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 26C5F4CB5B; Wed, 25 Mar 2026 04:14:34 +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=1774412075; cv=none; b=RKwkyl2PD8rKYp05npurwgtqA+Ud3UZLklsnh8keOhSKr5WysVvFuGCX3ypNkQ02KPsHLk0Vpowtos4xhedoaj/WvXdIl0yUQq2AqTEZnPhRnTe4AMDWAKbiHZPoxQXEmMsV6YBEm8FsoTR8TlPcvKoRWJ6PIe2rI0SOsCkeNiE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774412075; c=relaxed/simple; bh=DjQNBELJeTo8/+IvhIZ195gGXomNRX+U9eI4gj1CDvQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=pGFUZfjjOEIPwpIhRsVc1T8o1RNbKmi7tbxhN/CbU2TBBcXyNZcAduKA/GAq8QGoV86BQtTUUDm3i+7sde0HuT8E3Gx4+9EHQDcM3DmhQKyL/cKa49VUyOPhvST7LAWkPIF9efhowmwymaXBmNQ6L+TDMSsB9xoEZpgEru2alIs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SRN8ph0p; 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="SRN8ph0p" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3C4AC4CEF7; Wed, 25 Mar 2026 04:14:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774412074; bh=DjQNBELJeTo8/+IvhIZ195gGXomNRX+U9eI4gj1CDvQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SRN8ph0pe1XZdbFseT7tE70r/KjEUXruc5OYrwNk9RqqxCpNBz3lKttBmjvyR/V+F LtJrTZ+7anfXtgnic7l5VIoLbzWClqhGy86LYc5jTJ5WiLlspuvWPVcH7tVEo3bTZQ B3/V2PjFQujB3TmjH/YZDXYjGSvefpMLSF6ujW4kNal6dqlrgdyZy3xe5uuN8qioVt C5T8kZxf9GojeAa9XddOx6PZakiiMDHaZ25yl5D3ZSoIxAugmHnvVJo6l2b5/Lv/S0 upiARQ+JCWrFKrTEs9313xFN7iKFbUBGQMZ2Z6A7i8ktSdEYDHgVOSA3WjPwRHv5Xc ZaeMKZnXKgm0Q== From: Kees Cook To: Catalin Marinas , Will Deacon , Huacai Chen , Madhavan Srinivasan , Michael Ellerman , Paul Walmsley , Palmer Dabbelt , Albert Ou , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Ingo Molnar , Borislav Petkov , Dave Hansen , "Gustavo A. R. Silva" , Arnd Bergmann , Mark Rutland , "Jason A. Donenfeld" , Ard Biesheuvel , Jeremy Linton , David Laight , Thomas Gleixner , Ryan Roberts Cc: Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH v5 0/2] Fix bugs and performance of kstack offset randomisation Date: Tue, 24 Mar 2026 21:14:20 -0700 Message-Id: <177441205756.1333400.7749975219620417508.b4-ty@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260303150840.3789438-1-ryan.roberts@arm.com> References: <20260303150840.3789438-1-ryan.roberts@arm.com> 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-Transfer-Encoding: 8bit On Tue, 03 Mar 2026 15:08:37 +0000, Ryan Roberts wrote: > [Kees; I'm hoping this is now good-to-go via your hardening tree? It would be > good to get some linux-next testing.] > > Hi All, > > As I reported at [1], kstack offset randomisation suffers from a couple of bugs > and, on arm64 at least, the performance is poor. This series attempts to fix > both; patch 1 provides back-portable fixes for the functional bugs. Patch 2 > proposes a performance improvement approach. > > [...] Sorry for the delay! Applied to for-next/hardening, thanks. :) [1/2] randomize_kstack: Maintain kstack_offset per task https://git.kernel.org/kees/c/37beb4256016 [2/2] randomize_kstack: Unify random source across arches https://git.kernel.org/kees/c/a96ef5848cb0 Take care, -- Kees Cook