From 8b9c5ff380aa4f10658171ed2b9abc1e0861b770 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Sat, 19 Apr 2008 14:26:54 -0700 Subject: [PATCH] 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: Roland McGrath Signed-off-by: Ingo Molnar --- arch/x86/ia32/ia32_signal.c | 6 ------ arch/x86/kernel/signal_32.c | 35 +++++++++++++++-------------------- arch/x86/kernel/signal_64.c | 19 +++++++++++++++---- 3 files changed, 30 insertions(+), 30 deletions(-) diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c index 05e155d..0866104 100644 --- a/arch/x86/ia32/ia32_signal.c +++ b/arch/x86/ia32/ia32_signal.c @@ -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", diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c index f1b1179..8e05e7f 100644 --- a/arch/x86/kernel/signal_32.c +++ b/arch/x86/kernel/signal_32.c @@ -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(¤t->sighand->siglock); sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask); if (!(ka->sa.sa_flags & SA_NODEFER)) diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c index 827179c..3a76702 100644 --- a/arch/x86/kernel/signal_64.c +++ b/arch/x86/kernel/signal_64.c @@ -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(¤t->sighand->siglock); sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); if (!(ka->sa.sa_flags & SA_NODEFER)) -- 2.7.4