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From: stian@nixia.no
To: user-mode-linux-devel@lists.sourceforge.net
Subject: Re: [uml-devel] [PATCH v6] um: Add a high resolution timer subsystem
Date: Tue, 26 May 2015 12:56:14 +0200	[thread overview]
Message-ID: <6c5810675c786f846a68b600d63e46bb@nixia.no> (raw)
In-Reply-To: <5550CE0F.40504@kot-begemot.co.uk>

>                  nsecs = timer.it_value.tv_sec *
>                      UM_NSEC_PER_SEC +
>                      timer.it_value.tv_usec *
>                      UM_NSEC_PER_USEC;
>                  nsecs += os_nsecs();

Not looking at the rest of the code, the first thing that comes to my 
mind is that this very easy overflows if 32 bit multiplications are used 
(tv_sec is usually 32bit and dictates the first multiplication unless 
typecast is used).

Stian Skjelstad

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  parent reply	other threads:[~2015-05-26 11:26 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-09 23:14 [uml-devel] [PATCH v6] um: Add a high resolution timer subsystem Thomas Meyer
2015-05-10 12:35 ` Richard Weinberger
2015-05-10 13:32   ` Anton Ivanov
2015-05-10 14:34   ` Thomas Meyer
2015-05-10 18:25     ` Anton Ivanov
2015-05-10 20:51     ` Richard Weinberger
2015-05-11 12:52     ` Anton Ivanov
2015-05-11 15:05       ` Anton Ivanov
2015-05-11 15:43         ` Anton Ivanov
2015-05-11 17:00           ` Thomas Meyer
2015-05-11 17:20             ` Anton Ivanov
2015-05-11 17:31               ` Anton Ivanov
2015-05-11 17:41                 ` Thomas Meyer
2015-05-11 19:42                   ` Anton Ivanov
2015-05-11 21:22                     ` Thomas Meyer
2015-05-26 10:56           ` stian [this message]
2015-05-11 22:34     ` Richard Weinberger

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