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authorAndi Kleen2006-09-26 10:52:34 +0200
committerAndi Kleen2006-09-26 10:52:34 +0200
commit3fa7c794fe4dc127f7fac3fad4d13628e68f89ce (patch)
tree855a6737a2275317bcd3f3a9934c33dcadba6e6f
parent[PATCH] x86: Some preparationary cleanup for stack trace (diff)
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[PATCH] 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 <ak@suse.de>
-rw-r--r--kernel/lockdep.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 900b4cb1a024..c088e5542e84 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -227,7 +227,11 @@ static int save_trace(struct stack_trace *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;