Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 13b0135..7b975db 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -2,13 +2,16 @@
/*
* inode.c - part of debugfs, a tiny little debug file system
*
- * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
+ * Copyright (C) 2004,2019 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2004 IBM Inc.
+ * Copyright (C) 2019 Linux Foundation <gregkh@linuxfoundation.org>
*
* debugfs is for people to use instead of /proc or /sys.
* See ./Documentation/core-api/kernel-api.rst for more details.
*/
+#define pr_fmt(fmt) "debugfs: " fmt
+
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/mount.h>
@@ -23,6 +26,7 @@
#include <linux/parser.h>
#include <linux/magic.h>
#include <linux/slab.h>
+#include <linux/security.h>
#include "internal.h"
@@ -32,6 +36,32 @@
static int debugfs_mount_count;
static bool debugfs_registered;
+/*
+ * Don't allow access attributes to be changed whilst the kernel is locked down
+ * so that we can use the file mode as part of a heuristic to determine whether
+ * to lock down individual files.
+ */
+static int debugfs_setattr(struct dentry *dentry, struct iattr *ia)
+{
+ int ret = security_locked_down(LOCKDOWN_DEBUGFS);
+
+ if (ret && (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)))
+ return ret;
+ return simple_setattr(dentry, ia);
+}
+
+static const struct inode_operations debugfs_file_inode_operations = {
+ .setattr = debugfs_setattr,
+};
+static const struct inode_operations debugfs_dir_inode_operations = {
+ .lookup = simple_lookup,
+ .setattr = debugfs_setattr,
+};
+static const struct inode_operations debugfs_symlink_inode_operations = {
+ .get_link = simple_get_link,
+ .setattr = debugfs_setattr,
+};
+
static struct inode *debugfs_get_inode(struct super_block *sb)
{
struct inode *inode = new_inode(sb);
@@ -163,19 +193,18 @@
return 0;
}
-static void debugfs_evict_inode(struct inode *inode)
+static void debugfs_free_inode(struct inode *inode)
{
- truncate_inode_pages_final(&inode->i_data);
- clear_inode(inode);
if (S_ISLNK(inode->i_mode))
kfree(inode->i_link);
+ free_inode_nonrcu(inode);
}
static const struct super_operations debugfs_super_operations = {
.statfs = simple_statfs,
.remount_fs = debugfs_remount,
.show_options = debugfs_show_options,
- .evict_inode = debugfs_evict_inode,
+ .free_inode = debugfs_free_inode,
};
static void debugfs_release_dentry(struct dentry *dentry)
@@ -286,15 +315,17 @@
struct dentry *dentry;
int error;
- pr_debug("debugfs: creating file '%s'\n",name);
+ pr_debug("creating file '%s'\n", name);
if (IS_ERR(parent))
return parent;
error = simple_pin_fs(&debug_fs_type, &debugfs_mount,
&debugfs_mount_count);
- if (error)
+ if (error) {
+ pr_err("Unable to pin filesystem for file '%s'\n", name);
return ERR_PTR(error);
+ }
/* If the parent is not specified, we create it in the root.
* We need the root dentry to do this, which is in the super
@@ -307,6 +338,12 @@
inode_lock(d_inode(parent));
dentry = lookup_one_len(name, parent, strlen(name));
if (!IS_ERR(dentry) && d_really_is_positive(dentry)) {
+ if (d_is_dir(dentry))
+ pr_err("Directory '%s' with parent '%s' already present!\n",
+ name, parent->d_name.name);
+ else
+ pr_err("File '%s' in directory '%s' already present!\n",
+ name, parent->d_name.name);
dput(dentry);
dentry = ERR_PTR(-EEXIST);
}
@@ -324,7 +361,7 @@
inode_unlock(d_inode(dentry->d_parent));
dput(dentry);
simple_release_fs(&debugfs_mount, &debugfs_mount_count);
- return NULL;
+ return ERR_PTR(-ENOMEM);
}
static struct dentry *end_creating(struct dentry *dentry)
@@ -347,15 +384,19 @@
dentry = start_creating(name, parent);
if (IS_ERR(dentry))
- return NULL;
+ return dentry;
inode = debugfs_get_inode(dentry->d_sb);
- if (unlikely(!inode))
+ if (unlikely(!inode)) {
+ pr_err("out of free dentries, can not create file '%s'\n",
+ name);
return failed_creating(dentry);
+ }
inode->i_mode = mode;
inode->i_private = data;
+ inode->i_op = &debugfs_file_inode_operations;
inode->i_fop = proxy_fops;
dentry->d_fsdata = (void *)((unsigned long)real_fops |
DEBUGFS_FSDATA_IS_REAL_FOPS_BIT);
@@ -386,7 +427,8 @@
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, %NULL will be returned.
+ * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
+ * returned.
*
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned.
@@ -422,8 +464,8 @@
* debugfs core.
*
* It is your responsibility to protect your struct file_operation
- * methods against file removals by means of debugfs_use_file_start()
- * and debugfs_use_file_finish(). ->open() is still protected by
+ * methods against file removals by means of debugfs_file_get()
+ * and debugfs_file_put(). ->open() is still protected by
* debugfs though.
*
* Any struct file_operations defined by means of
@@ -464,7 +506,8 @@
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, %NULL will be returned.
+ * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
+ * returned.
*
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned.
@@ -495,7 +538,8 @@
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, %NULL will be returned.
+ * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
+ * returned.
*
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned.
@@ -506,14 +550,17 @@
struct inode *inode;
if (IS_ERR(dentry))
- return NULL;
+ return dentry;
inode = debugfs_get_inode(dentry->d_sb);
- if (unlikely(!inode))
+ if (unlikely(!inode)) {
+ pr_err("out of free dentries, can not create directory '%s'\n",
+ name);
return failed_creating(dentry);
+ }
inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
- inode->i_op = &simple_dir_inode_operations;
+ inode->i_op = &debugfs_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
/* directory inodes start off with i_nlink == 2 (for "." entry) */
@@ -545,11 +592,14 @@
struct inode *inode;
if (IS_ERR(dentry))
- return NULL;
+ return dentry;
inode = debugfs_get_inode(dentry->d_sb);
- if (unlikely(!inode))
+ if (unlikely(!inode)) {
+ pr_err("out of free dentries, can not create automount '%s'\n",
+ name);
return failed_creating(dentry);
+ }
make_empty_dir_inode(inode);
inode->i_flags |= S_AUTOMOUNT;
@@ -581,8 +631,8 @@
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the symbolic
* link is to be removed (no automatic cleanup happens if your module is
- * unloaded, you are responsible here.) If an error occurs, %NULL will be
- * returned.
+ * unloaded, you are responsible here.) If an error occurs, %ERR_PTR(-ERROR)
+ * will be returned.
*
* If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned.
@@ -594,34 +644,33 @@
struct inode *inode;
char *link = kstrdup(target, GFP_KERNEL);
if (!link)
- return NULL;
+ return ERR_PTR(-ENOMEM);
dentry = start_creating(name, parent);
if (IS_ERR(dentry)) {
kfree(link);
- return NULL;
+ return dentry;
}
inode = debugfs_get_inode(dentry->d_sb);
if (unlikely(!inode)) {
+ pr_err("out of free dentries, can not create symlink '%s'\n",
+ name);
kfree(link);
return failed_creating(dentry);
}
inode->i_mode = S_IFLNK | S_IRWXUGO;
- inode->i_op = &simple_symlink_inode_operations;
+ inode->i_op = &debugfs_symlink_inode_operations;
inode->i_link = link;
d_instantiate(dentry, inode);
return end_creating(dentry);
}
EXPORT_SYMBOL_GPL(debugfs_create_symlink);
-static void __debugfs_remove_file(struct dentry *dentry, struct dentry *parent)
+static void __debugfs_file_removed(struct dentry *dentry)
{
struct debugfs_fsdata *fsd;
- simple_unlink(d_inode(parent), dentry);
- d_delete(dentry);
-
/*
* Paired with the closing smp_mb() implied by a successful
* cmpxchg() in debugfs_file_get(): either
@@ -642,16 +691,18 @@
if (simple_positive(dentry)) {
dget(dentry);
- if (!d_is_reg(dentry)) {
- if (d_is_dir(dentry))
- ret = simple_rmdir(d_inode(parent), dentry);
- else
- simple_unlink(d_inode(parent), dentry);
+ if (d_is_dir(dentry)) {
+ ret = simple_rmdir(d_inode(parent), dentry);
if (!ret)
- d_delete(dentry);
+ fsnotify_rmdir(d_inode(parent), dentry);
} else {
- __debugfs_remove_file(dentry, parent);
+ simple_unlink(d_inode(parent), dentry);
+ fsnotify_unlink(d_inode(parent), dentry);
}
+ if (!ret)
+ d_delete(dentry);
+ if (d_is_reg(dentry))
+ __debugfs_file_removed(dentry);
dput(dentry);
}
return ret;
@@ -787,6 +838,13 @@
struct dentry *dentry = NULL, *trap;
struct name_snapshot old_name;
+ if (IS_ERR(old_dir))
+ return old_dir;
+ if (IS_ERR(new_dir))
+ return new_dir;
+ if (IS_ERR_OR_NULL(old_dentry))
+ return old_dentry;
+
trap = lock_rename(new_dir, old_dir);
/* Source or destination directories don't exist? */
if (d_really_is_negative(old_dir) || d_really_is_negative(new_dir))
@@ -809,7 +867,7 @@
goto exit;
}
d_move(old_dentry, dentry);
- fsnotify_move(d_inode(old_dir), d_inode(new_dir), old_name.name,
+ fsnotify_move(d_inode(old_dir), d_inode(new_dir), &old_name.name,
d_is_dir(old_dentry),
NULL, old_dentry);
release_dentry_name_snapshot(&old_name);
@@ -820,7 +878,9 @@
if (dentry && !IS_ERR(dentry))
dput(dentry);
unlock_rename(new_dir, old_dir);
- return NULL;
+ if (IS_ERR(dentry))
+ return dentry;
+ return ERR_PTR(-EINVAL);
}
EXPORT_SYMBOL_GPL(debugfs_rename);