From: Greg KH <greg@kroah.com>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>,
Kees Cook <keescook@chromium.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Michal Marek <michal.lkml@markovi.net>,
linux-hardening@vger.kernel.org,
Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Justin Forbes <jforbes@redhat.com>,
Ondrej Mosnacek <omosnace@redhat.com>
Subject: Re: [PATCH RFC] gcc-plugins: Handle GCC version mismatch for OOT modules
Date: Tue, 26 Jan 2021 09:13:33 +0100 [thread overview]
Message-ID: <YA/PLdX5m9f4v+Yl@kroah.com> (raw)
In-Reply-To: <20210125220757.vxdsf6sttpy46cq7@treble>
On Mon, Jan 25, 2021 at 04:07:57PM -0600, Josh Poimboeuf wrote:
> On Tue, Jan 26, 2021 at 06:44:35AM +0900, Masahiro Yamada wrote:
> > > > If people use a different compiler, they must be
> > > > prepared for any possible problem.
> > > >
> > > > Using different compiler flags for in-tree and out-of-tree
> > > > is even more dangerous.
> > > >
> > > > For example, CONFIG_GCC_PLUGIN_RANDSTRUCT is enabled
> > > > for in-tree build, and then disabled for out-of-tree modules,
> > > > the struct layout will mismatch, won't it?
> > >
> > > If you read the patch you'll notice that it handles that case, when it's
> > > caused by GCC mismatch.
> > >
> > > However, as alluded to in the [1] footnote, it doesn't handle the case
> > > where the OOT build system doesn't have gcc-plugin-devel installed.
> > > Then CONFIG_GCC_PLUGIN_RANDSTRUCT gets silently disabled and the build
> > > succeeds! That happens even without a GCC mismatch.
> >
> >
> > Ah, sorry.
> >
> > I responded too early before reading the patch fully.
> >
> > But, I do not like to make RANDSTRUCT a special case.
> >
> > I'd rather want to stop building for any plugin.
>
> Other than RANDSTRUCT there doesn't seem to be any problem with
> disabling them (and printing a warning) in the OOT build. Why not give
> users that option? It's harmless, and will make distro's (and their
> users') lives easier.
>
> Either GCC mismatch is ok, or it's not. Let's not half-enforce it.
As I said earlier, it's not ok, we can not support it at all.
thanks,
greg k-h
next prev parent reply other threads:[~2021-01-26 18:27 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-25 20:42 [PATCH RFC] gcc-plugins: Handle GCC version mismatch for OOT modules Josh Poimboeuf
2021-01-25 21:16 ` Masahiro Yamada
2021-01-25 21:27 ` Josh Poimboeuf
2021-01-25 21:44 ` Masahiro Yamada
2021-01-25 22:07 ` Josh Poimboeuf
2021-01-26 8:13 ` Greg KH [this message]
2021-01-26 12:44 ` Justin Forbes
2021-01-26 13:51 ` Greg KH
2021-01-26 14:51 ` Josh Poimboeuf
2021-01-26 15:00 ` Greg KH
2021-01-26 15:15 ` Peter Zijlstra
2021-01-26 15:46 ` Josh Poimboeuf
2021-01-26 16:05 ` Peter Zijlstra
2021-01-26 16:15 ` Justin Forbes
2021-01-26 16:19 ` Josh Poimboeuf
2021-01-26 17:06 ` Greg KH
2021-01-26 17:47 ` Justin Forbes
2021-01-26 16:22 ` David Laight
2021-01-27 18:03 ` Christoph Hellwig
2021-01-26 8:12 ` Greg KH
2021-01-25 22:03 ` Kees Cook
2021-01-25 22:19 ` Josh Poimboeuf
2021-01-26 17:56 ` Kees Cook
2021-01-26 18:43 ` Josh Poimboeuf
2021-01-26 22:59 ` Kees Cook
2021-01-26 23:32 ` Josh Poimboeuf
2021-01-26 1:53 ` Masahiro Yamada
2021-01-26 12:16 ` David Laight
2021-01-27 18:02 ` Christoph Hellwig
2021-01-27 18:38 ` Josh Poimboeuf
2021-01-27 18:43 ` Christoph Hellwig
2021-01-27 18:51 ` Josh Poimboeuf
2021-01-27 22:09 ` David Laight
2021-01-28 14:29 ` Christoph Hellwig
2021-01-28 15:45 ` Josh Poimboeuf
2021-03-02 23:26 ` Josh Poimboeuf
2021-03-03 18:49 ` Masahiro Yamada
2021-03-03 19:15 ` Josh Poimboeuf
2021-03-03 19:25 ` Linus Torvalds
2021-03-03 19:38 ` Josh Poimboeuf
2021-03-03 19:57 ` Linus Torvalds
2021-03-03 20:24 ` Josh Poimboeuf
2021-03-03 20:31 ` Josh Poimboeuf
2021-03-03 20:56 ` Linus Torvalds
2021-03-03 21:45 ` Josh Poimboeuf
2021-03-04 12:27 ` Masahiro Yamada
2021-03-04 15:08 ` Josh Poimboeuf
2021-03-04 15:35 ` Masahiro Yamada
2021-03-04 19:12 ` Linus Torvalds
2021-03-05 2:41 ` Josh Poimboeuf
2021-03-05 2:49 ` Linus Torvalds
2021-03-05 16:03 ` Masahiro Yamada
2021-03-05 19:18 ` Josh Poimboeuf
2021-03-08 9:39 ` David Laight
2021-03-05 15:31 ` Masahiro Yamada
2021-03-03 21:52 ` Kees Cook
2021-03-04 12:26 ` Masahiro Yamada
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