y2038: linux: Provide __ntp_gettime64 implementation

This patch provides new __ntp_gettime64 explicit 64 bit function for getting
time parameters via NTP interface.

Internally, the __clock_adjtime64 syscall is used instead of __adjtimex. This
patch is necessary for having architectures with __WORDSIZE == 32 Y2038 safe.

Moreover, a 32 bit version - __ntp_gettime has been refactored to internally
use __ntp_gettime64.

The __ntp_gettime is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversions between struct
ntptimeval and 64 bit struct __ntptimeval64.

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 the proper usage of both __ntp_gettime64 and __ntp_gettime.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
This commit is contained in:
Lukasz Majewski 2020-04-22 10:54:01 +02:00
parent 10ae49d2ce
commit 5613afe9e3
2 changed files with 27 additions and 3 deletions

View File

@ -33,6 +33,7 @@ libc_hidden_proto (__adjtimex)
# define __clock_adjtime64 __clock_adjtime # define __clock_adjtime64 __clock_adjtime
# define ___adjtimex64 ___adjtimex # define ___adjtimex64 ___adjtimex
# define __ntptimeval64 ntptimeval # define __ntptimeval64 ntptimeval
# define __ntp_gettime64 __ntp_gettime
# else # else
struct __timex64 struct __timex64
@ -91,6 +92,9 @@ struct __ntptimeval64
long int __glibc_reserved3; long int __glibc_reserved3;
long int __glibc_reserved4; long int __glibc_reserved4;
}; };
extern int __ntp_gettime64 (struct __ntptimeval64 *ntv);
libc_hidden_proto (__ntp_gettime64)
# endif # endif
/* Convert a known valid struct timex into a struct __timex64. */ /* Convert a known valid struct timex into a struct __timex64. */

View File

@ -17,6 +17,7 @@
#define ntp_gettime ntp_gettime_redirect #define ntp_gettime ntp_gettime_redirect
#include <time.h>
#include <sys/timex.h> #include <sys/timex.h>
#undef ntp_gettime #undef ntp_gettime
@ -25,17 +26,36 @@
# define modes mode # define modes mode
#endif #endif
/* clock_adjtime64 with CLOCK_REALTIME does not trigger EINVAL,
ENODEV, or EOPNOTSUPP. It might still trigger EPERM. */
int int
ntp_gettime (struct ntptimeval *ntv) __ntp_gettime64 (struct __ntptimeval64 *ntv)
{ {
struct timex tntx; struct __timex64 tntx;
int result; int result;
tntx.modes = 0; tntx.modes = 0;
result = __adjtimex (&tntx); result = __clock_adjtime64 (CLOCK_REALTIME, &tntx);
ntv->time = tntx.time; ntv->time = tntx.time;
ntv->maxerror = tntx.maxerror; ntv->maxerror = tntx.maxerror;
ntv->esterror = tntx.esterror; ntv->esterror = tntx.esterror;
return result; return result;
} }
#if __TIMESIZE != 64
libc_hidden_def (__ntp_gettime64)
int
__ntp_gettime (struct ntptimeval *ntv)
{
struct __ntptimeval64 ntv64;
int result;
result = __ntp_gettime64 (&ntv64);
*ntv = valid_ntptimeval64_to_ntptimeval (ntv64);
return result;
}
#endif
strong_alias (__ntp_gettime, ntp_gettime)