On Jan 30, 1:03 am, François Bissey <f.r.bis...@massey.ac.nz> wrote: > Hi Bill, > > Let me try to clarify a bit. > > On Sat, 30 Jan 2010 12:18:54 Bill Hart wrote: > > > All of those object files seem to come from assembly code assembled by > > yasm. I actually don't understand the bug report though. So I am not > > sure what needs fixing. I don't know of any systems that these files > > don't work on. Besides that, the only architectures they get used on > > are x86_64! > > Do you mean x86/x86_64, I got the report from an x86 only machine.
Yes, sorry, that was a typo on my part. > > > > > Is the problem that the sections are writable? What sort of section > > should be used? Perhaps yasm has an option to output sections of that > > kind. > > > Regarding your question about how an assembler is chosen, yasm is only > > used on x86/x86_64. The file /mpn/Makeasm.am defines the build rules > > which distinguish files to be built with yasm and those to be built > > with gas or gcc. > > It is a bit more subtle than that, it should work most of the time. The main > case where things could go south is if you have a hardened system with > the NX bit turned on - my guess. > It is a QA issue meaning that actual side effects are hard to predict > depending > on what is actually done. The check just points out to "bad practise". I see. Well I added the recommended defines to one of the yasm assembler files and that didn't cause it to bomb out, so assuming this has no performance side effects, I guess it would be possible to write a script to update all the assembler files in MPIR (there's hundreds of them, so you don't want to do it by hand). > > I guess I gave you too much info in one go. A lot of stuff is explained there > with what kind of steps that can be taken to get rid of > them:http://hardened.gentoo.org/gnu-stack.xml > > You inherited that stuff from gmp, it is a known issue there as well. The > problem is you have an enormous amount of assembler files so some systematic > approach is needed. By the way > > My comment about yasm is that the fix is also different if you use yasm > compared > to other assembler. In Gentoo gmp has a quite ugly patch that get rid of > all the problem in one go - on linux only - but wouldn't work with yasm. > I can imagine something like that for the gas files. There aren't so many yasm files in total, perhaps 50 or so. We could give you svn access if you wanted to work on doing this in MPIR. We would only accept the patch if there were no performance degradations however. It's very odd to me that assembly code needs to be rewritten to support this hardware feature. It's certainly something I've never heard about before. Bill. -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
