Re: [PATCH 3/5] xen/livepatch: fix norevert test attempt to open-code revert

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Fri, Feb 23, 2024 at 10:10:38AM +0000, Ross Lagerwall wrote:
> On Thu, Nov 30, 2023 at 2:30 PM Roger Pau Monne <roger.pau@xxxxxxxxxx> wrote:
> > diff --git a/xen/test/livepatch/xen_action_hooks_norevert.c 
> > b/xen/test/livepatch/xen_action_hooks_norevert.c
> > index 3e21ade6abfc..074f8e1d56ce 100644
> > --- a/xen/test/livepatch/xen_action_hooks_norevert.c
> > +++ b/xen/test/livepatch/xen_action_hooks_norevert.c
> > @@ -96,26 +96,14 @@ static int revert_hook(livepatch_payload_t *payload)
> >
> >  static void post_revert_hook(livepatch_payload_t *payload)
> >  {
> > -    int i;
> > +    unsigned long flags;
> >
> >      printk(KERN_DEBUG "%s: Hook starting.\n", __func__);
> >
> > -    for (i = 0; i < payload->nfuncs; i++)
> > -    {
> > -        const struct livepatch_func *func = &payload->funcs[i];
> > -        struct livepatch_fstate *fstate = &payload->fstate[i];
> > -
> > -        BUG_ON(revert_cnt != 1);
> > -        BUG_ON(fstate->applied != LIVEPATCH_FUNC_APPLIED);
> > -
> > -        /* Outside of quiesce zone: MAY TRIGGER HOST CRASH/UNDEFINED 
> > BEHAVIOR */
> > -        arch_livepatch_quiesce();
> > -        common_livepatch_revert(payload);
> > -        arch_livepatch_revive();
> > -        BUG_ON(fstate->applied == LIVEPATCH_FUNC_APPLIED);
> > -
> > -        printk(KERN_DEBUG "%s: post reverted: %s\n", __func__, func->name);
> > -    }
> > +    local_irq_save(flags);
> > +    revert_payload(payload);
> 
> Should this check or assert the return value of revert_payload()?

Hm, yes, why not.  I will put this inside of a BUG_ON(), as
post-revert hook doesn't return any value.

Thanks, Roger.