diff options
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 72 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.h | 1 |
2 files changed, 43 insertions, 30 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 4f402dcdf372..5aa45f89da93 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -579,31 +579,6 @@ bpf_object__init_kversion(struct bpf_object *obj, return 0; } -static int -bpf_object__validate_maps(struct bpf_object *obj) -{ - int i; - - /* - * If there's only 1 map, the only error case should have been - * catched in bpf_object__init_maps(). - */ - if (!obj->maps || !obj->nr_maps || (obj->nr_maps == 1)) - return 0; - - for (i = 1; i < obj->nr_maps; i++) { - const struct bpf_map *a = &obj->maps[i - 1]; - const struct bpf_map *b = &obj->maps[i]; - - if (b->offset - a->offset < sizeof(struct bpf_map_def)) { - pr_warning("corrupted map section in %s: map \"%s\" too small\n", - obj->path, a->name); - return -EINVAL; - } - } - return 0; -} - static int compare_bpf_map(const void *_a, const void *_b) { const struct bpf_map *a = _a; @@ -615,7 +590,7 @@ static int compare_bpf_map(const void *_a, const void *_b) static int bpf_object__init_maps(struct bpf_object *obj) { - int i, map_idx, nr_maps = 0; + int i, map_idx, map_def_sz, nr_maps = 0; Elf_Scn *scn; Elf_Data *data; Elf_Data *symbols = obj->efile.symbols; @@ -658,6 +633,15 @@ bpf_object__init_maps(struct bpf_object *obj) if (!nr_maps) return 0; + /* Assume equally sized map definitions */ + map_def_sz = data->d_size / nr_maps; + if (!data->d_size || (data->d_size % nr_maps) != 0) { + pr_warning("unable to determine map definition size " + "section %s, %d maps in %zd bytes\n", + obj->path, nr_maps, data->d_size); + return -EINVAL; + } + obj->maps = calloc(nr_maps, sizeof(obj->maps[0])); if (!obj->maps) { pr_warning("alloc maps for object failed\n"); @@ -690,7 +674,7 @@ bpf_object__init_maps(struct bpf_object *obj) obj->efile.strtabidx, sym.st_name); obj->maps[map_idx].offset = sym.st_value; - if (sym.st_value + sizeof(struct bpf_map_def) > data->d_size) { + if (sym.st_value + map_def_sz > data->d_size) { pr_warning("corrupted maps section in %s: last map \"%s\" too small\n", obj->path, map_name); return -EINVAL; @@ -704,12 +688,40 @@ bpf_object__init_maps(struct bpf_object *obj) pr_debug("map %d is \"%s\"\n", map_idx, obj->maps[map_idx].name); def = (struct bpf_map_def *)(data->d_buf + sym.st_value); - obj->maps[map_idx].def = *def; + /* + * If the definition of the map in the object file fits in + * bpf_map_def, copy it. Any extra fields in our version + * of bpf_map_def will default to zero as a result of the + * calloc above. + */ + if (map_def_sz <= sizeof(struct bpf_map_def)) { + memcpy(&obj->maps[map_idx].def, def, map_def_sz); + } else { + /* + * Here the map structure being read is bigger than what + * we expect, truncate if the excess bits are all zero. + * If they are not zero, reject this map as + * incompatible. + */ + char *b; + for (b = ((char *)def) + sizeof(struct bpf_map_def); + b < ((char *)def) + map_def_sz; b++) { + if (*b != 0) { + pr_warning("maps section in %s: \"%s\" " + "has unrecognized, non-zero " + "options\n", + obj->path, map_name); + return -EINVAL; + } + } + memcpy(&obj->maps[map_idx].def, def, + sizeof(struct bpf_map_def)); + } map_idx++; } qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]), compare_bpf_map); - return bpf_object__validate_maps(obj); + return 0; } static int bpf_object__elf_collect(struct bpf_object *obj) @@ -930,7 +942,7 @@ bpf_object__create_maps(struct bpf_object *obj) def->key_size, def->value_size, def->max_entries, - 0); + def->map_flags); if (*pfd < 0) { size_t j; int err = *pfd; diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 7959086eb9c9..6e20003109e0 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -207,6 +207,7 @@ struct bpf_map_def { unsigned int key_size; unsigned int value_size; unsigned int max_entries; + unsigned int map_flags; }; /* |