Messages in this thread | | | Date | Mon, 10 Mar 2014 16:02:32 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [x86, vdso] BUG: unable to handle kernel paging request at d34bd000 |
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On 03/10/2014 02:39 PM, Linus Torvalds wrote: > On Mon, Mar 10, 2014 at 2:25 PM, <stefani@seibold.net> wrote: >> >> This was discovered by me. > > Sorry for the misattribution. > >> But this is not a real solution, at least when vcpu function support >> will be added, then the code size will exceed the page size. Reserving >> two pages for the VDSO is a good option. > > Quite frankly, there is no way in hell I will take a patch like that > for 3.14 any more, and I would argue against it for stable. > > Now, if this problem never happens with current kernels (because it's > purely due to the patch in -tip), then I don't much care. >
It is only for tip:x86/vdso, so current kernels don't matter.
There is going to be 32-bit use in the embedded sector for a long time to come, I suspect/fear, so I'm not opposed to giving it a bit of a performance boost as long as it isn't too invasive.
I think Andy's commentary applies, though :)
> IMO this is dumb. I can think of two sensible solutions: > > 1. Get rid of compat vdso and replace it with no vdso at all. This is > compatible with everything and requires almost no code > > 2. Fix compat vdso. Give it as much space as needed, make the address > dynamic, and relocate it to the right place.
-hpa
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