Commit 9a9e3478 authored by Mykyta Yatsenko's avatar Mykyta Yatsenko Committed by Alexei Starovoitov
Browse files

libbpf: Introduce more granular state for bpf_object 



We are going to split bpf_object loading into 2 stages: preparation and
loading. This will increase flexibility when working with bpf_object
and unlock some optimizations and use cases.
This patch substitutes a boolean flag (loaded) by more finely-grained
state for bpf_object.

Signed-off-by: default avatarMykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250303135752.158343-3-mykyta.yatsenko5@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 6ef78c41

tools/lib/bpf/libbpf.c

+22 −17
Original line number Diff line number Diff line
@@ -670,11 +670,18 @@ struct elf_state { 


struct usdt_manager;



enum bpf_object_state {

	OBJ_OPEN,

	OBJ_PREPARED,

	OBJ_LOADED,

};



struct bpf_object {

	char name[BPF_OBJ_NAME_LEN];

	char license[64];

	__u32 kern_version;



	enum bpf_object_state state;

	struct bpf_program *programs;

	size_t nr_programs;

	struct bpf_map *maps;
@@ -686,7 +693,6 @@ struct bpf_object { 
	int nr_extern;

	int kconfig_map_idx;



	bool loaded;

	bool has_subcalls;

	bool has_rodata;
@@ -1511,7 +1517,7 @@ static struct bpf_object *bpf_object__new(const char *path, 
	obj->kconfig_map_idx = -1;



	obj->kern_version = get_kernel_version();

	obj->loaded = false;

	obj->state  = OBJ_OPEN;



	return obj;

}
@@ -4847,7 +4853,7 @@ static int bpf_get_map_info_from_fdinfo(int fd, struct bpf_map_info *info) 


static bool map_is_created(const struct bpf_map *map)

{

	return map->obj->loaded || map->reused;

	return map->obj->state >= OBJ_PREPARED || map->reused;

}



bool bpf_map__autocreate(const struct bpf_map *map)
@@ -8550,7 +8556,7 @@ static int bpf_object_load(struct bpf_object *obj, int extra_log_level, const ch 
	if (!obj)

		return libbpf_err(-EINVAL);



	if (obj->loaded) {

	if (obj->state >= OBJ_LOADED) {

		pr_warn("object '%s': load can't be attempted twice\n", obj->name);

		return libbpf_err(-EINVAL);

	}
@@ -8602,8 +8608,7 @@ static int bpf_object_load(struct bpf_object *obj, int extra_log_level, const ch 
	btf__free(obj->btf_vmlinux);

	obj->btf_vmlinux = NULL;



	obj->loaded = true; /* doesn't matter if successfully or not */



	obj->state = OBJ_LOADED; /* doesn't matter if successfully or not */

	if (err)

		goto out;
@@ -8866,7 +8871,7 @@ int bpf_object__pin_maps(struct bpf_object *obj, const char *path) 
	if (!obj)

		return libbpf_err(-ENOENT);



	if (!obj->loaded) {

	if (obj->state < OBJ_PREPARED) {

		pr_warn("object not yet loaded; load it first\n");

		return libbpf_err(-ENOENT);

	}
@@ -8945,7 +8950,7 @@ int bpf_object__pin_programs(struct bpf_object *obj, const char *path) 
	if (!obj)

		return libbpf_err(-ENOENT);



	if (!obj->loaded) {

	if (obj->state < OBJ_LOADED) {

		pr_warn("object not yet loaded; load it first\n");

		return libbpf_err(-ENOENT);

	}
@@ -9132,7 +9137,7 @@ int bpf_object__btf_fd(const struct bpf_object *obj) 


int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version)

{

	if (obj->loaded)

	if (obj->state >= OBJ_LOADED)

		return libbpf_err(-EINVAL);



	obj->kern_version = kern_version;
@@ -9229,7 +9234,7 @@ bool bpf_program__autoload(const struct bpf_program *prog) 


int bpf_program__set_autoload(struct bpf_program *prog, bool autoload)

{

	if (prog->obj->loaded)

	if (prog->obj->state >= OBJ_LOADED)

		return libbpf_err(-EINVAL);



	prog->autoload = autoload;
@@ -9261,7 +9266,7 @@ int bpf_program__set_insns(struct bpf_program *prog, 
{

	struct bpf_insn *insns;



	if (prog->obj->loaded)

	if (prog->obj->state >= OBJ_LOADED)

		return libbpf_err(-EBUSY);



	insns = libbpf_reallocarray(prog->insns, new_insn_cnt, sizeof(*insns));
@@ -9304,7 +9309,7 @@ static int last_custom_sec_def_handler_id; 


int bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type)

{

	if (prog->obj->loaded)

	if (prog->obj->state >= OBJ_LOADED)

		return libbpf_err(-EBUSY);



	/* if type is not changed, do nothing */
@@ -9335,7 +9340,7 @@ enum bpf_attach_type bpf_program__expected_attach_type(const struct bpf_program 
int bpf_program__set_expected_attach_type(struct bpf_program *prog,

					   enum bpf_attach_type type)

{

	if (prog->obj->loaded)

	if (prog->obj->state >= OBJ_LOADED)

		return libbpf_err(-EBUSY);



	prog->expected_attach_type = type;
@@ -9349,7 +9354,7 @@ __u32 bpf_program__flags(const struct bpf_program *prog) 


int bpf_program__set_flags(struct bpf_program *prog, __u32 flags)

{

	if (prog->obj->loaded)

	if (prog->obj->state >= OBJ_LOADED)

		return libbpf_err(-EBUSY);



	prog->prog_flags = flags;
@@ -9363,7 +9368,7 @@ __u32 bpf_program__log_level(const struct bpf_program *prog) 


int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level)

{

	if (prog->obj->loaded)

	if (prog->obj->state >= OBJ_LOADED)

		return libbpf_err(-EBUSY);



	prog->log_level = log_level;
@@ -9382,7 +9387,7 @@ int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log 
		return libbpf_err(-EINVAL);

	if (prog->log_size > UINT_MAX)

		return libbpf_err(-EINVAL);

	if (prog->obj->loaded)

	if (prog->obj->state >= OBJ_LOADED)

		return libbpf_err(-EBUSY);



	prog->log_buf = log_buf;
@@ -13666,7 +13671,7 @@ int bpf_program__set_attach_target(struct bpf_program *prog, 
	if (!prog || attach_prog_fd < 0)

		return libbpf_err(-EINVAL);



	if (prog->obj->loaded)

	if (prog->obj->state >= OBJ_LOADED)

		return libbpf_err(-EINVAL);



	if (attach_prog_fd && !attach_func_name) {