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Date:   Mon, 26 Mar 2018 14:55:22 -0700
From:   Matthew Wilcox <willy@infradead.org>
To:     Arnd Bergmann <arnd@arndb.de>
Cc:     Jeff Moyer <jmoyer@redhat.com>,
        "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Benjamin LaHaise <bcrl@kvack.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        linux-aio <linux-aio@kvack.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Tianhong Ding <dingtianhong@huawei.com>,
        Hanjun Guo <guohanjun@huawei.com>,
        Libin <huawei.libin@huawei.com>,
        Kefeng Wang <wangkefeng.wang@huawei.com>,
        Deepa Dinamani <deepa.kernel@gmail.com>
Subject: Re: [PATCH 1/1] aio: make sure the input "timeout" value is valid
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On Mon, Mar 26, 2018 at 10:01:30PM +0200, Arnd Bergmann wrote:
> I had suggested a more complete helper function at some point,
> to take care of all combinations of checking/non-checking, 32/64
> bit, microsecond/nanosecond, and zeroing/checking the upper 32 bits
> of nanoseconds before comparing against 1 billion, but Deepa
> thought that was overkill, so I didn't continue that.

Yeah, that sounds like a nightmare to use ;-)

> For all I can tell, the get_timespec64() helper should almost always
> include the check, the one exception I know is utimensat() and related
> functions that may encode the special UTIME_NOW and UTIME_OMIT
> constants in the nanoseconds.

So do you endorse the get_valid_timespec64() patch I posted up-thread?
We can't just make get_timespec64 return an errno directly because it'll
require changing all the users.