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 A99431F30BB; Mon, 30 Mar 2026 05:36:09 +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=1774848969; cv=none; b=JhwgaWrKEqigqIY1G25UCjQhyCjcLKbky/atkYweKINUybVnEOVQauPzfO9VOLTBPZG/KrYaJB7fqfNg/JKRvzvYpdUBajZLKpNEfMpKpV3/kPiM3Jv0JzBAfDWA4a0PVBZxEFqSlyjnMy9+dX8H1nKOHE1HZFibZdz+aSmlxNw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774848969; c=relaxed/simple; bh=37J2FedFq2slx06L2Z6thQB9dbAq/5grAfI/7vhrH9c=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BXuc6Gt8bG4drkOLruf6IffNrh7n14sCJoKp04vDo/19dTgAOTSn4+Z0NtgZ/bjtXgESkQSlmefqpE/zHPqox2srmb5XJr1o5ypRidJPJb5MPdTAOpM5HhJOLWFWniz3876hvddB50Oyz6HDU+O3ITI9dz5ZzL911nnwC+GAxGA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=M0bfKkfZ; 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="M0bfKkfZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A5EEC4CEF7; Mon, 30 Mar 2026 05:36:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774848969; bh=37J2FedFq2slx06L2Z6thQB9dbAq/5grAfI/7vhrH9c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=M0bfKkfZfjuZwn6mM1WTeEaAxriNLOFG6mfcBIGKQ+khth0ZMNmyj61tqmtc3UAYA 8IxXapWKrI97J2BG7lJ+Dcf1u/KVgsLscMsc6gygfPqnwYT24Ucb3/skS8B63aHZSG DK6UVV6fGoeoyzq7ryj4AegEIaWs85CPn/lk4+T7vkWrh0OhhXC9IHQ9Zgy77aAoJZ S3EQkvtHybOTa1eTT6pLPHY9WWiifHbW2mu6yCOwx0l6tKMDcK1BCb8hjfNdmUXijs uYRwrXbbrYqcQyfgSd1T+DYh6PxsTGSJkYMQC5n+YRy0McZP2BR7PgVlBF4vagEiq9 9yFXxg2+L+/EA== Date: Mon, 30 Mar 2026 07:36:04 +0200 From: Nathan Chancellor To: Kees Cook Cc: Justin Stitt , Nicolas Schier , Nick Desaulniers , Bill Wendling , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH] kbuild: add -fdiagnostics-show-inlining-chain for FORTIFY_SOURCE Message-ID: <20260330053604.GA879042@ax162> References: <20260327-kbuild-show-inlining-v1-1-730ac2cae571@google.com> <20260327221837.GA3622500@ax162> <202603292059.01A4CB14F2@keescook> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <202603292059.01A4CB14F2@keescook> On Sun, Mar 29, 2026 at 08:59:51PM -0700, Kees Cook wrote: > On Fri, Mar 27, 2026 at 03:29:18PM -0700, Justin Stitt wrote: > > On Fri, Mar 27, 2026 at 3:18 PM Nathan Chancellor wrote: > > The compile time impact is not measurable (within expected noise). The > > peak memory usage may increase by somewhere in the 0.5% to 1.5% range > > depending on build configuration. > > > > I bundled this under fortify to limit initial impact as its had > > virtually no real-world testing and may produce unhelpful diagnostic > > notes under its heuristic mode. I don't expect folks to use `-g1` in > > the kernel (which would enable full-proof diagnostic notes). > > > > > If not, maybe worth adding a Kconfig option that is force selected by FORTIFY_SOURCE with > > > clang or can be optionally enabled by a user? > > > > I'll defer to you on this one. We could add > > CONFIG_SHOW_INLINING_CHAIN_NOTES or something similar? > > I would prefer to just unconditionally enable this when it is supported. Agreed. It cannot possibly be worse than the status quo, right? :) This feels very similar to -fdiagnostics-show-context=2, so maybe add it near there? Cheers, Nathan