From patchwork Sun Jul 16 21:51:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 703928 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C1FBEB64DD for ; Sun, 16 Jul 2023 21:55:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231146AbjGPVzT (ORCPT ); Sun, 16 Jul 2023 17:55:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230339AbjGPVyq (ORCPT ); Sun, 16 Jul 2023 17:54:46 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CDE57199C; Sun, 16 Jul 2023 14:54:04 -0700 (PDT) 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 AE18060ECD; Sun, 16 Jul 2023 21:54:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A8C6C433D9; Sun, 16 Jul 2023 21:53:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1689544444; bh=viG5anxcCcnETy6WTEqLj0O+gpdZleg7ylSYSUDSWcI=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=SwCpkJ/re/3QSPdOxaSvPmTUXqWyUYkc1452Z6mBhqiKzmB5dXQ/cYeSPFblePc64 8UJ+5qbsQHPqRV7eXlUH7stZtlnPKB7kI/LWN+cxruPahvww4EdxtsoO+sI/tTn0EQ qdNtuuJbES2trN5efTE+qv0nM1D/yG/Mim3jkmKJBLAwtXhWWtlmWthlc0A6bh9gXk 1C90UGVaHBe+F4P9Vy1v1jg6i6o58elJ5GmZlNCIB7YvkT5iri0JFOIA4f+OSbnjdJ 0x5z42vjeE3UCul3EOX6ZIBcyARUKPaIH7UVQriq9uQIjqWyf47XOUcN6EnZKBxx/p gjk/S9RqX2LpA== From: Mark Brown Date: Sun, 16 Jul 2023 22:51:08 +0100 Subject: [PATCH 12/35] arm64/mm: Map pages for guarded control stack MIME-Version: 1.0 Message-Id: <20230716-arm64-gcs-v1-12-bf567f93bba6@kernel.org> References: <20230716-arm64-gcs-v1-0-bf567f93bba6@kernel.org> In-Reply-To: <20230716-arm64-gcs-v1-0-bf567f93bba6@kernel.org> To: Catalin Marinas , 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 Cc: "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, Mark Brown X-Mailer: b4 0.13-dev-099c9 X-Developer-Signature: v=1; a=openpgp-sha256; l=1225; i=broonie@kernel.org; h=from:subject:message-id; bh=viG5anxcCcnETy6WTEqLj0O+gpdZleg7ylSYSUDSWcI=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBktGaYY8P9SxztwbReqsOD4EXSgrju2yjwCdYsxO7X ObL/CRyJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZLRmmAAKCRAk1otyXVSH0CFjB/ wITNeqHx2A9A/AJ1DNYpxUDzTwZ9+T8pd3XOVneuYwaTzi2MZZye6tNiKR7wiNv5QIUneXtkSg4tPn zzsu4E2T4EZd/99PiJr0CIU7iav1s9FW8s4SW7VitRAsaErFQQp+sBM6u7MnHrNS3iH+u4UBvtt9sl CKKObd7jfjgeFS+kmjiFsZSP9GjUQBkPW9DjXWJ8XNw7DkEK5KnmRY5yS5djZpGtZ7CGCkktenGhaQ 5DQjV/3Lb+1ksoB7g/SRlkIZCrnv5us2Evkh/UXqNufRoWbsJa4du5YWevpf0T/TfT1TXYEmXm+NJ6 PpE6d0otsGkuF72xIz5WxGxqAtuw7y X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Map pages flagged as being part of a GCS as such rather than using the full set of generic VM flags. This is done using a conditional rather than extending the size of protection_map since that would make for a very sparse array. Signed-off-by: Mark Brown --- arch/arm64/mm/mmap.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index 8f5b7ce857ed..e2ca770920ed 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -79,8 +79,23 @@ arch_initcall(adjust_protection_map); pgprot_t vm_get_page_prot(unsigned long vm_flags) { - pteval_t prot = pgprot_val(protection_map[vm_flags & + pteval_t prot; + + /* + * If this is a GCS then only interpret VM_WRITE. + * + * TODO: Just make protection_map[] bigger? Nothing seems + * ideal here. + */ + if (system_supports_gcs() && (vm_flags & VM_SHADOW_STACK)) { + if (vm_flags & VM_WRITE) + prot = _PAGE_GCS; + else + prot = _PAGE_GCS_RO; + } else { + prot = pgprot_val(protection_map[vm_flags & (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]); + } if (vm_flags & VM_ARM64_BTI) prot |= PTE_GP;