xref: /titanic_41/usr/src/uts/common/io/dump.c (revision 3eae19d9cf3390cf5b75e10c9c1945fd36ad856a)
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 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 /*
29  * Dump driver.  Provides ioctls to get/set crash dump configuration.
30  */
31 
32 #include <sys/types.h>
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/vnode.h>
36 #include <sys/uio.h>
37 #include <sys/cred.h>
38 #include <sys/kmem.h>
39 #include <sys/errno.h>
40 #include <sys/modctl.h>
41 #include <sys/dumphdr.h>
42 #include <sys/dumpadm.h>
43 #include <sys/pathname.h>
44 #include <sys/file.h>
45 #include <vm/anon.h>
46 #include <sys/stat.h>
47 #include <sys/conf.h>
48 #include <sys/ddi.h>
49 #include <sys/sunddi.h>
50 
51 static dev_info_t *dump_devi;
52 
53 static int
54 dump_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
55 {
56 	if (cmd != DDI_ATTACH)
57 		return (DDI_FAILURE);
58 	if (ddi_create_minor_node(devi, "dump", S_IFCHR, 0, DDI_PSEUDO, NULL) ==
59 	    DDI_FAILURE) {
60 		ddi_remove_minor_node(devi, NULL);
61 		return (DDI_FAILURE);
62 	}
63 	dump_devi = devi;
64 	return (DDI_SUCCESS);
65 }
66 
67 static int
68 dump_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
69 {
70 	if (cmd != DDI_DETACH)
71 		return (DDI_FAILURE);
72 	ddi_remove_minor_node(devi, NULL);
73 	return (DDI_SUCCESS);
74 }
75 
76 /*ARGSUSED*/
77 static int
78 dump_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
79 {
80 	switch (infocmd) {
81 	case DDI_INFO_DEVT2DEVINFO:
82 		*result = dump_devi;
83 		return (DDI_SUCCESS);
84 	case DDI_INFO_DEVT2INSTANCE:
85 		*result = 0;
86 		return (DDI_SUCCESS);
87 	}
88 	return (DDI_FAILURE);
89 }
90 
91 /*ARGSUSED*/
92 int
93 dump_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *cred, int *rvalp)
94 {
95 	uint64_t size;
96 	uint64_t dumpsize_in_pages;
97 	int error = 0;
98 	char *pathbuf = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
99 	vnode_t *vp;
100 
101 	switch (cmd) {
102 	case DIOCGETDUMPSIZE:
103 		if (dump_conflags & DUMP_ALL)
104 			size = ptob((uint64_t)physmem) / DUMP_COMPRESS_RATIO;
105 		else {
106 			/*
107 			 * We can't give a good answer for the DUMP_CURPROC
108 			 * because we won't know which process to use until it
109 			 * causes a panic.  We'll therefore punt and give the
110 			 * caller the size for the kernel.
111 			 *
112 			 * This kernel size equation takes care of the
113 			 * boot time kernel footprint and also accounts
114 			 * for availrmem changes due to user explicit locking.
115 			 * Refer to common/vm/vm_page.c for an explanation
116 			 * of these counters.
117 			 */
118 			dumpsize_in_pages = (physinstalled - obp_pages -
119 						availrmem -
120 						anon_segkp_pages_locked -
121 						k_anoninfo.ani_mem_resv -
122 						segvn_pages_locked -
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 		error = dumpinit(vp, pathbuf, cmd == DIOCTRYDEV);
177 		mutex_exit(&dump_lock);
178 		VN_RELE(vp);
179 		break;
180 
181 	case DIOCDUMP:
182 		mutex_enter(&dump_lock);
183 		if (dumpvp == NULL)
184 			error = ENODEV;
185 		else if (dumpvp->v_flag & VISSWAP)
186 			error = EBUSY;
187 		else
188 			dumpsys();
189 		mutex_exit(&dump_lock);
190 		break;
191 
192 	default:
193 		error = ENXIO;
194 	}
195 
196 	kmem_free(pathbuf, MAXPATHLEN);
197 	return (error);
198 }
199 
200 struct cb_ops dump_cb_ops = {
201 	nulldev,		/* open */
202 	nulldev,		/* close */
203 	nodev,			/* strategy */
204 	nodev,			/* print */
205 	nodev,			/* dump */
206 	nodev,			/* read */
207 	nodev,			/* write */
208 	dump_ioctl,		/* ioctl */
209 	nodev,			/* devmap */
210 	nodev,			/* mmap */
211 	nodev, 			/* segmap */
212 	nochpoll,		/* poll */
213 	ddi_prop_op,		/* prop_op */
214 	0,			/* streamtab  */
215 	D_NEW|D_MP		/* Driver compatibility flag */
216 };
217 
218 struct dev_ops dump_ops = {
219 	DEVO_REV,		/* devo_rev, */
220 	0,			/* refcnt */
221 	dump_info,		/* info */
222 	nulldev,		/* identify */
223 	nulldev,		/* probe */
224 	dump_attach,		/* attach */
225 	dump_detach,		/* detach */
226 	nodev,			/* reset */
227 	&dump_cb_ops,		/* driver operations */
228 	(struct bus_ops *)0	/* bus operations */
229 };
230 
231 static struct modldrv modldrv = {
232 	&mod_driverops, "crash dump driver %I%", &dump_ops,
233 };
234 
235 static struct modlinkage modlinkage = {
236 	MODREV_1, (void *)&modldrv, NULL
237 };
238 
239 int
240 _init(void)
241 {
242 	return (mod_install(&modlinkage));
243 }
244 
245 int
246 _fini(void)
247 {
248 	return (mod_remove(&modlinkage));
249 }
250 
251 int
252 _info(struct modinfo *modinfop)
253 {
254 	return (mod_info(&modlinkage, modinfop));
255 }
256