y2038: Support for Y2038 safe time on 32 bit systems

The time_t type is now Y2038 safe, which means that it is aliased to
__time64_t when __USE_TIME_BITS64 is defined or __time_t otherwise.

On the contrary the __time_t for 32 bit systems is only 32 bit, so for
Y2038 safe system it must be 64 bit (as is time_t)

This patch introduces the Y2038 specific code to make clock_settime/
__clock_settime64 Y2038 safe on 32 bit systems.
This goal is achieved by using aliasing to clock_settime names when
__USE_TIME_BITS64 is defined.
As a result user programs call 64 bit versions of functions (i.e.
__clock_settime64 instead of __clock_settime), which must have been
globally visible for this purpose - for non Y2038 safe code those are
hidden in glibc.

Additionally this patch also converts following syscalls to be Y2038:
- difftime
- mktime
- timegm
- ctime_r
- ctime
- gmtime_r
- gmtime
- clock_gettime64
- clock_settime64
- clock_getres64
- utimensat
- futimens
- clock_nanosleep_time64
- ppoll64
- timer_gettime
- timer_settime
- difftime
- timerfd_gettime
- timerfd_settime
- sched_rr_get_interval
- timespec_get
- settimeofday
- gettimeofday
- setitimer
- getitimer
- getrusage
- wait4_time64
- utimes
- utime
- mq_timedsend
- mq_timedreceive
- futimes
- lutimes
- futimesat
- semtimedop -> credits: Adhemerval Zanella
- pselect   -> credits: Adhemerval Zanella
- recvmmsg   -> credits: Adhemerval Zanella
- nanosleep  -> credits: Adhemerval Zanella
- select     -> credits: Adhemerval Zanella
- sigtimedwait -> credits: Adhemerval Zanella

- stat -> credits: Adhemerval Zanella
- fstat -> credits: Adhemerval Zanella
- lstat -> credits: Adhemerval Zanella
- fstatat -> credits: Adhemerval Zanella

- clock_adjtime64
- adjtime
- adjtimex
- ntp_gettime
- ntp_gettimex
- ntp_adjtime - just alias to ___adjtimex64 function

- wait3 -> credits: Adhemerval Zanella

- nptl (uses futex_time64):
        - pthread_timedjoin_np
        - pthread_clockjoin_np
        - pthread_cond_clockwait
        - pthread_cond_timedwait
        - sem_clockwait
        - sem_timedwait
        - pthread_rwlock_clockrdlock
        - pthread_rwlock_clockwrlock
        - pthread_rwlock_timedrdlock
        - pthread_rwlock_timedwrlock
        - pthread_mutex_clocklock
        - pthread_mutex_timedlock

- C11 threads
        - mtx_timedlock
        - cnd_timedwait
        - thrd_sleep

- time

Structures converted/exported:
-----------------------------
- struct timespec
- struct itimerspec
- struct timeval
- struct rusage
- WIP/RFC: export of struct stat{64}

TO DO:
------

- aio_suspend ()
- cnd_timedwait ()
- Make exportable struct __stat64_t64 and __rusage64 (to be usable when we
  redirect glibc syscalls symbols)
- utmp{x} and login in general - patches from Adhemerval Zanella waiting for
  review
- Provide Y2038 support for struct msqid_ds (and msgctl() syscall in general
- Provide Y2038 support for struct semid_ds
- Port tests from y2038-tests repository to glibc -master branch

include/features.h

@@ -380,6 +380,25 @@
 # define __USE_FILE_OFFSET64	1
 #endif
 
+/* We need to know the word size in order to check the time size.  */
+#include <bits/wordsize.h>
+
+#if defined _TIME_BITS
+# if _TIME_BITS == 64
+#  if ! defined (_FILE_OFFSET_BITS) || _FILE_OFFSET_BITS != 64
+#   error _TIME_BITS==64 is allowed only when _FILE_OFFSET_BITS==64
+#  elif __WORDSIZE == 32
+#   define __USE_TIME_BITS64	1
+#  endif
+# elif _TIME_BITS == 32
+#  if __WORDSIZE > 32
+#   error _TIME_BITS=32 is not compatible with __WORDSIZE > 32
+#  endif
+# else
+#  error Invalid _TIME_BITS value (can only be 32 or 64)
+# endif
+#endif
+
 #if defined _DEFAULT_SOURCE
 # define __USE_MISC	1
 #endif

io/Versions

@@ -146,5 +146,7 @@ libc {
     __file_change_detection_for_path;
     __file_change_detection_for_fp;
     __fstat64;
+    __ppoll64;
+    __utime64;
   }
 }

io/sys/poll.h

@@ -63,6 +63,17 @@ extern int poll (struct pollfd *__fds, nfds_t __nfds, int __timeout);
 extern int ppoll (struct pollfd *__fds, nfds_t __nfds,
 		  const struct timespec *__timeout,
 		  const __sigset_t *__ss);
+
+# ifdef __USE_TIME_BITS64
+#  if defined(__REDIRECT)
+extern int __REDIRECT (ppoll, (struct pollfd *__fds, nfds_t __nfds,
+                               const struct timespec *__timeout,
+                               const __sigset_t *__ss),
+                       __ppoll64);
+#  else
+#  define ppoll __ppoll64
+#  endif
+# endif
 #endif
 
 __END_DECLS

io/sys/stat.h

@@ -361,11 +361,31 @@ extern int utimensat (int __fd, const char *__path,
 		      const struct timespec __times[2],
 		      int __flags)
      __THROW __nonnull ((2));
+
+# ifdef __USE_TIME_BITS64
+#  if defined(__REDIRECT_NTH)
+extern int __REDIRECT_NTH (utimensat, (int fd, const char *__path,
+                                       const struct timespec __times[2],
+                                       int flags),
+                           __utimensat64) __nonnull ((2));
+#  else
+#  define utimensat __utimensat64
+#  endif
+# endif
 #endif
 
 #ifdef __USE_XOPEN2K8
 /* Set file access and modification times of the file associated with FD.  */
 extern int futimens (int __fd, const struct timespec __times[2]) __THROW;
+
+# ifdef __USE_TIME_BITS64
+#  if defined(__REDIRECT_NTH)
+extern int __REDIRECT_NTH (futimens, (int fd, const struct timespec __times[2]),
+                           __futimens64);
+#  else
+#  define futimens __futimens64
+#  endif
+# endif
 #endif
 
 #ifdef __USE_GNU

io/utime.h

@@ -35,8 +35,13 @@ __BEGIN_DECLS
 /* Structure describing file times.  */
 struct utimbuf
   {
+# ifdef __USE_TIME_BITS64
+    __time64_t actime;		/* Access time.  */
+    __time64_t modtime;		/* Modification time.  */
+# else
     __time_t actime;		/* Access time.  */
     __time_t modtime;		/* Modification time.  */
+# endif
   };
 
 /* Set the access and modification times of FILE to those given in
@@ -45,6 +50,16 @@ extern int utime (const char *__file,
 		  const struct utimbuf *__file_times)
      __THROW __nonnull ((1));
 
+#ifdef __USE_TIME_BITS64
+# if defined(__REDIRECT_NTH)
+extern int __REDIRECT_NTH (utime, (const char *__file,
+                                   const struct utimbuf *__file_times),
+                           __utime64);
+# else
+# define utime __utime64
+# endif
+#endif
+
 __END_DECLS
 
 #endif /* utime.h */

manual/creature.texi

@@ -165,6 +165,34 @@ This macro was introduced as part of the Large File Support extension
 (LFS).
 @end defvr
 
+@defvr Macro _TIME_BITS
+This macro determines the bit size of @code{time_t} (and therefore the
+bit size of all @code{time_t} derived types and the prototypes of all
+related functions). If @code{_TIME_BITS} is undefined, the bit size of
+time_t equals the bit size of the architecture.
+
+If @code{_TIME_BITS} is undefined, or if @code{_TIME_BITS} is defined
+to the value @code{32} and @code{__WORDSIZE} is defined to the value
+@code{32}, or or if @code{_TIME_BITS} is defined to the value @code{64}
+and @code{__WORDSIZE} is defined to the value @code{64}, nothing changes.
+
+If @code{_TIME_BITS} is defined to the value @code{64} and if
+@code{__WORDSIZE} is defined to the value @code{32}, then the @w{64 bit}
+time API and implementation are used even though the architecture word
+size is @code{32}. Also, if the kernel provides @w{64 bit} time support,
+it is used; otherwise, the @w{32 bit} kernel time support is used (with
+no provision to address kernel Y2038 shortcomings).
+
+If @code{_TIME_BITS} is defined to the value @code{32} and if
+@code{__WORDSIZE} is defined to the value @code{64}, then a compile-time
+error is emitted.
+
+If @code{_TIME_BITS} is defined to a value different from both @code{32}
+and @code{64}, then a compile-time error is emitted.
+
+This macro was introduced as part of the Y2038 support.
+@end defvr
+
 @defvr Macro _ISOC99_SOURCE
 @standards{GNU, (none)}
 If this macro is defined, features from ISO C99 are included.  Since

misc/Versions

@@ -172,5 +172,10 @@ libc {
     __mmap; __munmap; __mprotect;
     __sched_get_priority_min; __sched_get_priority_max;
     __libc_allocate_once_slow;
+    __utimes64;
+    __futimes64;
+    __lutimes64;
+    __futimesat64;
+    __select64;
   }
 }

misc/sys/select.h

@@ -103,6 +103,19 @@ extern int select (int __nfds, fd_set *__restrict __readfds,
 		   fd_set *__restrict __exceptfds,
 		   struct timeval *__restrict __timeout);
 
+#ifdef __USE_TIME_BITS64
+# if defined(__REDIRECT)
+extern int __REDIRECT (select,
+                       (int __nfds, fd_set *__restrict __readfds,
+                        fd_set *__restrict __writefds,
+                        fd_set *__restrict __exceptfds,
+                        struct timeval *__restrict __timeout),
+                       __select64);
+# else
+#  define select __select64
+# endif
+#endif
+
 #ifdef __USE_XOPEN2K
 /* Same as above only that the TIMEOUT value is given with higher
    resolution and a sigmask which is been set temporarily.  This version
@@ -115,6 +128,20 @@ extern int pselect (int __nfds, fd_set *__restrict __readfds,
 		    fd_set *__restrict __exceptfds,
 		    const struct timespec *__restrict __timeout,
 		    const __sigset_t *__restrict __sigmask);
+
+# ifdef __USE_TIME_BITS64
+#  if defined(__REDIRECT)
+extern int __REDIRECT (pselect,
+                       (int __nfds, fd_set *__restrict __readfds,
+                        fd_set *__restrict __writefds,
+                        fd_set *__restrict __exceptfds,
+                        const struct timespec *__restrict __timeout,
+                        const __sigset_t *__restrict __sigmask),
+                       __pselect64);
+#  else
+#   define pselect __pselect64
+#  endif
+# endif
 #endif
 
 

nptl/Versions

@@ -304,5 +304,17 @@ libpthread {
     __pthread_barrier_init; __pthread_barrier_wait;
     __shm_directory;
     __libpthread_freeres;
+    __pthread_timedjoin_np64;
+    __pthread_clockjoin_np64;
+    __pthread_cond_timedwait64;
+    __pthread_cond_clockwait64;
+    __sem_clockwait64;
+    __sem_timedwait64;
+    __pthread_rwlock_clockrdlock64;
+    __pthread_rwlock_clockwrlock64;
+    __pthread_rwlock_timedrdlock64;
+    __pthread_rwlock_timedwrlock64;
+    __pthread_mutex_timedlock64;
+    __pthread_mutex_clocklock64;
   }
 }

posix/Versions

@@ -150,5 +150,7 @@ libc {
   GLIBC_PRIVATE {
     __libc_fork; __libc_pread; __libc_pwrite;
     __nanosleep_nocancel; __pause_nocancel;
+    __wait4_time64; __pselect64;
+    __nanosleep64; __wait3_time64;
   }
 }

posix/sched.h

@@ -76,6 +76,15 @@ extern int sched_get_priority_min (int __algorithm) __THROW;
 /* Get the SCHED_RR interval for the named process.  */
 extern int sched_rr_get_interval (__pid_t __pid, struct timespec *__t) __THROW;
 
+#ifdef __USE_TIME_BITS64
+# if defined(__REDIRECT_NTH)
+extern int __REDIRECT_NTH (sched_rr_get_interval,
+                           (__pid_t __pid, struct timespec *__t),
+                           __sched_rr_get_interval64);
+# else
+# define sched_rr_get_interval __sched_rr_get_interval64
+# endif
+#endif
 
 #ifdef __USE_GNU
 /* Access macros for `cpu_set'.  */

posix/sys/wait.h

@@ -146,12 +146,32 @@ struct rusage;
    otherwise don't.  */
 extern __pid_t wait3 (int *__stat_loc, int __options,
 		      struct rusage * __usage) __THROWNL;
+
+# ifdef __USE_TIME_BITS64
+#  if defined(__REDIRECT_NTHNL)
+extern __pid_t __REDIRECT_NTHNL (wait3, (int *__stat_loc, int __options,
+                                         struct rusage * __usage)
+                                 __wait3_time64);
+#  else
+#  define wait3 __wait3_time64
+#  endif
+# endif
 #endif
 
 #ifdef __USE_MISC
 /* 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;
+
+# ifdef __USE_TIME_BITS64
+#  if defined(__REDIRECT_NTHNL)
+extern __pid_t __REDIRECT_NTHNL (wait4, (__pid_t __pid, int *__stat_loc,
+                                         int __options, struct rusage *__usage),
+                                 __wait4_time64);
+#  else
+#  define wait4 __wait4_time64
+#  endif
+# endif
 #endif /* Use misc.  */
 
 

resource/Versions

@@ -24,5 +24,6 @@ libc {
   }
   GLIBC_PRIVATE {
     __getrlimit;
+    __getrusage64;
   }
 }

resource/bits/types/struct_rusage.h

@@ -32,10 +32,15 @@
    for little-endian ones, like x32.  */
 struct rusage
   {
+#ifdef __USE_TIME_BITS64
+    struct __timeval64 ru_utime;
+    struct __timeval64 ru_stime;
+#else
     /* Total amount of user time used.  */
     struct timeval ru_utime;
     /* Total amount of system time used.  */
     struct timeval ru_stime;
+#endif
     /* Maximum resident set size (in kilobytes).  */
     __extension__ union
       {

resource/sys/resource.h

@@ -86,6 +86,16 @@ 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
+# if defined(__REDIRECT_NTH)
+extern int __REDIRECT_NTH (getrusage, (__rusage_who_t __who,
+                                       struct rusage *__usage),
+                           __getrusage64);
+# else
+# define getrusage __getrusage64
+# endif
+#endif
+
 /* Return the highest priority of any process specified by WHICH and WHO
    (see above); if WHO is zero, the current process, process group, or user
    (as specified by WHO) is used.  A lower priority number means higher

rt/Versions

@@ -1,4 +1,10 @@
 librt {
+  GLIBC_PRIVATE {
+    __timer_gettime64;
+    __timer_settime64;
+    __mq_timedsend_time64;
+    __mq_timedreceive_time64;
+  }
   GLIBC_2.1 {
     # AIO functions.
     aio_cancel; aio_cancel64; aio_error; aio_error64; aio_fsync; aio_fsync64;

rt/mqueue.h

@@ -79,12 +79,37 @@ extern ssize_t mq_timedreceive (mqd_t __mqdes, char *__restrict __msg_ptr,
 				const struct timespec *__restrict __abs_timeout)
   __nonnull ((2, 5));
 
+# ifdef __USE_TIME_BITS64
+#  if defined(__REDIRECT)
+extern int __REDIRECT (mq_timedreceive, (mqd_t __mqdes,
+                               char *__restrict __msg_ptr,
+                               size_t __msg_len,
+                               unsigned int *__restrict __msg_prio,
+                               const struct timespec *__restrict __abs_timeout),
+                       __mq_timedreceive_time64);
+#  else
+#   define mq_timedreceive __mq_timedreceive_time64
+#  endif
+# endif
+
 /* Add message pointed by MSG_PTR to message queue MQDES, stop blocking
    on full message queue if ABS_TIMEOUT expires.  */
 extern int mq_timedsend (mqd_t __mqdes, const char *__msg_ptr,
 			 size_t __msg_len, unsigned int __msg_prio,
 			 const struct timespec *__abs_timeout)
   __nonnull ((2, 5));
+
+# ifdef __USE_TIME_BITS64
+#  if defined(__REDIRECT)
+extern int __REDIRECT (mq_timedsend, (mqd_t __mqdes,
+                       const char *__msg_ptr, size_t __msg_len,
+                       unsigned int __msg_prio,
+                       const struct timespec *__abs_timeout),
+     __mq_timedsend_time64);
+#  else
+#   define mq_timedsend __mq_timedsend_time64
+#  endif
+# endif
 #endif
 
 /* Define some inlines helping to catch common problems.  */

signal/Versions

@@ -51,4 +51,7 @@ libc {
   }
   GLIBC_2.21 {
   }
+  GLIBC_PRIVATE {
+    __sigtimedwait64;
+  }
 }

signal/signal.h

@@ -274,6 +274,18 @@ extern int sigtimedwait (const sigset_t *__restrict __set,
 			 const struct timespec *__restrict __timeout)
      __nonnull ((1));
 
+#  ifdef __USE_TIME_BITS64
+#   if defined(__REDIRECT)
+extern int __REDIRECT (sigtimedwait,
+                       (const sigset_t *__restrict __set,
+                        siginfo_t *__restrict __info,
+                        const struct timespec *__restrict __timeout),
+                       __sigtimedwait64);
+#   else
+#    define sigtimedwait __sigtimedwait64
+#   endif
+#  endif
+
 /* Send signal SIG to the process PID.  Associate data in VAL with the
    signal.  */
 extern int sigqueue (__pid_t __pid, int __sig, const union sigval __val)