Messages in this thread | | | Date | Mon, 29 Apr 2013 14:59:16 +0000 | From | Christoph Lameter <> | Subject | Re: [linux-next-20130422] Bug in SLAB? |
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On Mon, 29 Apr 2013, Glauber Costa wrote:
> >> causes no warning at compile time and returns NULL at runtime. But > >> > >> unsigned int size = 8 * 1024 * 1024; > >> kmalloc(size, GFP_KERNEL); > >> > >> causes compile time warning > >> > >> include/linux/slab_def.h:136: warning: array subscript is above array bounds > >> > >> and runtime bug.
SLAB should have support up to 2 << 25 = 1 mb << 5 = 32M
> I believe this is because the code now always assume that the cache is > found when a constant is passed. Before this patch, we had a "found" > statement that was mistakenly removed.
The code in kmalloc_index() creates a BUG() and preferentially should create a compile time failure when a number that is too big is passed to it.
What is MAX_ORDER on the architecture?
An allocation size of more than MAX_ORDER is not supported by the page allocator or by slab. It is safe to return NULL in that case.
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