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#define _GNU_SOURCE
#include "tests/sys_mman.h"
#include <stdio.h>
#include <stdlib.h>
static char *mkmap(unsigned sz)
{
static char *map;
static unsigned mapsz;
char *p;
if (map != NULL)
munmap(map, mapsz);
p = (char *)mmap(0, sz, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
if (p == (char *)-1) {
perror("mmap");
exit(1);
}
map = p;
mapsz = sz;
return p;
}
int main()
{
char *np;
char *p;
p = mkmap(1024*1024);
np = mremap(p, 1024*1024, 256*1024, 0); /* shrink, fixed */
if (np == (char *)-1)
perror("mremap(shrink, fixed)");
if (np != p)
fprintf(stderr, "shrink, nomove: p=%p np=%p: shrink moved?!\n",
p, np);
if (np != (char *)-1)
munmap(np, 256*1024);
p = mkmap(1024*1024);
np = mremap(p, 1024*1024, 256*1024, MREMAP_MAYMOVE); /* shrink, maymove */
if (np == (char *)-1)
perror("mremap(shrink, maymove)");
if (np != p)
fprintf(stderr, "shrink, maymove: p=%p np=%p: shrink moved?!\n",
p, np);
if (np != (char *)-1)
munmap(np, 256*1024);
p = mkmap(1024*1024);
np = mremap(p, 1024*1024, 2048*1024, 0); /* grow, fixed */
if (np == (char *)-1)
perror("mremap(grow, fixed)");
if (np != p)
fprintf(stderr, "grow, nomove: p=%p np=%p: shrink moved?!\n",
p, np);
if (np != (char *)-1)
munmap(np, 2048*1024);
p = mkmap(1024*1024);
np = mremap(p, 1024*1024, 2048*1024, MREMAP_MAYMOVE); /* grow, maymove */
if (np == (char *)-1)
perror("mremap(grow, maymove)");
if (np != p)
fprintf(stderr, "grow, maymove: p=%p np=%p: shrink moved?!\n",
p, np);
if (np != (char *)-1)
munmap(np, 2048*1024);
p = mkmap(1024*1024);
munmap(p+512*1024, 4096);
np = mremap(p, 512*1024, 1024*1024, 0); /* grow, nomove, constrained */
if (np == (char *)-1)
perror("mremap(grow, nomove, constrained)");
else if (np == p)
fprintf(stderr, "grow, maymove, constrained: p=%p np=%p (managed to grow without moving?!)\n",
p, np);
if (np != (char *)-1)
munmap(np, 1024*1024);
p = mkmap(1024*1024);
munmap(p+512*1024, 4096);
np = mremap(p, 512*1024, 1024*1024, MREMAP_MAYMOVE); /* grow, maymove, constrained */
if (np == (char *)-1)
perror("mremap(grow, maymove, constrained)");
if (np == p)
fprintf(stderr, "grow, maymove, constrained: p=%p np=%p (managed to grow without moving?!)\n",
p, np);
if (np != (char *)-1)
munmap(np, 1024*1024);
return 0;
}
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