arm64: errata: Add -mpc-relative-literal-loads to build flags
authordann frazier <dann.frazier@canonical.com>
Mon, 25 Jan 2016 23:52:16 +0000 (16:52 -0700)
committerWill Deacon <will.deacon@arm.com>
Tue, 26 Jan 2016 11:17:23 +0000 (11:17 +0000)
GCC6 (and Linaro's 2015.12 snapshot of GCC5) has a new default that uses
adrp/ldr or adrp/add to address literal pools. When CONFIG_ARM64_ERRATUM_843419
is enabled, modules built with this toolchain fail to load:

  module libahci: unsupported RELA relocation: 275

This patch fixes the problem by passing '-mpc-relative-literal-loads'
to the compiler.

Cc: stable@vger.kernel.org
Fixes: df057cc7b4fa ("arm64: errata: add module build workaround for erratum #843419")
BugLink: http://bugs.launchpad.net/bugs/1533009
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Suggested-by: Christophe Lyon <christophe.lyon@linaro.org>
Signed-off-by: Dann Frazier <dann.frazier@canonical.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arch/arm64/Makefile

index 094a137f6083e8dbb6c2658b01c6cfa2908a3052..307237cfe728b152e350b5fb4f1c1abc18d6fb4c 100644 (file)
@@ -28,6 +28,7 @@ endif
 
 KBUILD_CFLAGS  += -mgeneral-regs-only $(lseinstr)
 KBUILD_CFLAGS  += -fno-asynchronous-unwind-tables
+KBUILD_CFLAGS  += $(call cc-option, -mpc-relative-literal-loads)
 KBUILD_AFLAGS  += $(lseinstr)
 
 ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)