Dear Allen Martin,
Disable sibling call optimization based on binutils version. This is to work around a bug in the assember in binutils versions < 2.22. Branches to weak symbols can be incorrectly optimized in thumb mode to a short branch (b.n instruction) that won't reach when the symbol gets preempted.
CC Albert ... Albert, let's pull this in as a part of this series.
I'm fine with it.
http://sourceware.org/bugzilla/show_bug.cgi?id=12532
Signed-off-by: Allen Martin amartin@nvidia.com
arch/arm/config.mk | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/arch/arm/config.mk b/arch/arm/config.mk index 3f4453a..24b9d7c 100644 --- a/arch/arm/config.mk +++ b/arch/arm/config.mk @@ -87,3 +87,21 @@ endif ifndef CONFIG_NAND_SPL LDFLAGS_u-boot += -pie endif
+# +# FIXME: binutils versions < 2.22 have a bug in the assembler where +# branches to weak symbols can be incorrectly optimized in thumb mode +# to a short branch (b.n instruction) that won't reach when the symbol +# gets preempted +# +# http://sourceware.org/bugzilla/show_bug.cgi?id=12532 +# +ifeq ($(CONFIG_SYS_THUMB_BUILD),y) +ifeq ($(GAS_BUG_12532),) +export GAS_BUG_12532:=$(shell if [ $(call binutils-version) -lt 0222 ] ; \
- then echo y; else echo n; fi)
+endif +ifeq ($(GAS_BUG_12532),y) +PLATFORM_RELFLAGS += -fno-optimize-sibling-calls +endif +endif
Best regards, Marek Vasut