From: Daniel Vetter <daniel@ffwll.ch>
To: Steven Price <steven.price@arm.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>,
Rob Herring <robh+dt@kernel.org>,
dri-devel@lists.freedesktop.org, stable@vger.kernel.org,
Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Subject: Re: [PATCH 2/8] drm/panfrost: Fix a race in panfrost_ioctl_madvise()
Date: Fri, 29 Nov 2019 21:07:33 +0100 [thread overview]
Message-ID: <20191129200733.GQ624164@phenom.ffwll.local> (raw)
In-Reply-To: <b159591d-1dd4-1ac7-e924-c02be1d8b1f3@arm.com>
On Fri, Nov 29, 2019 at 02:40:34PM +0000, Steven Price wrote:
> On 29/11/2019 14:33, Boris Brezillon wrote:
> > On Fri, 29 Nov 2019 14:24:48 +0000
> > Steven Price <steven.price@arm.com> wrote:
> >
> >> On 29/11/2019 13:59, Boris Brezillon wrote:
> >>> If 2 threads change the MADVISE property of the same BO in parallel we
> >>> might end up with an shmem->madv value that's inconsistent with the
> >>> presence of the BO in the shrinker list.
> >>
> >> I'm a bit worried from the point of view of user space sanity that you
> >> observed this - but clearly the kernel should be robust!
> >
> > It's not something I observed, just found the race by inspecting the
> > code, and I thought it was worth fixing it.
>
> Good! ;) Your cover letter referring to a "debug session" made me think
> you'd actually hit all these.
Time for some igt to make sure this is actually correct?
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
next prev parent reply other threads:[~2019-11-29 20:07 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20191129135908.2439529-1-boris.brezillon@collabora.com>
2019-11-29 13:59 ` [PATCH 1/8] drm/panfrost: Make panfrost_job_run() return an ERR_PTR() instead of NULL Boris Brezillon
2019-11-29 14:19 ` Steven Price
2019-11-29 14:31 ` Boris Brezillon
2019-11-29 14:38 ` Steven Price
2019-11-29 19:32 ` Boris Brezillon
2019-11-29 13:59 ` [PATCH 2/8] drm/panfrost: Fix a race in panfrost_ioctl_madvise() Boris Brezillon
2019-11-29 14:24 ` Steven Price
2019-11-29 14:33 ` Boris Brezillon
2019-11-29 14:40 ` Steven Price
2019-11-29 20:07 ` Daniel Vetter [this message]
2019-11-29 21:45 ` Boris Brezillon
2019-12-05 23:08 ` Rob Herring
2019-12-06 7:53 ` Boris Brezillon
2019-12-06 8:08 ` Boris Brezillon
2019-11-29 13:59 ` [PATCH 3/8] drm/panfrost: Fix a BO leak in panfrost_ioctl_mmap_bo() Boris Brezillon
2019-11-29 14:26 ` Steven Price
2019-11-29 13:59 ` [PATCH 4/8] drm/panfrost: Fix a race in panfrost_gem_free_object() Boris Brezillon
2019-11-29 14:28 ` Steven Price
2019-11-29 13:59 ` [PATCH 5/8] drm/panfrost: Open/close the perfcnt BO Boris Brezillon
2019-11-29 14:34 ` Steven Price
2019-11-29 13:59 ` [PATCH 6/8] drm/panfrost: Make sure imported/exported BOs are never purged Boris Brezillon
2019-11-29 14:14 ` Boris Brezillon
2019-11-29 14:45 ` Steven Price
2019-11-29 14:52 ` Boris Brezillon
2019-11-29 20:12 ` Daniel Vetter
2019-11-29 21:09 ` Boris Brezillon
2019-12-02 8:52 ` Daniel Vetter
2019-12-02 9:50 ` Boris Brezillon
2019-11-29 13:59 ` [PATCH 7/8] drm/panfrost: Add the panfrost_gem_mapping concept Boris Brezillon
2019-11-29 15:37 ` Steven Price
2019-11-29 20:14 ` Daniel Vetter
2019-11-29 21:36 ` Boris Brezillon
2019-12-02 8:55 ` Daniel Vetter
2019-12-02 9:13 ` Boris Brezillon
2019-12-02 9:44 ` Daniel Vetter
2019-12-04 11:41 ` Steven Price
2019-11-29 13:59 ` [PATCH 8/8] drm/panfrost: Make sure the shrinker does not reclaim referenced BOs Boris Brezillon
2019-11-29 15:48 ` Steven Price
2019-11-29 16:07 ` Boris Brezillon
2019-11-29 16:12 ` Steven Price
2019-12-02 12:50 ` Robin Murphy
2019-12-02 13:32 ` Boris Brezillon
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