From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753231AbdJSLrD (ORCPT ); Thu, 19 Oct 2017 07:47:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53206 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751320AbdJSLq5 (ORCPT ); Thu, 19 Oct 2017 07:46:57 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 7448013A62 Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=pbonzini@redhat.com Subject: Re: [PATCH v2 2/2] x86: convert x86_platform_ops to timespec64 To: Arnd Bergmann , Thomas Gleixner , x86@kernel.org Cc: y2038@lists.linaro.org, Ingo Molnar , "H. Peter Anvin" , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Boris Ostrovsky , Juergen Gross , Marcos Paulo de Souza , Dmitry Torokhov , Peter Zijlstra , John Stultz , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, xen-devel@lists.xenproject.org References: <20171019105451.2892046-1-arnd@arndb.de> <20171019105824.3035694-1-arnd@arndb.de> From: Paolo Bonzini Message-ID: <9f0b30dd-9d6e-8b31-bb08-f4ad20acbf9e@redhat.com> Date: Thu, 19 Oct 2017 13:46:50 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <20171019105824.3035694-1-arnd@arndb.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Thu, 19 Oct 2017 11:46:57 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19/10/2017 12:57, Arnd Bergmann wrote: > The x86 platform operations are fairly isolated, so we can > change them from using timespec to timespec64. I checked that > All the users and callers are safe, and there is only one > critical function that is broken beyond 2106: > > pvclock_read_wallclock() uses a 32-bit number of seconds since > the epoch to communicate the boot time between host and guest > in a virtual environment. This will work until 2106, but we > should ideally find a replacement anyway. I've added a comment > about it there. > > Reviewed-by: Boris Ostrovsky > Signed-off-by: Arnd Bergmann > --- > v2 changes: > - move comment block (Boris) > - remove unnecessary type cast (Boris) > - fix format string (0day bot) > - fix include order (0day bot) > --- > arch/x86/include/asm/intel_mid_vrtc.h | 4 ++-- > arch/x86/include/asm/mc146818rtc.h | 4 ++-- > arch/x86/include/asm/pvclock.h | 2 +- > arch/x86/include/asm/x86_init.h | 7 +++---- > arch/x86/kernel/kvmclock.c | 4 ++-- > arch/x86/kernel/pvclock.c | 15 +++++++++++---- > arch/x86/kernel/rtc.c | 16 ++++++++-------- > arch/x86/platform/intel-mid/intel_mid_vrtc.c | 12 ++++++------ > arch/x86/xen/time.c | 10 +++++----- > 9 files changed, 40 insertions(+), 34 deletions(-) > > diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c > index d88967659098..01c76e8cd4be 100644 > --- a/arch/x86/kernel/kvmclock.c > +++ b/arch/x86/kernel/kvmclock.c > @@ -58,7 +58,7 @@ EXPORT_SYMBOL_GPL(pvclock_pvti_cpu0_va); > * have elapsed since the hypervisor wrote the data. So we try to account for > * that with system time > */ > -static void kvm_get_wallclock(struct timespec *now) > +static void kvm_get_wallclock(struct timespec64 *now) > { > struct pvclock_vcpu_time_info *vcpu_time; > int low, high; > @@ -77,7 +77,7 @@ static void kvm_get_wallclock(struct timespec *now) > put_cpu(); > } > > -static int kvm_set_wallclock(const struct timespec *now) > +static int kvm_set_wallclock(const struct timespec64 *now) > { > return -1; > } > diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c > index 5c3f6d6a5078..013bef851664 100644 > --- a/arch/x86/kernel/pvclock.c > +++ b/arch/x86/kernel/pvclock.c > @@ -121,26 +121,33 @@ u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src) > > void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock, > struct pvclock_vcpu_time_info *vcpu_time, > - struct timespec *ts) > + struct timespec64 *ts) > { > u32 version; > u64 delta; > - struct timespec now; > + struct timespec64 now; > > /* get wallclock at system boot */ > do { > version = wall_clock->version; > rmb(); /* fetch version before time */ > + /* > + * Note: wall_clock->sec is a u32 value, so it can > + * only store dates between 1970 and 2106. To allow > + * times beyond that, we need to create a new hypercall > + * interface with an extended pvclock_wall_clock structure > + * like ARM has. > + */ > now.tv_sec = wall_clock->sec; > now.tv_nsec = wall_clock->nsec; > rmb(); /* fetch time before checking version */ > } while ((wall_clock->version & 1) || (version != wall_clock->version)); > > delta = pvclock_clocksource_read(vcpu_time); /* time since system boot */ > - delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec; > + delta += now.tv_sec * NSEC_PER_SEC + now.tv_nsec; > > now.tv_nsec = do_div(delta, NSEC_PER_SEC); > now.tv_sec = delta; > > - set_normalized_timespec(ts, now.tv_sec, now.tv_nsec); > + set_normalized_timespec64(ts, now.tv_sec, now.tv_nsec); > } For kvmclock.c and pvclock.c, Acked-by: Paolo Bonzini