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mm/vmscan.c: prevent useless kswapd loops
[linux/fpc-iii.git] / fs / proc / array.c
blob9eb99a43f849a045d60b6f196d22e665a0e73e20
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/proc/array.c
4 *
5 * Copyright (C) 1992 by Linus Torvalds
6 * based on ideas by Darren Senn
7 *
8 * Fixes:
9 * Michael. K. Johnson: stat,statm extensions.
10 * <johnsonm@stolaf.edu>
11 *
12 * Pauline Middelink : Made cmdline,envline only break at '\0's, to
13 * make sure SET_PROCTITLE works. Also removed
14 * bad '!' which forced address recalculation for
15 * EVERY character on the current page.
16 * <middelin@polyware.iaf.nl>
17 *
18 * Danny ter Haar : added cpuinfo
19 * <dth@cistron.nl>
20 *
21 * Alessandro Rubini : profile extension.
22 * <rubini@ipvvis.unipv.it>
23 *
24 * Jeff Tranter : added BogoMips field to cpuinfo
25 * <Jeff_Tranter@Mitel.COM>
26 *
27 * Bruno Haible : remove 4K limit for the maps file
28 * <haible@ma2s2.mathematik.uni-karlsruhe.de>
29 *
30 * Yves Arrouye : remove removal of trailing spaces in get_array.
31 * <Yves.Arrouye@marin.fdn.fr>
32 *
33 * Jerome Forissier : added per-CPU time information to /proc/stat
34 * and /proc/<pid>/cpu extension
35 * <forissier@isia.cma.fr>
36 * - Incorporation and non-SMP safe operation
37 * of forissier patch in 2.1.78 by
38 * Hans Marcus <crowbar@concepts.nl>
39 *
40 * aeb@cwi.nl : /proc/partitions
41 *
42 *
43 * Alan Cox : security fixes.
44 * <alan@lxorguk.ukuu.org.uk>
45 *
46 * Al Viro : safe handling of mm_struct
47 *
48 * Gerhard Wichert : added BIGMEM support
49 * Siemens AG <Gerhard.Wichert@pdb.siemens.de>
50 *
51 * Al Viro & Jeff Garzik : moved most of the thing into base.c and
52 * : proc_misc.c. The rest may eventually go into
53 * : base.c too.
54 */
55
56 #include <linux/types.h>
57 #include <linux/errno.h>
58 #include <linux/time.h>
59 #include <linux/kernel.h>
60 #include <linux/kernel_stat.h>
61 #include <linux/tty.h>
62 #include <linux/string.h>
63 #include <linux/mman.h>
64 #include <linux/sched/mm.h>
65 #include <linux/sched/numa_balancing.h>
66 #include <linux/sched/task_stack.h>
67 #include <linux/sched/task.h>
68 #include <linux/sched/cputime.h>
69 #include <linux/proc_fs.h>
70 #include <linux/ioport.h>
71 #include <linux/uaccess.h>
72 #include <linux/io.h>
73 #include <linux/mm.h>
74 #include <linux/hugetlb.h>
75 #include <linux/pagemap.h>
76 #include <linux/swap.h>
77 #include <linux/smp.h>
78 #include <linux/signal.h>
79 #include <linux/highmem.h>
80 #include <linux/file.h>
81 #include <linux/fdtable.h>
82 #include <linux/times.h>
83 #include <linux/cpuset.h>
84 #include <linux/rcupdate.h>
85 #include <linux/delayacct.h>
86 #include <linux/seq_file.h>
87 #include <linux/pid_namespace.h>
88 #include <linux/prctl.h>
89 #include <linux/ptrace.h>
90 #include <linux/tracehook.h>
91 #include <linux/string_helpers.h>
92 #include <linux/user_namespace.h>
93 #include <linux/fs_struct.h>
94
95 #include <asm/pgtable.h>
96 #include <asm/processor.h>
97 #include "internal.h"
98
99 void proc_task_name(struct seq_file *m, struct task_struct *p, bool escape)
100 {
101 char *buf;
102 size_t size;
103 char tcomm[64];
104 int ret;
105
106 if (p->flags & PF_WQ_WORKER)
107 wq_worker_comm(tcomm, sizeof(tcomm), p);
108 else
109 __get_task_comm(tcomm, sizeof(tcomm), p);
110
111 size = seq_get_buf(m, &buf);
112 if (escape) {
113 ret = string_escape_str(tcomm, buf, size,
114 ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");
115 if (ret >= size)
116 ret = -1;
117 } else {
118 ret = strscpy(buf, tcomm, size);
119 }
120
121 seq_commit(m, ret);
122 }
123
124 /*
125 * The task state array is a strange "bitmap" of
126 * reasons to sleep. Thus "running" is zero, and
127 * you can test for combinations of others with
128 * simple bit tests.
129 */
130 static const char * const task_state_array[] = {
131
132 /* states in TASK_REPORT: */
133 "R (running)", /* 0x00 */
134 "S (sleeping)", /* 0x01 */
135 "D (disk sleep)", /* 0x02 */
136 "T (stopped)", /* 0x04 */
137 "t (tracing stop)", /* 0x08 */
138 "X (dead)", /* 0x10 */
139 "Z (zombie)", /* 0x20 */
140 "P (parked)", /* 0x40 */
141
142 /* states beyond TASK_REPORT: */
143 "I (idle)", /* 0x80 */
144 };
145
146 static inline const char *get_task_state(struct task_struct *tsk)
147 {
148 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != ARRAY_SIZE(task_state_array));
149 return task_state_array[task_state_index(tsk)];
150 }
151
152 static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
153 struct pid *pid, struct task_struct *p)
154 {
155 struct user_namespace *user_ns = seq_user_ns(m);
156 struct group_info *group_info;
157 int g, umask = -1;
158 struct task_struct *tracer;
159 const struct cred *cred;
160 pid_t ppid, tpid = 0, tgid, ngid;
161 unsigned int max_fds = 0;
162
163 rcu_read_lock();
164 ppid = pid_alive(p) ?
165 task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
166
167 tracer = ptrace_parent(p);
168 if (tracer)
169 tpid = task_pid_nr_ns(tracer, ns);
170
171 tgid = task_tgid_nr_ns(p, ns);
172 ngid = task_numa_group_id(p);
173 cred = get_task_cred(p);
174
175 task_lock(p);
176 if (p->fs)
177 umask = p->fs->umask;
178 if (p->files)
179 max_fds = files_fdtable(p->files)->max_fds;
180 task_unlock(p);
181 rcu_read_unlock();
182
183 if (umask >= 0)
184 seq_printf(m, "Umask:\t%#04o\n", umask);
185 seq_puts(m, "State:\t");
186 seq_puts(m, get_task_state(p));
187
188 seq_put_decimal_ull(m, "\nTgid:\t", tgid);
189 seq_put_decimal_ull(m, "\nNgid:\t", ngid);
190 seq_put_decimal_ull(m, "\nPid:\t", pid_nr_ns(pid, ns));
191 seq_put_decimal_ull(m, "\nPPid:\t", ppid);
192 seq_put_decimal_ull(m, "\nTracerPid:\t", tpid);
193 seq_put_decimal_ull(m, "\nUid:\t", from_kuid_munged(user_ns, cred->uid));
194 seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->euid));
195 seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->suid));
196 seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->fsuid));
197 seq_put_decimal_ull(m, "\nGid:\t", from_kgid_munged(user_ns, cred->gid));
198 seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->egid));
199 seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->sgid));
200 seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->fsgid));
201 seq_put_decimal_ull(m, "\nFDSize:\t", max_fds);
202
203 seq_puts(m, "\nGroups:\t");
204 group_info = cred->group_info;
205 for (g = 0; g < group_info->ngroups; g++)
206 seq_put_decimal_ull(m, g ? " " : "",
207 from_kgid_munged(user_ns, group_info->gid[g]));
208 put_cred(cred);
209 /* Trailing space shouldn't have been added in the first place. */
210 seq_putc(m, ' ');
211
212 #ifdef CONFIG_PID_NS
213 seq_puts(m, "\nNStgid:");
214 for (g = ns->level; g <= pid->level; g++)
215 seq_put_decimal_ull(m, "\t", task_tgid_nr_ns(p, pid->numbers[g].ns));
216 seq_puts(m, "\nNSpid:");
217 for (g = ns->level; g <= pid->level; g++)
218 seq_put_decimal_ull(m, "\t", task_pid_nr_ns(p, pid->numbers[g].ns));
219 seq_puts(m, "\nNSpgid:");
220 for (g = ns->level; g <= pid->level; g++)
221 seq_put_decimal_ull(m, "\t", task_pgrp_nr_ns(p, pid->numbers[g].ns));
222 seq_puts(m, "\nNSsid:");
223 for (g = ns->level; g <= pid->level; g++)
224 seq_put_decimal_ull(m, "\t", task_session_nr_ns(p, pid->numbers[g].ns));
225 #endif
226 seq_putc(m, '\n');
227 }
228
229 void render_sigset_t(struct seq_file *m, const char *header,
230 sigset_t *set)
231 {
232 int i;
233
234 seq_puts(m, header);
235
236 i = _NSIG;
237 do {
238 int x = 0;
239
240 i -= 4;
241 if (sigismember(set, i+1)) x |= 1;
242 if (sigismember(set, i+2)) x |= 2;
243 if (sigismember(set, i+3)) x |= 4;
244 if (sigismember(set, i+4)) x |= 8;
245 seq_putc(m, hex_asc[x]);
246 } while (i >= 4);
247
248 seq_putc(m, '\n');
249 }
250
251 static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign,
252 sigset_t *catch)
253 {
254 struct k_sigaction *k;
255 int i;
256
257 k = p->sighand->action;
258 for (i = 1; i <= _NSIG; ++i, ++k) {
259 if (k->sa.sa_handler == SIG_IGN)
260 sigaddset(ign, i);
261 else if (k->sa.sa_handler != SIG_DFL)
262 sigaddset(catch, i);
263 }
264 }
265
266 static inline void task_sig(struct seq_file *m, struct task_struct *p)
267 {
268 unsigned long flags;
269 sigset_t pending, shpending, blocked, ignored, caught;
270 int num_threads = 0;
271 unsigned int qsize = 0;
272 unsigned long qlim = 0;
273
274 sigemptyset(&pending);
275 sigemptyset(&shpending);
276 sigemptyset(&blocked);
277 sigemptyset(&ignored);
278 sigemptyset(&caught);
279
280 if (lock_task_sighand(p, &flags)) {
281 pending = p->pending.signal;
282 shpending = p->signal->shared_pending.signal;
283 blocked = p->blocked;
284 collect_sigign_sigcatch(p, &ignored, &caught);
285 num_threads = get_nr_threads(p);
286 rcu_read_lock(); /* FIXME: is this correct? */
287 qsize = atomic_read(&__task_cred(p)->user->sigpending);
288 rcu_read_unlock();
289 qlim = task_rlimit(p, RLIMIT_SIGPENDING);
290 unlock_task_sighand(p, &flags);
291 }
292
293 seq_put_decimal_ull(m, "Threads:\t", num_threads);
294 seq_put_decimal_ull(m, "\nSigQ:\t", qsize);
295 seq_put_decimal_ull(m, "/", qlim);
296
297 /* render them all */
298 render_sigset_t(m, "\nSigPnd:\t", &pending);
299 render_sigset_t(m, "ShdPnd:\t", &shpending);
300 render_sigset_t(m, "SigBlk:\t", &blocked);
301 render_sigset_t(m, "SigIgn:\t", &ignored);
302 render_sigset_t(m, "SigCgt:\t", &caught);
303 }
304
305 static void render_cap_t(struct seq_file *m, const char *header,
306 kernel_cap_t *a)
307 {
308 unsigned __capi;
309
310 seq_puts(m, header);
311 CAP_FOR_EACH_U32(__capi) {
312 seq_put_hex_ll(m, NULL,
313 a->cap[CAP_LAST_U32 - __capi], 8);
314 }
315 seq_putc(m, '\n');
316 }
317
318 static inline void task_cap(struct seq_file *m, struct task_struct *p)
319 {
320 const struct cred *cred;
321 kernel_cap_t cap_inheritable, cap_permitted, cap_effective,
322 cap_bset, cap_ambient;
323
324 rcu_read_lock();
325 cred = __task_cred(p);
326 cap_inheritable = cred->cap_inheritable;
327 cap_permitted = cred->cap_permitted;
328 cap_effective = cred->cap_effective;
329 cap_bset = cred->cap_bset;
330 cap_ambient = cred->cap_ambient;
331 rcu_read_unlock();
332
333 render_cap_t(m, "CapInh:\t", &cap_inheritable);
334 render_cap_t(m, "CapPrm:\t", &cap_permitted);
335 render_cap_t(m, "CapEff:\t", &cap_effective);
336 render_cap_t(m, "CapBnd:\t", &cap_bset);
337 render_cap_t(m, "CapAmb:\t", &cap_ambient);
338 }
339
340 static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
341 {
342 seq_put_decimal_ull(m, "NoNewPrivs:\t", task_no_new_privs(p));
343 #ifdef CONFIG_SECCOMP
344 seq_put_decimal_ull(m, "\nSeccomp:\t", p->seccomp.mode);
345 #endif
346 seq_printf(m, "\nSpeculation_Store_Bypass:\t");
347 switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_STORE_BYPASS)) {
348 case -EINVAL:
349 seq_printf(m, "unknown");
350 break;
351 case PR_SPEC_NOT_AFFECTED:
352 seq_printf(m, "not vulnerable");
353 break;
354 case PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE:
355 seq_printf(m, "thread force mitigated");
356 break;
357 case PR_SPEC_PRCTL | PR_SPEC_DISABLE:
358 seq_printf(m, "thread mitigated");
359 break;
360 case PR_SPEC_PRCTL | PR_SPEC_ENABLE:
361 seq_printf(m, "thread vulnerable");
362 break;
363 case PR_SPEC_DISABLE:
364 seq_printf(m, "globally mitigated");
365 break;
366 default:
367 seq_printf(m, "vulnerable");
368 break;
369 }
370 seq_putc(m, '\n');
371 }
372
373 static inline void task_context_switch_counts(struct seq_file *m,
374 struct task_struct *p)
375 {
376 seq_put_decimal_ull(m, "voluntary_ctxt_switches:\t", p->nvcsw);
377 seq_put_decimal_ull(m, "\nnonvoluntary_ctxt_switches:\t", p->nivcsw);
378 seq_putc(m, '\n');
379 }
380
381 static void task_cpus_allowed(struct seq_file *m, struct task_struct *task)
382 {
383 seq_printf(m, "Cpus_allowed:\t%*pb\n",
384 cpumask_pr_args(&task->cpus_allowed));
385 seq_printf(m, "Cpus_allowed_list:\t%*pbl\n",
386 cpumask_pr_args(&task->cpus_allowed));
387 }
388
389 static inline void task_core_dumping(struct seq_file *m, struct mm_struct *mm)
390 {
391 seq_put_decimal_ull(m, "CoreDumping:\t", !!mm->core_state);
392 seq_putc(m, '\n');
393 }
394
395 int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
396 struct pid *pid, struct task_struct *task)
397 {
398 struct mm_struct *mm = get_task_mm(task);
399
400 seq_puts(m, "Name:\t");
401 proc_task_name(m, task, true);
402 seq_putc(m, '\n');
403
404 task_state(m, ns, pid, task);
405
406 if (mm) {
407 task_mem(m, mm);
408 task_core_dumping(m, mm);
409 mmput(mm);
410 }
411 task_sig(m, task);
412 task_cap(m, task);
413 task_seccomp(m, task);
414 task_cpus_allowed(m, task);
415 cpuset_task_status_allowed(m, task);
416 task_context_switch_counts(m, task);
417 return 0;
418 }
419
420 static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
421 struct pid *pid, struct task_struct *task, int whole)
422 {
423 unsigned long vsize, eip, esp, wchan = 0;
424 int priority, nice;
425 int tty_pgrp = -1, tty_nr = 0;
426 sigset_t sigign, sigcatch;
427 char state;
428 pid_t ppid = 0, pgid = -1, sid = -1;
429 int num_threads = 0;
430 int permitted;
431 struct mm_struct *mm;
432 unsigned long long start_time;
433 unsigned long cmin_flt = 0, cmaj_flt = 0;
434 unsigned long min_flt = 0, maj_flt = 0;
435 u64 cutime, cstime, utime, stime;
436 u64 cgtime, gtime;
437 unsigned long rsslim = 0;
438 unsigned long flags;
439
440 state = *get_task_state(task);
441 vsize = eip = esp = 0;
442 permitted = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS | PTRACE_MODE_NOAUDIT);
443 mm = get_task_mm(task);
444 if (mm) {
445 vsize = task_vsize(mm);
446 /*
447 * esp and eip are intentionally zeroed out. There is no
448 * non-racy way to read them without freezing the task.
449 * Programs that need reliable values can use ptrace(2).
450 *
451 * The only exception is if the task is core dumping because
452 * a program is not able to use ptrace(2) in that case. It is
453 * safe because the task has stopped executing permanently.
454 */
455 if (permitted && (task->flags & (PF_EXITING|PF_DUMPCORE))) {
456 if (try_get_task_stack(task)) {
457 eip = KSTK_EIP(task);
458 esp = KSTK_ESP(task);
459 put_task_stack(task);
460 }
461 }
462 }
463
464 sigemptyset(&sigign);
465 sigemptyset(&sigcatch);
466 cutime = cstime = utime = stime = 0;
467 cgtime = gtime = 0;
468
469 if (lock_task_sighand(task, &flags)) {
470 struct signal_struct *sig = task->signal;
471
472 if (sig->tty) {
473 struct pid *pgrp = tty_get_pgrp(sig->tty);
474 tty_pgrp = pid_nr_ns(pgrp, ns);
475 put_pid(pgrp);
476 tty_nr = new_encode_dev(tty_devnum(sig->tty));
477 }
478
479 num_threads = get_nr_threads(task);
480 collect_sigign_sigcatch(task, &sigign, &sigcatch);
481
482 cmin_flt = sig->cmin_flt;
483 cmaj_flt = sig->cmaj_flt;
484 cutime = sig->cutime;
485 cstime = sig->cstime;
486 cgtime = sig->cgtime;
487 rsslim = READ_ONCE(sig->rlim[RLIMIT_RSS].rlim_cur);
488
489 /* add up live thread stats at the group level */
490 if (whole) {
491 struct task_struct *t = task;
492 do {
493 min_flt += t->min_flt;
494 maj_flt += t->maj_flt;
495 gtime += task_gtime(t);
496 } while_each_thread(task, t);
497
498 min_flt += sig->min_flt;
499 maj_flt += sig->maj_flt;
500 thread_group_cputime_adjusted(task, &utime, &stime);
501 gtime += sig->gtime;
502 }
503
504 sid = task_session_nr_ns(task, ns);
505 ppid = task_tgid_nr_ns(task->real_parent, ns);
506 pgid = task_pgrp_nr_ns(task, ns);
507
508 unlock_task_sighand(task, &flags);
509 }
510
511 if (permitted && (!whole || num_threads < 2))
512 wchan = get_wchan(task);
513 if (!whole) {
514 min_flt = task->min_flt;
515 maj_flt = task->maj_flt;
516 task_cputime_adjusted(task, &utime, &stime);
517 gtime = task_gtime(task);
518 }
519
520 /* scale priority and nice values from timeslices to -20..20 */
521 /* to make it look like a "normal" Unix priority/nice value */
522 priority = task_prio(task);
523 nice = task_nice(task);
524
525 /* convert nsec -> ticks */
526 start_time = nsec_to_clock_t(task->real_start_time);
527
528 seq_put_decimal_ull(m, "", pid_nr_ns(pid, ns));
529 seq_puts(m, " (");
530 proc_task_name(m, task, false);
531 seq_puts(m, ") ");
532 seq_putc(m, state);
533 seq_put_decimal_ll(m, " ", ppid);
534 seq_put_decimal_ll(m, " ", pgid);
535 seq_put_decimal_ll(m, " ", sid);
536 seq_put_decimal_ll(m, " ", tty_nr);
537 seq_put_decimal_ll(m, " ", tty_pgrp);
538 seq_put_decimal_ull(m, " ", task->flags);
539 seq_put_decimal_ull(m, " ", min_flt);
540 seq_put_decimal_ull(m, " ", cmin_flt);
541 seq_put_decimal_ull(m, " ", maj_flt);
542 seq_put_decimal_ull(m, " ", cmaj_flt);
543 seq_put_decimal_ull(m, " ", nsec_to_clock_t(utime));
544 seq_put_decimal_ull(m, " ", nsec_to_clock_t(stime));
545 seq_put_decimal_ll(m, " ", nsec_to_clock_t(cutime));
546 seq_put_decimal_ll(m, " ", nsec_to_clock_t(cstime));
547 seq_put_decimal_ll(m, " ", priority);
548 seq_put_decimal_ll(m, " ", nice);
549 seq_put_decimal_ll(m, " ", num_threads);
550 seq_put_decimal_ull(m, " ", 0);
551 seq_put_decimal_ull(m, " ", start_time);
552 seq_put_decimal_ull(m, " ", vsize);
553 seq_put_decimal_ull(m, " ", mm ? get_mm_rss(mm) : 0);
554 seq_put_decimal_ull(m, " ", rsslim);
555 seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->start_code : 1) : 0);
556 seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->end_code : 1) : 0);
557 seq_put_decimal_ull(m, " ", (permitted && mm) ? mm->start_stack : 0);
558 seq_put_decimal_ull(m, " ", esp);
559 seq_put_decimal_ull(m, " ", eip);
560 /* The signal information here is obsolete.
561 * It must be decimal for Linux 2.0 compatibility.
562 * Use /proc/#/status for real-time signals.
563 */
564 seq_put_decimal_ull(m, " ", task->pending.signal.sig[0] & 0x7fffffffUL);
565 seq_put_decimal_ull(m, " ", task->blocked.sig[0] & 0x7fffffffUL);
566 seq_put_decimal_ull(m, " ", sigign.sig[0] & 0x7fffffffUL);
567 seq_put_decimal_ull(m, " ", sigcatch.sig[0] & 0x7fffffffUL);
568
569 /*
570 * We used to output the absolute kernel address, but that's an
571 * information leak - so instead we show a 0/1 flag here, to signal
572 * to user-space whether there's a wchan field in /proc/PID/wchan.
573 *
574 * This works with older implementations of procps as well.
575 */
576 if (wchan)
577 seq_puts(m, " 1");
578 else
579 seq_puts(m, " 0");
580
581 seq_put_decimal_ull(m, " ", 0);
582 seq_put_decimal_ull(m, " ", 0);
583 seq_put_decimal_ll(m, " ", task->exit_signal);
584 seq_put_decimal_ll(m, " ", task_cpu(task));
585 seq_put_decimal_ull(m, " ", task->rt_priority);
586 seq_put_decimal_ull(m, " ", task->policy);
587 seq_put_decimal_ull(m, " ", delayacct_blkio_ticks(task));
588 seq_put_decimal_ull(m, " ", nsec_to_clock_t(gtime));
589 seq_put_decimal_ll(m, " ", nsec_to_clock_t(cgtime));
590
591 if (mm && permitted) {
592 seq_put_decimal_ull(m, " ", mm->start_data);
593 seq_put_decimal_ull(m, " ", mm->end_data);
594 seq_put_decimal_ull(m, " ", mm->start_brk);
595 seq_put_decimal_ull(m, " ", mm->arg_start);
596 seq_put_decimal_ull(m, " ", mm->arg_end);
597 seq_put_decimal_ull(m, " ", mm->env_start);
598 seq_put_decimal_ull(m, " ", mm->env_end);
599 } else
600 seq_puts(m, " 0 0 0 0 0 0 0");
601
602 if (permitted)
603 seq_put_decimal_ll(m, " ", task->exit_code);
604 else
605 seq_puts(m, " 0");
606
607 seq_putc(m, '\n');
608 if (mm)
609 mmput(mm);
610 return 0;
611 }
612
613 int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
614 struct pid *pid, struct task_struct *task)
615 {
616 return do_task_stat(m, ns, pid, task, 0);
617 }
618
619 int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
620 struct pid *pid, struct task_struct *task)
621 {
622 return do_task_stat(m, ns, pid, task, 1);
623 }
624
625 int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
626 struct pid *pid, struct task_struct *task)
627 {
628 unsigned long size = 0, resident = 0, shared = 0, text = 0, data = 0;
629 struct mm_struct *mm = get_task_mm(task);
630
631 if (mm) {
632 size = task_statm(mm, &shared, &text, &data, &resident);
633 mmput(mm);
634 }
635 /*
636 * For quick read, open code by putting numbers directly
637 * expected format is
638 * seq_printf(m, "%lu %lu %lu %lu 0 %lu 0\n",
639 * size, resident, shared, text, data);
640 */
641 seq_put_decimal_ull(m, "", size);
642 seq_put_decimal_ull(m, " ", resident);
643 seq_put_decimal_ull(m, " ", shared);
644 seq_put_decimal_ull(m, " ", text);
645 seq_put_decimal_ull(m, " ", 0);
646 seq_put_decimal_ull(m, " ", data);
647 seq_put_decimal_ull(m, " ", 0);
648 seq_putc(m, '\n');
649
650 return 0;
651 }
652
653 #ifdef CONFIG_PROC_CHILDREN
654 static struct pid *
655 get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos)
656 {
657 struct task_struct *start, *task;
658 struct pid *pid = NULL;
659
660 read_lock(&tasklist_lock);
661
662 start = pid_task(proc_pid(inode), PIDTYPE_PID);
663 if (!start)
664 goto out;
665
666 /*
667 * Lets try to continue searching first, this gives
668 * us significant speedup on children-rich processes.
669 */
670 if (pid_prev) {
671 task = pid_task(pid_prev, PIDTYPE_PID);
672 if (task && task->real_parent == start &&
673 !(list_empty(&task->sibling))) {
674 if (list_is_last(&task->sibling, &start->children))
675 goto out;
676 task = list_first_entry(&task->sibling,
677 struct task_struct, sibling);
678 pid = get_pid(task_pid(task));
679 goto out;
680 }
681 }
682
683 /*
684 * Slow search case.
685 *
686 * We might miss some children here if children
687 * are exited while we were not holding the lock,
688 * but it was never promised to be accurate that
689 * much.
690 *
691 * "Just suppose that the parent sleeps, but N children
692 * exit after we printed their tids. Now the slow paths
693 * skips N extra children, we miss N tasks." (c)
694 *
695 * So one need to stop or freeze the leader and all
696 * its children to get a precise result.
697 */
698 list_for_each_entry(task, &start->children, sibling) {
699 if (pos-- == 0) {
700 pid = get_pid(task_pid(task));
701 break;
702 }
703 }
704
705 out:
706 read_unlock(&tasklist_lock);
707 return pid;
708 }
709
710 static int children_seq_show(struct seq_file *seq, void *v)
711 {
712 struct inode *inode = file_inode(seq->file);
713
714 seq_printf(seq, "%d ", pid_nr_ns(v, proc_pid_ns(inode)));
715 return 0;
716 }
717
718 static void *children_seq_start(struct seq_file *seq, loff_t *pos)
719 {
720 return get_children_pid(file_inode(seq->file), NULL, *pos);
721 }
722
723 static void *children_seq_next(struct seq_file *seq, void *v, loff_t *pos)
724 {
725 struct pid *pid;
726
727 pid = get_children_pid(file_inode(seq->file), v, *pos + 1);
728 put_pid(v);
729
730 ++*pos;
731 return pid;
732 }
733
734 static void children_seq_stop(struct seq_file *seq, void *v)
735 {
736 put_pid(v);
737 }
738
739 static const struct seq_operations children_seq_ops = {
740 .start = children_seq_start,
741 .next = children_seq_next,
742 .stop = children_seq_stop,
743 .show = children_seq_show,
744 };
745
746 static int children_seq_open(struct inode *inode, struct file *file)
747 {
748 return seq_open(file, &children_seq_ops);
749 }
750
751 const struct file_operations proc_tid_children_operations = {
752 .open = children_seq_open,
753 .read = seq_read,
754 .llseek = seq_lseek,
755 .release = seq_release,
756 };
757 #endif /* CONFIG_PROC_CHILDREN */
Linux with added FPC-III support