Re: [x86] copy_from{to}_user question

From: Borislav Petkov
Date: Thu Aug 13 2015 - 12:43:03 EST


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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