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