From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 71A14605CE; Thu, 2 May 2024 11:21:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714648897; cv=none; b=XZqnYYs7K7c79g1FjMzyhuhLWLBwFAT4CsP84mbbr8ffifYBGDwdUogyUNXzF44secsfRWLQcbv08BmNVQH6Hgsp2bu9z1v9Wb4tegXZ0QmdNwxO+Xf9aKOJgwm+Gro8nvqjTU/ON4TWHVduiguMkqpjbx0VA92pasgd956FFbs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714648897; c=relaxed/simple; bh=0ln9TXID18gsJMnDENXiItJGRtQ3Til5tzw9qOWE/sc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ri+CVDNOo1jI28yXf34FJsPTKbqHucNCdUMUiLDmKTHJDkNL5PPBTBecK6+U7+gX33oBiHUSCTSikj047KAEaKvykKOrXHuYHx1xlyTIZ9POiA8dY9zNWZYPfrRdAkthpZJJUGMFD2NhQPQXGLcMyVUMqLIKzRVnC41+Yft4tPk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oEKEViO8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oEKEViO8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 307A2C4AF18; Thu, 2 May 2024 11:21:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1714648897; bh=0ln9TXID18gsJMnDENXiItJGRtQ3Til5tzw9qOWE/sc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=oEKEViO8AxOjXR6iIdgwCu7M9Gy8KOg7xF4nyGPC+Q6kiqWHLioCWc+TKN1O1xGFU R5r916favQUmXsHYwF3hhP1H4QIqQhlQ5wBll2sEvQCjHIUs30q9p6EEUJISyRnuoX PHUjcgdQN9lWXGwzx/xhDdXqpWVdoLEkQ1youg+dV29CHaL49sDwtdB0b1hRj6Eg69 lcXC8doU0yUE99/DKUCyscpgTShpcBrE9CN7lHget3Yx3haAYwZdFxiJdtAF84yIlo C6EgORkHpFEimOrGiEho7ncdyeWM6rlP3wOVXAEfpup/tHM7MZKMUzUJzKk2OPSgFw Ug3evdCl5UR1w== Date: Thu, 2 May 2024 12:21:28 +0100 From: Will Deacon To: Kees Cook Cc: Mark Rutland , Peter Zijlstra , Boqun Feng , Catalin Marinas , linux-arm-kernel@lists.infradead.org, Jakub Kicinski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Arnd Bergmann , Andrew Morton , "David S. Miller" , David Ahern , Eric Dumazet , Paolo Abeni , "Paul E. McKenney" , Uros Bizjak , linux-kernel@vger.kernel.org, x86@kernel.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH 2/4] arm64: atomics: lse: Silence intentional wrapping addition Message-ID: <20240502112127.GA17013@willie-the-truck> References: <20240424191225.work.780-kees@kernel.org> <20240424191740.3088894-2-keescook@chromium.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240424191740.3088894-2-keescook@chromium.org> User-Agent: Mutt/1.10.1 (2018-07-13) On Wed, Apr 24, 2024 at 12:17:35PM -0700, Kees Cook wrote: > Annotate atomic_add_return() and atomic_sub_return() to avoid signed > overflow instrumentation. They are expected to wrap around. > > Signed-off-by: Kees Cook > --- > Cc: Will Deacon > Cc: Peter Zijlstra > Cc: Boqun Feng > Cc: Mark Rutland > Cc: Catalin Marinas > Cc: linux-arm-kernel@lists.infradead.org > --- > arch/arm64/include/asm/atomic_lse.h | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) How come the ll/sc routines (in atomic_ll_sc.h) don't need the same treatment? If that's just an oversight, then maybe it's better to instrument the higher-level wrappers in asm/atomic.h? Will