[PATCH bpf-next v2 14/15] selftests/bpf: Test ldsx with more complex cases

From: Yonghong Song <yhs@fb.com>
To: <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
	Andrii Nakryiko <andrii@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Fangrui Song <maskray@google.com>, <kernel-team@fb.com>
Subject: [PATCH bpf-next v2 14/15] selftests/bpf: Test ldsx with more complex cases
Date: Wed, 12 Jul 2023 23:08:41 -0700	[thread overview]
Message-ID: <20230713060841.397183-1-yhs@fb.com> (raw)
In-Reply-To: <20230713060718.388258-1-yhs@fb.com>

Test reading signed rdonly map value, read/write map value,
probed memory and ctx field. Without proper verifier/git handling,
the test will fail.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 .../selftests/bpf/bpf_testmod/bpf_testmod.c   |  9 +-
 .../selftests/bpf/prog_tests/test_ldsx_insn.c | 88 +++++++++++++++++++
 .../selftests/bpf/progs/test_ldsx_insn.c      | 75 ++++++++++++++++
 3 files changed, 171 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/test_ldsx_insn.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_ldsx_insn.c

diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
index aaf6ef1201c7..e14c9c6f69eb 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
@@ -75,6 +75,12 @@ bpf_testmod_test_struct_arg_6(struct bpf_testmod_struct_arg_3 *a) {
 	return bpf_testmod_test_struct_arg_result;
 }
 
+noinline int
+bpf_testmod_test_arg_ptr_to_struct(struct bpf_testmod_struct_arg_1 *a) {
+	bpf_testmod_test_struct_arg_result = a->a;
+	return bpf_testmod_test_struct_arg_result;
+}
+
 __bpf_kfunc void
 bpf_testmod_test_mod_kfunc(int i)
 {
@@ -203,7 +209,7 @@ bpf_testmod_test_read(struct file *file, struct kobject *kobj,
 		.off = off,
 		.len = len,
 	};
-	struct bpf_testmod_struct_arg_1 struct_arg1 = {10};
+	struct bpf_testmod_struct_arg_1 struct_arg1 = {10}, struct_arg1_2 = {-1};
 	struct bpf_testmod_struct_arg_2 struct_arg2 = {2, 3};
 	struct bpf_testmod_struct_arg_3 *struct_arg3;
 	int i = 1;
@@ -216,6 +222,7 @@ bpf_testmod_test_read(struct file *file, struct kobject *kobj,
 	(void)bpf_testmod_test_struct_arg_3(1, 4, struct_arg2);
 	(void)bpf_testmod_test_struct_arg_4(struct_arg1, 1, 2, 3, struct_arg2);
 	(void)bpf_testmod_test_struct_arg_5();
+	(void)bpf_testmod_test_arg_ptr_to_struct(&struct_arg1_2);
 
 	struct_arg3 = kmalloc((sizeof(struct bpf_testmod_struct_arg_3) +
 				sizeof(int)), GFP_KERNEL);
diff --git a/tools/testing/selftests/bpf/prog_tests/test_ldsx_insn.c b/tools/testing/selftests/bpf/prog_tests/test_ldsx_insn.c
new file mode 100644
index 000000000000..d18138ebd8f0
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/test_ldsx_insn.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates.*/
+
+#include <test_progs.h>
+#include "test_ldsx_insn.skel.h"
+
+static void test_map_val_and_probed_memory(void)
+{
+	struct test_ldsx_insn *skel;
+	int err;
+
+	skel = test_ldsx_insn__open();
+	if (!ASSERT_OK_PTR(skel, "test_ldsx_insn__open"))
+		return;
+
+	bpf_program__set_autoload(skel->progs.rdonly_map_prog, true);
+	bpf_program__set_autoload(skel->progs.map_val_prog, true);
+	bpf_program__set_autoload(skel->progs.test_ptr_struct_arg, true);
+
+	err = test_ldsx_insn__load(skel);
+	if (!ASSERT_OK(err, "test_ldsx_insn__load"))
+		goto out;
+
+	err = test_ldsx_insn__attach(skel);
+	if (!ASSERT_OK(err, "test_ldsx_insn__attach"))
+		goto out;
+
+	ASSERT_OK(trigger_module_test_read(256), "trigger_read");
+
+	ASSERT_EQ(skel->bss->done1, 1, "done1");
+	ASSERT_EQ(skel->bss->ret1, 1, "ret1");
+	ASSERT_EQ(skel->bss->done2, 1, "done2");
+	ASSERT_EQ(skel->bss->ret2, 1, "ret2");
+	ASSERT_EQ(skel->bss->int_member, -1, "int_member");
+out:
+	test_ldsx_insn__destroy(skel);
+}
+
+static void test_ctx_member(void)
+{
+	struct test_ldsx_insn *skel;
+	int err, fd, cgroup_fd;
+	char buf[16] = {0};
+	socklen_t optlen;
+
+	cgroup_fd = test__join_cgroup("/ldsx_test");
+	if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup /ldsx_test"))
+		return;
+
+	skel = test_ldsx_insn__open();
+	if (!ASSERT_OK_PTR(skel, "test_ldsx_insn__open"))
+		goto close_cgroup_fd;
+
+	bpf_program__set_autoload(skel->progs._getsockopt, true);
+
+	err = test_ldsx_insn__load(skel);
+	if (!ASSERT_OK(err, "test_ldsx_insn__load"))
+		goto destroy_skel;
+
+	skel->links._getsockopt =
+		bpf_program__attach_cgroup(skel->progs._getsockopt, cgroup_fd);
+	if (!ASSERT_OK_PTR(skel->links._getsockopt, "getsockopt_link"))
+		goto destroy_skel;
+
+	fd = socket(AF_INET, SOCK_STREAM, 0);
+	if (!ASSERT_GE(fd, 0, "socket"))
+		goto destroy_skel;
+
+	optlen = sizeof(buf);
+	(void)getsockopt(fd, SOL_IP, IP_TTL, buf, &optlen);
+
+	ASSERT_EQ(skel->bss->set_optlen, -1, "optlen");
+	ASSERT_EQ(skel->bss->set_retval, -1, "retval");
+
+	close(fd);
+destroy_skel:
+	test_ldsx_insn__destroy(skel);
+close_cgroup_fd:
+	close(cgroup_fd);
+}
+
+void test_ldsx_insn(void)
+{
+	if (test__start_subtest("map_val and probed_memory"))
+		test_map_val_and_probed_memory();
+	if (test__start_subtest("ctx_member"))
+		test_ctx_member();
+}
diff --git a/tools/testing/selftests/bpf/progs/test_ldsx_insn.c b/tools/testing/selftests/bpf/progs/test_ldsx_insn.c
new file mode 100644
index 000000000000..22befbfb02b9
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_ldsx_insn.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+volatile const short val1 = -1;
+volatile const int val2 = -1;
+short val3 = -1;
+int val4 = -1;
+int done1, done2, ret1, ret2;
+
+SEC("?raw_tp/sys_enter")
+int rdonly_map_prog(const void *ctx)
+{
+	if (done1)
+		return 0;
+
+	done1 = 1;
+	if (val1 == val2)
+		ret1 = 1;
+	return 0;
+
+}
+
+SEC("?raw_tp/sys_enter")
+int map_val_prog(const void *ctx)
+{
+	if (done2)
+		return 0;
+
+	done2 = 1;
+	if (val3 == val4)
+		ret2 = 1;
+	return 0;
+
+}
+
+struct bpf_testmod_struct_arg_1 {
+	int a;
+};
+
+long long int_member;
+
+SEC("?fentry/bpf_testmod_test_arg_ptr_to_struct")
+int BPF_PROG2(test_ptr_struct_arg, struct bpf_testmod_struct_arg_1 *, p)
+{
+	int_member = p->a;
+        return 0;
+}
+
+long long set_optlen, set_retval;
+
+SEC("?cgroup/getsockopt")
+int _getsockopt(volatile struct bpf_sockopt *ctx)
+{
+	int old_optlen, old_retval;
+
+	old_optlen = ctx->optlen;
+	old_retval = ctx->retval;
+
+	ctx->optlen = -1;
+	ctx->retval = -1;
+
+	set_optlen = ctx->optlen;
+	set_retval = ctx->retval;
+
+	ctx->optlen = old_optlen;
+	ctx->retval = old_retval;
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
-- 
2.34.1

