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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7DB58C3F6B0 for ; Mon, 15 Aug 2022 04:15:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2B0678D0005; Mon, 15 Aug 2022 00:15:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2377E6B007B; Mon, 15 Aug 2022 00:15:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0B0DF8D0005; Mon, 15 Aug 2022 00:15:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id E8F346B0078 for ; Mon, 15 Aug 2022 00:15:12 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id C19CF80CB8 for ; Mon, 15 Aug 2022 04:15:12 +0000 (UTC) X-FDA: 79800512064.26.FFE9E69 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by imf11.hostedemail.com (Postfix) with ESMTP id 2E4D7400B5 for ; Mon, 15 Aug 2022 04:15:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1660536912; x=1692072912; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=rGmRjWLsZd0MykLtxfW7HGQQOCTU/72uM1KezIjGuQ4=; b=cyTDKN/sdP0jqsZ0Z8sLhwam9ivrGprvaCgVBHcRbXxTOSxnURsd4mM+ ZiF9swrmR1mx7CoiOMExnifMgiwvU6hxVfRWGykYNYxcrey73mTkVoCmj 6E7p8YEgrNSAUuyv+XGiN8eNMuAzqrXbOnzZtELH2aB9wU2IFiaIgcWRj 14gc9ijpR3//WBFNV25LFVLi5Nwbw4AWPTm+ZA20isw+izMNJcfdFrmqE oySMhcj7X9fNIzd5tfGBhejoSv9D1sLq1nO6PVcOGPPabGPvdBpxnBjzz 8diEg9VJPj7LIUE8n1yU5ts2RfS7IPN0vRemXIPcKN1Tg7uRv3j4KxWwK w==; X-IronPort-AV: E=McAfee;i="6400,9594,10439"; a="290639867" X-IronPort-AV: E=Sophos;i="5.93,237,1654585200"; d="scan'208";a="290639867" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Aug 2022 21:15:10 -0700 X-IronPort-AV: E=Sophos;i="5.93,237,1654585200"; d="scan'208";a="582747731" Received: from dmalka-mobl.ger.corp.intel.com (HELO box.shutemov.name) ([10.249.42.26]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Aug 2022 21:15:07 -0700 Received: by box.shutemov.name (Postfix, from userid 1000) id 67CDA104A6B; Mon, 15 Aug 2022 07:18:04 +0300 (+03) 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: [PATCHv6 06/11] x86/mm: Provide arch_prctl() interface for LAM Date: Mon, 15 Aug 2022 07:17:58 +0300 Message-Id: <20220815041803.17954-7-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220815041803.17954-1-kirill.shutemov@linux.intel.com> References: <20220815041803.17954-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b="cyTDKN/s"; dmarc=fail reason="No valid SPF" header.from=intel.com (policy=none); spf=none (imf11.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 192.55.52.120) smtp.mailfrom=kirill.shutemov@linux.intel.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660536912; a=rsa-sha256; cv=none; b=XBWXG8XnCsTBbpKI+6qt1bcm8HdteVM0wy/+KxH3U4BbX8qvqtC3uKDM7GkXmzt3w9bZ1D 8NYUn00dUfqnIssYzf57o5PIxzYwcgY1uUFqB0QLXTe7RN5LeNrBVYzyFoLCPg0vK00Bmg NN9EJzgKscMEDm5m3q1pCSF7VYBoUtw= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660536912; 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=fhqDrQ4sbGWB617dWohRSE8WXiB0YVYsB9OuCX7XC3U=; b=lUnAxOueaODWVtwre+gki0NP+gjRg+TXaXOX8YuDfHBeHTQFARsTw2/AcHcWrp4xd7ovWQ LkFPiOb5z2odakzV3m+ASuy9Xf1EyINNvsYG99SQOOKxL2dg7IsMl6O2Qs/BFinm5rOfJP KhdHsRval9mNqcTUhfIiUQe4FQ+kz6M= X-Rspam-User: Authentication-Results: imf11.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b="cyTDKN/s"; dmarc=fail reason="No valid SPF" header.from=intel.com (policy=none); spf=none (imf11.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 192.55.52.120) smtp.mailfrom=kirill.shutemov@linux.intel.com X-Stat-Signature: iy89g5zmm46cumef69hm76mtijuzdjio X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 2E4D7400B5 X-HE-Tag: 1660536911-198047 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 --- arch/x86/include/uapi/asm/prctl.h | 4 ++ arch/x86/kernel/process_64.c | 65 ++++++++++++++++++++++++++++++- 2 files changed, 68 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..4f9f0f8ccd26 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 +883,16 @@ 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; -- 2.35.1