linux: Disentangle fstatat from fxstatat

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>

1 files changed, 27 insertions, 5 deletions

diff --git a/include/sys/stat.h b/include/sys/stat.h
index 1f832f6..3d4ea7f 100644
--- a/include/sys/stat.h
+++ b/include/sys/stat.h
@@ -3,6 +3,28 @@
 
 #ifndef _ISOMAC
 # include <xstatver.h>
+# include <stdbool.h>
+
+static inline bool
+in_ino_t_range (__ino64_t v)
+{
+  __ino_t s = v;
+  return s == v;
+}
+
+static inline bool
+in_off_t_range (__off64_t v)
+{
+  __off_t s = v;
+  return s == v;
+}
+
+static inline bool
+in_blkcnt_t_range (__blkcnt64_t v)
+{
+  __blkcnt_t s = v;
+  return s == v;
+}
 
 /* Now define the internal interfaces. */
 extern int __stat (const char *__file, struct stat *__buf);
@@ -54,19 +76,19 @@ int __xstat64 (int ver, const char *__filename, struct stat64 *__stat_buf);
 int __lxstat64 (int ver, const char *__filename, struct stat64 *__stat_buf);
 int __fxstatat64 (int ver, int __fildes, const char *__filename,
 		  struct stat64 *__stat_buf, int __flag);
+
+# ifdef NO_RTLD_HIDDEN
+/* These are still required for Hurd.  */
 libc_hidden_proto (__fxstat);
 libc_hidden_proto (__xstat);
 libc_hidden_proto (__lxstat);
 libc_hidden_proto (__fxstatat);
-# if IS_IN (libc) || (IS_IN (rtld) && !defined NO_RTLD_HIDDEN)
+#  if IS_IN (libc)
 hidden_proto (__fxstat64);
 hidden_proto (__xstat64);
 hidden_proto (__lxstat64);
 hidden_proto (__fxstatat64);
-# endif
-
-# ifdef NO_RTLD_HIDDEN
-/* These are still required for Hurd.  */
+#  endif
 #  define stat(fname, buf) __xstat (_STAT_VER, fname, buf)
 #  define lstat(fname, buf)  __lxstat (_STAT_VER, fname, buf)
 #  define __lstat(fname, buf)  __lxstat (_STAT_VER, fname, buf)