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 96E55CD6E55 for ; Mon, 1 Jun 2026 17:11:08 +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:MIME-Version:Message-ID:Date:References :In-Reply-To:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=IAaXVPjy0korAI/yTPPow8vUsNaua/iwIMe3KRhTkJc=; b=ToDi+iBvVpEz4m pHxn38YEFvNAbK2G3WSJMU0Gug1fxGT9mcUBEQbw1B5/w6P5OKG6j4qC/X6wn1z9OdXaqhrefSISB soTtgWsP2EQ52b8myEIvBT7Y6Tqt/4zZIwYdQVsRc7Wu+HNXmFKCPNFdOZOMTtq/LqxOMMq8aK10X KvBzKlCDh9FlbIzSvQm7eS+RY2wx+GceIMuOxTiykMQr/z5nW0ftE357Y8RI29+ti5dwMfEfn73oT Ycj1N3CumLmUYZSHIAoWXAhAnqJFILhMmWhM+7xNkwQBSd9+zN3Xdu5ZWxiHxX9waSkxSnAdMpdTV gkfwFRndh8b3CwtEbyqg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wU6AB-0000000BYe1-12ua; Mon, 01 Jun 2026 17:10:55 +0000 Received: from mail-out.m-online.net ([212.18.0.9]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wU6A8-0000000BYdM-09Vs for linux-riscv@lists.infradead.org; Mon, 01 Jun 2026 17:10:54 +0000 Received: from mail-out.m-online.net (mail-out.m-online.net [212.18.0.9]) by mail-out.m-online.net (Postfix) with ESMTP id 4gTgTK1XXDz1r5ht; Mon, 1 Jun 2026 19:10:45 +0200 (CEST) Received: from frontend03.mail.m-online.net (unknown [192.168.6.182]) by mail-out.m-online.net (Postfix) with ESMTP id 4gTgTC7201z1r5hh; Mon, 1 Jun 2026 19:10:39 +0200 (CEST) Received: from localhost (dynscan3.mnet-online.de [192.168.6.87]) by mail.m-online.net (Postfix) with ESMTP id 4gTgTC1bfWz1qqlT; Mon, 1 Jun 2026 19:10:39 +0200 (CEST) X-Virus-Scanned: amavis at mnet-online.de Received: from mail.mnet-online.de ([192.168.6.182]) by localhost (dynscan3.mail.m-online.net [192.168.6.87]) (amavis, port 10024) with ESMTP id Vz4wsk_EBIwO; Mon, 1 Jun 2026 19:10:37 +0200 (CEST) X-Auth-Info: 5KwVlaw+khWHn6gx4eE0zoJA0qIH7ypG7QdiocwwDCnNkXIZNIRcKtK9irFsGuR+ Received: from igel.home (aftr-82-135-83-133.dynamic.mnet-online.de [82.135.83.133]) (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 mail.mnet-online.de (Postfix) with ESMTPSA; Mon, 1 Jun 2026 19:10:37 +0200 (CEST) Received: by igel.home (Postfix, from userid 1000) id C844A2C16DB; Mon, 1 Jun 2026 19:10:36 +0200 (CEST) From: Andreas Schwab To: Deepak Gupta Cc: Deepak Gupta via B4 Relay , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Lorenzo Stoakes , Paul Walmsley , Palmer Dabbelt , Albert Ou , Conor Dooley , Rob Herring , Krzysztof Kozlowski , Arnd Bergmann , Christian Brauner , Peter Zijlstra , Oleg Nesterov , Eric Biederman , Kees Cook , Jonathan Corbet , Shuah Khan , Jann Horn , Conor Dooley , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?Q?Bj=C3=B6?= =?utf-8?Q?rn?= Roy Baron , Andreas Hindborg , Alice Ryhl , Trevor Gross , Benno Lossin , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, alistair.francis@wdc.com, richard.henderson@linaro.org, jim.shu@sifive.com, andybnac@gmail.com, kito.cheng@sifive.com, charlie@rivosinc.com, atishp@rivosinc.com, evan@rivosinc.com, cleger@rivosinc.com, alexghiti@rivosinc.com, samitolvanen@google.com, broonie@kernel.org, rick.p.edgecombe@intel.com, rust-for-linux@vger.kernel.org, Zong Li Subject: Re: [PATCH v23 06/28] riscv/mm : ensure PROT_WRITE leads to VM_READ | VM_WRITE In-Reply-To: (Deepak Gupta's message of "Mon, 1 Jun 2026 09:22:17 -0700") References: <20251112-v5_user_cfi_series-v23-0-b55691eacf4f@rivosinc.com> <20251112-v5_user_cfi_series-v23-6-b55691eacf4f@rivosinc.com> <87jyslndo4.fsf@igel.home> <875x44o9hj.fsf@igel.home> Date: Mon, 01 Jun 2026 19:10:36 +0200 Message-ID: <871peqgp9v.fsf@igel.home> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260601_101052_366874_531C141E X-CRM114-Status: GOOD ( 11.71 ) 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 Jun 01 2026, Deepak Gupta wrote: > This was settled when x86 introduced shadow stack. Instead of having > new `PROT_`, it was agreed to create a new syscall for mapping shadow > stack memory (syscall: `map_shadow_stack`). Scenarios like `clone3` or > co-routines required manufacturing a shadow stack, thus necessitating a > new mechanism to create shadow stack style memory in demand. Instead > of having a new PROT_ flag, a new syscall was created. So what prevents riscv from making use of VM_SHADOW_STACK similar as x86, without the user visible effects? -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 "And now for something completely different." _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv