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| author | Anshuman Khandual <anshuman.khandual@arm.com> | 2022-11-16 17:09:15 +0300 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2022-11-18 19:52:40 +0300 |
| commit | 44ecda71fd8a70185c270f5914ac563827fe1d4c (patch) | |
| tree | b9ff785dcba56c234b9a80aab7eb1bffb6fc63e4 /arch/arm64/include/asm/pgtable.h | |
| parent | 07e39e60bbf0ccd5f895568e1afca032193705c0 (diff) | |
| download | linux-44ecda71fd8a70185c270f5914ac563827fe1d4c.tar.xz | |
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 <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20221116140915.356601-3-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include/asm/pgtable.h')
| -rw-r--r-- | arch/arm64/include/asm/pgtable.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 71a1af42f0e8..fe76e5823d91 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -1096,6 +1096,15 @@ static inline bool pud_sect_supported(void) } +#define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION +#define ptep_modify_prot_start ptep_modify_prot_start +extern pte_t ptep_modify_prot_start(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep); + +#define ptep_modify_prot_commit ptep_modify_prot_commit +extern void ptep_modify_prot_commit(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep, + pte_t old_pte, pte_t new_pte); #endif /* !__ASSEMBLY__ */ #endif /* __ASM_PGTABLE_H */ |