[PATCH] fcntl cleanup

[Peter Mazinger]

Hi,

__libc_X() functions are relicts of locking implemented in linuxthreads_old, they (or their name) is only relevant, if linuxthreads_old is enabled

Regards, Peter



-------- Original-Nachricht --------
> Datum: Fri,  4 May 2012 08:16:34 -0400
> Von: Mark Salter <msalter at redhat.com>
> An: uclibc at uclibc.org
> Betreff: [PATCH] fcntl cleanup

> This patch aims to clean up the current support for fcntl in the
> following ways:
> 
>   * replace multiple istances of #ifdef selection between fcntl
>     and fcntl64 syscalls with a single INLINE_SYSCALL_FCNTL macro.
>     The fcntl64 syscall only exists on 32-bit systems and is
>     identical to the fcntl syscall except for the addition of
>     commands to support locking with 64-bit file offsets.
> 
>   * only check for unsupported 64-bit locking commands in the
>     case of no LFS support or no fcntl64 syscall. This eliminates
>     unnecessary code for configurations which do support the
>     64-bit locking commands.
> 
>   * add check for unsupported 64-bit locking commands which was
>     missing from the native threads case.
> 
>   * in the non-native threads case, __libc_fcntl and __fcntl_nocancel
>     are identical, so make __libc_fcntl an alias of __fcntl_nocancel
>     to avoid two functions with the same code.
> 
> Signed-off-by: Mark Salter <msalter at redhat.com>
> ---
>  libc/sysdeps/linux/common/__syscall_fcntl.c |   55
> ++++++++++++--------------
>  1 files changed, 25 insertions(+), 30 deletions(-)
> 
> diff --git a/libc/sysdeps/linux/common/__syscall_fcntl.c
> b/libc/sysdeps/linux/common/__syscall_fcntl.c
> index 6d4c339..06146b4 100644
> --- a/libc/sysdeps/linux/common/__syscall_fcntl.c
> +++ b/libc/sysdeps/linux/common/__syscall_fcntl.c
> @@ -16,6 +16,17 @@
>  #include <fcntl.h>
>  #include <bits/wordsize.h>
>  
> +/*
> + * The fcntl64 syscall only exists on 32-Bit systems. It is identical to
> + * the fcntl syscall except for additial commands providing 32-bit
> systems
> + * with file locking operations using 64-bit offsets.
> + */
> +#if defined __UCLIBC_HAS_LFS__ && defined __NR_fcntl64
> +#define INLINE_SYSCALL_FCNTL(a,b,c) INLINE_SYSCALL(fcntl64, 3, (a), (b),
> (c))
> +#else
> +#define INLINE_SYSCALL_FCNTL(a,b,c) INLINE_SYSCALL(fcntl, 3, (a), (b),
> (c))
> +#endif
> +
>  extern __typeof(fcntl) __libc_fcntl;
>  libc_hidden_proto(__libc_fcntl)
>  
> @@ -28,20 +39,17 @@ int __fcntl_nocancel (int fd, int cmd, ...)
>  	arg = va_arg (ap, void *);
>  	va_end (ap);
>  
> -# if __WORDSIZE == 32
> +# if __WORDSIZE == 32 && !(defined __UCLIBC_HAS_LFS__ && defined
> __NR_fcntl64)
>  	if (cmd == F_GETLK64 || cmd == F_SETLK64 || cmd == F_SETLKW64) {
> -#  if defined __UCLIBC_HAS_LFS__ && defined __NR_fcntl64
> -		return INLINE_SYSCALL (fcntl64, 3, fd, cmd, arg);
> -#  else
>  		__set_errno(ENOSYS);
>  		return -1;
> -#  endif
>  	}
>  # endif
> -	return INLINE_SYSCALL (fcntl, 3, fd, cmd, arg);
> +	return INLINE_SYSCALL_FCNTL (fd, cmd, arg);
>  }
>  libc_hidden_def(__fcntl_nocancel)
>  
> +#ifdef __UCLIBC_HAS_THREADS_NATIVE__
>  int __libc_fcntl (int fd, int cmd, ...)
>  {
>  	va_list ap;
> @@ -51,39 +59,26 @@ int __libc_fcntl (int fd, int cmd, ...)
>  	arg = va_arg (ap, void *);
>  	va_end (ap);
>  
> -#ifdef __UCLIBC_HAS_THREADS_NATIVE__
> -	if (SINGLE_THREAD_P || (cmd != F_SETLKW && cmd != F_SETLKW64))
> -# if defined __UCLIBC_HAS_LFS__ && defined __NR_fcntl64
> -		return INLINE_SYSCALL (fcntl64, 3, fd, cmd, arg);
> -# else
> -		return INLINE_SYSCALL (fcntl, 3, fd, cmd, arg);
> -# endif
> +#if __WORDSIZE == 32 && !(defined __UCLIBC_HAS_LFS__ && defined
> __NR_fcntl64)
> +	if (cmd == F_GETLK64 || cmd == F_SETLK64 || cmd == F_SETLKW64) {
> +		__set_errno(ENOSYS);
> +		return -1;
> +	}
> +#endif
>  
> +	if (SINGLE_THREAD_P || (cmd != F_SETLKW && cmd != F_SETLKW64))
> +		return INLINE_SYSCALL_FCNTL (fd, cmd, arg);
>  	int oldtype = LIBC_CANCEL_ASYNC ();
>  
> -# if defined __UCLIBC_HAS_LFS__ && defined __NR_fcntl64
> -	int result = INLINE_SYSCALL (fcntl64, 3, fd, cmd, arg);
> -# else
> -	int result = INLINE_SYSCALL (fcntl, 3, fd, cmd, arg);
> -# endif
> +	int result = INLINE_SYSCALL_FCNTL (fd, cmd, arg);
>  
>  	LIBC_CANCEL_RESET (oldtype);
>  
>  	return result;
> +}
>  #else
> -# if __WORDSIZE == 32
> -	if (cmd == F_GETLK64 || cmd == F_SETLK64 || cmd == F_SETLKW64) {
> -#  if defined __UCLIBC_HAS_LFS__ && defined __NR_fcntl64
> -		return INLINE_SYSCALL (fcntl64, 3, fd, cmd, arg);
> -#  else
> -		__set_errno(ENOSYS);
> -		return -1;
> -#  endif
> -	}
> -# endif
> -	return INLINE_SYSCALL (fcntl, 3, fd, cmd, arg);
> +strong_alias(__fcntl_nocancel,__libc_fcntl)
>  #endif
> -}
>  libc_hidden_def(__libc_fcntl)
>  
>  libc_hidden_proto(fcntl)
> -- 
> 1.7.9.1
> 
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> uClibc at uclibc.org
> http://lists.busybox.net/mailman/listinfo/uclibc

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