On 07/18/2012 11:06 PM, Albert ARIBAUD wrote:
Hi Allen,
On Wed, 18 Jul 2012 16:45:53 -0700, Allen Martin amartin@nvidia.com wrote:
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 v4: -removed warning print changes for v3: -split shell line to improve readability 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 | 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
Can previous reviewers ack or test this? I would like to have it in the ARM master branch in time for 12.07.
Acked-by: Tom Rini trini@ti.com