On Oct 23 08:04, Ken Brown wrote:
> On 10/23/2014 7:31 AM, Jon TURNEY wrote:
> >On 20/10/2014 14:03, Ken Brown wrote:
> >>Or is there some other plausible explanation for "impossible" crashes?
> >>This can't just be a result of a gdb bug, because in at least one case
> >>the assertion can be shown to be valid by using printf instead of gdb.
> >>
> >>[*] By "impossible" I mean that examination of the relevant variables in
> >>gdb shows that the assertions are in fact true.  Two ongoing examples are
> >>
> >>    http://debbugs.gnu.org/cgi/bugreport.cgi?bug=18438
> >>    http://debbugs.gnu.org/cgi/bugreport.cgi?bug=18769
> >
> >As a suggestion, you might want to also take a careful look at how signal
> >delivery is implemented in cygwin on x86_64
> >
> >I had a vague idea that there was, at some time in the past, a fix made for
> >register corruption on x86_64 after a signal was handled, but I can't find it
> >now, so maybe I imagined it.
> 
> Is this what you're thinking of?
> 
>   https://cygwin.com/ml/cygwin-cvs/2014-q1/msg00020.html
> 
> >But if for e.g. the flags register was getting
> >corrupted when a signal interrupts the main thread, that could perhaps also
> >explain what is being seen.
> 
> Yes, flags register corruption is exactly what Eli suggested in the other
> bug report I cited.

The aforementioned patch was supposed to fix this problem and it is
definitely in the current 1.7.32 release...


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
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