From patchwork Mon Aug 9 09:26:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 12425963 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3AD6EC4338F for ; Mon, 9 Aug 2021 09:27:22 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DE37E60EE7 for ; Mon, 9 Aug 2021 09:27:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org DE37E60EE7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 5A14F6B007B; Mon, 9 Aug 2021 05:27:21 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 550118D0003; Mon, 9 Aug 2021 05:27:21 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 43EA26B007E; Mon, 9 Aug 2021 05:27:21 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0077.hostedemail.com [216.40.44.77]) by kanga.kvack.org (Postfix) with ESMTP id 287C46B007B for ; Mon, 9 Aug 2021 05:27:21 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id C91F08249980 for ; Mon, 9 Aug 2021 09:27:20 +0000 (UTC) X-FDA: 78455013840.27.362FC04 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by imf24.hostedemail.com (Postfix) with ESMTP id 75D27B007B29 for ; Mon, 9 Aug 2021 09:27:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628501239; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=3zhESEW2Ji+uo2bsEAl1W/kp0ipaDd92cn/ErvGasJI=; b=G8MuNTQ2FPbqhpjO/m8a2VfHHl9wepM8hSXHO/F8kNIUfqK8uyY1t4JlEUALz21EWfnuvH 0Kv5GNMLRvHelCARXAlpxxm0Q09MvapWKlVe/2SV56SuoRHje77UVH5q8oI6P5iaCVbUD9 9K/Kscdq2AHYshb7XY4CxmwfI9q3uSc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-147-7gvd0McsOU2aASFitRALaQ-1; Mon, 09 Aug 2021 05:27:16 -0400 X-MC-Unique: 7gvd0McsOU2aASFitRALaQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6544618C89C4; Mon, 9 Aug 2021 09:27:14 +0000 (UTC) Received: from gshan.redhat.com (vpn2-54-155.bne.redhat.com [10.64.54.155]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B45F95D6AD; Mon, 9 Aug 2021 09:27:07 +0000 (UTC) From: Gavin Shan To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, anshuman.khandual@arm.com, gerald.schaefer@linux.ibm.com, aneesh.kumar@linux.ibm.com, christophe.leroy@csgroup.eu, cai@lca.pw, catalin.marinas@arm.com, will@kernel.org, vgupta@synopsys.com, akpm@linux-foundation.org, chuhu@redhat.com, shan.gavin@gmail.com Subject: [PATCH v6 00/12] mm/debug_vm_pgtable: Enhancements Date: Mon, 9 Aug 2021 17:26:19 +0800 Message-Id: <20210809092631.1888748-1-gshan@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 75D27B007B29 Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=G8MuNTQ2; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf24.hostedemail.com: domain of gshan@redhat.com has no SPF policy when checking 216.205.24.124) smtp.mailfrom=gshan@redhat.com X-Stat-Signature: dyozn19gm5wn9zzh4d9woenakuto4fg6 X-HE-Tag: 1628501240-149735 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: There are couple of issues with current implementations and this series tries to resolve the issues: (a) All needed information are scattered in variables, passed to various test functions. The code is organized in pretty much relaxed fashion. (b) The page isn't allocated from buddy during page table entry modifying tests. The page can be invalid, conflicting to the implementations of set_xxx_at() on ARM64. The target page is accessed so that the iCache can be flushed when execution permission is given on ARM64. Besides, the target page can be unmapped and accessing to it causes kernel crash. "struct pgtable_debug_args" is introduced to address issue (a). For issue (b), the used page is allocated from buddy in page table entry modifying tests. The corresponding tets will be skipped if we fail to allocate the (huge) page. For other test cases, the original page around to kernel symbol (@start_kernel) is still used. The patches are organized as below. PATCH[2-10] could be combined to one patch, but it will make the review harder: PATCH[1] introduces "struct pgtable_debug_args" as place holder of all needed information. With it, the old and new implementation can coexist. PATCH[2-10] uses "struct pgtable_debug_args" in various test functions. PATCH[11] removes the unused code for old implementation. PATCH[12] fixes the issue of corrupted page flag for ARM64 Changelog ========= v6: * Populate saved page table entry pointers after they're allocated in init_args() (Anshuman) * Fix imbalanced preemption count issue by replacing pte_alloc_mmap() with pte_alloc() in init_args() (syzbot) v5: * Pick r-bs from Anshuman and rebase to 5.14.rc4 (Gavin) * Use args->start_p4dp to free p4d entries (Anshuman) * Introduce helper to allocate huge page in init_arg() (Anshuman) * Bail early if the allocated page doesn't exist in swap_migration_tests() and correct the comments (Anshuman) * Add fixes tag to PATCH[v4 12/12] (Christophe) * Address misc comments (Anshuman) v4: * Determine the page allocation method according to MAX_ORDER (Anshuman) * Move existing comments to init_args() (Anshuman) * Code refactoring as suggested by Anshuman (Anshuman) * Improved commit log and add comments for flush_dcache_page() in PATCH[v4 12/12] (Anshuman) * Address misc comments (Anshuman) v3: * Fix the warning caused by allocating more pages than (1 << (MAX_ORDER - 1)) in init_args() (syzbot) * Fix build warning by dropping unused variables in separate patches (0-day) * Missed "WARN_ON(!pud_none(pud))" in pud_huge_tests() in PATCH[v2 09/12] (0-day) * Fix the subjects for PATCH[05/12] and PATCH[09/12] (Gavin) v2: * Rename struct vm_pgtable_debug to struct pgtable_debug_args. The parameter name to various test functions are renamed to "@args" (Anshuman) * Code changes as suggested by Anshuman (Anshuman) Gavin Shan (12): mm/debug_vm_pgtable: Introduce struct pgtable_debug_args mm/debug_vm_pgtable: Use struct pgtable_debug_args in basic tests mm/debug_vm_pgtable: Use struct pgtable_debug_args in leaf and savewrite tests mm/debug_vm_pgtable: Use struct pgtable_debug_args in protnone and devmap tests mm/debug_vm_pgtable: Use struct pgtable_debug_args in soft_dirty and swap tests mm/debug_vm_pgtable: Use struct pgtable_debug_args in migration and thp tests mm/debug_vm_pgtable: Use struct pgtable_debug_args in PTE modifying tests mm/debug_vm_pgtable: Use struct pgtable_debug_args in PMD modifying tests mm/debug_vm_pgtable: Use struct pgtable_debug_args in PUD modifying tests mm/debug_vm_pgtable: Use struct pgtable_debug_args in PGD and P4D modifying tests mm/debug_vm_pgtable: Remove unused code mm/debug_vm_pgtable: Fix corrupted page flag mm/debug_vm_pgtable.c | 918 +++++++++++++++++++++++++----------------- 1 file changed, 559 insertions(+), 359 deletions(-)