From: Kees Cook <keescook@chromium.org>
To: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Borislav Petkov <bp@suse.de>, "H.J. Lu" <hjl.tools@gmail.com>,
Russell King <linux@armlinux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Peter Collingbourne <pcc@google.com>,
James Morse <james.morse@arm.com>, Arnd Bergmann <arnd@arndb.de>,
Masahiro Yamada <masahiroy@kernel.org>,
x86@kernel.org, linux-arm-kernel@lists.infradead.org,
linux-arch@vger.kernel.org, linux-kbuild@vger.kernel.org,
Clang-Built-Linux ML <clang-built-linux@googlegroups.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/9] Enable orphan section warning
Date: Thu, 2 Apr 2020 10:26:38 -0700 [thread overview]
Message-ID: <202004021023.D3D8AA3BE@keescook> (raw)
In-Reply-To: <CA+icZUWTnP8DYfbaMwKtJbG30v7bB4w6=ywo8gn8fvwr731mUQ@mail.gmail.com>
On Thu, Apr 02, 2020 at 06:20:57PM +0200, Sedat Dilek wrote:
> On Fri, Feb 28, 2020 at 1:22 AM Kees Cook <keescook@chromium.org> wrote:
> >
> > Hi!
> >
> > A recent bug was solved for builds linked with ld.lld, and tracking
> > it down took way longer than it needed to (a year). Ultimately, it
> > boiled down to differences between ld.bfd and ld.lld's handling of
> > orphan sections. Similarly, the recent FGKASLR series brough up orphan
> > section handling too[2]. In both cases, it would have been nice if the
> > linker was running with --orphan-handling=warn so that surprise sections
> > wouldn't silently get mapped into the kernel image at locations up to
> > the whim of the linker's orphan handling logic. Instead, all desired
> > sections should be explicitly identified in the linker script (to be
> > either kept or discarded) with any orphans throwing a warning. The
> > powerpc architecture actually already does this, so this series seeks
> > to extend this coverage to x86, arm64, and arm.
> >
> > This series depends on tip/x86/boot (where recent .eh_frame fixes[3]
> > landed), and has a minor conflict[4] with the ARM tree (related to
> > the earlier mentioned bug). As it uses refactorings in the asm-generic
> > linker script, and makes changes to kbuild, I think the cleanest place
> > for this series to land would also be through -tip. Once again (like
> > my READ_IMPLIES_EXEC series), I'm looking to get maintainer Acks so
> > this can go all together with the least disruption. Splitting it up by
> > architecture seems needlessly difficult.
> >
> > Thanks!
> >
>
> Hi Kees,
>
> what is the status of this patchset?
> Looks like it is not in tip or linux-next Git.
Based on the feedback, I have 3 TODO items:
- track down and eliminate (or explain) the source of the .got.plt on arm64
- enable orphan warnings for _all_ architectures
- refactor final link logic to perform the orphan warning in a clean way
I'm working through these (and other work) still. I'm hoping to have
another version up some time next week.
--
Kees Cook
next prev parent reply other threads:[~2020-04-02 17:26 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-28 0:22 [PATCH 0/9] Enable orphan section warning Kees Cook
2020-02-28 0:22 ` [PATCH 1/9] scripts/link-vmlinux.sh: Delay orphan handling warnings until final link Kees Cook
2020-03-20 2:47 ` Nicholas Piggin
2020-03-20 18:24 ` Kees Cook
2020-03-22 9:16 ` Nicholas Piggin
2020-03-22 16:00 ` Kees Cook
2020-02-28 0:22 ` [PATCH 2/9] vmlinux.lds.h: Add .gnu.version* to DISCARDS Kees Cook
2020-02-28 0:22 ` [PATCH 3/9] x86/build: Warn on orphan section placement Kees Cook
2020-02-28 0:22 ` [PATCH 4/9] x86/boot: " Kees Cook
2020-02-28 0:22 ` [PATCH 5/9] Add RUNTIME_DISCARD_EXIT to generic DISCARDS Kees Cook
2020-02-28 0:22 ` [PATCH 6/9] arm64/build: Use common DISCARDS in linker script Kees Cook
2020-03-17 21:52 ` Will Deacon
2020-02-28 0:22 ` [PATCH 7/9] arm64/build: Warn on orphan section placement Kees Cook
2020-03-17 21:56 ` Will Deacon
2020-03-17 23:01 ` Kees Cook
2020-03-17 23:10 ` Nick Desaulniers
2020-02-28 0:22 ` [PATCH 8/9] arm/build: " Kees Cook
2020-02-28 0:22 ` [PATCH 9/9] arm/boot: " Kees Cook
2020-02-28 6:51 ` [PATCH 0/9] Enable orphan section warning Sedat Dilek
2020-03-03 4:32 ` Kees Cook
2020-04-02 16:20 ` Sedat Dilek
2020-04-02 17:26 ` Kees Cook [this message]
2020-04-05 11:15 ` Sedat Dilek
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