[PATCH 05/30] Linux: consolidate dup2 implementation

[Carlos O'Donell]

On 10/19/22 18:14, Adhemerval Zanella via Libc-alpha wrote:
> Use dup2 syscall if defined, otherwise use dup3.
> 
> Checked on x86_64-linux-gnu.

LGTM.

No regressions on x86_64 and i686.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

> ---
>  sysdeps/unix/sysv/linux/{generic => }/dup2.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
>  rename sysdeps/unix/sysv/linux/{generic => }/dup2.c (83%)
> 
> diff --git a/sysdeps/unix/sysv/linux/generic/dup2.c b/sysdeps/unix/sysv/linux/dup2.c
> similarity index 83%
> rename from sysdeps/unix/sysv/linux/generic/dup2.c
> rename to sysdeps/unix/sysv/linux/dup2.c
> index 0dc45e9b17..1182780e15 100644
> --- a/sysdeps/unix/sysv/linux/generic/dup2.c
> +++ b/sysdeps/unix/sysv/linux/dup2.c
> @@ -1,4 +1,5 @@
> -/* Copyright (C) 2011-2022 Free Software Foundation, Inc.
> +/* Duplicate a file descriptor.  Linux version.
> +   Copyright (C) 2011-2022 Free Software Foundation, Inc.
>     This file is part of the GNU C Library.
>  
>     The GNU C Library is free software; you can redistribute it and/or
> @@ -24,12 +25,16 @@
>  int
>  __dup2 (int fd, int fd2)
>  {
> +#ifdef __NR_dup2
> +  return INLINE_SYSCALL_CALL (dup2, fd, fd2);

OK.

> +#else
>    /* For the degenerate case, check if the fd is valid (by trying to
>       get the file status flags) and return it, or else return EBADF.  */
>    if (fd == fd2)
>      return __libc_fcntl (fd, F_GETFL, 0) < 0 ? -1 : fd;
>  
> -  return INLINE_SYSCALL (dup3, 3, fd, fd2, 0);
> +  return INLINE_SYSCALL_CALL (dup3, fd, fd2, 0);

OK.

> +#endif
>  }
>  libc_hidden_def (__dup2)
>  weak_alias (__dup2, dup2)

-- 
Cheers,
Carlos.