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: pi3or...@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
