kprobes: Add assertions for required lock

Add assertions for required locks instead of comment it
so that the lockdep can inspect locks automatically.

Link: https://lkml.kernel.org/r/163163039572.489837.18011973177537476885.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index ad39eeaa43713221c765a0c73232d55b4fac0801..ec3d97fd8c6b010d3d84002b38abb0cade525ca9 100644 (file)
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -959,11 +959,13 @@ int proc_kprobes_optimization_handler(struct ctl_table *table, int write,
 }
 #endif /* CONFIG_SYSCTL */
 
-/* Put a breakpoint for a probe. Must be called with 'text_mutex' locked. */
+/* Put a breakpoint for a probe. */
 static void __arm_kprobe(struct kprobe *p)
 {
        struct kprobe *_p;
 
+       lockdep_assert_held(&text_mutex);
+
        /* Find the overlapping optimized kprobes. */
        _p = get_optimized_kprobe((unsigned long)p->addr);
        if (unlikely(_p))
@@ -974,11 +976,13 @@ static void __arm_kprobe(struct kprobe *p)
        optimize_kprobe(p);     /* Try to optimize (add kprobe to a list) */
 }
 
-/* Remove the breakpoint of a probe. Must be called with 'text_mutex' locked. */
+/* Remove the breakpoint of a probe. */
 static void __disarm_kprobe(struct kprobe *p, bool reopt)
 {
        struct kprobe *_p;
 
+       lockdep_assert_held(&text_mutex);
+
        /* Try to unoptimize */
        unoptimize_kprobe(p, kprobes_all_disarmed);
 
@@ -1047,12 +1051,13 @@ static struct ftrace_ops kprobe_ipmodify_ops __read_mostly = {
 static int kprobe_ipmodify_enabled;
 static int kprobe_ftrace_enabled;
 
-/* Caller must lock 'kprobe_mutex' */
 static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops,
                               int *cnt)
 {
        int ret = 0;
 
+       lockdep_assert_held(&kprobe_mutex);
+
        ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 0, 0);
        if (WARN_ONCE(ret < 0, "Failed to arm kprobe-ftrace at %pS (error %d)\n", p->addr, ret))
                return ret;
@@ -1084,12 +1089,13 @@ static int arm_kprobe_ftrace(struct kprobe *p)
                ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled);
 }
 
-/* Caller must lock 'kprobe_mutex'. */
 static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops,
                                  int *cnt)
 {
        int ret = 0;
 
+       lockdep_assert_held(&kprobe_mutex);
+
        if (*cnt == 1) {
                ret = unregister_ftrace_function(ops);
                if (WARN(ret < 0, "Failed to unregister kprobe-ftrace (error %d)\n", ret))
@@ -1133,7 +1139,6 @@ static int prepare_kprobe(struct kprobe *p)
        return arch_prepare_kprobe(p);
 }
 
-/* Arm a kprobe with 'text_mutex'. */
 static int arm_kprobe(struct kprobe *kp)
 {
        if (unlikely(kprobe_ftrace(kp)))
@@ -1148,7 +1153,6 @@ static int arm_kprobe(struct kprobe *kp)
        return 0;
 }
 
-/* Disarm a kprobe with 'text_mutex'. */
 static int disarm_kprobe(struct kprobe *kp, bool reopt)
 {
        if (unlikely(kprobe_ftrace(kp)))
@@ -1691,12 +1695,13 @@ static int aggr_kprobe_disabled(struct kprobe *ap)
        return 1;
 }
 
-/* Disable one kprobe: Make sure called under 'kprobe_mutex' is locked. */
 static struct kprobe *__disable_kprobe(struct kprobe *p)
 {
        struct kprobe *orig_p;
        int ret;
 
+       lockdep_assert_held(&kprobe_mutex);
+
        /* Get an original kprobe for return */
        orig_p = __get_valid_kprobe(p);
        if (unlikely(orig_p == NULL))