fs/proc/array.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/proc/array.c
   4  *
   5  *  Copyright (C) 1992  by Linus Torvalds
   6  *  based on ideas by Darren Senn
   7  *
   8  * Fixes:
   9  * Michael. K. Johnson: stat,statm extensions.
  10  *                      <johnsonm@stolaf.edu>
  11  *
  12  * Pauline Middelink :  Made cmdline,envline only break at '\0's, to
  13  *                      make sure SET_PROCTITLE works. Also removed
  14  *                      bad '!' which forced address recalculation for
  15  *                      EVERY character on the current page.
  16  *                      <middelin@polyware.iaf.nl>
  17  *
  18  * Danny ter Haar    :  added cpuinfo
  19  *                      <dth@cistron.nl>
  20  *
  21  * Alessandro Rubini :  profile extension.
  22  *                      <rubini@ipvvis.unipv.it>
  23  *
  24  * Jeff Tranter      :  added BogoMips field to cpuinfo
  25  *                      <Jeff_Tranter@Mitel.COM>
  26  *
  27  * Bruno Haible      :  remove 4K limit for the maps file
  28  *                      <haible@ma2s2.mathematik.uni-karlsruhe.de>
  29  *
  30  * Yves Arrouye      :  remove removal of trailing spaces in get_array.
  31  *                      <Yves.Arrouye@marin.fdn.fr>
  32  *
  33  * Jerome Forissier  :  added per-CPU time information to /proc/stat
  34  *                      and /proc/<pid>/cpu extension
  35  *                      <forissier@isia.cma.fr>
  36  *                      - Incorporation and non-SMP safe operation
  37  *                      of forissier patch in 2.1.78 by
  38  *                      Hans Marcus <crowbar@concepts.nl>
  39  *
  40  * aeb@cwi.nl        :  /proc/partitions
  41  *
  42  *
  43  * Alan Cox          :  security fixes.
  44  *                      <alan@lxorguk.ukuu.org.uk>
  45  *
  46  * Al Viro           :  safe handling of mm_struct
  47  *
  48  * Gerhard Wichert   :  added BIGMEM support
  49  * Siemens AG           <Gerhard.Wichert@pdb.siemens.de>
  50  *
  51  * Al Viro & Jeff Garzik :  moved most of the thing into base.c and
  52  *                       :  proc_misc.c. The rest may eventually go into
  53  *                       :  base.c too.
  54  */
  55
  56 #include <linux/types.h>
  57 #include <linux/errno.h>
  58 #include <linux/time.h>
  59 #include <linux/kernel.h>
  60 #include <linux/kernel_stat.h>
  61 #include <linux/tty.h>
  62 #include <linux/string.h>
  63 #include <linux/mman.h>
  64 #include <linux/sched/mm.h>
  65 #include <linux/sched/numa_balancing.h>
  66 #include <linux/sched/task_stack.h>
  67 #include <linux/sched/task.h>
  68 #include <linux/sched/cputime.h>
  69 #include <linux/proc_fs.h>
  70 #include <linux/ioport.h>
  71 #include <linux/uaccess.h>
  72 #include <linux/io.h>
  73 #include <linux/mm.h>
  74 #include <linux/hugetlb.h>
  75 #include <linux/pagemap.h>
  76 #include <linux/swap.h>
  77 #include <linux/smp.h>
  78 #include <linux/signal.h>
  79 #include <linux/highmem.h>
  80 #include <linux/file.h>
  81 #include <linux/fdtable.h>
  82 #include <linux/times.h>
  83 #include <linux/cpuset.h>
  84 #include <linux/rcupdate.h>
  85 #include <linux/delayacct.h>
  86 #include <linux/seq_file.h>
  87 #include <linux/pid_namespace.h>
  88 #include <linux/prctl.h>
  89 #include <linux/ptrace.h>
  90 #include <linux/tracehook.h>
  91 #include <linux/string_helpers.h>
  92 #include <linux/user_namespace.h>
  93 #include <linux/fs_struct.h>
  94
  95 #include <asm/pgtable.h>
  96 #include <asm/processor.h>
  97 #include "internal.h"
  98
  99 static inline void task_name(struct seq_file *m, struct task_struct *p)
 100 {
 101         char *buf;
 102         size_t size;
 103         char tcomm[sizeof(p->comm)];
 104         int ret;
 105
 106         get_task_comm(tcomm, p);
 107
 108         seq_puts(m, "Name:\t");
 109
 110         size = seq_get_buf(m, &buf);
 111         ret = string_escape_str(tcomm, buf, size, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");
 112         seq_commit(m, ret < size ? ret : -1);
 113
 114         seq_putc(m, '\n');
 115 }
 116
 117 /*
 118  * The task state array is a strange "bitmap" of
 119  * reasons to sleep. Thus "running" is zero, and
 120  * you can test for combinations of others with
 121  * simple bit tests.
 122  */
 123 static const char * const task_state_array[] = {
 124
 125         /* states in TASK_REPORT: */
 126         "R (running)",          /* 0x00 */
 127         "S (sleeping)",         /* 0x01 */
 128         "D (disk sleep)",       /* 0x02 */
 129         "T (stopped)",          /* 0x04 */
 130         "t (tracing stop)",     /* 0x08 */
 131         "X (dead)",             /* 0x10 */
 132         "Z (zombie)",           /* 0x20 */
 133         "P (parked)",           /* 0x40 */
 134
 135         /* states beyond TASK_REPORT: */
 136         "I (idle)",             /* 0x80 */
 137 };
 138
 139 static inline const char *get_task_state(struct task_struct *tsk)
 140 {
 141         BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != ARRAY_SIZE(task_state_array));
 142         return task_state_array[task_state_index(tsk)];
 143 }
 144
 145 static inline int get_task_umask(struct task_struct *tsk)
 146 {
 147         struct fs_struct *fs;
 148         int umask = -ENOENT;
 149
 150         task_lock(tsk);
 151         fs = tsk->fs;
 152         if (fs)
 153                 umask = fs->umask;
 154         task_unlock(tsk);
 155         return umask;
 156 }
 157
 158 static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
 159                                 struct pid *pid, struct task_struct *p)
 160 {
 161         struct user_namespace *user_ns = seq_user_ns(m);
 162         struct group_info *group_info;
 163         int g, umask;
 164         struct task_struct *tracer;
 165         const struct cred *cred;
 166         pid_t ppid, tpid = 0, tgid, ngid;
 167         unsigned int max_fds = 0;
 168
 169         rcu_read_lock();
 170         ppid = pid_alive(p) ?
 171                 task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
 172
 173         tracer = ptrace_parent(p);
 174         if (tracer)
 175                 tpid = task_pid_nr_ns(tracer, ns);
 176
 177         tgid = task_tgid_nr_ns(p, ns);
 178         ngid = task_numa_group_id(p);
 179         cred = get_task_cred(p);
 180
 181         umask = get_task_umask(p);
 182         if (umask >= 0)
 183                 seq_printf(m, "Umask:\t%#04o\n", umask);
 184
 185         task_lock(p);
 186         if (p->files)
 187                 max_fds = files_fdtable(p->files)->max_fds;
 188         task_unlock(p);
 189         rcu_read_unlock();
 190
 191         seq_printf(m, "State:\t%s", get_task_state(p));
 192
 193         seq_put_decimal_ull(m, "\nTgid:\t", tgid);
 194         seq_put_decimal_ull(m, "\nNgid:\t", ngid);
 195         seq_put_decimal_ull(m, "\nPid:\t", pid_nr_ns(pid, ns));
 196         seq_put_decimal_ull(m, "\nPPid:\t", ppid);
 197         seq_put_decimal_ull(m, "\nTracerPid:\t", tpid);
 198         seq_put_decimal_ull(m, "\nUid:\t", from_kuid_munged(user_ns, cred->uid));
 199         seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->euid));
 200         seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->suid));
 201         seq_put_decimal_ull(m, "\t", from_kuid_munged(user_ns, cred->fsuid));
 202         seq_put_decimal_ull(m, "\nGid:\t", from_kgid_munged(user_ns, cred->gid));
 203         seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->egid));
 204         seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->sgid));
 205         seq_put_decimal_ull(m, "\t", from_kgid_munged(user_ns, cred->fsgid));
 206         seq_put_decimal_ull(m, "\nFDSize:\t", max_fds);
 207
 208         seq_puts(m, "\nGroups:\t");
 209         group_info = cred->group_info;
 210         for (g = 0; g < group_info->ngroups; g++)
 211                 seq_put_decimal_ull(m, g ? " " : "",
 212                                 from_kgid_munged(user_ns, group_info->gid[g]));
 213         put_cred(cred);
 214         /* Trailing space shouldn't have been added in the first place. */
 215         seq_putc(m, ' ');
 216
 217 #ifdef CONFIG_PID_NS
 218         seq_puts(m, "\nNStgid:");
 219         for (g = ns->level; g <= pid->level; g++)
 220                 seq_put_decimal_ull(m, "\t", task_tgid_nr_ns(p, pid->numbers[g].ns));
 221         seq_puts(m, "\nNSpid:");
 222         for (g = ns->level; g <= pid->level; g++)
 223                 seq_put_decimal_ull(m, "\t", task_pid_nr_ns(p, pid->numbers[g].ns));
 224         seq_puts(m, "\nNSpgid:");
 225         for (g = ns->level; g <= pid->level; g++)
 226                 seq_put_decimal_ull(m, "\t", task_pgrp_nr_ns(p, pid->numbers[g].ns));
 227         seq_puts(m, "\nNSsid:");
 228         for (g = ns->level; g <= pid->level; g++)
 229                 seq_put_decimal_ull(m, "\t", task_session_nr_ns(p, pid->numbers[g].ns));
 230 #endif
 231         seq_putc(m, '\n');
 232 }
 233
 234 void render_sigset_t(struct seq_file *m, const char *header,
 235                                 sigset_t *set)
 236 {
 237         int i;
 238
 239         seq_puts(m, header);
 240
 241         i = _NSIG;
 242         do {
 243                 int x = 0;
 244
 245                 i -= 4;
 246                 if (sigismember(set, i+1)) x |= 1;
 247                 if (sigismember(set, i+2)) x |= 2;
 248                 if (sigismember(set, i+3)) x |= 4;
 249                 if (sigismember(set, i+4)) x |= 8;
 250                 seq_putc(m, hex_asc[x]);
 251         } while (i >= 4);
 252
 253         seq_putc(m, '\n');
 254 }
 255
 256 static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign,
 257                                     sigset_t *catch)
 258 {
 259         struct k_sigaction *k;
 260         int i;
 261
 262         k = p->sighand->action;
 263         for (i = 1; i <= _NSIG; ++i, ++k) {
 264                 if (k->sa.sa_handler == SIG_IGN)
 265                         sigaddset(ign, i);
 266                 else if (k->sa.sa_handler != SIG_DFL)
 267                         sigaddset(catch, i);
 268         }
 269 }
 270
 271 static inline void task_sig(struct seq_file *m, struct task_struct *p)
 272 {
 273         unsigned long flags;
 274         sigset_t pending, shpending, blocked, ignored, caught;
 275         int num_threads = 0;
 276         unsigned long qsize = 0;
 277         unsigned long qlim = 0;
 278
 279         sigemptyset(&pending);
 280         sigemptyset(&shpending);
 281         sigemptyset(&blocked);
 282         sigemptyset(&ignored);
 283         sigemptyset(&caught);
 284
 285         if (lock_task_sighand(p, &flags)) {
 286                 pending = p->pending.signal;
 287                 shpending = p->signal->shared_pending.signal;
 288                 blocked = p->blocked;
 289                 collect_sigign_sigcatch(p, &ignored, &caught);
 290                 num_threads = get_nr_threads(p);
 291                 rcu_read_lock();  /* FIXME: is this correct? */
 292                 qsize = atomic_read(&__task_cred(p)->user->sigpending);
 293                 rcu_read_unlock();
 294                 qlim = task_rlimit(p, RLIMIT_SIGPENDING);
 295                 unlock_task_sighand(p, &flags);
 296         }
 297
 298         seq_put_decimal_ull(m, "Threads:\t", num_threads);
 299         seq_put_decimal_ull(m, "\nSigQ:\t", qsize);
 300         seq_put_decimal_ull(m, "/", qlim);
 301
 302         /* render them all */
 303         render_sigset_t(m, "\nSigPnd:\t", &pending);
 304         render_sigset_t(m, "ShdPnd:\t", &shpending);
 305         render_sigset_t(m, "SigBlk:\t", &blocked);
 306         render_sigset_t(m, "SigIgn:\t", &ignored);
 307         render_sigset_t(m, "SigCgt:\t", &caught);
 308 }
 309
 310 static void render_cap_t(struct seq_file *m, const char *header,
 311                         kernel_cap_t *a)
 312 {
 313         unsigned __capi;
 314
 315         seq_puts(m, header);
 316         CAP_FOR_EACH_U32(__capi) {
 317                 seq_printf(m, "%08x",
 318                            a->cap[CAP_LAST_U32 - __capi]);
 319         }
 320         seq_putc(m, '\n');
 321 }
 322
 323 static inline void task_cap(struct seq_file *m, struct task_struct *p)
 324 {
 325         const struct cred *cred;
 326         kernel_cap_t cap_inheritable, cap_permitted, cap_effective,
 327                         cap_bset, cap_ambient;
 328
 329         rcu_read_lock();
 330         cred = __task_cred(p);
 331         cap_inheritable = cred->cap_inheritable;
 332         cap_permitted   = cred->cap_permitted;
 333         cap_effective   = cred->cap_effective;
 334         cap_bset        = cred->cap_bset;
 335         cap_ambient     = cred->cap_ambient;
 336         rcu_read_unlock();
 337
 338         render_cap_t(m, "CapInh:\t", &cap_inheritable);
 339         render_cap_t(m, "CapPrm:\t", &cap_permitted);
 340         render_cap_t(m, "CapEff:\t", &cap_effective);
 341         render_cap_t(m, "CapBnd:\t", &cap_bset);
 342         render_cap_t(m, "CapAmb:\t", &cap_ambient);
 343 }
 344
 345 static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
 346 {
 347         seq_put_decimal_ull(m, "NoNewPrivs:\t", task_no_new_privs(p));
 348 #ifdef CONFIG_SECCOMP
 349         seq_put_decimal_ull(m, "\nSeccomp:\t", p->seccomp.mode);
 350 #endif
 351         seq_printf(m, "\nSpeculation_Store_Bypass:\t");
 352         switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_STORE_BYPASS)) {
 353         case -EINVAL:
 354                 seq_printf(m, "unknown");
 355                 break;
 356         case PR_SPEC_NOT_AFFECTED:
 357                 seq_printf(m, "not vulnerable");
 358                 break;
 359         case PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE:
 360                 seq_printf(m, "thread force mitigated");
 361                 break;
 362         case PR_SPEC_PRCTL | PR_SPEC_DISABLE:
 363                 seq_printf(m, "thread mitigated");
 364                 break;
 365         case PR_SPEC_PRCTL | PR_SPEC_ENABLE:
 366                 seq_printf(m, "thread vulnerable");
 367                 break;
 368         case PR_SPEC_DISABLE:
 369                 seq_printf(m, "globally mitigated");
 370                 break;
 371         default:
 372                 seq_printf(m, "vulnerable");
 373                 break;
 374         }
 375         seq_putc(m, '\n');
 376 }
 377
 378 static inline void task_context_switch_counts(struct seq_file *m,
 379                                                 struct task_struct *p)
 380 {
 381         seq_put_decimal_ull(m, "voluntary_ctxt_switches:\t", p->nvcsw);
 382         seq_put_decimal_ull(m, "\nnonvoluntary_ctxt_switches:\t", p->nivcsw);
 383         seq_putc(m, '\n');
 384 }
 385
 386 static void task_cpus_allowed(struct seq_file *m, struct task_struct *task)
 387 {
 388         seq_printf(m, "Cpus_allowed:\t%*pb\n",
 389                    cpumask_pr_args(&task->cpus_allowed));
 390         seq_printf(m, "Cpus_allowed_list:\t%*pbl\n",
 391                    cpumask_pr_args(&task->cpus_allowed));
 392 }
 393
 394 static inline void task_core_dumping(struct seq_file *m, struct mm_struct *mm)
 395 {
 396         seq_printf(m, "CoreDumping:\t%d\n", !!mm->core_state);
 397 }
 398
 399 int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
 400                         struct pid *pid, struct task_struct *task)
 401 {
 402         struct mm_struct *mm = get_task_mm(task);
 403
 404         task_name(m, task);
 405         task_state(m, ns, pid, task);
 406
 407         if (mm) {
 408                 task_mem(m, mm);
 409                 task_core_dumping(m, mm);
 410                 mmput(mm);
 411         }
 412         task_sig(m, task);
 413         task_cap(m, task);
 414         task_seccomp(m, task);
 415         task_cpus_allowed(m, task);
 416         cpuset_task_status_allowed(m, task);
 417         task_context_switch_counts(m, task);
 418         return 0;
 419 }
 420
 421 static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
 422                         struct pid *pid, struct task_struct *task, int whole)
 423 {
 424         unsigned long vsize, eip, esp, wchan = 0;
 425         int priority, nice;
 426         int tty_pgrp = -1, tty_nr = 0;
 427         sigset_t sigign, sigcatch;
 428         char state;
 429         pid_t ppid = 0, pgid = -1, sid = -1;
 430         int num_threads = 0;
 431         int permitted;
 432         struct mm_struct *mm;
 433         unsigned long long start_time;
 434         unsigned long cmin_flt = 0, cmaj_flt = 0;
 435         unsigned long  min_flt = 0,  maj_flt = 0;
 436         u64 cutime, cstime, utime, stime;
 437         u64 cgtime, gtime;
 438         unsigned long rsslim = 0;
 439         char tcomm[sizeof(task->comm)];
 440         unsigned long flags;
 441
 442         state = *get_task_state(task);
 443         vsize = eip = esp = 0;
 444         permitted = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS | PTRACE_MODE_NOAUDIT);
 445         mm = get_task_mm(task);
 446         if (mm) {
 447                 vsize = task_vsize(mm);
 448                 /*
 449                  * esp and eip are intentionally zeroed out.  There is no
 450                  * non-racy way to read them without freezing the task.
 451                  * Programs that need reliable values can use ptrace(2).
 452                  *
 453                  * The only exception is if the task is core dumping because
 454                  * a program is not able to use ptrace(2) in that case. It is
 455                  * safe because the task has stopped executing permanently.
 456                  */
 457                 if (permitted && (task->flags & PF_DUMPCORE)) {
 458                         if (try_get_task_stack(task)) {
 459                                 eip = KSTK_EIP(task);
 460                                 esp = KSTK_ESP(task);
 461                                 put_task_stack(task);
 462                         }
 463                 }
 464         }
 465
 466         get_task_comm(tcomm, task);
 467
 468         sigemptyset(&sigign);
 469         sigemptyset(&sigcatch);
 470         cutime = cstime = utime = stime = 0;
 471         cgtime = gtime = 0;
 472
 473         if (lock_task_sighand(task, &flags)) {
 474                 struct signal_struct *sig = task->signal;
 475
 476                 if (sig->tty) {
 477                         struct pid *pgrp = tty_get_pgrp(sig->tty);
 478                         tty_pgrp = pid_nr_ns(pgrp, ns);
 479                         put_pid(pgrp);
 480                         tty_nr = new_encode_dev(tty_devnum(sig->tty));
 481                 }
 482
 483                 num_threads = get_nr_threads(task);
 484                 collect_sigign_sigcatch(task, &sigign, &sigcatch);
 485
 486                 cmin_flt = sig->cmin_flt;
 487                 cmaj_flt = sig->cmaj_flt;
 488                 cutime = sig->cutime;
 489                 cstime = sig->cstime;
 490                 cgtime = sig->cgtime;
 491                 rsslim = READ_ONCE(sig->rlim[RLIMIT_RSS].rlim_cur);
 492
 493                 /* add up live thread stats at the group level */
 494                 if (whole) {
 495                         struct task_struct *t = task;
 496                         do {
 497                                 min_flt += t->min_flt;
 498                                 maj_flt += t->maj_flt;
 499                                 gtime += task_gtime(t);
 500                         } while_each_thread(task, t);
 501
 502                         min_flt += sig->min_flt;
 503                         maj_flt += sig->maj_flt;
 504                         thread_group_cputime_adjusted(task, &utime, &stime);
 505                         gtime += sig->gtime;
 506                 }
 507
 508                 sid = task_session_nr_ns(task, ns);
 509                 ppid = task_tgid_nr_ns(task->real_parent, ns);
 510                 pgid = task_pgrp_nr_ns(task, ns);
 511
 512                 unlock_task_sighand(task, &flags);
 513         }
 514
 515         if (permitted && (!whole || num_threads < 2))
 516                 wchan = get_wchan(task);
 517         if (!whole) {
 518                 min_flt = task->min_flt;
 519                 maj_flt = task->maj_flt;
 520                 task_cputime_adjusted(task, &utime, &stime);
 521                 gtime = task_gtime(task);
 522         }
 523
 524         /* scale priority and nice values from timeslices to -20..20 */
 525         /* to make it look like a "normal" Unix priority/nice value  */
 526         priority = task_prio(task);
 527         nice = task_nice(task);
 528
 529         /* convert nsec -> ticks */
 530         start_time = nsec_to_clock_t(task->real_start_time);
 531
 532         seq_printf(m, "%d (%s) %c", pid_nr_ns(pid, ns), tcomm, state);
 533         seq_put_decimal_ll(m, " ", ppid);
 534         seq_put_decimal_ll(m, " ", pgid);
 535         seq_put_decimal_ll(m, " ", sid);
 536         seq_put_decimal_ll(m, " ", tty_nr);
 537         seq_put_decimal_ll(m, " ", tty_pgrp);
 538         seq_put_decimal_ull(m, " ", task->flags);
 539         seq_put_decimal_ull(m, " ", min_flt);
 540         seq_put_decimal_ull(m, " ", cmin_flt);
 541         seq_put_decimal_ull(m, " ", maj_flt);
 542         seq_put_decimal_ull(m, " ", cmaj_flt);
 543         seq_put_decimal_ull(m, " ", nsec_to_clock_t(utime));
 544         seq_put_decimal_ull(m, " ", nsec_to_clock_t(stime));
 545         seq_put_decimal_ll(m, " ", nsec_to_clock_t(cutime));
 546         seq_put_decimal_ll(m, " ", nsec_to_clock_t(cstime));
 547         seq_put_decimal_ll(m, " ", priority);
 548         seq_put_decimal_ll(m, " ", nice);
 549         seq_put_decimal_ll(m, " ", num_threads);
 550         seq_put_decimal_ull(m, " ", 0);
 551         seq_put_decimal_ull(m, " ", start_time);
 552         seq_put_decimal_ull(m, " ", vsize);
 553         seq_put_decimal_ull(m, " ", mm ? get_mm_rss(mm) : 0);
 554         seq_put_decimal_ull(m, " ", rsslim);
 555         seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->start_code : 1) : 0);
 556         seq_put_decimal_ull(m, " ", mm ? (permitted ? mm->end_code : 1) : 0);
 557         seq_put_decimal_ull(m, " ", (permitted && mm) ? mm->start_stack : 0);
 558         seq_put_decimal_ull(m, " ", esp);
 559         seq_put_decimal_ull(m, " ", eip);
 560         /* The signal information here is obsolete.
 561          * It must be decimal for Linux 2.0 compatibility.
 562          * Use /proc/#/status for real-time signals.
 563          */
 564         seq_put_decimal_ull(m, " ", task->pending.signal.sig[0] & 0x7fffffffUL);
 565         seq_put_decimal_ull(m, " ", task->blocked.sig[0] & 0x7fffffffUL);
 566         seq_put_decimal_ull(m, " ", sigign.sig[0] & 0x7fffffffUL);
 567         seq_put_decimal_ull(m, " ", sigcatch.sig[0] & 0x7fffffffUL);
 568
 569         /*
 570          * We used to output the absolute kernel address, but that's an
 571          * information leak - so instead we show a 0/1 flag here, to signal
 572          * to user-space whether there's a wchan field in /proc/PID/wchan.
 573          *
 574          * This works with older implementations of procps as well.
 575          */
 576         if (wchan)
 577                 seq_puts(m, " 1");
 578         else
 579                 seq_puts(m, " 0");
 580
 581         seq_put_decimal_ull(m, " ", 0);
 582         seq_put_decimal_ull(m, " ", 0);
 583         seq_put_decimal_ll(m, " ", task->exit_signal);
 584         seq_put_decimal_ll(m, " ", task_cpu(task));
 585         seq_put_decimal_ull(m, " ", task->rt_priority);
 586         seq_put_decimal_ull(m, " ", task->policy);
 587         seq_put_decimal_ull(m, " ", delayacct_blkio_ticks(task));
 588         seq_put_decimal_ull(m, " ", nsec_to_clock_t(gtime));
 589         seq_put_decimal_ll(m, " ", nsec_to_clock_t(cgtime));
 590
 591         if (mm && permitted) {
 592                 seq_put_decimal_ull(m, " ", mm->start_data);
 593                 seq_put_decimal_ull(m, " ", mm->end_data);
 594                 seq_put_decimal_ull(m, " ", mm->start_brk);
 595                 seq_put_decimal_ull(m, " ", mm->arg_start);
 596                 seq_put_decimal_ull(m, " ", mm->arg_end);
 597                 seq_put_decimal_ull(m, " ", mm->env_start);
 598                 seq_put_decimal_ull(m, " ", mm->env_end);
 599         } else
 600                 seq_puts(m, " 0 0 0 0 0 0 0");
 601
 602         if (permitted)
 603                 seq_put_decimal_ll(m, " ", task->exit_code);
 604         else
 605                 seq_puts(m, " 0");
 606
 607         seq_putc(m, '\n');
 608         if (mm)
 609                 mmput(mm);
 610         return 0;
 611 }
 612
 613 int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
 614                         struct pid *pid, struct task_struct *task)
 615 {
 616         return do_task_stat(m, ns, pid, task, 0);
 617 }
 618
 619 int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
 620                         struct pid *pid, struct task_struct *task)
 621 {
 622         return do_task_stat(m, ns, pid, task, 1);
 623 }
 624
 625 int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
 626                         struct pid *pid, struct task_struct *task)
 627 {
 628         unsigned long size = 0, resident = 0, shared = 0, text = 0, data = 0;
 629         struct mm_struct *mm = get_task_mm(task);
 630
 631         if (mm) {
 632                 size = task_statm(mm, &shared, &text, &data, &resident);
 633                 mmput(mm);
 634         }
 635         /*
 636          * For quick read, open code by putting numbers directly
 637          * expected format is
 638          * seq_printf(m, "%lu %lu %lu %lu 0 %lu 0\n",
 639          *               size, resident, shared, text, data);
 640          */
 641         seq_put_decimal_ull(m, "", size);
 642         seq_put_decimal_ull(m, " ", resident);
 643         seq_put_decimal_ull(m, " ", shared);
 644         seq_put_decimal_ull(m, " ", text);
 645         seq_put_decimal_ull(m, " ", 0);
 646         seq_put_decimal_ull(m, " ", data);
 647         seq_put_decimal_ull(m, " ", 0);
 648         seq_putc(m, '\n');
 649
 650         return 0;
 651 }
 652
 653 #ifdef CONFIG_PROC_CHILDREN
 654 static struct pid *
 655 get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos)
 656 {
 657         struct task_struct *start, *task;
 658         struct pid *pid = NULL;
 659
 660         read_lock(&tasklist_lock);
 661
 662         start = pid_task(proc_pid(inode), PIDTYPE_PID);
 663         if (!start)
 664                 goto out;
 665
 666         /*
 667          * Lets try to continue searching first, this gives
 668          * us significant speedup on children-rich processes.
 669          */
 670         if (pid_prev) {
 671                 task = pid_task(pid_prev, PIDTYPE_PID);
 672                 if (task && task->real_parent == start &&
 673                     !(list_empty(&task->sibling))) {
 674                         if (list_is_last(&task->sibling, &start->children))
 675                                 goto out;
 676                         task = list_first_entry(&task->sibling,
 677                                                 struct task_struct, sibling);
 678                         pid = get_pid(task_pid(task));
 679                         goto out;
 680                 }
 681         }
 682
 683         /*
 684          * Slow search case.
 685          *
 686          * We might miss some children here if children
 687          * are exited while we were not holding the lock,
 688          * but it was never promised to be accurate that
 689          * much.
 690          *
 691          * "Just suppose that the parent sleeps, but N children
 692          *  exit after we printed their tids. Now the slow paths
 693          *  skips N extra children, we miss N tasks." (c)
 694          *
 695          * So one need to stop or freeze the leader and all
 696          * its children to get a precise result.
 697          */
 698         list_for_each_entry(task, &start->children, sibling) {
 699                 if (pos-- == 0) {
 700                         pid = get_pid(task_pid(task));
 701                         break;
 702                 }
 703         }
 704
 705 out:
 706         read_unlock(&tasklist_lock);
 707         return pid;
 708 }
 709
 710 static int children_seq_show(struct seq_file *seq, void *v)
 711 {
 712         struct inode *inode = seq->private;
 713         pid_t pid;
 714
 715         pid = pid_nr_ns(v, inode->i_sb->s_fs_info);
 716         seq_printf(seq, "%d ", pid);
 717
 718         return 0;
 719 }
 720
 721 static void *children_seq_start(struct seq_file *seq, loff_t *pos)
 722 {
 723         return get_children_pid(seq->private, NULL, *pos);
 724 }
 725
 726 static void *children_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 727 {
 728         struct pid *pid;
 729
 730         pid = get_children_pid(seq->private, v, *pos + 1);
 731         put_pid(v);
 732
 733         ++*pos;
 734         return pid;
 735 }
 736
 737 static void children_seq_stop(struct seq_file *seq, void *v)
 738 {
 739         put_pid(v);
 740 }
 741
 742 static const struct seq_operations children_seq_ops = {
 743         .start  = children_seq_start,
 744         .next   = children_seq_next,
 745         .stop   = children_seq_stop,
 746         .show   = children_seq_show,
 747 };
 748
 749 static int children_seq_open(struct inode *inode, struct file *file)
 750 {
 751         struct seq_file *m;
 752         int ret;
 753
 754         ret = seq_open(file, &children_seq_ops);
 755         if (ret)
 756                 return ret;
 757
 758         m = file->private_data;
 759         m->private = inode;
 760
 761         return ret;
 762 }
 763
 764 int children_seq_release(struct inode *inode, struct file *file)
 765 {
 766         seq_release(inode, file);
 767         return 0;
 768 }
 769
 770 const struct file_operations proc_tid_children_operations = {
 771         .open    = children_seq_open,
 772         .read    = seq_read,
 773         .llseek  = seq_lseek,
 774         .release = children_seq_release,
 775 };
 776 #endif /* CONFIG_PROC_CHILDREN */