libbpf: Add libbpf_kallsyms_parse function

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>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220316122419.933957-8-jolsa@kernel.org
This commit is contained in:
Jiri Olsa 2022-03-16 13:24:13 +01:00 committed by Alexei Starovoitov
parent ca74823c6e
commit 85153ac062
2 changed files with 43 additions and 24 deletions

View File

@ -7171,12 +7171,10 @@ 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(kallsyms_cb_t cb, void *ctx)
{
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;
@ -7195,35 +7193,51 @@ 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(sym_addr, sym_type, sym_name, ctx);
if (err)
break;
}
out:
fclose(f);
return err;
}
static int kallsyms_cb(unsigned long long sym_addr, char sym_type,
const char *sym_name, void *ctx)
{
struct bpf_object *obj = ctx;
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(kallsyms_cb, obj);
}
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)

View File

@ -449,6 +449,11 @@ __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)(unsigned long long sym_addr, char sym_type,
const char *sym_name, void *ctx);
int libbpf_kallsyms_parse(kallsyms_cb_t cb, void *arg);
/* handle direct returned errors */
static inline int libbpf_err(int ret)
{