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 2004 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include "lint.h" 30 #include <libc.h> 31 #include <fcntl.h> 32 #include <stdlib.h> 33 #include <unistd.h> 34 #include <sys/types.h> 35 #include <sys/stat.h> 36 #include <sys/auxv.h> 37 #include <mtlib.h> 38 #include <thread.h> 39 #include <synch.h> 40 41 static mutex_t auxlock = DEFAULTMUTEX; 42 43 /* 44 * Get auxiliary entry. 45 * Returns pointer to entry, or 0 if entry does not exist. 46 */ 47 static auxv_t * 48 _getaux(int type) 49 { 50 static auxv_t *auxb = NULL; 51 static size_t nauxv = 0; 52 ssize_t i; 53 54 /* 55 * The first time through, read the initial aux vector that was 56 * passed to the process at exec(2). Only do this once. 57 */ 58 if (auxb == NULL) { 59 struct stat statb; 60 int fd; 61 62 lmutex_lock(&auxlock); 63 64 if (auxb == NULL) { 65 if ((fd = open("/proc/self/auxv", O_RDONLY)) != -1 && 66 fstat(fd, &statb) != -1) 67 auxb = libc_malloc( 68 statb.st_size + sizeof (auxv_t)); 69 70 if (auxb != NULL) { 71 i = read(fd, auxb, statb.st_size); 72 if (i != -1) { 73 nauxv = i / sizeof (auxv_t); 74 auxb[nauxv].a_type = AT_NULL; 75 } else { 76 libc_free(auxb); 77 auxb = NULL; 78 } 79 } 80 81 if (fd != -1) 82 (void) close(fd); 83 } 84 85 lmutex_unlock(&auxlock); 86 } 87 88 /* 89 * Scan the auxiliary entries looking for the required type. 90 */ 91 for (i = 0; i < nauxv; i++) 92 if (auxb[i].a_type == type) 93 return (&auxb[i]); 94 95 /* 96 * No auxiliary array (static executable) or entry not found. 97 */ 98 return ((auxv_t *)0); 99 } 100 101 /* 102 * These two routines are utilities exported to the rest of libc. 103 */ 104 105 long 106 ___getauxval(int type) 107 { 108 auxv_t *auxp; 109 110 if ((auxp = _getaux(type)) != (auxv_t *)0) 111 return (auxp->a_un.a_val); 112 return (0); 113 } 114 115 void * 116 ___getauxptr(int type) 117 { 118 auxv_t *auxp; 119 120 if ((auxp = _getaux(type)) != (auxv_t *)0) 121 return (auxp->a_un.a_ptr); 122 return (0); 123 } 124