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linux: Consolidate fxstat{64}

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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>
This commit is contained in:
Adhemerval Zanella
2020-07-15 16:34:47 +00:00
parent 4f40e6adc4
commit 5febe6a38f
18 changed files with 105 additions and 266 deletions
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60
sysdeps/unix/sysv/linux/fxstat.c
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@ -16,46 +16,46 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/* Ho hum, if xstat == xstat64 we must get rid of the prototype or gcc
will complain since they don't strictly match. */
#define __fxstat64 __fxstat64_disable
#include <errno.h>
#include <stddef.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <kernel_stat.h>
#include <sysdep.h>
#include <sys/syscall.h>
#include <xstatconv.h>
#if !XSTAT_IS_XSTAT64
# include <xstatconv.h>
# include <xstatover.h>
/* Get information about the file FD in BUF. */
int
__fxstat (int vers, int fd, struct stat *buf)
{
if (vers == _STAT_VER_KERNEL)
return INLINE_SYSCALL (fstat, 2, fd, buf);
switch (vers)
{
case _STAT_VER_KERNEL:
{
# if STAT_IS_KERNEL_STAT
/* New kABIs which uses generic pre 64-bit time Linux ABI,
e.g. csky, nios2 */
int r = INLINE_SYSCALL_CALL (fstat64, fd, buf);
return r ?: stat_overflow (buf);
# else
/* Old kABIs with old non-LFS support, e.g. arm, i386, hppa, m68k,
microblaze, s390, sh, powerpc, and sparc. */
return INLINE_SYSCALL_CALL (fstat, fd, buf);
# endif
}
#if STAT_IS_KERNEL_STAT
return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
#else
struct kernel_stat kbuf;
int result;
result = INLINE_SYSCALL (fstat, 2, fd, &kbuf);
if (result == 0)
result = __xstat_conv (vers, &kbuf, buf);
return result;
default:
{
# if STAT_IS_KERNEL_STAT
return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
# else
struct stat64 buf64;
int r = INLINE_SYSCALL_CALL (fstat64, fd, &buf64);
return r ?: __xstat32_conv (vers, &buf64, buf);
#endif
}
}
}
hidden_def (__fxstat)
weak_alias (__fxstat, _fxstat);
#if XSTAT_IS_XSTAT64
#undef __fxstat64
strong_alias (__fxstat, __fxstat64);
hidden_ver (__fxstat, __fxstat64)
#endif
#endif /* XSTAT_IS_XSTAT64 */