1 // RUN: %clangxx_asan -std=c++11 -O0 %s -o %t 2 // RUN: not %run %t 2>&1 | FileCheck %s --check-prefix=READ 3 // RUN: not %run %t write 2>&1 | FileCheck %s --check-prefix=WRITE 4 // REQUIRES: x86-target-arch 5 6 #include <sys/mman.h> 7 8 static volatile int sink; 9 __attribute__((noinline)) void Read(int *ptr) { sink = *ptr; } 10 __attribute__((noinline)) void Write(int *ptr) { *ptr = 0; } 11 int main(int argc, char **argv) { 12 // Writes to shadow are detected as reads from shadow gap (because of how the 13 // shadow mapping works). This is kinda hard to fix. Test a random address in 14 // the application part of the address space. 15 void *volatile p = 16 mmap(nullptr, 4096, PROT_READ, MAP_PRIVATE | MAP_ANON, 0, 0); 17 munmap(p, 4096); 18 if (argc == 1) 19 Read((int *)p); 20 else 21 Write((int *)p); 22 } 23 // READ: AddressSanitizer: SEGV on unknown address 24 // READ: The signal is caused by a READ memory access. 25 // WRITE: AddressSanitizer: SEGV on unknown address 26 // WRITE: The signal is caused by a WRITE memory access. 27