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/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */
#include "lib.h"
#include "mmap-util.h"
#include <sys/stat.h>
void *mmap_file(int fd, size_t *length, int prot)
{
struct stat st;
if (fstat(fd, &st) < 0)
return MAP_FAILED;
#if OFF_T_MAX > SSIZE_T_MAX
if (st.st_size > SSIZE_T_MAX) {
/* too large file to map into memory */
errno = EFBIG;
return MAP_FAILED;
}
#endif
*length = (size_t)st.st_size;
if (*length == 0)
return NULL;
i_assert(*length > 0 && *length < SSIZE_T_MAX);
return mmap(NULL, *length, prot, MAP_SHARED, fd, 0);
}
void *mmap_ro_file(int fd, size_t *length)
{
return mmap_file(fd, length, PROT_READ);
}
void *mmap_rw_file(int fd, size_t *length)
{
return mmap_file(fd, length, PROT_READ | PROT_WRITE);
}
#undef madvise
int my_madvise(void *start ATTR_UNUSED, size_t length ATTR_UNUSED,
int advice ATTR_UNUSED)
{
#ifdef HAVE_MADVISE
/* Ignore ENOSYS errors, which happen if the kernel hasn't implemented
the syscall even if libc has. */
if (madvise(start, length, advice) < 0 && errno != ENOSYS)
return -1;
#endif
return 0;
}
size_t mmap_get_page_size(void)
{
static size_t size = 0;
if (size != 0)
return size;
size = getpagesize();
return size;
}
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