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 5D235C00140 for ; Fri, 5 Aug 2022 17:44:52 +0000 (UTC) Received: from localhost ([::1]:42154 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oK1NT-00069W-Bv for qemu-devel@archiver.kernel.org; Fri, 05 Aug 2022 13:44:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57166) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oK1LL-0004Up-1n for qemu-devel@nongnu.org; Fri, 05 Aug 2022 13:42:40 -0400 Received: from mail-yw1-x1135.google.com ([2607:f8b0:4864:20::1135]:45701) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1oK1LJ-0006IK-J1 for qemu-devel@nongnu.org; Fri, 05 Aug 2022 13:42:38 -0400 Received: by mail-yw1-x1135.google.com with SMTP id 00721157ae682-3246910dac3so30467427b3.12 for ; Fri, 05 Aug 2022 10:42:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc; bh=ifPtP1I+zKKihh9OhtzGg5JfI69+9uRMUEWS7Qx/Gjk=; b=vpUYsLT08JlKArOlmMRk2P9WZWhrjCiQJgBjl3BtACXq++Bpiqws24PMXJr+/LVACM 2zlsFU6fgLv9xjyCfeaDknyW+wzbO01gPjNxfHEbU2AGWH2+l87GmyEjmHX6Ls2zIFD0 ZfGe8li0t9nsskqrhzqvLU+bfDH2UjeWMDqlESDl2gr9T/NLjYAar8hNdu1JpRTsrag5 EWIv/AVasGNvxir01t3zcEpu+vzwWMpoq9oGJuUIZs5mToQG96/cEjwJgbpCLIQD9Enl U/UOZHC93DH5fRKhhNFRJF57lMhzy84nKz5BA384nrppGy0nJU6kqwJLuDYMrnDhAXTB 3KLw== 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; bh=ifPtP1I+zKKihh9OhtzGg5JfI69+9uRMUEWS7Qx/Gjk=; b=0fH/Z7vgW2UZGlPQQJFgXyVPpv6EV1Nq1QkYBH6Y3It0lkwGbHcIMl8XO91IKWZe4o 5IIDOr+iw4J7ZU7MHo3Eh4jseZ/P4pyfUwmZNYdVfyRsF0e3w+VUwU/TvTMZ7BUpgavh uA9h9eAJfump97x8qbCbMfxCJQBZ2sYGT63YSVjVP1bwjilnGyppybB3N2mKpJ1PWQ1g O/+Xw/WFl/6HUMiXYS39w1AW9ek33xHSVhEfdgli6M1qMg41UE/E6N7H6OAsioaQ5z30 mzVOYV5rA4c23ly2emIzqbVd5KNJjnvywI/9QRS6Re/dIpatX14mxs55be1UPCddu5D3 mAug== X-Gm-Message-State: ACgBeo0cPJFQWlkFOlyBoEZeP4n7GwOXerPJj08JcsF9ja+n025cO/0O dS3CRcKiiVKGl04AdiVU0B/I0BYRYoZL/7gciOarrA== X-Google-Smtp-Source: AA6agR7Rmj8USYGpGbJRsY64gVtgvcrVsevT/4UpSmEpt87773qqFcp6HlZ6N3ctOKUbvhxscw8fbFPjU72SZEJxn+M= X-Received: by 2002:a81:106:0:b0:2d0:e682:8a7a with SMTP id 6-20020a810106000000b002d0e6828a7amr7010938ywb.257.1659721356195; Fri, 05 Aug 2022 10:42:36 -0700 (PDT) MIME-Version: 1.0 References: <20220805160914.1106091-1-iii@linux.ibm.com> <20220805160914.1106091-2-iii@linux.ibm.com> In-Reply-To: <20220805160914.1106091-2-iii@linux.ibm.com> From: Peter Maydell Date: Fri, 5 Aug 2022 18:42:25 +0100 Message-ID: Subject: Re: [PATCH v2 1/4] accel/tcg: Invalidate translations when clearing PAGE_READ To: Ilya Leoshkevich Cc: Laurent Vivier , Eduardo Habkost , Marcel Apfelbaum , =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= , Yanan Wang , Richard Henderson , Paolo Bonzini , David Hildenbrand , qemu-devel@nongnu.org, qemu-s390x@nongnu.org, Christian Borntraeger Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2607:f8b0:4864:20::1135; envelope-from=peter.maydell@linaro.org; helo=mail-yw1-x1135.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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" On Fri, 5 Aug 2022 at 18:33, Ilya Leoshkevich wrote: > > After mprotect(addr, PROT_NONE), addr can still be executed if there > are cached translations. Drop them. > > Signed-off-by: Ilya Leoshkevich > --- > accel/tcg/translate-all.c | 17 ++++++++++++----- > 1 file changed, 12 insertions(+), 5 deletions(-) > > diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c > index ef62a199c7..9318ada6b9 100644 > --- a/accel/tcg/translate-all.c > +++ b/accel/tcg/translate-all.c > @@ -2295,12 +2295,19 @@ void page_set_flags(target_ulong start, target_ulong end, int flags) > len != 0; > len -= TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) { > PageDesc *p = page_find_alloc(addr >> TARGET_PAGE_BITS, 1); > + bool write_set, read_cleared; > > - /* If the write protection bit is set, then we invalidate > - the code inside. */ > - if (!(p->flags & PAGE_WRITE) && > - (flags & PAGE_WRITE) && > - p->first_tb) { > + /* > + * If the write protection bit is set, then we invalidate the code > + * inside. > + */ > + write_set = !(p->flags & PAGE_WRITE) && (flags & PAGE_WRITE); > + /* > + * If PAGE_READ is cleared, we also need to invalidate the code in > + * order to force a fault when trying to run it. > + */ > + read_cleared = (p->flags & PAGE_READ) && !(flags & PAGE_READ); Isn't it architecture-dependent whether you need PAGE_READ to execute code ? How about PAGE_EXEC ? thanks -- PMM