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 X-Spam-Level: X-Spam-Status: No, score=-7.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 542CEC4320E for ; Thu, 26 Aug 2021 17:23:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3791961058 for ; Thu, 26 Aug 2021 17:23:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243062AbhHZRXx (ORCPT ); Thu, 26 Aug 2021 13:23:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231313AbhHZRXx (ORCPT ); Thu, 26 Aug 2021 13:23:53 -0400 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DB93C061757; Thu, 26 Aug 2021 10:23:05 -0700 (PDT) Received: by mail-pj1-x102c.google.com with SMTP id fz10so2710129pjb.0; Thu, 26 Aug 2021 10:23:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=wH3hjz5Y0Xv45SIfl4mx52bhrdxx31yKbdxzt4w/j8Q=; b=O8img967zJnwZjYSbKm2y9nE2f5NAiup6+YiKzlbxApebuTStRcqBF5n2aNgfUKRoW 5oBh29+jF1/+4A0JMGrT5lxW4UYXxdcKvHXe03zJ+prbWmjl1YWAYy1d/3uc/vgFavbi 25btJb3NiF3ewfDY6f4pUP+66eUnTaiS/At7ripDnE3wBzIIemsVCoE9z92uoREez6Mn pyvJuwPh4/VHcxv66Pi4pOc6A2s1u8SlcbG5TO61JS30jMW3KqLsLajiCXD8eqeOy5SR A/LxxA5omWZ72vQVFtV22PQ2w0r6ApA1FAdnAM1WYrIci0ugb+w8PnkQbUjvPdzeXieH IeIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=wH3hjz5Y0Xv45SIfl4mx52bhrdxx31yKbdxzt4w/j8Q=; b=ewfNSz6CglXkYqpxblhZchqHV88FKO260ZmnBTAnsyeMsv4Vimcm8GTF8WBu8JusYH u7D3hSIFdy1OjF4OPPAxCh+R78wdDi8JCeNY7jlN/7bmiQGybYD+lOn9s2Tr0WFLpbyj LzjsQJmygjfE9TvFwcxUqyoMeuChEM/R04BIvxPh67Bztlhrhd/1TZtrAHeaEDsMAH8V Mb8uPDrt3jTToZA0ONbczVFlw83EUdmHaNO0xO77fBUzrGE8E2mWmXbh7LjvhhpwWvgT 2JzrifmL4VZkLMQbSwTMIVeNSIBPD0g982XQmyaBmhpCmdohvjbggMUYwXxHzW4Qm3Np NsYA== X-Gm-Message-State: AOAM5302qH+/zCuRaqA+VcO2EuL8RZToB3kmCf8yM86Fe93UpjZlFlb9 mietd3BrA7uBpINwa0+6xFdzOn6G7jrFcC6X4e8= X-Google-Smtp-Source: ABdhPJwJOWtbpTIuf1nV9PyAQQEEdDBk4aNy6OueVH9Kqnzqxo1RxNzQPIxgTc4FI2n/4NJ+QBmguIsoZ0wwsVopTTA= X-Received: by 2002:a17:90a:1917:: with SMTP id 23mr4407685pjg.136.1629998585112; Thu, 26 Aug 2021 10:23:05 -0700 (PDT) MIME-Version: 1.0 References: <20210820181201.31490-1-yu-cheng.yu@intel.com> <20210820181201.31490-26-yu-cheng.yu@intel.com> In-Reply-To: From: "H.J. Lu" Date: Thu, 26 Aug 2021 10:22:29 -0700 Message-ID: Subject: Re: [PATCH v29 25/32] x86/cet/shstk: Handle thread shadow stack To: Borislav Petkov Cc: Yu-cheng Yu , "the arch/x86 maintainers" , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , LKML , "open list:DOCUMENTATION" , Linux-MM , linux-arch , Linux API , Arnd Bergmann , Andy Lutomirski , Balbir Singh , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Dave Martin , Weijiang Yang , Pengfei Xu , Haitao Huang , Rick P Edgecombe Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Thu, Aug 26, 2021 at 9:49 AM Borislav Petkov wrote: > > On Fri, Aug 20, 2021 at 11:11:54AM -0700, Yu-cheng Yu wrote: > > diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c > > index 5993aa8db338..7c1ca2476a5e 100644 > > --- a/arch/x86/kernel/shstk.c > > +++ b/arch/x86/kernel/shstk.c > > @@ -75,6 +75,61 @@ int shstk_setup(void) > > return err; > > } > > > > +int shstk_alloc_thread_stack(struct task_struct *tsk, unsigned long clone_flags, > > + unsigned long stack_size) > > +{ > > + struct thread_shstk *shstk = &tsk->thread.shstk; > > + struct cet_user_state *state; > > + unsigned long addr; > > + > > + if (!shstk->size) > > + return 0; > > + > > + /* > > + * Earlier clone() does not pass stack_size. Use RLIMIT_STACK and > > What is "earlier clone()"? clone() doesn't have stack size info which was added to clone3(). > > + * cap to 4 GB. > > + */ > > -- > Regards/Gruss, > Boris. > > https://people.kernel.org/tglx/notes-about-netiquette -- H.J.