1 /* SPDX-License-Identifier: GPL-2.0 */
6 #include <linux/signal.h>
12 #include <linux/posix-timers.h>
17  * Types defining task->signal and task->sighand and APIs using them:
28  * Per-process accounting stats:
60  * struct thread_group_cputimer - thread group interval timer counts
61  * @cputime_atomic:	atomic thread group interval timers.
64  * used for thread group CPU timer calculations.
71 	sigset_t signal;  member
102 	/* current thread group signal load-balancing target: */
105 	/* shared signal handling: */
111 	/* thread group exit support */
117 	/* thread group stop support, overloads group_exit_code too */
125 	 * manager, to re-parent orphan (double-forking) child processes
153 	 * Thread group totals for process CPU timers.
171 	/* boolean value for session group leader */
180 	 * Cumulative resource counters for dead threads in the group,
181 	 * and for reaped dead child processes forked by this group.
183 	 * in __exit_signal, except for the group leader.
198 	 * group, not including a zombie group leader, (This only differs
209 	 * getrlimit/setrlimit use task_lock(current->group_leader) to
216 	struct pacct_struct pacct;	/* per-process accounting information */
234 	struct mm_struct *oom_mm;	/* recorded mm when the thread group got
255 #define SIGNAL_GROUP_EXIT	0x00000004 /* group exit in progress */
271 	WARN_ON(sig->flags & SIGNAL_GROUP_EXIT);  in signal_set_stop_flags()
272 	sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags;  in signal_set_stop_flags()
288 	spin_lock_irq(&task->sighand->siglock);  in kernel_dequeue_signal()
289 	ret = dequeue_signal(task, &task->blocked, &__info, &__type);  in kernel_dequeue_signal()
290 	spin_unlock_irq(&task->sighand->siglock);  in kernel_dequeue_signal()
297 	spin_lock_irq(&current->sighand->siglock);  in kernel_signal_stop()
298 	if (current->jobctl & JOBCTL_STOP_DEQUEUED) {  in kernel_signal_stop()
299 		current->jobctl |= JOBCTL_STOPPED;  in kernel_signal_stop()
302 	spin_unlock_irq(&current->sighand->siglock);  in kernel_signal_stop()
363  * user -> kernel to guarantee expedient run of TWA_SIGNAL based task_work.
384 	return -ERESTARTNOINTR;  in restart_syscall()
395 	 * TIF_NOTIFY_SIGNAL isn't really a signal, but it requires the same  in signal_pending()
397 	 * so that notify signal callbacks can be processed.  in signal_pending()
406 	return unlikely(sigismember(&p->pending.signal, SIGKILL));  in __fatal_signal_pending()
442  * callers must hold sighand->siglock.
453 	if (fatal && !(t->jobctl & JOBCTL_PTRACE_FROZEN)) {  in signal_wake_up()
454 		t->jobctl &= ~(JOBCTL_STOPPED | JOBCTL_TRACED);  in signal_wake_up()
463 		t->jobctl &= ~JOBCTL_TRACED;  in ptrace_signal_wake_up()
478  * set_restore_sigmask() - make sure saved_sigmask processing gets done
480  * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
486  * signal code always gets run when TIF_RESTORE_SIGMASK is set.
517 /* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */
520 	current->restore_sigmask = true;  in set_restore_sigmask()
524 	task->restore_sigmask = false;  in clear_tsk_restore_sigmask()
528 	current->restore_sigmask = false;  in clear_restore_sigmask()
532 	return current->restore_sigmask;  in test_restore_sigmask()
536 	return task->restore_sigmask;  in test_tsk_restore_sigmask()
540 	if (!current->restore_sigmask)  in test_and_clear_restore_sigmask()
542 	current->restore_sigmask = false;  in test_and_clear_restore_sigmask()
550 		__set_current_blocked(&current->saved_sigmask);  in restore_saved_sigmask()
565 	sigset_t *res = &current->blocked;  in sigmask_to_save()
567 		res = &current->saved_sigmask;  in sigmask_to_save()
583 	return sp >= current->sas_ss_sp &&  in __on_sig_stack()
584 		sp - current->sas_ss_sp < current->sas_ss_size;  in __on_sig_stack()
586 	return sp > current->sas_ss_sp &&  in __on_sig_stack()
587 		sp - current->sas_ss_sp <= current->sas_ss_size;  in __on_sig_stack()
592  * True if we are on the alternate signal stack.
597 	 * If the signal stack is SS_AUTODISARM then, by construction, we  in on_sig_stack()
598 	 * can't be on the signal stack unless user code deliberately set  in on_sig_stack()
602 	 * the stack pointer points very close to the end of the signal stack,  in on_sig_stack()
603 	 * then this check will enable the signal to be handled anyway.  in on_sig_stack()
605 	if (current->sas_ss_flags & SS_AUTODISARM)  in on_sig_stack()
613 	if (!current->sas_ss_size)  in sas_ss_flags()
621 	p->sas_ss_sp = 0;  in sas_ss_reset()
622 	p->sas_ss_size = 0;  in sas_ss_reset()
623 	p->sas_ss_flags = SS_DISABLE;  in sas_ss_reset()
628 	if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))  in sigsp()
630 		return current->sas_ss_sp;  in sigsp()
632 		return current->sas_ss_sp + current->sas_ss_size;  in sigsp()
644 	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
653  *          'break' will not work as expected - use goto instead.
661 #define __for_each_thread(signal, t)	\  argument
662 	list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
665 	__for_each_thread((p)->signal, t)
681 		pid = task->signal->pids[type];  in task_pid_type()
687 	return task->signal->pids[PIDTYPE_TGID];  in task_tgid()
697 	return task->signal->pids[PIDTYPE_PGID];  in task_pgrp()
702 	return task->signal->pids[PIDTYPE_SID];  in task_session()
707 	return task->signal->nr_threads;  in get_nr_threads()
712 	return p->exit_signal >= 0;  in thread_group_leader()
718 	return p1->signal == p2->signal;  in same_thread_group()
723 	return list_entry_rcu(p->thread_group.next,  in next_thread()
729 	return list_empty(&p->thread_group);  in thread_group_empty()
746 	(void)__cond_lock(&task->sighand->siglock, ret);  in lock_task_sighand()
753 	spin_unlock_irqrestore(&task->sighand->siglock, *flags);  in unlock_task_sighand()
765 	return READ_ONCE(task->signal->rlim[limit].rlim_cur);  in task_rlimit()
771 	return READ_ONCE(task->signal->rlim[limit].rlim_max);  in task_rlimit_max()