From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Kees Cook <keescook@chromium.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
PaX Team <pageexec@freemail.hu>, Jann Horn <jannh@google.com>,
Eric Biggers <ebiggers3@gmail.com>,
Christoph Hellwig <hch@infradead.org>,
"axboe@kernel.dk" <axboe@kernel.dk>,
James Bottomley <James.Bottomley@hansenpartnership.com>,
Elena Reshetova <elena.reshetova@intel.com>,
Hans Liljestrand <ishkamiel@gmail.com>,
David Windsor <dwindsor@gmail.com>,
"x86@kernel.org" <x86@kernel.org>, Ingo Molnar <mingo@kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"David S. Miller" <davem@davemloft.net>,
Rik van Riel <riel@redhat.com>,
linux-arch <linux-arch@vger.kernel.org>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>
Subject: Re: [PATCH v3 2/2] x86/refcount: Implement fast refcount overflow protection
Date: Mon, 8 May 2017 20:58:29 -0500 [thread overview]
Message-ID: <20170509015829.iycvxxbyblfgklsg@treble> (raw)
In-Reply-To: <CAGXu5j+J=o7hHceQn6pFtCmQcfUtSrtZ9uP8fLo0gkDWNdetAA@mail.gmail.com>
On Mon, May 08, 2017 at 04:31:11PM -0700, Kees Cook wrote:
> On Mon, May 8, 2017 at 3:53 PM, Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> > On Mon, May 08, 2017 at 12:32:52PM -0700, Kees Cook wrote:
> >> +#define REFCOUNT_EXCEPTION \
> >> + "movl $0x7fffffff, %[counter]\n\t" \
> >> + "int $"__stringify(X86_REFCOUNT_VECTOR)"\n" \
> >> + "0:\n\t" \
> >> + _ASM_EXTABLE(0b, 0b)
> >
> > Despite the objtool warnings going away, this still uses the exception
> > table in a new way, which will confuse objtool. I need to do some more
> > thinking about the best way to fix it, either as a change to your patch
> > or a change to objtool.
>
> In that it's not a "true" exception?
Right. And also that it doesn't need the "fixup" since it would return
to the same address anyway.
--
Josh
next prev parent reply other threads:[~2017-05-09 1:58 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-08 19:32 [PATCH v3 0/2] x86/refcount: Implement fast refcount overflow protection Kees Cook
2017-05-08 19:32 ` [PATCH v3 1/2] x86/asm: Add suffix macro for GEN_*_RMWcc() Kees Cook
2017-05-08 19:32 ` [PATCH v3 2/2] x86/refcount: Implement fast refcount overflow protection Kees Cook
2017-05-08 22:53 ` Josh Poimboeuf
2017-05-08 23:31 ` Kees Cook
2017-05-09 1:58 ` Josh Poimboeuf [this message]
2017-05-09 17:08 ` Josh Poimboeuf
2017-05-09 17:29 ` Kees Cook
2017-05-09 17:44 ` Josh Poimboeuf
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=20170509015829.iycvxxbyblfgklsg@treble \
--to=jpoimboe@redhat.com \
--cc=James.Bottomley@hansenpartnership.com \
--cc=arnd@arndb.de \
--cc=axboe@kernel.dk \
--cc=davem@davemloft.net \
--cc=dwindsor@gmail.com \
--cc=ebiggers3@gmail.com \
--cc=elena.reshetova@intel.com \
--cc=gregkh@linuxfoundation.org \
--cc=hch@infradead.org \
--cc=ishkamiel@gmail.com \
--cc=jannh@google.com \
--cc=keescook@chromium.org \
--cc=kernel-hardening@lists.openwall.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=pageexec@freemail.hu \
--cc=peterz@infradead.org \
--cc=riel@redhat.com \
--cc=x86@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).