Re: [Qemu-devel] [PATCH 3/7] configure: add CET support

[Richard Henderson]

On 3/13/19 5:40 AM, Paolo Bonzini wrote:
> +##########################################
> +# detect CET support in the toolchain
> +
> +if test "$cet" != no; then
> +  write_c_skeleton;
> +  if ! compile_prog "-fcf-protection" "" ; then
> +    if test "$cet" = yes; then
> +      feature_not_found "cet" 'CET is not supported by your toolchain'
> +    fi
> +    cet=no
> +  fi
> +fi
> +if test "$cet" = ""; then
> +  cet=yes
> +  QEMU_CFLAGS="-fcf-protection $QEMU_CFLAGS"
> +fi

Hmm.  The gcc for aarch64 names the similar feature -mbranch-protection.  I'm
rather annoyed that the i386 gcc folk appropriated a generic -f name without
actually making the feature generic at the same time.

Thankfully the aarch64 version does not include shadow stacks, and so is less
invasive into the normal abi -- ARM uses pointer authentication instead.


r~