tests/nxheap.c

   1 #include <stdlib.h>
   2 #include <unistd.h>
   3 #include <signal.h>
   4 #include <setjmp.h>
   5 #if __has_feature(ptrauth_calls) && !defined(__OPEN_SOURCE)
   6 #include <ptrauth.h>
   7 #endif
   8
   9 #include <darwintest.h>
  10
  11 static char *heap;
  12 static volatile int pass;
  13 static sigjmp_buf jbuf;
  14
  15 static void __dead2
  16 action(int signo, struct __siginfo *info, void *uap __attribute__((unused)))
  17 {
  18         if (info) {
  19                 pass = (signo == SIGBUS && info->si_addr == heap);
  20         }
  21         siglongjmp(jbuf, 0);
  22 }
  23
  24 T_DECL(nxheap, "Non-executable heap", T_META_CHECK_LEAKS(false), T_META_ASROOT(true))
  25 {
  26         struct sigaction sa = {
  27                 .__sigaction_u.__sa_sigaction = action,
  28                 .sa_flags = SA_SIGINFO,
  29         };
  30
  31         T_ASSERT_POSIX_ZERO(sigaction(SIGBUS, &sa, NULL), NULL);
  32
  33         if (sigsetjmp(jbuf, 0)) {
  34                 T_PASS("SIGBUS");
  35                 T_END;
  36         }
  37
  38         T_QUIET; T_ASSERT_NOTNULL((heap = malloc(1)), NULL);
  39
  40         *heap = (char)0xc3; // retq
  41 #if __has_feature(ptrauth_calls) && !defined(__OPEN_SOURCE)
  42         heap = ptrauth_sign_unauthenticated(heap, ptrauth_key_function_pointer, 0);
  43 #endif
  44         ((void (*)(void))heap)(); // call *%eax
  45
  46         T_FAIL("SIGBUS");
  47 }