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