On 30 March 2010 04:18, Gonzalo Tornaria <[email protected]> wrote:
> On Mon, Mar 29, 2010 at 8:16 PM, Dr. David Kirkby
> <[email protected]> wrote:
>> I don't know how practical it is going to be for a Sage developer to change
>> the the source code of PARI, NTL and whatever else has this problem, to add
>> mprotect() where needed. I suspect that might be a bit difficult, and
>> perhaps slow the code.
>
> uh?
>
>> The reason I used that code was to check if executing the stack caused a
>> problem. As such, there was little point in me adding mprotect - it rather
>> defeated the object of the program.
>
> I presume that the software which wants to execute code in the stack
> makes the call the mprotect as needed.
>
> The proper code (with the call to mprotect) shows that executing the
> stack doesn't cause a problem, if you follow the posix standard [
> stack is not executable by default (only this wasn't enforced before
> cpus had NX support). ] YMMV, but you didn't post any evidence on the
> contrary.
>
> Did you try the fixed code (i.e. with call to mprotect) both in a
> non-SELinux and a SELinux enabled kernel to see if there actually is a
> difference? Running the code under strace(1) may help know what is
> going on. I'd guess that SELinux will return EACCESS in the mprotect
> call...
>
> Gonzalo

I'll try it later under Solaris. I have no access to SELinux myself.

Dave

-- 
To post to this group, send an email to [email protected]
To unsubscribe from this group, send an email to 
[email protected]
For more options, visit this group at http://groups.google.com/group/sage-devel
URL: http://www.sagemath.org

To unsubscribe from this group, send email to 
sage-devel+unsubscribegooglegroups.com or reply to this email with the words 
"REMOVE ME" as the subject.

Reply via email to