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Relax /proc fix a bit
[linux-2.6/btrfs-unstable.git] / fs / proc / base.c
blob474eae345068337aad83b8b4f80d0e821cb67ed7
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/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"
75
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 */
85
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 */
93
94 #define fake_ino(pid,ino) (((pid)<<16)|(ino))
95
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,
184
185 /* Add new entries before this */
186 PROC_TID_FD_DIR = 0x8000, /* 0x8000-0xffff */
187 };
188
189 /* Worst case buffer size needed for holding an integer. */
190 #define PROC_NUMBUF 10
191
192 struct pid_entry {
193 int type;
194 int len;
195 char *name;
196 mode_t mode;
197 };
198
199 #define E(type,name,mode) {(type),sizeof(name)-1,(name),(mode)}
200
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 };
287
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
308
309 #undef E
310
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);
317
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 }
341
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 }
352
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;
358
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 }
365
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;
371
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 }
386
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;
392
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 }
407
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))
414
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 }
430
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 */
440
441 len = mm->arg_end - mm->arg_start;
442
443 if (len > PAGE_SIZE)
444 len = PAGE_SIZE;
445
446 res = access_process_vm(task, mm->arg_start, buffer, len, 0);
447
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 }
467
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 }
485
486
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];
498
499 wchan = get_wchan(task);
500
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 */
507
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
520
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;
527
528 do_posix_clock_monotonic_gettime(&uptime);
529 points = badness(task, uptime.tv_sec);
530 return sprintf(buffer, "%lu\n", points);
531 }
532
533 /************************************************************************/
534 /* Here the fs part begins */
535 /************************************************************************/
536
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 }
553
554 extern struct seq_operations mounts_op;
555 struct proc_mounts {
556 struct seq_file m;
557 int event;
558 };
559
560 static int mounts_open(struct inode *inode, struct file *file)
561 {
562 struct task_struct *task = get_proc_task(inode);
563 struct namespace *namespace = NULL;
564 struct proc_mounts *p;
565 int ret = -EINVAL;
566
567 if (task) {
568 task_lock(task);
569 namespace = task->namespace;
570 if (namespace)
571 get_namespace(namespace);
572 task_unlock(task);
573 put_task_struct(task);
574 }
575
576 if (namespace) {
577 ret = -ENOMEM;
578 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
579 if (p) {
580 file->private_data = &p->m;
581 ret = seq_open(file, &mounts_op);
582 if (!ret) {
583 p->m.private = namespace;
584 p->event = namespace->event;
585 return 0;
586 }
587 kfree(p);
588 }
589 put_namespace(namespace);
590 }
591 return ret;
592 }
593
594 static int mounts_release(struct inode *inode, struct file *file)
595 {
596 struct seq_file *m = file->private_data;
597 struct namespace *namespace = m->private;
598 put_namespace(namespace);
599 return seq_release(inode, file);
600 }
601
602 static unsigned mounts_poll(struct file *file, poll_table *wait)
603 {
604 struct proc_mounts *p = file->private_data;
605 struct namespace *ns = p->m.private;
606 unsigned res = 0;
607
608 poll_wait(file, &ns->poll, wait);
609
610 spin_lock(&vfsmount_lock);
611 if (p->event != ns->event) {
612 p->event = ns->event;
613 res = POLLERR;
614 }
615 spin_unlock(&vfsmount_lock);
616
617 return res;
618 }
619
620 static struct file_operations proc_mounts_operations = {
621 .open = mounts_open,
622 .read = seq_read,
623 .llseek = seq_lseek,
624 .release = mounts_release,
625 .poll = mounts_poll,
626 };
627
628 extern struct seq_operations mountstats_op;
629 static int mountstats_open(struct inode *inode, struct file *file)
630 {
631 int ret = seq_open(file, &mountstats_op);
632
633 if (!ret) {
634 struct seq_file *m = file->private_data;
635 struct namespace *namespace = NULL;
636 struct task_struct *task = get_proc_task(inode);
637
638 if (task) {
639 task_lock(task);
640 namespace = task->namespace;
641 if (namespace)
642 get_namespace(namespace);
643 task_unlock(task);
644 put_task_struct(task);
645 }
646
647 if (namespace)
648 m->private = namespace;
649 else {
650 seq_release(inode, file);
651 ret = -EINVAL;
652 }
653 }
654 return ret;
655 }
656
657 static struct file_operations proc_mountstats_operations = {
658 .open = mountstats_open,
659 .read = seq_read,
660 .llseek = seq_lseek,
661 .release = mounts_release,
662 };
663
664 #define PROC_BLOCK_SIZE (3*1024) /* 4K page size but our output routines use some slack for overruns */
665
666 static ssize_t proc_info_read(struct file * file, char __user * buf,
667 size_t count, loff_t *ppos)
668 {
669 struct inode * inode = file->f_dentry->d_inode;
670 unsigned long page;
671 ssize_t length;
672 struct task_struct *task = get_proc_task(inode);
673
674 length = -ESRCH;
675 if (!task)
676 goto out_no_task;
677
678 if (count > PROC_BLOCK_SIZE)
679 count = PROC_BLOCK_SIZE;
680
681 length = -ENOMEM;
682 if (!(page = __get_free_page(GFP_KERNEL)))
683 goto out;
684
685 length = PROC_I(inode)->op.proc_read(task, (char*)page);
686
687 if (length >= 0)
688 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
689 free_page(page);
690 out:
691 put_task_struct(task);
692 out_no_task:
693 return length;
694 }
695
696 static struct file_operations proc_info_file_operations = {
697 .read = proc_info_read,
698 };
699
700 static int mem_open(struct inode* inode, struct file* file)
701 {
702 file->private_data = (void*)((long)current->self_exec_id);
703 return 0;
704 }
705
706 static ssize_t mem_read(struct file * file, char __user * buf,
707 size_t count, loff_t *ppos)
708 {
709 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
710 char *page;
711 unsigned long src = *ppos;
712 int ret = -ESRCH;
713 struct mm_struct *mm;
714
715 if (!task)
716 goto out_no_task;
717
718 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
719 goto out;
720
721 ret = -ENOMEM;
722 page = (char *)__get_free_page(GFP_USER);
723 if (!page)
724 goto out;
725
726 ret = 0;
727
728 mm = get_task_mm(task);
729 if (!mm)
730 goto out_free;
731
732 ret = -EIO;
733
734 if (file->private_data != (void*)((long)current->self_exec_id))
735 goto out_put;
736
737 ret = 0;
738
739 while (count > 0) {
740 int this_len, retval;
741
742 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
743 retval = access_process_vm(task, src, page, this_len, 0);
744 if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) {
745 if (!ret)
746 ret = -EIO;
747 break;
748 }
749
750 if (copy_to_user(buf, page, retval)) {
751 ret = -EFAULT;
752 break;
753 }
754
755 ret += retval;
756 src += retval;
757 buf += retval;
758 count -= retval;
759 }
760 *ppos = src;
761
762 out_put:
763 mmput(mm);
764 out_free:
765 free_page((unsigned long) page);
766 out:
767 put_task_struct(task);
768 out_no_task:
769 return ret;
770 }
771
772 #define mem_write NULL
773
774 #ifndef mem_write
775 /* This is a security hazard */
776 static ssize_t mem_write(struct file * file, const char * buf,
777 size_t count, loff_t *ppos)
778 {
779 int copied = 0;
780 char *page;
781 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
782 unsigned long dst = *ppos;
783
784 copied = -ESRCH;
785 if (!task)
786 goto out_no_task;
787
788 if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
789 goto out;
790
791 copied = -ENOMEM;
792 page = (char *)__get_free_page(GFP_USER);
793 if (!page)
794 goto out;
795
796 while (count > 0) {
797 int this_len, retval;
798
799 this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
800 if (copy_from_user(page, buf, this_len)) {
801 copied = -EFAULT;
802 break;
803 }
804 retval = access_process_vm(task, dst, page, this_len, 1);
805 if (!retval) {
806 if (!copied)
807 copied = -EIO;
808 break;
809 }
810 copied += retval;
811 buf += retval;
812 dst += retval;
813 count -= retval;
814 }
815 *ppos = dst;
816 free_page((unsigned long) page);
817 out:
818 put_task_struct(task);
819 out_no_task:
820 return copied;
821 }
822 #endif
823
824 static loff_t mem_lseek(struct file * file, loff_t offset, int orig)
825 {
826 switch (orig) {
827 case 0:
828 file->f_pos = offset;
829 break;
830 case 1:
831 file->f_pos += offset;
832 break;
833 default:
834 return -EINVAL;
835 }
836 force_successful_syscall_return();
837 return file->f_pos;
838 }
839
840 static struct file_operations proc_mem_operations = {
841 .llseek = mem_lseek,
842 .read = mem_read,
843 .write = mem_write,
844 .open = mem_open,
845 };
846
847 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
848 size_t count, loff_t *ppos)
849 {
850 struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
851 char buffer[PROC_NUMBUF];
852 size_t len;
853 int oom_adjust;
854 loff_t __ppos = *ppos;
855
856 if (!task)
857 return -ESRCH;
858 oom_adjust = task->oomkilladj;
859 put_task_struct(task);
860
861 len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
862 if (__ppos >= len)
863 return 0;
864 if (count > len-__ppos)
865 count = len-__ppos;
866 if (copy_to_user(buf, buffer + __ppos, count))
867 return -EFAULT;
868 *ppos = __ppos + count;
869 return count;
870 }
871
872 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
873 size_t count, loff_t *ppos)
874 {
875 struct task_struct *task;
876 char buffer[PROC_NUMBUF], *end;
877 int oom_adjust;
878
879 if (!capable(CAP_SYS_RESOURCE))
880 return -EPERM;
881 memset(buffer, 0, sizeof(buffer));
882 if (count > sizeof(buffer) - 1)
883 count = sizeof(buffer) - 1;
884 if (copy_from_user(buffer, buf, count))
885 return -EFAULT;
886 oom_adjust = simple_strtol(buffer, &end, 0);
887 if ((oom_adjust < -16 || oom_adjust > 15) && oom_adjust != OOM_DISABLE)
888 return -EINVAL;
889 if (*end == '\n')
890 end++;
891 task = get_proc_task(file->f_dentry->d_inode);
892 if (!task)
893 return -ESRCH;
894 task->oomkilladj = oom_adjust;
895 put_task_struct(task);
896 if (end - buffer == 0)
897 return -EIO;
898 return end - buffer;
899 }
900
901 static struct file_operations proc_oom_adjust_operations = {
902 .read = oom_adjust_read,
903 .write = oom_adjust_write,
904 };
905
906 #ifdef CONFIG_AUDITSYSCALL
907 #define TMPBUFLEN 21
908 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
909 size_t count, loff_t *ppos)
910 {
911 struct inode * inode = file->f_dentry->d_inode;
912 struct task_struct *task = get_proc_task(inode);
913 ssize_t length;
914 char tmpbuf[TMPBUFLEN];
915
916 if (!task)
917 return -ESRCH;
918 length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
919 audit_get_loginuid(task->audit_context));
920 put_task_struct(task);
921 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
922 }
923
924 static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
925 size_t count, loff_t *ppos)
926 {
927 struct inode * inode = file->f_dentry->d_inode;
928 char *page, *tmp;
929 ssize_t length;
930 uid_t loginuid;
931
932 if (!capable(CAP_AUDIT_CONTROL))
933 return -EPERM;
934
935 if (current != pid_task(proc_pid(inode), PIDTYPE_PID))
936 return -EPERM;
937
938 if (count >= PAGE_SIZE)
939 count = PAGE_SIZE - 1;
940
941 if (*ppos != 0) {
942 /* No partial writes. */
943 return -EINVAL;
944 }
945 page = (char*)__get_free_page(GFP_USER);
946 if (!page)
947 return -ENOMEM;
948 length = -EFAULT;
949 if (copy_from_user(page, buf, count))
950 goto out_free_page;
951
952 page[count] = '\0';
953 loginuid = simple_strtoul(page, &tmp, 10);
954 if (tmp == page) {
955 length = -EINVAL;
956 goto out_free_page;
957
958 }
959 length = audit_set_loginuid(current, loginuid);
960 if (likely(length == 0))
961 length = count;
962
963 out_free_page:
964 free_page((unsigned long) page);
965 return length;
966 }
967
968 static struct file_operations proc_loginuid_operations = {
969 .read = proc_loginuid_read,
970 .write = proc_loginuid_write,
971 };
972 #endif
973
974 #ifdef CONFIG_SECCOMP
975 static ssize_t seccomp_read(struct file *file, char __user *buf,
976 size_t count, loff_t *ppos)
977 {
978 struct task_struct *tsk = get_proc_task(file->f_dentry->d_inode);
979 char __buf[20];
980 loff_t __ppos = *ppos;
981 size_t len;
982
983 if (!tsk)
984 return -ESRCH;
985 /* no need to print the trailing zero, so use only len */
986 len = sprintf(__buf, "%u\n", tsk->seccomp.mode);
987 put_task_struct(tsk);
988 if (__ppos >= len)
989 return 0;
990 if (count > len - __ppos)
991 count = len - __ppos;
992 if (copy_to_user(buf, __buf + __ppos, count))
993 return -EFAULT;
994 *ppos = __ppos + count;
995 return count;
996 }
997
998 static ssize_t seccomp_write(struct file *file, const char __user *buf,
999 size_t count, loff_t *ppos)
1000 {
1001 struct task_struct *tsk = get_proc_task(file->f_dentry->d_inode);
1002 char __buf[20], *end;
1003 unsigned int seccomp_mode;
1004 ssize_t result;
1005
1006 result = -ESRCH;
1007 if (!tsk)
1008 goto out_no_task;
1009
1010 /* can set it only once to be even more secure */
1011 result = -EPERM;
1012 if (unlikely(tsk->seccomp.mode))
1013 goto out;
1014
1015 result = -EFAULT;
1016 memset(__buf, 0, sizeof(__buf));
1017 count = min(count, sizeof(__buf) - 1);
1018 if (copy_from_user(__buf, buf, count))
1019 goto out;
1020
1021 seccomp_mode = simple_strtoul(__buf, &end, 0);
1022 if (*end == '\n')
1023 end++;
1024 result = -EINVAL;
1025 if (seccomp_mode && seccomp_mode <= NR_SECCOMP_MODES) {
1026 tsk->seccomp.mode = seccomp_mode;
1027 set_tsk_thread_flag(tsk, TIF_SECCOMP);
1028 } else
1029 goto out;
1030 result = -EIO;
1031 if (unlikely(!(end - __buf)))
1032 goto out;
1033 result = end - __buf;
1034 out:
1035 put_task_struct(tsk);
1036 out_no_task:
1037 return result;
1038 }
1039
1040 static struct file_operations proc_seccomp_operations = {
1041 .read = seccomp_read,
1042 .write = seccomp_write,
1043 };
1044 #endif /* CONFIG_SECCOMP */
1045
1046 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
1047 {
1048 struct inode *inode = dentry->d_inode;
1049 int error = -EACCES;
1050
1051 /* We don't need a base pointer in the /proc filesystem */
1052 path_release(nd);
1053
1054 /* Are we allowed to snoop on the tasks file descriptors? */
1055 if (!proc_fd_access_allowed(inode))
1056 goto out;
1057
1058 error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt);
1059 nd->last_type = LAST_BIND;
1060 out:
1061 return ERR_PTR(error);
1062 }
1063
1064 static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
1065 char __user *buffer, int buflen)
1066 {
1067 struct inode * inode;
1068 char *tmp = (char*)__get_free_page(GFP_KERNEL), *path;
1069 int len;
1070
1071 if (!tmp)
1072 return -ENOMEM;
1073
1074 inode = dentry->d_inode;
1075 path = d_path(dentry, mnt, tmp, PAGE_SIZE);
1076 len = PTR_ERR(path);
1077 if (IS_ERR(path))
1078 goto out;
1079 len = tmp + PAGE_SIZE - 1 - path;
1080
1081 if (len > buflen)
1082 len = buflen;
1083 if (copy_to_user(buffer, path, len))
1084 len = -EFAULT;
1085 out:
1086 free_page((unsigned long)tmp);
1087 return len;
1088 }
1089
1090 static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1091 {
1092 int error = -EACCES;
1093 struct inode *inode = dentry->d_inode;
1094 struct dentry *de;
1095 struct vfsmount *mnt = NULL;
1096
1097 /* Are we allowed to snoop on the tasks file descriptors? */
1098 if (!proc_fd_access_allowed(inode))
1099 goto out;
1100
1101 error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt);
1102 if (error)
1103 goto out;
1104
1105 error = do_proc_readlink(de, mnt, buffer, buflen);
1106 dput(de);
1107 mntput(mnt);
1108 out:
1109 return error;
1110 }
1111
1112 static struct inode_operations proc_pid_link_inode_operations = {
1113 .readlink = proc_pid_readlink,
1114 .follow_link = proc_pid_follow_link
1115 };
1116
1117 static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
1118 {
1119 struct dentry *dentry = filp->f_dentry;
1120 struct inode *inode = dentry->d_inode;
1121 struct task_struct *p = get_proc_task(inode);
1122 unsigned int fd, tid, ino;
1123 int retval;
1124 char buf[PROC_NUMBUF];
1125 struct files_struct * files;
1126 struct fdtable *fdt;
1127
1128 retval = -ENOENT;
1129 if (!p)
1130 goto out_no_task;
1131 retval = 0;
1132 tid = p->pid;
1133
1134 fd = filp->f_pos;
1135 switch (fd) {
1136 case 0:
1137 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
1138 goto out;
1139 filp->f_pos++;
1140 case 1:
1141 ino = parent_ino(dentry);
1142 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
1143 goto out;
1144 filp->f_pos++;
1145 default:
1146 files = get_files_struct(p);
1147 if (!files)
1148 goto out;
1149 rcu_read_lock();
1150 fdt = files_fdtable(files);
1151 for (fd = filp->f_pos-2;
1152 fd < fdt->max_fds;
1153 fd++, filp->f_pos++) {
1154 unsigned int i,j;
1155
1156 if (!fcheck_files(files, fd))
1157 continue;
1158 rcu_read_unlock();
1159
1160 j = PROC_NUMBUF;
1161 i = fd;
1162 do {
1163 j--;
1164 buf[j] = '0' + (i % 10);
1165 i /= 10;
1166 } while (i);
1167
1168 ino = fake_ino(tid, PROC_TID_FD_DIR + fd);
1169 if (filldir(dirent, buf+j, PROC_NUMBUF-j, fd+2, ino, DT_LNK) < 0) {
1170 rcu_read_lock();
1171 break;
1172 }
1173 rcu_read_lock();
1174 }
1175 rcu_read_unlock();
1176 put_files_struct(files);
1177 }
1178 out:
1179 put_task_struct(p);
1180 out_no_task:
1181 return retval;
1182 }
1183
1184 static int proc_pident_readdir(struct file *filp,
1185 void *dirent, filldir_t filldir,
1186 struct pid_entry *ents, unsigned int nents)
1187 {
1188 int i;
1189 int pid;
1190 struct dentry *dentry = filp->f_dentry;
1191 struct inode *inode = dentry->d_inode;
1192 struct task_struct *task = get_proc_task(inode);
1193 struct pid_entry *p;
1194 ino_t ino;
1195 int ret;
1196
1197 ret = -ENOENT;
1198 if (!task)
1199 goto out;
1200
1201 ret = 0;
1202 pid = task->pid;
1203 put_task_struct(task);
1204 i = filp->f_pos;
1205 switch (i) {
1206 case 0:
1207 ino = inode->i_ino;
1208 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
1209 goto out;
1210 i++;
1211 filp->f_pos++;
1212 /* fall through */
1213 case 1:
1214 ino = parent_ino(dentry);
1215 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
1216 goto out;
1217 i++;
1218 filp->f_pos++;
1219 /* fall through */
1220 default:
1221 i -= 2;
1222 if (i >= nents) {
1223 ret = 1;
1224 goto out;
1225 }
1226 p = ents + i;
1227 while (p->name) {
1228 if (filldir(dirent, p->name, p->len, filp->f_pos,
1229 fake_ino(pid, p->type), p->mode >> 12) < 0)
1230 goto out;
1231 filp->f_pos++;
1232 p++;
1233 }
1234 }
1235
1236 ret = 1;
1237 out:
1238 return ret;
1239 }
1240
1241 static int proc_tgid_base_readdir(struct file * filp,
1242 void * dirent, filldir_t filldir)
1243 {
1244 return proc_pident_readdir(filp,dirent,filldir,
1245 tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
1246 }
1247
1248 static int proc_tid_base_readdir(struct file * filp,
1249 void * dirent, filldir_t filldir)
1250 {
1251 return proc_pident_readdir(filp,dirent,filldir,
1252 tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
1253 }
1254
1255 /* building an inode */
1256
1257 static int task_dumpable(struct task_struct *task)
1258 {
1259 int dumpable = 0;
1260 struct mm_struct *mm;
1261
1262 task_lock(task);
1263 mm = task->mm;
1264 if (mm)
1265 dumpable = mm->dumpable;
1266 task_unlock(task);
1267 if(dumpable == 1)
1268 return 1;
1269 return 0;
1270 }
1271
1272
1273 static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task, int ino)
1274 {
1275 struct inode * inode;
1276 struct proc_inode *ei;
1277
1278 /* We need a new inode */
1279
1280 inode = new_inode(sb);
1281 if (!inode)
1282 goto out;
1283
1284 /* Common stuff */
1285 ei = PROC_I(inode);
1286 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1287 inode->i_ino = fake_ino(task->pid, ino);
1288
1289 /*
1290 * grab the reference to task.
1291 */
1292 ei->pid = get_pid(task->pids[PIDTYPE_PID].pid);
1293 if (!ei->pid)
1294 goto out_unlock;
1295
1296 inode->i_uid = 0;
1297 inode->i_gid = 0;
1298 if (task_dumpable(task)) {
1299 inode->i_uid = task->euid;
1300 inode->i_gid = task->egid;
1301 }
1302 security_task_to_inode(task, inode);
1303
1304 out:
1305 return inode;
1306
1307 out_unlock:
1308 iput(inode);
1309 return NULL;
1310 }
1311
1312 /* dentry stuff */
1313
1314 /*
1315 * Exceptional case: normally we are not allowed to unhash a busy
1316 * directory. In this case, however, we can do it - no aliasing problems
1317 * due to the way we treat inodes.
1318 *
1319 * Rewrite the inode's ownerships here because the owning task may have
1320 * performed a setuid(), etc.
1321 *
1322 * Before the /proc/pid/status file was created the only way to read
1323 * the effective uid of a /process was to stat /proc/pid. Reading
1324 * /proc/pid/status is slow enough that procps and other packages
1325 * kept stating /proc/pid. To keep the rules in /proc simple I have
1326 * made this apply to all per process world readable and executable
1327 * directories.
1328 */
1329 static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1330 {
1331 struct inode *inode = dentry->d_inode;
1332 struct task_struct *task = get_proc_task(inode);
1333 if (task) {
1334 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1335 task_dumpable(task)) {
1336 inode->i_uid = task->euid;
1337 inode->i_gid = task->egid;
1338 } else {
1339 inode->i_uid = 0;
1340 inode->i_gid = 0;
1341 }
1342 inode->i_mode &= ~(S_ISUID | S_ISGID);
1343 security_task_to_inode(task, inode);
1344 put_task_struct(task);
1345 return 1;
1346 }
1347 d_drop(dentry);
1348 return 0;
1349 }
1350
1351 static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
1352 {
1353 struct inode *inode = dentry->d_inode;
1354 struct task_struct *task;
1355 generic_fillattr(inode, stat);
1356
1357 rcu_read_lock();
1358 stat->uid = 0;
1359 stat->gid = 0;
1360 task = pid_task(proc_pid(inode), PIDTYPE_PID);
1361 if (task) {
1362 if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1363 task_dumpable(task)) {
1364 stat->uid = task->euid;
1365 stat->gid = task->egid;
1366 }
1367 }
1368 rcu_read_unlock();
1369 return 0;
1370 }
1371
1372 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1373 {
1374 struct inode *inode = dentry->d_inode;
1375 struct task_struct *task = get_proc_task(inode);
1376 int fd = proc_fd(inode);
1377 struct files_struct *files;
1378
1379 if (task) {
1380 files = get_files_struct(task);
1381 if (files) {
1382 rcu_read_lock();
1383 if (fcheck_files(files, fd)) {
1384 rcu_read_unlock();
1385 put_files_struct(files);
1386 if (task_dumpable(task)) {
1387 inode->i_uid = task->euid;
1388 inode->i_gid = task->egid;
1389 } else {
1390 inode->i_uid = 0;
1391 inode->i_gid = 0;
1392 }
1393 inode->i_mode &= ~(S_ISUID | S_ISGID);
1394 security_task_to_inode(task, inode);
1395 put_task_struct(task);
1396 return 1;
1397 }
1398 rcu_read_unlock();
1399 put_files_struct(files);
1400 }
1401 put_task_struct(task);
1402 }
1403 d_drop(dentry);
1404 return 0;
1405 }
1406
1407 static int pid_delete_dentry(struct dentry * dentry)
1408 {
1409 /* Is the task we represent dead?
1410 * If so, then don't put the dentry on the lru list,
1411 * kill it immediately.
1412 */
1413 return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1414 }
1415
1416 static struct dentry_operations tid_fd_dentry_operations =
1417 {
1418 .d_revalidate = tid_fd_revalidate,
1419 .d_delete = pid_delete_dentry,
1420 };
1421
1422 static struct dentry_operations pid_dentry_operations =
1423 {
1424 .d_revalidate = pid_revalidate,
1425 .d_delete = pid_delete_dentry,
1426 };
1427
1428 /* Lookups */
1429
1430 static unsigned name_to_int(struct dentry *dentry)
1431 {
1432 const char *name = dentry->d_name.name;
1433 int len = dentry->d_name.len;
1434 unsigned n = 0;
1435
1436 if (len > 1 && *name == '0')
1437 goto out;
1438 while (len-- > 0) {
1439 unsigned c = *name++ - '0';
1440 if (c > 9)
1441 goto out;
1442 if (n >= (~0U-9)/10)
1443 goto out;
1444 n *= 10;
1445 n += c;
1446 }
1447 return n;
1448 out:
1449 return ~0U;
1450 }
1451
1452 /* SMP-safe */
1453 static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
1454 {
1455 struct task_struct *task = get_proc_task(dir);
1456 unsigned fd = name_to_int(dentry);
1457 struct dentry *result = ERR_PTR(-ENOENT);
1458 struct file * file;
1459 struct files_struct * files;
1460 struct inode *inode;
1461 struct proc_inode *ei;
1462
1463 if (!task)
1464 goto out_no_task;
1465 if (fd == ~0U)
1466 goto out;
1467
1468 inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_FD_DIR+fd);
1469 if (!inode)
1470 goto out;
1471 ei = PROC_I(inode);
1472 ei->fd = fd;
1473 files = get_files_struct(task);
1474 if (!files)
1475 goto out_unlock;
1476 inode->i_mode = S_IFLNK;
1477
1478 /*
1479 * We are not taking a ref to the file structure, so we must
1480 * hold ->file_lock.
1481 */
1482 spin_lock(&files->file_lock);
1483 file = fcheck_files(files, fd);
1484 if (!file)
1485 goto out_unlock2;
1486 if (file->f_mode & 1)
1487 inode->i_mode |= S_IRUSR | S_IXUSR;
1488 if (file->f_mode & 2)
1489 inode->i_mode |= S_IWUSR | S_IXUSR;
1490 spin_unlock(&files->file_lock);
1491 put_files_struct(files);
1492 inode->i_op = &proc_pid_link_inode_operations;
1493 inode->i_size = 64;
1494 ei->op.proc_get_link = proc_fd_link;
1495 dentry->d_op = &tid_fd_dentry_operations;
1496 d_add(dentry, inode);
1497 /* Close the race of the process dying before we return the dentry */
1498 if (tid_fd_revalidate(dentry, NULL))
1499 result = NULL;
1500 out:
1501 put_task_struct(task);
1502 out_no_task:
1503 return result;
1504
1505 out_unlock2:
1506 spin_unlock(&files->file_lock);
1507 put_files_struct(files);
1508 out_unlock:
1509 iput(inode);
1510 goto out;
1511 }
1512
1513 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir);
1514 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd);
1515 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
1516
1517 static struct file_operations proc_fd_operations = {
1518 .read = generic_read_dir,
1519 .readdir = proc_readfd,
1520 };
1521
1522 static struct file_operations proc_task_operations = {
1523 .read = generic_read_dir,
1524 .readdir = proc_task_readdir,
1525 };
1526
1527 /*
1528 * proc directories can do almost nothing..
1529 */
1530 static struct inode_operations proc_fd_inode_operations = {
1531 .lookup = proc_lookupfd,
1532 };
1533
1534 static struct inode_operations proc_task_inode_operations = {
1535 .lookup = proc_task_lookup,
1536 .getattr = proc_task_getattr,
1537 };
1538
1539 #ifdef CONFIG_SECURITY
1540 static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
1541 size_t count, loff_t *ppos)
1542 {
1543 struct inode * inode = file->f_dentry->d_inode;
1544 unsigned long page;
1545 ssize_t length;
1546 struct task_struct *task = get_proc_task(inode);
1547
1548 length = -ESRCH;
1549 if (!task)
1550 goto out_no_task;
1551
1552 if (count > PAGE_SIZE)
1553 count = PAGE_SIZE;
1554 length = -ENOMEM;
1555 if (!(page = __get_free_page(GFP_KERNEL)))
1556 goto out;
1557
1558 length = security_getprocattr(task,
1559 (char*)file->f_dentry->d_name.name,
1560 (void*)page, count);
1561 if (length >= 0)
1562 length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
1563 free_page(page);
1564 out:
1565 put_task_struct(task);
1566 out_no_task:
1567 return length;
1568 }
1569
1570 static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
1571 size_t count, loff_t *ppos)
1572 {
1573 struct inode * inode = file->f_dentry->d_inode;
1574 char *page;
1575 ssize_t length;
1576 struct task_struct *task = get_proc_task(inode);
1577
1578 length = -ESRCH;
1579 if (!task)
1580 goto out_no_task;
1581 if (count > PAGE_SIZE)
1582 count = PAGE_SIZE;
1583
1584 /* No partial writes. */
1585 length = -EINVAL;
1586 if (*ppos != 0)
1587 goto out;
1588
1589 length = -ENOMEM;
1590 page = (char*)__get_free_page(GFP_USER);
1591 if (!page)
1592 goto out;
1593
1594 length = -EFAULT;
1595 if (copy_from_user(page, buf, count))
1596 goto out_free;
1597
1598 length = security_setprocattr(task,
1599 (char*)file->f_dentry->d_name.name,
1600 (void*)page, count);
1601 out_free:
1602 free_page((unsigned long) page);
1603 out:
1604 put_task_struct(task);
1605 out_no_task:
1606 return length;
1607 }
1608
1609 static struct file_operations proc_pid_attr_operations = {
1610 .read = proc_pid_attr_read,
1611 .write = proc_pid_attr_write,
1612 };
1613
1614 static struct file_operations proc_tid_attr_operations;
1615 static struct inode_operations proc_tid_attr_inode_operations;
1616 static struct file_operations proc_tgid_attr_operations;
1617 static struct inode_operations proc_tgid_attr_inode_operations;
1618 #endif
1619
1620 /* SMP-safe */
1621 static struct dentry *proc_pident_lookup(struct inode *dir,
1622 struct dentry *dentry,
1623 struct pid_entry *ents)
1624 {
1625 struct inode *inode;
1626 struct dentry *error;
1627 struct task_struct *task = get_proc_task(dir);
1628 struct pid_entry *p;
1629 struct proc_inode *ei;
1630
1631 error = ERR_PTR(-ENOENT);
1632 inode = NULL;
1633
1634 if (!task)
1635 goto out_no_task;
1636
1637 for (p = ents; p->name; p++) {
1638 if (p->len != dentry->d_name.len)
1639 continue;
1640 if (!memcmp(dentry->d_name.name, p->name, p->len))
1641 break;
1642 }
1643 if (!p->name)
1644 goto out;
1645
1646 error = ERR_PTR(-EINVAL);
1647 inode = proc_pid_make_inode(dir->i_sb, task, p->type);
1648 if (!inode)
1649 goto out;
1650
1651 ei = PROC_I(inode);
1652 inode->i_mode = p->mode;
1653 /*
1654 * Yes, it does not scale. And it should not. Don't add
1655 * new entries into /proc/<tgid>/ without very good reasons.
1656 */
1657 switch(p->type) {
1658 case PROC_TGID_TASK:
1659 inode->i_nlink = 2;
1660 inode->i_op = &proc_task_inode_operations;
1661 inode->i_fop = &proc_task_operations;
1662 break;
1663 case PROC_TID_FD:
1664 case PROC_TGID_FD:
1665 inode->i_nlink = 2;
1666 inode->i_op = &proc_fd_inode_operations;
1667 inode->i_fop = &proc_fd_operations;
1668 break;
1669 case PROC_TID_EXE:
1670 case PROC_TGID_EXE:
1671 inode->i_op = &proc_pid_link_inode_operations;
1672 ei->op.proc_get_link = proc_exe_link;
1673 break;
1674 case PROC_TID_CWD:
1675 case PROC_TGID_CWD:
1676 inode->i_op = &proc_pid_link_inode_operations;
1677 ei->op.proc_get_link = proc_cwd_link;
1678 break;
1679 case PROC_TID_ROOT:
1680 case PROC_TGID_ROOT:
1681 inode->i_op = &proc_pid_link_inode_operations;
1682 ei->op.proc_get_link = proc_root_link;
1683 break;
1684 case PROC_TID_ENVIRON:
1685 case PROC_TGID_ENVIRON:
1686 inode->i_fop = &proc_info_file_operations;
1687 ei->op.proc_read = proc_pid_environ;
1688 break;
1689 case PROC_TID_AUXV:
1690 case PROC_TGID_AUXV:
1691 inode->i_fop = &proc_info_file_operations;
1692 ei->op.proc_read = proc_pid_auxv;
1693 break;
1694 case PROC_TID_STATUS:
1695 case PROC_TGID_STATUS:
1696 inode->i_fop = &proc_info_file_operations;
1697 ei->op.proc_read = proc_pid_status;
1698 break;
1699 case PROC_TID_STAT:
1700 inode->i_fop = &proc_info_file_operations;
1701 ei->op.proc_read = proc_tid_stat;
1702 break;
1703 case PROC_TGID_STAT:
1704 inode->i_fop = &proc_info_file_operations;
1705 ei->op.proc_read = proc_tgid_stat;
1706 break;
1707 case PROC_TID_CMDLINE:
1708 case PROC_TGID_CMDLINE:
1709 inode->i_fop = &proc_info_file_operations;
1710 ei->op.proc_read = proc_pid_cmdline;
1711 break;
1712 case PROC_TID_STATM:
1713 case PROC_TGID_STATM:
1714 inode->i_fop = &proc_info_file_operations;
1715 ei->op.proc_read = proc_pid_statm;
1716 break;
1717 case PROC_TID_MAPS:
1718 case PROC_TGID_MAPS:
1719 inode->i_fop = &proc_maps_operations;
1720 break;
1721 #ifdef CONFIG_NUMA
1722 case PROC_TID_NUMA_MAPS:
1723 case PROC_TGID_NUMA_MAPS:
1724 inode->i_fop = &proc_numa_maps_operations;
1725 break;
1726 #endif
1727 case PROC_TID_MEM:
1728 case PROC_TGID_MEM:
1729 inode->i_fop = &proc_mem_operations;
1730 break;
1731 #ifdef CONFIG_SECCOMP
1732 case PROC_TID_SECCOMP:
1733 case PROC_TGID_SECCOMP:
1734 inode->i_fop = &proc_seccomp_operations;
1735 break;
1736 #endif /* CONFIG_SECCOMP */
1737 case PROC_TID_MOUNTS:
1738 case PROC_TGID_MOUNTS:
1739 inode->i_fop = &proc_mounts_operations;
1740 break;
1741 #ifdef CONFIG_MMU
1742 case PROC_TID_SMAPS:
1743 case PROC_TGID_SMAPS:
1744 inode->i_fop = &proc_smaps_operations;
1745 break;
1746 #endif
1747 case PROC_TID_MOUNTSTATS:
1748 case PROC_TGID_MOUNTSTATS:
1749 inode->i_fop = &proc_mountstats_operations;
1750 break;
1751 #ifdef CONFIG_SECURITY
1752 case PROC_TID_ATTR:
1753 inode->i_nlink = 2;
1754 inode->i_op = &proc_tid_attr_inode_operations;
1755 inode->i_fop = &proc_tid_attr_operations;
1756 break;
1757 case PROC_TGID_ATTR:
1758 inode->i_nlink = 2;
1759 inode->i_op = &proc_tgid_attr_inode_operations;
1760 inode->i_fop = &proc_tgid_attr_operations;
1761 break;
1762 case PROC_TID_ATTR_CURRENT:
1763 case PROC_TGID_ATTR_CURRENT:
1764 case PROC_TID_ATTR_PREV:
1765 case PROC_TGID_ATTR_PREV:
1766 case PROC_TID_ATTR_EXEC:
1767 case PROC_TGID_ATTR_EXEC:
1768 case PROC_TID_ATTR_FSCREATE:
1769 case PROC_TGID_ATTR_FSCREATE:
1770 case PROC_TID_ATTR_KEYCREATE:
1771 case PROC_TGID_ATTR_KEYCREATE:
1772 case PROC_TID_ATTR_SOCKCREATE:
1773 case PROC_TGID_ATTR_SOCKCREATE:
1774 inode->i_fop = &proc_pid_attr_operations;
1775 break;
1776 #endif
1777 #ifdef CONFIG_KALLSYMS
1778 case PROC_TID_WCHAN:
1779 case PROC_TGID_WCHAN:
1780 inode->i_fop = &proc_info_file_operations;
1781 ei->op.proc_read = proc_pid_wchan;
1782 break;
1783 #endif
1784 #ifdef CONFIG_SCHEDSTATS
1785 case PROC_TID_SCHEDSTAT:
1786 case PROC_TGID_SCHEDSTAT:
1787 inode->i_fop = &proc_info_file_operations;
1788 ei->op.proc_read = proc_pid_schedstat;
1789 break;
1790 #endif
1791 #ifdef CONFIG_CPUSETS
1792 case PROC_TID_CPUSET:
1793 case PROC_TGID_CPUSET:
1794 inode->i_fop = &proc_cpuset_operations;
1795 break;
1796 #endif
1797 case PROC_TID_OOM_SCORE:
1798 case PROC_TGID_OOM_SCORE:
1799 inode->i_fop = &proc_info_file_operations;
1800 ei->op.proc_read = proc_oom_score;
1801 break;
1802 case PROC_TID_OOM_ADJUST:
1803 case PROC_TGID_OOM_ADJUST:
1804 inode->i_fop = &proc_oom_adjust_operations;
1805 break;
1806 #ifdef CONFIG_AUDITSYSCALL
1807 case PROC_TID_LOGINUID:
1808 case PROC_TGID_LOGINUID:
1809 inode->i_fop = &proc_loginuid_operations;
1810 break;
1811 #endif
1812 default:
1813 printk("procfs: impossible type (%d)",p->type);
1814 iput(inode);
1815 error = ERR_PTR(-EINVAL);
1816 goto out;
1817 }
1818 dentry->d_op = &pid_dentry_operations;
1819 d_add(dentry, inode);
1820 /* Close the race of the process dying before we return the dentry */
1821 if (pid_revalidate(dentry, NULL))
1822 error = NULL;
1823 out:
1824 put_task_struct(task);
1825 out_no_task:
1826 return error;
1827 }
1828
1829 static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
1830 return proc_pident_lookup(dir, dentry, tgid_base_stuff);
1831 }
1832
1833 static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
1834 return proc_pident_lookup(dir, dentry, tid_base_stuff);
1835 }
1836
1837 static struct file_operations proc_tgid_base_operations = {
1838 .read = generic_read_dir,
1839 .readdir = proc_tgid_base_readdir,
1840 };
1841
1842 static struct file_operations proc_tid_base_operations = {
1843 .read = generic_read_dir,
1844 .readdir = proc_tid_base_readdir,
1845 };
1846
1847 static struct inode_operations proc_tgid_base_inode_operations = {
1848 .lookup = proc_tgid_base_lookup,
1849 .getattr = pid_getattr,
1850 };
1851
1852 static struct inode_operations proc_tid_base_inode_operations = {
1853 .lookup = proc_tid_base_lookup,
1854 .getattr = pid_getattr,
1855 };
1856
1857 #ifdef CONFIG_SECURITY
1858 static int proc_tgid_attr_readdir(struct file * filp,
1859 void * dirent, filldir_t filldir)
1860 {
1861 return proc_pident_readdir(filp,dirent,filldir,
1862 tgid_attr_stuff,ARRAY_SIZE(tgid_attr_stuff));
1863 }
1864
1865 static int proc_tid_attr_readdir(struct file * filp,
1866 void * dirent, filldir_t filldir)
1867 {
1868 return proc_pident_readdir(filp,dirent,filldir,
1869 tid_attr_stuff,ARRAY_SIZE(tid_attr_stuff));
1870 }
1871
1872 static struct file_operations proc_tgid_attr_operations = {
1873 .read = generic_read_dir,
1874 .readdir = proc_tgid_attr_readdir,
1875 };
1876
1877 static struct file_operations proc_tid_attr_operations = {
1878 .read = generic_read_dir,
1879 .readdir = proc_tid_attr_readdir,
1880 };
1881
1882 static struct dentry *proc_tgid_attr_lookup(struct inode *dir,
1883 struct dentry *dentry, struct nameidata *nd)
1884 {
1885 return proc_pident_lookup(dir, dentry, tgid_attr_stuff);
1886 }
1887
1888 static struct dentry *proc_tid_attr_lookup(struct inode *dir,
1889 struct dentry *dentry, struct nameidata *nd)
1890 {
1891 return proc_pident_lookup(dir, dentry, tid_attr_stuff);
1892 }
1893
1894 static struct inode_operations proc_tgid_attr_inode_operations = {
1895 .lookup = proc_tgid_attr_lookup,
1896 .getattr = pid_getattr,
1897 };
1898
1899 static struct inode_operations proc_tid_attr_inode_operations = {
1900 .lookup = proc_tid_attr_lookup,
1901 .getattr = pid_getattr,
1902 };
1903 #endif
1904
1905 /*
1906 * /proc/self:
1907 */
1908 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
1909 int buflen)
1910 {
1911 char tmp[PROC_NUMBUF];
1912 sprintf(tmp, "%d", current->tgid);
1913 return vfs_readlink(dentry,buffer,buflen,tmp);
1914 }
1915
1916 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
1917 {
1918 char tmp[PROC_NUMBUF];
1919 sprintf(tmp, "%d", current->tgid);
1920 return ERR_PTR(vfs_follow_link(nd,tmp));
1921 }
1922
1923 static struct inode_operations proc_self_inode_operations = {
1924 .readlink = proc_self_readlink,
1925 .follow_link = proc_self_follow_link,
1926 };
1927
1928 /**
1929 * proc_flush_task - Remove dcache entries for @task from the /proc dcache.
1930 *
1931 * @task: task that should be flushed.
1932 *
1933 * Looks in the dcache for
1934 * /proc/@pid
1935 * /proc/@tgid/task/@pid
1936 * if either directory is present flushes it and all of it'ts children
1937 * from the dcache.
1938 *
1939 * It is safe and reasonable to cache /proc entries for a task until
1940 * that task exits. After that they just clog up the dcache with
1941 * useless entries, possibly causing useful dcache entries to be
1942 * flushed instead. This routine is proved to flush those useless
1943 * dcache entries at process exit time.
1944 *
1945 * NOTE: This routine is just an optimization so it does not guarantee
1946 * that no dcache entries will exist at process exit time it
1947 * just makes it very unlikely that any will persist.
1948 */
1949 void proc_flush_task(struct task_struct *task)
1950 {
1951 struct dentry *dentry, *leader, *dir;
1952 char buf[PROC_NUMBUF];
1953 struct qstr name;
1954
1955 name.name = buf;
1956 name.len = snprintf(buf, sizeof(buf), "%d", task->pid);
1957 dentry = d_hash_and_lookup(proc_mnt->mnt_root, &name);
1958 if (dentry) {
1959 shrink_dcache_parent(dentry);
1960 d_drop(dentry);
1961 dput(dentry);
1962 }
1963
1964 if (thread_group_leader(task))
1965 goto out;
1966
1967 name.name = buf;
1968 name.len = snprintf(buf, sizeof(buf), "%d", task->tgid);
1969 leader = d_hash_and_lookup(proc_mnt->mnt_root, &name);
1970 if (!leader)
1971 goto out;
1972
1973 name.name = "task";
1974 name.len = strlen(name.name);
1975 dir = d_hash_and_lookup(leader, &name);
1976 if (!dir)
1977 goto out_put_leader;
1978
1979 name.name = buf;
1980 name.len = snprintf(buf, sizeof(buf), "%d", task->pid);
1981 dentry = d_hash_and_lookup(dir, &name);
1982 if (dentry) {
1983 shrink_dcache_parent(dentry);
1984 d_drop(dentry);
1985 dput(dentry);
1986 }
1987
1988 dput(dir);
1989 out_put_leader:
1990 dput(leader);
1991 out:
1992 return;
1993 }
1994
1995 /* SMP-safe */
1996 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
1997 {
1998 struct dentry *result = ERR_PTR(-ENOENT);
1999 struct task_struct *task;
2000 struct inode *inode;
2001 struct proc_inode *ei;
2002 unsigned tgid;
2003
2004 if (dentry->d_name.len == 4 && !memcmp(dentry->d_name.name,"self",4)) {
2005 inode = new_inode(dir->i_sb);
2006 if (!inode)
2007 return ERR_PTR(-ENOMEM);
2008 ei = PROC_I(inode);
2009 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2010 inode->i_ino = fake_ino(0, PROC_TGID_INO);
2011 ei->pde = NULL;
2012 inode->i_mode = S_IFLNK|S_IRWXUGO;
2013 inode->i_uid = inode->i_gid = 0;
2014 inode->i_size = 64;
2015 inode->i_op = &proc_self_inode_operations;
2016 d_add(dentry, inode);
2017 return NULL;
2018 }
2019 tgid = name_to_int(dentry);
2020 if (tgid == ~0U)
2021 goto out;
2022
2023 rcu_read_lock();
2024 task = find_task_by_pid(tgid);
2025 if (task)
2026 get_task_struct(task);
2027 rcu_read_unlock();
2028 if (!task)
2029 goto out;
2030
2031 inode = proc_pid_make_inode(dir->i_sb, task, PROC_TGID_INO);
2032 if (!inode)
2033 goto out_put_task;
2034
2035 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2036 inode->i_op = &proc_tgid_base_inode_operations;
2037 inode->i_fop = &proc_tgid_base_operations;
2038 inode->i_flags|=S_IMMUTABLE;
2039 #ifdef CONFIG_SECURITY
2040 inode->i_nlink = 5;
2041 #else
2042 inode->i_nlink = 4;
2043 #endif
2044
2045 dentry->d_op = &pid_dentry_operations;
2046
2047 d_add(dentry, inode);
2048 /* Close the race of the process dying before we return the dentry */
2049 if (pid_revalidate(dentry, NULL))
2050 result = NULL;
2051
2052 out_put_task:
2053 put_task_struct(task);
2054 out:
2055 return result;
2056 }
2057
2058 /* SMP-safe */
2059 static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
2060 {
2061 struct dentry *result = ERR_PTR(-ENOENT);
2062 struct task_struct *task;
2063 struct task_struct *leader = get_proc_task(dir);
2064 struct inode *inode;
2065 unsigned tid;
2066
2067 if (!leader)
2068 goto out_no_task;
2069
2070 tid = name_to_int(dentry);
2071 if (tid == ~0U)
2072 goto out;
2073
2074 rcu_read_lock();
2075 task = find_task_by_pid(tid);
2076 if (task)
2077 get_task_struct(task);
2078 rcu_read_unlock();
2079 if (!task)
2080 goto out;
2081 if (leader->tgid != task->tgid)
2082 goto out_drop_task;
2083
2084 inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_INO);
2085
2086
2087 if (!inode)
2088 goto out_drop_task;
2089 inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2090 inode->i_op = &proc_tid_base_inode_operations;
2091 inode->i_fop = &proc_tid_base_operations;
2092 inode->i_flags|=S_IMMUTABLE;
2093 #ifdef CONFIG_SECURITY
2094 inode->i_nlink = 4;
2095 #else
2096 inode->i_nlink = 3;
2097 #endif
2098
2099 dentry->d_op = &pid_dentry_operations;
2100
2101 d_add(dentry, inode);
2102 /* Close the race of the process dying before we return the dentry */
2103 if (pid_revalidate(dentry, NULL))
2104 result = NULL;
2105
2106 out_drop_task:
2107 put_task_struct(task);
2108 out:
2109 put_task_struct(leader);
2110 out_no_task:
2111 return result;
2112 }
2113
2114 /*
2115 * Find the first tgid to return to user space.
2116 *
2117 * Usually this is just whatever follows &init_task, but if the users
2118 * buffer was too small to hold the full list or there was a seek into
2119 * the middle of the directory we have more work to do.
2120 *
2121 * In the case of a short read we start with find_task_by_pid.
2122 *
2123 * In the case of a seek we start with &init_task and walk nr
2124 * threads past it.
2125 */
2126 static struct task_struct *first_tgid(int tgid, unsigned int nr)
2127 {
2128 struct task_struct *pos;
2129 rcu_read_lock();
2130 if (tgid && nr) {
2131 pos = find_task_by_pid(tgid);
2132 if (pos && thread_group_leader(pos))
2133 goto found;
2134 }
2135 /* If nr exceeds the number of processes get out quickly */
2136 pos = NULL;
2137 if (nr && nr >= nr_processes())
2138 goto done;
2139
2140 /* If we haven't found our starting place yet start with
2141 * the init_task and walk nr tasks forward.
2142 */
2143 for (pos = next_task(&init_task); nr > 0; --nr) {
2144 pos = next_task(pos);
2145 if (pos == &init_task) {
2146 pos = NULL;
2147 goto done;
2148 }
2149 }
2150 found:
2151 get_task_struct(pos);
2152 done:
2153 rcu_read_unlock();
2154 return pos;
2155 }
2156
2157 /*
2158 * Find the next task in the task list.
2159 * Return NULL if we loop or there is any error.
2160 *
2161 * The reference to the input task_struct is released.
2162 */
2163 static struct task_struct *next_tgid(struct task_struct *start)
2164 {
2165 struct task_struct *pos;
2166 rcu_read_lock();
2167 pos = start;
2168 if (pid_alive(start))
2169 pos = next_task(start);
2170 if (pid_alive(pos) && (pos != &init_task)) {
2171 get_task_struct(pos);
2172 goto done;
2173 }
2174 pos = NULL;
2175 done:
2176 rcu_read_unlock();
2177 put_task_struct(start);
2178 return pos;
2179 }
2180
2181 /* for the /proc/ directory itself, after non-process stuff has been done */
2182 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
2183 {
2184 char buf[PROC_NUMBUF];
2185 unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
2186 struct task_struct *task;
2187 int tgid;
2188
2189 if (!nr) {
2190 ino_t ino = fake_ino(0,PROC_TGID_INO);
2191 if (filldir(dirent, "self", 4, filp->f_pos, ino, DT_LNK) < 0)
2192 return 0;
2193 filp->f_pos++;
2194 nr++;
2195 }
2196 nr -= 1;
2197
2198 /* f_version caches the tgid value that the last readdir call couldn't
2199 * return. lseek aka telldir automagically resets f_version to 0.
2200 */
2201 tgid = filp->f_version;
2202 filp->f_version = 0;
2203 for (task = first_tgid(tgid, nr);
2204 task;
2205 task = next_tgid(task), filp->f_pos++) {
2206 int len;
2207 ino_t ino;
2208 tgid = task->pid;
2209 len = snprintf(buf, sizeof(buf), "%d", tgid);
2210 ino = fake_ino(tgid, PROC_TGID_INO);
2211 if (filldir(dirent, buf, len, filp->f_pos, ino, DT_DIR) < 0) {
2212 /* returning this tgid failed, save it as the first
2213 * pid for the next readir call */
2214 filp->f_version = tgid;
2215 put_task_struct(task);
2216 break;
2217 }
2218 }
2219 return 0;
2220 }
2221
2222 /*
2223 * Find the first tid of a thread group to return to user space.
2224 *
2225 * Usually this is just the thread group leader, but if the users
2226 * buffer was too small or there was a seek into the middle of the
2227 * directory we have more work todo.
2228 *
2229 * In the case of a short read we start with find_task_by_pid.
2230 *
2231 * In the case of a seek we start with the leader and walk nr
2232 * threads past it.
2233 */
2234 static struct task_struct *first_tid(struct task_struct *leader,
2235 int tid, int nr)
2236 {
2237 struct task_struct *pos;
2238
2239 rcu_read_lock();
2240 /* Attempt to start with the pid of a thread */
2241 if (tid && (nr > 0)) {
2242 pos = find_task_by_pid(tid);
2243 if (pos && (pos->group_leader == leader))
2244 goto found;
2245 }
2246
2247 /* If nr exceeds the number of threads there is nothing todo */
2248 pos = NULL;
2249 if (nr && nr >= get_nr_threads(leader))
2250 goto out;
2251
2252 /* If we haven't found our starting place yet start
2253 * with the leader and walk nr threads forward.
2254 */
2255 for (pos = leader; nr > 0; --nr) {
2256 pos = next_thread(pos);
2257 if (pos == leader) {
2258 pos = NULL;
2259 goto out;
2260 }
2261 }
2262 found:
2263 get_task_struct(pos);
2264 out:
2265 rcu_read_unlock();
2266 return pos;
2267 }
2268
2269 /*
2270 * Find the next thread in the thread list.
2271 * Return NULL if there is an error or no next thread.
2272 *
2273 * The reference to the input task_struct is released.
2274 */
2275 static struct task_struct *next_tid(struct task_struct *start)
2276 {
2277 struct task_struct *pos = NULL;
2278 rcu_read_lock();
2279 if (pid_alive(start)) {
2280 pos = next_thread(start);
2281 if (thread_group_leader(pos))
2282 pos = NULL;
2283 else
2284 get_task_struct(pos);
2285 }
2286 rcu_read_unlock();
2287 put_task_struct(start);
2288 return pos;
2289 }
2290
2291 /* for the /proc/TGID/task/ directories */
2292 static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
2293 {
2294 char buf[PROC_NUMBUF];
2295 struct dentry *dentry = filp->f_dentry;
2296 struct inode *inode = dentry->d_inode;
2297 struct task_struct *leader = get_proc_task(inode);
2298 struct task_struct *task;
2299 int retval = -ENOENT;
2300 ino_t ino;
2301 int tid;
2302 unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */
2303
2304 if (!leader)
2305 goto out_no_task;
2306 retval = 0;
2307
2308 switch (pos) {
2309 case 0:
2310 ino = inode->i_ino;
2311 if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
2312 goto out;
2313 pos++;
2314 /* fall through */
2315 case 1:
2316 ino = parent_ino(dentry);
2317 if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
2318 goto out;
2319 pos++;
2320 /* fall through */
2321 }
2322
2323 /* f_version caches the tgid value that the last readdir call couldn't
2324 * return. lseek aka telldir automagically resets f_version to 0.
2325 */
2326 tid = filp->f_version;
2327 filp->f_version = 0;
2328 for (task = first_tid(leader, tid, pos - 2);
2329 task;
2330 task = next_tid(task), pos++) {
2331 int len;
2332 tid = task->pid;
2333 len = snprintf(buf, sizeof(buf), "%d", tid);
2334 ino = fake_ino(tid, PROC_TID_INO);
2335 if (filldir(dirent, buf, len, pos, ino, DT_DIR < 0)) {
2336 /* returning this tgid failed, save it as the first
2337 * pid for the next readir call */
2338 filp->f_version = tid;
2339 put_task_struct(task);
2340 break;
2341 }
2342 }
2343 out:
2344 filp->f_pos = pos;
2345 put_task_struct(leader);
2346 out_no_task:
2347 return retval;
2348 }
2349
2350 static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
2351 {
2352 struct inode *inode = dentry->d_inode;
2353 struct task_struct *p = get_proc_task(inode);
2354 generic_fillattr(inode, stat);
2355
2356 if (p) {
2357 rcu_read_lock();
2358 stat->nlink += get_nr_threads(p);
2359 rcu_read_unlock();
2360 put_task_struct(p);
2361 }
2362
2363 return 0;
2364 }
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