Re: [PATCH v5 3/9] x86: vdso: Expose sigreturn address on vdso to the kernel

[Andy Lutomirski]

On Mon, Aug 10, 2020 at 4:26 PM Gabriel Krisman Bertazi
<krisman@xxxxxxxxxxxxx> 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.

Almost looks good.

> +int arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)

If you make that bool instead of int, feel free to add:

Acked-by: Andy Lutomirski <luto@xxxxxxxxxx>