[PATCH] selftests/nolibc: Fix up compile error for rv32

[Zhangjin Wu]

When compile nolibc-test.c for rv32, we got such error:

    tools/testing/selftests/nolibc/nolibc-test.c:599:57: error: ‘__NR_fstat’ undeclared (first use in this function)
      599 |   CASE_TEST(syscall_args);      EXPECT_SYSER(1, syscall(__NR_fstat, 0, NULL), -1, EFAULT); break;

The generic include/uapi/asm-generic/unistd.h used by rv32 doesn't
support __NR_fstat, using the common __NR_read functions as expected.

    Running test 'syscall'
    69 syscall_noargs = 1                                            [OK]
    70 syscall_args = -1 EBADF                                       [OK]

Btw, the latest riscv libc6-dev package is required, otherwise, we would
also get such error:

    In file included from /usr/riscv64-linux-gnu/include/sys/cdefs.h:452,
                     from /usr/riscv64-linux-gnu/include/features.h:461,
                     from /usr/riscv64-linux-gnu/include/bits/libc-header-start.h:33,
                     from /usr/riscv64-linux-gnu/include/limits.h:26,
                     from /usr/lib/gcc-cross/riscv64-linux-gnu/9/include/limits.h:194,
                     from /usr/lib/gcc-cross/riscv64-linux-gnu/9/include/syslimits.h:7,
                     from /usr/lib/gcc-cross/riscv64-linux-gnu/9/include/limits.h:34,
                     from /labs/linux-lab/src/linux-stable/tools/testing/selftests/nolibc/nolibc-test.c:6:
    /usr/riscv64-linux-gnu/include/bits/wordsize.h:28:3: error: #error "rv32i-based targets are not supported"
       28 | # error "rv32i-based targets are not supported"

The glibc commit 5b6113d62efa ("RISC-V: Support the 32-bit ABI
implementation") fixed up above error, so, glibc >= 2.33 (who includes
this commit) is required.

Signed-off-by: Zhangjin Wu <falcon at tinylab.org>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 063f9959ac44..d8b59c8f6c03 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -596,7 +596,7 @@ int run_syscall(int min, int max)
 		CASE_TEST(write_badf);        EXPECT_SYSER(1, write(-1, &tmp, 1), -1, EBADF); break;
 		CASE_TEST(write_zero);        EXPECT_SYSZR(1, write(1, &tmp, 0)); break;
 		CASE_TEST(syscall_noargs);    EXPECT_SYSEQ(1, syscall(__NR_getpid), getpid()); break;
-		CASE_TEST(syscall_args);      EXPECT_SYSER(1, syscall(__NR_fstat, 0, NULL), -1, EFAULT); break;
+		CASE_TEST(syscall_args);      EXPECT_SYSER(1, syscall(__NR_read, -1, &tmp, 1), -1, EBADF); break;
 		case __LINE__:
 			return ret; /* must be last */
 		/* note: do not set any defaults so as to permit holes above */
-- 
2.25.1