[PATCH v1 3/5] leds: is31fl319x: Fix devm vs. non-devm ordering

From: Andy Shevchenko
Date: Mon Jul 11 2022 - 17:35:43 EST


When non-devm resources are allocated they mustn't be followed by
devm allocations, otherwise it will break the tear down ordering
and might lead to crashes or other bugs during ->remove() stage.
Fix this by wrapping mutex_destroy() call with
devm_add_action_or_reset().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/leds/leds-is31fl319x.c | 32 +++++++++-----------------------
1 file changed, 9 insertions(+), 23 deletions(-)

diff --git a/drivers/leds/leds-is31fl319x.c b/drivers/leds/leds-is31fl319x.c
index d9cf70505c43..233ed67830a3 100644
--- a/drivers/leds/leds-is31fl319x.c
+++ b/drivers/leds/leds-is31fl319x.c
@@ -511,10 +511,13 @@ static int is31fl319x_probe(struct i2c_client *client,
return -ENOMEM;

mutex_init(&is31->lock);
+ err = devm_add_action(dev, (void (*)(void *))mutex_destroy, &is31->lock);
+ if (err)
+ return err;

err = is31fl319x_parse_fw(&client->dev, is31);
if (err)
- goto free_mutex;
+ return err;

if (is31->shutdown_gpio) {
gpiod_direction_output(is31->shutdown_gpio, 0);
@@ -524,19 +527,15 @@ static int is31fl319x_probe(struct i2c_client *client,

is31->client = client;
is31->regmap = devm_regmap_init_i2c(client, is31->cdef->is31fl319x_regmap_config);
- if (IS_ERR(is31->regmap)) {
- err = dev_err_probe(dev, PTR_ERR(is31->regmap), "failed to allocate register map\n");
- goto free_mutex;
- }
+ if (IS_ERR(is31->regmap))
+ return dev_err_probe(dev, PTR_ERR(is31->regmap), "failed to allocate register map\n");

i2c_set_clientdata(client, is31);

/* check for write-reply from chip (we can't read any registers) */
err = regmap_write(is31->regmap, is31->cdef->reset_reg, 0x00);
- if (err < 0) {
- err = dev_err_probe(dev, err, "no response from chip write\n");
- goto free_mutex;
- }
+ if (err < 0)
+ return dev_err_probe(dev, err, "no response from chip write\n");

/*
* Kernel conventions require per-LED led-max-microamp property.
@@ -568,22 +567,10 @@ static int is31fl319x_probe(struct i2c_client *client,

err = devm_led_classdev_register(&client->dev, &led->cdev);
if (err < 0)
- goto free_mutex;
+ return err;
}

return 0;
-
-free_mutex:
- mutex_destroy(&is31->lock);
- return err;
-}
-
-static int is31fl319x_remove(struct i2c_client *client)
-{
- struct is31fl319x_chip *is31 = i2c_get_clientdata(client);
-
- mutex_destroy(&is31->lock);
- return 0;
}

/*
@@ -611,7 +598,6 @@ static struct i2c_driver is31fl319x_driver = {
.of_match_table = of_is31fl319x_match,
},
.probe = is31fl319x_probe,
- .remove = is31fl319x_remove,
.id_table = is31fl319x_id,
};

--
2.35.1