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) 1994, by Sun Microsytems, Inc. 24 */ 25 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 /* 29 * Functions to sync up library list with that of the run time linker 30 */ 31 32 #ifndef DEBUG 33 #define NDEBUG 1 34 #endif 35 36 #include <assert.h> 37 38 #include "tnfctl_int.h" 39 #include "kernel_int.h" 40 #include "dbg.h" 41 42 tnfctl_errcode_t 43 tnfctl_check_libs(tnfctl_handle_t *hndl) 44 { 45 tnfctl_errcode_t prexstat; 46 enum event_op_t dl_evt; 47 boolean_t lmap_ok; 48 49 if (hndl->mode == KERNEL_MODE) { 50 prexstat = _tnfctl_refresh_kernel(hndl); 51 return (prexstat); 52 } 53 54 /* hndl refers to a process */ 55 56 /* return value of lmap_ok, dl_evt ignored */ 57 prexstat = _tnfctl_refresh_process(hndl, &lmap_ok, &dl_evt); 58 assert(lmap_ok == B_TRUE); 59 return (prexstat); 60 } 61 62 /* 63 * _tnfctl_lock_libs() locks the library list maintained in the prex 64 * handle against it changing by a dlopen or dlclose. 65 * 66 * This locking code is between the thread that owns the handle and 67 * another thread that may be doing a dlopen/dlclose. We do not support 68 * the situation of having multiple threads operating on the same 69 * handle - in effect the code per tnfctl_handle can be thought of as 70 * being single-threaded - that is why we can check "hndl->in_objlist" 71 * without first obtaining a lock. "in_objlist" is the re-entrancy 72 * protector on the lock i.e. we can call _tnfctl_lock_libs() safely even if 73 * this thread has the lock held. The return value "release_lock" indicates 74 * whether the lock should be released or not. It can be passed into 75 * _tnfctl_unlock_libs() which will do the right thing. 76 * 77 * All of this is a bit too complex for warlock. Here we give warlock a 78 * simpler view, that these routines have the side effect of acquiring and 79 * releasing the lock, period. 80 */ 81 82 tnfctl_errcode_t 83 _tnfctl_lock_libs(tnfctl_handle_t *hndl, boolean_t *release_lock) 84 { 85 #if defined(__lock_lint) 86 87 NOTE(MUTEX_ACQUIRED_AS_SIDE_EFFECT(&warlock_kludge->lmap_lock)) 88 mutex_lock(&warlock_kludge->lmap_lock); 89 90 #else 91 92 /* this interface is only for INTERNAL_MODE clients */ 93 assert(hndl->mode == INTERNAL_MODE); 94 95 if (hndl->in_objlist == B_TRUE) { 96 /* 97 * already have _tnfctl_lmap_lock held which implies that 98 * the library list has been sync'ed up 99 */ 100 *release_lock = B_FALSE; 101 return (TNFCTL_ERR_NONE); 102 } 103 104 /* lock is not currently held, so lock it */ 105 mutex_lock(&_tnfctl_lmap_lock); 106 hndl->in_objlist = B_TRUE; 107 108 *release_lock = B_TRUE; 109 return (TNFCTL_ERR_NONE); 110 111 #endif 112 } 113 114 void 115 _tnfctl_unlock_libs(tnfctl_handle_t *hndl, boolean_t release_lock) 116 { 117 #if defined(__lock_lint) 118 119 NOTE(LOCK_RELEASED_AS_SIDE_EFFECT(&warlock_kludge->lmap_lock)) 120 mutex_unlock(&warlock_kludge->lmap_lock); 121 122 #else 123 124 /* this interface is only for INTERNAL_MODE clients */ 125 assert(hndl->mode == INTERNAL_MODE); 126 127 if (release_lock) { 128 hndl->in_objlist = B_FALSE; 129 mutex_unlock(&_tnfctl_lmap_lock); 130 } 131 132 #endif 133 } 134 135 /* 136 * _tnfctl_syn_lib_list() syncs up the library list maintained 137 * in the prex handle with the libraries in the process (if needed) 138 * NOTE: Assumes _tnfctl_lmap_lock is held. 139 * 140 */ 141 tnfctl_errcode_t 142 _tnfctl_sync_lib_list(tnfctl_handle_t *hndl) 143 { 144 tnfctl_errcode_t prexstat = TNFCTL_ERR_NONE; 145 enum event_op_t dl_evt; 146 boolean_t lmap_ok; 147 148 /* this interface is only for INTERNAL_MODE clients */ 149 assert(hndl->mode == INTERNAL_MODE); 150 151 /* lmap_lock held and in_objlist marked as B_TRUE */ 152 if (_tnfctl_libs_changed == B_TRUE) { 153 prexstat = _tnfctl_refresh_process(hndl, &lmap_ok, &dl_evt); 154 if (prexstat) { 155 return (prexstat); 156 } 157 } 158 return (TNFCTL_ERR_NONE); 159 } 160