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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>
		
	
		
			
				
	
	
		
			62 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			62 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* fxstat using old-style Unix fstat 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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| #if !XSTAT_IS_XSTAT64
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| # include <xstatconv.h>
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| # include <xstatover.h>
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| 
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| /* Get information about the file FD in BUF.  */
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| int
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| __fxstat (int vers, int fd, 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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|       {
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| # if STAT_IS_KERNEL_STAT
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| 	/* New kABIs which uses generic pre 64-bit time Linux ABI,
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| 	   e.g. csky, nios2  */
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| 	int r = INLINE_SYSCALL_CALL (fstat64, fd, buf);
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| 	return r ?: stat_overflow (buf);
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| # else
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| 	/* Old kABIs with old non-LFS support, e.g. arm, i386, hppa, m68k,
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| 	   microblaze, s390, sh, powerpc, and sparc.  */
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| 	return INLINE_SYSCALL_CALL (fstat, fd, buf);
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| # endif
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|       }
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| 
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|     default:
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|       {
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| # if STAT_IS_KERNEL_STAT
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| 	return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
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| # else
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| 	struct stat64 buf64;
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| 	int r = INLINE_SYSCALL_CALL (fstat64, fd, &buf64);
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| 	return r ?: __xstat32_conv (vers, &buf64, buf);
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| #endif
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|       }
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|     }
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| }
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| hidden_def (__fxstat)
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| #endif /* XSTAT_IS_XSTAT64  */
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