[compiler-rt] r266006 - [safestack] A test for stackprotector canaries.

[Evgeniy Stepanov via llvm-commits]

Author: eugenis
Date: Mon Apr 11 17:28:13 2016
New Revision: 266006

URL: http://llvm.org/viewvc/llvm-project?rev=266006&view=rev
Log:
[safestack] A test for stackprotector canaries.

Added:
    compiler-rt/trunk/test/safestack/canary.c

Added: compiler-rt/trunk/test/safestack/canary.c
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/safestack/canary.c?rev=266006&view=auto
==============================================================================
--- compiler-rt/trunk/test/safestack/canary.c (added)
+++ compiler-rt/trunk/test/safestack/canary.c Mon Apr 11 17:28:13 2016
@@ -0,0 +1,37 @@
+// RUN: %clang_safestack -g %s -o %t.nossp
+// RUN: %run %t.nossp 2>&1 | FileCheck --check-prefix=NOSSP %s
+
+// RUN: %clang_safestack -fstack-protector-all -g %s -o %t.ssp
+// RUN: not --crash %run %t.ssp 2>&1 | FileCheck -check-prefix=SSP %s
+
+// Test stack canaries on the unsafe stack.
+
+// REQUIRES: stable-runtime
+
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+__attribute__((noinline)) void f(unsigned *y) {
+  char x;
+  char *volatile p = &x;
+  char *volatile q = (char *)y;
+  assert(p < q);
+  assert(q - p < 1024); // sanity
+  // This has technically undefined behavior, but we know the actual layout of
+  // the unsafe stack and this should not touch anything important.
+  memset(&x, 0xab, q - p + sizeof(*y));
+}
+
+int main(int argc, char **argv)
+{
+  unsigned y;
+  // NOSSP: main 1
+  // SSP: main 1
+  fprintf(stderr, "main 1\n");
+  f(&y);
+  // NOSSP: main 2
+  // SSP-NOT: main 2
+  fprintf(stderr, "main 2\n");
+  return 0;
+}