From mboxrd@z Thu Jan 1 00:00:00 1970 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=-15.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 040BFC63793 for ; Thu, 22 Jul 2021 05:56:08 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A8EF561264 for ; Thu, 22 Jul 2021 05:56:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A8EF561264 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3D7EC6B005D; Thu, 22 Jul 2021 01:56:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 388226B0071; Thu, 22 Jul 2021 01:56:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 275ED6B0072; Thu, 22 Jul 2021 01:56:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0219.hostedemail.com [216.40.44.219]) by kanga.kvack.org (Postfix) with ESMTP id 1170E6B005D for ; Thu, 22 Jul 2021 01:56:07 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 9E875181AF5F7 for ; Thu, 22 Jul 2021 05:56:06 +0000 (UTC) X-FDA: 78389163132.21.36FF3E2 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf13.hostedemail.com (Postfix) with ESMTP id 26E6D1028333 for ; Thu, 22 Jul 2021 05:56:06 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3FD4AD6E; Wed, 21 Jul 2021 22:56:05 -0700 (PDT) Received: from [10.163.65.134] (unknown [10.163.65.134]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0C6333F66F; Wed, 21 Jul 2021 22:56:02 -0700 (PDT) Subject: Re: [PATCH v3 07/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in PTE modifying tests To: Gavin Shan , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, chuhu@redhat.com, shan.gavin@gmail.com References: <20210719130613.334901-1-gshan@redhat.com> <20210719130613.334901-8-gshan@redhat.com> From: Anshuman Khandual Message-ID: Date: Thu, 22 Jul 2021 11:26:52 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210719130613.334901-8-gshan@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Authentication-Results: imf13.hostedemail.com; dkim=none; spf=pass (imf13.hostedemail.com: domain of anshuman.khandual@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=anshuman.khandual@arm.com; dmarc=pass (policy=none) header.from=arm.com X-Stat-Signature: 7yfje7t149kdgptcw31qff18c9mwttbt X-Rspamd-Queue-Id: 26E6D1028333 X-Rspamd-Server: rspam01 X-HE-Tag: 1626933366-609847 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: On 7/19/21 6:36 PM, Gavin Shan wrote: > This uses struct pgtable_debug_args in PTE modifying tests. The allocated > page is used as set_pte_at() is used there. The tests are skipped if > the allocated page doesn't exist. Besides, the unused variable @ptep > and @pte_aligned in debug_vm_pgtable() are dropped. Please dont drop @ptep and @pte_aligned just yet. > > Signed-off-by: Gavin Shan > --- > mm/debug_vm_pgtable.c | 75 ++++++++++++++++++++++--------------------- > 1 file changed, 39 insertions(+), 36 deletions(-) > > diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c > index d32e55a95c55..eb6dda88e0d9 100644 > --- a/mm/debug_vm_pgtable.c > +++ b/mm/debug_vm_pgtable.c > @@ -116,10 +116,7 @@ static void __init pte_basic_tests(struct pgtable_debug_args *args, int idx) > WARN_ON(!pte_dirty(pte_wrprotect(pte_mkdirty(pte)))); > } > > -static void __init pte_advanced_tests(struct mm_struct *mm, > - struct vm_area_struct *vma, pte_t *ptep, > - unsigned long pfn, unsigned long vaddr, > - pgprot_t prot) > +static void __init pte_advanced_tests(struct pgtable_debug_args *args) > { > pte_t pte; > > @@ -130,33 +127,38 @@ static void __init pte_advanced_tests(struct mm_struct *mm, > */ > > pr_debug("Validating PTE advanced\n"); > - pte = pfn_pte(pfn, prot); > - set_pte_at(mm, vaddr, ptep, pte); > - ptep_set_wrprotect(mm, vaddr, ptep); > - pte = ptep_get(ptep); > + if (args->pte_pfn == ULONG_MAX) { > + pr_debug("%s: Skipped\n", __func__); > + return; > + } Just return. Please dont call out "Skipped". Also this check should be performed before printing pr_debug("Validating PTE advanced\n"). The print indicates that the test has started. > + > + pte = pfn_pte(args->pte_pfn, args->page_prot); > + set_pte_at(args->mm, args->vaddr, args->ptep, pte); > + ptep_set_wrprotect(args->mm, args->vaddr, args->ptep); > + pte = ptep_get(args->ptep); > WARN_ON(pte_write(pte)); > - ptep_get_and_clear(mm, vaddr, ptep); > - pte = ptep_get(ptep); > + ptep_get_and_clear(args->mm, args->vaddr, args->ptep); > + pte = ptep_get(args->ptep); > WARN_ON(!pte_none(pte)); > > - pte = pfn_pte(pfn, prot); > + pte = pfn_pte(args->pte_pfn, args->page_prot); > pte = pte_wrprotect(pte); > pte = pte_mkclean(pte); > - set_pte_at(mm, vaddr, ptep, pte); > + set_pte_at(args->mm, args->vaddr, args->ptep, pte); > pte = pte_mkwrite(pte); > pte = pte_mkdirty(pte); > - ptep_set_access_flags(vma, vaddr, ptep, pte, 1); > - pte = ptep_get(ptep); > + ptep_set_access_flags(args->vma, args->vaddr, args->ptep, pte, 1); > + pte = ptep_get(args->ptep); > WARN_ON(!(pte_write(pte) && pte_dirty(pte))); > - ptep_get_and_clear_full(mm, vaddr, ptep, 1); > - pte = ptep_get(ptep); > + ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1); > + pte = ptep_get(args->ptep); > WARN_ON(!pte_none(pte)); > > - pte = pfn_pte(pfn, prot); > + pte = pfn_pte(args->pte_pfn, args->page_prot); > pte = pte_mkyoung(pte); > - set_pte_at(mm, vaddr, ptep, pte); > - ptep_test_and_clear_young(vma, vaddr, ptep); > - pte = ptep_get(ptep); > + set_pte_at(args->mm, args->vaddr, args->ptep, pte); > + ptep_test_and_clear_young(args->vma, args->vaddr, args->ptep); > + pte = ptep_get(args->ptep); > WARN_ON(pte_young(pte)); > } > > @@ -617,20 +619,24 @@ static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp, > } > #endif /* PAGETABLE_P4D_FOLDED */ > > -static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep, > - unsigned long pfn, unsigned long vaddr, > - pgprot_t prot) > +static void __init pte_clear_tests(struct pgtable_debug_args *args) > { > - pte_t pte = pfn_pte(pfn, prot); > + pte_t pte; > > pr_debug("Validating PTE clear\n"); > + if (args->pte_pfn == ULONG_MAX) { > + pr_debug("%s: Skipped\n", __func__); > + return; > + } Just return. Please dont call out "Skipped". Also this check should be performed before printing pr_debug("Validating PTE clear\n"). The print indicates that the test has started. > + > + pte = pfn_pte(args->pte_pfn, args->page_prot); Please keep this unchanged and move to its original position. > #ifndef CONFIG_RISCV > pte = __pte(pte_val(pte) | RANDOM_ORVALUE); > #endif > - set_pte_at(mm, vaddr, ptep, pte); > + set_pte_at(args->mm, args->vaddr, args->ptep, pte); > barrier(); > - pte_clear(mm, vaddr, ptep); > - pte = ptep_get(ptep); > + pte_clear(args->mm, args->vaddr, args->ptep); > + pte = ptep_get(args->ptep); > WARN_ON(!pte_none(pte)); > } > > @@ -1150,11 +1156,10 @@ static int __init debug_vm_pgtable(void) > p4d_t *p4dp, *saved_p4dp; > pud_t *pudp, *saved_pudp; > pmd_t *pmdp, *saved_pmdp, pmd; > - pte_t *ptep; > pgtable_t saved_ptep; > pgprot_t prot; > phys_addr_t paddr; > - unsigned long vaddr, pte_aligned, pmd_aligned; > + unsigned long vaddr, pmd_aligned; > unsigned long pud_aligned; > spinlock_t *ptl = NULL; > int idx, ret; > @@ -1189,10 +1194,8 @@ static int __init debug_vm_pgtable(void) > */ > paddr = __pa_symbol(&start_kernel); > > - pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT; Please dont drop pte_aligned just yet. > pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT; > pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT; > - WARN_ON(!pfn_valid(pte_aligned)); This should go into init_args() at the right place as the following, after evaluating it from 'start_kernel' symbol - just to be sure. WARN_ON(!pfn_valid(args->fixed_pte_pfn)) > > pgdp = pgd_offset(mm, vaddr); > p4dp = p4d_alloc(mm, pgdp, vaddr); > @@ -1272,11 +1275,11 @@ static int __init debug_vm_pgtable(void) > * Page table modifying tests. They need to hold > * proper page table lock. > */ > - > - ptep = pte_offset_map_lock(mm, pmdp, vaddr, &ptl); > - pte_clear_tests(mm, ptep, pte_aligned, vaddr, prot); > - pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot); > - pte_unmap_unlock(ptep, ptl); > + ptl = pte_lockptr(args.mm, args.pmdp); > + spin_lock(ptl); > + pte_clear_tests(&args); > + pte_advanced_tests(&args); > + spin_unlock(ptl); Why pte_offset_map_lock()/pte_unmap_unlock() has been dropped and spin_lock()/spin_unlock() sequence has been added ? Please dont change the tests in these patches. > > ptl = pmd_lock(mm, pmdp); > pmd_clear_tests(mm, pmdp); >