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

Thomas Weißschuh
2023-05-24T19:49:40Z

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

Thomas