Index: lib/asan/asan_flags.inc
===================================================================
--- lib/asan/asan_flags.inc
+++ lib/asan/asan_flags.inc
@@ -138,3 +138,6 @@
 ASAN_FLAG(bool, halt_on_error, true,
           "Crash the program after printing the first error report "
           "(WARNING: USE AT YOUR OWN RISK!)")
+ASAN_FLAG(bool, deduplicate_reports, true,
+          "Deduplicate multiple reports for single source location in "
+          "halt_on_error = false mode.")
Index: lib/asan/asan_rtl.cc
===================================================================
--- lib/asan/asan_rtl.cc
+++ lib/asan/asan_rtl.cc
@@ -37,7 +37,10 @@
 
 namespace __asan {
 
+const unsigned kAsanBuggyPcPoolSize = 25;
+
 uptr AsanMappingProfile[kAsanMappingProfileSize];
+uptr AsanBuggyPcPool[kAsanBuggyPcPoolSize];
 
 static void AsanDie() {
   static atomic_uint32_t num_calls;
@@ -107,6 +110,28 @@
   PoisonShadow(ptr, size, kAsanInternalHeapMagic);
 }
 
+// -------------- SuppressErrorReport -------------- {{{1
+// We need to avoid error reports duplicating for ASan recover mode.
+static bool SuppressErrorReport(uptr pc) {
+  if (!flags()->deduplicate_reports) return false;
+  static u32 pc_num;
+  // We have exceeded reasonable number of different reports, subsequent
+  // errors are likely artificial, so exit here.
+  if (pc_num >= kAsanBuggyPcPoolSize) {
+    if (!flags()->sleep_before_dying)
+      SleepForMillis(100);
+    internal__exit(1);
+  }
+
+  for (int i = pc_num; i >= 0; --i)
+    if (pc == AsanBuggyPcPool[i]) return true;
+
+  AsanBuggyPcPool[pc_num] = pc;
+  atomic_fetch_add((__sanitizer::atomic_uint32_t *)&pc_num, 1,
+                   memory_order_acq_rel);
+  return false;
+}
+
 // -------------------------- Run-time entry ------------------- {{{1
 // exported functions
 #define ASAN_REPORT_ERROR(type, is_write, size)                     \
@@ -123,6 +148,7 @@
 extern "C" NOINLINE INTERFACE_ATTRIBUTE                             \
 void __asan_report_ ## type ## size ## _noabort(uptr addr) {        \
   GET_CALLER_PC_BP_SP;                                              \
+  if (SuppressErrorReport(pc)) return;                              \
   ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false);   \
 }                                                                   \
 
@@ -151,6 +177,7 @@
 extern "C" NOINLINE INTERFACE_ATTRIBUTE                                     \
 void __asan_report_ ## type ## _n_noabort(uptr addr, uptr size) {           \
   GET_CALLER_PC_BP_SP;                                                      \
+  if (SuppressErrorReport(pc)) return;                                      \
   ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false);           \
 }                                                                           \
 
@@ -169,6 +196,7 @@
           *__asan_test_only_reported_buggy_pointer = addr;                     \
         } else {                                                               \
           GET_CALLER_PC_BP_SP;                                                 \
+          if (SuppressErrorReport(pc)) return;                                 \
           ReportGenericError(pc, bp, sp, addr, is_write, size, exp_arg,        \
                               fatal);                                          \
         }                                                                      \
@@ -223,6 +251,7 @@
 void __asan_loadN_noabort(uptr addr, uptr size) {
   if (__asan_region_is_poisoned(addr, size)) {
     GET_CALLER_PC_BP_SP;
+    if (SuppressErrorReport(pc)) return;
     ReportGenericError(pc, bp, sp, addr, false, size, 0, false);
   }
 }
@@ -250,6 +279,7 @@
 void __asan_storeN_noabort(uptr addr, uptr size) {
   if (__asan_region_is_poisoned(addr, size)) {
     GET_CALLER_PC_BP_SP;
+    if (SuppressErrorReport(pc)) return;
     ReportGenericError(pc, bp, sp, addr, true, size, 0, false);
   }
 }
Index: test/asan/TestCases/Posix/halt_on_error-torture.cc
===================================================================
--- test/asan/TestCases/Posix/halt_on_error-torture.cc
+++ test/asan/TestCases/Posix/halt_on_error-torture.cc
@@ -2,13 +2,13 @@
 //
 // RUN: %clangxx_asan -fsanitize-recover=address -pthread %s -o %t
 //
-// RUN: %env_asan_opts=halt_on_error=false %run %t 1 10 >1.txt 2>&1
+// RUN: %env_asan_opts=halt_on_error=false:deduplicate_reports=false %run %t 1 10 >1.txt 2>&1
 // RUN: FileCheck %s < 1.txt
 // RUN: [ $(grep -c 'ERROR: AddressSanitizer: use-after-poison' 1.txt) -eq 10 ]
 // RUN: FileCheck --check-prefix=CHECK-NO-COLLISION %s < 1.txt
 //
 // Collisions are unlikely but still possible so we need the ||.
-// RUN: %env_asan_opts=halt_on_error=false %run %t 10 20 >10.txt 2>&1 || true
+// RUN: %env_asan_opts=halt_on_error=false:deduplicate_reports=false %run %t 10 20 >10.txt 2>&1 || true
 // This one is racy although _very_ unlikely to fail:
 // RUN: FileCheck %s < 10.txt
 // RUN: FileCheck --check-prefix=CHECK-COLLISION %s < 1.txt || FileCheck --check-prefix=CHECK-NO-COLLISION %s < 1.txt
Index: test/asan/TestCases/halt_on_error-2.c
===================================================================
--- /dev/null
+++ test/asan/TestCases/halt_on_error-2.c
@@ -0,0 +1,23 @@
+// Test reports dedupication for recovery mode.
+//
+// RUN: %clang_asan -fsanitize-recover=address %s -o %t
+// RUN: %env_asan_opts=halt_on_error=false %run %t >2.txt 2>&1
+// RUN: FileCheck %s < 2.txt
+// RUN: [ $(grep -c 'ERROR: AddressSanitizer: stack-buffer-overflow' 2.txt) -eq 3 ]
+
+volatile int ten = 10;
+unsigned kNumIterations = 10;
+
+int main() {
+  char x[10];
+  for (int i = 0; i < kNumIterations; ++i) {
+    // CHECK: READ of size 1
+    volatile int res = x[ten + i];
+    // CHECK: WRITE of size 1
+     x[i + ten] = res + 3;
+    // CHECK: READ of size 1
+     res = x[ten + i];
+  }
+  return  0;
+}
+