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>
13 #include <linux/proc_fs.h>
19 static int seq_show(struct seq_file *m, void *v)
21 struct files_struct *files = NULL;
22 int f_flags = 0, ret = -ENOENT;
23 struct file *file = NULL;
24 struct task_struct *task;
26 task = get_proc_task(m->private);
30 files = get_files_struct(task);
31 put_task_struct(task);
34 int fd = proc_fd(m->private);
36 spin_lock(&files->file_lock);
37 file = fcheck_files(files, fd);
39 struct fdtable *fdt = files_fdtable(files);
41 f_flags = file->f_flags;
42 if (close_on_exec(fd, fdt))
48 spin_unlock(&files->file_lock);
49 put_files_struct(files);
55 seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\n",
56 (long long)file->f_pos, f_flags,
57 real_mount(file->f_path.mnt)->mnt_id);
59 show_fd_locks(m, file, files);
60 if (seq_has_overflowed(m))
63 if (file->f_op->show_fdinfo)
64 file->f_op->show_fdinfo(m, file);
71 static int seq_fdinfo_open(struct inode *inode, struct file *file)
73 return single_open(file, seq_show, inode);
76 static const struct file_operations proc_fdinfo_file_operations = {
77 .open = seq_fdinfo_open,
80 .release = single_release,
83 static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
85 struct files_struct *files;
86 struct task_struct *task;
87 const struct cred *cred;
91 if (flags & LOOKUP_RCU)
94 inode = d_inode(dentry);
95 task = get_proc_task(inode);
99 files = get_files_struct(task);
104 file = fcheck_files(files, fd);
106 unsigned f_mode = file->f_mode;
109 put_files_struct(files);
111 if (task_dumpable(task)) {
113 cred = __task_cred(task);
114 inode->i_uid = cred->euid;
115 inode->i_gid = cred->egid;
118 inode->i_uid = GLOBAL_ROOT_UID;
119 inode->i_gid = GLOBAL_ROOT_GID;
122 if (S_ISLNK(inode->i_mode)) {
123 unsigned i_mode = S_IFLNK;
124 if (f_mode & FMODE_READ)
125 i_mode |= S_IRUSR | S_IXUSR;
126 if (f_mode & FMODE_WRITE)
127 i_mode |= S_IWUSR | S_IXUSR;
128 inode->i_mode = i_mode;
131 security_task_to_inode(task, inode);
132 put_task_struct(task);
136 put_files_struct(files);
138 put_task_struct(task);
143 static const struct dentry_operations tid_fd_dentry_operations = {
144 .d_revalidate = tid_fd_revalidate,
145 .d_delete = pid_delete_dentry,
148 static int proc_fd_link(struct dentry *dentry, struct path *path)
150 struct files_struct *files = NULL;
151 struct task_struct *task;
154 task = get_proc_task(d_inode(dentry));
156 files = get_files_struct(task);
157 put_task_struct(task);
161 int fd = proc_fd(d_inode(dentry));
162 struct file *fd_file;
164 spin_lock(&files->file_lock);
165 fd_file = fcheck_files(files, fd);
167 *path = fd_file->f_path;
168 path_get(&fd_file->f_path);
171 spin_unlock(&files->file_lock);
172 put_files_struct(files);
179 proc_fd_instantiate(struct inode *dir, struct dentry *dentry,
180 struct task_struct *task, const void *ptr)
182 unsigned fd = (unsigned long)ptr;
183 struct proc_inode *ei;
186 inode = proc_pid_make_inode(dir->i_sb, task);
193 inode->i_mode = S_IFLNK;
194 inode->i_op = &proc_pid_link_inode_operations;
197 ei->op.proc_get_link = proc_fd_link;
199 d_set_d_op(dentry, &tid_fd_dentry_operations);
200 d_add(dentry, inode);
202 /* Close the race of the process dying before we return the dentry */
203 if (tid_fd_revalidate(dentry, 0))
209 static struct dentry *proc_lookupfd_common(struct inode *dir,
210 struct dentry *dentry,
211 instantiate_t instantiate)
213 struct task_struct *task = get_proc_task(dir);
214 int result = -ENOENT;
215 unsigned fd = name_to_int(&dentry->d_name);
222 result = instantiate(dir, dentry, task, (void *)(unsigned long)fd);
224 put_task_struct(task);
226 return ERR_PTR(result);
229 static int proc_readfd_common(struct file *file, struct dir_context *ctx,
230 instantiate_t instantiate)
232 struct task_struct *p = get_proc_task(file_inode(file));
233 struct files_struct *files;
239 if (!dir_emit_dots(file, ctx))
241 files = get_files_struct(p);
246 for (fd = ctx->pos - 2;
247 fd < files_fdtable(files)->max_fds;
249 char name[PROC_NUMBUF];
252 if (!fcheck_files(files, fd))
256 len = snprintf(name, sizeof(name), "%d", fd);
257 if (!proc_fill_cache(file, ctx,
258 name, len, instantiate, p,
259 (void *)(unsigned long)fd))
265 put_files_struct(files);
271 static int proc_readfd(struct file *file, struct dir_context *ctx)
273 return proc_readfd_common(file, ctx, proc_fd_instantiate);
276 const struct file_operations proc_fd_operations = {
277 .read = generic_read_dir,
278 .iterate = proc_readfd,
279 .llseek = default_llseek,
282 static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
285 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
289 * /proc/pid/fd needs a special permission handler so that a process can still
290 * access /proc/self/fd after it has executed a setuid().
292 int proc_fd_permission(struct inode *inode, int mask)
294 int rv = generic_permission(inode, mask);
297 if (task_tgid(current) == proc_pid(inode))
302 const struct inode_operations proc_fd_inode_operations = {
303 .lookup = proc_lookupfd,
304 .permission = proc_fd_permission,
305 .setattr = proc_setattr,
309 proc_fdinfo_instantiate(struct inode *dir, struct dentry *dentry,
310 struct task_struct *task, const void *ptr)
312 unsigned fd = (unsigned long)ptr;
313 struct proc_inode *ei;
316 inode = proc_pid_make_inode(dir->i_sb, task);
323 inode->i_mode = S_IFREG | S_IRUSR;
324 inode->i_fop = &proc_fdinfo_file_operations;
326 d_set_d_op(dentry, &tid_fd_dentry_operations);
327 d_add(dentry, inode);
329 /* Close the race of the process dying before we return the dentry */
330 if (tid_fd_revalidate(dentry, 0))
336 static struct dentry *
337 proc_lookupfdinfo(struct inode *dir, struct dentry *dentry, unsigned int flags)
339 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
342 static int proc_readfdinfo(struct file *file, struct dir_context *ctx)
344 return proc_readfd_common(file, ctx,
345 proc_fdinfo_instantiate);
348 const struct inode_operations proc_fdinfo_inode_operations = {
349 .lookup = proc_lookupfdinfo,
350 .setattr = proc_setattr,
353 const struct file_operations proc_fdinfo_operations = {
354 .read = generic_read_dir,
355 .iterate = proc_readfdinfo,
356 .llseek = default_llseek,