Re: [PATCH v21 2/2] arm64: expose FAR_EL1 tag bits in siginfo

On Fri, Nov 20, 2020 at 12:33:46PM -0800, Peter Collingbourne wrote:

The kernel currently clears the tag bits (i.e. bits 56-63) in the fault
address exposed via siginfo.si_addr and sigcontext.fault_address. However,
the tag bits may be needed by tools in order to accurately diagnose
memory errors, such as HWASan [1] or future tools based on the Memory
Tagging Extension (MTE).

Expose these bits via the arch_untagged_si_addr mechanism, so that
they are only exposed to signal handlers with the SA_EXPOSE_TAGBITS
flag set.

[1] http://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html

Signed-off-by: Peter Collingbourne <redacted>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://linux-review.googlesource.com/id/Ia8876bad8c798e0a32df7c2ce1256c4771c81446

Applied to arm64 (for-next/signal-tag-bits), thanks!

[2/2] arm64: expose FAR_EL1 tag bits in siginfo
      https://git.kernel.org/arm64/c/dceec3ff7807

-- 
Catalin