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Add linux-next specific files for 20110716
[linux-2.6/next.git] / fs / proc / base.c
blob0a7df77da745e27ce4617468f6437fc88aba79fc
1 /*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50 #include <asm/uaccess.h>
51
52 #include <linux/errno.h>
53 #include <linux/time.h>
54 #include <linux/proc_fs.h>
55 #include <linux/stat.h>
56 #include <linux/task_io_accounting_ops.h>
57 #include <linux/init.h>
58 #include <linux/capability.h>
59 #include <linux/file.h>
60 #include <linux/fdtable.h>
61 #include <linux/string.h>
62 #include <linux/seq_file.h>
63 #include <linux/namei.h>
64 #include <linux/mnt_namespace.h>
65 #include <linux/mm.h>
66 #include <linux/swap.h>
67 #include <linux/rcupdate.h>
68 #include <linux/kallsyms.h>
69 #include <linux/stacktrace.h>
70 #include <linux/resource.h>
71 #include <linux/module.h>
72 #include <linux/mount.h>
73 #include <linux/security.h>
74 #include <linux/ptrace.h>
75 #include <linux/tracehook.h>
76 #include <linux/cgroup.h>
77 #include <linux/cpuset.h>
78 #include <linux/audit.h>
79 #include <linux/poll.h>
80 #include <linux/nsproxy.h>
81 #include <linux/oom.h>
82 #include <linux/elf.h>
83 #include <linux/pid_namespace.h>
84 #include <linux/fs_struct.h>
85 #include <linux/slab.h>
86 #ifdef CONFIG_HARDWALL
87 #include <asm/hardwall.h>
88 #endif
89 #include "internal.h"
90
91 /* NOTE:
92 * Implementing inode permission operations in /proc is almost
93 * certainly an error. Permission checks need to happen during
94 * each system call not at open time. The reason is that most of
95 * what we wish to check for permissions in /proc varies at runtime.
96 *
97 * The classic example of a problem is opening file descriptors
98 * in /proc for a task before it execs a suid executable.
99 */
100
101 struct pid_entry {
102 char *name;
103 int len;
104 mode_t mode;
105 const struct inode_operations *iop;
106 const struct file_operations *fop;
107 union proc_op op;
108 };
109
110 #define NOD(NAME, MODE, IOP, FOP, OP) { \
111 .name = (NAME), \
112 .len = sizeof(NAME) - 1, \
113 .mode = MODE, \
114 .iop = IOP, \
115 .fop = FOP, \
116 .op = OP, \
117 }
118
119 #define DIR(NAME, MODE, iops, fops) \
120 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
121 #define LNK(NAME, get_link) \
122 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
123 &proc_pid_link_inode_operations, NULL, \
124 { .proc_get_link = get_link } )
125 #define REG(NAME, MODE, fops) \
126 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
127 #define INF(NAME, MODE, read) \
128 NOD(NAME, (S_IFREG|(MODE)), \
129 NULL, &proc_info_file_operations, \
130 { .proc_read = read } )
131 #define ONE(NAME, MODE, show) \
132 NOD(NAME, (S_IFREG|(MODE)), \
133 NULL, &proc_single_file_operations, \
134 { .proc_show = show } )
135
136 /*
137 * Count the number of hardlinks for the pid_entry table, excluding the .
138 * and .. links.
139 */
140 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
141 unsigned int n)
142 {
143 unsigned int i;
144 unsigned int count;
145
146 count = 0;
147 for (i = 0; i < n; ++i) {
148 if (S_ISDIR(entries[i].mode))
149 ++count;
150 }
151
152 return count;
153 }
154
155 static int get_task_root(struct task_struct *task, struct path *root)
156 {
157 int result = -ENOENT;
158
159 task_lock(task);
160 if (task->fs) {
161 get_fs_root(task->fs, root);
162 result = 0;
163 }
164 task_unlock(task);
165 return result;
166 }
167
168 static int proc_cwd_link(struct inode *inode, struct path *path)
169 {
170 struct task_struct *task = get_proc_task(inode);
171 int result = -ENOENT;
172
173 if (task) {
174 task_lock(task);
175 if (task->fs) {
176 get_fs_pwd(task->fs, path);
177 result = 0;
178 }
179 task_unlock(task);
180 put_task_struct(task);
181 }
182 return result;
183 }
184
185 static int proc_root_link(struct inode *inode, struct path *path)
186 {
187 struct task_struct *task = get_proc_task(inode);
188 int result = -ENOENT;
189
190 if (task) {
191 result = get_task_root(task, path);
192 put_task_struct(task);
193 }
194 return result;
195 }
196
197 static struct mm_struct *__check_mem_permission(struct task_struct *task)
198 {
199 struct mm_struct *mm;
200
201 mm = get_task_mm(task);
202 if (!mm)
203 return ERR_PTR(-EINVAL);
204
205 /*
206 * A task can always look at itself, in case it chooses
207 * to use system calls instead of load instructions.
208 */
209 if (task == current)
210 return mm;
211
212 /*
213 * If current is actively ptrace'ing, and would also be
214 * permitted to freshly attach with ptrace now, permit it.
215 */
216 if (task_is_stopped_or_traced(task)) {
217 int match;
218 rcu_read_lock();
219 match = (ptrace_parent(task) == current);
220 rcu_read_unlock();
221 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
222 return mm;
223 }
224
225 /*
226 * No one else is allowed.
227 */
228 mmput(mm);
229 return ERR_PTR(-EPERM);
230 }
231
232 /*
233 * If current may access user memory in @task return a reference to the
234 * corresponding mm, otherwise ERR_PTR.
235 */
236 static struct mm_struct *check_mem_permission(struct task_struct *task)
237 {
238 struct mm_struct *mm;
239 int err;
240
241 /*
242 * Avoid racing if task exec's as we might get a new mm but validate
243 * against old credentials.
244 */
245 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
246 if (err)
247 return ERR_PTR(err);
248
249 mm = __check_mem_permission(task);
250 mutex_unlock(&task->signal->cred_guard_mutex);
251
252 return mm;
253 }
254
255 struct mm_struct *mm_for_maps(struct task_struct *task)
256 {
257 struct mm_struct *mm;
258 int err;
259
260 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
261 if (err)
262 return ERR_PTR(err);
263
264 mm = get_task_mm(task);
265 if (mm && mm != current->mm &&
266 !ptrace_may_access(task, PTRACE_MODE_READ)) {
267 mmput(mm);
268 mm = ERR_PTR(-EACCES);
269 }
270 mutex_unlock(&task->signal->cred_guard_mutex);
271
272 return mm;
273 }
274
275 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
276 {
277 int res = 0;
278 unsigned int len;
279 struct mm_struct *mm = get_task_mm(task);
280 if (!mm)
281 goto out;
282 if (!mm->arg_end)
283 goto out_mm; /* Shh! No looking before we're done */
284
285 len = mm->arg_end - mm->arg_start;
286
287 if (len > PAGE_SIZE)
288 len = PAGE_SIZE;
289
290 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
291
292 // If the nul at the end of args has been overwritten, then
293 // assume application is using setproctitle(3).
294 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
295 len = strnlen(buffer, res);
296 if (len < res) {
297 res = len;
298 } else {
299 len = mm->env_end - mm->env_start;
300 if (len > PAGE_SIZE - res)
301 len = PAGE_SIZE - res;
302 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
303 res = strnlen(buffer, res);
304 }
305 }
306 out_mm:
307 mmput(mm);
308 out:
309 return res;
310 }
311
312 static int proc_pid_auxv(struct task_struct *task, char *buffer)
313 {
314 struct mm_struct *mm = mm_for_maps(task);
315 int res = PTR_ERR(mm);
316 if (mm && !IS_ERR(mm)) {
317 unsigned int nwords = 0;
318 do {
319 nwords += 2;
320 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
321 res = nwords * sizeof(mm->saved_auxv[0]);
322 if (res > PAGE_SIZE)
323 res = PAGE_SIZE;
324 memcpy(buffer, mm->saved_auxv, res);
325 mmput(mm);
326 }
327 return res;
328 }
329
330
331 #ifdef CONFIG_KALLSYMS
332 /*
333 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
334 * Returns the resolved symbol. If that fails, simply return the address.
335 */
336 static int proc_pid_wchan(struct task_struct *task, char *buffer)
337 {
338 unsigned long wchan;
339 char symname[KSYM_NAME_LEN];
340
341 wchan = get_wchan(task);
342
343 if (lookup_symbol_name(wchan, symname) < 0)
344 if (!ptrace_may_access(task, PTRACE_MODE_READ))
345 return 0;
346 else
347 return sprintf(buffer, "%lu", wchan);
348 else
349 return sprintf(buffer, "%s", symname);
350 }
351 #endif /* CONFIG_KALLSYMS */
352
353 static int lock_trace(struct task_struct *task)
354 {
355 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
356 if (err)
357 return err;
358 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
359 mutex_unlock(&task->signal->cred_guard_mutex);
360 return -EPERM;
361 }
362 return 0;
363 }
364
365 static void unlock_trace(struct task_struct *task)
366 {
367 mutex_unlock(&task->signal->cred_guard_mutex);
368 }
369
370 #ifdef CONFIG_STACKTRACE
371
372 #define MAX_STACK_TRACE_DEPTH 64
373
374 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
375 struct pid *pid, struct task_struct *task)
376 {
377 struct stack_trace trace;
378 unsigned long *entries;
379 int err;
380 int i;
381
382 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
383 if (!entries)
384 return -ENOMEM;
385
386 trace.nr_entries = 0;
387 trace.max_entries = MAX_STACK_TRACE_DEPTH;
388 trace.entries = entries;
389 trace.skip = 0;
390
391 err = lock_trace(task);
392 if (!err) {
393 save_stack_trace_tsk(task, &trace);
394
395 for (i = 0; i < trace.nr_entries; i++) {
396 seq_printf(m, "[<%pK>] %pS\n",
397 (void *)entries[i], (void *)entries[i]);
398 }
399 unlock_trace(task);
400 }
401 kfree(entries);
402
403 return err;
404 }
405 #endif
406
407 #ifdef CONFIG_SCHEDSTATS
408 /*
409 * Provides /proc/PID/schedstat
410 */
411 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
412 {
413 return sprintf(buffer, "%llu %llu %lu\n",
414 (unsigned long long)task->se.sum_exec_runtime,
415 (unsigned long long)task->sched_info.run_delay,
416 task->sched_info.pcount);
417 }
418 #endif
419
420 #ifdef CONFIG_LATENCYTOP
421 static int lstats_show_proc(struct seq_file *m, void *v)
422 {
423 int i;
424 struct inode *inode = m->private;
425 struct task_struct *task = get_proc_task(inode);
426
427 if (!task)
428 return -ESRCH;
429 seq_puts(m, "Latency Top version : v0.1\n");
430 for (i = 0; i < 32; i++) {
431 struct latency_record *lr = &task->latency_record[i];
432 if (lr->backtrace[0]) {
433 int q;
434 seq_printf(m, "%i %li %li",
435 lr->count, lr->time, lr->max);
436 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
437 unsigned long bt = lr->backtrace[q];
438 if (!bt)
439 break;
440 if (bt == ULONG_MAX)
441 break;
442 seq_printf(m, " %ps", (void *)bt);
443 }
444 seq_putc(m, '\n');
445 }
446
447 }
448 put_task_struct(task);
449 return 0;
450 }
451
452 static int lstats_open(struct inode *inode, struct file *file)
453 {
454 return single_open(file, lstats_show_proc, inode);
455 }
456
457 static ssize_t lstats_write(struct file *file, const char __user *buf,
458 size_t count, loff_t *offs)
459 {
460 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
461
462 if (!task)
463 return -ESRCH;
464 clear_all_latency_tracing(task);
465 put_task_struct(task);
466
467 return count;
468 }
469
470 static const struct file_operations proc_lstats_operations = {
471 .open = lstats_open,
472 .read = seq_read,
473 .write = lstats_write,
474 .llseek = seq_lseek,
475 .release = single_release,
476 };
477
478 #endif
479
480 static int proc_oom_score(struct task_struct *task, char *buffer)
481 {
482 unsigned long points = 0;
483
484 read_lock(&tasklist_lock);
485 if (pid_alive(task))
486 points = oom_badness(task, NULL, NULL,
487 totalram_pages + total_swap_pages);
488 read_unlock(&tasklist_lock);
489 return sprintf(buffer, "%lu\n", points);
490 }
491
492 struct limit_names {
493 char *name;
494 char *unit;
495 };
496
497 static const struct limit_names lnames[RLIM_NLIMITS] = {
498 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
499 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
500 [RLIMIT_DATA] = {"Max data size", "bytes"},
501 [RLIMIT_STACK] = {"Max stack size", "bytes"},
502 [RLIMIT_CORE] = {"Max core file size", "bytes"},
503 [RLIMIT_RSS] = {"Max resident set", "bytes"},
504 [RLIMIT_NPROC] = {"Max processes", "processes"},
505 [RLIMIT_NOFILE] = {"Max open files", "files"},
506 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
507 [RLIMIT_AS] = {"Max address space", "bytes"},
508 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
509 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
510 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
511 [RLIMIT_NICE] = {"Max nice priority", NULL},
512 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
513 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
514 };
515
516 /* Display limits for a process */
517 static int proc_pid_limits(struct task_struct *task, char *buffer)
518 {
519 unsigned int i;
520 int count = 0;
521 unsigned long flags;
522 char *bufptr = buffer;
523
524 struct rlimit rlim[RLIM_NLIMITS];
525
526 if (!lock_task_sighand(task, &flags))
527 return 0;
528 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
529 unlock_task_sighand(task, &flags);
530
531 /*
532 * print the file header
533 */
534 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
535 "Limit", "Soft Limit", "Hard Limit", "Units");
536
537 for (i = 0; i < RLIM_NLIMITS; i++) {
538 if (rlim[i].rlim_cur == RLIM_INFINITY)
539 count += sprintf(&bufptr[count], "%-25s %-20s ",
540 lnames[i].name, "unlimited");
541 else
542 count += sprintf(&bufptr[count], "%-25s %-20lu ",
543 lnames[i].name, rlim[i].rlim_cur);
544
545 if (rlim[i].rlim_max == RLIM_INFINITY)
546 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
547 else
548 count += sprintf(&bufptr[count], "%-20lu ",
549 rlim[i].rlim_max);
550
551 if (lnames[i].unit)
552 count += sprintf(&bufptr[count], "%-10s\n",
553 lnames[i].unit);
554 else
555 count += sprintf(&bufptr[count], "\n");
556 }
557
558 return count;
559 }
560
561 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
562 static int proc_pid_syscall(struct task_struct *task, char *buffer)
563 {
564 long nr;
565 unsigned long args[6], sp, pc;
566 int res = lock_trace(task);
567 if (res)
568 return res;
569
570 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
571 res = sprintf(buffer, "running\n");
572 else if (nr < 0)
573 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
574 else
575 res = sprintf(buffer,
576 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
577 nr,
578 args[0], args[1], args[2], args[3], args[4], args[5],
579 sp, pc);
580 unlock_trace(task);
581 return res;
582 }
583 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
584
585 /************************************************************************/
586 /* Here the fs part begins */
587 /************************************************************************/
588
589 /* permission checks */
590 static int proc_fd_access_allowed(struct inode *inode)
591 {
592 struct task_struct *task;
593 int allowed = 0;
594 /* Allow access to a task's file descriptors if it is us or we
595 * may use ptrace attach to the process and find out that
596 * information.
597 */
598 task = get_proc_task(inode);
599 if (task) {
600 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
601 put_task_struct(task);
602 }
603 return allowed;
604 }
605
606 int proc_setattr(struct dentry *dentry, struct iattr *attr)
607 {
608 int error;
609 struct inode *inode = dentry->d_inode;
610
611 if (attr->ia_valid & ATTR_MODE)
612 return -EPERM;
613
614 error = inode_change_ok(inode, attr);
615 if (error)
616 return error;
617
618 if ((attr->ia_valid & ATTR_SIZE) &&
619 attr->ia_size != i_size_read(inode)) {
620 error = vmtruncate(inode, attr->ia_size);
621 if (error)
622 return error;
623 }
624
625 setattr_copy(inode, attr);
626 mark_inode_dirty(inode);
627 return 0;
628 }
629
630 static const struct inode_operations proc_def_inode_operations = {
631 .setattr = proc_setattr,
632 };
633
634 static int mounts_open_common(struct inode *inode, struct file *file,
635 const struct seq_operations *op)
636 {
637 struct task_struct *task = get_proc_task(inode);
638 struct nsproxy *nsp;
639 struct mnt_namespace *ns = NULL;
640 struct path root;
641 struct proc_mounts *p;
642 int ret = -EINVAL;
643
644 if (task) {
645 rcu_read_lock();
646 nsp = task_nsproxy(task);
647 if (nsp) {
648 ns = nsp->mnt_ns;
649 if (ns)
650 get_mnt_ns(ns);
651 }
652 rcu_read_unlock();
653 if (ns && get_task_root(task, &root) == 0)
654 ret = 0;
655 put_task_struct(task);
656 }
657
658 if (!ns)
659 goto err;
660 if (ret)
661 goto err_put_ns;
662
663 ret = -ENOMEM;
664 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
665 if (!p)
666 goto err_put_path;
667
668 file->private_data = &p->m;
669 ret = seq_open(file, op);
670 if (ret)
671 goto err_free;
672
673 p->m.private = p;
674 p->ns = ns;
675 p->root = root;
676 p->event = ns->event;
677
678 return 0;
679
680 err_free:
681 kfree(p);
682 err_put_path:
683 path_put(&root);
684 err_put_ns:
685 put_mnt_ns(ns);
686 err:
687 return ret;
688 }
689
690 static int mounts_release(struct inode *inode, struct file *file)
691 {
692 struct proc_mounts *p = file->private_data;
693 path_put(&p->root);
694 put_mnt_ns(p->ns);
695 return seq_release(inode, file);
696 }
697
698 static unsigned mounts_poll(struct file *file, poll_table *wait)
699 {
700 struct proc_mounts *p = file->private_data;
701 unsigned res = POLLIN | POLLRDNORM;
702
703 poll_wait(file, &p->ns->poll, wait);
704 if (mnt_had_events(p))
705 res |= POLLERR | POLLPRI;
706
707 return res;
708 }
709
710 static int mounts_open(struct inode *inode, struct file *file)
711 {
712 return mounts_open_common(inode, file, &mounts_op);
713 }
714
715 static const struct file_operations proc_mounts_operations = {
716 .open = mounts_open,
717 .read = seq_read,
718 .llseek = seq_lseek,
719 .release = mounts_release,
720 .poll = mounts_poll,
721 };
722
723 static int mountinfo_open(struct inode *inode, struct file *file)
724 {
725 return mounts_open_common(inode, file, &mountinfo_op);
726 }
727
728 static const struct file_operations proc_mountinfo_operations = {
729 .open = mountinfo_open,
730 .read = seq_read,
731 .llseek = seq_lseek,
732 .release = mounts_release,
733 .poll = mounts_poll,
734 };
735
736 static int mountstats_open(struct inode *inode, struct file *file)
737 {
738 return mounts_open_common(inode, file, &mountstats_op);
739 }
740
741 static const struct file_operations proc_mountstats_operations = {
742 .open = mountstats_open,
743 .read = seq_read,
744 .llseek = seq_lseek,
745 .release = mounts_release,
746 };
747
748 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
749
750 static ssize_t proc_info_read(struct file * file, char __user * buf,
751 size_t count, loff_t *ppos)
752 {
753 struct inode * inode = file->f_path.dentry->d_inode;
754 unsigned long page;
755 ssize_t length;
756 struct task_struct *task = get_proc_task(inode);
757
758 length = -ESRCH;
759 if (!task)
760 goto out_no_task;
761
762 if (count > PROC_BLOCK_SIZE)
763 count = PROC_BLOCK_SIZE;
764
765 length = -ENOMEM;
766 if (!(page = __get_free_page(GFP_TEMPORARY)))
767 goto out;
768
769 length = PROC_I(inode)->op.proc_read(task, (char*)page);
770
771 if (length >= 0)
772 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
773 free_page(page);
774 out:
775 put_task_struct(task);
776 out_no_task:
777 return length;
778 }
779
780 static const struct file_operations proc_info_file_operations = {
781 .read = proc_info_read,
782 .llseek = generic_file_llseek,
783 };
784
785 static int proc_single_show(struct seq_file *m, void *v)
786 {
787 struct inode *inode = m->private;
788 struct pid_namespace *ns;
789 struct pid *pid;
790 struct task_struct *task;
791 int ret;
792
793 ns = inode->i_sb->s_fs_info;
794 pid = proc_pid(inode);
795 task = get_pid_task(pid, PIDTYPE_PID);
796 if (!task)
797 return -ESRCH;
798
799 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
800
801 put_task_struct(task);
802 return ret;
803 }
804
805 static int proc_single_open(struct inode *inode, struct file *filp)
806 {
807 return single_open(filp, proc_single_show, inode);
808 }
809
810 static const struct file_operations proc_single_file_operations = {
811 .open = proc_single_open,
812 .read = seq_read,
813 .llseek = seq_lseek,
814 .release = single_release,
815 };
816
817 static int mem_open(struct inode* inode, struct file* file)
818 {
819 file->private_data = (void*)((long)current->self_exec_id);
820 /* OK to pass negative loff_t, we can catch out-of-range */
821 file->f_mode |= FMODE_UNSIGNED_OFFSET;
822 return 0;
823 }
824
825 static ssize_t mem_read(struct file * file, char __user * buf,
826 size_t count, loff_t *ppos)
827 {
828 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
829 char *page;
830 unsigned long src = *ppos;
831 int ret = -ESRCH;
832 struct mm_struct *mm;
833
834 if (!task)
835 goto out_no_task;
836
837 ret = -ENOMEM;
838 page = (char *)__get_free_page(GFP_TEMPORARY);
839 if (!page)
840 goto out;
841
842 mm = check_mem_permission(task);
843 ret = PTR_ERR(mm);
844 if (IS_ERR(mm))
845 goto out_free;
846
847 ret = -EIO;
848
849 if (file->private_data != (void*)((long)current->self_exec_id))
850 goto out_put;
851
852 ret = 0;
853
854 while (count > 0) {
855 int this_len, retval;
856
857 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
858 retval = access_remote_vm(mm, src, page, this_len, 0);
859 if (!retval) {
860 if (!ret)
861 ret = -EIO;
862 break;
863 }
864
865 if (copy_to_user(buf, page, retval)) {
866 ret = -EFAULT;
867 break;
868 }
869
870 ret += retval;
871 src += retval;
872 buf += retval;
873 count -= retval;
874 }
875 *ppos = src;
876
877 out_put:
878 mmput(mm);
879 out_free:
880 free_page((unsigned long) page);
881 out:
882 put_task_struct(task);
883 out_no_task:
884 return ret;
885 }
886
887 static ssize_t mem_write(struct file * file, const char __user *buf,
888 size_t count, loff_t *ppos)
889 {
890 int copied;
891 char *page;
892 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
893 unsigned long dst = *ppos;
894 struct mm_struct *mm;
895
896 copied = -ESRCH;
897 if (!task)
898 goto out_no_task;
899
900 copied = -ENOMEM;
901 page = (char *)__get_free_page(GFP_TEMPORARY);
902 if (!page)
903 goto out_task;
904
905 mm = check_mem_permission(task);
906 copied = PTR_ERR(mm);
907 if (IS_ERR(mm))
908 goto out_free;
909
910 copied = -EIO;
911 if (file->private_data != (void *)((long)current->self_exec_id))
912 goto out_mm;
913
914 copied = 0;
915 while (count > 0) {
916 int this_len, retval;
917
918 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
919 if (copy_from_user(page, buf, this_len)) {
920 copied = -EFAULT;
921 break;
922 }
923 retval = access_remote_vm(mm, dst, page, this_len, 1);
924 if (!retval) {
925 if (!copied)
926 copied = -EIO;
927 break;
928 }
929 copied += retval;
930 buf += retval;
931 dst += retval;
932 count -= retval;
933 }
934 *ppos = dst;
935
936 out_mm:
937 mmput(mm);
938 out_free:
939 free_page((unsigned long) page);
940 out_task:
941 put_task_struct(task);
942 out_no_task:
943 return copied;
944 }
945
946 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
947 {
948 switch (orig) {
949 case 0:
950 file->f_pos = offset;
951 break;
952 case 1:
953 file->f_pos += offset;
954 break;
955 default:
956 return -EINVAL;
957 }
958 force_successful_syscall_return();
959 return file->f_pos;
960 }
961
962 static const struct file_operations proc_mem_operations = {
963 .llseek = mem_lseek,
964 .read = mem_read,
965 .write = mem_write,
966 .open = mem_open,
967 };
968
969 static ssize_t environ_read(struct file *file, char __user *buf,
970 size_t count, loff_t *ppos)
971 {
972 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
973 char *page;
974 unsigned long src = *ppos;
975 int ret = -ESRCH;
976 struct mm_struct *mm;
977
978 if (!task)
979 goto out_no_task;
980
981 ret = -ENOMEM;
982 page = (char *)__get_free_page(GFP_TEMPORARY);
983 if (!page)
984 goto out;
985
986
987 mm = mm_for_maps(task);
988 ret = PTR_ERR(mm);
989 if (!mm || IS_ERR(mm))
990 goto out_free;
991
992 ret = 0;
993 while (count > 0) {
994 int this_len, retval, max_len;
995
996 this_len = mm->env_end - (mm->env_start + src);
997
998 if (this_len <= 0)
999 break;
1000
1001 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
1002 this_len = (this_len > max_len) ? max_len : this_len;
1003
1004 retval = access_process_vm(task, (mm->env_start + src),
1005 page, this_len, 0);
1006
1007 if (retval <= 0) {
1008 ret = retval;
1009 break;
1010 }
1011
1012 if (copy_to_user(buf, page, retval)) {
1013 ret = -EFAULT;
1014 break;
1015 }
1016
1017 ret += retval;
1018 src += retval;
1019 buf += retval;
1020 count -= retval;
1021 }
1022 *ppos = src;
1023
1024 mmput(mm);
1025 out_free:
1026 free_page((unsigned long) page);
1027 out:
1028 put_task_struct(task);
1029 out_no_task:
1030 return ret;
1031 }
1032
1033 static const struct file_operations proc_environ_operations = {
1034 .read = environ_read,
1035 .llseek = generic_file_llseek,
1036 };
1037
1038 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
1039 size_t count, loff_t *ppos)
1040 {
1041 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1042 char buffer[PROC_NUMBUF];
1043 size_t len;
1044 int oom_adjust = OOM_DISABLE;
1045 unsigned long flags;
1046
1047 if (!task)
1048 return -ESRCH;
1049
1050 if (lock_task_sighand(task, &flags)) {
1051 oom_adjust = task->signal->oom_adj;
1052 unlock_task_sighand(task, &flags);
1053 }
1054
1055 put_task_struct(task);
1056
1057 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
1058
1059 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1060 }
1061
1062 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1063 size_t count, loff_t *ppos)
1064 {
1065 struct task_struct *task;
1066 char buffer[PROC_NUMBUF];
1067 int oom_adjust;
1068 unsigned long flags;
1069 int err;
1070
1071 memset(buffer, 0, sizeof(buffer));
1072 if (count > sizeof(buffer) - 1)
1073 count = sizeof(buffer) - 1;
1074 if (copy_from_user(buffer, buf, count)) {
1075 err = -EFAULT;
1076 goto out;
1077 }
1078
1079 err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
1080 if (err)
1081 goto out;
1082 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1083 oom_adjust != OOM_DISABLE) {
1084 err = -EINVAL;
1085 goto out;
1086 }
1087
1088 task = get_proc_task(file->f_path.dentry->d_inode);
1089 if (!task) {
1090 err = -ESRCH;
1091 goto out;
1092 }
1093
1094 task_lock(task);
1095 if (!task->mm) {
1096 err = -EINVAL;
1097 goto err_task_lock;
1098 }
1099
1100 if (!lock_task_sighand(task, &flags)) {
1101 err = -ESRCH;
1102 goto err_task_lock;
1103 }
1104
1105 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1106 err = -EACCES;
1107 goto err_sighand;
1108 }
1109
1110 if (oom_adjust != task->signal->oom_adj) {
1111 if (oom_adjust == OOM_DISABLE)
1112 atomic_inc(&task->mm->oom_disable_count);
1113 if (task->signal->oom_adj == OOM_DISABLE)
1114 atomic_dec(&task->mm->oom_disable_count);
1115 }
1116
1117 /*
1118 * Warn that /proc/pid/oom_adj is deprecated, see
1119 * Documentation/feature-removal-schedule.txt.
1120 */
1121 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, "
1122 "please use /proc/%d/oom_score_adj instead.\n",
1123 current->comm, task_pid_nr(current),
1124 task_pid_nr(task), task_pid_nr(task));
1125 task->signal->oom_adj = oom_adjust;
1126 /*
1127 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1128 * value is always attainable.
1129 */
1130 if (task->signal->oom_adj == OOM_ADJUST_MAX)
1131 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
1132 else
1133 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
1134 -OOM_DISABLE;
1135 err_sighand:
1136 unlock_task_sighand(task, &flags);
1137 err_task_lock:
1138 task_unlock(task);
1139 put_task_struct(task);
1140 out:
1141 return err < 0 ? err : count;
1142 }
1143
1144 static const struct file_operations proc_oom_adjust_operations = {
1145 .read = oom_adjust_read,
1146 .write = oom_adjust_write,
1147 .llseek = generic_file_llseek,
1148 };
1149
1150 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1151 size_t count, loff_t *ppos)
1152 {
1153 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1154 char buffer[PROC_NUMBUF];
1155 int oom_score_adj = OOM_SCORE_ADJ_MIN;
1156 unsigned long flags;
1157 size_t len;
1158
1159 if (!task)
1160 return -ESRCH;
1161 if (lock_task_sighand(task, &flags)) {
1162 oom_score_adj = task->signal->oom_score_adj;
1163 unlock_task_sighand(task, &flags);
1164 }
1165 put_task_struct(task);
1166 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
1167 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1168 }
1169
1170 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1171 size_t count, loff_t *ppos)
1172 {
1173 struct task_struct *task;
1174 char buffer[PROC_NUMBUF];
1175 unsigned long flags;
1176 int oom_score_adj;
1177 int err;
1178
1179 memset(buffer, 0, sizeof(buffer));
1180 if (count > sizeof(buffer) - 1)
1181 count = sizeof(buffer) - 1;
1182 if (copy_from_user(buffer, buf, count)) {
1183 err = -EFAULT;
1184 goto out;
1185 }
1186
1187 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1188 if (err)
1189 goto out;
1190 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1191 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1192 err = -EINVAL;
1193 goto out;
1194 }
1195
1196 task = get_proc_task(file->f_path.dentry->d_inode);
1197 if (!task) {
1198 err = -ESRCH;
1199 goto out;
1200 }
1201
1202 task_lock(task);
1203 if (!task->mm) {
1204 err = -EINVAL;
1205 goto err_task_lock;
1206 }
1207
1208 if (!lock_task_sighand(task, &flags)) {
1209 err = -ESRCH;
1210 goto err_task_lock;
1211 }
1212
1213 if (oom_score_adj < task->signal->oom_score_adj_min &&
1214 !capable(CAP_SYS_RESOURCE)) {
1215 err = -EACCES;
1216 goto err_sighand;
1217 }
1218
1219 if (oom_score_adj != task->signal->oom_score_adj) {
1220 if (oom_score_adj == OOM_SCORE_ADJ_MIN)
1221 atomic_inc(&task->mm->oom_disable_count);
1222 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1223 atomic_dec(&task->mm->oom_disable_count);
1224 }
1225 task->signal->oom_score_adj = oom_score_adj;
1226 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1227 task->signal->oom_score_adj_min = oom_score_adj;
1228 /*
1229 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1230 * always attainable.
1231 */
1232 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1233 task->signal->oom_adj = OOM_DISABLE;
1234 else
1235 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1236 OOM_SCORE_ADJ_MAX;
1237 err_sighand:
1238 unlock_task_sighand(task, &flags);
1239 err_task_lock:
1240 task_unlock(task);
1241 put_task_struct(task);
1242 out:
1243 return err < 0 ? err : count;
1244 }
1245
1246 static const struct file_operations proc_oom_score_adj_operations = {
1247 .read = oom_score_adj_read,
1248 .write = oom_score_adj_write,
1249 .llseek = default_llseek,
1250 };
1251
1252 #ifdef CONFIG_AUDITSYSCALL
1253 #define TMPBUFLEN 21
1254 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1255 size_t count, loff_t *ppos)
1256 {
1257 struct inode * inode = file->f_path.dentry->d_inode;
1258 struct task_struct *task = get_proc_task(inode);
1259 ssize_t length;
1260 char tmpbuf[TMPBUFLEN];
1261
1262 if (!task)
1263 return -ESRCH;
1264 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1265 audit_get_loginuid(task));
1266 put_task_struct(task);
1267 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1268 }
1269
1270 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1271 size_t count, loff_t *ppos)
1272 {
1273 struct inode * inode = file->f_path.dentry->d_inode;
1274 char *page, *tmp;
1275 ssize_t length;
1276 uid_t loginuid;
1277
1278 if (!capable(CAP_AUDIT_CONTROL))
1279 return -EPERM;
1280
1281 rcu_read_lock();
1282 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1283 rcu_read_unlock();
1284 return -EPERM;
1285 }
1286 rcu_read_unlock();
1287
1288 if (count >= PAGE_SIZE)
1289 count = PAGE_SIZE - 1;
1290
1291 if (*ppos != 0) {
1292 /* No partial writes. */
1293 return -EINVAL;
1294 }
1295 page = (char*)__get_free_page(GFP_TEMPORARY);
1296 if (!page)
1297 return -ENOMEM;
1298 length = -EFAULT;
1299 if (copy_from_user(page, buf, count))
1300 goto out_free_page;
1301
1302 page[count] = '\0';
1303 loginuid = simple_strtoul(page, &tmp, 10);
1304 if (tmp == page) {
1305 length = -EINVAL;
1306 goto out_free_page;
1307
1308 }
1309 length = audit_set_loginuid(current, loginuid);
1310 if (likely(length == 0))
1311 length = count;
1312
1313 out_free_page:
1314 free_page((unsigned long) page);
1315 return length;
1316 }
1317
1318 static const struct file_operations proc_loginuid_operations = {
1319 .read = proc_loginuid_read,
1320 .write = proc_loginuid_write,
1321 .llseek = generic_file_llseek,
1322 };
1323
1324 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1325 size_t count, loff_t *ppos)
1326 {
1327 struct inode * inode = file->f_path.dentry->d_inode;
1328 struct task_struct *task = get_proc_task(inode);
1329 ssize_t length;
1330 char tmpbuf[TMPBUFLEN];
1331
1332 if (!task)
1333 return -ESRCH;
1334 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1335 audit_get_sessionid(task));
1336 put_task_struct(task);
1337 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1338 }
1339
1340 static const struct file_operations proc_sessionid_operations = {
1341 .read = proc_sessionid_read,
1342 .llseek = generic_file_llseek,
1343 };
1344 #endif
1345
1346 #ifdef CONFIG_FAULT_INJECTION
1347 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1348 size_t count, loff_t *ppos)
1349 {
1350 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1351 char buffer[PROC_NUMBUF];
1352 size_t len;
1353 int make_it_fail;
1354
1355 if (!task)
1356 return -ESRCH;
1357 make_it_fail = task->make_it_fail;
1358 put_task_struct(task);
1359
1360 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1361
1362 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1363 }
1364
1365 static ssize_t proc_fault_inject_write(struct file * file,
1366 const char __user * buf, size_t count, loff_t *ppos)
1367 {
1368 struct task_struct *task;
1369 char buffer[PROC_NUMBUF], *end;
1370 int make_it_fail;
1371
1372 if (!capable(CAP_SYS_RESOURCE))
1373 return -EPERM;
1374 memset(buffer, 0, sizeof(buffer));
1375 if (count > sizeof(buffer) - 1)
1376 count = sizeof(buffer) - 1;
1377 if (copy_from_user(buffer, buf, count))
1378 return -EFAULT;
1379 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1380 if (*end)
1381 return -EINVAL;
1382 task = get_proc_task(file->f_dentry->d_inode);
1383 if (!task)
1384 return -ESRCH;
1385 task->make_it_fail = make_it_fail;
1386 put_task_struct(task);
1387
1388 return count;
1389 }
1390
1391 static const struct file_operations proc_fault_inject_operations = {
1392 .read = proc_fault_inject_read,
1393 .write = proc_fault_inject_write,
1394 .llseek = generic_file_llseek,
1395 };
1396 #endif
1397
1398
1399 #ifdef CONFIG_SCHED_DEBUG
1400 /*
1401 * Print out various scheduling related per-task fields:
1402 */
1403 static int sched_show(struct seq_file *m, void *v)
1404 {
1405 struct inode *inode = m->private;
1406 struct task_struct *p;
1407
1408 p = get_proc_task(inode);
1409 if (!p)
1410 return -ESRCH;
1411 proc_sched_show_task(p, m);
1412
1413 put_task_struct(p);
1414
1415 return 0;
1416 }
1417
1418 static ssize_t
1419 sched_write(struct file *file, const char __user *buf,
1420 size_t count, loff_t *offset)
1421 {
1422 struct inode *inode = file->f_path.dentry->d_inode;
1423 struct task_struct *p;
1424
1425 p = get_proc_task(inode);
1426 if (!p)
1427 return -ESRCH;
1428 proc_sched_set_task(p);
1429
1430 put_task_struct(p);
1431
1432 return count;
1433 }
1434
1435 static int sched_open(struct inode *inode, struct file *filp)
1436 {
1437 return single_open(filp, sched_show, inode);
1438 }
1439
1440 static const struct file_operations proc_pid_sched_operations = {
1441 .open = sched_open,
1442 .read = seq_read,
1443 .write = sched_write,
1444 .llseek = seq_lseek,
1445 .release = single_release,
1446 };
1447
1448 #endif
1449
1450 #ifdef CONFIG_SCHED_AUTOGROUP
1451 /*
1452 * Print out autogroup related information:
1453 */
1454 static int sched_autogroup_show(struct seq_file *m, void *v)
1455 {
1456 struct inode *inode = m->private;
1457 struct task_struct *p;
1458
1459 p = get_proc_task(inode);
1460 if (!p)
1461 return -ESRCH;
1462 proc_sched_autogroup_show_task(p, m);
1463
1464 put_task_struct(p);
1465
1466 return 0;
1467 }
1468
1469 static ssize_t
1470 sched_autogroup_write(struct file *file, const char __user *buf,
1471 size_t count, loff_t *offset)
1472 {
1473 struct inode *inode = file->f_path.dentry->d_inode;
1474 struct task_struct *p;
1475 char buffer[PROC_NUMBUF];
1476 int nice;
1477 int err;
1478
1479 memset(buffer, 0, sizeof(buffer));
1480 if (count > sizeof(buffer) - 1)
1481 count = sizeof(buffer) - 1;
1482 if (copy_from_user(buffer, buf, count))
1483 return -EFAULT;
1484
1485 err = kstrtoint(strstrip(buffer), 0, &nice);
1486 if (err < 0)
1487 return err;
1488
1489 p = get_proc_task(inode);
1490 if (!p)
1491 return -ESRCH;
1492
1493 err = nice;
1494 err = proc_sched_autogroup_set_nice(p, &err);
1495 if (err)
1496 count = err;
1497
1498 put_task_struct(p);
1499
1500 return count;
1501 }
1502
1503 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1504 {
1505 int ret;
1506
1507 ret = single_open(filp, sched_autogroup_show, NULL);
1508 if (!ret) {
1509 struct seq_file *m = filp->private_data;
1510
1511 m->private = inode;
1512 }
1513 return ret;
1514 }
1515
1516 static const struct file_operations proc_pid_sched_autogroup_operations = {
1517 .open = sched_autogroup_open,
1518 .read = seq_read,
1519 .write = sched_autogroup_write,
1520 .llseek = seq_lseek,
1521 .release = single_release,
1522 };
1523
1524 #endif /* CONFIG_SCHED_AUTOGROUP */
1525
1526 static ssize_t comm_write(struct file *file, const char __user *buf,
1527 size_t count, loff_t *offset)
1528 {
1529 struct inode *inode = file->f_path.dentry->d_inode;
1530 struct task_struct *p;
1531 char buffer[TASK_COMM_LEN];
1532
1533 memset(buffer, 0, sizeof(buffer));
1534 if (count > sizeof(buffer) - 1)
1535 count = sizeof(buffer) - 1;
1536 if (copy_from_user(buffer, buf, count))
1537 return -EFAULT;
1538
1539 p = get_proc_task(inode);
1540 if (!p)
1541 return -ESRCH;
1542
1543 if (same_thread_group(current, p))
1544 set_task_comm(p, buffer);
1545 else
1546 count = -EINVAL;
1547
1548 put_task_struct(p);
1549
1550 return count;
1551 }
1552
1553 static int comm_show(struct seq_file *m, void *v)
1554 {
1555 struct inode *inode = m->private;
1556 struct task_struct *p;
1557
1558 p = get_proc_task(inode);
1559 if (!p)
1560 return -ESRCH;
1561
1562 task_lock(p);
1563 seq_printf(m, "%s\n", p->comm);
1564 task_unlock(p);
1565
1566 put_task_struct(p);
1567
1568 return 0;
1569 }
1570
1571 static int comm_open(struct inode *inode, struct file *filp)
1572 {
1573 return single_open(filp, comm_show, inode);
1574 }
1575
1576 static const struct file_operations proc_pid_set_comm_operations = {
1577 .open = comm_open,
1578 .read = seq_read,
1579 .write = comm_write,
1580 .llseek = seq_lseek,
1581 .release = single_release,
1582 };
1583
1584 static int proc_exe_link(struct inode *inode, struct path *exe_path)
1585 {
1586 struct task_struct *task;
1587 struct mm_struct *mm;
1588 struct file *exe_file;
1589
1590 task = get_proc_task(inode);
1591 if (!task)
1592 return -ENOENT;
1593 mm = get_task_mm(task);
1594 put_task_struct(task);
1595 if (!mm)
1596 return -ENOENT;
1597 exe_file = get_mm_exe_file(mm);
1598 mmput(mm);
1599 if (exe_file) {
1600 *exe_path = exe_file->f_path;
1601 path_get(&exe_file->f_path);
1602 fput(exe_file);
1603 return 0;
1604 } else
1605 return -ENOENT;
1606 }
1607
1608 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1609 {
1610 struct inode *inode = dentry->d_inode;
1611 int error = -EACCES;
1612
1613 /* We don't need a base pointer in the /proc filesystem */
1614 path_put(&nd->path);
1615
1616 /* Are we allowed to snoop on the tasks file descriptors? */
1617 if (!proc_fd_access_allowed(inode))
1618 goto out;
1619
1620 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1621 out:
1622 return ERR_PTR(error);
1623 }
1624
1625 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1626 {
1627 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1628 char *pathname;
1629 int len;
1630
1631 if (!tmp)
1632 return -ENOMEM;
1633
1634 pathname = d_path(path, tmp, PAGE_SIZE);
1635 len = PTR_ERR(pathname);
1636 if (IS_ERR(pathname))
1637 goto out;
1638 len = tmp + PAGE_SIZE - 1 - pathname;
1639
1640 if (len > buflen)
1641 len = buflen;
1642 if (copy_to_user(buffer, pathname, len))
1643 len = -EFAULT;
1644 out:
1645 free_page((unsigned long)tmp);
1646 return len;
1647 }
1648
1649 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1650 {
1651 int error = -EACCES;
1652 struct inode *inode = dentry->d_inode;
1653 struct path path;
1654
1655 /* Are we allowed to snoop on the tasks file descriptors? */
1656 if (!proc_fd_access_allowed(inode))
1657 goto out;
1658
1659 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1660 if (error)
1661 goto out;
1662
1663 error = do_proc_readlink(&path, buffer, buflen);
1664 path_put(&path);
1665 out:
1666 return error;
1667 }
1668
1669 static const struct inode_operations proc_pid_link_inode_operations = {
1670 .readlink = proc_pid_readlink,
1671 .follow_link = proc_pid_follow_link,
1672 .setattr = proc_setattr,
1673 };
1674
1675
1676 /* building an inode */
1677
1678 static int task_dumpable(struct task_struct *task)
1679 {
1680 int dumpable = 0;
1681 struct mm_struct *mm;
1682
1683 task_lock(task);
1684 mm = task->mm;
1685 if (mm)
1686 dumpable = get_dumpable(mm);
1687 task_unlock(task);
1688 if(dumpable == 1)
1689 return 1;
1690 return 0;
1691 }
1692
1693 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1694 {
1695 struct inode * inode;
1696 struct proc_inode *ei;
1697 const struct cred *cred;
1698
1699 /* We need a new inode */
1700
1701 inode = new_inode(sb);
1702 if (!inode)
1703 goto out;
1704
1705 /* Common stuff */
1706 ei = PROC_I(inode);
1707 inode->i_ino = get_next_ino();
1708 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1709 inode->i_op = &proc_def_inode_operations;
1710
1711 /*
1712 * grab the reference to task.
1713 */
1714 ei->pid = get_task_pid(task, PIDTYPE_PID);
1715 if (!ei->pid)
1716 goto out_unlock;
1717
1718 if (task_dumpable(task)) {
1719 rcu_read_lock();
1720 cred = __task_cred(task);
1721 inode->i_uid = cred->euid;
1722 inode->i_gid = cred->egid;
1723 rcu_read_unlock();
1724 }
1725 security_task_to_inode(task, inode);
1726
1727 out:
1728 return inode;
1729
1730 out_unlock:
1731 iput(inode);
1732 return NULL;
1733 }
1734
1735 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1736 {
1737 struct inode *inode = dentry->d_inode;
1738 struct task_struct *task;
1739 const struct cred *cred;
1740
1741 generic_fillattr(inode, stat);
1742
1743 rcu_read_lock();
1744 stat->uid = 0;
1745 stat->gid = 0;
1746 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1747 if (task) {
1748 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1749 task_dumpable(task)) {
1750 cred = __task_cred(task);
1751 stat->uid = cred->euid;
1752 stat->gid = cred->egid;
1753 }
1754 }
1755 rcu_read_unlock();
1756 return 0;
1757 }
1758
1759 /* dentry stuff */
1760
1761 /*
1762 * Exceptional case: normally we are not allowed to unhash a busy
1763 * directory. In this case, however, we can do it - no aliasing problems
1764 * due to the way we treat inodes.
1765 *
1766 * Rewrite the inode's ownerships here because the owning task may have
1767 * performed a setuid(), etc.
1768 *
1769 * Before the /proc/pid/status file was created the only way to read
1770 * the effective uid of a /process was to stat /proc/pid. Reading
1771 * /proc/pid/status is slow enough that procps and other packages
1772 * kept stating /proc/pid. To keep the rules in /proc simple I have
1773 * made this apply to all per process world readable and executable
1774 * directories.
1775 */
1776 int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1777 {
1778 struct inode *inode;
1779 struct task_struct *task;
1780 const struct cred *cred;
1781
1782 if (nd && nd->flags & LOOKUP_RCU)
1783 return -ECHILD;
1784
1785 inode = dentry->d_inode;
1786 task = get_proc_task(inode);
1787
1788 if (task) {
1789 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1790 task_dumpable(task)) {
1791 rcu_read_lock();
1792 cred = __task_cred(task);
1793 inode->i_uid = cred->euid;
1794 inode->i_gid = cred->egid;
1795 rcu_read_unlock();
1796 } else {
1797 inode->i_uid = 0;
1798 inode->i_gid = 0;
1799 }
1800 inode->i_mode &= ~(S_ISUID | S_ISGID);
1801 security_task_to_inode(task, inode);
1802 put_task_struct(task);
1803 return 1;
1804 }
1805 d_drop(dentry);
1806 return 0;
1807 }
1808
1809 static int pid_delete_dentry(const struct dentry * dentry)
1810 {
1811 /* Is the task we represent dead?
1812 * If so, then don't put the dentry on the lru list,
1813 * kill it immediately.
1814 */
1815 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1816 }
1817
1818 const struct dentry_operations pid_dentry_operations =
1819 {
1820 .d_revalidate = pid_revalidate,
1821 .d_delete = pid_delete_dentry,
1822 };
1823
1824 /* Lookups */
1825
1826 /*
1827 * Fill a directory entry.
1828 *
1829 * If possible create the dcache entry and derive our inode number and
1830 * file type from dcache entry.
1831 *
1832 * Since all of the proc inode numbers are dynamically generated, the inode
1833 * numbers do not exist until the inode is cache. This means creating the
1834 * the dcache entry in readdir is necessary to keep the inode numbers
1835 * reported by readdir in sync with the inode numbers reported
1836 * by stat.
1837 */
1838 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1839 const char *name, int len,
1840 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1841 {
1842 struct dentry *child, *dir = filp->f_path.dentry;
1843 struct inode *inode;
1844 struct qstr qname;
1845 ino_t ino = 0;
1846 unsigned type = DT_UNKNOWN;
1847
1848 qname.name = name;
1849 qname.len = len;
1850 qname.hash = full_name_hash(name, len);
1851
1852 child = d_lookup(dir, &qname);
1853 if (!child) {
1854 struct dentry *new;
1855 new = d_alloc(dir, &qname);
1856 if (new) {
1857 child = instantiate(dir->d_inode, new, task, ptr);
1858 if (child)
1859 dput(new);
1860 else
1861 child = new;
1862 }
1863 }
1864 if (!child || IS_ERR(child) || !child->d_inode)
1865 goto end_instantiate;
1866 inode = child->d_inode;
1867 if (inode) {
1868 ino = inode->i_ino;
1869 type = inode->i_mode >> 12;
1870 }
1871 dput(child);
1872 end_instantiate:
1873 if (!ino)
1874 ino = find_inode_number(dir, &qname);
1875 if (!ino)
1876 ino = 1;
1877 return filldir(dirent, name, len, filp->f_pos, ino, type);
1878 }
1879
1880 static unsigned name_to_int(struct dentry *dentry)
1881 {
1882 const char *name = dentry->d_name.name;
1883 int len = dentry->d_name.len;
1884 unsigned n = 0;
1885
1886 if (len > 1 && *name == '0')
1887 goto out;
1888 while (len-- > 0) {
1889 unsigned c = *name++ - '0';
1890 if (c > 9)
1891 goto out;
1892 if (n >= (~0U-9)/10)
1893 goto out;
1894 n *= 10;
1895 n += c;
1896 }
1897 return n;
1898 out:
1899 return ~0U;
1900 }
1901
1902 #define PROC_FDINFO_MAX 64
1903
1904 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1905 {
1906 struct task_struct *task = get_proc_task(inode);
1907 struct files_struct *files = NULL;
1908 struct file *file;
1909 int fd = proc_fd(inode);
1910
1911 if (task) {
1912 files = get_files_struct(task);
1913 put_task_struct(task);
1914 }
1915 if (files) {
1916 /*
1917 * We are not taking a ref to the file structure, so we must
1918 * hold ->file_lock.
1919 */
1920 spin_lock(&files->file_lock);
1921 file = fcheck_files(files, fd);
1922 if (file) {
1923 if (path) {
1924 *path = file->f_path;
1925 path_get(&file->f_path);
1926 }
1927 if (info)
1928 snprintf(info, PROC_FDINFO_MAX,
1929 "pos:\t%lli\n"
1930 "flags:\t0%o\n",
1931 (long long) file->f_pos,
1932 file->f_flags);
1933 spin_unlock(&files->file_lock);
1934 put_files_struct(files);
1935 return 0;
1936 }
1937 spin_unlock(&files->file_lock);
1938 put_files_struct(files);
1939 }
1940 return -ENOENT;
1941 }
1942
1943 static int proc_fd_link(struct inode *inode, struct path *path)
1944 {
1945 return proc_fd_info(inode, path, NULL);
1946 }
1947
1948 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1949 {
1950 struct inode *inode;
1951 struct task_struct *task;
1952 int fd;
1953 struct files_struct *files;
1954 const struct cred *cred;
1955
1956 if (nd && nd->flags & LOOKUP_RCU)
1957 return -ECHILD;
1958
1959 inode = dentry->d_inode;
1960 task = get_proc_task(inode);
1961 fd = proc_fd(inode);
1962
1963 if (task) {
1964 files = get_files_struct(task);
1965 if (files) {
1966 rcu_read_lock();
1967 if (fcheck_files(files, fd)) {
1968 rcu_read_unlock();
1969 put_files_struct(files);
1970 if (task_dumpable(task)) {
1971 rcu_read_lock();
1972 cred = __task_cred(task);
1973 inode->i_uid = cred->euid;
1974 inode->i_gid = cred->egid;
1975 rcu_read_unlock();
1976 } else {
1977 inode->i_uid = 0;
1978 inode->i_gid = 0;
1979 }
1980 inode->i_mode &= ~(S_ISUID | S_ISGID);
1981 security_task_to_inode(task, inode);
1982 put_task_struct(task);
1983 return 1;
1984 }
1985 rcu_read_unlock();
1986 put_files_struct(files);
1987 }
1988 put_task_struct(task);
1989 }
1990 d_drop(dentry);
1991 return 0;
1992 }
1993
1994 static const struct dentry_operations tid_fd_dentry_operations =
1995 {
1996 .d_revalidate = tid_fd_revalidate,
1997 .d_delete = pid_delete_dentry,
1998 };
1999
2000 static struct dentry *proc_fd_instantiate(struct inode *dir,
2001 struct dentry *dentry, struct task_struct *task, const void *ptr)
2002 {
2003 unsigned fd = *(const unsigned *)ptr;
2004 struct file *file;
2005 struct files_struct *files;
2006 struct inode *inode;
2007 struct proc_inode *ei;
2008 struct dentry *error = ERR_PTR(-ENOENT);
2009
2010 inode = proc_pid_make_inode(dir->i_sb, task);
2011 if (!inode)
2012 goto out;
2013 ei = PROC_I(inode);
2014 ei->fd = fd;
2015 files = get_files_struct(task);
2016 if (!files)
2017 goto out_iput;
2018 inode->i_mode = S_IFLNK;
2019
2020 /*
2021 * We are not taking a ref to the file structure, so we must
2022 * hold ->file_lock.
2023 */
2024 spin_lock(&files->file_lock);
2025 file = fcheck_files(files, fd);
2026 if (!file)
2027 goto out_unlock;
2028 if (file->f_mode & FMODE_READ)
2029 inode->i_mode |= S_IRUSR | S_IXUSR;
2030 if (file->f_mode & FMODE_WRITE)
2031 inode->i_mode |= S_IWUSR | S_IXUSR;
2032 spin_unlock(&files->file_lock);
2033 put_files_struct(files);
2034
2035 inode->i_op = &proc_pid_link_inode_operations;
2036 inode->i_size = 64;
2037 ei->op.proc_get_link = proc_fd_link;
2038 d_set_d_op(dentry, &tid_fd_dentry_operations);
2039 d_add(dentry, inode);
2040 /* Close the race of the process dying before we return the dentry */
2041 if (tid_fd_revalidate(dentry, NULL))
2042 error = NULL;
2043
2044 out:
2045 return error;
2046 out_unlock:
2047 spin_unlock(&files->file_lock);
2048 put_files_struct(files);
2049 out_iput:
2050 iput(inode);
2051 goto out;
2052 }
2053
2054 static struct dentry *proc_lookupfd_common(struct inode *dir,
2055 struct dentry *dentry,
2056 instantiate_t instantiate)
2057 {
2058 struct task_struct *task = get_proc_task(dir);
2059 unsigned fd = name_to_int(dentry);
2060 struct dentry *result = ERR_PTR(-ENOENT);
2061
2062 if (!task)
2063 goto out_no_task;
2064 if (fd == ~0U)
2065 goto out;
2066
2067 result = instantiate(dir, dentry, task, &fd);
2068 out:
2069 put_task_struct(task);
2070 out_no_task:
2071 return result;
2072 }
2073
2074 static int proc_readfd_common(struct file * filp, void * dirent,
2075 filldir_t filldir, instantiate_t instantiate)
2076 {
2077 struct dentry *dentry = filp->f_path.dentry;
2078 struct inode *inode = dentry->d_inode;
2079 struct task_struct *p = get_proc_task(inode);
2080 unsigned int fd, ino;
2081 int retval;
2082 struct files_struct * files;
2083
2084 retval = -ENOENT;
2085 if (!p)
2086 goto out_no_task;
2087 retval = 0;
2088
2089 fd = filp->f_pos;
2090 switch (fd) {
2091 case 0:
2092 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
2093 goto out;
2094 filp->f_pos++;
2095 case 1:
2096 ino = parent_ino(dentry);
2097 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2098 goto out;
2099 filp->f_pos++;
2100 default:
2101 files = get_files_struct(p);
2102 if (!files)
2103 goto out;
2104 rcu_read_lock();
2105 for (fd = filp->f_pos-2;
2106 fd < files_fdtable(files)->max_fds;
2107 fd++, filp->f_pos++) {
2108 char name[PROC_NUMBUF];
2109 int len;
2110
2111 if (!fcheck_files(files, fd))
2112 continue;
2113 rcu_read_unlock();
2114
2115 len = snprintf(name, sizeof(name), "%d", fd);
2116 if (proc_fill_cache(filp, dirent, filldir,
2117 name, len, instantiate,
2118 p, &fd) < 0) {
2119 rcu_read_lock();
2120 break;
2121 }
2122 rcu_read_lock();
2123 }
2124 rcu_read_unlock();
2125 put_files_struct(files);
2126 }
2127 out:
2128 put_task_struct(p);
2129 out_no_task:
2130 return retval;
2131 }
2132
2133 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
2134 struct nameidata *nd)
2135 {
2136 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
2137 }
2138
2139 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
2140 {
2141 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
2142 }
2143
2144 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
2145 size_t len, loff_t *ppos)
2146 {
2147 char tmp[PROC_FDINFO_MAX];
2148 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
2149 if (!err)
2150 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
2151 return err;
2152 }
2153
2154 static const struct file_operations proc_fdinfo_file_operations = {
2155 .open = nonseekable_open,
2156 .read = proc_fdinfo_read,
2157 .llseek = no_llseek,
2158 };
2159
2160 static const struct file_operations proc_fd_operations = {
2161 .read = generic_read_dir,
2162 .readdir = proc_readfd,
2163 .llseek = default_llseek,
2164 };
2165
2166 /*
2167 * /proc/pid/fd needs a special permission handler so that a process can still
2168 * access /proc/self/fd after it has executed a setuid().
2169 */
2170 static int proc_fd_permission(struct inode *inode, int mask)
2171 {
2172 int rv = generic_permission(inode, mask);
2173 if (rv == 0)
2174 return 0;
2175 if (task_pid(current) == proc_pid(inode))
2176 rv = 0;
2177 return rv;
2178 }
2179
2180 /*
2181 * proc directories can do almost nothing..
2182 */
2183 static const struct inode_operations proc_fd_inode_operations = {
2184 .lookup = proc_lookupfd,
2185 .permission = proc_fd_permission,
2186 .setattr = proc_setattr,
2187 };
2188
2189 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2190 struct dentry *dentry, struct task_struct *task, const void *ptr)
2191 {
2192 unsigned fd = *(unsigned *)ptr;
2193 struct inode *inode;
2194 struct proc_inode *ei;
2195 struct dentry *error = ERR_PTR(-ENOENT);
2196
2197 inode = proc_pid_make_inode(dir->i_sb, task);
2198 if (!inode)
2199 goto out;
2200 ei = PROC_I(inode);
2201 ei->fd = fd;
2202 inode->i_mode = S_IFREG | S_IRUSR;
2203 inode->i_fop = &proc_fdinfo_file_operations;
2204 d_set_d_op(dentry, &tid_fd_dentry_operations);
2205 d_add(dentry, inode);
2206 /* Close the race of the process dying before we return the dentry */
2207 if (tid_fd_revalidate(dentry, NULL))
2208 error = NULL;
2209
2210 out:
2211 return error;
2212 }
2213
2214 static struct dentry *proc_lookupfdinfo(struct inode *dir,
2215 struct dentry *dentry,
2216 struct nameidata *nd)
2217 {
2218 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2219 }
2220
2221 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2222 {
2223 return proc_readfd_common(filp, dirent, filldir,
2224 proc_fdinfo_instantiate);
2225 }
2226
2227 static const struct file_operations proc_fdinfo_operations = {
2228 .read = generic_read_dir,
2229 .readdir = proc_readfdinfo,
2230 .llseek = default_llseek,
2231 };
2232
2233 /*
2234 * proc directories can do almost nothing..
2235 */
2236 static const struct inode_operations proc_fdinfo_inode_operations = {
2237 .lookup = proc_lookupfdinfo,
2238 .setattr = proc_setattr,
2239 };
2240
2241
2242 static struct dentry *proc_pident_instantiate(struct inode *dir,
2243 struct dentry *dentry, struct task_struct *task, const void *ptr)
2244 {
2245 const struct pid_entry *p = ptr;
2246 struct inode *inode;
2247 struct proc_inode *ei;
2248 struct dentry *error = ERR_PTR(-ENOENT);
2249
2250 inode = proc_pid_make_inode(dir->i_sb, task);
2251 if (!inode)
2252 goto out;
2253
2254 ei = PROC_I(inode);
2255 inode->i_mode = p->mode;
2256 if (S_ISDIR(inode->i_mode))
2257 inode->i_nlink = 2; /* Use getattr to fix if necessary */
2258 if (p->iop)
2259 inode->i_op = p->iop;
2260 if (p->fop)
2261 inode->i_fop = p->fop;
2262 ei->op = p->op;
2263 d_set_d_op(dentry, &pid_dentry_operations);
2264 d_add(dentry, inode);
2265 /* Close the race of the process dying before we return the dentry */
2266 if (pid_revalidate(dentry, NULL))
2267 error = NULL;
2268 out:
2269 return error;
2270 }
2271
2272 static struct dentry *proc_pident_lookup(struct inode *dir,
2273 struct dentry *dentry,
2274 const struct pid_entry *ents,
2275 unsigned int nents)
2276 {
2277 struct dentry *error;
2278 struct task_struct *task = get_proc_task(dir);
2279 const struct pid_entry *p, *last;
2280
2281 error = ERR_PTR(-ENOENT);
2282
2283 if (!task)
2284 goto out_no_task;
2285
2286 /*
2287 * Yes, it does not scale. And it should not. Don't add
2288 * new entries into /proc/<tgid>/ without very good reasons.
2289 */
2290 last = &ents[nents - 1];
2291 for (p = ents; p <= last; p++) {
2292 if (p->len != dentry->d_name.len)
2293 continue;
2294 if (!memcmp(dentry->d_name.name, p->name, p->len))
2295 break;
2296 }
2297 if (p > last)
2298 goto out;
2299
2300 error = proc_pident_instantiate(dir, dentry, task, p);
2301 out:
2302 put_task_struct(task);
2303 out_no_task:
2304 return error;
2305 }
2306
2307 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2308 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2309 {
2310 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2311 proc_pident_instantiate, task, p);
2312 }
2313
2314 static int proc_pident_readdir(struct file *filp,
2315 void *dirent, filldir_t filldir,
2316 const struct pid_entry *ents, unsigned int nents)
2317 {
2318 int i;
2319 struct dentry *dentry = filp->f_path.dentry;
2320 struct inode *inode = dentry->d_inode;
2321 struct task_struct *task = get_proc_task(inode);
2322 const struct pid_entry *p, *last;
2323 ino_t ino;
2324 int ret;
2325
2326 ret = -ENOENT;
2327 if (!task)
2328 goto out_no_task;
2329
2330 ret = 0;
2331 i = filp->f_pos;
2332 switch (i) {
2333 case 0:
2334 ino = inode->i_ino;
2335 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2336 goto out;
2337 i++;
2338 filp->f_pos++;
2339 /* fall through */
2340 case 1:
2341 ino = parent_ino(dentry);
2342 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2343 goto out;
2344 i++;
2345 filp->f_pos++;
2346 /* fall through */
2347 default:
2348 i -= 2;
2349 if (i >= nents) {
2350 ret = 1;
2351 goto out;
2352 }
2353 p = ents + i;
2354 last = &ents[nents - 1];
2355 while (p <= last) {
2356 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2357 goto out;
2358 filp->f_pos++;
2359 p++;
2360 }
2361 }
2362
2363 ret = 1;
2364 out:
2365 put_task_struct(task);
2366 out_no_task:
2367 return ret;
2368 }
2369
2370 #ifdef CONFIG_SECURITY
2371 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2372 size_t count, loff_t *ppos)
2373 {
2374 struct inode * inode = file->f_path.dentry->d_inode;
2375 char *p = NULL;
2376 ssize_t length;
2377 struct task_struct *task = get_proc_task(inode);
2378
2379 if (!task)
2380 return -ESRCH;
2381
2382 length = security_getprocattr(task,
2383 (char*)file->f_path.dentry->d_name.name,
2384 &p);
2385 put_task_struct(task);
2386 if (length > 0)
2387 length = simple_read_from_buffer(buf, count, ppos, p, length);
2388 kfree(p);
2389 return length;
2390 }
2391
2392 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2393 size_t count, loff_t *ppos)
2394 {
2395 struct inode * inode = file->f_path.dentry->d_inode;
2396 char *page;
2397 ssize_t length;
2398 struct task_struct *task = get_proc_task(inode);
2399
2400 length = -ESRCH;
2401 if (!task)
2402 goto out_no_task;
2403 if (count > PAGE_SIZE)
2404 count = PAGE_SIZE;
2405
2406 /* No partial writes. */
2407 length = -EINVAL;
2408 if (*ppos != 0)
2409 goto out;
2410
2411 length = -ENOMEM;
2412 page = (char*)__get_free_page(GFP_TEMPORARY);
2413 if (!page)
2414 goto out;
2415
2416 length = -EFAULT;
2417 if (copy_from_user(page, buf, count))
2418 goto out_free;
2419
2420 /* Guard against adverse ptrace interaction */
2421 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2422 if (length < 0)
2423 goto out_free;
2424
2425 length = security_setprocattr(task,
2426 (char*)file->f_path.dentry->d_name.name,
2427 (void*)page, count);
2428 mutex_unlock(&task->signal->cred_guard_mutex);
2429 out_free:
2430 free_page((unsigned long) page);
2431 out:
2432 put_task_struct(task);
2433 out_no_task:
2434 return length;
2435 }
2436
2437 static const struct file_operations proc_pid_attr_operations = {
2438 .read = proc_pid_attr_read,
2439 .write = proc_pid_attr_write,
2440 .llseek = generic_file_llseek,
2441 };
2442
2443 static const struct pid_entry attr_dir_stuff[] = {
2444 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2445 REG("prev", S_IRUGO, proc_pid_attr_operations),
2446 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2447 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2448 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2449 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2450 };
2451
2452 static int proc_attr_dir_readdir(struct file * filp,
2453 void * dirent, filldir_t filldir)
2454 {
2455 return proc_pident_readdir(filp,dirent,filldir,
2456 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2457 }
2458
2459 static const struct file_operations proc_attr_dir_operations = {
2460 .read = generic_read_dir,
2461 .readdir = proc_attr_dir_readdir,
2462 .llseek = default_llseek,
2463 };
2464
2465 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2466 struct dentry *dentry, struct nameidata *nd)
2467 {
2468 return proc_pident_lookup(dir, dentry,
2469 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2470 }
2471
2472 static const struct inode_operations proc_attr_dir_inode_operations = {
2473 .lookup = proc_attr_dir_lookup,
2474 .getattr = pid_getattr,
2475 .setattr = proc_setattr,
2476 };
2477
2478 #endif
2479
2480 #ifdef CONFIG_ELF_CORE
2481 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2482 size_t count, loff_t *ppos)
2483 {
2484 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2485 struct mm_struct *mm;
2486 char buffer[PROC_NUMBUF];
2487 size_t len;
2488 int ret;
2489
2490 if (!task)
2491 return -ESRCH;
2492
2493 ret = 0;
2494 mm = get_task_mm(task);
2495 if (mm) {
2496 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2497 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2498 MMF_DUMP_FILTER_SHIFT));
2499 mmput(mm);
2500 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2501 }
2502
2503 put_task_struct(task);
2504
2505 return ret;
2506 }
2507
2508 static ssize_t proc_coredump_filter_write(struct file *file,
2509 const char __user *buf,
2510 size_t count,
2511 loff_t *ppos)
2512 {
2513 struct task_struct *task;
2514 struct mm_struct *mm;
2515 char buffer[PROC_NUMBUF], *end;
2516 unsigned int val;
2517 int ret;
2518 int i;
2519 unsigned long mask;
2520
2521 ret = -EFAULT;
2522 memset(buffer, 0, sizeof(buffer));
2523 if (count > sizeof(buffer) - 1)
2524 count = sizeof(buffer) - 1;
2525 if (copy_from_user(buffer, buf, count))
2526 goto out_no_task;
2527
2528 ret = -EINVAL;
2529 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2530 if (*end == '\n')
2531 end++;
2532 if (end - buffer == 0)
2533 goto out_no_task;
2534
2535 ret = -ESRCH;
2536 task = get_proc_task(file->f_dentry->d_inode);
2537 if (!task)
2538 goto out_no_task;
2539
2540 ret = end - buffer;
2541 mm = get_task_mm(task);
2542 if (!mm)
2543 goto out_no_mm;
2544
2545 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2546 if (val & mask)
2547 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2548 else
2549 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2550 }
2551
2552 mmput(mm);
2553 out_no_mm:
2554 put_task_struct(task);
2555 out_no_task:
2556 return ret;
2557 }
2558
2559 static const struct file_operations proc_coredump_filter_operations = {
2560 .read = proc_coredump_filter_read,
2561 .write = proc_coredump_filter_write,
2562 .llseek = generic_file_llseek,
2563 };
2564 #endif
2565
2566 /*
2567 * /proc/self:
2568 */
2569 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2570 int buflen)
2571 {
2572 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2573 pid_t tgid = task_tgid_nr_ns(current, ns);
2574 char tmp[PROC_NUMBUF];
2575 if (!tgid)
2576 return -ENOENT;
2577 sprintf(tmp, "%d", tgid);
2578 return vfs_readlink(dentry,buffer,buflen,tmp);
2579 }
2580
2581 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2582 {
2583 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2584 pid_t tgid = task_tgid_nr_ns(current, ns);
2585 char *name = ERR_PTR(-ENOENT);
2586 if (tgid) {
2587 name = __getname();
2588 if (!name)
2589 name = ERR_PTR(-ENOMEM);
2590 else
2591 sprintf(name, "%d", tgid);
2592 }
2593 nd_set_link(nd, name);
2594 return NULL;
2595 }
2596
2597 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2598 void *cookie)
2599 {
2600 char *s = nd_get_link(nd);
2601 if (!IS_ERR(s))
2602 __putname(s);
2603 }
2604
2605 static const struct inode_operations proc_self_inode_operations = {
2606 .readlink = proc_self_readlink,
2607 .follow_link = proc_self_follow_link,
2608 .put_link = proc_self_put_link,
2609 };
2610
2611 /*
2612 * proc base
2613 *
2614 * These are the directory entries in the root directory of /proc
2615 * that properly belong to the /proc filesystem, as they describe
2616 * describe something that is process related.
2617 */
2618 static const struct pid_entry proc_base_stuff[] = {
2619 NOD("self", S_IFLNK|S_IRWXUGO,
2620 &proc_self_inode_operations, NULL, {}),
2621 };
2622
2623 static struct dentry *proc_base_instantiate(struct inode *dir,
2624 struct dentry *dentry, struct task_struct *task, const void *ptr)
2625 {
2626 const struct pid_entry *p = ptr;
2627 struct inode *inode;
2628 struct proc_inode *ei;
2629 struct dentry *error;
2630
2631 /* Allocate the inode */
2632 error = ERR_PTR(-ENOMEM);
2633 inode = new_inode(dir->i_sb);
2634 if (!inode)
2635 goto out;
2636
2637 /* Initialize the inode */
2638 ei = PROC_I(inode);
2639 inode->i_ino = get_next_ino();
2640 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2641
2642 /*
2643 * grab the reference to the task.
2644 */
2645 ei->pid = get_task_pid(task, PIDTYPE_PID);
2646 if (!ei->pid)
2647 goto out_iput;
2648
2649 inode->i_mode = p->mode;
2650 if (S_ISDIR(inode->i_mode))
2651 inode->i_nlink = 2;
2652 if (S_ISLNK(inode->i_mode))
2653 inode->i_size = 64;
2654 if (p->iop)
2655 inode->i_op = p->iop;
2656 if (p->fop)
2657 inode->i_fop = p->fop;
2658 ei->op = p->op;
2659 d_add(dentry, inode);
2660 error = NULL;
2661 out:
2662 return error;
2663 out_iput:
2664 iput(inode);
2665 goto out;
2666 }
2667
2668 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2669 {
2670 struct dentry *error;
2671 struct task_struct *task = get_proc_task(dir);
2672 const struct pid_entry *p, *last;
2673
2674 error = ERR_PTR(-ENOENT);
2675
2676 if (!task)
2677 goto out_no_task;
2678
2679 /* Lookup the directory entry */
2680 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2681 for (p = proc_base_stuff; p <= last; p++) {
2682 if (p->len != dentry->d_name.len)
2683 continue;
2684 if (!memcmp(dentry->d_name.name, p->name, p->len))
2685 break;
2686 }
2687 if (p > last)
2688 goto out;
2689
2690 error = proc_base_instantiate(dir, dentry, task, p);
2691
2692 out:
2693 put_task_struct(task);
2694 out_no_task:
2695 return error;
2696 }
2697
2698 static int proc_base_fill_cache(struct file *filp, void *dirent,
2699 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2700 {
2701 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2702 proc_base_instantiate, task, p);
2703 }
2704
2705 #ifdef CONFIG_TASK_IO_ACCOUNTING
2706 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2707 {
2708 struct task_io_accounting acct = task->ioac;
2709 unsigned long flags;
2710
2711 if (!ptrace_may_access(task, PTRACE_MODE_READ))
2712 return -EACCES;
2713
2714 if (whole && lock_task_sighand(task, &flags)) {
2715 struct task_struct *t = task;
2716
2717 task_io_accounting_add(&acct, &task->signal->ioac);
2718 while_each_thread(task, t)
2719 task_io_accounting_add(&acct, &t->ioac);
2720
2721 unlock_task_sighand(task, &flags);
2722 }
2723 return sprintf(buffer,
2724 "rchar: %llu\n"
2725 "wchar: %llu\n"
2726 "syscr: %llu\n"
2727 "syscw: %llu\n"
2728 "read_bytes: %llu\n"
2729 "write_bytes: %llu\n"
2730 "cancelled_write_bytes: %llu\n",
2731 (unsigned long long)acct.rchar,
2732 (unsigned long long)acct.wchar,
2733 (unsigned long long)acct.syscr,
2734 (unsigned long long)acct.syscw,
2735 (unsigned long long)acct.read_bytes,
2736 (unsigned long long)acct.write_bytes,
2737 (unsigned long long)acct.cancelled_write_bytes);
2738 }
2739
2740 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2741 {
2742 return do_io_accounting(task, buffer, 0);
2743 }
2744
2745 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2746 {
2747 return do_io_accounting(task, buffer, 1);
2748 }
2749 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2750
2751 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2752 struct pid *pid, struct task_struct *task)
2753 {
2754 int err = lock_trace(task);
2755 if (!err) {
2756 seq_printf(m, "%08x\n", task->personality);
2757 unlock_trace(task);
2758 }
2759 return err;
2760 }
2761
2762 /*
2763 * Thread groups
2764 */
2765 static const struct file_operations proc_task_operations;
2766 static const struct inode_operations proc_task_inode_operations;
2767
2768 static const struct pid_entry tgid_base_stuff[] = {
2769 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2770 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2771 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2772 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2773 #ifdef CONFIG_NET
2774 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2775 #endif
2776 REG("environ", S_IRUSR, proc_environ_operations),
2777 INF("auxv", S_IRUSR, proc_pid_auxv),
2778 ONE("status", S_IRUGO, proc_pid_status),
2779 ONE("personality", S_IRUGO, proc_pid_personality),
2780 INF("limits", S_IRUGO, proc_pid_limits),
2781 #ifdef CONFIG_SCHED_DEBUG
2782 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2783 #endif
2784 #ifdef CONFIG_SCHED_AUTOGROUP
2785 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2786 #endif
2787 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2788 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2789 INF("syscall", S_IRUGO, proc_pid_syscall),
2790 #endif
2791 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2792 ONE("stat", S_IRUGO, proc_tgid_stat),
2793 ONE("statm", S_IRUGO, proc_pid_statm),
2794 REG("maps", S_IRUGO, proc_maps_operations),
2795 #ifdef CONFIG_NUMA
2796 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2797 #endif
2798 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2799 LNK("cwd", proc_cwd_link),
2800 LNK("root", proc_root_link),
2801 LNK("exe", proc_exe_link),
2802 REG("mounts", S_IRUGO, proc_mounts_operations),
2803 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2804 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2805 #ifdef CONFIG_PROC_PAGE_MONITOR
2806 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2807 REG("smaps", S_IRUGO, proc_smaps_operations),
2808 REG("pagemap", S_IRUGO, proc_pagemap_operations),
2809 #endif
2810 #ifdef CONFIG_SECURITY
2811 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2812 #endif
2813 #ifdef CONFIG_KALLSYMS
2814 INF("wchan", S_IRUGO, proc_pid_wchan),
2815 #endif
2816 #ifdef CONFIG_STACKTRACE
2817 ONE("stack", S_IRUGO, proc_pid_stack),
2818 #endif
2819 #ifdef CONFIG_SCHEDSTATS
2820 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2821 #endif
2822 #ifdef CONFIG_LATENCYTOP
2823 REG("latency", S_IRUGO, proc_lstats_operations),
2824 #endif
2825 #ifdef CONFIG_PROC_PID_CPUSET
2826 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2827 #endif
2828 #ifdef CONFIG_CGROUPS
2829 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2830 #endif
2831 INF("oom_score", S_IRUGO, proc_oom_score),
2832 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2833 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2834 #ifdef CONFIG_AUDITSYSCALL
2835 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2836 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2837 #endif
2838 #ifdef CONFIG_FAULT_INJECTION
2839 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2840 #endif
2841 #ifdef CONFIG_ELF_CORE
2842 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2843 #endif
2844 #ifdef CONFIG_TASK_IO_ACCOUNTING
2845 INF("io", S_IRUSR, proc_tgid_io_accounting),
2846 #endif
2847 #ifdef CONFIG_HARDWALL
2848 INF("hardwall", S_IRUGO, proc_pid_hardwall),
2849 #endif
2850 };
2851
2852 static int proc_tgid_base_readdir(struct file * filp,
2853 void * dirent, filldir_t filldir)
2854 {
2855 return proc_pident_readdir(filp,dirent,filldir,
2856 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2857 }
2858
2859 static const struct file_operations proc_tgid_base_operations = {
2860 .read = generic_read_dir,
2861 .readdir = proc_tgid_base_readdir,
2862 .llseek = default_llseek,
2863 };
2864
2865 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2866 return proc_pident_lookup(dir, dentry,
2867 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2868 }
2869
2870 static const struct inode_operations proc_tgid_base_inode_operations = {
2871 .lookup = proc_tgid_base_lookup,
2872 .getattr = pid_getattr,
2873 .setattr = proc_setattr,
2874 };
2875
2876 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2877 {
2878 struct dentry *dentry, *leader, *dir;
2879 char buf[PROC_NUMBUF];
2880 struct qstr name;
2881
2882 name.name = buf;
2883 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2884 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2885 if (dentry) {
2886 shrink_dcache_parent(dentry);
2887 d_drop(dentry);
2888 dput(dentry);
2889 }
2890
2891 name.name = buf;
2892 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2893 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2894 if (!leader)
2895 goto out;
2896
2897 name.name = "task";
2898 name.len = strlen(name.name);
2899 dir = d_hash_and_lookup(leader, &name);
2900 if (!dir)
2901 goto out_put_leader;
2902
2903 name.name = buf;
2904 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2905 dentry = d_hash_and_lookup(dir, &name);
2906 if (dentry) {
2907 shrink_dcache_parent(dentry);
2908 d_drop(dentry);
2909 dput(dentry);
2910 }
2911
2912 dput(dir);
2913 out_put_leader:
2914 dput(leader);
2915 out:
2916 return;
2917 }
2918
2919 /**
2920 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2921 * @task: task that should be flushed.
2922 *
2923 * When flushing dentries from proc, one needs to flush them from global
2924 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2925 * in. This call is supposed to do all of this job.
2926 *
2927 * Looks in the dcache for
2928 * /proc/@pid
2929 * /proc/@tgid/task/@pid
2930 * if either directory is present flushes it and all of it'ts children
2931 * from the dcache.
2932 *
2933 * It is safe and reasonable to cache /proc entries for a task until
2934 * that task exits. After that they just clog up the dcache with
2935 * useless entries, possibly causing useful dcache entries to be
2936 * flushed instead. This routine is proved to flush those useless
2937 * dcache entries at process exit time.
2938 *
2939 * NOTE: This routine is just an optimization so it does not guarantee
2940 * that no dcache entries will exist at process exit time it
2941 * just makes it very unlikely that any will persist.
2942 */
2943
2944 void proc_flush_task(struct task_struct *task)
2945 {
2946 int i;
2947 struct pid *pid, *tgid;
2948 struct upid *upid;
2949
2950 pid = task_pid(task);
2951 tgid = task_tgid(task);
2952
2953 for (i = 0; i <= pid->level; i++) {
2954 upid = &pid->numbers[i];
2955 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2956 tgid->numbers[i].nr);
2957 }
2958
2959 upid = &pid->numbers[pid->level];
2960 if (upid->nr == 1)
2961 pid_ns_release_proc(upid->ns);
2962 }
2963
2964 static struct dentry *proc_pid_instantiate(struct inode *dir,
2965 struct dentry * dentry,
2966 struct task_struct *task, const void *ptr)
2967 {
2968 struct dentry *error = ERR_PTR(-ENOENT);
2969 struct inode *inode;
2970
2971 inode = proc_pid_make_inode(dir->i_sb, task);
2972 if (!inode)
2973 goto out;
2974
2975 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2976 inode->i_op = &proc_tgid_base_inode_operations;
2977 inode->i_fop = &proc_tgid_base_operations;
2978 inode->i_flags|=S_IMMUTABLE;
2979
2980 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2981 ARRAY_SIZE(tgid_base_stuff));
2982
2983 d_set_d_op(dentry, &pid_dentry_operations);
2984
2985 d_add(dentry, inode);
2986 /* Close the race of the process dying before we return the dentry */
2987 if (pid_revalidate(dentry, NULL))
2988 error = NULL;
2989 out:
2990 return error;
2991 }
2992
2993 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2994 {
2995 struct dentry *result;
2996 struct task_struct *task;
2997 unsigned tgid;
2998 struct pid_namespace *ns;
2999
3000 result = proc_base_lookup(dir, dentry);
3001 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
3002 goto out;
3003
3004 tgid = name_to_int(dentry);
3005 if (tgid == ~0U)
3006 goto out;
3007
3008 ns = dentry->d_sb->s_fs_info;
3009 rcu_read_lock();
3010 task = find_task_by_pid_ns(tgid, ns);
3011 if (task)
3012 get_task_struct(task);
3013 rcu_read_unlock();
3014 if (!task)
3015 goto out;
3016
3017 result = proc_pid_instantiate(dir, dentry, task, NULL);
3018 put_task_struct(task);
3019 out:
3020 return result;
3021 }
3022
3023 /*
3024 * Find the first task with tgid >= tgid
3025 *
3026 */
3027 struct tgid_iter {
3028 unsigned int tgid;
3029 struct task_struct *task;
3030 };
3031 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3032 {
3033 struct pid *pid;
3034
3035 if (iter.task)
3036 put_task_struct(iter.task);
3037 rcu_read_lock();
3038 retry:
3039 iter.task = NULL;
3040 pid = find_ge_pid(iter.tgid, ns);
3041 if (pid) {
3042 iter.tgid = pid_nr_ns(pid, ns);
3043 iter.task = pid_task(pid, PIDTYPE_PID);
3044 /* What we to know is if the pid we have find is the
3045 * pid of a thread_group_leader. Testing for task
3046 * being a thread_group_leader is the obvious thing
3047 * todo but there is a window when it fails, due to
3048 * the pid transfer logic in de_thread.
3049 *
3050 * So we perform the straight forward test of seeing
3051 * if the pid we have found is the pid of a thread
3052 * group leader, and don't worry if the task we have
3053 * found doesn't happen to be a thread group leader.
3054 * As we don't care in the case of readdir.
3055 */
3056 if (!iter.task || !has_group_leader_pid(iter.task)) {
3057 iter.tgid += 1;
3058 goto retry;
3059 }
3060 get_task_struct(iter.task);
3061 }
3062 rcu_read_unlock();
3063 return iter;
3064 }
3065
3066 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3067
3068 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3069 struct tgid_iter iter)
3070 {
3071 char name[PROC_NUMBUF];
3072 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3073 return proc_fill_cache(filp, dirent, filldir, name, len,
3074 proc_pid_instantiate, iter.task, NULL);
3075 }
3076
3077 /* for the /proc/ directory itself, after non-process stuff has been done */
3078 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3079 {
3080 unsigned int nr;
3081 struct task_struct *reaper;
3082 struct tgid_iter iter;
3083 struct pid_namespace *ns;
3084
3085 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3086 goto out_no_task;
3087 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3088
3089 reaper = get_proc_task(filp->f_path.dentry->d_inode);
3090 if (!reaper)
3091 goto out_no_task;
3092
3093 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3094 const struct pid_entry *p = &proc_base_stuff[nr];
3095 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3096 goto out;
3097 }
3098
3099 ns = filp->f_dentry->d_sb->s_fs_info;
3100 iter.task = NULL;
3101 iter.tgid = filp->f_pos - TGID_OFFSET;
3102 for (iter = next_tgid(ns, iter);
3103 iter.task;
3104 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3105 filp->f_pos = iter.tgid + TGID_OFFSET;
3106 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
3107 put_task_struct(iter.task);
3108 goto out;
3109 }
3110 }
3111 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3112 out:
3113 put_task_struct(reaper);
3114 out_no_task:
3115 return 0;
3116 }
3117
3118 /*
3119 * Tasks
3120 */
3121 static const struct pid_entry tid_base_stuff[] = {
3122 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3123 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3124 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3125 REG("environ", S_IRUSR, proc_environ_operations),
3126 INF("auxv", S_IRUSR, proc_pid_auxv),
3127 ONE("status", S_IRUGO, proc_pid_status),
3128 ONE("personality", S_IRUGO, proc_pid_personality),
3129 INF("limits", S_IRUGO, proc_pid_limits),
3130 #ifdef CONFIG_SCHED_DEBUG
3131 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3132 #endif
3133 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3134 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3135 INF("syscall", S_IRUGO, proc_pid_syscall),
3136 #endif
3137 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3138 ONE("stat", S_IRUGO, proc_tid_stat),
3139 ONE("statm", S_IRUGO, proc_pid_statm),
3140 REG("maps", S_IRUGO, proc_maps_operations),
3141 #ifdef CONFIG_NUMA
3142 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3143 #endif
3144 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3145 LNK("cwd", proc_cwd_link),
3146 LNK("root", proc_root_link),
3147 LNK("exe", proc_exe_link),
3148 REG("mounts", S_IRUGO, proc_mounts_operations),
3149 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3150 #ifdef CONFIG_PROC_PAGE_MONITOR
3151 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3152 REG("smaps", S_IRUGO, proc_smaps_operations),
3153 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3154 #endif
3155 #ifdef CONFIG_SECURITY
3156 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3157 #endif
3158 #ifdef CONFIG_KALLSYMS
3159 INF("wchan", S_IRUGO, proc_pid_wchan),
3160 #endif
3161 #ifdef CONFIG_STACKTRACE
3162 ONE("stack", S_IRUGO, proc_pid_stack),
3163 #endif
3164 #ifdef CONFIG_SCHEDSTATS
3165 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3166 #endif
3167 #ifdef CONFIG_LATENCYTOP
3168 REG("latency", S_IRUGO, proc_lstats_operations),
3169 #endif
3170 #ifdef CONFIG_PROC_PID_CPUSET
3171 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3172 #endif
3173 #ifdef CONFIG_CGROUPS
3174 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3175 #endif
3176 INF("oom_score", S_IRUGO, proc_oom_score),
3177 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3178 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3179 #ifdef CONFIG_AUDITSYSCALL
3180 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3181 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3182 #endif
3183 #ifdef CONFIG_FAULT_INJECTION
3184 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3185 #endif
3186 #ifdef CONFIG_TASK_IO_ACCOUNTING
3187 INF("io", S_IRUSR, proc_tid_io_accounting),
3188 #endif
3189 #ifdef CONFIG_HARDWALL
3190 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3191 #endif
3192 };
3193
3194 static int proc_tid_base_readdir(struct file * filp,
3195 void * dirent, filldir_t filldir)
3196 {
3197 return proc_pident_readdir(filp,dirent,filldir,
3198 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3199 }
3200
3201 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3202 return proc_pident_lookup(dir, dentry,
3203 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3204 }
3205
3206 static const struct file_operations proc_tid_base_operations = {
3207 .read = generic_read_dir,
3208 .readdir = proc_tid_base_readdir,
3209 .llseek = default_llseek,
3210 };
3211
3212 static const struct inode_operations proc_tid_base_inode_operations = {
3213 .lookup = proc_tid_base_lookup,
3214 .getattr = pid_getattr,
3215 .setattr = proc_setattr,
3216 };
3217
3218 static struct dentry *proc_task_instantiate(struct inode *dir,
3219 struct dentry *dentry, struct task_struct *task, const void *ptr)
3220 {
3221 struct dentry *error = ERR_PTR(-ENOENT);
3222 struct inode *inode;
3223 inode = proc_pid_make_inode(dir->i_sb, task);
3224
3225 if (!inode)
3226 goto out;
3227 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3228 inode->i_op = &proc_tid_base_inode_operations;
3229 inode->i_fop = &proc_tid_base_operations;
3230 inode->i_flags|=S_IMMUTABLE;
3231
3232 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3233 ARRAY_SIZE(tid_base_stuff));
3234
3235 d_set_d_op(dentry, &pid_dentry_operations);
3236
3237 d_add(dentry, inode);
3238 /* Close the race of the process dying before we return the dentry */
3239 if (pid_revalidate(dentry, NULL))
3240 error = NULL;
3241 out:
3242 return error;
3243 }
3244
3245 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3246 {
3247 struct dentry *result = ERR_PTR(-ENOENT);
3248 struct task_struct *task;
3249 struct task_struct *leader = get_proc_task(dir);
3250 unsigned tid;
3251 struct pid_namespace *ns;
3252
3253 if (!leader)
3254 goto out_no_task;
3255
3256 tid = name_to_int(dentry);
3257 if (tid == ~0U)
3258 goto out;
3259
3260 ns = dentry->d_sb->s_fs_info;
3261 rcu_read_lock();
3262 task = find_task_by_pid_ns(tid, ns);
3263 if (task)
3264 get_task_struct(task);
3265 rcu_read_unlock();
3266 if (!task)
3267 goto out;
3268 if (!same_thread_group(leader, task))
3269 goto out_drop_task;
3270
3271 result = proc_task_instantiate(dir, dentry, task, NULL);
3272 out_drop_task:
3273 put_task_struct(task);
3274 out:
3275 put_task_struct(leader);
3276 out_no_task:
3277 return result;
3278 }
3279
3280 /*
3281 * Find the first tid of a thread group to return to user space.
3282 *
3283 * Usually this is just the thread group leader, but if the users
3284 * buffer was too small or there was a seek into the middle of the
3285 * directory we have more work todo.
3286 *
3287 * In the case of a short read we start with find_task_by_pid.
3288 *
3289 * In the case of a seek we start with the leader and walk nr
3290 * threads past it.
3291 */
3292 static struct task_struct *first_tid(struct task_struct *leader,
3293 int tid, int nr, struct pid_namespace *ns)
3294 {
3295 struct task_struct *pos;
3296
3297 rcu_read_lock();
3298 /* Attempt to start with the pid of a thread */
3299 if (tid && (nr > 0)) {
3300 pos = find_task_by_pid_ns(tid, ns);
3301 if (pos && (pos->group_leader == leader))
3302 goto found;
3303 }
3304
3305 /* If nr exceeds the number of threads there is nothing todo */
3306 pos = NULL;
3307 if (nr && nr >= get_nr_threads(leader))
3308 goto out;
3309
3310 /* If we haven't found our starting place yet start
3311 * with the leader and walk nr threads forward.
3312 */
3313 for (pos = leader; nr > 0; --nr) {
3314 pos = next_thread(pos);
3315 if (pos == leader) {
3316 pos = NULL;
3317 goto out;
3318 }
3319 }
3320 found:
3321 get_task_struct(pos);
3322 out:
3323 rcu_read_unlock();
3324 return pos;
3325 }
3326
3327 /*
3328 * Find the next thread in the thread list.
3329 * Return NULL if there is an error or no next thread.
3330 *
3331 * The reference to the input task_struct is released.
3332 */
3333 static struct task_struct *next_tid(struct task_struct *start)
3334 {
3335 struct task_struct *pos = NULL;
3336 rcu_read_lock();
3337 if (pid_alive(start)) {
3338 pos = next_thread(start);
3339 if (thread_group_leader(pos))
3340 pos = NULL;
3341 else
3342 get_task_struct(pos);
3343 }
3344 rcu_read_unlock();
3345 put_task_struct(start);
3346 return pos;
3347 }
3348
3349 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3350 struct task_struct *task, int tid)
3351 {
3352 char name[PROC_NUMBUF];
3353 int len = snprintf(name, sizeof(name), "%d", tid);
3354 return proc_fill_cache(filp, dirent, filldir, name, len,
3355 proc_task_instantiate, task, NULL);
3356 }
3357
3358 /* for the /proc/TGID/task/ directories */
3359 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3360 {
3361 struct dentry *dentry = filp->f_path.dentry;
3362 struct inode *inode = dentry->d_inode;
3363 struct task_struct *leader = NULL;
3364 struct task_struct *task;
3365 int retval = -ENOENT;
3366 ino_t ino;
3367 int tid;
3368 struct pid_namespace *ns;
3369
3370 task = get_proc_task(inode);
3371 if (!task)
3372 goto out_no_task;
3373 rcu_read_lock();
3374 if (pid_alive(task)) {
3375 leader = task->group_leader;
3376 get_task_struct(leader);
3377 }
3378 rcu_read_unlock();
3379 put_task_struct(task);
3380 if (!leader)
3381 goto out_no_task;
3382 retval = 0;
3383
3384 switch ((unsigned long)filp->f_pos) {
3385 case 0:
3386 ino = inode->i_ino;
3387 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3388 goto out;
3389 filp->f_pos++;
3390 /* fall through */
3391 case 1:
3392 ino = parent_ino(dentry);
3393 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3394 goto out;
3395 filp->f_pos++;
3396 /* fall through */
3397 }
3398
3399 /* f_version caches the tgid value that the last readdir call couldn't
3400 * return. lseek aka telldir automagically resets f_version to 0.
3401 */
3402 ns = filp->f_dentry->d_sb->s_fs_info;
3403 tid = (int)filp->f_version;
3404 filp->f_version = 0;
3405 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3406 task;
3407 task = next_tid(task), filp->f_pos++) {
3408 tid = task_pid_nr_ns(task, ns);
3409 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3410 /* returning this tgid failed, save it as the first
3411 * pid for the next readir call */
3412 filp->f_version = (u64)tid;
3413 put_task_struct(task);
3414 break;
3415 }
3416 }
3417 out:
3418 put_task_struct(leader);
3419 out_no_task:
3420 return retval;
3421 }
3422
3423 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3424 {
3425 struct inode *inode = dentry->d_inode;
3426 struct task_struct *p = get_proc_task(inode);
3427 generic_fillattr(inode, stat);
3428
3429 if (p) {
3430 stat->nlink += get_nr_threads(p);
3431 put_task_struct(p);
3432 }
3433
3434 return 0;
3435 }
3436
3437 static const struct inode_operations proc_task_inode_operations = {
3438 .lookup = proc_task_lookup,
3439 .getattr = proc_task_getattr,
3440 .setattr = proc_setattr,
3441 };
3442
3443 static const struct file_operations proc_task_operations = {
3444 .read = generic_read_dir,
3445 .readdir = proc_task_readdir,
3446 .llseek = default_llseek,
3447 };
linux-next