xref: /openbmc/linux/fs/proc/array.c (revision 827beb77)
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/time_namespace.h>
60 #include <linux/kernel.h>
61 #include <linux/kernel_stat.h>
62 #include <linux/tty.h>
63 #include <linux/string.h>
64 #include <linux/mman.h>
65 #include <linux/sched/mm.h>
66 #include <linux/sched/numa_balancing.h>
67 #include <linux/sched/task_stack.h>
68 #include <linux/sched/task.h>
69 #include <linux/sched/cputime.h>
70 #include <linux/proc_fs.h>
71 #include <linux/ioport.h>
72 #include <linux/uaccess.h>
73 #include <linux/io.h>
74 #include <linux/mm.h>
75 #include <linux/hugetlb.h>
76 #include <linux/pagemap.h>
77 #include <linux/swap.h>
78 #include <linux/smp.h>
79 #include <linux/signal.h>
80 #include <linux/highmem.h>
81 #include <linux/file.h>
82 #include <linux/fdtable.h>
83 #include <linux/times.h>
84 #include <linux/cpuset.h>
85 #include <linux/rcupdate.h>
86 #include <linux/delayacct.h>
87 #include <linux/seq_file.h>
88 #include <linux/pid_namespace.h>
89 #include <linux/prctl.h>
90 #include <linux/ptrace.h>
91 #include <linux/tracehook.h>
92 #include <linux/string_helpers.h>
93 #include <linux/user_namespace.h>
94 #include <linux/fs_struct.h>
95 
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 tcomm[64];
102 
103 	if (p->flags & PF_WQ_WORKER)
104 		wq_worker_comm(tcomm, sizeof(tcomm), p);
105 	else
106 		__get_task_comm(tcomm, sizeof(tcomm), p);
107 
108 	if (escape)
109 		seq_escape_str(m, tcomm, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");
110 	else
111 		seq_printf(m, "%.64s", tcomm);
112 }
113 
114 /*
115  * The task state array is a strange "bitmap" of
116  * reasons to sleep. Thus "running" is zero, and
117  * you can test for combinations of others with
118  * simple bit tests.
119  */
120 static const char * const task_state_array[] = {
121 
122 	/* states in TASK_REPORT: */
123 	"R (running)",		/* 0x00 */
124 	"S (sleeping)",		/* 0x01 */
125 	"D (disk sleep)",	/* 0x02 */
126 	"T (stopped)",		/* 0x04 */
127 	"t (tracing stop)",	/* 0x08 */
128 	"X (dead)",		/* 0x10 */
129 	"Z (zombie)",		/* 0x20 */
130 	"P (parked)",		/* 0x40 */
131 
132 	/* states beyond TASK_REPORT: */
133 	"I (idle)",		/* 0x80 */
134 };
135 
136 static inline const char *get_task_state(struct task_struct *tsk)
137 {
138 	BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != ARRAY_SIZE(task_state_array));
139 	return task_state_array[task_state_index(tsk)];
140 }
141 
142 static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
143 				struct pid *pid, struct task_struct *p)
144 {
145 	struct user_namespace *user_ns = seq_user_ns(m);
146 	struct group_info *group_info;
147 	int g, umask = -1;
148 	struct task_struct *tracer;
149 	const struct cred *cred;
150 	pid_t ppid, tpid = 0, tgid, ngid;
151 	unsigned int max_fds = 0;
152 
153 	rcu_read_lock();
154 	ppid = pid_alive(p) ?
155 		task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
156 
157 	tracer = ptrace_parent(p);
158 	if (tracer)
159 		tpid = task_pid_nr_ns(tracer, ns);
160 
161 	tgid = task_tgid_nr_ns(p, ns);
162 	ngid = task_numa_group_id(p);
163 	cred = get_task_cred(p);
164 
165 	task_lock(p);
166 	if (p->fs)
167 		umask = p->fs->umask;
168 	if (p->files)
169 		max_fds = files_fdtable(p->files)->max_fds;
170 	task_unlock(p);
171 	rcu_read_unlock();
172 
173 	if (umask >= 0)
174 		seq_printf(m, "Umask:\t%#04o\n", umask);
175 	seq_puts(m, "State:\t");
176 	seq_puts(m, get_task_state(p));
177 
178 	seq_put_decimal_ull(m, "\nTgid:\t", tgid);
179 	seq_put_decimal_ull(m, "\nNgid:\t", ngid);
180 	seq_put_decimal_ull(m, "\nPid:\t", pid_nr_ns(pid, ns));
181 	seq_put_decimal_ull(m, "\nPPid:\t", ppid);
182 	seq_put_decimal_ull(m, "\nTracerPid:\t", tpid);
183 	seq_put_decimal_ull(m, "\nUid:\t", from_kuid_munged(user_ns, cred->uid));
184 	seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->euid));
185 	seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->suid));
186 	seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->fsuid));
187 	seq_put_decimal_ull(m, "\nGid:\t", from_kgid_munged(user_ns, cred->gid));
188 	seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->egid));
189 	seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->sgid));
190 	seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->fsgid));
191 	seq_put_decimal_ull(m, "\nFDSize:\t", max_fds);
192 
193 	seq_puts(m, "\nGroups:\t");
194 	group_info = cred->group_info;
195 	for (g = 0; g < group_info->ngroups; g++)
196 		seq_put_decimal_ull(m, g ? " " : "",
197 				from_kgid_munged(user_ns, group_info->gid[g]));
198 	put_cred(cred);
199 	/* Trailing space shouldn't have been added in the first place. */
200 	seq_putc(m, ' ');
201 
202 #ifdef CONFIG_PID_NS
203 	seq_puts(m, "\nNStgid:");
204 	for (g = ns->level; g <= pid->level; g++)
205 		seq_put_decimal_ull(m, "\t", task_tgid_nr_ns(p, pid->numbers[g].ns));
206 	seq_puts(m, "\nNSpid:");
207 	for (g = ns->level; g <= pid->level; g++)
208 		seq_put_decimal_ull(m, "\t", task_pid_nr_ns(p, pid->numbers[g].ns));
209 	seq_puts(m, "\nNSpgid:");
210 	for (g = ns->level; g <= pid->level; g++)
211 		seq_put_decimal_ull(m, "\t", task_pgrp_nr_ns(p, pid->numbers[g].ns));
212 	seq_puts(m, "\nNSsid:");
213 	for (g = ns->level; g <= pid->level; g++)
214 		seq_put_decimal_ull(m, "\t", task_session_nr_ns(p, pid->numbers[g].ns));
215 #endif
216 	seq_putc(m, '\n');
217 }
218 
219 void render_sigset_t(struct seq_file *m, const char *header,
220 				sigset_t *set)
221 {
222 	int i;
223 
224 	seq_puts(m, header);
225 
226 	i = _NSIG;
227 	do {
228 		int x = 0;
229 
230 		i -= 4;
231 		if (sigismember(set, i+1)) x |= 1;
232 		if (sigismember(set, i+2)) x |= 2;
233 		if (sigismember(set, i+3)) x |= 4;
234 		if (sigismember(set, i+4)) x |= 8;
235 		seq_putc(m, hex_asc[x]);
236 	} while (i >= 4);
237 
238 	seq_putc(m, '\n');
239 }
240 
241 static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *sigign,
242 				    sigset_t *sigcatch)
243 {
244 	struct k_sigaction *k;
245 	int i;
246 
247 	k = p->sighand->action;
248 	for (i = 1; i <= _NSIG; ++i, ++k) {
249 		if (k->sa.sa_handler == SIG_IGN)
250 			sigaddset(sigign, i);
251 		else if (k->sa.sa_handler != SIG_DFL)
252 			sigaddset(sigcatch, i);
253 	}
254 }
255 
256 static inline void task_sig(struct seq_file *m, struct task_struct *p)
257 {
258 	unsigned long flags;
259 	sigset_t pending, shpending, blocked, ignored, caught;
260 	int num_threads = 0;
261 	unsigned int qsize = 0;
262 	unsigned long qlim = 0;
263 
264 	sigemptyset(&pending);
265 	sigemptyset(&shpending);
266 	sigemptyset(&blocked);
267 	sigemptyset(&ignored);
268 	sigemptyset(&caught);
269 
270 	if (lock_task_sighand(p, &flags)) {
271 		pending = p->pending.signal;
272 		shpending = p->signal->shared_pending.signal;
273 		blocked = p->blocked;
274 		collect_sigign_sigcatch(p, &ignored, &caught);
275 		num_threads = get_nr_threads(p);
276 		rcu_read_lock();  /* FIXME: is this correct? */
277 		qsize = get_ucounts_value(task_ucounts(p), UCOUNT_RLIMIT_SIGPENDING);
278 		rcu_read_unlock();
279 		qlim = task_rlimit(p, RLIMIT_SIGPENDING);
280 		unlock_task_sighand(p, &flags);
281 	}
282 
283 	seq_put_decimal_ull(m, "Threads:\t", num_threads);
284 	seq_put_decimal_ull(m, "\nSigQ:\t", qsize);
285 	seq_put_decimal_ull(m, "/", qlim);
286 
287 	/* render them all */
288 	render_sigset_t(m, "\nSigPnd:\t", &pending);
289 	render_sigset_t(m, "ShdPnd:\t", &shpending);
290 	render_sigset_t(m, "SigBlk:\t", &blocked);
291 	render_sigset_t(m, "SigIgn:\t", &ignored);
292 	render_sigset_t(m, "SigCgt:\t", &caught);
293 }
294 
295 static void render_cap_t(struct seq_file *m, const char *header,
296 			kernel_cap_t *a)
297 {
298 	unsigned __capi;
299 
300 	seq_puts(m, header);
301 	CAP_FOR_EACH_U32(__capi) {
302 		seq_put_hex_ll(m, NULL,
303 			   a->cap[CAP_LAST_U32 - __capi], 8);
304 	}
305 	seq_putc(m, '\n');
306 }
307 
308 static inline void task_cap(struct seq_file *m, struct task_struct *p)
309 {
310 	const struct cred *cred;
311 	kernel_cap_t cap_inheritable, cap_permitted, cap_effective,
312 			cap_bset, cap_ambient;
313 
314 	rcu_read_lock();
315 	cred = __task_cred(p);
316 	cap_inheritable	= cred->cap_inheritable;
317 	cap_permitted	= cred->cap_permitted;
318 	cap_effective	= cred->cap_effective;
319 	cap_bset	= cred->cap_bset;
320 	cap_ambient	= cred->cap_ambient;
321 	rcu_read_unlock();
322 
323 	render_cap_t(m, "CapInh:\t", &cap_inheritable);
324 	render_cap_t(m, "CapPrm:\t", &cap_permitted);
325 	render_cap_t(m, "CapEff:\t", &cap_effective);
326 	render_cap_t(m, "CapBnd:\t", &cap_bset);
327 	render_cap_t(m, "CapAmb:\t", &cap_ambient);
328 }
329 
330 static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
331 {
332 	seq_put_decimal_ull(m, "NoNewPrivs:\t", task_no_new_privs(p));
333 #ifdef CONFIG_SECCOMP
334 	seq_put_decimal_ull(m, "\nSeccomp:\t", p->seccomp.mode);
335 #ifdef CONFIG_SECCOMP_FILTER
336 	seq_put_decimal_ull(m, "\nSeccomp_filters:\t",
337 			    atomic_read(&p->seccomp.filter_count));
338 #endif
339 #endif
340 	seq_puts(m, "\nSpeculation_Store_Bypass:\t");
341 	switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_STORE_BYPASS)) {
342 	case -EINVAL:
343 		seq_puts(m, "unknown");
344 		break;
345 	case PR_SPEC_NOT_AFFECTED:
346 		seq_puts(m, "not vulnerable");
347 		break;
348 	case PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE:
349 		seq_puts(m, "thread force mitigated");
350 		break;
351 	case PR_SPEC_PRCTL | PR_SPEC_DISABLE:
352 		seq_puts(m, "thread mitigated");
353 		break;
354 	case PR_SPEC_PRCTL | PR_SPEC_ENABLE:
355 		seq_puts(m, "thread vulnerable");
356 		break;
357 	case PR_SPEC_DISABLE:
358 		seq_puts(m, "globally mitigated");
359 		break;
360 	default:
361 		seq_puts(m, "vulnerable");
362 		break;
363 	}
364 
365 	seq_puts(m, "\nSpeculationIndirectBranch:\t");
366 	switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_INDIRECT_BRANCH)) {
367 	case -EINVAL:
368 		seq_puts(m, "unsupported");
369 		break;
370 	case PR_SPEC_NOT_AFFECTED:
371 		seq_puts(m, "not affected");
372 		break;
373 	case PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE:
374 		seq_puts(m, "conditional force disabled");
375 		break;
376 	case PR_SPEC_PRCTL | PR_SPEC_DISABLE:
377 		seq_puts(m, "conditional disabled");
378 		break;
379 	case PR_SPEC_PRCTL | PR_SPEC_ENABLE:
380 		seq_puts(m, "conditional enabled");
381 		break;
382 	case PR_SPEC_ENABLE:
383 		seq_puts(m, "always enabled");
384 		break;
385 	case PR_SPEC_DISABLE:
386 		seq_puts(m, "always disabled");
387 		break;
388 	default:
389 		seq_puts(m, "unknown");
390 		break;
391 	}
392 	seq_putc(m, '\n');
393 }
394 
395 static inline void task_context_switch_counts(struct seq_file *m,
396 						struct task_struct *p)
397 {
398 	seq_put_decimal_ull(m, "voluntary_ctxt_switches:\t", p->nvcsw);
399 	seq_put_decimal_ull(m, "\nnonvoluntary_ctxt_switches:\t", p->nivcsw);
400 	seq_putc(m, '\n');
401 }
402 
403 static void task_cpus_allowed(struct seq_file *m, struct task_struct *task)
404 {
405 	seq_printf(m, "Cpus_allowed:\t%*pb\n",
406 		   cpumask_pr_args(&task->cpus_mask));
407 	seq_printf(m, "Cpus_allowed_list:\t%*pbl\n",
408 		   cpumask_pr_args(&task->cpus_mask));
409 }
410 
411 static inline void task_core_dumping(struct seq_file *m, struct mm_struct *mm)
412 {
413 	seq_put_decimal_ull(m, "CoreDumping:\t", !!mm->core_state);
414 	seq_putc(m, '\n');
415 }
416 
417 static inline void task_thp_status(struct seq_file *m, struct mm_struct *mm)
418 {
419 	bool thp_enabled = IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE);
420 
421 	if (thp_enabled)
422 		thp_enabled = !test_bit(MMF_DISABLE_THP, &mm->flags);
423 	seq_printf(m, "THP_enabled:\t%d\n", thp_enabled);
424 }
425 
426 int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
427 			struct pid *pid, struct task_struct *task)
428 {
429 	struct mm_struct *mm = get_task_mm(task);
430 
431 	seq_puts(m, "Name:\t");
432 	proc_task_name(m, task, true);
433 	seq_putc(m, '\n');
434 
435 	task_state(m, ns, pid, task);
436 
437 	if (mm) {
438 		task_mem(m, mm);
439 		task_core_dumping(m, mm);
440 		task_thp_status(m, mm);
441 		mmput(mm);
442 	}
443 	task_sig(m, task);
444 	task_cap(m, task);
445 	task_seccomp(m, task);
446 	task_cpus_allowed(m, task);
447 	cpuset_task_status_allowed(m, task);
448 	task_context_switch_counts(m, task);
449 	return 0;
450 }
451 
452 static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
453 			struct pid *pid, struct task_struct *task, int whole)
454 {
455 	unsigned long vsize, eip, esp, wchan = 0;
456 	int priority, nice;
457 	int tty_pgrp = -1, tty_nr = 0;
458 	sigset_t sigign, sigcatch;
459 	char state;
460 	pid_t ppid = 0, pgid = -1, sid = -1;
461 	int num_threads = 0;
462 	int permitted;
463 	struct mm_struct *mm;
464 	unsigned long long start_time;
465 	unsigned long cmin_flt = 0, cmaj_flt = 0;
466 	unsigned long  min_flt = 0,  maj_flt = 0;
467 	u64 cutime, cstime, utime, stime;
468 	u64 cgtime, gtime;
469 	unsigned long rsslim = 0;
470 	unsigned long flags;
471 
472 	state = *get_task_state(task);
473 	vsize = eip = esp = 0;
474 	permitted = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS | PTRACE_MODE_NOAUDIT);
475 	mm = get_task_mm(task);
476 	if (mm) {
477 		vsize = task_vsize(mm);
478 		/*
479 		 * esp and eip are intentionally zeroed out.  There is no
480 		 * non-racy way to read them without freezing the task.
481 		 * Programs that need reliable values can use ptrace(2).
482 		 *
483 		 * The only exception is if the task is core dumping because
484 		 * a program is not able to use ptrace(2) in that case. It is
485 		 * safe because the task has stopped executing permanently.
486 		 */
487 		if (permitted && (task->flags & (PF_EXITING|PF_DUMPCORE))) {
488 			if (try_get_task_stack(task)) {
489 				eip = KSTK_EIP(task);
490 				esp = KSTK_ESP(task);
491 				put_task_stack(task);
492 			}
493 		}
494 	}
495 
496 	sigemptyset(&sigign);
497 	sigemptyset(&sigcatch);
498 	cutime = cstime = utime = stime = 0;
499 	cgtime = gtime = 0;
500 
501 	if (lock_task_sighand(task, &flags)) {
502 		struct signal_struct *sig = task->signal;
503 
504 		if (sig->tty) {
505 			struct pid *pgrp = tty_get_pgrp(sig->tty);
506 			tty_pgrp = pid_nr_ns(pgrp, ns);
507 			put_pid(pgrp);
508 			tty_nr = new_encode_dev(tty_devnum(sig->tty));
509 		}
510 
511 		num_threads = get_nr_threads(task);
512 		collect_sigign_sigcatch(task, &sigign, &sigcatch);
513 
514 		cmin_flt = sig->cmin_flt;
515 		cmaj_flt = sig->cmaj_flt;
516 		cutime = sig->cutime;
517 		cstime = sig->cstime;
518 		cgtime = sig->cgtime;
519 		rsslim = READ_ONCE(sig->rlim[RLIMIT_RSS].rlim_cur);
520 
521 		/* add up live thread stats at the group level */
522 		if (whole) {
523 			struct task_struct *t = task;
524 			do {
525 				min_flt += t->min_flt;
526 				maj_flt += t->maj_flt;
527 				gtime += task_gtime(t);
528 			} while_each_thread(task, t);
529 
530 			min_flt += sig->min_flt;
531 			maj_flt += sig->maj_flt;
532 			thread_group_cputime_adjusted(task, &utime, &stime);
533 			gtime += sig->gtime;
534 		}
535 
536 		sid = task_session_nr_ns(task, ns);
537 		ppid = task_tgid_nr_ns(task->real_parent, ns);
538 		pgid = task_pgrp_nr_ns(task, ns);
539 
540 		unlock_task_sighand(task, &flags);
541 	}
542 
543 	if (permitted && (!whole || num_threads < 2))
544 		wchan = !task_is_running(task);
545 	if (!whole) {
546 		min_flt = task->min_flt;
547 		maj_flt = task->maj_flt;
548 		task_cputime_adjusted(task, &utime, &stime);
549 		gtime = task_gtime(task);
550 	}
551 
552 	/* scale priority and nice values from timeslices to -20..20 */
553 	/* to make it look like a "normal" Unix priority/nice value  */
554 	priority = task_prio(task);
555 	nice = task_nice(task);
556 
557 	/* apply timens offset for boottime and convert nsec -> ticks */
558 	start_time =
559 		nsec_to_clock_t(timens_add_boottime_ns(task->start_boottime));
560 
561 	seq_put_decimal_ull(m, "", pid_nr_ns(pid, ns));
562 	seq_puts(m, " (");
563 	proc_task_name(m, task, false);
564 	seq_puts(m, ") ");
565 	seq_putc(m, state);
566 	seq_put_decimal_ll(m, " ", ppid);
567 	seq_put_decimal_ll(m, " ", pgid);
568 	seq_put_decimal_ll(m, " ", sid);
569 	seq_put_decimal_ll(m, " ", tty_nr);
570 	seq_put_decimal_ll(m, " ", tty_pgrp);
571 	seq_put_decimal_ull(m, " ", task->flags);
572 	seq_put_decimal_ull(m, " ", min_flt);
573 	seq_put_decimal_ull(m, " ", cmin_flt);
574 	seq_put_decimal_ull(m, " ", maj_flt);
575 	seq_put_decimal_ull(m, " ", cmaj_flt);
576 	seq_put_decimal_ull(m, " ", nsec_to_clock_t(utime));
577 	seq_put_decimal_ull(m, " ", nsec_to_clock_t(stime));
578 	seq_put_decimal_ll(m, " ", nsec_to_clock_t(cutime));
579 	seq_put_decimal_ll(m, " ", nsec_to_clock_t(cstime));
580 	seq_put_decimal_ll(m, " ", priority);
581 	seq_put_decimal_ll(m, " ", nice);
582 	seq_put_decimal_ll(m, " ", num_threads);
583 	seq_put_decimal_ull(m, " ", 0);
584 	seq_put_decimal_ull(m, " ", start_time);
585 	seq_put_decimal_ull(m, " ", vsize);
586 	seq_put_decimal_ull(m, " ", mm ? get_mm_rss(mm) : 0);
587 	seq_put_decimal_ull(m, " ", rsslim);
588 	seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->start_code : 1) : 0);
589 	seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->end_code : 1) : 0);
590 	seq_put_decimal_ull(m, " ", (permitted && mm) ? mm->start_stack : 0);
591 	seq_put_decimal_ull(m, " ", esp);
592 	seq_put_decimal_ull(m, " ", eip);
593 	/* The signal information here is obsolete.
594 	 * It must be decimal for Linux 2.0 compatibility.
595 	 * Use /proc/#/status for real-time signals.
596 	 */
597 	seq_put_decimal_ull(m, " ", task->pending.signal.sig[0] & 0x7fffffffUL);
598 	seq_put_decimal_ull(m, " ", task->blocked.sig[0] & 0x7fffffffUL);
599 	seq_put_decimal_ull(m, " ", sigign.sig[0] & 0x7fffffffUL);
600 	seq_put_decimal_ull(m, " ", sigcatch.sig[0] & 0x7fffffffUL);
601 
602 	/*
603 	 * We used to output the absolute kernel address, but that's an
604 	 * information leak - so instead we show a 0/1 flag here, to signal
605 	 * to user-space whether there's a wchan field in /proc/PID/wchan.
606 	 *
607 	 * This works with older implementations of procps as well.
608 	 */
609 	seq_put_decimal_ull(m, " ", wchan);
610 
611 	seq_put_decimal_ull(m, " ", 0);
612 	seq_put_decimal_ull(m, " ", 0);
613 	seq_put_decimal_ll(m, " ", task->exit_signal);
614 	seq_put_decimal_ll(m, " ", task_cpu(task));
615 	seq_put_decimal_ull(m, " ", task->rt_priority);
616 	seq_put_decimal_ull(m, " ", task->policy);
617 	seq_put_decimal_ull(m, " ", delayacct_blkio_ticks(task));
618 	seq_put_decimal_ull(m, " ", nsec_to_clock_t(gtime));
619 	seq_put_decimal_ll(m, " ", nsec_to_clock_t(cgtime));
620 
621 	if (mm && permitted) {
622 		seq_put_decimal_ull(m, " ", mm->start_data);
623 		seq_put_decimal_ull(m, " ", mm->end_data);
624 		seq_put_decimal_ull(m, " ", mm->start_brk);
625 		seq_put_decimal_ull(m, " ", mm->arg_start);
626 		seq_put_decimal_ull(m, " ", mm->arg_end);
627 		seq_put_decimal_ull(m, " ", mm->env_start);
628 		seq_put_decimal_ull(m, " ", mm->env_end);
629 	} else
630 		seq_puts(m, " 0 0 0 0 0 0 0");
631 
632 	if (permitted)
633 		seq_put_decimal_ll(m, " ", task->exit_code);
634 	else
635 		seq_puts(m, " 0");
636 
637 	seq_putc(m, '\n');
638 	if (mm)
639 		mmput(mm);
640 	return 0;
641 }
642 
643 int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
644 			struct pid *pid, struct task_struct *task)
645 {
646 	return do_task_stat(m, ns, pid, task, 0);
647 }
648 
649 int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
650 			struct pid *pid, struct task_struct *task)
651 {
652 	return do_task_stat(m, ns, pid, task, 1);
653 }
654 
655 int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
656 			struct pid *pid, struct task_struct *task)
657 {
658 	struct mm_struct *mm = get_task_mm(task);
659 
660 	if (mm) {
661 		unsigned long size;
662 		unsigned long resident = 0;
663 		unsigned long shared = 0;
664 		unsigned long text = 0;
665 		unsigned long data = 0;
666 
667 		size = task_statm(mm, &shared, &text, &data, &resident);
668 		mmput(mm);
669 
670 		/*
671 		 * For quick read, open code by putting numbers directly
672 		 * expected format is
673 		 * seq_printf(m, "%lu %lu %lu %lu 0 %lu 0\n",
674 		 *               size, resident, shared, text, data);
675 		 */
676 		seq_put_decimal_ull(m, "", size);
677 		seq_put_decimal_ull(m, " ", resident);
678 		seq_put_decimal_ull(m, " ", shared);
679 		seq_put_decimal_ull(m, " ", text);
680 		seq_put_decimal_ull(m, " ", 0);
681 		seq_put_decimal_ull(m, " ", data);
682 		seq_put_decimal_ull(m, " ", 0);
683 		seq_putc(m, '\n');
684 	} else {
685 		seq_write(m, "0 0 0 0 0 0 0\n", 14);
686 	}
687 	return 0;
688 }
689 
690 #ifdef CONFIG_PROC_CHILDREN
691 static struct pid *
692 get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos)
693 {
694 	struct task_struct *start, *task;
695 	struct pid *pid = NULL;
696 
697 	read_lock(&tasklist_lock);
698 
699 	start = pid_task(proc_pid(inode), PIDTYPE_PID);
700 	if (!start)
701 		goto out;
702 
703 	/*
704 	 * Lets try to continue searching first, this gives
705 	 * us significant speedup on children-rich processes.
706 	 */
707 	if (pid_prev) {
708 		task = pid_task(pid_prev, PIDTYPE_PID);
709 		if (task && task->real_parent == start &&
710 		    !(list_empty(&task->sibling))) {
711 			if (list_is_last(&task->sibling, &start->children))
712 				goto out;
713 			task = list_first_entry(&task->sibling,
714 						struct task_struct, sibling);
715 			pid = get_pid(task_pid(task));
716 			goto out;
717 		}
718 	}
719 
720 	/*
721 	 * Slow search case.
722 	 *
723 	 * We might miss some children here if children
724 	 * are exited while we were not holding the lock,
725 	 * but it was never promised to be accurate that
726 	 * much.
727 	 *
728 	 * "Just suppose that the parent sleeps, but N children
729 	 *  exit after we printed their tids. Now the slow paths
730 	 *  skips N extra children, we miss N tasks." (c)
731 	 *
732 	 * So one need to stop or freeze the leader and all
733 	 * its children to get a precise result.
734 	 */
735 	list_for_each_entry(task, &start->children, sibling) {
736 		if (pos-- == 0) {
737 			pid = get_pid(task_pid(task));
738 			break;
739 		}
740 	}
741 
742 out:
743 	read_unlock(&tasklist_lock);
744 	return pid;
745 }
746 
747 static int children_seq_show(struct seq_file *seq, void *v)
748 {
749 	struct inode *inode = file_inode(seq->file);
750 
751 	seq_printf(seq, "%d ", pid_nr_ns(v, proc_pid_ns(inode->i_sb)));
752 	return 0;
753 }
754 
755 static void *children_seq_start(struct seq_file *seq, loff_t *pos)
756 {
757 	return get_children_pid(file_inode(seq->file), NULL, *pos);
758 }
759 
760 static void *children_seq_next(struct seq_file *seq, void *v, loff_t *pos)
761 {
762 	struct pid *pid;
763 
764 	pid = get_children_pid(file_inode(seq->file), v, *pos + 1);
765 	put_pid(v);
766 
767 	++*pos;
768 	return pid;
769 }
770 
771 static void children_seq_stop(struct seq_file *seq, void *v)
772 {
773 	put_pid(v);
774 }
775 
776 static const struct seq_operations children_seq_ops = {
777 	.start	= children_seq_start,
778 	.next	= children_seq_next,
779 	.stop	= children_seq_stop,
780 	.show	= children_seq_show,
781 };
782 
783 static int children_seq_open(struct inode *inode, struct file *file)
784 {
785 	return seq_open(file, &children_seq_ops);
786 }
787 
788 const struct file_operations proc_tid_children_operations = {
789 	.open    = children_seq_open,
790 	.read    = seq_read,
791 	.llseek  = seq_lseek,
792 	.release = seq_release,
793 };
794 #endif /* CONFIG_PROC_CHILDREN */
795