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 X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9FDE1C43381 for ; Mon, 11 Jan 2021 13:41:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 75F5D22211 for ; Mon, 11 Jan 2021 13:41:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387556AbhAKNk6 (ORCPT ); Mon, 11 Jan 2021 08:40:58 -0500 Received: from mail.kernel.org ([198.145.29.99]:47014 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733114AbhAKNkA (ORCPT ); Mon, 11 Jan 2021 08:40:00 -0500 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 41B0F223E8; Mon, 11 Jan 2021 13:38:55 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1kyxFN-006gPD-G1; Mon, 11 Jan 2021 13:28:37 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Mark Rutland , David Brazdil , Alexandru Elisei , Ard Biesheuvel , Jing Zhang , Ajay Patil , Prasad Sodagudi , Srinivas Ramana , James Morse , Julien Thierry , Suzuki K Poulose , kernel-team@android.com Subject: [PATCH v3 21/21] arm64: cpufeatures: Allow disabling of Pointer Auth from the command-line Date: Mon, 11 Jan 2021 13:28:11 +0000 Message-Id: <20210111132811.2455113-22-maz@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210111132811.2455113-1-maz@kernel.org> References: <20210111132811.2455113-1-maz@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, dbrazdil@google.com, alexandru.elisei@arm.com, ardb@kernel.org, jingzhangos@google.com, pajay@qti.qualcomm.com, psodagud@codeaurora.org, sramana@codeaurora.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In order to be able to disable Pointer Authentication at runtime, whether it is for testing purposes, or to work around HW issues, let's add support for overriding the ID_AA64ISAR1_EL1.{GPI,GPA,API,APA} fields. This is further mapped on the arm64.nopauth command-line alias. Signed-off-by: Marc Zyngier --- Documentation/admin-guide/kernel-parameters.txt | 3 +++ arch/arm64/include/asm/cpufeature.h | 2 ++ arch/arm64/kernel/cpufeature.c | 5 ++++- arch/arm64/kernel/idreg-override.c | 17 +++++++++++++++++ 4 files changed, 26 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 7599fd0f1ad7..f9cb28a39bd0 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -376,6 +376,9 @@ arm64.nobti [ARM64] Unconditionally disable Branch Target Identification support + arm64.nopauth [ARM64] Unconditionally disable Pointer Authentication + support + ataflop= [HW,M68k] atarimouse= [HW,MOUSE] Atari Mouse diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index d3e0f6dd43c4..9d8dcf380ad5 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -818,6 +818,8 @@ extern u64 id_aa64mmfr1_val; extern u64 id_aa64mmfr1_mask; extern u64 id_aa64pfr1_val; extern u64 id_aa64pfr1_mask; +extern u64 id_aa64isar1_val; +extern u64 id_aa64isar1_mask; u32 get_kvm_ipa_limit(void); void dump_cpu_features(void); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 48dc0333bb4b..894af60b9669 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -559,6 +559,8 @@ u64 id_aa64mmfr1_val; u64 id_aa64mmfr1_mask; u64 id_aa64pfr1_val; u64 id_aa64pfr1_mask; +u64 id_aa64isar1_val; +u64 id_aa64isar1_mask; static const struct __ftr_reg_entry { u32 sys_id; @@ -604,7 +606,8 @@ static const struct __ftr_reg_entry { /* Op1 = 0, CRn = 0, CRm = 6 */ ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0), - ARM64_FTR_REG(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1), + ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1, + &id_aa64isar1_val, &id_aa64isar1_mask), /* Op1 = 0, CRn = 0, CRm = 7 */ ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0), diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c index a9e3ed193fd4..7037c9b214d0 100644 --- a/arch/arm64/kernel/idreg-override.c +++ b/arch/arm64/kernel/idreg-override.c @@ -43,6 +43,19 @@ static const struct reg_desc pfr1 __initdata = { }, }; +static const struct reg_desc isar1 __initdata = { + .name = "id_aa64isar1", + .val = &id_aa64isar1_val, + .mask = &id_aa64isar1_mask, + .fields = { + { "gpi", ID_AA64ISAR1_GPI_SHIFT }, + { "gpa", ID_AA64ISAR1_GPA_SHIFT }, + { "api", ID_AA64ISAR1_API_SHIFT }, + { "apa", ID_AA64ISAR1_APA_SHIFT }, + {} + }, +}; + extern u64 kaslr_feature_val; extern u64 kaslr_feature_mask; @@ -61,6 +74,7 @@ static const struct reg_desc kaslr __initdata = { static const struct reg_desc * const regs[] __initdata = { &mmfr1, &pfr1, + &isar1, &kaslr, }; @@ -71,6 +85,9 @@ static const struct { { "kvm-arm.mode=nvhe", "id_aa64mmfr1.vh=0" }, { "kvm-arm.mode=protected", "id_aa64mmfr1.vh=0" }, { "arm64.nobti", "id_aa64pfr1.bt=0" }, + { "arm64.nopauth", + "id_aa64isar1.gpi=0 id_aa64isar1.gpa=0 " + "id_aa64isar1.api=0 id_aa64isar1.apa=0" }, { "nokaslr", "kaslr.disabled=1" }, }; -- 2.29.2