From f278809475f6835b56de78b28dc2cc0c7e2c20a4 Mon Sep 17 00:00:00 2001 From: Aaron Thompson Date: Thu, 20 Nov 2025 10:26:33 +0000 Subject: debugfs: Remove broken no-mount mode debugfs access modes were added in Linux 5.10 (Dec 2020) [1], but the no-mount mode has behaved effectively the same as the off mode since Linux 5.12 (Apr 2021) [2]. The only difference is the specific error code returned by the debugfs_create_* functions, which is -ENOENT in no-mount mode and -EPERM in off mode. Given that no-mount hasn't worked for several years with no complaints, just remove it. [1] a24c6f7bc923 ("debugfs: Add access restriction option") [2] bc6de804d36b ("debugfs: be more robust at handling improper input in debugfs_lookup()") 56348560d495 ("debugfs: do not attempt to create a new file before the filesystem is initalized") Signed-off-by: Aaron Thompson Link: https://patch.msgid.link/20251120102222.18371-3-dev@null.aaront.org Signed-off-by: Greg Kroah-Hartman --- fs/debugfs/inode.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) (limited to 'fs/debugfs/inode.c') diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index b6e401c46b6b..0284b0256195 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -35,7 +35,7 @@ static struct vfsmount *debugfs_mount; static int debugfs_mount_count; static bool debugfs_registered; -static unsigned int debugfs_allow __ro_after_init = DEFAULT_DEBUGFS_ALLOW_BITS; +static bool debugfs_enabled __ro_after_init = IS_ENABLED(DEBUG_FS_ALLOW_ALL); /* * Don't allow access attributes to be changed whilst the kernel is locked down @@ -365,7 +365,7 @@ static struct dentry *debugfs_start_creating(const char *name, struct dentry *dentry; int error; - if (!(debugfs_allow & DEBUGFS_ALLOW_API)) + if (!debugfs_enabled) return ERR_PTR(-EPERM); if (!debugfs_initialized()) @@ -885,21 +885,25 @@ static int __init debugfs_kernel(char *str) { if (str) { if (!strcmp(str, "on")) - debugfs_allow = DEBUGFS_ALLOW_API | DEBUGFS_ALLOW_MOUNT; - else if (!strcmp(str, "no-mount")) - debugfs_allow = DEBUGFS_ALLOW_API; + debugfs_enabled = true; else if (!strcmp(str, "off")) - debugfs_allow = 0; + debugfs_enabled = false; + else if (!strcmp(str, "no-mount")) { + pr_notice("debugfs=no-mount is a deprecated alias " + "for debugfs=off\n"); + debugfs_enabled = false; + } } return 0; } early_param("debugfs", debugfs_kernel); + static int __init debugfs_init(void) { int retval; - if (!(debugfs_allow & DEBUGFS_ALLOW_MOUNT)) + if (!debugfs_enabled) return -EPERM; retval = sysfs_create_mount_point(kernel_kobj, "debug"); -- cgit v1.2.3