From 0b3d1efade1b7e2ccaf79c40a7481c93cfb5090a Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Wed, 1 Jul 2015 02:13:58 +0000 Subject: [PATCH] bpf tools: Collect map definitions from 'maps' section If maps are used by eBPF programs, corresponding object file(s) should contain a section named 'map'. Which contains map definitions. This patch copies the data of the whole section. Map data parsing should be acted just before map loading. Signed-off-by: Wang Nan Acked-by: Alexei Starovoitov Cc: Brendan Gregg Cc: Daniel Borkmann Cc: David Ahern Cc: He Kuang Cc: Jiri Olsa Cc: Kaixu Xia Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1435716878-189507-11-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/bpf/libbpf.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 95c8d8e5c350..87f5054a9efb 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -81,6 +81,9 @@ void libbpf_set_print(libbpf_print_fn_t warn, struct bpf_object { char license[64]; u32 kern_version; + void *maps_buf; + size_t maps_buf_sz; + /* * Information when doing elf related work. Only valid if fd * is valid. @@ -250,6 +253,28 @@ bpf_object__init_kversion(struct bpf_object *obj, return 0; } +static int +bpf_object__init_maps(struct bpf_object *obj, void *data, + size_t size) +{ + if (size == 0) { + 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); + return -ENOMEM; + } + + obj->maps_buf_sz = size; + memcpy(obj->maps_buf, data, size); + pr_debug("maps in %s: %ld bytes\n", obj->path, (long)size); + return 0; +} + static int bpf_object__elf_collect(struct bpf_object *obj) { Elf *elf = obj->efile.elf; @@ -305,6 +330,9 @@ static int bpf_object__elf_collect(struct bpf_object *obj) err = bpf_object__init_kversion(obj, data->d_buf, data->d_size); + else if (strcmp(name, "maps") == 0) + err = bpf_object__init_maps(obj, data->d_buf, + data->d_size); if (err) goto out; } @@ -382,5 +410,6 @@ void bpf_object__close(struct bpf_object *obj) bpf_object__elf_finish(obj); + zfree(&obj->maps_buf); free(obj); } -- 2.30.2