Date:   Wed, 15 Feb 2023 14:49:22 +0100
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Heiko Carstens <hca@linux.ibm.com>
Cc:     Sumanth Korikkar <sumanthk@linux.ibm.com>, stable@vger.kernel.org,
        debian-s390@lists.debian.org, debian-kernel@lists.debian.org,
        svens@linux.ibm.com, gor@linux.ibm.com, Ulrich.Weigand@de.ibm.com,
        dipak.zope1@ibm.com
Subject: Re: [PATCH 0/1] s390: fix endless loop in do_signal
Message-ID: <Y+zi4mVr7JftBaXk@kroah.com>
References: <20230215120413.949348-1-sumanthk@linux.ibm.com>
 <Y+zcyBGnQ9BuLwFv@kroah.com>
 <Y+zfnNPp6SZ4lXxe@osiris>
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On Wed, Feb 15, 2023 at 02:35:24PM +0100, Heiko Carstens wrote:
> On Wed, Feb 15, 2023 at 02:23:20PM +0100, Greg KH wrote:
> > On Wed, Feb 15, 2023 at 01:04:12PM +0100, Sumanth Korikkar wrote:
> > > Hi,
> > > 
> > > This patch fixes the issue for s390  stable kernel starting  5.10.162.
> > > The issue was specifically seen after stable version 5.10.162:
> > > Following commits can trigger it:
> > > 1. stable commit id - 788d0824269b ("io_uring: import 5.15-stable
> > > io_uring") can trigger this problem.
> > > 2. upstream commit id - 75309018a24d ("s390: add support for
> > > TIF_NOTIFY_SIGNAL")
> > > 
> > > Problem:
> > > qemu and user processes could stall when TIF_NOTIFY_SIGNAL is set from
> > > io_uring work.
> > > 
> > > Affected users:
> > > The issue was first raised by the debian team, where the s390
> > > bullseye build systems are affected.
> > > 
> > > Upstream commit Id:
> > > * The attached patch has no upstream commit. However, the stable kernel
> > > 5.10.162+ uses upstream commit id - 75309018a24d ("s390: add support for
> > > TIF_NOTIFY_SIGNAL"), which would need this fix
> > > * Starting from v5.12, there are s390 generic entry commits 
> > > 56e62a737028 ("s390: convert to generic entry")  and its relevant fixes,
> > > which are recommended and should address these problems.
> > 
> > I'm sorry, but I do not understand.  What exact commits should be added
> > to the 5.10.y tree to resolve this?
> 
> Only the patch sent by Sumanth as reply to this cover letter should be
> added to the 5.10.y tree.
> 
> The problem that is addressed here is that commit 75309018a24d ("s390: add
> support for TIF_NOTIFY_SIGNAL") was backported to 5.10. This commit is
> broken, but nobody noticed upstream, since shortly after s390 converted to
> generic entry with commit 56e62a737028 ("s390: convert to generic entry"),
> which implicitly fixed that.

Ok, then please say that in the changelog text.

thanks,

greg k-h