Re: [PATCH v6 3/9] x86: vdso: Expose sigreturn address on vdso to the kernel

[Kees Cook]

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@xxxxxxxxxx>
> Acked-by: Andy Lutomirski <luto@xxxxxxxxxx>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>

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

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-- 
Kees Cook