ia64/linux-2.6.18-xen.hg

view fs/proc/base.c @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
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 */
50 #include <asm/uaccess.h>
52 #include <linux/errno.h>
53 #include <linux/time.h>
54 #include <linux/proc_fs.h>
55 #include <linux/stat.h>
56 #include <linux/init.h>
57 #include <linux/capability.h>
58 #include <linux/file.h>
59 #include <linux/string.h>
60 #include <linux/seq_file.h>
61 #include <linux/namei.h>
62 #include <linux/namespace.h>
63 #include <linux/mm.h>
64 #include <linux/smp_lock.h>
65 #include <linux/rcupdate.h>
66 #include <linux/kallsyms.h>
67 #include <linux/mount.h>
68 #include <linux/security.h>
69 #include <linux/ptrace.h>
70 #include <linux/seccomp.h>
71 #include <linux/cpuset.h>
72 #include <linux/audit.h>
73 #include <linux/poll.h>
74 #include "internal.h"
76 /* NOTE:
77 * Implementing inode permission operations in /proc is almost
78 * certainly an error. Permission checks need to happen during
79 * each system call not at open time. The reason is that most of
80 * what we wish to check for permissions in /proc varies at runtime.
81 *
82 * The classic example of a problem is opening file descriptors
83 * in /proc for a task before it execs a suid executable.
84 */
86 /*
87 * For hysterical raisins we keep the same inumbers as in the old procfs.
88 * Feel free to change the macro below - just keep the range distinct from
89 * inumbers of the rest of procfs (currently those are in 0x0000--0xffff).
90 * As soon as we'll get a separate superblock we will be able to forget
91 * about magical ranges too.
92 */
94 #define fake_ino(pid,ino) (((pid)<<16)|(ino))
96 enum pid_directory_inos {
97 PROC_TGID_INO = 2,
98 PROC_TGID_TASK,
99 PROC_TGID_STATUS,
100 PROC_TGID_MEM,
101 #ifdef CONFIG_SECCOMP
102 PROC_TGID_SECCOMP,
103 #endif
104 PROC_TGID_CWD,
105 PROC_TGID_ROOT,
106 PROC_TGID_EXE,
107 PROC_TGID_FD,
108 PROC_TGID_ENVIRON,
109 PROC_TGID_AUXV,
110 PROC_TGID_CMDLINE,
111 PROC_TGID_STAT,
112 PROC_TGID_STATM,
113 PROC_TGID_MAPS,
114 PROC_TGID_NUMA_MAPS,
115 PROC_TGID_MOUNTS,
116 PROC_TGID_MOUNTSTATS,
117 PROC_TGID_WCHAN,
118 #ifdef CONFIG_MMU
119 PROC_TGID_SMAPS,
120 #endif
121 #ifdef CONFIG_SCHEDSTATS
122 PROC_TGID_SCHEDSTAT,
123 #endif
124 #ifdef CONFIG_CPUSETS
125 PROC_TGID_CPUSET,
126 #endif
127 #ifdef CONFIG_SECURITY
128 PROC_TGID_ATTR,
129 PROC_TGID_ATTR_CURRENT,
130 PROC_TGID_ATTR_PREV,
131 PROC_TGID_ATTR_EXEC,
132 PROC_TGID_ATTR_FSCREATE,
133 PROC_TGID_ATTR_KEYCREATE,
134 PROC_TGID_ATTR_SOCKCREATE,
135 #endif
136 #ifdef CONFIG_AUDITSYSCALL
137 PROC_TGID_LOGINUID,
138 #endif
139 PROC_TGID_OOM_SCORE,
140 PROC_TGID_OOM_ADJUST,
141 PROC_TID_INO,
142 PROC_TID_STATUS,
143 PROC_TID_MEM,
144 #ifdef CONFIG_SECCOMP
145 PROC_TID_SECCOMP,
146 #endif
147 PROC_TID_CWD,
148 PROC_TID_ROOT,
149 PROC_TID_EXE,
150 PROC_TID_FD,
151 PROC_TID_ENVIRON,
152 PROC_TID_AUXV,
153 PROC_TID_CMDLINE,
154 PROC_TID_STAT,
155 PROC_TID_STATM,
156 PROC_TID_MAPS,
157 PROC_TID_NUMA_MAPS,
158 PROC_TID_MOUNTS,
159 PROC_TID_MOUNTSTATS,
160 PROC_TID_WCHAN,
161 #ifdef CONFIG_MMU
162 PROC_TID_SMAPS,
163 #endif
164 #ifdef CONFIG_SCHEDSTATS
165 PROC_TID_SCHEDSTAT,
166 #endif
167 #ifdef CONFIG_CPUSETS
168 PROC_TID_CPUSET,
169 #endif
170 #ifdef CONFIG_SECURITY
171 PROC_TID_ATTR,
172 PROC_TID_ATTR_CURRENT,
173 PROC_TID_ATTR_PREV,
174 PROC_TID_ATTR_EXEC,
175 PROC_TID_ATTR_FSCREATE,
176 PROC_TID_ATTR_KEYCREATE,
177 PROC_TID_ATTR_SOCKCREATE,
178 #endif
179 #ifdef CONFIG_AUDITSYSCALL
180 PROC_TID_LOGINUID,
181 #endif
182 PROC_TID_OOM_SCORE,
183 PROC_TID_OOM_ADJUST,
185 /* Add new entries before this */
186 PROC_TID_FD_DIR = 0x8000, /* 0x8000-0xffff */
187 };
189 /* Worst case buffer size needed for holding an integer. */
190 #define PROC_NUMBUF 10
192 struct pid_entry {
193 int type;
194 int len;
195 char *name;
196 mode_t mode;
197 };
199 #define E(type,name,mode) {(type),sizeof(name)-1,(name),(mode)}
201 static struct pid_entry tgid_base_stuff[] = {
202 E(PROC_TGID_TASK, "task", S_IFDIR|S_IRUGO|S_IXUGO),
203 E(PROC_TGID_FD, "fd", S_IFDIR|S_IRUSR|S_IXUSR),
204 E(PROC_TGID_ENVIRON, "environ", S_IFREG|S_IRUSR),
205 E(PROC_TGID_AUXV, "auxv", S_IFREG|S_IRUSR),
206 E(PROC_TGID_STATUS, "status", S_IFREG|S_IRUGO),
207 E(PROC_TGID_CMDLINE, "cmdline", S_IFREG|S_IRUGO),
208 E(PROC_TGID_STAT, "stat", S_IFREG|S_IRUGO),
209 E(PROC_TGID_STATM, "statm", S_IFREG|S_IRUGO),
210 E(PROC_TGID_MAPS, "maps", S_IFREG|S_IRUGO),
211 #ifdef CONFIG_NUMA
212 E(PROC_TGID_NUMA_MAPS, "numa_maps", S_IFREG|S_IRUGO),
213 #endif
214 E(PROC_TGID_MEM, "mem", S_IFREG|S_IRUSR|S_IWUSR),
215 #ifdef CONFIG_SECCOMP
216 E(PROC_TGID_SECCOMP, "seccomp", S_IFREG|S_IRUSR|S_IWUSR),
217 #endif
218 E(PROC_TGID_CWD, "cwd", S_IFLNK|S_IRWXUGO),
219 E(PROC_TGID_ROOT, "root", S_IFLNK|S_IRWXUGO),
220 E(PROC_TGID_EXE, "exe", S_IFLNK|S_IRWXUGO),
221 E(PROC_TGID_MOUNTS, "mounts", S_IFREG|S_IRUGO),
222 E(PROC_TGID_MOUNTSTATS, "mountstats", S_IFREG|S_IRUSR),
223 #ifdef CONFIG_MMU
224 E(PROC_TGID_SMAPS, "smaps", S_IFREG|S_IRUGO),
225 #endif
226 #ifdef CONFIG_SECURITY
227 E(PROC_TGID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO),
228 #endif
229 #ifdef CONFIG_KALLSYMS
230 E(PROC_TGID_WCHAN, "wchan", S_IFREG|S_IRUGO),
231 #endif
232 #ifdef CONFIG_SCHEDSTATS
233 E(PROC_TGID_SCHEDSTAT, "schedstat", S_IFREG|S_IRUGO),
234 #endif
235 #ifdef CONFIG_CPUSETS
236 E(PROC_TGID_CPUSET, "cpuset", S_IFREG|S_IRUGO),
237 #endif
238 E(PROC_TGID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO),
239 E(PROC_TGID_OOM_ADJUST,"oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
240 #ifdef CONFIG_AUDITSYSCALL
241 E(PROC_TGID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
242 #endif
243 {0,0,NULL,0}
244 };
245 static struct pid_entry tid_base_stuff[] = {
246 E(PROC_TID_FD, "fd", S_IFDIR|S_IRUSR|S_IXUSR),
247 E(PROC_TID_ENVIRON, "environ", S_IFREG|S_IRUSR),
248 E(PROC_TID_AUXV, "auxv", S_IFREG|S_IRUSR),
249 E(PROC_TID_STATUS, "status", S_IFREG|S_IRUGO),
250 E(PROC_TID_CMDLINE, "cmdline", S_IFREG|S_IRUGO),
251 E(PROC_TID_STAT, "stat", S_IFREG|S_IRUGO),
252 E(PROC_TID_STATM, "statm", S_IFREG|S_IRUGO),
253 E(PROC_TID_MAPS, "maps", S_IFREG|S_IRUGO),
254 #ifdef CONFIG_NUMA
255 E(PROC_TID_NUMA_MAPS, "numa_maps", S_IFREG|S_IRUGO),
256 #endif
257 E(PROC_TID_MEM, "mem", S_IFREG|S_IRUSR|S_IWUSR),
258 #ifdef CONFIG_SECCOMP
259 E(PROC_TID_SECCOMP, "seccomp", S_IFREG|S_IRUSR|S_IWUSR),
260 #endif
261 E(PROC_TID_CWD, "cwd", S_IFLNK|S_IRWXUGO),
262 E(PROC_TID_ROOT, "root", S_IFLNK|S_IRWXUGO),
263 E(PROC_TID_EXE, "exe", S_IFLNK|S_IRWXUGO),
264 E(PROC_TID_MOUNTS, "mounts", S_IFREG|S_IRUGO),
265 #ifdef CONFIG_MMU
266 E(PROC_TID_SMAPS, "smaps", S_IFREG|S_IRUGO),
267 #endif
268 #ifdef CONFIG_SECURITY
269 E(PROC_TID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO),
270 #endif
271 #ifdef CONFIG_KALLSYMS
272 E(PROC_TID_WCHAN, "wchan", S_IFREG|S_IRUGO),
273 #endif
274 #ifdef CONFIG_SCHEDSTATS
275 E(PROC_TID_SCHEDSTAT, "schedstat",S_IFREG|S_IRUGO),
276 #endif
277 #ifdef CONFIG_CPUSETS
278 E(PROC_TID_CPUSET, "cpuset", S_IFREG|S_IRUGO),
279 #endif
280 E(PROC_TID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO),
281 E(PROC_TID_OOM_ADJUST, "oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
282 #ifdef CONFIG_AUDITSYSCALL
283 E(PROC_TID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
284 #endif
285 {0,0,NULL,0}
286 };
288 #ifdef CONFIG_SECURITY
289 static struct pid_entry tgid_attr_stuff[] = {
290 E(PROC_TGID_ATTR_CURRENT, "current", S_IFREG|S_IRUGO|S_IWUGO),
291 E(PROC_TGID_ATTR_PREV, "prev", S_IFREG|S_IRUGO),
292 E(PROC_TGID_ATTR_EXEC, "exec", S_IFREG|S_IRUGO|S_IWUGO),
293 E(PROC_TGID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
294 E(PROC_TGID_ATTR_KEYCREATE, "keycreate", S_IFREG|S_IRUGO|S_IWUGO),
295 E(PROC_TGID_ATTR_SOCKCREATE, "sockcreate", S_IFREG|S_IRUGO|S_IWUGO),
296 {0,0,NULL,0}
297 };
298 static struct pid_entry tid_attr_stuff[] = {
299 E(PROC_TID_ATTR_CURRENT, "current", S_IFREG|S_IRUGO|S_IWUGO),
300 E(PROC_TID_ATTR_PREV, "prev", S_IFREG|S_IRUGO),
301 E(PROC_TID_ATTR_EXEC, "exec", S_IFREG|S_IRUGO|S_IWUGO),
302 E(PROC_TID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
303 E(PROC_TID_ATTR_KEYCREATE, "keycreate", S_IFREG|S_IRUGO|S_IWUGO),
304 E(PROC_TID_ATTR_SOCKCREATE, "sockcreate", S_IFREG|S_IRUGO|S_IWUGO),
305 {0,0,NULL,0}
306 };
307 #endif
309 #undef E
311 static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
312 {
313 struct task_struct *task = get_proc_task(inode);
314 struct files_struct *files = NULL;
315 struct file *file;
316 int fd = proc_fd(inode);
318 if (task) {
319 files = get_files_struct(task);
320 put_task_struct(task);
321 }
322 if (files) {
323 /*
324 * We are not taking a ref to the file structure, so we must
325 * hold ->file_lock.
326 */
327 spin_lock(&files->file_lock);
328 file = fcheck_files(files, fd);
329 if (file) {
330 *mnt = mntget(file->f_vfsmnt);
331 *dentry = dget(file->f_dentry);
332 spin_unlock(&files->file_lock);
333 put_files_struct(files);
334 return 0;
335 }
336 spin_unlock(&files->file_lock);
337 put_files_struct(files);
338 }
339 return -ENOENT;
340 }
342 static struct fs_struct *get_fs_struct(struct task_struct *task)
343 {
344 struct fs_struct *fs;
345 task_lock(task);
346 fs = task->fs;
347 if(fs)
348 atomic_inc(&fs->count);
349 task_unlock(task);
350 return fs;
351 }
353 static int get_nr_threads(struct task_struct *tsk)
354 {
355 /* Must be called with the rcu_read_lock held */
356 unsigned long flags;
357 int count = 0;
359 if (lock_task_sighand(tsk, &flags)) {
360 count = atomic_read(&tsk->signal->count);
361 unlock_task_sighand(tsk, &flags);
362 }
363 return count;
364 }
366 static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
367 {
368 struct task_struct *task = get_proc_task(inode);
369 struct fs_struct *fs = NULL;
370 int result = -ENOENT;
372 if (task) {
373 fs = get_fs_struct(task);
374 put_task_struct(task);
375 }
376 if (fs) {
377 read_lock(&fs->lock);
378 *mnt = mntget(fs->pwdmnt);
379 *dentry = dget(fs->pwd);
380 read_unlock(&fs->lock);
381 result = 0;
382 put_fs_struct(fs);
383 }
384 return result;
385 }
387 static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
388 {
389 struct task_struct *task = get_proc_task(inode);
390 struct fs_struct *fs = NULL;
391 int result = -ENOENT;
393 if (task) {
394 fs = get_fs_struct(task);
395 put_task_struct(task);
396 }
397 if (fs) {
398 read_lock(&fs->lock);
399 *mnt = mntget(fs->rootmnt);
400 *dentry = dget(fs->root);
401 read_unlock(&fs->lock);
402 result = 0;
403 put_fs_struct(fs);
404 }
405 return result;
406 }
408 #define MAY_PTRACE(task) \
409 (task == current || \
410 (task->parent == current && \
411 (task->ptrace & PT_PTRACED) && \
412 (task->state == TASK_STOPPED || task->state == TASK_TRACED) && \
413 security_ptrace(current,task) == 0))
415 static int proc_pid_environ(struct task_struct *task, char * buffer)
416 {
417 int res = 0;
418 struct mm_struct *mm = get_task_mm(task);
419 if (mm) {
420 unsigned int len = mm->env_end - mm->env_start;
421 if (len > PAGE_SIZE)
422 len = PAGE_SIZE;
423 res = access_process_vm(task, mm->env_start, buffer, len, 0);
424 if (!ptrace_may_attach(task))
425 res = -ESRCH;
426 mmput(mm);
427 }
428 return res;
429 }
431 static int proc_pid_cmdline(struct task_struct *task, char * buffer)
432 {
433 int res = 0;
434 unsigned int len;
435 struct mm_struct *mm = get_task_mm(task);
436 if (!mm)
437 goto out;
438 if (!mm->arg_end)
439 goto out_mm; /* Shh! No looking before we're done */
441 len = mm->arg_end - mm->arg_start;
443 if (len > PAGE_SIZE)
444 len = PAGE_SIZE;
446 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
448 // If the nul at the end of args has been overwritten, then
449 // assume application is using setproctitle(3).
450 if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
451 len = strnlen(buffer, res);
452 if (len < res) {
453 res = len;
454 } else {
455 len = mm->env_end - mm->env_start;
456 if (len > PAGE_SIZE - res)
457 len = PAGE_SIZE - res;
458 res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
459 res = strnlen(buffer, res);
460 }
461 }
462 out_mm:
463 mmput(mm);
464 out:
465 return res;
466 }
468 static int proc_pid_auxv(struct task_struct *task, char *buffer)
469 {
470 int res = 0;
471 struct mm_struct *mm = get_task_mm(task);
472 if (mm) {
473 unsigned int nwords = 0;
474 do
475 nwords += 2;
476 while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
477 res = nwords * sizeof(mm->saved_auxv[0]);
478 if (res > PAGE_SIZE)
479 res = PAGE_SIZE;
480 memcpy(buffer, mm->saved_auxv, res);
481 mmput(mm);
482 }
483 return res;
484 }
487 #ifdef CONFIG_KALLSYMS
488 /*
489 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
490 * Returns the resolved symbol. If that fails, simply return the address.
491 */
492 static int proc_pid_wchan(struct task_struct *task, char *buffer)
493 {
494 char *modname;
495 const char *sym_name;
496 unsigned long wchan, size, offset;
497 char namebuf[KSYM_NAME_LEN+1];
499 wchan = get_wchan(task);
501 sym_name = kallsyms_lookup(wchan, &size, &offset, &modname, namebuf);
502 if (sym_name)
503 return sprintf(buffer, "%s", sym_name);
504 return sprintf(buffer, "%lu", wchan);
505 }
506 #endif /* CONFIG_KALLSYMS */
508 #ifdef CONFIG_SCHEDSTATS
509 /*
510 * Provides /proc/PID/schedstat
511 */
512 static int proc_pid_schedstat(struct task_struct *task, char *buffer)
513 {
514 return sprintf(buffer, "%lu %lu %lu\n",
515 task->sched_info.cpu_time,
516 task->sched_info.run_delay,
517 task->sched_info.pcnt);
518 }
519 #endif
521 /* The badness from the OOM killer */
522 unsigned long badness(struct task_struct *p, unsigned long uptime);
523 static int proc_oom_score(struct task_struct *task, char *buffer)
524 {
525 unsigned long points;
526 struct timespec uptime;
528 do_posix_clock_monotonic_gettime(&uptime);
529 points = badness(task, uptime.tv_sec);
530 return sprintf(buffer, "%lu\n", points);
531 }
533 /************************************************************************/
534 /* Here the fs part begins */
535 /************************************************************************/
537 /* permission checks */
538 static int proc_fd_access_allowed(struct inode *inode)
539 {
540 struct task_struct *task;
541 int allowed = 0;
542 /* Allow access to a task's file descriptors if it is us or we
543 * may use ptrace attach to the process and find out that
544 * information.
545 */
546 task = get_proc_task(inode);
547 if (task) {
548 allowed = ptrace_may_attach(task);
549 put_task_struct(task);
550 }
551 return allowed;
552 }
554 static int proc_setattr(struct dentry *dentry, struct iattr *attr)
555 {
556 int error;
557 struct inode *inode = dentry->d_inode;
559 if (attr->ia_valid & ATTR_MODE)
560 return -EPERM;
562 error = inode_change_ok(inode, attr);
563 if (!error) {
564 error = security_inode_setattr(dentry, attr);
565 if (!error)
566 error = inode_setattr(inode, attr);
567 }
568 return error;
569 }
571 static struct inode_operations proc_def_inode_operations = {
572 .setattr = proc_setattr,
573 };
575 extern struct seq_operations mounts_op;
576 struct proc_mounts {
577 struct seq_file m;
578 int event;
579 };
581 static int mounts_open(struct inode *inode, struct file *file)
582 {
583 struct task_struct *task = get_proc_task(inode);
584 struct namespace *namespace = NULL;
585 struct proc_mounts *p;
586 int ret = -EINVAL;
588 if (task) {
589 task_lock(task);
590 namespace = task->namespace;
591 if (namespace)
592 get_namespace(namespace);
593 task_unlock(task);
594 put_task_struct(task);
595 }
597 if (namespace) {
598 ret = -ENOMEM;
599 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
600 if (p) {
601 file->private_data = &p->m;
602 ret = seq_open(file, &mounts_op);
603 if (!ret) {
604 p->m.private = namespace;
605 p->event = namespace->event;
606 return 0;
607 }
608 kfree(p);
609 }
610 put_namespace(namespace);
611 }
612 return ret;
613 }
615 static int mounts_release(struct inode *inode, struct file *file)
616 {
617 struct seq_file *m = file->private_data;
618 struct namespace *namespace = m->private;
619 put_namespace(namespace);
620 return seq_release(inode, file);
621 }
623 static unsigned mounts_poll(struct file *file, poll_table *wait)
624 {
625 struct proc_mounts *p = file->private_data;
626 struct namespace *ns = p->m.private;
627 unsigned res = 0;
629 poll_wait(file, &ns->poll, wait);
631 spin_lock(&vfsmount_lock);
632 if (p->event != ns->event) {
633 p->event = ns->event;
634 res = POLLERR;
635 }
636 spin_unlock(&vfsmount_lock);
638 return res;
639 }
641 static struct file_operations proc_mounts_operations = {
642 .open = mounts_open,
643 .read = seq_read,
644 .llseek = seq_lseek,
645 .release = mounts_release,
646 .poll = mounts_poll,
647 };
649 extern struct seq_operations mountstats_op;
650 static int mountstats_open(struct inode *inode, struct file *file)
651 {
652 int ret = seq_open(file, &mountstats_op);
654 if (!ret) {
655 struct seq_file *m = file->private_data;
656 struct namespace *namespace = NULL;
657 struct task_struct *task = get_proc_task(inode);
659 if (task) {
660 task_lock(task);
661 namespace = task->namespace;
662 if (namespace)
663 get_namespace(namespace);
664 task_unlock(task);
665 put_task_struct(task);
666 }
668 if (namespace)
669 m->private = namespace;
670 else {
671 seq_release(inode, file);
672 ret = -EINVAL;
673 }
674 }
675 return ret;
676 }
678 static struct file_operations proc_mountstats_operations = {
679 .open = mountstats_open,
680 .read = seq_read,
681 .llseek = seq_lseek,
682 .release = mounts_release,
683 };
685 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
687 static ssize_t proc_info_read(struct file * file, char __user * buf,
688 size_t count, loff_t *ppos)
689 {
690 struct inode * inode = file->f_dentry->d_inode;
691 unsigned long page;
692 ssize_t length;
693 struct task_struct *task = get_proc_task(inode);
695 length = -ESRCH;
696 if (!task)
697 goto out_no_task;
699 if (count > PROC_BLOCK_SIZE)
700 count = PROC_BLOCK_SIZE;
702 length = -ENOMEM;
703 if (!(page = __get_free_page(GFP_KERNEL)))
704 goto out;
706 length = PROC_I(inode)->op.proc_read(task, (char*)page);
708 if (length >= 0)
709 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
710 free_page(page);
711 out:
712 put_task_struct(task);
713 out_no_task:
714 return length;
715 }
717 static struct file_operations proc_info_file_operations = {
718 .read = proc_info_read,
719 };
721 static int mem_open(struct inode* inode, struct file* file)
722 {
723 file->private_data = (void*)((long)current->self_exec_id);
724 return 0;
725 }
727 static ssize_t mem_read(struct file * file, char __user * buf,
728 size_t count, loff_t *ppos)
729 {
730 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
731 char *page;
732 unsigned long src = *ppos;
733 int ret = -ESRCH;
734 struct mm_struct *mm;
736 if (!task)
737 goto out_no_task;
739 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
740 goto out;
742 ret = -ENOMEM;
743 page = (char *)__get_free_page(GFP_USER);
744 if (!page)
745 goto out;
747 ret = 0;
749 mm = get_task_mm(task);
750 if (!mm)
751 goto out_free;
753 ret = -EIO;
755 if (file->private_data != (void*)((long)current->self_exec_id))
756 goto out_put;
758 ret = 0;
760 while (count > 0) {
761 int this_len, retval;
763 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
764 retval = access_process_vm(task, src, page, this_len, 0);
765 if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) {
766 if (!ret)
767 ret = -EIO;
768 break;
769 }
771 if (copy_to_user(buf, page, retval)) {
772 ret = -EFAULT;
773 break;
774 }
776 ret += retval;
777 src += retval;
778 buf += retval;
779 count -= retval;
780 }
781 *ppos = src;
783 out_put:
784 mmput(mm);
785 out_free:
786 free_page((unsigned long) page);
787 out:
788 put_task_struct(task);
789 out_no_task:
790 return ret;
791 }
793 #define mem_write NULL
795 #ifndef mem_write
796 /* This is a security hazard */
797 static ssize_t mem_write(struct file * file, const char * buf,
798 size_t count, loff_t *ppos)
799 {
800 int copied = 0;
801 char *page;
802 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
803 unsigned long dst = *ppos;
805 copied = -ESRCH;
806 if (!task)
807 goto out_no_task;
809 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
810 goto out;
812 copied = -ENOMEM;
813 page = (char *)__get_free_page(GFP_USER);
814 if (!page)
815 goto out;
817 while (count > 0) {
818 int this_len, retval;
820 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
821 if (copy_from_user(page, buf, this_len)) {
822 copied = -EFAULT;
823 break;
824 }
825 retval = access_process_vm(task, dst, page, this_len, 1);
826 if (!retval) {
827 if (!copied)
828 copied = -EIO;
829 break;
830 }
831 copied += retval;
832 buf += retval;
833 dst += retval;
834 count -= retval;
835 }
836 *ppos = dst;
837 free_page((unsigned long) page);
838 out:
839 put_task_struct(task);
840 out_no_task:
841 return copied;
842 }
843 #endif
845 static loff_t mem_lseek(struct file * file, loff_t offset, int orig)
846 {
847 switch (orig) {
848 case 0:
849 file->f_pos = offset;
850 break;
851 case 1:
852 file->f_pos += offset;
853 break;
854 default:
855 return -EINVAL;
856 }
857 force_successful_syscall_return();
858 return file->f_pos;
859 }
861 static struct file_operations proc_mem_operations = {
862 .llseek = mem_lseek,
863 .read = mem_read,
864 .write = mem_write,
865 .open = mem_open,
866 };
868 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
869 size_t count, loff_t *ppos)
870 {
871 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
872 char buffer[PROC_NUMBUF];
873 size_t len;
874 int oom_adjust;
875 loff_t __ppos = *ppos;
877 if (!task)
878 return -ESRCH;
879 oom_adjust = task->oomkilladj;
880 put_task_struct(task);
882 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
883 if (__ppos >= len)
884 return 0;
885 if (count > len-__ppos)
886 count = len-__ppos;
887 if (copy_to_user(buf, buffer + __ppos, count))
888 return -EFAULT;
889 *ppos = __ppos + count;
890 return count;
891 }
893 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
894 size_t count, loff_t *ppos)
895 {
896 struct task_struct *task;
897 char buffer[PROC_NUMBUF], *end;
898 int oom_adjust;
900 if (!capable(CAP_SYS_RESOURCE))
901 return -EPERM;
902 memset(buffer, 0, sizeof(buffer));
903 if (count > sizeof(buffer) - 1)
904 count = sizeof(buffer) - 1;
905 if (copy_from_user(buffer, buf, count))
906 return -EFAULT;
907 oom_adjust = simple_strtol(buffer, &end, 0);
908 if ((oom_adjust < -16 || oom_adjust > 15) && oom_adjust != OOM_DISABLE)
909 return -EINVAL;
910 if (*end == '\n')
911 end++;
912 task = get_proc_task(file->f_dentry->d_inode);
913 if (!task)
914 return -ESRCH;
915 task->oomkilladj = oom_adjust;
916 put_task_struct(task);
917 if (end - buffer == 0)
918 return -EIO;
919 return end - buffer;
920 }
922 static struct file_operations proc_oom_adjust_operations = {
923 .read = oom_adjust_read,
924 .write = oom_adjust_write,
925 };
927 #ifdef CONFIG_AUDITSYSCALL
928 #define TMPBUFLEN 21
929 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
930 size_t count, loff_t *ppos)
931 {
932 struct inode * inode = file->f_dentry->d_inode;
933 struct task_struct *task = get_proc_task(inode);
934 ssize_t length;
935 char tmpbuf[TMPBUFLEN];
937 if (!task)
938 return -ESRCH;
939 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
940 audit_get_loginuid(task->audit_context));
941 put_task_struct(task);
942 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
943 }
945 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
946 size_t count, loff_t *ppos)
947 {
948 struct inode * inode = file->f_dentry->d_inode;
949 char *page, *tmp;
950 ssize_t length;
951 uid_t loginuid;
953 if (!capable(CAP_AUDIT_CONTROL))
954 return -EPERM;
956 if (current != pid_task(proc_pid(inode), PIDTYPE_PID))
957 return -EPERM;
959 if (count >= PAGE_SIZE)
960 count = PAGE_SIZE - 1;
962 if (*ppos != 0) {
963 /* No partial writes. */
964 return -EINVAL;
965 }
966 page = (char*)__get_free_page(GFP_USER);
967 if (!page)
968 return -ENOMEM;
969 length = -EFAULT;
970 if (copy_from_user(page, buf, count))
971 goto out_free_page;
973 page[count] = '\0';
974 loginuid = simple_strtoul(page, &tmp, 10);
975 if (tmp == page) {
976 length = -EINVAL;
977 goto out_free_page;
979 }
980 length = audit_set_loginuid(current, loginuid);
981 if (likely(length == 0))
982 length = count;
984 out_free_page:
985 free_page((unsigned long) page);
986 return length;
987 }
989 static struct file_operations proc_loginuid_operations = {
990 .read = proc_loginuid_read,
991 .write = proc_loginuid_write,
992 };
993 #endif
995 #ifdef CONFIG_SECCOMP
996 static ssize_t seccomp_read(struct file *file, char __user *buf,
997 size_t count, loff_t *ppos)
998 {
999 struct task_struct *tsk = get_proc_task(file->f_dentry->d_inode);
1000 char __buf[20];
1001 loff_t __ppos = *ppos;
1002 size_t len;
1004 if (!tsk)
1005 return -ESRCH;
1006 /* no need to print the trailing zero, so use only len */
1007 len = sprintf(__buf, "%u\n", tsk->seccomp.mode);
1008 put_task_struct(tsk);
1009 if (__ppos >= len)
1010 return 0;
1011 if (count > len - __ppos)
1012 count = len - __ppos;
1013 if (copy_to_user(buf, __buf + __ppos, count))
1014 return -EFAULT;
1015 *ppos = __ppos + count;
1016 return count;
1019 static ssize_t seccomp_write(struct file *file, const char __user *buf,
1020 size_t count, loff_t *ppos)
1022 struct task_struct *tsk = get_proc_task(file->f_dentry->d_inode);
1023 char __buf[20], *end;
1024 unsigned int seccomp_mode;
1025 ssize_t result;
1027 result = -ESRCH;
1028 if (!tsk)
1029 goto out_no_task;
1031 /* can set it only once to be even more secure */
1032 result = -EPERM;
1033 if (unlikely(tsk->seccomp.mode))
1034 goto out;
1036 result = -EFAULT;
1037 memset(__buf, 0, sizeof(__buf));
1038 count = min(count, sizeof(__buf) - 1);
1039 if (copy_from_user(__buf, buf, count))
1040 goto out;
1042 seccomp_mode = simple_strtoul(__buf, &end, 0);
1043 if (*end == '\n')
1044 end++;
1045 result = -EINVAL;
1046 if (seccomp_mode && seccomp_mode <= NR_SECCOMP_MODES) {
1047 tsk->seccomp.mode = seccomp_mode;
1048 set_tsk_thread_flag(tsk, TIF_SECCOMP);
1049 } else
1050 goto out;
1051 result = -EIO;
1052 if (unlikely(!(end - __buf)))
1053 goto out;
1054 result = end - __buf;
1055 out:
1056 put_task_struct(tsk);
1057 out_no_task:
1058 return result;
1061 static struct file_operations proc_seccomp_operations = {
1062 .read = seccomp_read,
1063 .write = seccomp_write,
1064 };
1065 #endif /* CONFIG_SECCOMP */
1067 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1069 struct inode *inode = dentry->d_inode;
1070 int error = -EACCES;
1072 /* We don't need a base pointer in the /proc filesystem */
1073 path_release(nd);
1075 /* Are we allowed to snoop on the tasks file descriptors? */
1076 if (!proc_fd_access_allowed(inode))
1077 goto out;
1079 error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt);
1080 nd->last_type = LAST_BIND;
1081 out:
1082 return ERR_PTR(error);
1085 static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
1086 char __user *buffer, int buflen)
1088 struct inode * inode;
1089 char *tmp = (char*)__get_free_page(GFP_KERNEL), *path;
1090 int len;
1092 if (!tmp)
1093 return -ENOMEM;
1095 inode = dentry->d_inode;
1096 path = d_path(dentry, mnt, tmp, PAGE_SIZE);
1097 len = PTR_ERR(path);
1098 if (IS_ERR(path))
1099 goto out;
1100 len = tmp + PAGE_SIZE - 1 - path;
1102 if (len > buflen)
1103 len = buflen;
1104 if (copy_to_user(buffer, path, len))
1105 len = -EFAULT;
1106 out:
1107 free_page((unsigned long)tmp);
1108 return len;
1111 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1113 int error = -EACCES;
1114 struct inode *inode = dentry->d_inode;
1115 struct dentry *de;
1116 struct vfsmount *mnt = NULL;
1118 /* Are we allowed to snoop on the tasks file descriptors? */
1119 if (!proc_fd_access_allowed(inode))
1120 goto out;
1122 error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt);
1123 if (error)
1124 goto out;
1126 error = do_proc_readlink(de, mnt, buffer, buflen);
1127 dput(de);
1128 mntput(mnt);
1129 out:
1130 return error;
1133 static struct inode_operations proc_pid_link_inode_operations = {
1134 .readlink = proc_pid_readlink,
1135 .follow_link = proc_pid_follow_link,
1136 .setattr = proc_setattr,
1137 };
1139 static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
1141 struct dentry *dentry = filp->f_dentry;
1142 struct inode *inode = dentry->d_inode;
1143 struct task_struct *p = get_proc_task(inode);
1144 unsigned int fd, tid, ino;
1145 int retval;
1146 char buf[PROC_NUMBUF];
1147 struct files_struct * files;
1148 struct fdtable *fdt;
1150 retval = -ENOENT;
1151 if (!p)
1152 goto out_no_task;
1153 retval = 0;
1154 tid = p->pid;
1156 fd = filp->f_pos;
1157 switch (fd) {
1158 case 0:
1159 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1160 goto out;
1161 filp->f_pos++;
1162 case 1:
1163 ino = parent_ino(dentry);
1164 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1165 goto out;
1166 filp->f_pos++;
1167 default:
1168 files = get_files_struct(p);
1169 if (!files)
1170 goto out;
1171 rcu_read_lock();
1172 fdt = files_fdtable(files);
1173 for (fd = filp->f_pos-2;
1174 fd < fdt->max_fds;
1175 fd++, filp->f_pos++) {
1176 unsigned int i,j;
1178 if (!fcheck_files(files, fd))
1179 continue;
1180 rcu_read_unlock();
1182 j = PROC_NUMBUF;
1183 i = fd;
1184 do {
1185 j--;
1186 buf[j] = '0' + (i % 10);
1187 i /= 10;
1188 } while (i);
1190 ino = fake_ino(tid, PROC_TID_FD_DIR + fd);
1191 if (filldir(dirent, buf+j, PROC_NUMBUF-j, fd+2, ino, DT_LNK) < 0) {
1192 rcu_read_lock();
1193 break;
1195 rcu_read_lock();
1197 rcu_read_unlock();
1198 put_files_struct(files);
1200 out:
1201 put_task_struct(p);
1202 out_no_task:
1203 return retval;
1206 static int proc_pident_readdir(struct file *filp,
1207 void *dirent, filldir_t filldir,
1208 struct pid_entry *ents, unsigned int nents)
1210 int i;
1211 int pid;
1212 struct dentry *dentry = filp->f_dentry;
1213 struct inode *inode = dentry->d_inode;
1214 struct task_struct *task = get_proc_task(inode);
1215 struct pid_entry *p;
1216 ino_t ino;
1217 int ret;
1219 ret = -ENOENT;
1220 if (!task)
1221 goto out;
1223 ret = 0;
1224 pid = task->pid;
1225 put_task_struct(task);
1226 i = filp->f_pos;
1227 switch (i) {
1228 case 0:
1229 ino = inode->i_ino;
1230 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
1231 goto out;
1232 i++;
1233 filp->f_pos++;
1234 /* fall through */
1235 case 1:
1236 ino = parent_ino(dentry);
1237 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
1238 goto out;
1239 i++;
1240 filp->f_pos++;
1241 /* fall through */
1242 default:
1243 i -= 2;
1244 if (i >= nents) {
1245 ret = 1;
1246 goto out;
1248 p = ents + i;
1249 while (p->name) {
1250 if (filldir(dirent, p->name, p->len, filp->f_pos,
1251 fake_ino(pid, p->type), p->mode >> 12) < 0)
1252 goto out;
1253 filp->f_pos++;
1254 p++;
1258 ret = 1;
1259 out:
1260 return ret;
1263 static int proc_tgid_base_readdir(struct file * filp,
1264 void * dirent, filldir_t filldir)
1266 return proc_pident_readdir(filp,dirent,filldir,
1267 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
1270 static int proc_tid_base_readdir(struct file * filp,
1271 void * dirent, filldir_t filldir)
1273 return proc_pident_readdir(filp,dirent,filldir,
1274 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
1277 /* building an inode */
1279 static int task_dumpable(struct task_struct *task)
1281 int dumpable = 0;
1282 struct mm_struct *mm;
1284 task_lock(task);
1285 mm = task->mm;
1286 if (mm)
1287 dumpable = mm->dumpable;
1288 task_unlock(task);
1289 if(dumpable == 1)
1290 return 1;
1291 return 0;
1295 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task, int ino)
1297 struct inode * inode;
1298 struct proc_inode *ei;
1300 /* We need a new inode */
1302 inode = new_inode(sb);
1303 if (!inode)
1304 goto out;
1306 /* Common stuff */
1307 ei = PROC_I(inode);
1308 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1309 inode->i_ino = fake_ino(task->pid, ino);
1310 inode->i_op = &proc_def_inode_operations;
1312 /*
1313 * grab the reference to task.
1314 */
1315 ei->pid = get_pid(task->pids[PIDTYPE_PID].pid);
1316 if (!ei->pid)
1317 goto out_unlock;
1319 inode->i_uid = 0;
1320 inode->i_gid = 0;
1321 if (task_dumpable(task)) {
1322 inode->i_uid = task->euid;
1323 inode->i_gid = task->egid;
1325 security_task_to_inode(task, inode);
1327 out:
1328 return inode;
1330 out_unlock:
1331 iput(inode);
1332 return NULL;
1335 /* dentry stuff */
1337 /*
1338 * Exceptional case: normally we are not allowed to unhash a busy
1339 * directory. In this case, however, we can do it - no aliasing problems
1340 * due to the way we treat inodes.
1342 * Rewrite the inode's ownerships here because the owning task may have
1343 * performed a setuid(), etc.
1345 * Before the /proc/pid/status file was created the only way to read
1346 * the effective uid of a /process was to stat /proc/pid. Reading
1347 * /proc/pid/status is slow enough that procps and other packages
1348 * kept stating /proc/pid. To keep the rules in /proc simple I have
1349 * made this apply to all per process world readable and executable
1350 * directories.
1351 */
1352 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1354 struct inode *inode = dentry->d_inode;
1355 struct task_struct *task = get_proc_task(inode);
1356 if (task) {
1357 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1358 task_dumpable(task)) {
1359 inode->i_uid = task->euid;
1360 inode->i_gid = task->egid;
1361 } else {
1362 inode->i_uid = 0;
1363 inode->i_gid = 0;
1365 inode->i_mode &= ~(S_ISUID | S_ISGID);
1366 security_task_to_inode(task, inode);
1367 put_task_struct(task);
1368 return 1;
1370 d_drop(dentry);
1371 return 0;
1374 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1376 struct inode *inode = dentry->d_inode;
1377 struct task_struct *task;
1378 generic_fillattr(inode, stat);
1380 rcu_read_lock();
1381 stat->uid = 0;
1382 stat->gid = 0;
1383 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1384 if (task) {
1385 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1386 task_dumpable(task)) {
1387 stat->uid = task->euid;
1388 stat->gid = task->egid;
1391 rcu_read_unlock();
1392 return 0;
1395 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1397 struct inode *inode = dentry->d_inode;
1398 struct task_struct *task = get_proc_task(inode);
1399 int fd = proc_fd(inode);
1400 struct files_struct *files;
1402 if (task) {
1403 files = get_files_struct(task);
1404 if (files) {
1405 rcu_read_lock();
1406 if (fcheck_files(files, fd)) {
1407 rcu_read_unlock();
1408 put_files_struct(files);
1409 if (task_dumpable(task)) {
1410 inode->i_uid = task->euid;
1411 inode->i_gid = task->egid;
1412 } else {
1413 inode->i_uid = 0;
1414 inode->i_gid = 0;
1416 inode->i_mode &= ~(S_ISUID | S_ISGID);
1417 security_task_to_inode(task, inode);
1418 put_task_struct(task);
1419 return 1;
1421 rcu_read_unlock();
1422 put_files_struct(files);
1424 put_task_struct(task);
1426 d_drop(dentry);
1427 return 0;
1430 static int pid_delete_dentry(struct dentry * dentry)
1432 /* Is the task we represent dead?
1433 * If so, then don't put the dentry on the lru list,
1434 * kill it immediately.
1435 */
1436 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1439 static struct dentry_operations tid_fd_dentry_operations =
1441 .d_revalidate = tid_fd_revalidate,
1442 .d_delete = pid_delete_dentry,
1443 };
1445 static struct dentry_operations pid_dentry_operations =
1447 .d_revalidate = pid_revalidate,
1448 .d_delete = pid_delete_dentry,
1449 };
1451 /* Lookups */
1453 static unsigned name_to_int(struct dentry *dentry)
1455 const char *name = dentry->d_name.name;
1456 int len = dentry->d_name.len;
1457 unsigned n = 0;
1459 if (len > 1 && *name == '0')
1460 goto out;
1461 while (len-- > 0) {
1462 unsigned c = *name++ - '0';
1463 if (c > 9)
1464 goto out;
1465 if (n >= (~0U-9)/10)
1466 goto out;
1467 n *= 10;
1468 n += c;
1470 return n;
1471 out:
1472 return ~0U;
1475 /* SMP-safe */
1476 static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
1478 struct task_struct *task = get_proc_task(dir);
1479 unsigned fd = name_to_int(dentry);
1480 struct dentry *result = ERR_PTR(-ENOENT);
1481 struct file * file;
1482 struct files_struct * files;
1483 struct inode *inode;
1484 struct proc_inode *ei;
1486 if (!task)
1487 goto out_no_task;
1488 if (fd == ~0U)
1489 goto out;
1491 inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_FD_DIR+fd);
1492 if (!inode)
1493 goto out;
1494 ei = PROC_I(inode);
1495 ei->fd = fd;
1496 files = get_files_struct(task);
1497 if (!files)
1498 goto out_unlock;
1499 inode->i_mode = S_IFLNK;
1501 /*
1502 * We are not taking a ref to the file structure, so we must
1503 * hold ->file_lock.
1504 */
1505 spin_lock(&files->file_lock);
1506 file = fcheck_files(files, fd);
1507 if (!file)
1508 goto out_unlock2;
1509 if (file->f_mode & 1)
1510 inode->i_mode |= S_IRUSR | S_IXUSR;
1511 if (file->f_mode & 2)
1512 inode->i_mode |= S_IWUSR | S_IXUSR;
1513 spin_unlock(&files->file_lock);
1514 put_files_struct(files);
1515 inode->i_op = &proc_pid_link_inode_operations;
1516 inode->i_size = 64;
1517 ei->op.proc_get_link = proc_fd_link;
1518 dentry->d_op = &tid_fd_dentry_operations;
1519 d_add(dentry, inode);
1520 /* Close the race of the process dying before we return the dentry */
1521 if (tid_fd_revalidate(dentry, NULL))
1522 result = NULL;
1523 out:
1524 put_task_struct(task);
1525 out_no_task:
1526 return result;
1528 out_unlock2:
1529 spin_unlock(&files->file_lock);
1530 put_files_struct(files);
1531 out_unlock:
1532 iput(inode);
1533 goto out;
1536 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir);
1537 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd);
1538 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
1540 static struct file_operations proc_fd_operations = {
1541 .read = generic_read_dir,
1542 .readdir = proc_readfd,
1543 };
1545 static struct file_operations proc_task_operations = {
1546 .read = generic_read_dir,
1547 .readdir = proc_task_readdir,
1548 };
1550 /*
1551 * proc directories can do almost nothing..
1552 */
1553 static struct inode_operations proc_fd_inode_operations = {
1554 .lookup = proc_lookupfd,
1555 .setattr = proc_setattr,
1556 };
1558 static struct inode_operations proc_task_inode_operations = {
1559 .lookup = proc_task_lookup,
1560 .getattr = proc_task_getattr,
1561 .setattr = proc_setattr,
1562 };
1564 #ifdef CONFIG_SECURITY
1565 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
1566 size_t count, loff_t *ppos)
1568 struct inode * inode = file->f_dentry->d_inode;
1569 unsigned long page;
1570 ssize_t length;
1571 struct task_struct *task = get_proc_task(inode);
1573 length = -ESRCH;
1574 if (!task)
1575 goto out_no_task;
1577 if (count > PAGE_SIZE)
1578 count = PAGE_SIZE;
1579 length = -ENOMEM;
1580 if (!(page = __get_free_page(GFP_KERNEL)))
1581 goto out;
1583 length = security_getprocattr(task,
1584 (char*)file->f_dentry->d_name.name,
1585 (void*)page, count);
1586 if (length >= 0)
1587 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
1588 free_page(page);
1589 out:
1590 put_task_struct(task);
1591 out_no_task:
1592 return length;
1595 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
1596 size_t count, loff_t *ppos)
1598 struct inode * inode = file->f_dentry->d_inode;
1599 char *page;
1600 ssize_t length;
1601 struct task_struct *task = get_proc_task(inode);
1603 length = -ESRCH;
1604 if (!task)
1605 goto out_no_task;
1606 if (count > PAGE_SIZE)
1607 count = PAGE_SIZE;
1609 /* No partial writes. */
1610 length = -EINVAL;
1611 if (*ppos != 0)
1612 goto out;
1614 length = -ENOMEM;
1615 page = (char*)__get_free_page(GFP_USER);
1616 if (!page)
1617 goto out;
1619 length = -EFAULT;
1620 if (copy_from_user(page, buf, count))
1621 goto out_free;
1623 length = security_setprocattr(task,
1624 (char*)file->f_dentry->d_name.name,
1625 (void*)page, count);
1626 out_free:
1627 free_page((unsigned long) page);
1628 out:
1629 put_task_struct(task);
1630 out_no_task:
1631 return length;
1634 static struct file_operations proc_pid_attr_operations = {
1635 .read = proc_pid_attr_read,
1636 .write = proc_pid_attr_write,
1637 };
1639 static struct file_operations proc_tid_attr_operations;
1640 static struct inode_operations proc_tid_attr_inode_operations;
1641 static struct file_operations proc_tgid_attr_operations;
1642 static struct inode_operations proc_tgid_attr_inode_operations;
1643 #endif
1645 /* SMP-safe */
1646 static struct dentry *proc_pident_lookup(struct inode *dir,
1647 struct dentry *dentry,
1648 struct pid_entry *ents)
1650 struct inode *inode;
1651 struct dentry *error;
1652 struct task_struct *task = get_proc_task(dir);
1653 struct pid_entry *p;
1654 struct proc_inode *ei;
1656 error = ERR_PTR(-ENOENT);
1657 inode = NULL;
1659 if (!task)
1660 goto out_no_task;
1662 for (p = ents; p->name; p++) {
1663 if (p->len != dentry->d_name.len)
1664 continue;
1665 if (!memcmp(dentry->d_name.name, p->name, p->len))
1666 break;
1668 if (!p->name)
1669 goto out;
1671 error = ERR_PTR(-EINVAL);
1672 inode = proc_pid_make_inode(dir->i_sb, task, p->type);
1673 if (!inode)
1674 goto out;
1676 ei = PROC_I(inode);
1677 inode->i_mode = p->mode;
1678 /*
1679 * Yes, it does not scale. And it should not. Don't add
1680 * new entries into /proc/<tgid>/ without very good reasons.
1681 */
1682 switch(p->type) {
1683 case PROC_TGID_TASK:
1684 inode->i_nlink = 2;
1685 inode->i_op = &proc_task_inode_operations;
1686 inode->i_fop = &proc_task_operations;
1687 break;
1688 case PROC_TID_FD:
1689 case PROC_TGID_FD:
1690 inode->i_nlink = 2;
1691 inode->i_op = &proc_fd_inode_operations;
1692 inode->i_fop = &proc_fd_operations;
1693 break;
1694 case PROC_TID_EXE:
1695 case PROC_TGID_EXE:
1696 inode->i_op = &proc_pid_link_inode_operations;
1697 ei->op.proc_get_link = proc_exe_link;
1698 break;
1699 case PROC_TID_CWD:
1700 case PROC_TGID_CWD:
1701 inode->i_op = &proc_pid_link_inode_operations;
1702 ei->op.proc_get_link = proc_cwd_link;
1703 break;
1704 case PROC_TID_ROOT:
1705 case PROC_TGID_ROOT:
1706 inode->i_op = &proc_pid_link_inode_operations;
1707 ei->op.proc_get_link = proc_root_link;
1708 break;
1709 case PROC_TID_ENVIRON:
1710 case PROC_TGID_ENVIRON:
1711 inode->i_fop = &proc_info_file_operations;
1712 ei->op.proc_read = proc_pid_environ;
1713 break;
1714 case PROC_TID_AUXV:
1715 case PROC_TGID_AUXV:
1716 inode->i_fop = &proc_info_file_operations;
1717 ei->op.proc_read = proc_pid_auxv;
1718 break;
1719 case PROC_TID_STATUS:
1720 case PROC_TGID_STATUS:
1721 inode->i_fop = &proc_info_file_operations;
1722 ei->op.proc_read = proc_pid_status;
1723 break;
1724 case PROC_TID_STAT:
1725 inode->i_fop = &proc_info_file_operations;
1726 ei->op.proc_read = proc_tid_stat;
1727 break;
1728 case PROC_TGID_STAT:
1729 inode->i_fop = &proc_info_file_operations;
1730 ei->op.proc_read = proc_tgid_stat;
1731 break;
1732 case PROC_TID_CMDLINE:
1733 case PROC_TGID_CMDLINE:
1734 inode->i_fop = &proc_info_file_operations;
1735 ei->op.proc_read = proc_pid_cmdline;
1736 break;
1737 case PROC_TID_STATM:
1738 case PROC_TGID_STATM:
1739 inode->i_fop = &proc_info_file_operations;
1740 ei->op.proc_read = proc_pid_statm;
1741 break;
1742 case PROC_TID_MAPS:
1743 case PROC_TGID_MAPS:
1744 inode->i_fop = &proc_maps_operations;
1745 break;
1746 #ifdef CONFIG_NUMA
1747 case PROC_TID_NUMA_MAPS:
1748 case PROC_TGID_NUMA_MAPS:
1749 inode->i_fop = &proc_numa_maps_operations;
1750 break;
1751 #endif
1752 case PROC_TID_MEM:
1753 case PROC_TGID_MEM:
1754 inode->i_fop = &proc_mem_operations;
1755 break;
1756 #ifdef CONFIG_SECCOMP
1757 case PROC_TID_SECCOMP:
1758 case PROC_TGID_SECCOMP:
1759 inode->i_fop = &proc_seccomp_operations;
1760 break;
1761 #endif /* CONFIG_SECCOMP */
1762 case PROC_TID_MOUNTS:
1763 case PROC_TGID_MOUNTS:
1764 inode->i_fop = &proc_mounts_operations;
1765 break;
1766 #ifdef CONFIG_MMU
1767 case PROC_TID_SMAPS:
1768 case PROC_TGID_SMAPS:
1769 inode->i_fop = &proc_smaps_operations;
1770 break;
1771 #endif
1772 case PROC_TID_MOUNTSTATS:
1773 case PROC_TGID_MOUNTSTATS:
1774 inode->i_fop = &proc_mountstats_operations;
1775 break;
1776 #ifdef CONFIG_SECURITY
1777 case PROC_TID_ATTR:
1778 inode->i_nlink = 2;
1779 inode->i_op = &proc_tid_attr_inode_operations;
1780 inode->i_fop = &proc_tid_attr_operations;
1781 break;
1782 case PROC_TGID_ATTR:
1783 inode->i_nlink = 2;
1784 inode->i_op = &proc_tgid_attr_inode_operations;
1785 inode->i_fop = &proc_tgid_attr_operations;
1786 break;
1787 case PROC_TID_ATTR_CURRENT:
1788 case PROC_TGID_ATTR_CURRENT:
1789 case PROC_TID_ATTR_PREV:
1790 case PROC_TGID_ATTR_PREV:
1791 case PROC_TID_ATTR_EXEC:
1792 case PROC_TGID_ATTR_EXEC:
1793 case PROC_TID_ATTR_FSCREATE:
1794 case PROC_TGID_ATTR_FSCREATE:
1795 case PROC_TID_ATTR_KEYCREATE:
1796 case PROC_TGID_ATTR_KEYCREATE:
1797 case PROC_TID_ATTR_SOCKCREATE:
1798 case PROC_TGID_ATTR_SOCKCREATE:
1799 inode->i_fop = &proc_pid_attr_operations;
1800 break;
1801 #endif
1802 #ifdef CONFIG_KALLSYMS
1803 case PROC_TID_WCHAN:
1804 case PROC_TGID_WCHAN:
1805 inode->i_fop = &proc_info_file_operations;
1806 ei->op.proc_read = proc_pid_wchan;
1807 break;
1808 #endif
1809 #ifdef CONFIG_SCHEDSTATS
1810 case PROC_TID_SCHEDSTAT:
1811 case PROC_TGID_SCHEDSTAT:
1812 inode->i_fop = &proc_info_file_operations;
1813 ei->op.proc_read = proc_pid_schedstat;
1814 break;
1815 #endif
1816 #ifdef CONFIG_CPUSETS
1817 case PROC_TID_CPUSET:
1818 case PROC_TGID_CPUSET:
1819 inode->i_fop = &proc_cpuset_operations;
1820 break;
1821 #endif
1822 case PROC_TID_OOM_SCORE:
1823 case PROC_TGID_OOM_SCORE:
1824 inode->i_fop = &proc_info_file_operations;
1825 ei->op.proc_read = proc_oom_score;
1826 break;
1827 case PROC_TID_OOM_ADJUST:
1828 case PROC_TGID_OOM_ADJUST:
1829 inode->i_fop = &proc_oom_adjust_operations;
1830 break;
1831 #ifdef CONFIG_AUDITSYSCALL
1832 case PROC_TID_LOGINUID:
1833 case PROC_TGID_LOGINUID:
1834 inode->i_fop = &proc_loginuid_operations;
1835 break;
1836 #endif
1837 default:
1838 printk("procfs: impossible type (%d)",p->type);
1839 iput(inode);
1840 error = ERR_PTR(-EINVAL);
1841 goto out;
1843 dentry->d_op = &pid_dentry_operations;
1844 d_add(dentry, inode);
1845 /* Close the race of the process dying before we return the dentry */
1846 if (pid_revalidate(dentry, NULL))
1847 error = NULL;
1848 out:
1849 put_task_struct(task);
1850 out_no_task:
1851 return error;
1854 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
1855 return proc_pident_lookup(dir, dentry, tgid_base_stuff);
1858 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
1859 return proc_pident_lookup(dir, dentry, tid_base_stuff);
1862 static struct file_operations proc_tgid_base_operations = {
1863 .read = generic_read_dir,
1864 .readdir = proc_tgid_base_readdir,
1865 };
1867 static struct file_operations proc_tid_base_operations = {
1868 .read = generic_read_dir,
1869 .readdir = proc_tid_base_readdir,
1870 };
1872 static struct inode_operations proc_tgid_base_inode_operations = {
1873 .lookup = proc_tgid_base_lookup,
1874 .getattr = pid_getattr,
1875 .setattr = proc_setattr,
1876 };
1878 static struct inode_operations proc_tid_base_inode_operations = {
1879 .lookup = proc_tid_base_lookup,
1880 .getattr = pid_getattr,
1881 .setattr = proc_setattr,
1882 };
1884 #ifdef CONFIG_SECURITY
1885 static int proc_tgid_attr_readdir(struct file * filp,
1886 void * dirent, filldir_t filldir)
1888 return proc_pident_readdir(filp,dirent,filldir,
1889 tgid_attr_stuff,ARRAY_SIZE(tgid_attr_stuff));
1892 static int proc_tid_attr_readdir(struct file * filp,
1893 void * dirent, filldir_t filldir)
1895 return proc_pident_readdir(filp,dirent,filldir,
1896 tid_attr_stuff,ARRAY_SIZE(tid_attr_stuff));
1899 static struct file_operations proc_tgid_attr_operations = {
1900 .read = generic_read_dir,
1901 .readdir = proc_tgid_attr_readdir,
1902 };
1904 static struct file_operations proc_tid_attr_operations = {
1905 .read = generic_read_dir,
1906 .readdir = proc_tid_attr_readdir,
1907 };
1909 static struct dentry *proc_tgid_attr_lookup(struct inode *dir,
1910 struct dentry *dentry, struct nameidata *nd)
1912 return proc_pident_lookup(dir, dentry, tgid_attr_stuff);
1915 static struct dentry *proc_tid_attr_lookup(struct inode *dir,
1916 struct dentry *dentry, struct nameidata *nd)
1918 return proc_pident_lookup(dir, dentry, tid_attr_stuff);
1921 static struct inode_operations proc_tgid_attr_inode_operations = {
1922 .lookup = proc_tgid_attr_lookup,
1923 .getattr = pid_getattr,
1924 .setattr = proc_setattr,
1925 };
1927 static struct inode_operations proc_tid_attr_inode_operations = {
1928 .lookup = proc_tid_attr_lookup,
1929 .getattr = pid_getattr,
1930 .setattr = proc_setattr,
1931 };
1932 #endif
1934 /*
1935 * /proc/self:
1936 */
1937 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
1938 int buflen)
1940 char tmp[PROC_NUMBUF];
1941 sprintf(tmp, "%d", current->tgid);
1942 return vfs_readlink(dentry,buffer,buflen,tmp);
1945 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
1947 char tmp[PROC_NUMBUF];
1948 sprintf(tmp, "%d", current->tgid);
1949 return ERR_PTR(vfs_follow_link(nd,tmp));
1952 static struct inode_operations proc_self_inode_operations = {
1953 .readlink = proc_self_readlink,
1954 .follow_link = proc_self_follow_link,
1955 };
1957 /**
1958 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
1960 * @task: task that should be flushed.
1962 * Looks in the dcache for
1963 * /proc/@pid
1964 * /proc/@tgid/task/@pid
1965 * if either directory is present flushes it and all of it'ts children
1966 * from the dcache.
1968 * It is safe and reasonable to cache /proc entries for a task until
1969 * that task exits. After that they just clog up the dcache with
1970 * useless entries, possibly causing useful dcache entries to be
1971 * flushed instead. This routine is proved to flush those useless
1972 * dcache entries at process exit time.
1974 * NOTE: This routine is just an optimization so it does not guarantee
1975 * that no dcache entries will exist at process exit time it
1976 * just makes it very unlikely that any will persist.
1977 */
1978 void proc_flush_task(struct task_struct *task)
1980 struct dentry *dentry, *leader, *dir;
1981 char buf[PROC_NUMBUF];
1982 struct qstr name;
1984 name.name = buf;
1985 name.len = snprintf(buf, sizeof(buf), "%d", task->pid);
1986 dentry = d_hash_and_lookup(proc_mnt->mnt_root, &name);
1987 if (dentry) {
1988 shrink_dcache_parent(dentry);
1989 d_drop(dentry);
1990 dput(dentry);
1993 if (thread_group_leader(task))
1994 goto out;
1996 name.name = buf;
1997 name.len = snprintf(buf, sizeof(buf), "%d", task->tgid);
1998 leader = d_hash_and_lookup(proc_mnt->mnt_root, &name);
1999 if (!leader)
2000 goto out;
2002 name.name = "task";
2003 name.len = strlen(name.name);
2004 dir = d_hash_and_lookup(leader, &name);
2005 if (!dir)
2006 goto out_put_leader;
2008 name.name = buf;
2009 name.len = snprintf(buf, sizeof(buf), "%d", task->pid);
2010 dentry = d_hash_and_lookup(dir, &name);
2011 if (dentry) {
2012 shrink_dcache_parent(dentry);
2013 d_drop(dentry);
2014 dput(dentry);
2017 dput(dir);
2018 out_put_leader:
2019 dput(leader);
2020 out:
2021 return;
2024 /* SMP-safe */
2025 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2027 struct dentry *result = ERR_PTR(-ENOENT);
2028 struct task_struct *task;
2029 struct inode *inode;
2030 struct proc_inode *ei;
2031 unsigned tgid;
2033 if (dentry->d_name.len == 4 && !memcmp(dentry->d_name.name,"self",4)) {
2034 inode = new_inode(dir->i_sb);
2035 if (!inode)
2036 return ERR_PTR(-ENOMEM);
2037 ei = PROC_I(inode);
2038 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2039 inode->i_ino = fake_ino(0, PROC_TGID_INO);
2040 ei->pde = NULL;
2041 inode->i_mode = S_IFLNK|S_IRWXUGO;
2042 inode->i_uid = inode->i_gid = 0;
2043 inode->i_size = 64;
2044 inode->i_op = &proc_self_inode_operations;
2045 d_add(dentry, inode);
2046 return NULL;
2048 tgid = name_to_int(dentry);
2049 if (tgid == ~0U)
2050 goto out;
2052 rcu_read_lock();
2053 task = find_task_by_pid(tgid);
2054 if (task)
2055 get_task_struct(task);
2056 rcu_read_unlock();
2057 if (!task)
2058 goto out;
2060 inode = proc_pid_make_inode(dir->i_sb, task, PROC_TGID_INO);
2061 if (!inode)
2062 goto out_put_task;
2064 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2065 inode->i_op = &proc_tgid_base_inode_operations;
2066 inode->i_fop = &proc_tgid_base_operations;
2067 inode->i_flags|=S_IMMUTABLE;
2068 #ifdef CONFIG_SECURITY
2069 inode->i_nlink = 5;
2070 #else
2071 inode->i_nlink = 4;
2072 #endif
2074 dentry->d_op = &pid_dentry_operations;
2076 d_add(dentry, inode);
2077 /* Close the race of the process dying before we return the dentry */
2078 if (pid_revalidate(dentry, NULL))
2079 result = NULL;
2081 out_put_task:
2082 put_task_struct(task);
2083 out:
2084 return result;
2087 /* SMP-safe */
2088 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2090 struct dentry *result = ERR_PTR(-ENOENT);
2091 struct task_struct *task;
2092 struct task_struct *leader = get_proc_task(dir);
2093 struct inode *inode;
2094 unsigned tid;
2096 if (!leader)
2097 goto out_no_task;
2099 tid = name_to_int(dentry);
2100 if (tid == ~0U)
2101 goto out;
2103 rcu_read_lock();
2104 task = find_task_by_pid(tid);
2105 if (task)
2106 get_task_struct(task);
2107 rcu_read_unlock();
2108 if (!task)
2109 goto out;
2110 if (leader->tgid != task->tgid)
2111 goto out_drop_task;
2113 inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_INO);
2116 if (!inode)
2117 goto out_drop_task;
2118 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2119 inode->i_op = &proc_tid_base_inode_operations;
2120 inode->i_fop = &proc_tid_base_operations;
2121 inode->i_flags|=S_IMMUTABLE;
2122 #ifdef CONFIG_SECURITY
2123 inode->i_nlink = 4;
2124 #else
2125 inode->i_nlink = 3;
2126 #endif
2128 dentry->d_op = &pid_dentry_operations;
2130 d_add(dentry, inode);
2131 /* Close the race of the process dying before we return the dentry */
2132 if (pid_revalidate(dentry, NULL))
2133 result = NULL;
2135 out_drop_task:
2136 put_task_struct(task);
2137 out:
2138 put_task_struct(leader);
2139 out_no_task:
2140 return result;
2143 /*
2144 * Find the first tgid to return to user space.
2146 * Usually this is just whatever follows &init_task, but if the users
2147 * buffer was too small to hold the full list or there was a seek into
2148 * the middle of the directory we have more work to do.
2150 * In the case of a short read we start with find_task_by_pid.
2152 * In the case of a seek we start with &init_task and walk nr
2153 * threads past it.
2154 */
2155 static struct task_struct *first_tgid(int tgid, unsigned int nr)
2157 struct task_struct *pos;
2158 rcu_read_lock();
2159 if (tgid && nr) {
2160 pos = find_task_by_pid(tgid);
2161 if (pos && thread_group_leader(pos))
2162 goto found;
2164 /* If nr exceeds the number of processes get out quickly */
2165 pos = NULL;
2166 if (nr && nr >= nr_processes())
2167 goto done;
2169 /* If we haven't found our starting place yet start with
2170 * the init_task and walk nr tasks forward.
2171 */
2172 for (pos = next_task(&init_task); nr > 0; --nr) {
2173 pos = next_task(pos);
2174 if (pos == &init_task) {
2175 pos = NULL;
2176 goto done;
2179 found:
2180 get_task_struct(pos);
2181 done:
2182 rcu_read_unlock();
2183 return pos;
2186 /*
2187 * Find the next task in the task list.
2188 * Return NULL if we loop or there is any error.
2190 * The reference to the input task_struct is released.
2191 */
2192 static struct task_struct *next_tgid(struct task_struct *start)
2194 struct task_struct *pos;
2195 rcu_read_lock();
2196 pos = start;
2197 if (pid_alive(start))
2198 pos = next_task(start);
2199 if (pid_alive(pos) && (pos != &init_task)) {
2200 get_task_struct(pos);
2201 goto done;
2203 pos = NULL;
2204 done:
2205 rcu_read_unlock();
2206 put_task_struct(start);
2207 return pos;
2210 /* for the /proc/ directory itself, after non-process stuff has been done */
2211 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2213 char buf[PROC_NUMBUF];
2214 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2215 struct task_struct *task;
2216 int tgid;
2218 if (!nr) {
2219 ino_t ino = fake_ino(0,PROC_TGID_INO);
2220 if (filldir(dirent, "self", 4, filp->f_pos, ino, DT_LNK) < 0)
2221 return 0;
2222 filp->f_pos++;
2223 nr++;
2225 nr -= 1;
2227 /* f_version caches the tgid value that the last readdir call couldn't
2228 * return. lseek aka telldir automagically resets f_version to 0.
2229 */
2230 tgid = filp->f_version;
2231 filp->f_version = 0;
2232 for (task = first_tgid(tgid, nr);
2233 task;
2234 task = next_tgid(task), filp->f_pos++) {
2235 int len;
2236 ino_t ino;
2237 tgid = task->pid;
2238 len = snprintf(buf, sizeof(buf), "%d", tgid);
2239 ino = fake_ino(tgid, PROC_TGID_INO);
2240 if (filldir(dirent, buf, len, filp->f_pos, ino, DT_DIR) < 0) {
2241 /* returning this tgid failed, save it as the first
2242 * pid for the next readir call */
2243 filp->f_version = tgid;
2244 put_task_struct(task);
2245 break;
2248 return 0;
2251 /*
2252 * Find the first tid of a thread group to return to user space.
2254 * Usually this is just the thread group leader, but if the users
2255 * buffer was too small or there was a seek into the middle of the
2256 * directory we have more work todo.
2258 * In the case of a short read we start with find_task_by_pid.
2260 * In the case of a seek we start with the leader and walk nr
2261 * threads past it.
2262 */
2263 static struct task_struct *first_tid(struct task_struct *leader,
2264 int tid, int nr)
2266 struct task_struct *pos;
2268 rcu_read_lock();
2269 /* Attempt to start with the pid of a thread */
2270 if (tid && (nr > 0)) {
2271 pos = find_task_by_pid(tid);
2272 if (pos && (pos->group_leader == leader))
2273 goto found;
2276 /* If nr exceeds the number of threads there is nothing todo */
2277 pos = NULL;
2278 if (nr && nr >= get_nr_threads(leader))
2279 goto out;
2281 /* If we haven't found our starting place yet start
2282 * with the leader and walk nr threads forward.
2283 */
2284 for (pos = leader; nr > 0; --nr) {
2285 pos = next_thread(pos);
2286 if (pos == leader) {
2287 pos = NULL;
2288 goto out;
2291 found:
2292 get_task_struct(pos);
2293 out:
2294 rcu_read_unlock();
2295 return pos;
2298 /*
2299 * Find the next thread in the thread list.
2300 * Return NULL if there is an error or no next thread.
2302 * The reference to the input task_struct is released.
2303 */
2304 static struct task_struct *next_tid(struct task_struct *start)
2306 struct task_struct *pos = NULL;
2307 rcu_read_lock();
2308 if (pid_alive(start)) {
2309 pos = next_thread(start);
2310 if (thread_group_leader(pos))
2311 pos = NULL;
2312 else
2313 get_task_struct(pos);
2315 rcu_read_unlock();
2316 put_task_struct(start);
2317 return pos;
2320 /* for the /proc/TGID/task/ directories */
2321 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
2323 char buf[PROC_NUMBUF];
2324 struct dentry *dentry = filp->f_dentry;
2325 struct inode *inode = dentry->d_inode;
2326 struct task_struct *leader = get_proc_task(inode);
2327 struct task_struct *task;
2328 int retval = -ENOENT;
2329 ino_t ino;
2330 int tid;
2331 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */
2333 if (!leader)
2334 goto out_no_task;
2335 retval = 0;
2337 switch (pos) {
2338 case 0:
2339 ino = inode->i_ino;
2340 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
2341 goto out;
2342 pos++;
2343 /* fall through */
2344 case 1:
2345 ino = parent_ino(dentry);
2346 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
2347 goto out;
2348 pos++;
2349 /* fall through */
2352 /* f_version caches the tgid value that the last readdir call couldn't
2353 * return. lseek aka telldir automagically resets f_version to 0.
2354 */
2355 tid = filp->f_version;
2356 filp->f_version = 0;
2357 for (task = first_tid(leader, tid, pos - 2);
2358 task;
2359 task = next_tid(task), pos++) {
2360 int len;
2361 tid = task->pid;
2362 len = snprintf(buf, sizeof(buf), "%d", tid);
2363 ino = fake_ino(tid, PROC_TID_INO);
2364 if (filldir(dirent, buf, len, pos, ino, DT_DIR < 0)) {
2365 /* returning this tgid failed, save it as the first
2366 * pid for the next readir call */
2367 filp->f_version = tid;
2368 put_task_struct(task);
2369 break;
2372 out:
2373 filp->f_pos = pos;
2374 put_task_struct(leader);
2375 out_no_task:
2376 return retval;
2379 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
2381 struct inode *inode = dentry->d_inode;
2382 struct task_struct *p = get_proc_task(inode);
2383 generic_fillattr(inode, stat);
2385 if (p) {
2386 rcu_read_lock();
2387 stat->nlink += get_nr_threads(p);
2388 rcu_read_unlock();
2389 put_task_struct(p);
2392 return 0;