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From: Arnd Bergmann <arnd@arndb.de>
Date: Wed, 16 May 2018 21:13:05 -0400
Message-ID: <CAK8P3a0d6j2KF+pSZQ5uM3jQ7=OZQXnc+ZjPb--52kdBV=k_vQ@mail.gmail.com>
Subject: Re: [PATCH 6/6] vfs: change inode times to use struct timespec64
To: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Kees Cook <keescook@chromium.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Thomas Gleixner <tglx@linutronix.de>,
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On Mon, May 14, 2018 at 2:23 PM, Deepa Dinamani <deepa.kernel@gmail.com> wrote:
> On Mon, May 14, 2018 at 10:53 AM, Kees Cook <keescook@chromium.org> wrote:
>> On Mon, May 14, 2018 at 10:25 AM, Deepa Dinamani <deepa.kernel@gmail.com> wrote:
>>> On Mon, May 14, 2018 at 9:30 AM, Kees Cook <keescook@chromium.org> wrote:
>>
>> Can we do something like:
>>
>> #if __BITS_PER_LONG == 64
>> # define TVSEC_FMT "%ld"
>> #else
>> # define TVSEC_FMT "%lld"
>> #endif
>>
>> so we can do stuff like:  sprintf(buf, "seconds: " KTIME_FMT, time->tv_sec)
>>
>> ? It seems easier to clean up than casts.
>
> We have already introduced these casts in many places now.
> It would be easier to do the clean up if they all follow a similar
> pattern. ( I could probably write a coccinelle script that is not very
> long).
> But, it would be not much trouble if you wanted to follow this for pstore.
>
> We also contemplated adding a format specifier for time. But, I think
> we deferred it until we have a uniform way of using time internally.

I have recently submitted a patch to completely remove the hack that
leads to 'timespec64' and 'timespec' being aliases for the same type on
64-bit architectures. Once that goes in, we can just remove the type casts
that got added over time, and won't need a format macro.

        Arnd