From: Frank Rowand <frowand.list@gmail.com>
To: Rob Herring <robh+dt@kernel.org>,
Pantelis Antoniou <pantelis.antoniou@konsulko.com>,
David Airlie <airlied@linux.ie>, Jyri Sarha <jsarha@ti.com>
Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
Mark Rutland <mark.rutland@arm.com>,
Tomi Valkeinen <tomi.valkeinen@ti.com>,
dri-devel@lists.freedesktop.org
Subject: Re: [PATCH v2 09/12] of: overlay: avoid race condition between applying multiple overlays
Date: Mon, 16 Oct 2017 19:04:28 -0700 [thread overview]
Message-ID: <59E5652C.3020206@gmail.com> (raw)
In-Reply-To: <1508203074-26917-10-git-send-email-frowand.list@gmail.com>
On 10/16/17 18:17, frowand.list@gmail.com wrote:
> From: Frank Rowand <frank.rowand@sony.com>
>
> The process of applying an overlay consists of:
> - unflatten an overlay FDT (flattened device tree) into an
> EDT (expanded device tree)
> - fixup the phandle values in the overlay EDT to fit in a
> range above the phandle values in the live device tree
> - create the overlay changeset to reflect the contents of
> the overlay EDT
> - apply the overlay changeset, to modify the live device tree,
> potentially changing the maximum phandle value in the live
> device tree
>
> There is currently no protection against two overlay applies
> concurrently determining what range of phandle values are in use
> in the live device tree, and subsequently changing that range.
> Add a mutex to prevent multiple overlay applies from occurring
> simultaneously.
>
> Move of_resolve_phandles() into of_overlay_apply() so that it does not
> have to be duplicated by each caller of of_overlay_apply().
>
> The test in of_resolve_phandles() that the overlay tree is detached is
> temporarily disabled so that old style overlay unittests do not fail.
>
> Signed-off-by: Frank Rowand <frank.rowand@sony.com>
> ---
Brown paper bag time.
Changes from version 1:
squash "[PATCH] of: overlay: move resolve phandles into of_overlay_apply()"
into "[PATCH 09/12] of: overlay: avoid race condition between applying multiple overlays"
> drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c | 6 ------
> drivers/of/of_private.h | 12 +++++++++++
> drivers/of/overlay.c | 32 ++++++++++++++++++++++++++++
> drivers/of/resolver.c | 7 ++++++
> drivers/of/unittest.c | 22 +++++++++++++------
> include/linux/of.h | 3 ---
> 6 files changed, 67 insertions(+), 15 deletions(-)
>
< snip >
next prev parent reply other threads:[~2017-10-17 2:04 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-17 1:17 [PATCH v2 00/12] of: overlay: clean up device tree overlay code frowand.list-Re5JQEeQqe8AvxtiuMwx3w
2017-10-17 1:17 ` [PATCH v2 01/12] of: overlay.c: Remove comments that state the obvious, to reduce clutter frowand.list
2017-10-17 1:17 ` [PATCH v2 02/12] of: overlay.c: Convert comparisons to zero or NULL to logical expressions frowand.list
2017-10-17 1:17 ` [PATCH v2 03/12] of: overlay: rename identifiers to more reflect what they do frowand.list
2017-10-17 14:38 ` Rob Herring
[not found] ` <CAL_JsqJDZFznVm0TvCePHq_J-FhNyEXoLEue_ZRhOm6LyXC5kQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-10-17 18:53 ` Frank Rowand
2017-10-17 1:17 ` [PATCH v2 04/12] of: overlay: rename identifiers in dup_and_fixup_symbol_prop() frowand.list
2017-10-17 1:17 ` [PATCH v2 05/12] of: overlay: minor restructuring frowand.list
2017-10-17 1:17 ` [PATCH v2 06/12] of: overlay: detect cases where device tree may become corrupt frowand.list
2017-10-17 1:17 ` [PATCH v2 07/12] of: overlay: expand check of whether overlay changeset can be removed frowand.list
2017-10-17 1:17 ` [PATCH v2 08/12] of: overlay: loosen overly strict phandle clash check frowand.list
2017-10-17 1:17 ` [PATCH v2 09/12] of: overlay: avoid race condition between applying multiple overlays frowand.list
2017-10-17 2:04 ` Frank Rowand [this message]
2017-10-17 1:17 ` [PATCH v2 10/12] of: overlay: simplify applying symbols from an overlay frowand.list
[not found] ` <1508203074-26917-1-git-send-email-frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2017-10-17 1:17 ` [PATCH v2 11/12] of: overlay: remove a dependency on device node full_name frowand.list-Re5JQEeQqe8AvxtiuMwx3w
2017-10-17 1:17 ` [PATCH v2 12/12] of: overlay: remove unneeded check for NULL kbasename() frowand.list
2017-10-17 2:04 ` [PATCH v2 00/12] of: overlay: clean up device tree overlay code Frank Rowand
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