xref: /illumos-gate/usr/src/uts/common/kmdb/kdrv.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 
27 /*
28  * The driver portion of kmdb, which manages /dev/kmdb and passes requests along
29  * to the kmdb misc module (kmdbmod).
30  */
31 
32 #include <sys/conf.h>
33 #include <sys/stat.h>
34 #include <sys/modctl.h>
35 #include <sys/ddi.h>
36 #include <sys/sunddi.h>
37 #include <sys/open.h>
38 #include <sys/kobj.h>
39 #include <sys/kdi.h>
40 #include <sys/policy.h>
41 #include <sys/kobj_impl.h>
42 #include <sys/kmdb.h>
43 #include <sys/sysmacros.h>
44 #include <sys/consdev.h>
45 
46 #define	KDRV_CFG_MAXLEN		2048
47 
48 static dev_info_t 		*kdrv_dip;
49 
50 /*ARGSUSED*/
51 static int
52 kdrv_open(dev_t *dev, int openflags, int otyp, cred_t *credp)
53 {
54 	if (otyp != OTYP_CHR)
55 		return (EINVAL);
56 
57 	if (secpolicy_kmdb(credp) != 0)
58 		return (EPERM);
59 
60 	return (0);
61 }
62 
63 /*ARGSUSED*/
64 static int
65 kdrv_close(dev_t dev, int openflags, int otyp, cred_t *credp)
66 {
67 	return (0);
68 }
69 
70 typedef struct kdrv_flags_map {
71 	const char *fm_name;
72 	int fm_defval;
73 	uint_t fm_flag;
74 } kdrv_flags_map_t;
75 
76 static const kdrv_flags_map_t kdrv_flags_map[] = {
77 	{ "kmdb-auto-entry", 1, KMDB_F_AUTO_ENTRY },
78 	{ "kmdb-trap-noswitch", 0, KMDB_F_TRAP_NOSWITCH },
79 	{ "kmdb-driver-debug", 0, KMDB_F_DRV_DEBUG },
80 	{ NULL }
81 };
82 
83 static int
84 kdrv_activate(intptr_t arg)
85 {
86 	uint_t flags;
87 	size_t memsz;
88 	char *cfg;
89 	size_t got;
90 	int i, rc;
91 
92 #if defined(__x86)
93 	if (cons_polledio == NULL) {
94 		cmn_err(CE_NOTE, "kmdb not supported: no console polled I/O");
95 		return (ENOTSUP);
96 	}
97 #endif
98 
99 	memsz = ddi_prop_get_int(DDI_DEV_T_ANY, kdrv_dip,
100 	    DDI_PROP_DONTPASS, "kmdb-memseg-size", 0);
101 
102 	for (flags = 0, i = 0; kdrv_flags_map[i].fm_name != NULL; i++) {
103 		const kdrv_flags_map_t *fm = &kdrv_flags_map[i];
104 		if (ddi_prop_get_int(DDI_DEV_T_ANY, kdrv_dip, DDI_PROP_DONTPASS,
105 		    (char *)fm->fm_name, fm->fm_defval))
106 			flags |= fm->fm_flag;
107 	}
108 
109 	cfg = kmem_alloc(KDRV_CFG_MAXLEN, KM_SLEEP);
110 
111 	if ((rc = copyinstr((caddr_t)arg, cfg, KDRV_CFG_MAXLEN, &got)) != 0) {
112 		kmem_free(cfg, KDRV_CFG_MAXLEN);
113 		return (rc == ENAMETOOLONG ? E2BIG : EFAULT);
114 	}
115 
116 	rc = kctl_modload_activate(memsz, cfg, flags);
117 
118 	kmem_free(cfg, KDRV_CFG_MAXLEN);
119 
120 	return (rc);
121 }
122 
123 static int
124 kdrv_deactivate(void)
125 {
126 	return (kctl_deactivate());
127 }
128 
129 /*ARGSUSED*/
130 static int
131 kdrv_ioctl(dev_t dev, int cmd, intptr_t arg, int flags, cred_t *credp,
132     int *rvalp)
133 {
134 	switch (cmd) {
135 	case KMDB_IOC_START:
136 		return (kdrv_activate(arg));
137 
138 	case KMDB_IOC_STOP:
139 		return (kdrv_deactivate());
140 
141 	default:
142 		return (EINVAL);
143 	}
144 }
145 
146 /*ARGSUSED*/
147 static int
148 kdrv_getinfo(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
149 {
150 	int error = DDI_SUCCESS;
151 
152 	switch (infocmd) {
153 	case DDI_INFO_DEVT2DEVINFO:
154 		*result = kdrv_dip;
155 		break;
156 	case DDI_INFO_DEVT2INSTANCE:
157 		*result = (void *)(uintptr_t)getminor((dev_t)arg);
158 		break;
159 	default:
160 		*result = NULL;
161 		error = DDI_FAILURE;
162 	}
163 
164 	return (error);
165 }
166 
167 static int
168 kdrv_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
169 {
170 	if (cmd != DDI_ATTACH)
171 		return (DDI_FAILURE);
172 
173 	if (ddi_create_minor_node(dip, ddi_get_name(dip), S_IFCHR,
174 	    ddi_get_instance(dip), DDI_PSEUDO, 0) != DDI_SUCCESS)
175 		return (DDI_FAILURE);
176 
177 	kdrv_dip = dip;
178 
179 	if (kctl_attach(dip) != 0)
180 		return (DDI_FAILURE);
181 
182 	return (DDI_SUCCESS);
183 }
184 
185 static int
186 kdrv_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
187 {
188 	if (cmd != DDI_DETACH)
189 		return (DDI_FAILURE);
190 
191 	if (kctl_detach() == EBUSY)
192 		return (DDI_FAILURE);
193 
194 	ddi_remove_minor_node(dip, NULL);
195 
196 	return (DDI_SUCCESS);
197 }
198 
199 static struct cb_ops kdrv_cb_ops = {
200 	kdrv_open,
201 	kdrv_close,
202 	nodev,			/* not a block driver	*/
203 	nodev,			/* no print routine	*/
204 	nodev,			/* no dump routine	*/
205 	nodev,			/* no read routine	*/
206 	nodev,			/* no write routine	*/
207 	kdrv_ioctl,
208 	nodev,			/* no devmap routine	*/
209 	nodev,			/* no mmap routine	*/
210 	nodev,			/* no segmap routine	*/
211 	nochpoll,		/* no chpoll routine	*/
212 	ddi_prop_op,
213 	0,			/* not a STREAMS driver	*/
214 	D_NEW | D_MP,		/* safe for multi-thread/multi-processor */
215 };
216 
217 static struct dev_ops kdrv_ops = {
218 	DEVO_REV,		/* devo_rev */
219 	0,			/* devo_refcnt */
220 	kdrv_getinfo,		/* devo_getinfo */
221 	nulldev,		/* devo_identify */
222 	nulldev,		/* devo_probe */
223 	kdrv_attach,		/* devo_attach */
224 	kdrv_detach,		/* devo_detach */
225 	nodev,			/* devo_reset */
226 	&kdrv_cb_ops,		/* devo_cb_ops */
227 	(struct bus_ops *)0,	/* devo_bus_ops */
228 	NULL,			/* devo_power */
229 	ddi_quiesce_not_needed,		/* devo_quiesce */
230 };
231 
232 static struct modldrv modldrv = {
233 	&mod_driverops,
234 	"kmdb driver",
235 	&kdrv_ops
236 };
237 
238 static struct modlinkage modlinkage = {
239 	MODREV_1,
240 	(void *)&modldrv,
241 	NULL
242 };
243 
244 int
245 _init(void)
246 {
247 	return (mod_install(&modlinkage));
248 }
249 
250 int
251 _info(struct modinfo *modinfop)
252 {
253 	return (mod_info(&modlinkage, modinfop));
254 }
255 
256 int
257 _fini(void)
258 {
259 	return (mod_remove(&modlinkage));
260 }
261