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Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / proc / base.c
blobb5918ae8ca79a7823bd6a4d3eb0ecfc0b08d30f6
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/resource.h>
69 #include <linux/module.h>
70 #include <linux/mount.h>
71 #include <linux/security.h>
72 #include <linux/ptrace.h>
73 #include <linux/tracehook.h>
74 #include <linux/cgroup.h>
75 #include <linux/cpuset.h>
76 #include <linux/audit.h>
77 #include <linux/poll.h>
78 #include <linux/nsproxy.h>
79 #include <linux/oom.h>
80 #include <linux/elf.h>
81 #include <linux/pid_namespace.h>
82 #include "internal.h"
83
84 /* NOTE:
85 * Implementing inode permission operations in /proc is almost
86 * certainly an error. Permission checks need to happen during
87 * each system call not at open time. The reason is that most of
88 * what we wish to check for permissions in /proc varies at runtime.
89 *
90 * The classic example of a problem is opening file descriptors
91 * in /proc for a task before it execs a suid executable.
92 */
93
94 struct pid_entry {
95 char *name;
96 int len;
97 mode_t mode;
98 const struct inode_operations *iop;
99 const struct file_operations *fop;
100 union proc_op op;
101 };
102
103 #define NOD(NAME, MODE, IOP, FOP, OP) { \
104 .name = (NAME), \
105 .len = sizeof(NAME) - 1, \
106 .mode = MODE, \
107 .iop = IOP, \
108 .fop = FOP, \
109 .op = OP, \
110 }
111
112 #define DIR(NAME, MODE, OTYPE) \
113 NOD(NAME, (S_IFDIR|(MODE)), \
114 &proc_##OTYPE##_inode_operations, &proc_##OTYPE##_operations, \
115 {} )
116 #define LNK(NAME, OTYPE) \
117 NOD(NAME, (S_IFLNK|S_IRWXUGO), \
118 &proc_pid_link_inode_operations, NULL, \
119 { .proc_get_link = &proc_##OTYPE##_link } )
120 #define REG(NAME, MODE, OTYPE) \
121 NOD(NAME, (S_IFREG|(MODE)), NULL, \
122 &proc_##OTYPE##_operations, {})
123 #define INF(NAME, MODE, OTYPE) \
124 NOD(NAME, (S_IFREG|(MODE)), \
125 NULL, &proc_info_file_operations, \
126 { .proc_read = &proc_##OTYPE } )
127 #define ONE(NAME, MODE, OTYPE) \
128 NOD(NAME, (S_IFREG|(MODE)), \
129 NULL, &proc_single_file_operations, \
130 { .proc_show = &proc_##OTYPE } )
131
132 /*
133 * Count the number of hardlinks for the pid_entry table, excluding the .
134 * and .. links.
135 */
136 static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
137 unsigned int n)
138 {
139 unsigned int i;
140 unsigned int count;
141
142 count = 0;
143 for (i = 0; i < n; ++i) {
144 if (S_ISDIR(entries[i].mode))
145 ++count;
146 }
147
148 return count;
149 }
150
151 static struct fs_struct *get_fs_struct(struct task_struct *task)
152 {
153 struct fs_struct *fs;
154 task_lock(task);
155 fs = task->fs;
156 if(fs)
157 atomic_inc(&fs->count);
158 task_unlock(task);
159 return fs;
160 }
161
162 static int get_nr_threads(struct task_struct *tsk)
163 {
164 unsigned long flags;
165 int count = 0;
166
167 if (lock_task_sighand(tsk, &flags)) {
168 count = atomic_read(&tsk->signal->count);
169 unlock_task_sighand(tsk, &flags);
170 }
171 return count;
172 }
173
174 static int proc_cwd_link(struct inode *inode, struct path *path)
175 {
176 struct task_struct *task = get_proc_task(inode);
177 struct fs_struct *fs = NULL;
178 int result = -ENOENT;
179
180 if (task) {
181 fs = get_fs_struct(task);
182 put_task_struct(task);
183 }
184 if (fs) {
185 read_lock(&fs->lock);
186 *path = fs->pwd;
187 path_get(&fs->pwd);
188 read_unlock(&fs->lock);
189 result = 0;
190 put_fs_struct(fs);
191 }
192 return result;
193 }
194
195 static int proc_root_link(struct inode *inode, struct path *path)
196 {
197 struct task_struct *task = get_proc_task(inode);
198 struct fs_struct *fs = NULL;
199 int result = -ENOENT;
200
201 if (task) {
202 fs = get_fs_struct(task);
203 put_task_struct(task);
204 }
205 if (fs) {
206 read_lock(&fs->lock);
207 *path = fs->root;
208 path_get(&fs->root);
209 read_unlock(&fs->lock);
210 result = 0;
211 put_fs_struct(fs);
212 }
213 return result;
214 }
215
216 /*
217 * Return zero if current may access user memory in @task, -error if not.
218 */
219 static int check_mem_permission(struct task_struct *task)
220 {
221 /*
222 * A task can always look at itself, in case it chooses
223 * to use system calls instead of load instructions.
224 */
225 if (task == current)
226 return 0;
227
228 /*
229 * If current is actively ptrace'ing, and would also be
230 * permitted to freshly attach with ptrace now, permit it.
231 */
232 if (task_is_stopped_or_traced(task)) {
233 int match;
234 rcu_read_lock();
235 match = (tracehook_tracer_task(task) == current);
236 rcu_read_unlock();
237 if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
238 return 0;
239 }
240
241 /*
242 * Noone else is allowed.
243 */
244 return -EPERM;
245 }
246
247 struct mm_struct *mm_for_maps(struct task_struct *task)
248 {
249 struct mm_struct *mm = get_task_mm(task);
250 if (!mm)
251 return NULL;
252 down_read(&mm->mmap_sem);
253 task_lock(task);
254 if (task->mm != mm)
255 goto out;
256 if (task->mm != current->mm &&
257 __ptrace_may_access(task, PTRACE_MODE_READ) < 0)
258 goto out;
259 task_unlock(task);
260 return mm;
261 out:
262 task_unlock(task);
263 up_read(&mm->mmap_sem);
264 mmput(mm);
265 return NULL;
266 }
267
268 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
269 {
270 int res = 0;
271 unsigned int len;
272 struct mm_struct *mm = get_task_mm(task);
273 if (!mm)
274 goto out;
275 if (!mm->arg_end)
276 goto out_mm; /* Shh! No looking before we're done */
277
278 len = mm->arg_end - mm->arg_start;
279
280 if (len > PAGE_SIZE)
281 len = PAGE_SIZE;
282
283 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
284
285 // If the nul at the end of args has been overwritten, then
286 // assume application is using setproctitle(3).
287 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
288 len = strnlen(buffer, res);
289 if (len < res) {
290 res = len;
291 } else {
292 len = mm->env_end - mm->env_start;
293 if (len > PAGE_SIZE - res)
294 len = PAGE_SIZE - res;
295 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
296 res = strnlen(buffer, res);
297 }
298 }
299 out_mm:
300 mmput(mm);
301 out:
302 return res;
303 }
304
305 static int proc_pid_auxv(struct task_struct *task, char *buffer)
306 {
307 int res = 0;
308 struct mm_struct *mm = get_task_mm(task);
309 if (mm) {
310 unsigned int nwords = 0;
311 do
312 nwords += 2;
313 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
314 res = nwords * sizeof(mm->saved_auxv[0]);
315 if (res > PAGE_SIZE)
316 res = PAGE_SIZE;
317 memcpy(buffer, mm->saved_auxv, res);
318 mmput(mm);
319 }
320 return res;
321 }
322
323
324 #ifdef CONFIG_KALLSYMS
325 /*
326 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
327 * Returns the resolved symbol. If that fails, simply return the address.
328 */
329 static int proc_pid_wchan(struct task_struct *task, char *buffer)
330 {
331 unsigned long wchan;
332 char symname[KSYM_NAME_LEN];
333
334 wchan = get_wchan(task);
335
336 if (lookup_symbol_name(wchan, symname) < 0)
337 return sprintf(buffer, "%lu", wchan);
338 else
339 return sprintf(buffer, "%s", symname);
340 }
341 #endif /* CONFIG_KALLSYMS */
342
343 #ifdef CONFIG_SCHEDSTATS
344 /*
345 * Provides /proc/PID/schedstat
346 */
347 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
348 {
349 return sprintf(buffer, "%llu %llu %lu\n",
350 task->sched_info.cpu_time,
351 task->sched_info.run_delay,
352 task->sched_info.pcount);
353 }
354 #endif
355
356 #ifdef CONFIG_LATENCYTOP
357 static int lstats_show_proc(struct seq_file *m, void *v)
358 {
359 int i;
360 struct inode *inode = m->private;
361 struct task_struct *task = get_proc_task(inode);
362
363 if (!task)
364 return -ESRCH;
365 seq_puts(m, "Latency Top version : v0.1\n");
366 for (i = 0; i < 32; i++) {
367 if (task->latency_record[i].backtrace[0]) {
368 int q;
369 seq_printf(m, "%i %li %li ",
370 task->latency_record[i].count,
371 task->latency_record[i].time,
372 task->latency_record[i].max);
373 for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
374 char sym[KSYM_NAME_LEN];
375 char *c;
376 if (!task->latency_record[i].backtrace[q])
377 break;
378 if (task->latency_record[i].backtrace[q] == ULONG_MAX)
379 break;
380 sprint_symbol(sym, task->latency_record[i].backtrace[q]);
381 c = strchr(sym, '+');
382 if (c)
383 *c = 0;
384 seq_printf(m, "%s ", sym);
385 }
386 seq_printf(m, "\n");
387 }
388
389 }
390 put_task_struct(task);
391 return 0;
392 }
393
394 static int lstats_open(struct inode *inode, struct file *file)
395 {
396 return single_open(file, lstats_show_proc, inode);
397 }
398
399 static ssize_t lstats_write(struct file *file, const char __user *buf,
400 size_t count, loff_t *offs)
401 {
402 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
403
404 if (!task)
405 return -ESRCH;
406 clear_all_latency_tracing(task);
407 put_task_struct(task);
408
409 return count;
410 }
411
412 static const struct file_operations proc_lstats_operations = {
413 .open = lstats_open,
414 .read = seq_read,
415 .write = lstats_write,
416 .llseek = seq_lseek,
417 .release = single_release,
418 };
419
420 #endif
421
422 /* The badness from the OOM killer */
423 unsigned long badness(struct task_struct *p, unsigned long uptime);
424 static int proc_oom_score(struct task_struct *task, char *buffer)
425 {
426 unsigned long points;
427 struct timespec uptime;
428
429 do_posix_clock_monotonic_gettime(&uptime);
430 read_lock(&tasklist_lock);
431 points = badness(task, uptime.tv_sec);
432 read_unlock(&tasklist_lock);
433 return sprintf(buffer, "%lu\n", points);
434 }
435
436 struct limit_names {
437 char *name;
438 char *unit;
439 };
440
441 static const struct limit_names lnames[RLIM_NLIMITS] = {
442 [RLIMIT_CPU] = {"Max cpu time", "ms"},
443 [RLIMIT_FSIZE] = {"Max file size", "bytes"},
444 [RLIMIT_DATA] = {"Max data size", "bytes"},
445 [RLIMIT_STACK] = {"Max stack size", "bytes"},
446 [RLIMIT_CORE] = {"Max core file size", "bytes"},
447 [RLIMIT_RSS] = {"Max resident set", "bytes"},
448 [RLIMIT_NPROC] = {"Max processes", "processes"},
449 [RLIMIT_NOFILE] = {"Max open files", "files"},
450 [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
451 [RLIMIT_AS] = {"Max address space", "bytes"},
452 [RLIMIT_LOCKS] = {"Max file locks", "locks"},
453 [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
454 [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
455 [RLIMIT_NICE] = {"Max nice priority", NULL},
456 [RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
457 [RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
458 };
459
460 /* Display limits for a process */
461 static int proc_pid_limits(struct task_struct *task, char *buffer)
462 {
463 unsigned int i;
464 int count = 0;
465 unsigned long flags;
466 char *bufptr = buffer;
467
468 struct rlimit rlim[RLIM_NLIMITS];
469
470 if (!lock_task_sighand(task, &flags))
471 return 0;
472 memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
473 unlock_task_sighand(task, &flags);
474
475 /*
476 * print the file header
477 */
478 count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
479 "Limit", "Soft Limit", "Hard Limit", "Units");
480
481 for (i = 0; i < RLIM_NLIMITS; i++) {
482 if (rlim[i].rlim_cur == RLIM_INFINITY)
483 count += sprintf(&bufptr[count], "%-25s %-20s ",
484 lnames[i].name, "unlimited");
485 else
486 count += sprintf(&bufptr[count], "%-25s %-20lu ",
487 lnames[i].name, rlim[i].rlim_cur);
488
489 if (rlim[i].rlim_max == RLIM_INFINITY)
490 count += sprintf(&bufptr[count], "%-20s ", "unlimited");
491 else
492 count += sprintf(&bufptr[count], "%-20lu ",
493 rlim[i].rlim_max);
494
495 if (lnames[i].unit)
496 count += sprintf(&bufptr[count], "%-10s\n",
497 lnames[i].unit);
498 else
499 count += sprintf(&bufptr[count], "\n");
500 }
501
502 return count;
503 }
504
505 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
506 static int proc_pid_syscall(struct task_struct *task, char *buffer)
507 {
508 long nr;
509 unsigned long args[6], sp, pc;
510
511 if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
512 return sprintf(buffer, "running\n");
513
514 if (nr < 0)
515 return sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
516
517 return sprintf(buffer,
518 "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
519 nr,
520 args[0], args[1], args[2], args[3], args[4], args[5],
521 sp, pc);
522 }
523 #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
524
525 /************************************************************************/
526 /* Here the fs part begins */
527 /************************************************************************/
528
529 /* permission checks */
530 static int proc_fd_access_allowed(struct inode *inode)
531 {
532 struct task_struct *task;
533 int allowed = 0;
534 /* Allow access to a task's file descriptors if it is us or we
535 * may use ptrace attach to the process and find out that
536 * information.
537 */
538 task = get_proc_task(inode);
539 if (task) {
540 allowed = ptrace_may_access(task, PTRACE_MODE_READ);
541 put_task_struct(task);
542 }
543 return allowed;
544 }
545
546 static int proc_setattr(struct dentry *dentry, struct iattr *attr)
547 {
548 int error;
549 struct inode *inode = dentry->d_inode;
550
551 if (attr->ia_valid & ATTR_MODE)
552 return -EPERM;
553
554 error = inode_change_ok(inode, attr);
555 if (!error)
556 error = inode_setattr(inode, attr);
557 return error;
558 }
559
560 static const struct inode_operations proc_def_inode_operations = {
561 .setattr = proc_setattr,
562 };
563
564 static int mounts_open_common(struct inode *inode, struct file *file,
565 const struct seq_operations *op)
566 {
567 struct task_struct *task = get_proc_task(inode);
568 struct nsproxy *nsp;
569 struct mnt_namespace *ns = NULL;
570 struct fs_struct *fs = NULL;
571 struct path root;
572 struct proc_mounts *p;
573 int ret = -EINVAL;
574
575 if (task) {
576 rcu_read_lock();
577 nsp = task_nsproxy(task);
578 if (nsp) {
579 ns = nsp->mnt_ns;
580 if (ns)
581 get_mnt_ns(ns);
582 }
583 rcu_read_unlock();
584 if (ns)
585 fs = get_fs_struct(task);
586 put_task_struct(task);
587 }
588
589 if (!ns)
590 goto err;
591 if (!fs)
592 goto err_put_ns;
593
594 read_lock(&fs->lock);
595 root = fs->root;
596 path_get(&root);
597 read_unlock(&fs->lock);
598 put_fs_struct(fs);
599
600 ret = -ENOMEM;
601 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
602 if (!p)
603 goto err_put_path;
604
605 file->private_data = &p->m;
606 ret = seq_open(file, op);
607 if (ret)
608 goto err_free;
609
610 p->m.private = p;
611 p->ns = ns;
612 p->root = root;
613 p->event = ns->event;
614
615 return 0;
616
617 err_free:
618 kfree(p);
619 err_put_path:
620 path_put(&root);
621 err_put_ns:
622 put_mnt_ns(ns);
623 err:
624 return ret;
625 }
626
627 static int mounts_release(struct inode *inode, struct file *file)
628 {
629 struct proc_mounts *p = file->private_data;
630 path_put(&p->root);
631 put_mnt_ns(p->ns);
632 return seq_release(inode, file);
633 }
634
635 static unsigned mounts_poll(struct file *file, poll_table *wait)
636 {
637 struct proc_mounts *p = file->private_data;
638 struct mnt_namespace *ns = p->ns;
639 unsigned res = 0;
640
641 poll_wait(file, &ns->poll, wait);
642
643 spin_lock(&vfsmount_lock);
644 if (p->event != ns->event) {
645 p->event = ns->event;
646 res = POLLERR;
647 }
648 spin_unlock(&vfsmount_lock);
649
650 return res;
651 }
652
653 static int mounts_open(struct inode *inode, struct file *file)
654 {
655 return mounts_open_common(inode, file, &mounts_op);
656 }
657
658 static const struct file_operations proc_mounts_operations = {
659 .open = mounts_open,
660 .read = seq_read,
661 .llseek = seq_lseek,
662 .release = mounts_release,
663 .poll = mounts_poll,
664 };
665
666 static int mountinfo_open(struct inode *inode, struct file *file)
667 {
668 return mounts_open_common(inode, file, &mountinfo_op);
669 }
670
671 static const struct file_operations proc_mountinfo_operations = {
672 .open = mountinfo_open,
673 .read = seq_read,
674 .llseek = seq_lseek,
675 .release = mounts_release,
676 .poll = mounts_poll,
677 };
678
679 static int mountstats_open(struct inode *inode, struct file *file)
680 {
681 return mounts_open_common(inode, file, &mountstats_op);
682 }
683
684 static const struct file_operations proc_mountstats_operations = {
685 .open = mountstats_open,
686 .read = seq_read,
687 .llseek = seq_lseek,
688 .release = mounts_release,
689 };
690
691 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
692
693 static ssize_t proc_info_read(struct file * file, char __user * buf,
694 size_t count, loff_t *ppos)
695 {
696 struct inode * inode = file->f_path.dentry->d_inode;
697 unsigned long page;
698 ssize_t length;
699 struct task_struct *task = get_proc_task(inode);
700
701 length = -ESRCH;
702 if (!task)
703 goto out_no_task;
704
705 if (count > PROC_BLOCK_SIZE)
706 count = PROC_BLOCK_SIZE;
707
708 length = -ENOMEM;
709 if (!(page = __get_free_page(GFP_TEMPORARY)))
710 goto out;
711
712 length = PROC_I(inode)->op.proc_read(task, (char*)page);
713
714 if (length >= 0)
715 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
716 free_page(page);
717 out:
718 put_task_struct(task);
719 out_no_task:
720 return length;
721 }
722
723 static const struct file_operations proc_info_file_operations = {
724 .read = proc_info_read,
725 };
726
727 static int proc_single_show(struct seq_file *m, void *v)
728 {
729 struct inode *inode = m->private;
730 struct pid_namespace *ns;
731 struct pid *pid;
732 struct task_struct *task;
733 int ret;
734
735 ns = inode->i_sb->s_fs_info;
736 pid = proc_pid(inode);
737 task = get_pid_task(pid, PIDTYPE_PID);
738 if (!task)
739 return -ESRCH;
740
741 ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
742
743 put_task_struct(task);
744 return ret;
745 }
746
747 static int proc_single_open(struct inode *inode, struct file *filp)
748 {
749 int ret;
750 ret = single_open(filp, proc_single_show, NULL);
751 if (!ret) {
752 struct seq_file *m = filp->private_data;
753
754 m->private = inode;
755 }
756 return ret;
757 }
758
759 static const struct file_operations proc_single_file_operations = {
760 .open = proc_single_open,
761 .read = seq_read,
762 .llseek = seq_lseek,
763 .release = single_release,
764 };
765
766 static int mem_open(struct inode* inode, struct file* file)
767 {
768 file->private_data = (void*)((long)current->self_exec_id);
769 return 0;
770 }
771
772 static ssize_t mem_read(struct file * file, char __user * buf,
773 size_t count, loff_t *ppos)
774 {
775 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
776 char *page;
777 unsigned long src = *ppos;
778 int ret = -ESRCH;
779 struct mm_struct *mm;
780
781 if (!task)
782 goto out_no_task;
783
784 if (check_mem_permission(task))
785 goto out;
786
787 ret = -ENOMEM;
788 page = (char *)__get_free_page(GFP_TEMPORARY);
789 if (!page)
790 goto out;
791
792 ret = 0;
793
794 mm = get_task_mm(task);
795 if (!mm)
796 goto out_free;
797
798 ret = -EIO;
799
800 if (file->private_data != (void*)((long)current->self_exec_id))
801 goto out_put;
802
803 ret = 0;
804
805 while (count > 0) {
806 int this_len, retval;
807
808 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
809 retval = access_process_vm(task, src, page, this_len, 0);
810 if (!retval || check_mem_permission(task)) {
811 if (!ret)
812 ret = -EIO;
813 break;
814 }
815
816 if (copy_to_user(buf, page, retval)) {
817 ret = -EFAULT;
818 break;
819 }
820
821 ret += retval;
822 src += retval;
823 buf += retval;
824 count -= retval;
825 }
826 *ppos = src;
827
828 out_put:
829 mmput(mm);
830 out_free:
831 free_page((unsigned long) page);
832 out:
833 put_task_struct(task);
834 out_no_task:
835 return ret;
836 }
837
838 #define mem_write NULL
839
840 #ifndef mem_write
841 /* This is a security hazard */
842 static ssize_t mem_write(struct file * file, const char __user *buf,
843 size_t count, loff_t *ppos)
844 {
845 int copied;
846 char *page;
847 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
848 unsigned long dst = *ppos;
849
850 copied = -ESRCH;
851 if (!task)
852 goto out_no_task;
853
854 if (check_mem_permission(task))
855 goto out;
856
857 copied = -ENOMEM;
858 page = (char *)__get_free_page(GFP_TEMPORARY);
859 if (!page)
860 goto out;
861
862 copied = 0;
863 while (count > 0) {
864 int this_len, retval;
865
866 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
867 if (copy_from_user(page, buf, this_len)) {
868 copied = -EFAULT;
869 break;
870 }
871 retval = access_process_vm(task, dst, page, this_len, 1);
872 if (!retval) {
873 if (!copied)
874 copied = -EIO;
875 break;
876 }
877 copied += retval;
878 buf += retval;
879 dst += retval;
880 count -= retval;
881 }
882 *ppos = dst;
883 free_page((unsigned long) page);
884 out:
885 put_task_struct(task);
886 out_no_task:
887 return copied;
888 }
889 #endif
890
891 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
892 {
893 switch (orig) {
894 case 0:
895 file->f_pos = offset;
896 break;
897 case 1:
898 file->f_pos += offset;
899 break;
900 default:
901 return -EINVAL;
902 }
903 force_successful_syscall_return();
904 return file->f_pos;
905 }
906
907 static const struct file_operations proc_mem_operations = {
908 .llseek = mem_lseek,
909 .read = mem_read,
910 .write = mem_write,
911 .open = mem_open,
912 };
913
914 static ssize_t environ_read(struct file *file, char __user *buf,
915 size_t count, loff_t *ppos)
916 {
917 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
918 char *page;
919 unsigned long src = *ppos;
920 int ret = -ESRCH;
921 struct mm_struct *mm;
922
923 if (!task)
924 goto out_no_task;
925
926 if (!ptrace_may_access(task, PTRACE_MODE_READ))
927 goto out;
928
929 ret = -ENOMEM;
930 page = (char *)__get_free_page(GFP_TEMPORARY);
931 if (!page)
932 goto out;
933
934 ret = 0;
935
936 mm = get_task_mm(task);
937 if (!mm)
938 goto out_free;
939
940 while (count > 0) {
941 int this_len, retval, max_len;
942
943 this_len = mm->env_end - (mm->env_start + src);
944
945 if (this_len <= 0)
946 break;
947
948 max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
949 this_len = (this_len > max_len) ? max_len : this_len;
950
951 retval = access_process_vm(task, (mm->env_start + src),
952 page, this_len, 0);
953
954 if (retval <= 0) {
955 ret = retval;
956 break;
957 }
958
959 if (copy_to_user(buf, page, retval)) {
960 ret = -EFAULT;
961 break;
962 }
963
964 ret += retval;
965 src += retval;
966 buf += retval;
967 count -= retval;
968 }
969 *ppos = src;
970
971 mmput(mm);
972 out_free:
973 free_page((unsigned long) page);
974 out:
975 put_task_struct(task);
976 out_no_task:
977 return ret;
978 }
979
980 static const struct file_operations proc_environ_operations = {
981 .read = environ_read,
982 };
983
984 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
985 size_t count, loff_t *ppos)
986 {
987 struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
988 char buffer[PROC_NUMBUF];
989 size_t len;
990 int oom_adjust;
991
992 if (!task)
993 return -ESRCH;
994 oom_adjust = task->oomkilladj;
995 put_task_struct(task);
996
997 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
998
999 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1000 }
1001
1002 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1003 size_t count, loff_t *ppos)
1004 {
1005 struct task_struct *task;
1006 char buffer[PROC_NUMBUF], *end;
1007 int oom_adjust;
1008
1009 memset(buffer, 0, sizeof(buffer));
1010 if (count > sizeof(buffer) - 1)
1011 count = sizeof(buffer) - 1;
1012 if (copy_from_user(buffer, buf, count))
1013 return -EFAULT;
1014 oom_adjust = simple_strtol(buffer, &end, 0);
1015 if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1016 oom_adjust != OOM_DISABLE)
1017 return -EINVAL;
1018 if (*end == '\n')
1019 end++;
1020 task = get_proc_task(file->f_path.dentry->d_inode);
1021 if (!task)
1022 return -ESRCH;
1023 if (oom_adjust < task->oomkilladj && !capable(CAP_SYS_RESOURCE)) {
1024 put_task_struct(task);
1025 return -EACCES;
1026 }
1027 task->oomkilladj = oom_adjust;
1028 put_task_struct(task);
1029 if (end - buffer == 0)
1030 return -EIO;
1031 return end - buffer;
1032 }
1033
1034 static const struct file_operations proc_oom_adjust_operations = {
1035 .read = oom_adjust_read,
1036 .write = oom_adjust_write,
1037 };
1038
1039 #ifdef CONFIG_AUDITSYSCALL
1040 #define TMPBUFLEN 21
1041 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1042 size_t count, loff_t *ppos)
1043 {
1044 struct inode * inode = file->f_path.dentry->d_inode;
1045 struct task_struct *task = get_proc_task(inode);
1046 ssize_t length;
1047 char tmpbuf[TMPBUFLEN];
1048
1049 if (!task)
1050 return -ESRCH;
1051 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1052 audit_get_loginuid(task));
1053 put_task_struct(task);
1054 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1055 }
1056
1057 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1058 size_t count, loff_t *ppos)
1059 {
1060 struct inode * inode = file->f_path.dentry->d_inode;
1061 char *page, *tmp;
1062 ssize_t length;
1063 uid_t loginuid;
1064
1065 if (!capable(CAP_AUDIT_CONTROL))
1066 return -EPERM;
1067
1068 if (current != pid_task(proc_pid(inode), PIDTYPE_PID))
1069 return -EPERM;
1070
1071 if (count >= PAGE_SIZE)
1072 count = PAGE_SIZE - 1;
1073
1074 if (*ppos != 0) {
1075 /* No partial writes. */
1076 return -EINVAL;
1077 }
1078 page = (char*)__get_free_page(GFP_TEMPORARY);
1079 if (!page)
1080 return -ENOMEM;
1081 length = -EFAULT;
1082 if (copy_from_user(page, buf, count))
1083 goto out_free_page;
1084
1085 page[count] = '\0';
1086 loginuid = simple_strtoul(page, &tmp, 10);
1087 if (tmp == page) {
1088 length = -EINVAL;
1089 goto out_free_page;
1090
1091 }
1092 length = audit_set_loginuid(current, loginuid);
1093 if (likely(length == 0))
1094 length = count;
1095
1096 out_free_page:
1097 free_page((unsigned long) page);
1098 return length;
1099 }
1100
1101 static const struct file_operations proc_loginuid_operations = {
1102 .read = proc_loginuid_read,
1103 .write = proc_loginuid_write,
1104 };
1105
1106 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1107 size_t count, loff_t *ppos)
1108 {
1109 struct inode * inode = file->f_path.dentry->d_inode;
1110 struct task_struct *task = get_proc_task(inode);
1111 ssize_t length;
1112 char tmpbuf[TMPBUFLEN];
1113
1114 if (!task)
1115 return -ESRCH;
1116 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1117 audit_get_sessionid(task));
1118 put_task_struct(task);
1119 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1120 }
1121
1122 static const struct file_operations proc_sessionid_operations = {
1123 .read = proc_sessionid_read,
1124 };
1125 #endif
1126
1127 #ifdef CONFIG_FAULT_INJECTION
1128 static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1129 size_t count, loff_t *ppos)
1130 {
1131 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1132 char buffer[PROC_NUMBUF];
1133 size_t len;
1134 int make_it_fail;
1135
1136 if (!task)
1137 return -ESRCH;
1138 make_it_fail = task->make_it_fail;
1139 put_task_struct(task);
1140
1141 len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1142
1143 return simple_read_from_buffer(buf, count, ppos, buffer, len);
1144 }
1145
1146 static ssize_t proc_fault_inject_write(struct file * file,
1147 const char __user * buf, size_t count, loff_t *ppos)
1148 {
1149 struct task_struct *task;
1150 char buffer[PROC_NUMBUF], *end;
1151 int make_it_fail;
1152
1153 if (!capable(CAP_SYS_RESOURCE))
1154 return -EPERM;
1155 memset(buffer, 0, sizeof(buffer));
1156 if (count > sizeof(buffer) - 1)
1157 count = sizeof(buffer) - 1;
1158 if (copy_from_user(buffer, buf, count))
1159 return -EFAULT;
1160 make_it_fail = simple_strtol(buffer, &end, 0);
1161 if (*end == '\n')
1162 end++;
1163 task = get_proc_task(file->f_dentry->d_inode);
1164 if (!task)
1165 return -ESRCH;
1166 task->make_it_fail = make_it_fail;
1167 put_task_struct(task);
1168 if (end - buffer == 0)
1169 return -EIO;
1170 return end - buffer;
1171 }
1172
1173 static const struct file_operations proc_fault_inject_operations = {
1174 .read = proc_fault_inject_read,
1175 .write = proc_fault_inject_write,
1176 };
1177 #endif
1178
1179
1180 #ifdef CONFIG_SCHED_DEBUG
1181 /*
1182 * Print out various scheduling related per-task fields:
1183 */
1184 static int sched_show(struct seq_file *m, void *v)
1185 {
1186 struct inode *inode = m->private;
1187 struct task_struct *p;
1188
1189 WARN_ON(!inode);
1190
1191 p = get_proc_task(inode);
1192 if (!p)
1193 return -ESRCH;
1194 proc_sched_show_task(p, m);
1195
1196 put_task_struct(p);
1197
1198 return 0;
1199 }
1200
1201 static ssize_t
1202 sched_write(struct file *file, const char __user *buf,
1203 size_t count, loff_t *offset)
1204 {
1205 struct inode *inode = file->f_path.dentry->d_inode;
1206 struct task_struct *p;
1207
1208 WARN_ON(!inode);
1209
1210 p = get_proc_task(inode);
1211 if (!p)
1212 return -ESRCH;
1213 proc_sched_set_task(p);
1214
1215 put_task_struct(p);
1216
1217 return count;
1218 }
1219
1220 static int sched_open(struct inode *inode, struct file *filp)
1221 {
1222 int ret;
1223
1224 ret = single_open(filp, sched_show, NULL);
1225 if (!ret) {
1226 struct seq_file *m = filp->private_data;
1227
1228 m->private = inode;
1229 }
1230 return ret;
1231 }
1232
1233 static const struct file_operations proc_pid_sched_operations = {
1234 .open = sched_open,
1235 .read = seq_read,
1236 .write = sched_write,
1237 .llseek = seq_lseek,
1238 .release = single_release,
1239 };
1240
1241 #endif
1242
1243 /*
1244 * We added or removed a vma mapping the executable. The vmas are only mapped
1245 * during exec and are not mapped with the mmap system call.
1246 * Callers must hold down_write() on the mm's mmap_sem for these
1247 */
1248 void added_exe_file_vma(struct mm_struct *mm)
1249 {
1250 mm->num_exe_file_vmas++;
1251 }
1252
1253 void removed_exe_file_vma(struct mm_struct *mm)
1254 {
1255 mm->num_exe_file_vmas--;
1256 if ((mm->num_exe_file_vmas == 0) && mm->exe_file){
1257 fput(mm->exe_file);
1258 mm->exe_file = NULL;
1259 }
1260
1261 }
1262
1263 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
1264 {
1265 if (new_exe_file)
1266 get_file(new_exe_file);
1267 if (mm->exe_file)
1268 fput(mm->exe_file);
1269 mm->exe_file = new_exe_file;
1270 mm->num_exe_file_vmas = 0;
1271 }
1272
1273 struct file *get_mm_exe_file(struct mm_struct *mm)
1274 {
1275 struct file *exe_file;
1276
1277 /* We need mmap_sem to protect against races with removal of
1278 * VM_EXECUTABLE vmas */
1279 down_read(&mm->mmap_sem);
1280 exe_file = mm->exe_file;
1281 if (exe_file)
1282 get_file(exe_file);
1283 up_read(&mm->mmap_sem);
1284 return exe_file;
1285 }
1286
1287 void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm)
1288 {
1289 /* It's safe to write the exe_file pointer without exe_file_lock because
1290 * this is called during fork when the task is not yet in /proc */
1291 newmm->exe_file = get_mm_exe_file(oldmm);
1292 }
1293
1294 static int proc_exe_link(struct inode *inode, struct path *exe_path)
1295 {
1296 struct task_struct *task;
1297 struct mm_struct *mm;
1298 struct file *exe_file;
1299
1300 task = get_proc_task(inode);
1301 if (!task)
1302 return -ENOENT;
1303 mm = get_task_mm(task);
1304 put_task_struct(task);
1305 if (!mm)
1306 return -ENOENT;
1307 exe_file = get_mm_exe_file(mm);
1308 mmput(mm);
1309 if (exe_file) {
1310 *exe_path = exe_file->f_path;
1311 path_get(&exe_file->f_path);
1312 fput(exe_file);
1313 return 0;
1314 } else
1315 return -ENOENT;
1316 }
1317
1318 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1319 {
1320 struct inode *inode = dentry->d_inode;
1321 int error = -EACCES;
1322
1323 /* We don't need a base pointer in the /proc filesystem */
1324 path_put(&nd->path);
1325
1326 /* Are we allowed to snoop on the tasks file descriptors? */
1327 if (!proc_fd_access_allowed(inode))
1328 goto out;
1329
1330 error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
1331 nd->last_type = LAST_BIND;
1332 out:
1333 return ERR_PTR(error);
1334 }
1335
1336 static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1337 {
1338 char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1339 char *pathname;
1340 int len;
1341
1342 if (!tmp)
1343 return -ENOMEM;
1344
1345 pathname = d_path(path, tmp, PAGE_SIZE);
1346 len = PTR_ERR(pathname);
1347 if (IS_ERR(pathname))
1348 goto out;
1349 len = tmp + PAGE_SIZE - 1 - pathname;
1350
1351 if (len > buflen)
1352 len = buflen;
1353 if (copy_to_user(buffer, pathname, len))
1354 len = -EFAULT;
1355 out:
1356 free_page((unsigned long)tmp);
1357 return len;
1358 }
1359
1360 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1361 {
1362 int error = -EACCES;
1363 struct inode *inode = dentry->d_inode;
1364 struct path path;
1365
1366 /* Are we allowed to snoop on the tasks file descriptors? */
1367 if (!proc_fd_access_allowed(inode))
1368 goto out;
1369
1370 error = PROC_I(inode)->op.proc_get_link(inode, &path);
1371 if (error)
1372 goto out;
1373
1374 error = do_proc_readlink(&path, buffer, buflen);
1375 path_put(&path);
1376 out:
1377 return error;
1378 }
1379
1380 static const struct inode_operations proc_pid_link_inode_operations = {
1381 .readlink = proc_pid_readlink,
1382 .follow_link = proc_pid_follow_link,
1383 .setattr = proc_setattr,
1384 };
1385
1386
1387 /* building an inode */
1388
1389 static int task_dumpable(struct task_struct *task)
1390 {
1391 int dumpable = 0;
1392 struct mm_struct *mm;
1393
1394 task_lock(task);
1395 mm = task->mm;
1396 if (mm)
1397 dumpable = get_dumpable(mm);
1398 task_unlock(task);
1399 if(dumpable == 1)
1400 return 1;
1401 return 0;
1402 }
1403
1404
1405 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
1406 {
1407 struct inode * inode;
1408 struct proc_inode *ei;
1409
1410 /* We need a new inode */
1411
1412 inode = new_inode(sb);
1413 if (!inode)
1414 goto out;
1415
1416 /* Common stuff */
1417 ei = PROC_I(inode);
1418 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1419 inode->i_op = &proc_def_inode_operations;
1420
1421 /*
1422 * grab the reference to task.
1423 */
1424 ei->pid = get_task_pid(task, PIDTYPE_PID);
1425 if (!ei->pid)
1426 goto out_unlock;
1427
1428 inode->i_uid = 0;
1429 inode->i_gid = 0;
1430 if (task_dumpable(task)) {
1431 inode->i_uid = task->euid;
1432 inode->i_gid = task->egid;
1433 }
1434 security_task_to_inode(task, inode);
1435
1436 out:
1437 return inode;
1438
1439 out_unlock:
1440 iput(inode);
1441 return NULL;
1442 }
1443
1444 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1445 {
1446 struct inode *inode = dentry->d_inode;
1447 struct task_struct *task;
1448 generic_fillattr(inode, stat);
1449
1450 rcu_read_lock();
1451 stat->uid = 0;
1452 stat->gid = 0;
1453 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1454 if (task) {
1455 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1456 task_dumpable(task)) {
1457 stat->uid = task->euid;
1458 stat->gid = task->egid;
1459 }
1460 }
1461 rcu_read_unlock();
1462 return 0;
1463 }
1464
1465 /* dentry stuff */
1466
1467 /*
1468 * Exceptional case: normally we are not allowed to unhash a busy
1469 * directory. In this case, however, we can do it - no aliasing problems
1470 * due to the way we treat inodes.
1471 *
1472 * Rewrite the inode's ownerships here because the owning task may have
1473 * performed a setuid(), etc.
1474 *
1475 * Before the /proc/pid/status file was created the only way to read
1476 * the effective uid of a /process was to stat /proc/pid. Reading
1477 * /proc/pid/status is slow enough that procps and other packages
1478 * kept stating /proc/pid. To keep the rules in /proc simple I have
1479 * made this apply to all per process world readable and executable
1480 * directories.
1481 */
1482 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1483 {
1484 struct inode *inode = dentry->d_inode;
1485 struct task_struct *task = get_proc_task(inode);
1486 if (task) {
1487 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1488 task_dumpable(task)) {
1489 inode->i_uid = task->euid;
1490 inode->i_gid = task->egid;
1491 } else {
1492 inode->i_uid = 0;
1493 inode->i_gid = 0;
1494 }
1495 inode->i_mode &= ~(S_ISUID | S_ISGID);
1496 security_task_to_inode(task, inode);
1497 put_task_struct(task);
1498 return 1;
1499 }
1500 d_drop(dentry);
1501 return 0;
1502 }
1503
1504 static int pid_delete_dentry(struct dentry * dentry)
1505 {
1506 /* Is the task we represent dead?
1507 * If so, then don't put the dentry on the lru list,
1508 * kill it immediately.
1509 */
1510 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1511 }
1512
1513 static struct dentry_operations pid_dentry_operations =
1514 {
1515 .d_revalidate = pid_revalidate,
1516 .d_delete = pid_delete_dentry,
1517 };
1518
1519 /* Lookups */
1520
1521 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
1522 struct task_struct *, const void *);
1523
1524 /*
1525 * Fill a directory entry.
1526 *
1527 * If possible create the dcache entry and derive our inode number and
1528 * file type from dcache entry.
1529 *
1530 * Since all of the proc inode numbers are dynamically generated, the inode
1531 * numbers do not exist until the inode is cache. This means creating the
1532 * the dcache entry in readdir is necessary to keep the inode numbers
1533 * reported by readdir in sync with the inode numbers reported
1534 * by stat.
1535 */
1536 static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1537 char *name, int len,
1538 instantiate_t instantiate, struct task_struct *task, const void *ptr)
1539 {
1540 struct dentry *child, *dir = filp->f_path.dentry;
1541 struct inode *inode;
1542 struct qstr qname;
1543 ino_t ino = 0;
1544 unsigned type = DT_UNKNOWN;
1545
1546 qname.name = name;
1547 qname.len = len;
1548 qname.hash = full_name_hash(name, len);
1549
1550 child = d_lookup(dir, &qname);
1551 if (!child) {
1552 struct dentry *new;
1553 new = d_alloc(dir, &qname);
1554 if (new) {
1555 child = instantiate(dir->d_inode, new, task, ptr);
1556 if (child)
1557 dput(new);
1558 else
1559 child = new;
1560 }
1561 }
1562 if (!child || IS_ERR(child) || !child->d_inode)
1563 goto end_instantiate;
1564 inode = child->d_inode;
1565 if (inode) {
1566 ino = inode->i_ino;
1567 type = inode->i_mode >> 12;
1568 }
1569 dput(child);
1570 end_instantiate:
1571 if (!ino)
1572 ino = find_inode_number(dir, &qname);
1573 if (!ino)
1574 ino = 1;
1575 return filldir(dirent, name, len, filp->f_pos, ino, type);
1576 }
1577
1578 static unsigned name_to_int(struct dentry *dentry)
1579 {
1580 const char *name = dentry->d_name.name;
1581 int len = dentry->d_name.len;
1582 unsigned n = 0;
1583
1584 if (len > 1 && *name == '0')
1585 goto out;
1586 while (len-- > 0) {
1587 unsigned c = *name++ - '0';
1588 if (c > 9)
1589 goto out;
1590 if (n >= (~0U-9)/10)
1591 goto out;
1592 n *= 10;
1593 n += c;
1594 }
1595 return n;
1596 out:
1597 return ~0U;
1598 }
1599
1600 #define PROC_FDINFO_MAX 64
1601
1602 static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1603 {
1604 struct task_struct *task = get_proc_task(inode);
1605 struct files_struct *files = NULL;
1606 struct file *file;
1607 int fd = proc_fd(inode);
1608
1609 if (task) {
1610 files = get_files_struct(task);
1611 put_task_struct(task);
1612 }
1613 if (files) {
1614 /*
1615 * We are not taking a ref to the file structure, so we must
1616 * hold ->file_lock.
1617 */
1618 spin_lock(&files->file_lock);
1619 file = fcheck_files(files, fd);
1620 if (file) {
1621 if (path) {
1622 *path = file->f_path;
1623 path_get(&file->f_path);
1624 }
1625 if (info)
1626 snprintf(info, PROC_FDINFO_MAX,
1627 "pos:\t%lli\n"
1628 "flags:\t0%o\n",
1629 (long long) file->f_pos,
1630 file->f_flags);
1631 spin_unlock(&files->file_lock);
1632 put_files_struct(files);
1633 return 0;
1634 }
1635 spin_unlock(&files->file_lock);
1636 put_files_struct(files);
1637 }
1638 return -ENOENT;
1639 }
1640
1641 static int proc_fd_link(struct inode *inode, struct path *path)
1642 {
1643 return proc_fd_info(inode, path, NULL);
1644 }
1645
1646 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1647 {
1648 struct inode *inode = dentry->d_inode;
1649 struct task_struct *task = get_proc_task(inode);
1650 int fd = proc_fd(inode);
1651 struct files_struct *files;
1652
1653 if (task) {
1654 files = get_files_struct(task);
1655 if (files) {
1656 rcu_read_lock();
1657 if (fcheck_files(files, fd)) {
1658 rcu_read_unlock();
1659 put_files_struct(files);
1660 if (task_dumpable(task)) {
1661 inode->i_uid = task->euid;
1662 inode->i_gid = task->egid;
1663 } else {
1664 inode->i_uid = 0;
1665 inode->i_gid = 0;
1666 }
1667 inode->i_mode &= ~(S_ISUID | S_ISGID);
1668 security_task_to_inode(task, inode);
1669 put_task_struct(task);
1670 return 1;
1671 }
1672 rcu_read_unlock();
1673 put_files_struct(files);
1674 }
1675 put_task_struct(task);
1676 }
1677 d_drop(dentry);
1678 return 0;
1679 }
1680
1681 static struct dentry_operations tid_fd_dentry_operations =
1682 {
1683 .d_revalidate = tid_fd_revalidate,
1684 .d_delete = pid_delete_dentry,
1685 };
1686
1687 static struct dentry *proc_fd_instantiate(struct inode *dir,
1688 struct dentry *dentry, struct task_struct *task, const void *ptr)
1689 {
1690 unsigned fd = *(const unsigned *)ptr;
1691 struct file *file;
1692 struct files_struct *files;
1693 struct inode *inode;
1694 struct proc_inode *ei;
1695 struct dentry *error = ERR_PTR(-ENOENT);
1696
1697 inode = proc_pid_make_inode(dir->i_sb, task);
1698 if (!inode)
1699 goto out;
1700 ei = PROC_I(inode);
1701 ei->fd = fd;
1702 files = get_files_struct(task);
1703 if (!files)
1704 goto out_iput;
1705 inode->i_mode = S_IFLNK;
1706
1707 /*
1708 * We are not taking a ref to the file structure, so we must
1709 * hold ->file_lock.
1710 */
1711 spin_lock(&files->file_lock);
1712 file = fcheck_files(files, fd);
1713 if (!file)
1714 goto out_unlock;
1715 if (file->f_mode & 1)
1716 inode->i_mode |= S_IRUSR | S_IXUSR;
1717 if (file->f_mode & 2)
1718 inode->i_mode |= S_IWUSR | S_IXUSR;
1719 spin_unlock(&files->file_lock);
1720 put_files_struct(files);
1721
1722 inode->i_op = &proc_pid_link_inode_operations;
1723 inode->i_size = 64;
1724 ei->op.proc_get_link = proc_fd_link;
1725 dentry->d_op = &tid_fd_dentry_operations;
1726 d_add(dentry, inode);
1727 /* Close the race of the process dying before we return the dentry */
1728 if (tid_fd_revalidate(dentry, NULL))
1729 error = NULL;
1730
1731 out:
1732 return error;
1733 out_unlock:
1734 spin_unlock(&files->file_lock);
1735 put_files_struct(files);
1736 out_iput:
1737 iput(inode);
1738 goto out;
1739 }
1740
1741 static struct dentry *proc_lookupfd_common(struct inode *dir,
1742 struct dentry *dentry,
1743 instantiate_t instantiate)
1744 {
1745 struct task_struct *task = get_proc_task(dir);
1746 unsigned fd = name_to_int(dentry);
1747 struct dentry *result = ERR_PTR(-ENOENT);
1748
1749 if (!task)
1750 goto out_no_task;
1751 if (fd == ~0U)
1752 goto out;
1753
1754 result = instantiate(dir, dentry, task, &fd);
1755 out:
1756 put_task_struct(task);
1757 out_no_task:
1758 return result;
1759 }
1760
1761 static int proc_readfd_common(struct file * filp, void * dirent,
1762 filldir_t filldir, instantiate_t instantiate)
1763 {
1764 struct dentry *dentry = filp->f_path.dentry;
1765 struct inode *inode = dentry->d_inode;
1766 struct task_struct *p = get_proc_task(inode);
1767 unsigned int fd, ino;
1768 int retval;
1769 struct files_struct * files;
1770
1771 retval = -ENOENT;
1772 if (!p)
1773 goto out_no_task;
1774 retval = 0;
1775
1776 fd = filp->f_pos;
1777 switch (fd) {
1778 case 0:
1779 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1780 goto out;
1781 filp->f_pos++;
1782 case 1:
1783 ino = parent_ino(dentry);
1784 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1785 goto out;
1786 filp->f_pos++;
1787 default:
1788 files = get_files_struct(p);
1789 if (!files)
1790 goto out;
1791 rcu_read_lock();
1792 for (fd = filp->f_pos-2;
1793 fd < files_fdtable(files)->max_fds;
1794 fd++, filp->f_pos++) {
1795 char name[PROC_NUMBUF];
1796 int len;
1797
1798 if (!fcheck_files(files, fd))
1799 continue;
1800 rcu_read_unlock();
1801
1802 len = snprintf(name, sizeof(name), "%d", fd);
1803 if (proc_fill_cache(filp, dirent, filldir,
1804 name, len, instantiate,
1805 p, &fd) < 0) {
1806 rcu_read_lock();
1807 break;
1808 }
1809 rcu_read_lock();
1810 }
1811 rcu_read_unlock();
1812 put_files_struct(files);
1813 }
1814 out:
1815 put_task_struct(p);
1816 out_no_task:
1817 return retval;
1818 }
1819
1820 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
1821 struct nameidata *nd)
1822 {
1823 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
1824 }
1825
1826 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
1827 {
1828 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
1829 }
1830
1831 static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
1832 size_t len, loff_t *ppos)
1833 {
1834 char tmp[PROC_FDINFO_MAX];
1835 int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
1836 if (!err)
1837 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
1838 return err;
1839 }
1840
1841 static const struct file_operations proc_fdinfo_file_operations = {
1842 .open = nonseekable_open,
1843 .read = proc_fdinfo_read,
1844 };
1845
1846 static const struct file_operations proc_fd_operations = {
1847 .read = generic_read_dir,
1848 .readdir = proc_readfd,
1849 };
1850
1851 /*
1852 * /proc/pid/fd needs a special permission handler so that a process can still
1853 * access /proc/self/fd after it has executed a setuid().
1854 */
1855 static int proc_fd_permission(struct inode *inode, int mask)
1856 {
1857 int rv;
1858
1859 rv = generic_permission(inode, mask, NULL);
1860 if (rv == 0)
1861 return 0;
1862 if (task_pid(current) == proc_pid(inode))
1863 rv = 0;
1864 return rv;
1865 }
1866
1867 /*
1868 * proc directories can do almost nothing..
1869 */
1870 static const struct inode_operations proc_fd_inode_operations = {
1871 .lookup = proc_lookupfd,
1872 .permission = proc_fd_permission,
1873 .setattr = proc_setattr,
1874 };
1875
1876 static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
1877 struct dentry *dentry, struct task_struct *task, const void *ptr)
1878 {
1879 unsigned fd = *(unsigned *)ptr;
1880 struct inode *inode;
1881 struct proc_inode *ei;
1882 struct dentry *error = ERR_PTR(-ENOENT);
1883
1884 inode = proc_pid_make_inode(dir->i_sb, task);
1885 if (!inode)
1886 goto out;
1887 ei = PROC_I(inode);
1888 ei->fd = fd;
1889 inode->i_mode = S_IFREG | S_IRUSR;
1890 inode->i_fop = &proc_fdinfo_file_operations;
1891 dentry->d_op = &tid_fd_dentry_operations;
1892 d_add(dentry, inode);
1893 /* Close the race of the process dying before we return the dentry */
1894 if (tid_fd_revalidate(dentry, NULL))
1895 error = NULL;
1896
1897 out:
1898 return error;
1899 }
1900
1901 static struct dentry *proc_lookupfdinfo(struct inode *dir,
1902 struct dentry *dentry,
1903 struct nameidata *nd)
1904 {
1905 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
1906 }
1907
1908 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
1909 {
1910 return proc_readfd_common(filp, dirent, filldir,
1911 proc_fdinfo_instantiate);
1912 }
1913
1914 static const struct file_operations proc_fdinfo_operations = {
1915 .read = generic_read_dir,
1916 .readdir = proc_readfdinfo,
1917 };
1918
1919 /*
1920 * proc directories can do almost nothing..
1921 */
1922 static const struct inode_operations proc_fdinfo_inode_operations = {
1923 .lookup = proc_lookupfdinfo,
1924 .setattr = proc_setattr,
1925 };
1926
1927
1928 static struct dentry *proc_pident_instantiate(struct inode *dir,
1929 struct dentry *dentry, struct task_struct *task, const void *ptr)
1930 {
1931 const struct pid_entry *p = ptr;
1932 struct inode *inode;
1933 struct proc_inode *ei;
1934 struct dentry *error = ERR_PTR(-EINVAL);
1935
1936 inode = proc_pid_make_inode(dir->i_sb, task);
1937 if (!inode)
1938 goto out;
1939
1940 ei = PROC_I(inode);
1941 inode->i_mode = p->mode;
1942 if (S_ISDIR(inode->i_mode))
1943 inode->i_nlink = 2; /* Use getattr to fix if necessary */
1944 if (p->iop)
1945 inode->i_op = p->iop;
1946 if (p->fop)
1947 inode->i_fop = p->fop;
1948 ei->op = p->op;
1949 dentry->d_op = &pid_dentry_operations;
1950 d_add(dentry, inode);
1951 /* Close the race of the process dying before we return the dentry */
1952 if (pid_revalidate(dentry, NULL))
1953 error = NULL;
1954 out:
1955 return error;
1956 }
1957
1958 static struct dentry *proc_pident_lookup(struct inode *dir,
1959 struct dentry *dentry,
1960 const struct pid_entry *ents,
1961 unsigned int nents)
1962 {
1963 struct inode *inode;
1964 struct dentry *error;
1965 struct task_struct *task = get_proc_task(dir);
1966 const struct pid_entry *p, *last;
1967
1968 error = ERR_PTR(-ENOENT);
1969 inode = NULL;
1970
1971 if (!task)
1972 goto out_no_task;
1973
1974 /*
1975 * Yes, it does not scale. And it should not. Don't add
1976 * new entries into /proc/<tgid>/ without very good reasons.
1977 */
1978 last = &ents[nents - 1];
1979 for (p = ents; p <= last; p++) {
1980 if (p->len != dentry->d_name.len)
1981 continue;
1982 if (!memcmp(dentry->d_name.name, p->name, p->len))
1983 break;
1984 }
1985 if (p > last)
1986 goto out;
1987
1988 error = proc_pident_instantiate(dir, dentry, task, p);
1989 out:
1990 put_task_struct(task);
1991 out_no_task:
1992 return error;
1993 }
1994
1995 static int proc_pident_fill_cache(struct file *filp, void *dirent,
1996 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
1997 {
1998 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
1999 proc_pident_instantiate, task, p);
2000 }
2001
2002 static int proc_pident_readdir(struct file *filp,
2003 void *dirent, filldir_t filldir,
2004 const struct pid_entry *ents, unsigned int nents)
2005 {
2006 int i;
2007 struct dentry *dentry = filp->f_path.dentry;
2008 struct inode *inode = dentry->d_inode;
2009 struct task_struct *task = get_proc_task(inode);
2010 const struct pid_entry *p, *last;
2011 ino_t ino;
2012 int ret;
2013
2014 ret = -ENOENT;
2015 if (!task)
2016 goto out_no_task;
2017
2018 ret = 0;
2019 i = filp->f_pos;
2020 switch (i) {
2021 case 0:
2022 ino = inode->i_ino;
2023 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2024 goto out;
2025 i++;
2026 filp->f_pos++;
2027 /* fall through */
2028 case 1:
2029 ino = parent_ino(dentry);
2030 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2031 goto out;
2032 i++;
2033 filp->f_pos++;
2034 /* fall through */
2035 default:
2036 i -= 2;
2037 if (i >= nents) {
2038 ret = 1;
2039 goto out;
2040 }
2041 p = ents + i;
2042 last = &ents[nents - 1];
2043 while (p <= last) {
2044 if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2045 goto out;
2046 filp->f_pos++;
2047 p++;
2048 }
2049 }
2050
2051 ret = 1;
2052 out:
2053 put_task_struct(task);
2054 out_no_task:
2055 return ret;
2056 }
2057
2058 #ifdef CONFIG_SECURITY
2059 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2060 size_t count, loff_t *ppos)
2061 {
2062 struct inode * inode = file->f_path.dentry->d_inode;
2063 char *p = NULL;
2064 ssize_t length;
2065 struct task_struct *task = get_proc_task(inode);
2066
2067 if (!task)
2068 return -ESRCH;
2069
2070 length = security_getprocattr(task,
2071 (char*)file->f_path.dentry->d_name.name,
2072 &p);
2073 put_task_struct(task);
2074 if (length > 0)
2075 length = simple_read_from_buffer(buf, count, ppos, p, length);
2076 kfree(p);
2077 return length;
2078 }
2079
2080 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2081 size_t count, loff_t *ppos)
2082 {
2083 struct inode * inode = file->f_path.dentry->d_inode;
2084 char *page;
2085 ssize_t length;
2086 struct task_struct *task = get_proc_task(inode);
2087
2088 length = -ESRCH;
2089 if (!task)
2090 goto out_no_task;
2091 if (count > PAGE_SIZE)
2092 count = PAGE_SIZE;
2093
2094 /* No partial writes. */
2095 length = -EINVAL;
2096 if (*ppos != 0)
2097 goto out;
2098
2099 length = -ENOMEM;
2100 page = (char*)__get_free_page(GFP_TEMPORARY);
2101 if (!page)
2102 goto out;
2103
2104 length = -EFAULT;
2105 if (copy_from_user(page, buf, count))
2106 goto out_free;
2107
2108 length = security_setprocattr(task,
2109 (char*)file->f_path.dentry->d_name.name,
2110 (void*)page, count);
2111 out_free:
2112 free_page((unsigned long) page);
2113 out:
2114 put_task_struct(task);
2115 out_no_task:
2116 return length;
2117 }
2118
2119 static const struct file_operations proc_pid_attr_operations = {
2120 .read = proc_pid_attr_read,
2121 .write = proc_pid_attr_write,
2122 };
2123
2124 static const struct pid_entry attr_dir_stuff[] = {
2125 REG("current", S_IRUGO|S_IWUGO, pid_attr),
2126 REG("prev", S_IRUGO, pid_attr),
2127 REG("exec", S_IRUGO|S_IWUGO, pid_attr),
2128 REG("fscreate", S_IRUGO|S_IWUGO, pid_attr),
2129 REG("keycreate", S_IRUGO|S_IWUGO, pid_attr),
2130 REG("sockcreate", S_IRUGO|S_IWUGO, pid_attr),
2131 };
2132
2133 static int proc_attr_dir_readdir(struct file * filp,
2134 void * dirent, filldir_t filldir)
2135 {
2136 return proc_pident_readdir(filp,dirent,filldir,
2137 attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2138 }
2139
2140 static const struct file_operations proc_attr_dir_operations = {
2141 .read = generic_read_dir,
2142 .readdir = proc_attr_dir_readdir,
2143 };
2144
2145 static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2146 struct dentry *dentry, struct nameidata *nd)
2147 {
2148 return proc_pident_lookup(dir, dentry,
2149 attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2150 }
2151
2152 static const struct inode_operations proc_attr_dir_inode_operations = {
2153 .lookup = proc_attr_dir_lookup,
2154 .getattr = pid_getattr,
2155 .setattr = proc_setattr,
2156 };
2157
2158 #endif
2159
2160 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2161 static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2162 size_t count, loff_t *ppos)
2163 {
2164 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2165 struct mm_struct *mm;
2166 char buffer[PROC_NUMBUF];
2167 size_t len;
2168 int ret;
2169
2170 if (!task)
2171 return -ESRCH;
2172
2173 ret = 0;
2174 mm = get_task_mm(task);
2175 if (mm) {
2176 len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2177 ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2178 MMF_DUMP_FILTER_SHIFT));
2179 mmput(mm);
2180 ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2181 }
2182
2183 put_task_struct(task);
2184
2185 return ret;
2186 }
2187
2188 static ssize_t proc_coredump_filter_write(struct file *file,
2189 const char __user *buf,
2190 size_t count,
2191 loff_t *ppos)
2192 {
2193 struct task_struct *task;
2194 struct mm_struct *mm;
2195 char buffer[PROC_NUMBUF], *end;
2196 unsigned int val;
2197 int ret;
2198 int i;
2199 unsigned long mask;
2200
2201 ret = -EFAULT;
2202 memset(buffer, 0, sizeof(buffer));
2203 if (count > sizeof(buffer) - 1)
2204 count = sizeof(buffer) - 1;
2205 if (copy_from_user(buffer, buf, count))
2206 goto out_no_task;
2207
2208 ret = -EINVAL;
2209 val = (unsigned int)simple_strtoul(buffer, &end, 0);
2210 if (*end == '\n')
2211 end++;
2212 if (end - buffer == 0)
2213 goto out_no_task;
2214
2215 ret = -ESRCH;
2216 task = get_proc_task(file->f_dentry->d_inode);
2217 if (!task)
2218 goto out_no_task;
2219
2220 ret = end - buffer;
2221 mm = get_task_mm(task);
2222 if (!mm)
2223 goto out_no_mm;
2224
2225 for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2226 if (val & mask)
2227 set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2228 else
2229 clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2230 }
2231
2232 mmput(mm);
2233 out_no_mm:
2234 put_task_struct(task);
2235 out_no_task:
2236 return ret;
2237 }
2238
2239 static const struct file_operations proc_coredump_filter_operations = {
2240 .read = proc_coredump_filter_read,
2241 .write = proc_coredump_filter_write,
2242 };
2243 #endif
2244
2245 /*
2246 * /proc/self:
2247 */
2248 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2249 int buflen)
2250 {
2251 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2252 pid_t tgid = task_tgid_nr_ns(current, ns);
2253 char tmp[PROC_NUMBUF];
2254 if (!tgid)
2255 return -ENOENT;
2256 sprintf(tmp, "%d", tgid);
2257 return vfs_readlink(dentry,buffer,buflen,tmp);
2258 }
2259
2260 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2261 {
2262 struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2263 pid_t tgid = task_tgid_nr_ns(current, ns);
2264 char tmp[PROC_NUMBUF];
2265 if (!tgid)
2266 return ERR_PTR(-ENOENT);
2267 sprintf(tmp, "%d", task_tgid_nr_ns(current, ns));
2268 return ERR_PTR(vfs_follow_link(nd,tmp));
2269 }
2270
2271 static const struct inode_operations proc_self_inode_operations = {
2272 .readlink = proc_self_readlink,
2273 .follow_link = proc_self_follow_link,
2274 };
2275
2276 /*
2277 * proc base
2278 *
2279 * These are the directory entries in the root directory of /proc
2280 * that properly belong to the /proc filesystem, as they describe
2281 * describe something that is process related.
2282 */
2283 static const struct pid_entry proc_base_stuff[] = {
2284 NOD("self", S_IFLNK|S_IRWXUGO,
2285 &proc_self_inode_operations, NULL, {}),
2286 };
2287
2288 /*
2289 * Exceptional case: normally we are not allowed to unhash a busy
2290 * directory. In this case, however, we can do it - no aliasing problems
2291 * due to the way we treat inodes.
2292 */
2293 static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
2294 {
2295 struct inode *inode = dentry->d_inode;
2296 struct task_struct *task = get_proc_task(inode);
2297 if (task) {
2298 put_task_struct(task);
2299 return 1;
2300 }
2301 d_drop(dentry);
2302 return 0;
2303 }
2304
2305 static struct dentry_operations proc_base_dentry_operations =
2306 {
2307 .d_revalidate = proc_base_revalidate,
2308 .d_delete = pid_delete_dentry,
2309 };
2310
2311 static struct dentry *proc_base_instantiate(struct inode *dir,
2312 struct dentry *dentry, struct task_struct *task, const void *ptr)
2313 {
2314 const struct pid_entry *p = ptr;
2315 struct inode *inode;
2316 struct proc_inode *ei;
2317 struct dentry *error = ERR_PTR(-EINVAL);
2318
2319 /* Allocate the inode */
2320 error = ERR_PTR(-ENOMEM);
2321 inode = new_inode(dir->i_sb);
2322 if (!inode)
2323 goto out;
2324
2325 /* Initialize the inode */
2326 ei = PROC_I(inode);
2327 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2328
2329 /*
2330 * grab the reference to the task.
2331 */
2332 ei->pid = get_task_pid(task, PIDTYPE_PID);
2333 if (!ei->pid)
2334 goto out_iput;
2335
2336 inode->i_uid = 0;
2337 inode->i_gid = 0;
2338 inode->i_mode = p->mode;
2339 if (S_ISDIR(inode->i_mode))
2340 inode->i_nlink = 2;
2341 if (S_ISLNK(inode->i_mode))
2342 inode->i_size = 64;
2343 if (p->iop)
2344 inode->i_op = p->iop;
2345 if (p->fop)
2346 inode->i_fop = p->fop;
2347 ei->op = p->op;
2348 dentry->d_op = &proc_base_dentry_operations;
2349 d_add(dentry, inode);
2350 error = NULL;
2351 out:
2352 return error;
2353 out_iput:
2354 iput(inode);
2355 goto out;
2356 }
2357
2358 static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2359 {
2360 struct dentry *error;
2361 struct task_struct *task = get_proc_task(dir);
2362 const struct pid_entry *p, *last;
2363
2364 error = ERR_PTR(-ENOENT);
2365
2366 if (!task)
2367 goto out_no_task;
2368
2369 /* Lookup the directory entry */
2370 last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2371 for (p = proc_base_stuff; p <= last; p++) {
2372 if (p->len != dentry->d_name.len)
2373 continue;
2374 if (!memcmp(dentry->d_name.name, p->name, p->len))
2375 break;
2376 }
2377 if (p > last)
2378 goto out;
2379
2380 error = proc_base_instantiate(dir, dentry, task, p);
2381
2382 out:
2383 put_task_struct(task);
2384 out_no_task:
2385 return error;
2386 }
2387
2388 static int proc_base_fill_cache(struct file *filp, void *dirent,
2389 filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2390 {
2391 return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2392 proc_base_instantiate, task, p);
2393 }
2394
2395 #ifdef CONFIG_TASK_IO_ACCOUNTING
2396 static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2397 {
2398 struct task_io_accounting acct = task->ioac;
2399 unsigned long flags;
2400
2401 if (whole && lock_task_sighand(task, &flags)) {
2402 struct task_struct *t = task;
2403
2404 task_io_accounting_add(&acct, &task->signal->ioac);
2405 while_each_thread(task, t)
2406 task_io_accounting_add(&acct, &t->ioac);
2407
2408 unlock_task_sighand(task, &flags);
2409 }
2410 return sprintf(buffer,
2411 "rchar: %llu\n"
2412 "wchar: %llu\n"
2413 "syscr: %llu\n"
2414 "syscw: %llu\n"
2415 "read_bytes: %llu\n"
2416 "write_bytes: %llu\n"
2417 "cancelled_write_bytes: %llu\n",
2418 (unsigned long long)acct.rchar,
2419 (unsigned long long)acct.wchar,
2420 (unsigned long long)acct.syscr,
2421 (unsigned long long)acct.syscw,
2422 (unsigned long long)acct.read_bytes,
2423 (unsigned long long)acct.write_bytes,
2424 (unsigned long long)acct.cancelled_write_bytes);
2425 }
2426
2427 static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2428 {
2429 return do_io_accounting(task, buffer, 0);
2430 }
2431
2432 static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2433 {
2434 return do_io_accounting(task, buffer, 1);
2435 }
2436 #endif /* CONFIG_TASK_IO_ACCOUNTING */
2437
2438 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2439 struct pid *pid, struct task_struct *task)
2440 {
2441 seq_printf(m, "%08x\n", task->personality);
2442 return 0;
2443 }
2444
2445 /*
2446 * Thread groups
2447 */
2448 static const struct file_operations proc_task_operations;
2449 static const struct inode_operations proc_task_inode_operations;
2450
2451 static const struct pid_entry tgid_base_stuff[] = {
2452 DIR("task", S_IRUGO|S_IXUGO, task),
2453 DIR("fd", S_IRUSR|S_IXUSR, fd),
2454 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2455 #ifdef CONFIG_NET
2456 DIR("net", S_IRUGO|S_IXUGO, net),
2457 #endif
2458 REG("environ", S_IRUSR, environ),
2459 INF("auxv", S_IRUSR, pid_auxv),
2460 ONE("status", S_IRUGO, pid_status),
2461 ONE("personality", S_IRUSR, pid_personality),
2462 INF("limits", S_IRUSR, pid_limits),
2463 #ifdef CONFIG_SCHED_DEBUG
2464 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2465 #endif
2466 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2467 INF("syscall", S_IRUSR, pid_syscall),
2468 #endif
2469 INF("cmdline", S_IRUGO, pid_cmdline),
2470 ONE("stat", S_IRUGO, tgid_stat),
2471 ONE("statm", S_IRUGO, pid_statm),
2472 REG("maps", S_IRUGO, maps),
2473 #ifdef CONFIG_NUMA
2474 REG("numa_maps", S_IRUGO, numa_maps),
2475 #endif
2476 REG("mem", S_IRUSR|S_IWUSR, mem),
2477 LNK("cwd", cwd),
2478 LNK("root", root),
2479 LNK("exe", exe),
2480 REG("mounts", S_IRUGO, mounts),
2481 REG("mountinfo", S_IRUGO, mountinfo),
2482 REG("mountstats", S_IRUSR, mountstats),
2483 #ifdef CONFIG_PROC_PAGE_MONITOR
2484 REG("clear_refs", S_IWUSR, clear_refs),
2485 REG("smaps", S_IRUGO, smaps),
2486 REG("pagemap", S_IRUSR, pagemap),
2487 #endif
2488 #ifdef CONFIG_SECURITY
2489 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2490 #endif
2491 #ifdef CONFIG_KALLSYMS
2492 INF("wchan", S_IRUGO, pid_wchan),
2493 #endif
2494 #ifdef CONFIG_SCHEDSTATS
2495 INF("schedstat", S_IRUGO, pid_schedstat),
2496 #endif
2497 #ifdef CONFIG_LATENCYTOP
2498 REG("latency", S_IRUGO, lstats),
2499 #endif
2500 #ifdef CONFIG_PROC_PID_CPUSET
2501 REG("cpuset", S_IRUGO, cpuset),
2502 #endif
2503 #ifdef CONFIG_CGROUPS
2504 REG("cgroup", S_IRUGO, cgroup),
2505 #endif
2506 INF("oom_score", S_IRUGO, oom_score),
2507 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2508 #ifdef CONFIG_AUDITSYSCALL
2509 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2510 REG("sessionid", S_IRUGO, sessionid),
2511 #endif
2512 #ifdef CONFIG_FAULT_INJECTION
2513 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2514 #endif
2515 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
2516 REG("coredump_filter", S_IRUGO|S_IWUSR, coredump_filter),
2517 #endif
2518 #ifdef CONFIG_TASK_IO_ACCOUNTING
2519 INF("io", S_IRUGO, tgid_io_accounting),
2520 #endif
2521 };
2522
2523 static int proc_tgid_base_readdir(struct file * filp,
2524 void * dirent, filldir_t filldir)
2525 {
2526 return proc_pident_readdir(filp,dirent,filldir,
2527 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2528 }
2529
2530 static const struct file_operations proc_tgid_base_operations = {
2531 .read = generic_read_dir,
2532 .readdir = proc_tgid_base_readdir,
2533 };
2534
2535 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2536 return proc_pident_lookup(dir, dentry,
2537 tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
2538 }
2539
2540 static const struct inode_operations proc_tgid_base_inode_operations = {
2541 .lookup = proc_tgid_base_lookup,
2542 .getattr = pid_getattr,
2543 .setattr = proc_setattr,
2544 };
2545
2546 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2547 {
2548 struct dentry *dentry, *leader, *dir;
2549 char buf[PROC_NUMBUF];
2550 struct qstr name;
2551
2552 name.name = buf;
2553 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2554 dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2555 if (dentry) {
2556 if (!(current->flags & PF_EXITING))
2557 shrink_dcache_parent(dentry);
2558 d_drop(dentry);
2559 dput(dentry);
2560 }
2561
2562 if (tgid == 0)
2563 goto out;
2564
2565 name.name = buf;
2566 name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2567 leader = d_hash_and_lookup(mnt->mnt_root, &name);
2568 if (!leader)
2569 goto out;
2570
2571 name.name = "task";
2572 name.len = strlen(name.name);
2573 dir = d_hash_and_lookup(leader, &name);
2574 if (!dir)
2575 goto out_put_leader;
2576
2577 name.name = buf;
2578 name.len = snprintf(buf, sizeof(buf), "%d", pid);
2579 dentry = d_hash_and_lookup(dir, &name);
2580 if (dentry) {
2581 shrink_dcache_parent(dentry);
2582 d_drop(dentry);
2583 dput(dentry);
2584 }
2585
2586 dput(dir);
2587 out_put_leader:
2588 dput(leader);
2589 out:
2590 return;
2591 }
2592
2593 /**
2594 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
2595 * @task: task that should be flushed.
2596 *
2597 * When flushing dentries from proc, one needs to flush them from global
2598 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2599 * in. This call is supposed to do all of this job.
2600 *
2601 * Looks in the dcache for
2602 * /proc/@pid
2603 * /proc/@tgid/task/@pid
2604 * if either directory is present flushes it and all of it'ts children
2605 * from the dcache.
2606 *
2607 * It is safe and reasonable to cache /proc entries for a task until
2608 * that task exits. After that they just clog up the dcache with
2609 * useless entries, possibly causing useful dcache entries to be
2610 * flushed instead. This routine is proved to flush those useless
2611 * dcache entries at process exit time.
2612 *
2613 * NOTE: This routine is just an optimization so it does not guarantee
2614 * that no dcache entries will exist at process exit time it
2615 * just makes it very unlikely that any will persist.
2616 */
2617
2618 void proc_flush_task(struct task_struct *task)
2619 {
2620 int i;
2621 struct pid *pid, *tgid = NULL;
2622 struct upid *upid;
2623
2624 pid = task_pid(task);
2625 if (thread_group_leader(task))
2626 tgid = task_tgid(task);
2627
2628 for (i = 0; i <= pid->level; i++) {
2629 upid = &pid->numbers[i];
2630 proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2631 tgid ? tgid->numbers[i].nr : 0);
2632 }
2633
2634 upid = &pid->numbers[pid->level];
2635 if (upid->nr == 1)
2636 pid_ns_release_proc(upid->ns);
2637 }
2638
2639 static struct dentry *proc_pid_instantiate(struct inode *dir,
2640 struct dentry * dentry,
2641 struct task_struct *task, const void *ptr)
2642 {
2643 struct dentry *error = ERR_PTR(-ENOENT);
2644 struct inode *inode;
2645
2646 inode = proc_pid_make_inode(dir->i_sb, task);
2647 if (!inode)
2648 goto out;
2649
2650 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2651 inode->i_op = &proc_tgid_base_inode_operations;
2652 inode->i_fop = &proc_tgid_base_operations;
2653 inode->i_flags|=S_IMMUTABLE;
2654
2655 inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2656 ARRAY_SIZE(tgid_base_stuff));
2657
2658 dentry->d_op = &pid_dentry_operations;
2659
2660 d_add(dentry, inode);
2661 /* Close the race of the process dying before we return the dentry */
2662 if (pid_revalidate(dentry, NULL))
2663 error = NULL;
2664 out:
2665 return error;
2666 }
2667
2668 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2669 {
2670 struct dentry *result = ERR_PTR(-ENOENT);
2671 struct task_struct *task;
2672 unsigned tgid;
2673 struct pid_namespace *ns;
2674
2675 result = proc_base_lookup(dir, dentry);
2676 if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
2677 goto out;
2678
2679 tgid = name_to_int(dentry);
2680 if (tgid == ~0U)
2681 goto out;
2682
2683 ns = dentry->d_sb->s_fs_info;
2684 rcu_read_lock();
2685 task = find_task_by_pid_ns(tgid, ns);
2686 if (task)
2687 get_task_struct(task);
2688 rcu_read_unlock();
2689 if (!task)
2690 goto out;
2691
2692 result = proc_pid_instantiate(dir, dentry, task, NULL);
2693 put_task_struct(task);
2694 out:
2695 return result;
2696 }
2697
2698 /*
2699 * Find the first task with tgid >= tgid
2700 *
2701 */
2702 struct tgid_iter {
2703 unsigned int tgid;
2704 struct task_struct *task;
2705 };
2706 static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
2707 {
2708 struct pid *pid;
2709
2710 if (iter.task)
2711 put_task_struct(iter.task);
2712 rcu_read_lock();
2713 retry:
2714 iter.task = NULL;
2715 pid = find_ge_pid(iter.tgid, ns);
2716 if (pid) {
2717 iter.tgid = pid_nr_ns(pid, ns);
2718 iter.task = pid_task(pid, PIDTYPE_PID);
2719 /* What we to know is if the pid we have find is the
2720 * pid of a thread_group_leader. Testing for task
2721 * being a thread_group_leader is the obvious thing
2722 * todo but there is a window when it fails, due to
2723 * the pid transfer logic in de_thread.
2724 *
2725 * So we perform the straight forward test of seeing
2726 * if the pid we have found is the pid of a thread
2727 * group leader, and don't worry if the task we have
2728 * found doesn't happen to be a thread group leader.
2729 * As we don't care in the case of readdir.
2730 */
2731 if (!iter.task || !has_group_leader_pid(iter.task)) {
2732 iter.tgid += 1;
2733 goto retry;
2734 }
2735 get_task_struct(iter.task);
2736 }
2737 rcu_read_unlock();
2738 return iter;
2739 }
2740
2741 #define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
2742
2743 static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
2744 struct tgid_iter iter)
2745 {
2746 char name[PROC_NUMBUF];
2747 int len = snprintf(name, sizeof(name), "%d", iter.tgid);
2748 return proc_fill_cache(filp, dirent, filldir, name, len,
2749 proc_pid_instantiate, iter.task, NULL);
2750 }
2751
2752 /* for the /proc/ directory itself, after non-process stuff has been done */
2753 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2754 {
2755 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2756 struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode);
2757 struct tgid_iter iter;
2758 struct pid_namespace *ns;
2759
2760 if (!reaper)
2761 goto out_no_task;
2762
2763 for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
2764 const struct pid_entry *p = &proc_base_stuff[nr];
2765 if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
2766 goto out;
2767 }
2768
2769 ns = filp->f_dentry->d_sb->s_fs_info;
2770 iter.task = NULL;
2771 iter.tgid = filp->f_pos - TGID_OFFSET;
2772 for (iter = next_tgid(ns, iter);
2773 iter.task;
2774 iter.tgid += 1, iter = next_tgid(ns, iter)) {
2775 filp->f_pos = iter.tgid + TGID_OFFSET;
2776 if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
2777 put_task_struct(iter.task);
2778 goto out;
2779 }
2780 }
2781 filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
2782 out:
2783 put_task_struct(reaper);
2784 out_no_task:
2785 return 0;
2786 }
2787
2788 /*
2789 * Tasks
2790 */
2791 static const struct pid_entry tid_base_stuff[] = {
2792 DIR("fd", S_IRUSR|S_IXUSR, fd),
2793 DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
2794 REG("environ", S_IRUSR, environ),
2795 INF("auxv", S_IRUSR, pid_auxv),
2796 ONE("status", S_IRUGO, pid_status),
2797 ONE("personality", S_IRUSR, pid_personality),
2798 INF("limits", S_IRUSR, pid_limits),
2799 #ifdef CONFIG_SCHED_DEBUG
2800 REG("sched", S_IRUGO|S_IWUSR, pid_sched),
2801 #endif
2802 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2803 INF("syscall", S_IRUSR, pid_syscall),
2804 #endif
2805 INF("cmdline", S_IRUGO, pid_cmdline),
2806 ONE("stat", S_IRUGO, tid_stat),
2807 ONE("statm", S_IRUGO, pid_statm),
2808 REG("maps", S_IRUGO, maps),
2809 #ifdef CONFIG_NUMA
2810 REG("numa_maps", S_IRUGO, numa_maps),
2811 #endif
2812 REG("mem", S_IRUSR|S_IWUSR, mem),
2813 LNK("cwd", cwd),
2814 LNK("root", root),
2815 LNK("exe", exe),
2816 REG("mounts", S_IRUGO, mounts),
2817 REG("mountinfo", S_IRUGO, mountinfo),
2818 #ifdef CONFIG_PROC_PAGE_MONITOR
2819 REG("clear_refs", S_IWUSR, clear_refs),
2820 REG("smaps", S_IRUGO, smaps),
2821 REG("pagemap", S_IRUSR, pagemap),
2822 #endif
2823 #ifdef CONFIG_SECURITY
2824 DIR("attr", S_IRUGO|S_IXUGO, attr_dir),
2825 #endif
2826 #ifdef CONFIG_KALLSYMS
2827 INF("wchan", S_IRUGO, pid_wchan),
2828 #endif
2829 #ifdef CONFIG_SCHEDSTATS
2830 INF("schedstat", S_IRUGO, pid_schedstat),
2831 #endif
2832 #ifdef CONFIG_LATENCYTOP
2833 REG("latency", S_IRUGO, lstats),
2834 #endif
2835 #ifdef CONFIG_PROC_PID_CPUSET
2836 REG("cpuset", S_IRUGO, cpuset),
2837 #endif
2838 #ifdef CONFIG_CGROUPS
2839 REG("cgroup", S_IRUGO, cgroup),
2840 #endif
2841 INF("oom_score", S_IRUGO, oom_score),
2842 REG("oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
2843 #ifdef CONFIG_AUDITSYSCALL
2844 REG("loginuid", S_IWUSR|S_IRUGO, loginuid),
2845 REG("sessionid", S_IRUSR, sessionid),
2846 #endif
2847 #ifdef CONFIG_FAULT_INJECTION
2848 REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
2849 #endif
2850 #ifdef CONFIG_TASK_IO_ACCOUNTING
2851 INF("io", S_IRUGO, tid_io_accounting),
2852 #endif
2853 };
2854
2855 static int proc_tid_base_readdir(struct file * filp,
2856 void * dirent, filldir_t filldir)
2857 {
2858 return proc_pident_readdir(filp,dirent,filldir,
2859 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
2860 }
2861
2862 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
2863 return proc_pident_lookup(dir, dentry,
2864 tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
2865 }
2866
2867 static const struct file_operations proc_tid_base_operations = {
2868 .read = generic_read_dir,
2869 .readdir = proc_tid_base_readdir,
2870 };
2871
2872 static const struct inode_operations proc_tid_base_inode_operations = {
2873 .lookup = proc_tid_base_lookup,
2874 .getattr = pid_getattr,
2875 .setattr = proc_setattr,
2876 };
2877
2878 static struct dentry *proc_task_instantiate(struct inode *dir,
2879 struct dentry *dentry, struct task_struct *task, const void *ptr)
2880 {
2881 struct dentry *error = ERR_PTR(-ENOENT);
2882 struct inode *inode;
2883 inode = proc_pid_make_inode(dir->i_sb, task);
2884
2885 if (!inode)
2886 goto out;
2887 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2888 inode->i_op = &proc_tid_base_inode_operations;
2889 inode->i_fop = &proc_tid_base_operations;
2890 inode->i_flags|=S_IMMUTABLE;
2891
2892 inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
2893 ARRAY_SIZE(tid_base_stuff));
2894
2895 dentry->d_op = &pid_dentry_operations;
2896
2897 d_add(dentry, inode);
2898 /* Close the race of the process dying before we return the dentry */
2899 if (pid_revalidate(dentry, NULL))
2900 error = NULL;
2901 out:
2902 return error;
2903 }
2904
2905 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2906 {
2907 struct dentry *result = ERR_PTR(-ENOENT);
2908 struct task_struct *task;
2909 struct task_struct *leader = get_proc_task(dir);
2910 unsigned tid;
2911 struct pid_namespace *ns;
2912
2913 if (!leader)
2914 goto out_no_task;
2915
2916 tid = name_to_int(dentry);
2917 if (tid == ~0U)
2918 goto out;
2919
2920 ns = dentry->d_sb->s_fs_info;
2921 rcu_read_lock();
2922 task = find_task_by_pid_ns(tid, ns);
2923 if (task)
2924 get_task_struct(task);
2925 rcu_read_unlock();
2926 if (!task)
2927 goto out;
2928 if (!same_thread_group(leader, task))
2929 goto out_drop_task;
2930
2931 result = proc_task_instantiate(dir, dentry, task, NULL);
2932 out_drop_task:
2933 put_task_struct(task);
2934 out:
2935 put_task_struct(leader);
2936 out_no_task:
2937 return result;
2938 }
2939
2940 /*
2941 * Find the first tid of a thread group to return to user space.
2942 *
2943 * Usually this is just the thread group leader, but if the users
2944 * buffer was too small or there was a seek into the middle of the
2945 * directory we have more work todo.
2946 *
2947 * In the case of a short read we start with find_task_by_pid.
2948 *
2949 * In the case of a seek we start with the leader and walk nr
2950 * threads past it.
2951 */
2952 static struct task_struct *first_tid(struct task_struct *leader,
2953 int tid, int nr, struct pid_namespace *ns)
2954 {
2955 struct task_struct *pos;
2956
2957 rcu_read_lock();
2958 /* Attempt to start with the pid of a thread */
2959 if (tid && (nr > 0)) {
2960 pos = find_task_by_pid_ns(tid, ns);
2961 if (pos && (pos->group_leader == leader))
2962 goto found;
2963 }
2964
2965 /* If nr exceeds the number of threads there is nothing todo */
2966 pos = NULL;
2967 if (nr && nr >= get_nr_threads(leader))
2968 goto out;
2969
2970 /* If we haven't found our starting place yet start
2971 * with the leader and walk nr threads forward.
2972 */
2973 for (pos = leader; nr > 0; --nr) {
2974 pos = next_thread(pos);
2975 if (pos == leader) {
2976 pos = NULL;
2977 goto out;
2978 }
2979 }
2980 found:
2981 get_task_struct(pos);
2982 out:
2983 rcu_read_unlock();
2984 return pos;
2985 }
2986
2987 /*
2988 * Find the next thread in the thread list.
2989 * Return NULL if there is an error or no next thread.
2990 *
2991 * The reference to the input task_struct is released.
2992 */
2993 static struct task_struct *next_tid(struct task_struct *start)
2994 {
2995 struct task_struct *pos = NULL;
2996 rcu_read_lock();
2997 if (pid_alive(start)) {
2998 pos = next_thread(start);
2999 if (thread_group_leader(pos))
3000 pos = NULL;
3001 else
3002 get_task_struct(pos);
3003 }
3004 rcu_read_unlock();
3005 put_task_struct(start);
3006 return pos;
3007 }
3008
3009 static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3010 struct task_struct *task, int tid)
3011 {
3012 char name[PROC_NUMBUF];
3013 int len = snprintf(name, sizeof(name), "%d", tid);
3014 return proc_fill_cache(filp, dirent, filldir, name, len,
3015 proc_task_instantiate, task, NULL);
3016 }
3017
3018 /* for the /proc/TGID/task/ directories */
3019 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3020 {
3021 struct dentry *dentry = filp->f_path.dentry;
3022 struct inode *inode = dentry->d_inode;
3023 struct task_struct *leader = NULL;
3024 struct task_struct *task;
3025 int retval = -ENOENT;
3026 ino_t ino;
3027 int tid;
3028 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */
3029 struct pid_namespace *ns;
3030
3031 task = get_proc_task(inode);
3032 if (!task)
3033 goto out_no_task;
3034 rcu_read_lock();
3035 if (pid_alive(task)) {
3036 leader = task->group_leader;
3037 get_task_struct(leader);
3038 }
3039 rcu_read_unlock();
3040 put_task_struct(task);
3041 if (!leader)
3042 goto out_no_task;
3043 retval = 0;
3044
3045 switch (pos) {
3046 case 0:
3047 ino = inode->i_ino;
3048 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
3049 goto out;
3050 pos++;
3051 /* fall through */
3052 case 1:
3053 ino = parent_ino(dentry);
3054 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
3055 goto out;
3056 pos++;
3057 /* fall through */
3058 }
3059
3060 /* f_version caches the tgid value that the last readdir call couldn't
3061 * return. lseek aka telldir automagically resets f_version to 0.
3062 */
3063 ns = filp->f_dentry->d_sb->s_fs_info;
3064 tid = (int)filp->f_version;
3065 filp->f_version = 0;
3066 for (task = first_tid(leader, tid, pos - 2, ns);
3067 task;
3068 task = next_tid(task), pos++) {
3069 tid = task_pid_nr_ns(task, ns);
3070 if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
3071 /* returning this tgid failed, save it as the first
3072 * pid for the next readir call */
3073 filp->f_version = (u64)tid;
3074 put_task_struct(task);
3075 break;
3076 }
3077 }
3078 out:
3079 filp->f_pos = pos;
3080 put_task_struct(leader);
3081 out_no_task:
3082 return retval;
3083 }
3084
3085 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
3086 {
3087 struct inode *inode = dentry->d_inode;
3088 struct task_struct *p = get_proc_task(inode);
3089 generic_fillattr(inode, stat);
3090
3091 if (p) {
3092 stat->nlink += get_nr_threads(p);
3093 put_task_struct(p);
3094 }
3095
3096 return 0;
3097 }
3098
3099 static const struct inode_operations proc_task_inode_operations = {
3100 .lookup = proc_task_lookup,
3101 .getattr = proc_task_getattr,
3102 .setattr = proc_setattr,
3103 };
3104
3105 static const struct file_operations proc_task_operations = {
3106 .read = generic_read_dir,
3107 .readdir = proc_task_readdir,
3108 };
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree