From: Hsin-Yi Wang <hsinyi@chromium.org>
Date: Tue, 5 Jul 2022 17:16:49 +0000 (+0800)
Subject: PM: domains: Ensure genpd_debugfs_dir exists before remove
X-Git-Tag: v5.15.73~1592
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=764b8892d7da9ea18544e1bd8c15cfe10815f409;p=platform%2Fkernel%2Flinux-rpi.git

PM: domains: Ensure genpd_debugfs_dir exists before remove

[ Upstream commit 37101d3c719386040ded735a5ec06974f1d94d1f ]

Both genpd_debug_add() and genpd_debug_remove() may be called
indirectly by other drivers while genpd_debugfs_dir is not yet
set. For example, drivers can call pm_genpd_init() in probe or
pm_genpd_init() in probe fail/cleanup path:

pm_genpd_init()
 --> genpd_debug_add()

pm_genpd_remove()
 --> genpd_remove()
   --> genpd_debug_remove()

At this time, genpd_debug_init() may not yet be called.

genpd_debug_add() checks that if genpd_debugfs_dir is NULL, it
will return directly. Make sure this is also checked
in pm_genpd_remove(), otherwise components under debugfs root
which has the same name as other components under pm_genpd may
be accidentally removed, since NULL represents debugfs root.

Fixes: 718072ceb211 ("PM: domains: create debugfs nodes when adding power domains")
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 0f2e42f36851..7f3d21e6fdfb 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -219,6 +219,9 @@ static void genpd_debug_remove(struct generic_pm_domain *genpd)
 {
 	struct dentry *d;
 
+	if (!genpd_debugfs_dir)
+		return;
+
 	d = debugfs_lookup(genpd->name, genpd_debugfs_dir);
 	debugfs_remove(d);
 }