Re: any remaining for-6.0 issues?

[Cornelia Huck]

On Sun, 18 Apr 2021 11:38:09 +0100
Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> wrote:

> On 17/04/2021 20:46, Peter Maydell wrote:
> 
> >> On 14/04/2021 13:48, Thomas Huth wrote:  
> >>> I've seen some intermittend, non-reproducible crashes with usermode QEMU 
> >>> in some of
> >>> my CI runs, e.g.:
> >>>
> >>> https://gitlab.com/thuth/qemu/-/jobs/1178256498#L3876
> >>>
> >>> https://gitlab.com/thuth/qemu/-/jobs/1146276208#L3241
> >>>
> >>> This was only with ccache enabled, so I thought that it might be related 
> >>> to my
> >>> work-in-progress ccache patches...
> >>>
> >>> ... but now Cornelia reported that she has seen such a crash in one of 
> >>> her branches,
> >>> too (which is completely unrelated to my ccache patches):
> >>>
> >>> https://gitlab.com/cohuck/qemu/-/jobs/1178860927#L3867
> >>>
> >>> That makes me wonder whether we currently have a real problem with 
> >>> user-mode in the
> >>> master branch? Did anybody else see such problems?  
> >>
> >> I've definitely seen the same issue as Cornelia in my Gitlab CI builds for 
> >> the ESP
> >> security fixes (first version of which appeared just before rc0). The user 
> >> builds
> >> always fail on "run-tcg-tests-s390x-linux-user" for me.  
> > 
> > Do we have any better understanding yet of the cause here?
> > (I ask because I think we're going to need an rc4 for other reasons,
> > so if there's a ready-to-go fix then we could consider it.)  
> 
> I don't think so. I tried a run with a possible candidate patch reverted (see 
> https://lists.gnu.org/archive/html/qemu-devel/2021-04/msg02345.html) but 
> Cornelia's 
> response indicates that the result is still inconclusive :(

That patch seems to be our best candidate so far, but the intermittent
nature of the failures make it hard to pin down... I don't see anything
obviously wrong with the patch, maybe some linux-user experts have a
better idea?