diff mbox series

[v2,2/3] selftests/bpf: Test allowing NULL buffer in dynptr slice

Message ID 20230502005218.3627530-2-drosen@google.com (mailing list archive)
State New
Headers show
Series [v2,1/3] bpf: Allow NULL buffers in bpf_dynptr_slice(_rw) | expand

Commit Message

Daniel Rosenberg May 2, 2023, 12:52 a.m. UTC
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@google.com>
---
 tools/testing/selftests/bpf/prog_tests/dynptr.c |  1 +
 .../selftests/bpf/progs/dynptr_success.c        | 17 +++++++++++++++++
 2 files changed, 18 insertions(+)

Comments

Alexei Starovoitov May 3, 2023, 4:20 p.m. UTC | #1
On Mon, May 1, 2023 at 5:52 PM Daniel Rosenberg <drosen@google.com> wrote:
>
> 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@google.com>
> ---
>  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 d176c34a7d2e..ac1fcaddcddf 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_no_buff", SETUP_SKB_PROG},
>  };

Please rebase and resubmit targeting bpf-next and with [PATCH bpf-next] subject.

It doesn't apply:
Using index info to reconstruct a base tree...
M    tools/testing/selftests/bpf/prog_tests/dynptr.c
M    tools/testing/selftests/bpf/progs/dynptr_success.c
Falling back to patching base and 3-way merge...
Auto-merging tools/testing/selftests/bpf/progs/dynptr_success.c
CONFLICT (content): Merge conflict in
tools/testing/selftests/bpf/progs/dynptr_success.c
Auto-merging tools/testing/selftests/bpf/prog_tests/dynptr.c
CONFLICT (content): Merge conflict in
tools/testing/selftests/bpf/prog_tests/dynptr.c
error: Failed to merge in the changes.
Patch failed at 0002 selftests/bpf: Test allowing NULL buffer in dynptr slice
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/prog_tests/dynptr.c b/tools/testing/selftests/bpf/prog_tests/dynptr.c
index d176c34a7d2e..ac1fcaddcddf 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_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 b2fa6c47ecc0..16636a29242a 100644
--- a/tools/testing/selftests/bpf/progs/dynptr_success.c
+++ b/tools/testing/selftests/bpf/progs/dynptr_success.c
@@ -207,3 +207,20 @@  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 may return NULL. SKB may require a buffer */
+	data = bpf_dynptr_slice(&ptr, 0, NULL, 1);
+
+	return !!data;
+}