From: Hengqi Chen <hengqi.chen@gmail.com> mainline inclusion from mainline-5.15-rc1 commit 5aad03685185b5133a28e1ee1d4e98d3fd3642a3 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------------- 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 (cherry picked from commit 5aad03685185b5133a28e1ee1d4e98d3fd3642a3) Signed-off-by: Wang Yufen <wangyufen@huawei.com> --- tools/bpf/resolve_btfids/main.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c index 7ce4558a932f..efe0777854ae 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; @@ -485,7 +486,7 @@ 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; } @@ -556,8 +557,7 @@ 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++) { @@ -735,8 +735,9 @@ 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; } -- 2.20.1