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, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 #include <mdb/mdb_modapi.h>
30 #include <sys/buf.h>
31 #include <sys/var.h>
32 #include <vm/page.h>
33
34 #include "bio.h"
35
36 typedef struct buf_walk {
37 uintptr_t bw_hbufbase; /* Base address of hbuf buckets */
38 struct hbuf *bw_hbufs; /* Snapshot of hbuf buckets */
39 size_t bw_nhbufs; /* Number of hbuf buckets */
40 size_t bw_hbufi; /* Current hbuf index */
41 buf_t *bw_bufp; /* Current buffer */
42 } buf_walk_t;
43
44 int
buf_walk_init(mdb_walk_state_t * wsp)45 buf_walk_init(mdb_walk_state_t *wsp)
46 {
47 struct hbuf *hbufs;
48 struct var v;
49
50 uintptr_t hbuf_addr;
51 size_t nbytes;
52
53 buf_walk_t *bwp;
54
55 if (wsp->walk_addr != NULL) {
56 mdb_warn("only global buf walk supported\n");
57 return (WALK_ERR);
58 }
59
60 if (mdb_readvar(&v, "v") == -1) {
61 mdb_warn("failed to read var struct");
62 return (WALK_ERR);
63 }
64
65 if (mdb_readvar(&hbuf_addr, "hbuf") == -1) {
66 mdb_warn("failed to read hbuf pointer");
67 return (WALK_ERR);
68 }
69
70 nbytes = sizeof (struct hbuf) * v.v_hbuf;
71 hbufs = mdb_alloc(nbytes, UM_SLEEP);
72
73 if (mdb_vread(hbufs, nbytes, hbuf_addr) != nbytes) {
74 mdb_warn("failed to read hbufs");
75 mdb_free(hbufs, nbytes);
76 return (WALK_ERR);
77 }
78
79 bwp = mdb_alloc(sizeof (buf_walk_t), UM_SLEEP);
80
81 bwp->bw_hbufbase = hbuf_addr;
82 bwp->bw_hbufs = hbufs;
83 bwp->bw_nhbufs = v.v_hbuf;
84 bwp->bw_hbufi = 0;
85 bwp->bw_bufp = mdb_alloc(sizeof (buf_t), UM_SLEEP);
86
87 wsp->walk_addr = (uintptr_t)hbufs[0].b_forw;
88 wsp->walk_data = bwp;
89
90 return (WALK_NEXT);
91 }
92
93 int
buf_walk_step(mdb_walk_state_t * wsp)94 buf_walk_step(mdb_walk_state_t *wsp)
95 {
96 buf_walk_t *bwp = wsp->walk_data;
97 uintptr_t addr;
98
99 /*
100 * If the next buf_t address we want is NULL or points back at the
101 * hbuf itself, advance to the next hash bucket. When we reach
102 * bw_nhbufs, we're done.
103 */
104 while (wsp->walk_addr == NULL || wsp->walk_addr == (bwp->bw_hbufbase +
105 bwp->bw_hbufi * sizeof (struct hbuf))) {
106
107 if (++bwp->bw_hbufi == bwp->bw_nhbufs)
108 return (WALK_DONE);
109
110 wsp->walk_addr = (uintptr_t)
111 bwp->bw_hbufs[bwp->bw_hbufi].b_forw;
112 }
113
114 /*
115 * When we have a buf_t address, read the buffer and invoke our
116 * walk callback. We keep the next buf_t address in wsp->walk_addr.
117 */
118 addr = wsp->walk_addr;
119 (void) mdb_vread(bwp->bw_bufp, sizeof (buf_t), addr);
120 wsp->walk_addr = (uintptr_t)bwp->bw_bufp->b_forw;
121
122 return (wsp->walk_callback(addr, bwp->bw_bufp, wsp->walk_cbdata));
123 }
124
125 void
buf_walk_fini(mdb_walk_state_t * wsp)126 buf_walk_fini(mdb_walk_state_t *wsp)
127 {
128 buf_walk_t *bwp = wsp->walk_data;
129
130 mdb_free(bwp->bw_hbufs, sizeof (struct hbuf) * bwp->bw_nhbufs);
131 mdb_free(bwp->bw_bufp, sizeof (buf_t));
132 mdb_free(bwp, sizeof (buf_walk_t));
133 }
134
135 /*ARGSUSED*/
136 int
bufpagefind(uintptr_t addr,uint_t flags,int argc,const mdb_arg_t * argv)137 bufpagefind(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
138 {
139 uintptr_t b_addr = addr;
140 uintptr_t arg;
141
142 page_t p;
143 buf_t b;
144
145 if (argc != 1)
146 return (DCMD_USAGE);
147
148 if (argv->a_type == MDB_TYPE_IMMEDIATE)
149 arg = (uintptr_t)argv->a_un.a_val;
150 else
151 arg = (uintptr_t)mdb_strtoull(argv->a_un.a_str);
152
153 if (mdb_vread(&b, sizeof (buf_t), b_addr) == -1)
154 return (DCMD_ERR);
155
156 for (addr = (uintptr_t)b.b_pages; addr != NULL;
157 addr = (uintptr_t)p.p_next) {
158
159 if (addr == arg) {
160 mdb_printf("buf %p has page %p on b_pages list\n",
161 b_addr, addr);
162 break;
163 }
164
165 if (mdb_vread(&p, sizeof (page_t), addr) == -1)
166 return (DCMD_ERR);
167 }
168
169 return (DCMD_OK);
170 }
171