From patchwork Mon Aug 7 22:00:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13345109 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 855B4C001DF for ; Mon, 7 Aug 2023 22:04:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231159AbjHGWEC (ORCPT ); Mon, 7 Aug 2023 18:04:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230516AbjHGWD1 (ORCPT ); Mon, 7 Aug 2023 18:03:27 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 77F75131; Mon, 7 Aug 2023 15:02:40 -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 1019A622A9; Mon, 7 Aug 2023 22:02:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B665AC433CB; Mon, 7 Aug 2023 22:02:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691445759; bh=aGB9MytFbopKILsUP0kPuxTbIpt9GJuR7uXvXLP6vLo=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=B7+8io7JEg/LIWoZNhiKlYaOzexSqBArV056/ScJvMpxGs2kYB4Okzkzol5kScHYE 55HMmJFzcyF8LtgXCBJKWR7eLCptLh/oMa3OwoCIW/lmiSswqdleH9vkIljQqqI1NG HLehvcCG393fnl1siFCS/s7UzNZzDQUk8j/IEVppVkDJ+oI6SfDcO/ioLRso4uqmWd 0nFYrpM45VWM6oql/4rbBGH9Bwejm80beYj84++Sz29XVXXPZ08K9bNizQdES4ri9s TnarJsT6SfHg4wd1fb/cH2kV7WdxLpv3PjSjRekkZcxhPwSttByrH0KzubjmRIB62N obTS3NSXeRxEw== From: Mark Brown Date: Mon, 07 Aug 2023 23:00:16 +0100 Subject: [PATCH v4 11/36] arm64/mm: Map pages for guarded control stack MIME-Version: 1.0 Message-Id: <20230807-arm64-gcs-v4-11-68cfa37f9069@kernel.org> References: <20230807-arm64-gcs-v4-0-68cfa37f9069@kernel.org> In-Reply-To: <20230807-arm64-gcs-v4-0-68cfa37f9069@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-034f2 X-Developer-Signature: v=1; a=openpgp-sha256; l=1124; i=broonie@kernel.org; h=from:subject:message-id; bh=aGB9MytFbopKILsUP0kPuxTbIpt9GJuR7uXvXLP6vLo=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBk0WmgYE5sTjIW0s7MSSUHBmNdoL8mADFajoHMlxxa sLCcTiKJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZNFpoAAKCRAk1otyXVSH0CQmB/ 4hCrLHpUMmcfdaL24W2A5mDkcuuBM88bAHrKma9GqNW27peedUqdX7QojJVVcc8Pti+JDlRJQlF6eA QZEKYM3bKTE3mosdO+93NlHTPGn7gi26Pt1S42K8kRxwwm3mJo1gL/HQE1ao9d0KZg9o9LHWjR9UsG hAoZdZeodWYeIhnbOvuyIXIfGKTlRPnEOtzr//cVzV6vxPF3kggLcSNXBGXhBYJxComChKV/1oWfxG tHKcsX37YMulc8njZNNNcc7c79OcVYO4TFDHmUNkosm8ee1zIH4H+rIteZ0Pyhx3nAnQLUDe23kVjg n0K3NwP/ZpHSz6lX1gqzfW1nyN7hWy 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 | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index 8f5b7ce857ed..8f40198cd44e 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -79,8 +79,18 @@ 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. */ + 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;