[PATCH] signal, procfs: some lock_task_sighand() users do not need rcu_read_lock()
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / proc / array.c
1 /*
2 * linux/fs/proc/array.c
3 *
4 * Copyright (C) 1992 by Linus Torvalds
5 * based on ideas by Darren Senn
6 *
7 * Fixes:
8 * Michael. K. Johnson: stat,statm extensions.
9 * <johnsonm@stolaf.edu>
10 *
11 * Pauline Middelink : Made cmdline,envline only break at '\0's, to
12 * make sure SET_PROCTITLE works. Also removed
13 * bad '!' which forced address recalculation for
14 * EVERY character on the current page.
15 * <middelin@polyware.iaf.nl>
16 *
17 * Danny ter Haar : added cpuinfo
18 * <dth@cistron.nl>
19 *
20 * Alessandro Rubini : profile extension.
21 * <rubini@ipvvis.unipv.it>
22 *
23 * Jeff Tranter : added BogoMips field to cpuinfo
24 * <Jeff_Tranter@Mitel.COM>
25 *
26 * Bruno Haible : remove 4K limit for the maps file
27 * <haible@ma2s2.mathematik.uni-karlsruhe.de>
28 *
29 * Yves Arrouye : remove removal of trailing spaces in get_array.
30 * <Yves.Arrouye@marin.fdn.fr>
31 *
32 * Jerome Forissier : added per-CPU time information to /proc/stat
33 * and /proc/<pid>/cpu extension
34 * <forissier@isia.cma.fr>
35 * - Incorporation and non-SMP safe operation
36 * of forissier patch in 2.1.78 by
37 * Hans Marcus <crowbar@concepts.nl>
38 *
39 * aeb@cwi.nl : /proc/partitions
40 *
41 *
42 * Alan Cox : security fixes.
43 * <Alan.Cox@linux.org>
44 *
45 * Al Viro : safe handling of mm_struct
46 *
47 * Gerhard Wichert : added BIGMEM support
48 * Siemens AG <Gerhard.Wichert@pdb.siemens.de>
49 *
50 * Al Viro & Jeff Garzik : moved most of the thing into base.c and
51 * : proc_misc.c. The rest may eventually go into
52 * : base.c too.
53 */
54
55 #include <linux/types.h>
56 #include <linux/errno.h>
57 #include <linux/time.h>
58 #include <linux/kernel.h>
59 #include <linux/kernel_stat.h>
60 #include <linux/tty.h>
61 #include <linux/string.h>
62 #include <linux/mman.h>
63 #include <linux/proc_fs.h>
64 #include <linux/ioport.h>
65 #include <linux/uaccess.h>
66 #include <linux/io.h>
67 #include <linux/mm.h>
68 #include <linux/hugetlb.h>
69 #include <linux/pagemap.h>
70 #include <linux/swap.h>
71 #include <linux/slab.h>
72 #include <linux/smp.h>
73 #include <linux/signal.h>
74 #include <linux/highmem.h>
75 #include <linux/file.h>
76 #include <linux/fdtable.h>
77 #include <linux/times.h>
78 #include <linux/cpuset.h>
79 #include <linux/rcupdate.h>
80 #include <linux/delayacct.h>
81 #include <linux/seq_file.h>
82 #include <linux/pid_namespace.h>
83 #include <linux/tracehook.h>
84
85 #include <asm/pgtable.h>
86 #include <asm/processor.h>
87 #include "internal.h"
88
89 /* Gcc optimizes away "strlen(x)" for constant x */
90 #define ADDBUF(buffer, string) \
91 do { memcpy(buffer, string, strlen(string)); \
92 buffer += strlen(string); } while (0)
93
94 static inline void task_name(struct seq_file *m, struct task_struct *p)
95 {
96 int i;
97 char *buf, *end;
98 char *name;
99 char tcomm[sizeof(p->comm)];
100
101 get_task_comm(tcomm, p);
102
103 seq_printf(m, "Name:\t");
104 end = m->buf + m->size;
105 buf = m->buf + m->count;
106 name = tcomm;
107 i = sizeof(tcomm);
108 while (i && (buf < end)) {
109 unsigned char c = *name;
110 name++;
111 i--;
112 *buf = c;
113 if (!c)
114 break;
115 if (c == '\\') {
116 buf++;
117 if (buf < end)
118 *buf++ = c;
119 continue;
120 }
121 if (c == '\n') {
122 *buf++ = '\\';
123 if (buf < end)
124 *buf++ = 'n';
125 continue;
126 }
127 buf++;
128 }
129 m->count = buf - m->buf;
130 seq_printf(m, "\n");
131 }
132
133 /*
134 * The task state array is a strange "bitmap" of
135 * reasons to sleep. Thus "running" is zero, and
136 * you can test for combinations of others with
137 * simple bit tests.
138 */
139 static const char *task_state_array[] = {
140 "R (running)", /* 0 */
141 "S (sleeping)", /* 1 */
142 "D (disk sleep)", /* 2 */
143 "T (stopped)", /* 4 */
144 "T (tracing stop)", /* 8 */
145 "Z (zombie)", /* 16 */
146 "X (dead)" /* 32 */
147 };
148
149 static inline const char *get_task_state(struct task_struct *tsk)
150 {
151 unsigned int state = (tsk->state & TASK_REPORT) | tsk->exit_state;
152 const char **p = &task_state_array[0];
153
154 while (state) {
155 p++;
156 state >>= 1;
157 }
158 return *p;
159 }
160
161 static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
162 struct pid *pid, struct task_struct *p)
163 {
164 struct group_info *group_info;
165 int g;
166 struct fdtable *fdt = NULL;
167 pid_t ppid, tpid;
168
169 rcu_read_lock();
170 ppid = pid_alive(p) ?
171 task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
172 tpid = 0;
173 if (pid_alive(p)) {
174 struct task_struct *tracer = tracehook_tracer_task(p);
175 if (tracer)
176 tpid = task_pid_nr_ns(tracer, ns);
177 }
178 seq_printf(m,
179 "State:\t%s\n"
180 "Tgid:\t%d\n"
181 "Pid:\t%d\n"
182 "PPid:\t%d\n"
183 "TracerPid:\t%d\n"
184 "Uid:\t%d\t%d\t%d\t%d\n"
185 "Gid:\t%d\t%d\t%d\t%d\n",
186 get_task_state(p),
187 task_tgid_nr_ns(p, ns),
188 pid_nr_ns(pid, ns),
189 ppid, tpid,
190 p->uid, p->euid, p->suid, p->fsuid,
191 p->gid, p->egid, p->sgid, p->fsgid);
192
193 task_lock(p);
194 if (p->files)
195 fdt = files_fdtable(p->files);
196 seq_printf(m,
197 "FDSize:\t%d\n"
198 "Groups:\t",
199 fdt ? fdt->max_fds : 0);
200 rcu_read_unlock();
201
202 group_info = p->group_info;
203 get_group_info(group_info);
204 task_unlock(p);
205
206 for (g = 0; g < min(group_info->ngroups, NGROUPS_SMALL); g++)
207 seq_printf(m, "%d ", GROUP_AT(group_info, g));
208 put_group_info(group_info);
209
210 seq_printf(m, "\n");
211 }
212
213 static void render_sigset_t(struct seq_file *m, const char *header,
214 sigset_t *set)
215 {
216 int i;
217
218 seq_printf(m, "%s", header);
219
220 i = _NSIG;
221 do {
222 int x = 0;
223
224 i -= 4;
225 if (sigismember(set, i+1)) x |= 1;
226 if (sigismember(set, i+2)) x |= 2;
227 if (sigismember(set, i+3)) x |= 4;
228 if (sigismember(set, i+4)) x |= 8;
229 seq_printf(m, "%x", x);
230 } while (i >= 4);
231
232 seq_printf(m, "\n");
233 }
234
235 static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign,
236 sigset_t *catch)
237 {
238 struct k_sigaction *k;
239 int i;
240
241 k = p->sighand->action;
242 for (i = 1; i <= _NSIG; ++i, ++k) {
243 if (k->sa.sa_handler == SIG_IGN)
244 sigaddset(ign, i);
245 else if (k->sa.sa_handler != SIG_DFL)
246 sigaddset(catch, i);
247 }
248 }
249
250 static inline void task_sig(struct seq_file *m, struct task_struct *p)
251 {
252 unsigned long flags;
253 sigset_t pending, shpending, blocked, ignored, caught;
254 int num_threads = 0;
255 unsigned long qsize = 0;
256 unsigned long qlim = 0;
257
258 sigemptyset(&pending);
259 sigemptyset(&shpending);
260 sigemptyset(&blocked);
261 sigemptyset(&ignored);
262 sigemptyset(&caught);
263
264 if (lock_task_sighand(p, &flags)) {
265 pending = p->pending.signal;
266 shpending = p->signal->shared_pending.signal;
267 blocked = p->blocked;
268 collect_sigign_sigcatch(p, &ignored, &caught);
269 num_threads = atomic_read(&p->signal->count);
270 qsize = atomic_read(&p->user->sigpending);
271 qlim = p->signal->rlim[RLIMIT_SIGPENDING].rlim_cur;
272 unlock_task_sighand(p, &flags);
273 }
274
275 seq_printf(m, "Threads:\t%d\n", num_threads);
276 seq_printf(m, "SigQ:\t%lu/%lu\n", qsize, qlim);
277
278 /* render them all */
279 render_sigset_t(m, "SigPnd:\t", &pending);
280 render_sigset_t(m, "ShdPnd:\t", &shpending);
281 render_sigset_t(m, "SigBlk:\t", &blocked);
282 render_sigset_t(m, "SigIgn:\t", &ignored);
283 render_sigset_t(m, "SigCgt:\t", &caught);
284 }
285
286 static void render_cap_t(struct seq_file *m, const char *header,
287 kernel_cap_t *a)
288 {
289 unsigned __capi;
290
291 seq_printf(m, "%s", header);
292 CAP_FOR_EACH_U32(__capi) {
293 seq_printf(m, "%08x",
294 a->cap[(_KERNEL_CAPABILITY_U32S-1) - __capi]);
295 }
296 seq_printf(m, "\n");
297 }
298
299 static inline void task_cap(struct seq_file *m, struct task_struct *p)
300 {
301 render_cap_t(m, "CapInh:\t", &p->cap_inheritable);
302 render_cap_t(m, "CapPrm:\t", &p->cap_permitted);
303 render_cap_t(m, "CapEff:\t", &p->cap_effective);
304 render_cap_t(m, "CapBnd:\t", &p->cap_bset);
305 }
306
307 static inline void task_context_switch_counts(struct seq_file *m,
308 struct task_struct *p)
309 {
310 seq_printf(m, "voluntary_ctxt_switches:\t%lu\n"
311 "nonvoluntary_ctxt_switches:\t%lu\n",
312 p->nvcsw,
313 p->nivcsw);
314 }
315
316 int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
317 struct pid *pid, struct task_struct *task)
318 {
319 struct mm_struct *mm = get_task_mm(task);
320
321 task_name(m, task);
322 task_state(m, ns, pid, task);
323
324 if (mm) {
325 task_mem(m, mm);
326 mmput(mm);
327 }
328 task_sig(m, task);
329 task_cap(m, task);
330 cpuset_task_status_allowed(m, task);
331 #if defined(CONFIG_S390)
332 task_show_regs(m, task);
333 #endif
334 task_context_switch_counts(m, task);
335 return 0;
336 }
337
338 static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
339 struct pid *pid, struct task_struct *task, int whole)
340 {
341 unsigned long vsize, eip, esp, wchan = ~0UL;
342 long priority, nice;
343 int tty_pgrp = -1, tty_nr = 0;
344 sigset_t sigign, sigcatch;
345 char state;
346 pid_t ppid = 0, pgid = -1, sid = -1;
347 int num_threads = 0;
348 struct mm_struct *mm;
349 unsigned long long start_time;
350 unsigned long cmin_flt = 0, cmaj_flt = 0;
351 unsigned long min_flt = 0, maj_flt = 0;
352 cputime_t cutime, cstime, utime, stime;
353 cputime_t cgtime, gtime;
354 unsigned long rsslim = 0;
355 char tcomm[sizeof(task->comm)];
356 unsigned long flags;
357
358 state = *get_task_state(task);
359 vsize = eip = esp = 0;
360 mm = get_task_mm(task);
361 if (mm) {
362 vsize = task_vsize(mm);
363 eip = KSTK_EIP(task);
364 esp = KSTK_ESP(task);
365 }
366
367 get_task_comm(tcomm, task);
368
369 sigemptyset(&sigign);
370 sigemptyset(&sigcatch);
371 cutime = cstime = utime = stime = cputime_zero;
372 cgtime = gtime = cputime_zero;
373
374 if (lock_task_sighand(task, &flags)) {
375 struct signal_struct *sig = task->signal;
376
377 if (sig->tty) {
378 struct pid *pgrp = tty_get_pgrp(sig->tty);
379 tty_pgrp = pid_nr_ns(pgrp, ns);
380 put_pid(pgrp);
381 tty_nr = new_encode_dev(tty_devnum(sig->tty));
382 }
383
384 num_threads = atomic_read(&sig->count);
385 collect_sigign_sigcatch(task, &sigign, &sigcatch);
386
387 cmin_flt = sig->cmin_flt;
388 cmaj_flt = sig->cmaj_flt;
389 cutime = sig->cutime;
390 cstime = sig->cstime;
391 cgtime = sig->cgtime;
392 rsslim = sig->rlim[RLIMIT_RSS].rlim_cur;
393
394 /* add up live thread stats at the group level */
395 if (whole) {
396 struct task_struct *t = task;
397 do {
398 min_flt += t->min_flt;
399 maj_flt += t->maj_flt;
400 utime = cputime_add(utime, task_utime(t));
401 stime = cputime_add(stime, task_stime(t));
402 gtime = cputime_add(gtime, task_gtime(t));
403 t = next_thread(t);
404 } while (t != task);
405
406 min_flt += sig->min_flt;
407 maj_flt += sig->maj_flt;
408 utime = cputime_add(utime, sig->utime);
409 stime = cputime_add(stime, sig->stime);
410 gtime = cputime_add(gtime, sig->gtime);
411 }
412
413 sid = task_session_nr_ns(task, ns);
414 ppid = task_tgid_nr_ns(task->real_parent, ns);
415 pgid = task_pgrp_nr_ns(task, ns);
416
417 unlock_task_sighand(task, &flags);
418 }
419
420 if (!whole || num_threads < 2)
421 wchan = get_wchan(task);
422 if (!whole) {
423 min_flt = task->min_flt;
424 maj_flt = task->maj_flt;
425 utime = task_utime(task);
426 stime = task_stime(task);
427 gtime = task_gtime(task);
428 }
429
430 /* scale priority and nice values from timeslices to -20..20 */
431 /* to make it look like a "normal" Unix priority/nice value */
432 priority = task_prio(task);
433 nice = task_nice(task);
434
435 /* Temporary variable needed for gcc-2.96 */
436 /* convert timespec -> nsec*/
437 start_time =
438 (unsigned long long)task->real_start_time.tv_sec * NSEC_PER_SEC
439 + task->real_start_time.tv_nsec;
440 /* convert nsec -> ticks */
441 start_time = nsec_to_clock_t(start_time);
442
443 seq_printf(m, "%d (%s) %c %d %d %d %d %d %u %lu \
444 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
445 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %u %u %llu %lu %ld\n",
446 pid_nr_ns(pid, ns),
447 tcomm,
448 state,
449 ppid,
450 pgid,
451 sid,
452 tty_nr,
453 tty_pgrp,
454 task->flags,
455 min_flt,
456 cmin_flt,
457 maj_flt,
458 cmaj_flt,
459 cputime_to_clock_t(utime),
460 cputime_to_clock_t(stime),
461 cputime_to_clock_t(cutime),
462 cputime_to_clock_t(cstime),
463 priority,
464 nice,
465 num_threads,
466 start_time,
467 vsize,
468 mm ? get_mm_rss(mm) : 0,
469 rsslim,
470 mm ? mm->start_code : 0,
471 mm ? mm->end_code : 0,
472 mm ? mm->start_stack : 0,
473 esp,
474 eip,
475 /* The signal information here is obsolete.
476 * It must be decimal for Linux 2.0 compatibility.
477 * Use /proc/#/status for real-time signals.
478 */
479 task->pending.signal.sig[0] & 0x7fffffffUL,
480 task->blocked.sig[0] & 0x7fffffffUL,
481 sigign .sig[0] & 0x7fffffffUL,
482 sigcatch .sig[0] & 0x7fffffffUL,
483 wchan,
484 0UL,
485 0UL,
486 task->exit_signal,
487 task_cpu(task),
488 task->rt_priority,
489 task->policy,
490 (unsigned long long)delayacct_blkio_ticks(task),
491 cputime_to_clock_t(gtime),
492 cputime_to_clock_t(cgtime));
493 if (mm)
494 mmput(mm);
495 return 0;
496 }
497
498 int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
499 struct pid *pid, struct task_struct *task)
500 {
501 return do_task_stat(m, ns, pid, task, 0);
502 }
503
504 int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
505 struct pid *pid, struct task_struct *task)
506 {
507 return do_task_stat(m, ns, pid, task, 1);
508 }
509
510 int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
511 struct pid *pid, struct task_struct *task)
512 {
513 int size = 0, resident = 0, shared = 0, text = 0, lib = 0, data = 0;
514 struct mm_struct *mm = get_task_mm(task);
515
516 if (mm) {
517 size = task_statm(mm, &shared, &text, &data, &resident);
518 mmput(mm);
519 }
520 seq_printf(m, "%d %d %d %d %d %d %d\n",
521 size, resident, shared, text, lib, data, 0);
522
523 return 0;
524 }