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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 21struct 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 */ 31struct 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 39struct 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 */ 48struct 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 */ 67struct thread_group_cputimer { 68 struct task_cputime_atomic cputime_atomic; 69}; 70 71struct multiprocess_signals { 72 sigset_t signal; 73 struct hlist_node node; 74}; 75 76struct core_thread { 77 struct task_struct *task; 78 struct core_thread *next; 79}; 80 81struct 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 */ 94struct 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#ifdef CONFIG_CGROUPS 230 struct rw_semaphore cgroup_threadgroup_rwsem; 231#endif 232 233 /* 234 * Thread is the potential origin of an oom condition; kill first on 235 * oom 236 */ 237 bool oom_flag_origin; 238 short oom_score_adj; /* OOM kill score adjustment */ 239 short oom_score_adj_min; /* OOM kill score adjustment min value. 240 * Only settable by CAP_SYS_RESOURCE. */ 241 struct mm_struct *oom_mm; /* recorded mm when the thread group got 242 * killed by the oom killer */ 243 244 struct mutex cred_guard_mutex; /* guard against foreign influences on 245 * credential calculations 246 * (notably. ptrace) 247 * Deprecated do not use in new code. 248 * Use exec_update_lock instead. 249 */ 250 struct rw_semaphore exec_update_lock; /* Held while task_struct is 251 * being updated during exec, 252 * and may have inconsistent 253 * permissions. 254 */ 255} __randomize_layout; 256 257/* 258 * Bits in flags field of signal_struct. 259 */ 260#define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */ 261#define SIGNAL_STOP_CONTINUED 0x00000002 /* SIGCONT since WCONTINUED reap */ 262#define SIGNAL_GROUP_EXIT 0x00000004 /* group exit in progress */ 263/* 264 * Pending notifications to parent. 265 */ 266#define SIGNAL_CLD_STOPPED 0x00000010 267#define SIGNAL_CLD_CONTINUED 0x00000020 268#define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED) 269 270#define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */ 271 272#define SIGNAL_STOP_MASK (SIGNAL_CLD_MASK | SIGNAL_STOP_STOPPED | \ 273 SIGNAL_STOP_CONTINUED) 274 275static inline void signal_set_stop_flags(struct signal_struct *sig, 276 unsigned int flags) 277{ 278 WARN_ON(sig->flags & SIGNAL_GROUP_EXIT); 279 sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags; 280} 281 282extern void flush_signals(struct task_struct *); 283extern void ignore_signals(struct task_struct *); 284extern void flush_signal_handlers(struct task_struct *, int force_default); 285extern int dequeue_signal(sigset_t *mask, kernel_siginfo_t *info, enum pid_type *type); 286 287static inline int kernel_dequeue_signal(void) 288{ 289 struct task_struct *task = current; 290 kernel_siginfo_t __info; 291 enum pid_type __type; 292 int ret; 293 294 spin_lock_irq(&task->sighand->siglock); 295 ret = dequeue_signal(&task->blocked, &__info, &__type); 296 spin_unlock_irq(&task->sighand->siglock); 297 298 return ret; 299} 300 301static inline void kernel_signal_stop(void) 302{ 303 spin_lock_irq(&current->sighand->siglock); 304 if (current->jobctl & JOBCTL_STOP_DEQUEUED) { 305 current->jobctl |= JOBCTL_STOPPED; 306 set_special_state(TASK_STOPPED); 307 } 308 spin_unlock_irq(&current->sighand->siglock); 309 310 schedule(); 311} 312 313int force_sig_fault_to_task(int sig, int code, void __user *addr, 314 struct task_struct *t); 315int force_sig_fault(int sig, int code, void __user *addr); 316int send_sig_fault(int sig, int code, void __user *addr, struct task_struct *t); 317 318int force_sig_mceerr(int code, void __user *, short); 319int send_sig_mceerr(int code, void __user *, short, struct task_struct *); 320 321int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper); 322int force_sig_pkuerr(void __user *addr, u32 pkey); 323int send_sig_perf(void __user *addr, u32 type, u64 sig_data); 324 325int force_sig_ptrace_errno_trap(int errno, void __user *addr); 326int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno); 327int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno, 328 struct task_struct *t); 329int force_sig_seccomp(int syscall, int reason, bool force_coredump); 330 331extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *); 332extern void force_sigsegv(int sig); 333extern int force_sig_info(struct kernel_siginfo *); 334extern int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp); 335extern int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid); 336extern int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, struct pid *, 337 const struct cred *); 338extern int kill_pgrp(struct pid *pid, int sig, int priv); 339extern int kill_pid(struct pid *pid, int sig, int priv); 340extern __must_check bool do_notify_parent(struct task_struct *, int); 341extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent); 342extern void force_sig(int); 343extern void force_fatal_sig(int); 344extern void force_exit_sig(int); 345extern int send_sig(int, struct task_struct *, int); 346extern int zap_other_threads(struct task_struct *p); 347extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *); 348 349static inline void clear_notify_signal(void) 350{ 351 clear_thread_flag(TIF_NOTIFY_SIGNAL); 352 smp_mb__after_atomic(); 353} 354 355/* 356 * Returns 'true' if kick_process() is needed to force a transition from 357 * user -> kernel to guarantee expedient run of TWA_SIGNAL based task_work. 358 */ 359static inline bool __set_notify_signal(struct task_struct *task) 360{ 361 return !test_and_set_tsk_thread_flag(task, TIF_NOTIFY_SIGNAL) && 362 !wake_up_state(task, TASK_INTERRUPTIBLE); 363} 364 365/* 366 * Called to break out of interruptible wait loops, and enter the 367 * exit_to_user_mode_loop(). 368 */ 369static inline void set_notify_signal(struct task_struct *task) 370{ 371 if (__set_notify_signal(task)) 372 kick_process(task); 373} 374 375static inline int restart_syscall(void) 376{ 377 set_tsk_thread_flag(current, TIF_SIGPENDING); 378 return -ERESTARTNOINTR; 379} 380 381static inline int task_sigpending(struct task_struct *p) 382{ 383 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING)); 384} 385 386static inline int signal_pending(struct task_struct *p) 387{ 388 /* 389 * TIF_NOTIFY_SIGNAL isn't really a signal, but it requires the same 390 * behavior in terms of ensuring that we break out of wait loops 391 * so that notify signal callbacks can be processed. 392 */ 393 if (unlikely(test_tsk_thread_flag(p, TIF_NOTIFY_SIGNAL))) 394 return 1; 395 return task_sigpending(p); 396} 397 398static inline int __fatal_signal_pending(struct task_struct *p) 399{ 400 return unlikely(sigismember(&p->pending.signal, SIGKILL)); 401} 402 403static inline int fatal_signal_pending(struct task_struct *p) 404{ 405 return task_sigpending(p) && __fatal_signal_pending(p); 406} 407 408static inline int signal_pending_state(unsigned int state, struct task_struct *p) 409{ 410 if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL))) 411 return 0; 412 if (!signal_pending(p)) 413 return 0; 414 415 return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p); 416} 417 418/* 419 * This should only be used in fault handlers to decide whether we 420 * should stop the current fault routine to handle the signals 421 * instead, especially with the case where we've got interrupted with 422 * a VM_FAULT_RETRY. 423 */ 424static inline bool fault_signal_pending(vm_fault_t fault_flags, 425 struct pt_regs *regs) 426{ 427 return unlikely((fault_flags & VM_FAULT_RETRY) && 428 (fatal_signal_pending(current) || 429 (user_mode(regs) && signal_pending(current)))); 430} 431 432/* 433 * Reevaluate whether the task has signals pending delivery. 434 * Wake the task if so. 435 * This is required every time the blocked sigset_t changes. 436 * callers must hold sighand->siglock. 437 */ 438extern void recalc_sigpending(void); 439extern void calculate_sigpending(void); 440 441extern void signal_wake_up_state(struct task_struct *t, unsigned int state); 442 443static inline void signal_wake_up(struct task_struct *t, bool fatal) 444{ 445 unsigned int state = 0; 446 if (fatal && !(t->jobctl & JOBCTL_PTRACE_FROZEN)) { 447 t->jobctl &= ~(JOBCTL_STOPPED | JOBCTL_TRACED); 448 state = TASK_WAKEKILL | __TASK_TRACED; 449 } 450 signal_wake_up_state(t, state); 451} 452static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume) 453{ 454 unsigned int state = 0; 455 if (resume) { 456 t->jobctl &= ~JOBCTL_TRACED; 457 state = __TASK_TRACED; 458 } 459 signal_wake_up_state(t, state); 460} 461 462void task_join_group_stop(struct task_struct *task); 463 464#ifdef TIF_RESTORE_SIGMASK 465/* 466 * Legacy restore_sigmask accessors. These are inefficient on 467 * SMP architectures because they require atomic operations. 468 */ 469 470/** 471 * set_restore_sigmask() - make sure saved_sigmask processing gets done 472 * 473 * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code 474 * will run before returning to user mode, to process the flag. For 475 * all callers, TIF_SIGPENDING is already set or it's no harm to set 476 * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the 477 * arch code will notice on return to user mode, in case those bits 478 * are scarce. We set TIF_SIGPENDING here to ensure that the arch 479 * signal code always gets run when TIF_RESTORE_SIGMASK is set. 480 */ 481static inline void set_restore_sigmask(void) 482{ 483 set_thread_flag(TIF_RESTORE_SIGMASK); 484} 485 486static inline void clear_tsk_restore_sigmask(struct task_struct *task) 487{ 488 clear_tsk_thread_flag(task, TIF_RESTORE_SIGMASK); 489} 490 491static inline void clear_restore_sigmask(void) 492{ 493 clear_thread_flag(TIF_RESTORE_SIGMASK); 494} 495static inline bool test_tsk_restore_sigmask(struct task_struct *task) 496{ 497 return test_tsk_thread_flag(task, TIF_RESTORE_SIGMASK); 498} 499static inline bool test_restore_sigmask(void) 500{ 501 return test_thread_flag(TIF_RESTORE_SIGMASK); 502} 503static inline bool test_and_clear_restore_sigmask(void) 504{ 505 return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK); 506} 507 508#else /* TIF_RESTORE_SIGMASK */ 509 510/* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */ 511static inline void set_restore_sigmask(void) 512{ 513 current->restore_sigmask = true; 514} 515static inline void clear_tsk_restore_sigmask(struct task_struct *task) 516{ 517 task->restore_sigmask = false; 518} 519static inline void clear_restore_sigmask(void) 520{ 521 current->restore_sigmask = false; 522} 523static inline bool test_restore_sigmask(void) 524{ 525 return current->restore_sigmask; 526} 527static inline bool test_tsk_restore_sigmask(struct task_struct *task) 528{ 529 return task->restore_sigmask; 530} 531static inline bool test_and_clear_restore_sigmask(void) 532{ 533 if (!current->restore_sigmask) 534 return false; 535 current->restore_sigmask = false; 536 return true; 537} 538#endif 539 540static inline void restore_saved_sigmask(void) 541{ 542 if (test_and_clear_restore_sigmask()) 543 __set_current_blocked(&current->saved_sigmask); 544} 545 546extern int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize); 547 548static inline void restore_saved_sigmask_unless(bool interrupted) 549{ 550 if (interrupted) 551 WARN_ON(!signal_pending(current)); 552 else 553 restore_saved_sigmask(); 554} 555 556static inline sigset_t *sigmask_to_save(void) 557{ 558 sigset_t *res = &current->blocked; 559 if (unlikely(test_restore_sigmask())) 560 res = &current->saved_sigmask; 561 return res; 562} 563 564static inline int kill_cad_pid(int sig, int priv) 565{ 566 return kill_pid(cad_pid, sig, priv); 567} 568 569/* These can be the second arg to send_sig_info/send_group_sig_info. */ 570#define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0) 571#define SEND_SIG_PRIV ((struct kernel_siginfo *) 1) 572 573static inline int __on_sig_stack(unsigned long sp) 574{ 575#ifdef CONFIG_STACK_GROWSUP 576 return sp >= current->sas_ss_sp && 577 sp - current->sas_ss_sp < current->sas_ss_size; 578#else 579 return sp > current->sas_ss_sp && 580 sp - current->sas_ss_sp <= current->sas_ss_size; 581#endif 582} 583 584/* 585 * True if we are on the alternate signal stack. 586 */ 587static inline int on_sig_stack(unsigned long sp) 588{ 589 /* 590 * If the signal stack is SS_AUTODISARM then, by construction, we 591 * can't be on the signal stack unless user code deliberately set 592 * SS_AUTODISARM when we were already on it. 593 * 594 * This improves reliability: if user state gets corrupted such that 595 * the stack pointer points very close to the end of the signal stack, 596 * then this check will enable the signal to be handled anyway. 597 */ 598 if (current->sas_ss_flags & SS_AUTODISARM) 599 return 0; 600 601 return __on_sig_stack(sp); 602} 603 604static inline int sas_ss_flags(unsigned long sp) 605{ 606 if (!current->sas_ss_size) 607 return SS_DISABLE; 608 609 return on_sig_stack(sp) ? SS_ONSTACK : 0; 610} 611 612static inline void sas_ss_reset(struct task_struct *p) 613{ 614 p->sas_ss_sp = 0; 615 p->sas_ss_size = 0; 616 p->sas_ss_flags = SS_DISABLE; 617} 618 619static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig) 620{ 621 if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp)) 622#ifdef CONFIG_STACK_GROWSUP 623 return current->sas_ss_sp; 624#else 625 return current->sas_ss_sp + current->sas_ss_size; 626#endif 627 return sp; 628} 629 630extern void __cleanup_sighand(struct sighand_struct *); 631extern void flush_itimer_signals(void); 632 633#define tasklist_empty() \ 634 list_empty(&init_task.tasks) 635 636#define next_task(p) \ 637 list_entry_rcu((p)->tasks.next, struct task_struct, tasks) 638 639#define for_each_process(p) \ 640 for (p = &init_task ; (p = next_task(p)) != &init_task ; ) 641 642extern bool current_is_single_threaded(void); 643 644/* 645 * Without tasklist/siglock it is only rcu-safe if g can't exit/exec, 646 * otherwise next_thread(t) will never reach g after list_del_rcu(g). 647 */ 648#define while_each_thread(g, t) \ 649 while ((t = next_thread(t)) != g) 650 651#define for_other_threads(p, t) \ 652 for (t = p; (t = next_thread(t)) != p; ) 653 654#define __for_each_thread(signal, t) \ 655 list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node, \ 656 lockdep_is_held(&tasklist_lock)) 657 658#define for_each_thread(p, t) \ 659 __for_each_thread((p)->signal, t) 660 661/* Careful: this is a double loop, 'break' won't work as expected. */ 662#define for_each_process_thread(p, t) \ 663 for_each_process(p) for_each_thread(p, t) 664 665typedef int (*proc_visitor)(struct task_struct *p, void *data); 666void walk_process_tree(struct task_struct *top, proc_visitor, void *); 667 668static inline 669struct pid *task_pid_type(struct task_struct *task, enum pid_type type) 670{ 671 struct pid *pid; 672 if (type == PIDTYPE_PID) 673 pid = task_pid(task); 674 else 675 pid = task->signal->pids[type]; 676 return pid; 677} 678 679static inline struct pid *task_tgid(struct task_struct *task) 680{ 681 return task->signal->pids[PIDTYPE_TGID]; 682} 683 684/* 685 * Without tasklist or RCU lock it is not safe to dereference 686 * the result of task_pgrp/task_session even if task == current, 687 * we can race with another thread doing sys_setsid/sys_setpgid. 688 */ 689static inline struct pid *task_pgrp(struct task_struct *task) 690{ 691 return task->signal->pids[PIDTYPE_PGID]; 692} 693 694static inline struct pid *task_session(struct task_struct *task) 695{ 696 return task->signal->pids[PIDTYPE_SID]; 697} 698 699static inline int get_nr_threads(struct task_struct *task) 700{ 701 return task->signal->nr_threads; 702} 703 704static inline bool thread_group_leader(struct task_struct *p) 705{ 706 return p->exit_signal >= 0; 707} 708 709static inline 710bool same_thread_group(struct task_struct *p1, struct task_struct *p2) 711{ 712 return p1->signal == p2->signal; 713} 714 715/* 716 * returns NULL if p is the last thread in the thread group 717 */ 718static inline struct task_struct *__next_thread(struct task_struct *p) 719{ 720 return list_next_or_null_rcu(&p->signal->thread_head, 721 &p->thread_node, 722 struct task_struct, 723 thread_node); 724} 725 726static inline struct task_struct *next_thread(struct task_struct *p) 727{ 728 return __next_thread(p) ?: p->group_leader; 729} 730 731static inline int thread_group_empty(struct task_struct *p) 732{ 733 return thread_group_leader(p) && 734 list_is_last(&p->thread_node, &p->signal->thread_head); 735} 736 737#define delay_group_leader(p) \ 738 (thread_group_leader(p) && !thread_group_empty(p)) 739 740extern struct sighand_struct *__lock_task_sighand(struct task_struct *task, 741 unsigned long *flags); 742 743static inline struct sighand_struct *lock_task_sighand(struct task_struct *task, 744 unsigned long *flags) 745{ 746 struct sighand_struct *ret; 747 748 ret = __lock_task_sighand(task, flags); 749 (void)__cond_lock(&task->sighand->siglock, ret); 750 return ret; 751} 752 753static inline void unlock_task_sighand(struct task_struct *task, 754 unsigned long *flags) 755{ 756 spin_unlock_irqrestore(&task->sighand->siglock, *flags); 757} 758 759#ifdef CONFIG_LOCKDEP 760extern void lockdep_assert_task_sighand_held(struct task_struct *task); 761#else 762static inline void lockdep_assert_task_sighand_held(struct task_struct *task) { } 763#endif 764 765static inline unsigned long task_rlimit(const struct task_struct *task, 766 unsigned int limit) 767{ 768 return READ_ONCE(task->signal->rlim[limit].rlim_cur); 769} 770 771static inline unsigned long task_rlimit_max(const struct task_struct *task, 772 unsigned int limit) 773{ 774 return READ_ONCE(task->signal->rlim[limit].rlim_max); 775} 776 777static inline unsigned long rlimit(unsigned int limit) 778{ 779 return task_rlimit(current, limit); 780} 781 782static inline unsigned long rlimit_max(unsigned int limit) 783{ 784 return task_rlimit_max(current, limit); 785} 786 787#endif /* _LINUX_SCHED_SIGNAL_H */