From 9ecac394a8e84e5a5440f423d349722bc8d85b47 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 17 Mar 2015 12:15:02 +0000 Subject: arm64: errata: add module build workaround for erratum #843419 commit df057cc7b4fa59e9b55f07ffdb6c62bf02e99a00 upstream. Cortex-A53 processors <= r0p4 are affected by erratum #843419 which can lead to a memory access using an incorrect address in certain sequences headed by an ADRP instruction. There is a linker fix to generate veneers for ADRP instructions, but this doesn't work for kernel modules which are built as unlinked ELF objects. This patch adds a new config option for the erratum which, when enabled, builds kernel modules with the mcmodel=large flag. This uses absolute addressing for all kernel symbols, thereby removing the use of ADRP as a PC-relative form of addressing. The ADRP relocs are removed from the module loader so that we fail to load any potentially affected modules. Acked-by: Catalin Marinas Signed-off-by: Will Deacon Signed-off-by: Luis Henriques --- arch/arm64/Makefile | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/arm64/Makefile') diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 8185a913c5ed..be8b36304ac1 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -34,6 +34,10 @@ comma = , CHECKFLAGS += -D__aarch64__ +ifeq ($(CONFIG_ARM64_ERRATUM_843419), y) +CFLAGS_MODULE += -mcmodel=large +endif + # Default value head-y := arch/arm64/kernel/head.o -- cgit v1.2.3