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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>
		
	
		
			
				
	
	
		
			82 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			82 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* fxstat64 using Linux fstat64/statx system call.
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|    Copyright (C) 1997-2020 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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| #define __fxstat __redirect___fxstat
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| #include <sys/stat.h>
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| #undef __fxstat
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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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| #include <statx_cp.h>
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| 
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| /* Get information about the file FD in BUF.  */
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| 
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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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| #if XSTAT_IS_XSTAT64
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| # ifdef __NR_fstat64
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|   /* 64-bit kABI outlier, e.g. sparc64.  */
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|   if (vers == _STAT_VER_KERNEL)
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|     return INLINE_SYSCALL_CALL (fstat, fd, buf);
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|   else
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|     {
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|       struct stat64 st64;
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|       int r = INLINE_SYSCALL_CALL (fstat64, fd, &st64);
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|       return r ?: __xstat32_conv (vers, &st64, (struct stat *) buf);
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|     }
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| # elif defined __NR_fstat
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|   /* 64-bit kABI, e.g. aarch64, ia64, powerpc64*, s390x, riscv64,
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|      and x86_64.  */
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|   if (vers == _STAT_VER_KERNEL || vers == _STAT_VER_LINUX)
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|     return INLINE_SYSCALL_CALL (fstat, fd, buf);
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|   return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
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| # else
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|   /* New 32-bit kABIs with only 64-bit time_t support, e.g. arc, riscv32.  */
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|   struct statx tmp;
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|   int r = INLINE_SYSCALL_CALL (statx, fd, "", AT_EMPTY_PATH,
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| 			       STATX_BASIC_STATS, &tmp);
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|   if (r == 0)
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|     __cp_stat64_statx (buf, &tmp);
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|   return r;
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| # endif
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| #else
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|   /* All kABIs with non-LFS support, e.g. arm, csky, i386, hppa, m68k,
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|      microblaze, mips32, nios2, sh, powerpc32, and sparc32.  */
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|   return INLINE_SYSCALL_CALL (fstat64, fd, buf);
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| #endif /* XSTAT_IS_XSTAT64  */
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| }
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| 
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| #include <shlib-compat.h>
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| 
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| #if SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_2)
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| versioned_symbol (libc, ___fxstat64, __fxstat64, GLIBC_2_2);
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| strong_alias (___fxstat64, __old__fxstat64)
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| compat_symbol (libc, __old__fxstat64, __fxstat64, GLIBC_2_1);
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| hidden_ver (___fxstat64, __fxstat64)
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| #else
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| strong_alias (___fxstat64, __fxstat64)
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| hidden_def (__fxstat64)
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| #endif
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| 
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| #if XSTAT_IS_XSTAT64
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| strong_alias (__fxstat64, __fxstat);
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| hidden_ver (__fxstat64, __fxstat)
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| #endif
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