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Commit 5a8da0ea authored by Roland McGrath's avatar Roland McGrath Committed by Linus Torvalds
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signals: x86 TS_RESTORE_SIGMASK 



Replace TIF_RESTORE_SIGMASK with TS_RESTORE_SIGMASK and define our own
set_restore_sigmask() function.  This saves the costly SMP-safe set_bit
operation, which we do not need for the sigmask flag since TIF_SIGPENDING
always has to be set too.

Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f3de272b

arch/x86/ia32/ia32_signal.c

+1 −1
Original line number Diff line number Diff line
@@ -128,7 +128,7 @@ asmlinkage long sys32_sigsuspend(int history0, int history1, old_sigset_t mask) 


	current->state = TASK_INTERRUPTIBLE;

	schedule();

	set_thread_flag(TIF_RESTORE_SIGMASK);

	set_restore_sigmask();

	return -ERESTARTNOHAND;

}

arch/x86/kernel/signal_32.c

+8 −9
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ sys_sigsuspend(int history0, int history1, old_sigset_t mask) 


	current->state = TASK_INTERRUPTIBLE;

	schedule();

	set_thread_flag(TIF_RESTORE_SIGMASK);

	set_restore_sigmask();



	return -ERESTARTNOHAND;

}
@@ -593,7 +593,7 @@ static void do_signal(struct pt_regs *regs) 
	if (!user_mode(regs))

		return;



	if (test_thread_flag(TIF_RESTORE_SIGMASK))

	if (current_thread_info()->status & TS_RESTORE_SIGMASK)

		oldset = &current->saved_sigmask;

	else

		oldset = &current->blocked;
@@ -612,13 +612,12 @@ static void do_signal(struct pt_regs *regs) 
		/* Whee! Actually deliver the signal.  */

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

			/*

			 * a signal was successfully delivered; the saved

			 * 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 TIF_RESTORE_SIGMASK flag

			 * clear the TS_RESTORE_SIGMASK flag.

			 */

			if (test_thread_flag(TIF_RESTORE_SIGMASK))

				clear_thread_flag(TIF_RESTORE_SIGMASK);

			current_thread_info()->status &= ~TS_RESTORE_SIGMASK;

		}

		return;

	}
@@ -645,8 +644,8 @@ static void do_signal(struct pt_regs *regs) 
	 * If there's no signal to deliver, we just put the saved sigmask

	 * back.

	 */

	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {

		clear_thread_flag(TIF_RESTORE_SIGMASK);

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

		current_thread_info()->status &= ~TS_RESTORE_SIGMASK;

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

	}

}
@@ -665,7 +664,7 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) 
	}



	/* deal with pending signal delivery */

	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))

	if (thread_info_flags & _TIF_SIGPENDING)

		do_signal(regs);



	if (thread_info_flags & _TIF_HRTICK_RESCHED)

arch/x86/kernel/signal_64.c

+9 −7
Original line number Diff line number Diff line
@@ -427,7 +427,7 @@ static void do_signal(struct pt_regs *regs) 
	if (!user_mode(regs))

		return;



	if (test_thread_flag(TIF_RESTORE_SIGMASK))

	if (current_thread_info()->status & TS_RESTORE_SIGMASK)

		oldset = &current->saved_sigmask;

	else

		oldset = &current->blocked;
@@ -444,11 +444,13 @@ static void do_signal(struct pt_regs *regs) 


		/* Whee!  Actually deliver the signal.  */

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

			/* a signal was successfully delivered; the saved

			/*

			 * 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 TIF_RESTORE_SIGMASK flag */

			clear_thread_flag(TIF_RESTORE_SIGMASK);

			 * clear the TS_RESTORE_SIGMASK flag.

			 */

			current_thread_info()->status &= ~TS_RESTORE_SIGMASK;

		}

		return;

	}
@@ -476,8 +478,8 @@ static void do_signal(struct pt_regs *regs) 
	 * If there's no signal to deliver, we just put the saved sigmask

	 * back.

	 */

	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {

		clear_thread_flag(TIF_RESTORE_SIGMASK);

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

		current_thread_info()->status &= ~TS_RESTORE_SIGMASK;

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

	}

}
@@ -498,7 +500,7 @@ void do_notify_resume(struct pt_regs *regs, void *unused, 
#endif /* CONFIG_X86_MCE */



	/* deal with pending signal delivery */

	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))

	if (thread_info_flags & _TIF_SIGPENDING)

		do_signal(regs);



	if (thread_info_flags & _TIF_HRTICK_RESCHED)

include/asm-x86/thread_info_32.h

+11 −2
Original line number Diff line number Diff line
@@ -131,7 +131,6 @@ static inline struct thread_info *current_thread_info(void) 
#define TIF_SYSCALL_EMU		5	/* syscall emulation active */

#define TIF_SYSCALL_AUDIT	6	/* syscall auditing active */

#define TIF_SECCOMP		7	/* secure computing */

#define TIF_RESTORE_SIGMASK	8	/* restore signal mask in do_signal() */

#define TIF_HRTICK_RESCHED	9	/* reprogram hrtick timer */

#define TIF_MEMDIE		16

#define TIF_DEBUG		17	/* uses debug registers */
@@ -151,7 +150,6 @@ static inline struct thread_info *current_thread_info(void) 
#define _TIF_SYSCALL_EMU	(1 << TIF_SYSCALL_EMU)

#define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)

#define _TIF_SECCOMP		(1 << TIF_SECCOMP)

#define _TIF_RESTORE_SIGMASK	(1 << TIF_RESTORE_SIGMASK)

#define _TIF_HRTICK_RESCHED	(1 << TIF_HRTICK_RESCHED)

#define _TIF_DEBUG		(1 << TIF_DEBUG)

#define _TIF_IO_BITMAP		(1 << TIF_IO_BITMAP)
@@ -188,9 +186,20 @@ static inline struct thread_info *current_thread_info(void) 
					   this quantum (SMP) */

#define TS_POLLING		0x0002	/* True if in idle loop

					   and not sleeping */

#define TS_RESTORE_SIGMASK	0x0004	/* restore signal mask in do_signal() */



#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)



#ifndef __ASSEMBLY__

#define HAVE_SET_RESTORE_SIGMASK	1

static inline void set_restore_sigmask(void)

{

	struct thread_info *ti = current_thread_info();

	ti->status |= TS_RESTORE_SIGMASK;

	set_bit(TIF_SIGPENDING, &ti->flags);

}

#endif	/* !__ASSEMBLY__ */



#endif /* __KERNEL__ */



#endif /* _ASM_THREAD_INFO_H */

include/asm-x86/thread_info_64.h

+11 −2
Original line number Diff line number Diff line
@@ -109,7 +109,6 @@ static inline struct thread_info *stack_thread_info(void) 
#define TIF_IRET		5	/* force IRET */

#define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */

#define TIF_SECCOMP		8	/* secure computing */

#define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal */

#define TIF_MCE_NOTIFY		10	/* notify userspace of an MCE */

#define TIF_HRTICK_RESCHED	11	/* reprogram hrtick timer */

/* 16 free */
@@ -133,7 +132,6 @@ static inline struct thread_info *stack_thread_info(void) 
#define _TIF_IRET		(1 << TIF_IRET)

#define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)

#define _TIF_SECCOMP		(1 << TIF_SECCOMP)

#define _TIF_RESTORE_SIGMASK	(1 << TIF_RESTORE_SIGMASK)

#define _TIF_MCE_NOTIFY		(1 << TIF_MCE_NOTIFY)

#define _TIF_HRTICK_RESCHED	(1 << TIF_HRTICK_RESCHED)

#define _TIF_IA32		(1 << TIF_IA32)
@@ -178,9 +176,20 @@ static inline struct thread_info *stack_thread_info(void) 
#define TS_COMPAT		0x0002	/* 32bit syscall active */

#define TS_POLLING		0x0004	/* true if in idle loop

					   and not sleeping */

#define TS_RESTORE_SIGMASK	0x0008	/* restore signal mask in do_signal() */



#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)



#ifndef __ASSEMBLY__

#define HAVE_SET_RESTORE_SIGMASK	1

static inline void set_restore_sigmask(void)

{

	struct thread_info *ti = current_thread_info();

	ti->status |= TS_RESTORE_SIGMASK;

	set_bit(TIF_SIGPENDING, &ti->flags);

}

#endif	/* !__ASSEMBLY__ */



#endif /* __KERNEL__ */



#endif /* _ASM_THREAD_INFO_H */