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Commit 0341729b authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
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signals: mv {dis,}allow_signal() from sched.h/exit.c to signal.[ch] 



Move the declaration/definition of allow_signal/disallow_signal to
signal.h/signal.c.  The new place is more logical and allows to use the
static helpers in signal.c (see the next changes).

While at it, make them return void and remove the valid_signal() check.
Nobody checks the returned value, and in-kernel users must not pass the
wrong signal number.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent afe2b038

include/linux/sched.h

+0 −3
Original line number Diff line number Diff line
@@ -2414,9 +2414,6 @@ extern void flush_itimer_signals(void); 


extern void do_group_exit(int);



extern int allow_signal(int);

extern int disallow_signal(int);



extern int do_execve(struct filename *,

		     const char __user * const __user *,

		     const char __user * const __user *);

include/linux/signal.h

+2 −0
Original line number Diff line number Diff line
@@ -284,6 +284,8 @@ extern int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, 
extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);

extern void signal_delivered(int sig, siginfo_t *info, struct k_sigaction *ka, struct pt_regs *regs, int stepping);

extern void exit_signals(struct task_struct *tsk);

extern void allow_signal(int);

extern void disallow_signal(int);



/*

 * Eventually that'll replace get_signal_to_deliver(); macro for now,

kernel/exit.c

+0 −39
Original line number Diff line number Diff line
@@ -313,45 +313,6 @@ kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent) 
	}

}



/*

 * Let kernel threads use this to say that they allow a certain signal.

 * Must not be used if kthread was cloned with CLONE_SIGHAND.

 */

int allow_signal(int sig)

{

	if (!valid_signal(sig) || sig < 1)

		return -EINVAL;



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

	/* This is only needed for daemonize()'ed kthreads */

	sigdelset(&current->blocked, sig);

	/*

	 * Kernel threads handle their own signals. Let the signal code

	 * know it'll be handled, so that they don't get converted to

	 * SIGKILL or just silently dropped.

	 */

	current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2;

	recalc_sigpending();

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

	return 0;

}



EXPORT_SYMBOL(allow_signal);



int disallow_signal(int sig)

{

	if (!valid_signal(sig) || sig < 1)

		return -EINVAL;



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

	current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN;

	recalc_sigpending();

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

	return 0;

}



EXPORT_SYMBOL(disallow_signal);



#ifdef CONFIG_MEMCG

/*

 * A task is exiting.   If it owned this mm, find a new owner for the mm.

kernel/signal.c

+29 −0
Original line number Diff line number Diff line
@@ -3066,6 +3066,35 @@ COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo, 
}

#endif



/*

 * Let kernel threads use this to say that they allow a certain signal.

 * Must not be used if kthread was cloned with CLONE_SIGHAND.

 */

void allow_signal(int sig)

{

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

	/* This is only needed for daemonize()'ed kthreads */

	sigdelset(&current->blocked, sig);

	/*

	 * Kernel threads handle their own signals. Let the signal code

	 * know it'll be handled, so that they don't get converted to

	 * SIGKILL or just silently dropped.

	 */

	current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2;

	recalc_sigpending();

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

}

EXPORT_SYMBOL(allow_signal);



void disallow_signal(int sig)

{

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

	current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN;

	recalc_sigpending();

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

}

EXPORT_SYMBOL(disallow_signal);



int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)

{

	struct task_struct *p = current, *t;