From d61915da63e2ef03d9034e3b2ec7d8cca55d7584 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Sat, 16 Apr 2005 15:25:00 -0700 Subject: [PATCH] [PATCH] x86_64: Fix interaction of single stepping with debuggers Ported from i386/Linus Fix another TF corner case. Need to do the special TF handling for all signals to make debuggers happy Signed-off-by: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/signal.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/x86_64/kernel/signal.c b/arch/x86_64/kernel/signal.c index 4ff0f0117a09..7760224cdfe3 100644 --- a/arch/x86_64/kernel/signal.c +++ b/arch/x86_64/kernel/signal.c @@ -368,6 +368,18 @@ 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 (unlikely(regs->eflags & TF_MASK)) { + if (likely(current->ptrace & PT_DTRACE)) { + current->ptrace &= ~PT_DTRACE; + regs->eflags &= ~TF_MASK; + } + } + #ifdef CONFIG_IA32_EMULATION if (test_thread_flag(TIF_IA32)) { if (ka->sa.sa_flags & SA_SIGINFO)