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staging: pi433: fix memory leak with using debugfs_lookup()

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When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time.  To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.  This requires saving off the root directory dentry to make
creation of individual device subdirectories easier.

Cc: Paulo Miguel Almeida <paulo.miguel.almeida.rodenas@gmail.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Sidong Yang <realwakka@gmail.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230202141138.2291946-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Greg Kroah-Hartman 2023-02-02 15:11:38 +01:00
parent eef4e616e7
commit 2f36e789e5
1 changed files with 5 additions and 6 deletions
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11
drivers/staging/pi433/pi433_if.c
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@ -55,6 +55,7 @@
static dev_t pi433_dev;
static DEFINE_IDR(pi433_idr);
static DEFINE_MUTEX(minor_lock); /* Protect idr accesses */
static struct dentry *root_dir; /* debugfs root directory for the driver */
static struct class *pi433_class; /* mainly for udev to create /dev/pi433 */
@ -1306,8 +1307,7 @@ static int pi433_probe(struct spi_device *spi)
/* spi setup */
spi_set_drvdata(spi, device);
entry = debugfs_create_dir(dev_name(device->dev),
debugfs_lookup(KBUILD_MODNAME, NULL));
entry = debugfs_create_dir(dev_name(device->dev), root_dir);
debugfs_create_file("regs", 0400, entry, device, &pi433_debugfs_regs_fops);
return 0;
@ -1333,9 +1333,8 @@ RX_failed:
static void pi433_remove(struct spi_device *spi)
{
struct pi433_device *device = spi_get_drvdata(spi);
struct dentry *mod_entry = debugfs_lookup(KBUILD_MODNAME, NULL);
debugfs_remove(debugfs_lookup(dev_name(device->dev), mod_entry));
debugfs_lookup_and_remove(dev_name(device->dev), root_dir);
/* free GPIOs */
free_gpio(device);
@ -1408,7 +1407,7 @@ static int __init pi433_init(void)
return PTR_ERR(pi433_class);
}
debugfs_create_dir(KBUILD_MODNAME, NULL);
root_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
status = spi_register_driver(&pi433_spi_driver);
if (status < 0) {
@ -1427,7 +1426,7 @@ static void __exit pi433_exit(void)
spi_unregister_driver(&pi433_spi_driver);
class_destroy(pi433_class);
unregister_chrdev(MAJOR(pi433_dev), pi433_spi_driver.driver.name);
debugfs_remove_recursive(debugfs_lookup(KBUILD_MODNAME, NULL));
debugfs_remove(root_dir);
}
module_exit(pi433_exit);