compiler-rt/test/gwp_asan/free_then_underflow.cpp

   1 // REQUIRES: gwp_asan
   2 // RUN: %clangxx_gwp_asan %s -o %t
   3 // RUN: %expect_crash %run %t 2>&1 | FileCheck %s
   4
   5 // RUN: %clangxx_gwp_asan %s -o %t -DTOUCH_GUARD_PAGE
   6 // RUN: %expect_crash %run %t 2>&1 | FileCheck %s
   7
   8 // CHECK: GWP-ASan detected a memory error
   9 // CHECK: Use After Free
  10 // CHECK-SAME: warning: buffer overflow/underflow detected on a free()'d allocation
  11 // CHECK-SAME: at 0x{{[a-f0-9]+}} (1 byte to the left
  12
  13 #include <cstdlib>
  14
  15 #include "page_size.h"
  16
  17 int main() {
  18   unsigned malloc_size = 1;
  19 #ifdef TOUCH_GUARD_PAGE
  20   malloc_size = pageSize();
  21 #endif // TOUCH_GUARD_PAGE
  22   char *Ptr = reinterpret_cast<char *>(malloc(malloc_size));
  23   free(Ptr);
  24   volatile char x = *(Ptr - 1);
  25   return 0;
  26 }