Re: [PATCH] random: fix crash on multiple early calls to add_bootloader_randomness()

From: Dominik Brodowski <linux@dominikbrodowski.net>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: "Theodore Y. Ts'o" <tytso@mit.edu>,
	"Ivan T. Ivanov" <iivanov@suse.de>,
	linux-efi <linux-efi@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] random: fix crash on multiple early calls to add_bootloader_randomness()
Date: Fri, 5 Nov 2021 07:04:39 +0100	[thread overview]
Message-ID: <YYTJd8zt7x8rNbjW@light.dominikbrodowski.net> (raw)
In-Reply-To: <CAMj1kXFCW4RQgXXNV7Z02Ljj36egidry0DyMm7+siSL6cocTOA@mail.gmail.com>

Am Wed, Nov 03, 2021 at 08:27:39AM +0100 schrieb Ard Biesheuvel:
> > > > -       if (unlikely(crng_init == 0)) {
> > > > +       /* We cannot do much with the input pool until it is set up in
> > > > +        * rand_initalize(); therefore just mix into the crng state.
> > > > +        * As this does not affect the input pool, we cannot credit
> > > > +        * entropy for this.
> > > > +        */
> > > > +       if (unlikely(crng_init == 0) || unlikely(crng_global_init_time == 0)) {
> > >
> > > Can we just drop the unlikely()s here?
> >
> > As that would be a different change to the one necessary to resolve the bug,
> > I'd like to defer that decision to the maintainer of random.c.
> >
> 
> In that case, can we at least using a single unlikely() for the whole condition?

Fixed for v3.

Thanks,
	Dominik