From e6cd0dc91ef9d24edda553343e64eb6b542c21dd Mon Sep 17 00:00:00 2001 From: Armin Wolf Date: Sun, 14 Jul 2024 01:48:13 +0200 Subject: [PATCH] eeprom: ee1004: Fix locking issues in ee1004_probe() Currently, the devres-based management of ee1004_bus_data has several issues when it comes to locking: 1. It does not call mutex_unlock() before returning an error. 2. When encountering an error, it deadlocks when trying to recursively lock a mutex. Fix this by moving the mutex-protected bus data initialization into a separate function so that devm_add_action_or_reset() is called without the mutex being held. Reported-by: Dan Carpenter Fixes: 55d57ef6fa97 ("eeprom: ee1004: Use devres for bus data cleanup") Signed-off-by: Armin Wolf Reviewed-by: Dan Carpenter Link: https://lore.kernel.org/r/20240713234813.21746-1-W_Armin@gmx.de Signed-off-by: Greg Kroah-Hartman --- drivers/misc/eeprom/ee1004.c | 85 +++++++++++++++++++++--------------- 1 file changed, 51 insertions(+), 34 deletions(-) diff --git a/drivers/misc/eeprom/ee1004.c b/drivers/misc/eeprom/ee1004.c index d4aeeb2b2169..89224d4af4a2 100644 --- a/drivers/misc/eeprom/ee1004.c +++ b/drivers/misc/eeprom/ee1004.c @@ -233,6 +233,49 @@ static void ee1004_cleanup_bus_data(void *data) mutex_unlock(&ee1004_bus_lock); } +static int ee1004_init_bus_data(struct i2c_client *client) +{ + struct ee1004_bus_data *bd; + int err, cnr = 0; + + bd = ee1004_get_bus_data(client->adapter); + if (!bd) + return dev_err_probe(&client->dev, -ENOSPC, "Only %d busses supported", + EE1004_MAX_BUSSES); + + i2c_set_clientdata(client, bd); + + if (++bd->dev_count == 1) { + /* Use 2 dummy devices for page select command */ + for (cnr = 0; cnr < EE1004_NUM_PAGES; cnr++) { + struct i2c_client *cl; + + cl = i2c_new_dummy_device(client->adapter, EE1004_ADDR_SET_PAGE + cnr); + if (IS_ERR(cl)) { + err = PTR_ERR(cl); + goto err_out; + } + + bd->set_page[cnr] = cl; + } + + /* Remember current page to avoid unneeded page select */ + err = ee1004_get_current_page(bd); + if (err < 0) + goto err_out; + + dev_dbg(&client->dev, "Currently selected page: %d\n", err); + bd->current_page = err; + } + + return 0; + +err_out: + ee1004_cleanup(cnr, bd); + + return err; +} + static int ee1004_probe(struct i2c_client *client) { struct nvmem_config config = { @@ -251,9 +294,8 @@ static int ee1004_probe(struct i2c_client *client) .compat = true, .base_dev = &client->dev, }; - struct ee1004_bus_data *bd; struct nvmem_device *ndev; - int err, cnr = 0; + int err; /* Make sure we can operate on this adapter */ if (!i2c_check_functionality(client->adapter, @@ -264,46 +306,21 @@ static int ee1004_probe(struct i2c_client *client) mutex_lock(&ee1004_bus_lock); - bd = ee1004_get_bus_data(client->adapter); - if (!bd) { + err = ee1004_init_bus_data(client); + if (err < 0) { mutex_unlock(&ee1004_bus_lock); - return dev_err_probe(&client->dev, -ENOSPC, - "Only %d busses supported", EE1004_MAX_BUSSES); - } - - err = devm_add_action_or_reset(&client->dev, ee1004_cleanup_bus_data, bd); - if (err < 0) return err; - - i2c_set_clientdata(client, bd); - - if (++bd->dev_count == 1) { - /* Use 2 dummy devices for page select command */ - for (cnr = 0; cnr < EE1004_NUM_PAGES; cnr++) { - struct i2c_client *cl; - - cl = i2c_new_dummy_device(client->adapter, EE1004_ADDR_SET_PAGE + cnr); - if (IS_ERR(cl)) { - mutex_unlock(&ee1004_bus_lock); - return PTR_ERR(cl); - } - bd->set_page[cnr] = cl; - } - - /* Remember current page to avoid unneeded page select */ - err = ee1004_get_current_page(bd); - if (err < 0) { - mutex_unlock(&ee1004_bus_lock); - return err; - } - dev_dbg(&client->dev, "Currently selected page: %d\n", err); - bd->current_page = err; } ee1004_probe_temp_sensor(client); mutex_unlock(&ee1004_bus_lock); + err = devm_add_action_or_reset(&client->dev, ee1004_cleanup_bus_data, + i2c_get_clientdata(client)); + if (err < 0) + return err; + ndev = devm_nvmem_register(&client->dev, &config); if (IS_ERR(ndev)) return PTR_ERR(ndev);