1 #define _GNU_SOURCE
2 #include <assert.h>
3 #include <fcntl.h>
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <string.h>
7 #include <sys/mman.h>
8 #include <sys/stat.h>
9 #include <sys/types.h>
10 #include <unistd.h>
11
12 typedef unsigned long long u64;
13
14 static size_t length = 1 << 24;
15
read_rss(void)16 static u64 read_rss(void)
17 {
18 char buf[4096], *s = buf;
19 int i, fd;
20 u64 rss;
21
22 fd = open("/proc/self/statm", O_RDONLY);
23 assert(fd > 2);
24 memset(buf, 0, sizeof(buf));
25 read(fd, buf, sizeof(buf) - 1);
26 for (i = 0; i < 1; i++)
27 s = strchr(s, ' ') + 1;
28 rss = strtoull(s, NULL, 10);
29 return rss << 12; /* assumes 4k pagesize */
30 }
31
do_mmap(int fd,int extra_flags,int unmap)32 static void do_mmap(int fd, int extra_flags, int unmap)
33 {
34 int *p;
35 int flags = MAP_PRIVATE | MAP_POPULATE | extra_flags;
36 u64 before, after;
37 int ret;
38
39 before = read_rss();
40 p = mmap(NULL, length, PROT_READ | PROT_WRITE, flags, fd, 0);
41 assert(p != MAP_FAILED ||
42 !"mmap returned an unexpected error");
43 after = read_rss();
44 assert(llabs(after - before - length) < 0x40000 ||
45 !"rss didn't grow as expected");
46 if (!unmap)
47 return;
48 ret = munmap(p, length);
49 assert(!ret || !"munmap returned an unexpected error");
50 after = read_rss();
51 assert(llabs(after - before) < 0x40000 ||
52 !"rss didn't shrink as expected");
53 }
54
open_file(const char * path)55 static int open_file(const char *path)
56 {
57 int fd, err;
58
59 unlink(path);
60 fd = open(path, O_CREAT | O_RDWR | O_TRUNC | O_EXCL
61 | O_LARGEFILE | O_CLOEXEC, 0600);
62 assert(fd > 2);
63 unlink(path);
64 err = ftruncate(fd, length);
65 assert(!err);
66 return fd;
67 }
68
main(void)69 int main(void)
70 {
71 int hugefd, fd;
72
73 fd = open_file("/dev/shm/hugetlbhog");
74 hugefd = open_file("/hugepages/hugetlbhog");
75
76 system("echo 100 > /proc/sys/vm/nr_hugepages");
77 do_mmap(-1, MAP_ANONYMOUS, 1);
78 do_mmap(fd, 0, 1);
79 do_mmap(-1, MAP_ANONYMOUS | MAP_HUGETLB, 1);
80 do_mmap(hugefd, 0, 1);
81 do_mmap(hugefd, MAP_HUGETLB, 1);
82 /* Leak the last one to test do_exit() */
83 do_mmap(-1, MAP_ANONYMOUS | MAP_HUGETLB, 0);
84 printf("oll korrekt.\n");
85 return 0;
86 }
87