1 files changed, 83 insertions, 0 deletions
diff --git a/lib/esan/esan_linux.cpp b/lib/esan/esan_linux.cpp
new file mode 100644
index 000000000000..aa961b66116b
--- /dev/null
+++ b/lib/esan/esan_linux.cpp
@@ -0,0 +1,83 @@
+//===-- esan.cpp ----------------------------------------------------------===//
+//
+//                     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 EfficiencySanitizer, a family of performance tuners.
+//
+// Linux-specific code for the Esan run-time.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_platform.h"
+#if SANITIZER_FREEBSD || SANITIZER_LINUX
+
+#include "esan.h"
+#include "esan_shadow.h"
+#include "interception/interception.h"
+#include "sanitizer_common/sanitizer_common.h"
+#include <sys/mman.h>
+#include <errno.h>
+
+namespace __esan {
+
+void verifyAddressSpace() {
+#if SANITIZER_LINUX && defined(__x86_64__)
+  // The kernel determines its mmap base from the stack size limit.
+  // Our Linux 64-bit shadow mapping assumes the stack limit is less than a
+  // terabyte, which keeps the mmap region above 0x7e00'.
+  uptr StackLimit = GetStackSizeLimitInBytes();
+  if (StackSizeIsUnlimited() || StackLimit > MaxStackSize) {
+    VReport(1, "The stack size limit is beyond the maximum supported.\n"
+            "Re-execing with a stack size below 1TB.\n");
+    SetStackSizeLimitInBytes(MaxStackSize);
+    ReExec();
+  }
+#endif
+}
+
+static bool liesWithinSingleAppRegion(uptr Start, SIZE_T Size) {
+  uptr AppStart, AppEnd;
+  for (int i = 0; getAppRegion(i, &AppStart, &AppEnd); ++i) {
+    if (Start >= AppStart && Start + Size - 1 <= AppEnd) {
+      return true;
+    }
+  }
+  return false;
+}
+
+bool fixMmapAddr(void **Addr, SIZE_T Size, int Flags) {
+  if (*Addr) {
+    if (!liesWithinSingleAppRegion((uptr)*Addr, Size)) {
+      VPrintf(1, "mmap conflict: [%p-%p) is not in an app region\n",
+              *Addr, (uptr)*Addr + Size);
+      if (Flags & MAP_FIXED) {
+        errno = EINVAL;
+        return false;
+      } else {
+        *Addr = 0;
+      }
+    }
+  }
+  return true;
+}
+
+uptr checkMmapResult(uptr Addr, SIZE_T Size) {
+  if ((void *)Addr == MAP_FAILED)
+    return Addr;
+  if (!liesWithinSingleAppRegion(Addr, Size)) {
+    // FIXME: attempt to dynamically add this as an app region if it
+    // fits our shadow criteria.
+    // We could also try to remap somewhere else.
+    Printf("ERROR: unsupported mapping at [%p-%p)\n", Addr, Addr+Size);
+    Die();
+  }
+  return Addr;
+}
+
+} // namespace __esan
+
+#endif // SANITIZER_FREEBSD || SANITIZER_LINUX