commit a383648d3a0057264882d4b4a54f06fe0a61f912
author Christopher Ferris <cferris@google.com> Fri May 13 12:09:39 2022 -0700
committer Christopher Ferris <cferris@google.com> Wed May 18 17:05:05 2022 -0700
tree 513852af8fd45f3f8ae02be4000cf7c0fcaa6607
parent c7b31befbfba5e96862bd75b24a6d2ba3bf7b0d4

Add options to only backtrace specific sizes.

Add backtrace_size for only backtracing a single size.
Add backtrace_min_size to set the minimum value of size to backtrace.
Add backtrace_max_size to set the maximum value of size to backtrace.

Documented the new options.

Test: New unit test pass.
Change-Id: I1a773737910cd4bc2af9546547b3a2740bbcb22b

libc/malloc_debug/PointerData.cpp

diff --git a/libc/malloc_debug/PointerData.cpp b/libc/malloc_debug/PointerData.cpp
index d062086..5ab2232 100644
--- a/libc/malloc_debug/PointerData.cpp
+++ b/libc/malloc_debug/PointerData.cpp
@@ -136,7 +136,22 @@
   return true;
 }
 
-size_t PointerData::AddBacktrace(size_t num_frames) {
+static inline bool ShouldBacktraceAllocSize(size_t size_bytes) {
+  static bool only_backtrace_specific_sizes =
+      g_debug->config().options() & BACKTRACE_SPECIFIC_SIZES;
+  if (!only_backtrace_specific_sizes) {
+    return true;
+  }
+  static size_t min_size_bytes = g_debug->config().backtrace_min_size_bytes();
+  static size_t max_size_bytes = g_debug->config().backtrace_max_size_bytes();
+  return size_bytes >= min_size_bytes && size_bytes <= max_size_bytes;
+}
+
+size_t PointerData::AddBacktrace(size_t num_frames, size_t size_bytes) {
+  if (!ShouldBacktraceAllocSize(size_bytes)) {
+    return kBacktraceEmptyIndex;
+  }
+
   std::vector<uintptr_t> frames;
   std::vector<unwindstack::FrameData> frames_info;
   if (g_debug->config().options() & BACKTRACE_FULL) {
@@ -198,7 +213,7 @@
 void PointerData::Add(const void* ptr, size_t pointer_size) {
   size_t hash_index = 0;
   if (backtrace_enabled_) {
-    hash_index = AddBacktrace(g_debug->config().backtrace_frames());
+    hash_index = AddBacktrace(g_debug->config().backtrace_frames(), pointer_size);
   }
 
   std::lock_guard<std::mutex> pointer_guard(pointer_mutex_);
@@ -336,11 +351,11 @@
   }
 }
 
-void* PointerData::AddFreed(const void* ptr) {
+void* PointerData::AddFreed(const void* ptr, size_t size_bytes) {
   size_t hash_index = 0;
   size_t num_frames = g_debug->config().free_track_backtrace_num_frames();
   if (num_frames) {
-    hash_index = AddBacktrace(num_frames);
+    hash_index = AddBacktrace(num_frames, size_bytes);
   }
 
   void* last = nullptr;