1 // SPDX-License-Identifier: GPL-2.0 <<
2 /* 1 /*
3 * fs/proc_namespace.c - handling of /proc/<pi 2 * fs/proc_namespace.c - handling of /proc/<pid>/{mounts,mountinfo,mountstats}
4 * 3 *
5 * In fact, that's a piece of procfs; it's *al 4 * In fact, that's a piece of procfs; it's *almost* isolated from
6 * the rest of fs/proc, but has rather close r 5 * the rest of fs/proc, but has rather close relationships with
7 * fs/namespace.c, thus here instead of fs/pro 6 * fs/namespace.c, thus here instead of fs/proc
8 * 7 *
9 */ 8 */
10 #include <linux/mnt_namespace.h> 9 #include <linux/mnt_namespace.h>
11 #include <linux/nsproxy.h> 10 #include <linux/nsproxy.h>
12 #include <linux/security.h> 11 #include <linux/security.h>
13 #include <linux/fs_struct.h> 12 #include <linux/fs_struct.h>
14 #include <linux/sched/task.h> <<
15 <<
16 #include "<proc/internal.h" /* only for get_pro 13 #include "<proc/internal.h" /* only for get_proc_task() in -?v=linux-4.4.302;a=alpha">a href="source/fs/proc/internal.h?v=linux-4.4.302;a=alpha">proc/internal.h" /* only for get_proc_task() in ->open() */
17 14
18 #include "pnode.h" 15 #include "pnode.h"
19 #include "internal.h" 16 #include "internal.h"
20 17
21 static __poll_t mounts_poll(struct file *file, !! 18 static unsigned mounts_poll(struct file *file, poll_table *wait)
22 { 19 {
23 struct seq_file *m = file->private_dat 20 struct seq_file *m = file->private_data;
24 struct proc_mounts *p = m->private; 21 struct proc_mounts *p = m->private;
25 struct mnt_namespace *ns = p->ns; 22 struct mnt_namespace *ns = p->ns;
26 __poll_t res = EPOLLIN | EPOLLRDNORM; !! 23 unsigned res = POLLIN | POLLRDNORM;
27 int event; 24 int event;
28 25
29 poll_wait(file, &p->ns->poll, wait); 26 poll_wait(file, &p->ns->poll, wait);
30 27
31 event = READ_ONCE(ns->event); !! 28 event = ACCESS_ONCE(ns->event);
32 if (m->poll_event != event) { 29 if (m->poll_event != event) {
33 m->poll_event = event; 30 m->poll_event = event;
34 res |= EPOLLERR | EPOLLPRI; !! 31 res |= POLLERR | POLLPRI;
35 } 32 }
36 33
37 return res; 34 return res;
38 } 35 }
39 36
40 struct proc_fs_opts { !! 37 struct proc_fs_info {
41 int flag; 38 int flag;
42 const char *str; 39 const char *str;
43 }; 40 };
44 41
45 static int show_sb_opts(struct seq_file *m, st 42 static int show_sb_opts(struct seq_file *m, struct super_block *sb)
46 { 43 {
47 static const struct proc_fs_opts fs_op !! 44 static const struct proc_fs_info fs_info[] = {
48 { SB_SYNCHRONOUS, ",sync" }, !! 45 { MS_SYNCHRONOUS, ",sync" },
49 { SB_DIRSYNC, ",dirsync" }, !! 46 { MS_DIRSYNC, ",dirsync" },
50 { SB_MANDLOCK, ",mand" }, !! 47 { MS_MANDLOCK, ",mand" },
51 { SB_LAZYTIME, ",lazytime" }, !! 48 { MS_LAZYTIME, ",lazytime" },
52 { 0, NULL } 49 { 0, NULL }
53 }; 50 };
54 const struct proc_fs_opts *fs_infop; !! 51 const struct proc_fs_info *fs_infop;
55 52
56 for (fs_infop = fs_opts; fs_infop->fla !! 53 for (fs_infop = fs_info; fs_infop->flag; fs_infop++) {
57 if (sb->s_flags & fs_infop->fl 54 if (sb->s_flags & fs_infop->flag)
58 seq_puts(m, fs_infop-> 55 seq_puts(m, fs_infop->str);
59 } 56 }
60 57
61 return security_sb_show_options(m, sb) 58 return security_sb_show_options(m, sb);
62 } 59 }
63 60
64 static void show_vfsmnt_opts(struct seq_file * !! 61 static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt)
65 { 62 {
66 static const struct proc_fs_opts mnt_o !! 63 static const struct proc_fs_info mnt_info[] = {
67 { MNT_NOSUID, ",nosuid" }, 64 { MNT_NOSUID, ",nosuid" },
68 { MNT_NODEV, ",nodev" }, 65 { MNT_NODEV, ",nodev" },
69 { MNT_NOEXEC, ",noexec" }, 66 { MNT_NOEXEC, ",noexec" },
70 { MNT_NOATIME, ",noatime" }, 67 { MNT_NOATIME, ",noatime" },
71 { MNT_NODIRATIME, ",nodiratime 68 { MNT_NODIRATIME, ",nodiratime" },
72 { MNT_RELATIME, ",relatime" }, 69 { MNT_RELATIME, ",relatime" },
73 { MNT_NOSYMFOLLOW, ",nosymfoll <<
74 { 0, NULL } 70 { 0, NULL }
75 }; 71 };
76 const struct proc_fs_opts *fs_infop; !! 72 const struct proc_fs_info *fs_infop;
77 73
78 for (fs_infop = mnt_opts; fs_infop->fl !! 74 for (fs_infop = mnt_info; fs_infop->flag; fs_infop++) {
79 if (mnt->mnt_flags & fs_infop- 75 if (mnt->mnt_flags & fs_infop->flag)
80 seq_puts(m, fs_infop-> 76 seq_puts(m, fs_infop->str);
81 } 77 }
82 <<
83 if (is_idmapped_mnt(mnt)) <<
84 seq_puts(m, ",idmapped"); <<
85 } 78 }
86 79
87 static inline void mangle(struct seq_file *m, 80 static inline void mangle(struct seq_file *m, const char *s)
88 { 81 {
89 seq_escape(m, s, " \t\n\\#"); !! 82 seq_escape(m, s, " \t\n\\");
90 } 83 }
91 84
92 static void show_type(struct seq_file *m, stru 85 static void show_type(struct seq_file *m, struct super_block *sb)
93 { 86 {
94 mangle(m, sb->s_type->name); 87 mangle(m, sb->s_type->name);
95 if (sb->s_subtype) { !! 88 if (sb->s_subtype && sb->s_subtype[0]) {
96 seq_putc(m, '.'); 89 seq_putc(m, '.');
97 mangle(m, sb->s_subtype); 90 mangle(m, sb->s_subtype);
98 } 91 }
99 } 92 }
100 93
101 static int show_vfsmnt(struct seq_file *m, str 94 static int show_vfsmnt(struct seq_file *m, struct vfsmount *mnt)
102 { 95 {
103 struct proc_mounts *p = m->private; 96 struct proc_mounts *p = m->private;
104 struct mount *r = real_mount(mnt); 97 struct mount *r = real_mount(mnt);
>> 98 int err = 0;
105 struct path mnt_path = { .dentry = mnt 99 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
106 struct super_block *sb = mnt_path.dent 100 struct super_block *sb = mnt_path.dentry->d_sb;
107 int err; <<
108 101
109 if (sb->s_op->show_devname) { 102 if (sb->s_op->show_devname) {
110 err = sb->s_op->show_devname(m 103 err = sb->s_op->show_devname(m, mnt_path.dentry);
111 if (err) 104 if (err)
112 goto out; 105 goto out;
113 } else { 106 } else {
114 mangle(m, r->mnt_devname ? r-> 107 mangle(m, r->mnt_devname ? r->mnt_devname : "none");
115 } 108 }
116 seq_putc(m, ' '); 109 seq_putc(m, ' ');
117 /* mountpoints outside of chroot jail 110 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
118 err = seq_path_root(m, &mnt_path, &p-> 111 err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
119 if (err) 112 if (err)
120 goto out; 113 goto out;
121 seq_putc(m, ' '); 114 seq_putc(m, ' ');
122 show_type(m, sb); 115 show_type(m, sb);
123 seq_puts(m, __mnt_is_readonly(mnt) ? " 116 seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw");
124 err = show_sb_opts(m, sb); 117 err = show_sb_opts(m, sb);
125 if (err) 118 if (err)
126 goto out; 119 goto out;
127 show_vfsmnt_opts(m, mnt); !! 120 show_mnt_opts(m, mnt);
128 if (sb->s_op->show_options) 121 if (sb->s_op->show_options)
129 err = sb->s_op->show_options(m 122 err = sb->s_op->show_options(m, mnt_path.dentry);
130 seq_puts(m, " 0 0\n"); 123 seq_puts(m, " 0 0\n");
131 out: 124 out:
132 return err; 125 return err;
133 } 126 }
134 127
135 static int show_mountinfo(struct seq_file *m, 128 static int show_mountinfo(struct seq_file *m, struct vfsmount *mnt)
136 { 129 {
137 struct proc_mounts *p = m->private; 130 struct proc_mounts *p = m->private;
138 struct mount *r = real_mount(mnt); 131 struct mount *r = real_mount(mnt);
139 struct super_block *sb = mnt->mnt_sb; 132 struct super_block *sb = mnt->mnt_sb;
140 struct path mnt_path = { .dentry = mnt 133 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
141 int err; !! 134 int err = 0;
142 135
143 seq_printf(m, "%i %i %u:%u ", r->mnt_i 136 seq_printf(m, "%i %i %u:%u ", r->mnt_id, r->mnt_parent->mnt_id,
144 MAJOR(sb->s_dev), MINOR(sb- 137 MAJOR(sb->s_dev), MINOR(sb->s_dev));
145 err = show_path(m, mnt->mnt_root); !! 138 if (sb->s_op->show_path)
>> 139 err = sb->s_op->show_path(m, mnt->mnt_root);
>> 140 else
>> 141 seq_dentry(m, mnt->mnt_root, " \t\n\\");
146 if (err) 142 if (err)
147 goto out; 143 goto out;
148 seq_putc(m, ' '); 144 seq_putc(m, ' ');
149 145
150 /* mountpoints outside of chroot jail 146 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
151 err = seq_path_root(m, &mnt_path, &p-> 147 err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
152 if (err) 148 if (err)
153 goto out; 149 goto out;
154 150
155 seq_puts(m, mnt->mnt_flags & MNT_READO 151 seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw");
156 show_vfsmnt_opts(m, mnt); !! 152 show_mnt_opts(m, mnt);
157 153
158 /* Tagged fields ("foo:X" or "bar") */ 154 /* Tagged fields ("foo:X" or "bar") */
159 if (IS_MNT_SHARED(r)) 155 if (IS_MNT_SHARED(r))
160 seq_printf(m, " shared:%i", r- 156 seq_printf(m, " shared:%i", r->mnt_group_id);
161 if (IS_MNT_SLAVE(r)) { 157 if (IS_MNT_SLAVE(r)) {
162 int master = r->mnt_master->mn 158 int master = r->mnt_master->mnt_group_id;
163 int dom = get_dominating_id(r, 159 int dom = get_dominating_id(r, &p->root);
164 seq_printf(m, " master:%i", ma 160 seq_printf(m, " master:%i", master);
165 if (dom && dom != master) 161 if (dom && dom != master)
166 seq_printf(m, " propag 162 seq_printf(m, " propagate_from:%i", dom);
167 } 163 }
168 if (IS_MNT_UNBINDABLE(r)) 164 if (IS_MNT_UNBINDABLE(r))
169 seq_puts(m, " unbindable"); 165 seq_puts(m, " unbindable");
170 166
171 /* Filesystem specific data */ 167 /* Filesystem specific data */
172 seq_puts(m, " - "); 168 seq_puts(m, " - ");
173 show_type(m, sb); 169 show_type(m, sb);
174 seq_putc(m, ' '); 170 seq_putc(m, ' ');
175 if (sb->s_op->show_devname) { !! 171 if (sb->s_op->show_devname)
176 err = sb->s_op->show_devname(m 172 err = sb->s_op->show_devname(m, mnt->mnt_root);
177 if (err) !! 173 else
178 goto out; <<
179 } else { <<
180 mangle(m, r->mnt_devname ? r-> 174 mangle(m, r->mnt_devname ? r->mnt_devname : "none");
181 } !! 175 if (err)
182 seq_puts(m, sb_rdonly(sb) ? " ro" : " !! 176 goto out;
>> 177 seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw");
183 err = show_sb_opts(m, sb); 178 err = show_sb_opts(m, sb);
184 if (err) 179 if (err)
185 goto out; 180 goto out;
186 if (sb->s_op->show_options) 181 if (sb->s_op->show_options)
187 err = sb->s_op->show_options(m 182 err = sb->s_op->show_options(m, mnt->mnt_root);
188 seq_putc(m, '\n'); 183 seq_putc(m, '\n');
189 out: 184 out:
190 return err; 185 return err;
191 } 186 }
192 187
193 static int show_vfsstat(struct seq_file *m, st 188 static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt)
194 { 189 {
195 struct proc_mounts *p = m->private; 190 struct proc_mounts *p = m->private;
196 struct mount *r = real_mount(mnt); 191 struct mount *r = real_mount(mnt);
197 struct path mnt_path = { .dentry = mnt 192 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
198 struct super_block *sb = mnt_path.dent 193 struct super_block *sb = mnt_path.dentry->d_sb;
199 int err; !! 194 int err = 0;
200 195
201 /* device */ 196 /* device */
202 if (sb->s_op->show_devname) { 197 if (sb->s_op->show_devname) {
203 seq_puts(m, "device "); 198 seq_puts(m, "device ");
204 err = sb->s_op->show_devname(m 199 err = sb->s_op->show_devname(m, mnt_path.dentry);
205 if (err) 200 if (err)
206 goto out; 201 goto out;
207 } else { 202 } else {
208 if (r->mnt_devname) { 203 if (r->mnt_devname) {
209 seq_puts(m, "device ") 204 seq_puts(m, "device ");
210 mangle(m, r->mnt_devna 205 mangle(m, r->mnt_devname);
211 } else 206 } else
212 seq_puts(m, "no device 207 seq_puts(m, "no device");
213 } 208 }
214 209
215 /* mount point */ 210 /* mount point */
216 seq_puts(m, " mounted on "); 211 seq_puts(m, " mounted on ");
217 /* mountpoints outside of chroot jail 212 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
218 err = seq_path_root(m, &mnt_path, &p-> 213 err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
219 if (err) 214 if (err)
220 goto out; 215 goto out;
221 seq_putc(m, ' '); 216 seq_putc(m, ' ');
222 217
223 /* file system type */ 218 /* file system type */
224 seq_puts(m, "with fstype "); 219 seq_puts(m, "with fstype ");
225 show_type(m, sb); 220 show_type(m, sb);
226 221
227 /* optional statistics */ 222 /* optional statistics */
228 if (sb->s_op->show_stats) { 223 if (sb->s_op->show_stats) {
229 seq_putc(m, ' '); 224 seq_putc(m, ' ');
230 err = sb->s_op->show_stats(m, !! 225 if (!err)
>> 226 err = sb->s_op->show_stats(m, mnt_path.dentry);
231 } 227 }
232 228
233 seq_putc(m, '\n'); 229 seq_putc(m, '\n');
234 out: 230 out:
235 return err; 231 return err;
236 } 232 }
237 233
238 static int mounts_open_common(struct inode *in 234 static int mounts_open_common(struct inode *inode, struct file *file,
239 int (*show)(stru 235 int (*show)(struct seq_file *, struct vfsmount *))
240 { 236 {
241 struct task_struct *task = get_proc_ta 237 struct task_struct *task = get_proc_task(inode);
242 struct nsproxy *nsp; 238 struct nsproxy *nsp;
243 struct mnt_namespace *ns = NULL; 239 struct mnt_namespace *ns = NULL;
244 struct path root; 240 struct path root;
245 struct proc_mounts *p; 241 struct proc_mounts *p;
246 struct seq_file *m; 242 struct seq_file *m;
247 int ret = -EINVAL; 243 int ret = -EINVAL;
248 244
249 if (!task) 245 if (!task)
250 goto err; 246 goto err;
251 247
252 task_lock(task); 248 task_lock(task);
253 nsp = task->nsproxy; 249 nsp = task->nsproxy;
254 if (!nsp || !nsp->mnt_ns) { 250 if (!nsp || !nsp->mnt_ns) {
255 task_unlock(task); 251 task_unlock(task);
256 put_task_struct(task); 252 put_task_struct(task);
257 goto err; 253 goto err;
258 } 254 }
259 ns = nsp->mnt_ns; 255 ns = nsp->mnt_ns;
260 get_mnt_ns(ns); 256 get_mnt_ns(ns);
261 if (!task->fs) { 257 if (!task->fs) {
262 task_unlock(task); 258 task_unlock(task);
263 put_task_struct(task); 259 put_task_struct(task);
264 ret = -ENOENT; 260 ret = -ENOENT;
265 goto err_put_ns; 261 goto err_put_ns;
266 } 262 }
267 get_fs_root(task->fs, &root); 263 get_fs_root(task->fs, &root);
268 task_unlock(task); 264 task_unlock(task);
269 put_task_struct(task); 265 put_task_struct(task);
270 266
271 ret = seq_open_private(file, &mounts_o 267 ret = seq_open_private(file, &mounts_op, sizeof(struct proc_mounts));
272 if (ret) 268 if (ret)
273 goto err_put_path; 269 goto err_put_path;
274 270
275 m = file->private_data; 271 m = file->private_data;
276 m->poll_event = ns->event; 272 m->poll_event = ns->event;
277 273
278 p = m->private; 274 p = m->private;
279 p->ns = ns; 275 p->ns = ns;
280 p->root = root; 276 p->root = root;
281 p->show = show; 277 p->show = show;
>> 278 p->cached_event = ~0ULL;
282 279
283 return 0; 280 return 0;
284 281
285 err_put_path: 282 err_put_path:
286 path_put(&root); 283 path_put(&root);
287 err_put_ns: 284 err_put_ns:
288 put_mnt_ns(ns); 285 put_mnt_ns(ns);
289 err: 286 err:
290 return ret; 287 return ret;
291 } 288 }
292 289
293 static int mounts_release(struct inode *inode, 290 static int mounts_release(struct inode *inode, struct file *file)
294 { 291 {
295 struct seq_file *m = file->private_dat 292 struct seq_file *m = file->private_data;
296 struct proc_mounts *p = m->private; 293 struct proc_mounts *p = m->private;
297 path_put(&p->root); 294 path_put(&p->root);
298 put_mnt_ns(p->ns); 295 put_mnt_ns(p->ns);
299 return seq_release_private(inode, file 296 return seq_release_private(inode, file);
300 } 297 }
301 298
302 static int mounts_open(struct inode *inode, st 299 static int mounts_open(struct inode *inode, struct file *file)
303 { 300 {
304 return mounts_open_common(inode, file, 301 return mounts_open_common(inode, file, show_vfsmnt);
305 } 302 }
306 303
307 static int mountinfo_open(struct inode *inode, 304 static int mountinfo_open(struct inode *inode, struct file *file)
308 { 305 {
309 return mounts_open_common(inode, file, 306 return mounts_open_common(inode, file, show_mountinfo);
310 } 307 }
311 308
312 static int mountstats_open(struct inode *inode 309 static int mountstats_open(struct inode *inode, struct file *file)
313 { 310 {
314 return mounts_open_common(inode, file, 311 return mounts_open_common(inode, file, show_vfsstat);
315 } 312 }
316 313
317 const struct file_operations proc_mounts_opera 314 const struct file_operations proc_mounts_operations = {
318 .open = mounts_open, 315 .open = mounts_open,
319 .read_iter = seq_read_iter, !! 316 .read = seq_read,
320 .splice_read = copy_splice_read, <<
321 .llseek = seq_lseek, 317 .llseek = seq_lseek,
322 .release = mounts_release, 318 .release = mounts_release,
323 .poll = mounts_poll, 319 .poll = mounts_poll,
324 }; 320 };
325 321
326 const struct file_operations proc_mountinfo_op 322 const struct file_operations proc_mountinfo_operations = {
327 .open = mountinfo_open, 323 .open = mountinfo_open,
328 .read_iter = seq_read_iter, !! 324 .read = seq_read,
329 .splice_read = copy_splice_read, <<
330 .llseek = seq_lseek, 325 .llseek = seq_lseek,
331 .release = mounts_release, 326 .release = mounts_release,
332 .poll = mounts_poll, 327 .poll = mounts_poll,
333 }; 328 };
334 329
335 const struct file_operations proc_mountstats_o 330 const struct file_operations proc_mountstats_operations = {
336 .open = mountstats_open, 331 .open = mountstats_open,
337 .read_iter = seq_read_iter, !! 332 .read = seq_read,
338 .splice_read = copy_splice_read, <<
339 .llseek = seq_lseek, 333 .llseek = seq_lseek,
340 .release = mounts_release, 334 .release = mounts_release,
341 }; 335 };
342 336
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