ARM: 8995/1: drop Thumb-2 workaround for ancient binutils

The CONFIG_THUMB2_AVOID_R_ARM_THM_JUMP11 workaround addresses an issue
which was fixed before the oldest supported binutils (2.23 at this time)
were released. So we can remove it now.

Acked-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 910e89f..1b65ff9 100644 (file)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1422,37 +1422,6 @@ config THUMB2_KERNEL
 
          If unsure, say N.
 
-config THUMB2_AVOID_R_ARM_THM_JUMP11
-       bool "Work around buggy Thumb-2 short branch relocations in gas"
-       depends on THUMB2_KERNEL && MODULES
-       default y
-       help
-         Various binutils versions can resolve Thumb-2 branches to
-         locally-defined, preemptible global symbols as short-range "b.n"
-         branch instructions.
-
-         This is a problem, because there's no guarantee the final
-         destination of the symbol, or any candidate locations for a
-         trampoline, are within range of the branch.  For this reason, the
-         kernel does not support fixing up the R_ARM_THM_JUMP11 (102)
-         relocation in modules at all, and it makes little sense to add
-         support.
-
-         The symptom is that the kernel fails with an "unsupported
-         relocation" error when loading some modules.
-
-         Until fixed tools are available, passing
-         -fno-optimize-sibling-calls to gcc should prevent gcc generating
-         code which hits this problem, at the cost of a bit of extra runtime
-         stack usage in some cases.
-
-         The problem is described in more detail at:
-             https://bugs.launchpad.net/binutils-linaro/+bug/725126
-
-         Only Thumb-2 kernels are affected.
-
-         Unless you are sure your tools don't have this problem, say Y.
-
 config ARM_PATCH_IDIV
        bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
        depends on CPU_32v7 && !XIP_KERNEL

diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 2731c20..f0ef238 100644 (file)
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -123,10 +123,6 @@ AFLAGS_NOWARN      :=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W)
 ifeq ($(CONFIG_THUMB2_KERNEL),y)
 CFLAGS_ISA     :=-mthumb -Wa,-mimplicit-it=always $(AFLAGS_NOWARN)
 AFLAGS_ISA     :=$(CFLAGS_ISA) -Wa$(comma)-mthumb
-# Work around buggy relocation from gas if requested:
-ifeq ($(CONFIG_THUMB2_AVOID_R_ARM_THM_JUMP11),y)
-KBUILD_CFLAGS_MODULE   +=-fno-optimize-sibling-calls
-endif
 else
 CFLAGS_ISA     :=$(call cc-option,-marm,) $(AFLAGS_NOWARN)
 AFLAGS_ISA     :=$(CFLAGS_ISA)