Re: general protection fault in send_sigurg_to_task

From: J. Bruce Fields
Date: Wed Aug 15 2018 - 14:53:47 EST

On Wed, Aug 15, 2018 at 10:11:20AM +1000, Stephen Rothwell wrote:
> Hi Bruce,
> On Tue, 14 Aug 2018 13:50:20 -0700 Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
> >
> > On Tue, Aug 14, 2018 at 12:11 PM, J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote:
> > > On Mon, Aug 13, 2018 at 06:33:02AM -0700, syzbot wrote:
> > >> syzbot has found a reproducer for the following crash on:
> > >>
> > >> HEAD commit: 5ed5da74de9e Add linux-next specific files for 20180813
> > >> git tree: linux-next
> > >
> > > I fetched linux-next but don't have 5ed5da74de9e.
> >
> > +Stephen for the disappeared linux-next commit.
> That is just the HEAD commit on linux-next that day. If you fetched
> linux-next after I released next-20180814 yesterday, then it would have
> a different HEAD commit. If you check out the tag next-20180813, you
> will get the above HEAD commit.
> > On the dashboard link you can see that it also happened on a more
> > recent commit 4e8b38549b50459a22573d756dd1f4e1963c2a8d that I do see
> > now in linux-next.
> Which is just the HEAD commit of next-20180814.
> Linux-next is rebuilt every day based on Linus' tree of the day,
> followed by merging all the other branches, so its HEAD is different
> every day.

I new it was rebuilt every day, but for some reason I expected git to
fetch all new tags. But that's wrong, it just fetches whatever
branch(es) you request and then only tags that happen to reference stuff
on that branch; from git-fetch(1): "By default, any tag that points into
the histories being fetched is also fetched; the effect is to fetch tags
that point at branches that you are interested in. This default behavior
can be changed by using the --tags or --no-tags options or by
configuring remote.<name>.tagOpt. By using a refspec that fetches tags
explicitly, you can fetch tags that do not point into branches you are
interested in as well."

Sorry for the confusion!