Commit 5c251e9d authored by Jens Axboe's avatar Jens Axboe Committed by Thomas Gleixner
Browse files

signal: Add task_sigpending() helper 



This is in preparation for maintaining signal_pending() as the decider of
whether or not a schedule() loop should be broken, or continue sleeping.
This is different than the core signal use cases, which really need to know
whether an actual signal is pending or not. task_sigpending() returns
non-zero if TIF_SIGPENDING is set.

Only core kernel use cases should care about the distinction between
the two, make sure those use the task_sigpending() helper.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarOleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20201026203230.386348-2-axboe@kernel.dk
parent 9123e3a7

include/linux/sched/signal.h

+7 −2
Original line number Diff line number Diff line
@@ -353,11 +353,16 @@ static inline int restart_syscall(void) 
	return -ERESTARTNOINTR;

}



static inline int signal_pending(struct task_struct *p)

static inline int task_sigpending(struct task_struct *p)

{

	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));

}



static inline int signal_pending(struct task_struct *p)

{

	return task_sigpending(p);

}



static inline int __fatal_signal_pending(struct task_struct *p)

{

	return unlikely(sigismember(&p->pending.signal, SIGKILL));
@@ -365,7 +370,7 @@ static inline int __fatal_signal_pending(struct task_struct *p) 


static inline int fatal_signal_pending(struct task_struct *p)

{

	return signal_pending(p) && __fatal_signal_pending(p);

	return task_sigpending(p) && __fatal_signal_pending(p);

}



static inline int signal_pending_state(long state, struct task_struct *p)

kernel/events/uprobes.c

+1 −1
Original line number Diff line number Diff line
@@ -1973,7 +1973,7 @@ bool uprobe_deny_signal(void) 


	WARN_ON_ONCE(utask->state != UTASK_SSTEP);



	if (signal_pending(t)) {

	if (task_sigpending(t)) {

		spin_lock_irq(&t->sighand->siglock);

		clear_tsk_thread_flag(t, TIF_SIGPENDING);

		spin_unlock_irq(&t->sighand->siglock);

kernel/signal.c

+4 −4
Original line number Diff line number Diff line
@@ -983,7 +983,7 @@ static inline bool wants_signal(int sig, struct task_struct *p) 
	if (task_is_stopped_or_traced(p))

		return false;



	return task_curr(p) || !signal_pending(p);

	return task_curr(p) || !task_sigpending(p);

}



static void complete_signal(int sig, struct task_struct *p, enum pid_type type)
@@ -2822,7 +2822,7 @@ static void retarget_shared_pending(struct task_struct *tsk, sigset_t *which) 
		/* Remove the signals this thread can handle. */

		sigandsets(&retarget, &retarget, &t->blocked);



		if (!signal_pending(t))

		if (!task_sigpending(t))

			signal_wake_up(t, 0);



		if (sigisemptyset(&retarget))
@@ -2856,7 +2856,7 @@ void exit_signals(struct task_struct *tsk) 


	cgroup_threadgroup_change_end(tsk);



	if (!signal_pending(tsk))

	if (!task_sigpending(tsk))

		goto out;



	unblocked = tsk->blocked;
@@ -2900,7 +2900,7 @@ long do_no_restart_syscall(struct restart_block *param) 


static void __set_task_blocked(struct task_struct *tsk, const sigset_t *newset)

{

	if (signal_pending(tsk) && !thread_group_empty(tsk)) {

	if (task_sigpending(tsk) && !thread_group_empty(tsk)) {

		sigset_t newblocked;

		/* A set of now blocked but previously unblocked signals. */

		sigandnsets(&newblocked, newset, &current->blocked);