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authorRoland McGrath <roland@redhat.com>2008-07-09 01:33:14 -0700
committerRoland McGrath <roland@redhat.com>2008-07-16 12:15:16 -0700
commit64f097331928b01d704047c1dbc738bb6d2a9bf9 (patch)
tree402fe071f26a9bbdbffdc98c2f592ff9eeb6a404 /arch/x86/kernel/signal_64.c
parent6718d0d6da2749d3bff522e6057e97e6aa85e4d1 (diff)
x86 ptrace: unify TIF_SINGLESTEP
This unifies the treatment of TIF_SINGLESTEP on i386 and x86_64. The bit is now excluded from _TIF_WORK_MASK on i386 as it has been on x86_64. This means the do_notify_resume() path using it is never used, so TIF_SINGLESTEP is not cleared on returning to user mode. Both now leave TIF_SINGLESTEP set when returning to user, so that it's already set on an int $0x80 system call entry. This removes the need for testing TF on the system_call path. Doing it this way fixes the regression for PTRACE_SINGLESTEP into a sigreturn syscall, introduced by commit 1e2e99f0e4aa6363e8515ed17011c210c8f1b52a. The clear_TF_reenable case that sets TIF_SINGLESTEP can only happen on a non-exception kernel entry, i.e. sysenter/syscall instruction. That will always get to the syscall exit tracing path. Signed-off-by: Roland McGrath <roland@redhat.com>
Diffstat (limited to 'arch/x86/kernel/signal_64.c')
-rw-r--r--arch/x86/kernel/signal_64.c6
1 files changed, 0 insertions, 6 deletions
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index e53b267662e..bf87684474f 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -487,12 +487,6 @@ static void do_signal(struct pt_regs *regs)
void do_notify_resume(struct pt_regs *regs, void *unused,
__u32 thread_info_flags)
{
- /* Pending single-step? */
- if (thread_info_flags & _TIF_SINGLESTEP) {
- regs->flags |= X86_EFLAGS_TF;
- clear_thread_flag(TIF_SINGLESTEP);
- }
-
#ifdef CONFIG_X86_MCE
/* notify userspace of pending MCEs */
if (thread_info_flags & _TIF_MCE_NOTIFY)