kprobes/x86: Clear TF bit in fault on single-stepping

[pandora-kernel.git] / arch / x86 / kernel / kprobes.c

diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index 083848f..29aed8d 100644 (file)
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -949,7 +949,19 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
                 * normal page fault.
                 */
                regs->ip = (unsigned long)cur->addr;
                 * normal page fault.
                 */
                regs->ip = (unsigned long)cur->addr;

+               /*
+                * Trap flag (TF) has been set here because this fault
+                * happened where the single stepping will be done.
+                * So clear it by resetting the current kprobe:
+                */
+               regs->flags &= ~X86_EFLAGS_TF;
+
+               /*
+                * If the TF flag was set before the kprobe hit,
+                * don't touch it:
+                */

                regs->flags |= kcb->kprobe_old_flags;
                regs->flags |= kcb->kprobe_old_flags;

+

                if (kcb->kprobe_status == KPROBE_REENTER)
                        restore_previous_kprobe(kcb);
                else
                if (kcb->kprobe_status == KPROBE_REENTER)
                        restore_previous_kprobe(kcb);
                else