linux/fs/proc/array.c
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   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
  99void 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 */
 130static 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
 146static 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
 152static 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
 229void 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
 251static 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
 266static 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
 305static 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
 318static 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
 340static 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_puts(m, "\nSpeculation_Store_Bypass:\t");
 347        switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_STORE_BYPASS)) {
 348        case -EINVAL:
 349                seq_puts(m, "unknown");
 350                break;
 351        case PR_SPEC_NOT_AFFECTED:
 352                seq_puts(m, "not vulnerable");
 353                break;
 354        case PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE:
 355                seq_puts(m, "thread force mitigated");
 356                break;
 357        case PR_SPEC_PRCTL | PR_SPEC_DISABLE:
 358                seq_puts(m, "thread mitigated");
 359                break;
 360        case PR_SPEC_PRCTL | PR_SPEC_ENABLE:
 361                seq_puts(m, "thread vulnerable");
 362                break;
 363        case PR_SPEC_DISABLE:
 364                seq_puts(m, "globally mitigated");
 365                break;
 366        default:
 367                seq_puts(m, "vulnerable");
 368                break;
 369        }
 370        seq_putc(m, '\n');
 371}
 372
 373static 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
 381static 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_ptr));
 385        seq_printf(m, "Cpus_allowed_list:\t%*pbl\n",
 386                   cpumask_pr_args(task->cpus_ptr));
 387}
 388
 389static 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
 395static inline void task_thp_status(struct seq_file *m, struct mm_struct *mm)
 396{
 397        bool thp_enabled = IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE);
 398
 399        if (thp_enabled)
 400                thp_enabled = !test_bit(MMF_DISABLE_THP, &mm->flags);
 401        seq_printf(m, "THP_enabled:\t%d\n", thp_enabled);
 402}
 403
 404int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
 405                        struct pid *pid, struct task_struct *task)
 406{
 407        struct mm_struct *mm = get_task_mm(task);
 408
 409        seq_puts(m, "Name:\t");
 410        proc_task_name(m, task, true);
 411        seq_putc(m, '\n');
 412
 413        task_state(m, ns, pid, task);
 414
 415        if (mm) {
 416                task_mem(m, mm);
 417                task_core_dumping(m, mm);
 418                task_thp_status(m, mm);
 419                mmput(mm);
 420        }
 421        task_sig(m, task);
 422        task_cap(m, task);
 423        task_seccomp(m, task);
 424        task_cpus_allowed(m, task);
 425        cpuset_task_status_allowed(m, task);
 426        task_context_switch_counts(m, task);
 427        return 0;
 428}
 429
 430static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
 431                        struct pid *pid, struct task_struct *task, int whole)
 432{
 433        unsigned long vsize, eip, esp, wchan = 0;
 434        int priority, nice;
 435        int tty_pgrp = -1, tty_nr = 0;
 436        sigset_t sigign, sigcatch;
 437        char state;
 438        pid_t ppid = 0, pgid = -1, sid = -1;
 439        int num_threads = 0;
 440        int permitted;
 441        struct mm_struct *mm;
 442        unsigned long long start_time;
 443        unsigned long cmin_flt = 0, cmaj_flt = 0;
 444        unsigned long  min_flt = 0,  maj_flt = 0;
 445        u64 cutime, cstime, utime, stime;
 446        u64 cgtime, gtime;
 447        unsigned long rsslim = 0;
 448        unsigned long flags;
 449
 450        state = *get_task_state(task);
 451        vsize = eip = esp = 0;
 452        permitted = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS | PTRACE_MODE_NOAUDIT);
 453        mm = get_task_mm(task);
 454        if (mm) {
 455                vsize = task_vsize(mm);
 456                /*
 457                 * esp and eip are intentionally zeroed out.  There is no
 458                 * non-racy way to read them without freezing the task.
 459                 * Programs that need reliable values can use ptrace(2).
 460                 *
 461                 * The only exception is if the task is core dumping because
 462                 * a program is not able to use ptrace(2) in that case. It is
 463                 * safe because the task has stopped executing permanently.
 464                 */
 465                if (permitted && (task->flags & (PF_EXITING|PF_DUMPCORE))) {
 466                        if (try_get_task_stack(task)) {
 467                                eip = KSTK_EIP(task);
 468                                esp = KSTK_ESP(task);
 469                                put_task_stack(task);
 470                        }
 471                }
 472        }
 473
 474        sigemptyset(&sigign);
 475        sigemptyset(&sigcatch);
 476        cutime = cstime = utime = stime = 0;
 477        cgtime = gtime = 0;
 478
 479        if (lock_task_sighand(task, &flags)) {
 480                struct signal_struct *sig = task->signal;
 481
 482                if (sig->tty) {
 483                        struct pid *pgrp = tty_get_pgrp(sig->tty);
 484                        tty_pgrp = pid_nr_ns(pgrp, ns);
 485                        put_pid(pgrp);
 486                        tty_nr = new_encode_dev(tty_devnum(sig->tty));
 487                }
 488
 489                num_threads = get_nr_threads(task);
 490                collect_sigign_sigcatch(task, &sigign, &sigcatch);
 491
 492                cmin_flt = sig->cmin_flt;
 493                cmaj_flt = sig->cmaj_flt;
 494                cutime = sig->cutime;
 495                cstime = sig->cstime;
 496                cgtime = sig->cgtime;
 497                rsslim = READ_ONCE(sig->rlim[RLIMIT_RSS].rlim_cur);
 498
 499                /* add up live thread stats at the group level */
 500                if (whole) {
 501                        struct task_struct *t = task;
 502                        do {
 503                                min_flt += t->min_flt;
 504                                maj_flt += t->maj_flt;
 505                                gtime += task_gtime(t);
 506                        } while_each_thread(task, t);
 507
 508                        min_flt += sig->min_flt;
 509                        maj_flt += sig->maj_flt;
 510                        thread_group_cputime_adjusted(task, &utime, &stime);
 511                        gtime += sig->gtime;
 512                }
 513
 514                sid = task_session_nr_ns(task, ns);
 515                ppid = task_tgid_nr_ns(task->real_parent, ns);
 516                pgid = task_pgrp_nr_ns(task, ns);
 517
 518                unlock_task_sighand(task, &flags);
 519        }
 520
 521        if (permitted && (!whole || num_threads < 2))
 522                wchan = get_wchan(task);
 523        if (!whole) {
 524                min_flt = task->min_flt;
 525                maj_flt = task->maj_flt;
 526                task_cputime_adjusted(task, &utime, &stime);
 527                gtime = task_gtime(task);
 528        }
 529
 530        /* scale priority and nice values from timeslices to -20..20 */
 531        /* to make it look like a "normal" Unix priority/nice value  */
 532        priority = task_prio(task);
 533        nice = task_nice(task);
 534
 535        /* convert nsec -> ticks */
 536        start_time = nsec_to_clock_t(task->start_boottime);
 537
 538        seq_put_decimal_ull(m, "", pid_nr_ns(pid, ns));
 539        seq_puts(m, " (");
 540        proc_task_name(m, task, false);
 541        seq_puts(m, ") ");
 542        seq_putc(m, state);
 543        seq_put_decimal_ll(m, " ", ppid);
 544        seq_put_decimal_ll(m, " ", pgid);
 545        seq_put_decimal_ll(m, " ", sid);
 546        seq_put_decimal_ll(m, " ", tty_nr);
 547        seq_put_decimal_ll(m, " ", tty_pgrp);
 548        seq_put_decimal_ull(m, " ", task->flags);
 549        seq_put_decimal_ull(m, " ", min_flt);
 550        seq_put_decimal_ull(m, " ", cmin_flt);
 551        seq_put_decimal_ull(m, " ", maj_flt);
 552        seq_put_decimal_ull(m, " ", cmaj_flt);
 553        seq_put_decimal_ull(m, " ", nsec_to_clock_t(utime));
 554        seq_put_decimal_ull(m, " ", nsec_to_clock_t(stime));
 555        seq_put_decimal_ll(m, " ", nsec_to_clock_t(cutime));
 556        seq_put_decimal_ll(m, " ", nsec_to_clock_t(cstime));
 557        seq_put_decimal_ll(m, " ", priority);
 558        seq_put_decimal_ll(m, " ", nice);
 559        seq_put_decimal_ll(m, " ", num_threads);
 560        seq_put_decimal_ull(m, " ", 0);
 561        seq_put_decimal_ull(m, " ", start_time);
 562        seq_put_decimal_ull(m, " ", vsize);
 563        seq_put_decimal_ull(m, " ", mm ? get_mm_rss(mm) : 0);
 564        seq_put_decimal_ull(m, " ", rsslim);
 565        seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->start_code : 1) : 0);
 566        seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->end_code : 1) : 0);
 567        seq_put_decimal_ull(m, " ", (permitted && mm) ? mm->start_stack : 0);
 568        seq_put_decimal_ull(m, " ", esp);
 569        seq_put_decimal_ull(m, " ", eip);
 570        /* The signal information here is obsolete.
 571         * It must be decimal for Linux 2.0 compatibility.
 572         * Use /proc/#/status for real-time signals.
 573         */
 574        seq_put_decimal_ull(m, " ", task->pending.signal.sig[0] & 0x7fffffffUL);
 575        seq_put_decimal_ull(m, " ", task->blocked.sig[0] & 0x7fffffffUL);
 576        seq_put_decimal_ull(m, " ", sigign.sig[0] & 0x7fffffffUL);
 577        seq_put_decimal_ull(m, " ", sigcatch.sig[0] & 0x7fffffffUL);
 578
 579        /*
 580         * We used to output the absolute kernel address, but that's an
 581         * information leak - so instead we show a 0/1 flag here, to signal
 582         * to user-space whether there's a wchan field in /proc/PID/wchan.
 583         *
 584         * This works with older implementations of procps as well.
 585         */
 586        if (wchan)
 587                seq_puts(m, " 1");
 588        else
 589                seq_puts(m, " 0");
 590
 591        seq_put_decimal_ull(m, " ", 0);
 592        seq_put_decimal_ull(m, " ", 0);
 593        seq_put_decimal_ll(m, " ", task->exit_signal);
 594        seq_put_decimal_ll(m, " ", task_cpu(task));
 595        seq_put_decimal_ull(m, " ", task->rt_priority);
 596        seq_put_decimal_ull(m, " ", task->policy);
 597        seq_put_decimal_ull(m, " ", delayacct_blkio_ticks(task));
 598        seq_put_decimal_ull(m, " ", nsec_to_clock_t(gtime));
 599        seq_put_decimal_ll(m, " ", nsec_to_clock_t(cgtime));
 600
 601        if (mm && permitted) {
 602                seq_put_decimal_ull(m, " ", mm->start_data);
 603                seq_put_decimal_ull(m, " ", mm->end_data);
 604                seq_put_decimal_ull(m, " ", mm->start_brk);
 605                seq_put_decimal_ull(m, " ", mm->arg_start);
 606                seq_put_decimal_ull(m, " ", mm->arg_end);
 607                seq_put_decimal_ull(m, " ", mm->env_start);
 608                seq_put_decimal_ull(m, " ", mm->env_end);
 609        } else
 610                seq_puts(m, " 0 0 0 0 0 0 0");
 611
 612        if (permitted)
 613                seq_put_decimal_ll(m, " ", task->exit_code);
 614        else
 615                seq_puts(m, " 0");
 616
 617        seq_putc(m, '\n');
 618        if (mm)
 619                mmput(mm);
 620        return 0;
 621}
 622
 623int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
 624                        struct pid *pid, struct task_struct *task)
 625{
 626        return do_task_stat(m, ns, pid, task, 0);
 627}
 628
 629int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
 630                        struct pid *pid, struct task_struct *task)
 631{
 632        return do_task_stat(m, ns, pid, task, 1);
 633}
 634
 635int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
 636                        struct pid *pid, struct task_struct *task)
 637{
 638        struct mm_struct *mm = get_task_mm(task);
 639
 640        if (mm) {
 641                unsigned long size;
 642                unsigned long resident = 0;
 643                unsigned long shared = 0;
 644                unsigned long text = 0;
 645                unsigned long data = 0;
 646
 647                size = task_statm(mm, &shared, &text, &data, &resident);
 648                mmput(mm);
 649
 650                /*
 651                 * For quick read, open code by putting numbers directly
 652                 * expected format is
 653                 * seq_printf(m, "%lu %lu %lu %lu 0 %lu 0\n",
 654                 *               size, resident, shared, text, data);
 655                 */
 656                seq_put_decimal_ull(m, "", size);
 657                seq_put_decimal_ull(m, " ", resident);
 658                seq_put_decimal_ull(m, " ", shared);
 659                seq_put_decimal_ull(m, " ", text);
 660                seq_put_decimal_ull(m, " ", 0);
 661                seq_put_decimal_ull(m, " ", data);
 662                seq_put_decimal_ull(m, " ", 0);
 663                seq_putc(m, '\n');
 664        } else {
 665                seq_write(m, "0 0 0 0 0 0 0\n", 14);
 666        }
 667        return 0;
 668}
 669
 670#ifdef CONFIG_PROC_CHILDREN
 671static struct pid *
 672get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos)
 673{
 674        struct task_struct *start, *task;
 675        struct pid *pid = NULL;
 676
 677        read_lock(&tasklist_lock);
 678
 679        start = pid_task(proc_pid(inode), PIDTYPE_PID);
 680        if (!start)
 681                goto out;
 682
 683        /*
 684         * Lets try to continue searching first, this gives
 685         * us significant speedup on children-rich processes.
 686         */
 687        if (pid_prev) {
 688                task = pid_task(pid_prev, PIDTYPE_PID);
 689                if (task && task->real_parent == start &&
 690                    !(list_empty(&task->sibling))) {
 691                        if (list_is_last(&task->sibling, &start->children))
 692                                goto out;
 693                        task = list_first_entry(&task->sibling,
 694                                                struct task_struct, sibling);
 695                        pid = get_pid(task_pid(task));
 696                        goto out;
 697                }
 698        }
 699
 700        /*
 701         * Slow search case.
 702         *
 703         * We might miss some children here if children
 704         * are exited while we were not holding the lock,
 705         * but it was never promised to be accurate that
 706         * much.
 707         *
 708         * "Just suppose that the parent sleeps, but N children
 709         *  exit after we printed their tids. Now the slow paths
 710         *  skips N extra children, we miss N tasks." (c)
 711         *
 712         * So one need to stop or freeze the leader and all
 713         * its children to get a precise result.
 714         */
 715        list_for_each_entry(task, &start->children, sibling) {
 716                if (pos-- == 0) {
 717                        pid = get_pid(task_pid(task));
 718                        break;
 719                }
 720        }
 721
 722out:
 723        read_unlock(&tasklist_lock);
 724        return pid;
 725}
 726
 727static int children_seq_show(struct seq_file *seq, void *v)
 728{
 729        struct inode *inode = file_inode(seq->file);
 730
 731        seq_printf(seq, "%d ", pid_nr_ns(v, proc_pid_ns(inode)));
 732        return 0;
 733}
 734
 735static void *children_seq_start(struct seq_file *seq, loff_t *pos)
 736{
 737        return get_children_pid(file_inode(seq->file), NULL, *pos);
 738}
 739
 740static void *children_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 741{
 742        struct pid *pid;
 743
 744        pid = get_children_pid(file_inode(seq->file), v, *pos + 1);
 745        put_pid(v);
 746
 747        ++*pos;
 748        return pid;
 749}
 750
 751static void children_seq_stop(struct seq_file *seq, void *v)
 752{
 753        put_pid(v);
 754}
 755
 756static const struct seq_operations children_seq_ops = {
 757        .start  = children_seq_start,
 758        .next   = children_seq_next,
 759        .stop   = children_seq_stop,
 760        .show   = children_seq_show,
 761};
 762
 763static int children_seq_open(struct inode *inode, struct file *file)
 764{
 765        return seq_open(file, &children_seq_ops);
 766}
 767
 768const struct file_operations proc_tid_children_operations = {
 769        .open    = children_seq_open,
 770        .read    = seq_read,
 771        .llseek  = seq_lseek,
 772        .release = seq_release,
 773};
 774#endif /* CONFIG_PROC_CHILDREN */
 775