Always define __USE_TIME_BITS64 when 64 bit time_t is used

It was raised on libc-help [1] that some Linux kernel interfaces expect
the libc to define __USE_TIME_BITS64 to indicate the time_t size for the
kABI.  Different than defined by the initial y2038 design document [2],
the __USE_TIME_BITS64 is only defined for ABIs that support more than
one time_t size (by defining the _TIME_BITS for each module).

The 64 bit time_t redirects are now enabled using a different internal
define (__USE_TIME64_REDIRECTS). There is no expected change in semantic
or code generation.

Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu, and
arm-linux-gnueabi

[1] https://sourceware.org/pipermail/libc-help/2024-January/006557.html
[2] https://sourceware.org/glibc/wiki/Y2038ProofnessDesign

Reviewed-by: DJ Delorie <dj@redhat.com>

io/bits/poll2.h

@@ -48,7 +48,7 @@ poll (__fortify_clang_overload_arg (struct pollfd *, ,__fds), nfds_t __nfds,
 
 
 #ifdef __USE_GNU
-# ifdef __USE_TIME_BITS64
+# ifdef __USE_TIME64_REDIRECTS
 extern int __REDIRECT (__ppoll64_alias, (struct pollfd *__fds, nfds_t __nfds,
 				       const struct timespec *__timeout,
 				       const __sigset_t *__ss), __ppoll64);

io/fcntl.h

@@ -172,7 +172,7 @@ typedef __pid_t pid_t;
 
    This function is a cancellation point and therefore not marked with
    __THROW.  */
-#ifndef __USE_TIME_BITS64
+#ifndef __USE_TIME64_REDIRECTS
 # ifndef __USE_FILE_OFFSET64
 extern int fcntl (int __fd, int __cmd, ...);
 # else
@@ -185,7 +185,7 @@ extern int __REDIRECT (fcntl, (int __fd, int __cmd, ...), fcntl64);
 # ifdef __USE_LARGEFILE64
 extern int fcntl64 (int __fd, int __cmd, ...);
 # endif
-#else /* __USE_TIME_BITS64 */
+#else /* __USE_TIME64_REDIRECTS */
 # ifdef __REDIRECT
 extern int __REDIRECT_NTH (fcntl, (int __fd, int __request, ...),
 			   __fcntl_time64);

io/fts.h

@@ -187,7 +187,7 @@ FTSENT	*fts_read (FTS *);
 int	 fts_set (FTS *, FTSENT *, int) __THROW;
 #else
 # ifdef __REDIRECT
-#  ifndef __USE_TIME_BITS64
+#  ifndef __USE_TIME64_REDIRECTS
 FTSENT	*__REDIRECT (fts_children, (FTS *, int), fts64_children);
 int	 __REDIRECT (fts_close, (FTS *), fts64_close);
 FTS	*__REDIRECT (fts_open, (char * const *, int,
@@ -206,7 +206,7 @@ int	 __REDIRECT_NTH (fts_set, (FTS *, FTSENT *, int),
 			 __fts64_set_time64);
 #  endif
 # else
-#  ifndef __USE_TIME_BITS64
+#  ifndef __USE_TIME64_REDIRECTS
 #   define fts_children fts64_children
 #   define fts_close fts64_close
 #   define fts_open fts64_open
@@ -217,7 +217,7 @@ int	 __REDIRECT_NTH (fts_set, (FTS *, FTSENT *, int),
 # endif
 #endif
 #ifdef __USE_LARGEFILE64
-# ifndef __USE_TIME_BITS64
+# ifndef __USE_TIME64_REDIRECTS
 FTSENT64 *fts64_children (FTS64 *, int);
 int	  fts64_close (FTS64 *);
 FTS64	 *fts64_open (char * const *, int,

io/ftw.h

@@ -137,7 +137,7 @@ extern int ftw (const char *__dir, __ftw_func_t __func, int __descriptors)
      __nonnull ((1, 2));
 #else
 # ifdef __REDIRECT
-#  ifndef __USE_TIME_BITS64
+#  ifndef __USE_TIME64_REDIRECTS
 extern int __REDIRECT (ftw, (const char *__dir, __ftw_func_t __func,
 			     int __descriptors), ftw64) __nonnull ((1, 2));
 #  else
@@ -146,15 +146,15 @@ extern int __REDIRECT (ftw, (const char *__dir, __ftw_func_t __func,
      __nonnull ((1, 2));
 #  endif
 # else
-#  ifndef __USE_TIME_BITS64
+#  ifndef __USE_TIME64_REDIRECTS
 #   define ftw ftw64
 #  else
 #   define ftw __ftw64_time64
 #  endif
 # endif
 #endif
 #ifdef __USE_LARGEFILE64
-# ifndef __USE_TIME_BITS64
+# ifndef __USE_TIME64_REDIRECTS
 extern int ftw64 (const char *__dir, __ftw64_func_t __func,
 		  int __descriptors) __nonnull ((1, 2));
 # else
@@ -180,7 +180,7 @@ extern int nftw (const char *__dir, __nftw_func_t __func, int __descriptors,
 		 int __flag) __nonnull ((1, 2));
 # else
 #  ifdef __REDIRECT
-#   ifndef __USE_TIME_BITS64
+#   ifndef __USE_TIME64_REDIRECTS
 extern int __REDIRECT (nftw, (const char *__dir, __nftw_func_t __func,
 			      int __descriptors, int __flag), nftw64)
      __nonnull ((1, 2));
@@ -190,15 +190,15 @@ extern int __REDIRECT (nftw, (const char *__dir, __nftw_func_t __func,
      __nonnull ((1, 2));
 #   endif
 #  else
-#   ifndef __USE_TIME_BITS64
+#   ifndef __USE_TIME64_REDIRECTS
 #    define nftw nftw64
 #   else
 #    define nftw __nftw64_time64
 #   endif
 #  endif
 # endif
 # ifdef __USE_LARGEFILE64
-#  ifndef __USE_TIME_BITS64
+#  ifndef __USE_TIME64_REDIRECTS
 extern int nftw64 (const char *__dir, __nftw64_func_t __func,
 		   int __descriptors, int __flag) __nonnull ((1, 2));
 #  else

io/sys/poll.h

@@ -66,7 +66,7 @@ extern int ppoll (struct pollfd *__fds, nfds_t __nfds,
 		  const __sigset_t *__ss)
     __fortified_attr_access (__write_only__, 1, 2);
 
-# ifdef __USE_TIME_BITS64
+# ifdef __USE_TIME64_REDIRECTS
 #  ifdef __REDIRECT
 extern int __REDIRECT (ppoll, (struct pollfd *__fds, nfds_t __nfds,
                                const struct timespec *__timeout,

io/sys/stat.h

@@ -209,7 +209,7 @@ extern int stat (const char *__restrict __file,
    that file descriptor FD is open on and put them in BUF.  */
 extern int fstat (int __fd, struct stat *__buf) __THROW __nonnull ((2));
 #else
-# ifdef __USE_TIME_BITS64
+# ifdef __USE_TIME64_REDIRECTS
 #  ifdef __REDIRECT_NTH
 extern int __REDIRECT_NTH (stat, (const char *__restrict __file,
 				  struct stat *__restrict __buf),
@@ -236,7 +236,7 @@ extern int __REDIRECT_NTH (fstat, (int __fd, struct stat *__buf), fstat64)
 # endif
 #endif
 #ifdef __USE_LARGEFILE64
-# ifndef __USE_TIME_BITS64
+# ifndef __USE_TIME64_REDIRECTS
 extern int stat64 (const char *__restrict __file,
 		   struct stat64 *__restrict __buf) __THROW __nonnull ((1, 2));
 extern int fstat64 (int __fd, struct stat64 *__buf) __THROW __nonnull ((2));
@@ -265,7 +265,7 @@ extern int fstatat (int __fd, const char *__restrict __file,
 		    struct stat *__restrict __buf, int __flag)
      __THROW __nonnull ((2, 3));
 # else
-#  ifdef __USE_TIME_BITS64
+#  ifdef __USE_TIME64_REDIRECTS
 #   ifdef __REDIRECT_NTH
 extern int __REDIRECT_NTH (fstatat, (int __fd, const char *__restrict __file,
 				     struct stat *__restrict __buf,
@@ -287,7 +287,7 @@ extern int __REDIRECT_NTH (fstatat, (int __fd, const char *__restrict __file,
 # endif
 
 # ifdef __USE_LARGEFILE64
-#  ifndef __USE_TIME_BITS64
+#  ifndef __USE_TIME64_REDIRECTS
 extern int fstatat64 (int __fd, const char *__restrict __file,
 		      struct stat64 *__restrict __buf, int __flag)
      __THROW __nonnull ((2, 3));
@@ -313,7 +313,7 @@ extern int __REDIRECT_NTH (fstatat64, (int __fd,
 extern int lstat (const char *__restrict __file,
 		  struct stat *__restrict __buf) __THROW __nonnull ((1, 2));
 # else
-#  ifdef __USE_TIME_BITS64
+#  ifdef __USE_TIME64_REDIRECTS
 #   ifdef __REDIRECT_NTH
 extern int __REDIRECT_NTH (lstat,
 			   (const char *__restrict __file,
@@ -334,7 +334,7 @@ extern int __REDIRECT_NTH (lstat,
 #  endif
 # endif
 # ifdef __USE_LARGEFILE64
-#  ifndef __USE_TIME_BITS64
+#  ifndef __USE_TIME64_REDIRECTS
 extern int lstat64 (const char *__restrict __file,
 		    struct stat64 *__restrict __buf)
      __THROW __nonnull ((1, 2));
@@ -427,7 +427,7 @@ extern int mkfifoat (int __fd, const char *__path, __mode_t __mode)
 #endif
 
 #ifdef __USE_ATFILE
-# ifndef __USE_TIME_BITS64
+# ifndef __USE_TIME64_REDIRECTS
 /* Set file access and modification times relative to directory file
    descriptor.  */
 extern int utimensat (int __fd, const char *__path,
@@ -447,7 +447,7 @@ extern int __REDIRECT_NTH (utimensat, (int fd, const char *__path,
 #endif
 
 #ifdef __USE_XOPEN2K8
-# ifndef __USE_TIME_BITS64
+# ifndef __USE_TIME64_REDIRECTS
 /* Set file access and modification times of the file associated with FD.  */
 extern int futimens (int __fd, const struct timespec __times[2]) __THROW;
 

io/utime.h

@@ -35,7 +35,7 @@ __BEGIN_DECLS
 /* Structure describing file times.  */
 struct utimbuf
   {
-#ifdef __USE_TIME_BITS64
+#ifdef __USE_TIME64_REDIRECTS
     __time64_t actime;		/* Access time.  */
     __time64_t modtime;		/* Modification time.  */
 #else
@@ -46,7 +46,7 @@ struct utimbuf
 
 /* Set the access and modification times of FILE to those given in
    *FILE_TIMES.  If FILE_TIMES is NULL, set them to the current time.  */
-#ifndef __USE_TIME_BITS64
+#ifndef __USE_TIME64_REDIRECTS
 extern int utime (const char *__file,
 		  const struct utimbuf *__file_times)
      __THROW __nonnull ((1));

manual/creature.texi

@@ -192,6 +192,12 @@ Linux kernel version on which the system is running. For Linux kernel
 version above @b{5.1} syscalls supporting 64-bit time are used. Otherwise,
 a fallback code is used with legacy (i.e. 32-bit) syscalls.
 
+On such platforms, @theglibc{} will also define @code{__USE_TIME64_REDIRECTS}
+to indicate whether the declarations are expanded to different ones
+(either by redefiniding the symbol name or using symbol aliais).
+For instance, if the symbol @code{clock_gettime} expands to
+@code{__glock_gettime64}.
+
 @item
 If @code{_TIME_BITS} is defined to be 32, @code{time_t} is defined to
 be a 32-bit integer where that is supported.  This is not recommended,

manual/maint.texi

@@ -491,6 +491,10 @@ derived as in the dual-time configuration case, and which expands to
 the symbol's name.  For instance, the macro @code{__clock_gettime64}
 expands to @code{clock_gettime}.
 
+When @code{__TIMESIZE} is set to 64, @theglibc{} will also define
+the@code{__USE_TIME_BITS64} macro.  It is used by the Linux kernel ABI
+to set the expected @code{time_t} size used on some syscalls.
+
 These macros are purely internal to @theglibc{} and exist only so that
 a single definition of the 64-bit time functions can be used on both
 single-time and dual-time configurations, and so that glibc code can

misc/sys/ioctl.h

@@ -38,7 +38,7 @@ __BEGIN_DECLS
 /* Perform the I/O control operation specified by REQUEST on FD.
    One argument may follow; its presence and type depend on REQUEST.
    Return value depends on REQUEST.  Usually -1 indicates error.  */
-#ifndef __USE_TIME_BITS64
+#ifndef __USE_TIME64_REDIRECTS
 extern int ioctl (int __fd, unsigned long int __request, ...) __THROW;
 #else
 # ifdef __REDIRECT

misc/sys/select.h

@@ -98,7 +98,7 @@ __BEGIN_DECLS
 
    This function is a cancellation point and therefore not marked with
    __THROW.  */
-#ifndef __USE_TIME_BITS64
+#ifndef __USE_TIME64_REDIRECTS
 extern int select (int __nfds, fd_set *__restrict __readfds,
 		   fd_set *__restrict __writefds,
 		   fd_set *__restrict __exceptfds,
@@ -123,7 +123,7 @@ extern int __REDIRECT (select,
 
    This function is a cancellation point and therefore not marked with
    __THROW.  */
-# ifndef __USE_TIME_BITS64
+# ifndef __USE_TIME64_REDIRECTS
 extern int pselect (int __nfds, fd_set *__restrict __readfds,
 		    fd_set *__restrict __writefds,
 		    fd_set *__restrict __exceptfds,

posix/glob.h

@@ -150,7 +150,7 @@ extern int glob (const char *__restrict __pattern, int __flags,
 /* Free storage allocated in PGLOB by a previous `glob' call.  */
 extern void globfree (glob_t *__pglob) __THROW;
 #else
-# ifdef __USE_TIME_BITS64
+# ifdef __USE_TIME64_REDIRECTS
 extern int __REDIRECT_NTHNL (glob, (const char *__restrict __pattern,
 				    int __flags,
 				    int (*__errfunc) (const char *, int),
@@ -170,7 +170,7 @@ extern void __REDIRECT_NTH (globfree, (glob_t *__pglob), globfree64);
 #endif
 
 #ifdef __USE_LARGEFILE64
-# ifdef __USE_TIME_BITS64
+# ifdef __USE_TIME64_REDIRECTS
 extern int __REDIRECT_NTHNL (glob64, (const char *__restrict __pattern,
 				      int __flags,
 				      int (*__errfunc) (const char *, int),

posix/sched.h

@@ -74,7 +74,7 @@ extern int sched_get_priority_max (int __algorithm) __THROW;
 extern int sched_get_priority_min (int __algorithm) __THROW;
 
 /* Get the SCHED_RR interval for the named process.  */
-#ifndef __USE_TIME_BITS64
+#ifndef __USE_TIME64_REDIRECTS
 extern int sched_rr_get_interval (__pid_t __pid, struct timespec *__t) __THROW;
 #else
 # ifdef __REDIRECT_NTH

posix/sys/wait.h

@@ -139,7 +139,7 @@ struct rusage;
    nil, store information about the child's resource usage there.  If the
    WUNTRACED bit is set in OPTIONS, return status for stopped children;
    otherwise don't.  */
-# ifndef __USE_TIME_BITS64
+# ifndef __USE_TIME64_REDIRECTS
 extern __pid_t wait3 (int *__stat_loc, int __options,
 		      struct rusage * __usage) __THROWNL;
 # else
@@ -154,7 +154,7 @@ extern __pid_t __REDIRECT_NTHNL (wait3, (int *__stat_loc, int __options,
 #endif
 
 #ifdef __USE_MISC
-# ifndef __USE_TIME_BITS64
+# ifndef __USE_TIME64_REDIRECTS
 /* PID is like waitpid.  Other args are like wait3.  */
 extern __pid_t wait4 (__pid_t __pid, int *__stat_loc, int __options,
 		      struct rusage *__usage) __THROWNL;

resolv/netdb.h

@@ -701,7 +701,7 @@ extern int getaddrinfo_a (int __mode, struct gaicb *__list[__restrict_arr],
 extern int gai_suspend (const struct gaicb *const __list[], int __ent,
 			const struct timespec *__timeout);
 
-# ifdef __USE_TIME_BITS64
+# ifdef __USE_TIME64_REDIRECTS
 #  if defined(__REDIRECT)
 extern int __REDIRECT (gai_suspend, (const struct gaicb *const __list[],
                                      int __ent,

resource/sys/resource.h

@@ -88,7 +88,7 @@ extern int setrlimit64 (__rlimit_resource_t __resource,
    and put it in *USAGE.  Returns 0 for success, -1 for failure.  */
 extern int getrusage (__rusage_who_t __who, struct rusage *__usage) __THROW;
 
-#ifdef __USE_TIME_BITS64
+#ifdef __USE_TIME64_REDIRECTS
 # if defined(__REDIRECT_NTH)
 extern int __REDIRECT_NTH (getrusage, (__rusage_who_t __who,
                                        struct rusage *__usage),

rt/aio.h

@@ -193,7 +193,7 @@ extern __ssize_t __REDIRECT_NTH (aio_return, (struct aiocb *__aiocbp),
 extern int __REDIRECT_NTH (aio_cancel,
 			   (int __fildes, struct aiocb *__aiocbp),
 			   aio_cancel64);
-#  ifdef __USE_TIME_BITS64
+#  ifdef __USE_TIME64_REDIRECTS
 extern int __REDIRECT_NTH (aio_suspend,
 			   (const struct aiocb *const __list[], int __nent,
 			    const struct timespec *__restrict __timeout),
@@ -215,7 +215,7 @@ extern int __REDIRECT_NTH (aio_fsync,
 #  define aio_error aio_error64
 #  define aio_return aio_return64
 #  define aio_cancel aio_cancel64
-#  ifdef __USE_TIME_BITS64
+#  ifdef __USE_TIME64_REDIRECTS
 #   define aio_suspend __aio_suspend_time64
 #  else
 #   define aio_suspend aio_suspend64

rt/mqueue.h

@@ -71,7 +71,7 @@ extern int mq_send (mqd_t __mqdes, const char *__msg_ptr, size_t __msg_len,
 		    unsigned int __msg_prio) __nonnull ((2));
 
 #ifdef __USE_XOPEN2K
-# ifndef __USE_TIME_BITS64
+# ifndef __USE_TIME64_REDIRECTS
 /* Receive the oldest from highest priority messages in message queue
    MQDES, stop waiting if ABS_TIMEOUT expires.  */
 extern ssize_t mq_timedreceive (mqd_t __mqdes, char *__restrict __msg_ptr,

signal/signal.h

@@ -269,7 +269,7 @@ extern int sigwaitinfo (const sigset_t *__restrict __set,
 
    This function is a cancellation point and therefore not marked with
    __THROW.  */
-#  ifndef __USE_TIME_BITS64
+#  ifndef __USE_TIME64_REDIRECTS
 extern int sigtimedwait (const sigset_t *__restrict __set,
 			 siginfo_t *__restrict __info,
 			 const struct timespec *__restrict __timeout)