From: Fabio Estevam festevam@denx.de
stable inclusion from stable-v5.10.94 commit d71fca5d0167f250a351f2fe9f9f0659aaa41a69 bugzilla: https://gitee.com/openeuler/kernel/issues/I531X9
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 530792efa6cb86f5612ff093333fec735793b582 ]
Since commit cffa4b2122f5 ("regmap: debugfs: Fix a memory leak when calling regmap_attach_dev"), the following debugfs error is seen on i.MX boards:
debugfs: Directory 'dummy-iomuxc-gpr@20e0000' with parent 'regmap' already present!
In the attempt to fix the memory leak, the above commit added a NULL check for map->debugfs_name. For the first debufs entry, map->debugfs_name is NULL and then the new name is allocated via kasprintf().
For the second debugfs entry, map->debugfs_name() is no longer NULL, so it will keep using the old entry name and the duplicate name error is seen.
Quoting Mark Brown:
"That means that if the device gets freed we'll end up with the old debugfs file hanging around pointing at nothing. ... To be more explicit this means we need a call to regmap_debugfs_exit() which will clean up all the existing debugfs stuff before we loose references to it."
Call regmap_debugfs_exit() prior to regmap_debugfs_init() to fix the problem.
Tested on i.MX6Q and i.MX6SX boards.
Fixes: cffa4b2122f5 ("regmap: debugfs: Fix a memory leak when calling regmap_attach_dev") Suggested-by: Mark Brown broonie@kernel.org Signed-off-by: Fabio Estevam festevam@denx.de Link: https://lore.kernel.org/r/20220107163307.335404-1-festevam@gmail.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- drivers/base/regmap/regmap.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 456a1787e18d..55a30afc14a0 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -620,6 +620,7 @@ int regmap_attach_dev(struct device *dev, struct regmap *map, if (ret) return ret;
+ regmap_debugfs_exit(map); regmap_debugfs_init(map);
/* Add a devres resource for dev_get_regmap() */