This patch collects more information from maps sections in BPF object files into 'struct bpf_object', enables later patches access those information (such as the type and size of the map).
In this patch, a new handler 'struct bpf_map' is extracted in parallel with bpf_object and bpf_program. Its iterator and accessor is also created. Signed-off-by: Wang Nan <wangn...@huawei.com> Cc: Arnaldo Carvalho de Melo <a...@redhat.com> Cc: Alexei Starovoitov <a...@plumgrid.com> Cc: Brendan Gregg <brendan.d.gr...@gmail.com> Cc: Daniel Borkmann <dan...@iogearbox.net> Cc: David Ahern <dsah...@gmail.com> Cc: He Kuang <heku...@huawei.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Kaixu Xia <xiaka...@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Paul Mackerras <pau...@samba.org> Cc: Peter Zijlstra <a.p.zijls...@chello.nl> Cc: Zefan Li <lize...@huawei.com> Cc: pi3or...@163.com Link: http://lkml.kernel.org/n/ebpf-oewgxlae7jpwqou9hba4e...@git.kernel.org --- tools/lib/bpf/libbpf.c | 186 +++++++++++++++++++++++++++++++++---------------- tools/lib/bpf/libbpf.h | 21 ++++++ 2 files changed, 147 insertions(+), 60 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 6a07b26..8ae501b 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -109,22 +109,24 @@ struct bpf_program { bpf_program_clear_priv_t clear_priv; }; +struct bpf_map { + int fd; + struct bpf_map_def def; + void *priv; + bpf_map_clear_priv_t clear_priv; +}; + static LIST_HEAD(bpf_objects_list); struct bpf_object { char license[64]; u32 kern_version; - void *maps_buf; - size_t maps_buf_sz; struct bpf_program *programs; size_t nr_programs; - int *map_fds; - /* - * This field is required because maps_buf will be freed and - * maps_buf_sz will be set to 0 after loaded. - */ - size_t nr_map_fds; + struct bpf_map *maps; + size_t nr_maps; + bool loaded; /* @@ -434,21 +436,38 @@ static int bpf_object__init_maps(struct bpf_object *obj, void *data, size_t size) { - if (size == 0) { + size_t nr_maps; + int i; + + nr_maps = size / sizeof(struct bpf_map_def); + if (!data || !nr_maps) { pr_debug("%s doesn't need map definition\n", obj->path); return 0; } - obj->maps_buf = malloc(size); - if (!obj->maps_buf) { - pr_warning("malloc maps failed: %s\n", obj->path); + pr_debug("maps in %s: %ld bytes\n", obj->path, (long)size); + + obj->maps = calloc(1, sizeof(obj->maps[0]) * nr_maps); + if (!obj->maps) { + pr_warning("alloc maps for object failed\n"); return -ENOMEM; } + obj->nr_maps = nr_maps; - obj->maps_buf_sz = size; - memcpy(obj->maps_buf, data, size); - pr_debug("maps in %s: %ld bytes\n", obj->path, (long)size); + for (i = 0; i < nr_maps; i++) { + struct bpf_map_def *def = &obj->maps[i].def; + + /* + * fill all fd with -1 so won't close incorrect + * fd (0, stdin) when failure. + */ + obj->maps[i].fd = -1; + + /* Save map definition into obj->maps */ + *def = *(struct bpf_map_def *)(data + + i * sizeof(struct bpf_map_def)); + } return 0; } @@ -632,37 +651,15 @@ static int bpf_object__create_maps(struct bpf_object *obj) { unsigned int i; - size_t nr_maps; - int *pfd; - - nr_maps = obj->maps_buf_sz / sizeof(struct bpf_map_def); - if (!obj->maps_buf || !nr_maps) { - pr_debug("don't need create maps for %s\n", - obj->path); - return 0; - } - - obj->map_fds = malloc(sizeof(int) * nr_maps); - if (!obj->map_fds) { - pr_warning("realloc perf_bpf_map_fds failed\n"); - return -ENOMEM; - } - obj->nr_map_fds = nr_maps; - /* fill all fd with -1 */ - memset(obj->map_fds, -1, sizeof(int) * nr_maps); + for (i = 0; i < obj->nr_maps; i++) { + struct bpf_map_def *def = &obj->maps[i].def; + int *pfd = &obj->maps[i].fd; - pfd = obj->map_fds; - for (i = 0; i < nr_maps; i++) { - struct bpf_map_def def; - - def = *(struct bpf_map_def *)(obj->maps_buf + - i * sizeof(struct bpf_map_def)); - - *pfd = bpf_create_map(def.type, - def.key_size, - def.value_size, - def.max_entries); + *pfd = bpf_create_map(def->type, + def->key_size, + def->value_size, + def->max_entries); if (*pfd < 0) { size_t j; int err = *pfd; @@ -670,22 +667,17 @@ bpf_object__create_maps(struct bpf_object *obj) pr_warning("failed to create map: %s\n", strerror(errno)); for (j = 0; j < i; j++) - zclose(obj->map_fds[j]); - obj->nr_map_fds = 0; - zfree(&obj->map_fds); + zclose(obj->maps[j].fd); return err; } pr_debug("create map: fd=%d\n", *pfd); - pfd++; } - zfree(&obj->maps_buf); - obj->maps_buf_sz = 0; return 0; } static int -bpf_program__relocate(struct bpf_program *prog, int *map_fds) +bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj) { int i; @@ -705,7 +697,7 @@ bpf_program__relocate(struct bpf_program *prog, int *map_fds) return -ERANGE; } insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD; - insns[insn_idx].imm = map_fds[map_idx]; + insns[insn_idx].imm = obj->maps[map_idx].fd; } zfree(&prog->reloc_desc); @@ -724,7 +716,7 @@ bpf_object__relocate(struct bpf_object *obj) for (i = 0; i < obj->nr_programs; i++) { prog = &obj->programs[i]; - err = bpf_program__relocate(prog, obj->map_fds); + err = bpf_program__relocate(prog, obj); if (err) { pr_warning("failed to relocate '%s'\n", prog->section_name); @@ -748,8 +740,7 @@ static int bpf_object__collect_reloc(struct bpf_object *obj) Elf_Data *data = obj->efile.reloc[i].data; int idx = shdr->sh_info; struct bpf_program *prog; - size_t nr_maps = obj->maps_buf_sz / - sizeof(struct bpf_map_def); + size_t nr_maps = obj->nr_maps; if (shdr->sh_type != SHT_REL) { pr_warning("internal error at %d\n", __LINE__); @@ -986,10 +977,8 @@ int bpf_object__unload(struct bpf_object *obj) if (!obj) return -EINVAL; - for (i = 0; i < obj->nr_map_fds; i++) - zclose(obj->map_fds[i]); - zfree(&obj->map_fds); - obj->nr_map_fds = 0; + for (i = 0; i < obj->nr_maps; i++) + zclose(obj->maps[i].fd); for (i = 0; i < obj->nr_programs; i++) bpf_program__unload(&obj->programs[i]); @@ -1032,7 +1021,15 @@ void bpf_object__close(struct bpf_object *obj) bpf_object__elf_finish(obj); bpf_object__unload(obj); - zfree(&obj->maps_buf); + for (i = 0; i < obj->nr_maps; i++) { + if (obj->maps[i].clear_priv) + obj->maps[i].clear_priv(&obj->maps[i], + obj->maps[i].priv); + obj->maps[i].priv = NULL; + obj->maps[i].clear_priv = NULL; + } + zfree(&obj->maps); + obj->nr_maps = 0; if (obj->programs && obj->nr_programs) { for (i = 0; i < obj->nr_programs; i++) @@ -1179,3 +1176,72 @@ int bpf_program__nth_fd(struct bpf_program *prog, int n) return fd; } + +int bpf_map__get_fd(struct bpf_map *map) +{ + if (!map) + return -EINVAL; + + return map->fd; +} + +int bpf_map__get_def(struct bpf_map *map, struct bpf_map_def *pdef) +{ + if (!map || !pdef) + return -EINVAL; + + *pdef = map->def; + return 0; +} + +int bpf_map__set_private(struct bpf_map *map, void *priv, + bpf_map_clear_priv_t clear_priv) +{ + if (!map) + return -EINVAL; + + if (map->priv) { + if (map->clear_priv) + map->clear_priv(map, map->priv); + } + + map->priv = priv; + map->clear_priv = clear_priv; + return 0; +} + +int bpf_map__get_private(struct bpf_map *map, void **ppriv) +{ + if (!map) + return -EINVAL; + + if (ppriv) + *ppriv = map->priv; + return 0; +} + +struct bpf_map * +bpf_map__next(struct bpf_map *prev, struct bpf_object *obj) +{ + size_t idx; + struct bpf_map *s, *e; + + if (!obj || !obj->maps) + return NULL; + + s = obj->maps; + e = obj->maps + obj->nr_maps; + + if (prev == NULL) + return s; + + if ((prev < s) || (prev >= e)) { + pr_warning("error: map handler doesn't belong to object\n"); + return NULL; + } + + idx = (prev - obj->maps) + 1; + if (idx >= obj->nr_maps) + return NULL; + return &obj->maps[idx]; +} diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index d82b89e..a3bf71e 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -102,4 +102,25 @@ struct bpf_map_def { unsigned int max_entries; }; +/* + * There is another 'struct bpf_map' in include/linux/map.h. However, + * it is not a uapi header so no need to consider name confliction. + */ +struct bpf_map; + +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__get_fd(struct bpf_map *map); +int bpf_map__get_def(struct bpf_map *map, struct bpf_map_def *pdef); + +typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *); +int bpf_map__set_private(struct bpf_map *map, void *priv, + bpf_map_clear_priv_t clear_priv); +int bpf_map__get_private(struct bpf_map *map, void **ppriv); + #endif -- 1.8.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
