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

From: Michael Matz
Date: Wed Mar 05 2008 - 17:51:31 EST


Hi,

On Wed, 5 Mar 2008, David Miller wrote:

> I will be sure to hunt you down to help debug when someone reports that
> once every few weeks their multi-day simulation gives incorrect results
> :-)

Give them a LD_PRELOADable DSO that intercepts signal() and sig_action(),
installing a trampoline that first does "cld" and then jumps to the real
handler. That ought to be a quick test if it's this or a different issue.
A hack, yes, but well... :)

> This is one of those cases where the bug is going to be a huge issue to
> people who actually hit it, and since we know about the problem,
> knowingly shipping something in that state is unforgivable.

Many bugs are a big issue to people who actually hit them, and we had (and
probably still have) far nastier corner case miscompilations here and
there and nevertheless released. It never was the end of the world :)

Let it be a data point that nobody noticed the problem which existed in
trunk since more than a year (since 2006-12-06 to be precise).


Ciao,
Michael.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/