1 /* $OpenBSD: util.c,v 1.21 2010/10/30 15:36:32 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 1998 Per Fogelstrom, Opsycon AB 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 */ 28 29 #include <sys/types.h> 30 #include <sys/param.h> 31 #include <sys/mman.h> 32 #include <sys/sysctl.h> 33 #include <string.h> 34 #include "archdep.h" 35 36 /* 37 * Stack protector dummies. 38 * Ideally, a scheme to compile these stubs from libc should be used, but 39 * this would end up dragging too much code from libc here. 40 */ 41 long __guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; 42 43 void __stack_smash_handler(char [], int); 44 45 void 46 __stack_smash_handler(char func[], int damaged) 47 { 48 _dl_exit(127); 49 } 50 51 /* 52 * Static vars usable after bootstrapping. 53 */ 54 static void *_dl_malloc_pool = 0; 55 static long *_dl_malloc_free = 0; 56 57 char * 58 _dl_strdup(const char *orig) 59 { 60 char *newstr; 61 int len; 62 63 len = _dl_strlen(orig)+1; 64 newstr = _dl_malloc(len); 65 _dl_strlcpy(newstr, orig, len); 66 return (newstr); 67 } 68 69 70 /* 71 * The following malloc/free code is a very simplified implementation 72 * of a malloc function. However, we do not need to be very complex here 73 * because we only free memory when 'dlclose()' is called and we can 74 * reuse at least the memory allocated for the object descriptor. We have 75 * one dynamic string allocated, the library name and it is likely that 76 * we can reuse that one to without a lot of complex colapsing code. 77 */ 78 void * 79 _dl_malloc(size_t need) 80 { 81 long *p, *t, *n, have; 82 83 need = (need + 2*DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1); 84 85 if ((t = _dl_malloc_free) != 0) { /* Try free list first */ 86 n = (long *)&_dl_malloc_free; 87 while (t && t[-1] < need) { 88 n = t; 89 t = (long *)*t; 90 } 91 if (t) { 92 *n = *t; 93 _dl_memset(t, 0, t[-1] - DL_MALLOC_ALIGN); 94 return((void *)t); 95 } 96 } 97 have = _dl_round_page((long)_dl_malloc_pool) - (long)_dl_malloc_pool; 98 if (need > have) { 99 if (have >= 8 + DL_MALLOC_ALIGN) { 100 p = _dl_malloc_pool; 101 p = (void *) ((long)p + DL_MALLOC_ALIGN); 102 p[-1] = have; 103 _dl_free((void *)p); /* move to freelist */ 104 } 105 _dl_malloc_pool = (void *)_dl_mmap((void *)0, 106 _dl_round_page(need), PROT_READ|PROT_WRITE, 107 MAP_ANON|MAP_PRIVATE, -1, 0); 108 if (_dl_malloc_pool == 0 || _dl_mmap_error(_dl_malloc_pool)) { 109 _dl_printf("Dynamic loader failure: malloc.\n"); 110 _dl_exit(7); 111 } 112 } 113 p = _dl_malloc_pool; 114 _dl_malloc_pool += need; 115 _dl_memset(p, 0, need); 116 p = (void *) ((long)p + DL_MALLOC_ALIGN); 117 p[-1] = need; 118 return (p); 119 } 120 121 void 122 _dl_free(void *p) 123 { 124 long *t = (long *)p; 125 126 *t = (long)_dl_malloc_free; 127 _dl_malloc_free = p; 128 } 129 130 131 unsigned int 132 _dl_random(void) 133 { 134 int mib[2]; 135 unsigned int rnd; 136 size_t len; 137 138 mib[0] = CTL_KERN; 139 mib[1] = KERN_ARND; 140 len = sizeof(rnd); 141 _dl_sysctl(mib, 2, &rnd, &len, NULL, 0); 142 143 return (rnd); 144 } 145 146 147