1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright 1996-1998 John D. Polstra. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <sys/param.h> 29 #include <machine/cpu.h> 30 #include <machine/cpufunc.h> 31 #include <stddef.h> 32 #include <stdlib.h> 33 #include <string.h> 34 #include <unistd.h> 35 #include "rtld.h" 36 #include "rtld_printf.h" 37 #include "rtld_malloc.h" 38 #include "rtld_libc.h" 39 40 static int rtld_malloc_spinlock; 41 42 /* 43 * Almost always the rtld malloc is called under the write-locked rtld 44 * bind lock. Due to this, xlock() would need a single CAS to take 45 * the spinlock. But some places only own read-locked rtld bind lock, 46 * and then the spinlock protects the malloc structures from the 47 * parallel updates. 48 */ 49 static void 50 xlock(void) 51 { 52 while (atomic_cmpset_acq_int(&rtld_malloc_spinlock, 0, 1) == 0) 53 cpu_spinwait(); 54 } 55 56 static void 57 xunlock(void) 58 { 59 atomic_store_rel_int(&rtld_malloc_spinlock, 0); 60 } 61 62 void * 63 xcalloc(size_t number, size_t size) 64 { 65 void *p; 66 67 xlock(); 68 p = __crt_calloc(number, size); 69 xunlock(); 70 if (p == NULL) { 71 rtld_fdputstr(STDERR_FILENO, "Out of memory\n"); 72 _exit(1); 73 } 74 return (p); 75 } 76 77 void * 78 xmalloc(size_t size) 79 { 80 void *p; 81 82 xlock(); 83 p = __crt_malloc(size); 84 xunlock(); 85 if (p == NULL) { 86 rtld_fdputstr(STDERR_FILENO, "Out of memory\n"); 87 _exit(1); 88 } 89 return (p); 90 } 91 92 char * 93 xstrdup(const char *str) 94 { 95 char *copy; 96 size_t len; 97 98 len = strlen(str) + 1; 99 copy = xmalloc(len); 100 memcpy(copy, str, len); 101 return (copy); 102 } 103 104 void * 105 xmalloc_aligned(size_t size, size_t align, size_t offset) 106 { 107 void *res; 108 109 offset &= align - 1; 110 if (align < sizeof(void *)) 111 align = sizeof(void *); 112 113 xlock(); 114 res = __crt_aligned_alloc_offset(align, size, offset); 115 xunlock(); 116 if (res == NULL) { 117 rtld_fdputstr(STDERR_FILENO, "Out of memory\n"); 118 _exit(1); 119 } 120 return (res); 121 } 122 123 void * 124 malloc(size_t size) 125 { 126 void *p; 127 128 xlock(); 129 p = __crt_malloc(size); 130 xunlock(); 131 return (p); 132 } 133 134 void * 135 calloc(size_t num, size_t size) 136 { 137 void *p; 138 139 xlock(); 140 p = __crt_calloc(num, size); 141 xunlock(); 142 return (p); 143 } 144 145 void 146 free(void *cp) 147 { 148 xlock(); 149 __crt_free(cp); 150 xunlock(); 151 } 152 153 void * 154 realloc(void *cp, size_t nbytes) 155 { 156 void *p; 157 158 xlock(); 159 p = __crt_realloc(cp, nbytes); 160 xunlock(); 161 return (p); 162 } 163