linux-kernel - Re: [PATCH] x86/ia32: State that IA32 emulation is disabled

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Date:   Thu, 30 Nov 2023 11:47:16 -0500
From:   Brian Gerst <brgerst@...il.com>
To:     Borislav Petkov <bp@...en8.de>
Cc:     X86 ML <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>,
        Nikolay Borisov <nik.borisov@...e.com>
Subject: Re: [PATCH] x86/ia32: State that IA32 emulation is disabled

On Thu, Nov 30, 2023 at 11:42 AM Brian Gerst <brgerst@...il.com> wrote:
>
> On Thu, Nov 30, 2023 at 11:09 AM Borislav Petkov <bp@...en8.de> wrote:
> >
> > On Thu, Nov 30, 2023 at 04:52:13PM +0100, Borislav Petkov wrote:
> > > +static inline bool ia32_enabled_verbose(void)
> > > +{
> > > +#ifdef CONFIG_IA32_EMULATION
> > > +     pr_notice_once("32-bit emulation disabled. You can reenable with ia32_emulation=on\n");
> > > +#endif
> > > +     return ia32_enabled();
> > > +}
> >
> > As Nik rightfully points out offlist, this should rather be something
> > like:
> >
> > ---
> >         bool enabled = ia32_enabled();
> >
> > #ifdef CONFIG_IA32_EMULATION
> >         if (!enabled)
> >                 pr_notice_once("32-bit emulation disabled. You can reenable with ia32_emulation=on\n");
> > #endif
> >
> >         return enabled;
>
> The #ifdef isn't necessary, as ia32_enabled() will always return false
> in that case.

Scratch that, I misread it.  If compat is disabled at build time you
don't want the message to appear, or at least would want a different
message.

Brian Gerst