Message ID | 20201016133218.20864-1-lukma@denx.de |
---|---|
State | New |
Headers | show |
Series | [v2] y2038: linux: Provide __time64 implementation | expand |
On 16/10/2020 10:32, Lukasz Majewski wrote: > 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. LGTM, thanks. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> > > --- > Changes for v2: > - Add guards #ifdef __x86_64__ and #ifdef __powerpc64__ to avoid using time > vDSO on 32 bit powerpc and x86 > - Remove comment about time syscall conversion to 64 bit > - Avoid implicit checks on timer (shall be timer != NULL) > - Add comment about disabling vDSO optimization on powerpc32 and x86 > --- > include/time.h | 7 +++++ > sysdeps/unix/sysv/linux/powerpc/time.c | 4 ++- > sysdeps/unix/sysv/linux/time.c | 37 +++++++++++++++++++++++++- > sysdeps/unix/sysv/linux/x86/time.c | 4 ++- > 4 files changed, 49 insertions(+), 3 deletions(-) > > diff --git a/include/time.h b/include/time.h > index edf6cdf829..caf2af5e74 100644 > --- a/include/time.h > +++ b/include/time.h > @@ -317,6 +317,13 @@ extern int __timespec_get64 (struct __timespec64 *ts, int base); > 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 Ok. > diff --git a/sysdeps/unix/sysv/linux/powerpc/time.c b/sysdeps/unix/sysv/linux/powerpc/time.c > index d10f449c5c..4fd5e138a3 100644 > --- a/sysdeps/unix/sysv/linux/powerpc/time.c > +++ b/sysdeps/unix/sysv/linux/powerpc/time.c > @@ -16,5 +16,7 @@ > 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> Ok. > diff --git a/sysdeps/unix/sysv/linux/time.c b/sysdeps/unix/sysv/linux/time.c > index 9d8e573c0a..80641d9ca4 100644 > --- a/sysdeps/unix/sysv/linux/time.c > +++ b/sysdeps/unix/sysv/linux/time.c > @@ -47,5 +47,40 @@ time (time_t *t) > } > # 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. */ > + I would add a new line between the includes and the comment. > +__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 Ok. > diff --git a/sysdeps/unix/sysv/linux/x86/time.c b/sysdeps/unix/sysv/linux/x86/time.c > index 1d158e443c..ed2c5f5dbb 100644 > --- a/sysdeps/unix/sysv/linux/x86/time.c > +++ b/sysdeps/unix/sysv/linux/x86/time.c > @@ -16,5 +16,7 @@ > 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> > Ok.
diff --git a/include/time.h b/include/time.h index edf6cdf829..caf2af5e74 100644 --- a/include/time.h +++ b/include/time.h @@ -317,6 +317,13 @@ extern int __timespec_get64 (struct __timespec64 *ts, int base); 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 diff --git a/sysdeps/unix/sysv/linux/powerpc/time.c b/sysdeps/unix/sysv/linux/powerpc/time.c index d10f449c5c..4fd5e138a3 100644 --- a/sysdeps/unix/sysv/linux/powerpc/time.c +++ b/sysdeps/unix/sysv/linux/powerpc/time.c @@ -16,5 +16,7 @@ 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> diff --git a/sysdeps/unix/sysv/linux/time.c b/sysdeps/unix/sysv/linux/time.c index 9d8e573c0a..80641d9ca4 100644 --- a/sysdeps/unix/sysv/linux/time.c +++ b/sysdeps/unix/sysv/linux/time.c @@ -47,5 +47,40 @@ time (time_t *t) } # 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 diff --git a/sysdeps/unix/sysv/linux/x86/time.c b/sysdeps/unix/sysv/linux/x86/time.c index 1d158e443c..ed2c5f5dbb 100644 --- a/sysdeps/unix/sysv/linux/x86/time.c +++ b/sysdeps/unix/sysv/linux/x86/time.c @@ -16,5 +16,7 @@ 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>