bybrooklyn/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-04-18 06:44:00 -04:00
Code Issues Packages Projects Releases Wiki Activity

debugfs: Remove broken no-mount mode

Browse Source 
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] a24c6f7bc9 ("debugfs: Add access restriction option")

[2] bc6de804d3 ("debugfs: be more robust at handling improper input in debugfs_lookup()")
    56348560d4 ("debugfs: do not attempt to create a new file before the filesystem is initalized")

Signed-off-by: Aaron Thompson <dev@aaront.org>
Link: https://patch.msgid.link/20251120102222.18371-3-dev@null.aaront.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Aaron Thompson
2025-11-20 10:26:33 +00:00
committed by Greg Kroah-Hartman
parent 3ae94a55d0
commit f278809475
4 changed files with 13 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
fs/debugfs/inode.c
View File

@@ -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");

13
fs/debugfs/internal.h
View File

@@ -55,17 +55,4 @@ enum {
HAS_IOCTL = 16
};
#define DEBUGFS_ALLOW_API BIT(0)
#define DEBUGFS_ALLOW_MOUNT BIT(1)
#ifdef CONFIG_DEBUG_FS_ALLOW_ALL
#define DEFAULT_DEBUGFS_ALLOW_BITS (DEBUGFS_ALLOW_MOUNT | DEBUGFS_ALLOW_API)
#endif
#ifdef CONFIG_DEBUG_FS_DISALLOW_MOUNT
#define DEFAULT_DEBUGFS_ALLOW_BITS (DEBUGFS_ALLOW_API)
#endif
#ifdef CONFIG_DEBUG_FS_ALLOW_NONE
#define DEFAULT_DEBUGFS_ALLOW_BITS (0)
#endif
#endif /* _DEBUGFS_INTERNAL_H_ */