In the glibc the time function can use vDSO (on power and x86 the
USE_IFUNC_TIME is defined), time syscall or 'default' time() from
./time/time.c (as a fallback).
In this patch the last function (time) has been refactored and moved
to ./sysdeps/unix/sysv/linux/time.c to be Linux specific.
The new __time64 explicit 64 bit function for providing 64 bit value of
seconds after epoch (by internally calling __clock_gettime64) has been
introduced.
Moreover, a 32 bit version - __time has been refactored to internally
use __time64.
The __time is now supposed to be used on systems still supporting 32 bit
time (__TIMESIZE != 64) - hence the necessary check for time_t potential
overflow.
The iFUNC vDSO direct call optimization has been removed from both i686 and
powerpc32 (USE_IFUNC_TIME is not defined for those architectures
anymore). The Linux kernel does not provide a y2038 safe implementation of
time neither it plans to provide it in the future, __clock_gettime64
should be used instead. Keeping support for this optimization would require
to handle another build permutation (!__ASSUME_TIME64_SYSCALLS &&
USE_IFUNC_TIME which adds more complexity and has limited use (since the
idea is to eventually have a y2038 safe glibc build).
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Above tests were performed with Y2038 redirection applied as well as
without to test proper usage of both __time64 and __time.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
libc_hidden_proto (__timespec_get64)
#endif
+#if __TIMESIZE == 64
+# define __time64 __time
+#else
+extern __time64_t __time64 (__time64_t *timer);
+libc_hidden_proto (__time64)
+#endif
+
/* Use in the clock_* functions. Size of the field representing the
actual clock ID. */
#define CLOCK_IDFIELD_SIZE 3
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
-#define USE_IFUNC_TIME
+#ifdef __powerpc64__
+# define USE_IFUNC_TIME
+#endif
#include <sysdeps/unix/sysv/linux/time.c>
}
# endif /* !SHARED */
#else /* USE_IFUNC_TIME */
-# include <time/time.c>
+# include <time.h>
+# include <time-clockid.h>
+# include <errno.h>
+
+/* Return the time now, and store it in *TIMER if not NULL. */
+
+__time64_t
+__time64 (__time64_t *timer)
+{
+ struct __timespec64 ts;
+ __clock_gettime64 (TIME_CLOCK_GETTIME_CLOCKID, &ts);
+
+ if (timer != NULL)
+ *timer = ts.tv_sec;
+ return ts.tv_sec;
+}
+
+# if __TIMESIZE != 64
+libc_hidden_def (__time64)
+
+time_t
+__time (time_t *timer)
+{
+ __time64_t t = __time64 (NULL);
+
+ if (! in_time_t_range (t))
+ {
+ __set_errno (EOVERFLOW);
+ return -1;
+ }
+
+ if (timer != NULL)
+ *timer = t;
+ return t;
+}
+# endif
+weak_alias (__time, time)
#endif
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
-#define USE_IFUNC_TIME
+#ifdef __x86_64__
+# define USE_IFUNC_TIME
+#endif
#include <sysdeps/unix/sysv/linux/time.c>