[PATCH -tip v3 09/10] kprobes: Prohibit probing on lockdep functions

Masami Hiramatsu
2019-02-12T16:15:31Z

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@kernel.org>
---
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 7f7db23fc002..c1653a1b57b7 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>

@@ -2796,6 +2797,7 @@ void lockdep_hardirqs_on(unsigned long ip)
__trace_hardirqs_on_caller(ip);
current->lockdep_recursion = 0;
}
+NOKPROBE_SYMBOL(lockdep_hardirqs_on);

/*
* Hardirqs were disabled:
@@ -2825,6 +2827,7 @@ void lockdep_hardirqs_off(unsigned long ip)
} else
debug_atomic_inc(redundant_hardirqs_off);
}
+NOKPROBE_SYMBOL(lockdep_hardirqs_off);

/*
* Softirqs will be enabled:
@@ -3638,7 +3641,8 @@ __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;
@@ -3871,6 +3875,7 @@ 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)
{