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
@@ -194,6 +194,8 @@
   __lsan::ScopedInterceptorDisabler disabler
 #endif
 
+#define SIGNAL_INTERCEPTOR_ENTER() ENSURE_ASAN_INITED()
+
 #include "sanitizer_common/sanitizer_common_interceptors.inc"
 #include "sanitizer_common/sanitizer_signal_interceptors.inc"
 
diff --git a/compiler-rt/lib/lsan/lsan_interceptors.cpp b/compiler-rt/lib/lsan/lsan_interceptors.cpp
--- a/compiler-rt/lib/lsan/lsan_interceptors.cpp
+++ b/compiler-rt/lib/lsan/lsan_interceptors.cpp
@@ -533,6 +533,7 @@
 }
 
 #define COMMON_INTERCEPT_FUNCTION(name) INTERCEPT_FUNCTION(name)
+#define SIGNAL_INTERCEPTOR_ENTER() ENSURE_LSAN_INITED
 #include "sanitizer_common/sanitizer_signal_interceptors.inc"
 
 #endif  // SANITIZER_POSIX
diff --git a/compiler-rt/lib/msan/msan_interceptors.cpp b/compiler-rt/lib/msan/msan_interceptors.cpp
--- a/compiler-rt/lib/msan/msan_interceptors.cpp
+++ b/compiler-rt/lib/msan/msan_interceptors.cpp
@@ -1441,6 +1441,8 @@
     return REAL(func)(signo, handler);                       \
   }
 
+#define SIGNAL_INTERCEPTOR_ENTER() ENSURE_MSAN_INITED()
+
 #include "sanitizer_common/sanitizer_signal_interceptors.inc"
 
 static int sigaction_impl(int signo, const __sanitizer_sigaction *act,
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_signal_interceptors.inc b/compiler-rt/lib/sanitizer_common/sanitizer_signal_interceptors.inc
--- a/compiler-rt/lib/sanitizer_common/sanitizer_signal_interceptors.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_signal_interceptors.inc
@@ -43,6 +43,7 @@
 
 #if SANITIZER_INTERCEPT_BSD_SIGNAL
 INTERCEPTOR(uptr, bsd_signal, int signum, uptr handler) {
+  SIGNAL_INTERCEPTOR_ENTER();
   if (GetHandleSignalMode(signum) == kHandleSignalExclusive) return 0;
   SIGNAL_INTERCEPTOR_SIGNAL_IMPL(bsd_signal, signum, handler);
 }
@@ -53,6 +54,7 @@
 
 #if SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION
 INTERCEPTOR(uptr, signal, int signum, uptr handler) {
+  SIGNAL_INTERCEPTOR_ENTER();
   if (GetHandleSignalMode(signum) == kHandleSignalExclusive)
     return (uptr) nullptr;
   SIGNAL_INTERCEPTOR_SIGNAL_IMPL(signal, signum, handler);
@@ -61,6 +63,7 @@
 
 INTERCEPTOR(int, sigaction_symname, int signum,
             const __sanitizer_sigaction *act, __sanitizer_sigaction *oldact) {
+  SIGNAL_INTERCEPTOR_ENTER();
   if (GetHandleSignalMode(signum) == kHandleSignalExclusive) {
     if (!oldact) return 0;
     act = nullptr;
diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
@@ -2543,6 +2543,8 @@
 #define SIGNAL_INTERCEPTOR_SIGNAL_IMPL(func, signo, handler) \
   { return (uptr)signal_impl(signo, (__sanitizer_sighandler_ptr)handler); }
 
+#define SIGNAL_INTERCEPTOR_ENTER() LazyInitialize(cur_thread_init())
+
 #include "sanitizer_common/sanitizer_signal_interceptors.inc"
 
 int sigaction_impl(int sig, const __sanitizer_sigaction *act,
diff --git a/compiler-rt/lib/ubsan/ubsan_signals_standalone.cpp b/compiler-rt/lib/ubsan/ubsan_signals_standalone.cpp
--- a/compiler-rt/lib/ubsan/ubsan_signals_standalone.cpp
+++ b/compiler-rt/lib/ubsan/ubsan_signals_standalone.cpp
@@ -34,7 +34,12 @@
 
 #else
 
+namespace __ubsan {
+void InitializeDeadlySignals();
+} // namespace __ubsan
+
 #define COMMON_INTERCEPT_FUNCTION(name) INTERCEPT_FUNCTION(name)
+#define SIGNAL_INTERCEPTOR_ENTER() __ubsan::InitializeDeadlySignals()
 #include "sanitizer_common/sanitizer_signal_interceptors.inc"
 
 // TODO(yln): Temporary workaround. Will be removed.
diff --git a/compiler-rt/test/asan/lit.cfg.py b/compiler-rt/test/asan/lit.cfg.py
--- a/compiler-rt/test/asan/lit.cfg.py
+++ b/compiler-rt/test/asan/lit.cfg.py
@@ -18,41 +18,6 @@
         )
     return attr_value
 
-
-def push_dynamic_library_lookup_path(config, new_path):
-    if platform.system() == "Windows":
-        dynamic_library_lookup_var = "PATH"
-    elif platform.system() == "Darwin":
-        dynamic_library_lookup_var = "DYLD_LIBRARY_PATH"
-    else:
-        dynamic_library_lookup_var = "LD_LIBRARY_PATH"
-
-    new_ld_library_path = os.path.pathsep.join(
-        (new_path, config.environment.get(dynamic_library_lookup_var, ""))
-    )
-    config.environment[dynamic_library_lookup_var] = new_ld_library_path
-
-    if platform.system() == "FreeBSD":
-        dynamic_library_lookup_var = "LD_32_LIBRARY_PATH"
-        new_ld_32_library_path = os.path.pathsep.join(
-            (new_path, config.environment.get(dynamic_library_lookup_var, ""))
-        )
-        config.environment[dynamic_library_lookup_var] = new_ld_32_library_path
-
-    if platform.system() == "SunOS":
-        dynamic_library_lookup_var = "LD_LIBRARY_PATH_32"
-        new_ld_library_path_32 = os.path.pathsep.join(
-            (new_path, config.environment.get(dynamic_library_lookup_var, ""))
-        )
-        config.environment[dynamic_library_lookup_var] = new_ld_library_path_32
-
-        dynamic_library_lookup_var = "LD_LIBRARY_PATH_64"
-        new_ld_library_path_64 = os.path.pathsep.join(
-            (new_path, config.environment.get(dynamic_library_lookup_var, ""))
-        )
-        config.environment[dynamic_library_lookup_var] = new_ld_library_path_64
-
-
 # Setup config name.
 config.name = "AddressSanitizer" + config.name_suffix
 
@@ -285,15 +250,6 @@
 ):
     config.available_features.add("leak-detection")
 
-# Set LD_LIBRARY_PATH to pick dynamic runtime up properly.
-push_dynamic_library_lookup_path(config, config.compiler_rt_libdir)
-
-# GCC-ASan uses dynamic runtime by default.
-if config.compiler_id == "GNU":
-    gcc_dir = os.path.dirname(config.clang)
-    libasan_dir = os.path.join(gcc_dir, "..", "lib" + config.bits)
-    push_dynamic_library_lookup_path(config, libasan_dir)
-
 # Add the RT libdir to PATH directly so that we can successfully run the gtest
 # binary to list its tests.
 if config.host_os == "Windows" and config.asan_dynamic:
diff --git a/compiler-rt/test/lit.common.cfg.py b/compiler-rt/test/lit.common.cfg.py
--- a/compiler-rt/test/lit.common.cfg.py
+++ b/compiler-rt/test/lit.common.cfg.py
@@ -76,6 +76,40 @@
     return None
 
 
+def push_dynamic_library_lookup_path(config, new_path):
+    if platform.system() == "Windows":
+        dynamic_library_lookup_var = "PATH"
+    elif platform.system() == "Darwin":
+        dynamic_library_lookup_var = "DYLD_LIBRARY_PATH"
+    else:
+        dynamic_library_lookup_var = "LD_LIBRARY_PATH"
+
+    new_ld_library_path = os.path.pathsep.join(
+        (new_path, config.environment.get(dynamic_library_lookup_var, ""))
+    )
+    config.environment[dynamic_library_lookup_var] = new_ld_library_path
+
+    if platform.system() == "FreeBSD":
+        dynamic_library_lookup_var = "LD_32_LIBRARY_PATH"
+        new_ld_32_library_path = os.path.pathsep.join(
+            (new_path, config.environment.get(dynamic_library_lookup_var, ""))
+        )
+        config.environment[dynamic_library_lookup_var] = new_ld_32_library_path
+
+    if platform.system() == "SunOS":
+        dynamic_library_lookup_var = "LD_LIBRARY_PATH_32"
+        new_ld_library_path_32 = os.path.pathsep.join(
+            (new_path, config.environment.get(dynamic_library_lookup_var, ""))
+        )
+        config.environment[dynamic_library_lookup_var] = new_ld_library_path_32
+
+        dynamic_library_lookup_var = "LD_LIBRARY_PATH_64"
+        new_ld_library_path_64 = os.path.pathsep.join(
+            (new_path, config.environment.get(dynamic_library_lookup_var, ""))
+        )
+        config.environment[dynamic_library_lookup_var] = new_ld_library_path_64
+
+
 # Choose between lit's internal shell pipeline runner and a real shell.  If
 # LIT_USE_INTERNAL_SHELL is in the environment, we use that as an override.
 use_lit_shell = os.environ.get("LIT_USE_INTERNAL_SHELL")
@@ -895,3 +929,12 @@
 # related is likely to cause issues with sanitizer tests, because it may
 # preempt something we're looking to trap (e.g. _FORTIFY_SOURCE vs our ASAN).
 config.environment["CLANG_NO_DEFAULT_CONFIG"] = "1"
+
+# Set LD_LIBRARY_PATH to pick dynamic runtime up properly.
+push_dynamic_library_lookup_path(config, config.compiler_rt_libdir)
+
+# GCC-ASan uses dynamic runtime by default.
+if config.compiler_id == "GNU":
+    gcc_dir = os.path.dirname(config.clang)
+    libasan_dir = os.path.join(gcc_dir, "..", "lib" + config.bits)
+    push_dynamic_library_lookup_path(config, libasan_dir)
diff --git a/compiler-rt/test/ubsan/TestCases/Misc/Linux/sigaction.cpp b/compiler-rt/test/ubsan/TestCases/Misc/Linux/sigaction.cpp
new file mode 100644
--- /dev/null
+++ b/compiler-rt/test/ubsan/TestCases/Misc/Linux/sigaction.cpp
@@ -0,0 +1,21 @@
+// RUN: %clangxx -fsanitize=undefined -shared-libsan %s -o %t && %run %t 2>&1 | FileCheck %s
+
+// Ensure ubsan runtime/interceptors are lazily initialized if called early.
+
+#include <assert.h>
+#include <signal.h>
+#include <stdio.h>
+
+__attribute__((constructor(0))) void ctor() {
+  fprintf(stderr, "INIT\n");
+  struct sigaction old;
+  assert(!sigaction(SIGSEGV, nullptr, &old));
+};
+
+int main() {
+  fprintf(stderr, "DONE\n");
+  return 0;
+}
+
+// CHECK: INIT
+// CHECK: DONE