From patchwork Mon Nov 7 21:37:09 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: 13035319 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 22CDFC433FE for ; Mon, 7 Nov 2022 21:37:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B6F826B0074; Mon, 7 Nov 2022 16:37:30 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id AD1946B0075; Mon, 7 Nov 2022 16:37:30 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9720E6B0078; Mon, 7 Nov 2022 16:37:30 -0500 (EST) 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 810456B0074 for ; Mon, 7 Nov 2022 16:37:30 -0500 (EST) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 2BEEC1209E5 for ; Mon, 7 Nov 2022 21:37:30 +0000 (UTC) X-FDA: 80107957860.03.03C6A63 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by imf19.hostedemail.com (Postfix) with ESMTP id 489FE1A0002 for ; Mon, 7 Nov 2022 21:37:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1667857049; x=1699393049; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=cWyRCW5aKXNWtiucVf5kkixxGLClq+OtEfuUo4LHoho=; b=ciH6zVYu3A0n0QcZ6PvjOseSVIFLdAsF2TE/k2aLJImBiNQDQVQwWOtx 6eHDYA8TzR1VXqBtfF/HjDpZzscDZ54Z3jMSPH/f7NI1ASjEajZURfhgJ 9LdZizMifQByCAoOugxAQtTXAT94ZKCTmUCxkznCbZ74zAqbJzXCC0i7O v8lutS+3fRo/o7Kh5Gvjr1PGQU4pGz0cDuiKbmWv/UuNOWtHJ2TKdWIlw otGRlae0FKvnuCbQRXpHDmvjHlfWKqdFpPffD47f/0tZxlYpPVxMWZkYG foSXY2XOgBFkJKkPxH9P15buU0lNC46tD81nVucAvsy/R7bkZkzWUreCm w==; X-IronPort-AV: E=McAfee;i="6500,9779,10524"; a="290919133" X-IronPort-AV: E=Sophos;i="5.96,145,1665471600"; d="scan'208";a="290919133" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Nov 2022 13:37:27 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10524"; a="965326539" X-IronPort-AV: E=Sophos;i="5.96,145,1665471600"; d="scan'208";a="965326539" Received: from biancabe-mobl1.ger.corp.intel.com (HELO box.shutemov.name) ([10.251.218.140]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Nov 2022 13:37:23 -0800 Received: by box.shutemov.name (Postfix, from userid 1000) id E49C010964A; Tue, 8 Nov 2022 00:37:20 +0300 (+03) From: "Kirill A. Shutemov" To: kirill.shutemov@linux.intel.com Cc: ak@linux.intel.com, andreyknvl@gmail.com, ashok.raj@intel.com, bharata@amd.com, dave.hansen@linux.intel.com, dvyukov@google.com, glider@google.com, hjl.tools@gmail.com, jacob.jun.pan@linux.intel.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: [PATCHv11.1 07/16] x86/mm: Provide arch_prctl() interface for LAM Date: Tue, 8 Nov 2022 00:37:09 +0300 Message-Id: <20221107213709.28330-1-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221025001722.17466-8-kirill.shutemov@linux.intel.com> References: <20221025001722.17466-8-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1667857049; a=rsa-sha256; cv=none; b=kpkuRPWPlR1u4dzF+2oMBtGC0G1HoQzjFmuBMgGj4GSauYcpUwX3o0daXAr9I3gSqp0xrV gdcBzGI9d7k7mg+tpHJV5YHhlgp0GZZEkhBzPB0pX6MHCiYFkawYX4Mm+Oto5Pp2Oc4+2S ZiD8W2d4hlDdu0PNNq9bWUWY79zsjFY= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=ciH6zVYu; spf=none (imf19.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 192.55.52.151) smtp.mailfrom=kirill.shutemov@linux.intel.com; dmarc=fail reason="No valid SPF" header.from=intel.com (policy=none) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1667857049; 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=/AHPNiprwO0cZDCn9T6ZmQ2fOpYm/X1SoaXHRjW9+Sk=; b=nBIxvXxfKt2BU1J64n098OvXZlZI5wlwX5J7gZYmb51qKXVRaXb+xrla380V/4IKL2GvbO gShuHxiHay56OKOG8U39AdysO2TVycbcBlQKtkQyaM31inCN8jUAIhp+BJhLL4j3Qul8cl JKZQiiRnv5tXEPVDBjGaIDEy24x3gbI= X-Stat-Signature: 7pfpm5cxyi8nd5swxwrhryskmgwoacye X-Rspam-User: Authentication-Results: imf19.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=ciH6zVYu; spf=none (imf19.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 192.55.52.151) smtp.mailfrom=kirill.shutemov@linux.intel.com; dmarc=fail reason="No valid SPF" header.from=intel.com (policy=none) X-Rspamd-Queue-Id: 489FE1A0002 X-Rspamd-Server: rspam09 X-HE-Tag: 1667857049-267755 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 | 71 ++++++++++++++++++++++++++++++- 2 files changed, 74 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 6b3418bff326..b8f2558a3aeb 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -743,6 +743,66 @@ 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. + * + * This might not actually need to update CR3 if a context switch + * happened between updating 'lam_cr3_mask' and running this IPI + * handler. Update it unconditionally for simplicity. + */ + 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; @@ -830,7 +890,16 @@ 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;