--- a/config/rules.mk
+++ b/config/rules.mk
@@ -739,21 +739,16 @@ ifneq (,$(HOST_CPPSRCS)$(USE_HOST_CXX))
 else
 	$(EXPAND_LIBS_EXEC) -- $(HOST_CC) $(HOST_OUTOPTION)$@ $(HOST_CFLAGS) $(INCLUDES) $< $(HOST_LIBS) $(HOST_EXTRA_LIBS)
 endif
 endif
 ifndef CROSS_COMPILE
 	$(call CHECK_STDCXX,$@)
 endif
 
-ifdef DTRACE_PROBE_OBJ
-EXTRA_DEPS += $(DTRACE_PROBE_OBJ)
-OBJS += $(DTRACE_PROBE_OBJ)
-endif
-
 $(filter %.$(LIB_SUFFIX),$(LIBRARY)): $(OBJS) $(STATIC_LIBS_DEPS) $(filter %.$(LIB_SUFFIX),$(EXTRA_LIBS)) $(EXTRA_DEPS) $(GLOBAL_DEPS)
 	$(REPORT_BUILD)
 # Always remove both library and library descriptor
 	$(RM) $(REAL_LIBRARY) $(REAL_LIBRARY).$(LIBS_DESC_SUFFIX)
 	$(EXPAND_AR) $(AR_FLAGS) $(OBJS) $(STATIC_LIBS) $(filter %.$(LIB_SUFFIX),$(EXTRA_LIBS))
 
 $(filter-out %.$(LIB_SUFFIX),$(LIBRARY)): $(filter %.$(LIB_SUFFIX),$(LIBRARY)) $(OBJS) $(STATIC_LIBS_DEPS) $(filter %.$(LIB_SUFFIX),$(EXTRA_LIBS)) $(EXTRA_DEPS) $(GLOBAL_DEPS)
 # When we only build a library descriptor, blow out any existing library
@@ -772,26 +767,16 @@ ifeq ($(OS_ARCH),WINNT)
 $(IMPORT_LIBRARY): $(SHARED_LIBRARY) ;
 endif
 
 $(HOST_LIBRARY): $(HOST_OBJS) Makefile
 	$(REPORT_BUILD)
 	$(RM) $@
 	$(EXPAND_LIBS_EXEC) --extract -- $(HOST_AR) $(HOST_AR_FLAGS) $(HOST_OBJS)
 
-ifdef HAVE_DTRACE
-ifndef XP_MACOSX
-ifdef DTRACE_PROBE_OBJ
-NON_DTRACE_OBJS := $(filter-out $(DTRACE_PROBE_OBJ),$(OBJS))
-$(DTRACE_PROBE_OBJ): $(NON_DTRACE_OBJS)
-	dtrace -x nolibs -G -C -s $(MOZILLA_DTRACE_SRC) -o $(DTRACE_PROBE_OBJ) $(NON_DTRACE_OBJS)
-endif
-endif
-endif
-
 # On Darwin (Mac OS X), dwarf2 debugging uses debug info left in .o files,
 # so instead of deleting .o files after repacking them into a dylib, we make
 # symlinks back to the originals. The symlinks are a no-op for stabs debugging,
 # so no need to conditionalize on OS version or debugging format.
 
 $(SHARED_LIBRARY): $(OBJS) $(RESFILE) $(RUST_STATIC_LIB_FOR_SHARED_LIB) $(STATIC_LIBS_DEPS) $(EXTRA_DEPS) $(GLOBAL_DEPS)
 	$(REPORT_BUILD)
 ifndef INCREMENTAL_LINKER

--- a/js/src/Makefile.in
+++ b/js/src/Makefile.in
@@ -13,23 +13,16 @@ ifneq ($(make_min_ver),$(firstword $(sor
 endif
 
 DASH_R		= -r
 
 # Define keyword generator before rules.mk, see bug 323979 comment 50
 
 USE_HOST_CXX = 1
 
-ifdef HAVE_DTRACE
-ifneq ($(OS_ARCH),Darwin)
-DTRACE_PROBE_OBJ = $(LIBRARY_NAME)-dtrace.$(OBJ_SUFFIX)
-endif
-MOZILLA_DTRACE_SRC = $(srcdir)/devtools/javascript-trace.d
-endif
-
 # Ensure symbol versions of shared library on Linux do not conflict
 # with those in libxul.
 ifeq (Linux,$(OS_TARGET))
 OS_LDFLAGS += -Wl,-version-script,symverscript
 
 symverscript: symverscript.in
 	$(call py_action,preprocessor, \
 		-DVERSION='$(subst -,_,$(LIBRARY_NAME))' $< -o $@)