blob: 657640015b335c8e21e15e223ecb88c3aa2cd475 [file] [log] [blame]
Andrew Scullb4b6d4a2019-01-02 15:54:55 +00001/* 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>
David Brazdil0f672f62019-12-10 10:32:29 +000011#include <linux/refcount.h>
12#include <linux/posix-timers.h>
Olivier Deprez157378f2022-04-04 15:47:50 +020013#include <linux/mm_types.h>
14#include <asm/ptrace.h>
Andrew Scullb4b6d4a2019-01-02 15:54:55 +000015
16/*
17 * Types defining task->signal and task->sighand and APIs using them:
18 */
19
20struct sighand_struct {
Andrew Scullb4b6d4a2019-01-02 15:54:55 +000021 spinlock_t siglock;
David Brazdil0f672f62019-12-10 10:32:29 +000022 refcount_t count;
Andrew Scullb4b6d4a2019-01-02 15:54:55 +000023 wait_queue_head_t signalfd_wqh;
David Brazdil0f672f62019-12-10 10:32:29 +000024 struct k_sigaction action[_NSIG];
Andrew Scullb4b6d4a2019-01-02 15:54:55 +000025};
26
27/*
28 * Per-process accounting stats:
29 */
30struct 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
38struct 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 */
47struct 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.
Andrew Scullb4b6d4a2019-01-02 15:54:55 +000062 *
63 * This structure contains the version of task_cputime, above, that is
64 * used for thread group CPU timer calculations.
65 */
66struct thread_group_cputimer {
67 struct task_cputime_atomic cputime_atomic;
Andrew Scullb4b6d4a2019-01-02 15:54:55 +000068};
69
70struct multiprocess_signals {
71 sigset_t signal;
72 struct hlist_node node;
73};
74
75/*
76 * NOTE! "signal_struct" does not have its own
77 * locking, because a shared signal_struct always
78 * implies a shared sighand_struct, so locking
79 * sighand_struct is always a proper superset of
80 * the locking of signal_struct.
81 */
82struct signal_struct {
David Brazdil0f672f62019-12-10 10:32:29 +000083 refcount_t sigcnt;
Andrew Scullb4b6d4a2019-01-02 15:54:55 +000084 atomic_t live;
85 int nr_threads;
86 struct list_head thread_head;
87
88 wait_queue_head_t wait_chldexit; /* for wait4() */
89
90 /* current thread group signal load-balancing target: */
91 struct task_struct *curr_target;
92
93 /* shared signal handling: */
94 struct sigpending shared_pending;
95
96 /* For collecting multiprocess signals during fork */
97 struct hlist_head multiprocess;
98
99 /* thread group exit support */
100 int group_exit_code;
101 /* overloaded:
102 * - notify group_exit_task when ->count is equal to notify_count
103 * - everyone except group_exit_task is stopped during signal delivery
104 * of fatal signals, group_exit_task processes the signal.
105 */
106 int notify_count;
107 struct task_struct *group_exit_task;
108
109 /* thread group stop support, overloads group_exit_code too */
110 int group_stop_count;
111 unsigned int flags; /* see SIGNAL_* flags below */
112
113 /*
114 * PR_SET_CHILD_SUBREAPER marks a process, like a service
115 * manager, to re-parent orphan (double-forking) child processes
116 * to this process instead of 'init'. The service manager is
117 * able to receive SIGCHLD signals and is able to investigate
118 * the process until it calls wait(). All children of this
119 * process will inherit a flag if they should look for a
120 * child_subreaper process at exit.
121 */
122 unsigned int is_child_subreaper:1;
123 unsigned int has_child_subreaper:1;
124
125#ifdef CONFIG_POSIX_TIMERS
126
127 /* POSIX.1b Interval Timers */
128 int posix_timer_id;
129 struct list_head posix_timers;
130
131 /* ITIMER_REAL timer for the process */
132 struct hrtimer real_timer;
133 ktime_t it_real_incr;
134
135 /*
136 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
137 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
138 * values are defined to 0 and 1 respectively
139 */
140 struct cpu_itimer it[2];
141
142 /*
143 * Thread group totals for process CPU timers.
144 * See thread_group_cputimer(), et al, for details.
145 */
146 struct thread_group_cputimer cputimer;
147
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000148#endif
David Brazdil0f672f62019-12-10 10:32:29 +0000149 /* Empty if CONFIG_POSIX_TIMERS=n */
150 struct posix_cputimers posix_cputimers;
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000151
152 /* PID/PID hash table linkage. */
153 struct pid *pids[PIDTYPE_MAX];
154
155#ifdef CONFIG_NO_HZ_FULL
156 atomic_t tick_dep_mask;
157#endif
158
159 struct pid *tty_old_pgrp;
160
161 /* boolean value for session group leader */
162 int leader;
163
164 struct tty_struct *tty; /* NULL if no tty */
165
166#ifdef CONFIG_SCHED_AUTOGROUP
167 struct autogroup *autogroup;
168#endif
169 /*
170 * Cumulative resource counters for dead threads in the group,
171 * and for reaped dead child processes forked by this group.
172 * Live threads maintain their own counters and add to these
173 * in __exit_signal, except for the group leader.
174 */
175 seqlock_t stats_lock;
176 u64 utime, stime, cutime, cstime;
177 u64 gtime;
178 u64 cgtime;
179 struct prev_cputime prev_cputime;
180 unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
181 unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
182 unsigned long inblock, oublock, cinblock, coublock;
183 unsigned long maxrss, cmaxrss;
184 struct task_io_accounting ioac;
185
186 /*
187 * Cumulative ns of schedule CPU time fo dead threads in the
188 * group, not including a zombie group leader, (This only differs
189 * from jiffies_to_ns(utime + stime) if sched_clock uses something
190 * other than jiffies.)
191 */
192 unsigned long long sum_sched_runtime;
193
194 /*
195 * We don't bother to synchronize most readers of this at all,
196 * because there is no reader checking a limit that actually needs
197 * to get both rlim_cur and rlim_max atomically, and either one
198 * alone is a single word that can safely be read normally.
199 * getrlimit/setrlimit use task_lock(current->group_leader) to
200 * protect this instead of the siglock, because they really
201 * have no need to disable irqs.
202 */
203 struct rlimit rlim[RLIM_NLIMITS];
204
205#ifdef CONFIG_BSD_PROCESS_ACCT
206 struct pacct_struct pacct; /* per-process accounting information */
207#endif
208#ifdef CONFIG_TASKSTATS
209 struct taskstats *stats;
210#endif
211#ifdef CONFIG_AUDIT
212 unsigned audit_tty;
213 struct tty_audit_buf *tty_audit_buf;
214#endif
215
216 /*
217 * Thread is the potential origin of an oom condition; kill first on
218 * oom
219 */
220 bool oom_flag_origin;
221 short oom_score_adj; /* OOM kill score adjustment */
222 short oom_score_adj_min; /* OOM kill score adjustment min value.
223 * Only settable by CAP_SYS_RESOURCE. */
224 struct mm_struct *oom_mm; /* recorded mm when the thread group got
225 * killed by the oom killer */
226
227 struct mutex cred_guard_mutex; /* guard against foreign influences on
228 * credential calculations
Olivier Deprez0e641232021-09-23 10:07:05 +0200229 * (notably. ptrace)
230 * Deprecated do not use in new code.
231 * Use exec_update_lock instead.
232 */
233 struct rw_semaphore exec_update_lock; /* Held while task_struct is
234 * being updated during exec,
235 * and may have inconsistent
236 * permissions.
237 */
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000238} __randomize_layout;
239
240/*
241 * Bits in flags field of signal_struct.
242 */
243#define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */
244#define SIGNAL_STOP_CONTINUED 0x00000002 /* SIGCONT since WCONTINUED reap */
245#define SIGNAL_GROUP_EXIT 0x00000004 /* group exit in progress */
246#define SIGNAL_GROUP_COREDUMP 0x00000008 /* coredump in progress */
247/*
248 * Pending notifications to parent.
249 */
250#define SIGNAL_CLD_STOPPED 0x00000010
251#define SIGNAL_CLD_CONTINUED 0x00000020
252#define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
253
254#define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */
255
256#define SIGNAL_STOP_MASK (SIGNAL_CLD_MASK | SIGNAL_STOP_STOPPED | \
257 SIGNAL_STOP_CONTINUED)
258
259static inline void signal_set_stop_flags(struct signal_struct *sig,
260 unsigned int flags)
261{
262 WARN_ON(sig->flags & (SIGNAL_GROUP_EXIT|SIGNAL_GROUP_COREDUMP));
263 sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags;
264}
265
266/* If true, all threads except ->group_exit_task have pending SIGKILL */
267static inline int signal_group_exit(const struct signal_struct *sig)
268{
269 return (sig->flags & SIGNAL_GROUP_EXIT) ||
270 (sig->group_exit_task != NULL);
271}
272
273extern void flush_signals(struct task_struct *);
274extern void ignore_signals(struct task_struct *);
275extern void flush_signal_handlers(struct task_struct *, int force_default);
David Brazdil0f672f62019-12-10 10:32:29 +0000276extern int dequeue_signal(struct task_struct *task,
277 sigset_t *mask, kernel_siginfo_t *info);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000278
David Brazdil0f672f62019-12-10 10:32:29 +0000279static inline int kernel_dequeue_signal(void)
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000280{
David Brazdil0f672f62019-12-10 10:32:29 +0000281 struct task_struct *task = current;
282 kernel_siginfo_t __info;
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000283 int ret;
284
David Brazdil0f672f62019-12-10 10:32:29 +0000285 spin_lock_irq(&task->sighand->siglock);
286 ret = dequeue_signal(task, &task->blocked, &__info);
287 spin_unlock_irq(&task->sighand->siglock);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000288
289 return ret;
290}
291
292static inline void kernel_signal_stop(void)
293{
294 spin_lock_irq(&current->sighand->siglock);
295 if (current->jobctl & JOBCTL_STOP_DEQUEUED)
296 set_special_state(TASK_STOPPED);
297 spin_unlock_irq(&current->sighand->siglock);
298
299 schedule();
300}
301#ifdef __ARCH_SI_TRAPNO
302# define ___ARCH_SI_TRAPNO(_a1) , _a1
303#else
304# define ___ARCH_SI_TRAPNO(_a1)
305#endif
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
David Brazdil0f672f62019-12-10 10:32:29 +0000312int force_sig_fault_to_task(int sig, int code, void __user *addr
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000313 ___ARCH_SI_TRAPNO(int trapno)
314 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
315 , struct task_struct *t);
David Brazdil0f672f62019-12-10 10:32:29 +0000316int force_sig_fault(int sig, int code, void __user *addr
317 ___ARCH_SI_TRAPNO(int trapno)
318 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr));
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000319int send_sig_fault(int sig, int code, void __user *addr
320 ___ARCH_SI_TRAPNO(int trapno)
321 ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
322 , struct task_struct *t);
323
David Brazdil0f672f62019-12-10 10:32:29 +0000324int force_sig_mceerr(int code, void __user *, short);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000325int send_sig_mceerr(int code, void __user *, short, struct task_struct *);
326
327int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper);
328int force_sig_pkuerr(void __user *addr, u32 pkey);
329
330int force_sig_ptrace_errno_trap(int errno, void __user *addr);
331
David Brazdil0f672f62019-12-10 10:32:29 +0000332extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
333extern void force_sigsegv(int sig);
334extern int force_sig_info(struct kernel_siginfo *);
335extern int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp);
336extern int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid);
337extern int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, struct pid *,
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000338 const struct cred *);
339extern int kill_pgrp(struct pid *pid, int sig, int priv);
340extern int kill_pid(struct pid *pid, int sig, int priv);
341extern __must_check bool do_notify_parent(struct task_struct *, int);
342extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
David Brazdil0f672f62019-12-10 10:32:29 +0000343extern void force_sig(int);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000344extern int send_sig(int, struct task_struct *, int);
345extern int zap_other_threads(struct task_struct *p);
346extern struct sigqueue *sigqueue_alloc(void);
347extern void sigqueue_free(struct sigqueue *);
348extern int send_sigqueue(struct sigqueue *, struct pid *, enum pid_type);
349extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
350
351static inline int restart_syscall(void)
352{
353 set_tsk_thread_flag(current, TIF_SIGPENDING);
354 return -ERESTARTNOINTR;
355}
356
357static inline int signal_pending(struct task_struct *p)
358{
359 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
360}
361
362static inline int __fatal_signal_pending(struct task_struct *p)
363{
364 return unlikely(sigismember(&p->pending.signal, SIGKILL));
365}
366
367static inline int fatal_signal_pending(struct task_struct *p)
368{
369 return signal_pending(p) && __fatal_signal_pending(p);
370}
371
372static inline int signal_pending_state(long state, struct task_struct *p)
373{
374 if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
375 return 0;
376 if (!signal_pending(p))
377 return 0;
378
379 return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
380}
381
382/*
Olivier Deprez157378f2022-04-04 15:47:50 +0200383 * This should only be used in fault handlers to decide whether we
384 * should stop the current fault routine to handle the signals
385 * instead, especially with the case where we've got interrupted with
386 * a VM_FAULT_RETRY.
387 */
388static inline bool fault_signal_pending(vm_fault_t fault_flags,
389 struct pt_regs *regs)
390{
391 return unlikely((fault_flags & VM_FAULT_RETRY) &&
392 (fatal_signal_pending(current) ||
393 (user_mode(regs) && signal_pending(current))));
394}
395
396/*
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000397 * Reevaluate whether the task has signals pending delivery.
398 * Wake the task if so.
399 * This is required every time the blocked sigset_t changes.
400 * callers must hold sighand->siglock.
401 */
402extern void recalc_sigpending_and_wake(struct task_struct *t);
403extern void recalc_sigpending(void);
404extern void calculate_sigpending(void);
405
406extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
407
408static inline void signal_wake_up(struct task_struct *t, bool resume)
409{
410 signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
411}
412static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
413{
414 signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
415}
416
417void task_join_group_stop(struct task_struct *task);
418
419#ifdef TIF_RESTORE_SIGMASK
420/*
421 * Legacy restore_sigmask accessors. These are inefficient on
422 * SMP architectures because they require atomic operations.
423 */
424
425/**
426 * set_restore_sigmask() - make sure saved_sigmask processing gets done
427 *
428 * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
429 * will run before returning to user mode, to process the flag. For
430 * all callers, TIF_SIGPENDING is already set or it's no harm to set
431 * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the
432 * arch code will notice on return to user mode, in case those bits
433 * are scarce. We set TIF_SIGPENDING here to ensure that the arch
434 * signal code always gets run when TIF_RESTORE_SIGMASK is set.
435 */
436static inline void set_restore_sigmask(void)
437{
438 set_thread_flag(TIF_RESTORE_SIGMASK);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000439}
David Brazdil0f672f62019-12-10 10:32:29 +0000440
441static inline void clear_tsk_restore_sigmask(struct task_struct *task)
442{
443 clear_tsk_thread_flag(task, TIF_RESTORE_SIGMASK);
444}
445
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000446static inline void clear_restore_sigmask(void)
447{
448 clear_thread_flag(TIF_RESTORE_SIGMASK);
449}
David Brazdil0f672f62019-12-10 10:32:29 +0000450static inline bool test_tsk_restore_sigmask(struct task_struct *task)
451{
452 return test_tsk_thread_flag(task, TIF_RESTORE_SIGMASK);
453}
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000454static inline bool test_restore_sigmask(void)
455{
456 return test_thread_flag(TIF_RESTORE_SIGMASK);
457}
458static inline bool test_and_clear_restore_sigmask(void)
459{
460 return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
461}
462
463#else /* TIF_RESTORE_SIGMASK */
464
465/* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */
466static inline void set_restore_sigmask(void)
467{
468 current->restore_sigmask = true;
David Brazdil0f672f62019-12-10 10:32:29 +0000469}
470static inline void clear_tsk_restore_sigmask(struct task_struct *task)
471{
472 task->restore_sigmask = false;
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000473}
474static inline void clear_restore_sigmask(void)
475{
476 current->restore_sigmask = false;
477}
478static inline bool test_restore_sigmask(void)
479{
480 return current->restore_sigmask;
481}
David Brazdil0f672f62019-12-10 10:32:29 +0000482static inline bool test_tsk_restore_sigmask(struct task_struct *task)
483{
484 return task->restore_sigmask;
485}
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000486static inline bool test_and_clear_restore_sigmask(void)
487{
488 if (!current->restore_sigmask)
489 return false;
490 current->restore_sigmask = false;
491 return true;
492}
493#endif
494
495static inline void restore_saved_sigmask(void)
496{
497 if (test_and_clear_restore_sigmask())
498 __set_current_blocked(&current->saved_sigmask);
499}
500
David Brazdil0f672f62019-12-10 10:32:29 +0000501extern int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize);
502
503static inline void restore_saved_sigmask_unless(bool interrupted)
504{
505 if (interrupted)
506 WARN_ON(!test_thread_flag(TIF_SIGPENDING));
507 else
508 restore_saved_sigmask();
509}
510
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000511static inline sigset_t *sigmask_to_save(void)
512{
513 sigset_t *res = &current->blocked;
514 if (unlikely(test_restore_sigmask()))
515 res = &current->saved_sigmask;
516 return res;
517}
518
519static inline int kill_cad_pid(int sig, int priv)
520{
521 return kill_pid(cad_pid, sig, priv);
522}
523
524/* These can be the second arg to send_sig_info/send_group_sig_info. */
David Brazdil0f672f62019-12-10 10:32:29 +0000525#define SEND_SIG_NOINFO ((struct kernel_siginfo *) 0)
526#define SEND_SIG_PRIV ((struct kernel_siginfo *) 1)
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000527
Olivier Deprez0e641232021-09-23 10:07:05 +0200528static inline int __on_sig_stack(unsigned long sp)
529{
530#ifdef CONFIG_STACK_GROWSUP
531 return sp >= current->sas_ss_sp &&
532 sp - current->sas_ss_sp < current->sas_ss_size;
533#else
534 return sp > current->sas_ss_sp &&
535 sp - current->sas_ss_sp <= current->sas_ss_size;
536#endif
537}
538
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000539/*
540 * True if we are on the alternate signal stack.
541 */
542static inline int on_sig_stack(unsigned long sp)
543{
544 /*
545 * If the signal stack is SS_AUTODISARM then, by construction, we
546 * can't be on the signal stack unless user code deliberately set
547 * SS_AUTODISARM when we were already on it.
548 *
549 * This improves reliability: if user state gets corrupted such that
550 * the stack pointer points very close to the end of the signal stack,
551 * then this check will enable the signal to be handled anyway.
552 */
553 if (current->sas_ss_flags & SS_AUTODISARM)
554 return 0;
555
Olivier Deprez0e641232021-09-23 10:07:05 +0200556 return __on_sig_stack(sp);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000557}
558
559static inline int sas_ss_flags(unsigned long sp)
560{
561 if (!current->sas_ss_size)
562 return SS_DISABLE;
563
564 return on_sig_stack(sp) ? SS_ONSTACK : 0;
565}
566
567static inline void sas_ss_reset(struct task_struct *p)
568{
569 p->sas_ss_sp = 0;
570 p->sas_ss_size = 0;
571 p->sas_ss_flags = SS_DISABLE;
572}
573
574static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
575{
576 if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
577#ifdef CONFIG_STACK_GROWSUP
578 return current->sas_ss_sp;
579#else
580 return current->sas_ss_sp + current->sas_ss_size;
581#endif
582 return sp;
583}
584
585extern void __cleanup_sighand(struct sighand_struct *);
586extern void flush_itimer_signals(void);
587
588#define tasklist_empty() \
589 list_empty(&init_task.tasks)
590
591#define next_task(p) \
592 list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
593
594#define for_each_process(p) \
595 for (p = &init_task ; (p = next_task(p)) != &init_task ; )
596
597extern bool current_is_single_threaded(void);
598
599/*
600 * Careful: do_each_thread/while_each_thread is a double loop so
601 * 'break' will not work as expected - use goto instead.
602 */
603#define do_each_thread(g, t) \
604 for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
605
606#define while_each_thread(g, t) \
607 while ((t = next_thread(t)) != g)
608
609#define __for_each_thread(signal, t) \
610 list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
611
612#define for_each_thread(p, t) \
613 __for_each_thread((p)->signal, t)
614
615/* Careful: this is a double loop, 'break' won't work as expected. */
616#define for_each_process_thread(p, t) \
617 for_each_process(p) for_each_thread(p, t)
618
619typedef int (*proc_visitor)(struct task_struct *p, void *data);
620void walk_process_tree(struct task_struct *top, proc_visitor, void *);
621
622static inline
623struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
624{
625 struct pid *pid;
626 if (type == PIDTYPE_PID)
627 pid = task_pid(task);
628 else
629 pid = task->signal->pids[type];
630 return pid;
631}
632
633static inline struct pid *task_tgid(struct task_struct *task)
634{
635 return task->signal->pids[PIDTYPE_TGID];
636}
637
638/*
639 * Without tasklist or RCU lock it is not safe to dereference
640 * the result of task_pgrp/task_session even if task == current,
641 * we can race with another thread doing sys_setsid/sys_setpgid.
642 */
643static inline struct pid *task_pgrp(struct task_struct *task)
644{
645 return task->signal->pids[PIDTYPE_PGID];
646}
647
648static inline struct pid *task_session(struct task_struct *task)
649{
650 return task->signal->pids[PIDTYPE_SID];
651}
652
David Brazdil0f672f62019-12-10 10:32:29 +0000653static inline int get_nr_threads(struct task_struct *task)
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000654{
David Brazdil0f672f62019-12-10 10:32:29 +0000655 return task->signal->nr_threads;
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000656}
657
658static inline bool thread_group_leader(struct task_struct *p)
659{
660 return p->exit_signal >= 0;
661}
662
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000663static inline
664bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
665{
666 return p1->signal == p2->signal;
667}
668
669static inline struct task_struct *next_thread(const struct task_struct *p)
670{
671 return list_entry_rcu(p->thread_group.next,
672 struct task_struct, thread_group);
673}
674
675static inline int thread_group_empty(struct task_struct *p)
676{
677 return list_empty(&p->thread_group);
678}
679
680#define delay_group_leader(p) \
681 (thread_group_leader(p) && !thread_group_empty(p))
682
Olivier Deprez157378f2022-04-04 15:47:50 +0200683extern bool thread_group_exited(struct pid *pid);
684
David Brazdil0f672f62019-12-10 10:32:29 +0000685extern struct sighand_struct *__lock_task_sighand(struct task_struct *task,
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000686 unsigned long *flags);
687
David Brazdil0f672f62019-12-10 10:32:29 +0000688static inline struct sighand_struct *lock_task_sighand(struct task_struct *task,
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000689 unsigned long *flags)
690{
691 struct sighand_struct *ret;
692
David Brazdil0f672f62019-12-10 10:32:29 +0000693 ret = __lock_task_sighand(task, flags);
694 (void)__cond_lock(&task->sighand->siglock, ret);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000695 return ret;
696}
697
David Brazdil0f672f62019-12-10 10:32:29 +0000698static inline void unlock_task_sighand(struct task_struct *task,
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000699 unsigned long *flags)
700{
David Brazdil0f672f62019-12-10 10:32:29 +0000701 spin_unlock_irqrestore(&task->sighand->siglock, *flags);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000702}
703
David Brazdil0f672f62019-12-10 10:32:29 +0000704static inline unsigned long task_rlimit(const struct task_struct *task,
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000705 unsigned int limit)
706{
David Brazdil0f672f62019-12-10 10:32:29 +0000707 return READ_ONCE(task->signal->rlim[limit].rlim_cur);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000708}
709
David Brazdil0f672f62019-12-10 10:32:29 +0000710static inline unsigned long task_rlimit_max(const struct task_struct *task,
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000711 unsigned int limit)
712{
David Brazdil0f672f62019-12-10 10:32:29 +0000713 return READ_ONCE(task->signal->rlim[limit].rlim_max);
Andrew Scullb4b6d4a2019-01-02 15:54:55 +0000714}
715
716static inline unsigned long rlimit(unsigned int limit)
717{
718 return task_rlimit(current, limit);
719}
720
721static inline unsigned long rlimit_max(unsigned int limit)
722{
723 return task_rlimit_max(current, limit);
724}
725
726#endif /* _LINUX_SCHED_SIGNAL_H */