10
#define CHECK(x) !(x) ? abort() : 0
13
/* Prefer MAP_ANON(YMOUS) to /dev/zero, since we don't need to keep a
16
# undef HAVE_MMAP_DEV_ZERO
18
# include <sys/mman.h>
20
# define MAP_FAILED -1
22
# if !defined (MAP_ANONYMOUS) && defined (MAP_ANON)
23
# define MAP_ANONYMOUS MAP_ANON
29
#ifdef HAVE_MMAP_DEV_ZERO
31
# include <sys/mman.h>
33
# define MAP_FAILED -1
41
allocate_mmap (size_t size)
44
#if defined (HAVE_MMAP_DEV_ZERO)
45
static int dev_zero_fd = -1;
48
#ifdef HAVE_MMAP_DEV_ZERO
49
if (dev_zero_fd == -1)
51
dev_zero_fd = open ("/dev/zero", O_RDONLY);
52
if (dev_zero_fd == -1)
54
perror ("open /dev/zero: %m");
62
page = mmap (NULL, size, PROT_READ | PROT_WRITE | PROT_EXEC,
63
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
65
#ifdef HAVE_MMAP_DEV_ZERO
66
page = mmap (NULL, size, PROT_READ | PROT_WRITE | PROT_EXEC,
67
MAP_PRIVATE, dev_zero_fd, 0);
70
if (page == (void *) MAP_FAILED)
72
perror ("virtual memory exhausted");