Avoid recording backtrace if alloc-size is outside range of interest

Steps:
1) setprop libc.debug.malloc.program <program name>
2) setprop libc.debug.malloc.options "backtrace leak_track"
3) setprop libc.debug.malloc.minalloctorecord <int> # defaults to 0
4) setprop libc.debug.malloc.maxalloctorecord <int> # defaults to SIZE_MAX

With this, backtrace recording of only those allocations which fall within
the desired range will be done.

CRs-Fixed: 2471840

Change-Id: I586dfd590e429b53e7b1b237294f0298ff7b4017

1 files changed, 23 insertions, 0 deletions

diff --git a/libc/malloc_debug/malloc_debug.cpp b/libc/malloc_debug/malloc_debug.cpp
index 53fcead01..423363fa9 100644
--- a/libc/malloc_debug/malloc_debug.cpp
+++ b/libc/malloc_debug/malloc_debug.cpp
@@ -37,6 +37,8 @@
 #include <sys/param.h>
 #include <unistd.h>
 
+#include <sys/system_properties.h>
+
 #include <mutex>
 #include <vector>
 
@@ -62,6 +64,10 @@ DebugData* g_debug;
 bool* g_zygote_child;
 
 const MallocDispatch* g_dispatch;
+
+size_t g_min_alloc_to_record = 0;
+size_t g_max_alloc_to_record = SIZE_MAX;
+
 // ------------------------------------------------------------------------
 
 // ------------------------------------------------------------------------
@@ -280,6 +286,23 @@ bool debug_initialize(const MallocDispatch* malloc_dispatch, bool* zygote_child,
   // of different error cases.
   backtrace_startup();
 
+  char min_alloc_to_record[10];
+  if (__system_property_get("libc.debug.malloc.minalloctorecord", min_alloc_to_record)) {
+    g_min_alloc_to_record = atoi(min_alloc_to_record);
+  }
+
+  char max_alloc_to_record[10];
+  if (__system_property_get("libc.debug.malloc.maxalloctorecord", max_alloc_to_record)) {
+    g_max_alloc_to_record = atoi(max_alloc_to_record);
+  }
+
+  if (g_min_alloc_to_record > g_max_alloc_to_record) {
+    error_log("%s: min_alloc_to_record > max_alloc_to_record!,"
+        "reverting back to default limits", getprogname());
+    g_min_alloc_to_record = 0;
+    g_max_alloc_to_record = SIZE_MAX;
+  }
+
   if (g_debug->config().options() & VERBOSE) {
     info_log("%s: malloc debug enabled", getprogname());
   }