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[2620:137:e000::1:20]) by mx.google.com with ESMTP id eb8-20020a0564020d0800b00442edebe687si3273642edb.633.2022.09.02.17.23.40; Fri, 02 Sep 2022 17:24:35 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20210112 header.b=glSgbFFX; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230438AbiICAQz (ORCPT + 99 others); Fri, 2 Sep 2022 20:16:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47178 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229511AbiICAQx (ORCPT ); Fri, 2 Sep 2022 20:16:53 -0400 Received: from mail-oa1-x30.google.com (mail-oa1-x30.google.com [IPv6:2001:4860:4864:20::30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C948BF2CA5 for ; Fri, 2 Sep 2022 17:16:52 -0700 (PDT) Received: by mail-oa1-x30.google.com with SMTP id 586e51a60fabf-12243fcaa67so8640692fac.8 for ; Fri, 02 Sep 2022 17:16:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date; bh=fBnAcPL60R4i5WvZyiptdvRLsZSLVLLRY1IeHgDEcNY=; b=glSgbFFXvowDD+JhZTH1Wr6MBVWTP8OZk46UaIj+wd1y55JidGWICHZGwkv+c+Lw4d aXu8IN1siiOO/t7uKCVmLkJd2hEvppP/hL0+Tcv4UAaoZUu1cwuqeaLlUgfIx4cwpJ0G oAXc/5U8xQWDPDXNM0619QYM18mv2N2rF1YKMi9XOT+rZxNSfjL8OoeuWm7BeNi44tyQ L5iucehN2mlY7JsTEhLof5GvuFhSzxFkOnRXKKkuwuGlWpjmsZzJfoO0FkWMKyX2Pd5H wKWTbn3Xs+80AD65ruo1EmSeCl3yjo9qMEWIgJIvDopvcJ+03OaniF2tn6mAChQq1wJ2 kK5g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date; bh=fBnAcPL60R4i5WvZyiptdvRLsZSLVLLRY1IeHgDEcNY=; b=l/yh43Z2BganjEXXrf5xJuSV/nCaQs2S9uEmmncVhbljVq4Mc/zd8b/cRk2Qx++egT KeMnunSPSAlo1YhLseifc6BETXgXA27sssVtANaQ9D7aH6CMsE38WH8tPLxuEy7GKMh9 6CO8GknCXoHIdmAXSpfzmVIrUTYBobDqow4uX54S51eDpc1Sqo2mmNtmsX88/+p4duCT l5Rt6upaCf90GaFxa06cUmiVx69zVaTDzLlC4uXyLgk9whflfbw2n/efyZoPDU6Xic10 /Aopz1WyKhE/kiXI+rXi9/5cReqPcUbSK6oDsWkOJEa3hIMd9etjXvE3wiRYauGNn/qz Bv0g== X-Gm-Message-State: ACgBeo11mG3VMhBJITVNXveRe0d7Ejc8pMIxcghwN8ZJHsiOXeSaeDUb HS3Bf24HEfwUyz9Ei9/EjWs= X-Received: by 2002:a05:6808:1441:b0:333:3929:d079 with SMTP id x1-20020a056808144100b003333929d079mr3062871oiv.21.1662164212159; Fri, 02 Sep 2022 17:16:52 -0700 (PDT) Received: from localhost ([104.183.150.195]) by smtp.gmail.com with UTF8SMTPSA id e38-20020a05687023a600b001048f70e03dsm1875121oap.15.2022.09.02.17.16.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 02 Sep 2022 17:16:51 -0700 (PDT) From: Fangfei Yang To: luto@kernel.org Cc: dave.hansen@intel.com, dave.hansen@linux.intel.com, keescook@chromium.org, linux-kernel@vger.kernel.org, sroettger@google.com, x86@kernel.org Subject: Re: PKU usage improvements for threads Date: Fri, 2 Sep 2022 19:16:48 -0500 Message-Id: <20220903001648.17171-1-yangff1@gmail.com> X-Mailer: git-send-email 2.36.0 In-Reply-To: <26078f2a-67be-4aa1-bbb2-dcd1168c9d12@www.fastmail.com> References: <26078f2a-67be-4aa1-bbb2-dcd1168c9d12@www.fastmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > sys_sigaltstack() is already pretty much useless with SHSTK, and it’s kinda busted with AVX512. How about we just add a whole new non-kludgy API? Hi, why is that useless? Signal is not going to change the SSP, all it needs to do is creating a token that can be restored by sigreturn in the future on the current shadow stack. Can you provide some examples about that? Thank you.