[PATCH v2] sample: bpf: syscall_tp_user: print result of verify_map

From: Song Chen
Date: Sat Apr 02 2022 - 04:50:40 EST


At the end of the test, we already print out
prog <prog number>: map ids <...> <...>
Value is the number read from kernel through bpf map, further print out
verify map:<map id> val:<...>
will help users to understand the program runs successfully.

Signed-off-by: Song Chen <chensong_2000@xxxxxx>
---
samples/bpf/syscall_tp_user.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/samples/bpf/syscall_tp_user.c b/samples/bpf/syscall_tp_user.c
index a0ebf1833ed3..c55383068384 100644
--- a/samples/bpf/syscall_tp_user.c
+++ b/samples/bpf/syscall_tp_user.c
@@ -36,6 +36,9 @@ static void verify_map(int map_id)
fprintf(stderr, "failed: map #%d returns value 0\n", map_id);
return;
}
+
+ printf("verify map:%d val: %d\n", map_id, val);
+
val = 0;
if (bpf_map_update_elem(map_id, &key, &val, BPF_ANY) != 0) {
fprintf(stderr, "map_update failed: %s\n", strerror(errno));
--
2.25.1