mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2024-11-21 19:46:16 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

eeprom: ee1004: Fix locking issues in ee1004_probe()

Browse Source 
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 <dan.carpenter@linaro.org>
Fixes: 55d57ef6fa ("eeprom: ee1004: Use devres for bus data cleanup")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20240713234813.21746-1-W_Armin@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Armin Wolf 2024-07-14 01:48:13 +02:00 committed by Greg Kroah-Hartman
parent be62f1289d
commit e6cd0dc91e
1 changed files with 51 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

85
drivers/misc/eeprom/ee1004.c
View File

@ -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);