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 (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 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 #pragma weak _isaexec = isaexec 30 31 #include "lint.h" 32 #include <sys/types.h> 33 #include <sys/systeminfo.h> 34 #include <unistd.h> 35 #include <string.h> 36 #include <errno.h> 37 #include <limits.h> 38 #include <stdarg.h> 39 #include <stdlib.h> 40 41 /* 42 * This is a utility routine to allow wrapper programs to simply 43 * implement the isalist exec algorithms. See PSARC/1997/220. 44 */ 45 int 46 isaexec(const char *execname, char *const *argv, char *const *envp) 47 { 48 const char *fname; 49 char *isalist; 50 char *pathname; 51 char *str; 52 char *lasts; 53 size_t isalen = 255; /* wild guess */ 54 size_t len; 55 int saved_errno; 56 57 /* 58 * Extract the isalist(5) for userland from the kernel. 59 */ 60 isalist = malloc(isalen); 61 do { 62 long ret = sysinfo(SI_ISALIST, isalist, isalen); 63 if (ret == -1l) { 64 free(isalist); 65 errno = ENOENT; 66 return (-1); 67 } 68 if (ret > isalen) { 69 isalen = ret; 70 isalist = realloc(isalist, isalen); 71 } else 72 break; 73 } while (isalist != NULL); 74 75 if (isalist == NULL) { 76 /* 77 * Then either a malloc or a realloc failed. 78 */ 79 errno = EAGAIN; 80 return (-1); 81 } 82 83 /* 84 * Allocate a full pathname buffer. The sum of the lengths of the 85 * 'path' and isalist strings is guaranteed to be big enough. 86 */ 87 len = strlen(execname) + isalen; 88 if ((pathname = malloc(len)) == NULL) { 89 free(isalist); 90 errno = EAGAIN; 91 return (-1); 92 } 93 94 /* 95 * Break the exec name into directory and file name components. 96 */ 97 (void) strcpy(pathname, execname); 98 if ((str = strrchr(pathname, '/')) != NULL) { 99 *++str = '\0'; 100 fname = execname + (str - pathname); 101 } else { 102 fname = execname; 103 *pathname = '\0'; 104 } 105 len = strlen(pathname); 106 107 /* 108 * For each name in the isa list, look for an executable file 109 * with the given file name in the corresponding subdirectory. 110 * If it's there, exec it. If it's not there, or the exec 111 * fails, then run the next version .. 112 */ 113 str = strtok_r(isalist, " ", &lasts); 114 saved_errno = ENOENT; 115 do { 116 (void) strcpy(pathname + len, str); 117 (void) strcat(pathname + len, "/"); 118 (void) strcat(pathname + len, fname); 119 if (access(pathname, X_OK) == 0) { 120 /* 121 * File exists and is marked executable. Attempt 122 * to execute the file from the subdirectory, 123 * using the user-supplied argv and envp. 124 */ 125 (void) execve(pathname, argv, envp); 126 127 /* 128 * If we failed to exec because of a temporary 129 * resource shortage, it's better to let our 130 * caller handle it (free memory, sleep for a while, 131 * or whatever before retrying) rather than drive 132 * on to run the "less capable" version. 133 */ 134 if (errno == EAGAIN) { 135 saved_errno = errno; 136 break; 137 } 138 } 139 } while ((str = strtok_r(NULL, " ", &lasts)) != NULL); 140 141 free(pathname); 142 free(isalist); 143 144 errno = saved_errno; 145 return (-1); 146 } 147