kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles

Move CFLAGS_KASAN*, CFLAGS_UBSAN, CFLAGS_KCSAN to Makefile.kasan, Makefile.ubsan, Makefile.kcsan, respectively. This commit also avoids the same -fsanitize=* flags being added to CFLAGS_UBSAN multiple times. Prior to this commit, the ubsan flags were appended by the '+=' operator, without any initialization. Some build targets such as 'make bindeb-pkg' recurses to the top Makefile, and ended up with adding the same flags to CFLAGS_UBSAN twice. Clear CFLAGS_UBSAN with ':=' to make it a simply expanded variable. This is better than a recursively expanded variable, which evaluates $(call cc-option, ...) multiple times before Kbuild starts descending to subdirectories. Signed-off-by: Masahiro Yamada <[email protected]> Acked-by: Marco Elver <[email protected]>
sm00th · Sep 24, 2020 · bb27321 · bb27321
1 parent 9909b76
commit bb27321
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Showing 4 changed files with 6 additions and 2 deletions.
diff --git a/Makefile b/Makefile
@@ -516,7 +516,6 @@ export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
 
 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
-export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN CFLAGS_KCSAN
 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL

diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
@@ -47,3 +47,5 @@ CFLAGS_KASAN := -fsanitize=kernel-hwaddress \
 		$(instrumentation_flags)
 
 endif # CONFIG_KASAN_SW_TAGS
+
+export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE
diff --git a/scripts/Makefile.kcsan b/scripts/Makefile.kcsan
@@ -9,7 +9,7 @@ endif
 
 # Keep most options here optional, to allow enabling more compilers if absence
 # of some options does not break KCSAN nor causes false positive reports.
-CFLAGS_KCSAN := -fsanitize=thread \
+export CFLAGS_KCSAN := -fsanitize=thread \
 	$(call cc-option,$(call cc-param,tsan-instrument-func-entry-exit=0) -fno-optimize-sibling-calls) \
 	$(call cc-option,$(call cc-param,tsan-instrument-read-before-write=1)) \
 	$(call cc-param,tsan-distinguish-volatile=1)
diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan
@@ -1,4 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
+
+export CFLAGS_UBSAN :=
+
 ifdef CONFIG_UBSAN_ALIGNMENT
       CFLAGS_UBSAN += $(call cc-option, -fsanitize=alignment)
 endif
Original file line number	Diff line number	Diff line change
Expand Up		@@ -47,3 +47,5 @@ CFLAGS_KASAN := -fsanitize=kernel-hwaddress \
		$(instrumentation_flags)

		endif # CONFIG_KASAN_SW_TAGS

		export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE