[PATCH] mm: Make it easier to catch NULL cache names

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

Right now, if you inadvertently pass NULL to kmem_cache_create() at boot
time, it crashes much later after boot somewhere deep inside sysfs which
makes it very non obvious to figure out what's going on.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

Yes, I did hit that :-) Something in ppc land using an array of caches
and got the names array out of sync with changes to the list of indices.

 mm/slub.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index b9f1491..e31fbe6 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3292,6 +3292,9 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size,
 {
 	struct kmem_cache *s;
 
+	if (WARN_ON(!name))
+		return NULL;
+
 	down_write(&slub_lock);
 	s = find_mergeable(size, align, flags, name, ctor);
 	if (s) {