[msan] MemorySanitizer runtime.

Initial commit of the MemorySanitizer runtime library.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@169858 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 90 insertions, 0 deletions

diff --git a/lib/msan/msan_linux.cc b/lib/msan/msan_linux.cc
new file mode 100644
index 000000000..aea29453c
--- /dev/null
+++ b/lib/msan/msan_linux.cc
@@ -0,0 +1,90 @@
+//===-- msan_linux.cc -----------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of MemorySanitizer.
+//
+// Linux-specific code.
+//===----------------------------------------------------------------------===//
+
+#ifdef __linux__
+
+#include "msan.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+#include <unwind.h>
+#include <execinfo.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+
+#include "sanitizer_common/sanitizer_common.h"
+#include "sanitizer_common/sanitizer_procmaps.h"
+
+namespace __msan {
+
+static const uptr kMemBeg     = 0x600000000000;
+static const uptr kMemEnd     = 0x7fffffffffff;
+static const uptr kShadowBeg  = MEM_TO_SHADOW(kMemBeg);
+static const uptr kShadowEnd  = MEM_TO_SHADOW(kMemEnd);
+static const uptr kBad1Beg    = 0x100000000;  // 4G
+static const uptr kBad1End    = kShadowBeg - 1;
+static const uptr kBad2Beg    = kShadowEnd + 1;
+static const uptr kBad2End    = kMemBeg - 1;
+static const uptr kOriginsBeg = kBad2Beg;
+static const uptr kOriginsEnd = kBad2End;
+
+bool InitShadow(bool prot1, bool prot2, bool map_shadow, bool init_origins) {
+  if (flags()->verbosity) {
+    Printf("__msan_init %p\n", &__msan_init);
+    Printf("Memory   : %p %p\n", kMemBeg, kMemEnd);
+    Printf("Bad2     : %p %p\n", kBad2Beg, kBad2End);
+    Printf("Origins  : %p %p\n", kOriginsBeg, kOriginsEnd);
+    Printf("Shadow   : %p %p\n", kShadowBeg, kShadowEnd);
+    Printf("Bad1     : %p %p\n", kBad1Beg, kBad1End);
+  }
+
+  if (prot1 && !Mprotect(kBad1Beg, kBad1End - kBad1Beg))
+    return false;
+  if (prot2 && !Mprotect(kBad2Beg, kBad2End - kBad2Beg))
+    return false;
+  if (map_shadow) {
+    void *shadow = MmapFixedNoReserve(kShadowBeg, kShadowEnd - kShadowBeg);
+    if (shadow != (void*)kShadowBeg) return false;
+  }
+  if (init_origins) {
+    void *origins = MmapFixedNoReserve(kOriginsBeg, kOriginsEnd - kOriginsBeg);
+    if (origins != (void*)kOriginsBeg) return false;
+  }
+  return true;
+}
+
+static void MsanTrap(int, siginfo_t *siginfo, void *context) {
+  ucontext_t *ucontext = (ucontext_t*)context;
+  uptr pc = ucontext->uc_mcontext.gregs[REG_RIP];
+  uptr bp = ucontext->uc_mcontext.gregs[REG_RBP];
+  PrintWarning(pc + 1 /*1 will be subtracted in StackTrace::Print */, bp);
+  ucontext->uc_mcontext.gregs[REG_RIP] += 2;
+}
+
+void InstallTrapHandler() {
+  struct sigaction sigact;
+  internal_memset(&sigact, 0, sizeof(sigact));
+  sigact.sa_sigaction = MsanTrap;
+  sigact.sa_flags = SA_SIGINFO;
+  CHECK_EQ(0, sigaction(SIGILL, &sigact, 0));
+}
+
+void MsanDie() {
+  _exit(flags()->exit_code);
+}
+}
+
+#endif  // __linux__