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