Re: linux-next: build failure after merge of the slab tree

[Vlastimil Babka]

On 9/6/22 08:51, Stephen Rothwell wrote:
> Hi all,

Hi,

> After merging the slab tree, today's linux-next build (powerpc
> ppc64_defconfig) failed like this:
>
> kernel/bpf/memalloc.c: In function 'bpf_mem_free':
> kernel/bpf/memalloc.c:613:33: error: implicit declaration of function '__ksize'; did you mean 'ksize'? [-Werror=implicit-function-declaration]
>    613 |         idx = bpf_mem_cache_idx(__ksize(ptr - LLIST_NODE_SZ));
>        |                                 ^~~~~~~
>        |                                 ksize

Could you use ksize() here? I'm guessing you picked __ksize() because 
kasan_unpoison_element() in mm/mempool.c did, but that's to avoid 
kasan_unpoison_range() in ksize() as this caller does it differently.
AFAICS your function doesn't handle kasan differently, so ksize() should 
be fine.

> Caused by commit
>
>    8dfa9d554061 ("mm/slab_common: move declaration of __ksize() to mm/slab.h")
>
> interacting with commit
>
>    7c8199e24fa0 ("bpf: Introduce any context BPF specific memory allocator.")
>
> from the bpf-next tree.
>
> I have reverted the slab tree commit for today.