Re: [PATCH] linux-user: Fix pipe() vs. pipe2() usage for ALPHA, MIPS, SH4 and SPARC

[Helge Deller]

On 7/17/22 18:08, Helge Deller wrote:
> In 2010, the commit b41a66edd0c added a thrird parameter "is_pipe2" to the
> internal do_pipe() function, but missed to actually use this parameter to
> decide if the pipe() or pipe2() syscall should be used.
> Instead it just continued to check the flags parameter and used pipe2()
> unconditionally if flags is non-zero.
>
> This change should make a difference for the ALPHA, MIPS, SH4 and SPARC
> targets if the emulated code calls pipe2() with a flags value of 0.
>
> Fixes: fb41a66edd0c ("alpha-linux-user: Fix pipe return mechanism.")

Signed-off-by: Helge Deller <deller@gmx.de>

> Cc: Richard Henderson <rth@twiddle.net>
> Cc: Aurelien Jarno <aurelien@aurel32.net>
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 991b85e6b4..1e6e814871 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -1600,7 +1600,7 @@ static abi_long do_pipe(CPUArchState *cpu_env, 
> abi_ulong pipedes,
>  {
>      int host_pipe[2];
>      abi_long ret;
> -    ret = flags ? do_pipe2(host_pipe, flags) : pipe(host_pipe);
> +    ret = is_pipe2 ? do_pipe2(host_pipe, flags) : pipe(host_pipe);
>
>      if (is_error(ret))
>          return get_errno(ret);