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.gnu.org (lists.gnu.org [209.51.188.17]) (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 A0219C7619A for ; Tue, 11 Apr 2023 05:37:08 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pm6gc-0000VK-Ur; Tue, 11 Apr 2023 01:36:58 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pm6gb-0000Ut-H1; Tue, 11 Apr 2023 01:36:57 -0400 Received: from mail-vs1-xe34.google.com ([2607:f8b0:4864:20::e34]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pm6gZ-0008Po-SV; Tue, 11 Apr 2023 01:36:57 -0400 Received: by mail-vs1-xe34.google.com with SMTP id g13so6100836vsk.12; Mon, 10 Apr 2023 22:36:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1681191414; x=1683783414; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=K+o6HFW7YIcoey1ju41Np2Ywz2uKMZkP6T0NrmrEWzk=; b=RjnX2JM/yoppV8rGY9n/F+g/cp0VCHTgG/DIwLRJLafd8rG2tgEiGckRJEr0qlPvS7 5Tw2SUEyrZxV/n14FZ5tm+sJTpg35TaSRbZ0l3hgIGAq/wKi69CQSDjD7B7lgIAvF6IX emVqpzGks9a7q401UJVouh51qIYDw7luY/w6VO76mVcODFuc46NC1Mgs2rzKbkP3Wxd1 YoNsFcChHMNWcURVAkp4wy9r8p2NNGdwY/eG2FpNkCO1y9r6sMYsMYPQc/pTsYGD6yLb 2gADg1M5+6LUqV3IyVh7Oo40VPQWa3ln4qaHfOLs4McjwwBnoc3XmTTBx5tyK/uV3N8B drgg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681191414; x=1683783414; h=content-transfer-encoding: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=K+o6HFW7YIcoey1ju41Np2Ywz2uKMZkP6T0NrmrEWzk=; b=ctLqHhlnQacd63dzJPHuu1nEOaSWjTl9mfVqdAS6dLDH7otR4krip4Zk0+aAIJ9nE0 rmnuNEYmxB/T3Tm5IU0RYbpNbErMth65qwejJ1hS8IyGDVWLRAGKyMKJZzkLHbJty7/h kjvCNLfE9fS18ZjH23nCaVurrw2COmwIeAfUY6dz8pzB0fd1UC99QHb89LPsFKwmnLpM dZbRE54WkrjuOXO+1XXGv7yQbELxiGI5+jGWbj2voI4UJ190mPh3brKD0hHZxxV9mikr mXT1CDmr9qwq+7+j9vG660IIB9zRqTX823Jgla5qQhO5KQeofpdnNtaGcupXnlVMht2c c4/Q== X-Gm-Message-State: AAQBX9czlFLUvV4Z5WWI3+PMKiH4da/1baUrBgaHEt4n4aCuLIgydvSt tmA3sYB58OXrHhOe+PFhmcrvskpS0O+k31Mge8w= X-Google-Smtp-Source: AKy350YOTo8tf19RBJ2IrjKHb/eiRPuhy5LL9J7AOlMzaFGmshI1RYrSbavgM9sLb6Dn00zOl6iC/805nG3EYUZ9ojE= X-Received: by 2002:a05:6102:470c:b0:425:87ab:c386 with SMTP id ei12-20020a056102470c00b0042587abc386mr7345480vsb.3.1681191414162; Mon, 10 Apr 2023 22:36:54 -0700 (PDT) MIME-Version: 1.0 References: <20230325105429.1142530-1-richard.henderson@linaro.org> <20230325105429.1142530-26-richard.henderson@linaro.org> In-Reply-To: <20230325105429.1142530-26-richard.henderson@linaro.org> From: Alistair Francis Date: Tue, 11 Apr 2023 15:36:28 +1000 Message-ID: Subject: Re: [PATCH v6 25/25] target/riscv: Reorg sum check in get_physical_address To: Richard Henderson Cc: qemu-devel@nongnu.org, qemu-riscv@nongnu.org, alistair.francis@wdc.com, palmer@dabbelt.com, zhiwei_liu@linux.alibaba.com, fei2.wu@intel.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=2607:f8b0:4864:20::e34; envelope-from=alistair23@gmail.com; helo=mail-vs1-xe34.google.com X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Sat, Mar 25, 2023 at 10:56=E2=80=AFPM Richard Henderson wrote: > > Implement this by adjusting prot, which reduces the set of > checks required. This prevents exec to be set for U pages > in MMUIdx_S_SUM. While it had been technically incorrect, > it did not manifest as a bug, because we will never attempt > to execute from MMUIdx_S_SUM. > > Signed-off-by: Richard Henderson Reviewed-by: Alistair Francis Alistair > --- > target/riscv/cpu_helper.c | 22 +++++++++++----------- > 1 file changed, 11 insertions(+), 11 deletions(-) > > diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c > index 725ca45106..7336d1273b 100644 > --- a/target/riscv/cpu_helper.c > +++ b/target/riscv/cpu_helper.c > @@ -800,7 +800,7 @@ static int get_physical_address(CPURISCVState *env, h= waddr *physical, > *ret_prot =3D 0; > > hwaddr base; > - int levels, ptidxbits, ptesize, vm, sum, widened; > + int levels, ptidxbits, ptesize, vm, widened; > > if (first_stage =3D=3D true) { > if (use_background) { > @@ -831,7 +831,7 @@ static int get_physical_address(CPURISCVState *env, h= waddr *physical, > } > widened =3D 2; > } > - sum =3D mmuidx_sum(mmu_idx); > + > switch (vm) { > case VM_1_10_SV32: > levels =3D 2; ptidxbits =3D 10; ptesize =3D 4; break; > @@ -999,15 +999,15 @@ restart: > prot |=3D PAGE_EXEC; > } > > - if ((pte & PTE_U) && > - ((mode !=3D PRV_U) && (!sum || access_type =3D=3D MMU_INST_FETCH= ))) { > - /* > - * User PTE flags when not U mode and mstatus.SUM is not set, > - * or the access type is an instruction fetch. > - */ > - return TRANSLATE_FAIL; > - } > - if (!(pte & PTE_U) && (mode !=3D PRV_S)) { > + if (pte & PTE_U) { > + if (mode !=3D PRV_U) { > + if (!mmuidx_sum(mmu_idx)) { > + return TRANSLATE_FAIL; > + } > + /* SUM allows only read+write, not execute. */ > + prot &=3D PAGE_READ | PAGE_WRITE; > + } > + } else if (mode !=3D PRV_S) { > /* Supervisor PTE flags when not S mode */ > return TRANSLATE_FAIL; > } > -- > 2.34.1 > >