Messages in this thread | | | Date | Thu, 13 Dec 2012 16:09:48 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] Add VDSO time function support for x86 32-bit kernel |
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On 12/13/2012 11:32 AM, Andy Lutomirski wrote: > > x32's vdso cheats -- x32 code can see high addresses just fine. The > toolchain just makes it difficult. > > Your best bet is probably to just map the vvar page twice -- once at > the same address as native 32-bit mode (but only for compat tasks) > would use and once in the usual fixmap location. You can't use the > fixmap for the compat mapping, though, since it would be a *user* > address. > > For HPET support, you'd have to have special support. I'd say to skip > it for compat mode. >
Whatever data you need you can just map it into the vdso range. There really shouldn't be anything special about that at all.
The fixmap stuff is an x86-64 legacy that you don't have to worry about, obviously.
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
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