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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>
7#include <linux/pid.h>
8#include <linux/security.h>
9#include <linux/file.h>
10#include <linux/seq_file.h>
11#include <linux/fs.h>
12
13#include <linux/proc_fs.h>
14
15#include "../mount.h"
16#include "internal.h"
17#include "fd.h"
18
19static int seq_show(struct seq_file *m, void *v)
20{
21 struct files_struct *files = NULL;
22 int f_flags = 0, ret = -ENOENT;
23 struct file *file = NULL;
24 struct task_struct *task;
25
26 task = get_proc_task(m->private);
27 if (!task)
28 return -ENOENT;
29
30 files = get_files_struct(task);
31 put_task_struct(task);
32
33 if (files) {
34 int fd = proc_fd(m->private);
35
36 spin_lock(&files->file_lock);
37 file = fcheck_files(files, fd);
38 if (file) {
39 struct fdtable *fdt = files_fdtable(files);
40
41 f_flags = file->f_flags;
42 if (close_on_exec(fd, fdt))
43 f_flags |= O_CLOEXEC;
44
45 get_file(file);
46 ret = 0;
47 }
48 spin_unlock(&files->file_lock);
49 put_files_struct(files);
50 }
51
52 if (ret)
53 return ret;
54
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);
58
59 show_fd_locks(m, file, files);
60 if (seq_has_overflowed(m))
61 goto out;
62
63 if (file->f_op->show_fdinfo)
64 file->f_op->show_fdinfo(m, file);
65
66out:
67 fput(file);
68 return 0;
69}
70
71static int seq_fdinfo_open(struct inode *inode, struct file *file)
72{
73 return single_open(file, seq_show, inode);
74}
75
76static const struct file_operations proc_fdinfo_file_operations = {
77 .open = seq_fdinfo_open,
78 .read = seq_read,
79 .llseek = seq_lseek,
80 .release = single_release,
81};
82
83static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
84{
85 struct files_struct *files;
86 struct task_struct *task;
87 const struct cred *cred;
88 struct inode *inode;
89 int fd;
90
91 if (flags & LOOKUP_RCU)
92 return -ECHILD;
93
94 inode = d_inode(dentry);
95 task = get_proc_task(inode);
96 fd = proc_fd(inode);
97
98 if (task) {
99 files = get_files_struct(task);
100 if (files) {
101 struct file *file;
102
103 rcu_read_lock();
104 file = fcheck_files(files, fd);
105 if (file) {
106 unsigned f_mode = file->f_mode;
107
108 rcu_read_unlock();
109 put_files_struct(files);
110
111 if (task_dumpable(task)) {
112 rcu_read_lock();
113 cred = __task_cred(task);
114 inode->i_uid = cred->euid;
115 inode->i_gid = cred->egid;
116 rcu_read_unlock();
117 } else {
118 inode->i_uid = GLOBAL_ROOT_UID;
119 inode->i_gid = GLOBAL_ROOT_GID;
120 }
121
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;
129 }
130
131 security_task_to_inode(task, inode);
132 put_task_struct(task);
133 return 1;
134 }
135 rcu_read_unlock();
136 put_files_struct(files);
137 }
138 put_task_struct(task);
139 }
140 return 0;
141}
142
143static const struct dentry_operations tid_fd_dentry_operations = {
144 .d_revalidate = tid_fd_revalidate,
145 .d_delete = pid_delete_dentry,
146};
147
148static int proc_fd_link(struct dentry *dentry, struct path *path)
149{
150 struct files_struct *files = NULL;
151 struct task_struct *task;
152 int ret = -ENOENT;
153
154 task = get_proc_task(d_inode(dentry));
155 if (task) {
156 files = get_files_struct(task);
157 put_task_struct(task);
158 }
159
160 if (files) {
161 int fd = proc_fd(d_inode(dentry));
162 struct file *fd_file;
163
164 spin_lock(&files->file_lock);
165 fd_file = fcheck_files(files, fd);
166 if (fd_file) {
167 *path = fd_file->f_path;
168 path_get(&fd_file->f_path);
169 ret = 0;
170 }
171 spin_unlock(&files->file_lock);
172 put_files_struct(files);
173 }
174
175 return ret;
176}
177
178static int
179proc_fd_instantiate(struct inode *dir, struct dentry *dentry,
180 struct task_struct *task, const void *ptr)
181{
182 unsigned fd = (unsigned long)ptr;
183 struct proc_inode *ei;
184 struct inode *inode;
185
186 inode = proc_pid_make_inode(dir->i_sb, task);
187 if (!inode)
188 goto out;
189
190 ei = PROC_I(inode);
191 ei->fd = fd;
192
193 inode->i_mode = S_IFLNK;
194 inode->i_op = &proc_pid_link_inode_operations;
195 inode->i_size = 64;
196
197 ei->op.proc_get_link = proc_fd_link;
198
199 d_set_d_op(dentry, &tid_fd_dentry_operations);
200 d_add(dentry, inode);
201
202 /* Close the race of the process dying before we return the dentry */
203 if (tid_fd_revalidate(dentry, 0))
204 return 0;
205 out:
206 return -ENOENT;
207}
208
209static struct dentry *proc_lookupfd_common(struct inode *dir,
210 struct dentry *dentry,
211 instantiate_t instantiate)
212{
213 struct task_struct *task = get_proc_task(dir);
214 int result = -ENOENT;
215 unsigned fd = name_to_int(&dentry->d_name);
216
217 if (!task)
218 goto out_no_task;
219 if (fd == ~0U)
220 goto out;
221
222 result = instantiate(dir, dentry, task, (void *)(unsigned long)fd);
223out:
224 put_task_struct(task);
225out_no_task:
226 return ERR_PTR(result);
227}
228
229static int proc_readfd_common(struct file *file, struct dir_context *ctx,
230 instantiate_t instantiate)
231{
232 struct task_struct *p = get_proc_task(file_inode(file));
233 struct files_struct *files;
234 unsigned int fd;
235
236 if (!p)
237 return -ENOENT;
238
239 if (!dir_emit_dots(file, ctx))
240 goto out;
241 files = get_files_struct(p);
242 if (!files)
243 goto out;
244
245 rcu_read_lock();
246 for (fd = ctx->pos - 2;
247 fd < files_fdtable(files)->max_fds;
248 fd++, ctx->pos++) {
249 char name[PROC_NUMBUF];
250 int len;
251
252 if (!fcheck_files(files, fd))
253 continue;
254 rcu_read_unlock();
255
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))
260 goto out_fd_loop;
261 cond_resched();
262 rcu_read_lock();
263 }
264 rcu_read_unlock();
265out_fd_loop:
266 put_files_struct(files);
267out:
268 put_task_struct(p);
269 return 0;
270}
271
272static int proc_readfd(struct file *file, struct dir_context *ctx)
273{
274 return proc_readfd_common(file, ctx, proc_fd_instantiate);
275}
276
277const struct file_operations proc_fd_operations = {
278 .read = generic_read_dir,
279 .iterate = proc_readfd,
280 .llseek = default_llseek,
281};
282
283static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
284 unsigned int flags)
285{
286 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
287}
288
289/*
290 * /proc/pid/fd needs a special permission handler so that a process can still
291 * access /proc/self/fd after it has executed a setuid().
292 */
293int proc_fd_permission(struct inode *inode, int mask)
294{
295 struct task_struct *p;
296 int rv;
297
298 rv = generic_permission(inode, mask);
299 if (rv == 0)
300 return rv;
301
302 rcu_read_lock();
303 p = pid_task(proc_pid(inode), PIDTYPE_PID);
304 if (p && same_thread_group(p, current))
305 rv = 0;
306 rcu_read_unlock();
307
308 return rv;
309}
310
311const struct inode_operations proc_fd_inode_operations = {
312 .lookup = proc_lookupfd,
313 .permission = proc_fd_permission,
314 .setattr = proc_setattr,
315};
316
317static int
318proc_fdinfo_instantiate(struct inode *dir, struct dentry *dentry,
319 struct task_struct *task, const void *ptr)
320{
321 unsigned fd = (unsigned long)ptr;
322 struct proc_inode *ei;
323 struct inode *inode;
324
325 inode = proc_pid_make_inode(dir->i_sb, task);
326 if (!inode)
327 goto out;
328
329 ei = PROC_I(inode);
330 ei->fd = fd;
331
332 inode->i_mode = S_IFREG | S_IRUSR;
333 inode->i_fop = &proc_fdinfo_file_operations;
334
335 d_set_d_op(dentry, &tid_fd_dentry_operations);
336 d_add(dentry, inode);
337
338 /* Close the race of the process dying before we return the dentry */
339 if (tid_fd_revalidate(dentry, 0))
340 return 0;
341 out:
342 return -ENOENT;
343}
344
345static struct dentry *
346proc_lookupfdinfo(struct inode *dir, struct dentry *dentry, unsigned int flags)
347{
348 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
349}
350
351static int proc_readfdinfo(struct file *file, struct dir_context *ctx)
352{
353 return proc_readfd_common(file, ctx,
354 proc_fdinfo_instantiate);
355}
356
357const struct inode_operations proc_fdinfo_inode_operations = {
358 .lookup = proc_lookupfdinfo,
359 .setattr = proc_setattr,
360};
361
362const struct file_operations proc_fdinfo_operations = {
363 .read = generic_read_dir,
364 .iterate = proc_readfdinfo,
365 .llseek = default_llseek,
366};
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>
7#include <linux/pid.h>
8#include <linux/security.h>
9#include <linux/file.h>
10#include <linux/seq_file.h>
11
12#include <linux/proc_fs.h>
13
14#include "../mount.h"
15#include "internal.h"
16#include "fd.h"
17
18static int seq_show(struct seq_file *m, void *v)
19{
20 struct files_struct *files = NULL;
21 int f_flags = 0, ret = -ENOENT;
22 struct file *file = NULL;
23 struct task_struct *task;
24
25 task = get_proc_task(m->private);
26 if (!task)
27 return -ENOENT;
28
29 files = get_files_struct(task);
30 put_task_struct(task);
31
32 if (files) {
33 int fd = proc_fd(m->private);
34
35 spin_lock(&files->file_lock);
36 file = fcheck_files(files, fd);
37 if (file) {
38 struct fdtable *fdt = files_fdtable(files);
39
40 f_flags = file->f_flags;
41 if (close_on_exec(fd, fdt))
42 f_flags |= O_CLOEXEC;
43
44 get_file(file);
45 ret = 0;
46 }
47 spin_unlock(&files->file_lock);
48 put_files_struct(files);
49 }
50
51 if (!ret) {
52 seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\n",
53 (long long)file->f_pos, f_flags,
54 real_mount(file->f_path.mnt)->mnt_id);
55 if (file->f_op->show_fdinfo)
56 ret = file->f_op->show_fdinfo(m, file);
57 fput(file);
58 }
59
60 return ret;
61}
62
63static int seq_fdinfo_open(struct inode *inode, struct file *file)
64{
65 return single_open(file, seq_show, inode);
66}
67
68static const struct file_operations proc_fdinfo_file_operations = {
69 .open = seq_fdinfo_open,
70 .read = seq_read,
71 .llseek = seq_lseek,
72 .release = single_release,
73};
74
75static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
76{
77 struct files_struct *files;
78 struct task_struct *task;
79 const struct cred *cred;
80 struct inode *inode;
81 int fd;
82
83 if (flags & LOOKUP_RCU)
84 return -ECHILD;
85
86 inode = dentry->d_inode;
87 task = get_proc_task(inode);
88 fd = proc_fd(inode);
89
90 if (task) {
91 files = get_files_struct(task);
92 if (files) {
93 struct file *file;
94
95 rcu_read_lock();
96 file = fcheck_files(files, fd);
97 if (file) {
98 unsigned f_mode = file->f_mode;
99
100 rcu_read_unlock();
101 put_files_struct(files);
102
103 if (task_dumpable(task)) {
104 rcu_read_lock();
105 cred = __task_cred(task);
106 inode->i_uid = cred->euid;
107 inode->i_gid = cred->egid;
108 rcu_read_unlock();
109 } else {
110 inode->i_uid = GLOBAL_ROOT_UID;
111 inode->i_gid = GLOBAL_ROOT_GID;
112 }
113
114 if (S_ISLNK(inode->i_mode)) {
115 unsigned i_mode = S_IFLNK;
116 if (f_mode & FMODE_READ)
117 i_mode |= S_IRUSR | S_IXUSR;
118 if (f_mode & FMODE_WRITE)
119 i_mode |= S_IWUSR | S_IXUSR;
120 inode->i_mode = i_mode;
121 }
122
123 security_task_to_inode(task, inode);
124 put_task_struct(task);
125 return 1;
126 }
127 rcu_read_unlock();
128 put_files_struct(files);
129 }
130 put_task_struct(task);
131 }
132
133 d_drop(dentry);
134 return 0;
135}
136
137static const struct dentry_operations tid_fd_dentry_operations = {
138 .d_revalidate = tid_fd_revalidate,
139 .d_delete = pid_delete_dentry,
140};
141
142static int proc_fd_link(struct dentry *dentry, struct path *path)
143{
144 struct files_struct *files = NULL;
145 struct task_struct *task;
146 int ret = -ENOENT;
147
148 task = get_proc_task(dentry->d_inode);
149 if (task) {
150 files = get_files_struct(task);
151 put_task_struct(task);
152 }
153
154 if (files) {
155 int fd = proc_fd(dentry->d_inode);
156 struct file *fd_file;
157
158 spin_lock(&files->file_lock);
159 fd_file = fcheck_files(files, fd);
160 if (fd_file) {
161 *path = fd_file->f_path;
162 path_get(&fd_file->f_path);
163 ret = 0;
164 }
165 spin_unlock(&files->file_lock);
166 put_files_struct(files);
167 }
168
169 return ret;
170}
171
172static int
173proc_fd_instantiate(struct inode *dir, struct dentry *dentry,
174 struct task_struct *task, const void *ptr)
175{
176 unsigned fd = (unsigned long)ptr;
177 struct proc_inode *ei;
178 struct inode *inode;
179
180 inode = proc_pid_make_inode(dir->i_sb, task);
181 if (!inode)
182 goto out;
183
184 ei = PROC_I(inode);
185 ei->fd = fd;
186
187 inode->i_mode = S_IFLNK;
188 inode->i_op = &proc_pid_link_inode_operations;
189 inode->i_size = 64;
190
191 ei->op.proc_get_link = proc_fd_link;
192
193 d_set_d_op(dentry, &tid_fd_dentry_operations);
194 d_add(dentry, inode);
195
196 /* Close the race of the process dying before we return the dentry */
197 if (tid_fd_revalidate(dentry, 0))
198 return 0;
199 out:
200 return -ENOENT;
201}
202
203static struct dentry *proc_lookupfd_common(struct inode *dir,
204 struct dentry *dentry,
205 instantiate_t instantiate)
206{
207 struct task_struct *task = get_proc_task(dir);
208 int result = -ENOENT;
209 unsigned fd = name_to_int(dentry);
210
211 if (!task)
212 goto out_no_task;
213 if (fd == ~0U)
214 goto out;
215
216 result = instantiate(dir, dentry, task, (void *)(unsigned long)fd);
217out:
218 put_task_struct(task);
219out_no_task:
220 return ERR_PTR(result);
221}
222
223static int proc_readfd_common(struct file *file, struct dir_context *ctx,
224 instantiate_t instantiate)
225{
226 struct task_struct *p = get_proc_task(file_inode(file));
227 struct files_struct *files;
228 unsigned int fd;
229
230 if (!p)
231 return -ENOENT;
232
233 if (!dir_emit_dots(file, ctx))
234 goto out;
235 files = get_files_struct(p);
236 if (!files)
237 goto out;
238
239 rcu_read_lock();
240 for (fd = ctx->pos - 2;
241 fd < files_fdtable(files)->max_fds;
242 fd++, ctx->pos++) {
243 char name[PROC_NUMBUF];
244 int len;
245
246 if (!fcheck_files(files, fd))
247 continue;
248 rcu_read_unlock();
249
250 len = snprintf(name, sizeof(name), "%d", fd);
251 if (!proc_fill_cache(file, ctx,
252 name, len, instantiate, p,
253 (void *)(unsigned long)fd))
254 goto out_fd_loop;
255 rcu_read_lock();
256 }
257 rcu_read_unlock();
258out_fd_loop:
259 put_files_struct(files);
260out:
261 put_task_struct(p);
262 return 0;
263}
264
265static int proc_readfd(struct file *file, struct dir_context *ctx)
266{
267 return proc_readfd_common(file, ctx, proc_fd_instantiate);
268}
269
270const struct file_operations proc_fd_operations = {
271 .read = generic_read_dir,
272 .iterate = proc_readfd,
273 .llseek = default_llseek,
274};
275
276static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
277 unsigned int flags)
278{
279 return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
280}
281
282/*
283 * /proc/pid/fd needs a special permission handler so that a process can still
284 * access /proc/self/fd after it has executed a setuid().
285 */
286int proc_fd_permission(struct inode *inode, int mask)
287{
288 int rv = generic_permission(inode, mask);
289 if (rv == 0)
290 return 0;
291 if (task_tgid(current) == proc_pid(inode))
292 rv = 0;
293 return rv;
294}
295
296const struct inode_operations proc_fd_inode_operations = {
297 .lookup = proc_lookupfd,
298 .permission = proc_fd_permission,
299 .setattr = proc_setattr,
300};
301
302static int
303proc_fdinfo_instantiate(struct inode *dir, struct dentry *dentry,
304 struct task_struct *task, const void *ptr)
305{
306 unsigned fd = (unsigned long)ptr;
307 struct proc_inode *ei;
308 struct inode *inode;
309
310 inode = proc_pid_make_inode(dir->i_sb, task);
311 if (!inode)
312 goto out;
313
314 ei = PROC_I(inode);
315 ei->fd = fd;
316
317 inode->i_mode = S_IFREG | S_IRUSR;
318 inode->i_fop = &proc_fdinfo_file_operations;
319
320 d_set_d_op(dentry, &tid_fd_dentry_operations);
321 d_add(dentry, inode);
322
323 /* Close the race of the process dying before we return the dentry */
324 if (tid_fd_revalidate(dentry, 0))
325 return 0;
326 out:
327 return -ENOENT;
328}
329
330static struct dentry *
331proc_lookupfdinfo(struct inode *dir, struct dentry *dentry, unsigned int flags)
332{
333 return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
334}
335
336static int proc_readfdinfo(struct file *file, struct dir_context *ctx)
337{
338 return proc_readfd_common(file, ctx,
339 proc_fdinfo_instantiate);
340}
341
342const struct inode_operations proc_fdinfo_inode_operations = {
343 .lookup = proc_lookupfdinfo,
344 .setattr = proc_setattr,
345};
346
347const struct file_operations proc_fdinfo_operations = {
348 .read = generic_read_dir,
349 .iterate = proc_readfdinfo,
350 .llseek = default_llseek,
351};