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	The LFS support is implemented on fxstat64.c, instead of fxstat.c for
64-bit architectures.  The fxstat.c implements the non-LFS and it is
a no-op for !XSTAT_IS_XSTAT64.
The generic non-LFS implementation handles two cases:
  1. New kABIs which uses generic pre 64-bit time Linux ABI (csky and
     nios): it issuess __NR_fstat64 plus handle the overflow on st_ino,
     st_size, or st_blocks.  It only handles _STAT_VER_KERNEL.
  2. Old KABIs with old non-LFS support (arm, i386, hppa, m68k,
     microblaze, s390, sh, powerpc, and sparc32).  For _STAT_VER_KERNEL
     it issues __NR_fstat, otherwise it calls __NR_fstat64 and convert
     to non-LFS stat struct and handle possible overflows on st_ino,
     st_size, or st_blocks.
Also non-LFS mips is an outlier and it has its own implementation since
_STAT_VER_LINUX requires a different conversion function (it uses the
kernel_stat as the sysissues argument since its exported ABI is
different than the kernel one for both non-LFS and LFS implementation).
The generic LFS implementation handles multiple cases:
  1. XSTAT_IS_XSTAT64 being 1:
    1.1. 64-bit kABI (aarch64, ia64, powerpc64*, s390x, riscv64, and
	 x86_64): it issuess __NR_fstat for _STAT_VER_KERNEL or
	 _STAT_VER_LINUX.
    1.2. Old 64-bit kABI with defines __NR_fstat64 instead of __NR_fstat
         (sparc64): it issues __NR_fstat for _STAT_VER_KERNEL or
         __NR_fstat64 and convert to struct stat64.
    1.3. New 32-bit kABIs with only 64-bit time_t support (arc and
	 riscv32): it issuess __NR_statx and covert to struct stat64.
  2. Old ABIs with XSTAT_IS_XSTAT64 being 0 (arm, csky, i386, hppa,
     m68k, microblaze, mips32, nios2, sh, powerpc32, and sparc32): it
     issues __NR_fstat64.
Also, two special cases requires specific implementations:
  1. alpha: it requires to handle _STAT_VER_KERNEL64 to issues
     __NR_fstat64 and use the kernel_stat with __NR_fstat otherwise.
  2. mips64: as for non-LFS implementation its ABIs differ from
     glibc exported one, which requires an specific conversion
     function to handle the kernel_stat.
Checked with a build for all affected ABIs. I also checked on x86_64,
i686, powerpc, powerpc64le, sparcv9, sparc64, s390, and s390x.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
		
	
		
			
				
	
	
		
			48 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			48 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* fxstat64 using old-style Unix stat system call.
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   Copyright (C) 2004-2020 Free Software Foundation, Inc.
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   This file is part of the GNU C Library.
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   The GNU C Library is free software; you can redistribute it and/or
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   modify it under the terms of the GNU Lesser General Public
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   License as published by the Free Software Foundation; either
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   version 2.1 of the License, or (at your option) any later version.
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   The GNU C Library is distributed in the hope that it will be useful,
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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   Lesser General Public License for more details.
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   You should have received a copy of the GNU Lesser General Public
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   License along with the GNU C Library.  If not, see
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   <https://www.gnu.org/licenses/>.  */
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#define __fxstat __redirect___fxstat64
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#include <sys/stat.h>
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#undef __fxstat
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#include <kernel_stat.h>
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#include <sysdep.h>
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#include <xstatconv.h>
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/* Get information about the file NAME in BUF.  */
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int
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__fxstat64 (int vers, int fd, struct stat64 *buf)
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{
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  switch (vers)
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    {
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    case _STAT_VER_KERNEL64:
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      return INLINE_SYSCALL_CALL (fstat64, fd, buf);
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    default:
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      {
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        struct kernel_stat kbuf;
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	int r = INTERNAL_SYSCALL_CALL (fstat, fd, &kbuf);
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	if (r == 0)
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	  return __xstat_conv (vers, &kbuf, buf);
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	return INLINE_SYSCALL_ERROR_RETURN_VALUE (-r);
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      }
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    }
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}
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hidden_def (__fxstat64)
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strong_alias (__fxstat64, __fxstat);
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hidden_ver (__fxstat64, __fxstat)
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