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author | Herve Codina <herve.codina@bootlin.com> | 2024-03-25 18:21:26 +0300 |
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committer | Rob Herring <robh@kernel.org> | 2024-03-26 23:32:32 +0300 |
commit | 8917e7385346bd6584890ed362985c219fe6ae84 (patch) | |
tree | b71098c7cb08f7269893ee7aedf2539b0ad83c64 /drivers | |
parent | 0462c56c290a99a7f03e817ae5b843116dfb575c (diff) | |
download | linux-8917e7385346bd6584890ed362985c219fe6ae84.tar.xz |
of: dynamic: Synchronize of_changeset_destroy() with the devlink removals
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@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Saravana Kannan <saravanak@google.com>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240325152140.198219-3-herve.codina@bootlin.com
Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/of/dynamic.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index 3bf27052832f..4d57a4e34105 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 +668,17 @@ void of_changeset_destroy(struct of_changeset *ocs) { struct of_changeset_entry *ce, *cen; + /* + * When a device is deleted, the device links to/from it are also queued + * for deletion. Until these device links are freed, the devices + * themselves aren't freed. If the device being deleted is due to an + * overlay change, this device might be holding a reference to a device + * node that will be freed. So, wait until all already pending device + * links are deleted before freeing a device node. This ensures we don't + * free any device node that has a non-zero reference count. + */ + device_link_wait_removal(); + list_for_each_entry_safe_reverse(ce, cen, &ocs->entries, node) __of_changeset_entry_destroy(ce); } |