Line data Source code
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 0 : static inline void signal_set_stop_flags(struct signal_struct *sig,
268 : unsigned int flags)
269 : {
270 0 : WARN_ON(sig->flags & SIGNAL_GROUP_EXIT);
271 0 : sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags;
272 0 : }
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 : set_special_state(TASK_STOPPED);
299 : spin_unlock_irq(¤t->sighand->siglock);
300 :
301 : schedule();
302 : }
303 : #ifdef __ia64__
304 : # define ___ARCH_SI_IA64(_a1, _a2, _a3) , _a1, _a2, _a3
305 : #else
306 : # define ___ARCH_SI_IA64(_a1, _a2, _a3)
307 : #endif
308 :
309 : int force_sig_fault_to_task(int sig, int code, void __user *addr
310 : ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
311 : , struct task_struct *t);
312 : int force_sig_fault(int sig, int code, void __user *addr
313 : ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr));
314 : int send_sig_fault(int sig, int code, void __user *addr
315 : ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
316 : , struct task_struct *t);
317 :
318 : int force_sig_mceerr(int code, void __user *, short);
319 : int send_sig_mceerr(int code, void __user *, short, struct task_struct *);
320 :
321 : int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper);
322 : int force_sig_pkuerr(void __user *addr, u32 pkey);
323 : int force_sig_perf(void __user *addr, u32 type, u64 sig_data);
324 :
325 : int force_sig_ptrace_errno_trap(int errno, void __user *addr);
326 : int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno);
327 : int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno,
328 : struct task_struct *t);
329 : int force_sig_seccomp(int syscall, int reason, bool force_coredump);
330 :
331 : extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
332 : extern void force_sigsegv(int sig);
333 : extern int force_sig_info(struct kernel_siginfo *);
334 : extern int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp);
335 : extern int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid);
336 : extern int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, struct pid *,
337 : const struct cred *);
338 : extern int kill_pgrp(struct pid *pid, int sig, int priv);
339 : extern int kill_pid(struct pid *pid, int sig, int priv);
340 : extern __must_check bool do_notify_parent(struct task_struct *, int);
341 : extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
342 : extern void force_sig(int);
343 : extern void force_fatal_sig(int);
344 : extern void force_exit_sig(int);
345 : extern int send_sig(int, struct task_struct *, int);
346 : extern int zap_other_threads(struct task_struct *p);
347 : extern struct sigqueue *sigqueue_alloc(void);
348 : extern void sigqueue_free(struct sigqueue *);
349 : extern int send_sigqueue(struct sigqueue *, struct pid *, enum pid_type);
350 : extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
351 :
352 : static inline void clear_notify_signal(void)
353 : {
354 0 : clear_thread_flag(TIF_NOTIFY_SIGNAL);
355 0 : smp_mb__after_atomic();
356 : }
357 :
358 : /*
359 : * Called to break out of interruptible wait loops, and enter the
360 : * exit_to_user_mode_loop().
361 : */
362 : static inline void set_notify_signal(struct task_struct *task)
363 : {
364 0 : if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_SIGNAL) &&
365 0 : !wake_up_state(task, TASK_INTERRUPTIBLE))
366 : kick_process(task);
367 : }
368 :
369 : static inline int restart_syscall(void)
370 : {
371 0 : set_tsk_thread_flag(current, TIF_SIGPENDING);
372 : return -ERESTARTNOINTR;
373 : }
374 :
375 : static inline int task_sigpending(struct task_struct *p)
376 : {
377 1256 : return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
378 : }
379 :
380 : static inline int signal_pending(struct task_struct *p)
381 : {
382 : /*
383 : * TIF_NOTIFY_SIGNAL isn't really a signal, but it requires the same
384 : * behavior in terms of ensuring that we break out of wait loops
385 : * so that notify signal callbacks can be processed.
386 : */
387 828 : if (unlikely(test_tsk_thread_flag(p, TIF_NOTIFY_SIGNAL)))
388 : return 1;
389 414 : return task_sigpending(p);
390 : }
391 :
392 : static inline int __fatal_signal_pending(struct task_struct *p)
393 : {
394 0 : return unlikely(sigismember(&p->pending.signal, SIGKILL));
395 : }
396 :
397 : static inline int fatal_signal_pending(struct task_struct *p)
398 : {
399 107 : return task_sigpending(p) && __fatal_signal_pending(p);
400 : }
401 :
402 819 : static inline int signal_pending_state(unsigned int state, struct task_struct *p)
403 : {
404 819 : if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
405 : return 0;
406 414 : if (!signal_pending(p))
407 : return 0;
408 :
409 0 : return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
410 : }
411 :
412 : /*
413 : * This should only be used in fault handlers to decide whether we
414 : * should stop the current fault routine to handle the signals
415 : * instead, especially with the case where we've got interrupted with
416 : * a VM_FAULT_RETRY.
417 : */
418 : static inline bool fault_signal_pending(vm_fault_t fault_flags,
419 : struct pt_regs *regs)
420 : {
421 : return unlikely((fault_flags & VM_FAULT_RETRY) &&
422 : (fatal_signal_pending(current) ||
423 : (user_mode(regs) && signal_pending(current))));
424 : }
425 :
426 : /*
427 : * Reevaluate whether the task has signals pending delivery.
428 : * Wake the task if so.
429 : * This is required every time the blocked sigset_t changes.
430 : * callers must hold sighand->siglock.
431 : */
432 : extern void recalc_sigpending_and_wake(struct task_struct *t);
433 : extern void recalc_sigpending(void);
434 : extern void calculate_sigpending(void);
435 :
436 : extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
437 :
438 : static inline void signal_wake_up(struct task_struct *t, bool resume)
439 : {
440 0 : signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
441 : }
442 : static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
443 : {
444 0 : signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
445 : }
446 :
447 : void task_join_group_stop(struct task_struct *task);
448 :
449 : #ifdef TIF_RESTORE_SIGMASK
450 : /*
451 : * Legacy restore_sigmask accessors. These are inefficient on
452 : * SMP architectures because they require atomic operations.
453 : */
454 :
455 : /**
456 : * set_restore_sigmask() - make sure saved_sigmask processing gets done
457 : *
458 : * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
459 : * will run before returning to user mode, to process the flag. For
460 : * all callers, TIF_SIGPENDING is already set or it's no harm to set
461 : * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the
462 : * arch code will notice on return to user mode, in case those bits
463 : * are scarce. We set TIF_SIGPENDING here to ensure that the arch
464 : * signal code always gets run when TIF_RESTORE_SIGMASK is set.
465 : */
466 : static inline void set_restore_sigmask(void)
467 : {
468 0 : set_thread_flag(TIF_RESTORE_SIGMASK);
469 : }
470 :
471 : static inline void clear_tsk_restore_sigmask(struct task_struct *task)
472 : {
473 0 : clear_tsk_thread_flag(task, TIF_RESTORE_SIGMASK);
474 : }
475 :
476 : static inline void clear_restore_sigmask(void)
477 : {
478 0 : clear_thread_flag(TIF_RESTORE_SIGMASK);
479 : }
480 : static inline bool test_tsk_restore_sigmask(struct task_struct *task)
481 : {
482 0 : return test_tsk_thread_flag(task, TIF_RESTORE_SIGMASK);
483 : }
484 : static inline bool test_restore_sigmask(void)
485 : {
486 0 : return test_thread_flag(TIF_RESTORE_SIGMASK);
487 : }
488 : static inline bool test_and_clear_restore_sigmask(void)
489 : {
490 0 : return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
491 : }
492 :
493 : #else /* TIF_RESTORE_SIGMASK */
494 :
495 : /* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */
496 : static inline void set_restore_sigmask(void)
497 : {
498 : current->restore_sigmask = true;
499 : }
500 : static inline void clear_tsk_restore_sigmask(struct task_struct *task)
501 : {
502 : task->restore_sigmask = false;
503 : }
504 : static inline void clear_restore_sigmask(void)
505 : {
506 : current->restore_sigmask = false;
507 : }
508 : static inline bool test_restore_sigmask(void)
509 : {
510 : return current->restore_sigmask;
511 : }
512 : static inline bool test_tsk_restore_sigmask(struct task_struct *task)
513 : {
514 : return task->restore_sigmask;
515 : }
516 : static inline bool test_and_clear_restore_sigmask(void)
517 : {
518 : if (!current->restore_sigmask)
519 : return false;
520 : current->restore_sigmask = false;
521 : return true;
522 : }
523 : #endif
524 :
525 0 : static inline void restore_saved_sigmask(void)
526 : {
527 0 : if (test_and_clear_restore_sigmask())
528 0 : __set_current_blocked(¤t->saved_sigmask);
529 0 : }
530 :
531 : extern int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize);
532 :
533 0 : static inline void restore_saved_sigmask_unless(bool interrupted)
534 : {
535 0 : if (interrupted)
536 0 : WARN_ON(!signal_pending(current));
537 : else
538 0 : restore_saved_sigmask();
539 0 : }
540 :
541 : static inline sigset_t *sigmask_to_save(void)
542 : {
543 0 : sigset_t *res = ¤t->blocked;
544 0 : if (unlikely(test_restore_sigmask()))
545 0 : res = ¤t->saved_sigmask;
546 : return res;
547 : }
548 :
549 : static inline int kill_cad_pid(int sig, int priv)
550 : {
551 0 : return kill_pid(cad_pid, sig, priv);
552 : }
553 :
554 : /* These can be the second arg to send_sig_info/send_group_sig_info. */
555 : #define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0)
556 : #define SEND_SIG_PRIV ((struct kernel_siginfo *) 1)
557 :
558 : static inline int __on_sig_stack(unsigned long sp)
559 : {
560 : #ifdef CONFIG_STACK_GROWSUP
561 : return sp >= current->sas_ss_sp &&
562 : sp - current->sas_ss_sp < current->sas_ss_size;
563 : #else
564 0 : return sp > current->sas_ss_sp &&
565 0 : sp - current->sas_ss_sp <= current->sas_ss_size;
566 : #endif
567 : }
568 :
569 : /*
570 : * True if we are on the alternate signal stack.
571 : */
572 0 : static inline int on_sig_stack(unsigned long sp)
573 : {
574 : /*
575 : * If the signal stack is SS_AUTODISARM then, by construction, we
576 : * can't be on the signal stack unless user code deliberately set
577 : * SS_AUTODISARM when we were already on it.
578 : *
579 : * This improves reliability: if user state gets corrupted such that
580 : * the stack pointer points very close to the end of the signal stack,
581 : * then this check will enable the signal to be handled anyway.
582 : */
583 0 : if (current->sas_ss_flags & SS_AUTODISARM)
584 : return 0;
585 :
586 : return __on_sig_stack(sp);
587 : }
588 :
589 : static inline int sas_ss_flags(unsigned long sp)
590 : {
591 0 : if (!current->sas_ss_size)
592 : return SS_DISABLE;
593 :
594 0 : return on_sig_stack(sp) ? SS_ONSTACK : 0;
595 : }
596 :
597 : static inline void sas_ss_reset(struct task_struct *p)
598 : {
599 107 : p->sas_ss_sp = 0;
600 107 : p->sas_ss_size = 0;
601 107 : p->sas_ss_flags = SS_DISABLE;
602 : }
603 :
604 : static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
605 : {
606 : if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
607 : #ifdef CONFIG_STACK_GROWSUP
608 : return current->sas_ss_sp;
609 : #else
610 : return current->sas_ss_sp + current->sas_ss_size;
611 : #endif
612 : return sp;
613 : }
614 :
615 : extern void __cleanup_sighand(struct sighand_struct *);
616 : extern void flush_itimer_signals(void);
617 :
618 : #define tasklist_empty() \
619 : list_empty(&init_task.tasks)
620 :
621 : #define next_task(p) \
622 : list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
623 :
624 : #define for_each_process(p) \
625 : for (p = &init_task ; (p = next_task(p)) != &init_task ; )
626 :
627 : extern bool current_is_single_threaded(void);
628 :
629 : /*
630 : * Careful: do_each_thread/while_each_thread is a double loop so
631 : * 'break' will not work as expected - use goto instead.
632 : */
633 : #define do_each_thread(g, t) \
634 : for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
635 :
636 : #define while_each_thread(g, t) \
637 : while ((t = next_thread(t)) != g)
638 :
639 : #define __for_each_thread(signal, t) \
640 : list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
641 :
642 : #define for_each_thread(p, t) \
643 : __for_each_thread((p)->signal, t)
644 :
645 : /* Careful: this is a double loop, 'break' won't work as expected. */
646 : #define for_each_process_thread(p, t) \
647 : for_each_process(p) for_each_thread(p, t)
648 :
649 : typedef int (*proc_visitor)(struct task_struct *p, void *data);
650 : void walk_process_tree(struct task_struct *top, proc_visitor, void *);
651 :
652 : static inline
653 : struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
654 : {
655 : struct pid *pid;
656 0 : if (type == PIDTYPE_PID)
657 0 : pid = task_pid(task);
658 : else
659 0 : pid = task->signal->pids[type];
660 : return pid;
661 : }
662 :
663 : static inline struct pid *task_tgid(struct task_struct *task)
664 : {
665 0 : return task->signal->pids[PIDTYPE_TGID];
666 : }
667 :
668 : /*
669 : * Without tasklist or RCU lock it is not safe to dereference
670 : * the result of task_pgrp/task_session even if task == current,
671 : * we can race with another thread doing sys_setsid/sys_setpgid.
672 : */
673 : static inline struct pid *task_pgrp(struct task_struct *task)
674 : {
675 293 : return task->signal->pids[PIDTYPE_PGID];
676 : }
677 :
678 : static inline struct pid *task_session(struct task_struct *task)
679 : {
680 107 : return task->signal->pids[PIDTYPE_SID];
681 : }
682 :
683 : static inline int get_nr_threads(struct task_struct *task)
684 : {
685 0 : return task->signal->nr_threads;
686 : }
687 :
688 : static inline bool thread_group_leader(struct task_struct *p)
689 : {
690 93 : return p->exit_signal >= 0;
691 : }
692 :
693 : static inline
694 : bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
695 : {
696 0 : return p1->signal == p2->signal;
697 : }
698 :
699 : static inline struct task_struct *next_thread(const struct task_struct *p)
700 : {
701 0 : return list_entry_rcu(p->thread_group.next,
702 : struct task_struct, thread_group);
703 : }
704 :
705 : static inline int thread_group_empty(struct task_struct *p)
706 : {
707 558 : return list_empty(&p->thread_group);
708 : }
709 :
710 : #define delay_group_leader(p) \
711 : (thread_group_leader(p) && !thread_group_empty(p))
712 :
713 : extern bool thread_group_exited(struct pid *pid);
714 :
715 : extern struct sighand_struct *__lock_task_sighand(struct task_struct *task,
716 : unsigned long *flags);
717 :
718 : static inline struct sighand_struct *lock_task_sighand(struct task_struct *task,
719 : unsigned long *flags)
720 : {
721 : struct sighand_struct *ret;
722 :
723 0 : ret = __lock_task_sighand(task, flags);
724 : (void)__cond_lock(&task->sighand->siglock, ret);
725 : return ret;
726 : }
727 :
728 : static inline void unlock_task_sighand(struct task_struct *task,
729 : unsigned long *flags)
730 : {
731 0 : spin_unlock_irqrestore(&task->sighand->siglock, *flags);
732 : }
733 :
734 : #ifdef CONFIG_LOCKDEP
735 : extern void lockdep_assert_task_sighand_held(struct task_struct *task);
736 : #else
737 : static inline void lockdep_assert_task_sighand_held(struct task_struct *task) { }
738 : #endif
739 :
740 : static inline unsigned long task_rlimit(const struct task_struct *task,
741 : unsigned int limit)
742 : {
743 107 : return READ_ONCE(task->signal->rlim[limit].rlim_cur);
744 : }
745 :
746 : static inline unsigned long task_rlimit_max(const struct task_struct *task,
747 : unsigned int limit)
748 : {
749 0 : return READ_ONCE(task->signal->rlim[limit].rlim_max);
750 : }
751 :
752 : static inline unsigned long rlimit(unsigned int limit)
753 : {
754 214 : return task_rlimit(current, limit);
755 : }
756 :
757 : static inline unsigned long rlimit_max(unsigned int limit)
758 : {
759 0 : return task_rlimit_max(current, limit);
760 : }
761 :
762 : #endif /* _LINUX_SCHED_SIGNAL_H */
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