bpf: fix order of args in call to bpf_map_kvcalloc

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 6ac99e8f23d4 ("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 2c321f3f70bc ("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 2c321f3f70bc is present - CONFIG_MEMCG is not enabled in .config - CONFIG_WERROR turns this from a compiler warning to error

Mohammad Shehar Yaar Tausif committed 2 years ago

Commit af253ae1 parent e1533b61 file · +2 −2Browse files

Unified · Split

kernel/bpf/bpf_local_storage.c+2−2

@@ -782,8 +782,8 @@ bpf_local_storage_map_alloc(union bpf_attr *attr, · 781 unmodified lines
782	782	nbuckets = max_t(u32, 2, nbuckets);
783	783	smap->bucket_log = ilog2(nbuckets);
784	784
785		− smap->buckets = bpf_map_kvcalloc(&smap->map, sizeof(*smap->buckets),
786		− nbuckets, GFP_USER \| __GFP_NOWARN);
	785	+ smap->buckets = bpf_map_kvcalloc(&smap->map, nbuckets,
	786	+ sizeof(*smap->buckets), GFP_USER \| __GFP_NOWARN);
787	787	if (!smap->buckets) {
788	788	err = -ENOMEM;
789	789	goto free_smap;