On Wed, 19 Aug 2009 11:08:36 am James Bottomley wrote: > On Tue, 2009-08-18 at 18:31 -0700, Roland McGrath wrote: > > > Actually, I think we do; the module loader is a runtime linker, after > > > all. [...] > > > > Indeed you do. I've just read some of the parts of ld that normally > > address this issue for HPPA. They don't run for ld -r. So this is just > > another fine example of the lunacy of the ET_REL .ko madness that would be > > naturally avoided by a sensible tweaked ET_DYN scheme. > > Using ET_DYN would have made our life easier when trying to code the > kernel module loader as well. The basic problem is, of course, that > this is simple on an x86, so it didn't matter that much for the initial > implementation. It just becomes less simple on anything else. Actually, x86 was one of the archs which fucked us. Richard Henderson and I *had* this, but ld -shared without -fPIC helpfully tells you "you're doing it wrong" on x86-64. There were other issues, ISTR MIPS was a showstopper. Google finds the following summary I wrote when this stuff was fresher: http://lkml.org/lkml/2003/1/12/271 : While ET_DYN modules are a reasonably serious win for ia64 (and probably hppa) (ie. -300 lines or so), they're a minor win for alpha and ppc64 (-100 lines or so), and no real change for arm, i386, ppc, sparc, and sparc64. It's a lose for x86_64 (toolchain fixes, unless they want to use -fPIC for modules), mips and mips64 (major toolchain fixes, unless they want to use -fPIC for modules and stop using r28 for current inside modules). > > But that battle was > > lost way, way back in the long, long ago, so long ago they were probably > > even still making HPPA machines then. This isn't quite true; userspace should handle ET_DYN fine (at least, it was supposed to). So you could change any arch to use that, but it's a fair refactor if we leave some archs behind. If anyone's really interested, I can dig out the bits I have... > So that leaves us stuck with the current implementation and still > needing a solution for the duplicate section names? If this is not a "don't do that" bug, we could try hacking around it in parisc's module_arch_frob_sections? Rusty. -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
