[PATCH] D15080: [asan] Reports suppressions for ASan recovery mode (compiler-rt part).

[Dmitry Vyukov via llvm-commits]

dvyukov added inline comments.

================
Comment at: lib/asan/asan_rtl.cc:116
@@ +115,3 @@
+// due to performance issue.
+static bool SuppressErrorReport(uptr pc) {
+  if (!common_flags()->suppress_equal_pcs) return false;
----------------
This is unnecessary complex and racy. And also produces excessive contention on AsanBuggyPcPool due to compare_exchange even when we are suppressing already reported pc. What you need is:

  static bool SuppressErrorReport(uptr pc) {
  	for (unsigned i = 0; i < kAsanBuggyPcPoolSize; i++) {
  		u64 cmp = atomic_load_relaxed(&AsanBuggyPcPool[i]);
  		if (cmp == 0 && atomic_compare_exchange_strong(&AsanBuggyPcPool[i], cmp, pc, memory_order_relaxed))
  			return false;
  		if (cmp == pc)
  			return true;
  	}
  	Die();
  }



http://reviews.llvm.org/D15080