Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [PATCH for mm] Remove iBCS support | Date | Wed, 23 Jan 2008 15:24:34 +0100 |
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On Wednesday 23 January 2008 15:12:22 Karl Kiniger wrote: > On Wed 080123, Andi Kleen wrote: > > Karl Kiniger <karl.kiniger@med.ge.com> writes: > > > FYI, > > > > > > on http://www.feise.com/~jfeise/Downloads/linux-abi/ > > > > > > a patch named linux-abi-2.6.22.3_3.diff.bz2 can be found. > > > > So just add a reversed version of my binfmt_elf patch to that. > > If people need to apply a patch anyways it doesn't make much > > difference if it has a few more hunks. > > it will force to recompile. The latest version of linux-abi on > SourceForge is named ibcs-3_4.tgz and IIRC it can be built > as an external module w/o kernel recompile.
Ok I wasn't aware of that earlier.
Does it really work on a recent kernel (as in .23 or .24-rc)? I have my doubts especially since the default_ldt is gone it will be probably difficult for an external module to implement the lcall7 and lcall27 entry points.
<reads code> Ok it seems to load its own GDT and IDT. With that lcall might still work. It's unclear how it works on SMP and how TLS rewriting still works. But you don't really expect us to support any kernel modules who do such hacks, do you? This thing is likely pure race country anyways. I hope nobody uses it in production.
Anyways what it could still do is to register an own copy or wrapper of the ELF loader that is registered before the normal binfmt_elf and then checks for its own flavour of ELF and handles that and passes all other binaries on.
I stand by my earlier point that it doesn't make sense to have all Linux kernels always execute these strcmps.
-Andi
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