static void *bpf_obj_do_get(const struct filename *pathname,
enum bpf_type *type)
{
struct inode *inode;
struct path path;
void *raw;
int ret;
ret = kern_path(pathname->name, LOOKUP_FOLLOW, &path);
if (ret)
return ERR_PTR(ret);
inode = d_backing_inode(path.dentry);
ret = inode_permission(inode, MAY_WRITE);
if (ret)
goto out;
ret = bpf_inode_type(inode, type);
if (ret)
goto out;
raw = bpf_any_get(inode->i_private, *type);
if (!IS_ERR(raw))
touch_atime(&path);
path_put(&path);
return raw;
out:
path_put(&path);
return ERR_PTR(ret);
}
SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
char __user *, buf, int, bufsiz)
{
struct path path;
int error;
if (bufsiz <= 0)
return -EINVAL;
error = user_path_at(dfd, pathname, 0, &path);
if (!error) {
struct inode *inode = path.dentry->d_inode;
error = -EINVAL;
if (inode->i_op->readlink) {
error = security_inode_readlink(path.dentry);
if (!error) {
touch_atime(path.mnt, path.dentry);
error = inode->i_op->readlink(path.dentry,
buf, bufsiz);
}
}
path_put(&path);
}
return error;
}
SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
char __user *, buf, int, bufsiz)
{
struct path path;
int error;
int empty = 0;
unsigned int lookup_flags = LOOKUP_EMPTY;
if (bufsiz <= 0)
return -EINVAL;
retry:
error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
if (!error) {
struct inode *inode = d_backing_inode(path.dentry);
error = empty ? -ENOENT : -EINVAL;
if (inode->i_op->readlink) {
error = security_inode_readlink(path.dentry);
if (!error) {
touch_atime(&path);
error = inode->i_op->readlink(path.dentry,
buf, bufsiz);
}
}
path_put(&path);
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
}
return error;
}
SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
char __user *, buf, int, bufsiz)
{
struct path path;
int error;
int empty = 0;
if (bufsiz <= 0)
return -EINVAL;
error = user_path_at_empty(dfd, pathname, LOOKUP_EMPTY, &path, &empty);
if (!error) {
struct inode *inode = path.dentry->d_inode;
error = empty ? -ENOENT : -EINVAL;
if (inode->i_op->readlink) {
error = security_inode_readlink(path.dentry);
if (!error) {
touch_atime(&path);
error = inode->i_op->readlink(path.dentry,
buf, bufsiz);
}
}
path_put(&path);
}
return error;
}
asmlinkage long sys_readlinkat(int dfd, const char __user *path,
char __user *buf, int bufsiz)
{
struct nameidata nd;
int error;
if (bufsiz <= 0)
return -EINVAL;
error = __user_walk_fd(dfd, path, 0, &nd);
if (!error) {
struct inode * inode = nd.dentry->d_inode;
error = -EINVAL;
if (inode->i_op && inode->i_op->readlink) {
error = security_inode_readlink(nd.dentry);
if (!error) {
touch_atime(nd.mnt, nd.dentry);
error = inode->i_op->readlink(nd.dentry, buf, bufsiz);
}
}
path_release(&nd);
}
return error;
}
/**
* ecryptfs_read_update_atime
*
* generic_file_read updates the atime of upper layer inode. But, it
* doesn't give us a chance to update the atime of the lower layer
* inode. This function is a wrapper to generic_file_read. It
* updates the atime of the lower level inode if generic_file_read
* returns without any errors. This is to be used only for file reads.
* The function to be used for directory reads is ecryptfs_read.
*/
static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,
struct iov_iter *to)
{
ssize_t rc;
struct path *path;
struct file *file = iocb->ki_filp;
rc = generic_file_read_iter(iocb, to);
if (rc >= 0) {
path = ecryptfs_dentry_to_lower_path(file->f_path.dentry);
touch_atime(path);
}
return rc;
}
static int ovl_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
{
struct path realpath;
struct inode *realinode;
ovl_path_real(dentry, &realpath);
realinode = realpath.dentry->d_inode;
if (!realinode->i_op->readlink)
return -EINVAL;
touch_atime(&realpath);
return realinode->i_op->readlink(realpath.dentry, buf, bufsiz);
}
/**
* ecryptfs_read_update_atime
*
* generic_file_read updates the atime of upper layer inode. But, it
* doesn't give us a chance to update the atime of the lower layer
* inode. This function is a wrapper to generic_file_read. It
* updates the atime of the lower level inode if generic_file_read
* returns without any errors. This is to be used only for file reads.
* The function to be used for directory reads is ecryptfs_read.
*/
static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,
struct iov_iter *to)
{
ssize_t rc;
struct path *path;
struct file *file = iocb->ki_filp;
rc = generic_file_read_iter(iocb, to);
/*
* Even though this is a async interface, we need to wait
* for IO to finish to update atime
*/
if (-EIOCBQUEUED == rc)
rc = wait_on_sync_kiocb(iocb);
if (rc >= 0) {
path = ecryptfs_dentry_to_lower_path(file->f_path.dentry);
touch_atime(path);
}
return rc;
}
/**
* ecryptfs_read_update_atime
*
* generic_file_read updates the atime of upper layer inode. But, it
* doesn't give us a chance to update the atime of the lower layer
* inode. This function is a wrapper to generic_file_read. It
* updates the atime of the lower level inode if generic_file_read
* returns without any errors. This is to be used only for file reads.
* The function to be used for directory reads is ecryptfs_read.
*/
static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,
const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
ssize_t rc;
struct path *path;
struct file *file = iocb->ki_filp;
rc = generic_file_aio_read(iocb, iov, nr_segs, pos);
/*
* Even though this is a async interface, we need to wait
* for IO to finish to update atime
*/
if (-EIOCBQUEUED == rc)
rc = wait_on_sync_kiocb(iocb);
if (rc >= 0) {
path = ecryptfs_dentry_to_lower_path(file->f_path.dentry);
touch_atime(path);
}
return rc;
}
/**
* ecryptfs_read_update_atime
*
* generic_file_read_iter updates the atime of upper layer inode. But, it
* doesn't give us a chance to update the atime of the lower layer
* inode. This function is a wrapper to generic_file_read_iter. It
* updates the atime of the lower level inode if generic_file_read_iter
* returns without any errors. This is to be used only for file reads.
* The function to be used for directory reads is ecryptfs_read.
*/
static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,
struct iov_iter *iter, loff_t pos)
{
ssize_t rc;
struct path lower;
struct file *file = iocb->ki_filp;
rc = generic_file_read_iter(iocb, iter, pos);
/*
* Even though this is a async interface, we need to wait
* for IO to finish to update atime
*/
if (-EIOCBQUEUED == rc)
rc = wait_on_sync_kiocb(iocb);
if (rc >= 0) {
lower.dentry = ecryptfs_dentry_to_lower(file->f_path.dentry);
lower.mnt = ecryptfs_dentry_to_lower_mnt(file->f_path.dentry);
touch_atime(&lower);
}
return rc;
}
static void ovl_file_accessed(struct file *file)
{
struct inode *inode, *upperinode;
if (file->f_flags & O_NOATIME)
return;
inode = file_inode(file);
upperinode = ovl_inode_upper(inode);
if (!upperinode)
return;
if ((!timespec64_equal(&inode->i_mtime, &upperinode->i_mtime) ||
!timespec64_equal(&inode->i_ctime, &upperinode->i_ctime))) {
inode->i_mtime = upperinode->i_mtime;
inode->i_ctime = upperinode->i_ctime;
}
touch_atime(&file->f_path);
}
int ovl_update_time(struct inode *inode, struct timespec *ts, int flags)
{
struct dentry *alias;
struct path upperpath;
if (!(flags & S_ATIME))
return 0;
alias = d_find_any_alias(inode);
if (!alias)
return 0;
ovl_path_upper(alias, &upperpath);
if (upperpath.dentry) {
touch_atime(&upperpath);
inode->i_atime = d_inode(upperpath.dentry)->i_atime;
}
dput(alias);
return 0;
}
long readlink_by_fd(int fd, char __user * buf, int buffsize)
{
int error = 0;
int fput_needed;
struct file *filep;
struct inode *inode;
filep = fget_light(fd, &fput_needed);
if(!filep)
return -EBADF;
inode = filep->f_dentry->d_inode;
error = -EINVAL;
if(inode->i_op && inode->i_op->readlink)
{
touch_atime(filep->f_vfsmnt, filep->f_dentry);
error = inode->i_op->readlink(filep->f_dentry, buf, buffsize);
}
fput_light(filep, fput_needed);
return error;
}
