1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2016-2018, Matthew Macy <[email protected]>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/queue.h>
35 #include <sys/blist.h>
36 #include <sys/conf.h>
37 #include <sys/exec.h>
38 #include <sys/filedesc.h>
39 #include <sys/kernel.h>
40 #include <sys/linker.h>
41 #include <sys/malloc.h>
42 #include <sys/mount.h>
43 #include <sys/mutex.h>
44 #include <sys/proc.h>
45 #include <sys/resourcevar.h>
46 #include <sys/sbuf.h>
47 #include <sys/smp.h>
48 #include <sys/socket.h>
49 #include <sys/vnode.h>
50 #include <sys/bus.h>
51 #include <sys/pciio.h>
52
53 #include <dev/pci/pcivar.h>
54 #include <dev/pci/pcireg.h>
55
56 #include <net/if.h>
57
58 #include <vm/vm.h>
59 #include <vm/pmap.h>
60 #include <vm/vm_map.h>
61 #include <vm/vm_param.h>
62 #include <vm/vm_object.h>
63 #include <vm/swap_pager.h>
64
65 #include <machine/bus.h>
66
67 #include <compat/linux/linux_ioctl.h>
68 #include <compat/linux/linux_mib.h>
69 #include <compat/linux/linux_util.h>
70 #include <fs/pseudofs/pseudofs.h>
71
72 #include <linux/debugfs.h>
73 #include <linux/seq_file.h>
74 #include <linux/compat.h>
75
76 MALLOC_DEFINE(M_DFSINT, "debugfsint", "Linux debugfs internal");
77
78 static struct pfs_node *debugfs_root;
79
80 #define DM_SYMLINK 0x1
81 #define DM_DIR 0x2
82 #define DM_FILE 0x3
83
84 struct dentry_meta {
85 struct dentry dm_dnode;
86 const struct file_operations *dm_fops;
87 void *dm_data;
88 umode_t dm_mode;
89 int dm_type;
90 };
91
92 static int
debugfs_attr(PFS_ATTR_ARGS)93 debugfs_attr(PFS_ATTR_ARGS)
94 {
95 struct dentry_meta *dm;
96
97 dm = pn->pn_data;
98
99 vap->va_mode = dm->dm_mode;
100 return (0);
101 }
102
103 static int
debugfs_destroy(PFS_DESTROY_ARGS)104 debugfs_destroy(PFS_DESTROY_ARGS)
105 {
106 struct dentry_meta *dm;
107
108 dm = pn->pn_data;
109 if (dm->dm_type == DM_SYMLINK)
110 free(dm->dm_data, M_DFSINT);
111
112 free(dm, M_DFSINT);
113 return (0);
114 }
115
116 static int
debugfs_fill(PFS_FILL_ARGS)117 debugfs_fill(PFS_FILL_ARGS)
118 {
119 struct dentry_meta *d;
120 struct linux_file lf = {};
121 struct seq_file *sf;
122 struct vnode vn;
123 void *buf;
124 int rc;
125 size_t len;
126 off_t off;
127
128 d = pn->pn_data;
129
130 if ((rc = linux_set_current_flags(curthread, M_NOWAIT)))
131 return (rc);
132 vn.v_data = d->dm_data;
133 if (uio->uio_rw == UIO_READ) {
134 buf = uio->uio_iov[0].iov_base;
135 len = min(uio->uio_iov[0].iov_len, uio->uio_resid);
136 } else {
137 sbuf_finish(sb);
138 buf = sbuf_data(sb);
139 len = sbuf_len(sb);
140 }
141 off = 0;
142 rc = d->dm_fops->open(&vn, &lf);
143 if (rc < 0) {
144 #ifdef INVARIANTS
145 printf("%s:%d open failed with %d\n", __FUNCTION__, __LINE__, rc);
146 #endif
147 return (-rc);
148 }
149 sf = lf.private_data;
150 sf->buf = sb;
151 if (uio->uio_rw == UIO_READ) {
152 if (d->dm_fops->read)
153 rc = d->dm_fops->read(&lf, NULL, len, &off);
154 else
155 rc = -ENODEV;
156 } else {
157 if (d->dm_fops->write)
158 rc = d->dm_fops->write(&lf, buf, len, &off);
159 else
160 rc = -ENODEV;
161 }
162 if (d->dm_fops->release)
163 d->dm_fops->release(&vn, &lf);
164 else
165 single_release(&vn, &lf);
166
167 if (rc < 0) {
168 #ifdef INVARIANTS
169 printf("%s:%d read/write failed with %d\n", __FUNCTION__, __LINE__, rc);
170 #endif
171 return (-rc);
172 }
173 return (0);
174 }
175
176 static int
debugfs_fill_data(PFS_FILL_ARGS)177 debugfs_fill_data(PFS_FILL_ARGS)
178 {
179 struct dentry_meta *dm;
180
181 dm = pn->pn_data;
182 sbuf_printf(sb, "%s", (char *)dm->dm_data);
183 return (0);
184 }
185
186 struct dentry *
debugfs_create_file(const char * name,umode_t mode,struct dentry * parent,void * data,const struct file_operations * fops)187 debugfs_create_file(const char *name, umode_t mode,
188 struct dentry *parent, void *data,
189 const struct file_operations *fops)
190 {
191 struct dentry_meta *dm;
192 struct dentry *dnode;
193 struct pfs_node *pnode;
194 int flags;
195
196 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO);
197 if (dm == NULL)
198 return (NULL);
199 dnode = &dm->dm_dnode;
200 dm->dm_fops = fops;
201 dm->dm_data = data;
202 dm->dm_mode = mode;
203 dm->dm_type = DM_FILE;
204 if (parent != NULL)
205 pnode = parent->d_pfs_node;
206 else
207 pnode = debugfs_root;
208
209 flags = fops->write ? PFS_RDWR : PFS_RD;
210 dnode->d_pfs_node = pfs_create_file(pnode, name, debugfs_fill,
211 debugfs_attr, NULL, debugfs_destroy, flags | PFS_NOWAIT);
212 if (dnode->d_pfs_node == NULL) {
213 free(dm, M_DFSINT);
214 return (NULL);
215 }
216 dnode->d_pfs_node->pn_data = dm;
217
218 return (dnode);
219 }
220
221 struct dentry *
debugfs_create_dir(const char * name,struct dentry * parent)222 debugfs_create_dir(const char *name, struct dentry *parent)
223 {
224 struct dentry_meta *dm;
225 struct dentry *dnode;
226 struct pfs_node *pnode;
227
228 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO);
229 if (dm == NULL)
230 return (NULL);
231 dnode = &dm->dm_dnode;
232 dm->dm_mode = 0700;
233 dm->dm_type = DM_DIR;
234 if (parent != NULL)
235 pnode = parent->d_pfs_node;
236 else
237 pnode = debugfs_root;
238
239 dnode->d_pfs_node = pfs_create_dir(pnode, name, debugfs_attr, NULL, debugfs_destroy, PFS_RD | PFS_NOWAIT);
240 if (dnode->d_pfs_node == NULL) {
241 free(dm, M_DFSINT);
242 return (NULL);
243 }
244 dnode->d_pfs_node->pn_data = dm;
245 return (dnode);
246 }
247
248 struct dentry *
debugfs_create_symlink(const char * name,struct dentry * parent,const char * dest)249 debugfs_create_symlink(const char *name, struct dentry *parent,
250 const char *dest)
251 {
252 struct dentry_meta *dm;
253 struct dentry *dnode;
254 struct pfs_node *pnode;
255 void *data;
256
257 data = strdup_flags(dest, M_DFSINT, M_NOWAIT);
258 if (data == NULL)
259 return (NULL);
260 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO);
261 if (dm == NULL)
262 goto fail1;
263 dnode = &dm->dm_dnode;
264 dm->dm_mode = 0700;
265 dm->dm_type = DM_SYMLINK;
266 dm->dm_data = data;
267 if (parent != NULL)
268 pnode = parent->d_pfs_node;
269 else
270 pnode = debugfs_root;
271
272 dnode->d_pfs_node = pfs_create_link(pnode, name, &debugfs_fill_data, NULL, NULL, NULL, PFS_NOWAIT);
273 if (dnode->d_pfs_node == NULL)
274 goto fail;
275 dnode->d_pfs_node->pn_data = dm;
276 return (dnode);
277 fail:
278 free(dm, M_DFSINT);
279 fail1:
280 free(data, M_DFSINT);
281 return (NULL);
282 }
283
284 void
debugfs_remove(struct dentry * dnode)285 debugfs_remove(struct dentry *dnode)
286 {
287 if (dnode == NULL)
288 return;
289
290 pfs_destroy(dnode->d_pfs_node);
291 }
292
293 void
debugfs_remove_recursive(struct dentry * dnode)294 debugfs_remove_recursive(struct dentry *dnode)
295 {
296 if (dnode == NULL)
297 return;
298
299 pfs_destroy(dnode->d_pfs_node);
300 }
301
302 static int
debugfs_init(PFS_INIT_ARGS)303 debugfs_init(PFS_INIT_ARGS)
304 {
305
306 debugfs_root = pi->pi_root;
307
308 (void)debugfs_create_symlink("kcov", NULL, "/dev/kcov");
309
310 return (0);
311 }
312
313 static int
debugfs_uninit(PFS_INIT_ARGS)314 debugfs_uninit(PFS_INIT_ARGS)
315 {
316 return (0);
317 }
318
319 #ifdef PR_ALLOW_MOUNT_LINSYSFS
320 PSEUDOFS(debugfs, 1, PR_ALLOW_MOUNT_LINSYSFS);
321 #else
322 PSEUDOFS(debugfs, 1, VFCF_JAIL);
323 #endif
324 MODULE_DEPEND(lindebugfs, linuxkpi, 1, 1, 1);
325