* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
-#include <qemu/mmap-alloc.h>
-#include <sys/types.h>
-#include <sys/mman.h>
-#include <assert.h>
+
+#include "qemu/osdep.h"
+#include "qemu/mmap-alloc.h"
+#include "qemu/host-utils.h"
#define HUGETLBFS_MAGIC 0x958458f6
#if defined(__powerpc64__) && defined(__linux__)
/* On ppc64 mappings in the same segment (aka slice) must share the same
* page size. Since we will be re-allocating part of this segment
- * from the supplied fd, we should make sure to use the same page size,
- * unless we are using the system page size, in which case anonymous memory
- * is OK. Use align as a hint for the page size.
- * In this case, set MAP_NORESERVE to avoid allocating backing store memory.
+ * from the supplied fd, we should make sure to use the same page size, to
+ * this end we mmap the supplied fd. In this case, set MAP_NORESERVE to
+ * avoid allocating backing store memory.
+ * We do this unless we are using the system page size, in which case
+ * anonymous memory is OK.
*/
int anonfd = fd == -1 || qemu_fd_getpagesize(fd) == getpagesize() ? -1 : fd;
int flags = anonfd == -1 ? MAP_ANONYMOUS : MAP_NORESERVE;
#else
void *ptr = mmap(0, total, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
#endif
- size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
+ size_t offset;
void *ptr1;
if (ptr == MAP_FAILED) {
return MAP_FAILED;
}
- /* Make sure align is a power of 2 */
- assert(!(align & (align - 1)));
+ assert(is_power_of_2(align));
/* Always align to host page size */
assert(align >= getpagesize());
+ offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
ptr1 = mmap(ptr + offset, size, PROT_READ | PROT_WRITE,
MAP_FIXED |
(fd == -1 ? MAP_ANONYMOUS : 0) |
return MAP_FAILED;
}
- ptr += offset;
- total -= offset;
-
if (offset > 0) {
- munmap(ptr - offset, offset);
+ munmap(ptr, offset);
}
/*
* Leave a single PROT_NONE page allocated after the RAM block, to serve as
* a guard page guarding against potential buffer overflows.
*/
+ total -= offset;
if (total > size + getpagesize()) {
- munmap(ptr + size + getpagesize(), total - size - getpagesize());
+ munmap(ptr1 + size + getpagesize(), total - size - getpagesize());
}
- return ptr;
+ return ptr1;
}
void qemu_ram_munmap(void *ptr, size_t size)