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-4.10.17;a=alpha">a href="source/fs/proc/internal.h?v=linux-4.10.17;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);
105 struct path mnt_path = { .dentry = mnt 98 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
106 struct super_block *sb = mnt_path.dent 99 struct super_block *sb = mnt_path.dentry->d_sb;
107 int err; 100 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;
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) {
146 if (err) !! 139 err = sb->s_op->show_path(m, mnt->mnt_root);
147 goto out; !! 140 if (err)
>> 141 goto out;
>> 142 } else {
>> 143 seq_dentry(m, mnt->mnt_root, " \t\n\\");
>> 144 }
148 seq_putc(m, ' '); 145 seq_putc(m, ' ');
149 146
150 /* mountpoints outside of chroot jail 147 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
151 err = seq_path_root(m, &mnt_path, &p-> 148 err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
152 if (err) 149 if (err)
153 goto out; 150 goto out;
154 151
155 seq_puts(m, mnt->mnt_flags & MNT_READO 152 seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw");
156 show_vfsmnt_opts(m, mnt); !! 153 show_mnt_opts(m, mnt);
157 154
158 /* Tagged fields ("foo:X" or "bar") */ 155 /* Tagged fields ("foo:X" or "bar") */
159 if (IS_MNT_SHARED(r)) 156 if (IS_MNT_SHARED(r))
160 seq_printf(m, " shared:%i", r- 157 seq_printf(m, " shared:%i", r->mnt_group_id);
161 if (IS_MNT_SLAVE(r)) { 158 if (IS_MNT_SLAVE(r)) {
162 int master = r->mnt_master->mn 159 int master = r->mnt_master->mnt_group_id;
163 int dom = get_dominating_id(r, 160 int dom = get_dominating_id(r, &p->root);
164 seq_printf(m, " master:%i", ma 161 seq_printf(m, " master:%i", master);
165 if (dom && dom != master) 162 if (dom && dom != master)
166 seq_printf(m, " propag 163 seq_printf(m, " propagate_from:%i", dom);
167 } 164 }
168 if (IS_MNT_UNBINDABLE(r)) 165 if (IS_MNT_UNBINDABLE(r))
169 seq_puts(m, " unbindable"); 166 seq_puts(m, " unbindable");
170 167
171 /* Filesystem specific data */ 168 /* Filesystem specific data */
172 seq_puts(m, " - "); 169 seq_puts(m, " - ");
173 show_type(m, sb); 170 show_type(m, sb);
174 seq_putc(m, ' '); 171 seq_putc(m, ' ');
175 if (sb->s_op->show_devname) { 172 if (sb->s_op->show_devname) {
176 err = sb->s_op->show_devname(m 173 err = sb->s_op->show_devname(m, mnt->mnt_root);
177 if (err) 174 if (err)
178 goto out; 175 goto out;
179 } else { 176 } else {
180 mangle(m, r->mnt_devname ? r-> 177 mangle(m, r->mnt_devname ? r->mnt_devname : "none");
181 } 178 }
182 seq_puts(m, sb_rdonly(sb) ? " ro" : " !! 179 seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw");
183 err = show_sb_opts(m, sb); 180 err = show_sb_opts(m, sb);
184 if (err) 181 if (err)
185 goto out; 182 goto out;
186 if (sb->s_op->show_options) 183 if (sb->s_op->show_options)
187 err = sb->s_op->show_options(m 184 err = sb->s_op->show_options(m, mnt->mnt_root);
188 seq_putc(m, '\n'); 185 seq_putc(m, '\n');
189 out: 186 out:
190 return err; 187 return err;
191 } 188 }
192 189
193 static int show_vfsstat(struct seq_file *m, st 190 static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt)
194 { 191 {
195 struct proc_mounts *p = m->private; 192 struct proc_mounts *p = m->private;
196 struct mount *r = real_mount(mnt); 193 struct mount *r = real_mount(mnt);
197 struct path mnt_path = { .dentry = mnt 194 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
198 struct super_block *sb = mnt_path.dent 195 struct super_block *sb = mnt_path.dentry->d_sb;
199 int err; 196 int err;
200 197
201 /* device */ 198 /* device */
202 if (sb->s_op->show_devname) { 199 if (sb->s_op->show_devname) {
203 seq_puts(m, "device "); 200 seq_puts(m, "device ");
204 err = sb->s_op->show_devname(m 201 err = sb->s_op->show_devname(m, mnt_path.dentry);
205 if (err) 202 if (err)
206 goto out; 203 goto out;
207 } else { 204 } else {
208 if (r->mnt_devname) { 205 if (r->mnt_devname) {
209 seq_puts(m, "device ") 206 seq_puts(m, "device ");
210 mangle(m, r->mnt_devna 207 mangle(m, r->mnt_devname);
211 } else 208 } else
212 seq_puts(m, "no device 209 seq_puts(m, "no device");
213 } 210 }
214 211
215 /* mount point */ 212 /* mount point */
216 seq_puts(m, " mounted on "); 213 seq_puts(m, " mounted on ");
217 /* mountpoints outside of chroot jail 214 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
218 err = seq_path_root(m, &mnt_path, &p-> 215 err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
219 if (err) 216 if (err)
220 goto out; 217 goto out;
221 seq_putc(m, ' '); 218 seq_putc(m, ' ');
222 219
223 /* file system type */ 220 /* file system type */
224 seq_puts(m, "with fstype "); 221 seq_puts(m, "with fstype ");
225 show_type(m, sb); 222 show_type(m, sb);
226 223
227 /* optional statistics */ 224 /* optional statistics */
228 if (sb->s_op->show_stats) { 225 if (sb->s_op->show_stats) {
229 seq_putc(m, ' '); 226 seq_putc(m, ' ');
230 err = sb->s_op->show_stats(m, 227 err = sb->s_op->show_stats(m, mnt_path.dentry);
231 } 228 }
232 229
233 seq_putc(m, '\n'); 230 seq_putc(m, '\n');
234 out: 231 out:
235 return err; 232 return err;
236 } 233 }
237 234
238 static int mounts_open_common(struct inode *in 235 static int mounts_open_common(struct inode *inode, struct file *file,
239 int (*show)(stru 236 int (*show)(struct seq_file *, struct vfsmount *))
240 { 237 {
241 struct task_struct *task = get_proc_ta 238 struct task_struct *task = get_proc_task(inode);
242 struct nsproxy *nsp; 239 struct nsproxy *nsp;
243 struct mnt_namespace *ns = NULL; 240 struct mnt_namespace *ns = NULL;
244 struct path root; 241 struct path root;
245 struct proc_mounts *p; 242 struct proc_mounts *p;
246 struct seq_file *m; 243 struct seq_file *m;
247 int ret = -EINVAL; 244 int ret = -EINVAL;
248 245
249 if (!task) 246 if (!task)
250 goto err; 247 goto err;
251 248
252 task_lock(task); 249 task_lock(task);
253 nsp = task->nsproxy; 250 nsp = task->nsproxy;
254 if (!nsp || !nsp->mnt_ns) { 251 if (!nsp || !nsp->mnt_ns) {
255 task_unlock(task); 252 task_unlock(task);
256 put_task_struct(task); 253 put_task_struct(task);
257 goto err; 254 goto err;
258 } 255 }
259 ns = nsp->mnt_ns; 256 ns = nsp->mnt_ns;
260 get_mnt_ns(ns); 257 get_mnt_ns(ns);
261 if (!task->fs) { 258 if (!task->fs) {
262 task_unlock(task); 259 task_unlock(task);
263 put_task_struct(task); 260 put_task_struct(task);
264 ret = -ENOENT; 261 ret = -ENOENT;
265 goto err_put_ns; 262 goto err_put_ns;
266 } 263 }
267 get_fs_root(task->fs, &root); 264 get_fs_root(task->fs, &root);
268 task_unlock(task); 265 task_unlock(task);
269 put_task_struct(task); 266 put_task_struct(task);
270 267
271 ret = seq_open_private(file, &mounts_o 268 ret = seq_open_private(file, &mounts_op, sizeof(struct proc_mounts));
272 if (ret) 269 if (ret)
273 goto err_put_path; 270 goto err_put_path;
274 271
275 m = file->private_data; 272 m = file->private_data;
276 m->poll_event = ns->event; 273 m->poll_event = ns->event;
277 274
278 p = m->private; 275 p = m->private;
279 p->ns = ns; 276 p->ns = ns;
280 p->root = root; 277 p->root = root;
281 p->show = show; 278 p->show = show;
>> 279 p->cached_event = ~0ULL;
282 280
283 return 0; 281 return 0;
284 282
285 err_put_path: 283 err_put_path:
286 path_put(&root); 284 path_put(&root);
287 err_put_ns: 285 err_put_ns:
288 put_mnt_ns(ns); 286 put_mnt_ns(ns);
289 err: 287 err:
290 return ret; 288 return ret;
291 } 289 }
292 290
293 static int mounts_release(struct inode *inode, 291 static int mounts_release(struct inode *inode, struct file *file)
294 { 292 {
295 struct seq_file *m = file->private_dat 293 struct seq_file *m = file->private_data;
296 struct proc_mounts *p = m->private; 294 struct proc_mounts *p = m->private;
297 path_put(&p->root); 295 path_put(&p->root);
298 put_mnt_ns(p->ns); 296 put_mnt_ns(p->ns);
299 return seq_release_private(inode, file 297 return seq_release_private(inode, file);
300 } 298 }
301 299
302 static int mounts_open(struct inode *inode, st 300 static int mounts_open(struct inode *inode, struct file *file)
303 { 301 {
304 return mounts_open_common(inode, file, 302 return mounts_open_common(inode, file, show_vfsmnt);
305 } 303 }
306 304
307 static int mountinfo_open(struct inode *inode, 305 static int mountinfo_open(struct inode *inode, struct file *file)
308 { 306 {
309 return mounts_open_common(inode, file, 307 return mounts_open_common(inode, file, show_mountinfo);
310 } 308 }
311 309
312 static int mountstats_open(struct inode *inode 310 static int mountstats_open(struct inode *inode, struct file *file)
313 { 311 {
314 return mounts_open_common(inode, file, 312 return mounts_open_common(inode, file, show_vfsstat);
315 } 313 }
316 314
317 const struct file_operations proc_mounts_opera 315 const struct file_operations proc_mounts_operations = {
318 .open = mounts_open, 316 .open = mounts_open,
319 .read_iter = seq_read_iter, !! 317 .read = seq_read,
320 .splice_read = copy_splice_read, <<
321 .llseek = seq_lseek, 318 .llseek = seq_lseek,
322 .release = mounts_release, 319 .release = mounts_release,
323 .poll = mounts_poll, 320 .poll = mounts_poll,
324 }; 321 };
325 322
326 const struct file_operations proc_mountinfo_op 323 const struct file_operations proc_mountinfo_operations = {
327 .open = mountinfo_open, 324 .open = mountinfo_open,
328 .read_iter = seq_read_iter, !! 325 .read = seq_read,
329 .splice_read = copy_splice_read, <<
330 .llseek = seq_lseek, 326 .llseek = seq_lseek,
331 .release = mounts_release, 327 .release = mounts_release,
332 .poll = mounts_poll, 328 .poll = mounts_poll,
333 }; 329 };
334 330
335 const struct file_operations proc_mountstats_o 331 const struct file_operations proc_mountstats_operations = {
336 .open = mountstats_open, 332 .open = mountstats_open,
337 .read_iter = seq_read_iter, !! 333 .read = seq_read,
338 .splice_read = copy_splice_read, <<
339 .llseek = seq_lseek, 334 .llseek = seq_lseek,
340 .release = mounts_release, 335 .release = mounts_release,
341 }; 336 };
342 337
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