[PATCH 4.18 090/235] regulator: qcom_spmi: Fix warning Bad of_node_put()

From: Greg Kroah-Hartman
Date: Mon Sep 24 2018 - 08:32:21 EST


4.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Niklas Cassel <niklas.cassel@xxxxxxxxxx>

[ Upstream commit fffe7f52eb5db41eedadba9a8038e982dcfaee0c ]

For of_find_node_by_name(), you typically pass what the previous call
returned. Therefore, of_find_node_by_name() increases the refcount of
the returned node, and decreases the refcount of the node passed as the
first argument.

of_find_node_by_name() is incorrectly used, and produces a warning.
Fix the warning by using the more suitable function
of_get_child_by_name().

Also add a missing of_node_put() for the returned value, since this was
previously being leaked.

OF: ERROR: Bad of_node_put() on /soc/qcom,spmi@400f000/pmic@3/regulators
CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W 4.18.0-rc4-00223-gefd7b360b70e #12
Hardware name: Qualcomm Technologies, Inc. DB820c (DT)
Call trace:
dump_backtrace+0x0/0x1a8
show_stack+0x14/0x20
dump_stack+0x90/0xb4
of_node_release+0x74/0x78
kobject_put+0x90/0x1f0
of_node_put+0x14/0x20
of_find_node_by_name+0x80/0xd8
qcom_spmi_regulator_probe+0x30c/0x508

Fixes: 0caecaa87202 ("regulator: qcom_spmi: Add support for SAW")
Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/regulator/qcom_spmi-regulator.c | 32 ++++++++++++++++++++------------
1 file changed, 20 insertions(+), 12 deletions(-)

--- a/drivers/regulator/qcom_spmi-regulator.c
+++ b/drivers/regulator/qcom_spmi-regulator.c
@@ -1752,7 +1752,8 @@ static int qcom_spmi_regulator_probe(str
const char *name;
struct device *dev = &pdev->dev;
struct device_node *node = pdev->dev.of_node;
- struct device_node *syscon;
+ struct device_node *syscon, *reg_node;
+ struct property *reg_prop;
int ret, lenp;
struct list_head *vreg_list;

@@ -1780,10 +1781,13 @@ static int qcom_spmi_regulator_probe(str

for (reg = match->data; reg->name; reg++) {

- if (saw_regmap && \
- of_find_property(of_find_node_by_name(node, reg->name), \
- "qcom,saw-slave", &lenp)) {
- continue;
+ if (saw_regmap) {
+ reg_node = of_get_child_by_name(node, reg->name);
+ reg_prop = of_find_property(reg_node, "qcom,saw-slave",
+ &lenp);
+ of_node_put(reg_node);
+ if (reg_prop)
+ continue;
}

vreg = devm_kzalloc(dev, sizeof(*vreg), GFP_KERNEL);
@@ -1816,13 +1820,17 @@ static int qcom_spmi_regulator_probe(str
if (ret)
continue;

- if (saw_regmap && \
- of_find_property(of_find_node_by_name(node, reg->name), \
- "qcom,saw-leader", &lenp)) {
- spmi_saw_ops = *(vreg->desc.ops);
- spmi_saw_ops.set_voltage_sel = \
- spmi_regulator_saw_set_voltage;
- vreg->desc.ops = &spmi_saw_ops;
+ if (saw_regmap) {
+ reg_node = of_get_child_by_name(node, reg->name);
+ reg_prop = of_find_property(reg_node, "qcom,saw-leader",
+ &lenp);
+ of_node_put(reg_node);
+ if (reg_prop) {
+ spmi_saw_ops = *(vreg->desc.ops);
+ spmi_saw_ops.set_voltage_sel =
+ spmi_regulator_saw_set_voltage;
+ vreg->desc.ops = &spmi_saw_ops;
+ }
}

config.dev = dev;