selftests/bpf: Add a test to confirm PT_REGS_PARM4_SYSCALL

Add a selftest to verify the behavior of PT_REGS_xxx
and the CORE variant.

Signed-off-by: Kenta Tada <Kenta.Tada@sony.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220124141622.4378-4-Kenta.Tada@sony.com

1 files changed, 63 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/test_bpf_syscall_macro.c b/tools/testing/selftests/bpf/prog_tests/test_bpf_syscall_macro.c
new file mode 100644
index 000000000000..f5f4c8adf539
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/test_bpf_syscall_macro.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2022 Sony Group Corporation */
+#include <sys/prctl.h>
+#include <test_progs.h>
+#include "bpf_syscall_macro.skel.h"
+
+void test_bpf_syscall_macro(void)
+{
+	struct bpf_syscall_macro *skel = NULL;
+	int err;
+	int exp_arg1 = 1001;
+	unsigned long exp_arg2 = 12;
+	unsigned long exp_arg3 = 13;
+	unsigned long exp_arg4 = 14;
+	unsigned long exp_arg5 = 15;
+
+	/* check whether it can open program */
+	skel = bpf_syscall_macro__open();
+	if (!ASSERT_OK_PTR(skel, "bpf_syscall_macro__open"))
+		return;
+
+	skel->rodata->filter_pid = getpid();
+
+	/* check whether it can load program */
+	err = bpf_syscall_macro__load(skel);
+	if (!ASSERT_OK(err, "bpf_syscall_macro__load"))
+		goto cleanup;
+
+	/* check whether it can attach kprobe */
+	err = bpf_syscall_macro__attach(skel);
+	if (!ASSERT_OK(err, "bpf_syscall_macro__attach"))
+		goto cleanup;
+
+	/* check whether args of syscall are copied correctly */
+	prctl(exp_arg1, exp_arg2, exp_arg3, exp_arg4, exp_arg5);
+	ASSERT_EQ(skel->bss->arg1, exp_arg1, "syscall_arg1");
+	ASSERT_EQ(skel->bss->arg2, exp_arg2, "syscall_arg2");
+	ASSERT_EQ(skel->bss->arg3, exp_arg3, "syscall_arg3");
+	/* it cannot copy arg4 when uses PT_REGS_PARM4 on x86_64 */
+#ifdef __x86_64__
+	ASSERT_NEQ(skel->bss->arg4_cx, exp_arg4, "syscall_arg4_from_cx");
+#else
+	ASSERT_EQ(skel->bss->arg4_cx, exp_arg4, "syscall_arg4_from_cx");
+#endif
+	ASSERT_EQ(skel->bss->arg4, exp_arg4, "syscall_arg4");
+	ASSERT_EQ(skel->bss->arg5, exp_arg5, "syscall_arg5");
+
+	/* check whether args of syscall are copied correctly for CORE variants */
+	ASSERT_EQ(skel->bss->arg1_core, exp_arg1, "syscall_arg1_core_variant");
+	ASSERT_EQ(skel->bss->arg2_core, exp_arg2, "syscall_arg2_core_variant");
+	ASSERT_EQ(skel->bss->arg3_core, exp_arg3, "syscall_arg3_core_variant");
+	/* it cannot copy arg4 when uses PT_REGS_PARM4_CORE on x86_64 */
+#ifdef __x86_64__
+	ASSERT_NEQ(skel->bss->arg4_core_cx, exp_arg4, "syscall_arg4_from_cx_core_variant");
+#else
+	ASSERT_EQ(skel->bss->arg4_core_cx, exp_arg4, "syscall_arg4_from_cx_core_variant");
+#endif
+	ASSERT_EQ(skel->bss->arg4_core, exp_arg4, "syscall_arg4_core_variant");
+	ASSERT_EQ(skel->bss->arg5_core, exp_arg5, "syscall_arg5_core_variant");
+
+cleanup:
+	bpf_syscall_macro__destroy(skel);
+}