regulator: core: Add locking to debugfs regulator_summary

Most functions that access the rdev lock the rdev mutex before looking
at data.  ...but not the code that implements the debugfs
regulator_summary.  It probably should though, so let's do it.

Note: this fixes no known issues.  The problem was found only by code
inspection.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index df55cf8f09f06d18628fb6e2e9bddf8aa66dbab6..f686f2311317ab0ef87409fae4afe6a189b417bc 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -3475,21 +3475,23 @@ int regulator_set_current_limit(struct regulator *regulator,
 }
 EXPORT_SYMBOL_GPL(regulator_set_current_limit);
 
+static int _regulator_get_current_limit_unlocked(struct regulator_dev *rdev)
+{
+       /* sanity check */
+       if (!rdev->desc->ops->get_current_limit)
+               return -EINVAL;
+
+       return rdev->desc->ops->get_current_limit(rdev);
+}
+
 static int _regulator_get_current_limit(struct regulator_dev *rdev)
 {
        int ret;
 
        regulator_lock(rdev);
-
-       /* sanity check */
-       if (!rdev->desc->ops->get_current_limit) {
-               ret = -EINVAL;
-               goto out;
-       }
-
-       ret = rdev->desc->ops->get_current_limit(rdev);
-out:
+       ret = _regulator_get_current_limit_unlocked(rdev);
        regulator_unlock(rdev);
+
        return ret;
 }
 
@@ -3554,21 +3556,23 @@ int regulator_set_mode(struct regulator *regulator, unsigned int mode)
 }
 EXPORT_SYMBOL_GPL(regulator_set_mode);
 
+static unsigned int _regulator_get_mode_unlocked(struct regulator_dev *rdev)
+{
+       /* sanity check */
+       if (!rdev->desc->ops->get_mode)
+               return -EINVAL;
+
+       return rdev->desc->ops->get_mode(rdev);
+}
+
 static unsigned int _regulator_get_mode(struct regulator_dev *rdev)
 {
        int ret;
 
        regulator_lock(rdev);
-
-       /* sanity check */
-       if (!rdev->desc->ops->get_mode) {
-               ret = -EINVAL;
-               goto out;
-       }
-
-       ret = rdev->desc->ops->get_mode(rdev);
-out:
+       ret = _regulator_get_mode_unlocked(rdev);
        regulator_unlock(rdev);
+
        return ret;
 }
 
@@ -4675,18 +4679,23 @@ static void regulator_summary_show_subtree(struct seq_file *s,
        struct regulation_constraints *c;
        struct regulator *consumer;
        struct summary_data summary_data;
+       unsigned int opmode;
 
        if (!rdev)
                return;
 
+       regulator_lock_nested(rdev, level);
+
+       opmode = _regulator_get_mode_unlocked(rdev);
        seq_printf(s, "%*s%-*s %3d %4d %6d %7s ",
                   level * 3 + 1, "",
                   30 - level * 3, rdev_get_name(rdev),
                   rdev->use_count, rdev->open_count, rdev->bypass_count,
-                  regulator_opmode_to_str(_regulator_get_mode(rdev)));
+                  regulator_opmode_to_str(opmode));
 
        seq_printf(s, "%5dmV ", _regulator_get_voltage(rdev) / 1000);
-       seq_printf(s, "%5dmA ", _regulator_get_current_limit(rdev) / 1000);
+       seq_printf(s, "%5dmA ",
+                  _regulator_get_current_limit_unlocked(rdev) / 1000);
 
        c = rdev->constraints;
        if (c) {
@@ -4733,6 +4742,8 @@ static void regulator_summary_show_subtree(struct seq_file *s,
 
        class_for_each_device(&regulator_class, NULL, &summary_data,
                              regulator_summary_show_children);
+
+       regulator_unlock(rdev);
 }
 
 static int regulator_summary_show_roots(struct device *dev, void *data)