[PATCH] libbpf: Fix uninitialized warning in btf_dump_dump_type_data

[David Michael <fedora.dm0@gmail.com>]

GCC 11.3.0 fails to compile btf_dump.c due to the following error,
which seems to originate in btf_dump_struct_data where the returned
value would be uninitialized if btf_vlen returns zero.

btf_dump.c: In function ‘btf_dump_dump_type_data’:
btf_dump.c:2363:12: error: ‘err’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
 2363 |         if (err < 0)
      |            ^

Fixes: 43174f0d4597 ("libbpf: Silence uninitialized warning/error in btf_dump_dump_type_data")
Signed-off-by: David Michael <fedora.dm0@gmail.com>
---

Hi,

I encountered this build failure when using Gentoo's hardened profile to
build sys-kernel/gentoo-kernel (at least some 5.19 and 6.0 versions).
The following patch fixes it.  Can this be applied?

Thanks.

David

 tools/lib/bpf/btf_dump.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index 12f7039e0..e9f849d82 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -1989,7 +1989,7 @@ static int btf_dump_struct_data(struct btf_dump *d,
 {
 	const struct btf_member *m = btf_members(t);
 	__u16 n = btf_vlen(t);
-	int i, err;
+	int i, err = 0;
 
 	/* note that we increment depth before calling btf_dump_print() below;
 	 * this is intentional.  btf_dump_data_newline() will not print a
-- 
2.38.1