From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2B1E32108 for ; Mon, 24 Apr 2023 13:26:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E1FDC4339C; Mon, 24 Apr 2023 13:26:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1682342809; bh=lSOBpUnFu9VK1D1fFEX3s0tqrCknH4atbNI6skVNVjY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GbV9sC8tVtSg/qUFpAFNZnwLix9B5q82iOUYBoHIdPal4iNy9OXTZnuObLDj6ottR iGKsybOR4pwBhHBqMGocPNRjCdfDvM8k/UoYoe1v3cU3l3v3R6XdDhmnbl+NLO9PoM 9mVEOpPjCjrw/C4u50w5Pp8nmBbngea5tnYHsspI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tudor Ambarus , Pratyush Yadav , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , linux-mtd@lists.infradead.org, Michael Walle , Sasha Levin Subject: [PATCH 6.1 48/98] mtd: spi-nor: fix memory leak when using debugfs_lookup() Date: Mon, 24 Apr 2023 15:17:11 +0200 Message-Id: <20230424131135.738833650@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230424131133.829259077@linuxfoundation.org> References: <20230424131133.829259077@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman [ 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(-) diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index cda57cb863089..75e694791d8d9 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 d18dafeb020ab..00bf0d0e955a0 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 df76cb5de3f93..5f56b23205d8b 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); +} -- 2.39.2