Re: compat ioctl32 for /dev/snapshot?

From: Pavel Machek
Date: Mon Jul 13 2009 - 16:21:32 EST


On Mon 2009-07-13 10:51:15, Michael Tokarev wrote:
> Arnd Bergmann wrote:
>> On Sunday 12 July 2009, Michael Tokarev wrote:
>>> As I mentioned in my first email, I'm not the right person to
>>> do the patch. But regardless, I spent about a day understanding
>>> this stuff (or trying to, anyway) - 100% useless day - and when
>>> I thought I have a patch someone else spoken up and said this
>>> way (compat_ioctl) is the wrong approach now. And sent another,
>>> also trivial patch, adding compat calls right to the proper
>>> place in kernel/power.c. Which (the patch) has been ignored
>>> too.
>>
>> I never got a reply from you saying whether or not the patch
>> I sent actually worked. If you or someone else can confirm it,
>> I'll resend with the fixes you mentioned.
>
> In order to (try to) check if it works or not, another userspace
> component has to be fixed to support 32/64 bit mode. It's uswsusp,
> which currently assumes swap space structures are all 32bits. So
> it isn't possible to immediately check if it works or not -- just
> ioctl(s) aren't enough. Complete fix (kernel+user space) requires
> both, fixing all remaining (yet unknown) issues in old and new
> code on the way.

Well, there seems to be single structure in s2disk; that does not seem
that hard to fix.

> For now, I think it's best to let Pavel or Rafael to decide what
> to do with all this.

I don't currently have easy access to 64bit machine, so I guess it is
up to someone else.

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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