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From: Christian Brauner <christian@brauner.io>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk,
	longman@redhat.com
Subject: Re: [PATCH 1/2] sysctl: add overflow detection to proc_get_long()
Date: Mon, 15 Oct 2018 00:43:53 +0200	[thread overview]
Message-ID: <FCEAD072-023C-4410-B434-2D6D2EE21889@brauner.io> (raw)
In-Reply-To: <20181014221325.GA26685@avx2>

On October 15, 2018 12:13:25 AM GMT+02:00, Alexey Dobriyan <adobriyan@gmail.com> wrote:
>> > Yecchh...  First of all, the cast back to unsigned long long is
>completely
>> > pointless.  What's more,
>> 
>> Sorry, seriously asking: why?
>
>In C everything is casted to the same type before doing an operation,

Oh, ok that's what we're talking about. I 
thought the whole check is pointless. I 
didn't read careful enough apparently.

Tbh, even if the second cast is not 
necessary it makes implicit behavior
explicit.
I've also seen this form more than
the one without the explicit cast.
But I won't fight it. If other people
prefer it without the second cast; fine.

>in this case comparison
>
>> This was meant to handle the case where
>> sizeof(unsigned long long) != sizeof(unsigned long) and I just looked
>at
>> _kstrtoul() which does the same:
>
>Second cast is unnecessary. I don't remember why I did 2 casts.


  reply	other threads:[~2018-10-14 22:44 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-14 22:13 [PATCH 1/2] sysctl: add overflow detection to proc_get_long() Alexey Dobriyan
2018-10-14 22:43 ` Christian Brauner [this message]
  -- strict thread matches above, loose matches on Subject: below --
2018-10-14 13:25 [PATCH 0/2] sysctl: cap file-max value at ULONG_MAX Christian Brauner
2018-10-14 13:25 ` [PATCH 1/2] sysctl: add overflow detection to proc_get_long() Christian Brauner
2018-10-14 17:18   ` Al Viro
2018-10-14 18:53     ` Christian Brauner
2018-10-15  0:03       ` Al Viro
2018-10-15  4:47         ` Christian Brauner

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