COMPAT_SYSCALL_DEFINE5(mount, const char __user *, dev_name,
const char __user *, dir_name,
const char __user *, type, compat_ulong_t, flags,
const void __user *, data)
{
char *kernel_type;
void *options;
char *kernel_dev;
int retval;
kernel_type = copy_mount_string(type);
retval = PTR_ERR(kernel_type);
if (IS_ERR(kernel_type))
goto out;
kernel_dev = copy_mount_string(dev_name);
retval = PTR_ERR(kernel_dev);
if (IS_ERR(kernel_dev))
goto out1;
options = copy_mount_options(data);
retval = PTR_ERR(options);
if (IS_ERR(options))
goto out2;
if (kernel_type && options) {
if (!strcmp(kernel_type, NCPFS_NAME)) {
do_ncp_super_data_conv(options);
} else if (!strcmp(kernel_type, NFS4_NAME)) {
retval = -EINVAL;
if (do_nfs4_super_data_conv(options))
goto out3;
}
}
retval = do_mount(kernel_dev, dir_name, kernel_type, flags, options);
out3:
kfree(options);
out2:
kfree(kernel_dev);
out1:
kfree(kernel_type);
out:
return retval;
}
asmlinkage long jprobe_sys_mount_handler(char __user *dev_name, char __user *dir_name,
char __user *type, unsigned long flags,
void __user *data)
{
int ret = 0;
char *kernel_type;
char *kernel_dir;
char *kernel_dev;
unsigned long data_page;
ret = copy_mount_string(type, &kernel_type);
if (ret < 0)
goto out_type;
ret = copy_mount_string(dir_name, &kernel_dir);
if (ret < 0)
goto out_dir;
ret = copy_mount_string(dev_name, &kernel_dev);
if (ret < 0)
goto out_dev;
ret = copy_mount_options(data, &data_page);
if (ret < 0)
goto out_data;
printk(KERN_INFO "%s() sys_mount(dev=%s, dir=%s, type=%s, flags=%lu)", __func__, kernel_dev, kernel_dir, kernel_type, flags);
free_page(data_page);
out_data:
kfree(kernel_dev);
out_dev:
kfree(kernel_dir);
out_dir:
kfree(kernel_type);
out_type:
jprobe_return();
}
/*
* Flags is a 16-bit value that allows up to 16 non-fs dependent flags to
* be given to the mount() call (ie: read-only, no-dev, no-suid etc).
*
* data is a (void *) that can point to any structure up to
* PAGE_SIZE-1 bytes, which can contain arbitrary fs-dependent
* information (or be NULL).
*
* NOTE! As old versions of mount() didn't use this setup, the flags
* has to have a special 16-bit magic number in the hight word:
* 0xC0ED. If this magic word isn't present, the flags and data info
* isn't used, as the syscall assumes we are talking to an older
* version that didn't understand them.
*/
asmlinkage int sys_mount(char * dev_name, char * dir_name, char * type,
unsigned long new_flags, void * data)
{
struct file_system_type * fstype;
struct inode * inode;
struct file_operations * fops;
kdev_t dev;
int retval;
const char * t;
unsigned long flags = 0;
unsigned long page = 0;
if (!suser())
return -EPERM;
if ((new_flags &
(MS_MGC_MSK | MS_REMOUNT)) == (MS_MGC_VAL | MS_REMOUNT)) {
retval = copy_mount_options (data, &page);
if (retval < 0)
return retval;
retval = do_remount(dir_name,
new_flags & ~MS_MGC_MSK & ~MS_REMOUNT,
(char *) page);
free_page(page);
return retval;
}
retval = copy_mount_options (type, &page);
if (retval < 0)
return retval;
fstype = get_fs_type((char *) page);
free_page(page);
if (!fstype)
return -ENODEV;
t = fstype->name;
fops = NULL;
if (fstype->requires_dev) {
retval = namei(dev_name, &inode);
if (retval)
return retval;
if (!S_ISBLK(inode->i_mode)) {
iput(inode);
return -ENOTBLK;
}
if (IS_NODEV(inode)) {
iput(inode);
return -EACCES;
}
dev = inode->i_rdev;
if (MAJOR(dev) >= MAX_BLKDEV) {
iput(inode);
return -ENXIO;
}
fops = get_blkfops(MAJOR(dev));
if (!fops) {
iput(inode);
return -ENOTBLK;
}
if (fops->open) {
struct file dummy; /* allows read-write or read-only flag */
memset(&dummy, 0, sizeof(dummy));
dummy.f_inode = inode;
dummy.f_mode = (new_flags & MS_RDONLY) ? 1 : 3;
retval = fops->open(inode, &dummy);
if (retval) {
iput(inode);
return retval;
}
}
} else {
if (!(dev = get_unnamed_dev()))
return -EMFILE;
inode = NULL;
}
page = 0;
if ((new_flags & MS_MGC_MSK) == MS_MGC_VAL) {
flags = new_flags & ~MS_MGC_MSK;
retval = copy_mount_options(data, &page);
if (retval < 0) {
iput(inode);
return retval;
}
}
retval = do_mount(dev,dev_name,dir_name,t,flags,(void *) page);
free_page(page);
if (retval && fops && fops->release)
fops->release(inode, NULL);
iput(inode);
return retval;
}
/*
* Flags is a 16-bit value that allows up to 16 non-fs dependent flags to
* be given to the mount() call (ie: read-only, no-dev, no-suid etc).
*
* data is a (void *) that can point to any structure up to
* PAGE_SIZE-1 bytes, which can contain arbitrary fs-dependent
* information (or be NULL).
*
* NOTE! As old versions of mount() didn't use this setup, the flags
* have to have a special 16-bit magic number in the high word:
* 0xC0ED. If this magic word isn't present, the flags and data info
* aren't used, as the syscall assumes we are talking to an older
* version that didn't understand them.
*/
asmlinkage int sys_mount(char * dev_name, char * dir_name, char * type,
unsigned long new_flags, void * data)
{
struct file_system_type * fstype;
struct dentry * dentry = NULL;
struct inode * inode = NULL;
kdev_t dev;
int retval = -EPERM;
unsigned long flags = 0;
unsigned long page = 0;
struct file dummy; /* allows read-write or read-only flag */
lock_kernel();
if (!capable(CAP_SYS_ADMIN))
goto out;
if ((new_flags &
(MS_MGC_MSK | MS_REMOUNT)) == (MS_MGC_VAL | MS_REMOUNT)) {
retval = copy_mount_options (data, &page);
if (retval < 0)
goto out;
retval = do_remount(dir_name,
new_flags & ~MS_MGC_MSK & ~MS_REMOUNT,
(char *) page);
free_mount_page(page);
goto out;
}
retval = copy_mount_options (type, &page);
if (retval < 0)
goto out;
fstype = get_fs_type((char *) page);
free_mount_page(page);
retval = -ENODEV;
if (!fstype)
goto out;
memset(&dummy, 0, sizeof(dummy));
if (fstype->fs_flags & FS_REQUIRES_DEV) {
dentry = namei(dev_name);
retval = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out;
inode = dentry->d_inode;
retval = -ENOTBLK;
if (!S_ISBLK(inode->i_mode))
goto dput_and_out;
retval = -EACCES;
if (IS_NODEV(inode))
goto dput_and_out;
dev = inode->i_rdev;
retval = -ENXIO;
if (MAJOR(dev) >= MAX_BLKDEV)
goto dput_and_out;
retval = -ENOTBLK;
dummy.f_op = get_blkfops(MAJOR(dev));
if (!dummy.f_op)
goto dput_and_out;
if (dummy.f_op->open) {
dummy.f_dentry = dentry;
dummy.f_mode = (new_flags & MS_RDONLY) ? 1 : 3;
retval = dummy.f_op->open(inode, &dummy);
if (retval)
goto dput_and_out;
}
} else {
retval = -EMFILE;
if (!(dev = get_unnamed_dev()))
goto out;
}
page = 0;
if ((new_flags & MS_MGC_MSK) == MS_MGC_VAL) {
flags = new_flags & ~MS_MGC_MSK;
retval = copy_mount_options(data, &page);
if (retval < 0)
goto clean_up;
}
retval = do_mount(dev, dev_name, dir_name, fstype->name, flags,
(void *) page);
free_mount_page(page);
if (retval)
goto clean_up;
dput_and_out:
dput(dentry);
out:
unlock_kernel();
return retval;
clean_up:
if (dummy.f_op) {
if (dummy.f_op->release)
dummy.f_op->release(inode, NULL);
} else
put_unnamed_dev(dev);
goto dput_and_out;
}
