From 8e610b699385834c0d1cee6dd45b92bf2b018e3e Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 8 Feb 2023 17:02:30 +0100 Subject: mtd: spi-nor: fix memory leak when using debugfs_lookup() [ Upstream commit ec738ca127d07ecac6afae36e2880341ec89150e ] 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 Signed-off-by: Sasha Levin --- 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(-) (limited to 'drivers') diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index cda57cb86308..75e694791d8d 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -3272,7 +3272,19 @@ 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 d18dafeb020a..00bf0d0e955a 100644 --- a/drivers/mtd/spi-nor/core.h +++ b/drivers/mtd/spi-nor/core.h @@ -709,8 +709,10 @@ 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 df76cb5de3f9..5f56b23205d8 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); +} -- cgit v1.2.3