From 8ac6c7a54ed1b98d142dce24b11c6de6a1e239a5 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 22 Oct 2024 10:36:11 +0000
Subject: [PATCH] 修改4g拨号为QMI,需要在系统里后台执行quectel-CM
---
kernel/fs/debugfs/inode.c | 324 +++++++++++++++++++++++++++--------------------------
1 files changed, 164 insertions(+), 160 deletions(-)
diff --git a/kernel/fs/debugfs/inode.c b/kernel/fs/debugfs/inode.c
index e5126fa..f47f0a7 100644
--- a/kernel/fs/debugfs/inode.c
+++ b/kernel/fs/debugfs/inode.c
@@ -2,12 +2,15 @@
/*
* 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>
@@ -23,6 +26,7 @@
#include <linux/parser.h>
#include <linux/magic.h>
#include <linux/slab.h>
+#include <linux/security.h>
#include "internal.h"
@@ -31,6 +35,33 @@
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;
+
+/*
+ * 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)
{
@@ -163,24 +194,18 @@
return 0;
}
-static void debugfs_i_callback(struct rcu_head *head)
+static void debugfs_free_inode(struct inode *inode)
{
- struct inode *inode = container_of(head, struct inode, i_rcu);
if (S_ISLNK(inode->i_mode))
kfree(inode->i_link);
free_inode_nonrcu(inode);
-}
-
-static void debugfs_destroy_inode(struct inode *inode)
-{
- call_rcu(&inode->i_rcu, debugfs_i_callback);
}
static const struct super_operations debugfs_super_operations = {
.statfs = simple_statfs,
.remount_fs = debugfs_remount,
.show_options = debugfs_show_options,
- .destroy_inode = debugfs_destroy_inode,
+ .free_inode = debugfs_free_inode,
};
static void debugfs_release_dentry(struct dentry *dentry)
@@ -242,6 +267,9 @@
int flags, const char *dev_name,
void *data)
{
+ if (!(debugfs_allow & DEBUGFS_ALLOW_API))
+ return ERR_PTR(-EPERM);
+
return mount_single(fs_type, flags, data, debug_fill_super);
}
@@ -269,19 +297,15 @@
{
struct dentry *dentry;
- if (IS_ERR(parent))
+ if (!debugfs_initialized() || IS_ERR_OR_NULL(name) || IS_ERR(parent))
return NULL;
if (!parent)
parent = debugfs_mount->mnt_root;
- dentry = lookup_one_len_unlocked(name, parent, strlen(name));
+ dentry = lookup_positive_unlocked(name, parent, strlen(name));
if (IS_ERR(dentry))
return NULL;
- if (!d_really_is_positive(dentry)) {
- dput(dentry);
- return NULL;
- }
return dentry;
}
EXPORT_SYMBOL_GPL(debugfs_lookup);
@@ -291,15 +315,23 @@
struct dentry *dentry;
int error;
- pr_debug("debugfs: creating file '%s'\n",name);
+ if (!(debugfs_allow & DEBUGFS_ALLOW_API))
+ return ERR_PTR(-EPERM);
+
+ if (!debugfs_initialized())
+ return ERR_PTR(-ENOENT);
+
+ 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
@@ -310,8 +342,17 @@
parent = debugfs_mount->mnt_root;
inode_lock(d_inode(parent));
- dentry = lookup_one_len(name, parent, strlen(name));
+ if (unlikely(IS_DEADDIR(d_inode(parent))))
+ dentry = ERR_PTR(-ENOENT);
+ else
+ 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);
}
@@ -329,7 +370,7 @@
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)
@@ -352,15 +393,24 @@
dentry = start_creating(name, parent);
if (IS_ERR(dentry))
- return NULL;
+ return dentry;
+
+ if (!(debugfs_allow & DEBUGFS_ALLOW_API)) {
+ failed_creating(dentry);
+ return ERR_PTR(-EPERM);
+ }
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);
@@ -391,7 +441,8 @@
* 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.
@@ -427,8 +478,8 @@
* 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
@@ -465,25 +516,16 @@
* wide range of flexibility in creating a file, or a directory (if you want
* to create a directory, the debugfs_create_dir() function is
* recommended to be used instead.)
- *
- * 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.
- *
- * If debugfs is not enabled in the kernel, the value -%ENODEV will be
- * returned.
*/
-struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
- struct dentry *parent, void *data,
- const struct file_operations *fops,
- loff_t file_size)
+void debugfs_create_file_size(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct file_operations *fops,
+ loff_t file_size)
{
struct dentry *de = debugfs_create_file(name, mode, parent, data, fops);
- if (de)
+ if (!IS_ERR(de))
d_inode(de)->i_size = file_size;
- return de;
}
EXPORT_SYMBOL_GPL(debugfs_create_file_size);
@@ -500,7 +542,8 @@
* 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.
@@ -511,14 +554,22 @@
struct inode *inode;
if (IS_ERR(dentry))
- return NULL;
+ return dentry;
+
+ if (!(debugfs_allow & DEBUGFS_ALLOW_API)) {
+ failed_creating(dentry);
+ return ERR_PTR(-EPERM);
+ }
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) */
@@ -550,11 +601,19 @@
struct inode *inode;
if (IS_ERR(dentry))
- return NULL;
+ return dentry;
+
+ if (!(debugfs_allow & DEBUGFS_ALLOW_API)) {
+ failed_creating(dentry);
+ return ERR_PTR(-EPERM);
+ }
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;
@@ -586,8 +645,8 @@
* 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.
@@ -599,33 +658,32 @@
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
@@ -641,60 +699,15 @@
wait_for_completion(&fsd->active_users_drained);
}
-static int __debugfs_remove(struct dentry *dentry, struct dentry *parent)
+static void remove_one(struct dentry *victim)
{
- int ret = 0;
-
- 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 (!ret)
- d_delete(dentry);
- } else {
- __debugfs_remove_file(dentry, parent);
- }
- dput(dentry);
- }
- return ret;
+ if (d_is_reg(victim))
+ __debugfs_file_removed(victim);
+ simple_release_fs(&debugfs_mount, &debugfs_mount_count);
}
/**
- * debugfs_remove - removes a file or directory from the debugfs filesystem
- * @dentry: a pointer to a the dentry of the file or directory to be
- * removed. If this parameter is NULL or an error value, nothing
- * will be done.
- *
- * This function removes a file or directory in debugfs that was previously
- * created with a call to another debugfs function (like
- * debugfs_create_file() or variants thereof.)
- *
- * This function is required to be called in order for the file to be
- * removed, no automatic cleanup of files will happen when a module is
- * removed, you are responsible here.
- */
-void debugfs_remove(struct dentry *dentry)
-{
- struct dentry *parent;
- int ret;
-
- if (IS_ERR_OR_NULL(dentry))
- return;
-
- parent = dentry->d_parent;
- inode_lock(d_inode(parent));
- ret = __debugfs_remove(dentry, parent);
- inode_unlock(d_inode(parent));
- if (!ret)
- simple_release_fs(&debugfs_mount, &debugfs_mount_count);
-}
-EXPORT_SYMBOL_GPL(debugfs_remove);
-
-/**
- * debugfs_remove_recursive - recursively removes a directory
+ * debugfs_remove - recursively removes a directory
* @dentry: a pointer to a the dentry of the directory to be removed. If this
* parameter is NULL or an error value, nothing will be done.
*
@@ -706,65 +719,38 @@
* removed, no automatic cleanup of files will happen when a module is
* removed, you are responsible here.
*/
-void debugfs_remove_recursive(struct dentry *dentry)
+void debugfs_remove(struct dentry *dentry)
{
- struct dentry *child, *parent;
-
if (IS_ERR_OR_NULL(dentry))
return;
- parent = dentry;
- down:
- inode_lock(d_inode(parent));
- loop:
- /*
- * The parent->d_subdirs is protected by the d_lock. Outside that
- * lock, the child can be unlinked and set to be freed which can
- * use the d_u.d_child as the rcu head and corrupt this list.
- */
- spin_lock(&parent->d_lock);
- list_for_each_entry(child, &parent->d_subdirs, d_child) {
- if (!simple_positive(child))
- continue;
-
- /* perhaps simple_empty(child) makes more sense */
- if (!list_empty(&child->d_subdirs)) {
- spin_unlock(&parent->d_lock);
- inode_unlock(d_inode(parent));
- parent = child;
- goto down;
- }
-
- spin_unlock(&parent->d_lock);
-
- if (!__debugfs_remove(child, parent))
- simple_release_fs(&debugfs_mount, &debugfs_mount_count);
-
- /*
- * The parent->d_lock protects agaist child from unlinking
- * from d_subdirs. When releasing the parent->d_lock we can
- * no longer trust that the next pointer is valid.
- * Restart the loop. We'll skip this one with the
- * simple_positive() check.
- */
- goto loop;
- }
- spin_unlock(&parent->d_lock);
-
- inode_unlock(d_inode(parent));
- child = parent;
- parent = parent->d_parent;
- inode_lock(d_inode(parent));
-
- if (child != dentry)
- /* go up */
- goto loop;
-
- if (!__debugfs_remove(child, parent))
- simple_release_fs(&debugfs_mount, &debugfs_mount_count);
- inode_unlock(d_inode(parent));
+ simple_pin_fs(&debug_fs_type, &debugfs_mount, &debugfs_mount_count);
+ simple_recursive_removal(dentry, remove_one);
+ simple_release_fs(&debugfs_mount, &debugfs_mount_count);
}
-EXPORT_SYMBOL_GPL(debugfs_remove_recursive);
+EXPORT_SYMBOL_GPL(debugfs_remove);
+
+/**
+ * debugfs_lookup_and_remove - lookup a directory or file and recursively remove it
+ * @name: a pointer to a string containing the name of the item to look up.
+ * @parent: a pointer to the parent dentry of the item.
+ *
+ * This is the equlivant of doing something like
+ * debugfs_remove(debugfs_lookup(..)) but with the proper reference counting
+ * handled for the directory being looked up.
+ */
+void debugfs_lookup_and_remove(const char *name, struct dentry *parent)
+{
+ struct dentry *dentry;
+
+ dentry = debugfs_lookup(name, parent);
+ if (!dentry)
+ return;
+
+ debugfs_remove(dentry);
+ dput(dentry);
+}
+EXPORT_SYMBOL_GPL(debugfs_lookup_and_remove);
/**
* debugfs_rename - rename a file/directory in the debugfs filesystem
@@ -821,7 +807,7 @@
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);
@@ -832,7 +818,9 @@
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);
@@ -845,9 +833,26 @@
}
EXPORT_SYMBOL_GPL(debugfs_initialized);
+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;
+ else if (!strcmp(str, "off"))
+ debugfs_allow = 0;
+ }
+
+ return 0;
+}
+early_param("debugfs", debugfs_kernel);
static int __init debugfs_init(void)
{
int retval;
+
+ if (!(debugfs_allow & DEBUGFS_ALLOW_MOUNT))
+ return -EPERM;
retval = sysfs_create_mount_point(kernel_kobj, "debug");
if (retval)
@@ -862,4 +867,3 @@
return retval;
}
core_initcall(debugfs_init);
-
--
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