From ab9e084821221b2eda57a512535fe35b49e672d8 Mon Sep 17 00:00:00 2001 From: Andrey Ignatov Date: Mon, 15 Oct 2018 22:50:34 -0700 Subject: libbpf: Per-symbol visibility for DSO Make global symbols in libbpf DSO hidden by default with -fvisibility=hidden and export symbols that are part of ABI explicitly with __attribute__((visibility("default"))). This is common practice that should prevent from accidentally exporting a symbol, that is not supposed to be a part of ABI what, in turn, improves both libbpf developer- and user-experiences. See [1] for more details. Export control becomes more important since more and more projects use libbpf. The patch doesn't export a bunch of netlink related functions since as agreed in [2] they'll be reworked. That doesn't break bpftool since bpftool links libbpf statically. [1] https://www.akkadia.org/drepper/dsohowto.pdf (2.2 Export Control) [2] https://www.mail-archive.com/netdev@vger.kernel.org/msg251434.html Signed-off-by: Andrey Ignatov Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.h | 186 ++++++++++++++++++++++++++----------------------- 1 file changed, 99 insertions(+), 87 deletions(-) (limited to 'tools/lib/bpf/libbpf.h') diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 7e9c801a9fdd..1354cc9f8cba 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -16,6 +16,10 @@ #include // for size_t #include +#ifndef LIBBPF_API +#define LIBBPF_API __attribute__((visibility("default"))) +#endif + enum libbpf_errno { __LIBBPF_ERRNO__START = 4000, @@ -37,7 +41,7 @@ enum libbpf_errno { __LIBBPF_ERRNO__END, }; -int libbpf_strerror(int err, char *buf, size_t size); +LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size); /* * __printf is defined in include/linux/compiler-gcc.h. However, @@ -47,9 +51,9 @@ int libbpf_strerror(int err, char *buf, size_t size); typedef int (*libbpf_print_fn_t)(const char *, ...) __attribute__((format(printf, 1, 2))); -void libbpf_set_print(libbpf_print_fn_t warn, - libbpf_print_fn_t info, - libbpf_print_fn_t debug); +LIBBPF_API void libbpf_set_print(libbpf_print_fn_t warn, + libbpf_print_fn_t info, + libbpf_print_fn_t debug); /* Hide internal to user */ struct bpf_object; @@ -59,27 +63,28 @@ struct bpf_object_open_attr { enum bpf_prog_type prog_type; }; -struct bpf_object *bpf_object__open(const char *path); -struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr); +LIBBPF_API struct bpf_object *bpf_object__open(const char *path); +LIBBPF_API struct bpf_object * +bpf_object__open_xattr(struct bpf_object_open_attr *attr); struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr, int flags); -struct bpf_object *bpf_object__open_buffer(void *obj_buf, - size_t obj_buf_sz, - const char *name); -int bpf_object__pin(struct bpf_object *object, const char *path); -void bpf_object__close(struct bpf_object *object); +LIBBPF_API struct bpf_object *bpf_object__open_buffer(void *obj_buf, + size_t obj_buf_sz, + const char *name); +LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path); +LIBBPF_API void bpf_object__close(struct bpf_object *object); /* Load/unload object into/from kernel */ -int bpf_object__load(struct bpf_object *obj); -int bpf_object__unload(struct bpf_object *obj); -const char *bpf_object__name(struct bpf_object *obj); -unsigned int bpf_object__kversion(struct bpf_object *obj); -int bpf_object__btf_fd(const struct bpf_object *obj); +LIBBPF_API int bpf_object__load(struct bpf_object *obj); +LIBBPF_API int bpf_object__unload(struct bpf_object *obj); +LIBBPF_API const char *bpf_object__name(struct bpf_object *obj); +LIBBPF_API unsigned int bpf_object__kversion(struct bpf_object *obj); +LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj); -struct bpf_program * +LIBBPF_API struct bpf_program * bpf_object__find_program_by_title(struct bpf_object *obj, const char *title); -struct bpf_object *bpf_object__next(struct bpf_object *prev); +LIBBPF_API struct bpf_object *bpf_object__next(struct bpf_object *prev); #define bpf_object__for_each_safe(pos, tmp) \ for ((pos) = bpf_object__next(NULL), \ (tmp) = bpf_object__next(pos); \ @@ -87,19 +92,20 @@ struct bpf_object *bpf_object__next(struct bpf_object *prev); (pos) = (tmp), (tmp) = bpf_object__next(tmp)) typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *); -int bpf_object__set_priv(struct bpf_object *obj, void *priv, - bpf_object_clear_priv_t clear_priv); -void *bpf_object__priv(struct bpf_object *prog); +LIBBPF_API int bpf_object__set_priv(struct bpf_object *obj, void *priv, + bpf_object_clear_priv_t clear_priv); +LIBBPF_API void *bpf_object__priv(struct bpf_object *prog); -int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, - enum bpf_attach_type *expected_attach_type); -int libbpf_attach_type_by_name(const char *name, - enum bpf_attach_type *attach_type); +LIBBPF_API int +libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, + enum bpf_attach_type *expected_attach_type); +LIBBPF_API int libbpf_attach_type_by_name(const char *name, + enum bpf_attach_type *attach_type); /* Accessors of bpf_program */ struct bpf_program; -struct bpf_program *bpf_program__next(struct bpf_program *prog, - struct bpf_object *obj); +LIBBPF_API struct bpf_program *bpf_program__next(struct bpf_program *prog, + struct bpf_object *obj); #define bpf_object__for_each_program(pos, obj) \ for ((pos) = bpf_program__next(NULL, (obj)); \ @@ -109,21 +115,24 @@ struct bpf_program *bpf_program__next(struct bpf_program *prog, typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, void *); -int bpf_program__set_priv(struct bpf_program *prog, void *priv, - bpf_program_clear_priv_t clear_priv); +LIBBPF_API int bpf_program__set_priv(struct bpf_program *prog, void *priv, + bpf_program_clear_priv_t clear_priv); -void *bpf_program__priv(struct bpf_program *prog); -void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex); +LIBBPF_API void *bpf_program__priv(struct bpf_program *prog); +LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog, + __u32 ifindex); -const char *bpf_program__title(struct bpf_program *prog, bool needs_copy); +LIBBPF_API const char *bpf_program__title(struct bpf_program *prog, + bool needs_copy); -int bpf_program__load(struct bpf_program *prog, char *license, - __u32 kern_version); -int bpf_program__fd(struct bpf_program *prog); -int bpf_program__pin_instance(struct bpf_program *prog, const char *path, - int instance); -int bpf_program__pin(struct bpf_program *prog, const char *path); -void bpf_program__unload(struct bpf_program *prog); +LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license, + __u32 kern_version); +LIBBPF_API int bpf_program__fd(struct bpf_program *prog); +LIBBPF_API int bpf_program__pin_instance(struct bpf_program *prog, + const char *path, + int instance); +LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path); +LIBBPF_API void bpf_program__unload(struct bpf_program *prog); struct bpf_insn; @@ -184,34 +193,36 @@ typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n, struct bpf_insn *insns, int insns_cnt, struct bpf_prog_prep_result *res); -int bpf_program__set_prep(struct bpf_program *prog, int nr_instance, - bpf_program_prep_t prep); +LIBBPF_API int bpf_program__set_prep(struct bpf_program *prog, int nr_instance, + bpf_program_prep_t prep); -int bpf_program__nth_fd(struct bpf_program *prog, int n); +LIBBPF_API int bpf_program__nth_fd(struct bpf_program *prog, int n); /* * Adjust type of BPF program. Default is kprobe. */ -int bpf_program__set_socket_filter(struct bpf_program *prog); -int bpf_program__set_tracepoint(struct bpf_program *prog); -int bpf_program__set_raw_tracepoint(struct bpf_program *prog); -int bpf_program__set_kprobe(struct bpf_program *prog); -int bpf_program__set_sched_cls(struct bpf_program *prog); -int bpf_program__set_sched_act(struct bpf_program *prog); -int bpf_program__set_xdp(struct bpf_program *prog); -int bpf_program__set_perf_event(struct bpf_program *prog); -void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type); -void bpf_program__set_expected_attach_type(struct bpf_program *prog, - enum bpf_attach_type type); - -bool bpf_program__is_socket_filter(struct bpf_program *prog); -bool bpf_program__is_tracepoint(struct bpf_program *prog); -bool bpf_program__is_raw_tracepoint(struct bpf_program *prog); -bool bpf_program__is_kprobe(struct bpf_program *prog); -bool bpf_program__is_sched_cls(struct bpf_program *prog); -bool bpf_program__is_sched_act(struct bpf_program *prog); -bool bpf_program__is_xdp(struct bpf_program *prog); -bool bpf_program__is_perf_event(struct bpf_program *prog); +LIBBPF_API int bpf_program__set_socket_filter(struct bpf_program *prog); +LIBBPF_API int bpf_program__set_tracepoint(struct bpf_program *prog); +LIBBPF_API int bpf_program__set_raw_tracepoint(struct bpf_program *prog); +LIBBPF_API int bpf_program__set_kprobe(struct bpf_program *prog); +LIBBPF_API int bpf_program__set_sched_cls(struct bpf_program *prog); +LIBBPF_API int bpf_program__set_sched_act(struct bpf_program *prog); +LIBBPF_API int bpf_program__set_xdp(struct bpf_program *prog); +LIBBPF_API int bpf_program__set_perf_event(struct bpf_program *prog); +LIBBPF_API void bpf_program__set_type(struct bpf_program *prog, + enum bpf_prog_type type); +LIBBPF_API void +bpf_program__set_expected_attach_type(struct bpf_program *prog, + enum bpf_attach_type type); + +LIBBPF_API bool bpf_program__is_socket_filter(struct bpf_program *prog); +LIBBPF_API bool bpf_program__is_tracepoint(struct bpf_program *prog); +LIBBPF_API bool bpf_program__is_raw_tracepoint(struct bpf_program *prog); +LIBBPF_API bool bpf_program__is_kprobe(struct bpf_program *prog); +LIBBPF_API bool bpf_program__is_sched_cls(struct bpf_program *prog); +LIBBPF_API bool bpf_program__is_sched_act(struct bpf_program *prog); +LIBBPF_API bool bpf_program__is_xdp(struct bpf_program *prog); +LIBBPF_API bool bpf_program__is_perf_event(struct bpf_program *prog); /* * No need for __attribute__((packed)), all members of 'bpf_map_def' @@ -232,39 +243,39 @@ struct bpf_map_def { * so no need to worry about a name clash. */ struct bpf_map; -struct bpf_map * +LIBBPF_API struct bpf_map * bpf_object__find_map_by_name(struct bpf_object *obj, const char *name); /* * Get bpf_map through the offset of corresponding struct bpf_map_def * in the BPF object file. */ -struct bpf_map * +LIBBPF_API struct bpf_map * bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset); -struct bpf_map * +LIBBPF_API struct bpf_map * bpf_map__next(struct bpf_map *map, struct bpf_object *obj); #define bpf_map__for_each(pos, obj) \ for ((pos) = bpf_map__next(NULL, (obj)); \ (pos) != NULL; \ (pos) = bpf_map__next((pos), (obj))) -int bpf_map__fd(struct bpf_map *map); -const struct bpf_map_def *bpf_map__def(struct bpf_map *map); -const char *bpf_map__name(struct bpf_map *map); -__u32 bpf_map__btf_key_type_id(const struct bpf_map *map); -__u32 bpf_map__btf_value_type_id(const struct bpf_map *map); +LIBBPF_API int bpf_map__fd(struct bpf_map *map); +LIBBPF_API const struct bpf_map_def *bpf_map__def(struct bpf_map *map); +LIBBPF_API const char *bpf_map__name(struct bpf_map *map); +LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map); +LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map); typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *); -int bpf_map__set_priv(struct bpf_map *map, void *priv, - bpf_map_clear_priv_t clear_priv); -void *bpf_map__priv(struct bpf_map *map); -int bpf_map__reuse_fd(struct bpf_map *map, int fd); -bool bpf_map__is_offload_neutral(struct bpf_map *map); -void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); -int bpf_map__pin(struct bpf_map *map, const char *path); +LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv, + bpf_map_clear_priv_t clear_priv); +LIBBPF_API void *bpf_map__priv(struct bpf_map *map); +LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd); +LIBBPF_API bool bpf_map__is_offload_neutral(struct bpf_map *map); +LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); +LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path); -long libbpf_get_error(const void *ptr); +LIBBPF_API long libbpf_get_error(const void *ptr); struct bpf_prog_load_attr { const char *file; @@ -273,12 +284,12 @@ struct bpf_prog_load_attr { int ifindex; }; -int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, - struct bpf_object **pobj, int *prog_fd); -int bpf_prog_load(const char *file, enum bpf_prog_type type, - struct bpf_object **pobj, int *prog_fd); +LIBBPF_API int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, + struct bpf_object **pobj, int *prog_fd); +LIBBPF_API int bpf_prog_load(const char *file, enum bpf_prog_type type, + struct bpf_object **pobj, int *prog_fd); -int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags); +LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags); enum bpf_perf_event_ret { LIBBPF_PERF_EVENT_DONE = 0, @@ -288,10 +299,11 @@ enum bpf_perf_event_ret { typedef enum bpf_perf_event_ret (*bpf_perf_event_print_t)(void *event, void *priv); -int bpf_perf_event_read_simple(void *mem, unsigned long size, - unsigned long page_size, - void **buf, size_t *buf_len, - bpf_perf_event_print_t fn, void *priv); +LIBBPF_API int bpf_perf_event_read_simple(void *mem, unsigned long size, + unsigned long page_size, + void **buf, size_t *buf_len, + bpf_perf_event_print_t fn, + void *priv); struct nlattr; typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb); -- cgit v1.2.3-59-g8ed1b