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Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
[linux-2.6/libata-dev.git] / fs / proc / base.c
blobdc5d5f51f3fe4dc564a19e06cb330d09abc9b6a4
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 "internal.h"
87
88 /* NOTE:
89 * Implementing inode permission operations in /proc is almost
90 * certainly an error. Permission checks need to happen during
91 * each system call not at open time. The reason is that most of
92 * what we wish to check for permissions in /proc varies at runtime.
93 *
94 * The classic example of a problem is opening file descriptors
95 * in /proc for a task before it execs a suid executable.
96 */
97
98 struct pid_entry {
99 char *name;
100 int len;
101 mode_t mode;
102 const struct inode_operations *iop;
103 const struct file_operations *fop;
104 union proc_op op;
105 };
106
107 #define NOD(NAME, MODE, IOP, FOP, OP) { \
108 .name = (NAME), \
109 .len = sizeof(NAME) - 1, \
110 .mode = MODE, \
111 .iop = IOP, \
112 .fop = FOP, \
113 .op = OP, \
114 }
115
116 #define DIR(NAME, MODE, iops, fops) \
117 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
118 #define LNK(NAME, get_link) \
119 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
120 &proc_pid_link_inode_operations, NULL, \
121 { .proc_get_link = get_link } )
122 #define REG(NAME, MODE, fops) \
123 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
124 #define INF(NAME, MODE, read) \
125 NOD(NAME, (S_IFREG|(MODE)), \
126 NULL, &proc_info_file_operations, \
127 { .proc_read = read } )
128 #define ONE(NAME, MODE, show) \
129 NOD(NAME, (S_IFREG|(MODE)), \
130 NULL, &proc_single_file_operations, \
131 { .proc_show = show } )
132
133 /*
134 * Count the number of hardlinks for the pid_entry table, excluding the .
135 * and .. links.
136 */
137 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
138 unsigned int n)
139 {
140 unsigned int i;
141 unsigned int count;
142
143 count = 0;
144 for (i = 0; i < n; ++i) {
145 if (S_ISDIR(entries[i].mode))
146 ++count;
147 }
148
149 return count;
150 }
151
152 static int get_task_root(struct task_struct *task, struct path *root)
153 {
154 int result = -ENOENT;
155
156 task_lock(task);
157 if (task->fs) {
158 get_fs_root(task->fs, root);
159 result = 0;
160 }
161 task_unlock(task);
162 return result;
163 }
164
165 static int proc_cwd_link(struct inode *inode, struct path *path)
166 {
167 struct task_struct *task = get_proc_task(inode);
168 int result = -ENOENT;
169
170 if (task) {
171 task_lock(task);
172 if (task->fs) {
173 get_fs_pwd(task->fs, path);
174 result = 0;
175 }
176 task_unlock(task);
177 put_task_struct(task);
178 }
179 return result;
180 }
181
182 static int proc_root_link(struct inode *inode, struct path *path)
183 {
184 struct task_struct *task = get_proc_task(inode);
185 int result = -ENOENT;
186
187 if (task) {
188 result = get_task_root(task, path);
189 put_task_struct(task);
190 }
191 return result;
192 }
193
194 /*
195 * Return zero if current may access user memory in @task, -error if not.
196 */
197 static int check_mem_permission(struct task_struct *task)
198 {
199 /*
200 * A task can always look at itself, in case it chooses
201 * to use system calls instead of load instructions.
202 */
203 if (task == current)
204 return 0;
205
206 /*
207 * If current is actively ptrace'ing, and would also be
208 * permitted to freshly attach with ptrace now, permit it.
209 */
210 if (task_is_stopped_or_traced(task)) {
211 int match;
212 rcu_read_lock();
213 match = (tracehook_tracer_task(task) == current);
214 rcu_read_unlock();
215 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
216 return 0;
217 }
218
219 /*
220 * Noone else is allowed.
221 */
222 return -EPERM;
223 }
224
225 struct mm_struct *mm_for_maps(struct task_struct *task)
226 {
227 struct mm_struct *mm;
228
229 if (mutex_lock_killable(&task->cred_guard_mutex))
230 return NULL;
231
232 mm = get_task_mm(task);
233 if (mm && mm != current->mm &&
234 !ptrace_may_access(task, PTRACE_MODE_READ)) {
235 mmput(mm);
236 mm = NULL;
237 }
238 mutex_unlock(&task->cred_guard_mutex);
239
240 return mm;
241 }
242
243 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
244 {
245 int res = 0;
246 unsigned int len;
247 struct mm_struct *mm = get_task_mm(task);
248 if (!mm)
249 goto out;
250 if (!mm->arg_end)
251 goto out_mm; /* Shh! No looking before we're done */
252
253 len = mm->arg_end - mm->arg_start;
254
255 if (len > PAGE_SIZE)
256 len = PAGE_SIZE;
257
258 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
259
260 // If the nul at the end of args has been overwritten, then
261 // assume application is using setproctitle(3).
262 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
263 len = strnlen(buffer, res);
264 if (len < res) {
265 res = len;
266 } else {
267 len = mm->env_end - mm->env_start;
268 if (len > PAGE_SIZE - res)
269 len = PAGE_SIZE - res;
270 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
271 res = strnlen(buffer, res);
272 }
273 }
274 out_mm:
275 mmput(mm);
276 out:
277 return res;
278 }
279
280 static int proc_pid_auxv(struct task_struct *task, char *buffer)
281 {
282 int res = 0;
283 struct mm_struct *mm = get_task_mm(task);
284 if (mm) {
285 unsigned int nwords = 0;
286 do {
287 nwords += 2;
288 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
289 res = nwords * sizeof(mm->saved_auxv[0]);
290 if (res > PAGE_SIZE)
291 res = PAGE_SIZE;
292 memcpy(buffer, mm->saved_auxv, res);
293 mmput(mm);
294 }
295 return res;
296 }
297
298
299 #ifdef CONFIG_KALLSYMS
300 /*
301 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
302 * Returns the resolved symbol. If that fails, simply return the address.
303 */
304 static int proc_pid_wchan(struct task_struct *task, char *buffer)
305 {
306 unsigned long wchan;
307 char symname[KSYM_NAME_LEN];
308
309 wchan = get_wchan(task);
310
311 if (lookup_symbol_name(wchan, symname) < 0)
312 if (!ptrace_may_access(task, PTRACE_MODE_READ))
313 return 0;
314 else
315 return sprintf(buffer, "%lu", wchan);
316 else
317 return sprintf(buffer, "%s", symname);
318 }
319 #endif /* CONFIG_KALLSYMS */
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 i;
331
332 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
333 if (!entries)
334 return -ENOMEM;
335
336 trace.nr_entries = 0;
337 trace.max_entries = MAX_STACK_TRACE_DEPTH;
338 trace.entries = entries;
339 trace.skip = 0;
340 save_stack_trace_tsk(task, &trace);
341
342 for (i = 0; i < trace.nr_entries; i++) {
343 seq_printf(m, "[<%p>] %pS\n",
344 (void *)entries[i], (void *)entries[i]);
345 }
346 kfree(entries);
347
348 return 0;
349 }
350 #endif
351
352 #ifdef CONFIG_SCHEDSTATS
353 /*
354 * Provides /proc/PID/schedstat
355 */
356 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
357 {
358 return sprintf(buffer, "%llu %llu %lu\n",
359 (unsigned long long)task->se.sum_exec_runtime,
360 (unsigned long long)task->sched_info.run_delay,
361 task->sched_info.pcount);
362 }
363 #endif
364
365 #ifdef CONFIG_LATENCYTOP
366 static int lstats_show_proc(struct seq_file *m, void *v)
367 {
368 int i;
369 struct inode *inode = m->private;
370 struct task_struct *task = get_proc_task(inode);
371
372 if (!task)
373 return -ESRCH;
374 seq_puts(m, "Latency Top version : v0.1\n");
375 for (i = 0; i < 32; i++) {
376 if (task->latency_record[i].backtrace[0]) {
377 int q;
378 seq_printf(m, "%i %li %li ",
379 task->latency_record[i].count,
380 task->latency_record[i].time,
381 task->latency_record[i].max);
382 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
383 char sym[KSYM_SYMBOL_LEN];
384 char *c;
385 if (!task->latency_record[i].backtrace[q])
386 break;
387 if (task->latency_record[i].backtrace[q] == ULONG_MAX)
388 break;
389 sprint_symbol(sym, task->latency_record[i].backtrace[q]);
390 c = strchr(sym, '+');
391 if (c)
392 *c = 0;
393 seq_printf(m, "%s ", sym);
394 }
395 seq_printf(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
518 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
519 return sprintf(buffer, "running\n");
520
521 if (nr < 0)
522 return sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
523
524 return sprintf(buffer,
525 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
526 nr,
527 args[0], args[1], args[2], args[3], args[4], args[5],
528 sp, pc);
529 }
530 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
531
532 /************************************************************************/
533 /* Here the fs part begins */
534 /************************************************************************/
535
536 /* permission checks */
537 static int proc_fd_access_allowed(struct inode *inode)
538 {
539 struct task_struct *task;
540 int allowed = 0;
541 /* Allow access to a task's file descriptors if it is us or we
542 * may use ptrace attach to the process and find out that
543 * information.
544 */
545 task = get_proc_task(inode);
546 if (task) {
547 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
548 put_task_struct(task);
549 }
550 return allowed;
551 }
552
553 static int proc_setattr(struct dentry *dentry, struct iattr *attr)
554 {
555 int error;
556 struct inode *inode = dentry->d_inode;
557
558 if (attr->ia_valid & ATTR_MODE)
559 return -EPERM;
560
561 error = inode_change_ok(inode, attr);
562 if (error)
563 return error;
564
565 if ((attr->ia_valid & ATTR_SIZE) &&
566 attr->ia_size != i_size_read(inode)) {
567 error = vmtruncate(inode, attr->ia_size);
568 if (error)
569 return error;
570 }
571
572 setattr_copy(inode, attr);
573 mark_inode_dirty(inode);
574 return 0;
575 }
576
577 static const struct inode_operations proc_def_inode_operations = {
578 .setattr = proc_setattr,
579 };
580
581 static int mounts_open_common(struct inode *inode, struct file *file,
582 const struct seq_operations *op)
583 {
584 struct task_struct *task = get_proc_task(inode);
585 struct nsproxy *nsp;
586 struct mnt_namespace *ns = NULL;
587 struct path root;
588 struct proc_mounts *p;
589 int ret = -EINVAL;
590
591 if (task) {
592 rcu_read_lock();
593 nsp = task_nsproxy(task);
594 if (nsp) {
595 ns = nsp->mnt_ns;
596 if (ns)
597 get_mnt_ns(ns);
598 }
599 rcu_read_unlock();
600 if (ns && get_task_root(task, &root) == 0)
601 ret = 0;
602 put_task_struct(task);
603 }
604
605 if (!ns)
606 goto err;
607 if (ret)
608 goto err_put_ns;
609
610 ret = -ENOMEM;
611 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
612 if (!p)
613 goto err_put_path;
614
615 file->private_data = &p->m;
616 ret = seq_open(file, op);
617 if (ret)
618 goto err_free;
619
620 p->m.private = p;
621 p->ns = ns;
622 p->root = root;
623 p->event = ns->event;
624
625 return 0;
626
627 err_free:
628 kfree(p);
629 err_put_path:
630 path_put(&root);
631 err_put_ns:
632 put_mnt_ns(ns);
633 err:
634 return ret;
635 }
636
637 static int mounts_release(struct inode *inode, struct file *file)
638 {
639 struct proc_mounts *p = file->private_data;
640 path_put(&p->root);
641 put_mnt_ns(p->ns);
642 return seq_release(inode, file);
643 }
644
645 static unsigned mounts_poll(struct file *file, poll_table *wait)
646 {
647 struct proc_mounts *p = file->private_data;
648 unsigned res = POLLIN | POLLRDNORM;
649
650 poll_wait(file, &p->ns->poll, wait);
651 if (mnt_had_events(p))
652 res |= POLLERR | POLLPRI;
653
654 return res;
655 }
656
657 static int mounts_open(struct inode *inode, struct file *file)
658 {
659 return mounts_open_common(inode, file, &mounts_op);
660 }
661
662 static const struct file_operations proc_mounts_operations = {
663 .open = mounts_open,
664 .read = seq_read,
665 .llseek = seq_lseek,
666 .release = mounts_release,
667 .poll = mounts_poll,
668 };
669
670 static int mountinfo_open(struct inode *inode, struct file *file)
671 {
672 return mounts_open_common(inode, file, &mountinfo_op);
673 }
674
675 static const struct file_operations proc_mountinfo_operations = {
676 .open = mountinfo_open,
677 .read = seq_read,
678 .llseek = seq_lseek,
679 .release = mounts_release,
680 .poll = mounts_poll,
681 };
682
683 static int mountstats_open(struct inode *inode, struct file *file)
684 {
685 return mounts_open_common(inode, file, &mountstats_op);
686 }
687
688 static const struct file_operations proc_mountstats_operations = {
689 .open = mountstats_open,
690 .read = seq_read,
691 .llseek = seq_lseek,
692 .release = mounts_release,
693 };
694
695 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
696
697 static ssize_t proc_info_read(struct file * file, char __user * buf,
698 size_t count, loff_t *ppos)
699 {
700 struct inode * inode = file->f_path.dentry->d_inode;
701 unsigned long page;
702 ssize_t length;
703 struct task_struct *task = get_proc_task(inode);
704
705 length = -ESRCH;
706 if (!task)
707 goto out_no_task;
708
709 if (count > PROC_BLOCK_SIZE)
710 count = PROC_BLOCK_SIZE;
711
712 length = -ENOMEM;
713 if (!(page = __get_free_page(GFP_TEMPORARY)))
714 goto out;
715
716 length = PROC_I(inode)->op.proc_read(task, (char*)page);
717
718 if (length >= 0)
719 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
720 free_page(page);
721 out:
722 put_task_struct(task);
723 out_no_task:
724 return length;
725 }
726
727 static const struct file_operations proc_info_file_operations = {
728 .read = proc_info_read,
729 .llseek = generic_file_llseek,
730 };
731
732 static int proc_single_show(struct seq_file *m, void *v)
733 {
734 struct inode *inode = m->private;
735 struct pid_namespace *ns;
736 struct pid *pid;
737 struct task_struct *task;
738 int ret;
739
740 ns = inode->i_sb->s_fs_info;
741 pid = proc_pid(inode);
742 task = get_pid_task(pid, PIDTYPE_PID);
743 if (!task)
744 return -ESRCH;
745
746 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
747
748 put_task_struct(task);
749 return ret;
750 }
751
752 static int proc_single_open(struct inode *inode, struct file *filp)
753 {
754 int ret;
755 ret = single_open(filp, proc_single_show, NULL);
756 if (!ret) {
757 struct seq_file *m = filp->private_data;
758
759 m->private = inode;
760 }
761 return ret;
762 }
763
764 static const struct file_operations proc_single_file_operations = {
765 .open = proc_single_open,
766 .read = seq_read,
767 .llseek = seq_lseek,
768 .release = single_release,
769 };
770
771 static int mem_open(struct inode* inode, struct file* file)
772 {
773 file->private_data = (void*)((long)current->self_exec_id);
774 return 0;
775 }
776
777 static ssize_t mem_read(struct file * file, char __user * buf,
778 size_t count, loff_t *ppos)
779 {
780 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
781 char *page;
782 unsigned long src = *ppos;
783 int ret = -ESRCH;
784 struct mm_struct *mm;
785
786 if (!task)
787 goto out_no_task;
788
789 if (check_mem_permission(task))
790 goto out;
791
792 ret = -ENOMEM;
793 page = (char *)__get_free_page(GFP_TEMPORARY);
794 if (!page)
795 goto out;
796
797 ret = 0;
798
799 mm = get_task_mm(task);
800 if (!mm)
801 goto out_free;
802
803 ret = -EIO;
804
805 if (file->private_data != (void*)((long)current->self_exec_id))
806 goto out_put;
807
808 ret = 0;
809
810 while (count > 0) {
811 int this_len, retval;
812
813 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
814 retval = access_process_vm(task, src, page, this_len, 0);
815 if (!retval || check_mem_permission(task)) {
816 if (!ret)
817 ret = -EIO;
818 break;
819 }
820
821 if (copy_to_user(buf, page, retval)) {
822 ret = -EFAULT;
823 break;
824 }
825
826 ret += retval;
827 src += retval;
828 buf += retval;
829 count -= retval;
830 }
831 *ppos = src;
832
833 out_put:
834 mmput(mm);
835 out_free:
836 free_page((unsigned long) page);
837 out:
838 put_task_struct(task);
839 out_no_task:
840 return ret;
841 }
842
843 #define mem_write NULL
844
845 #ifndef mem_write
846 /* This is a security hazard */
847 static ssize_t mem_write(struct file * file, const char __user *buf,
848 size_t count, loff_t *ppos)
849 {
850 int copied;
851 char *page;
852 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
853 unsigned long dst = *ppos;
854
855 copied = -ESRCH;
856 if (!task)
857 goto out_no_task;
858
859 if (check_mem_permission(task))
860 goto out;
861
862 copied = -ENOMEM;
863 page = (char *)__get_free_page(GFP_TEMPORARY);
864 if (!page)
865 goto out;
866
867 copied = 0;
868 while (count > 0) {
869 int this_len, retval;
870
871 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
872 if (copy_from_user(page, buf, this_len)) {
873 copied = -EFAULT;
874 break;
875 }
876 retval = access_process_vm(task, dst, page, this_len, 1);
877 if (!retval) {
878 if (!copied)
879 copied = -EIO;
880 break;
881 }
882 copied += retval;
883 buf += retval;
884 dst += retval;
885 count -= retval;
886 }
887 *ppos = dst;
888 free_page((unsigned long) page);
889 out:
890 put_task_struct(task);
891 out_no_task:
892 return copied;
893 }
894 #endif
895
896 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
897 {
898 switch (orig) {
899 case 0:
900 file->f_pos = offset;
901 break;
902 case 1:
903 file->f_pos += offset;
904 break;
905 default:
906 return -EINVAL;
907 }
908 force_successful_syscall_return();
909 return file->f_pos;
910 }
911
912 static const struct file_operations proc_mem_operations = {
913 .llseek = mem_lseek,
914 .read = mem_read,
915 .write = mem_write,
916 .open = mem_open,
917 };
918
919 static ssize_t environ_read(struct file *file, char __user *buf,
920 size_t count, loff_t *ppos)
921 {
922 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
923 char *page;
924 unsigned long src = *ppos;
925 int ret = -ESRCH;
926 struct mm_struct *mm;
927
928 if (!task)
929 goto out_no_task;
930
931 if (!ptrace_may_access(task, PTRACE_MODE_READ))
932 goto out;
933
934 ret = -ENOMEM;
935 page = (char *)__get_free_page(GFP_TEMPORARY);
936 if (!page)
937 goto out;
938
939 ret = 0;
940
941 mm = get_task_mm(task);
942 if (!mm)
943 goto out_free;
944
945 while (count > 0) {
946 int this_len, retval, max_len;
947
948 this_len = mm->env_end - (mm->env_start + src);
949
950 if (this_len <= 0)
951 break;
952
953 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
954 this_len = (this_len > max_len) ? max_len : this_len;
955
956 retval = access_process_vm(task, (mm->env_start + src),
957 page, this_len, 0);
958
959 if (retval <= 0) {
960 ret = retval;
961 break;
962 }
963
964 if (copy_to_user(buf, page, retval)) {
965 ret = -EFAULT;
966 break;
967 }
968
969 ret += retval;
970 src += retval;
971 buf += retval;
972 count -= retval;
973 }
974 *ppos = src;
975
976 mmput(mm);
977 out_free:
978 free_page((unsigned long) page);
979 out:
980 put_task_struct(task);
981 out_no_task:
982 return ret;
983 }
984
985 static const struct file_operations proc_environ_operations = {
986 .read = environ_read,
987 .llseek = generic_file_llseek,
988 };
989
990 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
991 size_t count, loff_t *ppos)
992 {
993 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
994 char buffer[PROC_NUMBUF];
995 size_t len;
996 int oom_adjust = OOM_DISABLE;
997 unsigned long flags;
998
999 if (!task)
1000 return -ESRCH;
1001
1002 if (lock_task_sighand(task, &flags)) {
1003 oom_adjust = task->signal->oom_adj;
1004 unlock_task_sighand(task, &flags);
1005 }
1006
1007 put_task_struct(task);
1008
1009 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
1010
1011 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1012 }
1013
1014 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1015 size_t count, loff_t *ppos)
1016 {
1017 struct task_struct *task;
1018 char buffer[PROC_NUMBUF];
1019 long oom_adjust;
1020 unsigned long flags;
1021 int err;
1022
1023 memset(buffer, 0, sizeof(buffer));
1024 if (count > sizeof(buffer) - 1)
1025 count = sizeof(buffer) - 1;
1026 if (copy_from_user(buffer, buf, count))
1027 return -EFAULT;
1028
1029 err = strict_strtol(strstrip(buffer), 0, &oom_adjust);
1030 if (err)
1031 return -EINVAL;
1032 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1033 oom_adjust != OOM_DISABLE)
1034 return -EINVAL;
1035
1036 task = get_proc_task(file->f_path.dentry->d_inode);
1037 if (!task)
1038 return -ESRCH;
1039 if (!lock_task_sighand(task, &flags)) {
1040 put_task_struct(task);
1041 return -ESRCH;
1042 }
1043
1044 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1045 unlock_task_sighand(task, &flags);
1046 put_task_struct(task);
1047 return -EACCES;
1048 }
1049
1050 /*
1051 * Warn that /proc/pid/oom_adj is deprecated, see
1052 * Documentation/feature-removal-schedule.txt.
1053 */
1054 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, "
1055 "please use /proc/%d/oom_score_adj instead.\n",
1056 current->comm, task_pid_nr(current),
1057 task_pid_nr(task), task_pid_nr(task));
1058 task->signal->oom_adj = oom_adjust;
1059 /*
1060 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1061 * value is always attainable.
1062 */
1063 if (task->signal->oom_adj == OOM_ADJUST_MAX)
1064 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
1065 else
1066 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
1067 -OOM_DISABLE;
1068 unlock_task_sighand(task, &flags);
1069 put_task_struct(task);
1070
1071 return count;
1072 }
1073
1074 static const struct file_operations proc_oom_adjust_operations = {
1075 .read = oom_adjust_read,
1076 .write = oom_adjust_write,
1077 .llseek = generic_file_llseek,
1078 };
1079
1080 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1081 size_t count, loff_t *ppos)
1082 {
1083 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1084 char buffer[PROC_NUMBUF];
1085 int oom_score_adj = OOM_SCORE_ADJ_MIN;
1086 unsigned long flags;
1087 size_t len;
1088
1089 if (!task)
1090 return -ESRCH;
1091 if (lock_task_sighand(task, &flags)) {
1092 oom_score_adj = task->signal->oom_score_adj;
1093 unlock_task_sighand(task, &flags);
1094 }
1095 put_task_struct(task);
1096 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
1097 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1098 }
1099
1100 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1101 size_t count, loff_t *ppos)
1102 {
1103 struct task_struct *task;
1104 char buffer[PROC_NUMBUF];
1105 unsigned long flags;
1106 long oom_score_adj;
1107 int err;
1108
1109 memset(buffer, 0, sizeof(buffer));
1110 if (count > sizeof(buffer) - 1)
1111 count = sizeof(buffer) - 1;
1112 if (copy_from_user(buffer, buf, count))
1113 return -EFAULT;
1114
1115 err = strict_strtol(strstrip(buffer), 0, &oom_score_adj);
1116 if (err)
1117 return -EINVAL;
1118 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1119 oom_score_adj > OOM_SCORE_ADJ_MAX)
1120 return -EINVAL;
1121
1122 task = get_proc_task(file->f_path.dentry->d_inode);
1123 if (!task)
1124 return -ESRCH;
1125 if (!lock_task_sighand(task, &flags)) {
1126 put_task_struct(task);
1127 return -ESRCH;
1128 }
1129 if (oom_score_adj < task->signal->oom_score_adj &&
1130 !capable(CAP_SYS_RESOURCE)) {
1131 unlock_task_sighand(task, &flags);
1132 put_task_struct(task);
1133 return -EACCES;
1134 }
1135
1136 task->signal->oom_score_adj = oom_score_adj;
1137 /*
1138 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1139 * always attainable.
1140 */
1141 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1142 task->signal->oom_adj = OOM_DISABLE;
1143 else
1144 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1145 OOM_SCORE_ADJ_MAX;
1146 unlock_task_sighand(task, &flags);
1147 put_task_struct(task);
1148 return count;
1149 }
1150
1151 static const struct file_operations proc_oom_score_adj_operations = {
1152 .read = oom_score_adj_read,
1153 .write = oom_score_adj_write,
1154 .llseek = default_llseek,
1155 };
1156
1157 #ifdef CONFIG_AUDITSYSCALL
1158 #define TMPBUFLEN 21
1159 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1160 size_t count, loff_t *ppos)
1161 {
1162 struct inode * inode = file->f_path.dentry->d_inode;
1163 struct task_struct *task = get_proc_task(inode);
1164 ssize_t length;
1165 char tmpbuf[TMPBUFLEN];
1166
1167 if (!task)
1168 return -ESRCH;
1169 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1170 audit_get_loginuid(task));
1171 put_task_struct(task);
1172 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1173 }
1174
1175 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1176 size_t count, loff_t *ppos)
1177 {
1178 struct inode * inode = file->f_path.dentry->d_inode;
1179 char *page, *tmp;
1180 ssize_t length;
1181 uid_t loginuid;
1182
1183 if (!capable(CAP_AUDIT_CONTROL))
1184 return -EPERM;
1185
1186 rcu_read_lock();
1187 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1188 rcu_read_unlock();
1189 return -EPERM;
1190 }
1191 rcu_read_unlock();
1192
1193 if (count >= PAGE_SIZE)
1194 count = PAGE_SIZE - 1;
1195
1196 if (*ppos != 0) {
1197 /* No partial writes. */
1198 return -EINVAL;
1199 }
1200 page = (char*)__get_free_page(GFP_TEMPORARY);
1201 if (!page)
1202 return -ENOMEM;
1203 length = -EFAULT;
1204 if (copy_from_user(page, buf, count))
1205 goto out_free_page;
1206
1207 page[count] = '\0';
1208 loginuid = simple_strtoul(page, &tmp, 10);
1209 if (tmp == page) {
1210 length = -EINVAL;
1211 goto out_free_page;
1212
1213 }
1214 length = audit_set_loginuid(current, loginuid);
1215 if (likely(length == 0))
1216 length = count;
1217
1218 out_free_page:
1219 free_page((unsigned long) page);
1220 return length;
1221 }
1222
1223 static const struct file_operations proc_loginuid_operations = {
1224 .read = proc_loginuid_read,
1225 .write = proc_loginuid_write,
1226 .llseek = generic_file_llseek,
1227 };
1228
1229 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1230 size_t count, loff_t *ppos)
1231 {
1232 struct inode * inode = file->f_path.dentry->d_inode;
1233 struct task_struct *task = get_proc_task(inode);
1234 ssize_t length;
1235 char tmpbuf[TMPBUFLEN];
1236
1237 if (!task)
1238 return -ESRCH;
1239 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1240 audit_get_sessionid(task));
1241 put_task_struct(task);
1242 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1243 }
1244
1245 static const struct file_operations proc_sessionid_operations = {
1246 .read = proc_sessionid_read,
1247 .llseek = generic_file_llseek,
1248 };
1249 #endif
1250
1251 #ifdef CONFIG_FAULT_INJECTION
1252 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1253 size_t count, loff_t *ppos)
1254 {
1255 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1256 char buffer[PROC_NUMBUF];
1257 size_t len;
1258 int make_it_fail;
1259
1260 if (!task)
1261 return -ESRCH;
1262 make_it_fail = task->make_it_fail;
1263 put_task_struct(task);
1264
1265 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1266
1267 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1268 }
1269
1270 static ssize_t proc_fault_inject_write(struct file * file,
1271 const char __user * buf, size_t count, loff_t *ppos)
1272 {
1273 struct task_struct *task;
1274 char buffer[PROC_NUMBUF], *end;
1275 int make_it_fail;
1276
1277 if (!capable(CAP_SYS_RESOURCE))
1278 return -EPERM;
1279 memset(buffer, 0, sizeof(buffer));
1280 if (count > sizeof(buffer) - 1)
1281 count = sizeof(buffer) - 1;
1282 if (copy_from_user(buffer, buf, count))
1283 return -EFAULT;
1284 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1285 if (*end)
1286 return -EINVAL;
1287 task = get_proc_task(file->f_dentry->d_inode);
1288 if (!task)
1289 return -ESRCH;
1290 task->make_it_fail = make_it_fail;
1291 put_task_struct(task);
1292
1293 return count;
1294 }
1295
1296 static const struct file_operations proc_fault_inject_operations = {
1297 .read = proc_fault_inject_read,
1298 .write = proc_fault_inject_write,
1299 .llseek = generic_file_llseek,
1300 };
1301 #endif
1302
1303
1304 #ifdef CONFIG_SCHED_DEBUG
1305 /*
1306 * Print out various scheduling related per-task fields:
1307 */
1308 static int sched_show(struct seq_file *m, void *v)
1309 {
1310 struct inode *inode = m->private;
1311 struct task_struct *p;
1312
1313 p = get_proc_task(inode);
1314 if (!p)
1315 return -ESRCH;
1316 proc_sched_show_task(p, m);
1317
1318 put_task_struct(p);
1319
1320 return 0;
1321 }
1322
1323 static ssize_t
1324 sched_write(struct file *file, const char __user *buf,
1325 size_t count, loff_t *offset)
1326 {
1327 struct inode *inode = file->f_path.dentry->d_inode;
1328 struct task_struct *p;
1329
1330 p = get_proc_task(inode);
1331 if (!p)
1332 return -ESRCH;
1333 proc_sched_set_task(p);
1334
1335 put_task_struct(p);
1336
1337 return count;
1338 }
1339
1340 static int sched_open(struct inode *inode, struct file *filp)
1341 {
1342 int ret;
1343
1344 ret = single_open(filp, sched_show, NULL);
1345 if (!ret) {
1346 struct seq_file *m = filp->private_data;
1347
1348 m->private = inode;
1349 }
1350 return ret;
1351 }
1352
1353 static const struct file_operations proc_pid_sched_operations = {
1354 .open = sched_open,
1355 .read = seq_read,
1356 .write = sched_write,
1357 .llseek = seq_lseek,
1358 .release = single_release,
1359 };
1360
1361 #endif
1362
1363 static ssize_t comm_write(struct file *file, const char __user *buf,
1364 size_t count, loff_t *offset)
1365 {
1366 struct inode *inode = file->f_path.dentry->d_inode;
1367 struct task_struct *p;
1368 char buffer[TASK_COMM_LEN];
1369
1370 memset(buffer, 0, sizeof(buffer));
1371 if (count > sizeof(buffer) - 1)
1372 count = sizeof(buffer) - 1;
1373 if (copy_from_user(buffer, buf, count))
1374 return -EFAULT;
1375
1376 p = get_proc_task(inode);
1377 if (!p)
1378 return -ESRCH;
1379
1380 if (same_thread_group(current, p))
1381 set_task_comm(p, buffer);
1382 else
1383 count = -EINVAL;
1384
1385 put_task_struct(p);
1386
1387 return count;
1388 }
1389
1390 static int comm_show(struct seq_file *m, void *v)
1391 {
1392 struct inode *inode = m->private;
1393 struct task_struct *p;
1394
1395 p = get_proc_task(inode);
1396 if (!p)
1397 return -ESRCH;
1398
1399 task_lock(p);
1400 seq_printf(m, "%s\n", p->comm);
1401 task_unlock(p);
1402
1403 put_task_struct(p);
1404
1405 return 0;
1406 }
1407
1408 static int comm_open(struct inode *inode, struct file *filp)
1409 {
1410 int ret;
1411
1412 ret = single_open(filp, comm_show, NULL);
1413 if (!ret) {
1414 struct seq_file *m = filp->private_data;
1415
1416 m->private = inode;
1417 }
1418 return ret;
1419 }
1420
1421 static const struct file_operations proc_pid_set_comm_operations = {
1422 .open = comm_open,
1423 .read = seq_read,
1424 .write = comm_write,
1425 .llseek = seq_lseek,
1426 .release = single_release,
1427 };
1428
1429 /*
1430 * We added or removed a vma mapping the executable. The vmas are only mapped
1431 * during exec and are not mapped with the mmap system call.
1432 * Callers must hold down_write() on the mm's mmap_sem for these
1433 */
1434 void added_exe_file_vma(struct mm_struct *mm)
1435 {
1436 mm->num_exe_file_vmas++;
1437 }
1438
1439 void removed_exe_file_vma(struct mm_struct *mm)
1440 {
1441 mm->num_exe_file_vmas--;
1442 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){
1443 fput(mm->exe_file);
1444 mm->exe_file = NULL;
1445 }
1446
1447 }
1448
1449 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
1450 {
1451 if (new_exe_file)
1452 get_file(new_exe_file);
1453 if (mm->exe_file)
1454 fput(mm->exe_file);
1455 mm->exe_file = new_exe_file;
1456 mm->num_exe_file_vmas = 0;
1457 }
1458
1459 struct file *get_mm_exe_file(struct mm_struct *mm)
1460 {
1461 struct file *exe_file;
1462
1463 /* We need mmap_sem to protect against races with removal of
1464 * VM_EXECUTABLE vmas */
1465 down_read(&mm->mmap_sem);
1466 exe_file = mm->exe_file;
1467 if (exe_file)
1468 get_file(exe_file);
1469 up_read(&mm->mmap_sem);
1470 return exe_file;
1471 }
1472
1473 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm)
1474 {
1475 /* It's safe to write the exe_file pointer without exe_file_lock because
1476 * this is called during fork when the task is not yet in /proc */
1477 newmm->exe_file = get_mm_exe_file(oldmm);
1478 }
1479
1480 static int proc_exe_link(struct inode *inode, struct path *exe_path)
1481 {
1482 struct task_struct *task;
1483 struct mm_struct *mm;
1484 struct file *exe_file;
1485
1486 task = get_proc_task(inode);
1487 if (!task)
1488 return -ENOENT;
1489 mm = get_task_mm(task);
1490 put_task_struct(task);
1491 if (!mm)
1492 return -ENOENT;
1493 exe_file = get_mm_exe_file(mm);
1494 mmput(mm);
1495 if (exe_file) {
1496 *exe_path = exe_file->f_path;
1497 path_get(&exe_file->f_path);
1498 fput(exe_file);
1499 return 0;
1500 } else
1501 return -ENOENT;
1502 }
1503
1504 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1505 {
1506 struct inode *inode = dentry->d_inode;
1507 int error = -EACCES;
1508
1509 /* We don't need a base pointer in the /proc filesystem */
1510 path_put(&nd->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(inode, &nd->path);
1517 out:
1518 return ERR_PTR(error);
1519 }
1520
1521 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1522 {
1523 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1524 char *pathname;
1525 int len;
1526
1527 if (!tmp)
1528 return -ENOMEM;
1529
1530 pathname = d_path_with_unreachable(path, tmp, PAGE_SIZE);
1531 len = PTR_ERR(pathname);
1532 if (IS_ERR(pathname))
1533 goto out;
1534 len = tmp + PAGE_SIZE - 1 - pathname;
1535
1536 if (len > buflen)
1537 len = buflen;
1538 if (copy_to_user(buffer, pathname, len))
1539 len = -EFAULT;
1540 out:
1541 free_page((unsigned long)tmp);
1542 return len;
1543 }
1544
1545 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1546 {
1547 int error = -EACCES;
1548 struct inode *inode = dentry->d_inode;
1549 struct path path;
1550
1551 /* Are we allowed to snoop on the tasks file descriptors? */
1552 if (!proc_fd_access_allowed(inode))
1553 goto out;
1554
1555 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1556 if (error)
1557 goto out;
1558
1559 error = do_proc_readlink(&path, buffer, buflen);
1560 path_put(&path);
1561 out:
1562 return error;
1563 }
1564
1565 static const struct inode_operations proc_pid_link_inode_operations = {
1566 .readlink = proc_pid_readlink,
1567 .follow_link = proc_pid_follow_link,
1568 .setattr = proc_setattr,
1569 };
1570
1571
1572 /* building an inode */
1573
1574 static int task_dumpable(struct task_struct *task)
1575 {
1576 int dumpable = 0;
1577 struct mm_struct *mm;
1578
1579 task_lock(task);
1580 mm = task->mm;
1581 if (mm)
1582 dumpable = get_dumpable(mm);
1583 task_unlock(task);
1584 if(dumpable == 1)
1585 return 1;
1586 return 0;
1587 }
1588
1589
1590 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1591 {
1592 struct inode * inode;
1593 struct proc_inode *ei;
1594 const struct cred *cred;
1595
1596 /* We need a new inode */
1597
1598 inode = new_inode(sb);
1599 if (!inode)
1600 goto out;
1601
1602 /* Common stuff */
1603 ei = PROC_I(inode);
1604 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1605 inode->i_op = &proc_def_inode_operations;
1606
1607 /*
1608 * grab the reference to task.
1609 */
1610 ei->pid = get_task_pid(task, PIDTYPE_PID);
1611 if (!ei->pid)
1612 goto out_unlock;
1613
1614 if (task_dumpable(task)) {
1615 rcu_read_lock();
1616 cred = __task_cred(task);
1617 inode->i_uid = cred->euid;
1618 inode->i_gid = cred->egid;
1619 rcu_read_unlock();
1620 }
1621 security_task_to_inode(task, inode);
1622
1623 out:
1624 return inode;
1625
1626 out_unlock:
1627 iput(inode);
1628 return NULL;
1629 }
1630
1631 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1632 {
1633 struct inode *inode = dentry->d_inode;
1634 struct task_struct *task;
1635 const struct cred *cred;
1636
1637 generic_fillattr(inode, stat);
1638
1639 rcu_read_lock();
1640 stat->uid = 0;
1641 stat->gid = 0;
1642 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1643 if (task) {
1644 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1645 task_dumpable(task)) {
1646 cred = __task_cred(task);
1647 stat->uid = cred->euid;
1648 stat->gid = cred->egid;
1649 }
1650 }
1651 rcu_read_unlock();
1652 return 0;
1653 }
1654
1655 /* dentry stuff */
1656
1657 /*
1658 * Exceptional case: normally we are not allowed to unhash a busy
1659 * directory. In this case, however, we can do it - no aliasing problems
1660 * due to the way we treat inodes.
1661 *
1662 * Rewrite the inode's ownerships here because the owning task may have
1663 * performed a setuid(), etc.
1664 *
1665 * Before the /proc/pid/status file was created the only way to read
1666 * the effective uid of a /process was to stat /proc/pid. Reading
1667 * /proc/pid/status is slow enough that procps and other packages
1668 * kept stating /proc/pid. To keep the rules in /proc simple I have
1669 * made this apply to all per process world readable and executable
1670 * directories.
1671 */
1672 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1673 {
1674 struct inode *inode = dentry->d_inode;
1675 struct task_struct *task = get_proc_task(inode);
1676 const struct cred *cred;
1677
1678 if (task) {
1679 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1680 task_dumpable(task)) {
1681 rcu_read_lock();
1682 cred = __task_cred(task);
1683 inode->i_uid = cred->euid;
1684 inode->i_gid = cred->egid;
1685 rcu_read_unlock();
1686 } else {
1687 inode->i_uid = 0;
1688 inode->i_gid = 0;
1689 }
1690 inode->i_mode &= ~(S_ISUID | S_ISGID);
1691 security_task_to_inode(task, inode);
1692 put_task_struct(task);
1693 return 1;
1694 }
1695 d_drop(dentry);
1696 return 0;
1697 }
1698
1699 static int pid_delete_dentry(struct dentry * dentry)
1700 {
1701 /* Is the task we represent dead?
1702 * If so, then don't put the dentry on the lru list,
1703 * kill it immediately.
1704 */
1705 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1706 }
1707
1708 static const struct dentry_operations pid_dentry_operations =
1709 {
1710 .d_revalidate = pid_revalidate,
1711 .d_delete = pid_delete_dentry,
1712 };
1713
1714 /* Lookups */
1715
1716 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1717 struct task_struct *, const void *);
1718
1719 /*
1720 * Fill a directory entry.
1721 *
1722 * If possible create the dcache entry and derive our inode number and
1723 * file type from dcache entry.
1724 *
1725 * Since all of the proc inode numbers are dynamically generated, the inode
1726 * numbers do not exist until the inode is cache. This means creating the
1727 * the dcache entry in readdir is necessary to keep the inode numbers
1728 * reported by readdir in sync with the inode numbers reported
1729 * by stat.
1730 */
1731 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1732 char *name, int len,
1733 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1734 {
1735 struct dentry *child, *dir = filp->f_path.dentry;
1736 struct inode *inode;
1737 struct qstr qname;
1738 ino_t ino = 0;
1739 unsigned type = DT_UNKNOWN;
1740
1741 qname.name = name;
1742 qname.len = len;
1743 qname.hash = full_name_hash(name, len);
1744
1745 child = d_lookup(dir, &qname);
1746 if (!child) {
1747 struct dentry *new;
1748 new = d_alloc(dir, &qname);
1749 if (new) {
1750 child = instantiate(dir->d_inode, new, task, ptr);
1751 if (child)
1752 dput(new);
1753 else
1754 child = new;
1755 }
1756 }
1757 if (!child || IS_ERR(child) || !child->d_inode)
1758 goto end_instantiate;
1759 inode = child->d_inode;
1760 if (inode) {
1761 ino = inode->i_ino;
1762 type = inode->i_mode >> 12;
1763 }
1764 dput(child);
1765 end_instantiate:
1766 if (!ino)
1767 ino = find_inode_number(dir, &qname);
1768 if (!ino)
1769 ino = 1;
1770 return filldir(dirent, name, len, filp->f_pos, ino, type);
1771 }
1772
1773 static unsigned name_to_int(struct dentry *dentry)
1774 {
1775 const char *name = dentry->d_name.name;
1776 int len = dentry->d_name.len;
1777 unsigned n = 0;
1778
1779 if (len > 1 && *name == '0')
1780 goto out;
1781 while (len-- > 0) {
1782 unsigned c = *name++ - '0';
1783 if (c > 9)
1784 goto out;
1785 if (n >= (~0U-9)/10)
1786 goto out;
1787 n *= 10;
1788 n += c;
1789 }
1790 return n;
1791 out:
1792 return ~0U;
1793 }
1794
1795 #define PROC_FDINFO_MAX 64
1796
1797 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1798 {
1799 struct task_struct *task = get_proc_task(inode);
1800 struct files_struct *files = NULL;
1801 struct file *file;
1802 int fd = proc_fd(inode);
1803
1804 if (task) {
1805 files = get_files_struct(task);
1806 put_task_struct(task);
1807 }
1808 if (files) {
1809 /*
1810 * We are not taking a ref to the file structure, so we must
1811 * hold ->file_lock.
1812 */
1813 spin_lock(&files->file_lock);
1814 file = fcheck_files(files, fd);
1815 if (file) {
1816 if (path) {
1817 *path = file->f_path;
1818 path_get(&file->f_path);
1819 }
1820 if (info)
1821 snprintf(info, PROC_FDINFO_MAX,
1822 "pos:\t%lli\n"
1823 "flags:\t0%o\n",
1824 (long long) file->f_pos,
1825 file->f_flags);
1826 spin_unlock(&files->file_lock);
1827 put_files_struct(files);
1828 return 0;
1829 }
1830 spin_unlock(&files->file_lock);
1831 put_files_struct(files);
1832 }
1833 return -ENOENT;
1834 }
1835
1836 static int proc_fd_link(struct inode *inode, struct path *path)
1837 {
1838 return proc_fd_info(inode, path, NULL);
1839 }
1840
1841 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1842 {
1843 struct inode *inode = dentry->d_inode;
1844 struct task_struct *task = get_proc_task(inode);
1845 int fd = proc_fd(inode);
1846 struct files_struct *files;
1847 const struct cred *cred;
1848
1849 if (task) {
1850 files = get_files_struct(task);
1851 if (files) {
1852 rcu_read_lock();
1853 if (fcheck_files(files, fd)) {
1854 rcu_read_unlock();
1855 put_files_struct(files);
1856 if (task_dumpable(task)) {
1857 rcu_read_lock();
1858 cred = __task_cred(task);
1859 inode->i_uid = cred->euid;
1860 inode->i_gid = cred->egid;
1861 rcu_read_unlock();
1862 } else {
1863 inode->i_uid = 0;
1864 inode->i_gid = 0;
1865 }
1866 inode->i_mode &= ~(S_ISUID | S_ISGID);
1867 security_task_to_inode(task, inode);
1868 put_task_struct(task);
1869 return 1;
1870 }
1871 rcu_read_unlock();
1872 put_files_struct(files);
1873 }
1874 put_task_struct(task);
1875 }
1876 d_drop(dentry);
1877 return 0;
1878 }
1879
1880 static const struct dentry_operations tid_fd_dentry_operations =
1881 {
1882 .d_revalidate = tid_fd_revalidate,
1883 .d_delete = pid_delete_dentry,
1884 };
1885
1886 static struct dentry *proc_fd_instantiate(struct inode *dir,
1887 struct dentry *dentry, struct task_struct *task, const void *ptr)
1888 {
1889 unsigned fd = *(const unsigned *)ptr;
1890 struct file *file;
1891 struct files_struct *files;
1892 struct inode *inode;
1893 struct proc_inode *ei;
1894 struct dentry *error = ERR_PTR(-ENOENT);
1895
1896 inode = proc_pid_make_inode(dir->i_sb, task);
1897 if (!inode)
1898 goto out;
1899 ei = PROC_I(inode);
1900 ei->fd = fd;
1901 files = get_files_struct(task);
1902 if (!files)
1903 goto out_iput;
1904 inode->i_mode = S_IFLNK;
1905
1906 /*
1907 * We are not taking a ref to the file structure, so we must
1908 * hold ->file_lock.
1909 */
1910 spin_lock(&files->file_lock);
1911 file = fcheck_files(files, fd);
1912 if (!file)
1913 goto out_unlock;
1914 if (file->f_mode & FMODE_READ)
1915 inode->i_mode |= S_IRUSR | S_IXUSR;
1916 if (file->f_mode & FMODE_WRITE)
1917 inode->i_mode |= S_IWUSR | S_IXUSR;
1918 spin_unlock(&files->file_lock);
1919 put_files_struct(files);
1920
1921 inode->i_op = &proc_pid_link_inode_operations;
1922 inode->i_size = 64;
1923 ei->op.proc_get_link = proc_fd_link;
1924 dentry->d_op = &tid_fd_dentry_operations;
1925 d_add(dentry, inode);
1926 /* Close the race of the process dying before we return the dentry */
1927 if (tid_fd_revalidate(dentry, NULL))
1928 error = NULL;
1929
1930 out:
1931 return error;
1932 out_unlock:
1933 spin_unlock(&files->file_lock);
1934 put_files_struct(files);
1935 out_iput:
1936 iput(inode);
1937 goto out;
1938 }
1939
1940 static struct dentry *proc_lookupfd_common(struct inode *dir,
1941 struct dentry *dentry,
1942 instantiate_t instantiate)
1943 {
1944 struct task_struct *task = get_proc_task(dir);
1945 unsigned fd = name_to_int(dentry);
1946 struct dentry *result = ERR_PTR(-ENOENT);
1947
1948 if (!task)
1949 goto out_no_task;
1950 if (fd == ~0U)
1951 goto out;
1952
1953 result = instantiate(dir, dentry, task, &fd);
1954 out:
1955 put_task_struct(task);
1956 out_no_task:
1957 return result;
1958 }
1959
1960 static int proc_readfd_common(struct file * filp, void * dirent,
1961 filldir_t filldir, instantiate_t instantiate)
1962 {
1963 struct dentry *dentry = filp->f_path.dentry;
1964 struct inode *inode = dentry->d_inode;
1965 struct task_struct *p = get_proc_task(inode);
1966 unsigned int fd, ino;
1967 int retval;
1968 struct files_struct * files;
1969
1970 retval = -ENOENT;
1971 if (!p)
1972 goto out_no_task;
1973 retval = 0;
1974
1975 fd = filp->f_pos;
1976 switch (fd) {
1977 case 0:
1978 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1979 goto out;
1980 filp->f_pos++;
1981 case 1:
1982 ino = parent_ino(dentry);
1983 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1984 goto out;
1985 filp->f_pos++;
1986 default:
1987 files = get_files_struct(p);
1988 if (!files)
1989 goto out;
1990 rcu_read_lock();
1991 for (fd = filp->f_pos-2;
1992 fd < files_fdtable(files)->max_fds;
1993 fd++, filp->f_pos++) {
1994 char name[PROC_NUMBUF];
1995 int len;
1996
1997 if (!fcheck_files(files, fd))
1998 continue;
1999 rcu_read_unlock();
2000
2001 len = snprintf(name, sizeof(name), "%d", fd);
2002 if (proc_fill_cache(filp, dirent, filldir,
2003 name, len, instantiate,
2004 p, &fd) < 0) {
2005 rcu_read_lock();
2006 break;
2007 }
2008 rcu_read_lock();
2009 }
2010 rcu_read_unlock();
2011 put_files_struct(files);
2012 }
2013 out:
2014 put_task_struct(p);
2015 out_no_task:
2016 return retval;
2017 }
2018
2019 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
2020 struct nameidata *nd)
2021 {
2022 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
2023 }
2024
2025 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
2026 {
2027 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
2028 }
2029
2030 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
2031 size_t len, loff_t *ppos)
2032 {
2033 char tmp[PROC_FDINFO_MAX];
2034 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
2035 if (!err)
2036 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
2037 return err;
2038 }
2039
2040 static const struct file_operations proc_fdinfo_file_operations = {
2041 .open = nonseekable_open,
2042 .read = proc_fdinfo_read,
2043 .llseek = no_llseek,
2044 };
2045
2046 static const struct file_operations proc_fd_operations = {
2047 .read = generic_read_dir,
2048 .readdir = proc_readfd,
2049 .llseek = default_llseek,
2050 };
2051
2052 /*
2053 * /proc/pid/fd needs a special permission handler so that a process can still
2054 * access /proc/self/fd after it has executed a setuid().
2055 */
2056 static int proc_fd_permission(struct inode *inode, int mask)
2057 {
2058 int rv;
2059
2060 rv = generic_permission(inode, mask, NULL);
2061 if (rv == 0)
2062 return 0;
2063 if (task_pid(current) == proc_pid(inode))
2064 rv = 0;
2065 return rv;
2066 }
2067
2068 /*
2069 * proc directories can do almost nothing..
2070 */
2071 static const struct inode_operations proc_fd_inode_operations = {
2072 .lookup = proc_lookupfd,
2073 .permission = proc_fd_permission,
2074 .setattr = proc_setattr,
2075 };
2076
2077 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2078 struct dentry *dentry, struct task_struct *task, const void *ptr)
2079 {
2080 unsigned fd = *(unsigned *)ptr;
2081 struct inode *inode;
2082 struct proc_inode *ei;
2083 struct dentry *error = ERR_PTR(-ENOENT);
2084
2085 inode = proc_pid_make_inode(dir->i_sb, task);
2086 if (!inode)
2087 goto out;
2088 ei = PROC_I(inode);
2089 ei->fd = fd;
2090 inode->i_mode = S_IFREG | S_IRUSR;
2091 inode->i_fop = &proc_fdinfo_file_operations;
2092 dentry->d_op = &tid_fd_dentry_operations;
2093 d_add(dentry, inode);
2094 /* Close the race of the process dying before we return the dentry */
2095 if (tid_fd_revalidate(dentry, NULL))
2096 error = NULL;
2097
2098 out:
2099 return error;
2100 }
2101
2102 static struct dentry *proc_lookupfdinfo(struct inode *dir,
2103 struct dentry *dentry,
2104 struct nameidata *nd)
2105 {
2106 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2107 }
2108
2109 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2110 {
2111 return proc_readfd_common(filp, dirent, filldir,
2112 proc_fdinfo_instantiate);
2113 }
2114
2115 static const struct file_operations proc_fdinfo_operations = {
2116 .read = generic_read_dir,
2117 .readdir = proc_readfdinfo,
2118 .llseek = default_llseek,
2119 };
2120
2121 /*
2122 * proc directories can do almost nothing..
2123 */
2124 static const struct inode_operations proc_fdinfo_inode_operations = {
2125 .lookup = proc_lookupfdinfo,
2126 .setattr = proc_setattr,
2127 };
2128
2129
2130 static struct dentry *proc_pident_instantiate(struct inode *dir,
2131 struct dentry *dentry, struct task_struct *task, const void *ptr)
2132 {
2133 const struct pid_entry *p = ptr;
2134 struct inode *inode;
2135 struct proc_inode *ei;
2136 struct dentry *error = ERR_PTR(-ENOENT);
2137
2138 inode = proc_pid_make_inode(dir->i_sb, task);
2139 if (!inode)
2140 goto out;
2141
2142 ei = PROC_I(inode);
2143 inode->i_mode = p->mode;
2144 if (S_ISDIR(inode->i_mode))
2145 inode->i_nlink = 2; /* Use getattr to fix if necessary */
2146 if (p->iop)
2147 inode->i_op = p->iop;
2148 if (p->fop)
2149 inode->i_fop = p->fop;
2150 ei->op = p->op;
2151 dentry->d_op = &pid_dentry_operations;
2152 d_add(dentry, inode);
2153 /* Close the race of the process dying before we return the dentry */
2154 if (pid_revalidate(dentry, NULL))
2155 error = NULL;
2156 out:
2157 return error;
2158 }
2159
2160 static struct dentry *proc_pident_lookup(struct inode *dir,
2161 struct dentry *dentry,
2162 const struct pid_entry *ents,
2163 unsigned int nents)
2164 {
2165 struct dentry *error;
2166 struct task_struct *task = get_proc_task(dir);
2167 const struct pid_entry *p, *last;
2168
2169 error = ERR_PTR(-ENOENT);
2170
2171 if (!task)
2172 goto out_no_task;
2173
2174 /*
2175 * Yes, it does not scale. And it should not. Don't add
2176 * new entries into /proc/<tgid>/ without very good reasons.
2177 */
2178 last = &ents[nents - 1];
2179 for (p = ents; p <= last; p++) {
2180 if (p->len != dentry->d_name.len)
2181 continue;
2182 if (!memcmp(dentry->d_name.name, p->name, p->len))
2183 break;
2184 }
2185 if (p > last)
2186 goto out;
2187
2188 error = proc_pident_instantiate(dir, dentry, task, p);
2189 out:
2190 put_task_struct(task);
2191 out_no_task:
2192 return error;
2193 }
2194
2195 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2196 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2197 {
2198 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2199 proc_pident_instantiate, task, p);
2200 }
2201
2202 static int proc_pident_readdir(struct file *filp,
2203 void *dirent, filldir_t filldir,
2204 const struct pid_entry *ents, unsigned int nents)
2205 {
2206 int i;
2207 struct dentry *dentry = filp->f_path.dentry;
2208 struct inode *inode = dentry->d_inode;
2209 struct task_struct *task = get_proc_task(inode);
2210 const struct pid_entry *p, *last;
2211 ino_t ino;
2212 int ret;
2213
2214 ret = -ENOENT;
2215 if (!task)
2216 goto out_no_task;
2217
2218 ret = 0;
2219 i = filp->f_pos;
2220 switch (i) {
2221 case 0:
2222 ino = inode->i_ino;
2223 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2224 goto out;
2225 i++;
2226 filp->f_pos++;
2227 /* fall through */
2228 case 1:
2229 ino = parent_ino(dentry);
2230 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2231 goto out;
2232 i++;
2233 filp->f_pos++;
2234 /* fall through */
2235 default:
2236 i -= 2;
2237 if (i >= nents) {
2238 ret = 1;
2239 goto out;
2240 }
2241 p = ents + i;
2242 last = &ents[nents - 1];
2243 while (p <= last) {
2244 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2245 goto out;
2246 filp->f_pos++;
2247 p++;
2248 }
2249 }
2250
2251 ret = 1;
2252 out:
2253 put_task_struct(task);
2254 out_no_task:
2255 return ret;
2256 }
2257
2258 #ifdef CONFIG_SECURITY
2259 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2260 size_t count, loff_t *ppos)
2261 {
2262 struct inode * inode = file->f_path.dentry->d_inode;
2263 char *p = NULL;
2264 ssize_t length;
2265 struct task_struct *task = get_proc_task(inode);
2266
2267 if (!task)
2268 return -ESRCH;
2269
2270 length = security_getprocattr(task,
2271 (char*)file->f_path.dentry->d_name.name,
2272 &p);
2273 put_task_struct(task);
2274 if (length > 0)
2275 length = simple_read_from_buffer(buf, count, ppos, p, length);
2276 kfree(p);
2277 return length;
2278 }
2279
2280 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2281 size_t count, loff_t *ppos)
2282 {
2283 struct inode * inode = file->f_path.dentry->d_inode;
2284 char *page;
2285 ssize_t length;
2286 struct task_struct *task = get_proc_task(inode);
2287
2288 length = -ESRCH;
2289 if (!task)
2290 goto out_no_task;
2291 if (count > PAGE_SIZE)
2292 count = PAGE_SIZE;
2293
2294 /* No partial writes. */
2295 length = -EINVAL;
2296 if (*ppos != 0)
2297 goto out;
2298
2299 length = -ENOMEM;
2300 page = (char*)__get_free_page(GFP_TEMPORARY);
2301 if (!page)
2302 goto out;
2303
2304 length = -EFAULT;
2305 if (copy_from_user(page, buf, count))
2306 goto out_free;
2307
2308 /* Guard against adverse ptrace interaction */
2309 length = mutex_lock_interruptible(&task->cred_guard_mutex);
2310 if (length < 0)
2311 goto out_free;
2312
2313 length = security_setprocattr(task,
2314 (char*)file->f_path.dentry->d_name.name,
2315 (void*)page, count);
2316 mutex_unlock(&task->cred_guard_mutex);
2317 out_free:
2318 free_page((unsigned long) page);
2319 out:
2320 put_task_struct(task);
2321 out_no_task:
2322 return length;
2323 }
2324
2325 static const struct file_operations proc_pid_attr_operations = {
2326 .read = proc_pid_attr_read,
2327 .write = proc_pid_attr_write,
2328 .llseek = generic_file_llseek,
2329 };
2330
2331 static const struct pid_entry attr_dir_stuff[] = {
2332 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2333 REG("prev", S_IRUGO, proc_pid_attr_operations),
2334 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2335 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2336 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2337 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2338 };
2339
2340 static int proc_attr_dir_readdir(struct file * filp,
2341 void * dirent, filldir_t filldir)
2342 {
2343 return proc_pident_readdir(filp,dirent,filldir,
2344 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2345 }
2346
2347 static const struct file_operations proc_attr_dir_operations = {
2348 .read = generic_read_dir,
2349 .readdir = proc_attr_dir_readdir,
2350 .llseek = default_llseek,
2351 };
2352
2353 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2354 struct dentry *dentry, struct nameidata *nd)
2355 {
2356 return proc_pident_lookup(dir, dentry,
2357 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2358 }
2359
2360 static const struct inode_operations proc_attr_dir_inode_operations = {
2361 .lookup = proc_attr_dir_lookup,
2362 .getattr = pid_getattr,
2363 .setattr = proc_setattr,
2364 };
2365
2366 #endif
2367
2368 #ifdef CONFIG_ELF_CORE
2369 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2370 size_t count, loff_t *ppos)
2371 {
2372 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2373 struct mm_struct *mm;
2374 char buffer[PROC_NUMBUF];
2375 size_t len;
2376 int ret;
2377
2378 if (!task)
2379 return -ESRCH;
2380
2381 ret = 0;
2382 mm = get_task_mm(task);
2383 if (mm) {
2384 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2385 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2386 MMF_DUMP_FILTER_SHIFT));
2387 mmput(mm);
2388 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2389 }
2390
2391 put_task_struct(task);
2392
2393 return ret;
2394 }
2395
2396 static ssize_t proc_coredump_filter_write(struct file *file,
2397 const char __user *buf,
2398 size_t count,
2399 loff_t *ppos)
2400 {
2401 struct task_struct *task;
2402 struct mm_struct *mm;
2403 char buffer[PROC_NUMBUF], *end;
2404 unsigned int val;
2405 int ret;
2406 int i;
2407 unsigned long mask;
2408
2409 ret = -EFAULT;
2410 memset(buffer, 0, sizeof(buffer));
2411 if (count > sizeof(buffer) - 1)
2412 count = sizeof(buffer) - 1;
2413 if (copy_from_user(buffer, buf, count))
2414 goto out_no_task;
2415
2416 ret = -EINVAL;
2417 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2418 if (*end == '\n')
2419 end++;
2420 if (end - buffer == 0)
2421 goto out_no_task;
2422
2423 ret = -ESRCH;
2424 task = get_proc_task(file->f_dentry->d_inode);
2425 if (!task)
2426 goto out_no_task;
2427
2428 ret = end - buffer;
2429 mm = get_task_mm(task);
2430 if (!mm)
2431 goto out_no_mm;
2432
2433 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2434 if (val & mask)
2435 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2436 else
2437 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2438 }
2439
2440 mmput(mm);
2441 out_no_mm:
2442 put_task_struct(task);
2443 out_no_task:
2444 return ret;
2445 }
2446
2447 static const struct file_operations proc_coredump_filter_operations = {
2448 .read = proc_coredump_filter_read,
2449 .write = proc_coredump_filter_write,
2450 .llseek = generic_file_llseek,
2451 };
2452 #endif
2453
2454 /*
2455 * /proc/self:
2456 */
2457 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2458 int buflen)
2459 {
2460 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2461 pid_t tgid = task_tgid_nr_ns(current, ns);
2462 char tmp[PROC_NUMBUF];
2463 if (!tgid)
2464 return -ENOENT;
2465 sprintf(tmp, "%d", tgid);
2466 return vfs_readlink(dentry,buffer,buflen,tmp);
2467 }
2468
2469 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2470 {
2471 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2472 pid_t tgid = task_tgid_nr_ns(current, ns);
2473 char *name = ERR_PTR(-ENOENT);
2474 if (tgid) {
2475 name = __getname();
2476 if (!name)
2477 name = ERR_PTR(-ENOMEM);
2478 else
2479 sprintf(name, "%d", tgid);
2480 }
2481 nd_set_link(nd, name);
2482 return NULL;
2483 }
2484
2485 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2486 void *cookie)
2487 {
2488 char *s = nd_get_link(nd);
2489 if (!IS_ERR(s))
2490 __putname(s);
2491 }
2492
2493 static const struct inode_operations proc_self_inode_operations = {
2494 .readlink = proc_self_readlink,
2495 .follow_link = proc_self_follow_link,
2496 .put_link = proc_self_put_link,
2497 };
2498
2499 /*
2500 * proc base
2501 *
2502 * These are the directory entries in the root directory of /proc
2503 * that properly belong to the /proc filesystem, as they describe
2504 * describe something that is process related.
2505 */
2506 static const struct pid_entry proc_base_stuff[] = {
2507 NOD("self", S_IFLNK|S_IRWXUGO,
2508 &proc_self_inode_operations, NULL, {}),
2509 };
2510
2511 /*
2512 * Exceptional case: normally we are not allowed to unhash a busy
2513 * directory. In this case, however, we can do it - no aliasing problems
2514 * due to the way we treat inodes.
2515 */
2516 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
2517 {
2518 struct inode *inode = dentry->d_inode;
2519 struct task_struct *task = get_proc_task(inode);
2520 if (task) {
2521 put_task_struct(task);
2522 return 1;
2523 }
2524 d_drop(dentry);
2525 return 0;
2526 }
2527
2528 static const struct dentry_operations proc_base_dentry_operations =
2529 {
2530 .d_revalidate = proc_base_revalidate,
2531 .d_delete = pid_delete_dentry,
2532 };
2533
2534 static struct dentry *proc_base_instantiate(struct inode *dir,
2535 struct dentry *dentry, struct task_struct *task, const void *ptr)
2536 {
2537 const struct pid_entry *p = ptr;
2538 struct inode *inode;
2539 struct proc_inode *ei;
2540 struct dentry *error;
2541
2542 /* Allocate the inode */
2543 error = ERR_PTR(-ENOMEM);
2544 inode = new_inode(dir->i_sb);
2545 if (!inode)
2546 goto out;
2547
2548 /* Initialize the inode */
2549 ei = PROC_I(inode);
2550 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2551
2552 /*
2553 * grab the reference to the task.
2554 */
2555 ei->pid = get_task_pid(task, PIDTYPE_PID);
2556 if (!ei->pid)
2557 goto out_iput;
2558
2559 inode->i_mode = p->mode;
2560 if (S_ISDIR(inode->i_mode))
2561 inode->i_nlink = 2;
2562 if (S_ISLNK(inode->i_mode))
2563 inode->i_size = 64;
2564 if (p->iop)
2565 inode->i_op = p->iop;
2566 if (p->fop)
2567 inode->i_fop = p->fop;
2568 ei->op = p->op;
2569 dentry->d_op = &proc_base_dentry_operations;
2570 d_add(dentry, inode);
2571 error = NULL;
2572 out:
2573 return error;
2574 out_iput:
2575 iput(inode);
2576 goto out;
2577 }
2578
2579 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2580 {
2581 struct dentry *error;
2582 struct task_struct *task = get_proc_task(dir);
2583 const struct pid_entry *p, *last;
2584
2585 error = ERR_PTR(-ENOENT);
2586
2587 if (!task)
2588 goto out_no_task;
2589
2590 /* Lookup the directory entry */
2591 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2592 for (p = proc_base_stuff; p <= last; p++) {
2593 if (p->len != dentry->d_name.len)
2594 continue;
2595 if (!memcmp(dentry->d_name.name, p->name, p->len))
2596 break;
2597 }
2598 if (p > last)
2599 goto out;
2600
2601 error = proc_base_instantiate(dir, dentry, task, p);
2602
2603 out:
2604 put_task_struct(task);
2605 out_no_task:
2606 return error;
2607 }
2608
2609 static int proc_base_fill_cache(struct file *filp, void *dirent,
2610 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2611 {
2612 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2613 proc_base_instantiate, task, p);
2614 }
2615
2616 #ifdef CONFIG_TASK_IO_ACCOUNTING
2617 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2618 {
2619 struct task_io_accounting acct = task->ioac;
2620 unsigned long flags;
2621
2622 if (whole && lock_task_sighand(task, &flags)) {
2623 struct task_struct *t = task;
2624
2625 task_io_accounting_add(&acct, &task->signal->ioac);
2626 while_each_thread(task, t)
2627 task_io_accounting_add(&acct, &t->ioac);
2628
2629 unlock_task_sighand(task, &flags);
2630 }
2631 return sprintf(buffer,
2632 "rchar: %llu\n"
2633 "wchar: %llu\n"
2634 "syscr: %llu\n"
2635 "syscw: %llu\n"
2636 "read_bytes: %llu\n"
2637 "write_bytes: %llu\n"
2638 "cancelled_write_bytes: %llu\n",
2639 (unsigned long long)acct.rchar,
2640 (unsigned long long)acct.wchar,
2641 (unsigned long long)acct.syscr,
2642 (unsigned long long)acct.syscw,
2643 (unsigned long long)acct.read_bytes,
2644 (unsigned long long)acct.write_bytes,
2645 (unsigned long long)acct.cancelled_write_bytes);
2646 }
2647
2648 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2649 {
2650 return do_io_accounting(task, buffer, 0);
2651 }
2652
2653 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2654 {
2655 return do_io_accounting(task, buffer, 1);
2656 }
2657 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2658
2659 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2660 struct pid *pid, struct task_struct *task)
2661 {
2662 seq_printf(m, "%08x\n", task->personality);
2663 return 0;
2664 }
2665
2666 /*
2667 * Thread groups
2668 */
2669 static const struct file_operations proc_task_operations;
2670 static const struct inode_operations proc_task_inode_operations;
2671
2672 static const struct pid_entry tgid_base_stuff[] = {
2673 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2674 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2675 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2676 #ifdef CONFIG_NET
2677 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2678 #endif
2679 REG("environ", S_IRUSR, proc_environ_operations),
2680 INF("auxv", S_IRUSR, proc_pid_auxv),
2681 ONE("status", S_IRUGO, proc_pid_status),
2682 ONE("personality", S_IRUSR, proc_pid_personality),
2683 INF("limits", S_IRUGO, proc_pid_limits),
2684 #ifdef CONFIG_SCHED_DEBUG
2685 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2686 #endif
2687 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2688 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2689 INF("syscall", S_IRUSR, proc_pid_syscall),
2690 #endif
2691 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2692 ONE("stat", S_IRUGO, proc_tgid_stat),
2693 ONE("statm", S_IRUGO, proc_pid_statm),
2694 REG("maps", S_IRUGO, proc_maps_operations),
2695 #ifdef CONFIG_NUMA
2696 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2697 #endif
2698 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2699 LNK("cwd", proc_cwd_link),
2700 LNK("root", proc_root_link),
2701 LNK("exe", proc_exe_link),
2702 REG("mounts", S_IRUGO, proc_mounts_operations),
2703 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2704 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2705 #ifdef CONFIG_PROC_PAGE_MONITOR
2706 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2707 REG("smaps", S_IRUGO, proc_smaps_operations),
2708 REG("pagemap", S_IRUSR, proc_pagemap_operations),
2709 #endif
2710 #ifdef CONFIG_SECURITY
2711 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2712 #endif
2713 #ifdef CONFIG_KALLSYMS
2714 INF("wchan", S_IRUGO, proc_pid_wchan),
2715 #endif
2716 #ifdef CONFIG_STACKTRACE
2717 ONE("stack", S_IRUSR, proc_pid_stack),
2718 #endif
2719 #ifdef CONFIG_SCHEDSTATS
2720 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2721 #endif
2722 #ifdef CONFIG_LATENCYTOP
2723 REG("latency", S_IRUGO, proc_lstats_operations),
2724 #endif
2725 #ifdef CONFIG_PROC_PID_CPUSET
2726 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2727 #endif
2728 #ifdef CONFIG_CGROUPS
2729 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2730 #endif
2731 INF("oom_score", S_IRUGO, proc_oom_score),
2732 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2733 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2734 #ifdef CONFIG_AUDITSYSCALL
2735 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2736 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2737 #endif
2738 #ifdef CONFIG_FAULT_INJECTION
2739 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2740 #endif
2741 #ifdef CONFIG_ELF_CORE
2742 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2743 #endif
2744 #ifdef CONFIG_TASK_IO_ACCOUNTING
2745 INF("io", S_IRUGO, proc_tgid_io_accounting),
2746 #endif
2747 };
2748
2749 static int proc_tgid_base_readdir(struct file * filp,
2750 void * dirent, filldir_t filldir)
2751 {
2752 return proc_pident_readdir(filp,dirent,filldir,
2753 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2754 }
2755
2756 static const struct file_operations proc_tgid_base_operations = {
2757 .read = generic_read_dir,
2758 .readdir = proc_tgid_base_readdir,
2759 .llseek = default_llseek,
2760 };
2761
2762 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2763 return proc_pident_lookup(dir, dentry,
2764 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2765 }
2766
2767 static const struct inode_operations proc_tgid_base_inode_operations = {
2768 .lookup = proc_tgid_base_lookup,
2769 .getattr = pid_getattr,
2770 .setattr = proc_setattr,
2771 };
2772
2773 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2774 {
2775 struct dentry *dentry, *leader, *dir;
2776 char buf[PROC_NUMBUF];
2777 struct qstr name;
2778
2779 name.name = buf;
2780 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2781 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2782 if (dentry) {
2783 shrink_dcache_parent(dentry);
2784 d_drop(dentry);
2785 dput(dentry);
2786 }
2787
2788 name.name = buf;
2789 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2790 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2791 if (!leader)
2792 goto out;
2793
2794 name.name = "task";
2795 name.len = strlen(name.name);
2796 dir = d_hash_and_lookup(leader, &name);
2797 if (!dir)
2798 goto out_put_leader;
2799
2800 name.name = buf;
2801 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2802 dentry = d_hash_and_lookup(dir, &name);
2803 if (dentry) {
2804 shrink_dcache_parent(dentry);
2805 d_drop(dentry);
2806 dput(dentry);
2807 }
2808
2809 dput(dir);
2810 out_put_leader:
2811 dput(leader);
2812 out:
2813 return;
2814 }
2815
2816 /**
2817 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2818 * @task: task that should be flushed.
2819 *
2820 * When flushing dentries from proc, one needs to flush them from global
2821 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2822 * in. This call is supposed to do all of this job.
2823 *
2824 * Looks in the dcache for
2825 * /proc/@pid
2826 * /proc/@tgid/task/@pid
2827 * if either directory is present flushes it and all of it'ts children
2828 * from the dcache.
2829 *
2830 * It is safe and reasonable to cache /proc entries for a task until
2831 * that task exits. After that they just clog up the dcache with
2832 * useless entries, possibly causing useful dcache entries to be
2833 * flushed instead. This routine is proved to flush those useless
2834 * dcache entries at process exit time.
2835 *
2836 * NOTE: This routine is just an optimization so it does not guarantee
2837 * that no dcache entries will exist at process exit time it
2838 * just makes it very unlikely that any will persist.
2839 */
2840
2841 void proc_flush_task(struct task_struct *task)
2842 {
2843 int i;
2844 struct pid *pid, *tgid;
2845 struct upid *upid;
2846
2847 pid = task_pid(task);
2848 tgid = task_tgid(task);
2849
2850 for (i = 0; i <= pid->level; i++) {
2851 upid = &pid->numbers[i];
2852 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2853 tgid->numbers[i].nr);
2854 }
2855
2856 upid = &pid->numbers[pid->level];
2857 if (upid->nr == 1)
2858 pid_ns_release_proc(upid->ns);
2859 }
2860
2861 static struct dentry *proc_pid_instantiate(struct inode *dir,
2862 struct dentry * dentry,
2863 struct task_struct *task, const void *ptr)
2864 {
2865 struct dentry *error = ERR_PTR(-ENOENT);
2866 struct inode *inode;
2867
2868 inode = proc_pid_make_inode(dir->i_sb, task);
2869 if (!inode)
2870 goto out;
2871
2872 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2873 inode->i_op = &proc_tgid_base_inode_operations;
2874 inode->i_fop = &proc_tgid_base_operations;
2875 inode->i_flags|=S_IMMUTABLE;
2876
2877 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2878 ARRAY_SIZE(tgid_base_stuff));
2879
2880 dentry->d_op = &pid_dentry_operations;
2881
2882 d_add(dentry, inode);
2883 /* Close the race of the process dying before we return the dentry */
2884 if (pid_revalidate(dentry, NULL))
2885 error = NULL;
2886 out:
2887 return error;
2888 }
2889
2890 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2891 {
2892 struct dentry *result;
2893 struct task_struct *task;
2894 unsigned tgid;
2895 struct pid_namespace *ns;
2896
2897 result = proc_base_lookup(dir, dentry);
2898 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2899 goto out;
2900
2901 tgid = name_to_int(dentry);
2902 if (tgid == ~0U)
2903 goto out;
2904
2905 ns = dentry->d_sb->s_fs_info;
2906 rcu_read_lock();
2907 task = find_task_by_pid_ns(tgid, ns);
2908 if (task)
2909 get_task_struct(task);
2910 rcu_read_unlock();
2911 if (!task)
2912 goto out;
2913
2914 result = proc_pid_instantiate(dir, dentry, task, NULL);
2915 put_task_struct(task);
2916 out:
2917 return result;
2918 }
2919
2920 /*
2921 * Find the first task with tgid >= tgid
2922 *
2923 */
2924 struct tgid_iter {
2925 unsigned int tgid;
2926 struct task_struct *task;
2927 };
2928 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2929 {
2930 struct pid *pid;
2931
2932 if (iter.task)
2933 put_task_struct(iter.task);
2934 rcu_read_lock();
2935 retry:
2936 iter.task = NULL;
2937 pid = find_ge_pid(iter.tgid, ns);
2938 if (pid) {
2939 iter.tgid = pid_nr_ns(pid, ns);
2940 iter.task = pid_task(pid, PIDTYPE_PID);
2941 /* What we to know is if the pid we have find is the
2942 * pid of a thread_group_leader. Testing for task
2943 * being a thread_group_leader is the obvious thing
2944 * todo but there is a window when it fails, due to
2945 * the pid transfer logic in de_thread.
2946 *
2947 * So we perform the straight forward test of seeing
2948 * if the pid we have found is the pid of a thread
2949 * group leader, and don't worry if the task we have
2950 * found doesn't happen to be a thread group leader.
2951 * As we don't care in the case of readdir.
2952 */
2953 if (!iter.task || !has_group_leader_pid(iter.task)) {
2954 iter.tgid += 1;
2955 goto retry;
2956 }
2957 get_task_struct(iter.task);
2958 }
2959 rcu_read_unlock();
2960 return iter;
2961 }
2962
2963 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
2964
2965 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2966 struct tgid_iter iter)
2967 {
2968 char name[PROC_NUMBUF];
2969 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
2970 return proc_fill_cache(filp, dirent, filldir, name, len,
2971 proc_pid_instantiate, iter.task, NULL);
2972 }
2973
2974 /* for the /proc/ directory itself, after non-process stuff has been done */
2975 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2976 {
2977 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2978 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
2979 struct tgid_iter iter;
2980 struct pid_namespace *ns;
2981
2982 if (!reaper)
2983 goto out_no_task;
2984
2985 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
2986 const struct pid_entry *p = &proc_base_stuff[nr];
2987 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
2988 goto out;
2989 }
2990
2991 ns = filp->f_dentry->d_sb->s_fs_info;
2992 iter.task = NULL;
2993 iter.tgid = filp->f_pos - TGID_OFFSET;
2994 for (iter = next_tgid(ns, iter);
2995 iter.task;
2996 iter.tgid += 1, iter = next_tgid(ns, iter)) {
2997 filp->f_pos = iter.tgid + TGID_OFFSET;
2998 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
2999 put_task_struct(iter.task);
3000 goto out;
3001 }
3002 }
3003 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3004 out:
3005 put_task_struct(reaper);
3006 out_no_task:
3007 return 0;
3008 }
3009
3010 /*
3011 * Tasks
3012 */
3013 static const struct pid_entry tid_base_stuff[] = {
3014 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3015 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3016 REG("environ", S_IRUSR, proc_environ_operations),
3017 INF("auxv", S_IRUSR, proc_pid_auxv),
3018 ONE("status", S_IRUGO, proc_pid_status),
3019 ONE("personality", S_IRUSR, proc_pid_personality),
3020 INF("limits", S_IRUGO, proc_pid_limits),
3021 #ifdef CONFIG_SCHED_DEBUG
3022 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3023 #endif
3024 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3025 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3026 INF("syscall", S_IRUSR, proc_pid_syscall),
3027 #endif
3028 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3029 ONE("stat", S_IRUGO, proc_tid_stat),
3030 ONE("statm", S_IRUGO, proc_pid_statm),
3031 REG("maps", S_IRUGO, proc_maps_operations),
3032 #ifdef CONFIG_NUMA
3033 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3034 #endif
3035 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3036 LNK("cwd", proc_cwd_link),
3037 LNK("root", proc_root_link),
3038 LNK("exe", proc_exe_link),
3039 REG("mounts", S_IRUGO, proc_mounts_operations),
3040 REG("mountinfo", S_IRUGO, proc_mountinfo_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_IRUSR, 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_IRUSR, 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_IRUSR, 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_TASK_IO_ACCOUNTING
3078 INF("io", S_IRUGO, proc_tid_io_accounting),
3079 #endif
3080 };
3081
3082 static int proc_tid_base_readdir(struct file * filp,
3083 void * dirent, filldir_t filldir)
3084 {
3085 return proc_pident_readdir(filp,dirent,filldir,
3086 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3087 }
3088
3089 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3090 return proc_pident_lookup(dir, dentry,
3091 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3092 }
3093
3094 static const struct file_operations proc_tid_base_operations = {
3095 .read = generic_read_dir,
3096 .readdir = proc_tid_base_readdir,
3097 .llseek = default_llseek,
3098 };
3099
3100 static const struct inode_operations proc_tid_base_inode_operations = {
3101 .lookup = proc_tid_base_lookup,
3102 .getattr = pid_getattr,
3103 .setattr = proc_setattr,
3104 };
3105
3106 static struct dentry *proc_task_instantiate(struct inode *dir,
3107 struct dentry *dentry, struct task_struct *task, const void *ptr)
3108 {
3109 struct dentry *error = ERR_PTR(-ENOENT);
3110 struct inode *inode;
3111 inode = proc_pid_make_inode(dir->i_sb, task);
3112
3113 if (!inode)
3114 goto out;
3115 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3116 inode->i_op = &proc_tid_base_inode_operations;
3117 inode->i_fop = &proc_tid_base_operations;
3118 inode->i_flags|=S_IMMUTABLE;
3119
3120 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3121 ARRAY_SIZE(tid_base_stuff));
3122
3123 dentry->d_op = &pid_dentry_operations;
3124
3125 d_add(dentry, inode);
3126 /* Close the race of the process dying before we return the dentry */
3127 if (pid_revalidate(dentry, NULL))
3128 error = NULL;
3129 out:
3130 return error;
3131 }
3132
3133 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3134 {
3135 struct dentry *result = ERR_PTR(-ENOENT);
3136 struct task_struct *task;
3137 struct task_struct *leader = get_proc_task(dir);
3138 unsigned tid;
3139 struct pid_namespace *ns;
3140
3141 if (!leader)
3142 goto out_no_task;
3143
3144 tid = name_to_int(dentry);
3145 if (tid == ~0U)
3146 goto out;
3147
3148 ns = dentry->d_sb->s_fs_info;
3149 rcu_read_lock();
3150 task = find_task_by_pid_ns(tid, ns);
3151 if (task)
3152 get_task_struct(task);
3153 rcu_read_unlock();
3154 if (!task)
3155 goto out;
3156 if (!same_thread_group(leader, task))
3157 goto out_drop_task;
3158
3159 result = proc_task_instantiate(dir, dentry, task, NULL);
3160 out_drop_task:
3161 put_task_struct(task);
3162 out:
3163 put_task_struct(leader);
3164 out_no_task:
3165 return result;
3166 }
3167
3168 /*
3169 * Find the first tid of a thread group to return to user space.
3170 *
3171 * Usually this is just the thread group leader, but if the users
3172 * buffer was too small or there was a seek into the middle of the
3173 * directory we have more work todo.
3174 *
3175 * In the case of a short read we start with find_task_by_pid.
3176 *
3177 * In the case of a seek we start with the leader and walk nr
3178 * threads past it.
3179 */
3180 static struct task_struct *first_tid(struct task_struct *leader,
3181 int tid, int nr, struct pid_namespace *ns)
3182 {
3183 struct task_struct *pos;
3184
3185 rcu_read_lock();
3186 /* Attempt to start with the pid of a thread */
3187 if (tid && (nr > 0)) {
3188 pos = find_task_by_pid_ns(tid, ns);
3189 if (pos && (pos->group_leader == leader))
3190 goto found;
3191 }
3192
3193 /* If nr exceeds the number of threads there is nothing todo */
3194 pos = NULL;
3195 if (nr && nr >= get_nr_threads(leader))
3196 goto out;
3197
3198 /* If we haven't found our starting place yet start
3199 * with the leader and walk nr threads forward.
3200 */
3201 for (pos = leader; nr > 0; --nr) {
3202 pos = next_thread(pos);
3203 if (pos == leader) {
3204 pos = NULL;
3205 goto out;
3206 }
3207 }
3208 found:
3209 get_task_struct(pos);
3210 out:
3211 rcu_read_unlock();
3212 return pos;
3213 }
3214
3215 /*
3216 * Find the next thread in the thread list.
3217 * Return NULL if there is an error or no next thread.
3218 *
3219 * The reference to the input task_struct is released.
3220 */
3221 static struct task_struct *next_tid(struct task_struct *start)
3222 {
3223 struct task_struct *pos = NULL;
3224 rcu_read_lock();
3225 if (pid_alive(start)) {
3226 pos = next_thread(start);
3227 if (thread_group_leader(pos))
3228 pos = NULL;
3229 else
3230 get_task_struct(pos);
3231 }
3232 rcu_read_unlock();
3233 put_task_struct(start);
3234 return pos;
3235 }
3236
3237 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3238 struct task_struct *task, int tid)
3239 {
3240 char name[PROC_NUMBUF];
3241 int len = snprintf(name, sizeof(name), "%d", tid);
3242 return proc_fill_cache(filp, dirent, filldir, name, len,
3243 proc_task_instantiate, task, NULL);
3244 }
3245
3246 /* for the /proc/TGID/task/ directories */
3247 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3248 {
3249 struct dentry *dentry = filp->f_path.dentry;
3250 struct inode *inode = dentry->d_inode;
3251 struct task_struct *leader = NULL;
3252 struct task_struct *task;
3253 int retval = -ENOENT;
3254 ino_t ino;
3255 int tid;
3256 struct pid_namespace *ns;
3257
3258 task = get_proc_task(inode);
3259 if (!task)
3260 goto out_no_task;
3261 rcu_read_lock();
3262 if (pid_alive(task)) {
3263 leader = task->group_leader;
3264 get_task_struct(leader);
3265 }
3266 rcu_read_unlock();
3267 put_task_struct(task);
3268 if (!leader)
3269 goto out_no_task;
3270 retval = 0;
3271
3272 switch ((unsigned long)filp->f_pos) {
3273 case 0:
3274 ino = inode->i_ino;
3275 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3276 goto out;
3277 filp->f_pos++;
3278 /* fall through */
3279 case 1:
3280 ino = parent_ino(dentry);
3281 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3282 goto out;
3283 filp->f_pos++;
3284 /* fall through */
3285 }
3286
3287 /* f_version caches the tgid value that the last readdir call couldn't
3288 * return. lseek aka telldir automagically resets f_version to 0.
3289 */
3290 ns = filp->f_dentry->d_sb->s_fs_info;
3291 tid = (int)filp->f_version;
3292 filp->f_version = 0;
3293 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3294 task;
3295 task = next_tid(task), filp->f_pos++) {
3296 tid = task_pid_nr_ns(task, ns);
3297 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3298 /* returning this tgid failed, save it as the first
3299 * pid for the next readir call */
3300 filp->f_version = (u64)tid;
3301 put_task_struct(task);
3302 break;
3303 }
3304 }
3305 out:
3306 put_task_struct(leader);
3307 out_no_task:
3308 return retval;
3309 }
3310
3311 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3312 {
3313 struct inode *inode = dentry->d_inode;
3314 struct task_struct *p = get_proc_task(inode);
3315 generic_fillattr(inode, stat);
3316
3317 if (p) {
3318 stat->nlink += get_nr_threads(p);
3319 put_task_struct(p);
3320 }
3321
3322 return 0;
3323 }
3324
3325 static const struct inode_operations proc_task_inode_operations = {
3326 .lookup = proc_task_lookup,
3327 .getattr = proc_task_getattr,
3328 .setattr = proc_setattr,
3329 };
3330
3331 static const struct file_operations proc_task_operations = {
3332 .read = generic_read_dir,
3333 .readdir = proc_task_readdir,
3334 .llseek = default_llseek,
3335 };
Linux 2.6 libata-dev (mirror)