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proc: put check_mem_permission after __get_free_page in mem_write
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / proc / base.c
blob4ede550517a66b42b0c646d227d32456d4245764
1 /*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50 #include <asm/uaccess.h>
51
52 #include <linux/errno.h>
53 #include <linux/time.h>
54 #include <linux/proc_fs.h>
55 #include <linux/stat.h>
56 #include <linux/task_io_accounting_ops.h>
57 #include <linux/init.h>
58 #include <linux/capability.h>
59 #include <linux/file.h>
60 #include <linux/fdtable.h>
61 #include <linux/string.h>
62 #include <linux/seq_file.h>
63 #include <linux/namei.h>
64 #include <linux/mnt_namespace.h>
65 #include <linux/mm.h>
66 #include <linux/swap.h>
67 #include <linux/rcupdate.h>
68 #include <linux/kallsyms.h>
69 #include <linux/stacktrace.h>
70 #include <linux/resource.h>
71 #include <linux/module.h>
72 #include <linux/mount.h>
73 #include <linux/security.h>
74 #include <linux/ptrace.h>
75 #include <linux/tracehook.h>
76 #include <linux/cgroup.h>
77 #include <linux/cpuset.h>
78 #include <linux/audit.h>
79 #include <linux/poll.h>
80 #include <linux/nsproxy.h>
81 #include <linux/oom.h>
82 #include <linux/elf.h>
83 #include <linux/pid_namespace.h>
84 #include <linux/fs_struct.h>
85 #include <linux/slab.h>
86 #include "internal.h"
87
88 /* NOTE:
89 * Implementing inode permission operations in /proc is almost
90 * certainly an error. Permission checks need to happen during
91 * each system call not at open time. The reason is that most of
92 * what we wish to check for permissions in /proc varies at runtime.
93 *
94 * The classic example of a problem is opening file descriptors
95 * in /proc for a task before it execs a suid executable.
96 */
97
98 struct pid_entry {
99 char *name;
100 int len;
101 mode_t mode;
102 const struct inode_operations *iop;
103 const struct file_operations *fop;
104 union proc_op op;
105 };
106
107 #define NOD(NAME, MODE, IOP, FOP, OP) { \
108 .name = (NAME), \
109 .len = sizeof(NAME) - 1, \
110 .mode = MODE, \
111 .iop = IOP, \
112 .fop = FOP, \
113 .op = OP, \
114 }
115
116 #define DIR(NAME, MODE, iops, fops) \
117 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
118 #define LNK(NAME, get_link) \
119 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
120 &proc_pid_link_inode_operations, NULL, \
121 { .proc_get_link = get_link } )
122 #define REG(NAME, MODE, fops) \
123 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
124 #define INF(NAME, MODE, read) \
125 NOD(NAME, (S_IFREG|(MODE)), \
126 NULL, &proc_info_file_operations, \
127 { .proc_read = read } )
128 #define ONE(NAME, MODE, show) \
129 NOD(NAME, (S_IFREG|(MODE)), \
130 NULL, &proc_single_file_operations, \
131 { .proc_show = show } )
132
133 /*
134 * Count the number of hardlinks for the pid_entry table, excluding the .
135 * and .. links.
136 */
137 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
138 unsigned int n)
139 {
140 unsigned int i;
141 unsigned int count;
142
143 count = 0;
144 for (i = 0; i < n; ++i) {
145 if (S_ISDIR(entries[i].mode))
146 ++count;
147 }
148
149 return count;
150 }
151
152 static int get_task_root(struct task_struct *task, struct path *root)
153 {
154 int result = -ENOENT;
155
156 task_lock(task);
157 if (task->fs) {
158 get_fs_root(task->fs, root);
159 result = 0;
160 }
161 task_unlock(task);
162 return result;
163 }
164
165 static int proc_cwd_link(struct inode *inode, struct path *path)
166 {
167 struct task_struct *task = get_proc_task(inode);
168 int result = -ENOENT;
169
170 if (task) {
171 task_lock(task);
172 if (task->fs) {
173 get_fs_pwd(task->fs, path);
174 result = 0;
175 }
176 task_unlock(task);
177 put_task_struct(task);
178 }
179 return result;
180 }
181
182 static int proc_root_link(struct inode *inode, struct path *path)
183 {
184 struct task_struct *task = get_proc_task(inode);
185 int result = -ENOENT;
186
187 if (task) {
188 result = get_task_root(task, path);
189 put_task_struct(task);
190 }
191 return result;
192 }
193
194 static struct mm_struct *__check_mem_permission(struct task_struct *task)
195 {
196 struct mm_struct *mm;
197
198 mm = get_task_mm(task);
199 if (!mm)
200 return ERR_PTR(-EINVAL);
201
202 /*
203 * A task can always look at itself, in case it chooses
204 * to use system calls instead of load instructions.
205 */
206 if (task == current)
207 return mm;
208
209 /*
210 * If current is actively ptrace'ing, and would also be
211 * permitted to freshly attach with ptrace now, permit it.
212 */
213 if (task_is_stopped_or_traced(task)) {
214 int match;
215 rcu_read_lock();
216 match = (tracehook_tracer_task(task) == current);
217 rcu_read_unlock();
218 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
219 return mm;
220 }
221
222 /*
223 * No one else is allowed.
224 */
225 mmput(mm);
226 return ERR_PTR(-EPERM);
227 }
228
229 /*
230 * If current may access user memory in @task return a reference to the
231 * corresponding mm, otherwise ERR_PTR.
232 */
233 static struct mm_struct *check_mem_permission(struct task_struct *task)
234 {
235 struct mm_struct *mm;
236 int err;
237
238 /*
239 * Avoid racing if task exec's as we might get a new mm but validate
240 * against old credentials.
241 */
242 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
243 if (err)
244 return ERR_PTR(err);
245
246 mm = __check_mem_permission(task);
247 mutex_unlock(&task->signal->cred_guard_mutex);
248
249 return mm;
250 }
251
252 struct mm_struct *mm_for_maps(struct task_struct *task)
253 {
254 struct mm_struct *mm;
255 int err;
256
257 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
258 if (err)
259 return ERR_PTR(err);
260
261 mm = get_task_mm(task);
262 if (mm && mm != current->mm &&
263 !ptrace_may_access(task, PTRACE_MODE_READ)) {
264 mmput(mm);
265 mm = ERR_PTR(-EACCES);
266 }
267 mutex_unlock(&task->signal->cred_guard_mutex);
268
269 return mm;
270 }
271
272 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
273 {
274 int res = 0;
275 unsigned int len;
276 struct mm_struct *mm = get_task_mm(task);
277 if (!mm)
278 goto out;
279 if (!mm->arg_end)
280 goto out_mm; /* Shh! No looking before we're done */
281
282 len = mm->arg_end - mm->arg_start;
283
284 if (len > PAGE_SIZE)
285 len = PAGE_SIZE;
286
287 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
288
289 // If the nul at the end of args has been overwritten, then
290 // assume application is using setproctitle(3).
291 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
292 len = strnlen(buffer, res);
293 if (len < res) {
294 res = len;
295 } else {
296 len = mm->env_end - mm->env_start;
297 if (len > PAGE_SIZE - res)
298 len = PAGE_SIZE - res;
299 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
300 res = strnlen(buffer, res);
301 }
302 }
303 out_mm:
304 mmput(mm);
305 out:
306 return res;
307 }
308
309 static int proc_pid_auxv(struct task_struct *task, char *buffer)
310 {
311 struct mm_struct *mm = mm_for_maps(task);
312 int res = PTR_ERR(mm);
313 if (mm && !IS_ERR(mm)) {
314 unsigned int nwords = 0;
315 do {
316 nwords += 2;
317 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
318 res = nwords * sizeof(mm->saved_auxv[0]);
319 if (res > PAGE_SIZE)
320 res = PAGE_SIZE;
321 memcpy(buffer, mm->saved_auxv, res);
322 mmput(mm);
323 }
324 return res;
325 }
326
327
328 #ifdef CONFIG_KALLSYMS
329 /*
330 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
331 * Returns the resolved symbol. If that fails, simply return the address.
332 */
333 static int proc_pid_wchan(struct task_struct *task, char *buffer)
334 {
335 unsigned long wchan;
336 char symname[KSYM_NAME_LEN];
337
338 wchan = get_wchan(task);
339
340 if (lookup_symbol_name(wchan, symname) < 0)
341 if (!ptrace_may_access(task, PTRACE_MODE_READ))
342 return 0;
343 else
344 return sprintf(buffer, "%lu", wchan);
345 else
346 return sprintf(buffer, "%s", symname);
347 }
348 #endif /* CONFIG_KALLSYMS */
349
350 static int lock_trace(struct task_struct *task)
351 {
352 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
353 if (err)
354 return err;
355 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
356 mutex_unlock(&task->signal->cred_guard_mutex);
357 return -EPERM;
358 }
359 return 0;
360 }
361
362 static void unlock_trace(struct task_struct *task)
363 {
364 mutex_unlock(&task->signal->cred_guard_mutex);
365 }
366
367 #ifdef CONFIG_STACKTRACE
368
369 #define MAX_STACK_TRACE_DEPTH 64
370
371 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
372 struct pid *pid, struct task_struct *task)
373 {
374 struct stack_trace trace;
375 unsigned long *entries;
376 int err;
377 int i;
378
379 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
380 if (!entries)
381 return -ENOMEM;
382
383 trace.nr_entries = 0;
384 trace.max_entries = MAX_STACK_TRACE_DEPTH;
385 trace.entries = entries;
386 trace.skip = 0;
387
388 err = lock_trace(task);
389 if (!err) {
390 save_stack_trace_tsk(task, &trace);
391
392 for (i = 0; i < trace.nr_entries; i++) {
393 seq_printf(m, "[<%pK>] %pS\n",
394 (void *)entries[i], (void *)entries[i]);
395 }
396 unlock_trace(task);
397 }
398 kfree(entries);
399
400 return err;
401 }
402 #endif
403
404 #ifdef CONFIG_SCHEDSTATS
405 /*
406 * Provides /proc/PID/schedstat
407 */
408 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
409 {
410 return sprintf(buffer, "%llu %llu %lu\n",
411 (unsigned long long)task->se.sum_exec_runtime,
412 (unsigned long long)task->sched_info.run_delay,
413 task->sched_info.pcount);
414 }
415 #endif
416
417 #ifdef CONFIG_LATENCYTOP
418 static int lstats_show_proc(struct seq_file *m, void *v)
419 {
420 int i;
421 struct inode *inode = m->private;
422 struct task_struct *task = get_proc_task(inode);
423
424 if (!task)
425 return -ESRCH;
426 seq_puts(m, "Latency Top version : v0.1\n");
427 for (i = 0; i < 32; i++) {
428 struct latency_record *lr = &task->latency_record[i];
429 if (lr->backtrace[0]) {
430 int q;
431 seq_printf(m, "%i %li %li",
432 lr->count, lr->time, lr->max);
433 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
434 unsigned long bt = lr->backtrace[q];
435 if (!bt)
436 break;
437 if (bt == ULONG_MAX)
438 break;
439 seq_printf(m, " %ps", (void *)bt);
440 }
441 seq_putc(m, '\n');
442 }
443
444 }
445 put_task_struct(task);
446 return 0;
447 }
448
449 static int lstats_open(struct inode *inode, struct file *file)
450 {
451 return single_open(file, lstats_show_proc, inode);
452 }
453
454 static ssize_t lstats_write(struct file *file, const char __user *buf,
455 size_t count, loff_t *offs)
456 {
457 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
458
459 if (!task)
460 return -ESRCH;
461 clear_all_latency_tracing(task);
462 put_task_struct(task);
463
464 return count;
465 }
466
467 static const struct file_operations proc_lstats_operations = {
468 .open = lstats_open,
469 .read = seq_read,
470 .write = lstats_write,
471 .llseek = seq_lseek,
472 .release = single_release,
473 };
474
475 #endif
476
477 static int proc_oom_score(struct task_struct *task, char *buffer)
478 {
479 unsigned long points = 0;
480
481 read_lock(&tasklist_lock);
482 if (pid_alive(task))
483 points = oom_badness(task, NULL, NULL,
484 totalram_pages + total_swap_pages);
485 read_unlock(&tasklist_lock);
486 return sprintf(buffer, "%lu\n", points);
487 }
488
489 struct limit_names {
490 char *name;
491 char *unit;
492 };
493
494 static const struct limit_names lnames[RLIM_NLIMITS] = {
495 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
496 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
497 [RLIMIT_DATA] = {"Max data size", "bytes"},
498 [RLIMIT_STACK] = {"Max stack size", "bytes"},
499 [RLIMIT_CORE] = {"Max core file size", "bytes"},
500 [RLIMIT_RSS] = {"Max resident set", "bytes"},
501 [RLIMIT_NPROC] = {"Max processes", "processes"},
502 [RLIMIT_NOFILE] = {"Max open files", "files"},
503 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
504 [RLIMIT_AS] = {"Max address space", "bytes"},
505 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
506 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
507 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
508 [RLIMIT_NICE] = {"Max nice priority", NULL},
509 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
510 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
511 };
512
513 /* Display limits for a process */
514 static int proc_pid_limits(struct task_struct *task, char *buffer)
515 {
516 unsigned int i;
517 int count = 0;
518 unsigned long flags;
519 char *bufptr = buffer;
520
521 struct rlimit rlim[RLIM_NLIMITS];
522
523 if (!lock_task_sighand(task, &flags))
524 return 0;
525 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
526 unlock_task_sighand(task, &flags);
527
528 /*
529 * print the file header
530 */
531 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
532 "Limit", "Soft Limit", "Hard Limit", "Units");
533
534 for (i = 0; i < RLIM_NLIMITS; i++) {
535 if (rlim[i].rlim_cur == RLIM_INFINITY)
536 count += sprintf(&bufptr[count], "%-25s %-20s ",
537 lnames[i].name, "unlimited");
538 else
539 count += sprintf(&bufptr[count], "%-25s %-20lu ",
540 lnames[i].name, rlim[i].rlim_cur);
541
542 if (rlim[i].rlim_max == RLIM_INFINITY)
543 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
544 else
545 count += sprintf(&bufptr[count], "%-20lu ",
546 rlim[i].rlim_max);
547
548 if (lnames[i].unit)
549 count += sprintf(&bufptr[count], "%-10s\n",
550 lnames[i].unit);
551 else
552 count += sprintf(&bufptr[count], "\n");
553 }
554
555 return count;
556 }
557
558 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
559 static int proc_pid_syscall(struct task_struct *task, char *buffer)
560 {
561 long nr;
562 unsigned long args[6], sp, pc;
563 int res = lock_trace(task);
564 if (res)
565 return res;
566
567 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
568 res = sprintf(buffer, "running\n");
569 else if (nr < 0)
570 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
571 else
572 res = sprintf(buffer,
573 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
574 nr,
575 args[0], args[1], args[2], args[3], args[4], args[5],
576 sp, pc);
577 unlock_trace(task);
578 return res;
579 }
580 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
581
582 /************************************************************************/
583 /* Here the fs part begins */
584 /************************************************************************/
585
586 /* permission checks */
587 static int proc_fd_access_allowed(struct inode *inode)
588 {
589 struct task_struct *task;
590 int allowed = 0;
591 /* Allow access to a task's file descriptors if it is us or we
592 * may use ptrace attach to the process and find out that
593 * information.
594 */
595 task = get_proc_task(inode);
596 if (task) {
597 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
598 put_task_struct(task);
599 }
600 return allowed;
601 }
602
603 int proc_setattr(struct dentry *dentry, struct iattr *attr)
604 {
605 int error;
606 struct inode *inode = dentry->d_inode;
607
608 if (attr->ia_valid & ATTR_MODE)
609 return -EPERM;
610
611 error = inode_change_ok(inode, attr);
612 if (error)
613 return error;
614
615 if ((attr->ia_valid & ATTR_SIZE) &&
616 attr->ia_size != i_size_read(inode)) {
617 error = vmtruncate(inode, attr->ia_size);
618 if (error)
619 return error;
620 }
621
622 setattr_copy(inode, attr);
623 mark_inode_dirty(inode);
624 return 0;
625 }
626
627 static const struct inode_operations proc_def_inode_operations = {
628 .setattr = proc_setattr,
629 };
630
631 static int mounts_open_common(struct inode *inode, struct file *file,
632 const struct seq_operations *op)
633 {
634 struct task_struct *task = get_proc_task(inode);
635 struct nsproxy *nsp;
636 struct mnt_namespace *ns = NULL;
637 struct path root;
638 struct proc_mounts *p;
639 int ret = -EINVAL;
640
641 if (task) {
642 rcu_read_lock();
643 nsp = task_nsproxy(task);
644 if (nsp) {
645 ns = nsp->mnt_ns;
646 if (ns)
647 get_mnt_ns(ns);
648 }
649 rcu_read_unlock();
650 if (ns && get_task_root(task, &root) == 0)
651 ret = 0;
652 put_task_struct(task);
653 }
654
655 if (!ns)
656 goto err;
657 if (ret)
658 goto err_put_ns;
659
660 ret = -ENOMEM;
661 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
662 if (!p)
663 goto err_put_path;
664
665 file->private_data = &p->m;
666 ret = seq_open(file, op);
667 if (ret)
668 goto err_free;
669
670 p->m.private = p;
671 p->ns = ns;
672 p->root = root;
673 p->event = ns->event;
674
675 return 0;
676
677 err_free:
678 kfree(p);
679 err_put_path:
680 path_put(&root);
681 err_put_ns:
682 put_mnt_ns(ns);
683 err:
684 return ret;
685 }
686
687 static int mounts_release(struct inode *inode, struct file *file)
688 {
689 struct proc_mounts *p = file->private_data;
690 path_put(&p->root);
691 put_mnt_ns(p->ns);
692 return seq_release(inode, file);
693 }
694
695 static unsigned mounts_poll(struct file *file, poll_table *wait)
696 {
697 struct proc_mounts *p = file->private_data;
698 unsigned res = POLLIN | POLLRDNORM;
699
700 poll_wait(file, &p->ns->poll, wait);
701 if (mnt_had_events(p))
702 res |= POLLERR | POLLPRI;
703
704 return res;
705 }
706
707 static int mounts_open(struct inode *inode, struct file *file)
708 {
709 return mounts_open_common(inode, file, &mounts_op);
710 }
711
712 static const struct file_operations proc_mounts_operations = {
713 .open = mounts_open,
714 .read = seq_read,
715 .llseek = seq_lseek,
716 .release = mounts_release,
717 .poll = mounts_poll,
718 };
719
720 static int mountinfo_open(struct inode *inode, struct file *file)
721 {
722 return mounts_open_common(inode, file, &mountinfo_op);
723 }
724
725 static const struct file_operations proc_mountinfo_operations = {
726 .open = mountinfo_open,
727 .read = seq_read,
728 .llseek = seq_lseek,
729 .release = mounts_release,
730 .poll = mounts_poll,
731 };
732
733 static int mountstats_open(struct inode *inode, struct file *file)
734 {
735 return mounts_open_common(inode, file, &mountstats_op);
736 }
737
738 static const struct file_operations proc_mountstats_operations = {
739 .open = mountstats_open,
740 .read = seq_read,
741 .llseek = seq_lseek,
742 .release = mounts_release,
743 };
744
745 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
746
747 static ssize_t proc_info_read(struct file * file, char __user * buf,
748 size_t count, loff_t *ppos)
749 {
750 struct inode * inode = file->f_path.dentry->d_inode;
751 unsigned long page;
752 ssize_t length;
753 struct task_struct *task = get_proc_task(inode);
754
755 length = -ESRCH;
756 if (!task)
757 goto out_no_task;
758
759 if (count > PROC_BLOCK_SIZE)
760 count = PROC_BLOCK_SIZE;
761
762 length = -ENOMEM;
763 if (!(page = __get_free_page(GFP_TEMPORARY)))
764 goto out;
765
766 length = PROC_I(inode)->op.proc_read(task, (char*)page);
767
768 if (length >= 0)
769 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
770 free_page(page);
771 out:
772 put_task_struct(task);
773 out_no_task:
774 return length;
775 }
776
777 static const struct file_operations proc_info_file_operations = {
778 .read = proc_info_read,
779 .llseek = generic_file_llseek,
780 };
781
782 static int proc_single_show(struct seq_file *m, void *v)
783 {
784 struct inode *inode = m->private;
785 struct pid_namespace *ns;
786 struct pid *pid;
787 struct task_struct *task;
788 int ret;
789
790 ns = inode->i_sb->s_fs_info;
791 pid = proc_pid(inode);
792 task = get_pid_task(pid, PIDTYPE_PID);
793 if (!task)
794 return -ESRCH;
795
796 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
797
798 put_task_struct(task);
799 return ret;
800 }
801
802 static int proc_single_open(struct inode *inode, struct file *filp)
803 {
804 return single_open(filp, proc_single_show, inode);
805 }
806
807 static const struct file_operations proc_single_file_operations = {
808 .open = proc_single_open,
809 .read = seq_read,
810 .llseek = seq_lseek,
811 .release = single_release,
812 };
813
814 static int mem_open(struct inode* inode, struct file* file)
815 {
816 file->private_data = (void*)((long)current->self_exec_id);
817 /* OK to pass negative loff_t, we can catch out-of-range */
818 file->f_mode |= FMODE_UNSIGNED_OFFSET;
819 return 0;
820 }
821
822 static ssize_t mem_read(struct file * file, char __user * buf,
823 size_t count, loff_t *ppos)
824 {
825 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
826 char *page;
827 unsigned long src = *ppos;
828 int ret = -ESRCH;
829 struct mm_struct *mm;
830
831 if (!task)
832 goto out_no_task;
833
834 ret = -ENOMEM;
835 page = (char *)__get_free_page(GFP_TEMPORARY);
836 if (!page)
837 goto out;
838
839 mm = check_mem_permission(task);
840 ret = PTR_ERR(mm);
841 if (IS_ERR(mm))
842 goto out_free;
843
844 ret = -EIO;
845
846 if (file->private_data != (void*)((long)current->self_exec_id))
847 goto out_put;
848
849 ret = 0;
850
851 while (count > 0) {
852 int this_len, retval;
853
854 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
855 retval = access_remote_vm(mm, src, page, this_len, 0);
856 if (!retval) {
857 if (!ret)
858 ret = -EIO;
859 break;
860 }
861
862 if (copy_to_user(buf, page, retval)) {
863 ret = -EFAULT;
864 break;
865 }
866
867 ret += retval;
868 src += retval;
869 buf += retval;
870 count -= retval;
871 }
872 *ppos = src;
873
874 out_put:
875 mmput(mm);
876 out_free:
877 free_page((unsigned long) page);
878 out:
879 put_task_struct(task);
880 out_no_task:
881 return ret;
882 }
883
884 static ssize_t mem_write(struct file * file, const char __user *buf,
885 size_t count, loff_t *ppos)
886 {
887 int copied;
888 char *page;
889 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
890 unsigned long dst = *ppos;
891 struct mm_struct *mm;
892
893 copied = -ESRCH;
894 if (!task)
895 goto out_no_task;
896
897 copied = -ENOMEM;
898 page = (char *)__get_free_page(GFP_TEMPORARY);
899 if (!page)
900 goto out_task;
901
902 mm = check_mem_permission(task);
903 copied = PTR_ERR(mm);
904 if (IS_ERR(mm))
905 goto out_free;
906
907 copied = -EIO;
908 if (file->private_data != (void *)((long)current->self_exec_id))
909 goto out_mm;
910
911 copied = 0;
912 while (count > 0) {
913 int this_len, retval;
914
915 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
916 if (copy_from_user(page, buf, this_len)) {
917 copied = -EFAULT;
918 break;
919 }
920 retval = access_remote_vm(mm, dst, page, this_len, 1);
921 if (!retval) {
922 if (!copied)
923 copied = -EIO;
924 break;
925 }
926 copied += retval;
927 buf += retval;
928 dst += retval;
929 count -= retval;
930 }
931 *ppos = dst;
932
933 out_mm:
934 mmput(mm);
935 out_free:
936 free_page((unsigned long) page);
937 out_task:
938 put_task_struct(task);
939 out_no_task:
940 return copied;
941 }
942
943 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
944 {
945 switch (orig) {
946 case 0:
947 file->f_pos = offset;
948 break;
949 case 1:
950 file->f_pos += offset;
951 break;
952 default:
953 return -EINVAL;
954 }
955 force_successful_syscall_return();
956 return file->f_pos;
957 }
958
959 static const struct file_operations proc_mem_operations = {
960 .llseek = mem_lseek,
961 .read = mem_read,
962 .write = mem_write,
963 .open = mem_open,
964 };
965
966 static ssize_t environ_read(struct file *file, char __user *buf,
967 size_t count, loff_t *ppos)
968 {
969 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
970 char *page;
971 unsigned long src = *ppos;
972 int ret = -ESRCH;
973 struct mm_struct *mm;
974
975 if (!task)
976 goto out_no_task;
977
978 ret = -ENOMEM;
979 page = (char *)__get_free_page(GFP_TEMPORARY);
980 if (!page)
981 goto out;
982
983
984 mm = mm_for_maps(task);
985 ret = PTR_ERR(mm);
986 if (!mm || IS_ERR(mm))
987 goto out_free;
988
989 ret = 0;
990 while (count > 0) {
991 int this_len, retval, max_len;
992
993 this_len = mm->env_end - (mm->env_start + src);
994
995 if (this_len <= 0)
996 break;
997
998 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
999 this_len = (this_len > max_len) ? max_len : this_len;
1000
1001 retval = access_process_vm(task, (mm->env_start + src),
1002 page, this_len, 0);
1003
1004 if (retval <= 0) {
1005 ret = retval;
1006 break;
1007 }
1008
1009 if (copy_to_user(buf, page, retval)) {
1010 ret = -EFAULT;
1011 break;
1012 }
1013
1014 ret += retval;
1015 src += retval;
1016 buf += retval;
1017 count -= retval;
1018 }
1019 *ppos = src;
1020
1021 mmput(mm);
1022 out_free:
1023 free_page((unsigned long) page);
1024 out:
1025 put_task_struct(task);
1026 out_no_task:
1027 return ret;
1028 }
1029
1030 static const struct file_operations proc_environ_operations = {
1031 .read = environ_read,
1032 .llseek = generic_file_llseek,
1033 };
1034
1035 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
1036 size_t count, loff_t *ppos)
1037 {
1038 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1039 char buffer[PROC_NUMBUF];
1040 size_t len;
1041 int oom_adjust = OOM_DISABLE;
1042 unsigned long flags;
1043
1044 if (!task)
1045 return -ESRCH;
1046
1047 if (lock_task_sighand(task, &flags)) {
1048 oom_adjust = task->signal->oom_adj;
1049 unlock_task_sighand(task, &flags);
1050 }
1051
1052 put_task_struct(task);
1053
1054 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
1055
1056 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1057 }
1058
1059 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1060 size_t count, loff_t *ppos)
1061 {
1062 struct task_struct *task;
1063 char buffer[PROC_NUMBUF];
1064 int oom_adjust;
1065 unsigned long flags;
1066 int err;
1067
1068 memset(buffer, 0, sizeof(buffer));
1069 if (count > sizeof(buffer) - 1)
1070 count = sizeof(buffer) - 1;
1071 if (copy_from_user(buffer, buf, count)) {
1072 err = -EFAULT;
1073 goto out;
1074 }
1075
1076 err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
1077 if (err)
1078 goto out;
1079 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1080 oom_adjust != OOM_DISABLE) {
1081 err = -EINVAL;
1082 goto out;
1083 }
1084
1085 task = get_proc_task(file->f_path.dentry->d_inode);
1086 if (!task) {
1087 err = -ESRCH;
1088 goto out;
1089 }
1090
1091 task_lock(task);
1092 if (!task->mm) {
1093 err = -EINVAL;
1094 goto err_task_lock;
1095 }
1096
1097 if (!lock_task_sighand(task, &flags)) {
1098 err = -ESRCH;
1099 goto err_task_lock;
1100 }
1101
1102 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1103 err = -EACCES;
1104 goto err_sighand;
1105 }
1106
1107 if (oom_adjust != task->signal->oom_adj) {
1108 if (oom_adjust == OOM_DISABLE)
1109 atomic_inc(&task->mm->oom_disable_count);
1110 if (task->signal->oom_adj == OOM_DISABLE)
1111 atomic_dec(&task->mm->oom_disable_count);
1112 }
1113
1114 /*
1115 * Warn that /proc/pid/oom_adj is deprecated, see
1116 * Documentation/feature-removal-schedule.txt.
1117 */
1118 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, "
1119 "please use /proc/%d/oom_score_adj instead.\n",
1120 current->comm, task_pid_nr(current),
1121 task_pid_nr(task), task_pid_nr(task));
1122 task->signal->oom_adj = oom_adjust;
1123 /*
1124 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1125 * value is always attainable.
1126 */
1127 if (task->signal->oom_adj == OOM_ADJUST_MAX)
1128 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
1129 else
1130 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
1131 -OOM_DISABLE;
1132 err_sighand:
1133 unlock_task_sighand(task, &flags);
1134 err_task_lock:
1135 task_unlock(task);
1136 put_task_struct(task);
1137 out:
1138 return err < 0 ? err : count;
1139 }
1140
1141 static const struct file_operations proc_oom_adjust_operations = {
1142 .read = oom_adjust_read,
1143 .write = oom_adjust_write,
1144 .llseek = generic_file_llseek,
1145 };
1146
1147 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1148 size_t count, loff_t *ppos)
1149 {
1150 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1151 char buffer[PROC_NUMBUF];
1152 int oom_score_adj = OOM_SCORE_ADJ_MIN;
1153 unsigned long flags;
1154 size_t len;
1155
1156 if (!task)
1157 return -ESRCH;
1158 if (lock_task_sighand(task, &flags)) {
1159 oom_score_adj = task->signal->oom_score_adj;
1160 unlock_task_sighand(task, &flags);
1161 }
1162 put_task_struct(task);
1163 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
1164 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1165 }
1166
1167 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1168 size_t count, loff_t *ppos)
1169 {
1170 struct task_struct *task;
1171 char buffer[PROC_NUMBUF];
1172 unsigned long flags;
1173 int oom_score_adj;
1174 int err;
1175
1176 memset(buffer, 0, sizeof(buffer));
1177 if (count > sizeof(buffer) - 1)
1178 count = sizeof(buffer) - 1;
1179 if (copy_from_user(buffer, buf, count)) {
1180 err = -EFAULT;
1181 goto out;
1182 }
1183
1184 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1185 if (err)
1186 goto out;
1187 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1188 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1189 err = -EINVAL;
1190 goto out;
1191 }
1192
1193 task = get_proc_task(file->f_path.dentry->d_inode);
1194 if (!task) {
1195 err = -ESRCH;
1196 goto out;
1197 }
1198
1199 task_lock(task);
1200 if (!task->mm) {
1201 err = -EINVAL;
1202 goto err_task_lock;
1203 }
1204
1205 if (!lock_task_sighand(task, &flags)) {
1206 err = -ESRCH;
1207 goto err_task_lock;
1208 }
1209
1210 if (oom_score_adj < task->signal->oom_score_adj_min &&
1211 !capable(CAP_SYS_RESOURCE)) {
1212 err = -EACCES;
1213 goto err_sighand;
1214 }
1215
1216 if (oom_score_adj != task->signal->oom_score_adj) {
1217 if (oom_score_adj == OOM_SCORE_ADJ_MIN)
1218 atomic_inc(&task->mm->oom_disable_count);
1219 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1220 atomic_dec(&task->mm->oom_disable_count);
1221 }
1222 task->signal->oom_score_adj = oom_score_adj;
1223 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1224 task->signal->oom_score_adj_min = oom_score_adj;
1225 /*
1226 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1227 * always attainable.
1228 */
1229 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1230 task->signal->oom_adj = OOM_DISABLE;
1231 else
1232 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1233 OOM_SCORE_ADJ_MAX;
1234 err_sighand:
1235 unlock_task_sighand(task, &flags);
1236 err_task_lock:
1237 task_unlock(task);
1238 put_task_struct(task);
1239 out:
1240 return err < 0 ? err : count;
1241 }
1242
1243 static const struct file_operations proc_oom_score_adj_operations = {
1244 .read = oom_score_adj_read,
1245 .write = oom_score_adj_write,
1246 .llseek = default_llseek,
1247 };
1248
1249 #ifdef CONFIG_AUDITSYSCALL
1250 #define TMPBUFLEN 21
1251 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1252 size_t count, loff_t *ppos)
1253 {
1254 struct inode * inode = file->f_path.dentry->d_inode;
1255 struct task_struct *task = get_proc_task(inode);
1256 ssize_t length;
1257 char tmpbuf[TMPBUFLEN];
1258
1259 if (!task)
1260 return -ESRCH;
1261 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1262 audit_get_loginuid(task));
1263 put_task_struct(task);
1264 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1265 }
1266
1267 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1268 size_t count, loff_t *ppos)
1269 {
1270 struct inode * inode = file->f_path.dentry->d_inode;
1271 char *page, *tmp;
1272 ssize_t length;
1273 uid_t loginuid;
1274
1275 if (!capable(CAP_AUDIT_CONTROL))
1276 return -EPERM;
1277
1278 rcu_read_lock();
1279 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1280 rcu_read_unlock();
1281 return -EPERM;
1282 }
1283 rcu_read_unlock();
1284
1285 if (count >= PAGE_SIZE)
1286 count = PAGE_SIZE - 1;
1287
1288 if (*ppos != 0) {
1289 /* No partial writes. */
1290 return -EINVAL;
1291 }
1292 page = (char*)__get_free_page(GFP_TEMPORARY);
1293 if (!page)
1294 return -ENOMEM;
1295 length = -EFAULT;
1296 if (copy_from_user(page, buf, count))
1297 goto out_free_page;
1298
1299 page[count] = '\0';
1300 loginuid = simple_strtoul(page, &tmp, 10);
1301 if (tmp == page) {
1302 length = -EINVAL;
1303 goto out_free_page;
1304
1305 }
1306 length = audit_set_loginuid(current, loginuid);
1307 if (likely(length == 0))
1308 length = count;
1309
1310 out_free_page:
1311 free_page((unsigned long) page);
1312 return length;
1313 }
1314
1315 static const struct file_operations proc_loginuid_operations = {
1316 .read = proc_loginuid_read,
1317 .write = proc_loginuid_write,
1318 .llseek = generic_file_llseek,
1319 };
1320
1321 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1322 size_t count, loff_t *ppos)
1323 {
1324 struct inode * inode = file->f_path.dentry->d_inode;
1325 struct task_struct *task = get_proc_task(inode);
1326 ssize_t length;
1327 char tmpbuf[TMPBUFLEN];
1328
1329 if (!task)
1330 return -ESRCH;
1331 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1332 audit_get_sessionid(task));
1333 put_task_struct(task);
1334 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1335 }
1336
1337 static const struct file_operations proc_sessionid_operations = {
1338 .read = proc_sessionid_read,
1339 .llseek = generic_file_llseek,
1340 };
1341 #endif
1342
1343 #ifdef CONFIG_FAULT_INJECTION
1344 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1345 size_t count, loff_t *ppos)
1346 {
1347 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1348 char buffer[PROC_NUMBUF];
1349 size_t len;
1350 int make_it_fail;
1351
1352 if (!task)
1353 return -ESRCH;
1354 make_it_fail = task->make_it_fail;
1355 put_task_struct(task);
1356
1357 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1358
1359 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1360 }
1361
1362 static ssize_t proc_fault_inject_write(struct file * file,
1363 const char __user * buf, size_t count, loff_t *ppos)
1364 {
1365 struct task_struct *task;
1366 char buffer[PROC_NUMBUF], *end;
1367 int make_it_fail;
1368
1369 if (!capable(CAP_SYS_RESOURCE))
1370 return -EPERM;
1371 memset(buffer, 0, sizeof(buffer));
1372 if (count > sizeof(buffer) - 1)
1373 count = sizeof(buffer) - 1;
1374 if (copy_from_user(buffer, buf, count))
1375 return -EFAULT;
1376 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1377 if (*end)
1378 return -EINVAL;
1379 task = get_proc_task(file->f_dentry->d_inode);
1380 if (!task)
1381 return -ESRCH;
1382 task->make_it_fail = make_it_fail;
1383 put_task_struct(task);
1384
1385 return count;
1386 }
1387
1388 static const struct file_operations proc_fault_inject_operations = {
1389 .read = proc_fault_inject_read,
1390 .write = proc_fault_inject_write,
1391 .llseek = generic_file_llseek,
1392 };
1393 #endif
1394
1395
1396 #ifdef CONFIG_SCHED_DEBUG
1397 /*
1398 * Print out various scheduling related per-task fields:
1399 */
1400 static int sched_show(struct seq_file *m, void *v)
1401 {
1402 struct inode *inode = m->private;
1403 struct task_struct *p;
1404
1405 p = get_proc_task(inode);
1406 if (!p)
1407 return -ESRCH;
1408 proc_sched_show_task(p, m);
1409
1410 put_task_struct(p);
1411
1412 return 0;
1413 }
1414
1415 static ssize_t
1416 sched_write(struct file *file, const char __user *buf,
1417 size_t count, loff_t *offset)
1418 {
1419 struct inode *inode = file->f_path.dentry->d_inode;
1420 struct task_struct *p;
1421
1422 p = get_proc_task(inode);
1423 if (!p)
1424 return -ESRCH;
1425 proc_sched_set_task(p);
1426
1427 put_task_struct(p);
1428
1429 return count;
1430 }
1431
1432 static int sched_open(struct inode *inode, struct file *filp)
1433 {
1434 return single_open(filp, sched_show, inode);
1435 }
1436
1437 static const struct file_operations proc_pid_sched_operations = {
1438 .open = sched_open,
1439 .read = seq_read,
1440 .write = sched_write,
1441 .llseek = seq_lseek,
1442 .release = single_release,
1443 };
1444
1445 #endif
1446
1447 #ifdef CONFIG_SCHED_AUTOGROUP
1448 /*
1449 * Print out autogroup related information:
1450 */
1451 static int sched_autogroup_show(struct seq_file *m, void *v)
1452 {
1453 struct inode *inode = m->private;
1454 struct task_struct *p;
1455
1456 p = get_proc_task(inode);
1457 if (!p)
1458 return -ESRCH;
1459 proc_sched_autogroup_show_task(p, m);
1460
1461 put_task_struct(p);
1462
1463 return 0;
1464 }
1465
1466 static ssize_t
1467 sched_autogroup_write(struct file *file, const char __user *buf,
1468 size_t count, loff_t *offset)
1469 {
1470 struct inode *inode = file->f_path.dentry->d_inode;
1471 struct task_struct *p;
1472 char buffer[PROC_NUMBUF];
1473 int nice;
1474 int err;
1475
1476 memset(buffer, 0, sizeof(buffer));
1477 if (count > sizeof(buffer) - 1)
1478 count = sizeof(buffer) - 1;
1479 if (copy_from_user(buffer, buf, count))
1480 return -EFAULT;
1481
1482 err = kstrtoint(strstrip(buffer), 0, &nice);
1483 if (err < 0)
1484 return err;
1485
1486 p = get_proc_task(inode);
1487 if (!p)
1488 return -ESRCH;
1489
1490 err = nice;
1491 err = proc_sched_autogroup_set_nice(p, &err);
1492 if (err)
1493 count = err;
1494
1495 put_task_struct(p);
1496
1497 return count;
1498 }
1499
1500 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1501 {
1502 int ret;
1503
1504 ret = single_open(filp, sched_autogroup_show, NULL);
1505 if (!ret) {
1506 struct seq_file *m = filp->private_data;
1507
1508 m->private = inode;
1509 }
1510 return ret;
1511 }
1512
1513 static const struct file_operations proc_pid_sched_autogroup_operations = {
1514 .open = sched_autogroup_open,
1515 .read = seq_read,
1516 .write = sched_autogroup_write,
1517 .llseek = seq_lseek,
1518 .release = single_release,
1519 };
1520
1521 #endif /* CONFIG_SCHED_AUTOGROUP */
1522
1523 static ssize_t comm_write(struct file *file, const char __user *buf,
1524 size_t count, loff_t *offset)
1525 {
1526 struct inode *inode = file->f_path.dentry->d_inode;
1527 struct task_struct *p;
1528 char buffer[TASK_COMM_LEN];
1529
1530 memset(buffer, 0, sizeof(buffer));
1531 if (count > sizeof(buffer) - 1)
1532 count = sizeof(buffer) - 1;
1533 if (copy_from_user(buffer, buf, count))
1534 return -EFAULT;
1535
1536 p = get_proc_task(inode);
1537 if (!p)
1538 return -ESRCH;
1539
1540 if (same_thread_group(current, p))
1541 set_task_comm(p, buffer);
1542 else
1543 count = -EINVAL;
1544
1545 put_task_struct(p);
1546
1547 return count;
1548 }
1549
1550 static int comm_show(struct seq_file *m, void *v)
1551 {
1552 struct inode *inode = m->private;
1553 struct task_struct *p;
1554
1555 p = get_proc_task(inode);
1556 if (!p)
1557 return -ESRCH;
1558
1559 task_lock(p);
1560 seq_printf(m, "%s\n", p->comm);
1561 task_unlock(p);
1562
1563 put_task_struct(p);
1564
1565 return 0;
1566 }
1567
1568 static int comm_open(struct inode *inode, struct file *filp)
1569 {
1570 return single_open(filp, comm_show, inode);
1571 }
1572
1573 static const struct file_operations proc_pid_set_comm_operations = {
1574 .open = comm_open,
1575 .read = seq_read,
1576 .write = comm_write,
1577 .llseek = seq_lseek,
1578 .release = single_release,
1579 };
1580
1581 static int proc_exe_link(struct inode *inode, struct path *exe_path)
1582 {
1583 struct task_struct *task;
1584 struct mm_struct *mm;
1585 struct file *exe_file;
1586
1587 task = get_proc_task(inode);
1588 if (!task)
1589 return -ENOENT;
1590 mm = get_task_mm(task);
1591 put_task_struct(task);
1592 if (!mm)
1593 return -ENOENT;
1594 exe_file = get_mm_exe_file(mm);
1595 mmput(mm);
1596 if (exe_file) {
1597 *exe_path = exe_file->f_path;
1598 path_get(&exe_file->f_path);
1599 fput(exe_file);
1600 return 0;
1601 } else
1602 return -ENOENT;
1603 }
1604
1605 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1606 {
1607 struct inode *inode = dentry->d_inode;
1608 int error = -EACCES;
1609
1610 /* We don't need a base pointer in the /proc filesystem */
1611 path_put(&nd->path);
1612
1613 /* Are we allowed to snoop on the tasks file descriptors? */
1614 if (!proc_fd_access_allowed(inode))
1615 goto out;
1616
1617 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1618 out:
1619 return ERR_PTR(error);
1620 }
1621
1622 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1623 {
1624 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1625 char *pathname;
1626 int len;
1627
1628 if (!tmp)
1629 return -ENOMEM;
1630
1631 pathname = d_path(path, tmp, PAGE_SIZE);
1632 len = PTR_ERR(pathname);
1633 if (IS_ERR(pathname))
1634 goto out;
1635 len = tmp + PAGE_SIZE - 1 - pathname;
1636
1637 if (len > buflen)
1638 len = buflen;
1639 if (copy_to_user(buffer, pathname, len))
1640 len = -EFAULT;
1641 out:
1642 free_page((unsigned long)tmp);
1643 return len;
1644 }
1645
1646 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1647 {
1648 int error = -EACCES;
1649 struct inode *inode = dentry->d_inode;
1650 struct path path;
1651
1652 /* Are we allowed to snoop on the tasks file descriptors? */
1653 if (!proc_fd_access_allowed(inode))
1654 goto out;
1655
1656 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1657 if (error)
1658 goto out;
1659
1660 error = do_proc_readlink(&path, buffer, buflen);
1661 path_put(&path);
1662 out:
1663 return error;
1664 }
1665
1666 static const struct inode_operations proc_pid_link_inode_operations = {
1667 .readlink = proc_pid_readlink,
1668 .follow_link = proc_pid_follow_link,
1669 .setattr = proc_setattr,
1670 };
1671
1672
1673 /* building an inode */
1674
1675 static int task_dumpable(struct task_struct *task)
1676 {
1677 int dumpable = 0;
1678 struct mm_struct *mm;
1679
1680 task_lock(task);
1681 mm = task->mm;
1682 if (mm)
1683 dumpable = get_dumpable(mm);
1684 task_unlock(task);
1685 if(dumpable == 1)
1686 return 1;
1687 return 0;
1688 }
1689
1690 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1691 {
1692 struct inode * inode;
1693 struct proc_inode *ei;
1694 const struct cred *cred;
1695
1696 /* We need a new inode */
1697
1698 inode = new_inode(sb);
1699 if (!inode)
1700 goto out;
1701
1702 /* Common stuff */
1703 ei = PROC_I(inode);
1704 inode->i_ino = get_next_ino();
1705 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1706 inode->i_op = &proc_def_inode_operations;
1707
1708 /*
1709 * grab the reference to task.
1710 */
1711 ei->pid = get_task_pid(task, PIDTYPE_PID);
1712 if (!ei->pid)
1713 goto out_unlock;
1714
1715 if (task_dumpable(task)) {
1716 rcu_read_lock();
1717 cred = __task_cred(task);
1718 inode->i_uid = cred->euid;
1719 inode->i_gid = cred->egid;
1720 rcu_read_unlock();
1721 }
1722 security_task_to_inode(task, inode);
1723
1724 out:
1725 return inode;
1726
1727 out_unlock:
1728 iput(inode);
1729 return NULL;
1730 }
1731
1732 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1733 {
1734 struct inode *inode = dentry->d_inode;
1735 struct task_struct *task;
1736 const struct cred *cred;
1737
1738 generic_fillattr(inode, stat);
1739
1740 rcu_read_lock();
1741 stat->uid = 0;
1742 stat->gid = 0;
1743 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1744 if (task) {
1745 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1746 task_dumpable(task)) {
1747 cred = __task_cred(task);
1748 stat->uid = cred->euid;
1749 stat->gid = cred->egid;
1750 }
1751 }
1752 rcu_read_unlock();
1753 return 0;
1754 }
1755
1756 /* dentry stuff */
1757
1758 /*
1759 * Exceptional case: normally we are not allowed to unhash a busy
1760 * directory. In this case, however, we can do it - no aliasing problems
1761 * due to the way we treat inodes.
1762 *
1763 * Rewrite the inode's ownerships here because the owning task may have
1764 * performed a setuid(), etc.
1765 *
1766 * Before the /proc/pid/status file was created the only way to read
1767 * the effective uid of a /process was to stat /proc/pid. Reading
1768 * /proc/pid/status is slow enough that procps and other packages
1769 * kept stating /proc/pid. To keep the rules in /proc simple I have
1770 * made this apply to all per process world readable and executable
1771 * directories.
1772 */
1773 int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1774 {
1775 struct inode *inode;
1776 struct task_struct *task;
1777 const struct cred *cred;
1778
1779 if (nd && nd->flags & LOOKUP_RCU)
1780 return -ECHILD;
1781
1782 inode = dentry->d_inode;
1783 task = get_proc_task(inode);
1784
1785 if (task) {
1786 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1787 task_dumpable(task)) {
1788 rcu_read_lock();
1789 cred = __task_cred(task);
1790 inode->i_uid = cred->euid;
1791 inode->i_gid = cred->egid;
1792 rcu_read_unlock();
1793 } else {
1794 inode->i_uid = 0;
1795 inode->i_gid = 0;
1796 }
1797 inode->i_mode &= ~(S_ISUID | S_ISGID);
1798 security_task_to_inode(task, inode);
1799 put_task_struct(task);
1800 return 1;
1801 }
1802 d_drop(dentry);
1803 return 0;
1804 }
1805
1806 static int pid_delete_dentry(const struct dentry * dentry)
1807 {
1808 /* Is the task we represent dead?
1809 * If so, then don't put the dentry on the lru list,
1810 * kill it immediately.
1811 */
1812 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1813 }
1814
1815 const struct dentry_operations pid_dentry_operations =
1816 {
1817 .d_revalidate = pid_revalidate,
1818 .d_delete = pid_delete_dentry,
1819 };
1820
1821 /* Lookups */
1822
1823 /*
1824 * Fill a directory entry.
1825 *
1826 * If possible create the dcache entry and derive our inode number and
1827 * file type from dcache entry.
1828 *
1829 * Since all of the proc inode numbers are dynamically generated, the inode
1830 * numbers do not exist until the inode is cache. This means creating the
1831 * the dcache entry in readdir is necessary to keep the inode numbers
1832 * reported by readdir in sync with the inode numbers reported
1833 * by stat.
1834 */
1835 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1836 const char *name, int len,
1837 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1838 {
1839 struct dentry *child, *dir = filp->f_path.dentry;
1840 struct inode *inode;
1841 struct qstr qname;
1842 ino_t ino = 0;
1843 unsigned type = DT_UNKNOWN;
1844
1845 qname.name = name;
1846 qname.len = len;
1847 qname.hash = full_name_hash(name, len);
1848
1849 child = d_lookup(dir, &qname);
1850 if (!child) {
1851 struct dentry *new;
1852 new = d_alloc(dir, &qname);
1853 if (new) {
1854 child = instantiate(dir->d_inode, new, task, ptr);
1855 if (child)
1856 dput(new);
1857 else
1858 child = new;
1859 }
1860 }
1861 if (!child || IS_ERR(child) || !child->d_inode)
1862 goto end_instantiate;
1863 inode = child->d_inode;
1864 if (inode) {
1865 ino = inode->i_ino;
1866 type = inode->i_mode >> 12;
1867 }
1868 dput(child);
1869 end_instantiate:
1870 if (!ino)
1871 ino = find_inode_number(dir, &qname);
1872 if (!ino)
1873 ino = 1;
1874 return filldir(dirent, name, len, filp->f_pos, ino, type);
1875 }
1876
1877 static unsigned name_to_int(struct dentry *dentry)
1878 {
1879 const char *name = dentry->d_name.name;
1880 int len = dentry->d_name.len;
1881 unsigned n = 0;
1882
1883 if (len > 1 && *name == '0')
1884 goto out;
1885 while (len-- > 0) {
1886 unsigned c = *name++ - '0';
1887 if (c > 9)
1888 goto out;
1889 if (n >= (~0U-9)/10)
1890 goto out;
1891 n *= 10;
1892 n += c;
1893 }
1894 return n;
1895 out:
1896 return ~0U;
1897 }
1898
1899 #define PROC_FDINFO_MAX 64
1900
1901 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1902 {
1903 struct task_struct *task = get_proc_task(inode);
1904 struct files_struct *files = NULL;
1905 struct file *file;
1906 int fd = proc_fd(inode);
1907
1908 if (task) {
1909 files = get_files_struct(task);
1910 put_task_struct(task);
1911 }
1912 if (files) {
1913 /*
1914 * We are not taking a ref to the file structure, so we must
1915 * hold ->file_lock.
1916 */
1917 spin_lock(&files->file_lock);
1918 file = fcheck_files(files, fd);
1919 if (file) {
1920 if (path) {
1921 *path = file->f_path;
1922 path_get(&file->f_path);
1923 }
1924 if (info)
1925 snprintf(info, PROC_FDINFO_MAX,
1926 "pos:\t%lli\n"
1927 "flags:\t0%o\n",
1928 (long long) file->f_pos,
1929 file->f_flags);
1930 spin_unlock(&files->file_lock);
1931 put_files_struct(files);
1932 return 0;
1933 }
1934 spin_unlock(&files->file_lock);
1935 put_files_struct(files);
1936 }
1937 return -ENOENT;
1938 }
1939
1940 static int proc_fd_link(struct inode *inode, struct path *path)
1941 {
1942 return proc_fd_info(inode, path, NULL);
1943 }
1944
1945 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1946 {
1947 struct inode *inode;
1948 struct task_struct *task;
1949 int fd;
1950 struct files_struct *files;
1951 const struct cred *cred;
1952
1953 if (nd && nd->flags & LOOKUP_RCU)
1954 return -ECHILD;
1955
1956 inode = dentry->d_inode;
1957 task = get_proc_task(inode);
1958 fd = proc_fd(inode);
1959
1960 if (task) {
1961 files = get_files_struct(task);
1962 if (files) {
1963 rcu_read_lock();
1964 if (fcheck_files(files, fd)) {
1965 rcu_read_unlock();
1966 put_files_struct(files);
1967 if (task_dumpable(task)) {
1968 rcu_read_lock();
1969 cred = __task_cred(task);
1970 inode->i_uid = cred->euid;
1971 inode->i_gid = cred->egid;
1972 rcu_read_unlock();
1973 } else {
1974 inode->i_uid = 0;
1975 inode->i_gid = 0;
1976 }
1977 inode->i_mode &= ~(S_ISUID | S_ISGID);
1978 security_task_to_inode(task, inode);
1979 put_task_struct(task);
1980 return 1;
1981 }
1982 rcu_read_unlock();
1983 put_files_struct(files);
1984 }
1985 put_task_struct(task);
1986 }
1987 d_drop(dentry);
1988 return 0;
1989 }
1990
1991 static const struct dentry_operations tid_fd_dentry_operations =
1992 {
1993 .d_revalidate = tid_fd_revalidate,
1994 .d_delete = pid_delete_dentry,
1995 };
1996
1997 static struct dentry *proc_fd_instantiate(struct inode *dir,
1998 struct dentry *dentry, struct task_struct *task, const void *ptr)
1999 {
2000 unsigned fd = *(const unsigned *)ptr;
2001 struct file *file;
2002 struct files_struct *files;
2003 struct inode *inode;
2004 struct proc_inode *ei;
2005 struct dentry *error = ERR_PTR(-ENOENT);
2006
2007 inode = proc_pid_make_inode(dir->i_sb, task);
2008 if (!inode)
2009 goto out;
2010 ei = PROC_I(inode);
2011 ei->fd = fd;
2012 files = get_files_struct(task);
2013 if (!files)
2014 goto out_iput;
2015 inode->i_mode = S_IFLNK;
2016
2017 /*
2018 * We are not taking a ref to the file structure, so we must
2019 * hold ->file_lock.
2020 */
2021 spin_lock(&files->file_lock);
2022 file = fcheck_files(files, fd);
2023 if (!file)
2024 goto out_unlock;
2025 if (file->f_mode & FMODE_READ)
2026 inode->i_mode |= S_IRUSR | S_IXUSR;
2027 if (file->f_mode & FMODE_WRITE)
2028 inode->i_mode |= S_IWUSR | S_IXUSR;
2029 spin_unlock(&files->file_lock);
2030 put_files_struct(files);
2031
2032 inode->i_op = &proc_pid_link_inode_operations;
2033 inode->i_size = 64;
2034 ei->op.proc_get_link = proc_fd_link;
2035 d_set_d_op(dentry, &tid_fd_dentry_operations);
2036 d_add(dentry, inode);
2037 /* Close the race of the process dying before we return the dentry */
2038 if (tid_fd_revalidate(dentry, NULL))
2039 error = NULL;
2040
2041 out:
2042 return error;
2043 out_unlock:
2044 spin_unlock(&files->file_lock);
2045 put_files_struct(files);
2046 out_iput:
2047 iput(inode);
2048 goto out;
2049 }
2050
2051 static struct dentry *proc_lookupfd_common(struct inode *dir,
2052 struct dentry *dentry,
2053 instantiate_t instantiate)
2054 {
2055 struct task_struct *task = get_proc_task(dir);
2056 unsigned fd = name_to_int(dentry);
2057 struct dentry *result = ERR_PTR(-ENOENT);
2058
2059 if (!task)
2060 goto out_no_task;
2061 if (fd == ~0U)
2062 goto out;
2063
2064 result = instantiate(dir, dentry, task, &fd);
2065 out:
2066 put_task_struct(task);
2067 out_no_task:
2068 return result;
2069 }
2070
2071 static int proc_readfd_common(struct file * filp, void * dirent,
2072 filldir_t filldir, instantiate_t instantiate)
2073 {
2074 struct dentry *dentry = filp->f_path.dentry;
2075 struct inode *inode = dentry->d_inode;
2076 struct task_struct *p = get_proc_task(inode);
2077 unsigned int fd, ino;
2078 int retval;
2079 struct files_struct * files;
2080
2081 retval = -ENOENT;
2082 if (!p)
2083 goto out_no_task;
2084 retval = 0;
2085
2086 fd = filp->f_pos;
2087 switch (fd) {
2088 case 0:
2089 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
2090 goto out;
2091 filp->f_pos++;
2092 case 1:
2093 ino = parent_ino(dentry);
2094 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2095 goto out;
2096 filp->f_pos++;
2097 default:
2098 files = get_files_struct(p);
2099 if (!files)
2100 goto out;
2101 rcu_read_lock();
2102 for (fd = filp->f_pos-2;
2103 fd < files_fdtable(files)->max_fds;
2104 fd++, filp->f_pos++) {
2105 char name[PROC_NUMBUF];
2106 int len;
2107
2108 if (!fcheck_files(files, fd))
2109 continue;
2110 rcu_read_unlock();
2111
2112 len = snprintf(name, sizeof(name), "%d", fd);
2113 if (proc_fill_cache(filp, dirent, filldir,
2114 name, len, instantiate,
2115 p, &fd) < 0) {
2116 rcu_read_lock();
2117 break;
2118 }
2119 rcu_read_lock();
2120 }
2121 rcu_read_unlock();
2122 put_files_struct(files);
2123 }
2124 out:
2125 put_task_struct(p);
2126 out_no_task:
2127 return retval;
2128 }
2129
2130 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
2131 struct nameidata *nd)
2132 {
2133 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
2134 }
2135
2136 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
2137 {
2138 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
2139 }
2140
2141 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
2142 size_t len, loff_t *ppos)
2143 {
2144 char tmp[PROC_FDINFO_MAX];
2145 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
2146 if (!err)
2147 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
2148 return err;
2149 }
2150
2151 static const struct file_operations proc_fdinfo_file_operations = {
2152 .open = nonseekable_open,
2153 .read = proc_fdinfo_read,
2154 .llseek = no_llseek,
2155 };
2156
2157 static const struct file_operations proc_fd_operations = {
2158 .read = generic_read_dir,
2159 .readdir = proc_readfd,
2160 .llseek = default_llseek,
2161 };
2162
2163 /*
2164 * /proc/pid/fd needs a special permission handler so that a process can still
2165 * access /proc/self/fd after it has executed a setuid().
2166 */
2167 static int proc_fd_permission(struct inode *inode, int mask, unsigned int flags)
2168 {
2169 int rv;
2170
2171 if (flags & IPERM_FLAG_RCU)
2172 return -ECHILD;
2173 rv = generic_permission(inode, mask, flags, NULL);
2174 if (rv == 0)
2175 return 0;
2176 if (task_pid(current) == proc_pid(inode))
2177 rv = 0;
2178 return rv;
2179 }
2180
2181 /*
2182 * proc directories can do almost nothing..
2183 */
2184 static const struct inode_operations proc_fd_inode_operations = {
2185 .lookup = proc_lookupfd,
2186 .permission = proc_fd_permission,
2187 .setattr = proc_setattr,
2188 };
2189
2190 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2191 struct dentry *dentry, struct task_struct *task, const void *ptr)
2192 {
2193 unsigned fd = *(unsigned *)ptr;
2194 struct inode *inode;
2195 struct proc_inode *ei;
2196 struct dentry *error = ERR_PTR(-ENOENT);
2197
2198 inode = proc_pid_make_inode(dir->i_sb, task);
2199 if (!inode)
2200 goto out;
2201 ei = PROC_I(inode);
2202 ei->fd = fd;
2203 inode->i_mode = S_IFREG | S_IRUSR;
2204 inode->i_fop = &proc_fdinfo_file_operations;
2205 d_set_d_op(dentry, &tid_fd_dentry_operations);
2206 d_add(dentry, inode);
2207 /* Close the race of the process dying before we return the dentry */
2208 if (tid_fd_revalidate(dentry, NULL))
2209 error = NULL;
2210
2211 out:
2212 return error;
2213 }
2214
2215 static struct dentry *proc_lookupfdinfo(struct inode *dir,
2216 struct dentry *dentry,
2217 struct nameidata *nd)
2218 {
2219 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2220 }
2221
2222 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2223 {
2224 return proc_readfd_common(filp, dirent, filldir,
2225 proc_fdinfo_instantiate);
2226 }
2227
2228 static const struct file_operations proc_fdinfo_operations = {
2229 .read = generic_read_dir,
2230 .readdir = proc_readfdinfo,
2231 .llseek = default_llseek,
2232 };
2233
2234 /*
2235 * proc directories can do almost nothing..
2236 */
2237 static const struct inode_operations proc_fdinfo_inode_operations = {
2238 .lookup = proc_lookupfdinfo,
2239 .setattr = proc_setattr,
2240 };
2241
2242
2243 static struct dentry *proc_pident_instantiate(struct inode *dir,
2244 struct dentry *dentry, struct task_struct *task, const void *ptr)
2245 {
2246 const struct pid_entry *p = ptr;
2247 struct inode *inode;
2248 struct proc_inode *ei;
2249 struct dentry *error = ERR_PTR(-ENOENT);
2250
2251 inode = proc_pid_make_inode(dir->i_sb, task);
2252 if (!inode)
2253 goto out;
2254
2255 ei = PROC_I(inode);
2256 inode->i_mode = p->mode;
2257 if (S_ISDIR(inode->i_mode))
2258 inode->i_nlink = 2; /* Use getattr to fix if necessary */
2259 if (p->iop)
2260 inode->i_op = p->iop;
2261 if (p->fop)
2262 inode->i_fop = p->fop;
2263 ei->op = p->op;
2264 d_set_d_op(dentry, &pid_dentry_operations);
2265 d_add(dentry, inode);
2266 /* Close the race of the process dying before we return the dentry */
2267 if (pid_revalidate(dentry, NULL))
2268 error = NULL;
2269 out:
2270 return error;
2271 }
2272
2273 static struct dentry *proc_pident_lookup(struct inode *dir,
2274 struct dentry *dentry,
2275 const struct pid_entry *ents,
2276 unsigned int nents)
2277 {
2278 struct dentry *error;
2279 struct task_struct *task = get_proc_task(dir);
2280 const struct pid_entry *p, *last;
2281
2282 error = ERR_PTR(-ENOENT);
2283
2284 if (!task)
2285 goto out_no_task;
2286
2287 /*
2288 * Yes, it does not scale. And it should not. Don't add
2289 * new entries into /proc/<tgid>/ without very good reasons.
2290 */
2291 last = &ents[nents - 1];
2292 for (p = ents; p <= last; p++) {
2293 if (p->len != dentry->d_name.len)
2294 continue;
2295 if (!memcmp(dentry->d_name.name, p->name, p->len))
2296 break;
2297 }
2298 if (p > last)
2299 goto out;
2300
2301 error = proc_pident_instantiate(dir, dentry, task, p);
2302 out:
2303 put_task_struct(task);
2304 out_no_task:
2305 return error;
2306 }
2307
2308 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2309 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2310 {
2311 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2312 proc_pident_instantiate, task, p);
2313 }
2314
2315 static int proc_pident_readdir(struct file *filp,
2316 void *dirent, filldir_t filldir,
2317 const struct pid_entry *ents, unsigned int nents)
2318 {
2319 int i;
2320 struct dentry *dentry = filp->f_path.dentry;
2321 struct inode *inode = dentry->d_inode;
2322 struct task_struct *task = get_proc_task(inode);
2323 const struct pid_entry *p, *last;
2324 ino_t ino;
2325 int ret;
2326
2327 ret = -ENOENT;
2328 if (!task)
2329 goto out_no_task;
2330
2331 ret = 0;
2332 i = filp->f_pos;
2333 switch (i) {
2334 case 0:
2335 ino = inode->i_ino;
2336 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2337 goto out;
2338 i++;
2339 filp->f_pos++;
2340 /* fall through */
2341 case 1:
2342 ino = parent_ino(dentry);
2343 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2344 goto out;
2345 i++;
2346 filp->f_pos++;
2347 /* fall through */
2348 default:
2349 i -= 2;
2350 if (i >= nents) {
2351 ret = 1;
2352 goto out;
2353 }
2354 p = ents + i;
2355 last = &ents[nents - 1];
2356 while (p <= last) {
2357 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2358 goto out;
2359 filp->f_pos++;
2360 p++;
2361 }
2362 }
2363
2364 ret = 1;
2365 out:
2366 put_task_struct(task);
2367 out_no_task:
2368 return ret;
2369 }
2370
2371 #ifdef CONFIG_SECURITY
2372 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2373 size_t count, loff_t *ppos)
2374 {
2375 struct inode * inode = file->f_path.dentry->d_inode;
2376 char *p = NULL;
2377 ssize_t length;
2378 struct task_struct *task = get_proc_task(inode);
2379
2380 if (!task)
2381 return -ESRCH;
2382
2383 length = security_getprocattr(task,
2384 (char*)file->f_path.dentry->d_name.name,
2385 &p);
2386 put_task_struct(task);
2387 if (length > 0)
2388 length = simple_read_from_buffer(buf, count, ppos, p, length);
2389 kfree(p);
2390 return length;
2391 }
2392
2393 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2394 size_t count, loff_t *ppos)
2395 {
2396 struct inode * inode = file->f_path.dentry->d_inode;
2397 char *page;
2398 ssize_t length;
2399 struct task_struct *task = get_proc_task(inode);
2400
2401 length = -ESRCH;
2402 if (!task)
2403 goto out_no_task;
2404 if (count > PAGE_SIZE)
2405 count = PAGE_SIZE;
2406
2407 /* No partial writes. */
2408 length = -EINVAL;
2409 if (*ppos != 0)
2410 goto out;
2411
2412 length = -ENOMEM;
2413 page = (char*)__get_free_page(GFP_TEMPORARY);
2414 if (!page)
2415 goto out;
2416
2417 length = -EFAULT;
2418 if (copy_from_user(page, buf, count))
2419 goto out_free;
2420
2421 /* Guard against adverse ptrace interaction */
2422 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2423 if (length < 0)
2424 goto out_free;
2425
2426 length = security_setprocattr(task,
2427 (char*)file->f_path.dentry->d_name.name,
2428 (void*)page, count);
2429 mutex_unlock(&task->signal->cred_guard_mutex);
2430 out_free:
2431 free_page((unsigned long) page);
2432 out:
2433 put_task_struct(task);
2434 out_no_task:
2435 return length;
2436 }
2437
2438 static const struct file_operations proc_pid_attr_operations = {
2439 .read = proc_pid_attr_read,
2440 .write = proc_pid_attr_write,
2441 .llseek = generic_file_llseek,
2442 };
2443
2444 static const struct pid_entry attr_dir_stuff[] = {
2445 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2446 REG("prev", S_IRUGO, proc_pid_attr_operations),
2447 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2448 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2449 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2450 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2451 };
2452
2453 static int proc_attr_dir_readdir(struct file * filp,
2454 void * dirent, filldir_t filldir)
2455 {
2456 return proc_pident_readdir(filp,dirent,filldir,
2457 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2458 }
2459
2460 static const struct file_operations proc_attr_dir_operations = {
2461 .read = generic_read_dir,
2462 .readdir = proc_attr_dir_readdir,
2463 .llseek = default_llseek,
2464 };
2465
2466 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2467 struct dentry *dentry, struct nameidata *nd)
2468 {
2469 return proc_pident_lookup(dir, dentry,
2470 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2471 }
2472
2473 static const struct inode_operations proc_attr_dir_inode_operations = {
2474 .lookup = proc_attr_dir_lookup,
2475 .getattr = pid_getattr,
2476 .setattr = proc_setattr,
2477 };
2478
2479 #endif
2480
2481 #ifdef CONFIG_ELF_CORE
2482 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2483 size_t count, loff_t *ppos)
2484 {
2485 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2486 struct mm_struct *mm;
2487 char buffer[PROC_NUMBUF];
2488 size_t len;
2489 int ret;
2490
2491 if (!task)
2492 return -ESRCH;
2493
2494 ret = 0;
2495 mm = get_task_mm(task);
2496 if (mm) {
2497 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2498 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2499 MMF_DUMP_FILTER_SHIFT));
2500 mmput(mm);
2501 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2502 }
2503
2504 put_task_struct(task);
2505
2506 return ret;
2507 }
2508
2509 static ssize_t proc_coredump_filter_write(struct file *file,
2510 const char __user *buf,
2511 size_t count,
2512 loff_t *ppos)
2513 {
2514 struct task_struct *task;
2515 struct mm_struct *mm;
2516 char buffer[PROC_NUMBUF], *end;
2517 unsigned int val;
2518 int ret;
2519 int i;
2520 unsigned long mask;
2521
2522 ret = -EFAULT;
2523 memset(buffer, 0, sizeof(buffer));
2524 if (count > sizeof(buffer) - 1)
2525 count = sizeof(buffer) - 1;
2526 if (copy_from_user(buffer, buf, count))
2527 goto out_no_task;
2528
2529 ret = -EINVAL;
2530 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2531 if (*end == '\n')
2532 end++;
2533 if (end - buffer == 0)
2534 goto out_no_task;
2535
2536 ret = -ESRCH;
2537 task = get_proc_task(file->f_dentry->d_inode);
2538 if (!task)
2539 goto out_no_task;
2540
2541 ret = end - buffer;
2542 mm = get_task_mm(task);
2543 if (!mm)
2544 goto out_no_mm;
2545
2546 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2547 if (val & mask)
2548 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2549 else
2550 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2551 }
2552
2553 mmput(mm);
2554 out_no_mm:
2555 put_task_struct(task);
2556 out_no_task:
2557 return ret;
2558 }
2559
2560 static const struct file_operations proc_coredump_filter_operations = {
2561 .read = proc_coredump_filter_read,
2562 .write = proc_coredump_filter_write,
2563 .llseek = generic_file_llseek,
2564 };
2565 #endif
2566
2567 /*
2568 * /proc/self:
2569 */
2570 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2571 int buflen)
2572 {
2573 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2574 pid_t tgid = task_tgid_nr_ns(current, ns);
2575 char tmp[PROC_NUMBUF];
2576 if (!tgid)
2577 return -ENOENT;
2578 sprintf(tmp, "%d", tgid);
2579 return vfs_readlink(dentry,buffer,buflen,tmp);
2580 }
2581
2582 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2583 {
2584 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2585 pid_t tgid = task_tgid_nr_ns(current, ns);
2586 char *name = ERR_PTR(-ENOENT);
2587 if (tgid) {
2588 name = __getname();
2589 if (!name)
2590 name = ERR_PTR(-ENOMEM);
2591 else
2592 sprintf(name, "%d", tgid);
2593 }
2594 nd_set_link(nd, name);
2595 return NULL;
2596 }
2597
2598 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2599 void *cookie)
2600 {
2601 char *s = nd_get_link(nd);
2602 if (!IS_ERR(s))
2603 __putname(s);
2604 }
2605
2606 static const struct inode_operations proc_self_inode_operations = {
2607 .readlink = proc_self_readlink,
2608 .follow_link = proc_self_follow_link,
2609 .put_link = proc_self_put_link,
2610 };
2611
2612 /*
2613 * proc base
2614 *
2615 * These are the directory entries in the root directory of /proc
2616 * that properly belong to the /proc filesystem, as they describe
2617 * describe something that is process related.
2618 */
2619 static const struct pid_entry proc_base_stuff[] = {
2620 NOD("self", S_IFLNK|S_IRWXUGO,
2621 &proc_self_inode_operations, NULL, {}),
2622 };
2623
2624 static struct dentry *proc_base_instantiate(struct inode *dir,
2625 struct dentry *dentry, struct task_struct *task, const void *ptr)
2626 {
2627 const struct pid_entry *p = ptr;
2628 struct inode *inode;
2629 struct proc_inode *ei;
2630 struct dentry *error;
2631
2632 /* Allocate the inode */
2633 error = ERR_PTR(-ENOMEM);
2634 inode = new_inode(dir->i_sb);
2635 if (!inode)
2636 goto out;
2637
2638 /* Initialize the inode */
2639 ei = PROC_I(inode);
2640 inode->i_ino = get_next_ino();
2641 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2642
2643 /*
2644 * grab the reference to the task.
2645 */
2646 ei->pid = get_task_pid(task, PIDTYPE_PID);
2647 if (!ei->pid)
2648 goto out_iput;
2649
2650 inode->i_mode = p->mode;
2651 if (S_ISDIR(inode->i_mode))
2652 inode->i_nlink = 2;
2653 if (S_ISLNK(inode->i_mode))
2654 inode->i_size = 64;
2655 if (p->iop)
2656 inode->i_op = p->iop;
2657 if (p->fop)
2658 inode->i_fop = p->fop;
2659 ei->op = p->op;
2660 d_add(dentry, inode);
2661 error = NULL;
2662 out:
2663 return error;
2664 out_iput:
2665 iput(inode);
2666 goto out;
2667 }
2668
2669 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2670 {
2671 struct dentry *error;
2672 struct task_struct *task = get_proc_task(dir);
2673 const struct pid_entry *p, *last;
2674
2675 error = ERR_PTR(-ENOENT);
2676
2677 if (!task)
2678 goto out_no_task;
2679
2680 /* Lookup the directory entry */
2681 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2682 for (p = proc_base_stuff; p <= last; p++) {
2683 if (p->len != dentry->d_name.len)
2684 continue;
2685 if (!memcmp(dentry->d_name.name, p->name, p->len))
2686 break;
2687 }
2688 if (p > last)
2689 goto out;
2690
2691 error = proc_base_instantiate(dir, dentry, task, p);
2692
2693 out:
2694 put_task_struct(task);
2695 out_no_task:
2696 return error;
2697 }
2698
2699 static int proc_base_fill_cache(struct file *filp, void *dirent,
2700 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2701 {
2702 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2703 proc_base_instantiate, task, p);
2704 }
2705
2706 #ifdef CONFIG_TASK_IO_ACCOUNTING
2707 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2708 {
2709 struct task_io_accounting acct = task->ioac;
2710 unsigned long flags;
2711
2712 if (whole && lock_task_sighand(task, &flags)) {
2713 struct task_struct *t = task;
2714
2715 task_io_accounting_add(&acct, &task->signal->ioac);
2716 while_each_thread(task, t)
2717 task_io_accounting_add(&acct, &t->ioac);
2718
2719 unlock_task_sighand(task, &flags);
2720 }
2721 return sprintf(buffer,
2722 "rchar: %llu\n"
2723 "wchar: %llu\n"
2724 "syscr: %llu\n"
2725 "syscw: %llu\n"
2726 "read_bytes: %llu\n"
2727 "write_bytes: %llu\n"
2728 "cancelled_write_bytes: %llu\n",
2729 (unsigned long long)acct.rchar,
2730 (unsigned long long)acct.wchar,
2731 (unsigned long long)acct.syscr,
2732 (unsigned long long)acct.syscw,
2733 (unsigned long long)acct.read_bytes,
2734 (unsigned long long)acct.write_bytes,
2735 (unsigned long long)acct.cancelled_write_bytes);
2736 }
2737
2738 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2739 {
2740 return do_io_accounting(task, buffer, 0);
2741 }
2742
2743 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2744 {
2745 return do_io_accounting(task, buffer, 1);
2746 }
2747 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2748
2749 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2750 struct pid *pid, struct task_struct *task)
2751 {
2752 int err = lock_trace(task);
2753 if (!err) {
2754 seq_printf(m, "%08x\n", task->personality);
2755 unlock_trace(task);
2756 }
2757 return err;
2758 }
2759
2760 /*
2761 * Thread groups
2762 */
2763 static const struct file_operations proc_task_operations;
2764 static const struct inode_operations proc_task_inode_operations;
2765
2766 static const struct pid_entry tgid_base_stuff[] = {
2767 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2768 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2769 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2770 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2771 #ifdef CONFIG_NET
2772 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2773 #endif
2774 REG("environ", S_IRUSR, proc_environ_operations),
2775 INF("auxv", S_IRUSR, proc_pid_auxv),
2776 ONE("status", S_IRUGO, proc_pid_status),
2777 ONE("personality", S_IRUGO, proc_pid_personality),
2778 INF("limits", S_IRUGO, proc_pid_limits),
2779 #ifdef CONFIG_SCHED_DEBUG
2780 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2781 #endif
2782 #ifdef CONFIG_SCHED_AUTOGROUP
2783 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2784 #endif
2785 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2786 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2787 INF("syscall", S_IRUGO, proc_pid_syscall),
2788 #endif
2789 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2790 ONE("stat", S_IRUGO, proc_tgid_stat),
2791 ONE("statm", S_IRUGO, proc_pid_statm),
2792 REG("maps", S_IRUGO, proc_maps_operations),
2793 #ifdef CONFIG_NUMA
2794 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2795 #endif
2796 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2797 LNK("cwd", proc_cwd_link),
2798 LNK("root", proc_root_link),
2799 LNK("exe", proc_exe_link),
2800 REG("mounts", S_IRUGO, proc_mounts_operations),
2801 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2802 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2803 #ifdef CONFIG_PROC_PAGE_MONITOR
2804 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2805 REG("smaps", S_IRUGO, proc_smaps_operations),
2806 REG("pagemap", S_IRUGO, proc_pagemap_operations),
2807 #endif
2808 #ifdef CONFIG_SECURITY
2809 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2810 #endif
2811 #ifdef CONFIG_KALLSYMS
2812 INF("wchan", S_IRUGO, proc_pid_wchan),
2813 #endif
2814 #ifdef CONFIG_STACKTRACE
2815 ONE("stack", S_IRUGO, proc_pid_stack),
2816 #endif
2817 #ifdef CONFIG_SCHEDSTATS
2818 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2819 #endif
2820 #ifdef CONFIG_LATENCYTOP
2821 REG("latency", S_IRUGO, proc_lstats_operations),
2822 #endif
2823 #ifdef CONFIG_PROC_PID_CPUSET
2824 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2825 #endif
2826 #ifdef CONFIG_CGROUPS
2827 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2828 #endif
2829 INF("oom_score", S_IRUGO, proc_oom_score),
2830 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2831 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2832 #ifdef CONFIG_AUDITSYSCALL
2833 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2834 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2835 #endif
2836 #ifdef CONFIG_FAULT_INJECTION
2837 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2838 #endif
2839 #ifdef CONFIG_ELF_CORE
2840 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2841 #endif
2842 #ifdef CONFIG_TASK_IO_ACCOUNTING
2843 INF("io", S_IRUGO, proc_tgid_io_accounting),
2844 #endif
2845 };
2846
2847 static int proc_tgid_base_readdir(struct file * filp,
2848 void * dirent, filldir_t filldir)
2849 {
2850 return proc_pident_readdir(filp,dirent,filldir,
2851 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2852 }
2853
2854 static const struct file_operations proc_tgid_base_operations = {
2855 .read = generic_read_dir,
2856 .readdir = proc_tgid_base_readdir,
2857 .llseek = default_llseek,
2858 };
2859
2860 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2861 return proc_pident_lookup(dir, dentry,
2862 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2863 }
2864
2865 static const struct inode_operations proc_tgid_base_inode_operations = {
2866 .lookup = proc_tgid_base_lookup,
2867 .getattr = pid_getattr,
2868 .setattr = proc_setattr,
2869 };
2870
2871 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2872 {
2873 struct dentry *dentry, *leader, *dir;
2874 char buf[PROC_NUMBUF];
2875 struct qstr name;
2876
2877 name.name = buf;
2878 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2879 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2880 if (dentry) {
2881 shrink_dcache_parent(dentry);
2882 d_drop(dentry);
2883 dput(dentry);
2884 }
2885
2886 name.name = buf;
2887 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2888 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2889 if (!leader)
2890 goto out;
2891
2892 name.name = "task";
2893 name.len = strlen(name.name);
2894 dir = d_hash_and_lookup(leader, &name);
2895 if (!dir)
2896 goto out_put_leader;
2897
2898 name.name = buf;
2899 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2900 dentry = d_hash_and_lookup(dir, &name);
2901 if (dentry) {
2902 shrink_dcache_parent(dentry);
2903 d_drop(dentry);
2904 dput(dentry);
2905 }
2906
2907 dput(dir);
2908 out_put_leader:
2909 dput(leader);
2910 out:
2911 return;
2912 }
2913
2914 /**
2915 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2916 * @task: task that should be flushed.
2917 *
2918 * When flushing dentries from proc, one needs to flush them from global
2919 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2920 * in. This call is supposed to do all of this job.
2921 *
2922 * Looks in the dcache for
2923 * /proc/@pid
2924 * /proc/@tgid/task/@pid
2925 * if either directory is present flushes it and all of it'ts children
2926 * from the dcache.
2927 *
2928 * It is safe and reasonable to cache /proc entries for a task until
2929 * that task exits. After that they just clog up the dcache with
2930 * useless entries, possibly causing useful dcache entries to be
2931 * flushed instead. This routine is proved to flush those useless
2932 * dcache entries at process exit time.
2933 *
2934 * NOTE: This routine is just an optimization so it does not guarantee
2935 * that no dcache entries will exist at process exit time it
2936 * just makes it very unlikely that any will persist.
2937 */
2938
2939 void proc_flush_task(struct task_struct *task)
2940 {
2941 int i;
2942 struct pid *pid, *tgid;
2943 struct upid *upid;
2944
2945 pid = task_pid(task);
2946 tgid = task_tgid(task);
2947
2948 for (i = 0; i <= pid->level; i++) {
2949 upid = &pid->numbers[i];
2950 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2951 tgid->numbers[i].nr);
2952 }
2953
2954 upid = &pid->numbers[pid->level];
2955 if (upid->nr == 1)
2956 pid_ns_release_proc(upid->ns);
2957 }
2958
2959 static struct dentry *proc_pid_instantiate(struct inode *dir,
2960 struct dentry * dentry,
2961 struct task_struct *task, const void *ptr)
2962 {
2963 struct dentry *error = ERR_PTR(-ENOENT);
2964 struct inode *inode;
2965
2966 inode = proc_pid_make_inode(dir->i_sb, task);
2967 if (!inode)
2968 goto out;
2969
2970 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2971 inode->i_op = &proc_tgid_base_inode_operations;
2972 inode->i_fop = &proc_tgid_base_operations;
2973 inode->i_flags|=S_IMMUTABLE;
2974
2975 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2976 ARRAY_SIZE(tgid_base_stuff));
2977
2978 d_set_d_op(dentry, &pid_dentry_operations);
2979
2980 d_add(dentry, inode);
2981 /* Close the race of the process dying before we return the dentry */
2982 if (pid_revalidate(dentry, NULL))
2983 error = NULL;
2984 out:
2985 return error;
2986 }
2987
2988 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2989 {
2990 struct dentry *result;
2991 struct task_struct *task;
2992 unsigned tgid;
2993 struct pid_namespace *ns;
2994
2995 result = proc_base_lookup(dir, dentry);
2996 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2997 goto out;
2998
2999 tgid = name_to_int(dentry);
3000 if (tgid == ~0U)
3001 goto out;
3002
3003 ns = dentry->d_sb->s_fs_info;
3004 rcu_read_lock();
3005 task = find_task_by_pid_ns(tgid, ns);
3006 if (task)
3007 get_task_struct(task);
3008 rcu_read_unlock();
3009 if (!task)
3010 goto out;
3011
3012 result = proc_pid_instantiate(dir, dentry, task, NULL);
3013 put_task_struct(task);
3014 out:
3015 return result;
3016 }
3017
3018 /*
3019 * Find the first task with tgid >= tgid
3020 *
3021 */
3022 struct tgid_iter {
3023 unsigned int tgid;
3024 struct task_struct *task;
3025 };
3026 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3027 {
3028 struct pid *pid;
3029
3030 if (iter.task)
3031 put_task_struct(iter.task);
3032 rcu_read_lock();
3033 retry:
3034 iter.task = NULL;
3035 pid = find_ge_pid(iter.tgid, ns);
3036 if (pid) {
3037 iter.tgid = pid_nr_ns(pid, ns);
3038 iter.task = pid_task(pid, PIDTYPE_PID);
3039 /* What we to know is if the pid we have find is the
3040 * pid of a thread_group_leader. Testing for task
3041 * being a thread_group_leader is the obvious thing
3042 * todo but there is a window when it fails, due to
3043 * the pid transfer logic in de_thread.
3044 *
3045 * So we perform the straight forward test of seeing
3046 * if the pid we have found is the pid of a thread
3047 * group leader, and don't worry if the task we have
3048 * found doesn't happen to be a thread group leader.
3049 * As we don't care in the case of readdir.
3050 */
3051 if (!iter.task || !has_group_leader_pid(iter.task)) {
3052 iter.tgid += 1;
3053 goto retry;
3054 }
3055 get_task_struct(iter.task);
3056 }
3057 rcu_read_unlock();
3058 return iter;
3059 }
3060
3061 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3062
3063 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3064 struct tgid_iter iter)
3065 {
3066 char name[PROC_NUMBUF];
3067 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3068 return proc_fill_cache(filp, dirent, filldir, name, len,
3069 proc_pid_instantiate, iter.task, NULL);
3070 }
3071
3072 /* for the /proc/ directory itself, after non-process stuff has been done */
3073 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3074 {
3075 unsigned int nr;
3076 struct task_struct *reaper;
3077 struct tgid_iter iter;
3078 struct pid_namespace *ns;
3079
3080 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3081 goto out_no_task;
3082 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3083
3084 reaper = get_proc_task(filp->f_path.dentry->d_inode);
3085 if (!reaper)
3086 goto out_no_task;
3087
3088 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3089 const struct pid_entry *p = &proc_base_stuff[nr];
3090 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3091 goto out;
3092 }
3093
3094 ns = filp->f_dentry->d_sb->s_fs_info;
3095 iter.task = NULL;
3096 iter.tgid = filp->f_pos - TGID_OFFSET;
3097 for (iter = next_tgid(ns, iter);
3098 iter.task;
3099 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3100 filp->f_pos = iter.tgid + TGID_OFFSET;
3101 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
3102 put_task_struct(iter.task);
3103 goto out;
3104 }
3105 }
3106 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3107 out:
3108 put_task_struct(reaper);
3109 out_no_task:
3110 return 0;
3111 }
3112
3113 /*
3114 * Tasks
3115 */
3116 static const struct pid_entry tid_base_stuff[] = {
3117 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3118 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3119 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3120 REG("environ", S_IRUSR, proc_environ_operations),
3121 INF("auxv", S_IRUSR, proc_pid_auxv),
3122 ONE("status", S_IRUGO, proc_pid_status),
3123 ONE("personality", S_IRUGO, proc_pid_personality),
3124 INF("limits", S_IRUGO, proc_pid_limits),
3125 #ifdef CONFIG_SCHED_DEBUG
3126 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3127 #endif
3128 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3129 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3130 INF("syscall", S_IRUGO, proc_pid_syscall),
3131 #endif
3132 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3133 ONE("stat", S_IRUGO, proc_tid_stat),
3134 ONE("statm", S_IRUGO, proc_pid_statm),
3135 REG("maps", S_IRUGO, proc_maps_operations),
3136 #ifdef CONFIG_NUMA
3137 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3138 #endif
3139 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3140 LNK("cwd", proc_cwd_link),
3141 LNK("root", proc_root_link),
3142 LNK("exe", proc_exe_link),
3143 REG("mounts", S_IRUGO, proc_mounts_operations),
3144 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3145 #ifdef CONFIG_PROC_PAGE_MONITOR
3146 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3147 REG("smaps", S_IRUGO, proc_smaps_operations),
3148 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3149 #endif
3150 #ifdef CONFIG_SECURITY
3151 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3152 #endif
3153 #ifdef CONFIG_KALLSYMS
3154 INF("wchan", S_IRUGO, proc_pid_wchan),
3155 #endif
3156 #ifdef CONFIG_STACKTRACE
3157 ONE("stack", S_IRUGO, proc_pid_stack),
3158 #endif
3159 #ifdef CONFIG_SCHEDSTATS
3160 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3161 #endif
3162 #ifdef CONFIG_LATENCYTOP
3163 REG("latency", S_IRUGO, proc_lstats_operations),
3164 #endif
3165 #ifdef CONFIG_PROC_PID_CPUSET
3166 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3167 #endif
3168 #ifdef CONFIG_CGROUPS
3169 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3170 #endif
3171 INF("oom_score", S_IRUGO, proc_oom_score),
3172 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3173 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3174 #ifdef CONFIG_AUDITSYSCALL
3175 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3176 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3177 #endif
3178 #ifdef CONFIG_FAULT_INJECTION
3179 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3180 #endif
3181 #ifdef CONFIG_TASK_IO_ACCOUNTING
3182 INF("io", S_IRUGO, proc_tid_io_accounting),
3183 #endif
3184 };
3185
3186 static int proc_tid_base_readdir(struct file * filp,
3187 void * dirent, filldir_t filldir)
3188 {
3189 return proc_pident_readdir(filp,dirent,filldir,
3190 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3191 }
3192
3193 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3194 return proc_pident_lookup(dir, dentry,
3195 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3196 }
3197
3198 static const struct file_operations proc_tid_base_operations = {
3199 .read = generic_read_dir,
3200 .readdir = proc_tid_base_readdir,
3201 .llseek = default_llseek,
3202 };
3203
3204 static const struct inode_operations proc_tid_base_inode_operations = {
3205 .lookup = proc_tid_base_lookup,
3206 .getattr = pid_getattr,
3207 .setattr = proc_setattr,
3208 };
3209
3210 static struct dentry *proc_task_instantiate(struct inode *dir,
3211 struct dentry *dentry, struct task_struct *task, const void *ptr)
3212 {
3213 struct dentry *error = ERR_PTR(-ENOENT);
3214 struct inode *inode;
3215 inode = proc_pid_make_inode(dir->i_sb, task);
3216
3217 if (!inode)
3218 goto out;
3219 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3220 inode->i_op = &proc_tid_base_inode_operations;
3221 inode->i_fop = &proc_tid_base_operations;
3222 inode->i_flags|=S_IMMUTABLE;
3223
3224 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3225 ARRAY_SIZE(tid_base_stuff));
3226
3227 d_set_d_op(dentry, &pid_dentry_operations);
3228
3229 d_add(dentry, inode);
3230 /* Close the race of the process dying before we return the dentry */
3231 if (pid_revalidate(dentry, NULL))
3232 error = NULL;
3233 out:
3234 return error;
3235 }
3236
3237 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3238 {
3239 struct dentry *result = ERR_PTR(-ENOENT);
3240 struct task_struct *task;
3241 struct task_struct *leader = get_proc_task(dir);
3242 unsigned tid;
3243 struct pid_namespace *ns;
3244
3245 if (!leader)
3246 goto out_no_task;
3247
3248 tid = name_to_int(dentry);
3249 if (tid == ~0U)
3250 goto out;
3251
3252 ns = dentry->d_sb->s_fs_info;
3253 rcu_read_lock();
3254 task = find_task_by_pid_ns(tid, ns);
3255 if (task)
3256 get_task_struct(task);
3257 rcu_read_unlock();
3258 if (!task)
3259 goto out;
3260 if (!same_thread_group(leader, task))
3261 goto out_drop_task;
3262
3263 result = proc_task_instantiate(dir, dentry, task, NULL);
3264 out_drop_task:
3265 put_task_struct(task);
3266 out:
3267 put_task_struct(leader);
3268 out_no_task:
3269 return result;
3270 }
3271
3272 /*
3273 * Find the first tid of a thread group to return to user space.
3274 *
3275 * Usually this is just the thread group leader, but if the users
3276 * buffer was too small or there was a seek into the middle of the
3277 * directory we have more work todo.
3278 *
3279 * In the case of a short read we start with find_task_by_pid.
3280 *
3281 * In the case of a seek we start with the leader and walk nr
3282 * threads past it.
3283 */
3284 static struct task_struct *first_tid(struct task_struct *leader,
3285 int tid, int nr, struct pid_namespace *ns)
3286 {
3287 struct task_struct *pos;
3288
3289 rcu_read_lock();
3290 /* Attempt to start with the pid of a thread */
3291 if (tid && (nr > 0)) {
3292 pos = find_task_by_pid_ns(tid, ns);
3293 if (pos && (pos->group_leader == leader))
3294 goto found;
3295 }
3296
3297 /* If nr exceeds the number of threads there is nothing todo */
3298 pos = NULL;
3299 if (nr && nr >= get_nr_threads(leader))
3300 goto out;
3301
3302 /* If we haven't found our starting place yet start
3303 * with the leader and walk nr threads forward.
3304 */
3305 for (pos = leader; nr > 0; --nr) {
3306 pos = next_thread(pos);
3307 if (pos == leader) {
3308 pos = NULL;
3309 goto out;
3310 }
3311 }
3312 found:
3313 get_task_struct(pos);
3314 out:
3315 rcu_read_unlock();
3316 return pos;
3317 }
3318
3319 /*
3320 * Find the next thread in the thread list.
3321 * Return NULL if there is an error or no next thread.
3322 *
3323 * The reference to the input task_struct is released.
3324 */
3325 static struct task_struct *next_tid(struct task_struct *start)
3326 {
3327 struct task_struct *pos = NULL;
3328 rcu_read_lock();
3329 if (pid_alive(start)) {
3330 pos = next_thread(start);
3331 if (thread_group_leader(pos))
3332 pos = NULL;
3333 else
3334 get_task_struct(pos);
3335 }
3336 rcu_read_unlock();
3337 put_task_struct(start);
3338 return pos;
3339 }
3340
3341 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3342 struct task_struct *task, int tid)
3343 {
3344 char name[PROC_NUMBUF];
3345 int len = snprintf(name, sizeof(name), "%d", tid);
3346 return proc_fill_cache(filp, dirent, filldir, name, len,
3347 proc_task_instantiate, task, NULL);
3348 }
3349
3350 /* for the /proc/TGID/task/ directories */
3351 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3352 {
3353 struct dentry *dentry = filp->f_path.dentry;
3354 struct inode *inode = dentry->d_inode;
3355 struct task_struct *leader = NULL;
3356 struct task_struct *task;
3357 int retval = -ENOENT;
3358 ino_t ino;
3359 int tid;
3360 struct pid_namespace *ns;
3361
3362 task = get_proc_task(inode);
3363 if (!task)
3364 goto out_no_task;
3365 rcu_read_lock();
3366 if (pid_alive(task)) {
3367 leader = task->group_leader;
3368 get_task_struct(leader);
3369 }
3370 rcu_read_unlock();
3371 put_task_struct(task);
3372 if (!leader)
3373 goto out_no_task;
3374 retval = 0;
3375
3376 switch ((unsigned long)filp->f_pos) {
3377 case 0:
3378 ino = inode->i_ino;
3379 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3380 goto out;
3381 filp->f_pos++;
3382 /* fall through */
3383 case 1:
3384 ino = parent_ino(dentry);
3385 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3386 goto out;
3387 filp->f_pos++;
3388 /* fall through */
3389 }
3390
3391 /* f_version caches the tgid value that the last readdir call couldn't
3392 * return. lseek aka telldir automagically resets f_version to 0.
3393 */
3394 ns = filp->f_dentry->d_sb->s_fs_info;
3395 tid = (int)filp->f_version;
3396 filp->f_version = 0;
3397 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3398 task;
3399 task = next_tid(task), filp->f_pos++) {
3400 tid = task_pid_nr_ns(task, ns);
3401 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3402 /* returning this tgid failed, save it as the first
3403 * pid for the next readir call */
3404 filp->f_version = (u64)tid;
3405 put_task_struct(task);
3406 break;
3407 }
3408 }
3409 out:
3410 put_task_struct(leader);
3411 out_no_task:
3412 return retval;
3413 }
3414
3415 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3416 {
3417 struct inode *inode = dentry->d_inode;
3418 struct task_struct *p = get_proc_task(inode);
3419 generic_fillattr(inode, stat);
3420
3421 if (p) {
3422 stat->nlink += get_nr_threads(p);
3423 put_task_struct(p);
3424 }
3425
3426 return 0;
3427 }
3428
3429 static const struct inode_operations proc_task_inode_operations = {
3430 .lookup = proc_task_lookup,
3431 .getattr = proc_task_getattr,
3432 .setattr = proc_setattr,
3433 };
3434
3435 static const struct file_operations proc_task_operations = {
3436 .read = generic_read_dir,
3437 .readdir = proc_task_readdir,
3438 .llseek = default_llseek,
3439 };
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree