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 : int quick_threads;
98 : struct list_head thread_head;
99 :
100 : wait_queue_head_t wait_chldexit; /* for wait4() */
101 :
102 : /* current thread group signal load-balancing target: */
103 : struct task_struct *curr_target;
104 :
105 : /* shared signal handling: */
106 : struct sigpending shared_pending;
107 :
108 : /* For collecting multiprocess signals during fork */
109 : struct hlist_head multiprocess;
110 :
111 : /* thread group exit support */
112 : int group_exit_code;
113 : /* notify group_exec_task when notify_count is less or equal to 0 */
114 : int notify_count;
115 : struct task_struct *group_exec_task;
116 :
117 : /* thread group stop support, overloads group_exit_code too */
118 : int group_stop_count;
119 : unsigned int flags; /* see SIGNAL_* flags below */
120 :
121 : struct core_state *core_state; /* coredumping support */
122 :
123 : /*
124 : * PR_SET_CHILD_SUBREAPER marks a process, like a service
125 : * manager, to re-parent orphan (double-forking) child processes
126 : * to this process instead of 'init'. The service manager is
127 : * able to receive SIGCHLD signals and is able to investigate
128 : * the process until it calls wait(). All children of this
129 : * process will inherit a flag if they should look for a
130 : * child_subreaper process at exit.
131 : */
132 : unsigned int is_child_subreaper:1;
133 : unsigned int has_child_subreaper:1;
134 :
135 : #ifdef CONFIG_POSIX_TIMERS
136 :
137 : /* POSIX.1b Interval Timers */
138 : unsigned int next_posix_timer_id;
139 : struct list_head posix_timers;
140 :
141 : /* ITIMER_REAL timer for the process */
142 : struct hrtimer real_timer;
143 : ktime_t it_real_incr;
144 :
145 : /*
146 : * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
147 : * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
148 : * values are defined to 0 and 1 respectively
149 : */
150 : struct cpu_itimer it[2];
151 :
152 : /*
153 : * Thread group totals for process CPU timers.
154 : * See thread_group_cputimer(), et al, for details.
155 : */
156 : struct thread_group_cputimer cputimer;
157 :
158 : #endif
159 : /* Empty if CONFIG_POSIX_TIMERS=n */
160 : struct posix_cputimers posix_cputimers;
161 :
162 : /* PID/PID hash table linkage. */
163 : struct pid *pids[PIDTYPE_MAX];
164 :
165 : #ifdef CONFIG_NO_HZ_FULL
166 : atomic_t tick_dep_mask;
167 : #endif
168 :
169 : struct pid *tty_old_pgrp;
170 :
171 : /* boolean value for session group leader */
172 : int leader;
173 :
174 : struct tty_struct *tty; /* NULL if no tty */
175 :
176 : #ifdef CONFIG_SCHED_AUTOGROUP
177 : struct autogroup *autogroup;
178 : #endif
179 : /*
180 : * Cumulative resource counters for dead threads in the group,
181 : * and for reaped dead child processes forked by this group.
182 : * Live threads maintain their own counters and add to these
183 : * in __exit_signal, except for the group leader.
184 : */
185 : seqlock_t stats_lock;
186 : u64 utime, stime, cutime, cstime;
187 : u64 gtime;
188 : u64 cgtime;
189 : struct prev_cputime prev_cputime;
190 : unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
191 : unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
192 : unsigned long inblock, oublock, cinblock, coublock;
193 : unsigned long maxrss, cmaxrss;
194 : struct task_io_accounting ioac;
195 :
196 : /*
197 : * Cumulative ns of schedule CPU time fo dead threads in the
198 : * group, not including a zombie group leader, (This only differs
199 : * from jiffies_to_ns(utime + stime) if sched_clock uses something
200 : * other than jiffies.)
201 : */
202 : unsigned long long sum_sched_runtime;
203 :
204 : /*
205 : * We don't bother to synchronize most readers of this at all,
206 : * because there is no reader checking a limit that actually needs
207 : * to get both rlim_cur and rlim_max atomically, and either one
208 : * alone is a single word that can safely be read normally.
209 : * getrlimit/setrlimit use task_lock(current->group_leader) to
210 : * protect this instead of the siglock, because they really
211 : * have no need to disable irqs.
212 : */
213 : struct rlimit rlim[RLIM_NLIMITS];
214 :
215 : #ifdef CONFIG_BSD_PROCESS_ACCT
216 : struct pacct_struct pacct; /* per-process accounting information */
217 : #endif
218 : #ifdef CONFIG_TASKSTATS
219 : struct taskstats *stats;
220 : #endif
221 : #ifdef CONFIG_AUDIT
222 : unsigned audit_tty;
223 : struct tty_audit_buf *tty_audit_buf;
224 : #endif
225 :
226 : /*
227 : * Thread is the potential origin of an oom condition; kill first on
228 : * oom
229 : */
230 : bool oom_flag_origin;
231 : short oom_score_adj; /* OOM kill score adjustment */
232 : short oom_score_adj_min; /* OOM kill score adjustment min value.
233 : * Only settable by CAP_SYS_RESOURCE. */
234 : struct mm_struct *oom_mm; /* recorded mm when the thread group got
235 : * killed by the oom killer */
236 :
237 : struct mutex cred_guard_mutex; /* guard against foreign influences on
238 : * credential calculations
239 : * (notably. ptrace)
240 : * Deprecated do not use in new code.
241 : * Use exec_update_lock instead.
242 : */
243 : struct rw_semaphore exec_update_lock; /* Held while task_struct is
244 : * being updated during exec,
245 : * and may have inconsistent
246 : * permissions.
247 : */
248 : } __randomize_layout;
249 :
250 : /*
251 : * Bits in flags field of signal_struct.
252 : */
253 : #define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */
254 : #define SIGNAL_STOP_CONTINUED 0x00000002 /* SIGCONT since WCONTINUED reap */
255 : #define SIGNAL_GROUP_EXIT 0x00000004 /* group exit in progress */
256 : /*
257 : * Pending notifications to parent.
258 : */
259 : #define SIGNAL_CLD_STOPPED 0x00000010
260 : #define SIGNAL_CLD_CONTINUED 0x00000020
261 : #define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
262 :
263 : #define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */
264 :
265 : #define SIGNAL_STOP_MASK (SIGNAL_CLD_MASK | SIGNAL_STOP_STOPPED | \
266 : SIGNAL_STOP_CONTINUED)
267 :
268 0 : static inline void signal_set_stop_flags(struct signal_struct *sig,
269 : unsigned int flags)
270 : {
271 0 : WARN_ON(sig->flags & SIGNAL_GROUP_EXIT);
272 0 : sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags;
273 0 : }
274 :
275 : extern void flush_signals(struct task_struct *);
276 : extern void ignore_signals(struct task_struct *);
277 : extern void flush_signal_handlers(struct task_struct *, int force_default);
278 : extern int dequeue_signal(struct task_struct *task, sigset_t *mask,
279 : kernel_siginfo_t *info, enum pid_type *type);
280 :
281 : static inline int kernel_dequeue_signal(void)
282 : {
283 : struct task_struct *task = current;
284 : kernel_siginfo_t __info;
285 : enum pid_type __type;
286 : int ret;
287 :
288 : spin_lock_irq(&task->sighand->siglock);
289 : ret = dequeue_signal(task, &task->blocked, &__info, &__type);
290 : spin_unlock_irq(&task->sighand->siglock);
291 :
292 : return ret;
293 : }
294 :
295 : static inline void kernel_signal_stop(void)
296 : {
297 : spin_lock_irq(¤t->sighand->siglock);
298 : if (current->jobctl & JOBCTL_STOP_DEQUEUED) {
299 : current->jobctl |= JOBCTL_STOPPED;
300 : set_special_state(TASK_STOPPED);
301 : }
302 : spin_unlock_irq(¤t->sighand->siglock);
303 :
304 : schedule();
305 : }
306 : #ifdef __ia64__
307 : # define ___ARCH_SI_IA64(_a1, _a2, _a3) , _a1, _a2, _a3
308 : #else
309 : # define ___ARCH_SI_IA64(_a1, _a2, _a3)
310 : #endif
311 :
312 : int force_sig_fault_to_task(int sig, int code, void __user *addr
313 : ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
314 : , struct task_struct *t);
315 : int force_sig_fault(int sig, int code, void __user *addr
316 : ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr));
317 : int send_sig_fault(int sig, int code, void __user *addr
318 : ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
319 : , struct task_struct *t);
320 :
321 : int force_sig_mceerr(int code, void __user *, short);
322 : int send_sig_mceerr(int code, void __user *, short, struct task_struct *);
323 :
324 : int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper);
325 : int force_sig_pkuerr(void __user *addr, u32 pkey);
326 : int send_sig_perf(void __user *addr, u32 type, u64 sig_data);
327 :
328 : int force_sig_ptrace_errno_trap(int errno, void __user *addr);
329 : int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno);
330 : int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno,
331 : struct task_struct *t);
332 : int force_sig_seccomp(int syscall, int reason, bool force_coredump);
333 :
334 : extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
335 : extern void force_sigsegv(int sig);
336 : extern int force_sig_info(struct kernel_siginfo *);
337 : extern int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp);
338 : extern int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid);
339 : extern int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, struct pid *,
340 : const struct cred *);
341 : extern int kill_pgrp(struct pid *pid, int sig, int priv);
342 : extern int kill_pid(struct pid *pid, int sig, int priv);
343 : extern __must_check bool do_notify_parent(struct task_struct *, int);
344 : extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
345 : extern void force_sig(int);
346 : extern void force_fatal_sig(int);
347 : extern void force_exit_sig(int);
348 : extern int send_sig(int, struct task_struct *, int);
349 : extern int zap_other_threads(struct task_struct *p);
350 : extern struct sigqueue *sigqueue_alloc(void);
351 : extern void sigqueue_free(struct sigqueue *);
352 : extern int send_sigqueue(struct sigqueue *, struct pid *, enum pid_type);
353 : extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
354 :
355 : static inline void clear_notify_signal(void)
356 : {
357 0 : clear_thread_flag(TIF_NOTIFY_SIGNAL);
358 0 : smp_mb__after_atomic();
359 : }
360 :
361 : /*
362 : * Returns 'true' if kick_process() is needed to force a transition from
363 : * user -> kernel to guarantee expedient run of TWA_SIGNAL based task_work.
364 : */
365 0 : static inline bool __set_notify_signal(struct task_struct *task)
366 : {
367 0 : return !test_and_set_tsk_thread_flag(task, TIF_NOTIFY_SIGNAL) &&
368 0 : !wake_up_state(task, TASK_INTERRUPTIBLE);
369 : }
370 :
371 : /*
372 : * Called to break out of interruptible wait loops, and enter the
373 : * exit_to_user_mode_loop().
374 : */
375 : static inline void set_notify_signal(struct task_struct *task)
376 : {
377 0 : if (__set_notify_signal(task))
378 : kick_process(task);
379 : }
380 :
381 : static inline int restart_syscall(void)
382 : {
383 0 : set_tsk_thread_flag(current, TIF_SIGPENDING);
384 : return -ERESTARTNOINTR;
385 : }
386 :
387 : static inline int task_sigpending(struct task_struct *p)
388 : {
389 2068 : return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
390 : }
391 :
392 684 : static inline int signal_pending(struct task_struct *p)
393 : {
394 : /*
395 : * TIF_NOTIFY_SIGNAL isn't really a signal, but it requires the same
396 : * behavior in terms of ensuring that we break out of wait loops
397 : * so that notify signal callbacks can be processed.
398 : */
399 1368 : if (unlikely(test_tsk_thread_flag(p, TIF_NOTIFY_SIGNAL)))
400 : return 1;
401 684 : return task_sigpending(p);
402 : }
403 :
404 : static inline int __fatal_signal_pending(struct task_struct *p)
405 : {
406 0 : return unlikely(sigismember(&p->pending.signal, SIGKILL));
407 : }
408 :
409 175 : static inline int fatal_signal_pending(struct task_struct *p)
410 : {
411 175 : return task_sigpending(p) && __fatal_signal_pending(p);
412 : }
413 :
414 1368 : static inline int signal_pending_state(unsigned int state, struct task_struct *p)
415 : {
416 1368 : if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
417 : return 0;
418 684 : if (!signal_pending(p))
419 : return 0;
420 :
421 0 : return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
422 : }
423 :
424 : /*
425 : * This should only be used in fault handlers to decide whether we
426 : * should stop the current fault routine to handle the signals
427 : * instead, especially with the case where we've got interrupted with
428 : * a VM_FAULT_RETRY.
429 : */
430 : static inline bool fault_signal_pending(vm_fault_t fault_flags,
431 : struct pt_regs *regs)
432 : {
433 : return unlikely((fault_flags & VM_FAULT_RETRY) &&
434 : (fatal_signal_pending(current) ||
435 : (user_mode(regs) && signal_pending(current))));
436 : }
437 :
438 : /*
439 : * Reevaluate whether the task has signals pending delivery.
440 : * Wake the task if so.
441 : * This is required every time the blocked sigset_t changes.
442 : * callers must hold sighand->siglock.
443 : */
444 : extern void recalc_sigpending_and_wake(struct task_struct *t);
445 : extern void recalc_sigpending(void);
446 : extern void calculate_sigpending(void);
447 :
448 : extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
449 :
450 0 : static inline void signal_wake_up(struct task_struct *t, bool fatal)
451 : {
452 0 : unsigned int state = 0;
453 0 : if (fatal && !(t->jobctl & JOBCTL_PTRACE_FROZEN)) {
454 0 : t->jobctl &= ~(JOBCTL_STOPPED | JOBCTL_TRACED);
455 0 : state = TASK_WAKEKILL | __TASK_TRACED;
456 : }
457 0 : signal_wake_up_state(t, state);
458 0 : }
459 : static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
460 : {
461 0 : unsigned int state = 0;
462 0 : if (resume) {
463 0 : t->jobctl &= ~JOBCTL_TRACED;
464 0 : state = __TASK_TRACED;
465 : }
466 0 : signal_wake_up_state(t, state);
467 : }
468 :
469 : void task_join_group_stop(struct task_struct *task);
470 :
471 : #ifdef TIF_RESTORE_SIGMASK
472 : /*
473 : * Legacy restore_sigmask accessors. These are inefficient on
474 : * SMP architectures because they require atomic operations.
475 : */
476 :
477 : /**
478 : * set_restore_sigmask() - make sure saved_sigmask processing gets done
479 : *
480 : * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
481 : * will run before returning to user mode, to process the flag. For
482 : * all callers, TIF_SIGPENDING is already set or it's no harm to set
483 : * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the
484 : * arch code will notice on return to user mode, in case those bits
485 : * are scarce. We set TIF_SIGPENDING here to ensure that the arch
486 : * signal code always gets run when TIF_RESTORE_SIGMASK is set.
487 : */
488 : static inline void set_restore_sigmask(void)
489 : {
490 0 : set_thread_flag(TIF_RESTORE_SIGMASK);
491 : }
492 :
493 : static inline void clear_tsk_restore_sigmask(struct task_struct *task)
494 : {
495 0 : clear_tsk_thread_flag(task, TIF_RESTORE_SIGMASK);
496 : }
497 :
498 : static inline void clear_restore_sigmask(void)
499 : {
500 0 : clear_thread_flag(TIF_RESTORE_SIGMASK);
501 : }
502 : static inline bool test_tsk_restore_sigmask(struct task_struct *task)
503 : {
504 0 : return test_tsk_thread_flag(task, TIF_RESTORE_SIGMASK);
505 : }
506 : static inline bool test_restore_sigmask(void)
507 : {
508 0 : return test_thread_flag(TIF_RESTORE_SIGMASK);
509 : }
510 : static inline bool test_and_clear_restore_sigmask(void)
511 : {
512 0 : return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
513 : }
514 :
515 : #else /* TIF_RESTORE_SIGMASK */
516 :
517 : /* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */
518 : static inline void set_restore_sigmask(void)
519 : {
520 : current->restore_sigmask = true;
521 : }
522 : static inline void clear_tsk_restore_sigmask(struct task_struct *task)
523 : {
524 : task->restore_sigmask = false;
525 : }
526 : static inline void clear_restore_sigmask(void)
527 : {
528 : current->restore_sigmask = false;
529 : }
530 : static inline bool test_restore_sigmask(void)
531 : {
532 : return current->restore_sigmask;
533 : }
534 : static inline bool test_tsk_restore_sigmask(struct task_struct *task)
535 : {
536 : return task->restore_sigmask;
537 : }
538 : static inline bool test_and_clear_restore_sigmask(void)
539 : {
540 : if (!current->restore_sigmask)
541 : return false;
542 : current->restore_sigmask = false;
543 : return true;
544 : }
545 : #endif
546 :
547 0 : static inline void restore_saved_sigmask(void)
548 : {
549 0 : if (test_and_clear_restore_sigmask())
550 0 : __set_current_blocked(¤t->saved_sigmask);
551 0 : }
552 :
553 : extern int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize);
554 :
555 0 : static inline void restore_saved_sigmask_unless(bool interrupted)
556 : {
557 0 : if (interrupted)
558 0 : WARN_ON(!signal_pending(current));
559 : else
560 0 : restore_saved_sigmask();
561 0 : }
562 :
563 0 : static inline sigset_t *sigmask_to_save(void)
564 : {
565 0 : sigset_t *res = ¤t->blocked;
566 0 : if (unlikely(test_restore_sigmask()))
567 0 : res = ¤t->saved_sigmask;
568 0 : return res;
569 : }
570 :
571 : static inline int kill_cad_pid(int sig, int priv)
572 : {
573 0 : return kill_pid(cad_pid, sig, priv);
574 : }
575 :
576 : /* These can be the second arg to send_sig_info/send_group_sig_info. */
577 : #define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0)
578 : #define SEND_SIG_PRIV ((struct kernel_siginfo *) 1)
579 :
580 : static inline int __on_sig_stack(unsigned long sp)
581 : {
582 : #ifdef CONFIG_STACK_GROWSUP
583 : return sp >= current->sas_ss_sp &&
584 : sp - current->sas_ss_sp < current->sas_ss_size;
585 : #else
586 0 : return sp > current->sas_ss_sp &&
587 0 : sp - current->sas_ss_sp <= current->sas_ss_size;
588 : #endif
589 : }
590 :
591 : /*
592 : * True if we are on the alternate signal stack.
593 : */
594 0 : static inline int on_sig_stack(unsigned long sp)
595 : {
596 : /*
597 : * If the signal stack is SS_AUTODISARM then, by construction, we
598 : * can't be on the signal stack unless user code deliberately set
599 : * SS_AUTODISARM when we were already on it.
600 : *
601 : * This improves reliability: if user state gets corrupted such that
602 : * the stack pointer points very close to the end of the signal stack,
603 : * then this check will enable the signal to be handled anyway.
604 : */
605 0 : if (current->sas_ss_flags & SS_AUTODISARM)
606 : return 0;
607 :
608 : return __on_sig_stack(sp);
609 : }
610 :
611 : static inline int sas_ss_flags(unsigned long sp)
612 : {
613 0 : if (!current->sas_ss_size)
614 : return SS_DISABLE;
615 :
616 0 : return on_sig_stack(sp) ? SS_ONSTACK : 0;
617 : }
618 :
619 : static inline void sas_ss_reset(struct task_struct *p)
620 : {
621 175 : p->sas_ss_sp = 0;
622 175 : p->sas_ss_size = 0;
623 175 : p->sas_ss_flags = SS_DISABLE;
624 : }
625 :
626 : static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
627 : {
628 : if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
629 : #ifdef CONFIG_STACK_GROWSUP
630 : return current->sas_ss_sp;
631 : #else
632 : return current->sas_ss_sp + current->sas_ss_size;
633 : #endif
634 : return sp;
635 : }
636 :
637 : extern void __cleanup_sighand(struct sighand_struct *);
638 : extern void flush_itimer_signals(void);
639 :
640 : #define tasklist_empty() \
641 : list_empty(&init_task.tasks)
642 :
643 : #define next_task(p) \
644 : list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
645 :
646 : #define for_each_process(p) \
647 : for (p = &init_task ; (p = next_task(p)) != &init_task ; )
648 :
649 : extern bool current_is_single_threaded(void);
650 :
651 : /*
652 : * Careful: do_each_thread/while_each_thread is a double loop so
653 : * 'break' will not work as expected - use goto instead.
654 : */
655 : #define do_each_thread(g, t) \
656 : for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
657 :
658 : #define while_each_thread(g, t) \
659 : while ((t = next_thread(t)) != g)
660 :
661 : #define __for_each_thread(signal, t) \
662 : list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
663 :
664 : #define for_each_thread(p, t) \
665 : __for_each_thread((p)->signal, t)
666 :
667 : /* Careful: this is a double loop, 'break' won't work as expected. */
668 : #define for_each_process_thread(p, t) \
669 : for_each_process(p) for_each_thread(p, t)
670 :
671 : typedef int (*proc_visitor)(struct task_struct *p, void *data);
672 : void walk_process_tree(struct task_struct *top, proc_visitor, void *);
673 :
674 : static inline
675 : struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
676 : {
677 : struct pid *pid;
678 0 : if (type == PIDTYPE_PID)
679 0 : pid = task_pid(task);
680 : else
681 0 : pid = task->signal->pids[type];
682 : return pid;
683 : }
684 :
685 : static inline struct pid *task_tgid(struct task_struct *task)
686 : {
687 0 : return task->signal->pids[PIDTYPE_TGID];
688 : }
689 :
690 : /*
691 : * Without tasklist or RCU lock it is not safe to dereference
692 : * the result of task_pgrp/task_session even if task == current,
693 : * we can race with another thread doing sys_setsid/sys_setpgid.
694 : */
695 : static inline struct pid *task_pgrp(struct task_struct *task)
696 : {
697 495 : return task->signal->pids[PIDTYPE_PGID];
698 : }
699 :
700 : static inline struct pid *task_session(struct task_struct *task)
701 : {
702 175 : return task->signal->pids[PIDTYPE_SID];
703 : }
704 :
705 : static inline int get_nr_threads(struct task_struct *task)
706 : {
707 0 : return task->signal->nr_threads;
708 : }
709 :
710 : static inline bool thread_group_leader(struct task_struct *p)
711 : {
712 160 : return p->exit_signal >= 0;
713 : }
714 :
715 : static inline
716 : bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
717 : {
718 0 : return p1->signal == p2->signal;
719 : }
720 :
721 : static inline struct task_struct *next_thread(const struct task_struct *p)
722 : {
723 0 : return list_entry_rcu(p->thread_group.next,
724 : struct task_struct, thread_group);
725 : }
726 :
727 : static inline int thread_group_empty(struct task_struct *p)
728 : {
729 960 : return list_empty(&p->thread_group);
730 : }
731 :
732 : #define delay_group_leader(p) \
733 : (thread_group_leader(p) && !thread_group_empty(p))
734 :
735 : extern bool thread_group_exited(struct pid *pid);
736 :
737 : extern struct sighand_struct *__lock_task_sighand(struct task_struct *task,
738 : unsigned long *flags);
739 :
740 : static inline struct sighand_struct *lock_task_sighand(struct task_struct *task,
741 : unsigned long *flags)
742 : {
743 : struct sighand_struct *ret;
744 :
745 0 : ret = __lock_task_sighand(task, flags);
746 : (void)__cond_lock(&task->sighand->siglock, ret);
747 : return ret;
748 : }
749 :
750 : static inline void unlock_task_sighand(struct task_struct *task,
751 : unsigned long *flags)
752 : {
753 0 : spin_unlock_irqrestore(&task->sighand->siglock, *flags);
754 : }
755 :
756 : #ifdef CONFIG_LOCKDEP
757 : extern void lockdep_assert_task_sighand_held(struct task_struct *task);
758 : #else
759 : static inline void lockdep_assert_task_sighand_held(struct task_struct *task) { }
760 : #endif
761 :
762 : static inline unsigned long task_rlimit(const struct task_struct *task,
763 : unsigned int limit)
764 : {
765 175 : return READ_ONCE(task->signal->rlim[limit].rlim_cur);
766 : }
767 :
768 : static inline unsigned long task_rlimit_max(const struct task_struct *task,
769 : unsigned int limit)
770 : {
771 0 : return READ_ONCE(task->signal->rlim[limit].rlim_max);
772 : }
773 :
774 : static inline unsigned long rlimit(unsigned int limit)
775 : {
776 350 : return task_rlimit(current, limit);
777 : }
778 :
779 : static inline unsigned long rlimit_max(unsigned int limit)
780 : {
781 0 : return task_rlimit_max(current, limit);
782 : }
783 :
784 : #endif /* _LINUX_SCHED_SIGNAL_H */
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