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 20 struct 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 */ 30 struct 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 38 struct 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 */ 47 struct 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 */ 66 struct thread_group_cputimer { 67 struct task_cputime_atomic cputime_atomic; 68 }; 69 70 struct multiprocess_signals { 71 sigset_t signal; 72 struct hlist_node node; 73 }; 74 75 struct core_thread { 76 struct task_struct *task; 77 struct core_thread *next; 78 }; 79 80 struct 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 */ 93 struct 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) 266 267 static 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 } 273 274 extern void flush_signals(struct task_struct *); 275 extern void ignore_signals(struct task_struct *); 276 extern void flush_signal_handlers(struct task_struct *, int force_default); 277 extern int dequeue_signal(struct task_struct *task, sigset_t *mask, 278 kernel_siginfo_t *info, enum pid_type *type); 279 280 static 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 } 293 294 static 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 310 311 int 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); 314 int force_sig_fault(int sig, int code, void __user *addr 315 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)); 316 int 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); 319 320 int force_sig_mceerr(int code, void __user *, short); 321 int send_sig_mceerr(int code, void __user *, short, struct task_struct *); 322 323 int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper); 324 int force_sig_pkuerr(void __user *addr, u32 pkey); 325 int send_sig_perf(void __user *addr, u32 type, u64 sig_data); 326 327 int force_sig_ptrace_errno_trap(int errno, void __user *addr); 328 int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno); 329 int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno, 330 struct task_struct *t); 331 int force_sig_seccomp(int syscall, int reason, bool force_coredump); 332 333 extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *); 334 extern void force_sigsegv(int sig); 335 extern int force_sig_info(struct kernel_siginfo *); 336 extern int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp); 337 extern int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid); 338 extern int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, struct pid *, 339 const struct cred *); 340 extern int kill_pgrp(struct pid *pid, int sig, int priv); 341 extern int kill_pid(struct pid *pid, int sig, int priv); 342 extern __must_check bool do_notify_parent(struct task_struct *, int); 343 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent); 344 extern void force_sig(int); 345 extern void force_fatal_sig(int); 346 extern void force_exit_sig(int); 347 extern int send_sig(int, struct task_struct *, int); 348 extern int zap_other_threads(struct task_struct *p); 349 extern struct sigqueue *sigqueue_alloc(void); 350 extern void sigqueue_free(struct sigqueue *); 351 extern int send_sigqueue(struct sigqueue *, struct pid *, enum pid_type); 352 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *); 353 354 static 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 */ 364 static 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 */ 374 static inline void set_notify_signal(struct task_struct *task) 375 { 376 if (__set_notify_signal(task)) 377 kick_process(task); 378 } 379 380 static inline int restart_syscall(void) 381 { 382 set_tsk_thread_flag(current, TIF_SIGPENDING); 383 return -ERESTARTNOINTR; 384 } 385 386 static inline int task_sigpending(struct task_struct *p) 387 { 388 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING)); 389 } 390 391 static 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 } 402 403 static inline int __fatal_signal_pending(struct task_struct *p) 404 { 405 return unlikely(sigismember(&p->pending.signal, SIGKILL)); 406 } 407 408 static inline int fatal_signal_pending(struct task_struct *p) 409 { 410 return task_sigpending(p) && __fatal_signal_pending(p); 411 } 412 413 static 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 */ 429 static 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 */ 443 extern void recalc_sigpending_and_wake(struct task_struct *t); 444 extern void recalc_sigpending(void); 445 extern void calculate_sigpending(void); 446 447 extern void signal_wake_up_state(struct task_struct *t, unsigned int state); 448 449 static 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 } 458 static 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 } 467 468 void 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 */ 487 static inline void set_restore_sigmask(void) 488 { 489 set_thread_flag(TIF_RESTORE_SIGMASK); 490 } 491 492 static inline void clear_tsk_restore_sigmask(struct task_struct *task) 493 { 494 clear_tsk_thread_flag(task, TIF_RESTORE_SIGMASK); 495 } 496 497 static inline void clear_restore_sigmask(void) 498 { 499 clear_thread_flag(TIF_RESTORE_SIGMASK); 500 } 501 static inline bool test_tsk_restore_sigmask(struct task_struct *task) 502 { 503 return test_tsk_thread_flag(task, TIF_RESTORE_SIGMASK); 504 } 505 static inline bool test_restore_sigmask(void) 506 { 507 return test_thread_flag(TIF_RESTORE_SIGMASK); 508 } 509 static 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. */ 517 static inline void set_restore_sigmask(void) 518 { 519 current->restore_sigmask = true; 520 } 521 static inline void clear_tsk_restore_sigmask(struct task_struct *task) 522 { 523 task->restore_sigmask = false; 524 } 525 static inline void clear_restore_sigmask(void) 526 { 527 current->restore_sigmask = false; 528 } 529 static inline bool test_restore_sigmask(void) 530 { 531 return current->restore_sigmask; 532 } 533 static inline bool test_tsk_restore_sigmask(struct task_struct *task) 534 { 535 return task->restore_sigmask; 536 } 537 static 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 545 546 static inline void restore_saved_sigmask(void) 547 { 548 if (test_and_clear_restore_sigmask()) 549 __set_current_blocked(¤t->saved_sigmask); 550 } 551 552 extern int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize); 553 554 static 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 } 561 562 static 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 } 569 570 static 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) 578 579 static 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 */ 593 static 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 } 609 610 static 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 } 617 618 static 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 } 624 625 static 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 } 635 636 extern void __cleanup_sighand(struct sighand_struct *); 637 extern 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 ; ) 647 648 extern 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) 669 670 typedef int (*proc_visitor)(struct task_struct *p, void *data); 671 void walk_process_tree(struct task_struct *top, proc_visitor, void *); 672 673 static inline 674 struct 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 } 683 684 static 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 */ 694 static inline struct pid *task_pgrp(struct task_struct *task) 695 { 696 return task->signal->pids[PIDTYPE_PGID]; 697 } 698 699 static inline struct pid *task_session(struct task_struct *task) 700 { 701 return task->signal->pids[PIDTYPE_SID]; 702 } 703 704 static inline int get_nr_threads(struct task_struct *task) 705 { 706 return task->signal->nr_threads; 707 } 708 709 static inline bool thread_group_leader(struct task_struct *p) 710 { 711 return p->exit_signal >= 0; 712 } 713 714 static inline 715 bool same_thread_group(struct task_struct *p1, struct task_struct *p2) 716 { 717 return p1->signal == p2->signal; 718 } 719 720 static 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 } 725 726 static 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)) 733 734 extern bool thread_group_exited(struct pid *pid); 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