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/pid.h> 13 #include <linux/posix-timers.h> 14 #include <linux/mm_types.h> 15 #include <asm/ptrace.h> 16 17 /* 18 * Types defining task->signal and task->sighand and APIs using them: 19 */ 20 21 struct sighand_struct { 22 spinlock_t siglock; 23 refcount_t count; 24 wait_queue_head_t signalfd_wqh; 25 struct k_sigaction action[_NSIG]; 26 }; 27 28 /* 29 * Per-process accounting stats: 30 */ 31 struct pacct_struct { 32 int ac_flag; 33 long ac_exitcode; 34 unsigned long ac_mem; 35 u64 ac_utime, ac_stime; 36 unsigned long ac_minflt, ac_majflt; 37 }; 38 39 struct cpu_itimer { 40 u64 expires; 41 u64 incr; 42 }; 43 44 /* 45 * This is the atomic variant of task_cputime, which can be used for 46 * storing and updating task_cputime statistics without locking. 47 */ 48 struct task_cputime_atomic { 49 atomic64_t utime; 50 atomic64_t stime; 51 atomic64_t sum_exec_runtime; 52 }; 53 54 #define INIT_CPUTIME_ATOMIC \ 55 (struct task_cputime_atomic) { \ 56 .utime = ATOMIC64_INIT(0), \ 57 .stime = ATOMIC64_INIT(0), \ 58 .sum_exec_runtime = ATOMIC64_INIT(0), \ 59 } 60 /** 61 * struct thread_group_cputimer - thread group interval timer counts 62 * @cputime_atomic: atomic thread group interval timers. 63 * 64 * This structure contains the version of task_cputime, above, that is 65 * used for thread group CPU timer calculations. 66 */ 67 struct thread_group_cputimer { 68 struct task_cputime_atomic cputime_atomic; 69 }; 70 71 struct multiprocess_signals { 72 sigset_t signal; 73 struct hlist_node node; 74 }; 75 76 struct core_thread { 77 struct task_struct *task; 78 struct core_thread *next; 79 }; 80 81 struct core_state { 82 atomic_t nr_threads; 83 struct core_thread dumper; 84 struct completion startup; 85 }; 86 87 /* 88 * NOTE! "signal_struct" does not have its own 89 * locking, because a shared signal_struct always 90 * implies a shared sighand_struct, so locking 91 * sighand_struct is always a proper superset of 92 * the locking of signal_struct. 93 */ 94 struct signal_struct { 95 refcount_t sigcnt; 96 atomic_t live; 97 int nr_threads; 98 int quick_threads; 99 struct list_head thread_head; 100 101 wait_queue_head_t wait_chldexit; /* for wait4() */ 102 103 /* current thread group signal load-balancing target: */ 104 struct task_struct *curr_target; 105 106 /* shared signal handling: */ 107 struct sigpending shared_pending; 108 109 /* For collecting multiprocess signals during fork */ 110 struct hlist_head multiprocess; 111 112 /* thread group exit support */ 113 int group_exit_code; 114 /* notify group_exec_task when notify_count is less or equal to 0 */ 115 int notify_count; 116 struct task_struct *group_exec_task; 117 118 /* thread group stop support, overloads group_exit_code too */ 119 int group_stop_count; 120 unsigned int flags; /* see SIGNAL_* flags below */ 121 122 struct core_state *core_state; /* coredumping support */ 123 124 /* 125 * PR_SET_CHILD_SUBREAPER marks a process, like a service 126 * manager, to re-parent orphan (double-forking) child processes 127 * to this process instead of 'init'. The service manager is 128 * able to receive SIGCHLD signals and is able to investigate 129 * the process until it calls wait(). All children of this 130 * process will inherit a flag if they should look for a 131 * child_subreaper process at exit. 132 */ 133 unsigned int is_child_subreaper:1; 134 unsigned int has_child_subreaper:1; 135 136 #ifdef CONFIG_POSIX_TIMERS 137 138 /* POSIX.1b Interval Timers */ 139 unsigned int timer_create_restore_ids:1; 140 atomic_t next_posix_timer_id; 141 struct hlist_head posix_timers; 142 struct hlist_head ignored_posix_timers; 143 144 /* ITIMER_REAL timer for the process */ 145 struct hrtimer real_timer; 146 ktime_t it_real_incr; 147 148 /* 149 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use 150 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these 151 * values are defined to 0 and 1 respectively 152 */ 153 struct cpu_itimer it[2]; 154 155 /* 156 * Thread group totals for process CPU timers. 157 * See thread_group_cputimer(), et al, for details. 158 */ 159 struct thread_group_cputimer cputimer; 160 161 #endif 162 /* Empty if CONFIG_POSIX_TIMERS=n */ 163 struct posix_cputimers posix_cputimers; 164 165 /* PID/PID hash table linkage. */ 166 struct pid *pids[PIDTYPE_MAX]; 167 168 #ifdef CONFIG_NO_HZ_FULL 169 atomic_t tick_dep_mask; 170 #endif 171 172 struct pid *tty_old_pgrp; 173 174 /* boolean value for session group leader */ 175 int leader; 176 177 struct tty_struct *tty; /* NULL if no tty */ 178 179 #ifdef CONFIG_SCHED_AUTOGROUP 180 struct autogroup *autogroup; 181 #endif 182 /* 183 * Cumulative resource counters for dead threads in the group, 184 * and for reaped dead child processes forked by this group. 185 * Live threads maintain their own counters and add to these 186 * in __exit_signal, except for the group leader. 187 */ 188 seqlock_t stats_lock; 189 u64 utime, stime, cutime, cstime; 190 u64 gtime; 191 u64 cgtime; 192 struct prev_cputime prev_cputime; 193 unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw; 194 unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt; 195 unsigned long inblock, oublock, cinblock, coublock; 196 unsigned long maxrss, cmaxrss; 197 struct task_io_accounting ioac; 198 199 /* 200 * Cumulative ns of schedule CPU time fo dead threads in the 201 * group, not including a zombie group leader, (This only differs 202 * from jiffies_to_ns(utime + stime) if sched_clock uses something 203 * other than jiffies.) 204 */ 205 unsigned long long sum_sched_runtime; 206 207 /* 208 * We don't bother to synchronize most readers of this at all, 209 * because there is no reader checking a limit that actually needs 210 * to get both rlim_cur and rlim_max atomically, and either one 211 * alone is a single word that can safely be read normally. 212 * getrlimit/setrlimit use task_lock(current->group_leader) to 213 * protect this instead of the siglock, because they really 214 * have no need to disable irqs. 215 */ 216 struct rlimit rlim[RLIM_NLIMITS]; 217 218 #ifdef CONFIG_BSD_PROCESS_ACCT 219 struct pacct_struct pacct; /* per-process accounting information */ 220 #endif 221 #ifdef CONFIG_TASKSTATS 222 struct taskstats *stats; 223 #endif 224 #ifdef CONFIG_AUDIT 225 unsigned audit_tty; 226 struct tty_audit_buf *tty_audit_buf; 227 #endif 228 229 /* 230 * Thread is the potential origin of an oom condition; kill first on 231 * oom 232 */ 233 bool oom_flag_origin; 234 short oom_score_adj; /* OOM kill score adjustment */ 235 short oom_score_adj_min; /* OOM kill score adjustment min value. 236 * Only settable by CAP_SYS_RESOURCE. */ 237 struct mm_struct *oom_mm; /* recorded mm when the thread group got 238 * killed by the oom killer */ 239 240 struct mutex cred_guard_mutex; /* guard against foreign influences on 241 * credential calculations 242 * (notably. ptrace) 243 * Deprecated do not use in new code. 244 * Use exec_update_lock instead. 245 */ 246 struct rw_semaphore exec_update_lock; /* Held while task_struct is 247 * being updated during exec, 248 * and may have inconsistent 249 * permissions. 250 */ 251 } __randomize_layout; 252 253 /* 254 * Bits in flags field of signal_struct. 255 */ 256 #define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */ 257 #define SIGNAL_STOP_CONTINUED 0x00000002 /* SIGCONT since WCONTINUED reap */ 258 #define SIGNAL_GROUP_EXIT 0x00000004 /* group exit in progress */ 259 /* 260 * Pending notifications to parent. 261 */ 262 #define SIGNAL_CLD_STOPPED 0x00000010 263 #define SIGNAL_CLD_CONTINUED 0x00000020 264 #define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED) 265 266 #define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */ 267 268 #define SIGNAL_STOP_MASK (SIGNAL_CLD_MASK | SIGNAL_STOP_STOPPED | \ 269 SIGNAL_STOP_CONTINUED) 270 271 static inline void signal_set_stop_flags(struct signal_struct *sig, 272 unsigned int flags) 273 { 274 WARN_ON(sig->flags & SIGNAL_GROUP_EXIT); 275 sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags; 276 } 277 278 extern void flush_signals(struct task_struct *); 279 extern void ignore_signals(struct task_struct *); 280 extern void flush_signal_handlers(struct task_struct *, int force_default); 281 extern int dequeue_signal(sigset_t *mask, kernel_siginfo_t *info, enum pid_type *type); 282 283 static inline int kernel_dequeue_signal(void) 284 { 285 struct task_struct *task = current; 286 kernel_siginfo_t __info; 287 enum pid_type __type; 288 int ret; 289 290 spin_lock_irq(&task->sighand->siglock); 291 ret = dequeue_signal(&task->blocked, &__info, &__type); 292 spin_unlock_irq(&task->sighand->siglock); 293 294 return ret; 295 } 296 297 static inline void kernel_signal_stop(void) 298 { 299 spin_lock_irq(¤t->sighand->siglock); 300 if (current->jobctl & JOBCTL_STOP_DEQUEUED) { 301 current->jobctl |= JOBCTL_STOPPED; 302 set_special_state(TASK_STOPPED); 303 } 304 spin_unlock_irq(¤t->sighand->siglock); 305 306 schedule(); 307 } 308 309 int force_sig_fault_to_task(int sig, int code, void __user *addr, 310 struct task_struct *t); 311 int force_sig_fault(int sig, int code, void __user *addr); 312 int send_sig_fault(int sig, int code, void __user *addr, struct task_struct *t); 313 314 int force_sig_mceerr(int code, void __user *, short); 315 int send_sig_mceerr(int code, void __user *, short, struct task_struct *); 316 317 int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper); 318 int force_sig_pkuerr(void __user *addr, u32 pkey); 319 int send_sig_perf(void __user *addr, u32 type, u64 sig_data); 320 321 int force_sig_ptrace_errno_trap(int errno, void __user *addr); 322 int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno); 323 int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno, 324 struct task_struct *t); 325 int force_sig_seccomp(int syscall, int reason, bool force_coredump); 326 327 extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *); 328 extern void force_sigsegv(int sig); 329 extern int force_sig_info(struct kernel_siginfo *); 330 extern int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp); 331 extern int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid); 332 extern int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, struct pid *, 333 const struct cred *); 334 extern int kill_pgrp(struct pid *pid, int sig, int priv); 335 extern int kill_pid(struct pid *pid, int sig, int priv); 336 extern __must_check bool do_notify_parent(struct task_struct *, int); 337 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent); 338 extern void force_sig(int); 339 extern void force_fatal_sig(int); 340 extern void force_exit_sig(int); 341 extern int send_sig(int, struct task_struct *, int); 342 extern int zap_other_threads(struct task_struct *p); 343 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *); 344 345 static inline void clear_notify_signal(void) 346 { 347 clear_thread_flag(TIF_NOTIFY_SIGNAL); 348 smp_mb__after_atomic(); 349 } 350 351 /* 352 * Returns 'true' if kick_process() is needed to force a transition from 353 * user -> kernel to guarantee expedient run of TWA_SIGNAL based task_work. 354 */ 355 static inline bool __set_notify_signal(struct task_struct *task) 356 { 357 return !test_and_set_tsk_thread_flag(task, TIF_NOTIFY_SIGNAL) && 358 !wake_up_state(task, TASK_INTERRUPTIBLE); 359 } 360 361 /* 362 * Called to break out of interruptible wait loops, and enter the 363 * exit_to_user_mode_loop(). 364 */ 365 static inline void set_notify_signal(struct task_struct *task) 366 { 367 if (__set_notify_signal(task)) 368 kick_process(task); 369 } 370 371 static inline int restart_syscall(void) 372 { 373 set_tsk_thread_flag(current, TIF_SIGPENDING); 374 return -ERESTARTNOINTR; 375 } 376 377 static inline int task_sigpending(struct task_struct *p) 378 { 379 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING)); 380 } 381 382 static inline int signal_pending(struct task_struct *p) 383 { 384 /* 385 * TIF_NOTIFY_SIGNAL isn't really a signal, but it requires the same 386 * behavior in terms of ensuring that we break out of wait loops 387 * so that notify signal callbacks can be processed. 388 */ 389 if (unlikely(test_tsk_thread_flag(p, TIF_NOTIFY_SIGNAL))) 390 return 1; 391 return task_sigpending(p); 392 } 393 394 static inline int __fatal_signal_pending(struct task_struct *p) 395 { 396 return unlikely(sigismember(&p->pending.signal, SIGKILL)); 397 } 398 399 static inline int fatal_signal_pending(struct task_struct *p) 400 { 401 return task_sigpending(p) && __fatal_signal_pending(p); 402 } 403 404 static inline int signal_pending_state(unsigned int state, struct task_struct *p) 405 { 406 if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL))) 407 return 0; 408 if (!signal_pending(p)) 409 return 0; 410 411 return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p); 412 } 413 414 /* 415 * This should only be used in fault handlers to decide whether we 416 * should stop the current fault routine to handle the signals 417 * instead, especially with the case where we've got interrupted with 418 * a VM_FAULT_RETRY. 419 */ 420 static inline bool fault_signal_pending(vm_fault_t fault_flags, 421 struct pt_regs *regs) 422 { 423 return unlikely((fault_flags & VM_FAULT_RETRY) && 424 (fatal_signal_pending(current) || 425 (user_mode(regs) && signal_pending(current)))); 426 } 427 428 /* 429 * Reevaluate whether the task has signals pending delivery. 430 * Wake the task if so. 431 * This is required every time the blocked sigset_t changes. 432 * callers must hold sighand->siglock. 433 */ 434 extern void recalc_sigpending(void); 435 extern void calculate_sigpending(void); 436 437 extern void signal_wake_up_state(struct task_struct *t, unsigned int state); 438 439 static inline void signal_wake_up(struct task_struct *t, bool fatal) 440 { 441 unsigned int state = 0; 442 if (fatal && !(t->jobctl & JOBCTL_PTRACE_FROZEN)) { 443 t->jobctl &= ~(JOBCTL_STOPPED | JOBCTL_TRACED); 444 state = TASK_WAKEKILL | __TASK_TRACED; 445 } 446 signal_wake_up_state(t, state); 447 } 448 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume) 449 { 450 unsigned int state = 0; 451 if (resume) { 452 t->jobctl &= ~JOBCTL_TRACED; 453 state = __TASK_TRACED; 454 } 455 signal_wake_up_state(t, state); 456 } 457 458 void task_join_group_stop(struct task_struct *task); 459 460 #ifdef TIF_RESTORE_SIGMASK 461 /* 462 * Legacy restore_sigmask accessors. These are inefficient on 463 * SMP architectures because they require atomic operations. 464 */ 465 466 /** 467 * set_restore_sigmask() - make sure saved_sigmask processing gets done 468 * 469 * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code 470 * will run before returning to user mode, to process the flag. For 471 * all callers, TIF_SIGPENDING is already set or it's no harm to set 472 * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the 473 * arch code will notice on return to user mode, in case those bits 474 * are scarce. We set TIF_SIGPENDING here to ensure that the arch 475 * signal code always gets run when TIF_RESTORE_SIGMASK is set. 476 */ 477 static inline void set_restore_sigmask(void) 478 { 479 set_thread_flag(TIF_RESTORE_SIGMASK); 480 } 481 482 static inline void clear_tsk_restore_sigmask(struct task_struct *task) 483 { 484 clear_tsk_thread_flag(task, TIF_RESTORE_SIGMASK); 485 } 486 487 static inline void clear_restore_sigmask(void) 488 { 489 clear_thread_flag(TIF_RESTORE_SIGMASK); 490 } 491 static inline bool test_tsk_restore_sigmask(struct task_struct *task) 492 { 493 return test_tsk_thread_flag(task, TIF_RESTORE_SIGMASK); 494 } 495 static inline bool test_restore_sigmask(void) 496 { 497 return test_thread_flag(TIF_RESTORE_SIGMASK); 498 } 499 static inline bool test_and_clear_restore_sigmask(void) 500 { 501 return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK); 502 } 503 504 #else /* TIF_RESTORE_SIGMASK */ 505 506 /* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */ 507 static inline void set_restore_sigmask(void) 508 { 509 current->restore_sigmask = true; 510 } 511 static inline void clear_tsk_restore_sigmask(struct task_struct *task) 512 { 513 task->restore_sigmask = false; 514 } 515 static inline void clear_restore_sigmask(void) 516 { 517 current->restore_sigmask = false; 518 } 519 static inline bool test_restore_sigmask(void) 520 { 521 return current->restore_sigmask; 522 } 523 static inline bool test_tsk_restore_sigmask(struct task_struct *task) 524 { 525 return task->restore_sigmask; 526 } 527 static inline bool test_and_clear_restore_sigmask(void) 528 { 529 if (!current->restore_sigmask) 530 return false; 531 current->restore_sigmask = false; 532 return true; 533 } 534 #endif 535 536 static inline void restore_saved_sigmask(void) 537 { 538 if (test_and_clear_restore_sigmask()) 539 __set_current_blocked(¤t->saved_sigmask); 540 } 541 542 extern int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize); 543 544 static inline void restore_saved_sigmask_unless(bool interrupted) 545 { 546 if (interrupted) 547 WARN_ON(!signal_pending(current)); 548 else 549 restore_saved_sigmask(); 550 } 551 552 static inline sigset_t *sigmask_to_save(void) 553 { 554 sigset_t *res = ¤t->blocked; 555 if (unlikely(test_restore_sigmask())) 556 res = ¤t->saved_sigmask; 557 return res; 558 } 559 560 static inline int kill_cad_pid(int sig, int priv) 561 { 562 return kill_pid(cad_pid, sig, priv); 563 } 564 565 /* These can be the second arg to send_sig_info/send_group_sig_info. */ 566 #define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0) 567 #define SEND_SIG_PRIV ((struct kernel_siginfo *) 1) 568 569 static inline int __on_sig_stack(unsigned long sp) 570 { 571 #ifdef CONFIG_STACK_GROWSUP 572 return sp >= current->sas_ss_sp && 573 sp - current->sas_ss_sp < current->sas_ss_size; 574 #else 575 return sp > current->sas_ss_sp && 576 sp - current->sas_ss_sp <= current->sas_ss_size; 577 #endif 578 } 579 580 /* 581 * True if we are on the alternate signal stack. 582 */ 583 static inline int on_sig_stack(unsigned long sp) 584 { 585 /* 586 * If the signal stack is SS_AUTODISARM then, by construction, we 587 * can't be on the signal stack unless user code deliberately set 588 * SS_AUTODISARM when we were already on it. 589 * 590 * This improves reliability: if user state gets corrupted such that 591 * the stack pointer points very close to the end of the signal stack, 592 * then this check will enable the signal to be handled anyway. 593 */ 594 if (current->sas_ss_flags & SS_AUTODISARM) 595 return 0; 596 597 return __on_sig_stack(sp); 598 } 599 600 static inline int sas_ss_flags(unsigned long sp) 601 { 602 if (!current->sas_ss_size) 603 return SS_DISABLE; 604 605 return on_sig_stack(sp) ? SS_ONSTACK : 0; 606 } 607 608 static inline void sas_ss_reset(struct task_struct *p) 609 { 610 p->sas_ss_sp = 0; 611 p->sas_ss_size = 0; 612 p->sas_ss_flags = SS_DISABLE; 613 } 614 615 static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig) 616 { 617 if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp)) 618 #ifdef CONFIG_STACK_GROWSUP 619 return current->sas_ss_sp; 620 #else 621 return current->sas_ss_sp + current->sas_ss_size; 622 #endif 623 return sp; 624 } 625 626 extern void __cleanup_sighand(struct sighand_struct *); 627 extern void flush_itimer_signals(void); 628 629 #define tasklist_empty() \ 630 list_empty(&init_task.tasks) 631 632 #define next_task(p) \ 633 list_entry_rcu((p)->tasks.next, struct task_struct, tasks) 634 635 #define for_each_process(p) \ 636 for (p = &init_task ; (p = next_task(p)) != &init_task ; ) 637 638 extern bool current_is_single_threaded(void); 639 640 /* 641 * Without tasklist/siglock it is only rcu-safe if g can't exit/exec, 642 * otherwise next_thread(t) will never reach g after list_del_rcu(g). 643 */ 644 #define while_each_thread(g, t) \ 645 while ((t = next_thread(t)) != g) 646 647 #define for_other_threads(p, t) \ 648 for (t = p; (t = next_thread(t)) != p; ) 649 650 #define __for_each_thread(signal, t) \ 651 list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node, \ 652 lockdep_is_held(&tasklist_lock)) 653 654 #define for_each_thread(p, t) \ 655 __for_each_thread((p)->signal, t) 656 657 /* Careful: this is a double loop, 'break' won't work as expected. */ 658 #define for_each_process_thread(p, t) \ 659 for_each_process(p) for_each_thread(p, t) 660 661 typedef int (*proc_visitor)(struct task_struct *p, void *data); 662 void walk_process_tree(struct task_struct *top, proc_visitor, void *); 663 664 static inline 665 struct pid *task_pid_type(struct task_struct *task, enum pid_type type) 666 { 667 struct pid *pid; 668 if (type == PIDTYPE_PID) 669 pid = task_pid(task); 670 else 671 pid = task->signal->pids[type]; 672 return pid; 673 } 674 675 static inline struct pid *task_tgid(struct task_struct *task) 676 { 677 return task->signal->pids[PIDTYPE_TGID]; 678 } 679 680 /* 681 * Without tasklist or RCU lock it is not safe to dereference 682 * the result of task_pgrp/task_session even if task == current, 683 * we can race with another thread doing sys_setsid/sys_setpgid. 684 */ 685 static inline struct pid *task_pgrp(struct task_struct *task) 686 { 687 return task->signal->pids[PIDTYPE_PGID]; 688 } 689 690 static inline struct pid *task_session(struct task_struct *task) 691 { 692 return task->signal->pids[PIDTYPE_SID]; 693 } 694 695 static inline int get_nr_threads(struct task_struct *task) 696 { 697 return task->signal->nr_threads; 698 } 699 700 static inline bool thread_group_leader(struct task_struct *p) 701 { 702 return p->exit_signal >= 0; 703 } 704 705 static inline 706 bool same_thread_group(struct task_struct *p1, struct task_struct *p2) 707 { 708 return p1->signal == p2->signal; 709 } 710 711 /* 712 * returns NULL if p is the last thread in the thread group 713 */ 714 static inline struct task_struct *__next_thread(struct task_struct *p) 715 { 716 return list_next_or_null_rcu(&p->signal->thread_head, 717 &p->thread_node, 718 struct task_struct, 719 thread_node); 720 } 721 722 static inline struct task_struct *next_thread(struct task_struct *p) 723 { 724 return __next_thread(p) ?: p->group_leader; 725 } 726 727 static inline int thread_group_empty(struct task_struct *p) 728 { 729 return thread_group_leader(p) && 730 list_is_last(&p->thread_node, &p->signal->thread_head); 731 } 732 733 #define delay_group_leader(p) \ 734 (thread_group_leader(p) && !thread_group_empty(p)) 735 736 extern struct sighand_struct *__lock_task_sighand(struct task_struct *task, 737 unsigned long *flags); 738 739 static 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 } 748 749 static 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 756 extern void lockdep_assert_task_sighand_held(struct task_struct *task); 757 #else 758 static inline void lockdep_assert_task_sighand_held(struct task_struct *task) { } 759 #endif 760 761 static 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 } 766 767 static 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 } 772 773 static inline unsigned long rlimit(unsigned int limit) 774 { 775 return task_rlimit(current, limit); 776 } 777 778 static inline unsigned long rlimit_max(unsigned int limit) 779 { 780 return task_rlimit_max(current, limit); 781 } 782 783 #endif /* _LINUX_SCHED_SIGNAL_H */ 784