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Message-ID: <1457630115.5784.1.camel@nexus-software.ie>
Subject: Re: Got FPU related warning on Intel Quark during boot
From: "Bryan O'Donoghue" <pure.logic@nexus-software.ie>
To: Borislav Petkov <bp@alien8.de>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>,
        Ingo Molnar <mingo@kernel.org>,
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        Fenghua Yu <fenghua.yu@intel.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        "H. Peter Anvin" <hpa@zytor.com>, Thomas Gleixner <tglx@linutronix.de>,
        Andrew Morton <akpm@linux-foundation.org>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Oleg Nesterov <oleg@redhat.com>,
        "Yu, Yu-cheng" <yu-cheng.yu@intel.com>
Date: Thu, 10 Mar 2016 17:15:15 +0000
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On Thu, 2016-03-10 at 17:49 +0100, Borislav Petkov wrote:
> On Thu, Mar 10, 2016 at 03:45:21PM +0000, Bryan O'Donoghue wrote:
> > It works but user-space FPU is broken; something's wrong with the
> > initial state of the FPU regs - it looks as though they aren't
> > being
> > properly initialized and FPU context in the signal handler is wrong
> > too.
> 
> What does your test prog say when you boot linux-next with
> "eagerfpu=off" and *without* my fix?
> 

root@galileo:~# ./fpu 
f is 10.000000 g is 10.100000
Double value is 0.000000
Double value is 0.100000
Double value is 0.200000
^Chandler value of variable is 0.300000
Double value is 0.300000
Double value is 0.400000
^Z
[1]+  Stopped                 ./fpu
root@galileo:~#