From: Josh Poimboeuf <jpoimboe@kernel.org>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: Kees Cook <kees@kernel.org>,
linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
linux-hardening@vger.kernel.org, Jan Beulich <jbeulich@suse.com>,
"Jose E. Marchesi" <jemarch@gnu.org>
Subject: Re: [PATCH] objtool: Deal with relative jump tables correctly
Date: Wed, 9 Oct 2024 22:20:58 -0700 [thread overview]
Message-ID: <20241010052058.7ftl2huxuzb2fwk7@treble.attlocal.net> (raw)
In-Reply-To: <20241010051649.wtarneasz7x7anaj@treble.attlocal.net>
On Wed, Oct 09, 2024 at 10:16:52PM -0700, Josh Poimboeuf wrote:
> > And has there been any movement on compiler annotations?
> > If this is worth while, it is something I could look into: Kees and I
> > work very closely with both the GCC and the Clang folks, and have
> > contributed other features that are specific to the kernel.
>
> I spoke with several people about this at GNU Cauldron last month and
> there is definitely interest in helping out. If you and Kees also want
> to help out, that would be awesome.
>
> Jan proposed an idea to apply a R_*_NONE relocation at the indirect
> branch instruction which references the jump table address. And then
> emit a sized ELF symbol for each jump table entry. That would be all we
> need.
While we're on the subject of objtool pain points, there's also the need
to have some kind of annotation for noreturn functions. One suggestion
has been a GCC plugin (which could in theory also work for jump tables).
--
Josh
prev parent reply other threads:[~2024-10-10 5:21 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-07 22:47 Ard Biesheuvel
2024-10-08 17:42 ` Josh Poimboeuf
2024-10-09 15:18 ` Ard Biesheuvel
2024-10-10 5:16 ` Josh Poimboeuf
2024-10-10 5:20 ` Josh Poimboeuf [this message]
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