Commit | Line | Data |
---|---|---|
3f07c014 | 1 | #include <linux/sched/signal.h> |
faf60af1 CG |
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> | |
ddd3e077 CG |
9 | #include <linux/file.h> |
10 | #include <linux/seq_file.h> | |
6c8c9031 | 11 | #include <linux/fs.h> |
faf60af1 CG |
12 | |
13 | #include <linux/proc_fs.h> | |
14 | ||
49d063cb | 15 | #include "../mount.h" |
faf60af1 CG |
16 | #include "internal.h" |
17 | #include "fd.h" | |
18 | ||
ddd3e077 | 19 | static int seq_show(struct seq_file *m, void *v) |
faf60af1 | 20 | { |
faf60af1 | 21 | struct files_struct *files = NULL; |
ddd3e077 CG |
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); | |
faf60af1 | 32 | |
faf60af1 | 33 | if (files) { |
771187d6 | 34 | unsigned int fd = proc_fd(m->private); |
ddd3e077 | 35 | |
faf60af1 CG |
36 | spin_lock(&files->file_lock); |
37 | file = fcheck_files(files, fd); | |
38 | if (file) { | |
ddd3e077 | 39 | struct fdtable *fdt = files_fdtable(files); |
faf60af1 | 40 | |
c6f3d811 | 41 | f_flags = file->f_flags; |
faf60af1 CG |
42 | if (close_on_exec(fd, fdt)) |
43 | f_flags |= O_CLOEXEC; | |
44 | ||
ddd3e077 CG |
45 | get_file(file); |
46 | ret = 0; | |
faf60af1 CG |
47 | } |
48 | spin_unlock(&files->file_lock); | |
49 | put_files_struct(files); | |
50 | } | |
ddd3e077 | 51 | |
6c8c9031 AV |
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); | |
ddd3e077 | 65 | |
6c8c9031 AV |
66 | out: |
67 | fput(file); | |
68 | return 0; | |
faf60af1 CG |
69 | } |
70 | ||
ddd3e077 CG |
71 | static int seq_fdinfo_open(struct inode *inode, struct file *file) |
72 | { | |
73 | return single_open(file, seq_show, inode); | |
74 | } | |
75 | ||
76 | static 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 | ||
faf60af1 CG |
83 | static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags) |
84 | { | |
85 | struct files_struct *files; | |
86 | struct task_struct *task; | |
faf60af1 | 87 | struct inode *inode; |
771187d6 | 88 | unsigned int fd; |
faf60af1 CG |
89 | |
90 | if (flags & LOOKUP_RCU) | |
91 | return -ECHILD; | |
92 | ||
2b0143b5 | 93 | inode = d_inode(dentry); |
faf60af1 CG |
94 | task = get_proc_task(inode); |
95 | fd = proc_fd(inode); | |
96 | ||
97 | if (task) { | |
98 | files = get_files_struct(task); | |
99 | if (files) { | |
100 | struct file *file; | |
101 | ||
102 | rcu_read_lock(); | |
103 | file = fcheck_files(files, fd); | |
104 | if (file) { | |
105 | unsigned f_mode = file->f_mode; | |
106 | ||
107 | rcu_read_unlock(); | |
108 | put_files_struct(files); | |
109 | ||
68eb94f1 | 110 | task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); |
faf60af1 CG |
111 | |
112 | if (S_ISLNK(inode->i_mode)) { | |
113 | unsigned i_mode = S_IFLNK; | |
114 | if (f_mode & FMODE_READ) | |
115 | i_mode |= S_IRUSR | S_IXUSR; | |
116 | if (f_mode & FMODE_WRITE) | |
117 | i_mode |= S_IWUSR | S_IXUSR; | |
118 | inode->i_mode = i_mode; | |
119 | } | |
120 | ||
121 | security_task_to_inode(task, inode); | |
122 | put_task_struct(task); | |
123 | return 1; | |
124 | } | |
125 | rcu_read_unlock(); | |
126 | put_files_struct(files); | |
127 | } | |
128 | put_task_struct(task); | |
129 | } | |
faf60af1 CG |
130 | return 0; |
131 | } | |
132 | ||
133 | static const struct dentry_operations tid_fd_dentry_operations = { | |
134 | .d_revalidate = tid_fd_revalidate, | |
135 | .d_delete = pid_delete_dentry, | |
136 | }; | |
137 | ||
138 | static int proc_fd_link(struct dentry *dentry, struct path *path) | |
139 | { | |
ddd3e077 CG |
140 | struct files_struct *files = NULL; |
141 | struct task_struct *task; | |
142 | int ret = -ENOENT; | |
143 | ||
2b0143b5 | 144 | task = get_proc_task(d_inode(dentry)); |
ddd3e077 CG |
145 | if (task) { |
146 | files = get_files_struct(task); | |
147 | put_task_struct(task); | |
148 | } | |
149 | ||
150 | if (files) { | |
771187d6 | 151 | unsigned int fd = proc_fd(d_inode(dentry)); |
ddd3e077 CG |
152 | struct file *fd_file; |
153 | ||
154 | spin_lock(&files->file_lock); | |
155 | fd_file = fcheck_files(files, fd); | |
156 | if (fd_file) { | |
157 | *path = fd_file->f_path; | |
158 | path_get(&fd_file->f_path); | |
159 | ret = 0; | |
160 | } | |
161 | spin_unlock(&files->file_lock); | |
162 | put_files_struct(files); | |
163 | } | |
164 | ||
165 | return ret; | |
faf60af1 CG |
166 | } |
167 | ||
c52a47ac | 168 | static int |
faf60af1 CG |
169 | proc_fd_instantiate(struct inode *dir, struct dentry *dentry, |
170 | struct task_struct *task, const void *ptr) | |
171 | { | |
faf60af1 CG |
172 | unsigned fd = (unsigned long)ptr; |
173 | struct proc_inode *ei; | |
174 | struct inode *inode; | |
175 | ||
db978da8 | 176 | inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK); |
faf60af1 CG |
177 | if (!inode) |
178 | goto out; | |
179 | ||
180 | ei = PROC_I(inode); | |
181 | ei->fd = fd; | |
182 | ||
faf60af1 CG |
183 | inode->i_op = &proc_pid_link_inode_operations; |
184 | inode->i_size = 64; | |
185 | ||
186 | ei->op.proc_get_link = proc_fd_link; | |
187 | ||
188 | d_set_d_op(dentry, &tid_fd_dentry_operations); | |
189 | d_add(dentry, inode); | |
190 | ||
191 | /* Close the race of the process dying before we return the dentry */ | |
192 | if (tid_fd_revalidate(dentry, 0)) | |
c52a47ac | 193 | return 0; |
faf60af1 | 194 | out: |
c52a47ac | 195 | return -ENOENT; |
faf60af1 CG |
196 | } |
197 | ||
198 | static struct dentry *proc_lookupfd_common(struct inode *dir, | |
199 | struct dentry *dentry, | |
200 | instantiate_t instantiate) | |
201 | { | |
202 | struct task_struct *task = get_proc_task(dir); | |
c52a47ac | 203 | int result = -ENOENT; |
dbcdb504 | 204 | unsigned fd = name_to_int(&dentry->d_name); |
faf60af1 CG |
205 | |
206 | if (!task) | |
207 | goto out_no_task; | |
208 | if (fd == ~0U) | |
209 | goto out; | |
210 | ||
211 | result = instantiate(dir, dentry, task, (void *)(unsigned long)fd); | |
212 | out: | |
213 | put_task_struct(task); | |
214 | out_no_task: | |
c52a47ac | 215 | return ERR_PTR(result); |
faf60af1 CG |
216 | } |
217 | ||
f0c3b509 AV |
218 | static int proc_readfd_common(struct file *file, struct dir_context *ctx, |
219 | instantiate_t instantiate) | |
faf60af1 | 220 | { |
f0c3b509 | 221 | struct task_struct *p = get_proc_task(file_inode(file)); |
faf60af1 | 222 | struct files_struct *files; |
f0c3b509 | 223 | unsigned int fd; |
faf60af1 | 224 | |
faf60af1 | 225 | if (!p) |
f0c3b509 | 226 | return -ENOENT; |
faf60af1 | 227 | |
f0c3b509 AV |
228 | if (!dir_emit_dots(file, ctx)) |
229 | goto out; | |
230 | files = get_files_struct(p); | |
231 | if (!files) | |
232 | goto out; | |
233 | ||
234 | rcu_read_lock(); | |
235 | for (fd = ctx->pos - 2; | |
236 | fd < files_fdtable(files)->max_fds; | |
237 | fd++, ctx->pos++) { | |
238 | char name[PROC_NUMBUF]; | |
239 | int len; | |
240 | ||
241 | if (!fcheck_files(files, fd)) | |
242 | continue; | |
243 | rcu_read_unlock(); | |
244 | ||
771187d6 | 245 | len = snprintf(name, sizeof(name), "%u", fd); |
f0c3b509 AV |
246 | if (!proc_fill_cache(file, ctx, |
247 | name, len, instantiate, p, | |
248 | (void *)(unsigned long)fd)) | |
249 | goto out_fd_loop; | |
3cc4a84e | 250 | cond_resched(); |
f0c3b509 | 251 | rcu_read_lock(); |
faf60af1 | 252 | } |
f0c3b509 AV |
253 | rcu_read_unlock(); |
254 | out_fd_loop: | |
255 | put_files_struct(files); | |
faf60af1 CG |
256 | out: |
257 | put_task_struct(p); | |
f0c3b509 | 258 | return 0; |
faf60af1 CG |
259 | } |
260 | ||
f0c3b509 | 261 | static int proc_readfd(struct file *file, struct dir_context *ctx) |
faf60af1 | 262 | { |
f0c3b509 | 263 | return proc_readfd_common(file, ctx, proc_fd_instantiate); |
faf60af1 CG |
264 | } |
265 | ||
266 | const struct file_operations proc_fd_operations = { | |
267 | .read = generic_read_dir, | |
f50752ea AV |
268 | .iterate_shared = proc_readfd, |
269 | .llseek = generic_file_llseek, | |
faf60af1 CG |
270 | }; |
271 | ||
272 | static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, | |
273 | unsigned int flags) | |
274 | { | |
275 | return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); | |
276 | } | |
277 | ||
278 | /* | |
279 | * /proc/pid/fd needs a special permission handler so that a process can still | |
280 | * access /proc/self/fd after it has executed a setuid(). | |
281 | */ | |
282 | int proc_fd_permission(struct inode *inode, int mask) | |
283 | { | |
54708d28 ON |
284 | struct task_struct *p; |
285 | int rv; | |
286 | ||
287 | rv = generic_permission(inode, mask); | |
faf60af1 | 288 | if (rv == 0) |
54708d28 ON |
289 | return rv; |
290 | ||
291 | rcu_read_lock(); | |
292 | p = pid_task(proc_pid(inode), PIDTYPE_PID); | |
293 | if (p && same_thread_group(p, current)) | |
faf60af1 | 294 | rv = 0; |
54708d28 ON |
295 | rcu_read_unlock(); |
296 | ||
faf60af1 CG |
297 | return rv; |
298 | } | |
299 | ||
300 | const struct inode_operations proc_fd_inode_operations = { | |
301 | .lookup = proc_lookupfd, | |
302 | .permission = proc_fd_permission, | |
303 | .setattr = proc_setattr, | |
304 | }; | |
305 | ||
c52a47ac | 306 | static int |
faf60af1 CG |
307 | proc_fdinfo_instantiate(struct inode *dir, struct dentry *dentry, |
308 | struct task_struct *task, const void *ptr) | |
309 | { | |
faf60af1 CG |
310 | unsigned fd = (unsigned long)ptr; |
311 | struct proc_inode *ei; | |
312 | struct inode *inode; | |
313 | ||
db978da8 | 314 | inode = proc_pid_make_inode(dir->i_sb, task, S_IFREG | S_IRUSR); |
faf60af1 CG |
315 | if (!inode) |
316 | goto out; | |
317 | ||
318 | ei = PROC_I(inode); | |
319 | ei->fd = fd; | |
320 | ||
faf60af1 CG |
321 | inode->i_fop = &proc_fdinfo_file_operations; |
322 | ||
323 | d_set_d_op(dentry, &tid_fd_dentry_operations); | |
324 | d_add(dentry, inode); | |
325 | ||
326 | /* Close the race of the process dying before we return the dentry */ | |
327 | if (tid_fd_revalidate(dentry, 0)) | |
c52a47ac | 328 | return 0; |
faf60af1 | 329 | out: |
c52a47ac | 330 | return -ENOENT; |
faf60af1 CG |
331 | } |
332 | ||
333 | static struct dentry * | |
334 | proc_lookupfdinfo(struct inode *dir, struct dentry *dentry, unsigned int flags) | |
335 | { | |
336 | return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); | |
337 | } | |
338 | ||
f0c3b509 | 339 | static int proc_readfdinfo(struct file *file, struct dir_context *ctx) |
faf60af1 | 340 | { |
f0c3b509 | 341 | return proc_readfd_common(file, ctx, |
faf60af1 CG |
342 | proc_fdinfo_instantiate); |
343 | } | |
344 | ||
345 | const struct inode_operations proc_fdinfo_inode_operations = { | |
346 | .lookup = proc_lookupfdinfo, | |
347 | .setattr = proc_setattr, | |
348 | }; | |
349 | ||
350 | const struct file_operations proc_fdinfo_operations = { | |
351 | .read = generic_read_dir, | |
f50752ea AV |
352 | .iterate_shared = proc_readfdinfo, |
353 | .llseek = generic_file_llseek, | |
faf60af1 | 354 | }; |