From nobody Tue Dec 16 23:30:45 2025 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 D7437E71D56 for ; Fri, 29 Sep 2023 21:12:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233812AbjI2VMK (ORCPT ); Fri, 29 Sep 2023 17:12:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233516AbjI2VME (ORCPT ); Fri, 29 Sep 2023 17:12:04 -0400 Received: from mail-pl1-x649.google.com (mail-pl1-x649.google.com [IPv6:2607:f8b0:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 647811A7 for ; Fri, 29 Sep 2023 14:12:02 -0700 (PDT) Received: by mail-pl1-x649.google.com with SMTP id d9443c01a7336-1c74e099ba9so6397305ad.1 for ; Fri, 29 Sep 2023 14:12:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1696021922; x=1696626722; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=19scQT+vZguMbMPGvwbswmmwWeMyYkP13y1R8IKgsdo=; b=Zd6JRriOPOX1x6aTOLFBCqzeK/oCDIqgP2b+sbpHWzAsxc6caGkOCYDY2Ks5XGVIz7 uhGkdjS/ImUVT2Iga+RfyKLbtFAf2ZfkqNEjRzGZ+AdrLnnHk1sHvMZqkvdbYIvj5YQe PeWI+aF6G+Hs+ilT6qhP22WbvLXXWY6ZsCNsxF6M8PIiaEL1Db9GE1huzhtYt+8yeQRd tWJxFZFt7W0ouxNi7gEZ2vkRcyPEVcRiTBFGf6G7VfPNia8/tTxqUbSpf4Ud3ZO5k6Zu rHDlx40FWz6xFRs/FMim9TScpVDgB0XTNOgUnZOlLPNfq9Ne7dcqOptWDmvIyVlhQSUm /KVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696021922; x=1696626722; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=19scQT+vZguMbMPGvwbswmmwWeMyYkP13y1R8IKgsdo=; b=IvsfoQz8j9hGriUzmYU8ObZRhjrS2rvJDX7eMX4v+jorHlStZYIQFVW6SaB494Yrla 73qKFW9+fBEHaGnrlKZ8jWNS5s7iWTPKOS0bjtUGWQVCiPD2VJE3xBuedM664G9YDJYz WVjYPEPa8c58m/wOfYjoxcd4WxzRWx7nwvz8ZuXBHT9ftF+RzZPl43iMUIBOyIti8Lbx bW/ajL/M2WG42Dp6ejDJLwsrJOOVEFcsKNof96e4TjRktV09WceosP97Rpu4lTY/ec0l Xa8sIWjVqCV+ErHSMkAfc2Mm7ugQce0rfvzwI87R1wLeECsyO36r/9E6sgkxjmbBmY2G /mNw== X-Gm-Message-State: AOJu0YwOr5ocU26oKV2oL9er3xa7kUlkpY5x8R5RAtN9KI0T5ZGB61L1 zSbj4hsTGbLe4Fk+Gol0axsnh5rDg7y8rWxa6j4= X-Google-Smtp-Source: AGHT+IEu8pWqkhn949EN2w2MEEmF4sIQU2CD0ztiPLeuQl+OuKcbvmbHD9LpYfISQSvkmvSO3SxPVHDUipdN2Hi1oC8= X-Received: from samitolvanen.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:4f92]) (user=samitolvanen job=sendgmr) by 2002:a17:903:1c8:b0:1c6:d25:8730 with SMTP id e8-20020a17090301c800b001c60d258730mr75155plh.0.1696021921796; Fri, 29 Sep 2023 14:12:01 -0700 (PDT) Date: Fri, 29 Sep 2023 21:11:58 +0000 In-Reply-To: <20230929211155.3910949-4-samitolvanen@google.com> Mime-Version: 1.0 References: <20230929211155.3910949-4-samitolvanen@google.com> X-Developer-Key: i=samitolvanen@google.com; a=openpgp; fpr=35CCFB63B283D6D3AEB783944CB5F6848BBC56EE X-Developer-Signature: v=1; a=openpgp-sha256; l=1191; i=samitolvanen@google.com; h=from:subject; bh=MSLQAq+u1Gq1vqQPv1L24OvfGxs9lQjVrKINsuZaDko=; b=owEB7QES/pANAwAKAUy19oSLvFbuAcsmYgBlFz2bXFheIUWsMCgpXroYNEMEHJSzh7lHXZPhb Ah07CUmBI2JAbMEAAEKAB0WIQQ1zPtjsoPW0663g5RMtfaEi7xW7gUCZRc9mwAKCRBMtfaEi7xW 7oPqC/9r2/xEbO/XFpLcUfW8kI4zwGyW+1Bc7PLy9I1XUD02QER16SuVa1TjN8rJQPDmOMsvTB5 T5jEE8zHkuv5iPAUTq/yfdsqgq7Z9o7WUqulun2nOY9Z455ZDOwLvbCIfEXhOthriqRBjm08Kd8 068lN/FADXcZatUB50UlQahfJo08fLC7oUQ5xDGv0aXR6pnqONVNs/F1FhlysA15ZmM0HVhJePX 6NcJ3HNNPyvbDbeafLIysEsEirdqqDLbxHXo6W0v7OFcevxKffQom+ZUD8w0SlBJsnrgLSQYfrL 4SDgYPIT3RgVrVY58SpSU/IrpswNMkcW1oGV+VpuE8vh5HfISvX0Y/jFIK76jIL1xM9gdG/5oKD xSBdaJPOnpK9Gcze/0uC08IM5oubP3raIy1qzWvrbWFce1KlRfKgkHLVVNp7KcJmqHe0lhZqoI4 gKx2VGQd8AOM+C9TUeca+0u6bNkxxIvvO6e8Zupt2MkaleKzO1xxv6N14XGwr2/VkIpsg= X-Mailer: git-send-email 2.42.0.582.g8ccd20d70d-goog Message-ID: <20230929211155.3910949-6-samitolvanen@google.com> Subject: [PATCH 2/2] riscv: mm: Update mmap_rnd_bits_max From: Sami Tolvanen To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Andrew Morton , Kees Cook Cc: linux-mm@kvack.org, linux-riscv@lists.infradead.org, llvm@lists.linux.dev, linux-kernel@vger.kernel.org, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" ARCH_MMAP_RND_BITS_MAX is based on Sv39, which leaves a few potential bits of mmap randomness on the table if we end up enabling 4/5-level paging. Update mmap_rnd_bits_max to take the final address space size into account. This increases mmap_rnd_bits_max from 24 to 33 with Sv48/57. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- arch/riscv/mm/init.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 0798bd861dcb..ff8d21a6cb2d 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -762,6 +762,11 @@ static int __init print_no5lvl(char *p) } early_param("no5lvl", print_no5lvl); =20 +static void __init set_mmap_rnd_bits_max(void) +{ + mmap_rnd_bits_max =3D MMAP_VA_BITS - PAGE_SHIFT - 3; +} + /* * There is a simple way to determine if 4-level is supported by the * underlying hardware: establish 1:1 mapping in 4-level page table mode @@ -1071,6 +1076,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) =20 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL) set_satp_mode(dtb_pa); + set_mmap_rnd_bits_max(); #endif =20 /* --=20 2.42.0.582.g8ccd20d70d-goog