Disable malloc debug intercepts when exiting.

There is a hang when enabling leak_track since the dumping of the
leak data can wind up doing an allocation.

Add new system unit test to make sure this doesn't happen again.

Bug: 111146059

Test: Test program that leaks does not hang forever.
Test: Unit tests pass.
Change-Id: Icf99be58ba5db98ee124a471b957a086045f5870

1 files changed, 4 insertions, 5 deletions

diff --git a/libc/malloc_debug/malloc_debug.cpp b/libc/malloc_debug/malloc_debug.cpp
index 1e7086c7d..2e3a0a333 100644
--- a/libc/malloc_debug/malloc_debug.cpp
+++ b/libc/malloc_debug/malloc_debug.cpp
@@ -254,6 +254,9 @@ void debug_finalize() {
     return;
   }
 
+  // Turn off capturing allocations calls.
+  DebugDisableSet(true);
+
   if (g_debug->config().options() & FREE_TRACK) {
     PointerData::VerifyAllFreed();
   }
@@ -263,15 +266,11 @@ void debug_finalize() {
   }
 
   if ((g_debug->config().options() & BACKTRACE) && g_debug->config().backtrace_dump_on_exit()) {
-    ScopedDisableDebugCalls disable;
     debug_dump_heap(android::base::StringPrintf("%s.%d.exit.txt",
                                                 g_debug->config().backtrace_dump_prefix().c_str(),
-                                                getpid())
-                        .c_str());
+                                                getpid()).c_str());
   }
 
-  DebugDisableSet(true);
-
   backtrace_shutdown();
 
   delete g_debug;