jump label: Fix deadlock b/w jump_label_mutex vs. text_mutex

[net-next-2.6.git] / kernel / kprobes.c

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 99865c33a60d6347f48d46976e75d2baee579156..9437e14f36bd406697397882b7907e2b41dfaa5d 100644 (file)
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1146,13 +1146,16 @@ int __kprobes register_kprobe(struct kprobe *p)
                return ret;
 
        preempt_disable();
+       jump_label_lock();
        if (!kernel_text_address((unsigned long) p->addr) ||
            in_kprobes_functions((unsigned long) p->addr) ||
            ftrace_text_reserved(p->addr, p->addr) ||
            jump_label_text_reserved(p->addr, p->addr)) {
                preempt_enable();
+               jump_label_unlock();
                return -EINVAL;
        }
+       jump_label_unlock();
 
        /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */
        p->flags &= KPROBE_FLAG_DISABLED;
@@ -1187,6 +1190,8 @@ int __kprobes register_kprobe(struct kprobe *p)
        INIT_LIST_HEAD(&p->list);
        mutex_lock(&kprobe_mutex);
 
+       jump_label_lock(); /* needed to call jump_label_text_reserved() */
+
        get_online_cpus();      /* For avoiding text_mutex deadlock. */
        mutex_lock(&text_mutex);
 
@@ -1214,6 +1219,7 @@ int __kprobes register_kprobe(struct kprobe *p)
 out:
        mutex_unlock(&text_mutex);
        put_online_cpus();
+       jump_label_unlock();
        mutex_unlock(&kprobe_mutex);
 
        if (probed_mod)