Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Masami Hiramatsu <mhiramat@kernel.org>
To:     Ingo Molnar <mingo@redhat.com>
Cc:     Masami Hiramatsu <mhiramat@kernel.org>, peterz@infradead.org,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Andrea Righi <righi.andrea@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>
Subject: [PATCH -tip v3 09/10] kprobes: Prohibit probing on lockdep functions
Date:   Wed, 13 Feb 2019 01:15:05 +0900
Message-Id: <154998810578.31052.1680977921449292812.stgit@devbox>
In-Reply-To: <154998785011.31052.1475728497912659748.stgit@devbox>
References: <154998785011.31052.1475728497912659748.stgit@devbox>
User-Agent: StGit/0.17.1-dirty
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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)
 {