From patchwork Fri Oct 18 14:57:20 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Majewski X-Patchwork-Id: 35146 Received: (qmail 106184 invoked by alias); 18 Oct 2019 14:57:49 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 106124 invoked by uid 89); 18 Oct 2019 14:57:48 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-19.5 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 spammy=correctness X-HELO: mail-out.m-online.net From: Lukasz Majewski To: Joseph Myers , Paul Eggert Cc: Alistair Francis , Arnd Bergmann , Alistair Francis , GNU C Library , Adhemerval Zanella , Florian Weimer , Carlos O'Donell , Stepan Golosunov , Florian Weimer , Zack Weinberg , Lukasz Majewski Subject: [PATCH 2/2] y2038: linux: Provide __clock_getres64 implementation Date: Fri, 18 Oct 2019 16:57:20 +0200 Message-Id: <20191018145720.11706-2-lukma@denx.de> In-Reply-To: <20191018145720.11706-1-lukma@denx.de> References: <20191018145720.11706-1-lukma@denx.de> MIME-Version: 1.0 This patch provides new __clock_getres64 explicit 64 bit function for getting the resolution (precision) of specified clock ID. Moreover, a 32 bit version - __clock_getres has been refactored to internally use __clock_getres64. The __clock_getres is now supposed to be used on systems still supporting 32 bit time (__TIMESIZE != 64) - hence the necessary conversion from 64 bit struct __timespec64 to struct timespec. The new clock_getres_time64 syscall available from Linux 5.1+ has been used, when applicable. On systems which are not supporting clock_getres_time64 (as their clock_getres supports 64 bit time ABI) the vDSO syscall is attempted. On the contrary the non-vDSO syscall is used for clock_getres_time64 as up till now the kernel is not providing such interface. When working on systems still supporting 32 bit time (__TIMESIZE != 64) without Y2038 time support the clock_getres returns error when received tv_sec excess time_t range (i.e. overflow 32 bit type). Moreover, the correctness of tv_nsec is checked. Build tests: - The code has been tested on x86_64/x86 (native compilation): make PARALLELMFLAGS="-j8" && make xcheck PARALLELMFLAGS="-j8" - The glibc has been build tested (make PARALLELMFLAGS="-j8") for x86 (i386), x86_64-x32, and armv7 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 - Use of cross-test-ssh.sh for ARM (armv7): make PARALLELMFLAGS="-j8" test-wrapper='./cross-test-ssh.sh root@192.168.7.2' xcheck Linux kernel, headers and minimal kernel version for glibc build test matrix: - Linux v5.1 (with clock_getres_time64) 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_getres_time64 syscall. - Linux v4.19 (no clock_getres_time64 support) with default minimal kernel version for contemporary glibc This kernel doesn't support clock_getres_time64 syscall, so the fallback to clock_getres is tested. The 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. --- include/time.h | 8 ++++++ sysdeps/unix/sysv/linux/clock_getres.c | 38 ++++++++++++++++++++++++-- 2 files changed, 43 insertions(+), 3 deletions(-) diff --git a/include/time.h b/include/time.h index c2b6c9b842..cefc27ebb9 100644 --- a/include/time.h +++ b/include/time.h @@ -133,6 +133,14 @@ extern int __clock_settime64 (clockid_t clock_id, libc_hidden_proto (__clock_settime64) #endif +#if __TIMESIZE == 64 +# define __clock_getres64 __clock_getres +#else +extern int __clock_getres64 (clockid_t clock_id, + struct __timespec64 *tp); +libc_hidden_proto (__clock_getres64); +#endif + /* Compute the `struct tm' representation of T, offset OFFSET seconds east of UTC, and store year, yday, mon, mday, wday, hour, min, sec into *TP. diff --git a/sysdeps/unix/sysv/linux/clock_getres.c b/sysdeps/unix/sysv/linux/clock_getres.c index 0b82759043..e5b4bf7cea 100644 --- a/sysdeps/unix/sysv/linux/clock_getres.c +++ b/sysdeps/unix/sysv/linux/clock_getres.c @@ -19,21 +19,53 @@ #include #include #include -#include "kernel-posix-cpu-timers.h" #ifdef HAVE_CLOCK_GETRES_VSYSCALL # define HAVE_VSYSCALL #endif #include - #include +#include /* Get resolution of clock. */ int -__clock_getres (clockid_t clock_id, struct timespec *res) +__clock_getres64 (clockid_t clock_id, struct __timespec64 *res) { +#ifdef __ASSUME_TIME64_SYSCALLS +# ifndef __NR_clock_getres_time64 return INLINE_VSYSCALL (clock_getres, 2, clock_id, res); +# else + return INLINE_SYSCALL (clock_getres_time64, 2, clock_id, res); +# endif +#else +# ifdef __NR_clock_getres_time64 + int ret = INLINE_SYSCALL (clock_getres_time64, 2, clock_id, res); + if (ret == 0 || errno != ENOSYS) + return ret; +# endif + struct timespec ts32; + int retval = INLINE_VSYSCALL (clock_getres, 2, clock_id, &ts32); + if (! retval && res) + *res = valid_timespec_to_timespec64 (ts32); + + return retval; +#endif +} + +#if __TIMESIZE != 64 +int +__clock_getres (clockid_t clock_id, struct timespec *res) +{ + struct __timespec64 ts64; + int retval; + + retval = __clock_getres64 (clock_id, &ts64); + if (! retval && res) + *res = timespec64_to_timespec (ts64); + + return retval; } +#endif versioned_symbol (libc, __clock_getres, clock_getres, GLIBC_2_17); /* clock_getres moved to libc in version 2.17;