xref: /llvm-project/compiler-rt/test/gwp_asan/free_then_underflow.cpp (revision dcf23e13615f88bdd4975058595ee60cf1d5811c)
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 
main()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 }
27