mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-20 18:54:09 +08:00
057f6c019f
Prevent permission checking from being performed when the kernel wants to unconditionally remove a sysfs group, by introducing an kernel-only variant of lookup_one_len(), lookup_one_len_kern(). Additionally, as sysfs_remove_group() does not check the return value of the lookup before using it, a BUG_ON has been added to pinpoint the cause of any problems potentially caused by this (and as a form of annotation). Signed-off-by: James Morris <jmorris@namei.org> Cc: Nagendra Singh Tomar <nagendra_tomar@adaptec.com> Cc: Tejun Heo <htejun@gmail.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
91 lines
1.8 KiB
C
91 lines
1.8 KiB
C
/*
|
|
* fs/sysfs/group.c - Operations for adding/removing multiple files at once.
|
|
*
|
|
* Copyright (c) 2003 Patrick Mochel
|
|
* Copyright (c) 2003 Open Source Development Lab
|
|
*
|
|
* This file is released undert the GPL v2.
|
|
*
|
|
*/
|
|
|
|
#include <linux/kobject.h>
|
|
#include <linux/module.h>
|
|
#include <linux/dcache.h>
|
|
#include <linux/namei.h>
|
|
#include <linux/err.h>
|
|
#include <linux/fs.h>
|
|
#include <asm/semaphore.h>
|
|
#include "sysfs.h"
|
|
|
|
|
|
static void remove_files(struct dentry * dir,
|
|
const struct attribute_group * grp)
|
|
{
|
|
struct attribute *const* attr;
|
|
|
|
for (attr = grp->attrs; *attr; attr++)
|
|
sysfs_hash_and_remove(dir,(*attr)->name);
|
|
}
|
|
|
|
static int create_files(struct dentry * dir,
|
|
const struct attribute_group * grp)
|
|
{
|
|
struct attribute *const* attr;
|
|
int error = 0;
|
|
|
|
for (attr = grp->attrs; *attr && !error; attr++) {
|
|
error = sysfs_add_file(dir, *attr, SYSFS_KOBJ_ATTR);
|
|
}
|
|
if (error)
|
|
remove_files(dir,grp);
|
|
return error;
|
|
}
|
|
|
|
|
|
int sysfs_create_group(struct kobject * kobj,
|
|
const struct attribute_group * grp)
|
|
{
|
|
struct dentry * dir;
|
|
int error;
|
|
|
|
BUG_ON(!kobj || !kobj->dentry);
|
|
|
|
if (grp->name) {
|
|
error = sysfs_create_subdir(kobj,grp->name,&dir);
|
|
if (error)
|
|
return error;
|
|
} else
|
|
dir = kobj->dentry;
|
|
dir = dget(dir);
|
|
if ((error = create_files(dir,grp))) {
|
|
if (grp->name)
|
|
sysfs_remove_subdir(dir);
|
|
}
|
|
dput(dir);
|
|
return error;
|
|
}
|
|
|
|
void sysfs_remove_group(struct kobject * kobj,
|
|
const struct attribute_group * grp)
|
|
{
|
|
struct dentry * dir;
|
|
|
|
if (grp->name) {
|
|
dir = lookup_one_len_kern(grp->name, kobj->dentry,
|
|
strlen(grp->name));
|
|
BUG_ON(IS_ERR(dir));
|
|
}
|
|
else
|
|
dir = dget(kobj->dentry);
|
|
|
|
remove_files(dir,grp);
|
|
if (grp->name)
|
|
sysfs_remove_subdir(dir);
|
|
/* release the ref. taken in this routine */
|
|
dput(dir);
|
|
}
|
|
|
|
|
|
EXPORT_SYMBOL_GPL(sysfs_create_group);
|
|
EXPORT_SYMBOL_GPL(sysfs_remove_group);
|