Re: [PATCH 04/13] selftests/nolibc: syscall_args: use __NR_statx for rv32

Hi, Thomas

On 2023-05-25 01:48:11+0800, Zhangjin Wu wrote:

...

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, use __NR_statx instead:

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

As tools/include/nolibc/sys.h shows, __NR_statx is either not supported by all platforms, so, both __NR_fstat and __NR_statx are required.

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.

It seems weird to require limits.h from the system libc at all.

The only thing used from there are INT_MAX and INT_MIN. Instead we could define our own versions of INT_MAX and INT_MIN in stdint.h.

#ifndef INT_MAX #define INT_MAX __INT_MAX__ #endif

#ifndef INT_MIN #define INT_MIN (- __INT_MAX__ - 1) #endif

Just verified and prepared a patch, it did work perfectly, thanks.

The above commit message exactly the error info will be cleaned up in v2.

Best regards, Zhangjin

Thomas