From a35df433bf7bf27940d1464441f497c3e8623a35 Mon Sep 17 00:00:00 2001
From: Dan Liew <dan@su-root.co.uk>
Date: Mon, 21 Jan 2019 01:41:12 +0000
Subject: [PATCH] [ASan] On Darwin record global allocator pointer and size in
 introspection struct.

This implements `mi_extra_init(...)` for the ASan allocator on
Darwin and uses the `__lsan::GetAllocatorGlobalRange(...)` function
to retrieve the allocator pointer and size.

rdar://problem/45284065

llvm-svn: 351713
---
 compiler-rt/lib/asan/asan_malloc_mac.cc | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/compiler-rt/lib/asan/asan_malloc_mac.cc b/compiler-rt/lib/asan/asan_malloc_mac.cc
index faa6c62dfcef..06dc1c289267 100644
--- a/compiler-rt/lib/asan/asan_malloc_mac.cc
+++ b/compiler-rt/lib/asan/asan_malloc_mac.cc
@@ -18,6 +18,7 @@
 #include "asan_report.h"
 #include "asan_stack.h"
 #include "asan_stats.h"
+#include "lsan/lsan_common.h"
 
 using namespace __asan;
 #define COMMON_MALLOC_ZONE_NAME "asan"
@@ -58,11 +59,12 @@ using namespace __asan;
   ReportMacMzReallocUnknown((uptr)ptr, (uptr)zone_ptr, zone_name, &stack);
 #define COMMON_MALLOC_NAMESPACE __asan
 #define COMMON_MALLOC_HAS_ZONE_ENUMERATOR 0
-#define COMMON_MALLOC_HAS_EXTRA_INTROSPECTION_INIT 0
+#define COMMON_MALLOC_HAS_EXTRA_INTROSPECTION_INIT 1
 
 #include "sanitizer_common/sanitizer_malloc_mac.inc"
 
 namespace COMMON_MALLOC_NAMESPACE {
+
 bool HandleDlopenInit() {
   static_assert(SANITIZER_SUPPORTS_INIT_FOR_DLOPEN,
                 "Expected SANITIZER_SUPPORTS_INIT_FOR_DLOPEN to be true");
@@ -83,4 +85,18 @@ bool HandleDlopenInit() {
 }
 }  // namespace COMMON_MALLOC_NAMESPACE
 
+namespace {
+
+void mi_extra_init(sanitizer_malloc_introspection_t *mi) {
+  uptr last_byte_plus_one = 0;
+  mi->allocator_ptr = 0;
+  // Range is [begin_ptr, end_ptr)
+  __lsan::GetAllocatorGlobalRange(&(mi->allocator_ptr), &last_byte_plus_one);
+  CHECK_NE(mi->allocator_ptr, 0);
+  CHECK_GT(last_byte_plus_one, mi->allocator_ptr);
+  mi->allocator_size = last_byte_plus_one - (mi->allocator_ptr);
+  CHECK_GT(mi->allocator_size, 0);
+}
+}  // namespace
+
 #endif