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 /* 24 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 25 * Use is subject to license terms. 26 */ 27 28 #pragma ident "%Z%%M% %I% %E% SMI" 29 30 #include "synonyms.h" 31 #include <libc.h> 32 #include <fcntl.h> 33 #include <stdlib.h> 34 #include <unistd.h> 35 #include <sys/types.h> 36 #include <sys/stat.h> 37 #include <sys/auxv.h> 38 #include <mtlib.h> 39 #include <thread.h> 40 #include <synch.h> 41 42 static mutex_t auxlock = DEFAULTMUTEX; 43 44 /* 45 * Get auxiliary entry. 46 * Returns pointer to entry, or 0 if entry does not exist. 47 */ 48 static auxv_t * 49 _getaux(int type) 50 { 51 static auxv_t *auxb = NULL; 52 static size_t nauxv = 0; 53 ssize_t i; 54 55 /* 56 * The first time through, read the initial aux vector that was 57 * passed to the process at exec(2). Only do this once. 58 */ 59 if (auxb == NULL) { 60 struct stat statb; 61 int fd; 62 63 lmutex_lock(&auxlock); 64 65 if (auxb == NULL) { 66 if ((fd = open("/proc/self/auxv", O_RDONLY)) != -1 && 67 fstat(fd, &statb) != -1) 68 auxb = libc_malloc( 69 statb.st_size + sizeof (auxv_t)); 70 71 if (auxb != NULL) { 72 i = read(fd, auxb, statb.st_size); 73 if (i != -1) { 74 nauxv = i / sizeof (auxv_t); 75 auxb[nauxv].a_type = AT_NULL; 76 } else { 77 libc_free(auxb); 78 auxb = NULL; 79 } 80 } 81 82 if (fd != -1) 83 (void) close(fd); 84 } 85 86 lmutex_unlock(&auxlock); 87 } 88 89 /* 90 * Scan the auxiliary entries looking for the required type. 91 */ 92 for (i = 0; i < nauxv; i++) 93 if (auxb[i].a_type == type) 94 return (&auxb[i]); 95 96 /* 97 * No auxiliary array (static executable) or entry not found. 98 */ 99 return ((auxv_t *)0); 100 } 101 102 /* 103 * These two routines are utilities exported to the rest of libc. 104 */ 105 106 long 107 ___getauxval(int type) 108 { 109 auxv_t *auxp; 110 111 if ((auxp = _getaux(type)) != (auxv_t *)0) 112 return (auxp->a_un.a_val); 113 return (0); 114 } 115 116 void * 117 ___getauxptr(int type) 118 { 119 auxv_t *auxp; 120 121 if ((auxp = _getaux(type)) != (auxv_t *)0) 122 return (auxp->a_un.a_ptr); 123 return (0); 124 } 125