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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5819DFEA806 for ; Wed, 25 Mar 2026 04:14:39 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4fgYTB03z4z2yTK; Wed, 25 Mar 2026 15:14:38 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip="2600:3c0a:e001:78e:0:1991:8:25" ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1774412077; cv=none; b=kABoYSGe2IKqVCC+ZFIzF19/1hWvEgzleF618SjLyiVY8hYMwV0itXINT3CjsR5mCh1e/kSGHvVLQWuRm6KldymxSCQ6OjGEysU6sc/2MPgfGooxIoMAaWYfk8c6zxLDzJfYj2PrHv+TQCVzLW6bAUa+QrjYF5/c23mDpYhSY82Z3El+WRmBivmLJ3HIj5l9ywXDio+UCWP/rcw9IqltwK+P2bKzx14A4fFdLVwaYKDdglkqn+cinfVHctK9wHC7RgC6PMBLctspiFYllezky9bCA/swOfM1rP1M+5r177/exrtTBkrPyBqj8nqtQ74qlhh5Lg7QwdmHBJbUqlEoVg== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1774412077; c=relaxed/relaxed; bh=27fWtX4e+LV3z70kuuRuZ5e8ys9OszIAeG99fDZYuvA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=M3RaFo4lVzWko90aZnm5V8nLqvOKM3sD4hYq+Hz+LiJWrLxvJXsmVw0ZOq4xIMX2fqkzQz5+BtYtdj/1eKG9dUtTQeOunXV+YJnrZTc54SNTTWUKnzyAbWM/JRK1CLah5OwvGw0Ctmw6398rMiBGsp0jxoK3RpIoUgtfsCnVL7NwgrH/xBVQDhlHe1mNOUjeRFxlkvJndgw3qyVZW2RyN5jPyBZEAtMoX+nrxXClQGN6EO2lfmiXDTEUPKg0ifQS52NOnK5ifK0IxKkvfOhxoSSP2TQ696gLaMjwzGDHHmCJYUWZPtTG1n/7ORh4sF4kQiSMxc5l6qDh/uHb2nKhYA== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=SRN8ph0p; dkim-atps=neutral; spf=pass (client-ip=2600:3c0a:e001:78e:0:1991:8:25; helo=sea.source.kernel.org; envelope-from=kees@kernel.org; receiver=lists.ozlabs.org) smtp.mailfrom=kernel.org Authentication-Results: lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=SRN8ph0p; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=2600:3c0a:e001:78e:0:1991:8:25; helo=sea.source.kernel.org; envelope-from=kees@kernel.org; receiver=lists.ozlabs.org) Received: from sea.source.kernel.org (sea.source.kernel.org [IPv6:2600:3c0a:e001:78e:0:1991:8:25]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4fgYT92CP2z2yRl for ; Wed, 25 Mar 2026 15:14:37 +1100 (AEDT) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id E09BA44182; Wed, 25 Mar 2026 04:14:34 +0000 (UTC) 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> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list 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