Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu

[Stas Sergeev <stsp@list.ru>]

13.08.2015 20:00, Brian Gerst пишет:
> On Thu, Aug 13, 2015 at 11:43 AM, Andy Lutomirski <luto@amacapital.net> wrote:
>> On Thu, Aug 13, 2015 at 8:37 AM, Linus Torvalds
>> <torvalds@linux-foundation.org> wrote:
>>> On Tue, Aug 11, 2015 at 5:17 PM, Stas Sergeev <stsp@list.ru> wrote:
>>>> I realize this patch may be good to have in general, but
>>>> breaking userspace without a single warning is a bit
>>>> discouraging. Seems like the old "we don't break userspace"
>>>> rule have gone.
>>> That rule hasn't gone anywhere.
>>>
>>> Does a plain revert just fix everything? Because if so, that's the
>>> right thing to do, and we can just re-visit this later.
>>>
>>> I don't understand why Andy and Ingo are even discussing this. What
>>> the f*ck, guys?
>>>
>> I'm trying to fix it without reverting.  If that doesn't work, then we
>> revert.  Yesterday, I thought I had a reasonably clean fix, but it
>> turned out that it only solved half of the problem.
>>
>> If we revert, I think I need to check what will break due to the
>> revert.  I need to check at least Wine, and we'll have to do something
>> about all the selftests that will start failing.  I also need to check
>> CRIU, and IIRC CRIU has started using the new sigcontext SS in new
>> versions.
> I don't think Wine will be a problem, at least how it is currently set
> up.  16-bit support is only in the 32-bit build.  The 64-bit build
> only supports Win64 apps, and will call the 32-bit version (installed
> in parallel) to run 32 and 16-bit apps.
Is this also because of the lack of the proper 32/16bit support in
a 64bit kernels? If so, dosemu's work-arounds do not look like the
too bad thing compared to that. :)