1 files changed, 146 insertions, 0 deletions
diff --git a/lib/asan/asan_debugging.cpp b/lib/asan/asan_debugging.cpp
new file mode 100644
index 0000000000000..c01360b52fc94
--- /dev/null
+++ b/lib/asan/asan_debugging.cpp
@@ -0,0 +1,146 @@
+//===-- asan_debugging.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 AddressSanitizer, an address sanity checker.
+//
+// This file contains various functions that are generally useful to call when
+// using a debugger (LLDB, GDB).
+//===----------------------------------------------------------------------===//
+
+#include "asan_allocator.h"
+#include "asan_descriptions.h"
+#include "asan_flags.h"
+#include "asan_internal.h"
+#include "asan_mapping.h"
+#include "asan_report.h"
+#include "asan_thread.h"
+
+namespace {
+using namespace __asan;
+
+static void FindInfoForStackVar(uptr addr, const char *frame_descr, uptr offset,
+                                char *name, uptr name_size,
+                                uptr *region_address, uptr *region_size) {
+  InternalMmapVector<StackVarDescr> vars;
+  vars.reserve(16);
+  if (!ParseFrameDescription(frame_descr, &vars)) {
+    return;
+  }
+
+  for (uptr i = 0; i < vars.size(); i++) {
+    if (offset <= vars[i].beg + vars[i].size) {
+      // We use name_len + 1 because strlcpy will guarantee a \0 at the end, so
+      // if we're limiting the copy due to name_len, we add 1 to ensure we copy
+      // the whole name and then terminate with '\0'.
+      internal_strlcpy(name, vars[i].name_pos,
+                       Min(name_size, vars[i].name_len + 1));
+      *region_address = addr - (offset - vars[i].beg);
+      *region_size = vars[i].size;
+      return;
+    }
+  }
+}
+
+uptr AsanGetStack(uptr addr, uptr *trace, u32 size, u32 *thread_id,
+                         bool alloc_stack) {
+  AsanChunkView chunk = FindHeapChunkByAddress(addr);
+  if (!chunk.IsValid()) return 0;
+
+  StackTrace stack(nullptr, 0);
+  if (alloc_stack) {
+    if (chunk.AllocTid() == kInvalidTid) return 0;
+    stack = chunk.GetAllocStack();
+    if (thread_id) *thread_id = chunk.AllocTid();
+  } else {
+    if (chunk.FreeTid() == kInvalidTid) return 0;
+    stack = chunk.GetFreeStack();
+    if (thread_id) *thread_id = chunk.FreeTid();
+  }
+
+  if (trace && size) {
+    size = Min(size, Min(stack.size, kStackTraceMax));
+    for (uptr i = 0; i < size; i++)
+      trace[i] = StackTrace::GetPreviousInstructionPc(stack.trace[i]);
+
+    return size;
+  }
+
+  return 0;
+}
+
+}  // namespace
+
+SANITIZER_INTERFACE_ATTRIBUTE
+const char *__asan_locate_address(uptr addr, char *name, uptr name_size,
+                                  uptr *region_address_ptr,
+                                  uptr *region_size_ptr) {
+  AddressDescription descr(addr);
+  uptr region_address = 0;
+  uptr region_size = 0;
+  const char *region_kind = nullptr;
+  if (name && name_size > 0) name[0] = 0;
+
+  if (auto shadow = descr.AsShadow()) {
+    // region_{address,size} are already 0
+    switch (shadow->kind) {
+      case kShadowKindLow:
+        region_kind = "low shadow";
+        break;
+      case kShadowKindGap:
+        region_kind = "shadow gap";
+        break;
+      case kShadowKindHigh:
+        region_kind = "high shadow";
+        break;
+    }
+  } else if (auto heap = descr.AsHeap()) {
+    region_kind = "heap";
+    region_address = heap->chunk_access.chunk_begin;
+    region_size = heap->chunk_access.chunk_size;
+  } else if (auto stack = descr.AsStack()) {
+    region_kind = "stack";
+    if (!stack->frame_descr) {
+      // region_{address,size} are already 0
+    } else {
+      FindInfoForStackVar(addr, stack->frame_descr, stack->offset, name,
+                          name_size, &region_address, &region_size);
+    }
+  } else if (auto global = descr.AsGlobal()) {
+    region_kind = "global";
+    auto &g = global->globals[0];
+    internal_strlcpy(name, g.name, name_size);
+    region_address = g.beg;
+    region_size = g.size;
+  } else {
+    // region_{address,size} are already 0
+    region_kind = "heap-invalid";
+  }
+
+  CHECK(region_kind);
+  if (region_address_ptr) *region_address_ptr = region_address;
+  if (region_size_ptr) *region_size_ptr = region_size;
+  return region_kind;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+uptr __asan_get_alloc_stack(uptr addr, uptr *trace, uptr size, u32 *thread_id) {
+  return AsanGetStack(addr, trace, size, thread_id, /* alloc_stack */ true);
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+uptr __asan_get_free_stack(uptr addr, uptr *trace, uptr size, u32 *thread_id) {
+  return AsanGetStack(addr, trace, size, thread_id, /* alloc_stack */ false);
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+void __asan_get_shadow_mapping(uptr *shadow_scale, uptr *shadow_offset) {
+  if (shadow_scale)
+    *shadow_scale = SHADOW_SCALE;
+  if (shadow_offset)
+    *shadow_offset = SHADOW_OFFSET;
+}