On 8/24/2020 5:33 PM, Andy Lutomirski wrote:

On Mon, Aug 24, 2020 at 5:30 PM Yu-cheng Yu [off-list ref] wrote:

quoted

From: "H.J. Lu" <redacted>

When Indirect Branch Tracking (IBT) is enabled, vDSO functions may be
called indirectly, and must have ENDBR32 or ENDBR64 as the first
instruction.  The compiler must support -fcf-protection=branch so that it
can be used to compile vDSO.

Signed-off-by: H.J. Lu <redacted>
Signed-off-by: Yu-cheng Yu <redacted>
Acked-by: Andy Lutomirski <luto@kernel.org>

I revoke my Ack.  Please don't repeat the list of object files.  Maybe
add the option to CFL?

I will update the patch.

Yu-cheng