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 #include <mdb/mdb_modapi.h>
28 #include <sys/buf.h>
29 #include <sys/var.h>
30 #include <vm/page.h>
31
32 #include "bio.h"
33
34 typedef struct buf_walk {
35 uintptr_t bw_hbufbase; /* Base address of hbuf buckets */
36 struct hbuf *bw_hbufs; /* Snapshot of hbuf buckets */
37 size_t bw_nhbufs; /* Number of hbuf buckets */
38 size_t bw_hbufi; /* Current hbuf index */
39 buf_t *bw_bufp; /* Current buffer */
40 } buf_walk_t;
41
42 int
buf_walk_init(mdb_walk_state_t * wsp)43 buf_walk_init(mdb_walk_state_t *wsp)
44 {
45 struct hbuf *hbufs;
46 struct var v;
47
48 uintptr_t hbuf_addr;
49 size_t nbytes;
50
51 buf_walk_t *bwp;
52
53 if (wsp->walk_addr != 0) {
54 mdb_warn("only global buf walk supported\n");
55 return (WALK_ERR);
56 }
57
58 if (mdb_readvar(&v, "v") == -1) {
59 mdb_warn("failed to read var struct");
60 return (WALK_ERR);
61 }
62
63 if (mdb_readvar(&hbuf_addr, "hbuf") == -1) {
64 mdb_warn("failed to read hbuf pointer");
65 return (WALK_ERR);
66 }
67
68 nbytes = sizeof (struct hbuf) * v.v_hbuf;
69 hbufs = mdb_alloc(nbytes, UM_SLEEP);
70
71 if (mdb_vread(hbufs, nbytes, hbuf_addr) != nbytes) {
72 mdb_warn("failed to read hbufs");
73 mdb_free(hbufs, nbytes);
74 return (WALK_ERR);
75 }
76
77 bwp = mdb_alloc(sizeof (buf_walk_t), UM_SLEEP);
78
79 bwp->bw_hbufbase = hbuf_addr;
80 bwp->bw_hbufs = hbufs;
81 bwp->bw_nhbufs = v.v_hbuf;
82 bwp->bw_hbufi = 0;
83 bwp->bw_bufp = mdb_alloc(sizeof (buf_t), UM_SLEEP);
84
85 wsp->walk_addr = (uintptr_t)hbufs[0].b_forw;
86 wsp->walk_data = bwp;
87
88 return (WALK_NEXT);
89 }
90
91 int
buf_walk_step(mdb_walk_state_t * wsp)92 buf_walk_step(mdb_walk_state_t *wsp)
93 {
94 buf_walk_t *bwp = wsp->walk_data;
95 uintptr_t addr;
96
97 /*
98 * If the next buf_t address we want is NULL or points back at the
99 * hbuf itself, advance to the next hash bucket. When we reach
100 * bw_nhbufs, we're done.
101 */
102 while (wsp->walk_addr == 0 || wsp->walk_addr == (bwp->bw_hbufbase +
103 bwp->bw_hbufi * sizeof (struct hbuf))) {
104
105 if (++bwp->bw_hbufi == bwp->bw_nhbufs)
106 return (WALK_DONE);
107
108 wsp->walk_addr = (uintptr_t)
109 bwp->bw_hbufs[bwp->bw_hbufi].b_forw;
110 }
111
112 /*
113 * When we have a buf_t address, read the buffer and invoke our
114 * walk callback. We keep the next buf_t address in wsp->walk_addr.
115 */
116 addr = wsp->walk_addr;
117 (void) mdb_vread(bwp->bw_bufp, sizeof (buf_t), addr);
118 wsp->walk_addr = (uintptr_t)bwp->bw_bufp->b_forw;
119
120 return (wsp->walk_callback(addr, bwp->bw_bufp, wsp->walk_cbdata));
121 }
122
123 void
buf_walk_fini(mdb_walk_state_t * wsp)124 buf_walk_fini(mdb_walk_state_t *wsp)
125 {
126 buf_walk_t *bwp = wsp->walk_data;
127
128 mdb_free(bwp->bw_hbufs, sizeof (struct hbuf) * bwp->bw_nhbufs);
129 mdb_free(bwp->bw_bufp, sizeof (buf_t));
130 mdb_free(bwp, sizeof (buf_walk_t));
131 }
132
133 /*ARGSUSED*/
134 int
bufpagefind(uintptr_t addr,uint_t flags,int argc,const mdb_arg_t * argv)135 bufpagefind(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
136 {
137 uintptr_t b_addr = addr;
138 uintptr_t arg;
139
140 page_t p;
141 buf_t b;
142
143 if (argc != 1)
144 return (DCMD_USAGE);
145
146 if (argv->a_type == MDB_TYPE_IMMEDIATE)
147 arg = (uintptr_t)argv->a_un.a_val;
148 else
149 arg = (uintptr_t)mdb_strtoull(argv->a_un.a_str);
150
151 if (mdb_vread(&b, sizeof (buf_t), b_addr) == -1)
152 return (DCMD_ERR);
153
154 for (addr = (uintptr_t)b.b_pages; addr != 0;
155 addr = (uintptr_t)p.p_next) {
156
157 if (addr == arg) {
158 mdb_printf("buf %p has page %p on b_pages list\n",
159 b_addr, addr);
160 break;
161 }
162
163 if (mdb_vread(&p, sizeof (page_t), addr) == -1)
164 return (DCMD_ERR);
165 }
166
167 return (DCMD_OK);
168 }
169