Commit 8b9c5ff3 authored by Roland McGrath's avatar Roland McGrath Committed by Ingo Molnar
Browse files

x86 signals: lift flags diddling code 



This lifts the code diddling the TF and DF bits for signal handler setup
out of the several places copying the same code into the one place that
calls them all.  There is no change in what it does.

I also separated the recently-added DF bit clearing from the TF diddling.
The compiler turns them back into one instruction anyway.  The tossing
in of DF to the same line of code with no new comments was a bit more
arcane than seems wise.

Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent f7f17a67

arch/x86/ia32/ia32_signal.c

+0 −6
Original line number Diff line number Diff line
@@ -500,9 +500,6 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka, 
	regs->ss = __USER32_DS;



	set_fs(USER_DS);

	regs->flags &= ~(X86_EFLAGS_TF | X86_EFLAGS_DF);

	if (test_thread_flag(TIF_SINGLESTEP))

		ptrace_notify(SIGTRAP);



#if DEBUG_SIG

	printk(KERN_DEBUG "SIG deliver (%s:%d): sp=%p pc=%lx ra=%u\n",
@@ -600,9 +597,6 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 
	regs->ss = __USER32_DS;



	set_fs(USER_DS);

	regs->flags &= ~(X86_EFLAGS_TF | X86_EFLAGS_DF);

	if (test_thread_flag(TIF_SINGLESTEP))

		ptrace_notify(SIGTRAP);



#if DEBUG_SIG

	printk(KERN_DEBUG "SIG deliver (%s:%d): sp=%p pc=%lx ra=%u\n",

arch/x86/kernel/signal_32.c

+15 −20
Original line number Diff line number Diff line
@@ -413,16 +413,6 @@ setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, 
	regs->ss = __USER_DS;

	regs->cs = __USER_CS;



	/*

	 * Clear TF when entering the signal handler, but

	 * notify any tracer that was single-stepping it.

	 * The tracer may want to single-step inside the

	 * handler too.

	 */

	regs->flags &= ~(X86_EFLAGS_TF | X86_EFLAGS_DF);

	if (test_thread_flag(TIF_SINGLESTEP))

		ptrace_notify(SIGTRAP);



	return 0;



give_sigsegv:
@@ -501,16 +491,6 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 
	regs->ss = __USER_DS;

	regs->cs = __USER_CS;



	/*

	 * Clear TF when entering the signal handler, but

	 * notify any tracer that was single-stepping it.

	 * The tracer may want to single-step inside the

	 * handler too.

	 */

	regs->flags &= ~(X86_EFLAGS_TF | X86_EFLAGS_DF);

	if (test_thread_flag(TIF_SINGLESTEP))

		ptrace_notify(SIGTRAP);



	return 0;



give_sigsegv:
@@ -566,6 +546,21 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, 
	if (ret)

		return ret;



	/*

	 * Clear the direction flag as per the ABI for function entry.

	 */

	regs->flags &= ~X86_EFLAGS_DF;



	/*

	 * Clear TF when entering the signal handler, but

	 * notify any tracer that was single-stepping it.

	 * The tracer may want to single-step inside the

	 * handler too.

	 */

	regs->flags &= ~X86_EFLAGS_TF;

	if (test_thread_flag(TIF_SINGLESTEP))

		ptrace_notify(SIGTRAP);



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

	sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);

	if (!(ka->sa.sa_flags & SA_NODEFER))

arch/x86/kernel/signal_64.c

+15 −4
Original line number Diff line number Diff line
@@ -289,10 +289,6 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 
	   see include/asm-x86_64/uaccess.h for details. */

	set_fs(USER_DS);



	regs->flags &= ~(X86_EFLAGS_TF | X86_EFLAGS_DF);

	if (test_thread_flag(TIF_SINGLESTEP))

		ptrace_notify(SIGTRAP);



	return 0;



give_sigsegv:
@@ -380,6 +376,21 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, 
	ret = setup_rt_frame(sig, ka, info, oldset, regs);



	if (ret == 0) {

		/*

		 * Clear the direction flag as per the ABI for function entry.

		 */

		regs->flags &= ~X86_EFLAGS_DF;



		/*

		 * Clear TF when entering the signal handler, but

		 * notify any tracer that was single-stepping it.

		 * The tracer may want to single-step inside the

		 * handler too.

		 */

		regs->flags &= ~X86_EFLAGS_TF;

		if (test_thread_flag(TIF_SINGLESTEP))

			ptrace_notify(SIGTRAP);



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

		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);

		if (!(ka->sa.sa_flags & SA_NODEFER))

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