Messages in this thread | | | Date | Wed, 13 Jul 2022 12:07:39 +0200 (CEST) | From | Christoph Lameter <> | Subject | Re: [PATCH 16/16] mm/sl[au]b: check if large object is valid in __ksize() |
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On Wed, 13 Jul 2022, Hyeonggon Yoo wrote:
> > Why return 0 if there is an error and why bother the callers with these > > checks. BUG()? > > I thought BUG should be used when there is no other solution.
Spurios returns of 0 that the caller has to check for is a solution?
> > I guess this is an error since the order-0 page cannot come from slab > > allocations. > > comment in ksize() says: > "The caller must guarantee that objp points to a valid object > previously allocated with either kmalloc() or kmem_cache_alloc()." > > It should not be used on order-0 page that is not allocated from slab. No?
I guess we would need to check. Code could exist that does this.
Getting a 0 size would be surprising too here. BUG()? Or WARN() and return PAGE_SIZE.
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