1 files changed, 149 insertions, 0 deletions
diff --git a/lib/sanitizer_common/sanitizer_stackdepot.cpp b/lib/sanitizer_common/sanitizer_stackdepot.cpp
new file mode 100644
index 000000000000..30073a96ceeb
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_stackdepot.cpp
@@ -0,0 +1,149 @@
+//===-- sanitizer_stackdepot.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 shared between AddressSanitizer and ThreadSanitizer
+// run-time libraries.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_stackdepot.h"
+
+#include "sanitizer_common.h"
+#include "sanitizer_hash.h"
+#include "sanitizer_stackdepotbase.h"
+
+namespace __sanitizer {
+
+struct StackDepotNode {
+  StackDepotNode *link;
+  u32 id;
+  atomic_uint32_t hash_and_use_count; // hash_bits : 12; use_count : 20;
+  u32 size;
+  u32 tag;
+  uptr stack[1];  // [size]
+
+  static const u32 kTabSizeLog = SANITIZER_ANDROID ? 16 : 20;
+  // Lower kTabSizeLog bits are equal for all items in one bucket.
+  // We use these bits to store the per-stack use counter.
+  static const u32 kUseCountBits = kTabSizeLog;
+  static const u32 kMaxUseCount = 1 << kUseCountBits;
+  static const u32 kUseCountMask = (1 << kUseCountBits) - 1;
+  static const u32 kHashMask = ~kUseCountMask;
+
+  typedef StackTrace args_type;
+  bool eq(u32 hash, const args_type &args) const {
+    u32 hash_bits =
+        atomic_load(&hash_and_use_count, memory_order_relaxed) & kHashMask;
+    if ((hash & kHashMask) != hash_bits || args.size != size || args.tag != tag)
+      return false;
+    uptr i = 0;
+    for (; i < size; i++) {
+      if (stack[i] != args.trace[i]) return false;
+    }
+    return true;
+  }
+  static uptr storage_size(const args_type &args) {
+    return sizeof(StackDepotNode) + (args.size - 1) * sizeof(uptr);
+  }
+  static u32 hash(const args_type &args) {
+    MurMur2HashBuilder H(args.size * sizeof(uptr));
+    for (uptr i = 0; i < args.size; i++) H.add(args.trace[i]);
+    return H.get();
+  }
+  static bool is_valid(const args_type &args) {
+    return args.size > 0 && args.trace;
+  }
+  void store(const args_type &args, u32 hash) {
+    atomic_store(&hash_and_use_count, hash & kHashMask, memory_order_relaxed);
+    size = args.size;
+    tag = args.tag;
+    internal_memcpy(stack, args.trace, size * sizeof(uptr));
+  }
+  args_type load() const {
+    return args_type(&stack[0], size, tag);
+  }
+  StackDepotHandle get_handle() { return StackDepotHandle(this); }
+
+  typedef StackDepotHandle handle_type;
+};
+
+COMPILER_CHECK(StackDepotNode::kMaxUseCount == (u32)kStackDepotMaxUseCount);
+
+u32 StackDepotHandle::id() { return node_->id; }
+int StackDepotHandle::use_count() {
+  return atomic_load(&node_->hash_and_use_count, memory_order_relaxed) &
+         StackDepotNode::kUseCountMask;
+}
+void StackDepotHandle::inc_use_count_unsafe() {
+  u32 prev =
+      atomic_fetch_add(&node_->hash_and_use_count, 1, memory_order_relaxed) &
+      StackDepotNode::kUseCountMask;
+  CHECK_LT(prev + 1, StackDepotNode::kMaxUseCount);
+}
+
+// FIXME(dvyukov): this single reserved bit is used in TSan.
+typedef StackDepotBase<StackDepotNode, 1, StackDepotNode::kTabSizeLog>
+    StackDepot;
+static StackDepot theDepot;
+
+StackDepotStats *StackDepotGetStats() {
+  return theDepot.GetStats();
+}
+
+u32 StackDepotPut(StackTrace stack) {
+  StackDepotHandle h = theDepot.Put(stack);
+  return h.valid() ? h.id() : 0;
+}
+
+StackDepotHandle StackDepotPut_WithHandle(StackTrace stack) {
+  return theDepot.Put(stack);
+}
+
+StackTrace StackDepotGet(u32 id) {
+  return theDepot.Get(id);
+}
+
+void StackDepotLockAll() {
+  theDepot.LockAll();
+}
+
+void StackDepotUnlockAll() {
+  theDepot.UnlockAll();
+}
+
+bool StackDepotReverseMap::IdDescPair::IdComparator(
+    const StackDepotReverseMap::IdDescPair &a,
+    const StackDepotReverseMap::IdDescPair &b) {
+  return a.id < b.id;
+}
+
+StackDepotReverseMap::StackDepotReverseMap() {
+  map_.reserve(StackDepotGetStats()->n_uniq_ids + 100);
+  for (int idx = 0; idx < StackDepot::kTabSize; idx++) {
+    atomic_uintptr_t *p = &theDepot.tab[idx];
+    uptr v = atomic_load(p, memory_order_consume);
+    StackDepotNode *s = (StackDepotNode*)(v & ~1);
+    for (; s; s = s->link) {
+      IdDescPair pair = {s->id, s};
+      map_.push_back(pair);
+    }
+  }
+  Sort(map_.data(), map_.size(), &IdDescPair::IdComparator);
+}
+
+StackTrace StackDepotReverseMap::Get(u32 id) {
+  if (!map_.size())
+    return StackTrace();
+  IdDescPair pair = {id, nullptr};
+  uptr idx =
+      InternalLowerBound(map_, 0, map_.size(), pair, IdDescPair::IdComparator);
+  if (idx > map_.size() || map_[idx].id != id)
+    return StackTrace();
+  return map_[idx].desc->load();
+}
+
+} // namespace __sanitizer