[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <39147ed6f3ece627ee0c18d90e00b37e636553f2.camel@gmail.com>
Date: Wed, 06 Mar 2024 10:21:02 +0100
From: Nuno Sá <noname.nuno@...il.com>
To: Herve Codina <herve.codina@...tlin.com>, Greg Kroah-Hartman
<gregkh@...uxfoundation.org>, "Rafael J. Wysocki" <rafael@...nel.org>, Rob
Herring <robh+dt@...nel.org>, Frank Rowand <frowand.list@...il.com>,
Saravana Kannan <saravanak@...gle.com>
Cc: Lizhi Hou <lizhi.hou@....com>, Max Zhen <max.zhen@....com>, Sonal Santan
<sonal.santan@....com>, Stefano Stabellini <stefano.stabellini@...inx.com>,
Jonathan Cameron <Jonathan.Cameron@...wei.com>,
linux-kernel@...r.kernel.org, devicetree@...r.kernel.org, Allan Nielsen
<allan.nielsen@...rochip.com>, Horatiu Vultur
<horatiu.vultur@...rochip.com>, Steen Hegelund
<steen.hegelund@...rochip.com>, Luca Ceresoli <luca.ceresoli@...tlin.com>,
Nuno Sa <nuno.sa@...log.com>, Thomas Petazzoni
<thomas.petazzoni@...tlin.com>, stable@...r.kernel.org
Subject: Re: [PATCH v4 2/2] of: dynamic: Synchronize of_changeset_destroy()
with the devlink removals
On Wed, 2024-03-06 at 09:50 +0100, Herve Codina wrote:
> In the following sequence:
> 1) of_platform_depopulate()
> 2) of_overlay_remove()
>
> During the step 1, devices are destroyed and devlinks are removed.
> During the step 2, OF nodes are destroyed but
> __of_changeset_entry_destroy() can raise warnings related to missing
> of_node_put():
> ERROR: memory leak, expected refcount 1 instead of 2 ...
>
> Indeed, during the devlink removals performed at step 1, the removal
> itself releasing the device (and the attached of_node) is done by a job
> queued in a workqueue and so, it is done asynchronously with respect to
> function calls.
> When the warning is present, of_node_put() will be called but wrongly
> too late from the workqueue job.
>
> In order to be sure that any ongoing devlink removals are done before
> the of_node destruction, synchronize the of_changeset_destroy() with the
> devlink removals.
>
> Fixes: 80dd33cf72d1 ("drivers: base: Fix device link removal")
> Cc: stable@...r.kernel.org
> Signed-off-by: Herve Codina <herve.codina@...tlin.com>
> ---
LGTM
Reviewed-by: Nuno Sa <nuno.sa@...log.com>
> drivers/of/dynamic.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
> index 3bf27052832f..169e2a9ae22f 100644
> --- a/drivers/of/dynamic.c
> +++ b/drivers/of/dynamic.c
> @@ -9,6 +9,7 @@
>
> #define pr_fmt(fmt) "OF: " fmt
>
> +#include <linux/device.h>
> #include <linux/of.h>
> #include <linux/spinlock.h>
> #include <linux/slab.h>
> @@ -667,6 +668,12 @@ void of_changeset_destroy(struct of_changeset *ocs)
> {
> struct of_changeset_entry *ce, *cen;
>
> + /*
> + * Wait for any ongoing device link removals before destroying some
> of
> + * nodes.
> + */
> + device_link_wait_removal();
> +
> list_for_each_entry_safe_reverse(ce, cen, &ocs->entries, node)
> __of_changeset_entry_destroy(ce);
> }
Powered by blists - more mailing lists