[RFC PATCH -tip 9/9] tracing: kprobes: Fix to not enabling preemption

[Masami Hiramatsu]

Since kprobes pre_handler doesn't need to recover preemption
even if it modifies regs->ip anymore, this fixes to remove
the preempt_enable_no_resched() from pre_handler.

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
 kernel/trace/trace_kprobe.c |    3 ---
 1 file changed, 3 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 5ce9b8cf7be3..6c894e2be8d6 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1221,12 +1221,9 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
 		 * We need to check and see if we modified the pc of the
 		 * pt_regs, and if so clear the kprobe and return 1 so that we
 		 * don't do the single stepping.
-		 * The ftrace kprobe handler leaves it up to us to re-enable
-		 * preemption here before returning if we've modified the ip.
 		 */
 		if (orig_ip != instruction_pointer(regs)) {
 			reset_current_kprobe();
-			preempt_enable_no_resched();
 			return 1;
 		}
 		if (!ret)