linux-kernel - Re: [PATCH v2 07/22] drm/msm: Do rpm get sooner in the submit path

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20201216052248.qi6fbo2dh6shw4rt@vireshk-i7>
Date:   Wed, 16 Dec 2020 10:52:48 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Rob Clark <robdclark@...il.com>
Cc:     Daniel Vetter <daniel@...ll.ch>,
        dri-devel <dri-devel@...ts.freedesktop.org>,
        Rob Clark <robdclark@...omium.org>,
        Sean Paul <sean@...rly.run>, David Airlie <airlied@...ux.ie>,
        "open list:DRM DRIVER FOR MSM ADRENO GPU" 
        <linux-arm-msm@...r.kernel.org>,
        "open list:DRM DRIVER FOR MSM ADRENO GPU" 
        <freedreno@...ts.freedesktop.org>,
        open list <linux-kernel@...r.kernel.org>,
        "Menon, Nishanth" <nm@...com>
Subject: Re: [PATCH v2 07/22] drm/msm: Do rpm get sooner in the submit path

On 07-12-20, 11:46, Viresh Kumar wrote:
> On 19-11-20, 11:35, Viresh Kumar wrote:
> > On 18-11-20, 08:53, Rob Clark wrote:
> > > On Tue, Nov 17, 2020 at 9:28 PM Viresh Kumar <viresh.kumar@...aro.org> wrote:
> > > >
> > > > On 17-11-20, 09:02, Rob Clark wrote:
> > > > > With that on top of the previous patch,
> > > >
> > > > Don't you still have this ? Which fixed the lockdep in the remove path.
> > > >
> > > > https://lore.kernel.org/lkml/20201022080644.2ck4okrxygmkuatn@vireshk-i7/
> > > >
> > > > To make it clear you need these patches to fix the OPP stuff:
> > > >
> > > > //From 5.10-rc3 (the one from the above link).
> > > > commit e0df59de670b ("opp: Reduce the size of critical section in _opp_table_kref_release()")
> > 
> > This fixes debugfs stuff while the OPP table is removed.
> > 
> > > > //Below two from linux-next
> > > > commit ef43f01ac069 ("opp: Always add entries in dev_list with opp_table->lock held")
> > > > commit 27c09484dd3d ("opp: Allocate the OPP table outside of opp_table_lock")
> > 
> > This fixes debugfs stuff while the OPP table is added.
> > 
> > > > This matches the diff I gave you earlier.
> > > >
> > > 
> > > no, I did not have all three, only "opp: Allocate the OPP table
> > > outside of opp_table_lock" plus the fixup.  But with all three:
> > 
> > And looking at the lockdep you gave now, it looks like we have a
> > problem with OPP table's internal lock (opp_table->lock) as well apart
> > from the global opp_table_lock.
> > 
> > I wish there was a way for me to reproduce the lockdep :(
> > 
> > I know this is exhausting for both of us and I really want to be over
> > with it as soon as possible, this really should be the last patch
> > here, please try this along with other two. This fixes the debugfs
> > thing while the OPPs in the OPP table are removed (they are already
> > added without a lock around debugfs stuff).
> > 
> > AFAIU, there is no further debugfs stuff that happens from within the
> > locks and so this really should be the last patch unless I missed
> > something.
> 
> Rob, were you able to test this patch ?

FWIW, this patch and everything else I had is merged into Linus's
master. You can test 5.11-rc1 to see if you still see a lockdep or
not.

-- 
viresh