Re: RELEASE BLOCKER: Linux doesn't follow x86/x86-64 ABI wrt direction flag

Michael Matz
2008-03-05T21:44:41Z

Hi,

On Wed, 5 Mar 2008, Joe Buck wrote:

>
>
> On Wed, 5 Mar 2008, Jan Hubicka wrote:
> > > Linux kernel is disabling red zone and use kernel code model, yet the
> > > ABI is not going to be adjusted for that.
> > >
> > > This is resonably easy to fix on kernel side in signal handling, or by
> > > removing std usage completely
>
> On Wed, Mar 05, 2008 at 10:02:07PM +0100, Michael Matz wrote:
> > That is true. But it requires updating the kernel to a fixed one if you
> > want to run your programs compiled by 4.3 :-/ Not something we'd like to
> > demand.
>
> I changed the title just for emphasis.
>
> I think that we can't ship 4.3.0 if signal handlers on x86/x86_64
> platforms for both Linux and BSD systems will mysteriously (to the users)
> fail, and it doesn't matter whose fault it is.

FWIW I don't think it's a release blocker for 4.3.0. The error is arcane
and happens seldomly if at all. And only on unfixed kernels. A program
needs to do std explicitely, which most don't do _and_ get hit by a signal
while begin in a std region. This happens so seldom that it didn't occur
in building the next openSuSE 11.0, and it continually builds packages
with 4.3 since months.

It should be worked around in 4.3.1 if at all.

Ciao,
Michael.