[RFC][PATCH 3/5] kprobes: Take get_online_cpus() before taking jump_label_lock()

[Steven Rostedt]

From: "Steven Rostedt (VMware)" <rost...@goodmis.org>

jump_label_lock() is taken under get_online_cpus(). Make sure that kprobes
follows suit.

Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org>
---
 kernel/kprobes.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index d733479a10ee..57cf73aef488 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1294,13 +1294,13 @@ static int register_aggr_kprobe(struct kprobe *orig_p, 
struct kprobe *p)
        int ret = 0;
        struct kprobe *ap = orig_p;
 
-       /* For preparing optimization, jump_label_text_reserved() is called */
-       jump_label_lock();
        /*
         * Get online CPUs to avoid text_mutex deadlock.with stop machine,
         * which is invoked by unoptimize_kprobe() in add_new_kprobe()
         */
        get_online_cpus();
+       /* For preparing optimization, jump_label_text_reserved() is called */
+       jump_label_lock();
        mutex_lock(&text_mutex);
 
        if (!kprobe_aggrprobe(orig_p)) {
@@ -1348,8 +1348,8 @@ static int register_aggr_kprobe(struct kprobe *orig_p, 
struct kprobe *p)
 
 out:
        mutex_unlock(&text_mutex);
-       put_online_cpus();
        jump_label_unlock();
+       put_online_cpus();
 
        if (ret == 0 && kprobe_disabled(ap) && !kprobe_disabled(p)) {
                ap->flags &= ~KPROBE_FLAG_DISABLED;
-- 
2.10.2