Add bound violation handling for Intel(R) Memory Protection Extensions (Intel(R) MPX)

Summary:
This patch adds support for handling the SIGSEGV signal with 'si_code ==
SEGV_BNDERR', which is thrown when a bound violation is caught by the
Intel(R) MPX technology.

Differential Revision: https://reviews.llvm.org/D25329

llvm-svn: 283474

3 files changed, 104 insertions, 0 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/register/intel_xtended_registers/mpx_bound_violation/Makefile b/lldb/packages/Python/lldbsuite/test/functionalities/register/intel_xtended_registers/mpx_bound_violation/Makefile
new file mode 100644
index 00000000000..aa88c47ff3f
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/register/intel_xtended_registers/mpx_bound_violation/Makefile
@@ -0,0 +1,7 @@
+LEVEL = ../../../../make
+
+CXX_SOURCES := main.cpp
+
+CFLAGS_EXTRAS += -mmpx -fcheck-pointer-bounds -fuse-ld=bfd
+
+include $(LEVEL)/Makefile.rules
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/register/intel_xtended_registers/mpx_bound_violation/TestBoundViolation.py b/lldb/packages/Python/lldbsuite/test/functionalities/register/intel_xtended_registers/mpx_bound_violation/TestBoundViolation.py
new file mode 100644
index 00000000000..45721dd260d
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/register/intel_xtended_registers/mpx_bound_violation/TestBoundViolation.py
@@ -0,0 +1,57 @@
+"""
+Test the Intel(R) MPX bound violation signal.
+"""
+
+from __future__ import print_function
+
+
+import os
+import sys
+import time
+import re
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class RegisterCommandsTestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    @skipIf(compiler="clang")
+    @skipIf(oslist=no_match(['linux']))
+    @skipIf(archs=no_match(['i386', 'x86_64']))
+    @skipIf(oslist=["linux"], compiler="gcc", compiler_version=["<", "5"]) #GCC version >= 5 supports Intel(R) MPX.
+    def test_mpx_boundary_violation(self):
+        """Test Intel(R) MPX bound violation signal."""
+        self.build()
+        self.mpx_boundary_violation()
+
+    def mpx_boundary_violation(self):
+        exe = os.path.join(os.getcwd(), "a.out")
+        self.runCmd("file " + exe, CURRENT_EXECUTABLE_SET)
+
+        self.runCmd("run", RUN_SUCCEEDED)
+
+        target = self.dbg.GetSelectedTarget()
+        process = target.GetProcess()
+
+        if (process.GetState() == lldb.eStateExited):
+            self.skipTest("Intel(R) MPX is not supported.")
+
+        if (process.GetState() == lldb.eStateStopped):
+            self.expect("thread backtrace", STOPPED_DUE_TO_SIGNAL,
+                        substrs = ['stop reason = signal SIGSEGV: upper bound violation',
+                                   'fault address:', 'lower bound:', 'upper bound:'])
+
+        self.runCmd("continue")
+
+        if (process.GetState() == lldb.eStateStopped):
+            self.expect("thread backtrace", STOPPED_DUE_TO_SIGNAL,
+                        substrs = ['stop reason = signal SIGSEGV: lower bound violation',
+                                   'fault address:', 'lower bound:', 'upper bound:'])
+
+        self.runCmd("continue")
+        self.assertTrue(process.GetState() == lldb.eStateExited,
+                        PROCESS_EXITED)
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/register/intel_xtended_registers/mpx_bound_violation/main.cpp b/lldb/packages/Python/lldbsuite/test/functionalities/register/intel_xtended_registers/mpx_bound_violation/main.cpp
new file mode 100644
index 00000000000..9c445aa8a27
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/register/intel_xtended_registers/mpx_bound_violation/main.cpp
@@ -0,0 +1,40 @@
+//===-- main.cpp ------------------------------------------------*- C++ -*-===//
+////
+////                     The LLVM Compiler Infrastructure
+////
+//// This file is distributed under the University of Illinois Open Source
+//// License. See LICENSE.TXT for details.
+////
+////===----------------------------------------------------------------------===//
+//
+
+#include <cstddef>
+#include <sys/prctl.h>
+
+static void violate_upper_bound(int *ptr, int size)
+{
+  int i;
+  i = *(ptr + size);
+}
+
+static void violate_lower_bound (int *ptr, int size)
+{
+  int i;
+  i = *(ptr - size);
+}
+
+int
+main(int argc, char const *argv[])
+{
+  unsigned int rax, rbx, rcx, rdx;
+  int array[5];
+
+  // This call returns 0 only if the CPU and the kernel support Intel(R) MPX.
+  if (prctl(PR_MPX_ENABLE_MANAGEMENT, 0, 0, 0, 0) != 0)
+    return -1;
+
+  violate_upper_bound(array, 5);
+  violate_lower_bound(array, 5);
+
+  return 0;
+}