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 <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
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 <acme@redhat.com>
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 95c8d8e..87f5054a9 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -81,6 +81,9 @@
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 @@
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 @@
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 @@
bpf_object__elf_finish(obj);
+ zfree(&obj->maps_buf);
free(obj);
}