From patchwork Mon Oct 31 22:25:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 13026414 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48A6BFA3741 for ; Mon, 31 Oct 2022 22:25:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229599AbiJaWZ4 convert rfc822-to-8bit (ORCPT ); Mon, 31 Oct 2022 18:25:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38288 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229479AbiJaWZ4 (ORCPT ); Mon, 31 Oct 2022 18:25:56 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 766AF14082 for ; Mon, 31 Oct 2022 15:25:55 -0700 (PDT) Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 29VMPHEP031035 for ; Mon, 31 Oct 2022 15:25:54 -0700 Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3kjn3f90wh-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 31 Oct 2022 15:25:54 -0700 Received: from twshared13940.35.frc1.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::e) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Mon, 31 Oct 2022 15:25:52 -0700 Received: by devbig932.frc1.facebook.com (Postfix, from userid 4523) id 1D1CAF0CC5A7; Mon, 31 Oct 2022 15:25:48 -0700 (PDT) From: Song Liu To: , CC: , , , , , , , Song Liu Subject: [PATCH bpf-next v1 RESEND 0/5] vmalloc_exec for modules and BPF programs Date: Mon, 31 Oct 2022 15:25:36 -0700 Message-ID: <20221031222541.1773452-1-song@kernel.org> X-Mailer: git-send-email 2.30.2 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: pNIGQPWWSyXnNfj3R6FHAG8QLrB99yTg X-Proofpoint-GUID: pNIGQPWWSyXnNfj3R6FHAG8QLrB99yTg X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-10-31_21,2022-10-31_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Original email didn't make to lore, resend with a shorter CC list. This set enables bpf programs and bpf dispatchers to share huge pages with new API: vmalloc_exec() vfree_exec() vcopy_exec() The idea is similar to Peter's suggestion in [1]. vmalloc_exec() manages a set of PMD_SIZE RO+X memory, and allocates these memory to its users. vfree_exec() is used to free memory allocated by vmalloc_exec(). vcopy_exec() is used to update memory allocated by vmalloc_exec(). Memory allocated by vmalloc_exec() is RO+X, so this doesnot violate W^X. The caller has to update the content with text_poke like mechanism. Specifically, vcopy_exec() is provided to update memory allocated by vmalloc_exec(). vcopy_exec() also makes sure the update stays in the boundary of one chunk allocated by vmalloc_exec(). Please refer to patch 1/5 for more details of Patch 3/5 uses these new APIs in bpf program and bpf dispatcher. Patch 4/5 and 5/5 allows static kernel text (_stext to _etext) to share PMD_SIZE pages with dynamic kernel text on x86_64. This is achieved by allocating PMD_SIZE pages to roundup(_etext, PMD_SIZE), and then use _etext to roundup(_etext, PMD_SIZE) for dynamic kernel text. [1] https://lore.kernel.org/bpf/Ys6cWUMHO8XwyYgr@hirez.programming.kicks-ass.net/ [2] RFC v1: https://lore.kernel.org/linux-mm/20220818224218.2399791-3-song@kernel.org/T/ Changes RFC v2 => PATCH v1: 1. Add vcopy_exec(), which updates memory allocated by vmalloc_exec(). It also ensures vcopy_exec() is only used to update memory from one single vmalloc_exec() call. (Christoph Hellwig) 2. Add arch_vcopy_exec() and arch_invalidate_exec() as wrapper for the text_poke() like logic. 3. Drop changes for kernel modules and focus on BPF side changes. Changes RFC v1 => RFC v2: 1. Major rewrite of the logic of vmalloc_exec and vfree_exec. They now work fine with BPF programs (patch 1, 2, 4). But module side (patch 3) still need some work. Song Liu (5): vmalloc: introduce vmalloc_exec, vfree_exec, and vcopy_exec x86/alternative: support vmalloc_exec() and vfree_exec() bpf: use vmalloc_exec for bpf program and bpf dispatcher vmalloc: introduce register_text_tail_vm() x86: use register_text_tail_vm arch/x86/include/asm/pgtable_64_types.h | 1 + arch/x86/kernel/alternative.c | 12 + arch/x86/mm/init_64.c | 4 +- arch/x86/net/bpf_jit_comp.c | 23 +- include/linux/bpf.h | 3 - include/linux/filter.h | 5 - include/linux/vmalloc.h | 9 + kernel/bpf/core.c | 180 +----------- kernel/bpf/dispatcher.c | 11 +- mm/nommu.c | 7 + mm/vmalloc.c | 351 ++++++++++++++++++++++++ 11 files changed, 404 insertions(+), 202 deletions(-) --- 2.30.2