This is a note to let you know that I've just added the patch titled
mmc: block: Ensure that debugfs files are removed
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: mmc-block-ensure-that-debugfs-files-are-removed.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From f9f0da98819503b06b35e61869d18cf3a8cd3323 Mon Sep 17 00:00:00 2001
From: Adrian Hunter adrian.hunter@intel.com Date: Tue, 21 Nov 2017 15:42:30 +0200 Subject: mmc: block: Ensure that debugfs files are removed
From: Adrian Hunter adrian.hunter@intel.com
commit f9f0da98819503b06b35e61869d18cf3a8cd3323 upstream.
The card is not necessarily being removed, but the debugfs files must be removed when the driver is removed, otherwise they will continue to exist after unbinding the card from the driver. e.g.
# echo "mmc1:0001" > /sys/bus/mmc/drivers/mmcblk/unbind # cat /sys/kernel/debug/mmc1/mmc1:0001/ext_csd [ 173.634584] BUG: unable to handle kernel NULL pointer dereference at 0000000000000050 [ 173.643356] IP: mmc_ext_csd_open+0x5e/0x170
A complication is that the debugfs_root may have already been removed, so check for that too.
Fixes: 627c3ccfb46a ("mmc: debugfs: Move block debugfs into block module") Signed-off-by: Adrian Hunter adrian.hunter@intel.com Reviewed-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mmc/core/block.c | 44 +++++++++++++++++++++++++++++++++++++------- drivers/mmc/core/debugfs.c | 1 + 2 files changed, 38 insertions(+), 7 deletions(-)
--- a/drivers/mmc/core/block.c +++ b/drivers/mmc/core/block.c @@ -119,6 +119,10 @@ struct mmc_blk_data { struct device_attribute force_ro; struct device_attribute power_ro_lock; int area_type; + + /* debugfs files (only in main mmc_blk_data) */ + struct dentry *status_dentry; + struct dentry *ext_csd_dentry; };
static DEFINE_MUTEX(open_lock); @@ -2417,7 +2421,7 @@ static const struct file_operations mmc_ .llseek = default_llseek, };
-static int mmc_blk_add_debugfs(struct mmc_card *card) +static int mmc_blk_add_debugfs(struct mmc_card *card, struct mmc_blk_data *md) { struct dentry *root;
@@ -2427,28 +2431,53 @@ static int mmc_blk_add_debugfs(struct mm root = card->debugfs_root;
if (mmc_card_mmc(card) || mmc_card_sd(card)) { - if (!debugfs_create_file("status", S_IRUSR, root, card, - &mmc_dbg_card_status_fops)) + md->status_dentry = + debugfs_create_file("status", S_IRUSR, root, card, + &mmc_dbg_card_status_fops); + if (!md->status_dentry) return -EIO; }
if (mmc_card_mmc(card)) { - if (!debugfs_create_file("ext_csd", S_IRUSR, root, card, - &mmc_dbg_ext_csd_fops)) + md->ext_csd_dentry = + debugfs_create_file("ext_csd", S_IRUSR, root, card, + &mmc_dbg_ext_csd_fops); + if (!md->ext_csd_dentry) return -EIO; }
return 0; }
+static void mmc_blk_remove_debugfs(struct mmc_card *card, + struct mmc_blk_data *md) +{ + if (!card->debugfs_root) + return; + + if (!IS_ERR_OR_NULL(md->status_dentry)) { + debugfs_remove(md->status_dentry); + md->status_dentry = NULL; + } + + if (!IS_ERR_OR_NULL(md->ext_csd_dentry)) { + debugfs_remove(md->ext_csd_dentry); + md->ext_csd_dentry = NULL; + } +}
#else
-static int mmc_blk_add_debugfs(struct mmc_card *card) +static int mmc_blk_add_debugfs(struct mmc_card *card, struct mmc_blk_data *md) { return 0; }
+static void mmc_blk_remove_debugfs(struct mmc_card *card, + struct mmc_blk_data *md) +{ +} + #endif /* CONFIG_DEBUG_FS */
static int mmc_blk_probe(struct mmc_card *card) @@ -2488,7 +2517,7 @@ static int mmc_blk_probe(struct mmc_card }
/* Add two debugfs entries */ - mmc_blk_add_debugfs(card); + mmc_blk_add_debugfs(card, md);
pm_runtime_set_autosuspend_delay(&card->dev, 3000); pm_runtime_use_autosuspend(&card->dev); @@ -2514,6 +2543,7 @@ static void mmc_blk_remove(struct mmc_ca { struct mmc_blk_data *md = dev_get_drvdata(&card->dev);
+ mmc_blk_remove_debugfs(card, md); mmc_blk_remove_parts(card, md); pm_runtime_get_sync(&card->dev); mmc_claim_host(card->host); --- a/drivers/mmc/core/debugfs.c +++ b/drivers/mmc/core/debugfs.c @@ -314,4 +314,5 @@ err: void mmc_remove_card_debugfs(struct mmc_card *card) { debugfs_remove_recursive(card->debugfs_root); + card->debugfs_root = NULL; }
Patches currently in stable-queue which might be from adrian.hunter@intel.com are
queue-4.14/mmc-block-check-return-value-of-blk_get_request.patch queue-4.14/mmc-block-fix-missing-blk_put_request.patch queue-4.14/mmc-block-ensure-that-debugfs-files-are-removed.patch queue-4.14/mmc-core-do-not-leave-the-block-driver-in-a-suspended-state.patch queue-4.14/mmc-sdhci-avoid-swiotlb-buffer-being-full.patch