From: Daniel Rosenberg <drosen@google.com>
Date: Sat, 6 May 2023 01:31:34 +0000 (-0700)
Subject: selftests/bpf: Accept mem from dynptr in helper funcs
X-Git-Tag: v6.6.7~2536^2~269^2~10^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=798e48fc28fa64aa4eca6e8a404fa20ac8f7c09e;p=platform%2Fkernel%2Flinux-starfive.git

selftests/bpf: Accept mem from dynptr in helper funcs

This ensures that buffers retrieved from dynptr_data are allowed to be
passed in to helpers that take mem, like bpf_strncmp

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Link: https://lore.kernel.org/r/20230506013134.2492210-6-drosen@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---

diff --git a/tools/testing/selftests/bpf/prog_tests/dynptr.c b/tools/testing/selftests/bpf/prog_tests/dynptr.c
index 13d4b9a..7cfac53 100644
--- a/tools/testing/selftests/bpf/prog_tests/dynptr.c
+++ b/tools/testing/selftests/bpf/prog_tests/dynptr.c
@@ -27,6 +27,7 @@ static struct {
 	{"test_dynptr_is_rdonly", SETUP_SKB_PROG},
 	{"test_dynptr_clone", SETUP_SKB_PROG},
 	{"test_dynptr_skb_no_buff", SETUP_SKB_PROG},
+	{"test_dynptr_skb_strcmp", 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 d299ef3..0c05397 100644
--- a/tools/testing/selftests/bpf/progs/dynptr_success.c
+++ b/tools/testing/selftests/bpf/progs/dynptr_success.c
@@ -522,3 +522,24 @@ int test_dynptr_skb_no_buff(struct __sk_buff *skb)
 
 	return !!data;
 }
+
+SEC("?cgroup_skb/egress")
+int test_dynptr_skb_strcmp(struct __sk_buff *skb)
+{
+	struct bpf_dynptr ptr;
+	char *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, 10);
+	if (data) {
+		bpf_strncmp(data, 10, "foo");
+		return 1;
+	}
+
+	return 1;
+}