On Fri, Sep 04, 2020 at 04:31:41PM -0400, Gabriel Krisman Bertazi wrote:

Syscall user redirection requires the signal trampoline code to not be
captured, in order to support returning with a locked selector while
avoiding recursion back into the signal handler.  For ia-32, which has
the trampoline in the vDSO, expose the entry points to the kernel, such
that it can avoid dispatching syscalls from that region to userspace.

Changes since V1
  - Change return address to bool (Andy)

Suggested-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Gabriel Krisman Bertazi <redacted>

Look good to me; would anything else benefit from this information?

Reviewed-by: Kees Cook <redacted>

-- 
Kees Cook