Commit 9b429620 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by H. Peter Anvin
Browse files

x86, do_signal: Simplify the TS_RESTORE_SIGMASK logic 



1. do_signal() looks at TS_RESTORE_SIGMASK and calculates the
   mask which should be stored in the signal frame, then it
   passes "oldset" to the callees, down to setup_rt_frame().

   This is ugly, setup_rt_frame() can do this itself and nobody
   else needs this sigset_t. Move this code into setup_rt_frame.

2. do_signal() also clears TS_RESTORE_SIGMASK if handle_signal()
   succeeds.

   We can move this to setup_rt_frame() as well, this avoids the
   unnecessary checks and makes the logic more clear.

3. use set_current_blocked() instead of sigprocmask(SIG_SETMASK),
   sigprocmask() should be avoided.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Link: http://lkml.kernel.org/r/20110710182203.GA27979@redhat.com


Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 3982294b

arch/x86/kernel/signal.c

+10 −19
Original line number Diff line number Diff line
@@ -651,11 +651,15 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka, 


static int

setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,

	       sigset_t *set, struct pt_regs *regs)

		struct pt_regs *regs)

{

	int usig = signr_convert(sig);

	sigset_t *set = &current->blocked;

	int ret;



	if (current_thread_info()->status & TS_RESTORE_SIGMASK)

		set = &current->saved_sigmask;



	/* Set up the stack frame */

	if (is_ia32) {

		if (ka->sa.sa_flags & SA_SIGINFO)
@@ -670,12 +674,13 @@ setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 
		return -EFAULT;

	}



	current_thread_info()->status &= ~TS_RESTORE_SIGMASK;

	return ret;

}



static int

handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,

	      sigset_t *oldset, struct pt_regs *regs)

		struct pt_regs *regs)

{

	sigset_t blocked;

	int ret;
@@ -710,7 +715,7 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, 
	    likely(test_and_clear_thread_flag(TIF_FORCED_TF)))

		regs->flags &= ~X86_EFLAGS_TF;



	ret = setup_rt_frame(sig, ka, info, oldset, regs);

	ret = setup_rt_frame(sig, ka, info, regs);



	if (ret)

		return ret;
@@ -765,7 +770,6 @@ static void do_signal(struct pt_regs *regs) 
	struct k_sigaction ka;

	siginfo_t info;

	int signr;

	sigset_t *oldset;



	/*

	 * We want the common case to go fast, which is why we may in certain
@@ -777,23 +781,10 @@ static void do_signal(struct pt_regs *regs) 
	if (!user_mode(regs))

		return;



	if (current_thread_info()->status & TS_RESTORE_SIGMASK)

		oldset = &current->saved_sigmask;

	else

		oldset = &current->blocked;



	signr = get_signal_to_deliver(&info, &ka, regs, NULL);

	if (signr > 0) {

		/* Whee! Actually deliver the signal.  */

		if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {

			/*

			 * A signal was successfully delivered; the saved

			 * sigmask will have been stored in the signal frame,

			 * and will be restored by sigreturn, so we can simply

			 * clear the TS_RESTORE_SIGMASK flag.

			 */

			current_thread_info()->status &= ~TS_RESTORE_SIGMASK;

		}

		handle_signal(signr, &info, &ka, regs);

		return;

	}
@@ -821,7 +812,7 @@ static void do_signal(struct pt_regs *regs) 
	 */

	if (current_thread_info()->status & TS_RESTORE_SIGMASK) {

		current_thread_info()->status &= ~TS_RESTORE_SIGMASK;

		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);

		set_current_blocked(&current->saved_sigmask);

	}

}

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