xref: /illumos-gate/usr/src/uts/common/io/dump.c (revision 8d3c0bf0)
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 (c) 1998, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Delphix (c) 2012 by Delphix. All rights reserved.
24  */
25 
26 
27 /*
28  * Dump driver.  Provides ioctls to get/set crash dump configuration.
29  */
30 
31 #include <sys/types.h>
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/vnode.h>
35 #include <sys/uio.h>
36 #include <sys/cred.h>
37 #include <sys/kmem.h>
38 #include <sys/errno.h>
39 #include <sys/modctl.h>
40 #include <sys/dumphdr.h>
41 #include <sys/dumpadm.h>
42 #include <sys/pathname.h>
43 #include <sys/file.h>
44 #include <vm/anon.h>
45 #include <sys/stat.h>
46 #include <sys/conf.h>
47 #include <sys/ddi.h>
48 #include <sys/sunddi.h>
49 
50 static dev_info_t *dump_devi;
51 
52 static int
dump_attach(dev_info_t * devi,ddi_attach_cmd_t cmd)53 dump_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
54 {
55 	if (cmd != DDI_ATTACH)
56 		return (DDI_FAILURE);
57 	if (ddi_create_minor_node(devi, "dump", S_IFCHR, 0, DDI_PSEUDO, 0) ==
58 	    DDI_FAILURE) {
59 		ddi_remove_minor_node(devi, NULL);
60 		return (DDI_FAILURE);
61 	}
62 	dump_devi = devi;
63 	return (DDI_SUCCESS);
64 }
65 
66 static int
dump_detach(dev_info_t * devi,ddi_detach_cmd_t cmd)67 dump_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
68 {
69 	if (cmd != DDI_DETACH)
70 		return (DDI_FAILURE);
71 	ddi_remove_minor_node(devi, NULL);
72 	return (DDI_SUCCESS);
73 }
74 
75 /*ARGSUSED*/
76 static int
dump_info(dev_info_t * dip,ddi_info_cmd_t infocmd,void * arg,void ** result)77 dump_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
78 {
79 	switch (infocmd) {
80 	case DDI_INFO_DEVT2DEVINFO:
81 		*result = dump_devi;
82 		return (DDI_SUCCESS);
83 	case DDI_INFO_DEVT2INSTANCE:
84 		*result = 0;
85 		return (DDI_SUCCESS);
86 	}
87 	return (DDI_FAILURE);
88 }
89 
90 /*ARGSUSED*/
91 int
dump_ioctl(dev_t dev,int cmd,intptr_t arg,int mode,cred_t * cred,int * rvalp)92 dump_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *cred, int *rvalp)
93 {
94 	uint64_t size;
95 	uint64_t dumpsize_in_pages;
96 	int error = 0;
97 	char *pathbuf = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
98 	char uuidbuf[36 + 1];
99 	size_t len;
100 	vnode_t *vp;
101 
102 	switch (cmd) {
103 	case DIOCGETDUMPSIZE:
104 		if (dump_conflags & DUMP_ALL)
105 			size = ptob((uint64_t)physmem) / DUMP_COMPRESS_RATIO;
106 		else {
107 			/*
108 			 * We can't give a good answer for the DUMP_CURPROC
109 			 * because we won't know which process to use until it
110 			 * causes a panic.  We'll therefore punt and give the
111 			 * caller the size for the kernel.
112 			 *
113 			 * This kernel size equation takes care of the
114 			 * boot time kernel footprint and also accounts
115 			 * for availrmem changes due to user explicit locking.
116 			 * Refer to common/vm/vm_page.c for an explanation
117 			 * of these counters.
118 			 */
119 			dumpsize_in_pages = (physinstalled - obp_pages -
120 			    availrmem -
121 			    anon_segkp_pages_locked -
122 			    k_anoninfo.ani_mem_resv -
123 			    pages_locked -
124 			    pages_claimed -
125 			    pages_useclaim);
126 
127 			/*
128 			 * Protect against vm vagaries.
129 			 */
130 			if (dumpsize_in_pages > (uint64_t)physmem)
131 				dumpsize_in_pages = (uint64_t)physmem;
132 
133 			size = ptob(dumpsize_in_pages) / DUMP_COMPRESS_RATIO;
134 		}
135 		if (copyout(&size, (void *)arg, sizeof (size)) < 0)
136 			error = EFAULT;
137 		break;
138 
139 	case DIOCGETCONF:
140 		mutex_enter(&dump_lock);
141 		*rvalp = dump_conflags;
142 		if (dumpvp && !(dumpvp->v_flag & VISSWAP))
143 			*rvalp |= DUMP_EXCL;
144 		mutex_exit(&dump_lock);
145 		break;
146 
147 	case DIOCSETCONF:
148 		mutex_enter(&dump_lock);
149 		if (arg == DUMP_KERNEL || arg == DUMP_ALL ||
150 		    arg == DUMP_CURPROC)
151 			dump_conflags = arg;
152 		else
153 			error = EINVAL;
154 		mutex_exit(&dump_lock);
155 		break;
156 
157 	case DIOCGETDEV:
158 		mutex_enter(&dump_lock);
159 		if (dumppath == NULL) {
160 			mutex_exit(&dump_lock);
161 			error = ENODEV;
162 			break;
163 		}
164 		(void) strcpy(pathbuf, dumppath);
165 		mutex_exit(&dump_lock);
166 		error = copyoutstr(pathbuf, (void *)arg, MAXPATHLEN, NULL);
167 		break;
168 
169 	case DIOCSETDEV:
170 	case DIOCTRYDEV:
171 		if ((error = copyinstr((char *)arg, pathbuf, MAXPATHLEN,
172 		    NULL)) != 0 || (error = lookupname(pathbuf, UIO_SYSSPACE,
173 		    FOLLOW, NULLVPP, &vp)) != 0)
174 			break;
175 		mutex_enter(&dump_lock);
176 		if (vp->v_type == VBLK)
177 			error = dumpinit(vp, pathbuf, cmd == DIOCTRYDEV);
178 		else
179 			error = ENOTBLK;
180 		mutex_exit(&dump_lock);
181 		VN_RELE(vp);
182 		break;
183 
184 	case DIOCDUMP:
185 		mutex_enter(&dump_lock);
186 		if (dumpvp == NULL)
187 			error = ENODEV;
188 		else if (dumpvp->v_flag & VISSWAP)
189 			error = EBUSY;
190 		else
191 			dumpsys();
192 		mutex_exit(&dump_lock);
193 		break;
194 
195 	case DIOCSETUUID:
196 		if ((error = copyinstr((char *)arg, uuidbuf, sizeof (uuidbuf),
197 		    &len)) != 0)
198 			break;
199 
200 		if (len != 37) {
201 			error = EINVAL;
202 			break;
203 		}
204 
205 		error = dump_set_uuid(uuidbuf);
206 		break;
207 
208 	case DIOCGETUUID:
209 		error = copyoutstr(dump_get_uuid(), (void *)arg, 37, NULL);
210 		break;
211 
212 	case DIOCRMDEV:
213 		mutex_enter(&dump_lock);
214 		if (dumpvp != NULL)
215 			dumpfini();
216 		mutex_exit(&dump_lock);
217 		break;
218 
219 	default:
220 		error = ENXIO;
221 	}
222 
223 	kmem_free(pathbuf, MAXPATHLEN);
224 	return (error);
225 }
226 
227 struct cb_ops dump_cb_ops = {
228 	nulldev,		/* open */
229 	nulldev,		/* close */
230 	nodev,			/* strategy */
231 	nodev,			/* print */
232 	nodev,			/* dump */
233 	nodev,			/* read */
234 	nodev,			/* write */
235 	dump_ioctl,		/* ioctl */
236 	nodev,			/* devmap */
237 	nodev,			/* mmap */
238 	nodev,			/* segmap */
239 	nochpoll,		/* poll */
240 	ddi_prop_op,		/* prop_op */
241 	0,			/* streamtab  */
242 	D_NEW|D_MP		/* Driver compatibility flag */
243 };
244 
245 struct dev_ops dump_ops = {
246 	DEVO_REV,		/* devo_rev, */
247 	0,			/* refcnt */
248 	dump_info,		/* info */
249 	nulldev,		/* identify */
250 	nulldev,		/* probe */
251 	dump_attach,		/* attach */
252 	dump_detach,		/* detach */
253 	nodev,			/* reset */
254 	&dump_cb_ops,		/* driver operations */
255 	(struct bus_ops *)0,	/* bus operations */
256 	NULL,			/* power */
257 	ddi_quiesce_not_needed,		/* quiesce */
258 };
259 
260 static struct modldrv modldrv = {
261 	&mod_driverops, "crash dump driver", &dump_ops,
262 };
263 
264 static struct modlinkage modlinkage = {
265 	MODREV_1, (void *)&modldrv, NULL
266 };
267 
268 int
_init(void)269 _init(void)
270 {
271 	return (mod_install(&modlinkage));
272 }
273 
274 int
_fini(void)275 _fini(void)
276 {
277 	return (mod_remove(&modlinkage));
278 }
279 
280 int
_info(struct modinfo * modinfop)281 _info(struct modinfo *modinfop)
282 {
283 	return (mod_info(&modlinkage, modinfop));
284 }
285