[GIT pull] perf fix for 4.7
Linus, please pull the latest perf-urgent-for-linus git tree from: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-for-linus A single fix clearing the TF bit when a fault is single stepped. Thanks, tglx --> Masami Hiramatsu (1): kprobes/x86: Clear TF bit in fault on single-stepping arch/x86/kernel/kprobes/core.c | 12 1 file changed, 12 insertions(+) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 38cf7a741250..7847e5c0e0b5 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -961,7 +961,19 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) * 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; + if (kcb->kprobe_status == KPROBE_REENTER) restore_previous_kprobe(kcb); else
[GIT pull] perf fix for 4.7
Linus, please pull the latest perf-urgent-for-linus git tree from: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-for-linus A single fix clearing the TF bit when a fault is single stepped. Thanks, tglx --> Masami Hiramatsu (1): kprobes/x86: Clear TF bit in fault on single-stepping arch/x86/kernel/kprobes/core.c | 12 1 file changed, 12 insertions(+) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 38cf7a741250..7847e5c0e0b5 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -961,7 +961,19 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) * 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; + if (kcb->kprobe_status == KPROBE_REENTER) restore_previous_kprobe(kcb); else
