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 * Copyright 2025 Oxide Computer Company 26 */ 27 28 #include <mdb/mdb_modapi.h> 29 #include <sys/buf.h> 30 #include <sys/var.h> 31 #include <vm/page.h> 32 33 #include "bio.h" 34 35 typedef struct buf_walk { 36 uintptr_t bw_hbufbase; /* Base address of hbuf buckets */ 37 struct hbuf *bw_hbufs; /* Snapshot of hbuf buckets */ 38 size_t bw_nhbufs; /* Number of hbuf buckets */ 39 size_t bw_hbufi; /* Current hbuf index */ 40 buf_t *bw_bufp; /* Current buffer */ 41 } buf_walk_t; 42 43 int 44 buf_walk_init(mdb_walk_state_t *wsp) 45 { 46 struct hbuf *hbufs; 47 struct var v; 48 49 uintptr_t hbuf_addr; 50 size_t nbytes; 51 52 buf_walk_t *bwp; 53 54 if (wsp->walk_addr != 0) { 55 mdb_warn("only global buf walk supported\n"); 56 return (WALK_ERR); 57 } 58 59 if (mdb_readvar(&v, "v") == -1) { 60 mdb_warn("failed to read var struct"); 61 return (WALK_ERR); 62 } 63 64 if (mdb_readvar(&hbuf_addr, "hbuf") == -1) { 65 mdb_warn("failed to read hbuf pointer"); 66 return (WALK_ERR); 67 } 68 69 nbytes = sizeof (struct hbuf) * v.v_hbuf; 70 hbufs = mdb_alloc(nbytes, UM_SLEEP); 71 72 if (mdb_vread(hbufs, nbytes, hbuf_addr) != nbytes) { 73 mdb_warn("failed to read hbufs"); 74 mdb_free(hbufs, nbytes); 75 return (WALK_ERR); 76 } 77 78 bwp = mdb_alloc(sizeof (buf_walk_t), UM_SLEEP); 79 80 bwp->bw_hbufbase = hbuf_addr; 81 bwp->bw_hbufs = hbufs; 82 bwp->bw_nhbufs = v.v_hbuf; 83 bwp->bw_hbufi = 0; 84 bwp->bw_bufp = mdb_alloc(sizeof (buf_t), UM_SLEEP); 85 86 wsp->walk_addr = (uintptr_t)hbufs[0].b_forw; 87 wsp->walk_data = bwp; 88 89 return (WALK_NEXT); 90 } 91 92 int 93 buf_walk_step(mdb_walk_state_t *wsp) 94 { 95 buf_walk_t *bwp = wsp->walk_data; 96 uintptr_t addr; 97 98 /* 99 * If the next buf_t address we want is NULL or points back at the 100 * hbuf itself, advance to the next hash bucket. When we reach 101 * bw_nhbufs, we're done. 102 */ 103 while (wsp->walk_addr == 0 || wsp->walk_addr == (bwp->bw_hbufbase + 104 bwp->bw_hbufi * sizeof (struct hbuf))) { 105 106 if (++bwp->bw_hbufi == bwp->bw_nhbufs) 107 return (WALK_DONE); 108 109 wsp->walk_addr = (uintptr_t) 110 bwp->bw_hbufs[bwp->bw_hbufi].b_forw; 111 } 112 113 /* 114 * When we have a buf_t address, read the buffer and invoke our 115 * walk callback. We keep the next buf_t address in wsp->walk_addr. 116 */ 117 addr = wsp->walk_addr; 118 (void) mdb_vread(bwp->bw_bufp, sizeof (buf_t), addr); 119 wsp->walk_addr = (uintptr_t)bwp->bw_bufp->b_forw; 120 121 return (wsp->walk_callback(addr, bwp->bw_bufp, wsp->walk_cbdata)); 122 } 123 124 void 125 buf_walk_fini(mdb_walk_state_t *wsp) 126 { 127 buf_walk_t *bwp = wsp->walk_data; 128 129 mdb_free(bwp->bw_hbufs, sizeof (struct hbuf) * bwp->bw_nhbufs); 130 mdb_free(bwp->bw_bufp, sizeof (buf_t)); 131 mdb_free(bwp, sizeof (buf_walk_t)); 132 } 133 134 /*ARGSUSED*/ 135 int 136 bufpagefind(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv) 137 { 138 uintptr_t b_addr = addr; 139 uintptr_t arg; 140 141 page_t p; 142 buf_t b; 143 144 if (argc != 1) 145 return (DCMD_USAGE); 146 147 arg = (uintptr_t)mdb_argtoull(argv); 148 149 if (mdb_vread(&b, sizeof (buf_t), b_addr) == -1) 150 return (DCMD_ERR); 151 152 for (addr = (uintptr_t)b.b_pages; addr != 0; 153 addr = (uintptr_t)p.p_next) { 154 155 if (addr == arg) { 156 mdb_printf("buf %p has page %p on b_pages list\n", 157 b_addr, addr); 158 break; 159 } 160 161 if (mdb_vread(&p, sizeof (page_t), addr) == -1) 162 return (DCMD_ERR); 163 } 164 165 return (DCMD_OK); 166 } 167