[PATCH] tools/resolve_btfids: Fix build error with older host toolchains

[Kun-Chuan Hsieh <jetswayss@gmail.com>]

Older versions of libelf cannot recognize the compressed section.
However, it's only required to fix the compressed section info when
compiling with CONFIG_DEBUG_INFO_COMPRESSED flag is set.

Only compile the compressed_section_fix function when necessary will make
it easier to enable the BTF function. Since the tool resolve_btfids is
compiled with host toolchain. The host toolchain might be older than the
cross compile toolchain.

Cc: stable@vger.kernel.org
Signed-off-by: Kun-Chuan Hsieh <jetswayss@gmail.com>
---
 tools/bpf/resolve_btfids/main.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
index 7409d7860aa6..ad40346c6631 100644
--- a/tools/bpf/resolve_btfids/main.c
+++ b/tools/bpf/resolve_btfids/main.c
@@ -260,6 +260,7 @@ static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size)
 	return btf_id__add(root, id, false);
 }
 
+#ifdef CONFIG_DEBUG_INFO_COMPRESSED
 /*
  * The data of compressed section should be aligned to 4
  * (for 32bit) or 8 (for 64 bit) bytes. The binutils ld
@@ -292,6 +293,7 @@ static int compressed_section_fix(Elf *elf, Elf_Scn *scn, GElf_Shdr *sh)
 	}
 	return 0;
 }
+#endif
 
 static int elf_collect(struct object *obj)
 {
@@ -370,8 +372,10 @@ static int elf_collect(struct object *obj)
 			obj->efile.idlist_addr  = sh.sh_addr;
 		}
 
+#ifdef CONFIG_DEBUG_INFO_COMPRESSED
 		if (compressed_section_fix(elf, scn, &sh))
 			return -1;
+#endif
 	}
 
 	return 0;
-- 
2.25.1