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pageexec on via c7

PostPosted: Sat Feb 02, 2008 8:44 am
by yiannis
Hello,

I am setting up a new pc based on via's c7 32bit processor which has the nx bit enabled(checked through cat /proc/cpuinfo). Is it possible for this to use pageexec? I have read that it is only enabled on 64bit platforms as they are(as it seems were) the only having the nx bit. If it is not possible, are there plans on supporting it?

Best regards

Yiannis

Re: pageexec on via c7

PostPosted: Sat Feb 02, 2008 10:28 am
by Alexei.Sheplyakov
yiannis wrote:I am setting up a new pc based on via's c7 32bit processor which has the nx
bit enabled(checked through cat /proc/cpuinfo). Is it possible for this to use
pageexec? I have read that it is only enabled on 64bit platforms as they
are(as it seems were) the only having the nx bit.


AFAIK PaX makes use of "nx bit" even when running in 32-bit mode, as long
as you have PAE enabled (CONFIG_HIGHMEM64G=y). That said, I've checked this
only for AMD and Intel CPUs. So, build your kernel with CONFIG_HIGHMEM64G=y,
and use paxtest to check if pageexec actually works.

Good luck,

Alexei

Re: pageexec on via c7

PostPosted: Wed Feb 06, 2008 3:02 pm
by Thrawn
I also think so.
Pax team - are we right? Does Pax use the nx bit if pae is enabled???

Re: pageexec on via c7

PostPosted: Wed Feb 06, 2008 4:52 pm
by PaX Team
Thrawn wrote:I also think so.
Pax team - are we right? Does Pax use the nx bit if pae is enabled???
yes, there's even a hint at it in the .config help ;-).