[PATCH AUTOSEL 5.6 042/149] libbpf: Fix handling of optional field_name in btf_dump__emit_type_decl

[Sasha Levin]

From: Andrii Nakryiko <andriin@xxxxxx>

[ Upstream commit 320a36063e1441210106aa33997ad3770d4c86b4 ]

Internal functions, used by btf_dump__emit_type_decl(), assume field_name is
never going to be NULL. Ensure it's always the case.

Fixes: 9f81654eebe8 ("libbpf: Expose BTF-to-C type declaration emitting API")
Signed-off-by: Andrii Nakryiko <andriin@xxxxxx>
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20200303180800.3303471-1-andriin@xxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 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 bd09ed1710f12..dc451e4de5ad4 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -1030,7 +1030,7 @@ int btf_dump__emit_type_decl(struct btf_dump *d, __u32 id,
 	if (!OPTS_VALID(opts, btf_dump_emit_type_decl_opts))
 		return -EINVAL;
 
-	fname = OPTS_GET(opts, field_name, NULL);
+	fname = OPTS_GET(opts, field_name, "");
 	lvl = OPTS_GET(opts, indent_level, 0);
 	btf_dump_emit_type_decl(d, id, fname, lvl);
 	return 0;
-- 
2.20.1