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proc: clean up and fix /proc/<pid>/mem handling
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / proc / base.c
blob662ddf2ec4f1ad7060f49d07ab1d26ebc631c72d
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 if (!capable(CAP_AUDIT_CONTROL))
1136 return -EPERM;
1137
1138 rcu_read_lock();
1139 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1140 rcu_read_unlock();
1141 return -EPERM;
1142 }
1143 rcu_read_unlock();
1144
1145 if (count >= PAGE_SIZE)
1146 count = PAGE_SIZE - 1;
1147
1148 if (*ppos != 0) {
1149 /* No partial writes. */
1150 return -EINVAL;
1151 }
1152 page = (char*)__get_free_page(GFP_TEMPORARY);
1153 if (!page)
1154 return -ENOMEM;
1155 length = -EFAULT;
1156 if (copy_from_user(page, buf, count))
1157 goto out_free_page;
1158
1159 page[count] = '\0';
1160 loginuid = simple_strtoul(page, &tmp, 10);
1161 if (tmp == page) {
1162 length = -EINVAL;
1163 goto out_free_page;
1164
1165 }
1166 length = audit_set_loginuid(current, loginuid);
1167 if (likely(length == 0))
1168 length = count;
1169
1170 out_free_page:
1171 free_page((unsigned long) page);
1172 return length;
1173 }
1174
1175 static const struct file_operations proc_loginuid_operations = {
1176 .read = proc_loginuid_read,
1177 .write = proc_loginuid_write,
1178 .llseek = generic_file_llseek,
1179 };
1180
1181 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1182 size_t count, loff_t *ppos)
1183 {
1184 struct inode * inode = file->f_path.dentry->d_inode;
1185 struct task_struct *task = get_proc_task(inode);
1186 ssize_t length;
1187 char tmpbuf[TMPBUFLEN];
1188
1189 if (!task)
1190 return -ESRCH;
1191 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1192 audit_get_sessionid(task));
1193 put_task_struct(task);
1194 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1195 }
1196
1197 static const struct file_operations proc_sessionid_operations = {
1198 .read = proc_sessionid_read,
1199 .llseek = generic_file_llseek,
1200 };
1201 #endif
1202
1203 #ifdef CONFIG_FAULT_INJECTION
1204 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1205 size_t count, loff_t *ppos)
1206 {
1207 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1208 char buffer[PROC_NUMBUF];
1209 size_t len;
1210 int make_it_fail;
1211
1212 if (!task)
1213 return -ESRCH;
1214 make_it_fail = task->make_it_fail;
1215 put_task_struct(task);
1216
1217 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1218
1219 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1220 }
1221
1222 static ssize_t proc_fault_inject_write(struct file * file,
1223 const char __user * buf, size_t count, loff_t *ppos)
1224 {
1225 struct task_struct *task;
1226 char buffer[PROC_NUMBUF], *end;
1227 int make_it_fail;
1228
1229 if (!capable(CAP_SYS_RESOURCE))
1230 return -EPERM;
1231 memset(buffer, 0, sizeof(buffer));
1232 if (count > sizeof(buffer) - 1)
1233 count = sizeof(buffer) - 1;
1234 if (copy_from_user(buffer, buf, count))
1235 return -EFAULT;
1236 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1237 if (*end)
1238 return -EINVAL;
1239 task = get_proc_task(file->f_dentry->d_inode);
1240 if (!task)
1241 return -ESRCH;
1242 task->make_it_fail = make_it_fail;
1243 put_task_struct(task);
1244
1245 return count;
1246 }
1247
1248 static const struct file_operations proc_fault_inject_operations = {
1249 .read = proc_fault_inject_read,
1250 .write = proc_fault_inject_write,
1251 .llseek = generic_file_llseek,
1252 };
1253 #endif
1254
1255
1256 #ifdef CONFIG_SCHED_DEBUG
1257 /*
1258 * Print out various scheduling related per-task fields:
1259 */
1260 static int sched_show(struct seq_file *m, void *v)
1261 {
1262 struct inode *inode = m->private;
1263 struct task_struct *p;
1264
1265 p = get_proc_task(inode);
1266 if (!p)
1267 return -ESRCH;
1268 proc_sched_show_task(p, m);
1269
1270 put_task_struct(p);
1271
1272 return 0;
1273 }
1274
1275 static ssize_t
1276 sched_write(struct file *file, const char __user *buf,
1277 size_t count, loff_t *offset)
1278 {
1279 struct inode *inode = file->f_path.dentry->d_inode;
1280 struct task_struct *p;
1281
1282 p = get_proc_task(inode);
1283 if (!p)
1284 return -ESRCH;
1285 proc_sched_set_task(p);
1286
1287 put_task_struct(p);
1288
1289 return count;
1290 }
1291
1292 static int sched_open(struct inode *inode, struct file *filp)
1293 {
1294 return single_open(filp, sched_show, inode);
1295 }
1296
1297 static const struct file_operations proc_pid_sched_operations = {
1298 .open = sched_open,
1299 .read = seq_read,
1300 .write = sched_write,
1301 .llseek = seq_lseek,
1302 .release = single_release,
1303 };
1304
1305 #endif
1306
1307 #ifdef CONFIG_SCHED_AUTOGROUP
1308 /*
1309 * Print out autogroup related information:
1310 */
1311 static int sched_autogroup_show(struct seq_file *m, void *v)
1312 {
1313 struct inode *inode = m->private;
1314 struct task_struct *p;
1315
1316 p = get_proc_task(inode);
1317 if (!p)
1318 return -ESRCH;
1319 proc_sched_autogroup_show_task(p, m);
1320
1321 put_task_struct(p);
1322
1323 return 0;
1324 }
1325
1326 static ssize_t
1327 sched_autogroup_write(struct file *file, const char __user *buf,
1328 size_t count, loff_t *offset)
1329 {
1330 struct inode *inode = file->f_path.dentry->d_inode;
1331 struct task_struct *p;
1332 char buffer[PROC_NUMBUF];
1333 int nice;
1334 int err;
1335
1336 memset(buffer, 0, sizeof(buffer));
1337 if (count > sizeof(buffer) - 1)
1338 count = sizeof(buffer) - 1;
1339 if (copy_from_user(buffer, buf, count))
1340 return -EFAULT;
1341
1342 err = kstrtoint(strstrip(buffer), 0, &nice);
1343 if (err < 0)
1344 return err;
1345
1346 p = get_proc_task(inode);
1347 if (!p)
1348 return -ESRCH;
1349
1350 err = nice;
1351 err = proc_sched_autogroup_set_nice(p, &err);
1352 if (err)
1353 count = err;
1354
1355 put_task_struct(p);
1356
1357 return count;
1358 }
1359
1360 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1361 {
1362 int ret;
1363
1364 ret = single_open(filp, sched_autogroup_show, NULL);
1365 if (!ret) {
1366 struct seq_file *m = filp->private_data;
1367
1368 m->private = inode;
1369 }
1370 return ret;
1371 }
1372
1373 static const struct file_operations proc_pid_sched_autogroup_operations = {
1374 .open = sched_autogroup_open,
1375 .read = seq_read,
1376 .write = sched_autogroup_write,
1377 .llseek = seq_lseek,
1378 .release = single_release,
1379 };
1380
1381 #endif /* CONFIG_SCHED_AUTOGROUP */
1382
1383 static ssize_t comm_write(struct file *file, const char __user *buf,
1384 size_t count, loff_t *offset)
1385 {
1386 struct inode *inode = file->f_path.dentry->d_inode;
1387 struct task_struct *p;
1388 char buffer[TASK_COMM_LEN];
1389
1390 memset(buffer, 0, sizeof(buffer));
1391 if (count > sizeof(buffer) - 1)
1392 count = sizeof(buffer) - 1;
1393 if (copy_from_user(buffer, buf, count))
1394 return -EFAULT;
1395
1396 p = get_proc_task(inode);
1397 if (!p)
1398 return -ESRCH;
1399
1400 if (same_thread_group(current, p))
1401 set_task_comm(p, buffer);
1402 else
1403 count = -EINVAL;
1404
1405 put_task_struct(p);
1406
1407 return count;
1408 }
1409
1410 static int comm_show(struct seq_file *m, void *v)
1411 {
1412 struct inode *inode = m->private;
1413 struct task_struct *p;
1414
1415 p = get_proc_task(inode);
1416 if (!p)
1417 return -ESRCH;
1418
1419 task_lock(p);
1420 seq_printf(m, "%s\n", p->comm);
1421 task_unlock(p);
1422
1423 put_task_struct(p);
1424
1425 return 0;
1426 }
1427
1428 static int comm_open(struct inode *inode, struct file *filp)
1429 {
1430 return single_open(filp, comm_show, inode);
1431 }
1432
1433 static const struct file_operations proc_pid_set_comm_operations = {
1434 .open = comm_open,
1435 .read = seq_read,
1436 .write = comm_write,
1437 .llseek = seq_lseek,
1438 .release = single_release,
1439 };
1440
1441 static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1442 {
1443 struct task_struct *task;
1444 struct mm_struct *mm;
1445 struct file *exe_file;
1446
1447 task = get_proc_task(dentry->d_inode);
1448 if (!task)
1449 return -ENOENT;
1450 mm = get_task_mm(task);
1451 put_task_struct(task);
1452 if (!mm)
1453 return -ENOENT;
1454 exe_file = get_mm_exe_file(mm);
1455 mmput(mm);
1456 if (exe_file) {
1457 *exe_path = exe_file->f_path;
1458 path_get(&exe_file->f_path);
1459 fput(exe_file);
1460 return 0;
1461 } else
1462 return -ENOENT;
1463 }
1464
1465 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1466 {
1467 struct inode *inode = dentry->d_inode;
1468 int error = -EACCES;
1469
1470 /* We don't need a base pointer in the /proc filesystem */
1471 path_put(&nd->path);
1472
1473 /* Are we allowed to snoop on the tasks file descriptors? */
1474 if (!proc_fd_access_allowed(inode))
1475 goto out;
1476
1477 error = PROC_I(inode)->op.proc_get_link(dentry, &nd->path);
1478 out:
1479 return ERR_PTR(error);
1480 }
1481
1482 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1483 {
1484 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1485 char *pathname;
1486 int len;
1487
1488 if (!tmp)
1489 return -ENOMEM;
1490
1491 pathname = d_path(path, tmp, PAGE_SIZE);
1492 len = PTR_ERR(pathname);
1493 if (IS_ERR(pathname))
1494 goto out;
1495 len = tmp + PAGE_SIZE - 1 - pathname;
1496
1497 if (len > buflen)
1498 len = buflen;
1499 if (copy_to_user(buffer, pathname, len))
1500 len = -EFAULT;
1501 out:
1502 free_page((unsigned long)tmp);
1503 return len;
1504 }
1505
1506 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1507 {
1508 int error = -EACCES;
1509 struct inode *inode = dentry->d_inode;
1510 struct path path;
1511
1512 /* Are we allowed to snoop on the tasks file descriptors? */
1513 if (!proc_fd_access_allowed(inode))
1514 goto out;
1515
1516 error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1517 if (error)
1518 goto out;
1519
1520 error = do_proc_readlink(&path, buffer, buflen);
1521 path_put(&path);
1522 out:
1523 return error;
1524 }
1525
1526 static const struct inode_operations proc_pid_link_inode_operations = {
1527 .readlink = proc_pid_readlink,
1528 .follow_link = proc_pid_follow_link,
1529 .setattr = proc_setattr,
1530 };
1531
1532
1533 /* building an inode */
1534
1535 static int task_dumpable(struct task_struct *task)
1536 {
1537 int dumpable = 0;
1538 struct mm_struct *mm;
1539
1540 task_lock(task);
1541 mm = task->mm;
1542 if (mm)
1543 dumpable = get_dumpable(mm);
1544 task_unlock(task);
1545 if(dumpable == 1)
1546 return 1;
1547 return 0;
1548 }
1549
1550 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1551 {
1552 struct inode * inode;
1553 struct proc_inode *ei;
1554 const struct cred *cred;
1555
1556 /* We need a new inode */
1557
1558 inode = new_inode(sb);
1559 if (!inode)
1560 goto out;
1561
1562 /* Common stuff */
1563 ei = PROC_I(inode);
1564 inode->i_ino = get_next_ino();
1565 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1566 inode->i_op = &proc_def_inode_operations;
1567
1568 /*
1569 * grab the reference to task.
1570 */
1571 ei->pid = get_task_pid(task, PIDTYPE_PID);
1572 if (!ei->pid)
1573 goto out_unlock;
1574
1575 if (task_dumpable(task)) {
1576 rcu_read_lock();
1577 cred = __task_cred(task);
1578 inode->i_uid = cred->euid;
1579 inode->i_gid = cred->egid;
1580 rcu_read_unlock();
1581 }
1582 security_task_to_inode(task, inode);
1583
1584 out:
1585 return inode;
1586
1587 out_unlock:
1588 iput(inode);
1589 return NULL;
1590 }
1591
1592 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1593 {
1594 struct inode *inode = dentry->d_inode;
1595 struct task_struct *task;
1596 const struct cred *cred;
1597 struct pid_namespace *pid = dentry->d_sb->s_fs_info;
1598
1599 generic_fillattr(inode, stat);
1600
1601 rcu_read_lock();
1602 stat->uid = 0;
1603 stat->gid = 0;
1604 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1605 if (task) {
1606 if (!has_pid_permissions(pid, task, 2)) {
1607 rcu_read_unlock();
1608 /*
1609 * This doesn't prevent learning whether PID exists,
1610 * it only makes getattr() consistent with readdir().
1611 */
1612 return -ENOENT;
1613 }
1614 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1615 task_dumpable(task)) {
1616 cred = __task_cred(task);
1617 stat->uid = cred->euid;
1618 stat->gid = cred->egid;
1619 }
1620 }
1621 rcu_read_unlock();
1622 return 0;
1623 }
1624
1625 /* dentry stuff */
1626
1627 /*
1628 * Exceptional case: normally we are not allowed to unhash a busy
1629 * directory. In this case, however, we can do it - no aliasing problems
1630 * due to the way we treat inodes.
1631 *
1632 * Rewrite the inode's ownerships here because the owning task may have
1633 * performed a setuid(), etc.
1634 *
1635 * Before the /proc/pid/status file was created the only way to read
1636 * the effective uid of a /process was to stat /proc/pid. Reading
1637 * /proc/pid/status is slow enough that procps and other packages
1638 * kept stating /proc/pid. To keep the rules in /proc simple I have
1639 * made this apply to all per process world readable and executable
1640 * directories.
1641 */
1642 int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1643 {
1644 struct inode *inode;
1645 struct task_struct *task;
1646 const struct cred *cred;
1647
1648 if (nd && nd->flags & LOOKUP_RCU)
1649 return -ECHILD;
1650
1651 inode = dentry->d_inode;
1652 task = get_proc_task(inode);
1653
1654 if (task) {
1655 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1656 task_dumpable(task)) {
1657 rcu_read_lock();
1658 cred = __task_cred(task);
1659 inode->i_uid = cred->euid;
1660 inode->i_gid = cred->egid;
1661 rcu_read_unlock();
1662 } else {
1663 inode->i_uid = 0;
1664 inode->i_gid = 0;
1665 }
1666 inode->i_mode &= ~(S_ISUID | S_ISGID);
1667 security_task_to_inode(task, inode);
1668 put_task_struct(task);
1669 return 1;
1670 }
1671 d_drop(dentry);
1672 return 0;
1673 }
1674
1675 static int pid_delete_dentry(const struct dentry * dentry)
1676 {
1677 /* Is the task we represent dead?
1678 * If so, then don't put the dentry on the lru list,
1679 * kill it immediately.
1680 */
1681 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1682 }
1683
1684 const struct dentry_operations pid_dentry_operations =
1685 {
1686 .d_revalidate = pid_revalidate,
1687 .d_delete = pid_delete_dentry,
1688 };
1689
1690 /* Lookups */
1691
1692 /*
1693 * Fill a directory entry.
1694 *
1695 * If possible create the dcache entry and derive our inode number and
1696 * file type from dcache entry.
1697 *
1698 * Since all of the proc inode numbers are dynamically generated, the inode
1699 * numbers do not exist until the inode is cache. This means creating the
1700 * the dcache entry in readdir is necessary to keep the inode numbers
1701 * reported by readdir in sync with the inode numbers reported
1702 * by stat.
1703 */
1704 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1705 const char *name, int len,
1706 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1707 {
1708 struct dentry *child, *dir = filp->f_path.dentry;
1709 struct inode *inode;
1710 struct qstr qname;
1711 ino_t ino = 0;
1712 unsigned type = DT_UNKNOWN;
1713
1714 qname.name = name;
1715 qname.len = len;
1716 qname.hash = full_name_hash(name, len);
1717
1718 child = d_lookup(dir, &qname);
1719 if (!child) {
1720 struct dentry *new;
1721 new = d_alloc(dir, &qname);
1722 if (new) {
1723 child = instantiate(dir->d_inode, new, task, ptr);
1724 if (child)
1725 dput(new);
1726 else
1727 child = new;
1728 }
1729 }
1730 if (!child || IS_ERR(child) || !child->d_inode)
1731 goto end_instantiate;
1732 inode = child->d_inode;
1733 if (inode) {
1734 ino = inode->i_ino;
1735 type = inode->i_mode >> 12;
1736 }
1737 dput(child);
1738 end_instantiate:
1739 if (!ino)
1740 ino = find_inode_number(dir, &qname);
1741 if (!ino)
1742 ino = 1;
1743 return filldir(dirent, name, len, filp->f_pos, ino, type);
1744 }
1745
1746 static unsigned name_to_int(struct dentry *dentry)
1747 {
1748 const char *name = dentry->d_name.name;
1749 int len = dentry->d_name.len;
1750 unsigned n = 0;
1751
1752 if (len > 1 && *name == '0')
1753 goto out;
1754 while (len-- > 0) {
1755 unsigned c = *name++ - '0';
1756 if (c > 9)
1757 goto out;
1758 if (n >= (~0U-9)/10)
1759 goto out;
1760 n *= 10;
1761 n += c;
1762 }
1763 return n;
1764 out:
1765 return ~0U;
1766 }
1767
1768 #define PROC_FDINFO_MAX 64
1769
1770 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1771 {
1772 struct task_struct *task = get_proc_task(inode);
1773 struct files_struct *files = NULL;
1774 struct file *file;
1775 int fd = proc_fd(inode);
1776
1777 if (task) {
1778 files = get_files_struct(task);
1779 put_task_struct(task);
1780 }
1781 if (files) {
1782 /*
1783 * We are not taking a ref to the file structure, so we must
1784 * hold ->file_lock.
1785 */
1786 spin_lock(&files->file_lock);
1787 file = fcheck_files(files, fd);
1788 if (file) {
1789 unsigned int f_flags;
1790 struct fdtable *fdt;
1791
1792 fdt = files_fdtable(files);
1793 f_flags = file->f_flags & ~O_CLOEXEC;
1794 if (FD_ISSET(fd, fdt->close_on_exec))
1795 f_flags |= O_CLOEXEC;
1796
1797 if (path) {
1798 *path = file->f_path;
1799 path_get(&file->f_path);
1800 }
1801 if (info)
1802 snprintf(info, PROC_FDINFO_MAX,
1803 "pos:\t%lli\n"
1804 "flags:\t0%o\n",
1805 (long long) file->f_pos,
1806 f_flags);
1807 spin_unlock(&files->file_lock);
1808 put_files_struct(files);
1809 return 0;
1810 }
1811 spin_unlock(&files->file_lock);
1812 put_files_struct(files);
1813 }
1814 return -ENOENT;
1815 }
1816
1817 static int proc_fd_link(struct dentry *dentry, struct path *path)
1818 {
1819 return proc_fd_info(dentry->d_inode, path, NULL);
1820 }
1821
1822 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1823 {
1824 struct inode *inode;
1825 struct task_struct *task;
1826 int fd;
1827 struct files_struct *files;
1828 const struct cred *cred;
1829
1830 if (nd && nd->flags & LOOKUP_RCU)
1831 return -ECHILD;
1832
1833 inode = dentry->d_inode;
1834 task = get_proc_task(inode);
1835 fd = proc_fd(inode);
1836
1837 if (task) {
1838 files = get_files_struct(task);
1839 if (files) {
1840 rcu_read_lock();
1841 if (fcheck_files(files, fd)) {
1842 rcu_read_unlock();
1843 put_files_struct(files);
1844 if (task_dumpable(task)) {
1845 rcu_read_lock();
1846 cred = __task_cred(task);
1847 inode->i_uid = cred->euid;
1848 inode->i_gid = cred->egid;
1849 rcu_read_unlock();
1850 } else {
1851 inode->i_uid = 0;
1852 inode->i_gid = 0;
1853 }
1854 inode->i_mode &= ~(S_ISUID | S_ISGID);
1855 security_task_to_inode(task, inode);
1856 put_task_struct(task);
1857 return 1;
1858 }
1859 rcu_read_unlock();
1860 put_files_struct(files);
1861 }
1862 put_task_struct(task);
1863 }
1864 d_drop(dentry);
1865 return 0;
1866 }
1867
1868 static const struct dentry_operations tid_fd_dentry_operations =
1869 {
1870 .d_revalidate = tid_fd_revalidate,
1871 .d_delete = pid_delete_dentry,
1872 };
1873
1874 static struct dentry *proc_fd_instantiate(struct inode *dir,
1875 struct dentry *dentry, struct task_struct *task, const void *ptr)
1876 {
1877 unsigned fd = *(const unsigned *)ptr;
1878 struct file *file;
1879 struct files_struct *files;
1880 struct inode *inode;
1881 struct proc_inode *ei;
1882 struct dentry *error = ERR_PTR(-ENOENT);
1883
1884 inode = proc_pid_make_inode(dir->i_sb, task);
1885 if (!inode)
1886 goto out;
1887 ei = PROC_I(inode);
1888 ei->fd = fd;
1889 files = get_files_struct(task);
1890 if (!files)
1891 goto out_iput;
1892 inode->i_mode = S_IFLNK;
1893
1894 /*
1895 * We are not taking a ref to the file structure, so we must
1896 * hold ->file_lock.
1897 */
1898 spin_lock(&files->file_lock);
1899 file = fcheck_files(files, fd);
1900 if (!file)
1901 goto out_unlock;
1902 if (file->f_mode & FMODE_READ)
1903 inode->i_mode |= S_IRUSR | S_IXUSR;
1904 if (file->f_mode & FMODE_WRITE)
1905 inode->i_mode |= S_IWUSR | S_IXUSR;
1906 spin_unlock(&files->file_lock);
1907 put_files_struct(files);
1908
1909 inode->i_op = &proc_pid_link_inode_operations;
1910 inode->i_size = 64;
1911 ei->op.proc_get_link = proc_fd_link;
1912 d_set_d_op(dentry, &tid_fd_dentry_operations);
1913 d_add(dentry, inode);
1914 /* Close the race of the process dying before we return the dentry */
1915 if (tid_fd_revalidate(dentry, NULL))
1916 error = NULL;
1917
1918 out:
1919 return error;
1920 out_unlock:
1921 spin_unlock(&files->file_lock);
1922 put_files_struct(files);
1923 out_iput:
1924 iput(inode);
1925 goto out;
1926 }
1927
1928 static struct dentry *proc_lookupfd_common(struct inode *dir,
1929 struct dentry *dentry,
1930 instantiate_t instantiate)
1931 {
1932 struct task_struct *task = get_proc_task(dir);
1933 unsigned fd = name_to_int(dentry);
1934 struct dentry *result = ERR_PTR(-ENOENT);
1935
1936 if (!task)
1937 goto out_no_task;
1938 if (fd == ~0U)
1939 goto out;
1940
1941 result = instantiate(dir, dentry, task, &fd);
1942 out:
1943 put_task_struct(task);
1944 out_no_task:
1945 return result;
1946 }
1947
1948 static int proc_readfd_common(struct file * filp, void * dirent,
1949 filldir_t filldir, instantiate_t instantiate)
1950 {
1951 struct dentry *dentry = filp->f_path.dentry;
1952 struct inode *inode = dentry->d_inode;
1953 struct task_struct *p = get_proc_task(inode);
1954 unsigned int fd, ino;
1955 int retval;
1956 struct files_struct * files;
1957
1958 retval = -ENOENT;
1959 if (!p)
1960 goto out_no_task;
1961 retval = 0;
1962
1963 fd = filp->f_pos;
1964 switch (fd) {
1965 case 0:
1966 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1967 goto out;
1968 filp->f_pos++;
1969 case 1:
1970 ino = parent_ino(dentry);
1971 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1972 goto out;
1973 filp->f_pos++;
1974 default:
1975 files = get_files_struct(p);
1976 if (!files)
1977 goto out;
1978 rcu_read_lock();
1979 for (fd = filp->f_pos-2;
1980 fd < files_fdtable(files)->max_fds;
1981 fd++, filp->f_pos++) {
1982 char name[PROC_NUMBUF];
1983 int len;
1984
1985 if (!fcheck_files(files, fd))
1986 continue;
1987 rcu_read_unlock();
1988
1989 len = snprintf(name, sizeof(name), "%d", fd);
1990 if (proc_fill_cache(filp, dirent, filldir,
1991 name, len, instantiate,
1992 p, &fd) < 0) {
1993 rcu_read_lock();
1994 break;
1995 }
1996 rcu_read_lock();
1997 }
1998 rcu_read_unlock();
1999 put_files_struct(files);
2000 }
2001 out:
2002 put_task_struct(p);
2003 out_no_task:
2004 return retval;
2005 }
2006
2007 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
2008 struct nameidata *nd)
2009 {
2010 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
2011 }
2012
2013 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
2014 {
2015 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
2016 }
2017
2018 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
2019 size_t len, loff_t *ppos)
2020 {
2021 char tmp[PROC_FDINFO_MAX];
2022 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
2023 if (!err)
2024 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
2025 return err;
2026 }
2027
2028 static const struct file_operations proc_fdinfo_file_operations = {
2029 .open = nonseekable_open,
2030 .read = proc_fdinfo_read,
2031 .llseek = no_llseek,
2032 };
2033
2034 static const struct file_operations proc_fd_operations = {
2035 .read = generic_read_dir,
2036 .readdir = proc_readfd,
2037 .llseek = default_llseek,
2038 };
2039
2040 #ifdef CONFIG_CHECKPOINT_RESTORE
2041
2042 /*
2043 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2044 * which represent vma start and end addresses.
2045 */
2046 static int dname_to_vma_addr(struct dentry *dentry,
2047 unsigned long *start, unsigned long *end)
2048 {
2049 if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
2050 return -EINVAL;
2051
2052 return 0;
2053 }
2054
2055 static int map_files_d_revalidate(struct dentry *dentry, struct nameidata *nd)
2056 {
2057 unsigned long vm_start, vm_end;
2058 bool exact_vma_exists = false;
2059 struct mm_struct *mm = NULL;
2060 struct task_struct *task;
2061 const struct cred *cred;
2062 struct inode *inode;
2063 int status = 0;
2064
2065 if (nd && nd->flags & LOOKUP_RCU)
2066 return -ECHILD;
2067
2068 if (!capable(CAP_SYS_ADMIN)) {
2069 status = -EACCES;
2070 goto out_notask;
2071 }
2072
2073 inode = dentry->d_inode;
2074 task = get_proc_task(inode);
2075 if (!task)
2076 goto out_notask;
2077
2078 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2079 goto out;
2080
2081 mm = get_task_mm(task);
2082 if (!mm)
2083 goto out;
2084
2085 if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2086 down_read(&mm->mmap_sem);
2087 exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
2088 up_read(&mm->mmap_sem);
2089 }
2090
2091 mmput(mm);
2092
2093 if (exact_vma_exists) {
2094 if (task_dumpable(task)) {
2095 rcu_read_lock();
2096 cred = __task_cred(task);
2097 inode->i_uid = cred->euid;
2098 inode->i_gid = cred->egid;
2099 rcu_read_unlock();
2100 } else {
2101 inode->i_uid = 0;
2102 inode->i_gid = 0;
2103 }
2104 security_task_to_inode(task, inode);
2105 status = 1;
2106 }
2107
2108 out:
2109 put_task_struct(task);
2110
2111 out_notask:
2112 if (status <= 0)
2113 d_drop(dentry);
2114
2115 return status;
2116 }
2117
2118 static const struct dentry_operations tid_map_files_dentry_operations = {
2119 .d_revalidate = map_files_d_revalidate,
2120 .d_delete = pid_delete_dentry,
2121 };
2122
2123 static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
2124 {
2125 unsigned long vm_start, vm_end;
2126 struct vm_area_struct *vma;
2127 struct task_struct *task;
2128 struct mm_struct *mm;
2129 int rc;
2130
2131 rc = -ENOENT;
2132 task = get_proc_task(dentry->d_inode);
2133 if (!task)
2134 goto out;
2135
2136 mm = get_task_mm(task);
2137 put_task_struct(task);
2138 if (!mm)
2139 goto out;
2140
2141 rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2142 if (rc)
2143 goto out_mmput;
2144
2145 down_read(&mm->mmap_sem);
2146 vma = find_exact_vma(mm, vm_start, vm_end);
2147 if (vma && vma->vm_file) {
2148 *path = vma->vm_file->f_path;
2149 path_get(path);
2150 rc = 0;
2151 }
2152 up_read(&mm->mmap_sem);
2153
2154 out_mmput:
2155 mmput(mm);
2156 out:
2157 return rc;
2158 }
2159
2160 struct map_files_info {
2161 struct file *file;
2162 unsigned long len;
2163 unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
2164 };
2165
2166 static struct dentry *
2167 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
2168 struct task_struct *task, const void *ptr)
2169 {
2170 const struct file *file = ptr;
2171 struct proc_inode *ei;
2172 struct inode *inode;
2173
2174 if (!file)
2175 return ERR_PTR(-ENOENT);
2176
2177 inode = proc_pid_make_inode(dir->i_sb, task);
2178 if (!inode)
2179 return ERR_PTR(-ENOENT);
2180
2181 ei = PROC_I(inode);
2182 ei->op.proc_get_link = proc_map_files_get_link;
2183
2184 inode->i_op = &proc_pid_link_inode_operations;
2185 inode->i_size = 64;
2186 inode->i_mode = S_IFLNK;
2187
2188 if (file->f_mode & FMODE_READ)
2189 inode->i_mode |= S_IRUSR;
2190 if (file->f_mode & FMODE_WRITE)
2191 inode->i_mode |= S_IWUSR;
2192
2193 d_set_d_op(dentry, &tid_map_files_dentry_operations);
2194 d_add(dentry, inode);
2195
2196 return NULL;
2197 }
2198
2199 static struct dentry *proc_map_files_lookup(struct inode *dir,
2200 struct dentry *dentry, struct nameidata *nd)
2201 {
2202 unsigned long vm_start, vm_end;
2203 struct vm_area_struct *vma;
2204 struct task_struct *task;
2205 struct dentry *result;
2206 struct mm_struct *mm;
2207
2208 result = ERR_PTR(-EACCES);
2209 if (!capable(CAP_SYS_ADMIN))
2210 goto out;
2211
2212 result = ERR_PTR(-ENOENT);
2213 task = get_proc_task(dir);
2214 if (!task)
2215 goto out;
2216
2217 result = ERR_PTR(-EACCES);
2218 if (lock_trace(task))
2219 goto out_put_task;
2220
2221 result = ERR_PTR(-ENOENT);
2222 if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2223 goto out_unlock;
2224
2225 mm = get_task_mm(task);
2226 if (!mm)
2227 goto out_unlock;
2228
2229 down_read(&mm->mmap_sem);
2230 vma = find_exact_vma(mm, vm_start, vm_end);
2231 if (!vma)
2232 goto out_no_vma;
2233
2234 result = proc_map_files_instantiate(dir, dentry, task, vma->vm_file);
2235
2236 out_no_vma:
2237 up_read(&mm->mmap_sem);
2238 mmput(mm);
2239 out_unlock:
2240 unlock_trace(task);
2241 out_put_task:
2242 put_task_struct(task);
2243 out:
2244 return result;
2245 }
2246
2247 static const struct inode_operations proc_map_files_inode_operations = {
2248 .lookup = proc_map_files_lookup,
2249 .permission = proc_fd_permission,
2250 .setattr = proc_setattr,
2251 };
2252
2253 static int
2254 proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
2255 {
2256 struct dentry *dentry = filp->f_path.dentry;
2257 struct inode *inode = dentry->d_inode;
2258 struct vm_area_struct *vma;
2259 struct task_struct *task;
2260 struct mm_struct *mm;
2261 ino_t ino;
2262 int ret;
2263
2264 ret = -EACCES;
2265 if (!capable(CAP_SYS_ADMIN))
2266 goto out;
2267
2268 ret = -ENOENT;
2269 task = get_proc_task(inode);
2270 if (!task)
2271 goto out;
2272
2273 ret = -EACCES;
2274 if (lock_trace(task))
2275 goto out_put_task;
2276
2277 ret = 0;
2278 switch (filp->f_pos) {
2279 case 0:
2280 ino = inode->i_ino;
2281 if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0)
2282 goto out_unlock;
2283 filp->f_pos++;
2284 case 1:
2285 ino = parent_ino(dentry);
2286 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2287 goto out_unlock;
2288 filp->f_pos++;
2289 default:
2290 {
2291 unsigned long nr_files, pos, i;
2292 struct flex_array *fa = NULL;
2293 struct map_files_info info;
2294 struct map_files_info *p;
2295
2296 mm = get_task_mm(task);
2297 if (!mm)
2298 goto out_unlock;
2299 down_read(&mm->mmap_sem);
2300
2301 nr_files = 0;
2302
2303 /*
2304 * We need two passes here:
2305 *
2306 * 1) Collect vmas of mapped files with mmap_sem taken
2307 * 2) Release mmap_sem and instantiate entries
2308 *
2309 * otherwise we get lockdep complained, since filldir()
2310 * routine might require mmap_sem taken in might_fault().
2311 */
2312
2313 for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2314 if (vma->vm_file && ++pos > filp->f_pos)
2315 nr_files++;
2316 }
2317
2318 if (nr_files) {
2319 fa = flex_array_alloc(sizeof(info), nr_files,
2320 GFP_KERNEL);
2321 if (!fa || flex_array_prealloc(fa, 0, nr_files,
2322 GFP_KERNEL)) {
2323 ret = -ENOMEM;
2324 if (fa)
2325 flex_array_free(fa);
2326 up_read(&mm->mmap_sem);
2327 mmput(mm);
2328 goto out_unlock;
2329 }
2330 for (i = 0, vma = mm->mmap, pos = 2; vma;
2331 vma = vma->vm_next) {
2332 if (!vma->vm_file)
2333 continue;
2334 if (++pos <= filp->f_pos)
2335 continue;
2336
2337 get_file(vma->vm_file);
2338 info.file = vma->vm_file;
2339 info.len = snprintf(info.name,
2340 sizeof(info.name), "%lx-%lx",
2341 vma->vm_start, vma->vm_end);
2342 if (flex_array_put(fa, i++, &info, GFP_KERNEL))
2343 BUG();
2344 }
2345 }
2346 up_read(&mm->mmap_sem);
2347
2348 for (i = 0; i < nr_files; i++) {
2349 p = flex_array_get(fa, i);
2350 ret = proc_fill_cache(filp, dirent, filldir,
2351 p->name, p->len,
2352 proc_map_files_instantiate,
2353 task, p->file);
2354 if (ret)
2355 break;
2356 filp->f_pos++;
2357 fput(p->file);
2358 }
2359 for (; i < nr_files; i++) {
2360 /*
2361 * In case of error don't forget
2362 * to put rest of file refs.
2363 */
2364 p = flex_array_get(fa, i);
2365 fput(p->file);
2366 }
2367 if (fa)
2368 flex_array_free(fa);
2369 mmput(mm);
2370 }
2371 }
2372
2373 out_unlock:
2374 unlock_trace(task);
2375 out_put_task:
2376 put_task_struct(task);
2377 out:
2378 return ret;
2379 }
2380
2381 static const struct file_operations proc_map_files_operations = {
2382 .read = generic_read_dir,
2383 .readdir = proc_map_files_readdir,
2384 .llseek = default_llseek,
2385 };
2386
2387 #endif /* CONFIG_CHECKPOINT_RESTORE */
2388
2389 /*
2390 * /proc/pid/fd needs a special permission handler so that a process can still
2391 * access /proc/self/fd after it has executed a setuid().
2392 */
2393 static int proc_fd_permission(struct inode *inode, int mask)
2394 {
2395 int rv = generic_permission(inode, mask);
2396 if (rv == 0)
2397 return 0;
2398 if (task_pid(current) == proc_pid(inode))
2399 rv = 0;
2400 return rv;
2401 }
2402
2403 /*
2404 * proc directories can do almost nothing..
2405 */
2406 static const struct inode_operations proc_fd_inode_operations = {
2407 .lookup = proc_lookupfd,
2408 .permission = proc_fd_permission,
2409 .setattr = proc_setattr,
2410 };
2411
2412 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2413 struct dentry *dentry, struct task_struct *task, const void *ptr)
2414 {
2415 unsigned fd = *(unsigned *)ptr;
2416 struct inode *inode;
2417 struct proc_inode *ei;
2418 struct dentry *error = ERR_PTR(-ENOENT);
2419
2420 inode = proc_pid_make_inode(dir->i_sb, task);
2421 if (!inode)
2422 goto out;
2423 ei = PROC_I(inode);
2424 ei->fd = fd;
2425 inode->i_mode = S_IFREG | S_IRUSR;
2426 inode->i_fop = &proc_fdinfo_file_operations;
2427 d_set_d_op(dentry, &tid_fd_dentry_operations);
2428 d_add(dentry, inode);
2429 /* Close the race of the process dying before we return the dentry */
2430 if (tid_fd_revalidate(dentry, NULL))
2431 error = NULL;
2432
2433 out:
2434 return error;
2435 }
2436
2437 static struct dentry *proc_lookupfdinfo(struct inode *dir,
2438 struct dentry *dentry,
2439 struct nameidata *nd)
2440 {
2441 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2442 }
2443
2444 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2445 {
2446 return proc_readfd_common(filp, dirent, filldir,
2447 proc_fdinfo_instantiate);
2448 }
2449
2450 static const struct file_operations proc_fdinfo_operations = {
2451 .read = generic_read_dir,
2452 .readdir = proc_readfdinfo,
2453 .llseek = default_llseek,
2454 };
2455
2456 /*
2457 * proc directories can do almost nothing..
2458 */
2459 static const struct inode_operations proc_fdinfo_inode_operations = {
2460 .lookup = proc_lookupfdinfo,
2461 .setattr = proc_setattr,
2462 };
2463
2464
2465 static struct dentry *proc_pident_instantiate(struct inode *dir,
2466 struct dentry *dentry, struct task_struct *task, const void *ptr)
2467 {
2468 const struct pid_entry *p = ptr;
2469 struct inode *inode;
2470 struct proc_inode *ei;
2471 struct dentry *error = ERR_PTR(-ENOENT);
2472
2473 inode = proc_pid_make_inode(dir->i_sb, task);
2474 if (!inode)
2475 goto out;
2476
2477 ei = PROC_I(inode);
2478 inode->i_mode = p->mode;
2479 if (S_ISDIR(inode->i_mode))
2480 set_nlink(inode, 2); /* Use getattr to fix if necessary */
2481 if (p->iop)
2482 inode->i_op = p->iop;
2483 if (p->fop)
2484 inode->i_fop = p->fop;
2485 ei->op = p->op;
2486 d_set_d_op(dentry, &pid_dentry_operations);
2487 d_add(dentry, inode);
2488 /* Close the race of the process dying before we return the dentry */
2489 if (pid_revalidate(dentry, NULL))
2490 error = NULL;
2491 out:
2492 return error;
2493 }
2494
2495 static struct dentry *proc_pident_lookup(struct inode *dir,
2496 struct dentry *dentry,
2497 const struct pid_entry *ents,
2498 unsigned int nents)
2499 {
2500 struct dentry *error;
2501 struct task_struct *task = get_proc_task(dir);
2502 const struct pid_entry *p, *last;
2503
2504 error = ERR_PTR(-ENOENT);
2505
2506 if (!task)
2507 goto out_no_task;
2508
2509 /*
2510 * Yes, it does not scale. And it should not. Don't add
2511 * new entries into /proc/<tgid>/ without very good reasons.
2512 */
2513 last = &ents[nents - 1];
2514 for (p = ents; p <= last; p++) {
2515 if (p->len != dentry->d_name.len)
2516 continue;
2517 if (!memcmp(dentry->d_name.name, p->name, p->len))
2518 break;
2519 }
2520 if (p > last)
2521 goto out;
2522
2523 error = proc_pident_instantiate(dir, dentry, task, p);
2524 out:
2525 put_task_struct(task);
2526 out_no_task:
2527 return error;
2528 }
2529
2530 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2531 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2532 {
2533 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2534 proc_pident_instantiate, task, p);
2535 }
2536
2537 static int proc_pident_readdir(struct file *filp,
2538 void *dirent, filldir_t filldir,
2539 const struct pid_entry *ents, unsigned int nents)
2540 {
2541 int i;
2542 struct dentry *dentry = filp->f_path.dentry;
2543 struct inode *inode = dentry->d_inode;
2544 struct task_struct *task = get_proc_task(inode);
2545 const struct pid_entry *p, *last;
2546 ino_t ino;
2547 int ret;
2548
2549 ret = -ENOENT;
2550 if (!task)
2551 goto out_no_task;
2552
2553 ret = 0;
2554 i = filp->f_pos;
2555 switch (i) {
2556 case 0:
2557 ino = inode->i_ino;
2558 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2559 goto out;
2560 i++;
2561 filp->f_pos++;
2562 /* fall through */
2563 case 1:
2564 ino = parent_ino(dentry);
2565 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2566 goto out;
2567 i++;
2568 filp->f_pos++;
2569 /* fall through */
2570 default:
2571 i -= 2;
2572 if (i >= nents) {
2573 ret = 1;
2574 goto out;
2575 }
2576 p = ents + i;
2577 last = &ents[nents - 1];
2578 while (p <= last) {
2579 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2580 goto out;
2581 filp->f_pos++;
2582 p++;
2583 }
2584 }
2585
2586 ret = 1;
2587 out:
2588 put_task_struct(task);
2589 out_no_task:
2590 return ret;
2591 }
2592
2593 #ifdef CONFIG_SECURITY
2594 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2595 size_t count, loff_t *ppos)
2596 {
2597 struct inode * inode = file->f_path.dentry->d_inode;
2598 char *p = NULL;
2599 ssize_t length;
2600 struct task_struct *task = get_proc_task(inode);
2601
2602 if (!task)
2603 return -ESRCH;
2604
2605 length = security_getprocattr(task,
2606 (char*)file->f_path.dentry->d_name.name,
2607 &p);
2608 put_task_struct(task);
2609 if (length > 0)
2610 length = simple_read_from_buffer(buf, count, ppos, p, length);
2611 kfree(p);
2612 return length;
2613 }
2614
2615 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2616 size_t count, loff_t *ppos)
2617 {
2618 struct inode * inode = file->f_path.dentry->d_inode;
2619 char *page;
2620 ssize_t length;
2621 struct task_struct *task = get_proc_task(inode);
2622
2623 length = -ESRCH;
2624 if (!task)
2625 goto out_no_task;
2626 if (count > PAGE_SIZE)
2627 count = PAGE_SIZE;
2628
2629 /* No partial writes. */
2630 length = -EINVAL;
2631 if (*ppos != 0)
2632 goto out;
2633
2634 length = -ENOMEM;
2635 page = (char*)__get_free_page(GFP_TEMPORARY);
2636 if (!page)
2637 goto out;
2638
2639 length = -EFAULT;
2640 if (copy_from_user(page, buf, count))
2641 goto out_free;
2642
2643 /* Guard against adverse ptrace interaction */
2644 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2645 if (length < 0)
2646 goto out_free;
2647
2648 length = security_setprocattr(task,
2649 (char*)file->f_path.dentry->d_name.name,
2650 (void*)page, count);
2651 mutex_unlock(&task->signal->cred_guard_mutex);
2652 out_free:
2653 free_page((unsigned long) page);
2654 out:
2655 put_task_struct(task);
2656 out_no_task:
2657 return length;
2658 }
2659
2660 static const struct file_operations proc_pid_attr_operations = {
2661 .read = proc_pid_attr_read,
2662 .write = proc_pid_attr_write,
2663 .llseek = generic_file_llseek,
2664 };
2665
2666 static const struct pid_entry attr_dir_stuff[] = {
2667 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2668 REG("prev", S_IRUGO, proc_pid_attr_operations),
2669 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2670 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2671 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2672 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2673 };
2674
2675 static int proc_attr_dir_readdir(struct file * filp,
2676 void * dirent, filldir_t filldir)
2677 {
2678 return proc_pident_readdir(filp,dirent,filldir,
2679 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2680 }
2681
2682 static const struct file_operations proc_attr_dir_operations = {
2683 .read = generic_read_dir,
2684 .readdir = proc_attr_dir_readdir,
2685 .llseek = default_llseek,
2686 };
2687
2688 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2689 struct dentry *dentry, struct nameidata *nd)
2690 {
2691 return proc_pident_lookup(dir, dentry,
2692 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2693 }
2694
2695 static const struct inode_operations proc_attr_dir_inode_operations = {
2696 .lookup = proc_attr_dir_lookup,
2697 .getattr = pid_getattr,
2698 .setattr = proc_setattr,
2699 };
2700
2701 #endif
2702
2703 #ifdef CONFIG_ELF_CORE
2704 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2705 size_t count, loff_t *ppos)
2706 {
2707 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2708 struct mm_struct *mm;
2709 char buffer[PROC_NUMBUF];
2710 size_t len;
2711 int ret;
2712
2713 if (!task)
2714 return -ESRCH;
2715
2716 ret = 0;
2717 mm = get_task_mm(task);
2718 if (mm) {
2719 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2720 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2721 MMF_DUMP_FILTER_SHIFT));
2722 mmput(mm);
2723 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2724 }
2725
2726 put_task_struct(task);
2727
2728 return ret;
2729 }
2730
2731 static ssize_t proc_coredump_filter_write(struct file *file,
2732 const char __user *buf,
2733 size_t count,
2734 loff_t *ppos)
2735 {
2736 struct task_struct *task;
2737 struct mm_struct *mm;
2738 char buffer[PROC_NUMBUF], *end;
2739 unsigned int val;
2740 int ret;
2741 int i;
2742 unsigned long mask;
2743
2744 ret = -EFAULT;
2745 memset(buffer, 0, sizeof(buffer));
2746 if (count > sizeof(buffer) - 1)
2747 count = sizeof(buffer) - 1;
2748 if (copy_from_user(buffer, buf, count))
2749 goto out_no_task;
2750
2751 ret = -EINVAL;
2752 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2753 if (*end == '\n')
2754 end++;
2755 if (end - buffer == 0)
2756 goto out_no_task;
2757
2758 ret = -ESRCH;
2759 task = get_proc_task(file->f_dentry->d_inode);
2760 if (!task)
2761 goto out_no_task;
2762
2763 ret = end - buffer;
2764 mm = get_task_mm(task);
2765 if (!mm)
2766 goto out_no_mm;
2767
2768 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2769 if (val & mask)
2770 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2771 else
2772 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2773 }
2774
2775 mmput(mm);
2776 out_no_mm:
2777 put_task_struct(task);
2778 out_no_task:
2779 return ret;
2780 }
2781
2782 static const struct file_operations proc_coredump_filter_operations = {
2783 .read = proc_coredump_filter_read,
2784 .write = proc_coredump_filter_write,
2785 .llseek = generic_file_llseek,
2786 };
2787 #endif
2788
2789 /*
2790 * /proc/self:
2791 */
2792 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2793 int buflen)
2794 {
2795 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2796 pid_t tgid = task_tgid_nr_ns(current, ns);
2797 char tmp[PROC_NUMBUF];
2798 if (!tgid)
2799 return -ENOENT;
2800 sprintf(tmp, "%d", tgid);
2801 return vfs_readlink(dentry,buffer,buflen,tmp);
2802 }
2803
2804 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2805 {
2806 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2807 pid_t tgid = task_tgid_nr_ns(current, ns);
2808 char *name = ERR_PTR(-ENOENT);
2809 if (tgid) {
2810 name = __getname();
2811 if (!name)
2812 name = ERR_PTR(-ENOMEM);
2813 else
2814 sprintf(name, "%d", tgid);
2815 }
2816 nd_set_link(nd, name);
2817 return NULL;
2818 }
2819
2820 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2821 void *cookie)
2822 {
2823 char *s = nd_get_link(nd);
2824 if (!IS_ERR(s))
2825 __putname(s);
2826 }
2827
2828 static const struct inode_operations proc_self_inode_operations = {
2829 .readlink = proc_self_readlink,
2830 .follow_link = proc_self_follow_link,
2831 .put_link = proc_self_put_link,
2832 };
2833
2834 /*
2835 * proc base
2836 *
2837 * These are the directory entries in the root directory of /proc
2838 * that properly belong to the /proc filesystem, as they describe
2839 * describe something that is process related.
2840 */
2841 static const struct pid_entry proc_base_stuff[] = {
2842 NOD("self", S_IFLNK|S_IRWXUGO,
2843 &proc_self_inode_operations, NULL, {}),
2844 };
2845
2846 static struct dentry *proc_base_instantiate(struct inode *dir,
2847 struct dentry *dentry, struct task_struct *task, const void *ptr)
2848 {
2849 const struct pid_entry *p = ptr;
2850 struct inode *inode;
2851 struct proc_inode *ei;
2852 struct dentry *error;
2853
2854 /* Allocate the inode */
2855 error = ERR_PTR(-ENOMEM);
2856 inode = new_inode(dir->i_sb);
2857 if (!inode)
2858 goto out;
2859
2860 /* Initialize the inode */
2861 ei = PROC_I(inode);
2862 inode->i_ino = get_next_ino();
2863 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2864
2865 /*
2866 * grab the reference to the task.
2867 */
2868 ei->pid = get_task_pid(task, PIDTYPE_PID);
2869 if (!ei->pid)
2870 goto out_iput;
2871
2872 inode->i_mode = p->mode;
2873 if (S_ISDIR(inode->i_mode))
2874 set_nlink(inode, 2);
2875 if (S_ISLNK(inode->i_mode))
2876 inode->i_size = 64;
2877 if (p->iop)
2878 inode->i_op = p->iop;
2879 if (p->fop)
2880 inode->i_fop = p->fop;
2881 ei->op = p->op;
2882 d_add(dentry, inode);
2883 error = NULL;
2884 out:
2885 return error;
2886 out_iput:
2887 iput(inode);
2888 goto out;
2889 }
2890
2891 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2892 {
2893 struct dentry *error;
2894 struct task_struct *task = get_proc_task(dir);
2895 const struct pid_entry *p, *last;
2896
2897 error = ERR_PTR(-ENOENT);
2898
2899 if (!task)
2900 goto out_no_task;
2901
2902 /* Lookup the directory entry */
2903 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2904 for (p = proc_base_stuff; p <= last; p++) {
2905 if (p->len != dentry->d_name.len)
2906 continue;
2907 if (!memcmp(dentry->d_name.name, p->name, p->len))
2908 break;
2909 }
2910 if (p > last)
2911 goto out;
2912
2913 error = proc_base_instantiate(dir, dentry, task, p);
2914
2915 out:
2916 put_task_struct(task);
2917 out_no_task:
2918 return error;
2919 }
2920
2921 static int proc_base_fill_cache(struct file *filp, void *dirent,
2922 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2923 {
2924 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2925 proc_base_instantiate, task, p);
2926 }
2927
2928 #ifdef CONFIG_TASK_IO_ACCOUNTING
2929 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2930 {
2931 struct task_io_accounting acct = task->ioac;
2932 unsigned long flags;
2933 int result;
2934
2935 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2936 if (result)
2937 return result;
2938
2939 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2940 result = -EACCES;
2941 goto out_unlock;
2942 }
2943
2944 if (whole && lock_task_sighand(task, &flags)) {
2945 struct task_struct *t = task;
2946
2947 task_io_accounting_add(&acct, &task->signal->ioac);
2948 while_each_thread(task, t)
2949 task_io_accounting_add(&acct, &t->ioac);
2950
2951 unlock_task_sighand(task, &flags);
2952 }
2953 result = sprintf(buffer,
2954 "rchar: %llu\n"
2955 "wchar: %llu\n"
2956 "syscr: %llu\n"
2957 "syscw: %llu\n"
2958 "read_bytes: %llu\n"
2959 "write_bytes: %llu\n"
2960 "cancelled_write_bytes: %llu\n",
2961 (unsigned long long)acct.rchar,
2962 (unsigned long long)acct.wchar,
2963 (unsigned long long)acct.syscr,
2964 (unsigned long long)acct.syscw,
2965 (unsigned long long)acct.read_bytes,
2966 (unsigned long long)acct.write_bytes,
2967 (unsigned long long)acct.cancelled_write_bytes);
2968 out_unlock:
2969 mutex_unlock(&task->signal->cred_guard_mutex);
2970 return result;
2971 }
2972
2973 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2974 {
2975 return do_io_accounting(task, buffer, 0);
2976 }
2977
2978 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2979 {
2980 return do_io_accounting(task, buffer, 1);
2981 }
2982 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2983
2984 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2985 struct pid *pid, struct task_struct *task)
2986 {
2987 int err = lock_trace(task);
2988 if (!err) {
2989 seq_printf(m, "%08x\n", task->personality);
2990 unlock_trace(task);
2991 }
2992 return err;
2993 }
2994
2995 /*
2996 * Thread groups
2997 */
2998 static const struct file_operations proc_task_operations;
2999 static const struct inode_operations proc_task_inode_operations;
3000
3001 static const struct pid_entry tgid_base_stuff[] = {
3002 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3003 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3004 #ifdef CONFIG_CHECKPOINT_RESTORE
3005 DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3006 #endif
3007 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3008 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3009 #ifdef CONFIG_NET
3010 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3011 #endif
3012 REG("environ", S_IRUSR, proc_environ_operations),
3013 INF("auxv", S_IRUSR, proc_pid_auxv),
3014 ONE("status", S_IRUGO, proc_pid_status),
3015 ONE("personality", S_IRUGO, proc_pid_personality),
3016 INF("limits", S_IRUGO, proc_pid_limits),
3017 #ifdef CONFIG_SCHED_DEBUG
3018 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3019 #endif
3020 #ifdef CONFIG_SCHED_AUTOGROUP
3021 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3022 #endif
3023 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3024 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3025 INF("syscall", S_IRUGO, proc_pid_syscall),
3026 #endif
3027 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3028 ONE("stat", S_IRUGO, proc_tgid_stat),
3029 ONE("statm", S_IRUGO, proc_pid_statm),
3030 REG("maps", S_IRUGO, proc_maps_operations),
3031 #ifdef CONFIG_NUMA
3032 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3033 #endif
3034 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3035 LNK("cwd", proc_cwd_link),
3036 LNK("root", proc_root_link),
3037 LNK("exe", proc_exe_link),
3038 REG("mounts", S_IRUGO, proc_mounts_operations),
3039 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3040 REG("mountstats", S_IRUSR, proc_mountstats_operations),
3041 #ifdef CONFIG_PROC_PAGE_MONITOR
3042 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3043 REG("smaps", S_IRUGO, proc_smaps_operations),
3044 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3045 #endif
3046 #ifdef CONFIG_SECURITY
3047 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3048 #endif
3049 #ifdef CONFIG_KALLSYMS
3050 INF("wchan", S_IRUGO, proc_pid_wchan),
3051 #endif
3052 #ifdef CONFIG_STACKTRACE
3053 ONE("stack", S_IRUGO, proc_pid_stack),
3054 #endif
3055 #ifdef CONFIG_SCHEDSTATS
3056 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3057 #endif
3058 #ifdef CONFIG_LATENCYTOP
3059 REG("latency", S_IRUGO, proc_lstats_operations),
3060 #endif
3061 #ifdef CONFIG_PROC_PID_CPUSET
3062 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3063 #endif
3064 #ifdef CONFIG_CGROUPS
3065 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3066 #endif
3067 INF("oom_score", S_IRUGO, proc_oom_score),
3068 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3069 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3070 #ifdef CONFIG_AUDITSYSCALL
3071 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3072 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3073 #endif
3074 #ifdef CONFIG_FAULT_INJECTION
3075 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3076 #endif
3077 #ifdef CONFIG_ELF_CORE
3078 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3079 #endif
3080 #ifdef CONFIG_TASK_IO_ACCOUNTING
3081 INF("io", S_IRUSR, proc_tgid_io_accounting),
3082 #endif
3083 #ifdef CONFIG_HARDWALL
3084 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3085 #endif
3086 };
3087
3088 static int proc_tgid_base_readdir(struct file * filp,
3089 void * dirent, filldir_t filldir)
3090 {
3091 return proc_pident_readdir(filp,dirent,filldir,
3092 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
3093 }
3094
3095 static const struct file_operations proc_tgid_base_operations = {
3096 .read = generic_read_dir,
3097 .readdir = proc_tgid_base_readdir,
3098 .llseek = default_llseek,
3099 };
3100
3101 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3102 return proc_pident_lookup(dir, dentry,
3103 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3104 }
3105
3106 static const struct inode_operations proc_tgid_base_inode_operations = {
3107 .lookup = proc_tgid_base_lookup,
3108 .getattr = pid_getattr,
3109 .setattr = proc_setattr,
3110 .permission = proc_pid_permission,
3111 };
3112
3113 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
3114 {
3115 struct dentry *dentry, *leader, *dir;
3116 char buf[PROC_NUMBUF];
3117 struct qstr name;
3118
3119 name.name = buf;
3120 name.len = snprintf(buf, sizeof(buf), "%d", pid);
3121 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
3122 if (dentry) {
3123 shrink_dcache_parent(dentry);
3124 d_drop(dentry);
3125 dput(dentry);
3126 }
3127
3128 name.name = buf;
3129 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
3130 leader = d_hash_and_lookup(mnt->mnt_root, &name);
3131 if (!leader)
3132 goto out;
3133
3134 name.name = "task";
3135 name.len = strlen(name.name);
3136 dir = d_hash_and_lookup(leader, &name);
3137 if (!dir)
3138 goto out_put_leader;
3139
3140 name.name = buf;
3141 name.len = snprintf(buf, sizeof(buf), "%d", pid);
3142 dentry = d_hash_and_lookup(dir, &name);
3143 if (dentry) {
3144 shrink_dcache_parent(dentry);
3145 d_drop(dentry);
3146 dput(dentry);
3147 }
3148
3149 dput(dir);
3150 out_put_leader:
3151 dput(leader);
3152 out:
3153 return;
3154 }
3155
3156 /**
3157 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
3158 * @task: task that should be flushed.
3159 *
3160 * When flushing dentries from proc, one needs to flush them from global
3161 * proc (proc_mnt) and from all the namespaces' procs this task was seen
3162 * in. This call is supposed to do all of this job.
3163 *
3164 * Looks in the dcache for
3165 * /proc/@pid
3166 * /proc/@tgid/task/@pid
3167 * if either directory is present flushes it and all of it'ts children
3168 * from the dcache.
3169 *
3170 * It is safe and reasonable to cache /proc entries for a task until
3171 * that task exits. After that they just clog up the dcache with
3172 * useless entries, possibly causing useful dcache entries to be
3173 * flushed instead. This routine is proved to flush those useless
3174 * dcache entries at process exit time.
3175 *
3176 * NOTE: This routine is just an optimization so it does not guarantee
3177 * that no dcache entries will exist at process exit time it
3178 * just makes it very unlikely that any will persist.
3179 */
3180
3181 void proc_flush_task(struct task_struct *task)
3182 {
3183 int i;
3184 struct pid *pid, *tgid;
3185 struct upid *upid;
3186
3187 pid = task_pid(task);
3188 tgid = task_tgid(task);
3189
3190 for (i = 0; i <= pid->level; i++) {
3191 upid = &pid->numbers[i];
3192 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
3193 tgid->numbers[i].nr);
3194 }
3195
3196 upid = &pid->numbers[pid->level];
3197 if (upid->nr == 1)
3198 pid_ns_release_proc(upid->ns);
3199 }
3200
3201 static struct dentry *proc_pid_instantiate(struct inode *dir,
3202 struct dentry * dentry,
3203 struct task_struct *task, const void *ptr)
3204 {
3205 struct dentry *error = ERR_PTR(-ENOENT);
3206 struct inode *inode;
3207
3208 inode = proc_pid_make_inode(dir->i_sb, task);
3209 if (!inode)
3210 goto out;
3211
3212 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3213 inode->i_op = &proc_tgid_base_inode_operations;
3214 inode->i_fop = &proc_tgid_base_operations;
3215 inode->i_flags|=S_IMMUTABLE;
3216
3217 set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
3218 ARRAY_SIZE(tgid_base_stuff)));
3219
3220 d_set_d_op(dentry, &pid_dentry_operations);
3221
3222 d_add(dentry, inode);
3223 /* Close the race of the process dying before we return the dentry */
3224 if (pid_revalidate(dentry, NULL))
3225 error = NULL;
3226 out:
3227 return error;
3228 }
3229
3230 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3231 {
3232 struct dentry *result;
3233 struct task_struct *task;
3234 unsigned tgid;
3235 struct pid_namespace *ns;
3236
3237 result = proc_base_lookup(dir, dentry);
3238 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
3239 goto out;
3240
3241 tgid = name_to_int(dentry);
3242 if (tgid == ~0U)
3243 goto out;
3244
3245 ns = dentry->d_sb->s_fs_info;
3246 rcu_read_lock();
3247 task = find_task_by_pid_ns(tgid, ns);
3248 if (task)
3249 get_task_struct(task);
3250 rcu_read_unlock();
3251 if (!task)
3252 goto out;
3253
3254 result = proc_pid_instantiate(dir, dentry, task, NULL);
3255 put_task_struct(task);
3256 out:
3257 return result;
3258 }
3259
3260 /*
3261 * Find the first task with tgid >= tgid
3262 *
3263 */
3264 struct tgid_iter {
3265 unsigned int tgid;
3266 struct task_struct *task;
3267 };
3268 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3269 {
3270 struct pid *pid;
3271
3272 if (iter.task)
3273 put_task_struct(iter.task);
3274 rcu_read_lock();
3275 retry:
3276 iter.task = NULL;
3277 pid = find_ge_pid(iter.tgid, ns);
3278 if (pid) {
3279 iter.tgid = pid_nr_ns(pid, ns);
3280 iter.task = pid_task(pid, PIDTYPE_PID);
3281 /* What we to know is if the pid we have find is the
3282 * pid of a thread_group_leader. Testing for task
3283 * being a thread_group_leader is the obvious thing
3284 * todo but there is a window when it fails, due to
3285 * the pid transfer logic in de_thread.
3286 *
3287 * So we perform the straight forward test of seeing
3288 * if the pid we have found is the pid of a thread
3289 * group leader, and don't worry if the task we have
3290 * found doesn't happen to be a thread group leader.
3291 * As we don't care in the case of readdir.
3292 */
3293 if (!iter.task || !has_group_leader_pid(iter.task)) {
3294 iter.tgid += 1;
3295 goto retry;
3296 }
3297 get_task_struct(iter.task);
3298 }
3299 rcu_read_unlock();
3300 return iter;
3301 }
3302
3303 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3304
3305 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3306 struct tgid_iter iter)
3307 {
3308 char name[PROC_NUMBUF];
3309 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3310 return proc_fill_cache(filp, dirent, filldir, name, len,
3311 proc_pid_instantiate, iter.task, NULL);
3312 }
3313
3314 static int fake_filldir(void *buf, const char *name, int namelen,
3315 loff_t offset, u64 ino, unsigned d_type)
3316 {
3317 return 0;
3318 }
3319
3320 /* for the /proc/ directory itself, after non-process stuff has been done */
3321 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3322 {
3323 unsigned int nr;
3324 struct task_struct *reaper;
3325 struct tgid_iter iter;
3326 struct pid_namespace *ns;
3327 filldir_t __filldir;
3328
3329 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3330 goto out_no_task;
3331 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3332
3333 reaper = get_proc_task(filp->f_path.dentry->d_inode);
3334 if (!reaper)
3335 goto out_no_task;
3336
3337 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3338 const struct pid_entry *p = &proc_base_stuff[nr];
3339 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3340 goto out;
3341 }
3342
3343 ns = filp->f_dentry->d_sb->s_fs_info;
3344 iter.task = NULL;
3345 iter.tgid = filp->f_pos - TGID_OFFSET;
3346 for (iter = next_tgid(ns, iter);
3347 iter.task;
3348 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3349 if (has_pid_permissions(ns, iter.task, 2))
3350 __filldir = filldir;
3351 else
3352 __filldir = fake_filldir;
3353
3354 filp->f_pos = iter.tgid + TGID_OFFSET;
3355 if (proc_pid_fill_cache(filp, dirent, __filldir, iter) < 0) {
3356 put_task_struct(iter.task);
3357 goto out;
3358 }
3359 }
3360 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3361 out:
3362 put_task_struct(reaper);
3363 out_no_task:
3364 return 0;
3365 }
3366
3367 /*
3368 * Tasks
3369 */
3370 static const struct pid_entry tid_base_stuff[] = {
3371 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3372 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3373 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3374 REG("environ", S_IRUSR, proc_environ_operations),
3375 INF("auxv", S_IRUSR, proc_pid_auxv),
3376 ONE("status", S_IRUGO, proc_pid_status),
3377 ONE("personality", S_IRUGO, proc_pid_personality),
3378 INF("limits", S_IRUGO, proc_pid_limits),
3379 #ifdef CONFIG_SCHED_DEBUG
3380 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3381 #endif
3382 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3383 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3384 INF("syscall", S_IRUGO, proc_pid_syscall),
3385 #endif
3386 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3387 ONE("stat", S_IRUGO, proc_tid_stat),
3388 ONE("statm", S_IRUGO, proc_pid_statm),
3389 REG("maps", S_IRUGO, proc_maps_operations),
3390 #ifdef CONFIG_NUMA
3391 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3392 #endif
3393 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3394 LNK("cwd", proc_cwd_link),
3395 LNK("root", proc_root_link),
3396 LNK("exe", proc_exe_link),
3397 REG("mounts", S_IRUGO, proc_mounts_operations),
3398 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3399 #ifdef CONFIG_PROC_PAGE_MONITOR
3400 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3401 REG("smaps", S_IRUGO, proc_smaps_operations),
3402 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3403 #endif
3404 #ifdef CONFIG_SECURITY
3405 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3406 #endif
3407 #ifdef CONFIG_KALLSYMS
3408 INF("wchan", S_IRUGO, proc_pid_wchan),
3409 #endif
3410 #ifdef CONFIG_STACKTRACE
3411 ONE("stack", S_IRUGO, proc_pid_stack),
3412 #endif
3413 #ifdef CONFIG_SCHEDSTATS
3414 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3415 #endif
3416 #ifdef CONFIG_LATENCYTOP
3417 REG("latency", S_IRUGO, proc_lstats_operations),
3418 #endif
3419 #ifdef CONFIG_PROC_PID_CPUSET
3420 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3421 #endif
3422 #ifdef CONFIG_CGROUPS
3423 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3424 #endif
3425 INF("oom_score", S_IRUGO, proc_oom_score),
3426 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3427 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3428 #ifdef CONFIG_AUDITSYSCALL
3429 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3430 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3431 #endif
3432 #ifdef CONFIG_FAULT_INJECTION
3433 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3434 #endif
3435 #ifdef CONFIG_TASK_IO_ACCOUNTING
3436 INF("io", S_IRUSR, proc_tid_io_accounting),
3437 #endif
3438 #ifdef CONFIG_HARDWALL
3439 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3440 #endif
3441 };
3442
3443 static int proc_tid_base_readdir(struct file * filp,
3444 void * dirent, filldir_t filldir)
3445 {
3446 return proc_pident_readdir(filp,dirent,filldir,
3447 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3448 }
3449
3450 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3451 return proc_pident_lookup(dir, dentry,
3452 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3453 }
3454
3455 static const struct file_operations proc_tid_base_operations = {
3456 .read = generic_read_dir,
3457 .readdir = proc_tid_base_readdir,
3458 .llseek = default_llseek,
3459 };
3460
3461 static const struct inode_operations proc_tid_base_inode_operations = {
3462 .lookup = proc_tid_base_lookup,
3463 .getattr = pid_getattr,
3464 .setattr = proc_setattr,
3465 };
3466
3467 static struct dentry *proc_task_instantiate(struct inode *dir,
3468 struct dentry *dentry, struct task_struct *task, const void *ptr)
3469 {
3470 struct dentry *error = ERR_PTR(-ENOENT);
3471 struct inode *inode;
3472 inode = proc_pid_make_inode(dir->i_sb, task);
3473
3474 if (!inode)
3475 goto out;
3476 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3477 inode->i_op = &proc_tid_base_inode_operations;
3478 inode->i_fop = &proc_tid_base_operations;
3479 inode->i_flags|=S_IMMUTABLE;
3480
3481 set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
3482 ARRAY_SIZE(tid_base_stuff)));
3483
3484 d_set_d_op(dentry, &pid_dentry_operations);
3485
3486 d_add(dentry, inode);
3487 /* Close the race of the process dying before we return the dentry */
3488 if (pid_revalidate(dentry, NULL))
3489 error = NULL;
3490 out:
3491 return error;
3492 }
3493
3494 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3495 {
3496 struct dentry *result = ERR_PTR(-ENOENT);
3497 struct task_struct *task;
3498 struct task_struct *leader = get_proc_task(dir);
3499 unsigned tid;
3500 struct pid_namespace *ns;
3501
3502 if (!leader)
3503 goto out_no_task;
3504
3505 tid = name_to_int(dentry);
3506 if (tid == ~0U)
3507 goto out;
3508
3509 ns = dentry->d_sb->s_fs_info;
3510 rcu_read_lock();
3511 task = find_task_by_pid_ns(tid, ns);
3512 if (task)
3513 get_task_struct(task);
3514 rcu_read_unlock();
3515 if (!task)
3516 goto out;
3517 if (!same_thread_group(leader, task))
3518 goto out_drop_task;
3519
3520 result = proc_task_instantiate(dir, dentry, task, NULL);
3521 out_drop_task:
3522 put_task_struct(task);
3523 out:
3524 put_task_struct(leader);
3525 out_no_task:
3526 return result;
3527 }
3528
3529 /*
3530 * Find the first tid of a thread group to return to user space.
3531 *
3532 * Usually this is just the thread group leader, but if the users
3533 * buffer was too small or there was a seek into the middle of the
3534 * directory we have more work todo.
3535 *
3536 * In the case of a short read we start with find_task_by_pid.
3537 *
3538 * In the case of a seek we start with the leader and walk nr
3539 * threads past it.
3540 */
3541 static struct task_struct *first_tid(struct task_struct *leader,
3542 int tid, int nr, struct pid_namespace *ns)
3543 {
3544 struct task_struct *pos;
3545
3546 rcu_read_lock();
3547 /* Attempt to start with the pid of a thread */
3548 if (tid && (nr > 0)) {
3549 pos = find_task_by_pid_ns(tid, ns);
3550 if (pos && (pos->group_leader == leader))
3551 goto found;
3552 }
3553
3554 /* If nr exceeds the number of threads there is nothing todo */
3555 pos = NULL;
3556 if (nr && nr >= get_nr_threads(leader))
3557 goto out;
3558
3559 /* If we haven't found our starting place yet start
3560 * with the leader and walk nr threads forward.
3561 */
3562 for (pos = leader; nr > 0; --nr) {
3563 pos = next_thread(pos);
3564 if (pos == leader) {
3565 pos = NULL;
3566 goto out;
3567 }
3568 }
3569 found:
3570 get_task_struct(pos);
3571 out:
3572 rcu_read_unlock();
3573 return pos;
3574 }
3575
3576 /*
3577 * Find the next thread in the thread list.
3578 * Return NULL if there is an error or no next thread.
3579 *
3580 * The reference to the input task_struct is released.
3581 */
3582 static struct task_struct *next_tid(struct task_struct *start)
3583 {
3584 struct task_struct *pos = NULL;
3585 rcu_read_lock();
3586 if (pid_alive(start)) {
3587 pos = next_thread(start);
3588 if (thread_group_leader(pos))
3589 pos = NULL;
3590 else
3591 get_task_struct(pos);
3592 }
3593 rcu_read_unlock();
3594 put_task_struct(start);
3595 return pos;
3596 }
3597
3598 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3599 struct task_struct *task, int tid)
3600 {
3601 char name[PROC_NUMBUF];
3602 int len = snprintf(name, sizeof(name), "%d", tid);
3603 return proc_fill_cache(filp, dirent, filldir, name, len,
3604 proc_task_instantiate, task, NULL);
3605 }
3606
3607 /* for the /proc/TGID/task/ directories */
3608 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3609 {
3610 struct dentry *dentry = filp->f_path.dentry;
3611 struct inode *inode = dentry->d_inode;
3612 struct task_struct *leader = NULL;
3613 struct task_struct *task;
3614 int retval = -ENOENT;
3615 ino_t ino;
3616 int tid;
3617 struct pid_namespace *ns;
3618
3619 task = get_proc_task(inode);
3620 if (!task)
3621 goto out_no_task;
3622 rcu_read_lock();
3623 if (pid_alive(task)) {
3624 leader = task->group_leader;
3625 get_task_struct(leader);
3626 }
3627 rcu_read_unlock();
3628 put_task_struct(task);
3629 if (!leader)
3630 goto out_no_task;
3631 retval = 0;
3632
3633 switch ((unsigned long)filp->f_pos) {
3634 case 0:
3635 ino = inode->i_ino;
3636 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3637 goto out;
3638 filp->f_pos++;
3639 /* fall through */
3640 case 1:
3641 ino = parent_ino(dentry);
3642 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3643 goto out;
3644 filp->f_pos++;
3645 /* fall through */
3646 }
3647
3648 /* f_version caches the tgid value that the last readdir call couldn't
3649 * return. lseek aka telldir automagically resets f_version to 0.
3650 */
3651 ns = filp->f_dentry->d_sb->s_fs_info;
3652 tid = (int)filp->f_version;
3653 filp->f_version = 0;
3654 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3655 task;
3656 task = next_tid(task), filp->f_pos++) {
3657 tid = task_pid_nr_ns(task, ns);
3658 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3659 /* returning this tgid failed, save it as the first
3660 * pid for the next readir call */
3661 filp->f_version = (u64)tid;
3662 put_task_struct(task);
3663 break;
3664 }
3665 }
3666 out:
3667 put_task_struct(leader);
3668 out_no_task:
3669 return retval;
3670 }
3671
3672 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3673 {
3674 struct inode *inode = dentry->d_inode;
3675 struct task_struct *p = get_proc_task(inode);
3676 generic_fillattr(inode, stat);
3677
3678 if (p) {
3679 stat->nlink += get_nr_threads(p);
3680 put_task_struct(p);
3681 }
3682
3683 return 0;
3684 }
3685
3686 static const struct inode_operations proc_task_inode_operations = {
3687 .lookup = proc_task_lookup,
3688 .getattr = proc_task_getattr,
3689 .setattr = proc_setattr,
3690 .permission = proc_pid_permission,
3691 };
3692
3693 static const struct file_operations proc_task_operations = {
3694 .read = generic_read_dir,
3695 .readdir = proc_task_readdir,
3696 .llseek = default_llseek,
3697 };
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree