[asan] Use linker initialization for the allocator

[kubamracek]

Summary

This saves ~2 MB of dirty memory footprint. Can be a big deal on mobile devices especially when running multiple processes with ASan.

[alekseyshl]

lib/asan/asan_allocator.cc

823

And where's /*linker_initialized*/ true call?

[kubamracek]

lib/asan/asan_allocator.cc

823

There's none. ASan's allocator is currently always linker initialized. Would you prefer to just call InitLinkerInitialized always?

[alekseyshl]

lib/asan/asan_allocator.cc

823

No, I just don't see how this, seemingly no op, change saves 2 MB.

[kubamracek]

Ah, sorry. linker_initialized should of course be "true".

[alekseyshl]

In D40627#940878, @kubamracek wrote:

Ah, sorry. linker_initialized should of course be "true".

Great! I thought there's a file missing from the patch or something like this.

lib/asan/asan_allocator.cc

277

Rename this to InitLinkerInitialized and drop the parameter.

lib/asan/asan_allocator.cc

void SharedInitCode(const AllocatorOptions &options) {
     quarantine.Init((uptr)options.quarantine_size_mb << 20,
                     (uptr)options.thread_local_quarantine_size_kb << 10);
     atomic_store(&alloc_dealloc_mismatch, options.alloc_dealloc_mismatch,
                  memory_order_release);
     atomic_store(&min_redzone, options.min_redzone, memory_order_release);
     atomic_store(&max_redzone, options.max_redzone, memory_order_release);
   }
 
-  void Initialize(const AllocatorOptions &options) {
+  void Initialize(const AllocatorOptions &options, bool linker_initialized) {
     SetAllocatorMayReturnNull(options.may_return_null);
+    if (linker_initialized)
+      allocator.InitLinkerInitialized(options.release_to_os_interval_ms);
+    else
       allocator.Init(options.release_to_os_interval_ms);
     SharedInitCode(options);
   }
 
   bool RssLimitExceeded() {
     return atomic_load(&rss_limit_exceeded, memory_order_relaxed);
   }
 
   void SetRssLimitExceeded(bool limit_exceeded) {
StackTrace AsanChunkView::GetAllocStack() const {
   return GetStackTraceFromId(GetAllocStackId());
 }
 
 StackTrace AsanChunkView::GetFreeStack() const {
   return GetStackTraceFromId(GetFreeStackId());
 }
 
 void InitializeAllocator(const AllocatorOptions &options) {
-  instance.Initialize(options);
+  instance.Initialize(options, /*linker_initialized*/ false);
 }
 
 void ReInitializeAllocator(const AllocatorOptions &options) {
   instance.ReInitialize(options);
 }
 
 void GetAllocatorOptions(AllocatorOptions *options) {
   instance.GetOptions(options);