From: Wang Nan <wangn...@huawei.com> Add a new API to libbpf, caller is able to get bpf_map through the offset of bpf_map_def to 'maps' section.
The API will be used to help jitted perf hook code find fd of a map. Signed-off-by: Wang Nan <wangn...@huawei.com> Acked-by: Alexei Starovoitov <a...@kernel.org> Cc: He Kuang <heku...@huawei.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Joe Stringer <j...@ovn.org> Cc: Zefan Li <lize...@huawei.com> Cc: pi3or...@163.com Link: http://lkml.kernel.org/r/20161126070354.141764-4-wangn...@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/lib/bpf/libbpf.c | 12 ++++++++++++ tools/lib/bpf/libbpf.h | 8 ++++++++ 2 files changed, 20 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 866d5cdeffc7..2e974593f3e8 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1524,3 +1524,15 @@ bpf_object__find_map_by_name(struct bpf_object *obj, const char *name) } return NULL; } + +struct bpf_map * +bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset) +{ + int i; + + for (i = 0; i < obj->nr_maps; i++) { + if (obj->maps[i].offset == offset) + return &obj->maps[i]; + } + return ERR_PTR(-ENOENT); +} diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 0c0b0127e03e..a5a8b86a06fe 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -24,6 +24,7 @@ #include <stdio.h> #include <stdbool.h> #include <linux/err.h> +#include <sys/types.h> // for size_t enum libbpf_errno { __LIBBPF_ERRNO__START = 4000, @@ -200,6 +201,13 @@ struct bpf_map; 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 * +bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset); + struct bpf_map * bpf_map__next(struct bpf_map *map, struct bpf_object *obj); #define bpf_map__for_each(pos, obj) \ -- 2.9.3
