diff --git a/llvm/runtimes/CMakeLists.txt b/llvm/runtimes/CMakeLists.txt
--- a/llvm/runtimes/CMakeLists.txt
+++ b/llvm/runtimes/CMakeLists.txt
@@ -96,20 +96,35 @@
                            ${EXTRA_ARGS})
 endfunction()
 
-function(builtin_register_target compiler_rt_path target)
-  cmake_parse_arguments(ARG "" "" "DEPENDS" ${ARGN})
-
-  check_apple_target(${target} builtin)
-
+# Find variables with names of the form:
+# ${kind}_${target}_<runtimes cmake option>
+# Rename them so they can be passed directly to the runtime or builtins that
+# they apply to.
+#
+# For example:
+# RUNTIMES_armv8l-unknown-linux-gnueabihf_COMPILER_RT_BUILD_GWP_ASAN=OFF
+# Would be changed to:
+# COMPILER_RT_BUILD_GWP_ASAN=OFF
+# So it can be passed directly to compiler-rt.
+function (get_extra_cmake_args kind target)
   get_cmake_property(variableNames VARIABLES)
   foreach(variableName ${variableNames})
-    string(FIND "${variableName}" "BUILTINS_${target}" out)
+    string(FIND "${variableName}" "${kind}_${target}" out)
     if("${out}" EQUAL 0)
-      string(REPLACE "BUILTINS_${target}_" "" new_name ${variableName})
+      string(REPLACE "${kind}_${target}_" "" new_name ${variableName})
       string(REPLACE ";" "|" new_value "${${variableName}}")
       list(APPEND ${target}_extra_args "-D${new_name}=${new_value}")
     endif()
   endforeach()
+  set(${target}_extra_args ${${target}_extra_args} PARENT_SCOPE)
+endfunction()
+
+function(builtin_register_target compiler_rt_path target)
+  cmake_parse_arguments(ARG "" "" "DEPENDS" ${ARGN})
+
+  check_apple_target(${target} builtin)
+
+  get_extra_cmake_args("BUILTINS" ${target})
 
   llvm_ExternalProject_Add(builtins-${target}
                            ${compiler_rt_path}/lib/builtins
@@ -193,7 +208,7 @@
 endforeach()
 
 function(runtime_default_target)
-  cmake_parse_arguments(ARG "" "" "DEPENDS;PREFIXES" ${ARGN})
+  cmake_parse_arguments(ARG "" "" "DEPENDS;PREFIXES;CMAKE_ARGS" ${ARGN})
 
   include(${LLVM_BINARY_DIR}/runtimes/Components.cmake OPTIONAL)
   set(SUB_CHECK_TARGETS ${SUB_CHECK_TARGETS} PARENT_SCOPE)
@@ -219,6 +234,8 @@
     list(APPEND test_targets runtimes-test-depends check-runtimes)
   endif()
 
+  get_extra_cmake_args("RUNTIMES" ${LLVM_TARGET_TRIPLE})
+
   set_enable_per_target_runtime_dir()
 
   llvm_ExternalProject_Add(runtimes
@@ -236,6 +253,7 @@
                                       -DCMAKE_ASM_COMPILER_WORKS=ON
                                       ${COMMON_CMAKE_ARGS}
                                       ${RUNTIMES_CMAKE_ARGS}
+                                      ${${LLVM_TARGET_TRIPLE}_extra_args}
                            PASSTHROUGH_PREFIXES LLVM_ENABLE_RUNTIMES
                                                 LLVM_USE_LINKER
                                                 ${ARG_PREFIXES}