From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Miroslav Benes <mbenes@suse.cz>
Cc: Kristen Carlson Accardi <kristen@linux.intel.com>,
Kees Cook <keescook@chromium.org>,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
arjan@linux.intel.com, x86@kernel.org,
linux-kernel@vger.kernel.org,
kernel-hardening@lists.openwall.com, rick.p.edgecombe@intel.com,
live-patching@vger.kernel.org, Hongjiu Lu <hongjiu.lu@intel.com>,
joe.lawrence@redhat.com
Subject: Re: [PATCH v4 00/10] Function Granular KASLR
Date: Fri, 28 Aug 2020 14:24:13 -0500 [thread overview]
Message-ID: <20200828192413.p6rctr42xtuh2c2e@treble> (raw)
In-Reply-To: <alpine.LSU.2.21.2008281216031.29208@pobox.suse.cz>
On Fri, Aug 28, 2020 at 12:21:13PM +0200, Miroslav Benes wrote:
> > Hi there! I was trying to find a super easy way to address this, so I
> > thought the best thing would be if there were a compiler or linker
> > switch to just eliminate any duplicate symbols at compile time for
> > vmlinux. I filed this question on the binutils bugzilla looking to see
> > if there were existing flags that might do this, but H.J. Lu went ahead
> > and created a new one "-z unique", that seems to do what we would need
> > it to do.
> >
> > https://sourceware.org/bugzilla/show_bug.cgi?id=26391
> >
> > When I use this option, it renames any duplicate symbols with an
> > extension - for example duplicatefunc.1 or duplicatefunc.2. You could
> > either match on the full unique name of the specific binary you are
> > trying to patch, or you match the base name and use the extension to
> > determine original position. Do you think this solution would work?
>
> Yes, I think so (thanks, Joe, for testing!).
>
> It looks cleaner to me than the options above, but it may just be a matter
> of taste. Anyway, I'd go with full name matching, because -z unique-symbol
> would allow us to remove sympos altogether, which is appealing.
>
> > If
> > so, I can modify livepatch to refuse to patch on duplicated symbols if
> > CONFIG_FG_KASLR and when this option is merged into the tool chain I
> > can add it to KBUILD_LDFLAGS when CONFIG_FG_KASLR and livepatching
> > should work in all cases.
>
> Ok.
>
> Josh, Petr, would this work for you too?
Sounds good to me. Kristen, thanks for finding a solution!
--
Josh
next prev parent reply other threads:[~2020-08-28 19:24 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200717170008.5949-1-kristen@linux.intel.com>
2020-07-22 9:27 ` [PATCH v4 00/10] Function Granular KASLR Miroslav Benes
2020-07-22 14:39 ` Kees Cook
2020-07-22 14:51 ` Joe Lawrence
2020-07-22 14:56 ` Joe Lawrence
2020-07-22 18:24 ` Kristen Carlson Accardi
2020-07-22 16:07 ` Josh Poimboeuf
2020-07-22 19:42 ` Kees Cook
2020-07-22 19:56 ` Kristen Carlson Accardi
2020-07-22 21:33 ` Josh Poimboeuf
2020-08-21 23:02 ` Kristen Carlson Accardi
2020-08-25 16:16 ` Joe Lawrence
2020-08-28 10:21 ` Miroslav Benes
2020-08-28 19:24 ` Josh Poimboeuf [this message]
2021-01-23 22:59 ` Fangrui Song
2021-01-25 17:21 ` Josh Poimboeuf
2020-08-03 11:39 ` Evgenii Shatokhin
2020-08-03 17:45 ` Kees Cook
2020-08-03 18:17 ` Joe Lawrence
2020-08-03 19:38 ` Frank Ch. Eigler
2020-08-03 20:11 ` Kees Cook
2020-08-03 21:12 ` Frank Ch. Eigler
2020-08-03 21:41 ` Kees Cook
2020-08-04 0:48 ` Frank Ch. Eigler
2020-08-04 17:04 ` Jessica Yu
2020-08-04 18:23 ` Joe Lawrence
2020-08-07 16:38 ` Kristen Carlson Accardi
2020-08-07 17:20 ` Kees Cook
2020-08-10 16:10 ` Kristen Carlson Accardi
2020-08-12 17:18 ` Kristen Carlson Accardi
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=20200828192413.p6rctr42xtuh2c2e@treble \
--to=jpoimboe@redhat.com \
--cc=arjan@linux.intel.com \
--cc=bp@alien8.de \
--cc=hongjiu.lu@intel.com \
--cc=joe.lawrence@redhat.com \
--cc=keescook@chromium.org \
--cc=kernel-hardening@lists.openwall.com \
--cc=kristen@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=live-patching@vger.kernel.org \
--cc=mbenes@suse.cz \
--cc=mingo@redhat.com \
--cc=rick.p.edgecombe@intel.com \
--cc=tglx@linutronix.de \
--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).