From 63ff4a6d1732e7472cbfa59a8f31db0441269105 Mon Sep 17 00:00:00 2001 From: Lukasz Majewski Date: Tue, 21 Apr 2020 19:14:18 +0200 Subject: y2038: linux: Provide __clock_adjtime64 implementation This patch replaces auto generated wrapper (as described in sysdeps/unix/sysv/linux/syscalls.list) for clock_adjtime with one which adds extra support for reading 64 bit time values on machines with __TIMESIZE != 64. To achieve this goal new __clock_adjtime64 explicit 64 bit function for adjusting Linux clock has been added. Moreover, a 32 bit version - __clock_adjtime has been refactored to internally use __clock_adjtime64. The __clock_adjtime is now supposed to be used on systems still supporting 32 bit time (__TIMESIZE != 64) - hence the necessary conversions between 64 bit struct __timespec64 and struct timespec. The new __clock_adjtime64 syscall available from Linux 5.1+ has been used, when applicable. Up till v5.4 in the Linux kernel there was a bug preventing this call from obtaining correct struct's timex time.tv_sec time after time_t overflow (i.e. not being Y2038 safe). 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 Linux kernel, headers and minimal kernel version for glibc build test matrix: - Linux v5.1 (with clock_adjtime64) and glibc build with v5.1 as minimal kernel version (--enable-kernel="5.1.0") The __ASSUME_TIME64_SYSCALLS flag defined. - Linux v5.1 and default minimal kernel version The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports clock_adjtime64 syscall. - Linux v4.19 (no clock_adjtime64 support) with default minimal kernel version for contemporary glibc (3.2.0) This kernel doesn't support clock_adjtime64 syscall, so the fallback to clock_adjtime is tested. Above tests were performed with Y2038 redirection applied as well as without (so the __TIMESIZE != 64 execution path is checked as well). No regressions were observed. Reviewed-by: Adhemerval Zanella --- sysdeps/unix/sysv/linux/clock_adjtime.c | 73 +++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/clock_adjtime.c (limited to 'sysdeps/unix/sysv/linux/clock_adjtime.c') diff --git a/sysdeps/unix/sysv/linux/clock_adjtime.c b/sysdeps/unix/sysv/linux/clock_adjtime.c new file mode 100644 index 0000000000..764a60b9bf --- /dev/null +++ b/sysdeps/unix/sysv/linux/clock_adjtime.c @@ -0,0 +1,73 @@ +/* clock_adjtime -- tune kernel clock. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; see the file COPYING.LIB. If + not, see . */ + +#include +#include +#include +#include +#include +#include + +int +__clock_adjtime64 (const clockid_t clock_id, struct __timex64 *tx64) +{ +#ifdef __ASSUME_TIME64_SYSCALLS +# ifndef __NR_clock_adjtime64 +# define __NR_clock_adjtime64 __NR_clock_adjtime +# endif + return INLINE_SYSCALL_CALL (clock_adjtime64, clock_id, tx64); +#else + int ret = INLINE_SYSCALL_CALL (clock_adjtime64, clock_id, tx64); + if (errno != ENOSYS) + return ret; + + if (tx64->modes & ADJ_SETOFFSET + && ! in_time_t_range (tx64->time.tv_sec)) + { + __set_errno (EOVERFLOW); + return -1; + } + + struct timex tx32 = valid_timex64_to_timex (*tx64); + int retval = INLINE_SYSCALL_CALL (clock_adjtime, clock_id, &tx32); + if (retval >= 0) + *tx64 = valid_timex_to_timex64 (tx32); + + return retval; +#endif +} + +#if __TIMESIZE != 64 +libc_hidden_def (__clock_adjtime64) + +int +__clock_adjtime (const clockid_t clock_id, struct timex *tx) +{ + struct __timex64 tx64; + int retval; + + tx64 = valid_timex_to_timex64 (*tx); + retval = __clock_adjtime64 (clock_id, &tx64); + if (retval >= 0) + *tx = valid_timex64_to_timex (tx64); + + return retval; +} +#endif +libc_hidden_def (__clock_adjtime); +strong_alias (__clock_adjtime, clock_adjtime) -- cgit 1.4.1