From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f46.google.com (mail-ej1-f46.google.com [209.85.218.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6AB75256D for ; Thu, 3 Nov 2022 23:18:28 +0000 (UTC) Received: by mail-ej1-f46.google.com with SMTP id f27so9287889eje.1 for ; Thu, 03 Nov 2022 16:18:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=6nFukTkOw1gbW4oWy1dnnjZjTg02KMsHFw8GpjXtUYU=; b=geRfAiNqwqJECVjVtpvPh5ybjpsHLeWnh1QnALVgXWTQjFlb/Z0cQvQQ4/yQG4qQ8W NGbCmycbKo2k+riXNNdGIP4FXw2D2PKAZ68ecs2Gtq2Maj+ZMlrHLaV5DnH2sI8Tnqsh /Pd1th7/joC6KAYBLTaldAkqAMhJg1EitLf+TIKPllOfzF/Hsr1zAoKEAGihqSZOuFJg ZVNh6RIRYq3wmRyKf/HMfnBrtmLxiVan0NL/rHwzsowOMiWYsI7yUv4WGzI+9LkXKjRp vhCxhturzIsbZOtfnQ8RVpiSvbUz52uk5u/yxLAe0ch/8gBBBYOKOhLMKpqC3vtvFJP8 asgQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=6nFukTkOw1gbW4oWy1dnnjZjTg02KMsHFw8GpjXtUYU=; b=uMwHvMJzMg4N5X20xrBn5kyLHABnmz33NCDaFJXlTVbc9wx6PtSRJMDQEfVMmXiVX7 99TMHoU/KgDi9OKGwcznVHpVUM2zVEfdF+r9R4ZanX5MwYWlC5TV/4h390yLDJLCTj20 G6bFzPuAVgEREDh6mObuKIlGvC0N7zTdxwtOaH1SfunGqNvQ8JhcnJ5R+DNQ1GQNgBrh Zpf7PB6AjDQWP/AbDjlCbG31pj1MZDU8sAlqYP1z5atsHORDFYkRYU9QKZJ9a1XjCtSx bFqp56uvy3qcRtQ0YCxHp8jz6xnF+J/aPp8kLA5d2Y/fyR4tAz22RZ0JFK0RggZhM5Kh TyXw== X-Gm-Message-State: ACrzQf3TxhBswLSNQK4Kyb03kUN8BBem2BkM+I2AIKNct1GtlofsfMKQ XXxqukCy4+cbuz3s4RBo19YCRbZ4a+1YeqfiihdxQg== X-Google-Smtp-Source: AMsMyM6hsn6YVhgFd5QkS0dns+dZWnGy8H25gQirK3LwhxHjBI+5T14PQQIwPtGB4ESce7EVy5loikiB2S+qGFbmHic= X-Received: by 2002:a17:906:3f89:b0:7ae:35c9:f098 with SMTP id b9-20020a1709063f8900b007ae35c9f098mr53045ejj.303.1667517506498; Thu, 03 Nov 2022 16:18:26 -0700 (PDT) Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20221102163252.49175-1-nathan@kernel.org> <202211021259.9169F5CBE@keescook> In-Reply-To: <202211021259.9169F5CBE@keescook> From: Sami Tolvanen Date: Thu, 3 Nov 2022 16:17:50 -0700 Message-ID: Subject: Re: [PATCH 1/3] s390/ctcm: Fix return type of ctc{mp,}m_tx() To: Kees Cook Cc: Heiko Carstens , Nathan Chancellor , Alexandra Winter , Wenjia Zhang , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , linux-s390@vger.kernel.org, netdev@vger.kernel.org, Nick Desaulniers , Tom Rix , llvm@lists.linux.dev, linux-kernel@vger.kernel.org, patches@lists.linux.dev Content-Type: text/plain; charset="UTF-8" On Wed, Nov 2, 2022 at 1:01 PM Kees Cook wrote: > > On Wed, Nov 02, 2022 at 08:48:42PM +0100, Heiko Carstens wrote: > > On Wed, Nov 02, 2022 at 09:32:50AM -0700, Nathan Chancellor wrote: > > > should s390 select ARCH_SUPPORTS_CFI_CLANG in the future. > > > > Yes, s390 should select that :) > > > > But, is there any switch or option I need to set when compiling clang, > > so it knows about the kcfi sanitizer? > > > > I get: > > clang-16: error: unsupported option '-fsanitize=kcfi' for target 's390x-ibm-linux' > > > > > clang --version > > clang version 16.0.0 (https://github.com/llvm/llvm-project.git e02110e2ab4dd71b276e887483f0e6e286d243ed) > > You'll need the "generic arch support": https://reviews.llvm.org/D135411 > which is _almost_ landed. Testing would be welcome, for sure! > > Sami, do you have any notes on what common things were needed to get > arm64 and x86_64 booting under kCFI? My only oh-so-helpful notes are > "keep CFI away from early boot code". :P You don't need to keep CFI away from early boot code, but bringing this up in qemu+gdb initially is probably the best way forward. We also had plenty of type mismatches in syscall wrappers in the currently supported architectures, so that's another thing to watch out for once your kernel boots far enough to start init. Sami