diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -520,8 +520,14 @@
 
 set(LLVM_INTEGRATED_CRT_ALLOC "" CACHE PATH "Replace the Windows CRT allocator with any of {rpmalloc|mimalloc|snmalloc}. Only works with /MT enabled.")
 if(LLVM_INTEGRATED_CRT_ALLOC)
-  if(NOT WIN32)
-    message(FATAL_ERROR "LLVM_INTEGRATED_CRT_ALLOC is only supported on Windows.")
+  if(NOT (CMAKE_SYSTEM_NAME MATCHES "(Linux|Windows)"))
+    message(FATAL_ERROR "LLVM_INTEGRATED_CRT_ALLOC is only supported on Windows and Linux.")
+  elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
+    if(NOT (LLVM_INTEGRATED_CRT_ALLOC MATCHES "mimalloc$"))
+      message(FATAL_ERROR "LLVM_INTEGRATED_CRT_ALLOC currently only supports mimalloc on Linux!")
+    elseif(LLVM_BUILD_LLVM_DYLIB AND LLVM_LINK_LLVM_DYLIB)
+      message(FATAL_ERROR "LLVM_INTEGRATED_CRT_ALLOC cannot be used with LLVM_LINK_LLVM_DYLIB on Linux!")
+    endif()
   endif()
   if(LLVM_USE_SANITIZER)
     message(FATAL_ERROR "LLVM_INTEGRATED_CRT_ALLOC cannot be used along with LLVM_USE_SANITIZER!")
diff --git a/llvm/lib/Support/CMakeLists.txt b/llvm/lib/Support/CMakeLists.txt
--- a/llvm/lib/Support/CMakeLists.txt
+++ b/llvm/lib/Support/CMakeLists.txt
@@ -72,11 +72,18 @@
     set(ALLOCATOR_FILES "${LLVM_INTEGRATED_CRT_ALLOC}/src/override/malloc.cc" "${LLVM_INTEGRATED_CRT_ALLOC}/src/override/new.cc")
     set(system_libs ${system_libs} "mincore.lib" "-INCLUDE:malloc")
   elseif(LLVM_INTEGRATED_CRT_ALLOC MATCHES "mimalloc$")
-    set(MIMALLOC_LIB "${LLVM_INTEGRATED_CRT_ALLOC}/out/msvc-x64/Release/mimalloc-static.lib")
-    if(NOT EXISTS "${MIMALLOC_LIB}")
-	  message(FATAL_ERROR "Cannot find the mimalloc static library. To build it, first apply the patch from https://github.com/microsoft/mimalloc/issues/268 then build the Release x64 target through ${LLVM_INTEGRATED_CRT_ALLOC}\\ide\\vs2019\\mimalloc.sln")
+    if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
+      set(MI_OVERRIDE ON CACHE BOOL "Override the standard malloc")
+      add_subdirectory(${LLVM_INTEGRATED_CRT_ALLOC} mimalloc)
+      export(EXPORT mimalloc)
+      set(system_libs ${system_libs} "mimalloc-static")
+    else()
+      set(MIMALLOC_LIB "${LLVM_INTEGRATED_CRT_ALLOC}/out/msvc-x64/Release/mimalloc-static.lib")
+      if(NOT EXISTS "${MIMALLOC_LIB}")
+         message(FATAL_ERROR "Cannot find the mimalloc static library. To build it, first apply the patch from https://github.com/microsoft/mimalloc/issues/268 then build the Release x64 target through ${LLVM_INTEGRATED_CRT_ALLOC}\\ide\\vs2019\\mimalloc.sln")
+      endif()
+      set(system_libs ${system_libs} "${MIMALLOC_LIB}" "-INCLUDE:malloc")
     endif()
-    set(system_libs ${system_libs} "${MIMALLOC_LIB}" "-INCLUDE:malloc")
   endif()
 endif()