Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966342AbcKOELJ (ORCPT ); Mon, 14 Nov 2016 23:11:09 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:25528 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965960AbcKOEIZ (ORCPT ); Mon, 14 Nov 2016 23:08:25 -0500 From: Wang Nan To: , CC: , , , , Wang Nan , Alexei Starovoitov , Jiri Olsa Subject: [PATCH 07/34] tools lib bpf: Retrive bpf_map through offset of bpf_map_def Date: Tue, 15 Nov 2016 04:05:50 +0000 Message-ID: <20161115040617.69788-8-wangnan0@huawei.com> X-Mailer: git-send-email 2.10.1 In-Reply-To: <20161115040617.69788-1-wangnan0@huawei.com> References: <20161115040617.69788-1-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.193.248] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1814 Lines: 64 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 Cc: Arnaldo Carvalho de Melo Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Zefan Li Cc: pi3orama@163.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 866d5cd..2e97459 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 0c0b012..a5a8b86 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -24,6 +24,7 @@ #include #include #include +#include // 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) \ -- 2.10.1