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[2620:137:e000::3:1]) by mx.google.com with ESMTPS id a34-20020a056a001d2200b0068fb4842092si9981435pfx.183.2023.10.10.10.52.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 10 Oct 2023 10:52:24 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:1 as permitted sender) client-ip=2620:137:e000::3:1; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=VupZYlx2; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:1 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by morse.vger.email (Postfix) with ESMTP id 233A3826EB47; Tue, 10 Oct 2023 10:52:22 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at morse.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234041AbjJJRwP (ORCPT + 99 others); Tue, 10 Oct 2023 13:52:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233993AbjJJRwN (ORCPT ); Tue, 10 Oct 2023 13:52:13 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0AA0A94 for ; Tue, 10 Oct 2023 10:52:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=CDFnZc21Ozvf7XO4JeN+a4VGrAwW58tlsLbHLVG80K0=; b=VupZYlx2yVrvQieDO2CGUkUpWw IZFTPEzjZkVZiRWtl4V+gLlfAMAnU9oard2MPfFOQ9wRbqLHbvt0eDQVIzBX05THcy+DmBeoOgMBT X3VRNWDfbHact6Meorvsj0CXSpoNO5XaX8pgd8gKkZbcF6AdEF+HQ+zhkn6xckPQZz7JjRlQtEwjd d+ZQe8ppLuVxoYayAyOXOMQNGUv5JgD4doypWy28Bz/XAXoGUq9ExHE7BFJOVBBEFTAX3Qz/D2V80 OrqImwp5yvqexxjmP6iB0MhqGnBnKjmNSY5XoSKB4OJDEOvb5U9dOLsr4dOXN7FXbxtCWlPTgEhNE ATiyo3Kw==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1qqGtr-005zJx-Ql; Tue, 10 Oct 2023 17:52:08 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 7FC20300392; Tue, 10 Oct 2023 19:52:07 +0200 (CEST) Date: Tue, 10 Oct 2023 19:52:07 +0200 From: Peter Zijlstra To: David Kaplan Cc: x86@kernel.org, luto@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] Ensure default return thunk isn't used at runtime Message-ID: <20231010175207.GH14330@noisy.programming.kicks-ass.net> References: <20231010171020.462211-1-david.kaplan@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231010171020.462211-1-david.kaplan@amd.com> X-Spam-Status: No, score=2.7 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_SBL_CSS,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on morse.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (morse.vger.email [0.0.0.0]); Tue, 10 Oct 2023 10:52:22 -0700 (PDT) X-Spam-Level: ** On Tue, Oct 10, 2023 at 12:10:17PM -0500, David Kaplan wrote: > David Kaplan (3): > Revert "x86/retpoline: Remove .text..__x86.return_thunk section" > x86/vdso: Run objtool on vdso32-setup > x86/retpoline: Ensure default return thunk isn't used at runtime > > arch/x86/entry/vdso/Makefile | 3 ++- > arch/x86/kernel/vmlinux.lds.S | 3 +++ > arch/x86/lib/retpoline.S | 10 +++++++--- > 3 files changed, 12 insertions(+), 4 deletions(-) Acked-by: Peter Zijlstra (Intel) That said, I'm afraid we might have broken rethunk for i386 somewhere along the SRSO series. I suspect the easiest fix is to make CONFIG_RETHUNK hard depend on x86_64 or something.