4.19-stable review patch. If anyone has any objections, please let me know.
------------------
[ Upstream commit a39f15b9644fac3f950f522c39e667c3af25c588 ]
Since kprobe itself depends on RCU, probing on RCU debug
routine can cause recursive breakpoint bugs.
Prohibit probing on RCU debug routines.
int3
->do_int3()
->ist_enter()
->RCU_LOCKDEP_WARN()
->debug_lockdep_rcu_enabled() -> int3
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andrea Righi <righi.andrea@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/154998807741.31052.11229157537816341591.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
kernel/rcu/update.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 39cb23d22109..81688a133552 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -52,6 +52,7 @@
#include <linux/tick.h>
#include <linux/rcupdate_wait.h>
#include <linux/sched/isolation.h>
+#include <linux/kprobes.h>
#define CREATE_TRACE_POINTS
@@ -253,6 +254,7 @@ int notrace debug_lockdep_rcu_enabled(void)
current->lockdep_recursion == 0;
}
EXPORT_SYMBOL_GPL(debug_lockdep_rcu_enabled);
+NOKPROBE_SYMBOL(debug_lockdep_rcu_enabled);
/**
* rcu_read_lock_held() - might we be in RCU read-side critical section?
--
2.19.1
