {
1979 char name[PROC_NUMBUF];
1980 int len;
1981
1982 if (!fcheck_files(files, fd))
1983 continue;
1984 rcu_read_unlock();
1985
1986 len = snprintf(name, sizeof(name), "%d", fd);
1987 if (proc_fill_cache(filp, dirent, filldir,
1988 name, len, instantiate,
1989 p, &fd) < 0) {
1990 rcu_read_lock();
1991 break;
1992 }
1993 rcu_read_lock();
1994 }
1995 rcu_read_unlock();
1996 put_files_struct(files);
1997 }
1998 out:
1999 put_task_struct(p);
2000 out_no_task:
2001 return retval;
2002 }
2003
2004 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
2005 struct nameidata *nd)
2006 {
2007 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
2008 }
2009
2010 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
2011 {
2012 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
2013 }
2014
2015 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
2016 size_t len, loff_t *ppos)
2017 {
2018 char tmp[PROC_FDINFO_MAX];
2019 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
2020 if (!err)
2021 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
2022 return err;
2023 }
2024
2025 static const struct file_operations proc_fdinfo_file_operations = {
2026 .open = nonseekable_open,
2027 .read = proc_fdinfo_read,
2028 .llseek = no_llseek,
2029 };
2030
2031 static const struct file_operations proc_fd_operations = {
2032 .read = generic_read_dir,
2033 .readdir = proc_readfd,
2034 .llseek = default_llseek,
2035 };
2036
2037 #ifdef CONFIG_CHECKPOINT_RESTORE
2038
2039 /*
2040 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2041 * which represent vma start and end addresses.
2042 */
2043 static int dname_to_vma_addr(struct dentry *dentry,
2044 unsigned long *start, unsigned long *end)
2045 {
2046 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
2047 return -EINVAL;
2048
2049 return 0;
2050 }
2051
2052 static int map_files_d_revalidate(struct dentry *dentry, struct nameidata *nd)
2053 {
2054 unsigned long vm_start, vm_end;
2055 bool exact_vma_exists = false;
2056 struct mm_struct *mm = NULL;
2057 struct task_struct *task;
2058 const struct cred *cred;
2059 struct inode *inode;
2060 int status = 0;
2061
2062 if (nd && nd->flags & LOOKUP_RCU)
2063 return -ECHILD;
2064
2065 if (!capable(CAP_SYS_ADMIN)) {
2066 status = -EACCES;
2067 goto out_notask;
2068 }
2069
2070 inode = dentry->d_inode;
2071 task = get_proc_task(inode);
2072 if (!task)
2073 goto out_notask;
2074
2075 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2076 goto out;
2077
2078 mm = get_task_mm(task);
2079 if (!mm)
2080 goto out;
2081
2082 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2083 down_read(&mm->mmap_sem);
2084 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
2085 up_read(&mm->mmap_sem);
2086 }
2087
2088 mmput(mm);
2089
2090 if (exact_vma_exists) {
2091 if (task_dumpable(task)) {
2092 rcu_read_lock();
2093 cred = __task_cred(task);
2094 inode->i_uid = cred->euid;
2095 inode->i_gid = cred->egid;
2096 rcu_read_unlock();
2097 } else {
2098 inode->i_uid = 0;
2099 inode->i_gid = 0;
2100 }
2101 security_task_to_inode(task, inode);
2102 status = 1;
2103 }
2104
2105 out:
2106 put_task_struct(task);
2107
2108 out_notask:
2109 if (status <= 0)
2110 d_drop(dentry);
2111
2112 return status;
2113 }
2114
2115 static const struct dentry_operations tid_map_files_dentry_operations = {
2116 .d_revalidate = map_files_d_revalidate,
2117 .d_delete = pid_delete_dentry,
2118 };
2119
2120 static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
2121 {
2122 unsigned long vm_start, vm_end;
2123 struct vm_area_struct *vma;
2124 struct task_struct *task;
2125 struct mm_struct *mm;
2126 int rc;
2127
2128 rc = -ENOENT;
2129 task = get_proc_task(dentry->d_inode);
2130 if (!task)
2131 goto out;
2132
2133 mm = get_task_mm(task);
2134 put_task_struct(task);
2135 if (!mm)
2136 goto out;
2137
2138 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2139 if (rc)
2140 goto out_mmput;
2141
2142 down_read(&mm->mmap_sem);
2143 vma = find_exact_vma(mm, vm_start, vm_end);
2144 if (vma && vma->vm_file) {
2145 *path = vma->vm_file->f_path;
2146 path_get(path);
2147 rc = 0;
2148 }
2149 up_read(&mm->mmap_sem);
2150
2151 out_mmput:
2152 mmput(mm);
2153 out:
2154 return rc;
2155 }
2156
2157 struct map_files_info {
2158 struct file *file;
2159 unsigned long len;
2160 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
2161 };
2162
2163 static struct dentry *
2164 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
2165 struct task_struct *task, const void *ptr)
2166 {
2167 const struct file *file = ptr;
2168 struct proc_inode *ei;
2169 struct inode *inode;
2170
2171 if (!file)
2172 return ERR_PTR(-ENOENT);
2173
2174 inode = proc_pid_make_inode(dir->i_sb, task);
2175 if (!inode)
2176 return ERR_PTR(-ENOENT);
2177
2178 ei = PROC_I(inode);
2179 ei->op.proc_get_link = proc_map_files_get_link;
2180
2181 inode->i_op = &proc_pid_link_inode_operations;
2182 inode->i_size = 64;
2183 inode->i_mode = S_IFLNK;
2184
2185 if (file->f_mode & FMODE_READ)
2186 inode->i_mode |= S_IRUSR;
2187 if (file->f_mode & FMODE_WRITE)
2188 inode->i_mode |= S_IWUSR;
2189
2190 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2191 d_add(dentry, inode);
2192
2193 return NULL;
2194 }
2195
2196 static struct dentry *proc_map_files_lookup(struct inode *dir,
2197 struct dentry *dentry, struct nameidata *nd)
2198 {
2199 unsigned long vm_start, vm_end;
2200 struct vm_area_struct *vma;
2201 struct task_struct *task;
2202 struct dentry *result;
2203 struct mm_struct *mm;
2204
2205 result = ERR_PTR(-EACCES);
2206 if (!capable(CAP_SYS_ADMIN))
2207 goto out;
2208
2209 result = ERR_PTR(-ENOENT);
2210 task = get_proc_task(dir);
2211 if (!task)
2212 goto out;
2213
2214 result = ERR_PTR(-EACCES);
2215 if (lock_trace(task))
2216 goto out_put_task;
2217
2218 result = ERR_PTR(-ENOENT);
2219 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2220 goto out_unlock;
2221
2222 mm = get_task_mm(task);
2223 if (!mm)
2224 goto out_unlock;
2225
2226 down_read(&mm->mmap_sem);
2227 vma = find_exact_vma(mm, vm_start, vm_end);
2228 if (!vma)
2229 goto out_no_vma;
2230
2231 result = proc_map_files_instantiate(dir, dentry, task, vma->vm_file);
2232
2233 out_no_vma:
2234 up_read(&mm->mmap_sem);
2235 mmput(mm);
2236 out_unlock:
2237 unlock_trace(task);
2238 out_put_task:
2239 put_task_struct(task);
2240 out:
2241 return result;
2242 }
2243
2244 static const struct inode_operations proc_map_files_inode_operations = {
2245 .lookup = proc_map_files_lookup,
2246 .permission = proc_fd_permission,
2247 .setattr = proc_setattr,
2248 };
2249
2250 static int
2251 proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
2252 {
2253 struct dentry *dentry = filp->f_path.dentry;
2254 struct inode *inode = dentry->d_inode;
2255 struct vm_area_struct *vma;
2256 struct task_struct *task;
2257 struct mm_struct *mm;
2258 ino_t ino;
2259 int ret;
2260
2261 ret = -EACCES;
2262 if (!capable(CAP_SYS_ADMIN))
2263 goto out;
2264
2265 ret = -ENOENT;
2266 task = get_proc_task(inode);
2267 if (!task)
2268 goto out;
2269
2270 ret = -EACCES;
2271 if (lock_trace(task))
2272 goto out_put_task;
2273
2274 ret = 0;
2275 switch (filp->f_pos) {
2276 case 0:
2277 ino = inode->i_ino;
2278 if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0)
2279 goto out_unlock;
2280 filp->f_pos++;
2281 case 1:
2282 ino = parent_ino(dentry);
2283 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2284 goto out_unlock;
2285 filp->f_pos++;
2286 default:
2287 {
2288 unsigned long nr_files, pos, i;
2289 struct flex_array *fa = NULL;
2290 struct map_files_info info;
2291 struct map_files_info *p;
2292
2293 mm = get_task_mm(task);
2294 if (!mm)
2295 goto out_unlock;
2296 down_read(&mm->mmap_sem);
2297
2298 nr_files = 0;
2299
2300 /*
2301 * We need two passes here:
2302 *
2303 * 1) Collect vmas of mapped files with mmap_sem taken
2304 * 2) Release mmap_sem and instantiate entries
2305 *
2306 * otherwise we get lockdep complained, since filldir()
2307 * routine might require mmap_sem taken in might_fault().
2308 */
2309
2310 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2311 if (vma->vm_file && ++pos > filp->f_pos)
2312 nr_files++;
2313 }
2314
2315 if (nr_files) {
2316 fa = flex_array_alloc(sizeof(info), nr_files,
2317 GFP_KERNEL);
2318 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2319 GFP_KERNEL)) {
2320 ret = -ENOMEM;
2321 if (fa)
2322 flex_array_free(fa);
2323 up_read(&mm->mmap_sem);
2324 mmput(mm);
2325 goto out_unlock;
2326 }
2327 for (i = 0, vma = mm->mmap, pos = 2; vma;
2328 vma = vma->vm_next) {
2329 if (!vma->vm_file)
2330 continue;
2331 if (++pos <= filp->f_pos)
2332 continue;
2333
2334 get_file(vma->vm_file);
2335 info.file = vma->vm_file;
2336 info.len = snprintf(info.name,
2337 sizeof(info.name), "%lx-%lx",
2338 vma->vm_start, vma->vm_end);
2339 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2340 BUG();
2341 }
2342 }
2343 up_read(&mm->mmap_sem);
2344
2345 for (i = 0; i < nr_files; i++) {
2346 p = flex_array_get(fa, i);
2347 ret = proc_fill_cache(filp, dirent, filldir,
2348 p->name, p->len,
2349 proc_map_files_instantiate,
2350 task, p->file);
2351 if (ret)
2352 break;
2353 filp->f_pos++;
2354 fput(p->file);
2355 }
2356 for (; i < nr_files; i++) {
2357 /*
2358 * In case of error don't forget
2359 * to put rest of file refs.
2360 */
2361 p = flex_array_get(fa, i);
2362 fput(p->file);
2363 }
2364 if (fa)
2365 flex_array_free(fa);
2366 mmput(mm);
2367 }
2368 }
2369
2370 out_unlock:
2371 unlock_trace(task);
2372 out_put_task:
2373 put_task_struct(task);
2374 out:
2375 return ret;
2376 }
2377
2378 static const struct file_operations proc_map_files_operations = {
2379 .read = generic_read_dir,
2380 .readdir = proc_map_files_readdir,
2381 .llseek = default_llseek,
2382 };
2383
2384 #endif /* CONFIG_CHECKPOINT_RESTORE */
2385
2386 /*
2387 * /proc/pid/fd needs a special permission handler so that a process can still
2388 * access /proc/self/fd after it has executed a setuid().
2389 */
2390 static int proc_fd_permission(struct inode *inode, int mask)
2391 {
2392 int rv = generic_permission(inode, mask);
2393 if (rv == 0)
2394 return 0;
2395 if (task_pid(current) == proc_pid(inode))
2396 rv = 0;
2397 return rv;
2398 }
2399
2400 /*
2401 * proc directories can do almost nothing..
2402 */
2403 static const struct inode_operations proc_fd_inode_operations = {
2404 .lookup = proc_lookupfd,
2405 .permission = proc_fd_permission,
2406 .setattr = proc_setattr,
2407 };
2408
2409 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2410 struct dentry *dentry, struct task_struct *task, const void *ptr)
2411 {
2412 unsigned fd = *(unsigned *)ptr;
2413 struct inode *inode;
2414 struct proc_inode *ei;
2415 struct dentry *error = ERR_PTR(-ENOENT);
2416
2417 inode = proc_pid_make_inode(dir->i_sb, task);
2418 if (!inode)
2419 goto out;
2420 ei = PROC_I(inode);
2421 ei->fd = fd;
2422 inode->i_mode = S_IFREG | S_IRUSR;
2423 inode->i_fop = &proc_fdinfo_file_operations;
2424 d_set_d_op(dentry, &tid_fd_dentry_operations);
2425 d_add(dentry, inode);
2426 /* Close the race of the process dying before we return the dentry */
2427 if (tid_fd_revalidate(dentry, NULL))
2428 error = NULL;
2429
2430 out:
2431 return error;
2432 }
2433
2434 static struct dentry *proc_lookupfdinfo(struct inode *dir,
2435 struct dentry *dentry,
2436 struct nameidata *nd)
2437 {
2438 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2439 }
2440
2441 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2442 {
2443 return proc_readfd_common(filp, dirent, filldir,
2444 proc_fdinfo_instantiate);
2445 }
2446
2447 static const struct file_operations proc_fdinfo_operations = {
2448 .read = generic_read_dir,
2449 .readdir = proc_readfdinfo,
2450 .llseek = default_llseek,
2451 };
2452
2453 /*
2454 * proc directories can do almost nothing..
2455 */
2456 static const struct inode_operations proc_fdinfo_inode_operations = {
2457 .lookup = proc_lookupfdinfo,
2458 .setattr = proc_setattr,
2459 };
2460
2461
2462 static struct dentry *proc_pident_instantiate(struct inode *dir,
2463 struct dentry *dentry, struct task_struct *task, const void *ptr)
2464 {
2465 const struct pid_entry *p = ptr;
2466 struct inode *inode;
2467 struct proc_inode *ei;
2468 struct dentry *error = ERR_PTR(-ENOENT);
2469
2470 inode = proc_pid_make_inode(dir->i_sb, task);
2471 if (!inode)
2472 goto out;
2473
2474 ei = PROC_I(inode);
2475 inode->i_mode = p->mode;
2476 if (S_ISDIR(inode->i_mode))
2477 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2478 if (p->iop)
2479 inode->i_op = p->iop;
2480 if (p->fop)
2481 inode->i_fop = p->fop;
2482 ei->op = p->op;
2483 d_set_d_op(dentry, &pid_dentry_operations);
2484 d_add(dentry, inode);
2485 /* Close the race of the process dying before we return the dentry */
2486 if (pid_revalidate(dentry, NULL))
2487 error = NULL;
2488 out:
2489 return error;
2490 }
2491
2492 static struct dentry *proc_pident_lookup(struct inode *dir,
2493 struct dentry *dentry,
2494 const struct pid_entry *ents,
2495 unsigned int nents)
2496 {
2497 struct dentry *error;
2498 struct task_struct *task = get_proc_task(dir);
2499 const struct pid_entry *p, *last;
2500
2501 error = ERR_PTR(-ENOENT);
2502
2503 if (!task)
2504 goto out_no_task;
2505
2506 /*
2507 * Yes, it does not scale. And it should not. Don't add
2508 * new entries into /proc/<tgid>/ without very good reasons.
2509 */
2510 last = &ents[nents - 1];
2511 for (p = ents; p <= last; p++) {
2512 if (p->len != dentry->d_name.len)
2513 continue;
2514 if (!memcmp(dentry->d_name.name, p->name, p->len))
2515 break;
2516 }
2517 if (p > last)
2518 goto out;
2519
2520 error = proc_pident_instantiate(dir, dentry, task, p);
2521 out:
2522 put_task_struct(task);
2523 out_no_task:
2524 return error;
2525 }
2526
2527 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2528 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2529 {
2530 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2531 proc_pident_instantiate, task, p);
2532 }
2533
2534 static int proc_pident_readdir(struct file *filp,
2535 void *dirent, filldir_t filldir,
2536 const struct pid_entry *ents, unsigned int nents)
2537 {
2538 int i;
2539 struct dentry *dentry = filp->f_path.dentry;
2540 struct inode *inode = dentry->d_inode;
2541 struct task_struct *task = get_proc_task(inode);
2542 const struct pid_entry *p, *last;
2543 ino_t ino;
2544 int ret;
2545
2546 ret = -ENOENT;
2547 if (!task)
2548 goto out_no_task;
2549
2550 ret = 0;
2551 i = filp->f_pos;
2552 switch (i) {
2553 case 0:
2554 ino = inode->i_ino;
2555 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2556 goto out;
2557 i++;
2558 filp->f_pos++;
2559 /* fall through */
2560 case 1:
2561 ino = parent_ino(dentry);
2562 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2563 goto out;
2564 i++;
2565 filp->f_pos++;
2566 /* fall through */
2567 default:
2568 i -= 2;
2569 if (i >= nents) {
2570 ret = 1;
2571 goto out;
2572 }
2573 p = ents + i;
2574 last = &ents[nents - 1];
2575 while (p <= last) {
2576 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2577 goto out;
2578 filp->f_pos++;
2579 p++;
2580 }
2581 }
2582
2583 ret = 1;
2584 out:
2585 put_task_struct(task);
2586 out_no_task:
2587 return ret;
2588 }
2589
2590 #ifdef CONFIG_SECURITY
2591 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2592 size_t count, loff_t *ppos)
2593 {
2594 struct inode * inode = file->f_path.dentry->d_inode;
2595 char *p = NULL;
2596 ssize_t length;
2597 struct task_struct *task = get_proc_task(inode);
2598
2599 if (!task)
2600 return -ESRCH;
2601
2602 length = security_getprocattr(task,
2603 (char*)file->f_path.dentry->d_name.name,
2604 &p);
2605 put_task_struct(task);
2606 if (length > 0)
2607 length = simple_read_from_buffer(buf, count, ppos, p, length);
2608 kfree(p);
2609 return length;
2610 }
2611
2612 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2613 size_t count, loff_t *ppos)
2614 {
2615 struct inode * inode = file->f_path.dentry->d_inode;
2616 char *page;
2617 ssize_t length;
2618 struct task_struct *task = get_proc_task(inode);
2619
2620 length = -ESRCH;
2621 if (!task)
2622 goto out_no_task;
2623 if (count > PAGE_SIZE)
2624 count = PAGE_SIZE;
2625
2626 /* No partial writes. */
2627 length = -EINVAL;
2628 if (*ppos != 0)
2629 goto out;
2630
2631 length = -ENOMEM;
2632 page = (char*)__get_free_page(GFP_TEMPORARY);
2633 if (!page)
2634 goto out;
2635
2636 length = -EFAULT;
2637 if (copy_from_user(page, buf, count))
2638 goto out_free;
2639
2640 /* Guard against adverse ptrace interaction */
2641 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2642 if (length < 0)
2643 goto out_free;
2644
2645 length = security_setprocattr(task,
2646 (char*)file->f_path.dentry->d_name.name,
2647 (void*)page, count);
2648 mutex_unlock(&task->signal->cred_guard_mutex);
2649 out_free:
2650 free_page((unsigned long) page);
2651 out:
2652 put_task_struct(task);
2653 out_no_task:
2654 return length;
2655 }
2656
2657 static const struct file_operations proc_pid_attr_operations = {
2658 .read = proc_pid_attr_read,
2659 .write = proc_pid_attr_write,
2660 .llseek = generic_file_llseek,
2661 };
2662
2663 static const struct pid_entry attr_dir_stuff[] = {
2664 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2665 REG("prev", S_IRUGO, proc_pid_attr_operations),
2666 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2667 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2668 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2669 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2670 };
2671
2672 static int proc_attr_dir_readdir(struct file * filp,
2673 void * dirent, filldir_t filldir)
2674 {
2675 return proc_pident_readdir(filp,dirent,filldir,
2676 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2677 }
2678
2679 static const struct file_operations proc_attr_dir_operations = {
2680 .read = generic_read_dir,
2681 .readdir = proc_attr_dir_readdir,
2682 .llseek = default_llseek,
2683 };
2684
2685 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2686 struct dentry *dentry, struct nameidata *nd)
2687 {
2688 return proc_pident_lookup(dir, dentry,
2689 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2690 }
2691
2692 static const struct inode_operations proc_attr_dir_inode_operations = {
2693 .lookup = proc_attr_dir_lookup,
2694 .getattr = pid_getattr,
2695 .setattr = proc_setattr,
2696 };
2697
2698 #endif
2699
2700 #ifdef CONFIG_ELF_CORE
2701 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2702 size_t count, loff_t *ppos)
2703 {
2704 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2705 struct mm_struct *mm;
2706 char buffer[PROC_NUMBUF];
2707 size_t len;
2708 int ret;
2709
2710 if (!task)
2711 return -ESRCH;
2712
2713 ret = 0;
2714 mm = get_task_mm(task);
2715 if (mm) {
2716 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2717 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2718 MMF_DUMP_FILTER_SHIFT));
2719 mmput(mm);
2720 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2721 }
2722
2723 put_task_struct(task);
2724
2725 return ret;
2726 }
2727
2728 static ssize_t proc_coredump_filter_write(struct file *file,
2729 const char __user *buf,
2730 size_t count,
2731 loff_t *ppos)
2732 {
2733 struct task_struct *task;
2734 struct mm_struct *mm;
2735 char buffer[PROC_NUMBUF], *end;
2736 unsigned int val;
2737 int ret;
2738 int i;
2739 unsigned long mask;
2740
2741 ret = -EFAULT;
2742 memset(buffer, 0, sizeof(buffer));
2743 if (count > sizeof(buffer) - 1)
2744 count = sizeof(buffer) - 1;
2745 if (copy_from_user(buffer, buf, count))
2746 goto out_no_task;
2747
2748 ret = -EINVAL;
2749 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2750 if (*end == '\n')
2751 end++;
2752 if (end - buffer == 0)
2753 goto out_no_task;
2754
2755 ret = -ESRCH;
2756 task = get_proc_task(file->f_dentry->d_inode);
2757 if (!task)
2758 goto out_no_task;
2759
2760 ret = end - buffer;
2761 mm = get_task_mm(task);
2762 if (!mm)
2763 goto out_no_mm;
2764
2765 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2766 if (val & mask)
2767 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2768 else
2769 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2770 }
2771
2772 mmput(mm);
2773 out_no_mm:
2774 put_task_struct(task);
2775 out_no_task:
2776 return ret;
2777 }
2778
2779 static const struct file_operations proc_coredump_filter_operations = {
2780 .read = proc_coredump_filter_read,
2781 .write = proc_coredump_filter_write,
2782 .llseek = generic_file_llseek,
2783 };
2784 #endif
2785
2786 /*
2787 * /proc/self:
2788 */
2789 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2790 int buflen)
2791 {
2792 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2793 pid_t tgid = task_tgid_nr_ns(current, ns);
2794 char tmp[PROC_NUMBUF];
2795 if (!tgid)
2796 return -ENOENT;
2797 sprintf(tmp, "%d", tgid);
2798 return vfs_readlink(dentry,buffer,buflen,tmp);
2799 }
2800
2801 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2802 {
2803 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2804 pid_t tgid = task_tgid_nr_ns(current, ns);
2805 char *name = ERR_PTR(-ENOENT);
2806 if (tgid) {
2807 name = __getname();
2808 if (!name)
2809 name = ERR_PTR(-ENOMEM);
2810 else
2811 sprintf(name, "%d", tgid);
2812 }
2813 nd_set_link(nd, name);
2814 return NULL;
2815 }
2816
2817 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2818 void *cookie)
2819 {
2820 char *s = nd_get_link(nd);
2821 if (!IS_ERR(s))
2822 __putname(s);
2823 }
2824
2825 static const struct inode_operations proc_self_inode_operations = {
2826 .readlink = proc_self_readlink,
2827 .follow_link = proc_self_follow_link,
2828 .put_link = proc_self_put_link,
2829 };
2830
2831 /*
2832 * proc base
2833 *
2834 * These are the directory entries in the root directory of /proc
2835 * that properly belong to the /proc filesystem, as they describe
2836 * describe something that is process related.
2837 */
2838 static const struct pid_entry proc_base_stuff[] = {
2839 NOD("self", S_IFLNK|S_IRWXUGO,
2840 &proc_self_inode_operations, NULL, {}),
2841 };
2842
2843 static struct dentry *proc_base_instantiate(struct inode *dir,
2844 struct dentry *dentry, struct task_struct *task, const void *ptr)
2845 {
2846 const struct pid_entry *p = ptr;
2847 struct inode *inode;
2848 struct proc_inode *ei;
2849 struct dentry *error;
2850
2851 /* Allocate the inode */
2852 error = ERR_PTR(-ENOMEM);
2853 inode = new_inode(dir->i_sb);
2854 if (!inode)
2855 goto out;
2856
2857 /* Initialize the inode */
2858 ei = PROC_I(inode);
2859 inode->i_ino = get_next_ino();
2860 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2861
2862 /*
2863 * grab the reference to the task.
2864 */
2865 ei->pid = get_task_pid(task, PIDTYPE_PID);
2866 if (!ei->pid)
2867 goto out_iput;
2868
2869 inode->i_mode = p->mode;
2870 if (S_ISDIR(inode->i_mode))
2871 set_nlink(inode, 2);
2872 if (S_ISLNK(inode->i_mode))
2873 inode->i_size = 64;
2874 if (p->iop)
2875 inode->i_op = p->iop;
2876 if (p->fop)
2877 inode->i_fop = p->fop;
2878 ei->op = p->op;
2879 d_add(dentry, inode);
2880 error = NULL;
2881 out:
2882 return error;
2883 out_iput:
2884 iput(inode);
2885 goto out;
2886 }
2887
2888 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2889 {
2890 struct dentry *error;
2891 struct task_struct *task = get_proc_task(dir);
2892 const struct pid_entry *p, *last;
2893
2894 error = ERR_PTR(-ENOENT);
2895
2896 if (!task)
2897 goto out_no_task;
2898
2899 /* Lookup the directory entry */
2900 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2901 for (p = proc_base_stuff; p <= last; p++) {
2902 if (p->len != dentry->d_name.len)
2903 continue;
2904 if (!memcmp(dentry->d_name.name, p->name, p->len))
2905 break;
2906 }
2907 if (p > last)
2908 goto out;
2909
2910 error = proc_base_instantiate(dir, dentry, task, p);
2911
2912 out:
2913 put_task_struct(task);
2914 out_no_task:
2915 return error;
2916 }
2917
2918 static int proc_base_fill_cache(struct file *filp, void *dirent,
2919 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2920 {
2921 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2922 proc_base_instantiate, task, p);
2923 }
2924
2925 #ifdef CONFIG_TASK_IO_ACCOUNTING
2926 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2927 {
2928 struct task_io_accounting acct = task->ioac;
2929 unsigned long flags;
2930 int result;
2931
2932 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2933 if (result)
2934 return result;
2935
2936 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2937 result = -EACCES;
2938 goto out_unlock;
2939 }
2940
2941 if (whole && lock_task_sighand(task, &flags)) {
2942 struct task_struct *t = task;
2943
2944 task_io_accounting_add(&acct, &task->signal->ioac);
2945 while_each_thread(task, t)
2946 task_io_accounting_add(&acct, &t->ioac);
2947
2948 unlock_task_sighand(task, &flags);
2949 }
2950 result = sprintf(buffer,
2951 "rchar: %llu\n"
2952 "wchar: %llu\n"
2953 "syscr: %llu\n"
2954 "syscw: %llu\n"
2955 "read_bytes: %llu\n"
2956 "write_bytes: %llu\n"
2957 "cancelled_write_bytes: %llu\n",
2958 (unsigned long long)acct.rchar,
2959 (unsigned long long)acct.wchar,
2960 (unsigned long long)acct.syscr,
2961 (unsigned long long)acct.syscw,
2962 (unsigned long long)acct.read_bytes,
2963 (unsigned long long)acct.write_bytes,
2964 (unsigned long long)acct.cancelled_write_bytes);
2965 out_unlock:
2966 mutex_unlock(&task->signal->cred_guard_mutex);
2967 return result;
2968 }
2969
2970 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2971 {
2972 return do_io_accounting(task, buffer, 0);
2973 }
2974
2975 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2976 {
2977 return do_io_accounting(task, buffer, 1);
2978 }
2979 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2980
2981 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2982 struct pid *pid, struct task_struct *task)
2983 {
2984 int err = lock_trace(task);
2985 if (!err) {
2986 seq_printf(m, "%08x\n", task->personality);
2987 unlock_trace(task);
2988 }
2989 return err;
2990 }
2991
2992 /*
2993 * Thread groups
2994 */
2995 static const struct file_operations proc_task_operations;
2996 static const struct inode_operations proc_task_inode_operations;
2997
2998 static const struct pid_entry tgid_base_stuff[] = {
2999 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3000 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3001 #ifdef CONFIG_CHECKPOINT_RESTORE
3002 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3003 #endif
3004 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3005 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3006 #ifdef CONFIG_NET
3007 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3008 #endif
3009 REG("environ", S_IRUSR, proc_environ_operations),
3010 INF("auxv", S_IRUSR, proc_pid_auxv),
3011 ONE("status", S_IRUGO, proc_pid_status),
3012 ONE("personality", S_IRUGO, proc_pid_personality),
3013 INF("limits", S_IRUGO, proc_pid_limits),
3014 #ifdef CONFIG_SCHED_DEBUG
3015 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3016 #endif
3017 #ifdef CONFIG_SCHED_AUTOGROUP
3018 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3019 #endif
3020 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3021 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3022 INF("syscall", S_IRUGO, proc_pid_syscall),
3023 #endif
3024 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3025 ONE("stat", S_IRUGO, proc_tgid_stat),
3026 ONE("statm", S_IRUGO, proc_pid_statm),
3027 REG("maps", S_IRUGO, proc_maps_operations),
3028 #ifdef CONFIG_NUMA
3029 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3030 #endif
3031 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3032 LNK("cwd", proc_cwd_link),
3033 LNK("root", proc_root_link),
3034 LNK("exe", proc_exe_link),
3035 REG("mounts", S_IRUGO, proc_mounts_operations),
3036 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3037 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3038 #ifdef CONFIG_PROC_PAGE_MONITOR
3039 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3040 REG("smaps", S_IRUGO, proc_smaps_operations),
3041 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3042 #endif
3043 #ifdef CONFIG_SECURITY
3044 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3045 #endif
3046 #ifdef CONFIG_KALLSYMS
3047 INF("wchan", S_IRUGO, proc_pid_wchan),
3048 #endif
3049 #ifdef CONFIG_STACKTRACE
3050 ONE("stack", S_IRUGO, proc_pid_stack),
3051 #endif
3052 #ifdef CONFIG_SCHEDSTATS
3053 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3054 #endif
3055 #ifdef CONFIG_LATENCYTOP
3056 REG("latency", S_IRUGO, proc_lstats_operations),
3057 #endif
3058 #ifdef CONFIG_PROC_PID_CPUSET
3059 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3060 #endif
3061 #ifdef CONFIG_CGROUPS
3062 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3063 #endif
3064 INF("oom_score", S_IRUGO, proc_oom_score),
3065 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3066 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3067 #ifdef CONFIG_AUDITSYSCALL
3068 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3069 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3070 #endif
3071 #ifdef CONFIG_FAULT_INJECTION
3072 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3073 #endif
3074 #ifdef CONFIG_ELF_CORE
3075 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3076 #endif
3077 #ifdef CONFIG_TASK_IO_ACCOUNTING
3078 INF("io", S_IRUSR, proc_tgid_io_accounting),
3079 #endif
3080 #ifdef CONFIG_HARDWALL
3081 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3082 #endif
3083 };
3084
3085 static int proc_tgid_base_readdir(struct file * filp,
3086 void * dirent, filldir_t filldir)
3087 {
3088 return proc_pident_readdir(filp,dirent,filldir,
3089 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
3090 }
3091
3092 static const struct file_operations proc_tgid_base_operations = {
3093 .read = generic_read_dir,
3094 .readdir = proc_tgid_base_readdir,
3095 .llseek = default_llseek,
3096 };
3097
3098 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3099 return proc_pident_lookup(dir, dentry,
3100 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3101 }
3102
3103 static const struct inode_operations proc_tgid_base_inode_operations = {
3104 .lookup = proc_tgid_base_lookup,
3105 .getattr = pid_getattr,
3106 .setattr = proc_setattr,
3107 .permission = proc_pid_permission,
3108 };
3109
3110 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
3111 {
3112 struct dentry *dentry, *leader, *dir;
3113 char buf[PROC_NUMBUF];
3114 struct qstr name;
3115
3116 name.name = buf;
3117 name.len = snprintf(buf, sizeof(buf), "%d", pid);
3118 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
3119 if (dentry) {
3120 shrink_dcache_parent(dentry);
3121 d_drop(dentry);
3122 dput(dentry);
3123 }
3124
3125 name.name = buf;
3126 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
3127 leader = d_hash_and_lookup(mnt->mnt_root, &name);
3128 if (!leader)
3129 goto out;
3130
3131 name.name = "task";
3132 name.len = strlen(name.name);
3133 dir = d_hash_and_lookup(leader, &name);
3134 if (!dir)
3135 goto out_put_leader;
3136
3137 name.name = buf;
3138 name.len = snprintf(buf, sizeof(buf), "%d", pid);
3139 dentry = d_hash_and_lookup(dir, &name);
3140 if (dentry) {
3141 shrink_dcache_parent(dentry);
3142 d_drop(dentry);
3143 dput(dentry);
3144 }
3145
3146 dput(dir);
3147 out_put_leader:
3148 dput(leader);
3149 out:
3150 return;
3151 }
3152
3153 /**
3154 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3155 * @task: task that should be flushed.
3156 *
3157 * When flushing dentries from proc, one needs to flush them from global
3158 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3159 * in. This call is supposed to do all of this job.
3160 *
3161 * Looks in the dcache for
3162 * /proc/@pid
3163 * /proc/@tgid/task/@pid
3164 * if either directory is present flushes it and all of it'ts children
3165 * from the dcache.
3166 *
3167 * It is safe and reasonable to cache /proc entries for a task until
3168 * that task exits. After that they just clog up the dcache with
3169 * useless entries, possibly causing useful dcache entries to be
3170 * flushed instead. This routine is proved to flush those useless
3171 * dcache entries at process exit time.
3172 *
3173 * NOTE: This routine is just an optimization so it does not guarantee
3174 * that no dcache entries will exist at process exit time it
3175 * just makes it very unlikely that any will persist.
3176 */
3177
3178 void proc_flush_task(struct task_struct *task)
3179 {
3180 int i;
3181 struct pid *pid, *tgid;
3182 struct upid *upid;
3183
3184 pid = task_pid(task);
3185 tgid = task_tgid(task);
3186
3187 for (i = 0; i <= pid->level; i++) {
3188 upid = &pid->numbers[i];
3189 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3190 tgid->numbers[i].nr);
3191 }
3192
3193 upid = &pid->numbers[pid->level];
3194 if (upid->nr == 1)
3195 pid_ns_release_proc(upid->ns);
3196 }
3197
3198 static struct dentry *proc_pid_instantiate(struct inode *dir,
3199 struct dentry * dentry,
3200 struct task_struct *task, const void *ptr)
3201 {
3202 struct dentry *error = ERR_PTR(-ENOENT);
3203 struct inode *inode;
3204
3205 inode = proc_pid_make_inode(dir->i_sb, task);
3206 if (!inode)
3207 goto out;
3208
3209 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3210 inode->i_op = &proc_tgid_base_inode_operations;
3211 inode->i_fop = &proc_tgid_base_operations;
3212 inode->i_flags|=S_IMMUTABLE;
3213
3214 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
3215 ARRAY_SIZE(tgid_base_stuff)));
3216
3217 d_set_d_op(dentry, &pid_dentry_operations);
3218
3219 d_add(dentry, inode);
3220 /* Close the race of the process dying before we return the dentry */
3221 if (pid_revalidate(dentry, NULL))
3222 error = NULL;
3223 out:
3224 return error;
3225 }
3226
3227 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3228 {
3229 struct dentry *result;
3230 struct task_struct *task;
3231 unsigned tgid;
3232 struct pid_namespace *ns;
3233
3234 result = proc_base_lookup(dir, dentry);
3235 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
3236 goto out;
3237
3238 tgid = name_to_int(dentry);
3239 if (tgid == ~0U)
3240 goto out;
3241
3242 ns = dentry->d_sb->s_fs_info;
3243 rcu_read_lock();
3244 task = find_task_by_pid_ns(tgid, ns);
3245 if (task)
3246 get_task_struct(task);
3247 rcu_read_unlock();
3248 if (!task)
3249 goto out;
3250
3251 result = proc_pid_instantiate(dir, dentry, task, NULL);
3252 put_task_struct(task);
3253 out:
3254 return result;
3255 }
3256
3257 /*
3258 * Find the first task with tgid >= tgid
3259 *
3260 */
3261 struct tgid_iter {
3262 unsigned int tgid;
3263 struct task_struct *task;
3264 };
3265 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3266 {
3267 struct pid *pid;
3268
3269 if (iter.task)
3270 put_task_struct(iter.task);
3271 rcu_read_lock();
3272 retry:
3273 iter.task = NULL;
3274 pid = find_ge_pid(iter.tgid, ns);
3275 if (pid) {
3276 iter.tgid = pid_nr_ns(pid, ns);
3277 iter.task = pid_task(pid, PIDTYPE_PID);
3278 /* What we to know is if the pid we have find is the
3279 * pid of a thread_group_leader. Testing for task
3280 * being a thread_group_leader is the obvious thing
3281 * todo but there is a window when it fails, due to
3282 * the pid transfer logic in de_thread.
3283 *
3284 * So we perform the straight forward test of seeing
3285 * if the pid we have found is the pid of a thread
3286 * group leader, and don't worry if the task we have
3287 * found doesn't happen to be a thread group leader.
3288 * As we don't care in the case of readdir.
3289 */
3290 if (!iter.task || !has_group_leader_pid(iter.task)) {
3291 iter.tgid += 1;
3292 goto retry;
3293 }
3294 get_task_struct(iter.task);
3295 }
3296 rcu_read_unlock();
3297 return iter;
3298 }
3299
3300 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3301
3302 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3303 struct tgid_iter iter)
3304 {
3305 char name[PROC_NUMBUF];
3306 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3307 return proc_fill_cache(filp, dirent, filldir, name, len,
3308 proc_pid_instantiate, iter.task, NULL);
3309 }
3310
3311 static int fake_filldir(void *buf, const char *name, int namelen,
3312 loff_t offset, u64 ino, unsigned d_type)
3313 {
3314 return 0;
3315 }
3316
3317 /* for the /proc/ directory itself, after non-process stuff has been done */
3318 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3319 {
3320 unsigned int nr;
3321 struct task_struct *reaper;
3322 struct tgid_iter iter;
3323 struct pid_namespace *ns;
3324 filldir_t __filldir;
3325
3326 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3327 goto out_no_task;
3328 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3329
3330 reaper = get_proc_task(filp->f_path.dentry->d_inode);
3331 if (!reaper)
3332 goto out_no_task;
3333
3334 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3335 const struct pid_entry *p = &proc_base_stuff[nr];
3336 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3337 goto out;
3338 }
3339
3340 ns = filp->f_dentry->d_sb->s_fs_info;
3341 iter.task = NULL;
3342 iter.tgid = filp->f_pos - TGID_OFFSET;
3343 for (iter = next_tgid(ns, iter);
3344 iter.task;
3345 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3346 if (has_pid_permissions(ns, iter.task, 2))
3347 __filldir = filldir;
3348 else
3349 __filldir = fake_filldir;
3350
3351 filp->f_pos = iter.tgid + TGID_OFFSET;
3352 if (proc_pid_fill_cache(filp, dirent, __filldir, iter) < 0) {
3353 put_task_struct(iter.task);
3354 goto out;
3355 }
3356 }
3357 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3358 out:
3359 put_task_struct(reaper);
3360 out_no_task:
3361 return 0;
3362 }
3363
3364 /*
3365 * Tasks
3366 */
3367 static const struct pid_entry tid_base_stuff[] = {
3368 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3369 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3370 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3371 REG("environ", S_IRUSR, proc_environ_operations),
3372 INF("auxv", S_IRUSR, proc_pid_auxv),
3373 ONE("status", S_IRUGO, proc_pid_status),
3374 ONE("personality", S_IRUGO, proc_pid_personality),
3375 INF("limits", S_IRUGO, proc_pid_limits),
3376 #ifdef CONFIG_SCHED_DEBUG
3377 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3378 #endif
3379 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3380 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3381 INF("syscall", S_IRUGO, proc_pid_syscall),
3382 #endif
3383 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3384 ONE("stat", S_IRUGO, proc_tid_stat),
3385 ONE("statm", S_IRUGO, proc_pid_statm),
3386 REG("maps", S_IRUGO, proc_maps_operations),
3387 #ifdef CONFIG_NUMA
3388 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3389 #endif
3390 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3391 LNK("cwd", proc_cwd_link),
3392 LNK("root", proc_root_link),
3393 LNK("exe", proc_exe_link),
3394 REG("mounts", S_IRUGO, proc_mounts_operations),
3395 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3396 #ifdef CONFIG_PROC_PAGE_MONITOR
3397 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3398 REG("smaps", S_IRUGO, proc_smaps_operations),
3399 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3400 #endif
3401 #ifdef CONFIG_SECURITY
3402 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3403 #endif
3404 #ifdef CONFIG_KALLSYMS
3405 INF("wchan", S_IRUGO, proc_pid_wchan),
3406 #endif
3407 #ifdef CONFIG_STACKTRACE
3408 ONE("stack", S_IRUGO, proc_pid_stack),
3409 #endif
3410 #ifdef CONFIG_SCHEDSTATS
3411 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3412 #endif
3413 #ifdef CONFIG_LATENCYTOP
3414 REG("latency", S_IRUGO, proc_lstats_operations),
3415 #endif
3416 #ifdef CONFIG_PROC_PID_CPUSET
3417 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3418 #endif
3419 #ifdef CONFIG_CGROUPS
3420 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3421 #endif
3422 INF("oom_score", S_IRUGO, proc_oom_score),
3423 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3424 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3425 #ifdef CONFIG_AUDITSYSCALL
3426 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3427 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3428 #endif
3429 #ifdef CONFIG_FAULT_INJECTION
3430 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3431 #endif
3432 #ifdef CONFIG_TASK_IO_ACCOUNTING
3433 INF("io", S_IRUSR, proc_tid_io_accounting),
3434 #endif
3435 #ifdef CONFIG_HARDWALL
3436 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3437 #endif
3438 };
3439
3440 static int proc_tid_base_readdir(struct file * filp,
3441 void * dirent, filldir_t filldir)
3442 {
3443 return proc_pident_readdir(filp,dirent,filldir,
3444 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3445 }
3446
3447 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3448 return proc_pident_lookup(dir, dentry,
3449 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3450 }
3451
3452 static const struct file_operations proc_tid_base_operations = {
3453 .read = generic_read_dir,
3454 .readdir = proc_tid_base_readdir,
3455 .llseek = default_llseek,
3456 };
3457
3458 static const struct inode_operations proc_tid_base_inode_operations = {
3459 .lookup = proc_tid_base_lookup,
3460 .getattr = pid_getattr,
3461 .setattr = proc_setattr,
3462 };
3463
3464 static struct dentry *proc_task_instantiate(struct inode *dir,
3465 struct dentry *dentry, struct task_struct *task, const void *ptr)
3466 {
3467 struct dentry *error = ERR_PTR(-ENOENT);
3468 struct inode *inode;
3469 inode = proc_pid_make_inode(dir->i_sb, task);
3470
3471 if (!inode)
3472 goto out;
3473 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3474 inode->i_op = &proc_tid_base_inode_operations;
3475 inode->i_fop = &proc_tid_base_operations;
3476 inode->i_flags|=S_IMMUTABLE;
3477
3478 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3479 ARRAY_SIZE(tid_base_stuff)));
3480
3481 d_set_d_op(dentry, &pid_dentry_operations);
3482
3483 d_add(dentry, inode);
3484 /* Close the race of the process dying before we return the dentry */
3485 if (pid_revalidate(dentry, NULL))
3486 error = NULL;
3487 out:
3488 return error;
3489 }
3490
3491 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3492 {
3493 struct dentry *result = ERR_PTR(-ENOENT);
3494 struct task_struct *task;
3495 struct task_struct *leader = get_proc_task(dir);
3496 unsigned tid;
3497 struct pid_namespace *ns;
3498
3499 if (!leader)
3500 goto out_no_task;
3501
3502 tid = name_to_int(dentry);
3503 if (tid == ~0U)
3504 goto out;
3505
3506 ns = dentry->d_sb->s_fs_info;
3507 rcu_read_lock();
3508 task = find_task_by_pid_ns(tid, ns);
3509 if (task)
3510 get_task_struct(task);
3511 rcu_read_unlock();
3512 if (!task)
3513 goto out;
3514 if (!same_thread_group(leader, task))
3515 goto out_drop_task;
3516
3517 result = proc_task_instantiate(dir, dentry, task, NULL);
3518 out_drop_task:
3519 put_task_struct(task);
3520 out:
3521 put_task_struct(leader);
3522 out_no_task:
3523 return result;
3524 }
3525
3526 /*
3527 * Find the first tid of a thread group to return to user space.
3528 *
3529 * Usually this is just the thread group leader, but if the users
3530 * buffer was too small or there was a seek into the middle of the
3531 * directory we have more work todo.
3532 *
3533 * In the case of a short read we start with find_task_by_pid.
3534 *
3535 * In the case of a seek we start with the leader and walk nr
3536 * threads past it.
3537 */
3538 static struct task_struct *first_tid(struct task_struct *leader,
3539 int tid, int nr, struct pid_namespace *ns)
3540 {
3541 struct task_struct *pos;
3542
3543 rcu_read_lock();
3544 /* Attempt to start with the pid of a thread */
3545 if (tid && (nr > 0)) {
3546 pos = find_task_by_pid_ns(tid, ns);
3547 if (pos && (pos->group_leader == leader))
3548 goto found;
3549 }
3550
3551 /* If nr exceeds the number of threads there is nothing todo */
3552 pos = NULL;
3553 if (nr && nr >= get_nr_threads(leader))
3554 goto out;
3555
3556 /* If we haven't found our starting place yet start
3557 * with the leader and walk nr threads forward.
3558 */
3559 for (pos = leader; nr > 0; --nr) {
3560 pos = next_thread(pos);
3561 if (pos == leader) {
3562 pos = NULL;
3563 goto out;
3564 }
3565 }
3566 found:
3567 get_task_struct(pos);
3568 out:
3569 rcu_read_unlock();
3570 return pos;
3571 }
3572
3573 /*
3574 * Find the next thread in the thread list.
3575 * Return NULL if there is an error or no next thread.
3576 *
3577 * The reference to the input task_struct is released.
3578 */
3579 static struct task_struct *next_tid(struct task_struct *start)
3580 {
3581 struct task_struct *pos = NULL;
3582 rcu_read_lock();
3583 if (pid_alive(start)) {
3584 pos = next_thread(start);
3585 if (thread_group_leader(pos))
3586 pos = NULL;
3587 else
3588 get_task_struct(pos);
3589 }
3590 rcu_read_unlock();
3591 put_task_struct(start);
3592 return pos;
3593 }
3594
3595 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3596 struct task_struct *task, int tid)
3597 {
3598 char name[PROC_NUMBUF];
3599 int len = snprintf(name, sizeof(name), "%d", tid);
3600 return proc_fill_cache(filp, dirent, filldir, name, len,
3601 proc_task_instantiate, task, NULL);
3602 }
3603
3604 /* for the /proc/TGID/task/ directories */
3605 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3606 {
3607 struct dentry *dentry = filp->f_path.dentry;
3608 struct inode *inode = dentry->d_inode;
3609 struct task_struct *leader = NULL;
3610 struct task_struct *task;
3611 int retval = -ENOENT;
3612 ino_t ino;
3613 int tid;
3614 struct pid_namespace *ns;
3615
3616 task = get_proc_task(inode);
3617 if (!task)
3618 goto out_no_task;
3619 rcu_read_lock();
3620 if (pid_alive(task)) {
3621 leader = task->group_leader;
3622 get_task_struct(leader);
3623 }
3624 rcu_read_unlock();
3625 put_task_struct(task);
3626 if (!leader)
3627 goto out_no_task;
3628 retval = 0;
3629
3630 switch ((unsigned long)filp->f_pos) {
3631 case 0:
3632 ino = inode->i_ino;
3633 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3634 goto out;
3635 filp->f_pos++;
3636 /* fall through */
3637 case 1:
3638 ino = parent_ino(dentry);
3639 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3640 goto out;
3641 filp->f_pos++;
3642 /* fall through */
3643 }
3644
3645 /* f_version caches the tgid value that the last readdir call couldn't
3646 * return. lseek aka telldir automagically resets f_version to 0.
3647 */
3648 ns = filp->f_dentry->d_sb->s_fs_info;
3649 tid = (int)filp->f_version;
3650 filp->f_version = 0;
3651 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3652 task;
3653 task = next_tid(task), filp->f_pos++) {
3654 tid = task_pid_nr_ns(task, ns);
3655 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3656 /* returning this tgid failed, save it as the first
3657 * pid for the next readir call */
3658 filp->f_version = (u64)tid;
3659 put_task_struct(task);
3660 break;
3661 }
3662 }
3663 out:
3664 put_task_struct(leader);
3665 out_no_task:
3666 return retval;
3667 }
3668
3669 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3670 {
3671 struct inode *inode = dentry->d_inode;
3672 struct task_struct *p = get_proc_task(inode);
3673 generic_fillattr(inode, stat);
3674
3675 if (p) {
3676 stat->nlink += get_nr_threads(p);
3677 put_task_struct(p);
3678 }
3679
3680 return 0;
3681 }
3682
3683 static const struct inode_operations proc_task_inode_operations = {
3684 .lookup = proc_task_lookup,
3685 .getattr = proc_task_getattr,
3686 .setattr = proc_setattr,
3687 .permission = proc_pid_permission,
3688 };
3689
3690 static const struct file_operations proc_task_operations = {
3691 .read = generic_read_dir,
3692 .readdir = proc_task_readdir,
3693 .llseek = default_llseek,
3694 };
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree