commit d75d4bea54a788dada3f2538a33cc491e4c56ed4
author Colin Cross <ccross@android.com> Mon Feb 08 14:29:03 2016 -0800
committer Colin Cross <ccross@android.com> Thu Feb 18 16:09:17 2016 -0800
tree 2afb4a19e32539b11eda85948225ef456b4cf638
parent 2c75991359df165ca7cc7a6213fb227c0b5ed87c

malloc_debug: reread /proc/pid/maps when entry is missing

Reread /proc/pid/maps on demand in case a new library has been loaded.

Change-Id: Iac8109b3e6a07bf02c38300b21eecabf4bcd54df

libc/malloc_debug/backtrace.cpp

diff --git a/libc/malloc_debug/backtrace.cpp b/libc/malloc_debug/backtrace.cpp
index 716e672..18ce8b8 100644
--- a/libc/malloc_debug/backtrace.cpp
+++ b/libc/malloc_debug/backtrace.cpp
@@ -50,7 +50,7 @@
 
 extern "C" char* __cxa_demangle(const char*, char*, size_t*, int*);
 
-static MapData* g_map_data = nullptr;
+static MapData g_map_data;
 static const MapEntry* g_current_code_map = nullptr;
 
 static _Unwind_Reason_Code find_current_map(__unwind_context* context, void*) {
@@ -59,20 +59,15 @@
   if (ip == 0) {
     return _URC_END_OF_STACK;
   }
-  g_current_code_map = g_map_data->find(ip);
+  g_current_code_map = g_map_data.find(ip);
   return _URC_END_OF_STACK;
 }
 
 void backtrace_startup() {
-  g_map_data = MapData::Create();
-  if (g_map_data) {
-    _Unwind_Backtrace(find_current_map, nullptr);
-  }
+  _Unwind_Backtrace(find_current_map, nullptr);
 }
 
 void backtrace_shutdown() {
-  delete g_map_data;
-  g_map_data = nullptr;
 }
 
 struct stack_crawl_state_t {
@@ -150,10 +145,8 @@
     }
 
     uintptr_t rel_pc = offset;
-    const MapEntry* entry = nullptr;
-    if (g_map_data) {
-      entry = g_map_data->find(frames[frame_num], &rel_pc);
-    }
+    const MapEntry* entry = g_map_data.find(frames[frame_num], &rel_pc);
+
     const char* soname = (entry != nullptr) ? entry->name.c_str() : info.dli_fname;
     if (soname == nullptr) {
       soname = "<unknown>";