Commit 4a30debf authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

signals: introduce do_send_sig_info() helper 



Introduce do_send_sig_info() and convert group_send_sig_info(),
send_sig_info(), do_send_specific() to use this helper.

Hopefully it will have more users soon, it allows to specify
specific/group behaviour via "bool group" argument.

Shaves 80 bytes from .text.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stephane eranian <eranian@googlemail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 964ee7df

include/linux/signal.h

+2 −0
Original line number Diff line number Diff line
@@ -233,6 +233,8 @@ static inline int valid_signal(unsigned long sig) 
}



extern int next_signal(struct sigpending *pending, sigset_t *mask);

extern int do_send_sig_info(int sig, struct siginfo *info,

				struct task_struct *p, bool group);

extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p);

extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *);

extern long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig,

kernel/signal.c

+27 −29
Original line number Diff line number Diff line
@@ -971,6 +971,20 @@ specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t) 
	return send_signal(sig, info, t, 0);

}



int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p,

			bool group)

{

	unsigned long flags;

	int ret = -ESRCH;



	if (lock_task_sighand(p, &flags)) {

		ret = send_signal(sig, info, p, group);

		unlock_task_sighand(p, &flags);

	}



	return ret;

}



/*

 * Force a signal that the process can't ignore: if necessary

 * we unblock the signal and change any SIG_IGN to SIG_DFL.
@@ -1068,18 +1082,10 @@ struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long 
 */

int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p)

{

	unsigned long flags;

	int ret;

	int ret = check_kill_permission(sig, info, p);



	ret = check_kill_permission(sig, info, p);



	if (!ret && sig) {

		ret = -ESRCH;

		if (lock_task_sighand(p, &flags)) {

			ret = __group_send_sig_info(sig, info, p);

			unlock_task_sighand(p, &flags);

		}

	}

	if (!ret && sig)

		ret = do_send_sig_info(sig, info, p, true);



	return ret;

}
@@ -1224,15 +1230,9 @@ static int kill_something_info(int sig, struct siginfo *info, pid_t pid) 
 * These are for backward compatibility with the rest of the kernel source.

 */



/*

 * The caller must ensure the task can't exit.

 */

int

send_sig_info(int sig, struct siginfo *info, struct task_struct *p)

{

	int ret;

	unsigned long flags;



	/*

	 * Make sure legacy kernel users don't send in bad values

	 * (normal paths check this in check_kill_permission).
@@ -1240,10 +1240,7 @@ send_sig_info(int sig, struct siginfo *info, struct task_struct *p) 
	if (!valid_signal(sig))

		return -EINVAL;



	spin_lock_irqsave(&p->sighand->siglock, flags);

	ret = specific_send_sig_info(sig, info, p);

	spin_unlock_irqrestore(&p->sighand->siglock, flags);

	return ret;

	return do_send_sig_info(sig, info, p, false);

}



#define __si_special(priv) \
@@ -2278,7 +2275,6 @@ static int 
do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info)

{

	struct task_struct *p;

	unsigned long flags;

	int error = -ESRCH;



	rcu_read_lock();
@@ -2288,14 +2284,16 @@ do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info) 
		/*

		 * The null signal is a permissions and process existence

		 * probe.  No signal is actually delivered.

		 *

		 * If lock_task_sighand() fails we pretend the task dies

		 * after receiving the signal. The window is tiny, and the

		 * signal is private anyway.

		 */

		if (!error && sig && lock_task_sighand(p, &flags)) {

			error = specific_send_sig_info(sig, info, p);

			unlock_task_sighand(p, &flags);

		if (!error && sig) {

			error = do_send_sig_info(sig, info, p, false);

			/*

			 * If lock_task_sighand() failed we pretend the task

			 * dies after receiving the signal. The window is tiny,

			 * and the signal is private anyway.

			 */

			if (unlikely(error == -ESRCH))

				error = 0;

		}

	}

	rcu_read_unlock();

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