1 /* 2 * memalign.c: Allocate an aligned memory region 3 * 4 * Copyright (c) 2003-2008 Fabrice Bellard 5 * Copyright (c) 2010-2016 Red Hat, Inc. 6 * Copyright (c) 2022 Linaro Ltd 7 * 8 * Permission is hereby granted, free of charge, to any person obtaining a copy 9 * of this software and associated documentation files (the "Software"), to deal 10 * in the Software without restriction, including without limitation the rights 11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 12 * copies of the Software, and to permit persons to whom the Software is 13 * furnished to do so, subject to the following conditions: 14 * 15 * The above copyright notice and this permission notice shall be included in 16 * all copies or substantial portions of the Software. 17 * 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 21 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 24 * THE SOFTWARE. 25 */ 26 27 #include "qemu/osdep.h" 28 #include "qemu/host-utils.h" 29 #include "qemu/memalign.h" 30 #include "trace.h" 31 32 void *qemu_try_memalign(size_t alignment, size_t size) 33 { 34 void *ptr; 35 36 if (alignment < sizeof(void*)) { 37 alignment = sizeof(void*); 38 } else { 39 g_assert(is_power_of_2(alignment)); 40 } 41 42 /* 43 * Handling of 0 allocations varies among the different 44 * platform APIs (for instance _aligned_malloc() will 45 * fail) -- ensure that we always return a valid non-NULL 46 * pointer that can be freed by qemu_vfree(). 47 */ 48 if (size == 0) { 49 size++; 50 } 51 #if defined(CONFIG_POSIX_MEMALIGN) 52 int ret; 53 ret = posix_memalign(&ptr, alignment, size); 54 if (ret != 0) { 55 errno = ret; 56 ptr = NULL; 57 } 58 #elif defined(CONFIG_ALIGNED_MALLOC) 59 ptr = _aligned_malloc(size, alignment); 60 #elif defined(CONFIG_VALLOC) 61 ptr = valloc(size); 62 #elif defined(CONFIG_MEMALIGN) 63 ptr = memalign(alignment, size); 64 #else 65 #error No function to allocate aligned memory available 66 #endif 67 trace_qemu_memalign(alignment, size, ptr); 68 return ptr; 69 } 70 71 void *qemu_memalign(size_t alignment, size_t size) 72 { 73 void *p = qemu_try_memalign(alignment, size); 74 if (p) { 75 return p; 76 } 77 fprintf(stderr, 78 "qemu_memalign: failed to allocate %zu bytes at alignment %zu: %s\n", 79 size, alignment, strerror(errno)); 80 abort(); 81 } 82 83 void qemu_vfree(void *ptr) 84 { 85 trace_qemu_vfree(ptr); 86 #if !defined(CONFIG_POSIX_MEMALIGN) && defined(CONFIG_ALIGNED_MALLOC) 87 /* Only Windows _aligned_malloc needs a special free function */ 88 _aligned_free(ptr); 89 #else 90 free(ptr); 91 #endif 92 } 93