diff options
| author | Roland McGrath <roland@redhat.com> | 2008-01-30 13:30:50 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:30:50 +0100 |
| commit | e1f287735c1e58c653b516931b5d3dd899edcb77 (patch) | |
| tree | 1a2948cfe8ff679135971e2c573d11b847fee93d /arch/x86/kernel/signal_32.c | |
| parent | 7122ec8158b0f88befd94f4da8feae2c8d08d1b4 (diff) | |
x86 single_step: TIF_FORCED_TF
This changes the single-step support to use a new thread_info flag
TIF_FORCED_TF instead of the PT_DTRACE flag in task_struct.ptrace.
This keeps arch implementation uses out of this non-arch field.
This changes the ptrace access to eflags to mask TF and maintain
the TIF_FORCED_TF flag directly if userland sets TF, instead of
relying on ptrace_signal_deliver. The 64-bit and 32-bit kernels
are harmonized on this same behavior. The ptrace_signal_deliver
approach works now, but this change makes the low-level register
access code reliable when called from different contexts than a
ptrace stop, which will be possible in the future.
The 64-bit do_debug exception handler is also changed not to clear TF
from user-mode registers. This matches the 32-bit kernel's behavior.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/signal_32.c')
| -rw-r--r-- | arch/x86/kernel/signal_32.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c index 1ac53e9a0859..0a7c812212c9 100644 --- a/arch/x86/kernel/signal_32.c +++ b/arch/x86/kernel/signal_32.c @@ -545,14 +545,12 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, } /* - * If TF is set due to a debugger (PT_DTRACE), clear the TF flag so - * that register information in the sigcontext is correct. + * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF + * flag so that register information in the sigcontext is correct. */ - if (unlikely(regs->eflags & TF_MASK) - && likely(current->ptrace & PT_DTRACE)) { - current->ptrace &= ~PT_DTRACE; - regs->eflags &= ~TF_MASK; - } + if (unlikely(regs->eflags & X86_EFLAGS_TF) && + likely(test_and_clear_thread_flag(TIF_FORCED_TF))) + regs->eflags &= ~X86_EFLAGS_TF; /* Set up the stack frame */ if (ka->sa.sa_flags & SA_SIGINFO) |