From patchwork Mon Jul 31 13:43:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13334719 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 B3D3BC001DE for ; Mon, 31 Jul 2023 13:53:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231501AbjGaNxX (ORCPT ); Mon, 31 Jul 2023 09:53:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231320AbjGaNw0 (ORCPT ); Mon, 31 Jul 2023 09:52:26 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 68D87210A; Mon, 31 Jul 2023 06:51:59 -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 D6EC861158; Mon, 31 Jul 2023 13:51:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91AA8C433C8; Mon, 31 Jul 2023 13:51:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690811518; bh=viG5anxcCcnETy6WTEqLj0O+gpdZleg7ylSYSUDSWcI=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=mSSSKzu/+QPBBakkr45wlX9iKeJxSV3cpcmQLgAc4ESbF/iG02+RnaTU3bQ5T4R1R Kw6LX+osxC9ep54R3iYjYNgQ+6DT6w7VDzmxi98o2AEGXQOppTzll2hpPv3eBxu/B2 rwMAkkj7K0zr+kT0apzE2k+Tue7Fgxe5UejX54nFqsn7yoFZPLCZJCkxh1wT6qRBxg wdoK63KoGSo5kBnLWsJAnOBxxKxS7UmF+wY79mBh/GPrFVaCENDT4L5MC8AbRw+wNf MQMBzeYPtbwAUNwOXLFT1KOQnCTxZve755M5cURARwYJUkYgPsMg/IE/rbeDS9hkit 7twM1r/XoxEag== From: Mark Brown Date: Mon, 31 Jul 2023 14:43:20 +0100 Subject: [PATCH v3 11/36] arm64/mm: Map pages for guarded control stack MIME-Version: 1.0 Message-Id: <20230731-arm64-gcs-v3-11-cddf9f980d98@kernel.org> References: <20230731-arm64-gcs-v3-0-cddf9f980d98@kernel.org> In-Reply-To: <20230731-arm64-gcs-v3-0-cddf9f980d98@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/pANAwAKASTWi3JdVIfQAcsmYgBkx7wcNNzB4eHbwePmvMbzyb2eKoUsPKpySJhqxMYO VO/4ZKaJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZMe8HAAKCRAk1otyXVSH0E3bB/ 9kkSCSHClFMS8SVmSHhi/kdEidEpwq32cAUbFcwXkdeJjv/CrJsT5T8aku4YfmN1sY57bMYWiOFJCR rFY9qUYZhNPKyVK111nZII+nZtmV4F3UkxDrfeEkNH6xkOECetiv67QQOmgxwuMd6Mql/p94935ORh jgjiwaG54dImasHCJz8MxPQKdfrNGJHycnUS11u+lW7Vy0+tdh6Q90ATBtt0mrn8zi11TrpPzLB6lQ zhmwTiknW/gyPJFn9WIj1tzw3E3areua+5W8q1LF2N58SVUiovl4RgsSDgWKBCRuV7TMOgnVg8piHU Q4ZHM9VIPmML5AZAJsLnLlvAfvCar1 X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@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;