lkml.org 
[lkml]   [2014]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [x86, vdso] BUG: unable to handle kernel paging request at d34bd000
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



\
 
 \ /
  Last update: 2014-03-11 00:41    [W:0.112 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site