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	The LFS support is implemented on lxstat64.c, instead of lxstat.c for
64-bit architectures.  The xstat.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 issues __NR_fstat64 with AT_SYMLINK_NOFOLLOW plus handles
     the possible overflow off 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_lstat, otherwise it isseus __NR_lstat64 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 syscall 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. Old 64-bit kABI (ia64, powerpc64*, s390x, sparc64, x86_64): it
         issues __NR_lstat for _STAT_VER_KERNEL or _STAT_VER_LINUX.
    1.2. Old 64-bit kABI with defines __NR_lstat64 instead of __NR_lstat
         (sparc64): it issues __NR_lstat for _STAT_VER_KERNEL or
         __NR_lstat64 and convert to struct stat64.
    1.3. New kABIs which uses generic 64-bit Linux ABI (aarch64 and
         riscv64): it issues __NR_newfstatat with AT_SYMLINK_NOFOLLOW
	 and only for _STAT_VER_KERNEL.
    1.4. New 32-bit kABIs with only 64-bit time_t support (arc and
         riscv32): it issues __NR_statx and covert to struct stat64.
  2. Old ABIs with XSTAT_IS_XSTAT64 being 0:
    2.1. New kABIs which uses generic pre 64-bit time Linux ABI (csky
	 and nios2): it issues __NR_fstatat64 for _STAT_VER_KERNEL.
    2.2. Old kABIs with old non-LFS support (arm, i386, hppa, m68k,
	 microblaze, s390, sh, mips32, powerpc32, and sparc32): it
	 issues __NR_lstat64.
Also, two special cases requires specific LFS implementations:
  1. alpha: it requires to handle _STAT_VER_KERNEL64 to issue
     __NR_lstat64 and use the kernel_stat with __NR_lstat otherwise.
  2. mips64: as for non-LFS implementation its ABIs differ from
     glibc exported one, which requires a 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>
		
	
		
			
				
	
	
		
			43 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			43 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* lxstat using old-style Unix stat system call.
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   Copyright (C) 1991-2020 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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#include <sys/stat.h>
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#include <fcntl.h>
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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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__lxstat (int vers, const char *name, struct stat *buf)
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{
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  switch (vers)
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    {
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    case _STAT_VER_KERNEL:
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      return INLINE_SYSCALL_CALL (lstat, name, 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 (lstat, name, &kbuf);
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	return r ?: __xstat_conv (vers, &kbuf, buf);
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      }
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    }
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}
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hidden_def (__lxstat)
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