diff options
author | Will Deacon <will.deacon@arm.com> | 2015-03-17 15:15:02 +0300 |
---|---|---|
committer | Will Deacon <will.deacon@arm.com> | 2015-09-17 13:57:03 +0300 |
commit | df057cc7b4fa59e9b55f07ffdb6c62bf02e99a00 (patch) | |
tree | 866dd49a0acc98317cc3866738f3b417f44eccf2 /arch/arm64/Kconfig | |
parent | bdec97a855ef1e239f130f7a11584721c9a1bf04 (diff) | |
download | linux-df057cc7b4fa59e9b55f07ffdb6c62bf02e99a00.tar.xz |
arm64: errata: add module build workaround for erratum #843419
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.
Cc: <stable@vger.kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/Kconfig')
-rw-r--r-- | arch/arm64/Kconfig | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 8b6e378992d2..07d1811aa03f 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -332,6 +332,22 @@ config ARM64_ERRATUM_845719 If unsure, say Y. +config ARM64_ERRATUM_843419 + bool "Cortex-A53: 843419: A load or store might access an incorrect address" + depends on MODULES + default y + help + This option builds kernel modules using the large memory model in + order to avoid the use of the ADRP instruction, which can cause + a subsequent memory access to use an incorrect address on Cortex-A53 + parts up to r0p4. + + Note that the kernel itself must be linked with a version of ld + which fixes potentially affected ADRP instructions through the + use of veneers. + + If unsure, say Y. + endmenu |