[tip:perf/core] kprobes: Prohibit probing on lockdep functions

tip-bot for Masami Hiramatsu
2019-02-13T09:04:33Z

Commit-ID: 2f43c6022d84b2f562623a7023f49f1431e50747
Gitweb: https://git.kernel.org/tip/2f43c6022d84b2f562623a7023f49f1431e50747
Author: Masami Hiramatsu <mhiramat@kernel.org>
AuthorDate: Wed, 13 Feb 2019 01:15:05 +0900
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 13 Feb 2019 08:16:41 +0100

kprobes: Prohibit probing on lockdep functions

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>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrea Righi <righi.andrea@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/154998810578.31052.1680977921449292812.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@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 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)
{