From d04c02f8aa96d82e4cbe783f85a820aae820e746 Mon Sep 17 00:00:00 2001 From: "Naveen N. Rao" Date: Mon, 15 May 2017 23:40:05 +0530 Subject: [PATCH] powerpc/kprobes: Fix handling of instruction emulation on probe re-entry Commit 22d8b3dec214c ("powerpc/kprobes: Emulate instructions on kprobe handler re-entry") enabled emulating instructions on kprobe re-entry, rather than single-stepping always. However, we didn't update the single stepping code to only be run if the emulation fails. Also, we missed re-enabling preemption if the instruction emulation was successful. Fix those issues. Fixes: 22d8b3dec214c ("powerpc/kprobes: Emulate instructions on kprobe handler re-entry") Signed-off-by: Naveen N. Rao Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/kprobes.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 160ae0fa7d0d..fc4343514bed 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -305,16 +305,17 @@ int kprobe_handler(struct pt_regs *regs) save_previous_kprobe(kcb); set_current_kprobe(p, regs, kcb); kprobes_inc_nmissed_count(p); - prepare_singlestep(p, regs); kcb->kprobe_status = KPROBE_REENTER; if (p->ainsn.boostable >= 0) { ret = try_to_emulate(p, regs); if (ret > 0) { restore_previous_kprobe(kcb); + preempt_enable_no_resched(); return 1; } } + prepare_singlestep(p, regs); return 1; } else { if (*addr != BREAKPOINT_INSTRUCTION) { -- 2.20.1