From patchwork Tue Aug 16 00:10:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirill A. Shutemov" X-Patchwork-Id: 12944132 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF095C00140 for ; Tue, 16 Aug 2022 00:07:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 79BE06B0073; Mon, 15 Aug 2022 20:07:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 74AE26B0075; Mon, 15 Aug 2022 20:07:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5C6388D0001; Mon, 15 Aug 2022 20:07:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 48D406B0073 for ; Mon, 15 Aug 2022 20:07:26 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 243FE40F40 for ; Tue, 16 Aug 2022 00:07:26 +0000 (UTC) X-FDA: 79803516492.27.FD4658C Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by imf04.hostedemail.com (Postfix) with ESMTP id 2A7F440026 for ; Tue, 16 Aug 2022 00:07:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1660608445; x=1692144445; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Dm62JUBwIyAaLuk4bDQ0xZJ3mBhSTUqA23F0UfzoqnQ=; b=kSQdjEUF2O60WmIA0wnARlk8uqonG88bFPO5LeH3m/fJSYPsKlB/ePhA 8umtodqM6UUqVSxgmrE+kExBHbwBB23lH7CPglI/4k+NA0Sd+fHbLHJ4X CbkIY4Cafr1hOPv5p2d5DhR+QBims6xRg9nA7DsPe5GQ8i8pjoPYtpG7K 3WSOVOaONOHBq3v+/bVzDnxbhdw+FaiUv5tw0P6FpwgXQKpZ1kp/VZ7cr mBNkT1uHb5Zc8OD+uHP2I45DKfJNm6cBoeHnNxDIDqq+nOVzw1ra+Nh5X keSmEzC3hTKTJ8tpb+kDgEVJNYaN56O6KopifgjonxEkuhOwEA/wq3nY9 A==; X-IronPort-AV: E=McAfee;i="6400,9594,10440"; a="292083042" X-IronPort-AV: E=Sophos;i="5.93,239,1654585200"; d="scan'208";a="292083042" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Aug 2022 17:07:23 -0700 X-IronPort-AV: E=Sophos;i="5.93,239,1654585200"; d="scan'208";a="696145142" Received: from mpetrica-mobl.ger.corp.intel.com (HELO box.shutemov.name) ([10.252.38.195]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Aug 2022 17:07:19 -0700 Received: by box.shutemov.name (Postfix, from userid 1000) id CDA15104A4B; Tue, 16 Aug 2022 03:10:22 +0300 (+03) From: "Kirill A. Shutemov" To: kirill.shutemov@linux.intel.com Cc: ak@linux.intel.com, andreyknvl@gmail.com, dave.hansen@linux.intel.com, dvyukov@google.com, glider@google.com, hjl.tools@gmail.com, kcc@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, luto@kernel.org, peterz@infradead.org, rick.p.edgecombe@intel.com, ryabinin.a.a@gmail.com, tarasmadan@google.com, x86@kernel.org Subject: [PATCHv6.1 06/11] x86/mm: Provide arch_prctl() interface for LAM Date: Tue, 16 Aug 2022 03:10:21 +0300 Message-Id: <20220816001021.9476-1-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220815041803.17954-7-kirill.shutemov@linux.intel.com> References: <20220815041803.17954-7-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660608445; a=rsa-sha256; cv=none; b=g6JoxCajnp4vhubnrhlQaHj3zfPb5xRlJzH8d98L2ZepQbGlAy9EHe8Y4zjlsd2McA+27N X70GCoRcaDYZpAEZ3bgkvLVblfzynY49slf8ynGQsFFuEMIbfTzigLw6WxalNtkwoKcSb4 5P3r2Pm8DlvOO5YXOIMq07O4I1vU8Uc= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=kSQdjEUF; dmarc=fail reason="No valid SPF" header.from=intel.com (policy=none); spf=none (imf04.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 192.55.52.115) smtp.mailfrom=kirill.shutemov@linux.intel.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660608445; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=gRQ+9ZKOIoJqrIzgPdnIg2VDldiMoQdqT1l7HonUIbU=; b=ngWGd2Mv0pNaH6705VFIvXKgOqAeBjiXaAHMhoZnvDzYjwD8GCt9I7/W9e3YhcER5yWgEv ms31dBVuDMSo0Lk9hCXG82eLWVUjOdOsDgfblZM4KBXkLeXUyNFSTaMQjuTZ2fmx/VtdHv SXLlAwxVMGLzlWN5kQIusi7iApKtf2A= X-Stat-Signature: 5fyhjc6oxwsu5swgemquop3o5x75tjrf X-Rspamd-Queue-Id: 2A7F440026 Authentication-Results: imf04.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=kSQdjEUF; dmarc=fail reason="No valid SPF" header.from=intel.com (policy=none); spf=none (imf04.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 192.55.52.115) smtp.mailfrom=kirill.shutemov@linux.intel.com X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1660608444-714119 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Add a couple of arch_prctl() handles: - ARCH_ENABLE_TAGGED_ADDR enabled LAM. The argument is required number of tag bits. It is rounded up to the nearest LAM mode that can provide it. For now only LAM_U57 is supported, with 6 tag bits. - ARCH_GET_UNTAG_MASK returns untag mask. It can indicates where tag bits located in the address. - ARCH_GET_MAX_TAG_BITS returns the maximum tag bits user can request. Zero if LAM is not supported. Signed-off-by: Kirill A. Shutemov --- v6.1: - Drop redundant smb_mb() in prctl_enable_tagged_addr(); --- arch/x86/include/uapi/asm/prctl.h | 4 ++ arch/x86/kernel/process_64.c | 62 ++++++++++++++++++++++++++++++- 2 files changed, 65 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/uapi/asm/prctl.h b/arch/x86/include/uapi/asm/prctl.h index 500b96e71f18..a31e27b95b19 100644 --- a/arch/x86/include/uapi/asm/prctl.h +++ b/arch/x86/include/uapi/asm/prctl.h @@ -20,4 +20,8 @@ #define ARCH_MAP_VDSO_32 0x2002 #define ARCH_MAP_VDSO_64 0x2003 +#define ARCH_GET_UNTAG_MASK 0x4001 +#define ARCH_ENABLE_TAGGED_ADDR 0x4002 +#define ARCH_GET_MAX_TAG_BITS 0x4003 + #endif /* _ASM_X86_PRCTL_H */ diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 1962008fe743..28b9657ce2d0 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -742,6 +742,57 @@ static long prctl_map_vdso(const struct vdso_image *image, unsigned long addr) } #endif +static void enable_lam_func(void *mm) +{ + struct mm_struct *loaded_mm = this_cpu_read(cpu_tlbstate.loaded_mm); + unsigned long lam_mask; + unsigned long cr3; + + if (loaded_mm != mm) + return; + + lam_mask = READ_ONCE(loaded_mm->context.lam_cr3_mask); + + /* Update CR3 to get LAM active on the CPU */ + cr3 = __read_cr3(); + cr3 &= ~(X86_CR3_LAM_U48 | X86_CR3_LAM_U57); + cr3 |= lam_mask; + write_cr3(cr3); + set_tlbstate_cr3_lam_mask(lam_mask); +} + +static int prctl_enable_tagged_addr(struct mm_struct *mm, unsigned long nr_bits) +{ + int ret = 0; + + if (!cpu_feature_enabled(X86_FEATURE_LAM)) + return -ENODEV; + + mutex_lock(&mm->context.lock); + + /* Already enabled? */ + if (mm->context.lam_cr3_mask) { + ret = -EBUSY; + goto out; + } + + if (!nr_bits) { + ret = -EINVAL; + goto out; + } else if (nr_bits <= 6) { + mm->context.lam_cr3_mask = X86_CR3_LAM_U57; + mm->context.untag_mask = ~GENMASK(62, 57); + } else { + ret = -EINVAL; + goto out; + } + + on_each_cpu_mask(mm_cpumask(mm), enable_lam_func, mm, true); +out: + mutex_unlock(&mm->context.lock); + return ret; +} + long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2) { int ret = 0; @@ -829,7 +880,16 @@ long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2) case ARCH_MAP_VDSO_64: return prctl_map_vdso(&vdso_image_64, arg2); #endif - + case ARCH_GET_UNTAG_MASK: + return put_user(task->mm->context.untag_mask, + (unsigned long __user *)arg2); + case ARCH_ENABLE_TAGGED_ADDR: + return prctl_enable_tagged_addr(task->mm, arg2); + case ARCH_GET_MAX_TAG_BITS: + if (!cpu_feature_enabled(X86_FEATURE_LAM)) + return put_user(0, (unsigned long __user *)arg2); + else + return put_user(6, (unsigned long __user *)arg2); default: ret = -EINVAL; break;