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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2A38C433F5 for ; Tue, 5 Oct 2021 15:19:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A188A61506 for ; Tue, 5 Oct 2021 15:19:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235541AbhJEPVA (ORCPT ); Tue, 5 Oct 2021 11:21:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57224 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229488AbhJEPU6 (ORCPT ); Tue, 5 Oct 2021 11:20:58 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EAAC9C061749 for ; Tue, 5 Oct 2021 08:19:07 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1633447145; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=F0jteui4C6o0n+swDYTpF6sOj/mmEYS1bk4mq9FjiP4=; b=DeUb9vQkV0wiNp495ETKeWOcKBMgsVqpWPJzT9DjdZXjWhYTT1NuI6wX5zuRdSVVkPZcD6 vahBakH5S/DndLIPfTDbDkEvyRwj305Uvt44uT32CPVAtJFm+ECJO1YDGA8hRKK8cgOkMs XjdLT65kf7IYrKEHG0sDkXdLoWwofKZbowZeqCONfqd3hCqH4BRbWSlN2HRkD6WYk0+wnc e6MCTOrW28hk51oS8Ld/EiSBbzyddo1vH5ZO9lkrHKmGNhbr+7laFVHk2N2ohvtoCmU7cn eRfLwESRSRIu9QeQ82RkNPjVUvJ8g7l/UiD2sGsIDoR+uyi6V/AUPKevzf08pw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1633447145; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=F0jteui4C6o0n+swDYTpF6sOj/mmEYS1bk4mq9FjiP4=; b=CjNa9TDULa5Nb1xmArNOlDqsBkhq6px6YRQX+tyjs3PDcPsONW8G/pd9MBejSa/enhgihl yW+3ERdzphUdkzAw== To: "Chang S. Bae" , bp@suse.de, luto@kernel.org, mingo@kernel.org, x86@kernel.org Cc: len.brown@intel.com, lenb@kernel.org, dave.hansen@intel.com, thiago.macieira@intel.com, jing2.liu@intel.com, ravi.v.shankar@intel.com, linux-kernel@vger.kernel.org, chang.seok.bae@intel.com Subject: Re: [PATCH v11 16/29] x86/fpu/xstate: Support both legacy and expanded signal XSTATE size In-Reply-To: <20211001223728.9309-17-chang.seok.bae@intel.com> References: <20211001223728.9309-1-chang.seok.bae@intel.com> <20211001223728.9309-17-chang.seok.bae@intel.com> Date: Tue, 05 Oct 2021 17:19:04 +0200 Message-ID: <87zgrnebyv.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 01 2021 at 15:37, Chang S. Bae wrote: > @@ -1252,6 +1267,13 @@ long do_arch_prctl_state(struct task_struct *tsk, int option, unsigned long arg2 > if (!state_perm) > return 0; > > + /* > + * Disallow when sigaltstack is not enough for the > + * AT_MINSIGSTKSZ value. > + */ > + if (tsk->sas_ss_size > 0 && tsk->sas_ss_size < get_sigframe_size()) > + return -EPERM; This is not enough: T1 sigaltstack(minsize) ... T2 libinit() prctl(....) --> success enable_amx() libfunc() if (amx_enabled()) AMXINSN -->#NM --> success handle_signal() die(because altstack too small); Thanks, tglx