All of lore.kernel.org
 help / color / mirror / Atom feed
From: Kees Cook <keescook@chromium.org>
To: Nick Desaulniers <ndesaulniers@google.com>
Cc: Russell King <linux@armlinux.org.uk>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Nathan Chancellor <natechancellor@gmail.com>,
	Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>,
	Arnd Bergmann <arnd@arndb.de>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Eli Friedman <efriedma@quicinc.com>
Subject: Re: [PATCH v2 1/2] arm/build: Warn on orphan section placement
Date: Wed, 24 Jun 2020 12:43:41 -0700	[thread overview]
Message-ID: <202006241242.9A6E0E2387@keescook> (raw)
In-Reply-To: <CAKwvOdmYa6V=W2eupEmHcuF8+479F8XHxm1NAo0s2N=sawbKAw@mail.gmail.com>

On Tue, Jun 23, 2020 at 05:03:46PM -0700, Nick Desaulniers wrote:
> On Mon, Jun 22, 2020 at 1:49 PM Kees Cook <keescook@chromium.org> wrote:
> > [...]
> > @@ -37,6 +38,13 @@
> >                 *(.idmap.text)                                          \
> >                 __idmap_text_end = .;                                   \
> >
> > +#define ARM_COMMON_DISCARD                                             \
> > +               *(.ARM.attributes)                                      \
> 
> I could have sworn that someone (Eli?) once told me that this section
> (.ARM.attributes) is used for disambiguating which ARM version or
> which optional extensions were used when compiling, and that without
> this section, one would not be able to disassemble 32b ARM precisely.
> If that's the case, we might not want to discard it?

Perhaps we want to treat it like .comment and include it in the ELF?

> > +#define ARM_STUBS_TEXT                                                 \
> > +               *(.gnu.warning)                                         \
> > +               *(.glue_7t)                                             \
> > +               *(.glue_7)                                              \
> 
> This changes the order of .glue_7t relative to .glue_7.  Maybe that
> doesn't matter.

Good point. I'll swap it just for consistency.

Thanks!

-- 
Kees Cook

WARNING: multiple messages have this Message-ID (diff)
From: Kees Cook <keescook@chromium.org>
To: Nick Desaulniers <ndesaulniers@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Eli Friedman <efriedma@quicinc.com>,
	Russell King <linux@armlinux.org.uk>,
	LKML <linux-kernel@vger.kernel.org>,
	Nathan Chancellor <natechancellor@gmail.com>,
	Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v2 1/2] arm/build: Warn on orphan section placement
Date: Wed, 24 Jun 2020 12:43:41 -0700	[thread overview]
Message-ID: <202006241242.9A6E0E2387@keescook> (raw)
In-Reply-To: <CAKwvOdmYa6V=W2eupEmHcuF8+479F8XHxm1NAo0s2N=sawbKAw@mail.gmail.com>

On Tue, Jun 23, 2020 at 05:03:46PM -0700, Nick Desaulniers wrote:
> On Mon, Jun 22, 2020 at 1:49 PM Kees Cook <keescook@chromium.org> wrote:
> > [...]
> > @@ -37,6 +38,13 @@
> >                 *(.idmap.text)                                          \
> >                 __idmap_text_end = .;                                   \
> >
> > +#define ARM_COMMON_DISCARD                                             \
> > +               *(.ARM.attributes)                                      \
> 
> I could have sworn that someone (Eli?) once told me that this section
> (.ARM.attributes) is used for disambiguating which ARM version or
> which optional extensions were used when compiling, and that without
> this section, one would not be able to disassemble 32b ARM precisely.
> If that's the case, we might not want to discard it?

Perhaps we want to treat it like .comment and include it in the ELF?

> > +#define ARM_STUBS_TEXT                                                 \
> > +               *(.gnu.warning)                                         \
> > +               *(.glue_7t)                                             \
> > +               *(.glue_7)                                              \
> 
> This changes the order of .glue_7t relative to .glue_7.  Maybe that
> doesn't matter.

Good point. I'll swap it just for consistency.

Thanks!

-- 
Kees Cook

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2020-06-24 19:43 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-22 20:49 [PATCH v2 0/2] arm: Warn on orphan section placement Kees Cook
2020-06-22 20:49 ` [PATCH v2 1/2] arm/build: " Kees Cook
2020-06-24  0:03   ` Nick Desaulniers
2020-06-24  0:03     ` Nick Desaulniers
2020-06-24 19:43     ` Kees Cook [this message]
2020-06-24 19:43       ` Kees Cook
2020-06-26 21:36     ` Nick Desaulniers
2020-06-26 21:36       ` Nick Desaulniers
2020-06-26 21:55       ` Kees Cook
2020-06-26 21:55         ` Kees Cook
2020-06-25 13:43   ` kernel test robot
2020-06-22 20:49 ` [PATCH v2 2/2] arm/boot: " Kees Cook
2020-06-24  0:08   ` Nick Desaulniers
2020-06-24  0:08     ` Nick Desaulniers

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=202006241242.9A6E0E2387@keescook \
    --to=keescook@chromium.org \
    --cc=ardb@kernel.org \
    --cc=arnd@arndb.de \
    --cc=efriedma@quicinc.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=masahiroy@kernel.org \
    --cc=natechancellor@gmail.com \
    --cc=ndesaulniers@google.com \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.