path: root/tools/testing/selftests
diff options
authorSuraj Jitindar Singh <sjitindarsingh@gmail.com>2016-02-29 17:29:55 +1100
committerMichael Ellerman <mpe@ellerman.id.au>2016-03-02 23:34:46 +1100
commita4cf0a2e1d3b98cac5fd5ba92803722255374e9e (patch)
tree1f3c0e66496528182b0b417a293f66dc3096bb58 /tools/testing/selftests
parentselftests/powerpc: Fix out of bounds access in TM signal test (diff)
selftests/powerpc: Remove -flto from common CFLAGS
LTO can cause GCC to inline some functions which have attributes set. The act of inlining the functions can lead to GCC forgetting about the attributes which leads to incorrect tests. Notable example being: __attribute__((__target__("no-vsx"))) LTO can also interact strangely with custom assembly functions and cause tests to intermittently fail. Both these cases are hard to detect and require manual inspection of binaries which is unlikely to happen for all tests. Furthermore, LTO optimisations are not necessary for selftests and correctness is paramount and as such it is best to disable LTO. LTO can be enabled on a per test basis. A pseries_le_defconfig kernel on a POWER8 was used to determine that the same subset of selftests pass and fail with and without -flto in the common Makefile. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'tools/testing/selftests')
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile
index 0c2706bda330..7925a9655bfb 100644
--- a/tools/testing/selftests/powerpc/Makefile
+++ b/tools/testing/selftests/powerpc/Makefile
@@ -8,7 +8,7 @@ ifeq ($(ARCH),powerpc)
GIT_VERSION = $(shell git describe --always --long --dirty || echo "unknown")
-CFLAGS := -Wall -O2 -flto -Wall -Werror -DGIT_VERSION='"$(GIT_VERSION)"' -I$(CURDIR) $(CFLAGS)
+CFLAGS := -Wall -O2 -Wall -Werror -DGIT_VERSION='"$(GIT_VERSION)"' -I$(CURDIR) $(CFLAGS)
export CFLAGS