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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2FBADC7EE23 for ; Wed, 31 May 2023 23:02:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230389AbjEaXCp (ORCPT ); Wed, 31 May 2023 19:02:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230213AbjEaXCn (ORCPT ); Wed, 31 May 2023 19:02:43 -0400 Received: from mail-yb1-xb2b.google.com (mail-yb1-xb2b.google.com [IPv6:2607:f8b0:4864:20::b2b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E363E13E for ; Wed, 31 May 2023 16:02:38 -0700 (PDT) Received: by mail-yb1-xb2b.google.com with SMTP id 3f1490d57ef6-bb167972cffso180910276.1 for ; Wed, 31 May 2023 16:02:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1685574158; x=1688166158; 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=0nzIRRbGx22h7W4dzVmFren/95lkctbr3Uctdnt7nnU=; b=WmPDmQ1h0qMnUeHvgUMsjpTh6VPEpTtOoNQ11MIJWu8Yqw0fd3oAGLpJdpSMotScGS spn0YANEwG/lKK1g4Gi1omZBv815jXYv6S6kCYbkEuBs2j/MYKV3FUNEHcvO7f+QbHQM Z8eo/LSR+Uy2F4fCrZWf5thKAUw2VrOtPnSl4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685574158; x=1688166158; 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=0nzIRRbGx22h7W4dzVmFren/95lkctbr3Uctdnt7nnU=; b=CS78jpKWIfZyL91HVzKnSIlDIu1G3SJbk9xutJH+5NlRrhCplwJjUZ1hfAKQJwPrYX pTXsniOf7ODSlxa5h8iUvWVRnPi69UqBcFeqEaioSSKhWbL6TAsqlkjfNYSwzN0rzVoH 7oJ6vv7XjOXBjjA5BSw7Rpxby0dqJlAyFH+yitOpz9kAAl4BksyxyO1zDCl/FsebUya+ whS39lCCOFRQcWbDXXYp84kUJHFjqZP1lWwAQMNFK97SgP2+8e4XdeVcpVVj+OdCbYf2 A9hkElyQnm4P9wf3feM4yoM4TY1r3VM0tbSKUHUt6/BGlMB1I2GOhZvRbORkAHUIPJyS uSUw== X-Gm-Message-State: AC+VfDzDVyaTUBGMsFd+Vw0C1DWwVH5GUnxis2kkeXal0DMMiQkVLjI/ /+S5KEXZZr5NzvDxtlcpjbbMrGVtaKxuidnPYPKvZw== X-Google-Smtp-Source: ACHHUZ5hYf4p5U4e13Z1TleOH6isd0dp1HozTXSttchtojblNVlRPE54CQdz6YsI5G/k0FTvb1SR8akrNc+ZPON09N4= X-Received: by 2002:a25:7303:0:b0:bab:ab4a:83e0 with SMTP id o3-20020a257303000000b00babab4a83e0mr7718310ybc.26.1685574158132; Wed, 31 May 2023 16:02:38 -0700 (PDT) MIME-Version: 1.0 References: <20230515130553.2311248-1-jeffxu@chromium.org> <2bcffc9f-9244-0362-2da9-ece230055320@intel.com> <2b14036e-aed8-4212-bc0f-51ec4fe5a5c1@intel.com> In-Reply-To: <2b14036e-aed8-4212-bc0f-51ec4fe5a5c1@intel.com> From: Jeff Xu Date: Wed, 31 May 2023 16:02:00 -0700 Message-ID: Subject: Re: [PATCH 0/6] Memory Mapping (VMA) protection using PKU - set 1 To: Dave Hansen Cc: Jeff Xu , =?UTF-8?Q?Stephen_R=C3=B6ttger?= , luto@kernel.org, jorgelo@chromium.org, keescook@chromium.org, groeck@chromium.org, jannh@google.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-hardening@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Dave, Regarding siglongjmp: On Thu, May 18, 2023 at 8:37=E2=80=AFAM Dave Hansen = wrote: > > On 5/17/23 16:48, Jeff Xu wrote: > > However, there are a few challenges I have not yet worked through. > > First, the code needs to track when the first signaling entry occurs > > (saving the PKRU register to the thread struct) and when it is last > > returned (restoring the PKRU register from the thread struct). > > Would tracking signal "depth" work in the face of things like siglongjmp? > siglongjmp is interesting, thanks for bringing this up. With siglongjmp, the thread doesn't go back to the place where signal is raised, indeed, this idea of tracking the first signaling entry doesn't work well with siglongjmp. Thanks for your insight! -Jeff -Jeff