Avoid recursion in lockdep when stack tracer takes locks The new dwarf2 unwinder needs to take locks to do backtraces inside modules. This patch makes sure lockdep which calls stacktrace is not reentered. Thanks to Ingo for suggesting this simpler approach. Cc: mingo@elte.hu Signed-off-by: Andi Kleen --- kernel/lockdep.c | 4 ++++ 1 file changed, 4 insertions(+) Index: linux/kernel/lockdep.c =================================================================== --- linux.orig/kernel/lockdep.c +++ linux/kernel/lockdep.c @@ -227,7 +227,11 @@ static int save_trace(struct stack_trace trace->skip = 3; trace->all_contexts = 0; + /* Make sure to not recurse in case the the unwinder needs to tak +e locks. */ + lockdep_off(); save_stack_trace(trace, NULL); + lockdep_on(); trace->max_entries = trace->nr_entries;