none/tests/solaris/mmap_noreserve.c

   1 /* Maps several pages with or without MAP_NORESEVE.
   2    Mappings with MAP_NORESEVE do not show in /proc/self/xmap
   3    (only in /proc/self/rmap) until they actually materialize.
   4    Very nice from Solaris kernel :-(
   5  */
   6
   7 #include <dlfcn.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <unistd.h>
  11 #include <wait.h>
  12 #include <sys/mman.h>
  13 #include <sys/param.h>
  14
  15 static void *do_map(int flags)
  16 {
  17    flags |= MAP_PRIVATE | MAP_ANON;
  18    void *addr = mmap(0, PAGESIZE, PROT_READ | PROT_WRITE, flags, -1, 0);
  19    if (addr == NULL) {
  20       perror("mmap");
  21       exit(1);
  22    } else {
  23       return addr;
  24    }
  25 }
  26
  27 static void *do_dlopen(const char *pathname)
  28 {
  29    int mode = RTLD_LAZY | RTLD_LOCAL;
  30    void *handle = dlopen(pathname, mode);
  31    if (handle == NULL) {
  32       fprintf(stderr, "dlopen failed for %s: %s",
  33               pathname, dlerror());
  34       exit(1);
  35    } else {
  36       return handle;
  37    }
  38 }
  39
  40 int main(int argc, const char *argv[])
  41 {
  42    do_map(MAP_NORESERVE);
  43    do_dlopen("libm.so");
  44    do_map(0);
  45    do_map(0);
  46    do_map(MAP_NORESERVE);
  47    do_dlopen("liby.so");
  48    do_map(MAP_NORESERVE);
  49    do_map(0);
  50    do_map(0);
  51    do_map(MAP_NORESERVE);
  52    do_map(MAP_NORESERVE);
  53    do_dlopen("libz.so");
  54    do_map(MAP_NORESERVE);
  55    do_map(MAP_NORESERVE);
  56    do_map(0);
  57
  58    pid_t pid = fork();
  59    if (pid == -1) {
  60       perror("fork");
  61       exit(1);
  62    }
  63
  64    if (pid == 0) {
  65       do_map(MAP_NORESERVE);
  66       do_map(0);
  67       do_map(0);
  68       do_dlopen("libw.so");
  69       do_map(0);
  70       do_map(MAP_NORESERVE);
  71       do_map(MAP_NORESERVE);
  72       do_map(0);
  73       printf("CHILD: PASSED\n");
  74       fflush(stdout);
  75       return 0;
  76    }
  77
  78    int status;
  79    if (waitpid(pid, &status, 0) != pid) {
  80       perror("waitpid");
  81    } else if ((WIFEXITED(status) != 0) && (WEXITSTATUS(status) == 0)) {
  82       printf("PASSED\n");
  83    } else {
  84       fprintf(stderr, "FAILED: child exited with unexpected status %s %d\n",
  85               WIFEXITED(status) ? "exit" : "signal",
  86               WIFEXITED(status) ? WEXITSTATUS(status) : WTERMSIG(status));
  87    }
  88
  89    return 0;
  90 }