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>
---
.../testing/selftests/bpf/prog_tests/dynptr.c | 1 +
.../selftests/bpf/progs/dynptr_success.c | 21 +++++++++++++++++++
2 files changed, 22 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/dynptr.c b/tools/testing/selftests/bpf/prog_tests/dynptr.c
index d176c34a7d2e..db22cad32657 100644
--- a/tools/testing/selftests/bpf/prog_tests/dynptr.c
+++ b/tools/testing/selftests/bpf/prog_tests/dynptr.c
@@ -20,6 +20,7 @@ static struct {
{"test_ringbuf", SETUP_SYSCALL_SLEEP},
{"test_skb_readonly", SETUP_SKB_PROG},
{"test_dynptr_skb_data", SETUP_SKB_PROG},
+ {"test_dynptr_skb_nobuff", 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 b2fa6c47ecc0..a059ed8d4590 100644
--- a/tools/testing/selftests/bpf/progs/dynptr_success.c
+++ b/tools/testing/selftests/bpf/progs/dynptr_success.c
@@ -207,3 +207,24 @@ int test_dynptr_skb_data(struct __sk_buff *skb)
return 1;
}
+
+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 should return NULL. SKB may require a buffer */
+ data = bpf_dynptr_slice(&ptr, 0, NULL, 1);
+ if (data) {
+ err = 2;
+ return 1;
+ }
+
+ return 1;
+}
--
2.40.0.634.g4ca3ef3211-goog
