From patchwork Wed Jun 22 16:22:28 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: 12891143 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 79285C43334 for ; Wed, 22 Jun 2022 16:23:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DBA1E8E00CA; Wed, 22 Jun 2022 12:23:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D6A6B8E00C9; Wed, 22 Jun 2022 12:23:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C32188E00CA; Wed, 22 Jun 2022 12:23:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id B56868E00C9 for ; Wed, 22 Jun 2022 12:23:55 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay13.hostedemail.com (Postfix) with ESMTP id 8C414604D6 for ; Wed, 22 Jun 2022 16:23:55 +0000 (UTC) X-FDA: 79606393230.19.FCE0554 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by imf26.hostedemail.com (Postfix) with ESMTP id C2263140018 for ; Wed, 22 Jun 2022 16:23:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1655915032; x=1687451032; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=BkKX7P64WZcLjWfGUU0r+pKJ4TB5dZSWjwFRGFzJ7l0=; b=LkgGesQ3h5gMG+J6lTLtfXLbid+4eTY9jOFf8FMowyVo/X1OEUDOKdA4 PPWIbx1GGuGfV6i8Cp1C/DpkKDspv/m0d4X87byTbMdBzpM8f2hiwh/HB nKmJm9gGH9E0mmaJjtjePE/hkQzZ0p67qbXXANgJTJvpBXFzsV8E4biIX 0BMIiBqYrjNoqNhmc0uUDVcW5CZgpApculqOKWDoPRkh1eMCPRhQwJ3Gj IHEXXSq2clIw45F4H5yysSeL9y/rYYopikAWYHMvDmWJ1XQivTjcf1YpH exK7wX6askGKU8YN16+uiIrm2mGP7Hngkjk62O3t/tGLop1RI9LyJO4OD w==; X-IronPort-AV: E=McAfee;i="6400,9594,10386"; a="260898817" X-IronPort-AV: E=Sophos;i="5.92,212,1650956400"; d="scan'208";a="260898817" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jun 2022 09:22:46 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.92,212,1650956400"; d="scan'208";a="592264460" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga007.fm.intel.com with ESMTP; 22 Jun 2022 09:22:42 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 6060572D; Wed, 22 Jun 2022 19:22:43 +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 , Dmitry Vyukov , "H . J . Lu" , Andi Kleen , Rick Edgecombe , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv4 6/8] x86/mm: Provide ARCH_GET_UNTAG_MASK and ARCH_ENABLE_TAGGED_ADDR Date: Wed, 22 Jun 2022 19:22:28 +0300 Message-Id: <20220622162230.83474-7-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220622162230.83474-1-kirill.shutemov@linux.intel.com> References: <20220622162230.83474-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 ARC-Authentication-Results: i=1; imf26.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=LkgGesQ3; dmarc=pass (policy=none) header.from=intel.com; spf=temperror (imf26.hostedemail.com: error in processing during lookup of kirill.shutemov@linux.intel.com: DNS error) 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=1655915033; 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=RG5CC9jax/qRT1tXBwQsr47lCeLR7LTO/W6+ecQ8jgc=; b=KxYcE1OZRnKUHATJghY8QRVbVBsk7yPujp0BqSWTBbSEDmhTz1OHOdeFTbfPoJymJefmFP K6evWuuGlasePvFNfAGoUF13ipJ23sTbsF3+qbNaP/LetLxCzW9GfI2S20UVASyYYjMf1k 676IlNocE4R7W5TGt8DSvpl3FCxn8MA= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1655915033; a=rsa-sha256; cv=none; b=8QbjuQ1jkEwSLhRWPAgjQf2xHsCX1y/GQnG/gdYwsWIdjN+wDaD4K6lObX+wbkQTTI6R8b 0K6U80olSmTUZk/HJyqy0ee9ZI9kWND4TMaUzXF5xzgoTKprhsVvPW3JGCwgd/GaWGwi1J AGUHj4mN8rWTmfcLm329d8/BkixekhI= X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: C2263140018 X-Rspam-User: Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=LkgGesQ3; dmarc=pass (policy=none) header.from=intel.com; spf=temperror (imf26.hostedemail.com: error in processing during lookup of kirill.shutemov@linux.intel.com: DNS error) smtp.mailfrom=kirill.shutemov@linux.intel.com X-Stat-Signature: 4mx6bx56gh8axyroa91yyhiwt5uadop9 X-HE-Tag: 1655915032-392279 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 | 55 ++++++++++++++++++++++++++++++- 2 files changed, 57 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..e328b91d1492 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -742,6 +742,55 @@ 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); + + if (loaded_mm != mm) + return; + + /* Counterpart of smp_wmb() in prctl_enable_tagged_addr() */ + smp_rmb(); + + /* Update CR3 to get LAM active on the CPU */ + switch_mm(loaded_mm, loaded_mm, current); +} + +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_wmb(); + + 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 +878,11 @@ 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;