[PATCH 01/10] PM / devfreq: strengthen check for freq_table

[Samuel Holland]

Since commit ea572f816032 ("PM / devfreq: Change return type of
devfreq_set_freq_table()"), all devfreq devices are expected to have a
valid freq_table. The devfreq core unconditionally dereferences
freq_table in the sysfs code and in get_freq_range().

Therefore, we need to ensure that freq_table is both non-null and
non-empty (length is > 0). If either check fails, replace the table
using set_freq_table() or return the error.

Signed-off-by: Samuel Holland <samuel at sholland.org>
---
 drivers/devfreq/devfreq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 28f3e0ba6cdd..7a8b022ba456 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -827,7 +827,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
 		goto err_dev;
 	}
 
-	if (!devfreq->profile->max_state && !devfreq->profile->freq_table) {
+	if (!devfreq->profile->max_state || !devfreq->profile->freq_table) {
 		mutex_unlock(&devfreq->lock);
 		err = set_freq_table(devfreq);
 		if (err < 0)
-- 
2.31.1