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> 13 #include <linux/sched/task.h>
15 14
16 #include "<proc/internal.h" /* only for get_pro 15 #include "<proc/internal.h" /* only for get_proc_task() in -?v=linux-4.12.14;a=alpha">a href="source/fs/proc/internal.h?v=linux-4.12.14;a=alpha">proc/internal.h" /* only for get_proc_task() in ->open() */
17 16
18 #include "pnode.h" 17 #include "pnode.h"
19 #include "internal.h" 18 #include "internal.h"
20 19
21 static __poll_t mounts_poll(struct file *file, !! 20 static unsigned mounts_poll(struct file *file, poll_table *wait)
22 { 21 {
23 struct seq_file *m = file->private_dat 22 struct seq_file *m = file->private_data;
24 struct proc_mounts *p = m->private; 23 struct proc_mounts *p = m->private;
25 struct mnt_namespace *ns = p->ns; 24 struct mnt_namespace *ns = p->ns;
26 __poll_t res = EPOLLIN | EPOLLRDNORM; !! 25 unsigned res = POLLIN | POLLRDNORM;
27 int event; 26 int event;
28 27
29 poll_wait(file, &p->ns->poll, wait); 28 poll_wait(file, &p->ns->poll, wait);
30 29
31 event = READ_ONCE(ns->event); !! 30 event = ACCESS_ONCE(ns->event);
32 if (m->poll_event != event) { 31 if (m->poll_event != event) {
33 m->poll_event = event; 32 m->poll_event = event;
34 res |= EPOLLERR | EPOLLPRI; !! 33 res |= POLLERR | POLLPRI;
35 } 34 }
36 35
37 return res; 36 return res;
38 } 37 }
39 38
40 struct proc_fs_opts { !! 39 struct proc_fs_info {
41 int flag; 40 int flag;
42 const char *str; 41 const char *str;
43 }; 42 };
44 43
45 static int show_sb_opts(struct seq_file *m, st 44 static int show_sb_opts(struct seq_file *m, struct super_block *sb)
46 { 45 {
47 static const struct proc_fs_opts fs_op !! 46 static const struct proc_fs_info fs_info[] = {
48 { SB_SYNCHRONOUS, ",sync" }, !! 47 { MS_SYNCHRONOUS, ",sync" },
49 { SB_DIRSYNC, ",dirsync" }, !! 48 { MS_DIRSYNC, ",dirsync" },
50 { SB_MANDLOCK, ",mand" }, !! 49 { MS_MANDLOCK, ",mand" },
51 { SB_LAZYTIME, ",lazytime" }, !! 50 { MS_LAZYTIME, ",lazytime" },
52 { 0, NULL } 51 { 0, NULL }
53 }; 52 };
54 const struct proc_fs_opts *fs_infop; !! 53 const struct proc_fs_info *fs_infop;
55 54
56 for (fs_infop = fs_opts; fs_infop->fla !! 55 for (fs_infop = fs_info; fs_infop->flag; fs_infop++) {
57 if (sb->s_flags & fs_infop->fl 56 if (sb->s_flags & fs_infop->flag)
58 seq_puts(m, fs_infop-> 57 seq_puts(m, fs_infop->str);
59 } 58 }
60 59
61 return security_sb_show_options(m, sb) 60 return security_sb_show_options(m, sb);
62 } 61 }
63 62
64 static void show_vfsmnt_opts(struct seq_file * !! 63 static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt)
65 { 64 {
66 static const struct proc_fs_opts mnt_o !! 65 static const struct proc_fs_info mnt_info[] = {
67 { MNT_NOSUID, ",nosuid" }, 66 { MNT_NOSUID, ",nosuid" },
68 { MNT_NODEV, ",nodev" }, 67 { MNT_NODEV, ",nodev" },
69 { MNT_NOEXEC, ",noexec" }, 68 { MNT_NOEXEC, ",noexec" },
70 { MNT_NOATIME, ",noatime" }, 69 { MNT_NOATIME, ",noatime" },
71 { MNT_NODIRATIME, ",nodiratime 70 { MNT_NODIRATIME, ",nodiratime" },
72 { MNT_RELATIME, ",relatime" }, 71 { MNT_RELATIME, ",relatime" },
73 { MNT_NOSYMFOLLOW, ",nosymfoll <<
74 { 0, NULL } 72 { 0, NULL }
75 }; 73 };
76 const struct proc_fs_opts *fs_infop; !! 74 const struct proc_fs_info *fs_infop;
77 75
78 for (fs_infop = mnt_opts; fs_infop->fl !! 76 for (fs_infop = mnt_info; fs_infop->flag; fs_infop++) {
79 if (mnt->mnt_flags & fs_infop- 77 if (mnt->mnt_flags & fs_infop->flag)
80 seq_puts(m, fs_infop-> 78 seq_puts(m, fs_infop->str);
81 } 79 }
82 <<
83 if (is_idmapped_mnt(mnt)) <<
84 seq_puts(m, ",idmapped"); <<
85 } 80 }
86 81
87 static inline void mangle(struct seq_file *m, 82 static inline void mangle(struct seq_file *m, const char *s)
88 { 83 {
89 seq_escape(m, s, " \t\n\\#"); !! 84 seq_escape(m, s, " \t\n\\");
90 } 85 }
91 86
92 static void show_type(struct seq_file *m, stru 87 static void show_type(struct seq_file *m, struct super_block *sb)
93 { 88 {
94 mangle(m, sb->s_type->name); 89 mangle(m, sb->s_type->name);
95 if (sb->s_subtype) { !! 90 if (sb->s_subtype && sb->s_subtype[0]) {
96 seq_putc(m, '.'); 91 seq_putc(m, '.');
97 mangle(m, sb->s_subtype); 92 mangle(m, sb->s_subtype);
98 } 93 }
99 } 94 }
100 95
101 static int show_vfsmnt(struct seq_file *m, str 96 static int show_vfsmnt(struct seq_file *m, struct vfsmount *mnt)
102 { 97 {
103 struct proc_mounts *p = m->private; 98 struct proc_mounts *p = m->private;
104 struct mount *r = real_mount(mnt); 99 struct mount *r = real_mount(mnt);
105 struct path mnt_path = { .dentry = mnt 100 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
106 struct super_block *sb = mnt_path.dent 101 struct super_block *sb = mnt_path.dentry->d_sb;
107 int err; 102 int err;
108 103
109 if (sb->s_op->show_devname) { 104 if (sb->s_op->show_devname) {
110 err = sb->s_op->show_devname(m 105 err = sb->s_op->show_devname(m, mnt_path.dentry);
111 if (err) 106 if (err)
112 goto out; 107 goto out;
113 } else { 108 } else {
114 mangle(m, r->mnt_devname ? r-> 109 mangle(m, r->mnt_devname ? r->mnt_devname : "none");
115 } 110 }
116 seq_putc(m, ' '); 111 seq_putc(m, ' ');
117 /* mountpoints outside of chroot jail 112 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
118 err = seq_path_root(m, &mnt_path, &p-> 113 err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
119 if (err) 114 if (err)
120 goto out; 115 goto out;
121 seq_putc(m, ' '); 116 seq_putc(m, ' ');
122 show_type(m, sb); 117 show_type(m, sb);
123 seq_puts(m, __mnt_is_readonly(mnt) ? " 118 seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw");
124 err = show_sb_opts(m, sb); 119 err = show_sb_opts(m, sb);
125 if (err) 120 if (err)
126 goto out; 121 goto out;
127 show_vfsmnt_opts(m, mnt); !! 122 show_mnt_opts(m, mnt);
128 if (sb->s_op->show_options) 123 if (sb->s_op->show_options)
129 err = sb->s_op->show_options(m 124 err = sb->s_op->show_options(m, mnt_path.dentry);
130 seq_puts(m, " 0 0\n"); 125 seq_puts(m, " 0 0\n");
131 out: 126 out:
132 return err; 127 return err;
133 } 128 }
134 129
135 static int show_mountinfo(struct seq_file *m, 130 static int show_mountinfo(struct seq_file *m, struct vfsmount *mnt)
136 { 131 {
137 struct proc_mounts *p = m->private; 132 struct proc_mounts *p = m->private;
138 struct mount *r = real_mount(mnt); 133 struct mount *r = real_mount(mnt);
139 struct super_block *sb = mnt->mnt_sb; 134 struct super_block *sb = mnt->mnt_sb;
140 struct path mnt_path = { .dentry = mnt 135 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
141 int err; 136 int err;
142 137
143 seq_printf(m, "%i %i %u:%u ", r->mnt_i 138 seq_printf(m, "%i %i %u:%u ", r->mnt_id, r->mnt_parent->mnt_id,
144 MAJOR(sb->s_dev), MINOR(sb- 139 MAJOR(sb->s_dev), MINOR(sb->s_dev));
145 err = show_path(m, mnt->mnt_root); !! 140 if (sb->s_op->show_path) {
146 if (err) !! 141 err = sb->s_op->show_path(m, mnt->mnt_root);
147 goto out; !! 142 if (err)
>> 143 goto out;
>> 144 } else {
>> 145 seq_dentry(m, mnt->mnt_root, " \t\n\\");
>> 146 }
148 seq_putc(m, ' '); 147 seq_putc(m, ' ');
149 148
150 /* mountpoints outside of chroot jail 149 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
151 err = seq_path_root(m, &mnt_path, &p-> 150 err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
152 if (err) 151 if (err)
153 goto out; 152 goto out;
154 153
155 seq_puts(m, mnt->mnt_flags & MNT_READO 154 seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw");
156 show_vfsmnt_opts(m, mnt); !! 155 show_mnt_opts(m, mnt);
157 156
158 /* Tagged fields ("foo:X" or "bar") */ 157 /* Tagged fields ("foo:X" or "bar") */
159 if (IS_MNT_SHARED(r)) 158 if (IS_MNT_SHARED(r))
160 seq_printf(m, " shared:%i", r- 159 seq_printf(m, " shared:%i", r->mnt_group_id);
161 if (IS_MNT_SLAVE(r)) { 160 if (IS_MNT_SLAVE(r)) {
162 int master = r->mnt_master->mn 161 int master = r->mnt_master->mnt_group_id;
163 int dom = get_dominating_id(r, 162 int dom = get_dominating_id(r, &p->root);
164 seq_printf(m, " master:%i", ma 163 seq_printf(m, " master:%i", master);
165 if (dom && dom != master) 164 if (dom && dom != master)
166 seq_printf(m, " propag 165 seq_printf(m, " propagate_from:%i", dom);
167 } 166 }
168 if (IS_MNT_UNBINDABLE(r)) 167 if (IS_MNT_UNBINDABLE(r))
169 seq_puts(m, " unbindable"); 168 seq_puts(m, " unbindable");
170 169
171 /* Filesystem specific data */ 170 /* Filesystem specific data */
172 seq_puts(m, " - "); 171 seq_puts(m, " - ");
173 show_type(m, sb); 172 show_type(m, sb);
174 seq_putc(m, ' '); 173 seq_putc(m, ' ');
175 if (sb->s_op->show_devname) { 174 if (sb->s_op->show_devname) {
176 err = sb->s_op->show_devname(m 175 err = sb->s_op->show_devname(m, mnt->mnt_root);
177 if (err) 176 if (err)
178 goto out; 177 goto out;
179 } else { 178 } else {
180 mangle(m, r->mnt_devname ? r-> 179 mangle(m, r->mnt_devname ? r->mnt_devname : "none");
181 } 180 }
182 seq_puts(m, sb_rdonly(sb) ? " ro" : " !! 181 seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw");
183 err = show_sb_opts(m, sb); 182 err = show_sb_opts(m, sb);
184 if (err) 183 if (err)
185 goto out; 184 goto out;
186 if (sb->s_op->show_options) 185 if (sb->s_op->show_options)
187 err = sb->s_op->show_options(m 186 err = sb->s_op->show_options(m, mnt->mnt_root);
188 seq_putc(m, '\n'); 187 seq_putc(m, '\n');
189 out: 188 out:
190 return err; 189 return err;
191 } 190 }
192 191
193 static int show_vfsstat(struct seq_file *m, st 192 static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt)
194 { 193 {
195 struct proc_mounts *p = m->private; 194 struct proc_mounts *p = m->private;
196 struct mount *r = real_mount(mnt); 195 struct mount *r = real_mount(mnt);
197 struct path mnt_path = { .dentry = mnt 196 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
198 struct super_block *sb = mnt_path.dent 197 struct super_block *sb = mnt_path.dentry->d_sb;
199 int err; 198 int err;
200 199
201 /* device */ 200 /* device */
202 if (sb->s_op->show_devname) { 201 if (sb->s_op->show_devname) {
203 seq_puts(m, "device "); 202 seq_puts(m, "device ");
204 err = sb->s_op->show_devname(m 203 err = sb->s_op->show_devname(m, mnt_path.dentry);
205 if (err) 204 if (err)
206 goto out; 205 goto out;
207 } else { 206 } else {
208 if (r->mnt_devname) { 207 if (r->mnt_devname) {
209 seq_puts(m, "device ") 208 seq_puts(m, "device ");
210 mangle(m, r->mnt_devna 209 mangle(m, r->mnt_devname);
211 } else 210 } else
212 seq_puts(m, "no device 211 seq_puts(m, "no device");
213 } 212 }
214 213
215 /* mount point */ 214 /* mount point */
216 seq_puts(m, " mounted on "); 215 seq_puts(m, " mounted on ");
217 /* mountpoints outside of chroot jail 216 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
218 err = seq_path_root(m, &mnt_path, &p-> 217 err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
219 if (err) 218 if (err)
220 goto out; 219 goto out;
221 seq_putc(m, ' '); 220 seq_putc(m, ' ');
222 221
223 /* file system type */ 222 /* file system type */
224 seq_puts(m, "with fstype "); 223 seq_puts(m, "with fstype ");
225 show_type(m, sb); 224 show_type(m, sb);
226 225
227 /* optional statistics */ 226 /* optional statistics */
228 if (sb->s_op->show_stats) { 227 if (sb->s_op->show_stats) {
229 seq_putc(m, ' '); 228 seq_putc(m, ' ');
230 err = sb->s_op->show_stats(m, 229 err = sb->s_op->show_stats(m, mnt_path.dentry);
231 } 230 }
232 231
233 seq_putc(m, '\n'); 232 seq_putc(m, '\n');
234 out: 233 out:
235 return err; 234 return err;
236 } 235 }
237 236
238 static int mounts_open_common(struct inode *in 237 static int mounts_open_common(struct inode *inode, struct file *file,
239 int (*show)(stru 238 int (*show)(struct seq_file *, struct vfsmount *))
240 { 239 {
241 struct task_struct *task = get_proc_ta 240 struct task_struct *task = get_proc_task(inode);
242 struct nsproxy *nsp; 241 struct nsproxy *nsp;
243 struct mnt_namespace *ns = NULL; 242 struct mnt_namespace *ns = NULL;
244 struct path root; 243 struct path root;
245 struct proc_mounts *p; 244 struct proc_mounts *p;
246 struct seq_file *m; 245 struct seq_file *m;
247 int ret = -EINVAL; 246 int ret = -EINVAL;
248 247
249 if (!task) 248 if (!task)
250 goto err; 249 goto err;
251 250
252 task_lock(task); 251 task_lock(task);
253 nsp = task->nsproxy; 252 nsp = task->nsproxy;
254 if (!nsp || !nsp->mnt_ns) { 253 if (!nsp || !nsp->mnt_ns) {
255 task_unlock(task); 254 task_unlock(task);
256 put_task_struct(task); 255 put_task_struct(task);
257 goto err; 256 goto err;
258 } 257 }
259 ns = nsp->mnt_ns; 258 ns = nsp->mnt_ns;
260 get_mnt_ns(ns); 259 get_mnt_ns(ns);
261 if (!task->fs) { 260 if (!task->fs) {
262 task_unlock(task); 261 task_unlock(task);
263 put_task_struct(task); 262 put_task_struct(task);
264 ret = -ENOENT; 263 ret = -ENOENT;
265 goto err_put_ns; 264 goto err_put_ns;
266 } 265 }
267 get_fs_root(task->fs, &root); 266 get_fs_root(task->fs, &root);
268 task_unlock(task); 267 task_unlock(task);
269 put_task_struct(task); 268 put_task_struct(task);
270 269
271 ret = seq_open_private(file, &mounts_o 270 ret = seq_open_private(file, &mounts_op, sizeof(struct proc_mounts));
272 if (ret) 271 if (ret)
273 goto err_put_path; 272 goto err_put_path;
274 273
275 m = file->private_data; 274 m = file->private_data;
276 m->poll_event = ns->event; 275 m->poll_event = ns->event;
277 276
278 p = m->private; 277 p = m->private;
279 p->ns = ns; 278 p->ns = ns;
280 p->root = root; 279 p->root = root;
281 p->show = show; 280 p->show = show;
>> 281 p->cached_event = ~0ULL;
282 282
283 return 0; 283 return 0;
284 284
285 err_put_path: 285 err_put_path:
286 path_put(&root); 286 path_put(&root);
287 err_put_ns: 287 err_put_ns:
288 put_mnt_ns(ns); 288 put_mnt_ns(ns);
289 err: 289 err:
290 return ret; 290 return ret;
291 } 291 }
292 292
293 static int mounts_release(struct inode *inode, 293 static int mounts_release(struct inode *inode, struct file *file)
294 { 294 {
295 struct seq_file *m = file->private_dat 295 struct seq_file *m = file->private_data;
296 struct proc_mounts *p = m->private; 296 struct proc_mounts *p = m->private;
297 path_put(&p->root); 297 path_put(&p->root);
298 put_mnt_ns(p->ns); 298 put_mnt_ns(p->ns);
299 return seq_release_private(inode, file 299 return seq_release_private(inode, file);
300 } 300 }
301 301
302 static int mounts_open(struct inode *inode, st 302 static int mounts_open(struct inode *inode, struct file *file)
303 { 303 {
304 return mounts_open_common(inode, file, 304 return mounts_open_common(inode, file, show_vfsmnt);
305 } 305 }
306 306
307 static int mountinfo_open(struct inode *inode, 307 static int mountinfo_open(struct inode *inode, struct file *file)
308 { 308 {
309 return mounts_open_common(inode, file, 309 return mounts_open_common(inode, file, show_mountinfo);
310 } 310 }
311 311
312 static int mountstats_open(struct inode *inode 312 static int mountstats_open(struct inode *inode, struct file *file)
313 { 313 {
314 return mounts_open_common(inode, file, 314 return mounts_open_common(inode, file, show_vfsstat);
315 } 315 }
316 316
317 const struct file_operations proc_mounts_opera 317 const struct file_operations proc_mounts_operations = {
318 .open = mounts_open, 318 .open = mounts_open,
319 .read_iter = seq_read_iter, !! 319 .read = seq_read,
320 .splice_read = copy_splice_read, <<
321 .llseek = seq_lseek, 320 .llseek = seq_lseek,
322 .release = mounts_release, 321 .release = mounts_release,
323 .poll = mounts_poll, 322 .poll = mounts_poll,
324 }; 323 };
325 324
326 const struct file_operations proc_mountinfo_op 325 const struct file_operations proc_mountinfo_operations = {
327 .open = mountinfo_open, 326 .open = mountinfo_open,
328 .read_iter = seq_read_iter, !! 327 .read = seq_read,
329 .splice_read = copy_splice_read, <<
330 .llseek = seq_lseek, 328 .llseek = seq_lseek,
331 .release = mounts_release, 329 .release = mounts_release,
332 .poll = mounts_poll, 330 .poll = mounts_poll,
333 }; 331 };
334 332
335 const struct file_operations proc_mountstats_o 333 const struct file_operations proc_mountstats_operations = {
336 .open = mountstats_open, 334 .open = mountstats_open,
337 .read_iter = seq_read_iter, !! 335 .read = seq_read,
338 .splice_read = copy_splice_read, <<
339 .llseek = seq_lseek, 336 .llseek = seq_lseek,
340 .release = mounts_release, 337 .release = mounts_release,
341 }; 338 };
342 339
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