selftests/bpf: Skip test_bpf_syscall_macro's syscall_arg1 on arm64 and s390

These architectures can provide access to the first syscall argument
only through PT_REGS_PARM1_CORE_SYSCALL().

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220209021745.2215452-8-iii@linux.ibm.com

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
index f5f4c8a..8bc58bd 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/test_bpf_syscall_macro.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_bpf_syscall_macro.c
@@ -33,7 +33,11 @@ void test_bpf_syscall_macro(void)
 
        /* check whether args of syscall are copied correctly */
        prctl(exp_arg1, exp_arg2, exp_arg3, exp_arg4, exp_arg5);
+#if defined(__aarch64__) || defined(__s390__)
+       ASSERT_NEQ(skel->bss->arg1, exp_arg1, "syscall_arg1");
+#else
        ASSERT_EQ(skel->bss->arg1, exp_arg1, "syscall_arg1");
+#endif
        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 */

diff --git a/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c b/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c
index e7c622c..496e54d 100644 (file)
--- a/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c
+++ b/tools/testing/selftests/bpf/progs/bpf_syscall_macro.c
@@ -28,7 +28,7 @@ int BPF_KPROBE(handle_sys_prctl)
 {
        struct pt_regs *real_regs;
        pid_t pid = bpf_get_current_pid_tgid() >> 32;
-       unsigned long tmp;
+       unsigned long tmp = 0;
 
        if (pid != filter_pid)
                return 0;
@@ -37,7 +37,9 @@ int BPF_KPROBE(handle_sys_prctl)
 
        /* test for PT_REGS_PARM */
 
+#if !defined(bpf_target_arm64) && !defined(bpf_target_s390)
        bpf_probe_read_kernel(&tmp, sizeof(tmp), &PT_REGS_PARM1_SYSCALL(real_regs));
+#endif
        arg1 = tmp;
        bpf_probe_read_kernel(&arg2, sizeof(arg2), &PT_REGS_PARM2_SYSCALL(real_regs));
        bpf_probe_read_kernel(&arg3, sizeof(arg3), &PT_REGS_PARM3_SYSCALL(real_regs));