Re: [PATCH] unlock before bug returns

From: Rene Herman
Date: Mon Oct 22 2007 - 08:52:37 EST


On 10/22/2007 02:40 PM, Pekka Enberg wrote:

On 10/22/07, Roel Kluin <12o3l@xxxxxxxxxx> wrote:
diff --git a/mm/slab.c b/mm/slab.c
index cfa6be4..20c58dc 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1606,8 +1606,10 @@ void __init kmem_cache_init(void)
struct kmem_cache *cachep;
mutex_lock(&cache_chain_mutex);
list_for_each_entry(cachep, &cache_chain, next)
- if (enable_cpucache(cachep))
+ if (enable_cpucache(cachep)) {
+ mutex_unlock(&cache_chain_mutex);
BUG();
+ }
mutex_unlock(&cache_chain_mutex);
}

NAK. This will cause double-unlock when CONFIG_BUG is disabled. It's
incorrect to assume that BUG() will always terminate the current
process.

(which by the way also means that the "return;" delete from your original patch changes behaviour for !CONFIG_BUG, and probably not for the better).

Rene.

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