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 <pcc@xxxxxxxxxx> > Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> > 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
