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Commit | Line | Data |
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faf60af1 CG |
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> | |
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; | |
87 | const struct cred *cred; | |
88 | struct inode *inode; | |
771187d6 | 89 | unsigned int fd; |
faf60af1 CG |
90 | |
91 | if (flags & LOOKUP_RCU) | |
92 | return -ECHILD; | |
93 | ||
2b0143b5 | 94 | inode = d_inode(dentry); |
faf60af1 CG |
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 | } | |
faf60af1 CG |
140 | return 0; |
141 | } | |
142 | ||
143 | static const struct dentry_operations tid_fd_dentry_operations = { | |
144 | .d_revalidate = tid_fd_revalidate, | |
145 | .d_delete = pid_delete_dentry, | |
146 | }; | |
147 | ||
148 | static int proc_fd_link(struct dentry *dentry, struct path *path) | |
149 | { | |
ddd3e077 CG |
150 | struct files_struct *files = NULL; |
151 | struct task_struct *task; | |
152 | int ret = -ENOENT; | |
153 | ||
2b0143b5 | 154 | task = get_proc_task(d_inode(dentry)); |
ddd3e077 CG |
155 | if (task) { |
156 | files = get_files_struct(task); | |
157 | put_task_struct(task); | |
158 | } | |
159 | ||
160 | if (files) { | |
771187d6 | 161 | unsigned int fd = proc_fd(d_inode(dentry)); |
ddd3e077 CG |
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; | |
faf60af1 CG |
176 | } |
177 | ||
c52a47ac | 178 | static int |
faf60af1 CG |
179 | proc_fd_instantiate(struct inode *dir, struct dentry *dentry, |
180 | struct task_struct *task, const void *ptr) | |
181 | { | |
faf60af1 CG |
182 | unsigned fd = (unsigned long)ptr; |
183 | struct proc_inode *ei; | |
184 | struct inode *inode; | |
185 | ||
db978da8 | 186 | inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK); |
faf60af1 CG |
187 | if (!inode) |
188 | goto out; | |
189 | ||
190 | ei = PROC_I(inode); | |
191 | ei->fd = fd; | |
192 | ||
faf60af1 CG |
193 | inode->i_op = &proc_pid_link_inode_operations; |
194 | inode->i_size = 64; | |
195 | ||
196 | ei->op.proc_get_link = proc_fd_link; | |
197 | ||
198 | d_set_d_op(dentry, &tid_fd_dentry_operations); | |
199 | d_add(dentry, inode); | |
200 | ||
201 | /* Close the race of the process dying before we return the dentry */ | |
202 | if (tid_fd_revalidate(dentry, 0)) | |
c52a47ac | 203 | return 0; |
faf60af1 | 204 | out: |
c52a47ac | 205 | return -ENOENT; |
faf60af1 CG |
206 | } |
207 | ||
208 | static struct dentry *proc_lookupfd_common(struct inode *dir, | |
209 | struct dentry *dentry, | |
210 | instantiate_t instantiate) | |
211 | { | |
212 | struct task_struct *task = get_proc_task(dir); | |
c52a47ac | 213 | int result = -ENOENT; |
dbcdb504 | 214 | unsigned fd = name_to_int(&dentry->d_name); |
faf60af1 CG |
215 | |
216 | if (!task) | |
217 | goto out_no_task; | |
218 | if (fd == ~0U) | |
219 | goto out; | |
220 | ||
221 | result = instantiate(dir, dentry, task, (void *)(unsigned long)fd); | |
222 | out: | |
223 | put_task_struct(task); | |
224 | out_no_task: | |
c52a47ac | 225 | return ERR_PTR(result); |
faf60af1 CG |
226 | } |
227 | ||
f0c3b509 AV |
228 | static int proc_readfd_common(struct file *file, struct dir_context *ctx, |
229 | instantiate_t instantiate) | |
faf60af1 | 230 | { |
f0c3b509 | 231 | struct task_struct *p = get_proc_task(file_inode(file)); |
faf60af1 | 232 | struct files_struct *files; |
f0c3b509 | 233 | unsigned int fd; |
faf60af1 | 234 | |
faf60af1 | 235 | if (!p) |
f0c3b509 | 236 | return -ENOENT; |
faf60af1 | 237 | |
f0c3b509 AV |
238 | if (!dir_emit_dots(file, ctx)) |
239 | goto out; | |
240 | files = get_files_struct(p); | |
241 | if (!files) | |
242 | goto out; | |
243 | ||
244 | rcu_read_lock(); | |
245 | for (fd = ctx->pos - 2; | |
246 | fd < files_fdtable(files)->max_fds; | |
247 | fd++, ctx->pos++) { | |
248 | char name[PROC_NUMBUF]; | |
249 | int len; | |
250 | ||
251 | if (!fcheck_files(files, fd)) | |
252 | continue; | |
253 | rcu_read_unlock(); | |
254 | ||
771187d6 | 255 | len = snprintf(name, sizeof(name), "%u", fd); |
f0c3b509 AV |
256 | if (!proc_fill_cache(file, ctx, |
257 | name, len, instantiate, p, | |
258 | (void *)(unsigned long)fd)) | |
259 | goto out_fd_loop; | |
3cc4a84e | 260 | cond_resched(); |
f0c3b509 | 261 | rcu_read_lock(); |
faf60af1 | 262 | } |
f0c3b509 AV |
263 | rcu_read_unlock(); |
264 | out_fd_loop: | |
265 | put_files_struct(files); | |
faf60af1 CG |
266 | out: |
267 | put_task_struct(p); | |
f0c3b509 | 268 | return 0; |
faf60af1 CG |
269 | } |
270 | ||
f0c3b509 | 271 | static int proc_readfd(struct file *file, struct dir_context *ctx) |
faf60af1 | 272 | { |
f0c3b509 | 273 | return proc_readfd_common(file, ctx, proc_fd_instantiate); |
faf60af1 CG |
274 | } |
275 | ||
276 | const struct file_operations proc_fd_operations = { | |
277 | .read = generic_read_dir, | |
f50752ea AV |
278 | .iterate_shared = proc_readfd, |
279 | .llseek = generic_file_llseek, | |
faf60af1 CG |
280 | }; |
281 | ||
282 | static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, | |
283 | unsigned int flags) | |
284 | { | |
285 | return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); | |
286 | } | |
287 | ||
288 | /* | |
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(). | |
291 | */ | |
292 | int proc_fd_permission(struct inode *inode, int mask) | |
293 | { | |
54708d28 ON |
294 | struct task_struct *p; |
295 | int rv; | |
296 | ||
297 | rv = generic_permission(inode, mask); | |
faf60af1 | 298 | if (rv == 0) |
54708d28 ON |
299 | return rv; |
300 | ||
301 | rcu_read_lock(); | |
302 | p = pid_task(proc_pid(inode), PIDTYPE_PID); | |
303 | if (p && same_thread_group(p, current)) | |
faf60af1 | 304 | rv = 0; |
54708d28 ON |
305 | rcu_read_unlock(); |
306 | ||
faf60af1 CG |
307 | return rv; |
308 | } | |
309 | ||
310 | const struct inode_operations proc_fd_inode_operations = { | |
311 | .lookup = proc_lookupfd, | |
312 | .permission = proc_fd_permission, | |
313 | .setattr = proc_setattr, | |
314 | }; | |
315 | ||
c52a47ac | 316 | static int |
faf60af1 CG |
317 | proc_fdinfo_instantiate(struct inode *dir, struct dentry *dentry, |
318 | struct task_struct *task, const void *ptr) | |
319 | { | |
faf60af1 CG |
320 | unsigned fd = (unsigned long)ptr; |
321 | struct proc_inode *ei; | |
322 | struct inode *inode; | |
323 | ||
db978da8 | 324 | inode = proc_pid_make_inode(dir->i_sb, task, S_IFREG | S_IRUSR); |
faf60af1 CG |
325 | if (!inode) |
326 | goto out; | |
327 | ||
328 | ei = PROC_I(inode); | |
329 | ei->fd = fd; | |
330 | ||
faf60af1 CG |
331 | inode->i_fop = &proc_fdinfo_file_operations; |
332 | ||
333 | d_set_d_op(dentry, &tid_fd_dentry_operations); | |
334 | d_add(dentry, inode); | |
335 | ||
336 | /* Close the race of the process dying before we return the dentry */ | |
337 | if (tid_fd_revalidate(dentry, 0)) | |
c52a47ac | 338 | return 0; |
faf60af1 | 339 | out: |
c52a47ac | 340 | return -ENOENT; |
faf60af1 CG |
341 | } |
342 | ||
343 | static struct dentry * | |
344 | proc_lookupfdinfo(struct inode *dir, struct dentry *dentry, unsigned int flags) | |
345 | { | |
346 | return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); | |
347 | } | |
348 | ||
f0c3b509 | 349 | static int proc_readfdinfo(struct file *file, struct dir_context *ctx) |
faf60af1 | 350 | { |
f0c3b509 | 351 | return proc_readfd_common(file, ctx, |
faf60af1 CG |
352 | proc_fdinfo_instantiate); |
353 | } | |
354 | ||
355 | const struct inode_operations proc_fdinfo_inode_operations = { | |
356 | .lookup = proc_lookupfdinfo, | |
357 | .setattr = proc_setattr, | |
358 | }; | |
359 | ||
360 | const struct file_operations proc_fdinfo_operations = { | |
361 | .read = generic_read_dir, | |
f50752ea AV |
362 | .iterate_shared = proc_readfdinfo, |
363 | .llseek = generic_file_llseek, | |
faf60af1 | 364 | }; |