[asan] Refactor shadow memory initialization out of AsanInitInternal [NFC]

[kubamracek]

Summary

NFC, just factoring out the shadow memory setup into a static function.

[eugenis]

LGTM

lib/asan/asan_rtl.cc

466

maybe move this call out of InitializeShadowMemory

[kubamracek]

lib/asan/asan_rtl.cc

466

ok, will do.

lib/asan/asan_rtl.cc

static void PrintAddressSpaceLayout() {
   Printf("SHADOW_OFFSET: 0x%zx\n", (uptr)SHADOW_OFFSET);
   CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7);
   if (kMidMemBeg)
     CHECK(kMidShadowBeg > kLowShadowEnd &&
           kMidMemBeg > kMidShadowEnd &&
           kHighShadowBeg > kMidMemEnd);
 }
 
-static void AsanInitInternal() {
-  if (LIKELY(asan_inited)) return;
-  SanitizerToolName = "AddressSanitizer";
-  CHECK(!asan_init_is_running && "ASan init calls itself!");
-  asan_init_is_running = true;
-
-  CacheBinaryName();
-
-  // Initialize flags. This must be done early, because most of the
-  // initialization steps look at flags().
-  InitializeFlags();
-
-  AsanCheckIncompatibleRT();
-  AsanCheckDynamicRTPrereqs();
-  AvoidCVE_2016_2143();
-
-  SetCanPoisonMemory(flags()->poison_heap);
-  SetMallocContextSize(common_flags()->malloc_context_size);
-
-  InitializePlatformExceptionHandlers();
-
-  InitializeHighMemEnd();
-
-  // Make sure we are not statically linked.
-  AsanDoesNotSupportStaticLinkage();
-
-  // Install tool-specific callbacks in sanitizer_common.
-  AddDieCallback(AsanDie);
-  SetCheckFailedCallback(AsanCheckFailed);
-  SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
-
-  __sanitizer_set_report_path(common_flags()->log_path);
-
-  __asan_option_detect_stack_use_after_return =
-      flags()->detect_stack_use_after_return;
-
-  // Re-exec ourselves if we need to set additional env or command line args.
-  MaybeReexec();
-
-  // Setup internal allocator callback.
-  SetLowLevelAllocateCallback(OnLowLevelAllocate);
-
-  InitializeAsanInterceptors();
-
-  // Enable system log ("adb logcat") on Android.
-  // Doing this before interceptors are initialized crashes in:
-  // AsanInitInternal -> android_log_write -> __interceptor_strcmp
-  AndroidLogInit();
-
-  ReplaceSystemMalloc();
-
+static void InitializeShadowMemory() {
   // Set the shadow memory address to uninitialized.
   __asan_shadow_memory_dynamic_address = kDefaultShadowSentinel;
 
   uptr shadow_start = kLowShadowBeg;
   // Detect if a dynamic shadow address must used and find a available location
   // when necessary. When dynamic address is used, the macro |kLowShadowBeg|
   // expands to |__asan_shadow_memory_dynamic_address| which is
   // |kDefaultShadowSentinel|.
#if SANITIZER_LINUX && defined(__x86_64__) && defined(_LP64) &&                \
   if (!full_shadow_is_available) {
     kMidMemBeg = kLowMemEnd < 0x3000000000ULL ? 0x3000000000ULL : 0;
     kMidMemEnd = kLowMemEnd < 0x3000000000ULL ? 0x4fffffffffULL : 0;
   }
 #endif
 
   if (Verbosity()) PrintAddressSpaceLayout();
 
   DisableCoreDumperIfNecessary();
 
   if (full_shadow_is_available) {
     // mmap the low shadow plus at least one page at the left.
     if (kLowShadowBeg)
       ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
     // mmap the high shadow.
     ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
     // protect the gap.
#endif
   } else {
     Report("Shadow memory range interleaves with an existing memory mapping. "
            "ASan cannot proceed correctly. ABORTING.\n");
     Report("ASan shadow was supposed to be located in the [%p-%p] range.\n",
            shadow_start, kHighShadowEnd);
     DumpProcessMap();
     Die();
   }
+}
+
+static void AsanInitInternal() {
+  if (LIKELY(asan_inited)) return;
+  SanitizerToolName = "AddressSanitizer";
+  CHECK(!asan_init_is_running && "ASan init calls itself!");
+  asan_init_is_running = true;
+
+  CacheBinaryName();
+
+  // Initialize flags. This must be done early, because most of the
+  // initialization steps look at flags().
+  InitializeFlags();
+
+  AsanCheckIncompatibleRT();
+  AsanCheckDynamicRTPrereqs();
+  AvoidCVE_2016_2143();
+
+  SetCanPoisonMemory(flags()->poison_heap);
+  SetMallocContextSize(common_flags()->malloc_context_size);
+
+  InitializePlatformExceptionHandlers();
+
+  InitializeHighMemEnd();
+
+  // Make sure we are not statically linked.
+  AsanDoesNotSupportStaticLinkage();
+
+  // Install tool-specific callbacks in sanitizer_common.
+  AddDieCallback(AsanDie);
+  SetCheckFailedCallback(AsanCheckFailed);
+  SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
+
+  __sanitizer_set_report_path(common_flags()->log_path);
+
+  __asan_option_detect_stack_use_after_return =
+      flags()->detect_stack_use_after_return;
+
+  // Re-exec ourselves if we need to set additional env or command line args.
+  MaybeReexec();
+
+  // Setup internal allocator callback.
+  SetLowLevelAllocateCallback(OnLowLevelAllocate);
+
+  InitializeAsanInterceptors();
+
+  // Enable system log ("adb logcat") on Android.
+  // Doing this before interceptors are initialized crashes in:
+  // AsanInitInternal -> android_log_write -> __interceptor_strcmp
+  AndroidLogInit();
+
+  ReplaceSystemMalloc();
+
+  InitializeShadowMemory();
 
   AsanTSDInit(PlatformTSDDtor);
   InstallDeadlySignalHandlers(AsanOnDeadlySignal);
 
   AllocatorOptions allocator_options;
   allocator_options.SetFrom(flags(), common_flags());
   InitializeAllocator(allocator_options);