From patchwork Mon May 20 10:27:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Majewski X-Patchwork-Id: 1101933 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=sourceware.org (client-ip=209.132.180.131; helo=sourceware.org; envelope-from=libc-alpha-return-102099-incoming=patchwork.ozlabs.org@sourceware.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=denx.de Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=sourceware.org header.i=@sourceware.org header.b="XYjZPQQc"; dkim-atps=neutral Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 456w8d1rPVz9s3Z for ; Mon, 20 May 2019 20:28:17 +1000 (AEST) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:cc:subject:date:message-id:in-reply-to :references; q=dns; s=default; b=IbHzk4FjWn0hCnfZaul+9KDG+hRPyBW 6wfWZtj4/N6l1yCKP0i6vGty90EKAqLLmSlmt59WGcPeumdZ05gZpw4D8h6Jnvl9 ektIjPLZgwx4GtjRvoXhjFRuT35t+hNJR6iSMgq75UJ5p+9mfUrN76uCiYwfHsM4 QJjBtIpDUL4s= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:cc:subject:date:message-id:in-reply-to :references; s=default; bh=ZvyEDKouWDOTFiqX23P/DZTRl7Q=; b=XYjZP QQcF2Nbz2SzKyIFLFDMxEFpZtHFT2W9HY3jMvQndfFrDvgbhA7tlm75SmKHQTJUT xtqZrSI5tNAwGos1mtFogPwtQpmJiv7GcEdPX+cUZWq0Pht3XbRtwsmG3MktuFHZ 5CsIyoY2Rks+3uINDRW8p3XFTyQwh+eybz+5SU= Received: (qmail 123136 invoked by alias); 20 May 2019 10:27:50 -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 123098 invoked by uid 89); 20 May 2019 10:27:49 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-20.1 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=ignorance, applicable, exclude, 1911 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 v4 3/3] y2038: linux: Provide __clock_settime64 implementation Date: Mon, 20 May 2019 12:27:23 +0200 Message-Id: <20190520102723.5380-4-lukma@denx.de> In-Reply-To: <20190520102723.5380-1-lukma@denx.de> References: <20190414220841.20243-1-lukma@denx.de> <20190520102723.5380-1-lukma@denx.de> This patch provides new __clock_settime64 explicit 64 bit function for setting the time. Moreover, a 32 bit version - __clock_settime - has been refactored to internally use __clock_settime64. The __clock_settime is now supposed to be used on systems still supporting 32 bit time (__TIMESIZE != 64) - hence the necessary checks and conversion to 64 bit struct timespec. After this change it is intrinsically Y2038 safe. The new clock_settime64 syscall available from Linux 5.1+ has been used, when applicable, on systems supporting ILP32 data model. The __ASSUME_TIME64_SYSCALLS flag indicates if the Linux kernel supports 64 bit version of clock_settime (i.e. clock_settime64). For systems with __TIMESIZE != 64 as well as ones not supporting this call (returning -ENOSYS) the fall back code, which supports 32 bit kernel syscalls ABI (hence the check for __SYSCALL_WORDSIZE to exclude 'x32'), is executed. When working on 32 bit systems without Y2038 time support the clock_settime returns error when one wants to set time with wrong (overflowed) tv_sec value. Moreover, the correctness of tv_nsec is checked. In this patch the internal padding (tv_pad) of struct __timespec64 is left untouched (on 32 bit systems) as Linux kernel ignores upper 32 bits of tv_nsec. The execution path on 64 bit systems has not been changed or affected in any way. Tests: - The code has been tested with x86_64/x86 (native compilation): make PARALLELMFLAGS="-j8" && make xcheck PARALLELMFLAGS="-j8" - 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 on kernels with and without 64 bit time support. No regressions were observed. * include/time.h (__clock_settime64): Add __clock_settime alias according to __TIMESIZE define * sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime): Refactor this function to be used only on 32 bit machines as a wrapper on __clock_settime64. * sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime64): Add * sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime64): Use clock_settime64 kernel syscall (available from 5.1-rc1+ Linux) by 32 bit Y2038 safe systems --- Changes for v4: - __ASSUME_TIME64_SYSCALLS for fall back path - Use __SYSCALL_WORDSIZE to exclude 'x32' from execution path (so it will use x86_64 syscall - Rewrite the commit message Changes for v3: - Rename __ASSUME_64BIT_TIME to __ASSUME_TIME64_SYSCALLS - Refactor in-code comment (add information regarding Linux kernel ignorance of padding - Do not use __TIMESIZE to select main execution path (for Y2038 systems __TIMESIZE would be changed from 32 to 64 bits at some point to indicate full Y2038 support Changes for v2: - Add support for __ASSUME_64BIT_TIME flag when Linux kernel provides syscalls supporting 64 bit time on 32 bit systems - Provide fallback to 32 bit version of clock_settime when clock_settime64 is not available - Do not copy *tp to timespec - this seems like an overkill as in clock_settime() the 32 bit struct timespec is copied to internal 64 bit struct __timespec64 --- include/time.h | 8 +++++++ sysdeps/unix/sysv/linux/clock_settime.c | 38 ++++++++++++++++++++++++++++++--- 2 files changed, 43 insertions(+), 3 deletions(-) diff --git a/include/time.h b/include/time.h index 6ca4911235..88413d8031 100644 --- a/include/time.h +++ b/include/time.h @@ -127,6 +127,14 @@ extern __time64_t __timegm64 (struct tm *__tp) __THROW; libc_hidden_proto (__timegm64) #endif +#if __TIMESIZE == 64 +# define __clock_settime64 __clock_settime +#else +extern int __clock_settime64 (clockid_t clock_id, + const struct __timespec64 *tp); +libc_hidden_proto (__clock_settime64) +#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_settime.c b/sysdeps/unix/sysv/linux/clock_settime.c index d837e3019c..19559d1e76 100644 --- a/sysdeps/unix/sysv/linux/clock_settime.c +++ b/sysdeps/unix/sysv/linux/clock_settime.c @@ -19,11 +19,9 @@ #include #include -#include "kernel-posix-cpu-timers.h" - /* Set CLOCK to value TP. */ int -__clock_settime (clockid_t clock_id, const struct timespec *tp) +__clock_settime64 (clockid_t clock_id, const struct __timespec64 *tp) { /* Make sure the time cvalue is OK. */ if (tp->tv_nsec < 0 || tp->tv_nsec >= 1000000000) @@ -32,6 +30,40 @@ __clock_settime (clockid_t clock_id, const struct timespec *tp) return -1; } +#if __WORDSIZE == 32 +# ifdef __NR_clock_settime64 + int ret = INLINE_SYSCALL_CALL (clock_settime64, clock_id, tp); +# ifdef __ASSUME_TIME64_SYSCALLS + return ret; +# else + if (ret == 0 || errno != ENOSYS) + return ret; +# endif +# endif + /* Fall back to syscall supporting 32bit struct timespec. */ +# if (!defined __SYSCALL_WORDSIZE || __SYSCALL_WORDSIZE != 64) + struct timespec ts32; + valid_timespec64_to_timespec (tp, &ts32); + return INLINE_SYSCALL_CALL (clock_settime, clock_id, &ts32); +# endif +#endif return INLINE_SYSCALL_CALL (clock_settime, clock_id, tp); } weak_alias (__clock_settime, clock_settime) + +#if __TIMESIZE != 64 +int +__clock_settime (clockid_t clock_id, const struct timespec *tp) +{ + struct __timespec64 ts64; + + if (! in_time_t_range (tp->tv_sec)) + { + __set_errno (EOVERFLOW); + return -1; + } + + valid_timespec_to_timespec64 (tp, &ts64); + return __clock_settime64 (clock_id, &ts64); +} +#endif