From patchwork Mon Jan 16 16:04:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13103458 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 EC4A9C46467 for ; Mon, 16 Jan 2023 16:11:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232712AbjAPQLj (ORCPT ); Mon, 16 Jan 2023 11:11:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232064AbjAPQKp (ORCPT ); Mon, 16 Jan 2023 11:10:45 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5BE0125E0C; Mon, 16 Jan 2023 08:06:59 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 304CA61047; Mon, 16 Jan 2023 16:06:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1208AC433EF; Mon, 16 Jan 2023 16:06:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673885218; bh=2YOBVimbOAlOwnAm7tznf/cjypJqXMfRlXBaYMPdFhs=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=rmwA/Dz6Ko5s/az79B6zLle6sjfyZSz+LKEr6yff8kKzseqLBwNsX/JKosES3O8LU +fIgR/RgfXKXjdGLFdTttTMeA0PVtZSK3SQYJ/nSi8aXcCD/gTy/C2isH0T9VWg9Q5 q+Pp/rCHDPVmcyA2rTW4/qwsUMajRBCQiA49kY/g0qp2RF5Ms0bHZnR1a0KSnIYsFO UTYkqEaMTlm8DNrCoQld307vdHPWdiN7u0AQzFjxfr6mPTO/vvMP63DYSqoePoajZ3 ev1hUlFePdgqz5we9LpUsv5lTAK3FBS6FMfFvhR4QM32rzVgfdGAOFjJVyxvztHQLw OHepKg4zpAWYQ== From: Mark Brown Date: Mon, 16 Jan 2023 16:04:47 +0000 Subject: [PATCH v4 12/21] arm64/sme: Implement ZT0 ptrace support MIME-Version: 1.0 Message-Id: <20221208-arm64-sme2-v4-12-f2fa0aef982f@kernel.org> References: <20221208-arm64-sme2-v4-0-f2fa0aef982f@kernel.org> In-Reply-To: <20221208-arm64-sme2-v4-0-f2fa0aef982f@kernel.org> To: Catalin Marinas , Will Deacon , Oleg Nesterov , Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Oliver Upton , Shuah Khan Cc: Alan Hayward , Luis Machado , Szabolcs Nagy , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-kselftest@vger.kernel.org, Mark Brown X-Mailer: b4 0.12-dev-77e06 X-Developer-Signature: v=1; a=openpgp-sha256; l=3356; i=broonie@kernel.org; h=from:subject:message-id; bh=2YOBVimbOAlOwnAm7tznf/cjypJqXMfRlXBaYMPdFhs=; b=owEBbAGT/pANAwAKASTWi3JdVIfQAcsmYgBjxXWrQeAvoNt06cDlcz7hwVhWkcIVPp7m1c5ALsop f3C1VwGJATIEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCY8V1qwAKCRAk1otyXVSH0CYpB/ iYSEkOo7kBOAWrbmjoRgVVylYXKpICQBnTz9f1THWnrvVrG/qSP9kGauq1IInee6HGCBGdk/CJHXH5 jJ1XHH1LMgJaDe9c+9mDcs0igB3HqQF7FYLhicOB5B+ZGu0j/3pvwQy/s+AvKjXyPXVT+03tNhRfDA 4moMysf92DT8NiH8EaqRHsFbwIOxoxK6Sn/0EcBia03j8trQ/unC16xn35bjDzHey2OuGdQz4OjjrH YHkBixcPCNqQqFe/JOdIYeu042iz0l4XLs1OspQTJp9AKhvbIksayOUdg+g89QjbFq/QzH/ZXAIckf NU1i0rHhTDTfFpEoX726an0Pyv71Y= X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Implement support for a new note type NT_ARM64_ZT providing access to ZT0 when implemented. Since ZT0 is a register with constant size this is much simpler than for other SME state. As ZT0 is only accessible when PSTATE.ZA is set writes to ZT0 cause PSTATE.ZA to be set, the main alternative would be to return -EBUSY in this case but this seemed more constructive. Practical users are also going to be working with ZA anyway and have some understanding of the state. Signed-off-by: Mark Brown --- arch/arm64/kernel/ptrace.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++ include/uapi/linux/elf.h | 1 + 2 files changed, 55 insertions(+) diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 67256e7772e4..38be7ca202af 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -1138,6 +1138,51 @@ static int za_set(struct task_struct *target, return ret; } +static int zt_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + if (!system_supports_sme2()) + return -EINVAL; + + /* + * If PSTATE.ZA is not set then ZT will be zeroed when it is + * enabled so report the current register value as zero. + */ + if (thread_za_enabled(&target->thread)) + membuf_write(&to, thread_zt_state(&target->thread), + ZT_SIG_REG_BYTES); + else + membuf_zero(&to, ZT_SIG_REG_BYTES); + + return 0; +} + +static int zt_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + int ret; + + if (!system_supports_sme2()) + return -EINVAL; + + if (!thread_za_enabled(&target->thread)) { + sme_alloc(target); + if (!target->thread.sme_state) + return -ENOMEM; + } + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + thread_zt_state(&target->thread), + 0, ZT_SIG_REG_BYTES); + if (ret == 0) + target->thread.svcr |= SVCR_ZA_MASK; + + return ret; +} + #endif /* CONFIG_ARM64_SME */ #ifdef CONFIG_ARM64_PTR_AUTH @@ -1360,6 +1405,7 @@ enum aarch64_regset { #ifdef CONFIG_ARM64_SVE REGSET_SSVE, REGSET_ZA, + REGSET_ZT, #endif #ifdef CONFIG_ARM64_PTR_AUTH REGSET_PAC_MASK, @@ -1467,6 +1513,14 @@ static const struct user_regset aarch64_regsets[] = { .regset_get = za_get, .set = za_set, }, + [REGSET_ZT] = { /* SME ZT */ + .core_note_type = NT_ARM_ZT, + .n = 1, + .size = ZT_SIG_REG_BYTES, + .align = sizeof(u64), + .regset_get = zt_get, + .set = zt_set, + }, #endif #ifdef CONFIG_ARM64_PTR_AUTH [REGSET_PAC_MASK] = { diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index 4c6a8fa5e7ed..68de6f4c4eee 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -434,6 +434,7 @@ typedef struct elf64_shdr { #define NT_ARM_PAC_ENABLED_KEYS 0x40a /* arm64 ptr auth enabled keys (prctl()) */ #define NT_ARM_SSVE 0x40b /* ARM Streaming SVE registers */ #define NT_ARM_ZA 0x40c /* ARM SME ZA registers */ +#define NT_ARM_ZT 0x40d /* ARM SME ZT registers */ #define NT_ARC_V2 0x600 /* ARCv2 accumulator/extra registers */ #define NT_VMCOREDD 0x700 /* Vmcore Device Dump Note */ #define NT_MIPS_DSP 0x800 /* MIPS DSP ASE registers */