[PATCH -rcu/kcsan 06/23] kcsan, kbuild: Add option for barrier instrumentation only
From: Marco Elver <elver@google.com>
Date: 2021-10-05 11:00:25
Also in:
linux-doc, linux-kbuild, linux-mm, lkml
Subsystem:
kernel build + files below scripts/ (unless maintained elsewhere), the rest · Maintainers:
Nathan Chancellor, Nicolas Schier, Linus Torvalds
Source files that disable KCSAN via KCSAN_SANITIZE := n, remove all instrumentation, including explicit barrier instrumentation. With instrumentation for memory barriers, in few places it is required to enable just the explicit instrumentation for memory barriers to avoid false positives. Providing the Makefile variable KCSAN_INSTRUMENT_BARRIERS_obj.o or KCSAN_INSTRUMENT_BARRIERS (for all files) set to 'y' only enables the explicit barrier instrumentation. Signed-off-by: Marco Elver <elver@google.com> --- scripts/Makefile.lib | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 54582673fc1a..2118f63b2bc5 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib@@ -182,6 +182,11 @@ ifeq ($(CONFIG_KCSAN),y) _c_flags += $(if $(patsubst n%,, \ $(KCSAN_SANITIZE_$(basetarget).o)$(KCSAN_SANITIZE)y), \ $(CFLAGS_KCSAN)) +# Some uninstrumented files provide implied barriers required to avoid false +# positives: set KCSAN_INSTRUMENT_BARRIERS for barrier instrumentation only. +_c_flags += $(if $(patsubst n%,, \ + $(KCSAN_INSTRUMENT_BARRIERS_$(basetarget).o)$(KCSAN_INSTRUMENT_BARRIERS)n), \ + -D__KCSAN_INSTRUMENT_BARRIERS__) endif # $(srctree)/$(src) for including checkin headers from generated source files
--
2.33.0.800.g4c38ced690-goog