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author | Lukasz Majewski <lukma@denx.de> | 2020-01-27 15:37:07 +0100 |
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committer | Lukasz Majewski <lukma@denx.de> | 2020-02-18 23:55:47 +0100 |
commit | 7455b700279ec8baccf8dd7b119648f8b3e34eec (patch) | |
tree | 3a973eeef955d4de9f3e312dedc7c7ce20d8cb8e /sysdeps/unix/sysv | |
parent | a492b1e5ef7ab50c6fdd4e4e9879ea5569ab0a6c (diff) | |
download | glibc-7455b700279ec8baccf8dd7b119648f8b3e34eec.tar.gz glibc-7455b700279ec8baccf8dd7b119648f8b3e34eec.tar.xz glibc-7455b700279ec8baccf8dd7b119648f8b3e34eec.zip |
y2038: linux: Provide __gettimeofday64 implementation
In the glibc the gettimeofday can use vDSO (on power and x86 the USE_IFUNC_GETTIMEOFDAY is defined), gettimeofday syscall or 'default' ___gettimeofday() from ./time/gettime.c (as a fallback). In this patch the last function (___gettimeofday) has been refactored and moved to ./sysdeps/unix/sysv/linux/gettimeofday.c to be Linux specific. The new __gettimeofday64 explicit 64 bit function for getting 64 bit time from the kernel (by internally calling __clock_gettime64) has been introduced. Moreover, a 32 bit version - __gettimeofday has been refactored to internally use __gettimeofday64. The __gettimeofday is now supposed to be used on systems still supporting 32 bit time (__TIMESIZE != 64) - hence the necessary check for time_t potential overflow and conversion of struct __timeval64 to 32 bit struct timespec. The iFUNC vDSO direct call optimization has been removed from both i686 and powerpc32 (USE_IFUNC_GETTIMEOFDAY is not defined for those architectures anymore). The Linux kernel does not provide a y2038 safe implementation of gettimeofday 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_GETTIMEOFDAY) 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 __gettimeofday64 and __gettimeofday. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> [Including some commit message improvement]
Diffstat (limited to 'sysdeps/unix/sysv')
-rw-r--r-- | sysdeps/unix/sysv/linux/gettimeofday.c | 40 | ||||
-rw-r--r-- | sysdeps/unix/sysv/linux/powerpc/gettimeofday.c | 4 | ||||
-rw-r--r-- | sysdeps/unix/sysv/linux/x86/gettimeofday.c | 4 |
3 files changed, 45 insertions, 3 deletions
diff --git a/sysdeps/unix/sysv/linux/gettimeofday.c b/sysdeps/unix/sysv/linux/gettimeofday.c index d5cdb22495..cb57bc9cf2 100644 --- a/sysdeps/unix/sysv/linux/gettimeofday.c +++ b/sysdeps/unix/sysv/linux/gettimeofday.c @@ -54,5 +54,43 @@ __gettimeofday (struct timeval *restrict tv, void *restrict tz) # endif weak_alias (__gettimeofday, gettimeofday) #else /* USE_IFUNC_GETTIMEOFDAY */ -# include <time/gettimeofday.c> +/* Conversion of gettimeofday function to support 64 bit time on archs + with __WORDSIZE == 32 and __TIMESIZE == 32/64 */ +#include <errno.h> + +int +__gettimeofday64 (struct __timeval64 *restrict tv, void *restrict tz) +{ + if (__glibc_unlikely (tz != 0)) + memset (tz, 0, sizeof (struct timezone)); + + struct __timespec64 ts64; + if (__clock_gettime64 (CLOCK_REALTIME, &ts64)) + return -1; + + *tv = timespec64_to_timeval64 (ts64); + return 0; +} + +# if __TIMESIZE != 64 +libc_hidden_def (__gettimeofday64) + +int +__gettimeofday (struct timeval *restrict tv, void *restrict tz) +{ + struct __timeval64 tv64; + if (__gettimeofday64 (&tv64, tz)) + return -1; + + if (! in_time_t_range (tv64.tv_sec)) + { + __set_errno (EOVERFLOW); + return -1; + } + + *tv = valid_timeval64_to_timeval (tv64); + return 0; +} +# endif +weak_alias (__gettimeofday, gettimeofday) #endif diff --git a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c index 183fb0ac70..2d6978f333 100644 --- a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c +++ b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c @@ -15,5 +15,7 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ -#define USE_IFUNC_GETTIMEOFDAY +#ifdef __powerpc64__ +# define USE_IFUNC_GETTIMEOFDAY +#endif #include <sysdeps/unix/sysv/linux/gettimeofday.c> diff --git a/sysdeps/unix/sysv/linux/x86/gettimeofday.c b/sysdeps/unix/sysv/linux/x86/gettimeofday.c index 1b7aa880a2..0c1779dc83 100644 --- a/sysdeps/unix/sysv/linux/x86/gettimeofday.c +++ b/sysdeps/unix/sysv/linux/x86/gettimeofday.c @@ -16,5 +16,7 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ -#define USE_IFUNC_GETTIMEOFDAY +#ifdef __x86_64__ +# define USE_IFUNC_GETTIMEOFDAY +#endif #include <sysdeps/unix/sysv/linux/gettimeofday.c> |