From: Kumar Kartikeya Dwivedi memxor@gmail.com
mainline inclusion from mainline-5.16-rc1 commit f614f2c755b6125c646d680d1c990b3b262bd0a9 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...
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This commit allows specifying the base BTF for resolving btf id lists/sets during link time in the resolve_btfids tool. The base BTF is set to NULL if no path is passed. This allows resolving BTF ids for module kernel objects.
Also, drop the --no-fail option, as it is only used in case .BTF_ids section is not present, instead make no-fail the default mode. The long option name is same as that of pahole.
Signed-off-by: Kumar Kartikeya Dwivedi memxor@gmail.com Signed-off-by: Alexei Starovoitov ast@kernel.org Acked-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20211002011757.311265-5-memxor@gmail.com (cherry picked from commit f614f2c755b6125c646d680d1c990b3b262bd0a9) Signed-off-by: Wang Yufen wangyufen@huawei.com --- tools/bpf/resolve_btfids/main.c | 28 +++++++++++++++++++--------- tools/testing/selftests/bpf/Makefile | 2 +- 2 files changed, 20 insertions(+), 10 deletions(-)
diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c index efe0777854ae..2bb362aae3d3 100644 --- a/tools/bpf/resolve_btfids/main.c +++ b/tools/bpf/resolve_btfids/main.c @@ -89,6 +89,7 @@ struct btf_id { struct object { const char *path; const char *btf; + const char *base_btf_path;
struct { int fd; @@ -478,16 +479,27 @@ static int symbols_resolve(struct object *obj) int nr_structs = obj->nr_structs; int nr_unions = obj->nr_unions; int nr_funcs = obj->nr_funcs; + struct btf *base_btf = NULL; int err, type_id; struct btf *btf; __u32 nr_types;
- btf = btf__parse(obj->btf ?: obj->path, NULL); + if (obj->base_btf_path) { + base_btf = btf__parse(obj->base_btf_path, NULL); + err = libbpf_get_error(base_btf); + if (err) { + pr_err("FAILED: load base BTF from %s: %s\n", + obj->base_btf_path, strerror(-err)); + return -1; + } + } + + btf = btf__parse_split(obj->btf ?: obj->path, base_btf); err = libbpf_get_error(btf); if (err) { pr_err("FAILED: load BTF from %s: %s\n", obj->btf ?: obj->path, strerror(-err)); - return -1; + goto out; }
err = -1; @@ -546,6 +558,7 @@ static int symbols_resolve(struct object *obj)
err = 0; out: + btf__free(base_btf); btf__free(btf); return err; } @@ -679,7 +692,6 @@ static const char * const resolve_btfids_usage[] = {
int main(int argc, const char **argv) { - bool no_fail = false; struct object obj = { .efile = { .idlist_shndx = -1, @@ -696,8 +708,8 @@ int main(int argc, const char **argv) "be more verbose (show errors, etc)"), OPT_STRING(0, "btf", &obj.btf, "BTF data", "BTF data"), - OPT_BOOLEAN(0, "no-fail", &no_fail, - "do not fail if " BTF_IDS_SECTION " section is not found"), + OPT_STRING('b', "btf_base", &obj.base_btf_path, "file", + "path of file providing base BTF"), OPT_END() }; int err = -1; @@ -718,10 +730,8 @@ int main(int argc, const char **argv) */ if (obj.efile.idlist_shndx == -1 || obj.efile.symbols_shndx == -1) { - if (no_fail) - return 0; - pr_err("FAILED to find needed sections\n"); - return -1; + pr_debug("Cannot find .BTF_ids or symbols sections, nothing to do\n"); + return 0; }
if (symbols_collect(&obj)) diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index bc0b59e3f87f..5a46b71a33ff 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -431,7 +431,7 @@ $(OUTPUT)/$(TRUNNER_BINARY): $(TRUNNER_TEST_OBJS) \ | $(TRUNNER_BINARY)-extras $$(call msg,BINARY,,$$@) $(Q)$$(CC) $$(CFLAGS) $$(filter %.a %.o,$$^) $$(LDLIBS) -o $$@ - $(Q)$(RESOLVE_BTFIDS) --no-fail --btf $(TRUNNER_OUTPUT)/btf_data.o $$@ + $(Q)$(RESOLVE_BTFIDS) --btf $(TRUNNER_OUTPUT)/btf_data.o $$@
endef