From ec738ca127d07ecac6afae36e2880341ec89150e Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 8 Feb 2023 17:02:30 +0100 Subject: [PATCH] mtd: spi-nor: fix memory leak when using debugfs_lookup() When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To solve this, remove the lookup and create the directory on the first device found, and then remove it when the module is unloaded. Cc: Tudor Ambarus Cc: Pratyush Yadav Cc: Miquel Raynal Cc: Richard Weinberger Cc: Vignesh Raghavendra Cc: linux-mtd@lists.infradead.org Reviewed-by: Michael Walle Link: https://lore.kernel.org/r/20230208160230.2179905-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman --- drivers/mtd/spi-nor/core.c | 14 +++++++++++++- drivers/mtd/spi-nor/core.h | 2 ++ drivers/mtd/spi-nor/debugfs.c | 11 ++++++++--- 3 files changed, 23 insertions(+), 4 deletions(-) diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index 0a78045..522d375 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -3343,7 +3343,19 @@ static struct spi_mem_driver spi_nor_driver = { .remove = spi_nor_remove, .shutdown = spi_nor_shutdown, }; -module_spi_mem_driver(spi_nor_driver); + +static int __init spi_nor_module_init(void) +{ + return spi_mem_driver_register(&spi_nor_driver); +} +module_init(spi_nor_module_init); + +static void __exit spi_nor_module_exit(void) +{ + spi_mem_driver_unregister(&spi_nor_driver); + spi_nor_debugfs_shutdown(); +} +module_exit(spi_nor_module_exit); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Huang Shijie "); diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h index 25423225..e0cc42a 100644 --- a/drivers/mtd/spi-nor/core.h +++ b/drivers/mtd/spi-nor/core.h @@ -711,8 +711,10 @@ static inline struct spi_nor *mtd_to_spi_nor(struct mtd_info *mtd) #ifdef CONFIG_DEBUG_FS void spi_nor_debugfs_register(struct spi_nor *nor); +void spi_nor_debugfs_shutdown(void); #else static inline void spi_nor_debugfs_register(struct spi_nor *nor) {} +static inline void spi_nor_debugfs_shutdown(void) {} #endif #endif /* __LINUX_MTD_SPI_NOR_INTERNAL_H */ diff --git a/drivers/mtd/spi-nor/debugfs.c b/drivers/mtd/spi-nor/debugfs.c index 845b78c..fc7ad20 100644 --- a/drivers/mtd/spi-nor/debugfs.c +++ b/drivers/mtd/spi-nor/debugfs.c @@ -226,13 +226,13 @@ static void spi_nor_debugfs_unregister(void *data) nor->debugfs_root = NULL; } +static struct dentry *rootdir; + void spi_nor_debugfs_register(struct spi_nor *nor) { - struct dentry *rootdir, *d; + struct dentry *d; int ret; - /* Create rootdir once. Will never be deleted again. */ - rootdir = debugfs_lookup(SPI_NOR_DEBUGFS_ROOT, NULL); if (!rootdir) rootdir = debugfs_create_dir(SPI_NOR_DEBUGFS_ROOT, NULL); @@ -247,3 +247,8 @@ void spi_nor_debugfs_register(struct spi_nor *nor) debugfs_create_file("capabilities", 0444, d, nor, &spi_nor_capabilities_fops); } + +void spi_nor_debugfs_shutdown(void) +{ + debugfs_remove(rootdir); +} -- 2.7.4