Date: Thu, 13 Aug 2015 18:43:02 +0200
From: Borislav Petkov <bp@suse.de>
To: yalin wang <yalin.wang2010@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>, mingo@redhat.com, hpa@zytor.com,
        x86@kernel.org, open list <linux-kernel@vger.kernel.org>,
        Will Deacon <will.deacon@arm.com>
Subject: Re: [x86] copy_from{to}_user question
Message-ID: <20150813164302.GA15881@nazgul.tnic>
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 <20150812100738.GA14020@nazgul.tnic>
 <9232AF8E-87A3-40B2-852A-D07889F9E1B4@gmail.com>
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On Thu, Aug 13, 2015 at 06:04:54PM +0800, yalin wang wrote:
> we store type into one fix register, for example r12 ,
> then in fix up code, we can know the exception is caused by copy_from
> copy_to or copy_in user function by check r12 value(0 , 1 ,2 value), then if 
> it is copy_from, we only allow read fault, if the exception is write fault, panic() .
> 
> the same rules also apply to copy_to / copy_in function .
> 
> is it possible to change it like this ?

... and we'll do all that jumping through hoops to fix what actual,
real-life problem exactly?

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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