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ARM: 7409/1: Do not call flush_cache_user_range with mmap_sem held
[linux/fpc-iii.git] / fs / proc / base.c
blob22794e8ab996d7760176b9395e9acd2eb18e698b
1 /*
2 * linux/fs/proc/base.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * proc base directory handling functions
7 *
8 * 1999, Al Viro. Rewritten. Now it covers the whole per-process part.
9 * Instead of using magical inumbers to determine the kind of object
10 * we allocate and fill in-core inodes upon lookup. They don't even
11 * go into icache. We cache the reference to task_struct upon lookup too.
12 * Eventually it should become a filesystem in its own. We don't use the
13 * rest of procfs anymore.
14 *
15 *
16 * Changelog:
17 * 17-Jan-2005
18 * Allan Bezerra
19 * Bruna Moreira <bruna.moreira@indt.org.br>
20 * Edjard Mota <edjard.mota@indt.org.br>
21 * Ilias Biris <ilias.biris@indt.org.br>
22 * Mauricio Lin <mauricio.lin@indt.org.br>
23 *
24 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
25 *
26 * A new process specific entry (smaps) included in /proc. It shows the
27 * size of rss for each memory area. The maps entry lacks information
28 * about physical memory size (rss) for each mapped file, i.e.,
29 * rss information for executables and library files.
30 * This additional information is useful for any tools that need to know
31 * about physical memory consumption for a process specific library.
32 *
33 * Changelog:
34 * 21-Feb-2005
35 * Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
36 * Pud inclusion in the page table walking.
37 *
38 * ChangeLog:
39 * 10-Mar-2005
40 * 10LE Instituto Nokia de Tecnologia - INdT:
41 * A better way to walks through the page table as suggested by Hugh Dickins.
42 *
43 * Simo Piiroinen <simo.piiroinen@nokia.com>:
44 * Smaps information related to shared, private, clean and dirty pages.
45 *
46 * Paul Mundt <paul.mundt@nokia.com>:
47 * Overall revision about smaps.
48 */
49
50 #include <asm/uaccess.h>
51
52 #include <linux/errno.h>
53 #include <linux/time.h>
54 #include <linux/proc_fs.h>
55 #include <linux/stat.h>
56 #include <linux/task_io_accounting_ops.h>
57 #include <linux/init.h>
58 #include <linux/capability.h>
59 #include <linux/file.h>
60 #include <linux/fdtable.h>
61 #include <linux/string.h>
62 #include <linux/seq_file.h>
63 #include <linux/namei.h>
64 #include <linux/mnt_namespace.h>
65 #include <linux/mm.h>
66 #include <linux/swap.h>
67 #include <linux/rcupdate.h>
68 #include <linux/kallsyms.h>
69 #include <linux/stacktrace.h>
70 #include <linux/resource.h>
71 #include <linux/module.h>
72 #include <linux/mount.h>
73 #include <linux/security.h>
74 #include <linux/ptrace.h>
75 #include <linux/tracehook.h>
76 #include <linux/cgroup.h>
77 #include <linux/cpuset.h>
78 #include <linux/audit.h>
79 #include <linux/poll.h>
80 #include <linux/nsproxy.h>
81 #include <linux/oom.h>
82 #include <linux/elf.h>
83 #include <linux/pid_namespace.h>
84 #include <linux/fs_struct.h>
85 #include <linux/slab.h>
86 #ifdef CONFIG_HARDWALL
87 #include <asm/hardwall.h>
88 #endif
89 #include "internal.h"
90
91 /* NOTE:
92 * Implementing inode permission operations in /proc is almost
93 * certainly an error. Permission checks need to happen during
94 * each system call not at open time. The reason is that most of
95 * what we wish to check for permissions in /proc varies at runtime.
96 *
97 * The classic example of a problem is opening file descriptors
98 * in /proc for a task before it execs a suid executable.
99 */
100
101 struct pid_entry {
102 char *name;
103 int len;
104 mode_t mode;
105 const struct inode_operations *iop;
106 const struct file_operations *fop;
107 union proc_op op;
108 };
109
110 #define NOD(NAME, MODE, IOP, FOP, OP) { \
111 .name = (NAME), \
112 .len = sizeof(NAME) - 1, \
113 .mode = MODE, \
114 .iop = IOP, \
115 .fop = FOP, \
116 .op = OP, \
117 }
118
119 #define DIR(NAME, MODE, iops, fops) \
120 NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
121 #define LNK(NAME, get_link) \
122 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
123 &proc_pid_link_inode_operations, NULL, \
124 { .proc_get_link = get_link } )
125 #define REG(NAME, MODE, fops) \
126 NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
127 #define INF(NAME, MODE, read) \
128 NOD(NAME, (S_IFREG|(MODE)), \
129 NULL, &proc_info_file_operations, \
130 { .proc_read = read } )
131 #define ONE(NAME, MODE, show) \
132 NOD(NAME, (S_IFREG|(MODE)), \
133 NULL, &proc_single_file_operations, \
134 { .proc_show = show } )
135
136 /*
137 * Count the number of hardlinks for the pid_entry table, excluding the .
138 * and .. links.
139 */
140 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
141 unsigned int n)
142 {
143 unsigned int i;
144 unsigned int count;
145
146 count = 0;
147 for (i = 0; i < n; ++i) {
148 if (S_ISDIR(entries[i].mode))
149 ++count;
150 }
151
152 return count;
153 }
154
155 static int get_task_root(struct task_struct *task, struct path *root)
156 {
157 int result = -ENOENT;
158
159 task_lock(task);
160 if (task->fs) {
161 get_fs_root(task->fs, root);
162 result = 0;
163 }
164 task_unlock(task);
165 return result;
166 }
167
168 static int proc_cwd_link(struct inode *inode, struct path *path)
169 {
170 struct task_struct *task = get_proc_task(inode);
171 int result = -ENOENT;
172
173 if (task) {
174 task_lock(task);
175 if (task->fs) {
176 get_fs_pwd(task->fs, path);
177 result = 0;
178 }
179 task_unlock(task);
180 put_task_struct(task);
181 }
182 return result;
183 }
184
185 static int proc_root_link(struct inode *inode, struct path *path)
186 {
187 struct task_struct *task = get_proc_task(inode);
188 int result = -ENOENT;
189
190 if (task) {
191 result = get_task_root(task, path);
192 put_task_struct(task);
193 }
194 return result;
195 }
196
197 static struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
198 {
199 struct mm_struct *mm;
200 int err;
201
202 err = mutex_lock_killable(&task->signal->cred_guard_mutex);
203 if (err)
204 return ERR_PTR(err);
205
206 mm = get_task_mm(task);
207 if (mm && mm != current->mm &&
208 !ptrace_may_access(task, mode)) {
209 mmput(mm);
210 mm = ERR_PTR(-EACCES);
211 }
212 mutex_unlock(&task->signal->cred_guard_mutex);
213
214 return mm;
215 }
216
217 struct mm_struct *mm_for_maps(struct task_struct *task)
218 {
219 return mm_access(task, PTRACE_MODE_READ);
220 }
221
222 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
223 {
224 int res = 0;
225 unsigned int len;
226 struct mm_struct *mm = get_task_mm(task);
227 if (!mm)
228 goto out;
229 if (!mm->arg_end)
230 goto out_mm; /* Shh! No looking before we're done */
231
232 len = mm->arg_end - mm->arg_start;
233
234 if (len > PAGE_SIZE)
235 len = PAGE_SIZE;
236
237 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
238
239 // If the nul at the end of args has been overwritten, then
240 // assume application is using setproctitle(3).
241 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
242 len = strnlen(buffer, res);
243 if (len < res) {
244 res = len;
245 } else {
246 len = mm->env_end - mm->env_start;
247 if (len > PAGE_SIZE - res)
248 len = PAGE_SIZE - res;
249 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
250 res = strnlen(buffer, res);
251 }
252 }
253 out_mm:
254 mmput(mm);
255 out:
256 return res;
257 }
258
259 static int proc_pid_auxv(struct task_struct *task, char *buffer)
260 {
261 struct mm_struct *mm = mm_for_maps(task);
262 int res = PTR_ERR(mm);
263 if (mm && !IS_ERR(mm)) {
264 unsigned int nwords = 0;
265 do {
266 nwords += 2;
267 } while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
268 res = nwords * sizeof(mm->saved_auxv[0]);
269 if (res > PAGE_SIZE)
270 res = PAGE_SIZE;
271 memcpy(buffer, mm->saved_auxv, res);
272 mmput(mm);
273 }
274 return res;
275 }
276
277
278 #ifdef CONFIG_KALLSYMS
279 /*
280 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
281 * Returns the resolved symbol. If that fails, simply return the address.
282 */
283 static int proc_pid_wchan(struct task_struct *task, char *buffer)
284 {
285 unsigned long wchan;
286 char symname[KSYM_NAME_LEN];
287
288 wchan = get_wchan(task);
289
290 if (lookup_symbol_name(wchan, symname) < 0)
291 if (!ptrace_may_access(task, PTRACE_MODE_READ))
292 return 0;
293 else
294 return sprintf(buffer, "%lu", wchan);
295 else
296 return sprintf(buffer, "%s", symname);
297 }
298 #endif /* CONFIG_KALLSYMS */
299
300 static int lock_trace(struct task_struct *task)
301 {
302 int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
303 if (err)
304 return err;
305 if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
306 mutex_unlock(&task->signal->cred_guard_mutex);
307 return -EPERM;
308 }
309 return 0;
310 }
311
312 static void unlock_trace(struct task_struct *task)
313 {
314 mutex_unlock(&task->signal->cred_guard_mutex);
315 }
316
317 #ifdef CONFIG_STACKTRACE
318
319 #define MAX_STACK_TRACE_DEPTH 64
320
321 static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
322 struct pid *pid, struct task_struct *task)
323 {
324 struct stack_trace trace;
325 unsigned long *entries;
326 int err;
327 int i;
328
329 entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
330 if (!entries)
331 return -ENOMEM;
332
333 trace.nr_entries = 0;
334 trace.max_entries = MAX_STACK_TRACE_DEPTH;
335 trace.entries = entries;
336 trace.skip = 0;
337
338 err = lock_trace(task);
339 if (!err) {
340 save_stack_trace_tsk(task, &trace);
341
342 for (i = 0; i < trace.nr_entries; i++) {
343 seq_printf(m, "[<%pK>] %pS\n",
344 (void *)entries[i], (void *)entries[i]);
345 }
346 unlock_trace(task);
347 }
348 kfree(entries);
349
350 return err;
351 }
352 #endif
353
354 #ifdef CONFIG_SCHEDSTATS
355 /*
356 * Provides /proc/PID/schedstat
357 */
358 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
359 {
360 return sprintf(buffer, "%llu %llu %lu\n",
361 (unsigned long long)task->se.sum_exec_runtime,
362 (unsigned long long)task->sched_info.run_delay,
363 task->sched_info.pcount);
364 }
365 #endif
366
367 #ifdef CONFIG_LATENCYTOP
368 static int lstats_show_proc(struct seq_file *m, void *v)
369 {
370 int i;
371 struct inode *inode = m->private;
372 struct task_struct *task = get_proc_task(inode);
373
374 if (!task)
375 return -ESRCH;
376 seq_puts(m, "Latency Top version : v0.1\n");
377 for (i = 0; i < 32; i++) {
378 struct latency_record *lr = &task->latency_record[i];
379 if (lr->backtrace[0]) {
380 int q;
381 seq_printf(m, "%i %li %li",
382 lr->count, lr->time, lr->max);
383 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
384 unsigned long bt = lr->backtrace[q];
385 if (!bt)
386 break;
387 if (bt == ULONG_MAX)
388 break;
389 seq_printf(m, " %ps", (void *)bt);
390 }
391 seq_putc(m, '\n');
392 }
393
394 }
395 put_task_struct(task);
396 return 0;
397 }
398
399 static int lstats_open(struct inode *inode, struct file *file)
400 {
401 return single_open(file, lstats_show_proc, inode);
402 }
403
404 static ssize_t lstats_write(struct file *file, const char __user *buf,
405 size_t count, loff_t *offs)
406 {
407 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
408
409 if (!task)
410 return -ESRCH;
411 clear_all_latency_tracing(task);
412 put_task_struct(task);
413
414 return count;
415 }
416
417 static const struct file_operations proc_lstats_operations = {
418 .open = lstats_open,
419 .read = seq_read,
420 .write = lstats_write,
421 .llseek = seq_lseek,
422 .release = single_release,
423 };
424
425 #endif
426
427 static int proc_oom_score(struct task_struct *task, char *buffer)
428 {
429 unsigned long points = 0;
430
431 read_lock(&tasklist_lock);
432 if (pid_alive(task))
433 points = oom_badness(task, NULL, NULL,
434 totalram_pages + total_swap_pages);
435 read_unlock(&tasklist_lock);
436 return sprintf(buffer, "%lu\n", points);
437 }
438
439 struct limit_names {
440 char *name;
441 char *unit;
442 };
443
444 static const struct limit_names lnames[RLIM_NLIMITS] = {
445 [RLIMIT_CPU] = {"Max cpu time", "seconds"},
446 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
447 [RLIMIT_DATA] = {"Max data size", "bytes"},
448 [RLIMIT_STACK] = {"Max stack size", "bytes"},
449 [RLIMIT_CORE] = {"Max core file size", "bytes"},
450 [RLIMIT_RSS] = {"Max resident set", "bytes"},
451 [RLIMIT_NPROC] = {"Max processes", "processes"},
452 [RLIMIT_NOFILE] = {"Max open files", "files"},
453 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
454 [RLIMIT_AS] = {"Max address space", "bytes"},
455 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
456 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
457 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
458 [RLIMIT_NICE] = {"Max nice priority", NULL},
459 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
460 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
461 };
462
463 /* Display limits for a process */
464 static int proc_pid_limits(struct task_struct *task, char *buffer)
465 {
466 unsigned int i;
467 int count = 0;
468 unsigned long flags;
469 char *bufptr = buffer;
470
471 struct rlimit rlim[RLIM_NLIMITS];
472
473 if (!lock_task_sighand(task, &flags))
474 return 0;
475 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
476 unlock_task_sighand(task, &flags);
477
478 /*
479 * print the file header
480 */
481 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
482 "Limit", "Soft Limit", "Hard Limit", "Units");
483
484 for (i = 0; i < RLIM_NLIMITS; i++) {
485 if (rlim[i].rlim_cur == RLIM_INFINITY)
486 count += sprintf(&bufptr[count], "%-25s %-20s ",
487 lnames[i].name, "unlimited");
488 else
489 count += sprintf(&bufptr[count], "%-25s %-20lu ",
490 lnames[i].name, rlim[i].rlim_cur);
491
492 if (rlim[i].rlim_max == RLIM_INFINITY)
493 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
494 else
495 count += sprintf(&bufptr[count], "%-20lu ",
496 rlim[i].rlim_max);
497
498 if (lnames[i].unit)
499 count += sprintf(&bufptr[count], "%-10s\n",
500 lnames[i].unit);
501 else
502 count += sprintf(&bufptr[count], "\n");
503 }
504
505 return count;
506 }
507
508 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
509 static int proc_pid_syscall(struct task_struct *task, char *buffer)
510 {
511 long nr;
512 unsigned long args[6], sp, pc;
513 int res = lock_trace(task);
514 if (res)
515 return res;
516
517 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
518 res = sprintf(buffer, "running\n");
519 else if (nr < 0)
520 res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
521 else
522 res = sprintf(buffer,
523 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
524 nr,
525 args[0], args[1], args[2], args[3], args[4], args[5],
526 sp, pc);
527 unlock_trace(task);
528 return res;
529 }
530 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
531
532 /************************************************************************/
533 /* Here the fs part begins */
534 /************************************************************************/
535
536 /* permission checks */
537 static int proc_fd_access_allowed(struct inode *inode)
538 {
539 struct task_struct *task;
540 int allowed = 0;
541 /* Allow access to a task's file descriptors if it is us or we
542 * may use ptrace attach to the process and find out that
543 * information.
544 */
545 task = get_proc_task(inode);
546 if (task) {
547 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
548 put_task_struct(task);
549 }
550 return allowed;
551 }
552
553 int proc_setattr(struct dentry *dentry, struct iattr *attr)
554 {
555 int error;
556 struct inode *inode = dentry->d_inode;
557
558 if (attr->ia_valid & ATTR_MODE)
559 return -EPERM;
560
561 error = inode_change_ok(inode, attr);
562 if (error)
563 return error;
564
565 if ((attr->ia_valid & ATTR_SIZE) &&
566 attr->ia_size != i_size_read(inode)) {
567 error = vmtruncate(inode, attr->ia_size);
568 if (error)
569 return error;
570 }
571
572 setattr_copy(inode, attr);
573 mark_inode_dirty(inode);
574 return 0;
575 }
576
577 static const struct inode_operations proc_def_inode_operations = {
578 .setattr = proc_setattr,
579 };
580
581 static int mounts_open_common(struct inode *inode, struct file *file,
582 const struct seq_operations *op)
583 {
584 struct task_struct *task = get_proc_task(inode);
585 struct nsproxy *nsp;
586 struct mnt_namespace *ns = NULL;
587 struct path root;
588 struct proc_mounts *p;
589 int ret = -EINVAL;
590
591 if (task) {
592 rcu_read_lock();
593 nsp = task_nsproxy(task);
594 if (nsp) {
595 ns = nsp->mnt_ns;
596 if (ns)
597 get_mnt_ns(ns);
598 }
599 rcu_read_unlock();
600 if (ns && get_task_root(task, &root) == 0)
601 ret = 0;
602 put_task_struct(task);
603 }
604
605 if (!ns)
606 goto err;
607 if (ret)
608 goto err_put_ns;
609
610 ret = -ENOMEM;
611 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
612 if (!p)
613 goto err_put_path;
614
615 file->private_data = &p->m;
616 ret = seq_open(file, op);
617 if (ret)
618 goto err_free;
619
620 p->m.private = p;
621 p->ns = ns;
622 p->root = root;
623 p->event = ns->event;
624
625 return 0;
626
627 err_free:
628 kfree(p);
629 err_put_path:
630 path_put(&root);
631 err_put_ns:
632 put_mnt_ns(ns);
633 err:
634 return ret;
635 }
636
637 static int mounts_release(struct inode *inode, struct file *file)
638 {
639 struct proc_mounts *p = file->private_data;
640 path_put(&p->root);
641 put_mnt_ns(p->ns);
642 return seq_release(inode, file);
643 }
644
645 static unsigned mounts_poll(struct file *file, poll_table *wait)
646 {
647 struct proc_mounts *p = file->private_data;
648 unsigned res = POLLIN | POLLRDNORM;
649
650 poll_wait(file, &p->ns->poll, wait);
651 if (mnt_had_events(p))
652 res |= POLLERR | POLLPRI;
653
654 return res;
655 }
656
657 static int mounts_open(struct inode *inode, struct file *file)
658 {
659 return mounts_open_common(inode, file, &mounts_op);
660 }
661
662 static const struct file_operations proc_mounts_operations = {
663 .open = mounts_open,
664 .read = seq_read,
665 .llseek = seq_lseek,
666 .release = mounts_release,
667 .poll = mounts_poll,
668 };
669
670 static int mountinfo_open(struct inode *inode, struct file *file)
671 {
672 return mounts_open_common(inode, file, &mountinfo_op);
673 }
674
675 static const struct file_operations proc_mountinfo_operations = {
676 .open = mountinfo_open,
677 .read = seq_read,
678 .llseek = seq_lseek,
679 .release = mounts_release,
680 .poll = mounts_poll,
681 };
682
683 static int mountstats_open(struct inode *inode, struct file *file)
684 {
685 return mounts_open_common(inode, file, &mountstats_op);
686 }
687
688 static const struct file_operations proc_mountstats_operations = {
689 .open = mountstats_open,
690 .read = seq_read,
691 .llseek = seq_lseek,
692 .release = mounts_release,
693 };
694
695 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
696
697 static ssize_t proc_info_read(struct file * file, char __user * buf,
698 size_t count, loff_t *ppos)
699 {
700 struct inode * inode = file->f_path.dentry->d_inode;
701 unsigned long page;
702 ssize_t length;
703 struct task_struct *task = get_proc_task(inode);
704
705 length = -ESRCH;
706 if (!task)
707 goto out_no_task;
708
709 if (count > PROC_BLOCK_SIZE)
710 count = PROC_BLOCK_SIZE;
711
712 length = -ENOMEM;
713 if (!(page = __get_free_page(GFP_TEMPORARY)))
714 goto out;
715
716 length = PROC_I(inode)->op.proc_read(task, (char*)page);
717
718 if (length >= 0)
719 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
720 free_page(page);
721 out:
722 put_task_struct(task);
723 out_no_task:
724 return length;
725 }
726
727 static const struct file_operations proc_info_file_operations = {
728 .read = proc_info_read,
729 .llseek = generic_file_llseek,
730 };
731
732 static int proc_single_show(struct seq_file *m, void *v)
733 {
734 struct inode *inode = m->private;
735 struct pid_namespace *ns;
736 struct pid *pid;
737 struct task_struct *task;
738 int ret;
739
740 ns = inode->i_sb->s_fs_info;
741 pid = proc_pid(inode);
742 task = get_pid_task(pid, PIDTYPE_PID);
743 if (!task)
744 return -ESRCH;
745
746 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
747
748 put_task_struct(task);
749 return ret;
750 }
751
752 static int proc_single_open(struct inode *inode, struct file *filp)
753 {
754 return single_open(filp, proc_single_show, inode);
755 }
756
757 static const struct file_operations proc_single_file_operations = {
758 .open = proc_single_open,
759 .read = seq_read,
760 .llseek = seq_lseek,
761 .release = single_release,
762 };
763
764 static int mem_open(struct inode* inode, struct file* file)
765 {
766 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
767 struct mm_struct *mm;
768
769 if (!task)
770 return -ESRCH;
771
772 mm = mm_access(task, PTRACE_MODE_ATTACH);
773 put_task_struct(task);
774
775 if (IS_ERR(mm))
776 return PTR_ERR(mm);
777
778 if (mm) {
779 /* ensure this mm_struct can't be freed */
780 atomic_inc(&mm->mm_count);
781 /* but do not pin its memory */
782 mmput(mm);
783 }
784
785 /* OK to pass negative loff_t, we can catch out-of-range */
786 file->f_mode |= FMODE_UNSIGNED_OFFSET;
787 file->private_data = mm;
788
789 return 0;
790 }
791
792 static ssize_t mem_rw(struct file *file, char __user *buf,
793 size_t count, loff_t *ppos, int write)
794 {
795 struct mm_struct *mm = file->private_data;
796 unsigned long addr = *ppos;
797 ssize_t copied;
798 char *page;
799
800 if (!mm)
801 return 0;
802
803 page = (char *)__get_free_page(GFP_TEMPORARY);
804 if (!page)
805 return -ENOMEM;
806
807 copied = 0;
808 if (!atomic_inc_not_zero(&mm->mm_users))
809 goto free;
810
811 while (count > 0) {
812 int this_len = min_t(int, count, PAGE_SIZE);
813
814 if (write && copy_from_user(page, buf, this_len)) {
815 copied = -EFAULT;
816 break;
817 }
818
819 this_len = access_remote_vm(mm, addr, page, this_len, write);
820 if (!this_len) {
821 if (!copied)
822 copied = -EIO;
823 break;
824 }
825
826 if (!write && copy_to_user(buf, page, this_len)) {
827 copied = -EFAULT;
828 break;
829 }
830
831 buf += this_len;
832 addr += this_len;
833 copied += this_len;
834 count -= this_len;
835 }
836 *ppos = addr;
837
838 mmput(mm);
839 free:
840 free_page((unsigned long) page);
841 return copied;
842 }
843
844 static ssize_t mem_read(struct file *file, char __user *buf,
845 size_t count, loff_t *ppos)
846 {
847 return mem_rw(file, buf, count, ppos, 0);
848 }
849
850 static ssize_t mem_write(struct file *file, const char __user *buf,
851 size_t count, loff_t *ppos)
852 {
853 return mem_rw(file, (char __user*)buf, count, ppos, 1);
854 }
855
856 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
857 {
858 switch (orig) {
859 case 0:
860 file->f_pos = offset;
861 break;
862 case 1:
863 file->f_pos += offset;
864 break;
865 default:
866 return -EINVAL;
867 }
868 force_successful_syscall_return();
869 return file->f_pos;
870 }
871
872 static int mem_release(struct inode *inode, struct file *file)
873 {
874 struct mm_struct *mm = file->private_data;
875 if (mm)
876 mmdrop(mm);
877 return 0;
878 }
879
880 static const struct file_operations proc_mem_operations = {
881 .llseek = mem_lseek,
882 .read = mem_read,
883 .write = mem_write,
884 .open = mem_open,
885 .release = mem_release,
886 };
887
888 static ssize_t environ_read(struct file *file, char __user *buf,
889 size_t count, loff_t *ppos)
890 {
891 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
892 char *page;
893 unsigned long src = *ppos;
894 int ret = -ESRCH;
895 struct mm_struct *mm;
896
897 if (!task)
898 goto out_no_task;
899
900 ret = -ENOMEM;
901 page = (char *)__get_free_page(GFP_TEMPORARY);
902 if (!page)
903 goto out;
904
905
906 mm = mm_for_maps(task);
907 ret = PTR_ERR(mm);
908 if (!mm || IS_ERR(mm))
909 goto out_free;
910
911 ret = 0;
912 while (count > 0) {
913 int this_len, retval, max_len;
914
915 this_len = mm->env_end - (mm->env_start + src);
916
917 if (this_len <= 0)
918 break;
919
920 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
921 this_len = (this_len > max_len) ? max_len : this_len;
922
923 retval = access_process_vm(task, (mm->env_start + src),
924 page, this_len, 0);
925
926 if (retval <= 0) {
927 ret = retval;
928 break;
929 }
930
931 if (copy_to_user(buf, page, retval)) {
932 ret = -EFAULT;
933 break;
934 }
935
936 ret += retval;
937 src += retval;
938 buf += retval;
939 count -= retval;
940 }
941 *ppos = src;
942
943 mmput(mm);
944 out_free:
945 free_page((unsigned long) page);
946 out:
947 put_task_struct(task);
948 out_no_task:
949 return ret;
950 }
951
952 static const struct file_operations proc_environ_operations = {
953 .read = environ_read,
954 .llseek = generic_file_llseek,
955 };
956
957 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
958 size_t count, loff_t *ppos)
959 {
960 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
961 char buffer[PROC_NUMBUF];
962 size_t len;
963 int oom_adjust = OOM_DISABLE;
964 unsigned long flags;
965
966 if (!task)
967 return -ESRCH;
968
969 if (lock_task_sighand(task, &flags)) {
970 oom_adjust = task->signal->oom_adj;
971 unlock_task_sighand(task, &flags);
972 }
973
974 put_task_struct(task);
975
976 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
977
978 return simple_read_from_buffer(buf, count, ppos, buffer, len);
979 }
980
981 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
982 size_t count, loff_t *ppos)
983 {
984 struct task_struct *task;
985 char buffer[PROC_NUMBUF];
986 int oom_adjust;
987 unsigned long flags;
988 int err;
989
990 memset(buffer, 0, sizeof(buffer));
991 if (count > sizeof(buffer) - 1)
992 count = sizeof(buffer) - 1;
993 if (copy_from_user(buffer, buf, count)) {
994 err = -EFAULT;
995 goto out;
996 }
997
998 err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
999 if (err)
1000 goto out;
1001 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1002 oom_adjust != OOM_DISABLE) {
1003 err = -EINVAL;
1004 goto out;
1005 }
1006
1007 task = get_proc_task(file->f_path.dentry->d_inode);
1008 if (!task) {
1009 err = -ESRCH;
1010 goto out;
1011 }
1012
1013 task_lock(task);
1014 if (!task->mm) {
1015 err = -EINVAL;
1016 goto err_task_lock;
1017 }
1018
1019 if (!lock_task_sighand(task, &flags)) {
1020 err = -ESRCH;
1021 goto err_task_lock;
1022 }
1023
1024 if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1025 err = -EACCES;
1026 goto err_sighand;
1027 }
1028
1029 if (oom_adjust != task->signal->oom_adj) {
1030 if (oom_adjust == OOM_DISABLE)
1031 atomic_inc(&task->mm->oom_disable_count);
1032 if (task->signal->oom_adj == OOM_DISABLE)
1033 atomic_dec(&task->mm->oom_disable_count);
1034 }
1035
1036 /*
1037 * Warn that /proc/pid/oom_adj is deprecated, see
1038 * Documentation/feature-removal-schedule.txt.
1039 */
1040 printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, "
1041 "please use /proc/%d/oom_score_adj instead.\n",
1042 current->comm, task_pid_nr(current),
1043 task_pid_nr(task), task_pid_nr(task));
1044 task->signal->oom_adj = oom_adjust;
1045 /*
1046 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1047 * value is always attainable.
1048 */
1049 if (task->signal->oom_adj == OOM_ADJUST_MAX)
1050 task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
1051 else
1052 task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
1053 -OOM_DISABLE;
1054 err_sighand:
1055 unlock_task_sighand(task, &flags);
1056 err_task_lock:
1057 task_unlock(task);
1058 put_task_struct(task);
1059 out:
1060 return err < 0 ? err : count;
1061 }
1062
1063 static const struct file_operations proc_oom_adjust_operations = {
1064 .read = oom_adjust_read,
1065 .write = oom_adjust_write,
1066 .llseek = generic_file_llseek,
1067 };
1068
1069 static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1070 size_t count, loff_t *ppos)
1071 {
1072 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1073 char buffer[PROC_NUMBUF];
1074 int oom_score_adj = OOM_SCORE_ADJ_MIN;
1075 unsigned long flags;
1076 size_t len;
1077
1078 if (!task)
1079 return -ESRCH;
1080 if (lock_task_sighand(task, &flags)) {
1081 oom_score_adj = task->signal->oom_score_adj;
1082 unlock_task_sighand(task, &flags);
1083 }
1084 put_task_struct(task);
1085 len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
1086 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1087 }
1088
1089 static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1090 size_t count, loff_t *ppos)
1091 {
1092 struct task_struct *task;
1093 char buffer[PROC_NUMBUF];
1094 unsigned long flags;
1095 int oom_score_adj;
1096 int err;
1097
1098 memset(buffer, 0, sizeof(buffer));
1099 if (count > sizeof(buffer) - 1)
1100 count = sizeof(buffer) - 1;
1101 if (copy_from_user(buffer, buf, count)) {
1102 err = -EFAULT;
1103 goto out;
1104 }
1105
1106 err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1107 if (err)
1108 goto out;
1109 if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1110 oom_score_adj > OOM_SCORE_ADJ_MAX) {
1111 err = -EINVAL;
1112 goto out;
1113 }
1114
1115 task = get_proc_task(file->f_path.dentry->d_inode);
1116 if (!task) {
1117 err = -ESRCH;
1118 goto out;
1119 }
1120
1121 task_lock(task);
1122 if (!task->mm) {
1123 err = -EINVAL;
1124 goto err_task_lock;
1125 }
1126
1127 if (!lock_task_sighand(task, &flags)) {
1128 err = -ESRCH;
1129 goto err_task_lock;
1130 }
1131
1132 if (oom_score_adj < task->signal->oom_score_adj_min &&
1133 !capable(CAP_SYS_RESOURCE)) {
1134 err = -EACCES;
1135 goto err_sighand;
1136 }
1137
1138 if (oom_score_adj != task->signal->oom_score_adj) {
1139 if (oom_score_adj == OOM_SCORE_ADJ_MIN)
1140 atomic_inc(&task->mm->oom_disable_count);
1141 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1142 atomic_dec(&task->mm->oom_disable_count);
1143 }
1144 task->signal->oom_score_adj = oom_score_adj;
1145 if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1146 task->signal->oom_score_adj_min = oom_score_adj;
1147 /*
1148 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1149 * always attainable.
1150 */
1151 if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1152 task->signal->oom_adj = OOM_DISABLE;
1153 else
1154 task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1155 OOM_SCORE_ADJ_MAX;
1156 err_sighand:
1157 unlock_task_sighand(task, &flags);
1158 err_task_lock:
1159 task_unlock(task);
1160 put_task_struct(task);
1161 out:
1162 return err < 0 ? err : count;
1163 }
1164
1165 static const struct file_operations proc_oom_score_adj_operations = {
1166 .read = oom_score_adj_read,
1167 .write = oom_score_adj_write,
1168 .llseek = default_llseek,
1169 };
1170
1171 #ifdef CONFIG_AUDITSYSCALL
1172 #define TMPBUFLEN 21
1173 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1174 size_t count, loff_t *ppos)
1175 {
1176 struct inode * inode = file->f_path.dentry->d_inode;
1177 struct task_struct *task = get_proc_task(inode);
1178 ssize_t length;
1179 char tmpbuf[TMPBUFLEN];
1180
1181 if (!task)
1182 return -ESRCH;
1183 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1184 audit_get_loginuid(task));
1185 put_task_struct(task);
1186 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1187 }
1188
1189 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1190 size_t count, loff_t *ppos)
1191 {
1192 struct inode * inode = file->f_path.dentry->d_inode;
1193 char *page, *tmp;
1194 ssize_t length;
1195 uid_t loginuid;
1196
1197 if (!capable(CAP_AUDIT_CONTROL))
1198 return -EPERM;
1199
1200 rcu_read_lock();
1201 if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1202 rcu_read_unlock();
1203 return -EPERM;
1204 }
1205 rcu_read_unlock();
1206
1207 if (count >= PAGE_SIZE)
1208 count = PAGE_SIZE - 1;
1209
1210 if (*ppos != 0) {
1211 /* No partial writes. */
1212 return -EINVAL;
1213 }
1214 page = (char*)__get_free_page(GFP_TEMPORARY);
1215 if (!page)
1216 return -ENOMEM;
1217 length = -EFAULT;
1218 if (copy_from_user(page, buf, count))
1219 goto out_free_page;
1220
1221 page[count] = '\0';
1222 loginuid = simple_strtoul(page, &tmp, 10);
1223 if (tmp == page) {
1224 length = -EINVAL;
1225 goto out_free_page;
1226
1227 }
1228 length = audit_set_loginuid(current, loginuid);
1229 if (likely(length == 0))
1230 length = count;
1231
1232 out_free_page:
1233 free_page((unsigned long) page);
1234 return length;
1235 }
1236
1237 static const struct file_operations proc_loginuid_operations = {
1238 .read = proc_loginuid_read,
1239 .write = proc_loginuid_write,
1240 .llseek = generic_file_llseek,
1241 };
1242
1243 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1244 size_t count, loff_t *ppos)
1245 {
1246 struct inode * inode = file->f_path.dentry->d_inode;
1247 struct task_struct *task = get_proc_task(inode);
1248 ssize_t length;
1249 char tmpbuf[TMPBUFLEN];
1250
1251 if (!task)
1252 return -ESRCH;
1253 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1254 audit_get_sessionid(task));
1255 put_task_struct(task);
1256 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1257 }
1258
1259 static const struct file_operations proc_sessionid_operations = {
1260 .read = proc_sessionid_read,
1261 .llseek = generic_file_llseek,
1262 };
1263 #endif
1264
1265 #ifdef CONFIG_FAULT_INJECTION
1266 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1267 size_t count, loff_t *ppos)
1268 {
1269 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1270 char buffer[PROC_NUMBUF];
1271 size_t len;
1272 int make_it_fail;
1273
1274 if (!task)
1275 return -ESRCH;
1276 make_it_fail = task->make_it_fail;
1277 put_task_struct(task);
1278
1279 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1280
1281 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1282 }
1283
1284 static ssize_t proc_fault_inject_write(struct file * file,
1285 const char __user * buf, size_t count, loff_t *ppos)
1286 {
1287 struct task_struct *task;
1288 char buffer[PROC_NUMBUF], *end;
1289 int make_it_fail;
1290
1291 if (!capable(CAP_SYS_RESOURCE))
1292 return -EPERM;
1293 memset(buffer, 0, sizeof(buffer));
1294 if (count > sizeof(buffer) - 1)
1295 count = sizeof(buffer) - 1;
1296 if (copy_from_user(buffer, buf, count))
1297 return -EFAULT;
1298 make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1299 if (*end)
1300 return -EINVAL;
1301 task = get_proc_task(file->f_dentry->d_inode);
1302 if (!task)
1303 return -ESRCH;
1304 task->make_it_fail = make_it_fail;
1305 put_task_struct(task);
1306
1307 return count;
1308 }
1309
1310 static const struct file_operations proc_fault_inject_operations = {
1311 .read = proc_fault_inject_read,
1312 .write = proc_fault_inject_write,
1313 .llseek = generic_file_llseek,
1314 };
1315 #endif
1316
1317
1318 #ifdef CONFIG_SCHED_DEBUG
1319 /*
1320 * Print out various scheduling related per-task fields:
1321 */
1322 static int sched_show(struct seq_file *m, void *v)
1323 {
1324 struct inode *inode = m->private;
1325 struct task_struct *p;
1326
1327 p = get_proc_task(inode);
1328 if (!p)
1329 return -ESRCH;
1330 proc_sched_show_task(p, m);
1331
1332 put_task_struct(p);
1333
1334 return 0;
1335 }
1336
1337 static ssize_t
1338 sched_write(struct file *file, const char __user *buf,
1339 size_t count, loff_t *offset)
1340 {
1341 struct inode *inode = file->f_path.dentry->d_inode;
1342 struct task_struct *p;
1343
1344 p = get_proc_task(inode);
1345 if (!p)
1346 return -ESRCH;
1347 proc_sched_set_task(p);
1348
1349 put_task_struct(p);
1350
1351 return count;
1352 }
1353
1354 static int sched_open(struct inode *inode, struct file *filp)
1355 {
1356 return single_open(filp, sched_show, inode);
1357 }
1358
1359 static const struct file_operations proc_pid_sched_operations = {
1360 .open = sched_open,
1361 .read = seq_read,
1362 .write = sched_write,
1363 .llseek = seq_lseek,
1364 .release = single_release,
1365 };
1366
1367 #endif
1368
1369 #ifdef CONFIG_SCHED_AUTOGROUP
1370 /*
1371 * Print out autogroup related information:
1372 */
1373 static int sched_autogroup_show(struct seq_file *m, void *v)
1374 {
1375 struct inode *inode = m->private;
1376 struct task_struct *p;
1377
1378 p = get_proc_task(inode);
1379 if (!p)
1380 return -ESRCH;
1381 proc_sched_autogroup_show_task(p, m);
1382
1383 put_task_struct(p);
1384
1385 return 0;
1386 }
1387
1388 static ssize_t
1389 sched_autogroup_write(struct file *file, const char __user *buf,
1390 size_t count, loff_t *offset)
1391 {
1392 struct inode *inode = file->f_path.dentry->d_inode;
1393 struct task_struct *p;
1394 char buffer[PROC_NUMBUF];
1395 int nice;
1396 int err;
1397
1398 memset(buffer, 0, sizeof(buffer));
1399 if (count > sizeof(buffer) - 1)
1400 count = sizeof(buffer) - 1;
1401 if (copy_from_user(buffer, buf, count))
1402 return -EFAULT;
1403
1404 err = kstrtoint(strstrip(buffer), 0, &nice);
1405 if (err < 0)
1406 return err;
1407
1408 p = get_proc_task(inode);
1409 if (!p)
1410 return -ESRCH;
1411
1412 err = nice;
1413 err = proc_sched_autogroup_set_nice(p, &err);
1414 if (err)
1415 count = err;
1416
1417 put_task_struct(p);
1418
1419 return count;
1420 }
1421
1422 static int sched_autogroup_open(struct inode *inode, struct file *filp)
1423 {
1424 int ret;
1425
1426 ret = single_open(filp, sched_autogroup_show, NULL);
1427 if (!ret) {
1428 struct seq_file *m = filp->private_data;
1429
1430 m->private = inode;
1431 }
1432 return ret;
1433 }
1434
1435 static const struct file_operations proc_pid_sched_autogroup_operations = {
1436 .open = sched_autogroup_open,
1437 .read = seq_read,
1438 .write = sched_autogroup_write,
1439 .llseek = seq_lseek,
1440 .release = single_release,
1441 };
1442
1443 #endif /* CONFIG_SCHED_AUTOGROUP */
1444
1445 static ssize_t comm_write(struct file *file, const char __user *buf,
1446 size_t count, loff_t *offset)
1447 {
1448 struct inode *inode = file->f_path.dentry->d_inode;
1449 struct task_struct *p;
1450 char buffer[TASK_COMM_LEN];
1451
1452 memset(buffer, 0, sizeof(buffer));
1453 if (count > sizeof(buffer) - 1)
1454 count = sizeof(buffer) - 1;
1455 if (copy_from_user(buffer, buf, count))
1456 return -EFAULT;
1457
1458 p = get_proc_task(inode);
1459 if (!p)
1460 return -ESRCH;
1461
1462 if (same_thread_group(current, p))
1463 set_task_comm(p, buffer);
1464 else
1465 count = -EINVAL;
1466
1467 put_task_struct(p);
1468
1469 return count;
1470 }
1471
1472 static int comm_show(struct seq_file *m, void *v)
1473 {
1474 struct inode *inode = m->private;
1475 struct task_struct *p;
1476
1477 p = get_proc_task(inode);
1478 if (!p)
1479 return -ESRCH;
1480
1481 task_lock(p);
1482 seq_printf(m, "%s\n", p->comm);
1483 task_unlock(p);
1484
1485 put_task_struct(p);
1486
1487 return 0;
1488 }
1489
1490 static int comm_open(struct inode *inode, struct file *filp)
1491 {
1492 return single_open(filp, comm_show, inode);
1493 }
1494
1495 static const struct file_operations proc_pid_set_comm_operations = {
1496 .open = comm_open,
1497 .read = seq_read,
1498 .write = comm_write,
1499 .llseek = seq_lseek,
1500 .release = single_release,
1501 };
1502
1503 static int proc_exe_link(struct inode *inode, struct path *exe_path)
1504 {
1505 struct task_struct *task;
1506 struct mm_struct *mm;
1507 struct file *exe_file;
1508
1509 task = get_proc_task(inode);
1510 if (!task)
1511 return -ENOENT;
1512 mm = get_task_mm(task);
1513 put_task_struct(task);
1514 if (!mm)
1515 return -ENOENT;
1516 exe_file = get_mm_exe_file(mm);
1517 mmput(mm);
1518 if (exe_file) {
1519 *exe_path = exe_file->f_path;
1520 path_get(&exe_file->f_path);
1521 fput(exe_file);
1522 return 0;
1523 } else
1524 return -ENOENT;
1525 }
1526
1527 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1528 {
1529 struct inode *inode = dentry->d_inode;
1530 int error = -EACCES;
1531
1532 /* We don't need a base pointer in the /proc filesystem */
1533 path_put(&nd->path);
1534
1535 /* Are we allowed to snoop on the tasks file descriptors? */
1536 if (!proc_fd_access_allowed(inode))
1537 goto out;
1538
1539 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1540 out:
1541 return ERR_PTR(error);
1542 }
1543
1544 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1545 {
1546 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1547 char *pathname;
1548 int len;
1549
1550 if (!tmp)
1551 return -ENOMEM;
1552
1553 pathname = d_path(path, tmp, PAGE_SIZE);
1554 len = PTR_ERR(pathname);
1555 if (IS_ERR(pathname))
1556 goto out;
1557 len = tmp + PAGE_SIZE - 1 - pathname;
1558
1559 if (len > buflen)
1560 len = buflen;
1561 if (copy_to_user(buffer, pathname, len))
1562 len = -EFAULT;
1563 out:
1564 free_page((unsigned long)tmp);
1565 return len;
1566 }
1567
1568 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1569 {
1570 int error = -EACCES;
1571 struct inode *inode = dentry->d_inode;
1572 struct path path;
1573
1574 /* Are we allowed to snoop on the tasks file descriptors? */
1575 if (!proc_fd_access_allowed(inode))
1576 goto out;
1577
1578 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1579 if (error)
1580 goto out;
1581
1582 error = do_proc_readlink(&path, buffer, buflen);
1583 path_put(&path);
1584 out:
1585 return error;
1586 }
1587
1588 static const struct inode_operations proc_pid_link_inode_operations = {
1589 .readlink = proc_pid_readlink,
1590 .follow_link = proc_pid_follow_link,
1591 .setattr = proc_setattr,
1592 };
1593
1594
1595 /* building an inode */
1596
1597 static int task_dumpable(struct task_struct *task)
1598 {
1599 int dumpable = 0;
1600 struct mm_struct *mm;
1601
1602 task_lock(task);
1603 mm = task->mm;
1604 if (mm)
1605 dumpable = get_dumpable(mm);
1606 task_unlock(task);
1607 if(dumpable == 1)
1608 return 1;
1609 return 0;
1610 }
1611
1612 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1613 {
1614 struct inode * inode;
1615 struct proc_inode *ei;
1616 const struct cred *cred;
1617
1618 /* We need a new inode */
1619
1620 inode = new_inode(sb);
1621 if (!inode)
1622 goto out;
1623
1624 /* Common stuff */
1625 ei = PROC_I(inode);
1626 inode->i_ino = get_next_ino();
1627 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1628 inode->i_op = &proc_def_inode_operations;
1629
1630 /*
1631 * grab the reference to task.
1632 */
1633 ei->pid = get_task_pid(task, PIDTYPE_PID);
1634 if (!ei->pid)
1635 goto out_unlock;
1636
1637 if (task_dumpable(task)) {
1638 rcu_read_lock();
1639 cred = __task_cred(task);
1640 inode->i_uid = cred->euid;
1641 inode->i_gid = cred->egid;
1642 rcu_read_unlock();
1643 }
1644 security_task_to_inode(task, inode);
1645
1646 out:
1647 return inode;
1648
1649 out_unlock:
1650 iput(inode);
1651 return NULL;
1652 }
1653
1654 int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1655 {
1656 struct inode *inode = dentry->d_inode;
1657 struct task_struct *task;
1658 const struct cred *cred;
1659
1660 generic_fillattr(inode, stat);
1661
1662 rcu_read_lock();
1663 stat->uid = 0;
1664 stat->gid = 0;
1665 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1666 if (task) {
1667 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1668 task_dumpable(task)) {
1669 cred = __task_cred(task);
1670 stat->uid = cred->euid;
1671 stat->gid = cred->egid;
1672 }
1673 }
1674 rcu_read_unlock();
1675 return 0;
1676 }
1677
1678 /* dentry stuff */
1679
1680 /*
1681 * Exceptional case: normally we are not allowed to unhash a busy
1682 * directory. In this case, however, we can do it - no aliasing problems
1683 * due to the way we treat inodes.
1684 *
1685 * Rewrite the inode's ownerships here because the owning task may have
1686 * performed a setuid(), etc.
1687 *
1688 * Before the /proc/pid/status file was created the only way to read
1689 * the effective uid of a /process was to stat /proc/pid. Reading
1690 * /proc/pid/status is slow enough that procps and other packages
1691 * kept stating /proc/pid. To keep the rules in /proc simple I have
1692 * made this apply to all per process world readable and executable
1693 * directories.
1694 */
1695 int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1696 {
1697 struct inode *inode;
1698 struct task_struct *task;
1699 const struct cred *cred;
1700
1701 if (nd && nd->flags & LOOKUP_RCU)
1702 return -ECHILD;
1703
1704 inode = dentry->d_inode;
1705 task = get_proc_task(inode);
1706
1707 if (task) {
1708 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1709 task_dumpable(task)) {
1710 rcu_read_lock();
1711 cred = __task_cred(task);
1712 inode->i_uid = cred->euid;
1713 inode->i_gid = cred->egid;
1714 rcu_read_unlock();
1715 } else {
1716 inode->i_uid = 0;
1717 inode->i_gid = 0;
1718 }
1719 inode->i_mode &= ~(S_ISUID | S_ISGID);
1720 security_task_to_inode(task, inode);
1721 put_task_struct(task);
1722 return 1;
1723 }
1724 d_drop(dentry);
1725 return 0;
1726 }
1727
1728 static int pid_delete_dentry(const struct dentry * dentry)
1729 {
1730 /* Is the task we represent dead?
1731 * If so, then don't put the dentry on the lru list,
1732 * kill it immediately.
1733 */
1734 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1735 }
1736
1737 const struct dentry_operations pid_dentry_operations =
1738 {
1739 .d_revalidate = pid_revalidate,
1740 .d_delete = pid_delete_dentry,
1741 };
1742
1743 /* Lookups */
1744
1745 /*
1746 * Fill a directory entry.
1747 *
1748 * If possible create the dcache entry and derive our inode number and
1749 * file type from dcache entry.
1750 *
1751 * Since all of the proc inode numbers are dynamically generated, the inode
1752 * numbers do not exist until the inode is cache. This means creating the
1753 * the dcache entry in readdir is necessary to keep the inode numbers
1754 * reported by readdir in sync with the inode numbers reported
1755 * by stat.
1756 */
1757 int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1758 const char *name, int len,
1759 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1760 {
1761 struct dentry *child, *dir = filp->f_path.dentry;
1762 struct inode *inode;
1763 struct qstr qname;
1764 ino_t ino = 0;
1765 unsigned type = DT_UNKNOWN;
1766
1767 qname.name = name;
1768 qname.len = len;
1769 qname.hash = full_name_hash(name, len);
1770
1771 child = d_lookup(dir, &qname);
1772 if (!child) {
1773 struct dentry *new;
1774 new = d_alloc(dir, &qname);
1775 if (new) {
1776 child = instantiate(dir->d_inode, new, task, ptr);
1777 if (child)
1778 dput(new);
1779 else
1780 child = new;
1781 }
1782 }
1783 if (!child || IS_ERR(child) || !child->d_inode)
1784 goto end_instantiate;
1785 inode = child->d_inode;
1786 if (inode) {
1787 ino = inode->i_ino;
1788 type = inode->i_mode >> 12;
1789 }
1790 dput(child);
1791 end_instantiate:
1792 if (!ino)
1793 ino = find_inode_number(dir, &qname);
1794 if (!ino)
1795 ino = 1;
1796 return filldir(dirent, name, len, filp->f_pos, ino, type);
1797 }
1798
1799 static unsigned name_to_int(struct dentry *dentry)
1800 {
1801 const char *name = dentry->d_name.name;
1802 int len = dentry->d_name.len;
1803 unsigned n = 0;
1804
1805 if (len > 1 && *name == '0')
1806 goto out;
1807 while (len-- > 0) {
1808 unsigned c = *name++ - '0';
1809 if (c > 9)
1810 goto out;
1811 if (n >= (~0U-9)/10)
1812 goto out;
1813 n *= 10;
1814 n += c;
1815 }
1816 return n;
1817 out:
1818 return ~0U;
1819 }
1820
1821 #define PROC_FDINFO_MAX 64
1822
1823 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1824 {
1825 struct task_struct *task = get_proc_task(inode);
1826 struct files_struct *files = NULL;
1827 struct file *file;
1828 int fd = proc_fd(inode);
1829
1830 if (task) {
1831 files = get_files_struct(task);
1832 put_task_struct(task);
1833 }
1834 if (files) {
1835 /*
1836 * We are not taking a ref to the file structure, so we must
1837 * hold ->file_lock.
1838 */
1839 spin_lock(&files->file_lock);
1840 file = fcheck_files(files, fd);
1841 if (file) {
1842 unsigned int f_flags;
1843 struct fdtable *fdt;
1844
1845 fdt = files_fdtable(files);
1846 f_flags = file->f_flags & ~O_CLOEXEC;
1847 if (FD_ISSET(fd, fdt->close_on_exec))
1848 f_flags |= O_CLOEXEC;
1849
1850 if (path) {
1851 *path = file->f_path;
1852 path_get(&file->f_path);
1853 }
1854 if (info)
1855 snprintf(info, PROC_FDINFO_MAX,
1856 "pos:\t%lli\n"
1857 "flags:\t0%o\n",
1858 (long long) file->f_pos,
1859 f_flags);
1860 spin_unlock(&files->file_lock);
1861 put_files_struct(files);
1862 return 0;
1863 }
1864 spin_unlock(&files->file_lock);
1865 put_files_struct(files);
1866 }
1867 return -ENOENT;
1868 }
1869
1870 static int proc_fd_link(struct inode *inode, struct path *path)
1871 {
1872 return proc_fd_info(inode, path, NULL);
1873 }
1874
1875 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1876 {
1877 struct inode *inode;
1878 struct task_struct *task;
1879 int fd;
1880 struct files_struct *files;
1881 const struct cred *cred;
1882
1883 if (nd && nd->flags & LOOKUP_RCU)
1884 return -ECHILD;
1885
1886 inode = dentry->d_inode;
1887 task = get_proc_task(inode);
1888 fd = proc_fd(inode);
1889
1890 if (task) {
1891 files = get_files_struct(task);
1892 if (files) {
1893 rcu_read_lock();
1894 if (fcheck_files(files, fd)) {
1895 rcu_read_unlock();
1896 put_files_struct(files);
1897 if (task_dumpable(task)) {
1898 rcu_read_lock();
1899 cred = __task_cred(task);
1900 inode->i_uid = cred->euid;
1901 inode->i_gid = cred->egid;
1902 rcu_read_unlock();
1903 } else {
1904 inode->i_uid = 0;
1905 inode->i_gid = 0;
1906 }
1907 inode->i_mode &= ~(S_ISUID | S_ISGID);
1908 security_task_to_inode(task, inode);
1909 put_task_struct(task);
1910 return 1;
1911 }
1912 rcu_read_unlock();
1913 put_files_struct(files);
1914 }
1915 put_task_struct(task);
1916 }
1917 d_drop(dentry);
1918 return 0;
1919 }
1920
1921 static const struct dentry_operations tid_fd_dentry_operations =
1922 {
1923 .d_revalidate = tid_fd_revalidate,
1924 .d_delete = pid_delete_dentry,
1925 };
1926
1927 static struct dentry *proc_fd_instantiate(struct inode *dir,
1928 struct dentry *dentry, struct task_struct *task, const void *ptr)
1929 {
1930 unsigned fd = *(const unsigned *)ptr;
1931 struct file *file;
1932 struct files_struct *files;
1933 struct inode *inode;
1934 struct proc_inode *ei;
1935 struct dentry *error = ERR_PTR(-ENOENT);
1936
1937 inode = proc_pid_make_inode(dir->i_sb, task);
1938 if (!inode)
1939 goto out;
1940 ei = PROC_I(inode);
1941 ei->fd = fd;
1942 files = get_files_struct(task);
1943 if (!files)
1944 goto out_iput;
1945 inode->i_mode = S_IFLNK;
1946
1947 /*
1948 * We are not taking a ref to the file structure, so we must
1949 * hold ->file_lock.
1950 */
1951 spin_lock(&files->file_lock);
1952 file = fcheck_files(files, fd);
1953 if (!file)
1954 goto out_unlock;
1955 if (file->f_mode & FMODE_READ)
1956 inode->i_mode |= S_IRUSR | S_IXUSR;
1957 if (file->f_mode & FMODE_WRITE)
1958 inode->i_mode |= S_IWUSR | S_IXUSR;
1959 spin_unlock(&files->file_lock);
1960 put_files_struct(files);
1961
1962 inode->i_op = &proc_pid_link_inode_operations;
1963 inode->i_size = 64;
1964 ei->op.proc_get_link = proc_fd_link;
1965 d_set_d_op(dentry, &tid_fd_dentry_operations);
1966 d_add(dentry, inode);
1967 /* Close the race of the process dying before we return the dentry */
1968 if (tid_fd_revalidate(dentry, NULL))
1969 error = NULL;
1970
1971 out:
1972 return error;
1973 out_unlock:
1974 spin_unlock(&files->file_lock);
1975 put_files_struct(files);
1976 out_iput:
1977 iput(inode);
1978 goto out;
1979 }
1980
1981 static struct dentry *proc_lookupfd_common(struct inode *dir,
1982 struct dentry *dentry,
1983 instantiate_t instantiate)
1984 {
1985 struct task_struct *task = get_proc_task(dir);
1986 unsigned fd = name_to_int(dentry);
1987 struct dentry *result = ERR_PTR(-ENOENT);
1988
1989 if (!task)
1990 goto out_no_task;
1991 if (fd == ~0U)
1992 goto out;
1993
1994 result = instantiate(dir, dentry, task, &fd);
1995 out:
1996 put_task_struct(task);
1997 out_no_task:
1998 return result;
1999 }
2000
2001 static int proc_readfd_common(struct file * filp, void * dirent,
2002 filldir_t filldir, instantiate_t instantiate)
2003 {
2004 struct dentry *dentry = filp->f_path.dentry;
2005 struct inode *inode = dentry->d_inode;
2006 struct task_struct *p = get_proc_task(inode);
2007 unsigned int fd, ino;
2008 int retval;
2009 struct files_struct * files;
2010
2011 retval = -ENOENT;
2012 if (!p)
2013 goto out_no_task;
2014 retval = 0;
2015
2016 fd = filp->f_pos;
2017 switch (fd) {
2018 case 0:
2019 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
2020 goto out;
2021 filp->f_pos++;
2022 case 1:
2023 ino = parent_ino(dentry);
2024 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2025 goto out;
2026 filp->f_pos++;
2027 default:
2028 files = get_files_struct(p);
2029 if (!files)
2030 goto out;
2031 rcu_read_lock();
2032 for (fd = filp->f_pos-2;
2033 fd < files_fdtable(files)->max_fds;
2034 fd++, filp->f_pos++) {
2035 char name[PROC_NUMBUF];
2036 int len;
2037
2038 if (!fcheck_files(files, fd))
2039 continue;
2040 rcu_read_unlock();
2041
2042 len = snprintf(name, sizeof(name), "%d", fd);
2043 if (proc_fill_cache(filp, dirent, filldir,
2044 name, len, instantiate,
2045 p, &fd) < 0) {
2046 rcu_read_lock();
2047 break;
2048 }
2049 rcu_read_lock();
2050 }
2051 rcu_read_unlock();
2052 put_files_struct(files);
2053 }
2054 out:
2055 put_task_struct(p);
2056 out_no_task:
2057 return retval;
2058 }
2059
2060 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
2061 struct nameidata *nd)
2062 {
2063 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
2064 }
2065
2066 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
2067 {
2068 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
2069 }
2070
2071 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
2072 size_t len, loff_t *ppos)
2073 {
2074 char tmp[PROC_FDINFO_MAX];
2075 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
2076 if (!err)
2077 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
2078 return err;
2079 }
2080
2081 static const struct file_operations proc_fdinfo_file_operations = {
2082 .open = nonseekable_open,
2083 .read = proc_fdinfo_read,
2084 .llseek = no_llseek,
2085 };
2086
2087 static const struct file_operations proc_fd_operations = {
2088 .read = generic_read_dir,
2089 .readdir = proc_readfd,
2090 .llseek = default_llseek,
2091 };
2092
2093 /*
2094 * /proc/pid/fd needs a special permission handler so that a process can still
2095 * access /proc/self/fd after it has executed a setuid().
2096 */
2097 static int proc_fd_permission(struct inode *inode, int mask, unsigned int flags)
2098 {
2099 int rv = generic_permission(inode, mask, flags, NULL);
2100 if (rv == 0)
2101 return 0;
2102 if (task_pid(current) == proc_pid(inode))
2103 rv = 0;
2104 return rv;
2105 }
2106
2107 /*
2108 * proc directories can do almost nothing..
2109 */
2110 static const struct inode_operations proc_fd_inode_operations = {
2111 .lookup = proc_lookupfd,
2112 .permission = proc_fd_permission,
2113 .setattr = proc_setattr,
2114 };
2115
2116 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2117 struct dentry *dentry, struct task_struct *task, const void *ptr)
2118 {
2119 unsigned fd = *(unsigned *)ptr;
2120 struct inode *inode;
2121 struct proc_inode *ei;
2122 struct dentry *error = ERR_PTR(-ENOENT);
2123
2124 inode = proc_pid_make_inode(dir->i_sb, task);
2125 if (!inode)
2126 goto out;
2127 ei = PROC_I(inode);
2128 ei->fd = fd;
2129 inode->i_mode = S_IFREG | S_IRUSR;
2130 inode->i_fop = &proc_fdinfo_file_operations;
2131 d_set_d_op(dentry, &tid_fd_dentry_operations);
2132 d_add(dentry, inode);
2133 /* Close the race of the process dying before we return the dentry */
2134 if (tid_fd_revalidate(dentry, NULL))
2135 error = NULL;
2136
2137 out:
2138 return error;
2139 }
2140
2141 static struct dentry *proc_lookupfdinfo(struct inode *dir,
2142 struct dentry *dentry,
2143 struct nameidata *nd)
2144 {
2145 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
2146 }
2147
2148 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2149 {
2150 return proc_readfd_common(filp, dirent, filldir,
2151 proc_fdinfo_instantiate);
2152 }
2153
2154 static const struct file_operations proc_fdinfo_operations = {
2155 .read = generic_read_dir,
2156 .readdir = proc_readfdinfo,
2157 .llseek = default_llseek,
2158 };
2159
2160 /*
2161 * proc directories can do almost nothing..
2162 */
2163 static const struct inode_operations proc_fdinfo_inode_operations = {
2164 .lookup = proc_lookupfdinfo,
2165 .setattr = proc_setattr,
2166 };
2167
2168
2169 static struct dentry *proc_pident_instantiate(struct inode *dir,
2170 struct dentry *dentry, struct task_struct *task, const void *ptr)
2171 {
2172 const struct pid_entry *p = ptr;
2173 struct inode *inode;
2174 struct proc_inode *ei;
2175 struct dentry *error = ERR_PTR(-ENOENT);
2176
2177 inode = proc_pid_make_inode(dir->i_sb, task);
2178 if (!inode)
2179 goto out;
2180
2181 ei = PROC_I(inode);
2182 inode->i_mode = p->mode;
2183 if (S_ISDIR(inode->i_mode))
2184 inode->i_nlink = 2; /* Use getattr to fix if necessary */
2185 if (p->iop)
2186 inode->i_op = p->iop;
2187 if (p->fop)
2188 inode->i_fop = p->fop;
2189 ei->op = p->op;
2190 d_set_d_op(dentry, &pid_dentry_operations);
2191 d_add(dentry, inode);
2192 /* Close the race of the process dying before we return the dentry */
2193 if (pid_revalidate(dentry, NULL))
2194 error = NULL;
2195 out:
2196 return error;
2197 }
2198
2199 static struct dentry *proc_pident_lookup(struct inode *dir,
2200 struct dentry *dentry,
2201 const struct pid_entry *ents,
2202 unsigned int nents)
2203 {
2204 struct dentry *error;
2205 struct task_struct *task = get_proc_task(dir);
2206 const struct pid_entry *p, *last;
2207
2208 error = ERR_PTR(-ENOENT);
2209
2210 if (!task)
2211 goto out_no_task;
2212
2213 /*
2214 * Yes, it does not scale. And it should not. Don't add
2215 * new entries into /proc/<tgid>/ without very good reasons.
2216 */
2217 last = &ents[nents - 1];
2218 for (p = ents; p <= last; p++) {
2219 if (p->len != dentry->d_name.len)
2220 continue;
2221 if (!memcmp(dentry->d_name.name, p->name, p->len))
2222 break;
2223 }
2224 if (p > last)
2225 goto out;
2226
2227 error = proc_pident_instantiate(dir, dentry, task, p);
2228 out:
2229 put_task_struct(task);
2230 out_no_task:
2231 return error;
2232 }
2233
2234 static int proc_pident_fill_cache(struct file *filp, void *dirent,
2235 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2236 {
2237 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2238 proc_pident_instantiate, task, p);
2239 }
2240
2241 static int proc_pident_readdir(struct file *filp,
2242 void *dirent, filldir_t filldir,
2243 const struct pid_entry *ents, unsigned int nents)
2244 {
2245 int i;
2246 struct dentry *dentry = filp->f_path.dentry;
2247 struct inode *inode = dentry->d_inode;
2248 struct task_struct *task = get_proc_task(inode);
2249 const struct pid_entry *p, *last;
2250 ino_t ino;
2251 int ret;
2252
2253 ret = -ENOENT;
2254 if (!task)
2255 goto out_no_task;
2256
2257 ret = 0;
2258 i = filp->f_pos;
2259 switch (i) {
2260 case 0:
2261 ino = inode->i_ino;
2262 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2263 goto out;
2264 i++;
2265 filp->f_pos++;
2266 /* fall through */
2267 case 1:
2268 ino = parent_ino(dentry);
2269 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2270 goto out;
2271 i++;
2272 filp->f_pos++;
2273 /* fall through */
2274 default:
2275 i -= 2;
2276 if (i >= nents) {
2277 ret = 1;
2278 goto out;
2279 }
2280 p = ents + i;
2281 last = &ents[nents - 1];
2282 while (p <= last) {
2283 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2284 goto out;
2285 filp->f_pos++;
2286 p++;
2287 }
2288 }
2289
2290 ret = 1;
2291 out:
2292 put_task_struct(task);
2293 out_no_task:
2294 return ret;
2295 }
2296
2297 #ifdef CONFIG_SECURITY
2298 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2299 size_t count, loff_t *ppos)
2300 {
2301 struct inode * inode = file->f_path.dentry->d_inode;
2302 char *p = NULL;
2303 ssize_t length;
2304 struct task_struct *task = get_proc_task(inode);
2305
2306 if (!task)
2307 return -ESRCH;
2308
2309 length = security_getprocattr(task,
2310 (char*)file->f_path.dentry->d_name.name,
2311 &p);
2312 put_task_struct(task);
2313 if (length > 0)
2314 length = simple_read_from_buffer(buf, count, ppos, p, length);
2315 kfree(p);
2316 return length;
2317 }
2318
2319 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2320 size_t count, loff_t *ppos)
2321 {
2322 struct inode * inode = file->f_path.dentry->d_inode;
2323 char *page;
2324 ssize_t length;
2325 struct task_struct *task = get_proc_task(inode);
2326
2327 length = -ESRCH;
2328 if (!task)
2329 goto out_no_task;
2330 if (count > PAGE_SIZE)
2331 count = PAGE_SIZE;
2332
2333 /* No partial writes. */
2334 length = -EINVAL;
2335 if (*ppos != 0)
2336 goto out;
2337
2338 length = -ENOMEM;
2339 page = (char*)__get_free_page(GFP_TEMPORARY);
2340 if (!page)
2341 goto out;
2342
2343 length = -EFAULT;
2344 if (copy_from_user(page, buf, count))
2345 goto out_free;
2346
2347 /* Guard against adverse ptrace interaction */
2348 length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2349 if (length < 0)
2350 goto out_free;
2351
2352 length = security_setprocattr(task,
2353 (char*)file->f_path.dentry->d_name.name,
2354 (void*)page, count);
2355 mutex_unlock(&task->signal->cred_guard_mutex);
2356 out_free:
2357 free_page((unsigned long) page);
2358 out:
2359 put_task_struct(task);
2360 out_no_task:
2361 return length;
2362 }
2363
2364 static const struct file_operations proc_pid_attr_operations = {
2365 .read = proc_pid_attr_read,
2366 .write = proc_pid_attr_write,
2367 .llseek = generic_file_llseek,
2368 };
2369
2370 static const struct pid_entry attr_dir_stuff[] = {
2371 REG("current", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2372 REG("prev", S_IRUGO, proc_pid_attr_operations),
2373 REG("exec", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2374 REG("fscreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2375 REG("keycreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2376 REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2377 };
2378
2379 static int proc_attr_dir_readdir(struct file * filp,
2380 void * dirent, filldir_t filldir)
2381 {
2382 return proc_pident_readdir(filp,dirent,filldir,
2383 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2384 }
2385
2386 static const struct file_operations proc_attr_dir_operations = {
2387 .read = generic_read_dir,
2388 .readdir = proc_attr_dir_readdir,
2389 .llseek = default_llseek,
2390 };
2391
2392 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2393 struct dentry *dentry, struct nameidata *nd)
2394 {
2395 return proc_pident_lookup(dir, dentry,
2396 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2397 }
2398
2399 static const struct inode_operations proc_attr_dir_inode_operations = {
2400 .lookup = proc_attr_dir_lookup,
2401 .getattr = pid_getattr,
2402 .setattr = proc_setattr,
2403 };
2404
2405 #endif
2406
2407 #ifdef CONFIG_ELF_CORE
2408 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2409 size_t count, loff_t *ppos)
2410 {
2411 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2412 struct mm_struct *mm;
2413 char buffer[PROC_NUMBUF];
2414 size_t len;
2415 int ret;
2416
2417 if (!task)
2418 return -ESRCH;
2419
2420 ret = 0;
2421 mm = get_task_mm(task);
2422 if (mm) {
2423 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2424 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2425 MMF_DUMP_FILTER_SHIFT));
2426 mmput(mm);
2427 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2428 }
2429
2430 put_task_struct(task);
2431
2432 return ret;
2433 }
2434
2435 static ssize_t proc_coredump_filter_write(struct file *file,
2436 const char __user *buf,
2437 size_t count,
2438 loff_t *ppos)
2439 {
2440 struct task_struct *task;
2441 struct mm_struct *mm;
2442 char buffer[PROC_NUMBUF], *end;
2443 unsigned int val;
2444 int ret;
2445 int i;
2446 unsigned long mask;
2447
2448 ret = -EFAULT;
2449 memset(buffer, 0, sizeof(buffer));
2450 if (count > sizeof(buffer) - 1)
2451 count = sizeof(buffer) - 1;
2452 if (copy_from_user(buffer, buf, count))
2453 goto out_no_task;
2454
2455 ret = -EINVAL;
2456 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2457 if (*end == '\n')
2458 end++;
2459 if (end - buffer == 0)
2460 goto out_no_task;
2461
2462 ret = -ESRCH;
2463 task = get_proc_task(file->f_dentry->d_inode);
2464 if (!task)
2465 goto out_no_task;
2466
2467 ret = end - buffer;
2468 mm = get_task_mm(task);
2469 if (!mm)
2470 goto out_no_mm;
2471
2472 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2473 if (val & mask)
2474 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2475 else
2476 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2477 }
2478
2479 mmput(mm);
2480 out_no_mm:
2481 put_task_struct(task);
2482 out_no_task:
2483 return ret;
2484 }
2485
2486 static const struct file_operations proc_coredump_filter_operations = {
2487 .read = proc_coredump_filter_read,
2488 .write = proc_coredump_filter_write,
2489 .llseek = generic_file_llseek,
2490 };
2491 #endif
2492
2493 /*
2494 * /proc/self:
2495 */
2496 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2497 int buflen)
2498 {
2499 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2500 pid_t tgid = task_tgid_nr_ns(current, ns);
2501 char tmp[PROC_NUMBUF];
2502 if (!tgid)
2503 return -ENOENT;
2504 sprintf(tmp, "%d", tgid);
2505 return vfs_readlink(dentry,buffer,buflen,tmp);
2506 }
2507
2508 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2509 {
2510 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2511 pid_t tgid = task_tgid_nr_ns(current, ns);
2512 char *name = ERR_PTR(-ENOENT);
2513 if (tgid) {
2514 name = __getname();
2515 if (!name)
2516 name = ERR_PTR(-ENOMEM);
2517 else
2518 sprintf(name, "%d", tgid);
2519 }
2520 nd_set_link(nd, name);
2521 return NULL;
2522 }
2523
2524 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2525 void *cookie)
2526 {
2527 char *s = nd_get_link(nd);
2528 if (!IS_ERR(s))
2529 __putname(s);
2530 }
2531
2532 static const struct inode_operations proc_self_inode_operations = {
2533 .readlink = proc_self_readlink,
2534 .follow_link = proc_self_follow_link,
2535 .put_link = proc_self_put_link,
2536 };
2537
2538 /*
2539 * proc base
2540 *
2541 * These are the directory entries in the root directory of /proc
2542 * that properly belong to the /proc filesystem, as they describe
2543 * describe something that is process related.
2544 */
2545 static const struct pid_entry proc_base_stuff[] = {
2546 NOD("self", S_IFLNK|S_IRWXUGO,
2547 &proc_self_inode_operations, NULL, {}),
2548 };
2549
2550 static struct dentry *proc_base_instantiate(struct inode *dir,
2551 struct dentry *dentry, struct task_struct *task, const void *ptr)
2552 {
2553 const struct pid_entry *p = ptr;
2554 struct inode *inode;
2555 struct proc_inode *ei;
2556 struct dentry *error;
2557
2558 /* Allocate the inode */
2559 error = ERR_PTR(-ENOMEM);
2560 inode = new_inode(dir->i_sb);
2561 if (!inode)
2562 goto out;
2563
2564 /* Initialize the inode */
2565 ei = PROC_I(inode);
2566 inode->i_ino = get_next_ino();
2567 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2568
2569 /*
2570 * grab the reference to the task.
2571 */
2572 ei->pid = get_task_pid(task, PIDTYPE_PID);
2573 if (!ei->pid)
2574 goto out_iput;
2575
2576 inode->i_mode = p->mode;
2577 if (S_ISDIR(inode->i_mode))
2578 inode->i_nlink = 2;
2579 if (S_ISLNK(inode->i_mode))
2580 inode->i_size = 64;
2581 if (p->iop)
2582 inode->i_op = p->iop;
2583 if (p->fop)
2584 inode->i_fop = p->fop;
2585 ei->op = p->op;
2586 d_add(dentry, inode);
2587 error = NULL;
2588 out:
2589 return error;
2590 out_iput:
2591 iput(inode);
2592 goto out;
2593 }
2594
2595 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2596 {
2597 struct dentry *error;
2598 struct task_struct *task = get_proc_task(dir);
2599 const struct pid_entry *p, *last;
2600
2601 error = ERR_PTR(-ENOENT);
2602
2603 if (!task)
2604 goto out_no_task;
2605
2606 /* Lookup the directory entry */
2607 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2608 for (p = proc_base_stuff; p <= last; p++) {
2609 if (p->len != dentry->d_name.len)
2610 continue;
2611 if (!memcmp(dentry->d_name.name, p->name, p->len))
2612 break;
2613 }
2614 if (p > last)
2615 goto out;
2616
2617 error = proc_base_instantiate(dir, dentry, task, p);
2618
2619 out:
2620 put_task_struct(task);
2621 out_no_task:
2622 return error;
2623 }
2624
2625 static int proc_base_fill_cache(struct file *filp, void *dirent,
2626 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2627 {
2628 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2629 proc_base_instantiate, task, p);
2630 }
2631
2632 #ifdef CONFIG_TASK_IO_ACCOUNTING
2633 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2634 {
2635 struct task_io_accounting acct = task->ioac;
2636 unsigned long flags;
2637 int result;
2638
2639 result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2640 if (result)
2641 return result;
2642
2643 if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2644 result = -EACCES;
2645 goto out_unlock;
2646 }
2647
2648 if (whole && lock_task_sighand(task, &flags)) {
2649 struct task_struct *t = task;
2650
2651 task_io_accounting_add(&acct, &task->signal->ioac);
2652 while_each_thread(task, t)
2653 task_io_accounting_add(&acct, &t->ioac);
2654
2655 unlock_task_sighand(task, &flags);
2656 }
2657 result = sprintf(buffer,
2658 "rchar: %llu\n"
2659 "wchar: %llu\n"
2660 "syscr: %llu\n"
2661 "syscw: %llu\n"
2662 "read_bytes: %llu\n"
2663 "write_bytes: %llu\n"
2664 "cancelled_write_bytes: %llu\n",
2665 (unsigned long long)acct.rchar,
2666 (unsigned long long)acct.wchar,
2667 (unsigned long long)acct.syscr,
2668 (unsigned long long)acct.syscw,
2669 (unsigned long long)acct.read_bytes,
2670 (unsigned long long)acct.write_bytes,
2671 (unsigned long long)acct.cancelled_write_bytes);
2672 out_unlock:
2673 mutex_unlock(&task->signal->cred_guard_mutex);
2674 return result;
2675 }
2676
2677 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2678 {
2679 return do_io_accounting(task, buffer, 0);
2680 }
2681
2682 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2683 {
2684 return do_io_accounting(task, buffer, 1);
2685 }
2686 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2687
2688 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2689 struct pid *pid, struct task_struct *task)
2690 {
2691 int err = lock_trace(task);
2692 if (!err) {
2693 seq_printf(m, "%08x\n", task->personality);
2694 unlock_trace(task);
2695 }
2696 return err;
2697 }
2698
2699 /*
2700 * Thread groups
2701 */
2702 static const struct file_operations proc_task_operations;
2703 static const struct inode_operations proc_task_inode_operations;
2704
2705 static const struct pid_entry tgid_base_stuff[] = {
2706 DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2707 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
2708 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2709 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2710 #ifdef CONFIG_NET
2711 DIR("net", S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2712 #endif
2713 REG("environ", S_IRUSR, proc_environ_operations),
2714 INF("auxv", S_IRUSR, proc_pid_auxv),
2715 ONE("status", S_IRUGO, proc_pid_status),
2716 ONE("personality", S_IRUGO, proc_pid_personality),
2717 INF("limits", S_IRUGO, proc_pid_limits),
2718 #ifdef CONFIG_SCHED_DEBUG
2719 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2720 #endif
2721 #ifdef CONFIG_SCHED_AUTOGROUP
2722 REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2723 #endif
2724 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2725 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2726 INF("syscall", S_IRUGO, proc_pid_syscall),
2727 #endif
2728 INF("cmdline", S_IRUGO, proc_pid_cmdline),
2729 ONE("stat", S_IRUGO, proc_tgid_stat),
2730 ONE("statm", S_IRUGO, proc_pid_statm),
2731 REG("maps", S_IRUGO, proc_maps_operations),
2732 #ifdef CONFIG_NUMA
2733 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
2734 #endif
2735 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
2736 LNK("cwd", proc_cwd_link),
2737 LNK("root", proc_root_link),
2738 LNK("exe", proc_exe_link),
2739 REG("mounts", S_IRUGO, proc_mounts_operations),
2740 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
2741 REG("mountstats", S_IRUSR, proc_mountstats_operations),
2742 #ifdef CONFIG_PROC_PAGE_MONITOR
2743 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2744 REG("smaps", S_IRUGO, proc_smaps_operations),
2745 REG("pagemap", S_IRUGO, proc_pagemap_operations),
2746 #endif
2747 #ifdef CONFIG_SECURITY
2748 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2749 #endif
2750 #ifdef CONFIG_KALLSYMS
2751 INF("wchan", S_IRUGO, proc_pid_wchan),
2752 #endif
2753 #ifdef CONFIG_STACKTRACE
2754 ONE("stack", S_IRUGO, proc_pid_stack),
2755 #endif
2756 #ifdef CONFIG_SCHEDSTATS
2757 INF("schedstat", S_IRUGO, proc_pid_schedstat),
2758 #endif
2759 #ifdef CONFIG_LATENCYTOP
2760 REG("latency", S_IRUGO, proc_lstats_operations),
2761 #endif
2762 #ifdef CONFIG_PROC_PID_CPUSET
2763 REG("cpuset", S_IRUGO, proc_cpuset_operations),
2764 #endif
2765 #ifdef CONFIG_CGROUPS
2766 REG("cgroup", S_IRUGO, proc_cgroup_operations),
2767 #endif
2768 INF("oom_score", S_IRUGO, proc_oom_score),
2769 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2770 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2771 #ifdef CONFIG_AUDITSYSCALL
2772 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
2773 REG("sessionid", S_IRUGO, proc_sessionid_operations),
2774 #endif
2775 #ifdef CONFIG_FAULT_INJECTION
2776 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
2777 #endif
2778 #ifdef CONFIG_ELF_CORE
2779 REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2780 #endif
2781 #ifdef CONFIG_TASK_IO_ACCOUNTING
2782 INF("io", S_IRUSR, proc_tgid_io_accounting),
2783 #endif
2784 #ifdef CONFIG_HARDWALL
2785 INF("hardwall", S_IRUGO, proc_pid_hardwall),
2786 #endif
2787 };
2788
2789 static int proc_tgid_base_readdir(struct file * filp,
2790 void * dirent, filldir_t filldir)
2791 {
2792 return proc_pident_readdir(filp,dirent,filldir,
2793 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2794 }
2795
2796 static const struct file_operations proc_tgid_base_operations = {
2797 .read = generic_read_dir,
2798 .readdir = proc_tgid_base_readdir,
2799 .llseek = default_llseek,
2800 };
2801
2802 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2803 return proc_pident_lookup(dir, dentry,
2804 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2805 }
2806
2807 static const struct inode_operations proc_tgid_base_inode_operations = {
2808 .lookup = proc_tgid_base_lookup,
2809 .getattr = pid_getattr,
2810 .setattr = proc_setattr,
2811 };
2812
2813 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2814 {
2815 struct dentry *dentry, *leader, *dir;
2816 char buf[PROC_NUMBUF];
2817 struct qstr name;
2818
2819 name.name = buf;
2820 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2821 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2822 if (dentry) {
2823 shrink_dcache_parent(dentry);
2824 d_drop(dentry);
2825 dput(dentry);
2826 }
2827
2828 name.name = buf;
2829 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2830 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2831 if (!leader)
2832 goto out;
2833
2834 name.name = "task";
2835 name.len = strlen(name.name);
2836 dir = d_hash_and_lookup(leader, &name);
2837 if (!dir)
2838 goto out_put_leader;
2839
2840 name.name = buf;
2841 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2842 dentry = d_hash_and_lookup(dir, &name);
2843 if (dentry) {
2844 shrink_dcache_parent(dentry);
2845 d_drop(dentry);
2846 dput(dentry);
2847 }
2848
2849 dput(dir);
2850 out_put_leader:
2851 dput(leader);
2852 out:
2853 return;
2854 }
2855
2856 /**
2857 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2858 * @task: task that should be flushed.
2859 *
2860 * When flushing dentries from proc, one needs to flush them from global
2861 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2862 * in. This call is supposed to do all of this job.
2863 *
2864 * Looks in the dcache for
2865 * /proc/@pid
2866 * /proc/@tgid/task/@pid
2867 * if either directory is present flushes it and all of it'ts children
2868 * from the dcache.
2869 *
2870 * It is safe and reasonable to cache /proc entries for a task until
2871 * that task exits. After that they just clog up the dcache with
2872 * useless entries, possibly causing useful dcache entries to be
2873 * flushed instead. This routine is proved to flush those useless
2874 * dcache entries at process exit time.
2875 *
2876 * NOTE: This routine is just an optimization so it does not guarantee
2877 * that no dcache entries will exist at process exit time it
2878 * just makes it very unlikely that any will persist.
2879 */
2880
2881 void proc_flush_task(struct task_struct *task)
2882 {
2883 int i;
2884 struct pid *pid, *tgid;
2885 struct upid *upid;
2886
2887 pid = task_pid(task);
2888 tgid = task_tgid(task);
2889
2890 for (i = 0; i <= pid->level; i++) {
2891 upid = &pid->numbers[i];
2892 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2893 tgid->numbers[i].nr);
2894 }
2895
2896 upid = &pid->numbers[pid->level];
2897 if (upid->nr == 1)
2898 pid_ns_release_proc(upid->ns);
2899 }
2900
2901 static struct dentry *proc_pid_instantiate(struct inode *dir,
2902 struct dentry * dentry,
2903 struct task_struct *task, const void *ptr)
2904 {
2905 struct dentry *error = ERR_PTR(-ENOENT);
2906 struct inode *inode;
2907
2908 inode = proc_pid_make_inode(dir->i_sb, task);
2909 if (!inode)
2910 goto out;
2911
2912 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2913 inode->i_op = &proc_tgid_base_inode_operations;
2914 inode->i_fop = &proc_tgid_base_operations;
2915 inode->i_flags|=S_IMMUTABLE;
2916
2917 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2918 ARRAY_SIZE(tgid_base_stuff));
2919
2920 d_set_d_op(dentry, &pid_dentry_operations);
2921
2922 d_add(dentry, inode);
2923 /* Close the race of the process dying before we return the dentry */
2924 if (pid_revalidate(dentry, NULL))
2925 error = NULL;
2926 out:
2927 return error;
2928 }
2929
2930 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2931 {
2932 struct dentry *result;
2933 struct task_struct *task;
2934 unsigned tgid;
2935 struct pid_namespace *ns;
2936
2937 result = proc_base_lookup(dir, dentry);
2938 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2939 goto out;
2940
2941 tgid = name_to_int(dentry);
2942 if (tgid == ~0U)
2943 goto out;
2944
2945 ns = dentry->d_sb->s_fs_info;
2946 rcu_read_lock();
2947 task = find_task_by_pid_ns(tgid, ns);
2948 if (task)
2949 get_task_struct(task);
2950 rcu_read_unlock();
2951 if (!task)
2952 goto out;
2953
2954 result = proc_pid_instantiate(dir, dentry, task, NULL);
2955 put_task_struct(task);
2956 out:
2957 return result;
2958 }
2959
2960 /*
2961 * Find the first task with tgid >= tgid
2962 *
2963 */
2964 struct tgid_iter {
2965 unsigned int tgid;
2966 struct task_struct *task;
2967 };
2968 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2969 {
2970 struct pid *pid;
2971
2972 if (iter.task)
2973 put_task_struct(iter.task);
2974 rcu_read_lock();
2975 retry:
2976 iter.task = NULL;
2977 pid = find_ge_pid(iter.tgid, ns);
2978 if (pid) {
2979 iter.tgid = pid_nr_ns(pid, ns);
2980 iter.task = pid_task(pid, PIDTYPE_PID);
2981 /* What we to know is if the pid we have find is the
2982 * pid of a thread_group_leader. Testing for task
2983 * being a thread_group_leader is the obvious thing
2984 * todo but there is a window when it fails, due to
2985 * the pid transfer logic in de_thread.
2986 *
2987 * So we perform the straight forward test of seeing
2988 * if the pid we have found is the pid of a thread
2989 * group leader, and don't worry if the task we have
2990 * found doesn't happen to be a thread group leader.
2991 * As we don't care in the case of readdir.
2992 */
2993 if (!iter.task || !has_group_leader_pid(iter.task)) {
2994 iter.tgid += 1;
2995 goto retry;
2996 }
2997 get_task_struct(iter.task);
2998 }
2999 rcu_read_unlock();
3000 return iter;
3001 }
3002
3003 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3004
3005 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3006 struct tgid_iter iter)
3007 {
3008 char name[PROC_NUMBUF];
3009 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3010 return proc_fill_cache(filp, dirent, filldir, name, len,
3011 proc_pid_instantiate, iter.task, NULL);
3012 }
3013
3014 /* for the /proc/ directory itself, after non-process stuff has been done */
3015 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3016 {
3017 unsigned int nr;
3018 struct task_struct *reaper;
3019 struct tgid_iter iter;
3020 struct pid_namespace *ns;
3021
3022 if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3023 goto out_no_task;
3024 nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3025
3026 reaper = get_proc_task(filp->f_path.dentry->d_inode);
3027 if (!reaper)
3028 goto out_no_task;
3029
3030 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3031 const struct pid_entry *p = &proc_base_stuff[nr];
3032 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3033 goto out;
3034 }
3035
3036 ns = filp->f_dentry->d_sb->s_fs_info;
3037 iter.task = NULL;
3038 iter.tgid = filp->f_pos - TGID_OFFSET;
3039 for (iter = next_tgid(ns, iter);
3040 iter.task;
3041 iter.tgid += 1, iter = next_tgid(ns, iter)) {
3042 filp->f_pos = iter.tgid + TGID_OFFSET;
3043 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
3044 put_task_struct(iter.task);
3045 goto out;
3046 }
3047 }
3048 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3049 out:
3050 put_task_struct(reaper);
3051 out_no_task:
3052 return 0;
3053 }
3054
3055 /*
3056 * Tasks
3057 */
3058 static const struct pid_entry tid_base_stuff[] = {
3059 DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3060 DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3061 DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3062 REG("environ", S_IRUSR, proc_environ_operations),
3063 INF("auxv", S_IRUSR, proc_pid_auxv),
3064 ONE("status", S_IRUGO, proc_pid_status),
3065 ONE("personality", S_IRUGO, proc_pid_personality),
3066 INF("limits", S_IRUGO, proc_pid_limits),
3067 #ifdef CONFIG_SCHED_DEBUG
3068 REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3069 #endif
3070 REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3071 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3072 INF("syscall", S_IRUGO, proc_pid_syscall),
3073 #endif
3074 INF("cmdline", S_IRUGO, proc_pid_cmdline),
3075 ONE("stat", S_IRUGO, proc_tid_stat),
3076 ONE("statm", S_IRUGO, proc_pid_statm),
3077 REG("maps", S_IRUGO, proc_maps_operations),
3078 #ifdef CONFIG_NUMA
3079 REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3080 #endif
3081 REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
3082 LNK("cwd", proc_cwd_link),
3083 LNK("root", proc_root_link),
3084 LNK("exe", proc_exe_link),
3085 REG("mounts", S_IRUGO, proc_mounts_operations),
3086 REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
3087 #ifdef CONFIG_PROC_PAGE_MONITOR
3088 REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3089 REG("smaps", S_IRUGO, proc_smaps_operations),
3090 REG("pagemap", S_IRUGO, proc_pagemap_operations),
3091 #endif
3092 #ifdef CONFIG_SECURITY
3093 DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3094 #endif
3095 #ifdef CONFIG_KALLSYMS
3096 INF("wchan", S_IRUGO, proc_pid_wchan),
3097 #endif
3098 #ifdef CONFIG_STACKTRACE
3099 ONE("stack", S_IRUGO, proc_pid_stack),
3100 #endif
3101 #ifdef CONFIG_SCHEDSTATS
3102 INF("schedstat", S_IRUGO, proc_pid_schedstat),
3103 #endif
3104 #ifdef CONFIG_LATENCYTOP
3105 REG("latency", S_IRUGO, proc_lstats_operations),
3106 #endif
3107 #ifdef CONFIG_PROC_PID_CPUSET
3108 REG("cpuset", S_IRUGO, proc_cpuset_operations),
3109 #endif
3110 #ifdef CONFIG_CGROUPS
3111 REG("cgroup", S_IRUGO, proc_cgroup_operations),
3112 #endif
3113 INF("oom_score", S_IRUGO, proc_oom_score),
3114 REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3115 REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3116 #ifdef CONFIG_AUDITSYSCALL
3117 REG("loginuid", S_IWUSR|S_IRUGO, proc_loginuid_operations),
3118 REG("sessionid", S_IRUGO, proc_sessionid_operations),
3119 #endif
3120 #ifdef CONFIG_FAULT_INJECTION
3121 REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3122 #endif
3123 #ifdef CONFIG_TASK_IO_ACCOUNTING
3124 INF("io", S_IRUSR, proc_tid_io_accounting),
3125 #endif
3126 #ifdef CONFIG_HARDWALL
3127 INF("hardwall", S_IRUGO, proc_pid_hardwall),
3128 #endif
3129 };
3130
3131 static int proc_tid_base_readdir(struct file * filp,
3132 void * dirent, filldir_t filldir)
3133 {
3134 return proc_pident_readdir(filp,dirent,filldir,
3135 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3136 }
3137
3138 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
3139 return proc_pident_lookup(dir, dentry,
3140 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3141 }
3142
3143 static const struct file_operations proc_tid_base_operations = {
3144 .read = generic_read_dir,
3145 .readdir = proc_tid_base_readdir,
3146 .llseek = default_llseek,
3147 };
3148
3149 static const struct inode_operations proc_tid_base_inode_operations = {
3150 .lookup = proc_tid_base_lookup,
3151 .getattr = pid_getattr,
3152 .setattr = proc_setattr,
3153 };
3154
3155 static struct dentry *proc_task_instantiate(struct inode *dir,
3156 struct dentry *dentry, struct task_struct *task, const void *ptr)
3157 {
3158 struct dentry *error = ERR_PTR(-ENOENT);
3159 struct inode *inode;
3160 inode = proc_pid_make_inode(dir->i_sb, task);
3161
3162 if (!inode)
3163 goto out;
3164 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3165 inode->i_op = &proc_tid_base_inode_operations;
3166 inode->i_fop = &proc_tid_base_operations;
3167 inode->i_flags|=S_IMMUTABLE;
3168
3169 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3170 ARRAY_SIZE(tid_base_stuff));
3171
3172 d_set_d_op(dentry, &pid_dentry_operations);
3173
3174 d_add(dentry, inode);
3175 /* Close the race of the process dying before we return the dentry */
3176 if (pid_revalidate(dentry, NULL))
3177 error = NULL;
3178 out:
3179 return error;
3180 }
3181
3182 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3183 {
3184 struct dentry *result = ERR_PTR(-ENOENT);
3185 struct task_struct *task;
3186 struct task_struct *leader = get_proc_task(dir);
3187 unsigned tid;
3188 struct pid_namespace *ns;
3189
3190 if (!leader)
3191 goto out_no_task;
3192
3193 tid = name_to_int(dentry);
3194 if (tid == ~0U)
3195 goto out;
3196
3197 ns = dentry->d_sb->s_fs_info;
3198 rcu_read_lock();
3199 task = find_task_by_pid_ns(tid, ns);
3200 if (task)
3201 get_task_struct(task);
3202 rcu_read_unlock();
3203 if (!task)
3204 goto out;
3205 if (!same_thread_group(leader, task))
3206 goto out_drop_task;
3207
3208 result = proc_task_instantiate(dir, dentry, task, NULL);
3209 out_drop_task:
3210 put_task_struct(task);
3211 out:
3212 put_task_struct(leader);
3213 out_no_task:
3214 return result;
3215 }
3216
3217 /*
3218 * Find the first tid of a thread group to return to user space.
3219 *
3220 * Usually this is just the thread group leader, but if the users
3221 * buffer was too small or there was a seek into the middle of the
3222 * directory we have more work todo.
3223 *
3224 * In the case of a short read we start with find_task_by_pid.
3225 *
3226 * In the case of a seek we start with the leader and walk nr
3227 * threads past it.
3228 */
3229 static struct task_struct *first_tid(struct task_struct *leader,
3230 int tid, int nr, struct pid_namespace *ns)
3231 {
3232 struct task_struct *pos;
3233
3234 rcu_read_lock();
3235 /* Attempt to start with the pid of a thread */
3236 if (tid && (nr > 0)) {
3237 pos = find_task_by_pid_ns(tid, ns);
3238 if (pos && (pos->group_leader == leader))
3239 goto found;
3240 }
3241
3242 /* If nr exceeds the number of threads there is nothing todo */
3243 pos = NULL;
3244 if (nr && nr >= get_nr_threads(leader))
3245 goto out;
3246
3247 /* If we haven't found our starting place yet start
3248 * with the leader and walk nr threads forward.
3249 */
3250 for (pos = leader; nr > 0; --nr) {
3251 pos = next_thread(pos);
3252 if (pos == leader) {
3253 pos = NULL;
3254 goto out;
3255 }
3256 }
3257 found:
3258 get_task_struct(pos);
3259 out:
3260 rcu_read_unlock();
3261 return pos;
3262 }
3263
3264 /*
3265 * Find the next thread in the thread list.
3266 * Return NULL if there is an error or no next thread.
3267 *
3268 * The reference to the input task_struct is released.
3269 */
3270 static struct task_struct *next_tid(struct task_struct *start)
3271 {
3272 struct task_struct *pos = NULL;
3273 rcu_read_lock();
3274 if (pid_alive(start)) {
3275 pos = next_thread(start);
3276 if (thread_group_leader(pos))
3277 pos = NULL;
3278 else
3279 get_task_struct(pos);
3280 }
3281 rcu_read_unlock();
3282 put_task_struct(start);
3283 return pos;
3284 }
3285
3286 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3287 struct task_struct *task, int tid)
3288 {
3289 char name[PROC_NUMBUF];
3290 int len = snprintf(name, sizeof(name), "%d", tid);
3291 return proc_fill_cache(filp, dirent, filldir, name, len,
3292 proc_task_instantiate, task, NULL);
3293 }
3294
3295 /* for the /proc/TGID/task/ directories */
3296 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3297 {
3298 struct dentry *dentry = filp->f_path.dentry;
3299 struct inode *inode = dentry->d_inode;
3300 struct task_struct *leader = NULL;
3301 struct task_struct *task;
3302 int retval = -ENOENT;
3303 ino_t ino;
3304 int tid;
3305 struct pid_namespace *ns;
3306
3307 task = get_proc_task(inode);
3308 if (!task)
3309 goto out_no_task;
3310 rcu_read_lock();
3311 if (pid_alive(task)) {
3312 leader = task->group_leader;
3313 get_task_struct(leader);
3314 }
3315 rcu_read_unlock();
3316 put_task_struct(task);
3317 if (!leader)
3318 goto out_no_task;
3319 retval = 0;
3320
3321 switch ((unsigned long)filp->f_pos) {
3322 case 0:
3323 ino = inode->i_ino;
3324 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3325 goto out;
3326 filp->f_pos++;
3327 /* fall through */
3328 case 1:
3329 ino = parent_ino(dentry);
3330 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3331 goto out;
3332 filp->f_pos++;
3333 /* fall through */
3334 }
3335
3336 /* f_version caches the tgid value that the last readdir call couldn't
3337 * return. lseek aka telldir automagically resets f_version to 0.
3338 */
3339 ns = filp->f_dentry->d_sb->s_fs_info;
3340 tid = (int)filp->f_version;
3341 filp->f_version = 0;
3342 for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3343 task;
3344 task = next_tid(task), filp->f_pos++) {
3345 tid = task_pid_nr_ns(task, ns);
3346 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3347 /* returning this tgid failed, save it as the first
3348 * pid for the next readir call */
3349 filp->f_version = (u64)tid;
3350 put_task_struct(task);
3351 break;
3352 }
3353 }
3354 out:
3355 put_task_struct(leader);
3356 out_no_task:
3357 return retval;
3358 }
3359
3360 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3361 {
3362 struct inode *inode = dentry->d_inode;
3363 struct task_struct *p = get_proc_task(inode);
3364 generic_fillattr(inode, stat);
3365
3366 if (p) {
3367 stat->nlink += get_nr_threads(p);
3368 put_task_struct(p);
3369 }
3370
3371 return 0;
3372 }
3373
3374 static const struct inode_operations proc_task_inode_operations = {
3375 .lookup = proc_task_lookup,
3376 .getattr = proc_task_getattr,
3377 .setattr = proc_setattr,
3378 };
3379
3380 static const struct file_operations proc_task_operations = {
3381 .read = generic_read_dir,
3382 .readdir = proc_task_readdir,
3383 .llseek = default_llseek,
3384 };
Linux with added FPC-III support