From 44ecda71fd8a70185c270f5914ac563827fe1d4c Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Wed, 16 Nov 2022 19:39:15 +0530 Subject: arm64: errata: Workaround possible Cortex-A715 [ESR|FAR]_ELx corruption If a Cortex-A715 cpu sees a page mapping permissions change from executable to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers, on the next instruction abort caused by permission fault. Only user-space does executable to non-executable permission transition via mprotect() system call which calls ptep_modify_prot_start() and ptep_modify _prot_commit() helpers, while changing the page mapping. The platform code can override these helpers via __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION. Work around the problem via doing a break-before-make TLB invalidation, for all executable user space mappings, that go through mprotect() system call. This overrides ptep_modify_prot_start() and ptep_modify_prot_commit(), via defining HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION on the platform thus giving an opportunity to intercept user space exec mappings, and do the necessary TLB invalidation. Similar interceptions are also implemented for HugeTLB. Cc: Catalin Marinas Cc: Will Deacon Cc: Jonathan Corbet Cc: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual Reviewed-by: Catalin Marinas Link: https://lore.kernel.org/r/20221116140915.356601-3-anshuman.khandual@arm.com Signed-off-by: Will Deacon --- arch/arm64/Kconfig | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'arch/arm64/Kconfig') diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 505c8a1ccbe0..56c3381e9d94 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -964,6 +964,22 @@ config ARM64_ERRATUM_2457168 If unsure, say Y. +config ARM64_ERRATUM_2645198 + bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" + default y + help + This option adds the workaround for ARM Cortex-A715 erratum 2645198. + + If a Cortex-A715 cpu sees a page mapping permissions change from executable + to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the + next instruction abort caused by permission fault. + + Only user-space does executable to non-executable permission transition via + mprotect() system call. Workaround the problem by doing a break-before-make + TLB invalidation, for all changes to executable user space mappings. + + If unsure, say Y. + config CAVIUM_ERRATUM_22375 bool "Cavium erratum 22375, 24313" default y -- cgit v1.2.3