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 #include <linux/android_kabi.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 /* 77 * NOTE! "signal_struct" does not have its own 78 * locking, because a shared signal_struct always 79 * implies a shared sighand_struct, so locking 80 * sighand_struct is always a proper superset of 81 * the locking of signal_struct. 82 */ 83 struct signal_struct { 84 refcount_t sigcnt; 85 atomic_t live; 86 int nr_threads; 87 struct list_head thread_head; 88 89 wait_queue_head_t wait_chldexit; /* for wait4() */ 90 91 /* current thread group signal load-balancing target: */ 92 struct task_struct *curr_target; 93 94 /* shared signal handling: */ 95 struct sigpending shared_pending; 96 97 /* For collecting multiprocess signals during fork */ 98 struct hlist_head multiprocess; 99 100 /* thread group exit support */ 101 int group_exit_code; 102 /* overloaded: 103 * - notify group_exit_task when ->count is equal to notify_count 104 * - everyone except group_exit_task is stopped during signal delivery 105 * of fatal signals, group_exit_task processes the signal. 106 */ 107 int notify_count; 108 struct task_struct *group_exit_task; 109 110 /* thread group stop support, overloads group_exit_code too */ 111 int group_stop_count; 112 unsigned int flags; /* see SIGNAL_* flags below */ 113 114 /* 115 * PR_SET_CHILD_SUBREAPER marks a process, like a service 116 * manager, to re-parent orphan (double-forking) child processes 117 * to this process instead of 'init'. The service manager is 118 * able to receive SIGCHLD signals and is able to investigate 119 * the process until it calls wait(). All children of this 120 * process will inherit a flag if they should look for a 121 * child_subreaper process at exit. 122 */ 123 unsigned int is_child_subreaper:1; 124 unsigned int has_child_subreaper:1; 125 126 #ifdef CONFIG_POSIX_TIMERS 127 128 /* POSIX.1b Interval Timers */ 129 int posix_timer_id; 130 struct list_head posix_timers; 131 132 /* ITIMER_REAL timer for the process */ 133 struct hrtimer real_timer; 134 ktime_t it_real_incr; 135 136 /* 137 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use 138 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these 139 * values are defined to 0 and 1 respectively 140 */ 141 struct cpu_itimer it[2]; 142 143 /* 144 * Thread group totals for process CPU timers. 145 * See thread_group_cputimer(), et al, for details. 146 */ 147 struct thread_group_cputimer cputimer; 148 149 #endif 150 /* Empty if CONFIG_POSIX_TIMERS=n */ 151 struct posix_cputimers posix_cputimers; 152 153 /* PID/PID hash table linkage. */ 154 struct pid *pids[PIDTYPE_MAX]; 155 156 #ifdef CONFIG_NO_HZ_FULL 157 atomic_t tick_dep_mask; 158 #endif 159 160 struct pid *tty_old_pgrp; 161 162 /* boolean value for session group leader */ 163 int leader; 164 165 struct tty_struct *tty; /* NULL if no tty */ 166 167 #ifdef CONFIG_SCHED_AUTOGROUP 168 struct autogroup *autogroup; 169 #endif 170 /* 171 * Cumulative resource counters for dead threads in the group, 172 * and for reaped dead child processes forked by this group. 173 * Live threads maintain their own counters and add to these 174 * in __exit_signal, except for the group leader. 175 */ 176 seqlock_t stats_lock; 177 u64 utime, stime, cutime, cstime; 178 u64 gtime; 179 u64 cgtime; 180 struct prev_cputime prev_cputime; 181 unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw; 182 unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt; 183 unsigned long inblock, oublock, cinblock, coublock; 184 unsigned long maxrss, cmaxrss; 185 struct task_io_accounting ioac; 186 187 /* 188 * Cumulative ns of schedule CPU time fo dead threads in the 189 * group, not including a zombie group leader, (This only differs 190 * from jiffies_to_ns(utime + stime) if sched_clock uses something 191 * other than jiffies.) 192 */ 193 unsigned long long sum_sched_runtime; 194 195 /* 196 * We don't bother to synchronize most readers of this at all, 197 * because there is no reader checking a limit that actually needs 198 * to get both rlim_cur and rlim_max atomically, and either one 199 * alone is a single word that can safely be read normally. 200 * getrlimit/setrlimit use task_lock(current->group_leader) to 201 * protect this instead of the siglock, because they really 202 * have no need to disable irqs. 203 */ 204 struct rlimit rlim[RLIM_NLIMITS]; 205 206 #ifdef CONFIG_BSD_PROCESS_ACCT 207 struct pacct_struct pacct; /* per-process accounting information */ 208 #endif 209 #ifdef CONFIG_TASKSTATS 210 struct taskstats *stats; 211 #endif 212 #ifdef CONFIG_AUDIT 213 unsigned audit_tty; 214 struct tty_audit_buf *tty_audit_buf; 215 #endif 216 217 /* 218 * Thread is the potential origin of an oom condition; kill first on 219 * oom 220 */ 221 bool oom_flag_origin; 222 short oom_score_adj; /* OOM kill score adjustment */ 223 short oom_score_adj_min; /* OOM kill score adjustment min value. 224 * Only settable by CAP_SYS_RESOURCE. */ 225 struct mm_struct *oom_mm; /* recorded mm when the thread group got 226 * killed by the oom killer */ 227 228 struct mutex cred_guard_mutex; /* guard against foreign influences on 229 * credential calculations 230 * (notably. ptrace) 231 * Deprecated do not use in new code. 232 * Use exec_update_lock instead. 233 */ 234 struct rw_semaphore exec_update_lock; /* Held while task_struct is 235 * being updated during exec, 236 * and may have inconsistent 237 * permissions. 238 */ 239 240 ANDROID_KABI_RESERVE(1); 241 ANDROID_KABI_RESERVE(2); 242 ANDROID_KABI_RESERVE(3); 243 ANDROID_KABI_RESERVE(4); 244 } __randomize_layout; 245 246 /* 247 * Bits in flags field of signal_struct. 248 */ 249 #define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */ 250 #define SIGNAL_STOP_CONTINUED 0x00000002 /* SIGCONT since WCONTINUED reap */ 251 #define SIGNAL_GROUP_EXIT 0x00000004 /* group exit in progress */ 252 #define SIGNAL_GROUP_COREDUMP 0x00000008 /* coredump in progress */ 253 /* 254 * Pending notifications to parent. 255 */ 256 #define SIGNAL_CLD_STOPPED 0x00000010 257 #define SIGNAL_CLD_CONTINUED 0x00000020 258 #define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED) 259 260 #define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */ 261 262 #define SIGNAL_STOP_MASK (SIGNAL_CLD_MASK | SIGNAL_STOP_STOPPED | \ 263 SIGNAL_STOP_CONTINUED) 264 signal_set_stop_flags(struct signal_struct * sig,unsigned int flags)265 static inline void signal_set_stop_flags(struct signal_struct *sig, 266 unsigned int flags) 267 { 268 WARN_ON(sig->flags & (SIGNAL_GROUP_EXIT|SIGNAL_GROUP_COREDUMP)); 269 sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags; 270 } 271 272 /* If true, all threads except ->group_exit_task have pending SIGKILL */ signal_group_exit(const struct signal_struct * sig)273 static inline int signal_group_exit(const struct signal_struct *sig) 274 { 275 return (sig->flags & SIGNAL_GROUP_EXIT) || 276 (sig->group_exit_task != NULL); 277 } 278 279 extern void flush_signals(struct task_struct *); 280 extern void ignore_signals(struct task_struct *); 281 extern void flush_signal_handlers(struct task_struct *, int force_default); 282 extern int dequeue_signal(struct task_struct *task, 283 sigset_t *mask, kernel_siginfo_t *info); 284 kernel_dequeue_signal(void)285 static inline int kernel_dequeue_signal(void) 286 { 287 struct task_struct *task = current; 288 kernel_siginfo_t __info; 289 int ret; 290 291 spin_lock_irq(&task->sighand->siglock); 292 ret = dequeue_signal(task, &task->blocked, &__info); 293 spin_unlock_irq(&task->sighand->siglock); 294 295 return ret; 296 } 297 kernel_signal_stop(void)298 static inline void kernel_signal_stop(void) 299 { 300 spin_lock_irq(¤t->sighand->siglock); 301 if (current->jobctl & JOBCTL_STOP_DEQUEUED) 302 set_special_state(TASK_STOPPED); 303 spin_unlock_irq(¤t->sighand->siglock); 304 305 schedule(); 306 } 307 #ifdef __ia64__ 308 # define ___ARCH_SI_IA64(_a1, _a2, _a3) , _a1, _a2, _a3 309 #else 310 # define ___ARCH_SI_IA64(_a1, _a2, _a3) 311 #endif 312 313 int force_sig_fault_to_task(int sig, int code, void __user *addr 314 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr) 315 , struct task_struct *t); 316 int force_sig_fault(int sig, int code, void __user *addr 317 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)); 318 int send_sig_fault(int sig, int code, void __user *addr 319 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr) 320 , struct task_struct *t); 321 322 int force_sig_mceerr(int code, void __user *, short); 323 int send_sig_mceerr(int code, void __user *, short, struct task_struct *); 324 325 int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper); 326 int force_sig_pkuerr(void __user *addr, u32 pkey); 327 int force_sig_perf(void __user *addr, u32 type, u64 sig_data); 328 329 int force_sig_ptrace_errno_trap(int errno, void __user *addr); 330 int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno); 331 int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno, 332 struct task_struct *t); 333 int force_sig_seccomp(int syscall, int reason, bool force_coredump); 334 335 extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *); 336 extern void force_sigsegv(int sig); 337 extern int force_sig_info(struct kernel_siginfo *); 338 extern int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp); 339 extern int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid); 340 extern int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, struct pid *, 341 const struct cred *); 342 extern int kill_pgrp(struct pid *pid, int sig, int priv); 343 extern int kill_pid(struct pid *pid, int sig, int priv); 344 extern __must_check bool do_notify_parent(struct task_struct *, int); 345 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent); 346 extern void force_sig(int); 347 extern void force_fatal_sig(int); 348 extern void force_exit_sig(int); 349 extern int send_sig(int, struct task_struct *, int); 350 extern int zap_other_threads(struct task_struct *p); 351 extern struct sigqueue *sigqueue_alloc(void); 352 extern void sigqueue_free(struct sigqueue *); 353 extern int send_sigqueue(struct sigqueue *, struct pid *, enum pid_type); 354 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *); 355 restart_syscall(void)356 static inline int restart_syscall(void) 357 { 358 set_tsk_thread_flag(current, TIF_SIGPENDING); 359 return -ERESTARTNOINTR; 360 } 361 task_sigpending(struct task_struct * p)362 static inline int task_sigpending(struct task_struct *p) 363 { 364 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING)); 365 } 366 signal_pending(struct task_struct * p)367 static inline int signal_pending(struct task_struct *p) 368 { 369 /* 370 * TIF_NOTIFY_SIGNAL isn't really a signal, but it requires the same 371 * behavior in terms of ensuring that we break out of wait loops 372 * so that notify signal callbacks can be processed. 373 */ 374 if (unlikely(test_tsk_thread_flag(p, TIF_NOTIFY_SIGNAL))) 375 return 1; 376 return task_sigpending(p); 377 } 378 __fatal_signal_pending(struct task_struct * p)379 static inline int __fatal_signal_pending(struct task_struct *p) 380 { 381 return unlikely(sigismember(&p->pending.signal, SIGKILL)); 382 } 383 fatal_signal_pending(struct task_struct * p)384 static inline int fatal_signal_pending(struct task_struct *p) 385 { 386 return task_sigpending(p) && __fatal_signal_pending(p); 387 } 388 signal_pending_state(unsigned int state,struct task_struct * p)389 static inline int signal_pending_state(unsigned int state, struct task_struct *p) 390 { 391 if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL))) 392 return 0; 393 if (!signal_pending(p)) 394 return 0; 395 396 return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p); 397 } 398 399 /* 400 * This should only be used in fault handlers to decide whether we 401 * should stop the current fault routine to handle the signals 402 * instead, especially with the case where we've got interrupted with 403 * a VM_FAULT_RETRY. 404 */ fault_signal_pending(vm_fault_t fault_flags,struct pt_regs * regs)405 static inline bool fault_signal_pending(vm_fault_t fault_flags, 406 struct pt_regs *regs) 407 { 408 return unlikely((fault_flags & VM_FAULT_RETRY) && 409 (fatal_signal_pending(current) || 410 (user_mode(regs) && signal_pending(current)))); 411 } 412 413 /* 414 * Reevaluate whether the task has signals pending delivery. 415 * Wake the task if so. 416 * This is required every time the blocked sigset_t changes. 417 * callers must hold sighand->siglock. 418 */ 419 extern void recalc_sigpending_and_wake(struct task_struct *t); 420 extern void recalc_sigpending(void); 421 extern void calculate_sigpending(void); 422 423 extern void signal_wake_up_state(struct task_struct *t, unsigned int state); 424 signal_wake_up(struct task_struct * t,bool resume)425 static inline void signal_wake_up(struct task_struct *t, bool resume) 426 { 427 signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0); 428 } ptrace_signal_wake_up(struct task_struct * t,bool resume)429 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume) 430 { 431 signal_wake_up_state(t, resume ? __TASK_TRACED : 0); 432 } 433 434 void task_join_group_stop(struct task_struct *task); 435 436 #ifdef TIF_RESTORE_SIGMASK 437 /* 438 * Legacy restore_sigmask accessors. These are inefficient on 439 * SMP architectures because they require atomic operations. 440 */ 441 442 /** 443 * set_restore_sigmask() - make sure saved_sigmask processing gets done 444 * 445 * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code 446 * will run before returning to user mode, to process the flag. For 447 * all callers, TIF_SIGPENDING is already set or it's no harm to set 448 * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the 449 * arch code will notice on return to user mode, in case those bits 450 * are scarce. We set TIF_SIGPENDING here to ensure that the arch 451 * signal code always gets run when TIF_RESTORE_SIGMASK is set. 452 */ set_restore_sigmask(void)453 static inline void set_restore_sigmask(void) 454 { 455 set_thread_flag(TIF_RESTORE_SIGMASK); 456 } 457 clear_tsk_restore_sigmask(struct task_struct * task)458 static inline void clear_tsk_restore_sigmask(struct task_struct *task) 459 { 460 clear_tsk_thread_flag(task, TIF_RESTORE_SIGMASK); 461 } 462 clear_restore_sigmask(void)463 static inline void clear_restore_sigmask(void) 464 { 465 clear_thread_flag(TIF_RESTORE_SIGMASK); 466 } test_tsk_restore_sigmask(struct task_struct * task)467 static inline bool test_tsk_restore_sigmask(struct task_struct *task) 468 { 469 return test_tsk_thread_flag(task, TIF_RESTORE_SIGMASK); 470 } test_restore_sigmask(void)471 static inline bool test_restore_sigmask(void) 472 { 473 return test_thread_flag(TIF_RESTORE_SIGMASK); 474 } test_and_clear_restore_sigmask(void)475 static inline bool test_and_clear_restore_sigmask(void) 476 { 477 return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK); 478 } 479 480 #else /* TIF_RESTORE_SIGMASK */ 481 482 /* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */ set_restore_sigmask(void)483 static inline void set_restore_sigmask(void) 484 { 485 current->restore_sigmask = true; 486 } clear_tsk_restore_sigmask(struct task_struct * task)487 static inline void clear_tsk_restore_sigmask(struct task_struct *task) 488 { 489 task->restore_sigmask = false; 490 } clear_restore_sigmask(void)491 static inline void clear_restore_sigmask(void) 492 { 493 current->restore_sigmask = false; 494 } test_restore_sigmask(void)495 static inline bool test_restore_sigmask(void) 496 { 497 return current->restore_sigmask; 498 } test_tsk_restore_sigmask(struct task_struct * task)499 static inline bool test_tsk_restore_sigmask(struct task_struct *task) 500 { 501 return task->restore_sigmask; 502 } test_and_clear_restore_sigmask(void)503 static inline bool test_and_clear_restore_sigmask(void) 504 { 505 if (!current->restore_sigmask) 506 return false; 507 current->restore_sigmask = false; 508 return true; 509 } 510 #endif 511 restore_saved_sigmask(void)512 static inline void restore_saved_sigmask(void) 513 { 514 if (test_and_clear_restore_sigmask()) 515 __set_current_blocked(¤t->saved_sigmask); 516 } 517 518 extern int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize); 519 restore_saved_sigmask_unless(bool interrupted)520 static inline void restore_saved_sigmask_unless(bool interrupted) 521 { 522 if (interrupted) 523 WARN_ON(!signal_pending(current)); 524 else 525 restore_saved_sigmask(); 526 } 527 sigmask_to_save(void)528 static inline sigset_t *sigmask_to_save(void) 529 { 530 sigset_t *res = ¤t->blocked; 531 if (unlikely(test_restore_sigmask())) 532 res = ¤t->saved_sigmask; 533 return res; 534 } 535 kill_cad_pid(int sig,int priv)536 static inline int kill_cad_pid(int sig, int priv) 537 { 538 return kill_pid(cad_pid, sig, priv); 539 } 540 541 /* These can be the second arg to send_sig_info/send_group_sig_info. */ 542 #define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0) 543 #define SEND_SIG_PRIV ((struct kernel_siginfo *) 1) 544 __on_sig_stack(unsigned long sp)545 static inline int __on_sig_stack(unsigned long sp) 546 { 547 #ifdef CONFIG_STACK_GROWSUP 548 return sp >= current->sas_ss_sp && 549 sp - current->sas_ss_sp < current->sas_ss_size; 550 #else 551 return sp > current->sas_ss_sp && 552 sp - current->sas_ss_sp <= current->sas_ss_size; 553 #endif 554 } 555 556 /* 557 * True if we are on the alternate signal stack. 558 */ on_sig_stack(unsigned long sp)559 static inline int on_sig_stack(unsigned long sp) 560 { 561 /* 562 * If the signal stack is SS_AUTODISARM then, by construction, we 563 * can't be on the signal stack unless user code deliberately set 564 * SS_AUTODISARM when we were already on it. 565 * 566 * This improves reliability: if user state gets corrupted such that 567 * the stack pointer points very close to the end of the signal stack, 568 * then this check will enable the signal to be handled anyway. 569 */ 570 if (current->sas_ss_flags & SS_AUTODISARM) 571 return 0; 572 573 return __on_sig_stack(sp); 574 } 575 sas_ss_flags(unsigned long sp)576 static inline int sas_ss_flags(unsigned long sp) 577 { 578 if (!current->sas_ss_size) 579 return SS_DISABLE; 580 581 return on_sig_stack(sp) ? SS_ONSTACK : 0; 582 } 583 sas_ss_reset(struct task_struct * p)584 static inline void sas_ss_reset(struct task_struct *p) 585 { 586 p->sas_ss_sp = 0; 587 p->sas_ss_size = 0; 588 p->sas_ss_flags = SS_DISABLE; 589 } 590 sigsp(unsigned long sp,struct ksignal * ksig)591 static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig) 592 { 593 if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp)) 594 #ifdef CONFIG_STACK_GROWSUP 595 return current->sas_ss_sp; 596 #else 597 return current->sas_ss_sp + current->sas_ss_size; 598 #endif 599 return sp; 600 } 601 602 extern void __cleanup_sighand(struct sighand_struct *); 603 extern void flush_itimer_signals(void); 604 605 #define tasklist_empty() \ 606 list_empty(&init_task.tasks) 607 608 #define next_task(p) \ 609 list_entry_rcu((p)->tasks.next, struct task_struct, tasks) 610 611 #define for_each_process(p) \ 612 for (p = &init_task ; (p = next_task(p)) != &init_task ; ) 613 614 extern bool current_is_single_threaded(void); 615 616 /* 617 * Careful: do_each_thread/while_each_thread is a double loop so 618 * 'break' will not work as expected - use goto instead. 619 */ 620 #define do_each_thread(g, t) \ 621 for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do 622 623 #define while_each_thread(g, t) \ 624 while ((t = next_thread(t)) != g) 625 626 #define __for_each_thread(signal, t) \ 627 list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node) 628 629 #define for_each_thread(p, t) \ 630 __for_each_thread((p)->signal, t) 631 632 /* Careful: this is a double loop, 'break' won't work as expected. */ 633 #define for_each_process_thread(p, t) \ 634 for_each_process(p) for_each_thread(p, t) 635 636 typedef int (*proc_visitor)(struct task_struct *p, void *data); 637 void walk_process_tree(struct task_struct *top, proc_visitor, void *); 638 639 static inline task_pid_type(struct task_struct * task,enum pid_type type)640 struct pid *task_pid_type(struct task_struct *task, enum pid_type type) 641 { 642 struct pid *pid; 643 if (type == PIDTYPE_PID) 644 pid = task_pid(task); 645 else 646 pid = task->signal->pids[type]; 647 return pid; 648 } 649 task_tgid(struct task_struct * task)650 static inline struct pid *task_tgid(struct task_struct *task) 651 { 652 return task->signal->pids[PIDTYPE_TGID]; 653 } 654 655 /* 656 * Without tasklist or RCU lock it is not safe to dereference 657 * the result of task_pgrp/task_session even if task == current, 658 * we can race with another thread doing sys_setsid/sys_setpgid. 659 */ task_pgrp(struct task_struct * task)660 static inline struct pid *task_pgrp(struct task_struct *task) 661 { 662 return task->signal->pids[PIDTYPE_PGID]; 663 } 664 task_session(struct task_struct * task)665 static inline struct pid *task_session(struct task_struct *task) 666 { 667 return task->signal->pids[PIDTYPE_SID]; 668 } 669 get_nr_threads(struct task_struct * task)670 static inline int get_nr_threads(struct task_struct *task) 671 { 672 return task->signal->nr_threads; 673 } 674 thread_group_leader(struct task_struct * p)675 static inline bool thread_group_leader(struct task_struct *p) 676 { 677 return p->exit_signal >= 0; 678 } 679 680 static inline same_thread_group(struct task_struct * p1,struct task_struct * p2)681 bool same_thread_group(struct task_struct *p1, struct task_struct *p2) 682 { 683 return p1->signal == p2->signal; 684 } 685 next_thread(const struct task_struct * p)686 static inline struct task_struct *next_thread(const struct task_struct *p) 687 { 688 return list_entry_rcu(p->thread_group.next, 689 struct task_struct, thread_group); 690 } 691 thread_group_empty(struct task_struct * p)692 static inline int thread_group_empty(struct task_struct *p) 693 { 694 return list_empty(&p->thread_group); 695 } 696 697 #define delay_group_leader(p) \ 698 (thread_group_leader(p) && !thread_group_empty(p)) 699 700 extern bool thread_group_exited(struct pid *pid); 701 702 extern struct sighand_struct *__lock_task_sighand(struct task_struct *task, 703 unsigned long *flags); 704 lock_task_sighand(struct task_struct * task,unsigned long * flags)705 static inline struct sighand_struct *lock_task_sighand(struct task_struct *task, 706 unsigned long *flags) 707 { 708 struct sighand_struct *ret; 709 710 ret = __lock_task_sighand(task, flags); 711 (void)__cond_lock(&task->sighand->siglock, ret); 712 return ret; 713 } 714 unlock_task_sighand(struct task_struct * task,unsigned long * flags)715 static inline void unlock_task_sighand(struct task_struct *task, 716 unsigned long *flags) 717 { 718 spin_unlock_irqrestore(&task->sighand->siglock, *flags); 719 } 720 721 #ifdef CONFIG_LOCKDEP 722 extern void lockdep_assert_task_sighand_held(struct task_struct *task); 723 #else lockdep_assert_task_sighand_held(struct task_struct * task)724 static inline void lockdep_assert_task_sighand_held(struct task_struct *task) { } 725 #endif 726 task_rlimit(const struct task_struct * task,unsigned int limit)727 static inline unsigned long task_rlimit(const struct task_struct *task, 728 unsigned int limit) 729 { 730 return READ_ONCE(task->signal->rlim[limit].rlim_cur); 731 } 732 task_rlimit_max(const struct task_struct * task,unsigned int limit)733 static inline unsigned long task_rlimit_max(const struct task_struct *task, 734 unsigned int limit) 735 { 736 return READ_ONCE(task->signal->rlim[limit].rlim_max); 737 } 738 rlimit(unsigned int limit)739 static inline unsigned long rlimit(unsigned int limit) 740 { 741 return task_rlimit(current, limit); 742 } 743 rlimit_max(unsigned int limit)744 static inline unsigned long rlimit_max(unsigned int limit) 745 { 746 return task_rlimit_max(current, limit); 747 } 748 749 #endif /* _LINUX_SCHED_SIGNAL_H */ 750