kprobes: fix to use text_mutex around arm/disarm kprobe

Fix kprobes to lock text_mutex around some arch_arm/disarm_kprobe() which
are newly added by commit de5bd88d5a5cce3cacea904d3503e5ebdb3852a2.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 22 insertions, 9 deletions

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index a5e74ddee0e2..c0fa54b276d9 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -319,6 +319,22 @@ struct kprobe __kprobes *get_kprobe(void *addr)
         return NULL;
 }
 
+/* Arm a kprobe with text_mutex */
+static void __kprobes arm_kprobe(struct kprobe *kp)
+{
+        mutex_lock(&text_mutex);
+        arch_arm_kprobe(kp);
+        mutex_unlock(&text_mutex);
+}
+
+/* Disarm a kprobe with text_mutex */
+static void __kprobes disarm_kprobe(struct kprobe *kp)
+{
+        mutex_lock(&text_mutex);
+        arch_disarm_kprobe(kp);
+        mutex_unlock(&text_mutex);
+}
+
 /*
  * Aggregate handlers for multiple kprobes support - these handlers
  * take care of invoking the individual kprobe handlers on p->list
@@ -538,7 +554,7 @@ static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p)
                 ap->flags &= ~KPROBE_FLAG_DISABLED;
                 if (!kprobes_all_disarmed)
                         /* Arm the breakpoint again. */
-                        arch_arm_kprobe(ap);
+                        arm_kprobe(ap);
         }
         return 0;
 }
@@ -789,11 +805,8 @@ static int __kprobes __unregister_kprobe_top(struct kprobe *p)
                  * enabled and not gone - otherwise, the breakpoint would
                  * already have been removed. We save on flushing icache.
                  */
-                if (!kprobes_all_disarmed && !kprobe_disabled(old_p)) {
-                        mutex_lock(&text_mutex);
-                        arch_disarm_kprobe(p);
-                        mutex_unlock(&text_mutex);
-                }
+                if (!kprobes_all_disarmed && !kprobe_disabled(old_p))
+                        disarm_kprobe(p);
                 hlist_del_rcu(&old_p->hlist);
         } else {
                 if (p->break_handler && !kprobe_gone(p))
@@ -810,7 +823,7 @@ noclean:
                 if (!kprobe_disabled(old_p)) {
                         try_to_disable_aggr_kprobe(old_p);
                         if (!kprobes_all_disarmed && kprobe_disabled(old_p))
-                                arch_disarm_kprobe(old_p);
+                                disarm_kprobe(old_p);
                 }
         }
         return 0;
@@ -1364,7 +1377,7 @@ int __kprobes disable_kprobe(struct kprobe *kp)
                 try_to_disable_aggr_kprobe(p);
 
         if (!kprobes_all_disarmed && kprobe_disabled(p))
-                arch_disarm_kprobe(p);
+                disarm_kprobe(p);
 out:
         mutex_unlock(&kprobe_mutex);
         return ret;
@@ -1393,7 +1406,7 @@ int __kprobes enable_kprobe(struct kprobe *kp)
         }
 
         if (!kprobes_all_disarmed && kprobe_disabled(p))
-                arch_arm_kprobe(p);
+                arm_kprobe(p);
 
         p->flags &= ~KPROBE_FLAG_DISABLED;
         if (p != kp)