qemu

FORK: QEMU emulator
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memalign.c (2908B)

      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 }