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bpf: fix order of args in call to bpf_map_kvcalloc

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The original function call passed size of smap->bucket before the number of
buckets which raises the error 'calloc-transposed-args' on compilation.

Vlastimil Babka added:

The order of parameters can be traced back all the way to 6ac99e8f23
("bpf: Introduce bpf sk local storage") accross several refactorings,
and that's why the commit is used as a Fixes: tag.

In v6.10-rc1, a different commit 2c321f3f70 ("mm: change inlined
allocation helpers to account at the call site") however exposed the
order of args in a way that gcc-14 has enough visibility to start
warning about it, because (in !CONFIG_MEMCG case) bpf_map_kvcalloc is
then a macro alias for kvcalloc instead of a static inline wrapper.

To sum up the warning happens when the following conditions are all met:

- gcc-14 is used (didn't see it with gcc-13)
- commit 2c321f3f70 is present
- CONFIG_MEMCG is not enabled in .config
- CONFIG_WERROR turns this from a compiler warning to error

Fixes: 6ac99e8f23 ("bpf: Introduce bpf sk local storage")
Reviewed-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: Mohammad Shehar Yaar Tausif <sheharyaar48@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Link: https://lore.kernel.org/r/20240710100521.15061-2-vbabka@suse.cz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Mohammad Shehar Yaar Tausif 2024-07-10 12:05:22 +02:00 committed by Alexei Starovoitov
parent e1533b6319
commit af253aef18
1 changed files with 2 additions and 2 deletions
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4
kernel/bpf/bpf_local_storage.c
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@ -782,8 +782,8 @@ bpf_local_storage_map_alloc(union bpf_attr *attr,
nbuckets = max_t(u32, 2, nbuckets); nbuckets = max_t(u32, 2, nbuckets);
smap->bucket_log = ilog2(nbuckets); smap->bucket_log = ilog2(nbuckets);
smap->buckets = bpf_map_kvcalloc(&smap->map, sizeof(*smap->buckets), smap->buckets = bpf_map_kvcalloc(&smap->map, nbuckets,
nbuckets, GFP_USER | __GFP_NOWARN); sizeof(*smap->buckets), GFP_USER | __GFP_NOWARN);
if (!smap->buckets) { if (!smap->buckets) {
err = -ENOMEM; err = -ENOMEM;
goto free_smap; goto free_smap;