From patchwork Tue Jul 12 23:13:21 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: 12915803 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 620ACCCA47F for ; Tue, 12 Jul 2022 23:13:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C31609400E2; Tue, 12 Jul 2022 19:13:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BCAA39400E5; Tue, 12 Jul 2022 19:13:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9D28F9400E2; Tue, 12 Jul 2022 19:13:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 8D1589400E1 for ; Tue, 12 Jul 2022 19:13:32 -0400 (EDT) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 5A93D350EC for ; Tue, 12 Jul 2022 23:13:32 +0000 (UTC) X-FDA: 79680001464.02.71038E7 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by imf23.hostedemail.com (Postfix) with ESMTP id 87083140078 for ; Tue, 12 Jul 2022 23:13:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1657667611; x=1689203611; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=OJDuDjvUGA+HqDGHfFlodTRAfB+eKXuXU7w3WDfuVQk=; b=ZbY5m3QLAzrKT+10cITWjNHlMb7glJn4SxGRi2RfSdBI0O/0UrjF5499 zkEuQo0qYIeHRJNsooRdVwRDqHTjXEnSwa09Ndtvwkfpf9rekvnbhdIMB TFKHOUmjGRAl8NcCAu36nrALm5WVnb0AZu/Lfd5wHD7E7SYi1uIt7WE+R RM4oshCPKUstsNbGxwKbUrfA7CT/3whndlGSeA24JZivom5SySZ9viGj4 AkB8X6pQBJ+hmZXbr171j7m6WWlpryIARFeVD5/g0Z4Bp7wsVnB77DpZ+ C0N3vto6MsZYeFVxCLA+gCZVnZ5tGKqddEXOWd54Nu2nEFDdKac8PQdVh w==; X-IronPort-AV: E=McAfee;i="6400,9594,10406"; a="349038543" X-IronPort-AV: E=Sophos;i="5.92,266,1650956400"; d="scan'208";a="349038543" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jul 2022 16:13:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.92,266,1650956400"; d="scan'208";a="737658278" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga001.fm.intel.com with ESMTP; 12 Jul 2022 16:13:26 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id EC3853E3; Wed, 13 Jul 2022 02:13:29 +0300 (EEST) From: "Kirill A. Shutemov" To: Dave Hansen , Andy Lutomirski , Peter Zijlstra Cc: x86@kernel.org, Kostya Serebryany , Andrey Ryabinin , Andrey Konovalov , Alexander Potapenko , Taras Madan , Dmitry Vyukov , "H . J . Lu" , Andi Kleen , Rick Edgecombe , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv5 06/13] x86/mm: Provide ARCH_GET_UNTAG_MASK and ARCH_ENABLE_TAGGED_ADDR Date: Wed, 13 Jul 2022 02:13:21 +0300 Message-Id: <20220712231328.5294-7-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220712231328.5294-1-kirill.shutemov@linux.intel.com> References: <20220712231328.5294-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1657667611; a=rsa-sha256; cv=none; b=gukKVf8GykZ22aE7TdLBmuJAxJCc40o7KanHoEZShch7i2hOgxGmKLsST7Q32o/b0y7cjV W0S8ht2I6sqGXK++2iJFy095O6MWqfyF39zbPSWZ7vFyJNdZpjhqK/24qcuVrVswe6kqJn MHMma0viUZx+Q3R8k4xAG+OSS940CEY= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=ZbY5m3QL; spf=none (imf23.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 134.134.136.100) smtp.mailfrom=kirill.shutemov@linux.intel.com; dmarc=pass (policy=none) header.from=intel.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1657667611; 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=wzdj3nCsYMYGs5evgZL4Zh0Cq3r5TjVAZHGW3nheZ7w=; b=SREkGZq9vO2n/f4/P/4U/0Vfvc8JVmidgMSC1ecuQsQhVlUHq6qxNfTU3eNA7kQsxAkEdF e9gmtIolrfLFFdokAzddX4l3v6K44qNE8ysf7jz35t57WiqKaXtDaBLCpLmvio8IvzeB9z WPUn/Wbsd2qRaiCjAD7S0lLNK3Jh1yM= X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 87083140078 X-Rspam-User: Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=ZbY5m3QL; spf=none (imf23.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 134.134.136.100) smtp.mailfrom=kirill.shutemov@linux.intel.com; dmarc=pass (policy=none) header.from=intel.com X-Stat-Signature: o1m39c8w4gdbt44jtnjmogbpktqckmpz X-HE-Tag: 1657667611-842239 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. Signed-off-by: Kirill A. Shutemov --- arch/x86/include/uapi/asm/prctl.h | 3 ++ arch/x86/kernel/process_64.c | 60 ++++++++++++++++++++++++++++++- 2 files changed, 62 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/uapi/asm/prctl.h b/arch/x86/include/uapi/asm/prctl.h index 500b96e71f18..38164a05c23c 100644 --- a/arch/x86/include/uapi/asm/prctl.h +++ b/arch/x86/include/uapi/asm/prctl.h @@ -20,4 +20,7 @@ #define ARCH_MAP_VDSO_32 0x2002 #define ARCH_MAP_VDSO_64 0x2003 +#define ARCH_GET_UNTAG_MASK 0x4001 +#define ARCH_ENABLE_TAGGED_ADDR 0x4002 + #endif /* _ASM_X86_PRCTL_H */ diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 1962008fe743..82a19168bfa4 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -742,6 +742,60 @@ 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; + } + + /* Make lam_cr3_mask and untag_mask visible on other CPUs */ + smp_mb(); + + 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 +883,11 @@ 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); default: ret = -EINVAL; break;