found kernel trace when using java

[wippie]

True, all of Via's C7 cpus are supporting the NX bit and it will probably be the same with their new Isaiah/Nano cpu.
The reason i did use the SEGMEXEC is because there used to be kernel problems when trying to use the NX bit with a non-64 bit system and, what i heard, the SEGMEXEC had a lower performance hit than an emulated nx bit in PAGEEXEC? But i guess that NX problem is fixed by now soo..
let's see if i remember how to enable the pageexec/nx.
* PAGEEXEC instead of SEGMEXEC under 'PAX features --> Non-executable pages -->'
* 'PAE Support' and '64 bit Memory and IO resources' under 'Processor type and features -->'
* passing 'noexec=on noexec32=on' as kernel parameters.
or am i missing something now?

This thread is a bit off topic now but..well..

[PaX Team]

The reason i did use the SEGMEXEC is because there used to be kernel problems when trying to use the NX bit with a non-64 bit system

what problems (besides the obvious performance impact)?

and, what i heard, the SEGMEXEC had a lower performance hit than an emulated nx bit in PAGEEXEC?

that's still true, but i'm talking about the hw NX bit for which i added support on i386 last year, the kernel config help was updated as well, check it out .

let's see if i remember how to enable the pageexec/nx.
* PAGEEXEC instead of SEGMEXEC under 'PAX features --> Non-executable pages -->'

yes, although enabling both will still work because at runtime PaX will select the better one on a given CPU (this matters if you're building a distro kernel where you can't predict on what CPUs the kernel will run on).

* 'PAE Support' and '64 bit Memory and IO resources' under 'Processor type and features -->'

the latter is automatically selected by PAE, so you only need PAE. you can get PAE with or without HIGHMEM64G support.

* passing 'noexec=on noexec32=on' as kernel parameters.

noexec32 is a 64 bit kernel feature, so it doesn't exist on i386, and under PaX/PAE noexec is removed for good as well, effectively it's always on if the CPU supports the NX bit.

[wippie]

.. for which i added support on i386 last year.

Well that was the problem.
Now they will run pageexec/pae/nx.

# dmesg
..
NX (Execute Disable) protection: active
..

-- happy --