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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Thu, 14 Nov 2019 15:35:35 +0100
Message-ID: <CAK8P3a0qm1FW+mqcMvzyb8WVvqtF-POMpir+WVezEObaYLCCRg@mail.gmail.com>
Subject: Re: [PATCH 17/23] y2038: time: avoid timespec usage in settimeofday()
To:     Thomas Gleixner <tglx@linutronix.de>
Cc:     y2038 Mailman List <y2038@lists.linaro.org>,
        John Stultz <john.stultz@linaro.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Stephen Boyd <sboyd@kernel.org>,
        David Howells <dhowells@redhat.com>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Deepa Dinamani <deepa.kernel@gmail.com>,
        Christian Brauner <christian@brauner.io>,
        Jens Axboe <axboe@kernel.dk>, Ingo Molnar <mingo@kernel.org>,
        Corey Minyard <cminyard@mvista.com>,
        zhengbin <zhengbin13@huawei.com>,
        Li RongQing <lirongqing@baidu.com>,
        Linux API <linux-api@vger.kernel.org>
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On Thu, Nov 14, 2019 at 3:04 PM Thomas Gleixner <tglx@linutronix.de> wrote:
> On Thu, 14 Nov 2019, Arnd Bergmann wrote:
> > On Wed, Nov 13, 2019 at 10:53 PM Thomas Gleixner <tglx@linutronix.de> wrote:
> >
> > My idea was to not duplicate the range check that is done
> > in do_sys_settimeofday64() and again in do_settimeofday64:
> >
> >         if (!timespec64_valid_settod(ts))
> >                 return -EINVAL;
> >
> > The only check we should need in addition to this is to ensure
> > that passing an invalid tv_usec number doesn't become an
> > unexpectedly valid tv_nsec after the multiplication.
>
> Right, but please add a proper comment as you/we are going to scratch heads
> 4 weeks from now when staring at that check and wondering why it is
> incomplete.

Ok, done. I had just uploaded the branch with the fixup for
the __user pointer access in the same patch, but that version
had introduced another typo. I hope the version I uploaded
now has all known issues addressed for tomorrow's linux-next.

      Arnd