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1// SPDX-License-Identifier: GPL-2.02/*3 *  linux/fs/proc/array.c4 *5 *  Copyright (C) 1992  by Linus Torvalds6 *  based on ideas by Darren Senn7 *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, to13 *                      make sure SET_PROCTITLE works. Also removed14 *                      bad '!' which forced address recalculation for15 *                      EVERY character on the current page.16 *                      <middelin@polyware.iaf.nl>17 *18 * Danny ter Haar    :	added cpuinfo19 *			<dth@cistron.nl>20 *21 * Alessandro Rubini :  profile extension.22 *                      <rubini@ipvvis.unipv.it>23 *24 * Jeff Tranter      :  added BogoMips field to cpuinfo25 *                      <Jeff_Tranter@Mitel.COM>26 *27 * Bruno Haible      :  remove 4K limit for the maps file28 *			<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/stat34 *                      and /proc/<pid>/cpu extension35 *                      <forissier@isia.cma.fr>36 *			- Incorporation and non-SMP safe operation37 *			of forissier patch in 2.1.78 by38 *			Hans Marcus <crowbar@concepts.nl>39 *40 * aeb@cwi.nl        :  /proc/partitions41 *42 *43 * Alan Cox	     :  security fixes.44 *			<alan@lxorguk.ukuu.org.uk>45 *46 * Al Viro           :  safe handling of mm_struct47 *48 * Gerhard Wichert   :  added BIGMEM support49 * Siemens AG           <Gerhard.Wichert@pdb.siemens.de>50 *51 * Al Viro & Jeff Garzik :  moved most of the thing into base.c and52 *			 :  proc_misc.c. The rest may eventually go into53 *			 :  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 99void 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 are105	 * 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	else112		__get_task_comm(tcomm, sizeof(tcomm), p);113 114	if (escape)115		seq_escape_str(m, tcomm, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");116	else117		seq_printf(m, "%.64s", tcomm);118}119 120/*121 * The task state array is a strange "bitmap" of122 * reasons to sleep. Thus "running" is zero, and123 * you can test for combinations of others with124 * simple bit tests.125 */126static 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 142static 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 148static 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_NS209	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#endif222	seq_putc(m, '\n');223 224	seq_printf(m, "Kthread:\t%c\n", p->flags & PF_KTHREAD ? '1' : '0');225}226 227void render_sigset_t(struct seq_file *m, const char *header,228				sigset_t *set)229{230	int i;231 232	seq_puts(m, header);233 234	i = _NSIG;235	do {236		int x = 0;237 238		i -= 4;239		if (sigismember(set, i+1)) x |= 1;240		if (sigismember(set, i+2)) x |= 2;241		if (sigismember(set, i+3)) x |= 4;242		if (sigismember(set, i+4)) x |= 8;243		seq_putc(m, hex_asc[x]);244	} while (i >= 4);245 246	seq_putc(m, '\n');247}248 249static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *sigign,250				    sigset_t *sigcatch)251{252	struct k_sigaction *k;253	int i;254 255	k = p->sighand->action;256	for (i = 1; i <= _NSIG; ++i, ++k) {257		if (k->sa.sa_handler == SIG_IGN)258			sigaddset(sigign, i);259		else if (k->sa.sa_handler != SIG_DFL)260			sigaddset(sigcatch, i);261	}262}263 264static inline void task_sig(struct seq_file *m, struct task_struct *p)265{266	unsigned long flags;267	sigset_t pending, shpending, blocked, ignored, caught;268	int num_threads = 0;269	unsigned int qsize = 0;270	unsigned long qlim = 0;271 272	sigemptyset(&pending);273	sigemptyset(&shpending);274	sigemptyset(&blocked);275	sigemptyset(&ignored);276	sigemptyset(&caught);277 278	if (lock_task_sighand(p, &flags)) {279		pending = p->pending.signal;280		shpending = p->signal->shared_pending.signal;281		blocked = p->blocked;282		collect_sigign_sigcatch(p, &ignored, &caught);283		num_threads = get_nr_threads(p);284		rcu_read_lock();  /* FIXME: is this correct? */285		qsize = get_rlimit_value(task_ucounts(p), UCOUNT_RLIMIT_SIGPENDING);286		rcu_read_unlock();287		qlim = task_rlimit(p, RLIMIT_SIGPENDING);288		unlock_task_sighand(p, &flags);289	}290 291	seq_put_decimal_ull(m, "Threads:\t", num_threads);292	seq_put_decimal_ull(m, "\nSigQ:\t", qsize);293	seq_put_decimal_ull(m, "/", qlim);294 295	/* render them all */296	render_sigset_t(m, "\nSigPnd:\t", &pending);297	render_sigset_t(m, "ShdPnd:\t", &shpending);298	render_sigset_t(m, "SigBlk:\t", &blocked);299	render_sigset_t(m, "SigIgn:\t", &ignored);300	render_sigset_t(m, "SigCgt:\t", &caught);301}302 303static void render_cap_t(struct seq_file *m, const char *header,304			kernel_cap_t *a)305{306	seq_puts(m, header);307	seq_put_hex_ll(m, NULL, a->val, 16);308	seq_putc(m, '\n');309}310 311static inline void task_cap(struct seq_file *m, struct task_struct *p)312{313	const struct cred *cred;314	kernel_cap_t cap_inheritable, cap_permitted, cap_effective,315			cap_bset, cap_ambient;316 317	rcu_read_lock();318	cred = __task_cred(p);319	cap_inheritable	= cred->cap_inheritable;320	cap_permitted	= cred->cap_permitted;321	cap_effective	= cred->cap_effective;322	cap_bset	= cred->cap_bset;323	cap_ambient	= cred->cap_ambient;324	rcu_read_unlock();325 326	render_cap_t(m, "CapInh:\t", &cap_inheritable);327	render_cap_t(m, "CapPrm:\t", &cap_permitted);328	render_cap_t(m, "CapEff:\t", &cap_effective);329	render_cap_t(m, "CapBnd:\t", &cap_bset);330	render_cap_t(m, "CapAmb:\t", &cap_ambient);331}332 333static inline void task_seccomp(struct seq_file *m, struct task_struct *p)334{335	seq_put_decimal_ull(m, "NoNewPrivs:\t", task_no_new_privs(p));336#ifdef CONFIG_SECCOMP337	seq_put_decimal_ull(m, "\nSeccomp:\t", p->seccomp.mode);338#ifdef CONFIG_SECCOMP_FILTER339	seq_put_decimal_ull(m, "\nSeccomp_filters:\t",340			    atomic_read(&p->seccomp.filter_count));341#endif342#endif343	seq_puts(m, "\nSpeculation_Store_Bypass:\t");344	switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_STORE_BYPASS)) {345	case -EINVAL:346		seq_puts(m, "unknown");347		break;348	case PR_SPEC_NOT_AFFECTED:349		seq_puts(m, "not vulnerable");350		break;351	case PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE:352		seq_puts(m, "thread force mitigated");353		break;354	case PR_SPEC_PRCTL | PR_SPEC_DISABLE:355		seq_puts(m, "thread mitigated");356		break;357	case PR_SPEC_PRCTL | PR_SPEC_ENABLE:358		seq_puts(m, "thread vulnerable");359		break;360	case PR_SPEC_DISABLE:361		seq_puts(m, "globally mitigated");362		break;363	default:364		seq_puts(m, "vulnerable");365		break;366	}367 368	seq_puts(m, "\nSpeculationIndirectBranch:\t");369	switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_INDIRECT_BRANCH)) {370	case -EINVAL:371		seq_puts(m, "unsupported");372		break;373	case PR_SPEC_NOT_AFFECTED:374		seq_puts(m, "not affected");375		break;376	case PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE:377		seq_puts(m, "conditional force disabled");378		break;379	case PR_SPEC_PRCTL | PR_SPEC_DISABLE:380		seq_puts(m, "conditional disabled");381		break;382	case PR_SPEC_PRCTL | PR_SPEC_ENABLE:383		seq_puts(m, "conditional enabled");384		break;385	case PR_SPEC_ENABLE:386		seq_puts(m, "always enabled");387		break;388	case PR_SPEC_DISABLE:389		seq_puts(m, "always disabled");390		break;391	default:392		seq_puts(m, "unknown");393		break;394	}395	seq_putc(m, '\n');396}397 398static inline void task_context_switch_counts(struct seq_file *m,399						struct task_struct *p)400{401	seq_put_decimal_ull(m, "voluntary_ctxt_switches:\t", p->nvcsw);402	seq_put_decimal_ull(m, "\nnonvoluntary_ctxt_switches:\t", p->nivcsw);403	seq_putc(m, '\n');404}405 406static void task_cpus_allowed(struct seq_file *m, struct task_struct *task)407{408	seq_printf(m, "Cpus_allowed:\t%*pb\n",409		   cpumask_pr_args(&task->cpus_mask));410	seq_printf(m, "Cpus_allowed_list:\t%*pbl\n",411		   cpumask_pr_args(&task->cpus_mask));412}413 414static inline void task_core_dumping(struct seq_file *m, struct task_struct *task)415{416	seq_put_decimal_ull(m, "CoreDumping:\t", !!task->signal->core_state);417	seq_putc(m, '\n');418}419 420static inline void task_thp_status(struct seq_file *m, struct mm_struct *mm)421{422	bool thp_enabled = IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE);423 424	if (thp_enabled)425		thp_enabled = !test_bit(MMF_DISABLE_THP, &mm->flags);426	seq_printf(m, "THP_enabled:\t%d\n", thp_enabled);427}428 429static inline void task_untag_mask(struct seq_file *m, struct mm_struct *mm)430{431	seq_printf(m, "untag_mask:\t%#lx\n", mm_untag_mask(mm));432}433 434__weak void arch_proc_pid_thread_features(struct seq_file *m,435					  struct task_struct *task)436{437}438 439int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,440			struct pid *pid, struct task_struct *task)441{442	struct mm_struct *mm = get_task_mm(task);443 444	seq_puts(m, "Name:\t");445	proc_task_name(m, task, true);446	seq_putc(m, '\n');447 448	task_state(m, ns, pid, task);449 450	if (mm) {451		task_mem(m, mm);452		task_core_dumping(m, task);453		task_thp_status(m, mm);454		task_untag_mask(m, mm);455		mmput(mm);456	}457	task_sig(m, task);458	task_cap(m, task);459	task_seccomp(m, task);460	task_cpus_allowed(m, task);461	cpuset_task_status_allowed(m, task);462	task_context_switch_counts(m, task);463	arch_proc_pid_thread_features(m, task);464	return 0;465}466 467static HWJS_SUSPENDS int do_task_stat(struct seq_file *m, struct pid_namespace *ns,468			struct pid *pid, struct task_struct *task, int whole)469{470	unsigned long vsize, eip, esp, wchan = 0;471	int priority, nice;472	int tty_pgrp = -1, tty_nr = 0;473	sigset_t sigign, sigcatch;474	char state;475	pid_t ppid = 0, pgid = -1, sid = -1;476	int num_threads = 0;477	int permitted;478	struct mm_struct *mm;479	unsigned long long start_time;480	unsigned long cmin_flt, cmaj_flt, min_flt, maj_flt;481	u64 cutime, cstime, cgtime, utime, stime, gtime;482	unsigned long rsslim = 0;483	unsigned long flags;484	int exit_code = task->exit_code;485	struct signal_struct *sig = task->signal;486	unsigned int seq = 1;487 488	state = *get_task_state(task);489	vsize = eip = esp = 0;490	permitted = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS | PTRACE_MODE_NOAUDIT);491	mm = get_task_mm(task);492	if (mm) {493		vsize = task_vsize(mm);494		/*495		 * esp and eip are intentionally zeroed out.  There is no496		 * non-racy way to read them without freezing the task.497		 * Programs that need reliable values can use ptrace(2).498		 *499		 * The only exception is if the task is core dumping because500		 * a program is not able to use ptrace(2) in that case. It is501		 * safe because the task has stopped executing permanently.502		 */503		if (permitted && (task->flags & (PF_EXITING|PF_DUMPCORE))) {504			if (try_get_task_stack(task)) {505				eip = KSTK_EIP(task);506				esp = KSTK_ESP(task);507				put_task_stack(task);508			}509		}510	}511 512	sigemptyset(&sigign);513	sigemptyset(&sigcatch);514 515	if (lock_task_sighand(task, &flags)) {516		if (sig->tty) {517			struct pid *pgrp = tty_get_pgrp(sig->tty);518			tty_pgrp = pid_nr_ns(pgrp, ns);519			put_pid(pgrp);520			tty_nr = new_encode_dev(tty_devnum(sig->tty));521		}522 523		num_threads = get_nr_threads(task);524		collect_sigign_sigcatch(task, &sigign, &sigcatch);525 526		rsslim = READ_ONCE(sig->rlim[RLIMIT_RSS].rlim_cur);527 528		if (whole) {529			if (sig->flags & (SIGNAL_GROUP_EXIT | SIGNAL_STOP_STOPPED))530				exit_code = sig->group_exit_code;531		}532 533		sid = task_session_nr_ns(task, ns);534		ppid = task_tgid_nr_ns(task->real_parent, ns);535		pgid = task_pgrp_nr_ns(task, ns);536 537		unlock_task_sighand(task, &flags);538	}539 540	if (permitted && (!whole || num_threads < 2))541		wchan = !task_is_running(task);542 543	do {544		seq++; /* 2 on the 1st/lockless path, otherwise odd */545		flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq);546 547		cmin_flt = sig->cmin_flt;548		cmaj_flt = sig->cmaj_flt;549		cutime = sig->cutime;550		cstime = sig->cstime;551		cgtime = sig->cgtime;552 553		if (whole) {554			struct task_struct *t;555 556			min_flt = sig->min_flt;557			maj_flt = sig->maj_flt;558			gtime = sig->gtime;559 560			rcu_read_lock();561			__for_each_thread(sig, t) {562				min_flt += t->min_flt;563				maj_flt += t->maj_flt;564				gtime += task_gtime(t);565			}566			rcu_read_unlock();567		}568	} while (need_seqretry(&sig->stats_lock, seq));569	done_seqretry_irqrestore(&sig->stats_lock, seq, flags);570 571	if (whole) {572		thread_group_cputime_adjusted(task, &utime, &stime);573	} else {574		task_cputime_adjusted(task, &utime, &stime);575		min_flt = task->min_flt;576		maj_flt = task->maj_flt;577		gtime = task_gtime(task);578	}579 580	/* scale priority and nice values from timeslices to -20..20 */581	/* to make it look like a "normal" Unix priority/nice value  */582	priority = task_prio(task);583	nice = task_nice(task);584 585	/* apply timens offset for boottime and convert nsec -> ticks */586	start_time =587		nsec_to_clock_t(timens_add_boottime_ns(task->start_boottime));588 589	seq_put_decimal_ull(m, "", pid_nr_ns(pid, ns));590	seq_puts(m, " (");591	proc_task_name(m, task, false);592	seq_puts(m, ") ");593	seq_putc(m, state);594	seq_put_decimal_ll(m, " ", ppid);595	seq_put_decimal_ll(m, " ", pgid);596	seq_put_decimal_ll(m, " ", sid);597	seq_put_decimal_ll(m, " ", tty_nr);598	seq_put_decimal_ll(m, " ", tty_pgrp);599	seq_put_decimal_ull(m, " ", task->flags);600	seq_put_decimal_ull(m, " ", min_flt);601	seq_put_decimal_ull(m, " ", cmin_flt);602	seq_put_decimal_ull(m, " ", maj_flt);603	seq_put_decimal_ull(m, " ", cmaj_flt);604	seq_put_decimal_ull(m, " ", nsec_to_clock_t(utime));605	seq_put_decimal_ull(m, " ", nsec_to_clock_t(stime));606	seq_put_decimal_ll(m, " ", nsec_to_clock_t(cutime));607	seq_put_decimal_ll(m, " ", nsec_to_clock_t(cstime));608	seq_put_decimal_ll(m, " ", priority);609	seq_put_decimal_ll(m, " ", nice);610	seq_put_decimal_ll(m, " ", num_threads);611	seq_put_decimal_ull(m, " ", 0);612	seq_put_decimal_ull(m, " ", start_time);613	seq_put_decimal_ull(m, " ", vsize);614	seq_put_decimal_ull(m, " ", mm ? get_mm_rss(mm) : 0);615	seq_put_decimal_ull(m, " ", rsslim);616	seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->start_code : 1) : 0);617	seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->end_code : 1) : 0);618	seq_put_decimal_ull(m, " ", (permitted && mm) ? mm->start_stack : 0);619	seq_put_decimal_ull(m, " ", esp);620	seq_put_decimal_ull(m, " ", eip);621	/* The signal information here is obsolete.622	 * It must be decimal for Linux 2.0 compatibility.623	 * Use /proc/#/status for real-time signals.624	 */625	seq_put_decimal_ull(m, " ", task->pending.signal.sig[0] & 0x7fffffffUL);626	seq_put_decimal_ull(m, " ", task->blocked.sig[0] & 0x7fffffffUL);627	seq_put_decimal_ull(m, " ", sigign.sig[0] & 0x7fffffffUL);628	seq_put_decimal_ull(m, " ", sigcatch.sig[0] & 0x7fffffffUL);629 630	/*631	 * We used to output the absolute kernel address, but that's an632	 * information leak - so instead we show a 0/1 flag here, to signal633	 * to user-space whether there's a wchan field in /proc/PID/wchan.634	 *635	 * This works with older implementations of procps as well.636	 */637	seq_put_decimal_ull(m, " ", wchan);638 639	seq_put_decimal_ull(m, " ", 0);640	seq_put_decimal_ull(m, " ", 0);641	seq_put_decimal_ll(m, " ", task->exit_signal);642	seq_put_decimal_ll(m, " ", task_cpu(task));643	seq_put_decimal_ull(m, " ", task->rt_priority);644	seq_put_decimal_ull(m, " ", task->policy);645	seq_put_decimal_ull(m, " ", delayacct_blkio_ticks(task));646	seq_put_decimal_ull(m, " ", nsec_to_clock_t(gtime));647	seq_put_decimal_ll(m, " ", nsec_to_clock_t(cgtime));648 649	if (mm && permitted) {650		seq_put_decimal_ull(m, " ", mm->start_data);651		seq_put_decimal_ull(m, " ", mm->end_data);652		seq_put_decimal_ull(m, " ", mm->start_brk);653		seq_put_decimal_ull(m, " ", mm->arg_start);654		seq_put_decimal_ull(m, " ", mm->arg_end);655		seq_put_decimal_ull(m, " ", mm->env_start);656		seq_put_decimal_ull(m, " ", mm->env_end);657	} else658		seq_puts(m, " 0 0 0 0 0 0 0");659 660	if (permitted)661		seq_put_decimal_ll(m, " ", exit_code);662	else663		seq_puts(m, " 0");664 665	seq_putc(m, '\n');666	if (mm)667		mmput(mm);668	return 0;669}670 671int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,672			struct pid *pid, struct task_struct *task)673{674	return do_task_stat(m, ns, pid, task, 0);675}676 677int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,678			struct pid *pid, struct task_struct *task)679{680	return do_task_stat(m, ns, pid, task, 1);681}682 683int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,684			struct pid *pid, struct task_struct *task)685{686	struct mm_struct *mm = get_task_mm(task);687 688	if (mm) {689		unsigned long size;690		unsigned long resident = 0;691		unsigned long shared = 0;692		unsigned long text = 0;693		unsigned long data = 0;694 695		size = task_statm(mm, &shared, &text, &data, &resident);696		mmput(mm);697 698		/*699		 * For quick read, open code by putting numbers directly700		 * expected format is701		 * seq_printf(m, "%lu %lu %lu %lu 0 %lu 0\n",702		 *               size, resident, shared, text, data);703		 */704		seq_put_decimal_ull(m, "", size);705		seq_put_decimal_ull(m, " ", resident);706		seq_put_decimal_ull(m, " ", shared);707		seq_put_decimal_ull(m, " ", text);708		seq_put_decimal_ull(m, " ", 0);709		seq_put_decimal_ull(m, " ", data);710		seq_put_decimal_ull(m, " ", 0);711		seq_putc(m, '\n');712	} else {713		seq_write(m, "0 0 0 0 0 0 0\n", 14);714	}715	return 0;716}717 718#ifdef CONFIG_PROC_CHILDREN719static struct pid *720get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos)721{722	struct task_struct *start, *task;723	struct pid *pid = NULL;724 725	read_lock(&tasklist_lock);726 727	start = pid_task(proc_pid(inode), PIDTYPE_PID);728	if (!start)729		goto out;730 731	/*732	 * Lets try to continue searching first, this gives733	 * us significant speedup on children-rich processes.734	 */735	if (pid_prev) {736		task = pid_task(pid_prev, PIDTYPE_PID);737		if (task && task->real_parent == start &&738		    !(list_empty(&task->sibling))) {739			if (list_is_last(&task->sibling, &start->children))740				goto out;741			task = list_first_entry(&task->sibling,742						struct task_struct, sibling);743			pid = get_pid(task_pid(task));744			goto out;745		}746	}747 748	/*749	 * Slow search case.750	 *751	 * We might miss some children here if children752	 * are exited while we were not holding the lock,753	 * but it was never promised to be accurate that754	 * much.755	 *756	 * "Just suppose that the parent sleeps, but N children757	 *  exit after we printed their tids. Now the slow paths758	 *  skips N extra children, we miss N tasks." (c)759	 *760	 * So one need to stop or freeze the leader and all761	 * its children to get a precise result.762	 */763	list_for_each_entry(task, &start->children, sibling) {764		if (pos-- == 0) {765			pid = get_pid(task_pid(task));766			break;767		}768	}769 770out:771	read_unlock(&tasklist_lock);772	return pid;773}774 775static int children_seq_show(struct seq_file *seq, void *v)776{777	struct inode *inode = file_inode(seq->file);778 779	seq_printf(seq, "%d ", pid_nr_ns(v, proc_pid_ns(inode->i_sb)));780	return 0;781}782 783static void *children_seq_start(struct seq_file *seq, loff_t *pos)784{785	return get_children_pid(file_inode(seq->file), NULL, *pos);786}787 788static void *children_seq_next(struct seq_file *seq, void *v, loff_t *pos)789{790	struct pid *pid;791 792	pid = get_children_pid(file_inode(seq->file), v, *pos + 1);793	put_pid(v);794 795	++*pos;796	return pid;797}798 799static void children_seq_stop(struct seq_file *seq, void *v)800{801	put_pid(v);802}803 804static const struct seq_operations children_seq_ops = {805	.start	= children_seq_start,806	.next	= children_seq_next,807	.stop	= children_seq_stop,808	.show	= children_seq_show,809};810 811static int children_seq_open(struct inode *inode, struct file *file)812{813	return seq_open(file, &children_seq_ops);814}815 816const struct file_operations proc_tid_children_operations = {817	.open    = children_seq_open,818	.read    = seq_read,819	.llseek  = seq_lseek,820	.release = seq_release,821};822#endif /* CONFIG_PROC_CHILDREN */823