bpf_dynptr_slice(_rw) no longer requires a buffer for verification. If the
buffer is needed, but not present, the function will return NULL.
Signed-off-by: Daniel Rosenberg <drosen@xxxxxxxxxx>
---
tools/testing/selftests/bpf/prog_tests/dynptr.c | 1 +
.../selftests/bpf/progs/dynptr_success.c | 17 +++++++++++++++++
2 files changed, 18 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/dynptr.c b/tools/testing/selftests/bpf/prog_tests/dynptr.c
index 0478916aff37..13d4b9ab16e7 100644
--- a/tools/testing/selftests/bpf/prog_tests/dynptr.c
+++ b/tools/testing/selftests/bpf/prog_tests/dynptr.c
@@ -26,6 +26,7 @@ static struct {
{"test_dynptr_is_null", SETUP_SYSCALL_SLEEP},
{"test_dynptr_is_rdonly", SETUP_SKB_PROG},
{"test_dynptr_clone", SETUP_SKB_PROG},
+ {"test_dynptr_skb_no_buff", SETUP_SKB_PROG},
};
static void verify_success(const char *prog_name, enum test_setup_type setup_type)
diff --git a/tools/testing/selftests/bpf/progs/dynptr_success.c b/tools/testing/selftests/bpf/progs/dynptr_success.c
index be7de62de045..d299ef3b4d1f 100644
--- a/tools/testing/selftests/bpf/progs/dynptr_success.c
+++ b/tools/testing/selftests/bpf/progs/dynptr_success.c
@@ -505,3 +505,20 @@ int test_dynptr_clone(struct __sk_buff *skb)
return 0;
}
+
+SEC("?cgroup_skb/egress")
+int test_dynptr_skb_no_buff(struct __sk_buff *skb)
+{
+ struct bpf_dynptr ptr;
+ __u64 *data;
+
+ if (bpf_dynptr_from_skb(skb, 0, &ptr)) {
+ err = 1;
+ return 1;
+ }
+
+ /* This may return NULL. SKB may require a buffer */
+ data = bpf_dynptr_slice(&ptr, 0, NULL, 1);
+
+ return !!data;
+}
--
2.40.1.521.gf1e218fcd8-goog
