Protection against stack-based memory corruption errors using SafeStack: compiler-rt runtime support library

This patch adds runtime support for the Safe Stack protection to compiler-rt
(see http://reviews.llvm.org/D6094 for the detailed description of the
Safe Stack).

This patch is our implementation of the safe stack on top of compiler-rt. The
patch adds basic runtime support for the safe stack to compiler-rt that
manages unsafe stack allocation/deallocation for each thread.

Original patch by Volodymyr Kuznetsov and others at the Dependable Systems
Lab at EPFL; updates and upstreaming by myself.

Differential Revision: http://reviews.llvm.org/D6096

llvm-svn: 239763

1 files changed, 23 insertions, 0 deletions

diff --git a/compiler-rt/test/safestack/overflow.c b/compiler-rt/test/safestack/overflow.c
new file mode 100644
index 00000000000..14e29823cd9
--- /dev/null
+++ b/compiler-rt/test/safestack/overflow.c
@@ -0,0 +1,23 @@
+// RUN: %clang_safestack %s -o %t
+// RUN: %run %t
+
+// RUN: %clang_nosafestack -fno-stack-protector %s -o %t
+// RUN: not %run %t
+
+// Test that buffer overflows on the unsafe stack do not affect variables on the
+// safe stack.
+
+__attribute__((noinline))
+void fct(volatile int *buffer)
+{
+  memset(buffer - 1, 0, 7 * sizeof(int));
+}
+
+int main(int argc, char **argv)
+{
+  int value1 = 42;
+  int buffer[5];
+  int value2 = 42;
+  fct(buffer);
+  return value1 != 42 || value2 != 42;
+}