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authorHengqi Chen <hengqi.chen@gmail.com>2021-07-27 21:25:31 +0800
committerAndrii Nakryiko <andrii@kernel.org>2021-07-29 14:37:23 -0700
commit5aad03685185b5133a28e1ee1d4e98d3fd3642a3 (patch)
tree4e0c50e20b2394264c5b3031607c6bfd3bd9974d /tools
parent33b57e0cc78eb82f2921eb4c6d1c8fcaa733823b (diff)
downloadlinux-5aad03685185b5133a28e1ee1d4e98d3fd3642a3.tar.gz
tools/resolve_btfids: Emit warnings and patch zero id for missing symbols
Kernel functions referenced by .BTF_ids may be changed from global to static
and get inlined or get renamed/removed, and thus disappears from BTF.
This causes kernel build failure when resolve_btfids do id patch for symbols
in .BTF_ids in vmlinux. Update resolve_btfids to emit warning messages and
patch zero id for missing symbols instead of aborting kernel build process.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210727132532.2473636-2-hengqi.chen@gmail.com
Diffstat (limited to 'tools')
-rw-r--r--tools/bpf/resolve_btfids/main.c13
1 files changed, 7 insertions, 6 deletions
diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
index 3ad9301b0f00..de6365b53c9c 100644
--- a/tools/bpf/resolve_btfids/main.c
+++ b/tools/bpf/resolve_btfids/main.c
@@ -291,7 +291,7 @@ static int compressed_section_fix(Elf *elf, Elf_Scn *scn, GElf_Shdr *sh)
 	sh->sh_addralign = expected;
 
 	if (gelf_update_shdr(scn, sh) == 0) {
-		printf("FAILED cannot update section header: %s\n",
+		pr_err("FAILED cannot update section header: %s\n",
 			elf_errmsg(-1));
 		return -1;
 	}
@@ -317,6 +317,7 @@ static int elf_collect(struct object *obj)
 
 	elf = elf_begin(fd, ELF_C_RDWR_MMAP, NULL);
 	if (!elf) {
+		close(fd);
 		pr_err("FAILED cannot create ELF descriptor: %s\n",
 			elf_errmsg(-1));
 		return -1;
@@ -484,7 +485,7 @@ static int symbols_resolve(struct object *obj)
 	err = libbpf_get_error(btf);
 	if (err) {
 		pr_err("FAILED: load BTF from %s: %s\n",
-			obj->path, strerror(-err));
+			obj->btf ?: obj->path, strerror(-err));
 		return -1;
 	}
 
@@ -555,8 +556,7 @@ static int id_patch(struct object *obj, struct btf_id *id)
 	int i;
 
 	if (!id->id) {
-		pr_err("FAILED unresolved symbol %s\n", id->name);
-		return -EINVAL;
+		pr_err("WARN: resolve_btfids: unresolved symbol %s\n", id->name);
 	}
 
 	for (i = 0; i < id->addr_cnt; i++) {
@@ -734,8 +734,9 @@ int main(int argc, const char **argv)
 
 	err = 0;
 out:
-	if (obj.efile.elf)
+	if (obj.efile.elf) {
 		elf_end(obj.efile.elf);
-	close(obj.efile.fd);
+		close(obj.efile.fd);
+	}
 	return err;
 }