[PATCH 9/9] kprobes: Prohibit probing on lockdep functions

[Masami Hiramatsu]

Some lockdep functions can be involved in breakpoint handling
and probing on those functions can cause a breakpoint recursion.
Prohibit probing on those functions by blacklist.

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
 kernel/locking/lockdep.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 95932333a48b..bc35a54ae3d4 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -50,6 +50,7 @@
 #include <linux/random.h>
 #include <linux/jhash.h>
 #include <linux/nmi.h>
+#include <linux/kprobes.h>
 
 #include <asm/sections.h>
 
@@ -2814,6 +2815,7 @@ void lockdep_hardirqs_on(unsigned long ip)
 	__trace_hardirqs_on_caller(ip);
 	current->lockdep_recursion = 0;
 }
+NOKPROBE_SYMBOL(lockdep_hardirqs_on);
 
 /*
  * Hardirqs were disabled:
@@ -2843,6 +2845,7 @@ void lockdep_hardirqs_off(unsigned long ip)
 	} else
 		debug_atomic_inc(redundant_hardirqs_off);
 }
+NOKPROBE_SYMBOL(lockdep_hardirqs_off);
 
 /*
  * Softirqs will be enabled:
@@ -3650,7 +3653,8 @@ __lock_release(struct lockdep_map *lock, int nested, unsigned long ip)
 	return 0;
 }
 
-static int __lock_is_held(const struct lockdep_map *lock, int read)
+static nokprobe_inline
+int __lock_is_held(const struct lockdep_map *lock, int read)
 {
 	struct task_struct *curr = current;
 	int i;
@@ -3883,6 +3887,7 @@ int lock_is_held_type(const struct lockdep_map *lock, int read)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(lock_is_held_type);
+NOKPROBE_SYMBOL(lock_is_held_type);
 
 struct pin_cookie lock_pin_lock(struct lockdep_map *lock)
 {