From patchwork Wed May 8 15:56:08 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Majewski X-Patchwork-Id: 32607 Received: (qmail 117225 invoked by alias); 8 May 2019 15:56:33 -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 116461 invoked by uid 89); 8 May 2019 15:56:33 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-19.9 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=Moreover X-HELO: mail-out.m-online.net From: Lukasz Majewski To: libc-alpha@sourceware.org Cc: Stepan Golosunov , Arnd Bergmann , Paul Eggert , Joseph Myers , Lukasz Majewski Subject: [PATCH] y2038: Introduce __ASSUME_TIME64_SYSCALLS define Date: Wed, 8 May 2019 17:56:08 +0200 Message-Id: <20190508155608.24791-1-lukma@denx.de> In-Reply-To: <20190414220841.20243-1-lukma@denx.de> References: <20190414220841.20243-1-lukma@denx.de> This define indicates if the Linux kernel (5.1+) provides syscalls supporting 64 bit versions of struct timespec and timeval. For architectures with __WORDSIZE==64 && __TIMESIZE==64 (e.g. x86_64, aarch64 this flag is never defined (as those already use 64 bit versions of struct timespec and timeval). The __ASSUME_TIME64_SYSCALLS shall be only defined on systems with __WORDSIZE==32. For x32 this flag is explicitly undefined as this architecture has 64 bit registers but only 32 bit longs and pointers. Moreover, it uses syscalls from x86_64. * sysdeps/unix/sysv/linux/kernel-features.h: (__ASSUME_TIME64_SYSCALLS): [__LINUX_KERNEL_VERSION >= 0x050100]: Define. * sysdeps/unix/sysv/linux/x86_64/kernel-features.h (__ASSUME_TIME64_SYSCALLS): #undef the __ASSUME_TIME64_SYSCALLS for x32 architecture --- Changes for v4: - Exclude this patch from the clock_settime64 patch series - Rewrite the in-code comment - Change patch description Changes for v3: - Provide more detailed and verbose description - Change name to __ASSUME_TIME64_SYSCALLS - Undefine __ASSUME_TIME64_SYSCALLS on x32 Changes for v2: - New patch --- sysdeps/unix/sysv/linux/kernel-features.h | 38 ++++++++++++++++++++++++ sysdeps/unix/sysv/linux/x86_64/kernel-features.h | 9 ++++++ 2 files changed, 47 insertions(+) diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h index bc5c959f58..30e77dd213 100644 --- a/sysdeps/unix/sysv/linux/kernel-features.h +++ b/sysdeps/unix/sysv/linux/kernel-features.h @@ -143,3 +143,41 @@ */ #define __ASSUME_CLONE_DEFAULT 1 + +#include +#if __WORDSIZE != 64 +/* Support for Linux kernel syscalls, which are able to handle 64 bit + time on 32 bit systems (with 'long' and __WORDSIZE equal to 32 bits). + + Linux kernel, as of version 5.1, provides following set of syscalls, + which accept data based on struct timespec and timeval with 64 bit + tv_sec: + + clock_gettime64 + clock_settime64 + clock_adjtime64 + clock_getres_time64 + clock_nanosleep_time64 + timer_gettime64 + timer_settime64 + timerfd_gettime64 + timerfd_settime64 + utimensat_time64 + pselect6_time64 + ppoll_time64 + io_pgetevents_time64 + recvmmsg_time64 + mq_timedsend_time64 + mq_timedreceive_time64 + semtimedop_time64 + rt_sigtimedwait_time64 + futex_time64 + sched_rr_get_interval_time64 + + Above syscalls are supposed to replace legacy ones, which handle 32 + bit version of struct timespec and timeval (i.e. without the '64' + suffix). */ +# if __LINUX_KERNEL_VERSION >= 0x050100 +# define __ASSUME_TIME64_SYSCALLS 1 +# endif +#endif diff --git a/sysdeps/unix/sysv/linux/x86_64/kernel-features.h b/sysdeps/unix/sysv/linux/x86_64/kernel-features.h index 26280f57ec..e1e923f497 100644 --- a/sysdeps/unix/sysv/linux/x86_64/kernel-features.h +++ b/sysdeps/unix/sysv/linux/x86_64/kernel-features.h @@ -24,3 +24,12 @@ #endif #include_next + +/* For x32, which is a special case in respect to 64 bit time support, + the __ASSUME_TIME64_SYSCALLS define needs to be explicitly undefined. + + It uses Linux time related syscalls for x86_64 (in compatibility + mode). */ +#ifdef __ILP32__ +# undef __ASSUME_TIME64_SYSCALLS +#endif