1 files changed, 62 insertions, 0 deletions
diff --git a/contrib/llvm-project/compiler-rt/lib/memprof/memprof_shadow_setup.cpp b/contrib/llvm-project/compiler-rt/lib/memprof/memprof_shadow_setup.cpp
new file mode 100644
index 000000000000..e7832f656ee8
--- /dev/null
+++ b/contrib/llvm-project/compiler-rt/lib/memprof/memprof_shadow_setup.cpp
@@ -0,0 +1,62 @@
+//===-- memprof_shadow_setup.cpp -----------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of MemProfiler, a memory profiler.
+//
+// Set up the shadow memory.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_platform.h"
+
+#include "memprof_internal.h"
+#include "memprof_mapping.h"
+
+namespace __memprof {
+
+static void ProtectGap(uptr addr, uptr size) {
+  if (!flags()->protect_shadow_gap) {
+    // The shadow gap is unprotected, so there is a chance that someone
+    // is actually using this memory. Which means it needs a shadow...
+    uptr GapShadowBeg = RoundDownTo(MEM_TO_SHADOW(addr), GetPageSizeCached());
+    uptr GapShadowEnd =
+        RoundUpTo(MEM_TO_SHADOW(addr + size), GetPageSizeCached()) - 1;
+    if (Verbosity())
+      Printf("protect_shadow_gap=0:"
+             " not protecting shadow gap, allocating gap's shadow\n"
+             "|| `[%p, %p]` || ShadowGap's shadow ||\n",
+             GapShadowBeg, GapShadowEnd);
+    ReserveShadowMemoryRange(GapShadowBeg, GapShadowEnd,
+                             "unprotected gap shadow");
+    return;
+  }
+  __sanitizer::ProtectGap(addr, size, kZeroBaseShadowStart,
+                          kZeroBaseMaxShadowStart);
+}
+
+void InitializeShadowMemory() {
+  uptr shadow_start = FindDynamicShadowStart();
+  // Update the shadow memory address (potentially) used by instrumentation.
+  __memprof_shadow_memory_dynamic_address = shadow_start;
+
+  if (kLowShadowBeg)
+    shadow_start -= GetMmapGranularity();
+
+  if (Verbosity())
+    PrintAddressSpaceLayout();
+
+  // mmap the low shadow plus at least one page at the left.
+  if (kLowShadowBeg)
+    ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
+  // mmap the high shadow.
+  ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
+  // protect the gap.
+  ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
+  CHECK_EQ(kShadowGapEnd, kHighShadowBeg - 1);
+}
+
+} // namespace __memprof