Commit 85153ac0 authored by Jiri Olsa's avatar Jiri Olsa Committed by Alexei Starovoitov
Browse files

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: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220316122419.933957-8-jolsa@kernel.org
parent ca74823c

tools/lib/bpf/libbpf.c

+38 −24
Original line number Diff line number Diff line
@@ -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;
@@ -7195,33 +7193,49 @@ 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;

		}



		err = cb(sym_addr, sym_type, sym_name, ctx);

		if (err)

			break;

	}



	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)

			continue;

		return 0;



	t = btf__type_by_id(obj->btf, ext->btf_id);

	if (!btf_is_var(t))

			continue;

		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);

			err = -EINVAL;

			goto out;

		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;

}



out:

	fclose(f);

	return err;

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,

tools/lib/bpf/libbpf_internal.h

+5 −0
Original line number Diff line number Diff line
@@ -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)

{