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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68000C46CD4 for ; Sat, 30 Dec 2023 02:37:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A971C6B0130; Fri, 29 Dec 2023 21:37:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A46E96B0131; Fri, 29 Dec 2023 21:37:39 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 90E2D6B0132; Fri, 29 Dec 2023 21:37:39 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 7D4836B0130 for ; Fri, 29 Dec 2023 21:37:39 -0500 (EST) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id C41DC14036D for ; Sat, 30 Dec 2023 02:37:38 +0000 (UTC) X-FDA: 81621923796.25.BA3FDCA Received: from mail-qt1-f179.google.com (mail-qt1-f179.google.com [209.85.160.179]) by imf03.hostedemail.com (Postfix) with ESMTP id 338EB20003 for ; Sat, 30 Dec 2023 02:37:36 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=rivosinc-com.20230601.gappssmtp.com header.s=20230601 header.b=KckY8j4G; dmarc=none; spf=pass (imf03.hostedemail.com: domain of debug@rivosinc.com designates 209.85.160.179 as permitted sender) smtp.mailfrom=debug@rivosinc.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1703903856; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Zi7zPeVB3x2mGJ1Nu2v7GBTLEy5HH9AALnbu4XFSRD8=; b=CNba6BprwA22geOS7LeBbrEVN4cse++tlBlMrg6RhcHPD2F1J9Ntsppha89lCo2b5wbUhT aCla4i31JOWE25Sl0PekiGvKX5dUB6WvpY+kuJnFGTkFrTOoM/eGIydT+H6MBJy/tJ56Re ijM3jJgJytU4Y2xTB89Zx36wAOrH93E= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=rivosinc-com.20230601.gappssmtp.com header.s=20230601 header.b=KckY8j4G; dmarc=none; spf=pass (imf03.hostedemail.com: domain of debug@rivosinc.com designates 209.85.160.179 as permitted sender) smtp.mailfrom=debug@rivosinc.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1703903856; a=rsa-sha256; cv=none; b=j3ukneZokZh8vue+FyIrAp4cB75ieBZ93uiB2pu3swZyIWWwQq5cEIwGiHjj5ejmeR9p2s ATP+7FC6S5tgDDNRP2zUR+tX/jzNDm6v0CwPXXUasLTmzJxEedIawFKMvCS+dZgO10tjao G8STfa054Sw/jioyOcF9PQQH8+kzATg= Received: by mail-qt1-f179.google.com with SMTP id d75a77b69052e-427f5cc49afso13078801cf.2 for ; Fri, 29 Dec 2023 18:37:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1703903855; x=1704508655; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=Zi7zPeVB3x2mGJ1Nu2v7GBTLEy5HH9AALnbu4XFSRD8=; b=KckY8j4G3Z+0ifWn5g1lpsXRfVigXYA0dxkLNqqS1dlepcmYYVoMd3eSAUldWojJOS ep1oifWy5Oe/MDmA8yV/+FPAC8vqE50hdXTtVM+VXbkVo41CLa0guWoAY+OK/9ynkZ0g kKZs+WAvbR8PVZqvsex13Z7A5oNn1o82DjLe4YC63ZYPTxVeP8WX0VNwNmvatmRFna5y fD/MscenjSpU6mEVfOKMH7c9HppuSJfEIpfRwaqgfuNZ1fR9x2u7eKWNQLhcpFoQV2YT ZPxuCIJpi3ipp5nrcarT5fAY+In5copGRY6MwSSc8kupNo40kd5DLwlD748ynMfKT6iQ R5RA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1703903855; x=1704508655; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Zi7zPeVB3x2mGJ1Nu2v7GBTLEy5HH9AALnbu4XFSRD8=; b=uEjsvH3VBc0jwUJephKlJYSdH+QrggL6k3nnlasXKfJTiHVw9cCALBLFQeu0aX1iC6 gQw4BhELmDBKdx1WL9zR7NZTMo6oue3RApPpNkTWAM+D4M465yT1AF33nN8G/NenNTws 44HeY3z4EDNyhFw7jcolQaSskBCbVP3TQd+r5KAbnuctaRWXIwpXMuaquaTUyq35SPcX XnhpBbVbWtHdKZmgeKBf8AU67CrGxsft6Abt9sxE3J4kkQqR5h8PzHnpk9fuSAvCVb4M eQLjN/ctNtRxdKibuWObTBL0Q+Hft0zHCfMGkzRGqcuvOPn0ND8ybc/tjNVE9iaukehN FRxw== X-Gm-Message-State: AOJu0YxUOe5EwNj3akiDOLtyVupEVh15qXhAIbYNGb8OfrhF7OphbeCV cEWGPsLvK91Xhx9KwObEkIZAhrZo0LP3sCsPln17Aa7T3CrzU5bNqshxzGn5zE0= X-Google-Smtp-Source: AGHT+IFIZhu7nrGBZ7lGSPHP5/PBJHTcxsM11IKduP4jZ50sNyU/5ZWTHQb4Xxkd/JSjq8K0ZVaiUYv5KetvFgnbmJQ= X-Received: by 2002:a25:d6cc:0:b0:db7:c8b7:3f1d with SMTP id n195-20020a25d6cc000000b00db7c8b73f1dmr7030642ybg.19.1703903451078; Fri, 29 Dec 2023 18:30:51 -0800 (PST) MIME-Version: 1.0 References: <20231222235248.576482-1-debug@rivosinc.com> <20231227134514.13629032c39decdf1dddcc75@linux-foundation.org> <20231227142441.f9a76fa3c8b9b79eea8f93a2@linux-foundation.org> In-Reply-To: <20231227142441.f9a76fa3c8b9b79eea8f93a2@linux-foundation.org> From: Deepak Gupta Date: Fri, 29 Dec 2023 18:30:39 -0800 Message-ID: Subject: Re: [PATCH v1] mm: abstract shadow stack vma behind arch_is_shadow_stack_vma To: Andrew Morton Cc: rick.p.edgecombe@intel.com, broonie@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 338EB20003 X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: zzywdy95ynjxueg4em6g9caeuehim9eh X-HE-Tag: 1703903856-290044 X-HE-Meta: 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 P4ew8Ky7 l5/LqKZo98WvTM+xm64K9HXpnSKBcgXmy08vxruOLd4NOWQJIoowXUYw1GtZNfeyd956tUP9NnDJrh6/rJkObQ8GZjQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000042, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Dec 27, 2023 at 2:24=E2=80=AFPM Andrew Morton wrote: > > On Wed, 27 Dec 2023 14:20:36 -0800 Deepak Gupta wrot= e: > > > On Wed, Dec 27, 2023 at 1:45=E2=80=AFPM Andrew Morton wrote: > > > > > > On Fri, 22 Dec 2023 15:51:04 -0800 Deepak Gupta = wrote: > > > > > > > x86 has used VM_SHADOW_STACK (alias to VM_HIGH_ARCH_5) to encode sh= adow > > > > stack VMA. VM_SHADOW_STACK is thus not possible on 32bit. Some arch= es may > > > > need a way to encode shadow stack on 32bit and 64bit both and they = may > > > > encode this information differently in VMAs. > > > > > > Is such a patch in the pipeline? Otherwise we're making a change tha= t > > > serves no purpose. > > > > Yes I do have patches in the pipeline for riscv. > > On riscv, presence of only `VM_WRITE` (i.e. (flags & (VM_READ | > > VM_WRITE | VM_EXEC)) > > =3D=3D VM_WRITE) would mean a shadow stack. > > And yes there would be relevant patches to ensure that existing consum= ers using > > `PROT_WRITE` gets translated to (VM_WRITE | VM_READ) > > OK, please plan to carry this patch in whatever tree contains the above. > > ACK. Thanks