kprobes: Separate kprobe optimizing code from optimizer

Separate kprobe optimizing code from optimizer, this
will make easy to introducing unoptimizing code in
optimizer.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20101203095403.2961.91201.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index ab99caf2b16771d0f5d20c55888748a2b77e3f23..1f4f9b9d5c899969d393c54bacc7b4c99e1584ea 100644 (file)
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -427,26 +427,14 @@ static void kprobe_optimizer(struct work_struct *work);
 static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer);
 #define OPTIMIZE_DELAY 5
 
-/* Kprobe jump optimizer */
-static __kprobes void kprobe_optimizer(struct work_struct *work)
+/*
+ * Optimize (replace a breakpoint with a jump) kprobes listed on
+ * optimizing_list.
+ */
+static __kprobes void do_optimize_kprobes(void)
 {
        struct optimized_kprobe *op, *tmp;
 
-       /* Lock modules while optimizing kprobes */
-       mutex_lock(&module_mutex);
-       mutex_lock(&kprobe_mutex);
-       if (kprobes_all_disarmed || !kprobes_allow_optimization)
-               goto end;
-
-       /*
-        * Wait for quiesence period to ensure all running interrupts
-        * are done. Because optprobe may modify multiple instructions
-        * there is a chance that Nth instruction is interrupted. In that
-        * case, running interrupt can return to 2nd-Nth byte of jump
-        * instruction. This wait is for avoiding it.
-        */
-       synchronize_sched();
-
        /*
         * The optimization/unoptimization refers online_cpus via
         * stop_machine() and cpu-hotplug modifies online_cpus.
@@ -467,6 +455,27 @@ static __kprobes void kprobe_optimizer(struct work_struct *work)
        }
        mutex_unlock(&text_mutex);
        put_online_cpus();
+}
+
+/* Kprobe jump optimizer */
+static __kprobes void kprobe_optimizer(struct work_struct *work)
+{
+       /* Lock modules while optimizing kprobes */
+       mutex_lock(&module_mutex);
+       mutex_lock(&kprobe_mutex);
+       if (kprobes_all_disarmed || !kprobes_allow_optimization)
+               goto end;
+
+       /*
+        * Wait for quiesence period to ensure all running interrupts
+        * are done. Because optprobe may modify multiple instructions
+        * there is a chance that Nth instruction is interrupted. In that
+        * case, running interrupt can return to 2nd-Nth byte of jump
+        * instruction. This wait is for avoiding it.
+        */
+       synchronize_sched();
+
+       do_optimize_kprobes();
 end:
        mutex_unlock(&kprobe_mutex);
        mutex_unlock(&module_mutex);