diff --git a/compiler-rt/lib/asan/asan_interceptors.cpp b/compiler-rt/lib/asan/asan_interceptors.cpp
--- a/compiler-rt/lib/asan/asan_interceptors.cpp
+++ b/compiler-rt/lib/asan/asan_interceptors.cpp
@@ -261,6 +261,8 @@
   // API does not requires to have ucp clean, and sets only part of fields. We
   // use ucp->uc_stack to unpoison new stack. We prefer to have zeroes then
   // uninitialized bytes.
+  // We also override uc_stack.ss_flags to distinguish between contexts used
+  // for makecontext and uninitialized contexts used as oucp for swapcontext.
   ResetContextStack(ucp);
   return REAL(getcontext)(ucp);
 }
@@ -276,11 +278,12 @@
   // Clear shadow memory for new context (it may share stack
   // with current context).
   uptr stack, ssize;
-  ReadContextStack(ucp, &stack, &ssize);
-  ClearShadowMemoryForContextStack(stack, ssize);
-
+  int flags;
+  ReadContextStack(ucp, &stack, &ssize, &flags);
   // See getcontext interceptor.
-  ResetContextStack(oucp);
+  if (flags == 0 || flags == kAsanContextStackFlagsMagic) {
+    ClearShadowMemoryForContextStack(stack, ssize);
+  }
 
 #    if __has_attribute(__indirect_return__) && \
         (defined(__x86_64__) || defined(__i386__))
@@ -294,7 +297,9 @@
   // "oucp" later, that would look as if swapcontext() returned 0.
   // We need to clear shadow for ucp once again, as it may be in arbitrary
   // state.
-  ClearShadowMemoryForContextStack(stack, ssize);
+  if (flags == 0 || flags == kAsanContextStackFlagsMagic) {
+    ClearShadowMemoryForContextStack(stack, ssize);
+  }
   return res;
 }
 #endif  // ASAN_INTERCEPT_SWAPCONTEXT
diff --git a/compiler-rt/lib/asan/asan_internal.h b/compiler-rt/lib/asan/asan_internal.h
--- a/compiler-rt/lib/asan/asan_internal.h
+++ b/compiler-rt/lib/asan/asan_internal.h
@@ -105,7 +105,8 @@
 
 void AsanOnDeadlySignal(int, void *siginfo, void *context);
 
-void ReadContextStack(void *context, uptr *stack, uptr *ssize);
+constexpr int kAsanContextStackFlagsMagic = 1234567;
+void ReadContextStack(void *context, uptr *stack, uptr *ssize, int* flags);
 void ResetContextStack(void *context);
 void StopInitOrderChecking();
 
diff --git a/compiler-rt/lib/asan/asan_linux.cpp b/compiler-rt/lib/asan/asan_linux.cpp
--- a/compiler-rt/lib/asan/asan_linux.cpp
+++ b/compiler-rt/lib/asan/asan_linux.cpp
@@ -209,19 +209,21 @@
 #endif // SANITIZER_ANDROID
 
 #if !SANITIZER_ANDROID
-void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
+void ReadContextStack(void *context, uptr *stack, uptr *ssize, int *flags) {
   ucontext_t *ucp = (ucontext_t*)context;
   *stack = (uptr)ucp->uc_stack.ss_sp;
   *ssize = ucp->uc_stack.ss_size;
+  *flags = ucp->uc_stack.ss_flags;
 }
 
 void ResetContextStack(void *context) {
   ucontext_t *ucp = (ucontext_t *)context;
   ucp->uc_stack.ss_sp = nullptr;
   ucp->uc_stack.ss_size = 0;
+  ucp->uc_stack.ss_flags = kAsanContextStackFlagsMagic;
 }
 #  else
-void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
+void ReadContextStack(void *context, uptr *stack, uptr *ssize, int* flags) {
   UNIMPLEMENTED();
 }
 
diff --git a/compiler-rt/lib/asan/asan_mac.cpp b/compiler-rt/lib/asan/asan_mac.cpp
--- a/compiler-rt/lib/asan/asan_mac.cpp
+++ b/compiler-rt/lib/asan/asan_mac.cpp
@@ -95,7 +95,7 @@
   ReleaseMemoryPagesToOS(MemToShadow(p), MemToShadow(p + size));
 }
 
-void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
+void ReadContextStack(void *context, uptr *stack, uptr *ssize, int* flags) {
   UNIMPLEMENTED();
 }
 
diff --git a/compiler-rt/lib/asan/asan_win.cpp b/compiler-rt/lib/asan/asan_win.cpp
--- a/compiler-rt/lib/asan/asan_win.cpp
+++ b/compiler-rt/lib/asan/asan_win.cpp
@@ -263,7 +263,7 @@
 
 void AsanCheckIncompatibleRT() {}
 
-void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
+void ReadContextStack(void *context, uptr *stack, uptr *ssize, int* flags) {
   UNIMPLEMENTED();
 }
 
diff --git a/compiler-rt/test/asan/TestCases/Linux/swapcontext_test.cpp b/compiler-rt/test/asan/TestCases/Linux/swapcontext_test.cpp
--- a/compiler-rt/test/asan/TestCases/Linux/swapcontext_test.cpp
+++ b/compiler-rt/test/asan/TestCases/Linux/swapcontext_test.cpp
@@ -4,6 +4,10 @@
 // RUN: %clangxx_asan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
 // RUN: %clangxx_asan -O2 %s -o %t && %run %t 2>&1 | FileCheck %s
 // RUN: %clangxx_asan -O3 %s -o %t && %run %t 2>&1 | FileCheck %s
+// RUN: %clangxx_asan -fsanitize-address-use-after-return=never -O0 %s -o %t && %run %t 2>&1 | FileCheck %s
+// RUN: %clangxx_asan -fsanitize-address-use-after-return=never -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+// RUN: %clangxx_asan -fsanitize-address-use-after-return=never -O2 %s -o %t && %run %t 2>&1 | FileCheck %s
+// RUN: %clangxx_asan -fsanitize-address-use-after-return=never -O3 %s -o %t && %run %t 2>&1 | FileCheck %s
 //
 // This test is too sublte to try on non-x86 arch for now.
 // Android and musl do not support swapcontext.
@@ -20,25 +24,20 @@
 
 const int kStackSize = 1 << 20;
 
-__attribute__((noinline))
-void Throw() {
-  throw 1;
-}
+__attribute__((noinline)) void Throw() { throw 1; }
 
-__attribute__((noinline))
-void ThrowAndCatch() {
+__attribute__((noinline)) void ThrowAndCatch() {
   try {
     Throw();
-  } catch(int a) {
+  } catch (int a) {
     printf("ThrowAndCatch: %d\n", a);
   }
 }
 
 void Child(int mode) {
-  assert(orig_context.uc_stack.ss_size == 0);
-  char x[32] = {0};  // Stack gets poisoned.
+  char x[32] = {0}; // Stack gets poisoned.
   printf("Child: %p\n", x);
-  ThrowAndCatch();  // Simulate __asan_handle_no_return().
+  ThrowAndCatch(); // Simulate __asan_handle_no_return().
   // (a) Do nothing, just return to parent function.
   // (b) Jump into the original function. Stack remains poisoned unless we do
   //     something.
@@ -53,16 +52,13 @@
 int Run(int arg, int mode, char *child_stack) {
   printf("Child stack: %p\n", child_stack);
   // Setup child context.
-  memset(&child_context, 0xff, sizeof(child_context));
   getcontext(&child_context);
-  assert(child_context.uc_stack.ss_size == 0);
   child_context.uc_stack.ss_sp = child_stack;
   child_context.uc_stack.ss_size = kStackSize / 2;
   if (mode == 0) {
     child_context.uc_link = &orig_context;
   }
   makecontext(&child_context, (void (*)())Child, 1, mode);
-  memset(&orig_context, 0xff, sizeof(orig_context));
   if (swapcontext(&orig_context, &child_context) < 0) {
     perror("swapcontext");
     return 0;
@@ -74,6 +70,47 @@
   return child_stack[arg];
 }
 
+ucontext_t poll_context;
+ucontext_t poller_context;
+
+void Poll() {
+  swapcontext(&poll_context, &poller_context);
+
+  {
+    char x = 0;
+    printf("POLL: %p\n", &x);
+  }
+
+  swapcontext(&poll_context, &poller_context);
+}
+
+void DoRunPoll(char *poll_stack) {
+  getcontext(&poll_context);
+  poll_context.uc_stack.ss_sp = poll_stack;
+  poll_context.uc_stack.ss_size = kStackSize / 2;
+  makecontext(&poll_context, Poll, 0);
+
+  getcontext(&poller_context);
+
+  swapcontext(&poller_context, &poll_context);
+  swapcontext(&poller_context, &poll_context);
+
+  // Touch poll's stack to make sure it's unpoisoned.
+  for (int i = 0; i < kStackSize; i++) {
+    poll_stack[i] = i;
+  }
+}
+
+void RunPoll() {
+  char *poll_stack = new char[kStackSize];
+
+  for (size_t i = 0; i < 2; ++i) {
+    DoRunPoll(poll_stack);
+  }
+
+  delete[] poll_stack;
+}
+
 int main(int argc, char **argv) {
   char stack[kStackSize + 1];
   // CHECK: WARNING: ASan doesn't fully support makecontext/swapcontext
@@ -92,6 +129,10 @@
   printf("Test4 passed\n");
   // CHECK: Test4 passed
 
-  delete [] heap;
+  RunPoll();
+  printf("Test Poll passed\n");
+  // CHECK: Test Poll passed
+
+  delete[] heap;
   return ret;
 }