diff options
| author | Aurelien Jarno <aurelien@aurel32.net> | 2008-03-08 11:43:52 +0100 |
|---|---|---|
| committer | Chris Wright <chrisw@sous-sol.org> | 2008-03-24 11:47:10 -0700 |
| commit | cc7571b226c93b032164ebb3ff3b365651c4652f (patch) | |
| tree | f063eaded5a9544fd60d0b0e4a62d8f0e76c1ccf /arch | |
| parent | b83b97b0e5185e2c9c80824e2dd880419c200c09 (diff) | |
x86: Clear DF before calling signal handler
x86: Clear DF before calling signal handler
The Linux kernel currently does not clear the direction flag before
calling a signal handler, whereas the x86/x86-64 ABI requires that.
This become a real problem with gcc version 4.3, which assumes that
the direction flag is correctly cleared at the entry of a function.
This patches changes the setup_frame() functions to clear the
direction before entering the signal handler.
This is a backport of patch e40cd10ccff3d9fbffd57b93780bee4b7b9bff51
("x86: clear DF before calling signal handler") that has been applied
in 2.6.25-rc.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/ia32/ia32_signal.c | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/signal_32.c | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/signal_64.c | 2 |
3 files changed, 5 insertions, 5 deletions
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c index 6ea19c25f90d..4eaaf78a5202 100644 --- a/arch/x86/ia32/ia32_signal.c +++ b/arch/x86/ia32/ia32_signal.c @@ -494,7 +494,7 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka, regs->ss = __USER32_DS; set_fs(USER_DS); - regs->eflags &= ~TF_MASK; + regs->eflags &= ~(TF_MASK | X86_EFLAGS_DF); if (test_thread_flag(TIF_SINGLESTEP)) ptrace_notify(SIGTRAP); @@ -600,7 +600,7 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, regs->ss = __USER32_DS; set_fs(USER_DS); - regs->eflags &= ~TF_MASK; + regs->eflags &= ~(TF_MASK | X86_EFLAGS_DF); if (test_thread_flag(TIF_SINGLESTEP)) ptrace_notify(SIGTRAP); diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c index 9bdd83022f5f..20056db6e80f 100644 --- a/arch/x86/kernel/signal_32.c +++ b/arch/x86/kernel/signal_32.c @@ -396,7 +396,7 @@ static int setup_frame(int sig, struct k_sigaction *ka, * The tracer may want to single-step inside the * handler too. */ - regs->eflags &= ~TF_MASK; + regs->eflags &= ~(TF_MASK | X86_EFLAGS_DF); if (test_thread_flag(TIF_SINGLESTEP)) ptrace_notify(SIGTRAP); @@ -489,7 +489,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, * The tracer may want to single-step inside the * handler too. */ - regs->eflags &= ~TF_MASK; + regs->eflags &= ~(TF_MASK | X86_EFLAGS_DF); if (test_thread_flag(TIF_SINGLESTEP)) ptrace_notify(SIGTRAP); diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c index ab086b0357fc..62964c5a8e70 100644 --- a/arch/x86/kernel/signal_64.c +++ b/arch/x86/kernel/signal_64.c @@ -295,7 +295,7 @@ 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->eflags &= ~TF_MASK; + regs->eflags &= ~(TF_MASK | X86_EFLAGS_DF); if (test_thread_flag(TIF_SINGLESTEP)) ptrace_notify(SIGTRAP); #ifdef DEBUG_SIG |