Re: Compat 32-bit syscall entry from 64-bit task!?

From: H. Peter Anvin
Date: Wed Jan 18 2012 - 21:19:46 EST


On 01/18/2012 05:45 PM, Indan Zupancic wrote:
>
> For security reasons it should be impossible for userspace to set those bits
> themselves, otherwise the tracer can be easily fooled on an old kernel. That
> seems to be the case for the higher bits of eflags, so eflags would work. And
> the current code checks cs, also checking eflags would be very easy to add.
>

I think this goes without saying, and isn't an issue for the options
currently on the table (including regset).

-phpa


--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

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