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linux: Disentangle fstatat from fxstatat

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It implements all the required syscall for the all Linux kABIS on
fstatat{64} instead of calling fxstatat{64}.

On non-LFS implementation, it handles 3 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.

  2. Old KABIs with old non-LFS support (arm, i386, hppa, m68k,
     microblaze, mips32, s390, sh, powerpc, and sparc32): it issues
     __NR_fstatat64 and convert the result to struct stat.

  3. 64-bit kABI outliers (mips64 and mips64-n32): it issues
     __NR_newfstatat and convert the result to struct stat.

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 issues __NR_newfstatat.

    1.2. 64-bit kABI outlier (alpha): it issues __NR_fstatat64.

    1.3. 64-bit kABI outlier where struct stat64 does not match kernel
         one (sparc64): it issues __NR_fstatat64 and convert the result
         to struct stat64.

    1.4. 32-bit kABI with default 64-bit time_t (arc, riscv32): it
         issues __NR_statx and convert the result to struct stat64.

  2. Old ABIs with XSTAT_IS_XSTAT64 being 0:

    2.1. All kABIs with non-LFS support (arm, csky, i386, hppa, m68k,
         microblaze, nios2, sh, powerpc32, and sparc32): it issues
         __NR_fstatat64.

    2.2. 64-bit kABI outliers (mips64 and mips64-n32): it issues
         __NR_newfstatat and convert the result to struct stat64.

It allows to remove all the hidden definitions from the {f,l}xstat{64}
(some are still kept because Hurd requires it).

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
2020-07-18 08:20:46 -03:00
parent 30f1c74394
commit 6073bae64c
26 changed files with 251 additions and 45 deletions
Download Patch File Download Diff File Expand all files Collapse all files

54
sysdeps/unix/sysv/linux/fstatat.c
View File

@ -18,12 +18,64 @@
#include <sys/stat.h>
#include <kernel_stat.h>
#include <sysdep.h>
#if !XSTAT_IS_XSTAT64
# include <kstat_cp.h>
int
__fstatat (int fd, const char *file, struct stat *buf, int flag)
{
return __fxstatat (_STAT_VER, fd, file, buf, flag);
# 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 (fstatat64, fd, file, buf, flag);
if (r == 0 && (buf->__st_ino_pad != 0
|| buf->__st_size_pad != 0
|| buf->__st_blocks_pad != 0))
return INLINE_SYSCALL_ERROR_RETURN_VALUE (EOVERFLOW);
return r;
# else
# ifdef __NR_fstatat64
/* Old KABIs with old non-LFS support, e.g. arm, i386, hppa, m68k, mips32,
microblaze, s390, sh, powerpc, and sparc. */
struct stat64 st64;
int r = INLINE_SYSCALL_CALL (fstatat64, fd, file, &st64, flag);
if (r == 0)
{
if (! in_ino_t_range (st64.st_ino)
|| ! in_off_t_range (st64.st_size)
|| ! in_blkcnt_t_range (st64.st_blocks))
return INLINE_SYSCALL_ERROR_RETURN_VALUE (EOVERFLOW);
/* Clear internal pad and reserved fields. */
memset (buf, 0, sizeof (*buf));
buf->st_dev = st64.st_dev,
buf->st_ino = st64.st_ino;
buf->st_mode = st64.st_mode;
buf->st_nlink = st64.st_nlink;
buf->st_uid = st64.st_uid;
buf->st_gid = st64.st_gid;
buf->st_rdev = st64.st_rdev;
buf->st_size = st64.st_size;
buf->st_blksize = st64.st_blksize;
buf->st_blocks = st64.st_blocks;
buf->st_atim.tv_sec = st64.st_atim.tv_sec;
buf->st_atim.tv_nsec = st64.st_atim.tv_nsec;
buf->st_mtim.tv_sec = st64.st_mtim.tv_sec;
buf->st_mtim.tv_nsec = st64.st_mtim.tv_nsec;
buf->st_ctim.tv_sec = st64.st_ctim.tv_sec;
buf->st_ctim.tv_nsec = st64.st_ctim.tv_nsec;
}
return r;
# else
/* 64-bit kabi outlier, e.g. mips64 and mips64-n32. */
struct kernel_stat kst;
int r = INLINE_SYSCALL_CALL (newfstatat, fd, file, &kst, flag);
return r ?: __cp_kstat_stat (&kst, buf);
# endif /* __nr_fstatat64 */
# endif /* STAT_IS_KERNEL_STAT */
}
weak_alias (__fstatat, fstatat)