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Subject[PATCH -next] mm: delete oversized WARN_ON() in kvmalloc() calls
Date
Delete the WARN_ON() and return NULL directly for oversized parameter
in kvmalloc() calls.
Also add unlikely().

Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls")
Signed-off-by: Bixuan Cui <cuibixuan@linux.alibaba.com>
---
There are a lot of oversize warnings and patches about kvmalloc() calls
recently. Maybe these warnings are not very necessary.

https://lore.kernel.org/all/YadOjJXMTjP85MQx@unreal

The example of size check in __do_kmalloc_node():
__do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller)
{
struct kmem_cache *cachep;
void *ret;

if (unlikely(size > KMALLOC_MAX_CACHE_SIZE))
return NULL;
cachep = kmalloc_slab(size, flags);

mm/util.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/util.c b/mm/util.c
index 7e433690..d26f19c 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -587,7 +587,7 @@ void *kvmalloc_node(size_t size, gfp_t flags, int node)
return ret;

/* Don't even allow crazy sizes */
- if (WARN_ON_ONCE(size > INT_MAX))
+ if (unlikely(size > INT_MAX))
return NULL;

return __vmalloc_node(size, 1, flags, node,
--
1.8.3.1
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