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
qemu_try_memalign(size_t alignment,size_t size)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
qemu_memalign(size_t alignment,size_t size)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
qemu_vfree(void * ptr)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