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.
http://sourceware.org/bugzilla/show_bug.cgi?id=12532
Signed-off-by: Allen Martin amartin@nvidia.com --- changes for v2: -changed GAS_BUG_12532 from yes/no to y/n to be consistent -added additional warning about code size increase --- arch/arm/config.mk | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
diff --git a/arch/arm/config.mk b/arch/arm/config.mk index 3f4453a..bcabf17 100644 --- a/arch/arm/config.mk +++ b/arch/arm/config.mk @@ -87,3 +87,24 @@ endif ifndef CONFIG_NAND_SPL LDFLAGS_u-boot += -pie endif + +# +# 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 [ $(call binutils-version) -lt 0222 ] ; then echo y; else echo n; fi) +ifeq ($(GAS_BUG_12532),y) +$(warning *** disabling sibling call optimzation because binutils version < 2.22) +$(warning *** code size may be slightly larger) +endif +endif +ifeq ($(GAS_BUG_12532),y) +PLATFORM_RELFLAGS += -fno-optimize-sibling-calls +endif +endif