qemu/util/memalign.c
Peter Maydell 88454f844e util: Use meson checks for valloc() and memalign() presence
Instead of assuming that all CONFIG_BSD have valloc() and anything
else is memalign(), explicitly check for those functions in
meson.build and use the "is the function present" define.  Tests for
specific functionality are better than which-OS checks; this also
lets us give a helpful error message if somehow there's no usable
function present.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20220226180723.1706285-8-peter.maydell@linaro.org
2022-03-07 13:16:05 +00:00

81 lines
2.6 KiB
C

/*
* memalign.c: Allocate an aligned memory region
*
* Copyright (c) 2003-2008 Fabrice Bellard
* Copyright (c) 2010-2016 Red Hat, Inc.
* Copyright (c) 2022 Linaro Ltd
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "qemu/host-utils.h"
#include "trace.h"
void *qemu_try_memalign(size_t alignment, size_t size)
{
void *ptr;
if (alignment < sizeof(void*)) {
alignment = sizeof(void*);
} else {
g_assert(is_power_of_2(alignment));
}
/*
* Handling of 0 allocations varies among the different
* platform APIs (for instance _aligned_malloc() will
* fail) -- ensure that we always return a valid non-NULL
* pointer that can be freed by qemu_vfree().
*/
if (size == 0) {
size++;
}
#if defined(CONFIG_POSIX_MEMALIGN)
int ret;
ret = posix_memalign(&ptr, alignment, size);
if (ret != 0) {
errno = ret;
ptr = NULL;
}
#elif defined(CONFIG_ALIGNED_MALLOC)
ptr = _aligned_malloc(size, alignment);
#elif defined(CONFIG_VALLOC)
ptr = valloc(size);
#elif defined(CONFIG_MEMALIGN)
ptr = memalign(alignment, size);
#else
#error No function to allocate aligned memory available
#endif
trace_qemu_memalign(alignment, size, ptr);
return ptr;
}
void *qemu_memalign(size_t alignment, size_t size)
{
void *p = qemu_try_memalign(alignment, size);
if (p) {
return p;
}
fprintf(stderr,
"qemu_memalign: failed to allocate %zu bytes at alignment %zu: %s\n",
size, alignment, strerror(errno));
abort();
}