From patchwork Mon Jul 19 05:41:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 12384715 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 E1C6DC12002 for ; Mon, 19 Jul 2021 05:41:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8F3E36117A for ; Mon, 19 Jul 2021 05:41:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8F3E36117A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 35F6C8D00F7; Mon, 19 Jul 2021 01:41:38 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3367E8D00EC; Mon, 19 Jul 2021 01:41:38 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1B1608D00F7; Mon, 19 Jul 2021 01:41:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0143.hostedemail.com [216.40.44.143]) by kanga.kvack.org (Postfix) with ESMTP id ED9918D00EC for ; Mon, 19 Jul 2021 01:41:37 -0400 (EDT) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id EF2F62310E for ; Mon, 19 Jul 2021 05:41:34 +0000 (UTC) X-FDA: 78378240108.13.C05B877 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by imf26.hostedemail.com (Postfix) with ESMTP id 7A81F2001724 for ; Mon, 19 Jul 2021 05:41:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626673293; 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: in-reply-to:in-reply-to:references:references; bh=KK4Cv/zrWZI6h6OdfKBjcylOu+yTdhjEHvz7DX83I80=; b=h3YSjU/1GWP8sclRpYfGYA7KsJ8xJe+qicYmhn3nWe7i+rSfWbDCHnmNNQPtiE+NFNT4fd k7KKkefSWBiGzJjD8RidzXY1vCXnWDjwdzRhnyKF6SZ2uUF+Kss8zpG1LnRApQsGzmYQ+u NzddSbKt0Ybhi0lm1+Ybc2WFsc2rJx0= 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-511-YpFq1L7-Mzuvn0h014Td_w-1; Mon, 19 Jul 2021 01:41:31 -0400 X-MC-Unique: YpFq1L7-Mzuvn0h014Td_w-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1C264362F8; Mon, 19 Jul 2021 05:41:30 +0000 (UTC) Received: from gshan.redhat.com (vpn2-54-195.bne.redhat.com [10.64.54.195]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8DF9418F0A; Mon, 19 Jul 2021 05:41:27 +0000 (UTC) From: Gavin Shan To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, anshuman.khandual@arm.com, catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, chuhu@redhat.com, shan.gavin@gmail.com Subject: [PATCH v2 01/12] mm/debug_vm_pgtable: Introduce struct pgtable_debug_args Date: Mon, 19 Jul 2021 13:41:27 +0800 Message-Id: <20210719054138.198373-2-gshan@redhat.com> In-Reply-To: <20210719054138.198373-1-gshan@redhat.com> References: <20210719054138.198373-1-gshan@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="h3YSjU/1"; spf=none (imf26.hostedemail.com: domain of gshan@redhat.com has no SPF policy when checking 216.205.24.124) smtp.mailfrom=gshan@redhat.com; dmarc=pass (policy=none) header.from=redhat.com X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 7A81F2001724 X-Stat-Signature: sifzotyb4deh7pxws3ikupxb3c95wm68 X-HE-Tag: 1626673294-236820 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: In debug_vm_pgtable(), there are many local variables introduced to track the needed information and they are passed to the functions for various test cases. It'd better to introduce a struct as place holder for these information. With it, what the functions for various test cases need is the struct, to simplify the code. It also makes code easier to be maintained. Besides, set_xxx_at() could access the data on the corresponding pages in the page table modifying tests. So the accessed pages in the tests should have been allocated from buddy. Otherwise, we're accessing pages that aren't owned by us. This causes issues like page flag corruption. This introduces "struct pgtable_debug_args". The struct is initialized and destroyed, but the information in the struct isn't used yet. They will be used in subsequent patches. Signed-off-by: Gavin Shan --- mm/debug_vm_pgtable.c | 196 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 195 insertions(+), 1 deletion(-) diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index 1c922691aa61..0cc44e7c166e 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -58,6 +58,36 @@ #define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK) #define RANDOM_NZVALUE GENMASK(7, 0) +struct pgtable_debug_args { + struct mm_struct *mm; + struct vm_area_struct *vma; + + pgd_t *pgdp; + p4d_t *p4dp; + pud_t *pudp; + pmd_t *pmdp; + pte_t *ptep; + + p4d_t *start_p4dp; + pud_t *start_pudp; + pmd_t *start_pmdp; + pgtable_t start_ptep; + + unsigned long vaddr; + pgprot_t page_prot; + pgprot_t page_prot_none; + + unsigned long pud_pfn; + unsigned long pmd_pfn; + unsigned long pte_pfn; + + unsigned long fixed_pgd_pfn; + unsigned long fixed_p4d_pfn; + unsigned long fixed_pud_pfn; + unsigned long fixed_pmd_pfn; + unsigned long fixed_pte_pfn; +}; + static void __init pte_basic_tests(unsigned long pfn, int idx) { pgprot_t prot = protection_map[idx]; @@ -955,8 +985,166 @@ static unsigned long __init get_random_vaddr(void) return random_vaddr; } +static void __init destroy_args(struct pgtable_debug_args *args) +{ + struct page *page = NULL; + + /* Free (huge) page */ + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && + IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD) && + has_transparent_hugepage() && + args->pud_pfn != ULONG_MAX) { + page = pfn_to_page(args->pud_pfn); + __free_pages(page, HPAGE_PUD_SHIFT - PAGE_SHIFT); + } else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && + has_transparent_hugepage() && + args->pmd_pfn != ULONG_MAX) { + page = pfn_to_page(args->pmd_pfn); + __free_pages(page, HPAGE_PMD_ORDER); + } else if (args->pte_pfn != ULONG_MAX) { + page = pfn_to_page(args->pte_pfn); + __free_pages(page, 0); + } + + /* Free page table */ + if (args->start_ptep) { + pte_free(args->mm, args->start_ptep); + mm_dec_nr_ptes(args->mm); + } + + if (args->start_pmdp) { + pmd_free(args->mm, args->start_pmdp); + mm_dec_nr_pmds(args->mm); + } + + if (args->start_pudp) { + pud_free(args->mm, args->start_pudp); + mm_dec_nr_puds(args->mm); + } + + if (args->start_p4dp) + p4d_free(args->mm, args->p4dp); + + /* Free vma and mm struct */ + if (args->vma) + vm_area_free(args->vma); + if (args->mm) + mmdrop(args->mm); +} + +static int __init init_args(struct pgtable_debug_args *args) +{ + struct page *page = NULL; + phys_addr_t phys; + int ret = 0; + + /* Initialize the debugging data */ + memset(args, 0, sizeof(*args)); + args->page_prot = vm_get_page_prot(VMFLAGS); + args->page_prot_none = __P000; + args->pud_pfn = ULONG_MAX; + args->pmd_pfn = ULONG_MAX; + args->pte_pfn = ULONG_MAX; + args->fixed_pgd_pfn = ULONG_MAX; + args->fixed_p4d_pfn = ULONG_MAX; + args->fixed_pud_pfn = ULONG_MAX; + args->fixed_pmd_pfn = ULONG_MAX; + args->fixed_pte_pfn = ULONG_MAX; + + /* Allocate mm and vma */ + args->mm = mm_alloc(); + if (!args->mm) { + pr_err("Failed to allocate mm struct\n"); + ret = -ENOMEM; + goto error; + } + + args->vma = vm_area_alloc(args->mm); + if (!args->vma) { + pr_err("Failed to allocate vma\n"); + ret = -ENOMEM; + goto error; + } + + /* Figure out the virtual address and allocate page table entries */ + args->vaddr = get_random_vaddr(); + args->pgdp = pgd_offset(args->mm, args->vaddr); + args->p4dp = p4d_alloc(args->mm, args->pgdp, args->vaddr); + args->pudp = args->p4dp ? + pud_alloc(args->mm, args->p4dp, args->vaddr) : NULL; + args->pmdp = args->pudp ? + pmd_alloc(args->mm, args->pudp, args->vaddr) : NULL; + args->ptep = args->pmdp ? + pte_alloc_map(args->mm, args->pmdp, args->vaddr) : NULL; + if (!args->ptep) { + pr_err("Failed to allocate page table\n"); + ret = -ENOMEM; + goto error; + } + + /* + * The above page table entries will be modified. Lets save the + * page table entries so that they can be released when the tests + * are completed. + */ + args->start_p4dp = p4d_offset(args->pgdp, 0UL); + args->start_pudp = pud_offset(args->p4dp, 0UL); + args->start_pmdp = pmd_offset(args->pudp, 0UL); + args->start_ptep = pmd_pgtable(READ_ONCE(*(args->pmdp))); + + /* + * Figure out the fixed addresses, which are all around the kernel + * symbol (@start_kernel). The corresponding PFNs might be invalid, + * but it's fine as the following tests won't access the pages. + */ + phys = __pa_symbol(&start_kernel); + args->fixed_pgd_pfn = __phys_to_pfn(phys & PGDIR_MASK); + args->fixed_p4d_pfn = __phys_to_pfn(phys & P4D_MASK); + args->fixed_pud_pfn = __phys_to_pfn(phys & PUD_MASK); + args->fixed_pmd_pfn = __phys_to_pfn(phys & PMD_MASK); + args->fixed_pte_pfn = __phys_to_pfn(phys & PAGE_MASK); + + /* + * Allocate (huge) pages because some of the tests need to access + * the data in the pages. The corresponding tests will be skipped + * if we fail to allocate (huge) pages. + */ + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && + IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD) && + has_transparent_hugepage()) { + page = alloc_pages(GFP_KERNEL, HPAGE_PUD_SHIFT - PAGE_SHIFT); + if (page) { + args->pud_pfn = page_to_pfn(page); + args->pmd_pfn = args->pud_pfn; + args->pte_pfn = args->pud_pfn; + return 0; + } + } + + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && + has_transparent_hugepage()) { + page = alloc_pages(GFP_KERNEL, HPAGE_PMD_ORDER); + if (page) { + args->pmd_pfn = page_to_pfn(page); + args->pte_pfn = args->pmd_pfn; + return 0; + } + } + + page = alloc_pages(GFP_KERNEL, 0); + if (page) + args->pte_pfn = page_to_pfn(page); + + return 0; + +error: + destroy_args(args); + return ret; +} + static int __init debug_vm_pgtable(void) { + struct pgtable_debug_args args; struct vm_area_struct *vma; struct mm_struct *mm; pgd_t *pgdp; @@ -970,9 +1158,13 @@ static int __init debug_vm_pgtable(void) unsigned long vaddr, pte_aligned, pmd_aligned; unsigned long pud_aligned, p4d_aligned, pgd_aligned; spinlock_t *ptl = NULL; - int idx; + int idx, ret; pr_info("Validating architecture page table helpers\n"); + ret = init_args(&args); + if (ret) + return ret; + prot = vm_get_page_prot(VMFLAGS); vaddr = get_random_vaddr(); mm = mm_alloc(); @@ -1127,6 +1319,8 @@ static int __init debug_vm_pgtable(void) mm_dec_nr_pmds(mm); mm_dec_nr_ptes(mm); mmdrop(mm); + + destroy_args(&args); return 0; } late_initcall(debug_vm_pgtable);