1 #include <linux/sched.h>
2 #include <linux/errno.h>
3 #include <linux/dcache.h>
4 #include <linux/path.h>
5 #include <linux/fdtable.h>
6 #include <linux/namei.h>
8 #include <linux/security.h>
9 #include <linux/file.h>
10 #include <linux/seq_file.h>
12 #include <linux/proc_fs.h>
17 static int seq_show(struct seq_file *m, void *v)
19 struct files_struct *files = NULL;
20 int f_flags = 0, ret = -ENOENT;
21 struct file *file = NULL;
22 struct task_struct *task;
24 task = get_proc_task(m->private);
28 files = get_files_struct(task);
29 put_task_struct(task);
32 int fd = proc_fd(m->private);
34 spin_lock(&files->file_lock);
35 file = fcheck_files(files, fd);
37 struct fdtable *fdt = files_fdtable(files);
39 f_flags = file->f_flags;
40 if (close_on_exec(fd, fdt))
46 spin_unlock(&files->file_lock);
47 put_files_struct(files);
51 seq_printf(m, "pos:\t%lli\nflags:\t0%o\n",
52 (long long)file->f_pos, f_flags);
59 static int seq_fdinfo_open(struct inode *inode, struct file *file)
61 return single_open(file, seq_show, inode);
64 static const struct file_operations proc_fdinfo_file_operations = {
65 .open = seq_fdinfo_open,
68 .release = single_release,
71 static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
73 struct files_struct *files;
74 struct task_struct *task;
75 const struct cred *cred;
79 if (flags & LOOKUP_RCU)
82 inode = dentry->d_inode;
83 task = get_proc_task(inode);
87 files = get_files_struct(task);
92 file = fcheck_files(files, fd);
94 unsigned f_mode = file->f_mode;
97 put_files_struct(files);
99 if (task_dumpable(task)) {
101 cred = __task_cred(task);
102 inode->i_uid = cred->euid;
103 inode->i_gid = cred->egid;
106 inode->i_uid = GLOBAL_ROOT_UID;
107 inode->i_gid = GLOBAL_ROOT_GID;
110 if (S_ISLNK(inode->i_mode)) {
111 unsigned i_mode = S_IFLNK;
112 if (f_mode & FMODE_READ)
113 i_mode |= S_IRUSR | S_IXUSR;
114 if (f_mode & FMODE_WRITE)
115 i_mode |= S_IWUSR | S_IXUSR;
116 inode->i_mode = i_mode;
119 security_task_to_inode(task, inode);
120 put_task_struct(task);
124 put_files_struct(files);
126 put_task_struct(task);
133 static const struct dentry_operations tid_fd_dentry_operations = {
134 .d_revalidate = tid_fd_revalidate,
135 .d_delete = pid_delete_dentry,
138 static int proc_fd_link(struct dentry *dentry, struct path *path)
140 struct files_struct *files = NULL;
141 struct task_struct *task;
144 task = get_proc_task(dentry->d_inode);
146 files = get_files_struct(task);
147 put_task_struct(task);
151 int fd = proc_fd(dentry->d_inode);
152 struct file *fd_file;
154 spin_lock(&files->file_lock);
155 fd_file = fcheck_files(files, fd);
157 *path = fd_file->f_path;
158 path_get(&fd_file->f_path);
161 spin_unlock(&files->file_lock);
162 put_files_struct(files);
168 static struct dentry *
169 proc_fd_instantiate(struct inode *dir, struct dentry *dentry,
170 struct task_struct *task, const void *ptr)
172 struct dentry *error = ERR_PTR(-ENOENT);
173 unsigned fd = (unsigned long)ptr;
174 struct proc_inode *ei;
177 inode = proc_pid_make_inode(dir->i_sb, task);
184 inode->i_mode = S_IFLNK;
185 inode->i_op = &proc_pid_link_inode_operations;
188 ei->op.proc_get_link = proc_fd_link;
190 d_set_d_op(dentry, &tid_fd_dentry_operations);
191 d_add(dentry, inode);
193 /* Close the race of the process dying before we return the dentry */
194 if (tid_fd_revalidate(dentry, 0))
200 static struct dentry *proc_lookupfd_common(struct inode *dir,
201 struct dentry *dentry,
202 instantiate_t instantiate)
204 struct task_struct *task = get_proc_task(dir);
205 struct dentry *result = ERR_PTR(-ENOENT);
206 unsigned fd = name_to_int(dentry);
213 result = instantiate(dir, dentry, task, (void *)(unsigned long)fd);
215 put_task_struct(task);
220 static int proc_readfd_common(struct file * filp, void * dirent,
221 filldir_t filldir, instantiate_t instantiate)
223 struct dentry *dentry = filp->f_path.dentry;
224 struct inode *inode = dentry->d_inode;
225 struct task_struct *p = get_proc_task(inode);
226 struct files_struct *files;
227 unsigned int fd, ino;
238 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
242 ino = parent_ino(dentry);
243 if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
247 files = get_files_struct(p);
251 for (fd = filp->f_pos - 2;
252 fd < files_fdtable(files)->max_fds;
253 fd++, filp->f_pos++) {
254 char name[PROC_NUMBUF];
258 if (!fcheck_files(files, fd))
262 len = snprintf(name, sizeof(name), "%d", fd);
263 rv = proc_fill_cache(filp, dirent, filldir,
264 name, len, instantiate, p,
265 (void *)(unsigned long)fd);
272 put_files_struct(files);
280 static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
282 return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
285 const struct file_operations proc_fd_operations = {
286 .read = generic_read_dir,
287 .readdir = proc_readfd,
288 .llseek = default_llseek,
291 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
294 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
298 * /proc/pid/fd needs a special permission handler so that a process can still
299 * access /proc/self/fd after it has executed a setuid().
301 int proc_fd_permission(struct inode *inode, int mask)
303 int rv = generic_permission(inode, mask);
306 if (task_pid(current) == proc_pid(inode))
311 const struct inode_operations proc_fd_inode_operations = {
312 .lookup = proc_lookupfd,
313 .permission = proc_fd_permission,
314 .setattr = proc_setattr,
317 static struct dentry *
318 proc_fdinfo_instantiate(struct inode *dir, struct dentry *dentry,
319 struct task_struct *task, const void *ptr)
321 struct dentry *error = ERR_PTR(-ENOENT);
322 unsigned fd = (unsigned long)ptr;
323 struct proc_inode *ei;
326 inode = proc_pid_make_inode(dir->i_sb, task);
333 inode->i_mode = S_IFREG | S_IRUSR;
334 inode->i_fop = &proc_fdinfo_file_operations;
336 d_set_d_op(dentry, &tid_fd_dentry_operations);
337 d_add(dentry, inode);
339 /* Close the race of the process dying before we return the dentry */
340 if (tid_fd_revalidate(dentry, 0))
346 static struct dentry *
347 proc_lookupfdinfo(struct inode *dir, struct dentry *dentry, unsigned int flags)
349 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
352 static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
354 return proc_readfd_common(filp, dirent, filldir,
355 proc_fdinfo_instantiate);
358 const struct inode_operations proc_fdinfo_inode_operations = {
359 .lookup = proc_lookupfdinfo,
360 .setattr = proc_setattr,
363 const struct file_operations proc_fdinfo_operations = {
364 .read = generic_read_dir,
365 .readdir = proc_readfdinfo,
366 .llseek = default_llseek,