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	The LFS support is implemented on xstat64.c, instead of xstat.c for
64-bit architectures.  The xstat.c implements the non-LFS it is
no-op for !XSTAT_IS_XSTAT64.
The generic non-LFS implementation handle two cases:
  1. New kABIs which uses generic pre 64-bit time Linux ABI (csky and
     nios): it issues __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_stat, otherwise it issues __NR_stat64 and convert
     to non-LFS stat struct handling possible overflows on st_ino,
     st_size, or st_blocks.
Also the 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, x86_64): it
         issues __NR_stat for _STAT_VER_KERNEL or _STAT_VER_LINUX.
    1.2. Old 64-bit kABI with defines __NR_stat64 instead of __NR_stat
	 (sparc64): it issues __NR_stat for _STAT_VER_KERNEL or
	 __NR_stat64 and convert to struct stat64.
    1.3. New kABIs which uses generic 64-bit Linux ABI (aarch64 and
         riscv64): it issues __NR_newfstatat 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_stat64.
Also, two special cases requires specific LFS implementations:
  1. alpha: it requires to handle _STAT_VER_KERNEL64 to call __NR_stat64
     or use the kernel_stat with __NR_stat 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
		
	
	
	
	
	
| /* xstat 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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| 
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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 NAME in BUF.  */
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| int
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| __xstat (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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|       {
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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 (fstatat64, AT_FDCWD, name, buf, 0);
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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 sparc32.  */
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| 	return INLINE_SYSCALL_CALL (stat, name, 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 (stat64, name, &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 (__xstat)
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| #endif /* XSTAT_IS_XSTAT64  */
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