static int proc_fd_link(struct dentry *dentry, struct path *path)
{
struct files_struct *files = NULL;
struct task_struct *task;
int ret = -ENOENT;
task = get_proc_task(dentry->d_inode);
if (task) {
files = get_files_struct(task);
put_task_struct(task);
}
if (files) {
int fd = proc_fd(dentry->d_inode);
struct file *fd_file;
spin_lock(&files->file_lock);
fd_file = fcheck_files(files, fd);
if (fd_file) {
*path = fd_file->f_path;
path_get(&fd_file->f_path);
ret = 0;
}
spin_unlock(&files->file_lock);
put_files_struct(files);
}
return ret;
}
static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
{
struct files_struct *files;
struct task_struct *task;
const struct cred *cred;
struct inode *inode;
int fd;
if (flags & LOOKUP_RCU)
return -ECHILD;
inode = dentry->d_inode;
task = get_proc_task(inode);
fd = proc_fd(inode);
if (task) {
files = get_files_struct(task);
if (files) {
struct file *file;
rcu_read_lock();
file = fcheck_files(files, fd);
if (file) {
unsigned f_mode = file->f_mode;
rcu_read_unlock();
put_files_struct(files);
if (task_dumpable(task)) {
rcu_read_lock();
cred = __task_cred(task);
inode->i_uid = cred->euid;
inode->i_gid = cred->egid;
rcu_read_unlock();
} else {
inode->i_uid = GLOBAL_ROOT_UID;
inode->i_gid = GLOBAL_ROOT_GID;
}
if (S_ISLNK(inode->i_mode)) {
unsigned i_mode = S_IFLNK;
if (f_mode & FMODE_READ)
i_mode |= S_IRUSR | S_IXUSR;
if (f_mode & FMODE_WRITE)
i_mode |= S_IWUSR | S_IXUSR;
inode->i_mode = i_mode;
}
security_task_to_inode(task, inode);
put_task_struct(task);
return 1;
}
rcu_read_unlock();
put_files_struct(files);
}
put_task_struct(task);
}
return 0;
}
static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
{
struct files_struct *files;
struct task_struct *task;
struct inode *inode;
unsigned int fd;
if (flags & LOOKUP_RCU)
return -ECHILD;
inode = d_inode(dentry);
task = get_proc_task(inode);
fd = proc_fd(inode);
if (task) {
files = get_files_struct(task);
if (files) {
struct file *file;
rcu_read_lock();
file = fcheck_files(files, fd);
if (file) {
unsigned f_mode = file->f_mode;
rcu_read_unlock();
put_files_struct(files);
task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
if (S_ISLNK(inode->i_mode)) {
unsigned i_mode = S_IFLNK;
if (f_mode & FMODE_READ)
i_mode |= S_IRUSR | S_IXUSR;
if (f_mode & FMODE_WRITE)
i_mode |= S_IWUSR | S_IXUSR;
inode->i_mode = i_mode;
}
security_task_to_inode(task, inode);
put_task_struct(task);
return 1;
}
rcu_read_unlock();
put_files_struct(files);
}
put_task_struct(task);
}
return 0;
}