tests/ltable_exhaustion_test.c

   1 #include <darwintest.h>
   2 #include <darwintest_utils.h>
   3 #include <mach/mach.h>
   4 #include <unistd.h>
   5 #include <sys/wait.h>
   6 #include <signal.h>
   7
   8 #define ITER 100
   9
  10 T_DECL(ltable_exhaustion_test,
  11     "check if allocating not used ltable entries can panic the system",
  12     T_META_ASROOT(true))
  13 {
  14         int n_ltable_entries, n_ltable_entries_after;
  15         size_t len = sizeof(int);
  16         int i;
  17         mach_port_name_t portset;
  18
  19         /*
  20          * Get how many ltable entries are allocated right now.
  21          */
  22         T_EXPECT_POSIX_SUCCESS(sysctlbyname("kern.n_ltable_entries", &n_ltable_entries, &len, NULL, 0), "kern.n_ltable_entries");
  23
  24         for (i = 0; i < ITER; i++) {
  25                 mach_port_allocate(mach_task_self(), MACH_PORT_RIGHT_PORT_SET, &portset);
  26         }
  27
  28         /*
  29          * Get how many ltable entries are allocated after the loop. Other processes in the system might have allocated entries,
  30          * so don't expect the same value.
  31          */
  32         T_EXPECT_POSIX_SUCCESS(sysctlbyname("kern.n_ltable_entries", &n_ltable_entries_after, &len, NULL, 0), "kern.n_ltable_entries");
  33
  34         T_EXPECT_LE(n_ltable_entries_after, n_ltable_entries + ITER, "ltable before %d after %d iter %d", n_ltable_entries, n_ltable_entries_after, ITER);
  35 }