signal.h (22220B)
1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef _LINUX_SCHED_SIGNAL_H 3#define _LINUX_SCHED_SIGNAL_H 4 5#include <linux/rculist.h> 6#include <linux/signal.h> 7#include <linux/sched.h> 8#include <linux/sched/jobctl.h> 9#include <linux/sched/task.h> 10#include <linux/cred.h> 11#include <linux/refcount.h> 12#include <linux/posix-timers.h> 13#include <linux/mm_types.h> 14#include <asm/ptrace.h> 15 16/* 17 * Types defining task->signal and task->sighand and APIs using them: 18 */ 19 20struct sighand_struct { 21 spinlock_t siglock; 22 refcount_t count; 23 wait_queue_head_t signalfd_wqh; 24 struct k_sigaction action[_NSIG]; 25}; 26 27/* 28 * Per-process accounting stats: 29 */ 30struct pacct_struct { 31 int ac_flag; 32 long ac_exitcode; 33 unsigned long ac_mem; 34 u64 ac_utime, ac_stime; 35 unsigned long ac_minflt, ac_majflt; 36}; 37 38struct cpu_itimer { 39 u64 expires; 40 u64 incr; 41}; 42 43/* 44 * This is the atomic variant of task_cputime, which can be used for 45 * storing and updating task_cputime statistics without locking. 46 */ 47struct task_cputime_atomic { 48 atomic64_t utime; 49 atomic64_t stime; 50 atomic64_t sum_exec_runtime; 51}; 52 53#define INIT_CPUTIME_ATOMIC \ 54 (struct task_cputime_atomic) { \ 55 .utime = ATOMIC64_INIT(0), \ 56 .stime = ATOMIC64_INIT(0), \ 57 .sum_exec_runtime = ATOMIC64_INIT(0), \ 58 } 59/** 60 * struct thread_group_cputimer - thread group interval timer counts 61 * @cputime_atomic: atomic thread group interval timers. 62 * 63 * This structure contains the version of task_cputime, above, that is 64 * used for thread group CPU timer calculations. 65 */ 66struct thread_group_cputimer { 67 struct task_cputime_atomic cputime_atomic; 68}; 69 70struct multiprocess_signals { 71 sigset_t signal; 72 struct hlist_node node; 73}; 74 75struct core_thread { 76 struct task_struct *task; 77 struct core_thread *next; 78}; 79 80struct core_state { 81 atomic_t nr_threads; 82 struct core_thread dumper; 83 struct completion startup; 84}; 85 86/* 87 * NOTE! "signal_struct" does not have its own 88 * locking, because a shared signal_struct always 89 * implies a shared sighand_struct, so locking 90 * sighand_struct is always a proper superset of 91 * the locking of signal_struct. 92 */ 93struct signal_struct { 94 refcount_t sigcnt; 95 atomic_t live; 96 int nr_threads; 97 struct list_head thread_head; 98 99 wait_queue_head_t wait_chldexit; /* for wait4() */ 100 101 /* current thread group signal load-balancing target: */ 102 struct task_struct *curr_target; 103 104 /* shared signal handling: */ 105 struct sigpending shared_pending; 106 107 /* For collecting multiprocess signals during fork */ 108 struct hlist_head multiprocess; 109 110 /* thread group exit support */ 111 int group_exit_code; 112 /* notify group_exec_task when notify_count is less or equal to 0 */ 113 int notify_count; 114 struct task_struct *group_exec_task; 115 116 /* thread group stop support, overloads group_exit_code too */ 117 int group_stop_count; 118 unsigned int flags; /* see SIGNAL_* flags below */ 119 120 struct core_state *core_state; /* coredumping support */ 121 122 /* 123 * PR_SET_CHILD_SUBREAPER marks a process, like a service 124 * manager, to re-parent orphan (double-forking) child processes 125 * to this process instead of 'init'. The service manager is 126 * able to receive SIGCHLD signals and is able to investigate 127 * the process until it calls wait(). All children of this 128 * process will inherit a flag if they should look for a 129 * child_subreaper process at exit. 130 */ 131 unsigned int is_child_subreaper:1; 132 unsigned int has_child_subreaper:1; 133 134#ifdef CONFIG_POSIX_TIMERS 135 136 /* POSIX.1b Interval Timers */ 137 int posix_timer_id; 138 struct list_head posix_timers; 139 140 /* ITIMER_REAL timer for the process */ 141 struct hrtimer real_timer; 142 ktime_t it_real_incr; 143 144 /* 145 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use 146 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these 147 * values are defined to 0 and 1 respectively 148 */ 149 struct cpu_itimer it[2]; 150 151 /* 152 * Thread group totals for process CPU timers. 153 * See thread_group_cputimer(), et al, for details. 154 */ 155 struct thread_group_cputimer cputimer; 156 157#endif 158 /* Empty if CONFIG_POSIX_TIMERS=n */ 159 struct posix_cputimers posix_cputimers; 160 161 /* PID/PID hash table linkage. */ 162 struct pid *pids[PIDTYPE_MAX]; 163 164#ifdef CONFIG_NO_HZ_FULL 165 atomic_t tick_dep_mask; 166#endif 167 168 struct pid *tty_old_pgrp; 169 170 /* boolean value for session group leader */ 171 int leader; 172 173 struct tty_struct *tty; /* NULL if no tty */ 174 175#ifdef CONFIG_SCHED_AUTOGROUP 176 struct autogroup *autogroup; 177#endif 178 /* 179 * Cumulative resource counters for dead threads in the group, 180 * and for reaped dead child processes forked by this group. 181 * Live threads maintain their own counters and add to these 182 * in __exit_signal, except for the group leader. 183 */ 184 seqlock_t stats_lock; 185 u64 utime, stime, cutime, cstime; 186 u64 gtime; 187 u64 cgtime; 188 struct prev_cputime prev_cputime; 189 unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw; 190 unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt; 191 unsigned long inblock, oublock, cinblock, coublock; 192 unsigned long maxrss, cmaxrss; 193 struct task_io_accounting ioac; 194 195 /* 196 * Cumulative ns of schedule CPU time fo dead threads in the 197 * group, not including a zombie group leader, (This only differs 198 * from jiffies_to_ns(utime + stime) if sched_clock uses something 199 * other than jiffies.) 200 */ 201 unsigned long long sum_sched_runtime; 202 203 /* 204 * We don't bother to synchronize most readers of this at all, 205 * because there is no reader checking a limit that actually needs 206 * to get both rlim_cur and rlim_max atomically, and either one 207 * alone is a single word that can safely be read normally. 208 * getrlimit/setrlimit use task_lock(current->group_leader) to 209 * protect this instead of the siglock, because they really 210 * have no need to disable irqs. 211 */ 212 struct rlimit rlim[RLIM_NLIMITS]; 213 214#ifdef CONFIG_BSD_PROCESS_ACCT 215 struct pacct_struct pacct; /* per-process accounting information */ 216#endif 217#ifdef CONFIG_TASKSTATS 218 struct taskstats *stats; 219#endif 220#ifdef CONFIG_AUDIT 221 unsigned audit_tty; 222 struct tty_audit_buf *tty_audit_buf; 223#endif 224 225 /* 226 * Thread is the potential origin of an oom condition; kill first on 227 * oom 228 */ 229 bool oom_flag_origin; 230 short oom_score_adj; /* OOM kill score adjustment */ 231 short oom_score_adj_min; /* OOM kill score adjustment min value. 232 * Only settable by CAP_SYS_RESOURCE. */ 233 struct mm_struct *oom_mm; /* recorded mm when the thread group got 234 * killed by the oom killer */ 235 236 struct mutex cred_guard_mutex; /* guard against foreign influences on 237 * credential calculations 238 * (notably. ptrace) 239 * Deprecated do not use in new code. 240 * Use exec_update_lock instead. 241 */ 242 struct rw_semaphore exec_update_lock; /* Held while task_struct is 243 * being updated during exec, 244 * and may have inconsistent 245 * permissions. 246 */ 247} __randomize_layout; 248 249/* 250 * Bits in flags field of signal_struct. 251 */ 252#define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */ 253#define SIGNAL_STOP_CONTINUED 0x00000002 /* SIGCONT since WCONTINUED reap */ 254#define SIGNAL_GROUP_EXIT 0x00000004 /* group exit in progress */ 255/* 256 * Pending notifications to parent. 257 */ 258#define SIGNAL_CLD_STOPPED 0x00000010 259#define SIGNAL_CLD_CONTINUED 0x00000020 260#define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED) 261 262#define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */ 263 264#define SIGNAL_STOP_MASK (SIGNAL_CLD_MASK | SIGNAL_STOP_STOPPED | \ 265 SIGNAL_STOP_CONTINUED) 266 267static inline void signal_set_stop_flags(struct signal_struct *sig, 268 unsigned int flags) 269{ 270 WARN_ON(sig->flags & SIGNAL_GROUP_EXIT); 271 sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags; 272} 273 274extern void flush_signals(struct task_struct *); 275extern void ignore_signals(struct task_struct *); 276extern void flush_signal_handlers(struct task_struct *, int force_default); 277extern int dequeue_signal(struct task_struct *task, sigset_t *mask, 278 kernel_siginfo_t *info, enum pid_type *type); 279 280static inline int kernel_dequeue_signal(void) 281{ 282 struct task_struct *task = current; 283 kernel_siginfo_t __info; 284 enum pid_type __type; 285 int ret; 286 287 spin_lock_irq(&task->sighand->siglock); 288 ret = dequeue_signal(task, &task->blocked, &__info, &__type); 289 spin_unlock_irq(&task->sighand->siglock); 290 291 return ret; 292} 293 294static inline void kernel_signal_stop(void) 295{ 296 spin_lock_irq(¤t->sighand->siglock); 297 if (current->jobctl & JOBCTL_STOP_DEQUEUED) { 298 current->jobctl |= JOBCTL_STOPPED; 299 set_special_state(TASK_STOPPED); 300 } 301 spin_unlock_irq(¤t->sighand->siglock); 302 303 schedule(); 304} 305#ifdef __ia64__ 306# define ___ARCH_SI_IA64(_a1, _a2, _a3) , _a1, _a2, _a3 307#else 308# define ___ARCH_SI_IA64(_a1, _a2, _a3) 309#endif 310 311int force_sig_fault_to_task(int sig, int code, void __user *addr 312 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr) 313 , struct task_struct *t); 314int force_sig_fault(int sig, int code, void __user *addr 315 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)); 316int send_sig_fault(int sig, int code, void __user *addr 317 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr) 318 , struct task_struct *t); 319 320int force_sig_mceerr(int code, void __user *, short); 321int send_sig_mceerr(int code, void __user *, short, struct task_struct *); 322 323int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper); 324int force_sig_pkuerr(void __user *addr, u32 pkey); 325int send_sig_perf(void __user *addr, u32 type, u64 sig_data); 326 327int force_sig_ptrace_errno_trap(int errno, void __user *addr); 328int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno); 329int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno, 330 struct task_struct *t); 331int force_sig_seccomp(int syscall, int reason, bool force_coredump); 332 333extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *); 334extern void force_sigsegv(int sig); 335extern int force_sig_info(struct kernel_siginfo *); 336extern int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp); 337extern int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid); 338extern int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, struct pid *, 339 const struct cred *); 340extern int kill_pgrp(struct pid *pid, int sig, int priv); 341extern int kill_pid(struct pid *pid, int sig, int priv); 342extern __must_check bool do_notify_parent(struct task_struct *, int); 343extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent); 344extern void force_sig(int); 345extern void force_fatal_sig(int); 346extern void force_exit_sig(int); 347extern int send_sig(int, struct task_struct *, int); 348extern int zap_other_threads(struct task_struct *p); 349extern struct sigqueue *sigqueue_alloc(void); 350extern void sigqueue_free(struct sigqueue *); 351extern int send_sigqueue(struct sigqueue *, struct pid *, enum pid_type); 352extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *); 353 354static inline void clear_notify_signal(void) 355{ 356 clear_thread_flag(TIF_NOTIFY_SIGNAL); 357 smp_mb__after_atomic(); 358} 359 360/* 361 * Returns 'true' if kick_process() is needed to force a transition from 362 * user -> kernel to guarantee expedient run of TWA_SIGNAL based task_work. 363 */ 364static inline bool __set_notify_signal(struct task_struct *task) 365{ 366 return !test_and_set_tsk_thread_flag(task, TIF_NOTIFY_SIGNAL) && 367 !wake_up_state(task, TASK_INTERRUPTIBLE); 368} 369 370/* 371 * Called to break out of interruptible wait loops, and enter the 372 * exit_to_user_mode_loop(). 373 */ 374static inline void set_notify_signal(struct task_struct *task) 375{ 376 if (__set_notify_signal(task)) 377 kick_process(task); 378} 379 380static inline int restart_syscall(void) 381{ 382 set_tsk_thread_flag(current, TIF_SIGPENDING); 383 return -ERESTARTNOINTR; 384} 385 386static inline int task_sigpending(struct task_struct *p) 387{ 388 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING)); 389} 390 391static inline int signal_pending(struct task_struct *p) 392{ 393 /* 394 * TIF_NOTIFY_SIGNAL isn't really a signal, but it requires the same 395 * behavior in terms of ensuring that we break out of wait loops 396 * so that notify signal callbacks can be processed. 397 */ 398 if (unlikely(test_tsk_thread_flag(p, TIF_NOTIFY_SIGNAL))) 399 return 1; 400 return task_sigpending(p); 401} 402 403static inline int __fatal_signal_pending(struct task_struct *p) 404{ 405 return unlikely(sigismember(&p->pending.signal, SIGKILL)); 406} 407 408static inline int fatal_signal_pending(struct task_struct *p) 409{ 410 return task_sigpending(p) && __fatal_signal_pending(p); 411} 412 413static inline int signal_pending_state(unsigned int state, struct task_struct *p) 414{ 415 if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL))) 416 return 0; 417 if (!signal_pending(p)) 418 return 0; 419 420 return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p); 421} 422 423/* 424 * This should only be used in fault handlers to decide whether we 425 * should stop the current fault routine to handle the signals 426 * instead, especially with the case where we've got interrupted with 427 * a VM_FAULT_RETRY. 428 */ 429static inline bool fault_signal_pending(vm_fault_t fault_flags, 430 struct pt_regs *regs) 431{ 432 return unlikely((fault_flags & VM_FAULT_RETRY) && 433 (fatal_signal_pending(current) || 434 (user_mode(regs) && signal_pending(current)))); 435} 436 437/* 438 * Reevaluate whether the task has signals pending delivery. 439 * Wake the task if so. 440 * This is required every time the blocked sigset_t changes. 441 * callers must hold sighand->siglock. 442 */ 443extern void recalc_sigpending_and_wake(struct task_struct *t); 444extern void recalc_sigpending(void); 445extern void calculate_sigpending(void); 446 447extern void signal_wake_up_state(struct task_struct *t, unsigned int state); 448 449static inline void signal_wake_up(struct task_struct *t, bool fatal) 450{ 451 unsigned int state = 0; 452 if (fatal && !(t->jobctl & JOBCTL_PTRACE_FROZEN)) { 453 t->jobctl &= ~(JOBCTL_STOPPED | JOBCTL_TRACED); 454 state = TASK_WAKEKILL | __TASK_TRACED; 455 } 456 signal_wake_up_state(t, state); 457} 458static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume) 459{ 460 unsigned int state = 0; 461 if (resume) { 462 t->jobctl &= ~JOBCTL_TRACED; 463 state = __TASK_TRACED; 464 } 465 signal_wake_up_state(t, state); 466} 467 468void task_join_group_stop(struct task_struct *task); 469 470#ifdef TIF_RESTORE_SIGMASK 471/* 472 * Legacy restore_sigmask accessors. These are inefficient on 473 * SMP architectures because they require atomic operations. 474 */ 475 476/** 477 * set_restore_sigmask() - make sure saved_sigmask processing gets done 478 * 479 * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code 480 * will run before returning to user mode, to process the flag. For 481 * all callers, TIF_SIGPENDING is already set or it's no harm to set 482 * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the 483 * arch code will notice on return to user mode, in case those bits 484 * are scarce. We set TIF_SIGPENDING here to ensure that the arch 485 * signal code always gets run when TIF_RESTORE_SIGMASK is set. 486 */ 487static inline void set_restore_sigmask(void) 488{ 489 set_thread_flag(TIF_RESTORE_SIGMASK); 490} 491 492static inline void clear_tsk_restore_sigmask(struct task_struct *task) 493{ 494 clear_tsk_thread_flag(task, TIF_RESTORE_SIGMASK); 495} 496 497static inline void clear_restore_sigmask(void) 498{ 499 clear_thread_flag(TIF_RESTORE_SIGMASK); 500} 501static inline bool test_tsk_restore_sigmask(struct task_struct *task) 502{ 503 return test_tsk_thread_flag(task, TIF_RESTORE_SIGMASK); 504} 505static inline bool test_restore_sigmask(void) 506{ 507 return test_thread_flag(TIF_RESTORE_SIGMASK); 508} 509static inline bool test_and_clear_restore_sigmask(void) 510{ 511 return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK); 512} 513 514#else /* TIF_RESTORE_SIGMASK */ 515 516/* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */ 517static inline void set_restore_sigmask(void) 518{ 519 current->restore_sigmask = true; 520} 521static inline void clear_tsk_restore_sigmask(struct task_struct *task) 522{ 523 task->restore_sigmask = false; 524} 525static inline void clear_restore_sigmask(void) 526{ 527 current->restore_sigmask = false; 528} 529static inline bool test_restore_sigmask(void) 530{ 531 return current->restore_sigmask; 532} 533static inline bool test_tsk_restore_sigmask(struct task_struct *task) 534{ 535 return task->restore_sigmask; 536} 537static inline bool test_and_clear_restore_sigmask(void) 538{ 539 if (!current->restore_sigmask) 540 return false; 541 current->restore_sigmask = false; 542 return true; 543} 544#endif 545 546static inline void restore_saved_sigmask(void) 547{ 548 if (test_and_clear_restore_sigmask()) 549 __set_current_blocked(¤t->saved_sigmask); 550} 551 552extern int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize); 553 554static inline void restore_saved_sigmask_unless(bool interrupted) 555{ 556 if (interrupted) 557 WARN_ON(!signal_pending(current)); 558 else 559 restore_saved_sigmask(); 560} 561 562static inline sigset_t *sigmask_to_save(void) 563{ 564 sigset_t *res = ¤t->blocked; 565 if (unlikely(test_restore_sigmask())) 566 res = ¤t->saved_sigmask; 567 return res; 568} 569 570static inline int kill_cad_pid(int sig, int priv) 571{ 572 return kill_pid(cad_pid, sig, priv); 573} 574 575/* These can be the second arg to send_sig_info/send_group_sig_info. */ 576#define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0) 577#define SEND_SIG_PRIV ((struct kernel_siginfo *) 1) 578 579static inline int __on_sig_stack(unsigned long sp) 580{ 581#ifdef CONFIG_STACK_GROWSUP 582 return sp >= current->sas_ss_sp && 583 sp - current->sas_ss_sp < current->sas_ss_size; 584#else 585 return sp > current->sas_ss_sp && 586 sp - current->sas_ss_sp <= current->sas_ss_size; 587#endif 588} 589 590/* 591 * True if we are on the alternate signal stack. 592 */ 593static inline int on_sig_stack(unsigned long sp) 594{ 595 /* 596 * If the signal stack is SS_AUTODISARM then, by construction, we 597 * can't be on the signal stack unless user code deliberately set 598 * SS_AUTODISARM when we were already on it. 599 * 600 * This improves reliability: if user state gets corrupted such that 601 * the stack pointer points very close to the end of the signal stack, 602 * then this check will enable the signal to be handled anyway. 603 */ 604 if (current->sas_ss_flags & SS_AUTODISARM) 605 return 0; 606 607 return __on_sig_stack(sp); 608} 609 610static inline int sas_ss_flags(unsigned long sp) 611{ 612 if (!current->sas_ss_size) 613 return SS_DISABLE; 614 615 return on_sig_stack(sp) ? SS_ONSTACK : 0; 616} 617 618static inline void sas_ss_reset(struct task_struct *p) 619{ 620 p->sas_ss_sp = 0; 621 p->sas_ss_size = 0; 622 p->sas_ss_flags = SS_DISABLE; 623} 624 625static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig) 626{ 627 if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp)) 628#ifdef CONFIG_STACK_GROWSUP 629 return current->sas_ss_sp; 630#else 631 return current->sas_ss_sp + current->sas_ss_size; 632#endif 633 return sp; 634} 635 636extern void __cleanup_sighand(struct sighand_struct *); 637extern void flush_itimer_signals(void); 638 639#define tasklist_empty() \ 640 list_empty(&init_task.tasks) 641 642#define next_task(p) \ 643 list_entry_rcu((p)->tasks.next, struct task_struct, tasks) 644 645#define for_each_process(p) \ 646 for (p = &init_task ; (p = next_task(p)) != &init_task ; ) 647 648extern bool current_is_single_threaded(void); 649 650/* 651 * Careful: do_each_thread/while_each_thread is a double loop so 652 * 'break' will not work as expected - use goto instead. 653 */ 654#define do_each_thread(g, t) \ 655 for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do 656 657#define while_each_thread(g, t) \ 658 while ((t = next_thread(t)) != g) 659 660#define __for_each_thread(signal, t) \ 661 list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node) 662 663#define for_each_thread(p, t) \ 664 __for_each_thread((p)->signal, t) 665 666/* Careful: this is a double loop, 'break' won't work as expected. */ 667#define for_each_process_thread(p, t) \ 668 for_each_process(p) for_each_thread(p, t) 669 670typedef int (*proc_visitor)(struct task_struct *p, void *data); 671void walk_process_tree(struct task_struct *top, proc_visitor, void *); 672 673static inline 674struct pid *task_pid_type(struct task_struct *task, enum pid_type type) 675{ 676 struct pid *pid; 677 if (type == PIDTYPE_PID) 678 pid = task_pid(task); 679 else 680 pid = task->signal->pids[type]; 681 return pid; 682} 683 684static inline struct pid *task_tgid(struct task_struct *task) 685{ 686 return task->signal->pids[PIDTYPE_TGID]; 687} 688 689/* 690 * Without tasklist or RCU lock it is not safe to dereference 691 * the result of task_pgrp/task_session even if task == current, 692 * we can race with another thread doing sys_setsid/sys_setpgid. 693 */ 694static inline struct pid *task_pgrp(struct task_struct *task) 695{ 696 return task->signal->pids[PIDTYPE_PGID]; 697} 698 699static inline struct pid *task_session(struct task_struct *task) 700{ 701 return task->signal->pids[PIDTYPE_SID]; 702} 703 704static inline int get_nr_threads(struct task_struct *task) 705{ 706 return task->signal->nr_threads; 707} 708 709static inline bool thread_group_leader(struct task_struct *p) 710{ 711 return p->exit_signal >= 0; 712} 713 714static inline 715bool same_thread_group(struct task_struct *p1, struct task_struct *p2) 716{ 717 return p1->signal == p2->signal; 718} 719 720static inline struct task_struct *next_thread(const struct task_struct *p) 721{ 722 return list_entry_rcu(p->thread_group.next, 723 struct task_struct, thread_group); 724} 725 726static inline int thread_group_empty(struct task_struct *p) 727{ 728 return list_empty(&p->thread_group); 729} 730 731#define delay_group_leader(p) \ 732 (thread_group_leader(p) && !thread_group_empty(p)) 733 734extern bool thread_group_exited(struct pid *pid); 735 736extern struct sighand_struct *__lock_task_sighand(struct task_struct *task, 737 unsigned long *flags); 738 739static inline struct sighand_struct *lock_task_sighand(struct task_struct *task, 740 unsigned long *flags) 741{ 742 struct sighand_struct *ret; 743 744 ret = __lock_task_sighand(task, flags); 745 (void)__cond_lock(&task->sighand->siglock, ret); 746 return ret; 747} 748 749static inline void unlock_task_sighand(struct task_struct *task, 750 unsigned long *flags) 751{ 752 spin_unlock_irqrestore(&task->sighand->siglock, *flags); 753} 754 755#ifdef CONFIG_LOCKDEP 756extern void lockdep_assert_task_sighand_held(struct task_struct *task); 757#else 758static inline void lockdep_assert_task_sighand_held(struct task_struct *task) { } 759#endif 760 761static inline unsigned long task_rlimit(const struct task_struct *task, 762 unsigned int limit) 763{ 764 return READ_ONCE(task->signal->rlim[limit].rlim_cur); 765} 766 767static inline unsigned long task_rlimit_max(const struct task_struct *task, 768 unsigned int limit) 769{ 770 return READ_ONCE(task->signal->rlim[limit].rlim_max); 771} 772 773static inline unsigned long rlimit(unsigned int limit) 774{ 775 return task_rlimit(current, limit); 776} 777 778static inline unsigned long rlimit_max(unsigned int limit) 779{ 780 return task_rlimit_max(current, limit); 781} 782 783#endif /* _LINUX_SCHED_SIGNAL_H */