[PATCH 2/8] PM / domains: Protect reading loop over list of domains

Krzysztof Kozlowski
2017-06-09T16:09:16Z

The pm_genpd_present() iterates over list of domains so grabbing a
gpd_list_lock mutex is necessary before calling it. Otherwise we could
end up in iterating over and modifying the list at the same time.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
drivers/base/power/domain.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 2e8d0f423507..2a6935dc0164 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1099,8 +1099,13 @@ static void genpd_syscore_switch(struct device *dev, bool suspend)
struct generic_pm_domain *genpd;

genpd = dev_to_genpd(dev);
- if (!pm_genpd_present(genpd))
+
+ mutex_lock(&gpd_list_lock);
+ if (!pm_genpd_present(genpd)) {
+ mutex_unlock(&gpd_list_lock);
return;
+ }
+ mutex_unlock(&gpd_list_lock);

if (suspend) {
genpd->suspended_count++;
--
2.9.3