PM: Lock PM device list mutex in show_dev_hash()
Lock the PM device list mutex using device_pm_lock() and
device_pm_unlock() around the list iteration in show_dev_hash().
show_dev_hash() was reverse iterating dpm_list without first locking the
mutex that the functions in drivers/base/power/main.c lock. I assume
this was unintentional since there is no comment suggesting why the lock
might not be necessary.
Signed-off-by: James Hogan <james@albanarts.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/drivers/base/power/trace.c b/drivers/base/power/trace.c
index 0a1a2c4..17e24e3 100644
--- a/drivers/base/power/trace.c
+++ b/drivers/base/power/trace.c
@@ -188,8 +188,10 @@
static int show_dev_hash(unsigned int value)
{
int match = 0;
- struct list_head *entry = dpm_list.prev;
+ struct list_head *entry;
+ device_pm_lock();
+ entry = dpm_list.prev;
while (entry != &dpm_list) {
struct device * dev = to_device(entry);
unsigned int hash = hash_string(DEVSEED, dev_name(dev), DEVHASH);
@@ -199,6 +201,7 @@
}
entry = entry->prev;
}
+ device_pm_unlock();
return match;
}