kprobes: Prohibit probing on BUG() and WARN() address

[sfrench/cifs-2.6.git] / kernel / kprobes.c

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 9873fc627d61f14295545817547aa4b96f7a00eb..ebe8315a756a2593f0e9bab3f37efe7885a347ed 100644 (file)
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -470,6 +470,7 @@ static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer);
  */
 static void do_optimize_kprobes(void)
 {
+       lockdep_assert_held(&text_mutex);
        /*
         * The optimization/unoptimization refers online_cpus via
         * stop_machine() and cpu-hotplug modifies online_cpus.
@@ -487,9 +488,7 @@ static void do_optimize_kprobes(void)
            list_empty(&optimizing_list))
                return;
 
-       mutex_lock(&text_mutex);
        arch_optimize_kprobes(&optimizing_list);
-       mutex_unlock(&text_mutex);
 }
 
 /*
@@ -500,6 +499,7 @@ static void do_unoptimize_kprobes(void)
 {
        struct optimized_kprobe *op, *tmp;
 
+       lockdep_assert_held(&text_mutex);
        /* See comment in do_optimize_kprobes() */
        lockdep_assert_cpus_held();
 
@@ -507,7 +507,6 @@ static void do_unoptimize_kprobes(void)
        if (list_empty(&unoptimizing_list))
                return;
 
-       mutex_lock(&text_mutex);
        arch_unoptimize_kprobes(&unoptimizing_list, &freeing_list);
        /* Loop free_list for disarming */
        list_for_each_entry_safe(op, tmp, &freeing_list, list) {
@@ -524,7 +523,6 @@ static void do_unoptimize_kprobes(void)
                } else
                        list_del_init(&op->list);
        }
-       mutex_unlock(&text_mutex);
 }
 
 /* Reclaim all kprobes on the free_list */
@@ -556,6 +554,7 @@ static void kprobe_optimizer(struct work_struct *work)
 {
        mutex_lock(&kprobe_mutex);
        cpus_read_lock();
+       mutex_lock(&text_mutex);
        /* Lock modules while optimizing kprobes */
        mutex_lock(&module_mutex);
 
@@ -583,6 +582,7 @@ static void kprobe_optimizer(struct work_struct *work)
        do_free_cleaned_kprobes();
 
        mutex_unlock(&module_mutex);
+       mutex_unlock(&text_mutex);
        cpus_read_unlock();
        mutex_unlock(&kprobe_mutex);
 
@@ -1514,7 +1514,8 @@ static int check_kprobe_address_safe(struct kprobe *p,
        /* Ensure it is not in reserved area nor out of text */
        if (!kernel_text_address((unsigned long) p->addr) ||
            within_kprobe_blacklist((unsigned long) p->addr) ||
-           jump_label_text_reserved(p->addr, p->addr)) {
+           jump_label_text_reserved(p->addr, p->addr) ||
+           find_bug((unsigned long)p->addr)) {
                ret = -EINVAL;
                goto out;
        }