diff options
author | Anshuman Khandual <anshuman.khandual@arm.com> | 2023-01-02 09:16:51 +0300 |
---|---|---|
committer | Will Deacon <will@kernel.org> | 2023-01-06 20:14:55 +0300 |
commit | 5db568e748f6fb7d0d2e1bff4c2698ad4f50b982 (patch) | |
tree | 8839e1ca6a8f6ed5d166f2d357769df3d34860b0 /Documentation/core-api | |
parent | cef139299fd86098c6e3dbd389d1d0b2462d7710 (diff) | |
download | linux-5db568e748f6fb7d0d2e1bff4c2698ad4f50b982.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
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20230102061651.34745-1-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'Documentation/core-api')
0 files changed, 0 insertions, 0 deletions