From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EEA34C43334 for ; Fri, 24 Jun 2022 11:42:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231253AbiFXLmj (ORCPT ); Fri, 24 Jun 2022 07:42:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34196 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229546AbiFXLme (ORCPT ); Fri, 24 Jun 2022 07:42:34 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 094467A1BF; Fri, 24 Jun 2022 04:42:32 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 470E5CE2670; Fri, 24 Jun 2022 11:42:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0FC80C34114; Fri, 24 Jun 2022 11:42:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1656070949; bh=A9EbR0TTckgQYks+j0SLebZoHLsX7+FVTH3QCZLBNLI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lfAalIbsPwoYEqi/eNoEEg1XzTA80iuuuHjDWGSr+GpUJkK/uLurfchn3GmDl+VqU I5dzMOTCwocH0S4rK9pBaRu26LTcnt7NBRaiLQKNdT6LYS0d7P4wg9CqE+4ra4BHm6 Qbfzq1E8mIw8KEHX1VOPrYqTGJ9T8XW7+r7un5n1wTMyQzBekMq9/agKoRR3qunO/O OGt2rl8mi+rHQ1bj3gl2UBO9PXRMuVJiHRunmSmRbk3kAgD1XZDW8cOP8J8DNpUgeY u/4YoR0xOt9my1L/DSIl4JNJrsNi3+qhjQ0QXSpFNAgTmINbL9CyYwubXia8CFVtGm GJ7A2EjvNT76w== Date: Fri, 24 Jun 2022 12:42:23 +0100 From: Mark Brown To: Will Deacon Cc: madvenka@linux.microsoft.com, mark.rutland@arm.com, jpoimboe@redhat.com, ardb@kernel.org, nobuta.keiya@fujitsu.com, sjitindarsingh@gmail.com, catalin.marinas@arm.com, jamorris@linux.microsoft.com, linux-arm-kernel@lists.infradead.org, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v15 0/6] arm64: Reorganize the unwinder and implement stack trace reliability checks Message-ID: References: <20220617210717.27126-1-madvenka@linux.microsoft.com> <20220623173224.GB16966@willie-the-truck> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="TK6aEfPqnhW4wFA2" Content-Disposition: inline In-Reply-To: <20220623173224.GB16966@willie-the-truck> X-Cookie: Help! I'm trapped in a PDP 11/70! Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --TK6aEfPqnhW4wFA2 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Jun 23, 2022 at 06:32:24PM +0100, Will Deacon wrote: > On Fri, Jun 17, 2022 at 04:07:11PM -0500, madvenka@linux.microsoft.com wrote: > > as HAVE_RELIABLE_STACKTRACE depends on STACK_VALIDATION which is not present > > yet. This patch will be added in the future once Objtool is enhanced to > > provide stack validation in some form. > Given that it's not at all obvious that we're going to end up using objtool > for arm64, does this patch series gain us anything in isolation? Having the reliability information seems like it should be useful in general even without doing live patching - we can use it to annotate stack traces to warn people about anything that might be suspect in there. For live patching it's probably something we'll want regardless of the use of objtool, it's one more robustness check which always helps. --TK6aEfPqnhW4wFA2 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmK1ox8ACgkQJNaLcl1U h9AEiQf/WqiaUGRvZs/gEhhSFRXD9HBwdbVf2Yd0sL2zEILXUI9Ld3PVgtxktJyV 05a7Vrm2cj70mtTa9hgXijXG/TdpR1fdGVv+3fOe0PnH6yQQbywUrk/mk2HgmhqE 56t0MyabelWk9fN2+WqqRtbdko0mCxNE9d/gjH+SaggSuqVEb6WyrwNkb0XA7XlG dtNaq76s0mkYqx4owIkSjQouuJeQsy+1Hn2bcbbNa2c7ra/1zL4KOT9cTrK0zDdD usmOBhDorWpVeUNkg35q3OoQ+bh4cyLaipMQGVl2wEtGz6ODyBDzGGumHxGZf9Tg Z/RjJXHtd4LShvPqKsS9Pzjdpr9V+A== =j8JN -----END PGP SIGNATURE----- --TK6aEfPqnhW4wFA2--