From: Kees Cook <keescook@chromium.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>,
Emese Revfy <re.emese@gmail.com>,
Linux Next Mailing List <linux-next@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Willy Tarreau <w@1wt.eu>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Sami Tolvanen <samitolvanen@google.com>
Subject: Re: linux-next: build failure after merge of the origin tree
Date: Thu, 30 Jul 2020 11:47:22 -0700 [thread overview]
Message-ID: <202007301138.D8B018CB@keescook> (raw)
In-Reply-To: <CAHk-=wivHdh7yWmPMLDLVWzO-gVtu94KBq5RETPeU8EoBR2Qqg@mail.gmail.com>
On Thu, Jul 30, 2020 at 11:24:44AM -0700, Linus Torvalds wrote:
> On Wed, Jul 29, 2020 at 8:17 PM Kees Cook <keescook@chromium.org> wrote:
> >
> > I'll look into this more tomorrow. (But yes, __latent_entropy is
> > absolutely used for globals already, as you found, but this is the first
> > percpu it was applied to...)
>
> Note that it was always per-cpu.
>
> The only thing that changed was that it was declared static in
> lib/random.c vs being externally visible.
Yup, thanks. I realized that a bit after sending my email. :)
> Unrelated side note: I notice that the plugins could be simplified a
> bit now that we require gcc 4.9 or later. There's a fair amount of
> cruft for the earlier gcc versions.
Yup -- Masahiro keeps poking the build system, but I haven't cleaned up
the header file macros to keep up with the recent jumps. (It falls a bit
low on my TODO list since it's a bit of a mechanical cleanup. I'm open
to anyone that would like to send patches, though!)
> I'm not sure how seriously the gcc plugins are actually maintained (no
> offense) aside from just keeping them limping along. Does anybody
> actually use them in production? I thought google had mostly moved on
> to clang.
They're part of regular testing, and there is ongoing development
(e.g. see Alex Popov's recent series[1], which is in -next waiting for
the v5.9 merge window). I hear regularly from folks using randstruct,
stackleak, structleak, and latent_entropy. But yes, Google has moved
to Clang where we're using Clang's implementation of structleak
(auto-var-init) but there has been work to get randstruct ported (as
desired by at least one Android vendor), though it's currently stalled.
-Kees
[1] https://lore.kernel.org/lkml/20200624123330.83226-1-alex.popov@linux.com/
--
Kees Cook
next prev parent reply other threads:[~2020-07-30 18:47 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-29 23:08 linux-next: build failure after merge of the origin tree Stephen Rothwell
2020-07-29 23:43 ` Linus Torvalds
2020-07-30 0:09 ` Linus Torvalds
2020-07-30 2:12 ` Linus Torvalds
2020-07-30 2:30 ` Willy Tarreau
2020-07-30 3:17 ` Kees Cook
2020-07-30 3:22 ` Willy Tarreau
2020-07-30 6:14 ` Willy Tarreau
2020-07-30 9:59 ` Marc Zyngier
2020-07-30 10:09 ` Catalin Marinas
2020-07-30 15:00 ` Will Deacon
2020-07-30 17:49 ` Kees Cook
2020-07-30 18:24 ` Linus Torvalds
2020-07-30 18:47 ` Kees Cook [this message]
-- strict thread matches above, loose matches on Subject: below --
2023-06-30 2:59 Stephen Rothwell
2023-06-30 3:43 ` Linus Torvalds
2021-09-19 23:42 Stephen Rothwell
2021-09-14 0:08 Stephen Rothwell
2021-09-14 0:19 ` Linus Torvalds
2021-09-14 0:24 ` Linus Torvalds
2021-09-14 0:58 ` Stephen Rothwell
2021-09-14 1:29 ` Linus Torvalds
2021-09-14 1:37 ` Linus Torvalds
2021-09-14 2:03 ` Linus Torvalds
2021-09-14 2:08 ` Stephen Rothwell
2021-09-14 2:12 ` Linus Torvalds
2021-09-14 2:50 ` Michael Ellerman
2021-09-14 12:21 ` Michael Ellerman
2021-09-14 2:39 ` Stephen Rothwell
2021-09-07 23:07 Stephen Rothwell
2021-09-07 23:09 ` Stephen Rothwell
2021-09-07 23:17 ` Marco Elver
2021-09-07 23:38 ` Miguel Ojeda
2020-07-30 22:58 Stephen Rothwell
2020-07-30 23:15 ` Stephen Rothwell
2020-06-04 22:37 Stephen Rothwell
2020-06-05 0:04 ` Josh Poimboeuf
2020-06-05 9:48 ` Jessica Yu
2020-04-20 10:23 Stephen Rothwell
2020-01-31 4:12 Stephen Rothwell
2020-01-31 4:17 ` Randy Dunlap
2020-01-31 9:39 ` Daniel Lezcano
2012-10-09 23:21 Stephen Rothwell
2012-10-09 23:45 ` Andrew Morton
2012-10-09 23:52 ` Yasuaki Ishimatsu
2012-10-10 3:12 ` Stephen Rothwell
2012-10-10 0:07 ` Stephen Rothwell
2012-06-04 2:57 Stephen Rothwell
2012-06-04 7:39 ` Paul Mundt
2012-01-18 23:31 Stephen Rothwell
2012-01-19 8:21 ` Jens Axboe
2012-01-19 8:23 ` Jens Axboe
2011-11-06 23:12 Stephen Rothwell
2011-11-07 1:52 ` David Miller
2011-11-07 2:47 ` Stephen Rothwell
2011-11-07 3:36 ` David Miller
2011-11-07 5:29 ` Kirsher, Jeffrey T
2011-11-07 16:46 ` Rose, Gregory V
2011-11-07 17:46 ` Rose, Gregory V
2011-07-25 1:16 Stephen Rothwell
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