4 files changed, 46 insertions, 7 deletions

diff --git a/compiler-rt/lib/hwasan/hwasan.cc b/compiler-rt/lib/hwasan/hwasan.cc
index 02ba6b7b139..79fcc6a39f0 100644
--- a/compiler-rt/lib/hwasan/hwasan.cc
+++ b/compiler-rt/lib/hwasan/hwasan.cc
@@ -171,22 +171,53 @@ static void HWAsanCheckFailed(const char *file, int line, const char *cond,
   Die();
 }
 
-static void HwasanPrintMemoryUsage() {
+static constexpr uptr kMemoryUsageBufferSize = 4096;
+
+static void HwasanFormatMemoryUsage(InternalScopedString &s) {
   auto thread_stats = Thread::GetThreadStats();
   auto *sds = StackDepotGetStats();
   AllocatorStatCounters asc;
   GetAllocatorStats(asc);
-  Printf(
+  s.append(
       "HWASAN pid: %d rss: %zd threads: %zd stacks: %zd"
       " thr_aux: %zd stack_depot: %zd uniq_stacks: %zd"
-      " heap: %zd\n",
+      " heap: %zd",
       internal_getpid(), GetRSS(), thread_stats.n_live_threads,
       thread_stats.total_stack_size,
       thread_stats.n_live_threads * Thread::MemoryUsedPerThread(),
-      sds->allocated, sds->n_uniq_ids,
-      asc[AllocatorStatMapped]);
+      sds->allocated, sds->n_uniq_ids, asc[AllocatorStatMapped]);
+}
+
+#if SANITIZER_ANDROID
+static char *memory_usage_buffer = nullptr;
+
+#define PR_SET_VMA 0x53564d41
+#define PR_SET_VMA_ANON_NAME 0
+
+static void InitMemoryUsage() {
+  memory_usage_buffer =
+      (char *)MmapOrDie(kMemoryUsageBufferSize, "memory usage string");
+  CHECK(memory_usage_buffer);
+  memory_usage_buffer[0] = '\0';
+  CHECK(internal_prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME,
+                       (uptr)memory_usage_buffer, kMemoryUsageBufferSize,
+                       (uptr)memory_usage_buffer) == 0);
 }
 
+void UpdateMemoryUsage() {
+  if (!flags()->export_memory_stats)
+    return;
+  if (!memory_usage_buffer)
+    InitMemoryUsage();
+  InternalScopedString s(kMemoryUsageBufferSize);
+  HwasanFormatMemoryUsage(s);
+  internal_strncpy(memory_usage_buffer, s.data(), kMemoryUsageBufferSize - 1);
+  memory_usage_buffer[kMemoryUsageBufferSize - 1] = '\0';
+}
+#else
+void UpdateMemoryUsage() {}
+#endif
+
 } // namespace __hwasan
 
 // Interface.
@@ -455,7 +486,11 @@ void __hwasan_handle_longjmp(const void *sp_dst) {
   TagMemory(sp, dst - sp, 0);
 }
 
-void __hwasan_print_memory_usage() { HwasanPrintMemoryUsage(); }
+void __hwasan_print_memory_usage() {
+  InternalScopedString s(kMemoryUsageBufferSize);
+  HwasanFormatMemoryUsage(s);
+  Printf("%s\n", s.data());
+}
 
 static const u8 kFallbackTag = 0xBB;
 
diff --git a/compiler-rt/lib/hwasan/hwasan.h b/compiler-rt/lib/hwasan/hwasan.h
index e0ca688a9a6..bfd76759cd0 100644
--- a/compiler-rt/lib/hwasan/hwasan.h
+++ b/compiler-rt/lib/hwasan/hwasan.h
@@ -145,6 +145,8 @@ void HwasanTSDInit();
 
 void HwasanOnDeadlySignal(int signo, void *info, void *context);
 
+void UpdateMemoryUsage();
+
 }  // namespace __hwasan
 
 #define HWASAN_MALLOC_HOOK(ptr, size)       \
diff --git a/compiler-rt/lib/hwasan/hwasan_allocator.h b/compiler-rt/lib/hwasan/hwasan_allocator.h
index 6f50e58fcb3..3589212d852 100644
--- a/compiler-rt/lib/hwasan/hwasan_allocator.h
+++ b/compiler-rt/lib/hwasan/hwasan_allocator.h
@@ -34,7 +34,7 @@ struct Metadata {
 };
 
 struct HwasanMapUnmapCallback {
-  void OnMap(uptr p, uptr size) const {}
+  void OnMap(uptr p, uptr size) const { UpdateMemoryUsage(); }
   void OnUnmap(uptr p, uptr size) const {
     // We are about to unmap a chunk of user memory.
     // It can return as user-requested mmap() or another thread stack.
diff --git a/compiler-rt/lib/hwasan/hwasan_flags.inc b/compiler-rt/lib/hwasan/hwasan_flags.inc
index fa542424fc6..f806b83b5b1 100644
--- a/compiler-rt/lib/hwasan/hwasan_flags.inc
+++ b/compiler-rt/lib/hwasan/hwasan_flags.inc
@@ -49,3 +49,5 @@ HWASAN_FLAG(int, heap_history_size, 1023,
           "The number of heap (de)allocations remembered per thread. "
           "Affects the quality of heap-related reports, but not the ability "
           "to find bugs.")
+HWASAN_FLAG(bool, export_memory_stats, true,
+            "Export up-to-date memory stats through /proc")