On Sat, Nov 10, 2012 at 07:33:39AM +0000, Al Viro wrote: > I think I see what's going on there. It's PTREGSCALL blindly used for > clone wrapper in ia32entry.S. FWIW, it's wrong for all of those > suckers, anyway: > * fork/clone/vfork need to save extra registers, but don't need > to restore them; after unification we don't need pt_regs argument for any > of those - for fork/vfork it's useless, for clone it breaks things. > * execve doesn't need pt_regs argument; harmless, but useless. > * for sigaltstack() we simply need to get rid of stupid pt_regs > argument, along with the wrapper; current_pt_regs()->sp is all it needs. > * for sigreturn/rt_sigreturn we need to restore extra registers, > but we do *not* need to save them; just leave the space on stack. And > no need to pass pt_regs either - it'll be current_pt_regs() anyway. > * iopl() doesn't need to save/restore extras and it doesn't need > pt_regs argument - it's going to be current_pt_regs(). Alas, sigaltack() and iopl() do need a bit of a wrapper; they don't care about extras, but they wants ->sp and ->flags resp., which means needing to go through FIXUP_TOP_OF_STACK on amd64 ;-/ > On top of all that, there's an extra piece of crap - different order of > arguments for native and compat clone. ... and the same commit slightly buggers clone(2) on amd64 as well. Grr... Anyway, fixed and pushed; please, test for-next when it propagates, head should be at fae45353de587ae6a949dbf21ee06d5dd652248c -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
