xref: /linux-6.15/fs/proc/array.c (revision f7d30434)
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  *                      <[email protected]>
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  *                      <[email protected]>
17  *
18  * Danny ter Haar    :	added cpuinfo
19  *			<[email protected]>
20  *
21  * Alessandro Rubini :  profile extension.
22  *                      <[email protected]>
23  *
24  * Jeff Tranter      :  added BogoMips field to cpuinfo
25  *                      <[email protected]>
26  *
27  * Bruno Haible      :  remove 4K limit for the maps file
28  *			<[email protected]>
29  *
30  * Yves Arrouye      :  remove removal of trailing spaces in get_array.
31  *			<[email protected]>
32  *
33  * Jerome Forissier  :  added per-CPU time information to /proc/stat
34  *                      and /proc/<pid>/cpu extension
35  *                      <[email protected]>
36  *			- Incorporation and non-SMP safe operation
37  *			of forissier patch in 2.1.78 by
38  *			Hans Marcus <[email protected]>
39  *
40  * [email protected]        :  /proc/partitions
41  *
42  *
43  * Alan Cox	     :  security fixes.
44  *			<[email protected]>
45  *
46  * Al Viro           :  safe handling of mm_struct
47  *
48  * Gerhard Wichert   :  added BIGMEM support
49  * Siemens AG           <[email protected]>
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/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/string_helpers.h>
91 #include <linux/user_namespace.h>
92 #include <linux/fs_struct.h>
93 #include <linux/kthread.h>
94 #include <linux/mmu_context.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 	/*
104 	 * Test before PF_KTHREAD because all workqueue worker threads are
105 	 * kernel threads.
106 	 */
107 	if (p->flags & PF_WQ_WORKER)
108 		wq_worker_comm(tcomm, sizeof(tcomm), p);
109 	else if (p->flags & PF_KTHREAD)
110 		get_kthread_comm(tcomm, sizeof(tcomm), p);
111 	else
112 		__get_task_comm(tcomm, sizeof(tcomm), p);
113 
114 	if (escape)
115 		seq_escape_str(m, tcomm, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");
116 	else
117 		seq_printf(m, "%.64s", tcomm);
118 }
119 
120 /*
121  * The task state array is a strange "bitmap" of
122  * reasons to sleep. Thus "running" is zero, and
123  * you can test for combinations of others with
124  * simple bit tests.
125  */
126 static const char * const task_state_array[] = {
127 
128 	/* states in TASK_REPORT: */
129 	"R (running)",		/* 0x00 */
130 	"S (sleeping)",		/* 0x01 */
131 	"D (disk sleep)",	/* 0x02 */
132 	"T (stopped)",		/* 0x04 */
133 	"t (tracing stop)",	/* 0x08 */
134 	"X (dead)",		/* 0x10 */
135 	"Z (zombie)",		/* 0x20 */
136 	"P (parked)",		/* 0x40 */
137 
138 	/* states beyond TASK_REPORT: */
139 	"I (idle)",		/* 0x80 */
140 };
141 
142 static inline const char *get_task_state(struct task_struct *tsk)
143 {
144 	BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != ARRAY_SIZE(task_state_array));
145 	return task_state_array[task_state_index(tsk)];
146 }
147 
148 static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
149 				struct pid *pid, struct task_struct *p)
150 {
151 	struct user_namespace *user_ns = seq_user_ns(m);
152 	struct group_info *group_info;
153 	int g, umask = -1;
154 	struct task_struct *tracer;
155 	const struct cred *cred;
156 	pid_t ppid, tpid = 0, tgid, ngid;
157 	unsigned int max_fds = 0;
158 
159 	rcu_read_lock();
160 	ppid = pid_alive(p) ?
161 		task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
162 
163 	tracer = ptrace_parent(p);
164 	if (tracer)
165 		tpid = task_pid_nr_ns(tracer, ns);
166 
167 	tgid = task_tgid_nr_ns(p, ns);
168 	ngid = task_numa_group_id(p);
169 	cred = get_task_cred(p);
170 
171 	task_lock(p);
172 	if (p->fs)
173 		umask = p->fs->umask;
174 	if (p->files)
175 		max_fds = files_fdtable(p->files)->max_fds;
176 	task_unlock(p);
177 	rcu_read_unlock();
178 
179 	if (umask >= 0)
180 		seq_printf(m, "Umask:\t%#04o\n", umask);
181 	seq_puts(m, "State:\t");
182 	seq_puts(m, get_task_state(p));
183 
184 	seq_put_decimal_ull(m, "\nTgid:\t", tgid);
185 	seq_put_decimal_ull(m, "\nNgid:\t", ngid);
186 	seq_put_decimal_ull(m, "\nPid:\t", pid_nr_ns(pid, ns));
187 	seq_put_decimal_ull(m, "\nPPid:\t", ppid);
188 	seq_put_decimal_ull(m, "\nTracerPid:\t", tpid);
189 	seq_put_decimal_ull(m, "\nUid:\t", from_kuid_munged(user_ns, cred->uid));
190 	seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->euid));
191 	seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->suid));
192 	seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->fsuid));
193 	seq_put_decimal_ull(m, "\nGid:\t", from_kgid_munged(user_ns, cred->gid));
194 	seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->egid));
195 	seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->sgid));
196 	seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->fsgid));
197 	seq_put_decimal_ull(m, "\nFDSize:\t", max_fds);
198 
199 	seq_puts(m, "\nGroups:\t");
200 	group_info = cred->group_info;
201 	for (g = 0; g < group_info->ngroups; g++)
202 		seq_put_decimal_ull(m, g ? " " : "",
203 				from_kgid_munged(user_ns, group_info->gid[g]));
204 	put_cred(cred);
205 	/* Trailing space shouldn't have been added in the first place. */
206 	seq_putc(m, ' ');
207 
208 #ifdef CONFIG_PID_NS
209 	seq_puts(m, "\nNStgid:");
210 	for (g = ns->level; g <= pid->level; g++)
211 		seq_put_decimal_ull(m, "\t", task_tgid_nr_ns(p, pid->numbers[g].ns));
212 	seq_puts(m, "\nNSpid:");
213 	for (g = ns->level; g <= pid->level; g++)
214 		seq_put_decimal_ull(m, "\t", task_pid_nr_ns(p, pid->numbers[g].ns));
215 	seq_puts(m, "\nNSpgid:");
216 	for (g = ns->level; g <= pid->level; g++)
217 		seq_put_decimal_ull(m, "\t", task_pgrp_nr_ns(p, pid->numbers[g].ns));
218 	seq_puts(m, "\nNSsid:");
219 	for (g = ns->level; g <= pid->level; g++)
220 		seq_put_decimal_ull(m, "\t", task_session_nr_ns(p, pid->numbers[g].ns));
221 #endif
222 	seq_putc(m, '\n');
223 }
224 
225 void render_sigset_t(struct seq_file *m, const char *header,
226 				sigset_t *set)
227 {
228 	int i;
229 
230 	seq_puts(m, header);
231 
232 	i = _NSIG;
233 	do {
234 		int x = 0;
235 
236 		i -= 4;
237 		if (sigismember(set, i+1)) x |= 1;
238 		if (sigismember(set, i+2)) x |= 2;
239 		if (sigismember(set, i+3)) x |= 4;
240 		if (sigismember(set, i+4)) x |= 8;
241 		seq_putc(m, hex_asc[x]);
242 	} while (i >= 4);
243 
244 	seq_putc(m, '\n');
245 }
246 
247 static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *sigign,
248 				    sigset_t *sigcatch)
249 {
250 	struct k_sigaction *k;
251 	int i;
252 
253 	k = p->sighand->action;
254 	for (i = 1; i <= _NSIG; ++i, ++k) {
255 		if (k->sa.sa_handler == SIG_IGN)
256 			sigaddset(sigign, i);
257 		else if (k->sa.sa_handler != SIG_DFL)
258 			sigaddset(sigcatch, i);
259 	}
260 }
261 
262 static inline void task_sig(struct seq_file *m, struct task_struct *p)
263 {
264 	unsigned long flags;
265 	sigset_t pending, shpending, blocked, ignored, caught;
266 	int num_threads = 0;
267 	unsigned int qsize = 0;
268 	unsigned long qlim = 0;
269 
270 	sigemptyset(&pending);
271 	sigemptyset(&shpending);
272 	sigemptyset(&blocked);
273 	sigemptyset(&ignored);
274 	sigemptyset(&caught);
275 
276 	if (lock_task_sighand(p, &flags)) {
277 		pending = p->pending.signal;
278 		shpending = p->signal->shared_pending.signal;
279 		blocked = p->blocked;
280 		collect_sigign_sigcatch(p, &ignored, &caught);
281 		num_threads = get_nr_threads(p);
282 		rcu_read_lock();  /* FIXME: is this correct? */
283 		qsize = get_rlimit_value(task_ucounts(p), UCOUNT_RLIMIT_SIGPENDING);
284 		rcu_read_unlock();
285 		qlim = task_rlimit(p, RLIMIT_SIGPENDING);
286 		unlock_task_sighand(p, &flags);
287 	}
288 
289 	seq_put_decimal_ull(m, "Threads:\t", num_threads);
290 	seq_put_decimal_ull(m, "\nSigQ:\t", qsize);
291 	seq_put_decimal_ull(m, "/", qlim);
292 
293 	/* render them all */
294 	render_sigset_t(m, "\nSigPnd:\t", &pending);
295 	render_sigset_t(m, "ShdPnd:\t", &shpending);
296 	render_sigset_t(m, "SigBlk:\t", &blocked);
297 	render_sigset_t(m, "SigIgn:\t", &ignored);
298 	render_sigset_t(m, "SigCgt:\t", &caught);
299 }
300 
301 static void render_cap_t(struct seq_file *m, const char *header,
302 			kernel_cap_t *a)
303 {
304 	seq_puts(m, header);
305 	seq_put_hex_ll(m, NULL, a->val, 16);
306 	seq_putc(m, '\n');
307 }
308 
309 static inline void task_cap(struct seq_file *m, struct task_struct *p)
310 {
311 	const struct cred *cred;
312 	kernel_cap_t cap_inheritable, cap_permitted, cap_effective,
313 			cap_bset, cap_ambient;
314 
315 	rcu_read_lock();
316 	cred = __task_cred(p);
317 	cap_inheritable	= cred->cap_inheritable;
318 	cap_permitted	= cred->cap_permitted;
319 	cap_effective	= cred->cap_effective;
320 	cap_bset	= cred->cap_bset;
321 	cap_ambient	= cred->cap_ambient;
322 	rcu_read_unlock();
323 
324 	render_cap_t(m, "CapInh:\t", &cap_inheritable);
325 	render_cap_t(m, "CapPrm:\t", &cap_permitted);
326 	render_cap_t(m, "CapEff:\t", &cap_effective);
327 	render_cap_t(m, "CapBnd:\t", &cap_bset);
328 	render_cap_t(m, "CapAmb:\t", &cap_ambient);
329 }
330 
331 static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
332 {
333 	seq_put_decimal_ull(m, "NoNewPrivs:\t", task_no_new_privs(p));
334 #ifdef CONFIG_SECCOMP
335 	seq_put_decimal_ull(m, "\nSeccomp:\t", p->seccomp.mode);
336 #ifdef CONFIG_SECCOMP_FILTER
337 	seq_put_decimal_ull(m, "\nSeccomp_filters:\t",
338 			    atomic_read(&p->seccomp.filter_count));
339 #endif
340 #endif
341 	seq_puts(m, "\nSpeculation_Store_Bypass:\t");
342 	switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_STORE_BYPASS)) {
343 	case -EINVAL:
344 		seq_puts(m, "unknown");
345 		break;
346 	case PR_SPEC_NOT_AFFECTED:
347 		seq_puts(m, "not vulnerable");
348 		break;
349 	case PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE:
350 		seq_puts(m, "thread force mitigated");
351 		break;
352 	case PR_SPEC_PRCTL | PR_SPEC_DISABLE:
353 		seq_puts(m, "thread mitigated");
354 		break;
355 	case PR_SPEC_PRCTL | PR_SPEC_ENABLE:
356 		seq_puts(m, "thread vulnerable");
357 		break;
358 	case PR_SPEC_DISABLE:
359 		seq_puts(m, "globally mitigated");
360 		break;
361 	default:
362 		seq_puts(m, "vulnerable");
363 		break;
364 	}
365 
366 	seq_puts(m, "\nSpeculationIndirectBranch:\t");
367 	switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_INDIRECT_BRANCH)) {
368 	case -EINVAL:
369 		seq_puts(m, "unsupported");
370 		break;
371 	case PR_SPEC_NOT_AFFECTED:
372 		seq_puts(m, "not affected");
373 		break;
374 	case PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE:
375 		seq_puts(m, "conditional force disabled");
376 		break;
377 	case PR_SPEC_PRCTL | PR_SPEC_DISABLE:
378 		seq_puts(m, "conditional disabled");
379 		break;
380 	case PR_SPEC_PRCTL | PR_SPEC_ENABLE:
381 		seq_puts(m, "conditional enabled");
382 		break;
383 	case PR_SPEC_ENABLE:
384 		seq_puts(m, "always enabled");
385 		break;
386 	case PR_SPEC_DISABLE:
387 		seq_puts(m, "always disabled");
388 		break;
389 	default:
390 		seq_puts(m, "unknown");
391 		break;
392 	}
393 	seq_putc(m, '\n');
394 }
395 
396 static inline void task_context_switch_counts(struct seq_file *m,
397 						struct task_struct *p)
398 {
399 	seq_put_decimal_ull(m, "voluntary_ctxt_switches:\t", p->nvcsw);
400 	seq_put_decimal_ull(m, "\nnonvoluntary_ctxt_switches:\t", p->nivcsw);
401 	seq_putc(m, '\n');
402 }
403 
404 static void task_cpus_allowed(struct seq_file *m, struct task_struct *task)
405 {
406 	seq_printf(m, "Cpus_allowed:\t%*pb\n",
407 		   cpumask_pr_args(&task->cpus_mask));
408 	seq_printf(m, "Cpus_allowed_list:\t%*pbl\n",
409 		   cpumask_pr_args(&task->cpus_mask));
410 }
411 
412 static inline void task_core_dumping(struct seq_file *m, struct task_struct *task)
413 {
414 	seq_put_decimal_ull(m, "CoreDumping:\t", !!task->signal->core_state);
415 	seq_putc(m, '\n');
416 }
417 
418 static inline void task_thp_status(struct seq_file *m, struct mm_struct *mm)
419 {
420 	bool thp_enabled = IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE);
421 
422 	if (thp_enabled)
423 		thp_enabled = !test_bit(MMF_DISABLE_THP, &mm->flags);
424 	seq_printf(m, "THP_enabled:\t%d\n", thp_enabled);
425 }
426 
427 static inline void task_untag_mask(struct seq_file *m, struct mm_struct *mm)
428 {
429 	seq_printf(m, "untag_mask:\t%#lx\n", mm_untag_mask(mm));
430 }
431 
432 int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
433 			struct pid *pid, struct task_struct *task)
434 {
435 	struct mm_struct *mm = get_task_mm(task);
436 
437 	seq_puts(m, "Name:\t");
438 	proc_task_name(m, task, true);
439 	seq_putc(m, '\n');
440 
441 	task_state(m, ns, pid, task);
442 
443 	if (mm) {
444 		task_mem(m, mm);
445 		task_core_dumping(m, task);
446 		task_thp_status(m, mm);
447 		task_untag_mask(m, mm);
448 		mmput(mm);
449 	}
450 	task_sig(m, task);
451 	task_cap(m, task);
452 	task_seccomp(m, task);
453 	task_cpus_allowed(m, task);
454 	cpuset_task_status_allowed(m, task);
455 	task_context_switch_counts(m, task);
456 	return 0;
457 }
458 
459 static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
460 			struct pid *pid, struct task_struct *task, int whole)
461 {
462 	unsigned long vsize, eip, esp, wchan = 0;
463 	int priority, nice;
464 	int tty_pgrp = -1, tty_nr = 0;
465 	sigset_t sigign, sigcatch;
466 	char state;
467 	pid_t ppid = 0, pgid = -1, sid = -1;
468 	int num_threads = 0;
469 	int permitted;
470 	struct mm_struct *mm;
471 	unsigned long long start_time;
472 	unsigned long cmin_flt = 0, cmaj_flt = 0;
473 	unsigned long  min_flt = 0,  maj_flt = 0;
474 	u64 cutime, cstime, utime, stime;
475 	u64 cgtime, gtime;
476 	unsigned long rsslim = 0;
477 	unsigned long flags;
478 	int exit_code = task->exit_code;
479 
480 	state = *get_task_state(task);
481 	vsize = eip = esp = 0;
482 	permitted = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS | PTRACE_MODE_NOAUDIT);
483 	mm = get_task_mm(task);
484 	if (mm) {
485 		vsize = task_vsize(mm);
486 		/*
487 		 * esp and eip are intentionally zeroed out.  There is no
488 		 * non-racy way to read them without freezing the task.
489 		 * Programs that need reliable values can use ptrace(2).
490 		 *
491 		 * The only exception is if the task is core dumping because
492 		 * a program is not able to use ptrace(2) in that case. It is
493 		 * safe because the task has stopped executing permanently.
494 		 */
495 		if (permitted && (task->flags & (PF_EXITING|PF_DUMPCORE))) {
496 			if (try_get_task_stack(task)) {
497 				eip = KSTK_EIP(task);
498 				esp = KSTK_ESP(task);
499 				put_task_stack(task);
500 			}
501 		}
502 	}
503 
504 	sigemptyset(&sigign);
505 	sigemptyset(&sigcatch);
506 	cutime = cstime = utime = stime = 0;
507 	cgtime = gtime = 0;
508 
509 	if (lock_task_sighand(task, &flags)) {
510 		struct signal_struct *sig = task->signal;
511 
512 		if (sig->tty) {
513 			struct pid *pgrp = tty_get_pgrp(sig->tty);
514 			tty_pgrp = pid_nr_ns(pgrp, ns);
515 			put_pid(pgrp);
516 			tty_nr = new_encode_dev(tty_devnum(sig->tty));
517 		}
518 
519 		num_threads = get_nr_threads(task);
520 		collect_sigign_sigcatch(task, &sigign, &sigcatch);
521 
522 		cmin_flt = sig->cmin_flt;
523 		cmaj_flt = sig->cmaj_flt;
524 		cutime = sig->cutime;
525 		cstime = sig->cstime;
526 		cgtime = sig->cgtime;
527 		rsslim = READ_ONCE(sig->rlim[RLIMIT_RSS].rlim_cur);
528 
529 		/* add up live thread stats at the group level */
530 		if (whole) {
531 			struct task_struct *t = task;
532 			do {
533 				min_flt += t->min_flt;
534 				maj_flt += t->maj_flt;
535 				gtime += task_gtime(t);
536 			} while_each_thread(task, t);
537 
538 			min_flt += sig->min_flt;
539 			maj_flt += sig->maj_flt;
540 			thread_group_cputime_adjusted(task, &utime, &stime);
541 			gtime += sig->gtime;
542 
543 			if (sig->flags & (SIGNAL_GROUP_EXIT | SIGNAL_STOP_STOPPED))
544 				exit_code = sig->group_exit_code;
545 		}
546 
547 		sid = task_session_nr_ns(task, ns);
548 		ppid = task_tgid_nr_ns(task->real_parent, ns);
549 		pgid = task_pgrp_nr_ns(task, ns);
550 
551 		unlock_task_sighand(task, &flags);
552 	}
553 
554 	if (permitted && (!whole || num_threads < 2))
555 		wchan = !task_is_running(task);
556 	if (!whole) {
557 		min_flt = task->min_flt;
558 		maj_flt = task->maj_flt;
559 		task_cputime_adjusted(task, &utime, &stime);
560 		gtime = task_gtime(task);
561 	}
562 
563 	/* scale priority and nice values from timeslices to -20..20 */
564 	/* to make it look like a "normal" Unix priority/nice value  */
565 	priority = task_prio(task);
566 	nice = task_nice(task);
567 
568 	/* apply timens offset for boottime and convert nsec -> ticks */
569 	start_time =
570 		nsec_to_clock_t(timens_add_boottime_ns(task->start_boottime));
571 
572 	seq_put_decimal_ull(m, "", pid_nr_ns(pid, ns));
573 	seq_puts(m, " (");
574 	proc_task_name(m, task, false);
575 	seq_puts(m, ") ");
576 	seq_putc(m, state);
577 	seq_put_decimal_ll(m, " ", ppid);
578 	seq_put_decimal_ll(m, " ", pgid);
579 	seq_put_decimal_ll(m, " ", sid);
580 	seq_put_decimal_ll(m, " ", tty_nr);
581 	seq_put_decimal_ll(m, " ", tty_pgrp);
582 	seq_put_decimal_ull(m, " ", task->flags);
583 	seq_put_decimal_ull(m, " ", min_flt);
584 	seq_put_decimal_ull(m, " ", cmin_flt);
585 	seq_put_decimal_ull(m, " ", maj_flt);
586 	seq_put_decimal_ull(m, " ", cmaj_flt);
587 	seq_put_decimal_ull(m, " ", nsec_to_clock_t(utime));
588 	seq_put_decimal_ull(m, " ", nsec_to_clock_t(stime));
589 	seq_put_decimal_ll(m, " ", nsec_to_clock_t(cutime));
590 	seq_put_decimal_ll(m, " ", nsec_to_clock_t(cstime));
591 	seq_put_decimal_ll(m, " ", priority);
592 	seq_put_decimal_ll(m, " ", nice);
593 	seq_put_decimal_ll(m, " ", num_threads);
594 	seq_put_decimal_ull(m, " ", 0);
595 	seq_put_decimal_ull(m, " ", start_time);
596 	seq_put_decimal_ull(m, " ", vsize);
597 	seq_put_decimal_ull(m, " ", mm ? get_mm_rss(mm) : 0);
598 	seq_put_decimal_ull(m, " ", rsslim);
599 	seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->start_code : 1) : 0);
600 	seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->end_code : 1) : 0);
601 	seq_put_decimal_ull(m, " ", (permitted && mm) ? mm->start_stack : 0);
602 	seq_put_decimal_ull(m, " ", esp);
603 	seq_put_decimal_ull(m, " ", eip);
604 	/* The signal information here is obsolete.
605 	 * It must be decimal for Linux 2.0 compatibility.
606 	 * Use /proc/#/status for real-time signals.
607 	 */
608 	seq_put_decimal_ull(m, " ", task->pending.signal.sig[0] & 0x7fffffffUL);
609 	seq_put_decimal_ull(m, " ", task->blocked.sig[0] & 0x7fffffffUL);
610 	seq_put_decimal_ull(m, " ", sigign.sig[0] & 0x7fffffffUL);
611 	seq_put_decimal_ull(m, " ", sigcatch.sig[0] & 0x7fffffffUL);
612 
613 	/*
614 	 * We used to output the absolute kernel address, but that's an
615 	 * information leak - so instead we show a 0/1 flag here, to signal
616 	 * to user-space whether there's a wchan field in /proc/PID/wchan.
617 	 *
618 	 * This works with older implementations of procps as well.
619 	 */
620 	seq_put_decimal_ull(m, " ", wchan);
621 
622 	seq_put_decimal_ull(m, " ", 0);
623 	seq_put_decimal_ull(m, " ", 0);
624 	seq_put_decimal_ll(m, " ", task->exit_signal);
625 	seq_put_decimal_ll(m, " ", task_cpu(task));
626 	seq_put_decimal_ull(m, " ", task->rt_priority);
627 	seq_put_decimal_ull(m, " ", task->policy);
628 	seq_put_decimal_ull(m, " ", delayacct_blkio_ticks(task));
629 	seq_put_decimal_ull(m, " ", nsec_to_clock_t(gtime));
630 	seq_put_decimal_ll(m, " ", nsec_to_clock_t(cgtime));
631 
632 	if (mm && permitted) {
633 		seq_put_decimal_ull(m, " ", mm->start_data);
634 		seq_put_decimal_ull(m, " ", mm->end_data);
635 		seq_put_decimal_ull(m, " ", mm->start_brk);
636 		seq_put_decimal_ull(m, " ", mm->arg_start);
637 		seq_put_decimal_ull(m, " ", mm->arg_end);
638 		seq_put_decimal_ull(m, " ", mm->env_start);
639 		seq_put_decimal_ull(m, " ", mm->env_end);
640 	} else
641 		seq_puts(m, " 0 0 0 0 0 0 0");
642 
643 	if (permitted)
644 		seq_put_decimal_ll(m, " ", exit_code);
645 	else
646 		seq_puts(m, " 0");
647 
648 	seq_putc(m, '\n');
649 	if (mm)
650 		mmput(mm);
651 	return 0;
652 }
653 
654 int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
655 			struct pid *pid, struct task_struct *task)
656 {
657 	return do_task_stat(m, ns, pid, task, 0);
658 }
659 
660 int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
661 			struct pid *pid, struct task_struct *task)
662 {
663 	return do_task_stat(m, ns, pid, task, 1);
664 }
665 
666 int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
667 			struct pid *pid, struct task_struct *task)
668 {
669 	struct mm_struct *mm = get_task_mm(task);
670 
671 	if (mm) {
672 		unsigned long size;
673 		unsigned long resident = 0;
674 		unsigned long shared = 0;
675 		unsigned long text = 0;
676 		unsigned long data = 0;
677 
678 		size = task_statm(mm, &shared, &text, &data, &resident);
679 		mmput(mm);
680 
681 		/*
682 		 * For quick read, open code by putting numbers directly
683 		 * expected format is
684 		 * seq_printf(m, "%lu %lu %lu %lu 0 %lu 0\n",
685 		 *               size, resident, shared, text, data);
686 		 */
687 		seq_put_decimal_ull(m, "", size);
688 		seq_put_decimal_ull(m, " ", resident);
689 		seq_put_decimal_ull(m, " ", shared);
690 		seq_put_decimal_ull(m, " ", text);
691 		seq_put_decimal_ull(m, " ", 0);
692 		seq_put_decimal_ull(m, " ", data);
693 		seq_put_decimal_ull(m, " ", 0);
694 		seq_putc(m, '\n');
695 	} else {
696 		seq_write(m, "0 0 0 0 0 0 0\n", 14);
697 	}
698 	return 0;
699 }
700 
701 #ifdef CONFIG_PROC_CHILDREN
702 static struct pid *
703 get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos)
704 {
705 	struct task_struct *start, *task;
706 	struct pid *pid = NULL;
707 
708 	read_lock(&tasklist_lock);
709 
710 	start = pid_task(proc_pid(inode), PIDTYPE_PID);
711 	if (!start)
712 		goto out;
713 
714 	/*
715 	 * Lets try to continue searching first, this gives
716 	 * us significant speedup on children-rich processes.
717 	 */
718 	if (pid_prev) {
719 		task = pid_task(pid_prev, PIDTYPE_PID);
720 		if (task && task->real_parent == start &&
721 		    !(list_empty(&task->sibling))) {
722 			if (list_is_last(&task->sibling, &start->children))
723 				goto out;
724 			task = list_first_entry(&task->sibling,
725 						struct task_struct, sibling);
726 			pid = get_pid(task_pid(task));
727 			goto out;
728 		}
729 	}
730 
731 	/*
732 	 * Slow search case.
733 	 *
734 	 * We might miss some children here if children
735 	 * are exited while we were not holding the lock,
736 	 * but it was never promised to be accurate that
737 	 * much.
738 	 *
739 	 * "Just suppose that the parent sleeps, but N children
740 	 *  exit after we printed their tids. Now the slow paths
741 	 *  skips N extra children, we miss N tasks." (c)
742 	 *
743 	 * So one need to stop or freeze the leader and all
744 	 * its children to get a precise result.
745 	 */
746 	list_for_each_entry(task, &start->children, sibling) {
747 		if (pos-- == 0) {
748 			pid = get_pid(task_pid(task));
749 			break;
750 		}
751 	}
752 
753 out:
754 	read_unlock(&tasklist_lock);
755 	return pid;
756 }
757 
758 static int children_seq_show(struct seq_file *seq, void *v)
759 {
760 	struct inode *inode = file_inode(seq->file);
761 
762 	seq_printf(seq, "%d ", pid_nr_ns(v, proc_pid_ns(inode->i_sb)));
763 	return 0;
764 }
765 
766 static void *children_seq_start(struct seq_file *seq, loff_t *pos)
767 {
768 	return get_children_pid(file_inode(seq->file), NULL, *pos);
769 }
770 
771 static void *children_seq_next(struct seq_file *seq, void *v, loff_t *pos)
772 {
773 	struct pid *pid;
774 
775 	pid = get_children_pid(file_inode(seq->file), v, *pos + 1);
776 	put_pid(v);
777 
778 	++*pos;
779 	return pid;
780 }
781 
782 static void children_seq_stop(struct seq_file *seq, void *v)
783 {
784 	put_pid(v);
785 }
786 
787 static const struct seq_operations children_seq_ops = {
788 	.start	= children_seq_start,
789 	.next	= children_seq_next,
790 	.stop	= children_seq_stop,
791 	.show	= children_seq_show,
792 };
793 
794 static int children_seq_open(struct inode *inode, struct file *file)
795 {
796 	return seq_open(file, &children_seq_ops);
797 }
798 
799 const struct file_operations proc_tid_children_operations = {
800 	.open    = children_seq_open,
801 	.read    = seq_read,
802 	.llseek  = seq_lseek,
803 	.release = seq_release,
804 };
805 #endif /* CONFIG_PROC_CHILDREN */
806