From bab3354ede1d651a6655457339a6f3d446eb90ab Mon Sep 17 00:00:00 2001
From: Elliott Hughes <enh@google.com>
Date: Tue, 26 Sep 2017 11:54:49 -0700
Subject: [PATCH] Show the number of VMAs in the tombstone.

Tombstones (especially ones with lots of VMAs) are regularly truncated.
We can at least show the number of VMAs, though, for anyone interested
in knowing whether they got close to the default 64Ki limit.

Bug: http://b/66911122
Bug: 64709603 (presubmit balking at the line above)
Test: ran crasher, examined tombstone

(cherry picked from commit 868d39a82fb2d9830d253409a1c28f0ae1fcac33)

Change-Id: I286db66f28f132307d573dbe5164efc969dc6ddc
---
 debuggerd/libdebuggerd/tombstone.cpp          | 12 +++++++-----
 libbacktrace/include/backtrace/BacktraceMap.h |  2 ++
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/debuggerd/libdebuggerd/tombstone.cpp b/debuggerd/libdebuggerd/tombstone.cpp
index 5b6d42014..b9a0bc786 100644
--- a/debuggerd/libdebuggerd/tombstone.cpp
+++ b/debuggerd/libdebuggerd/tombstone.cpp
@@ -415,15 +415,17 @@ static void dump_all_maps(Backtrace* backtrace, BacktraceMap* map, log_t* log, p
   }
 
   ScopedBacktraceMapIteratorLock lock(map);
-  _LOG(log, logtype::MAPS, "\n");
-  if (!print_fault_address_marker) {
-    _LOG(log, logtype::MAPS, "memory map:\n");
-  } else {
-    _LOG(log, logtype::MAPS, "memory map: (fault address prefixed with --->)\n");
+  _LOG(log, logtype::MAPS,
+       "\n"
+       "memory map (%zu entries):\n",
+       map->size());
+  if (print_fault_address_marker) {
     if (map->begin() != map->end() && addr < map->begin()->start) {
       _LOG(log, logtype::MAPS, "--->Fault address falls at %s before any mapped regions\n",
            get_addr_string(addr).c_str());
       print_fault_address_marker = false;
+    } else {
+      _LOG(log, logtype::MAPS, "(fault address prefixed with --->)\n");
     }
   }
 
diff --git a/libbacktrace/include/backtrace/BacktraceMap.h b/libbacktrace/include/backtrace/BacktraceMap.h
index 02a50f738..f7a55b87a 100644
--- a/libbacktrace/include/backtrace/BacktraceMap.h
+++ b/libbacktrace/include/backtrace/BacktraceMap.h
@@ -89,6 +89,8 @@ public:
   const_iterator begin() const { return maps_.begin(); }
   const_iterator end() const { return maps_.end(); }
 
+  size_t size() const { return maps_.size(); }
+
   virtual bool Build();
 
   static inline bool IsValid(const backtrace_map_t& map) {