Re: [x86, vdso] BUG: unable to handle kernel paging request at d34bd000

From: H. Peter Anvin
Date: Mon Mar 10 2014 - 13:48:43 EST


On 03/10/2014 10:46 AM, Andy Lutomirski wrote:
>>
>> Yes, we'd have to switch the vdso to using syscall access. Doing that
>> from inside a system call is... "interesting".
>
> It's a little less interesting if it just involves changing a vma.
> It's still tricky, though -- would each struct mm have its own struct
> file for the vvar page? Can this be done with some
> vm_operations_struct magic? There are possible races, too, though --
> another thread could access the thing concurrently with a syscall.
>

Hint: where is your RIP? Where is the RIP of other processes?

-hpa

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