[sanitizers] read/write page fault detection on mac.

Subscribers: kubabrecka

Differential Revision: http://reviews.llvm.org/D19495

llvm-svn: 267477

1 files changed, 26 insertions, 0 deletions

diff --git a/compiler-rt/test/asan/TestCases/Posix/segv_read_write.c b/compiler-rt/test/asan/TestCases/Posix/segv_read_write.c
new file mode 100644
index 00000000000..d5a62c66db3
--- /dev/null
+++ b/compiler-rt/test/asan/TestCases/Posix/segv_read_write.c
@@ -0,0 +1,26 @@
+// RUN: %clangxx_asan -std=c++11 -O0 %s -o %t
+// RUN: not %run %t       2>&1 | FileCheck %s --check-prefix=READ
+// RUN: not %run %t write 2>&1 | FileCheck %s --check-prefix=WRITE
+// UNSUPPORTED: powerpc64,mips
+
+#include <sys/mman.h>
+
+static volatile int sink;
+__attribute__((noinline)) void Read(int *ptr) { sink = *ptr; }
+__attribute__((noinline)) void Write(int *ptr) { *ptr = 0; }
+int main(int argc, char **argv) {
+  // Writes to shadow are detected as reads from shadow gap (because of how the
+  // shadow mapping works). This is kinda hard to fix. Test a random address in
+  // the application part of the address space.
+  void *volatile p =
+      mmap(nullptr, 4096, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
+  munmap(p, 4096);
+  if (argc == 1)
+    Read((int *)p);
+  else
+    Write((int *)p);
+}
+// READ: AddressSanitizer: SEGV on unknown address
+// READ: The signal is caused by a READ memory access.
+// WRITE: AddressSanitizer: SEGV on unknown address
+// WRITE: The signal is caused by a WRITE memory access.