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 (c) 2000 by Sun Microsystems, Inc. 24 * All rights reserved. 25 */ 26 /* 27 * Copyright 2018 Joyent, Inc. 28 */ 29 30 #include <mdb/mdb_modapi.h> 31 #include <mdb/mdb_ctf.h> 32 #include "ctxop.h" 33 34 struct ctxop_walk_state { 35 uintptr_t cws_head; 36 uint_t cws_next_offset; 37 }; 38 39 int 40 ctxop_walk_init(mdb_walk_state_t *wsp) 41 { 42 struct ctxop_walk_state *priv; 43 int offset; 44 uintptr_t addr; 45 46 if (wsp->walk_addr == 0) { 47 mdb_warn("must specify thread for ctxop walk\n"); 48 return (WALK_ERR); 49 } 50 51 offset = mdb_ctf_offsetof_by_name("kthread_t", "t_ctx"); 52 if (offset == -1) 53 return (WALK_ERR); 54 55 if (mdb_vread(&addr, sizeof (addr), 56 wsp->walk_addr + offset) != sizeof (addr)) { 57 mdb_warn("failed to read thread %p", wsp->walk_addr); 58 return (WALK_ERR); 59 } 60 61 /* No further work for threads with a NULL t_ctx */ 62 if (addr == 0) { 63 wsp->walk_data = NULL; 64 return (WALK_DONE); 65 } 66 67 /* rely on CTF for the offset of the 'next' pointer */ 68 offset = mdb_ctf_offsetof_by_name("struct ctxop", "next"); 69 if (offset == -1) 70 return (WALK_ERR); 71 72 priv = mdb_alloc(sizeof (*priv), UM_SLEEP); 73 priv->cws_head = addr; 74 priv->cws_next_offset = (uint_t)offset; 75 76 wsp->walk_data = priv; 77 wsp->walk_addr = addr; 78 return (WALK_NEXT); 79 } 80 81 int 82 ctxop_walk_step(mdb_walk_state_t *wsp) 83 { 84 struct ctxop_walk_state *priv = wsp->walk_data; 85 uintptr_t next; 86 int status; 87 88 if (mdb_vread(&next, sizeof (next), 89 wsp->walk_addr + priv->cws_next_offset) == -1) { 90 mdb_warn("failed to read ctxop`next at %p", 91 wsp->walk_addr + priv->cws_next_offset); 92 return (WALK_DONE); 93 } 94 95 status = wsp->walk_callback(wsp->walk_addr, NULL, wsp->walk_cbdata); 96 97 if (status == WALK_NEXT) { 98 /* 99 * If a NULL terminator or a loop back to the head element is 100 * encountered, the walk is done. 101 */ 102 if (next == 0 || next == priv->cws_head) { 103 status = WALK_DONE; 104 } 105 } 106 107 wsp->walk_addr = next; 108 return (status); 109 } 110 111 void 112 ctxop_walk_fini(mdb_walk_state_t *wsp) 113 { 114 struct ctxop_walk_state *priv = wsp->walk_data; 115 116 if (priv != NULL) { 117 mdb_free(priv, sizeof (*priv)); 118 } 119 } 120