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authorWang Nan <wangnan0@huawei.com>2016-11-26 07:03:27 +0000
committerArnaldo Carvalho de Melo <acme@redhat.com>2016-11-29 12:10:19 -0300
commit5a6acad17d2e81765dd4c2fce7346a6f045eab25 (patch)
treec5ee94f9aec5b8ac2d1b09e7e1b8b28f927a1204 /tools/lib/bpf
parent10931d2413478239bdceac5546cce85d7a497a4e (diff)
tools lib bpf: Retrive bpf_map through offset of bpf_map_def
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 <wangnan0@huawei.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Joe Stringer <joe@ovn.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/20161126070354.141764-4-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/lib/bpf')
-rw-r--r--tools/lib/bpf/libbpf.c12
-rw-r--r--tools/lib/bpf/libbpf.h8
2 files changed, 20 insertions, 0 deletions
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) \