From patchwork Fri Sep 30 14:47:51 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: 12995574 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 548E5C433F5 for ; Fri, 30 Sep 2022 14:48:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E1D988D0007; Fri, 30 Sep 2022 10:48:28 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DD2668D0006; Fri, 30 Sep 2022 10:48:28 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BD3C88D0007; Fri, 30 Sep 2022 10:48:28 -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 A194F8D0006 for ; Fri, 30 Sep 2022 10:48:28 -0400 (EDT) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 6F8431403AD for ; Fri, 30 Sep 2022 14:48:28 +0000 (UTC) X-FDA: 79969032696.09.52AE7C2 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by imf27.hostedemail.com (Postfix) with ESMTP id DE3F540013 for ; Fri, 30 Sep 2022 14:48:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1664549307; x=1696085307; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=iE10WIJBtJTsaFxcXeBHtPpZOupPZSn9pP2DnyL7oJw=; b=LyM6LdcIdYZJxA+JUC5sRUijRHRTiUblyrPa66sMXGKkTcHdQ3Nl9h7h 51HwWAgHFGwTetBFVMjEN0wUA7ftAxu5UbEER+H4h+pen/TGgzZ4XIGXy kilQ+tZEk4kQMM7/cEbtX9DYO6FtSm1+Ie826gZgkXJr7kXNt4emb68hn +tEZdtmyyB5gWDvXysgp4CNRsQ1+nkKlmHKxMLjWc10XzLw3NGRdy4ePy dZSbzpvazWfUcweLb/QO13TxPE9yEc63HNPRj5ZQuLsYRLxzdKs9Ij7XS XErhZnCJ+Dtn5P0u4wj7PlZXzGheEFkfP+c0wNejpvEFsUyjE7L2Y1DS7 g==; X-IronPort-AV: E=McAfee;i="6500,9779,10486"; a="366256244" X-IronPort-AV: E=Sophos;i="5.93,358,1654585200"; d="scan'208";a="366256244" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Sep 2022 07:48:15 -0700 X-IronPort-AV: E=McAfee;i="6500,9779,10486"; a="691271800" X-IronPort-AV: E=Sophos;i="5.93,358,1654585200"; d="scan'208";a="691271800" Received: from herrerop-mobl1.ger.corp.intel.com (HELO box.shutemov.name) ([10.252.38.128]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Sep 2022 07:48:11 -0700 Received: by box.shutemov.name (Postfix, from userid 1000) id 6DD3E104D61; Fri, 30 Sep 2022 17:48:02 +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 , Bharata B Rao , Jacob Pan , Ashok Raj , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv9 07/14] x86/mm: Provide arch_prctl() interface for LAM Date: Fri, 30 Sep 2022 17:47:51 +0300 Message-Id: <20220930144758.30232-8-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220930144758.30232-1-kirill.shutemov@linux.intel.com> References: <20220930144758.30232-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=LyM6LdcI; spf=none (imf27.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=fail reason="No valid SPF" header.from=intel.com (policy=none) ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1664549308; a=rsa-sha256; cv=none; b=r/X7j1Aka3JAVHmnUEhkke0PYmm3qz2I+MXpoYOy1B1GGWvyT9ru+eiEc6jAk2tga8rJEb n7To3vS9pRpvMCNpSIFTlsVwWUOMKmOMWEXcAknon0806MP8nqQVrWOh3Djcv1hSrxJvY9 FaqwfkXZhKgeyTSwCdBB/0EThBs/uVM= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1664549308; 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=ohgAtFrtxJD/HigAL7+8dMtwCTZPADL2gZinlKi9QhU=; b=P+k5Dl95LdSeL4OhVnTP+sYW6NN8ys0kCFZhC1peEC2FLynhvRfa4lZxIW6gkpoycG8AIB +Q4JN7h3hKYcAkjyGhOJUWNHvY6cqwQ03SzhWHiXQuwS0TA+fn70xqF+O4UJjJ8xNEI1yB mTqQzVThzTiQpKai0BRxAD/Nk1YGqN8= X-Rspam-User: Authentication-Results: imf27.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=LyM6LdcI; spf=none (imf27.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=fail reason="No valid SPF" header.from=intel.com (policy=none) X-Rspamd-Server: rspam10 X-Stat-Signature: 1zsr1s99zw9hfpdy4ptgaadh6w5ottmx X-Rspamd-Queue-Id: DE3F540013 X-HE-Tag: 1664549307-707707 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 Tested-by: Alexander Potapenko Reviewed-by: Alexander Potapenko Acked-by: Peter Zijlstra (Intel) --- 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..d75252a5c7be 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); +} + +#define LAM_U57_BITS 6 + +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; + + if (mmap_write_lock_killable(mm)) + return -EINTR; + + /* Already enabled? */ + if (mm->context.lam_cr3_mask) { + ret = -EBUSY; + goto out; + } + + if (!nr_bits) { + ret = -EINVAL; + goto out; + } else if (nr_bits <= LAM_U57_BITS) { + 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: + mmap_write_unlock(mm); + 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(LAM_U57_BITS, (unsigned long __user *)arg2); default: ret = -EINVAL; break;