[PATCH 3/8] libbpf: Add libbpf__kallsyms_parse function
From: Jiri Olsa <hidden>
Date: 2021-11-24 08:43:15
Also in:
bpf, lkml
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [library] (libbpf), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Move the kallsyms parsing in internal libbpf__kallsyms_parse function, so it can be used from other places. It will be used in following changes. Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- tools/lib/bpf/libbpf.c | 62 ++++++++++++++++++++------------- tools/lib/bpf/libbpf_internal.h | 5 +++ 2 files changed, 43 insertions(+), 24 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index af405c38aadc..b55c0fbfcc03 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c@@ -6950,12 +6950,10 @@ static int bpf_object__sanitize_maps(struct bpf_object *obj) return 0; } -static int bpf_object__read_kallsyms_file(struct bpf_object *obj) +int libbpf__kallsyms_parse(void *arg, kallsyms_cb_t cb) { char sym_type, sym_name[500]; unsigned long long sym_addr; - const struct btf_type *t; - struct extern_desc *ext; int ret, err = 0; FILE *f;
@@ -6974,35 +6972,51 @@ static int bpf_object__read_kallsyms_file(struct bpf_object *obj) if (ret != 3) { pr_warn("failed to read kallsyms entry: %d\n", ret); err = -EINVAL; - goto out; + break; } - ext = find_extern_by_name(obj, sym_name); - if (!ext || ext->type != EXT_KSYM) - continue; - - t = btf__type_by_id(obj->btf, ext->btf_id); - if (!btf_is_var(t)) - continue; - - if (ext->is_set && ext->ksym.addr != sym_addr) { - pr_warn("extern (ksym) '%s' resolution is ambiguous: 0x%llx or 0x%llx\n", - sym_name, ext->ksym.addr, sym_addr); - err = -EINVAL; - goto out; - } - if (!ext->is_set) { - ext->is_set = true; - ext->ksym.addr = sym_addr; - pr_debug("extern (ksym) %s=0x%llx\n", sym_name, sym_addr); - } + err = cb(arg, sym_addr, sym_type, sym_name); + if (err) + break; } -out: fclose(f); return err; } +static int kallsyms_cb(void *arg, unsigned long long sym_addr, + char sym_type, const char *sym_name) +{ + struct bpf_object *obj = arg; + const struct btf_type *t; + struct extern_desc *ext; + + ext = find_extern_by_name(obj, sym_name); + if (!ext || ext->type != EXT_KSYM) + return 0; + + t = btf__type_by_id(obj->btf, ext->btf_id); + if (!btf_is_var(t)) + return 0; + + if (ext->is_set && ext->ksym.addr != sym_addr) { + pr_warn("extern (ksym) '%s' resolution is ambiguous: 0x%llx or 0x%llx\n", + sym_name, ext->ksym.addr, sym_addr); + return -EINVAL; + } + if (!ext->is_set) { + ext->is_set = true; + ext->ksym.addr = sym_addr; + pr_debug("extern (ksym) %s=0x%llx\n", sym_name, sym_addr); + } + return 0; +} + +static int bpf_object__read_kallsyms_file(struct bpf_object *obj) +{ + return libbpf__kallsyms_parse(obj, kallsyms_cb); +} + static int find_ksym_btf_id(struct bpf_object *obj, const char *ksym_name, __u16 kind, struct btf **res_btf, struct module_btf **res_mod_btf)
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index f7ac349650a1..511cb09f593f 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h@@ -406,6 +406,11 @@ __s32 btf__find_by_name_kind_own(const struct btf *btf, const char *type_name, extern enum libbpf_strict_mode libbpf_mode; +typedef int (*kallsyms_cb_t)(void *arg, unsigned long long sym_addr, + char sym_type, const char *sym_name); + +int libbpf__kallsyms_parse(void *arg, kallsyms_cb_t cb); + /* handle direct returned errors */ static inline int libbpf_err(int ret) {
--
2.33.1