bpf: Store cookies in kprobe_multi bpf_link_info data

Storing cookies in kprobe_multi bpf_link_info data. The cookies
field is optional and if provided it needs to be an array of
__u64 with kprobe_multi.count length.

Acked-by: Yafang Shao <[email protected]>
Signed-off-by: Jiri Olsa <[email protected]>
Acked-by: Song Liu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 181e744..287d057 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -6563,6 +6563,7 @@
 			__u32 count; /* in/out: kprobe_multi function count */
 			__u32 flags;
 			__u64 missed;
+			__aligned_u64 cookies;
 		} kprobe_multi;
 		struct {
 			__aligned_u64 path;