* Roland McGrath <[EMAIL PROTECTED]> wrote: > > Jan Beulich just posted a patch to do just this - relocate the > > vdso's ELF header. If that's all that's really required to keep > > COMPAT_VDSO viable under PARAVIRT, then it seems like the way to go. > > I found > http://marc.theaimsgroup.com/?l=xen-devel&m=117309332600075&w=2 and > that must be the one you meant. The ELF-grokking form of that is > exactly what I had in mind. The "find relocs with cmp" scheme is > pretty silly, but also works fine. It trades tweaky ELF knowledge > with tweaky fragile build methods, but it's all about the same to me.
this looks good to me too in principle, the #else branch. But the actual implementation will have to be redone quite a bit i fear. Some details: relocate_vdso() needs some major coding style cleanups. This bit: -# define VDSO_PRELINK VDSO_HIGH_BASE +# ifndef CONFIG_XEN +# define VDSO_PRELINK VDSO_HIGH_BASE +# else +# define VDSO_PRELINK (0UL - FIX_VDSO * PAGE_SIZE) +# endif should be Kconfig driven, not #ifdef driven, due to cleanliness and also because lguest wants to have the same thing. Plus: +#if defined(CONFIG_XEN) && defined(CONFIG_COMPAT_VDSO) i'd just make this depend on CONFIG_COMPAT_VDSO, always. Same here: +#if defined(CONFIG_XEN) && defined(CONFIG_COMPAT_VDSO) +static void __init relocate_vdso just make this driven in the normal CONFIG_COMPAT_VDSO case too - even though we 'prelink' the VDSO to the usual address - we better run through the same code all the time and reduce the number of variants as much as possible. furthermore, there should be a paravirt_ops method to chose the relocation address, unless i'm missing something. On the native kernel that address will default to 0xffffe000. (if CONFIG_COMPAT_VDSO is selected) this way there will only be two main variants to worry about: compat and modern (which is the current status quo anyway), instead of 4-5 variants. Ingo - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/