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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A9D0BEB64DD for ; Fri, 11 Aug 2023 16:38:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=lBNrNEC2WHhpznQxrwjYJh9DgG7/3OqDMNjHf2m24Ic=; b=bYewgkQqgDlpcG MOGWHBAguUI+UsifuxE/brCLRxTGVraTuYfFB+/oHROocOQ6vnhSSaL+ppl9sIpirvgN0YsVb4PaN 6ERaOyot+LuexxCn4tfzHajjsTC+ady4PNmYOeWgr1hj4Ssab2YqVKvr71BsMEvDMMFn03s9nZWo3 c14oW52VheOXKwT6SOx3wTliSKKdw/I6gb6IDJ8vMhhyl+as7q+gRXOwTKq4Q7IaH+OfkD1IwXTPM iZbDq41tJYBhkk4+J82akVwvcc4EUVOaYc1kg3jX1WCBqwpoSZxw8MrY/5KHoe5bdPORkvq7J2Krq Ljl+VHJA6oj1GCs0PHrg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qUV9n-00B8KY-0z; Fri, 11 Aug 2023 16:38:35 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qUV9k-00B8Ix-0K; Fri, 11 Aug 2023 16:38:33 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8EB84676AA; Fri, 11 Aug 2023 16:38:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 73644C433C7; Fri, 11 Aug 2023 16:38:26 +0000 (UTC) Date: Fri, 11 Aug 2023 17:38:24 +0100 From: Catalin Marinas To: Mark Brown Cc: Will Deacon , Jonathan Corbet , Andrew Morton , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Kees Cook , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy , "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: Re: [PATCH v4 21/36] arm64/mm: Implement map_shadow_stack() Message-ID: References: <20230807-arm64-gcs-v4-0-68cfa37f9069@kernel.org> <20230807-arm64-gcs-v4-21-68cfa37f9069@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230807-arm64-gcs-v4-21-68cfa37f9069@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230811_093832_186574_E2A7946B X-CRM114-Status: GOOD ( 13.96 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Mon, Aug 07, 2023 at 11:00:26PM +0100, Mark Brown wrote: > As discussed extensively in the changelog for the addition of this > syscall on x86 ("x86/shstk: Introduce map_shadow_stack syscall") the > existing mmap() and madvise() syscalls do not map entirely well onto the > security requirements for guarded control stacks since they lead to > windows where memory is allocated but not yet protected or stacks which > are not properly and safely initialised. Instead a new syscall > map_shadow_stack() has been defined which allocates and initialises a > shadow stack page. I guess I need to read the x86 discussion after all ;). Given that we won't have an mmap(PROT_SHADOW_STACK), are we going to have restrictions on mprotect()? E.g. it would be useful to reject a PROT_EXEC on the shadow stack. -- Catalin _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv