none/tests/map_unmap.c

   1 #include <stdio.h>
   2 #include "tests/sys_mman.h"
   3 #include <stdlib.h>
   4 #include <unistd.h>
   5
   6 /* The code testing MAP_HUGETLB huge pages is disabled by default,
   7    as many distros do not have huge pages configured
   8    by default.
   9    To have e.g. 20 huge pages configured, do (as root)
  10       echo 20 > /proc/sys/vm/nr_hugepages
  11   Once this is done, uncomment the below, and recompile.
  12 */
  13 //#define TEST_MAP_HUGETLB 1
  14
  15 /* Similarly, testing SHM_HUGETLB huge pages is disabled by default.
  16    To have shmget/shmat big pages working, do (as root)
  17       echo 500 > /proc/sys/vm/hugetlb_shm_group
  18    where 500 is the groupid of the user that runs this test
  19   Once this is done, uncomment the below, and recompile.
  20 */
  21 //#define TEST_SHM_HUGETLB 1
  22
  23 // Size to use for huge pages
  24 #define HUGESZ (4 * 1024 * 1024)
  25
  26 #ifdef TEST_MAP_HUGETLB
  27 /* Ensure this compiles on pre 2.6 systems, or on glibc missing MAP_HUGETLB */
  28 #ifndef MAP_HUGETLB
  29 /* The below works for me on an f12/x86 linux */
  30 #define MAP_HUGETLB 0x40000
  31 #endif
  32
  33 #endif /* TEST_MAP_HUGETLB */
  34
  35 #ifdef TEST_SHM_HUGETLB
  36 #include <sys/ipc.h>
  37 #include <sys/shm.h>
  38 #include <sys/stat.h>
  39 #ifndef SHM_HUGETLB
  40 #define SHM_HUGETLB 04000
  41 #endif
  42 #endif  /* TEST_SHM_HUGETLB */
  43
  44 static unsigned int pagesize;
  45
  46 #define PAGES   1024u
  47 #define LEN     (PAGES*pagesize)
  48
  49 static void *domap(size_t len, int addflags)
  50 {
  51         void *ret = mmap(0, len, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|addflags, -1, 0);
  52
  53         if (ret == (void *)-1) {
  54                 perror("mmap");
  55                 exit(1);
  56         }
  57
  58         return ret;
  59 }
  60
  61 /* unmap in pieces to exercise munmap more */
  62 static void nibblemap(void *p)
  63 {
  64         int off;
  65         int i;
  66
  67         off = (random() % LEN) & ~(pagesize-1);
  68
  69         for(i = 0; i < PAGES; i++) {
  70                 /* printf("unmapping off=%d\n", off/pagesize); */
  71                 munmap((char *)p + off, pagesize);
  72                 off += 619*pagesize;
  73                 off %= LEN;
  74         }
  75 }
  76
  77 static void prmaps()
  78 {
  79         char buf[100];
  80         sprintf(buf, "/bin/cat /proc/%ld/maps", (long) getpid());
  81         system(buf);
  82         exit(1);
  83 }
  84
  85 int main()
  86 {
  87         int i;
  88         void *expect1, *expect2;
  89
  90         pagesize = getpagesize();
  91
  92         expect1 = domap(LEN, 0);
  93         expect2 = domap(LEN, 0);
  94         munmap(expect1, LEN);
  95         munmap(expect2, LEN);
  96
  97         for(i = 0; i < 5; i++) {
  98                 void *m1, *m2;
  99
 100                 m1 = domap(LEN, 0);
 101                 if (m1 != expect1) {
 102                         printf("FAIL i=%d: m1=%p expect1=%p\n",
 103                                i, m1, expect1);
 104                         prmaps();
 105                         return 1;
 106                 }
 107                 m2 = domap(LEN, 0);
 108                 if (m2 != expect2) {
 109                         printf("FAIL i=%d: m2=%p expect2=%p\n",
 110                                i, m2, expect2);
 111                         prmaps();
 112                         return 1;
 113                 }
 114                 nibblemap(m2);
 115                 munmap(m1, LEN);
 116         }
 117
 118 #ifdef  TEST_MAP_HUGETLB
 119         {
 120            void *expect3;
 121            expect3 = domap(HUGESZ, MAP_HUGETLB);
 122            munmap(expect3, HUGESZ);
 123         }
 124 #endif
 125
 126 #ifdef TEST_SHM_HUGETLB
 127         {
 128            int shmid;
 129            void *expect4;
 130
 131
 132            shmid = shmget(IPC_PRIVATE, HUGESZ,
 133                           IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR | SHM_HUGETLB);
 134            if (shmid == -1) {
 135               perror("shmget");
 136               exit(1);
 137            }
 138            expect4 = shmat(shmid, NULL, 0);
 139            if (expect4 == (void*) -1){
 140               perror("shmat");
 141               exit(1);
 142            }
 143            if (shmdt(expect4) != 0) {
 144               perror("shmdt");
 145               exit(1);
 146            }
 147            if (shmctl(shmid, IPC_RMID, 0) != 0) {
 148               perror("shmctl IPC_RMID");
 149               exit(1);
 150            }
 151         }
 152 #endif
 153
 154         printf("PASS\n");
 155         return 0;
 156 }