Re: linux-next: build warning after merge of the bpf-next tree

[Qian Cai <cai@redhat.com>]

On Wed, 2020-11-11 at 12:01 +1100, Stephen Rothwell wrote:
> Hi all,
> 
> After merging the bpf-next tree, today's linux-next build (powerpc
> ppc64_defconfig) produced this warning:
> 
> kernel/bpf/btf.c:4481:20: warning: 'btf_parse_module' defined but not used [-
> Wunused-function]
>  4481 | static struct btf *btf_parse_module(const char *module_name, const
> void *data, unsigned int data_size)
>       |                    ^~~~~~~~~~~~~~~~
> 
> Introduced by commit
> 
>   36e68442d1af ("bpf: Load and verify kernel module BTFs")
> 

It loos like btf_parse_module() is only used when
CONFIG_DEBUG_INFO_BTF_MODULES=y, so this should fix it.

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 0f1fd2669d69..e877eeebc616 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -4478,6 +4478,7 @@ struct btf *btf_parse_vmlinux(void)
 	return ERR_PTR(err);
 }
 
+#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
 static struct btf *btf_parse_module(const char *module_name, const void *data, unsigned int data_size)
 {
 	struct btf_verifier_env *env = NULL;
@@ -4546,6 +4547,7 @@ static struct btf *btf_parse_module(const char *module_name, const void *data, u
 	}
 	return ERR_PTR(err);
 }
+#endif /* CONFIG_DEBUG_INFO_BTF_MODULES */
 
 struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog)
 {