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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 753AAC433FE for ; Mon, 25 Apr 2022 13:27:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 84F516B0078; Mon, 25 Apr 2022 09:27:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 823E36B007D; Mon, 25 Apr 2022 09:27:06 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4B0576B0074; Mon, 25 Apr 2022 09:27:06 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.27]) by kanga.kvack.org (Postfix) with ESMTP id 237076B007B for ; Mon, 25 Apr 2022 09:27:06 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay13.hostedemail.com (Postfix) with ESMTP id EB49C615AE for ; Mon, 25 Apr 2022 13:27:05 +0000 (UTC) X-FDA: 79395477210.13.1AEF46C Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by imf07.hostedemail.com (Postfix) with ESMTP id 43C1040040 for ; Mon, 25 Apr 2022 13:27:03 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Kn5QG2w2vzhYnQ; Mon, 25 Apr 2022 21:26:46 +0800 (CST) Received: from huawei.com (10.175.124.27) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Mon, 25 Apr 2022 21:27:01 +0800 From: Miaohe Lin To: , , CC: , , , , , , , Subject: [PATCH v2 4/4] mm/migration: fix potential pte_unmap on an not mapped pte Date: Mon, 25 Apr 2022 21:27:23 +0800 Message-ID: <20220425132723.34824-5-linmiaohe@huawei.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20220425132723.34824-1-linmiaohe@huawei.com> References: <20220425132723.34824-1-linmiaohe@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected X-Stat-Signature: nkofsca8kkkbf37pbymd68h1mrt4oek5 X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 43C1040040 X-Rspam-User: Authentication-Results: imf07.hostedemail.com; dkim=none; spf=pass (imf07.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.188 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-HE-Tag: 1650893223-38663 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: __migration_entry_wait and migration_entry_wait_on_locked assume pte is always mapped from caller. But this is not the case when it's called from migration_entry_wait_huge and follow_huge_pmd. Add a hugetlbfs variant that calls hugetlb_migration_entry_wait(ptep == NULL) to fix this issue. Fixes: 30dad30922cc ("mm: migration: add migrate_entry_wait_huge()") Suggested-by: David Hildenbrand Signed-off-by: Miaohe Lin --- include/linux/swapops.h | 12 ++++++++---- mm/hugetlb.c | 4 ++-- mm/migrate.c | 23 +++++++++++++++++++---- 3 files changed, 29 insertions(+), 10 deletions(-) diff --git a/include/linux/swapops.h b/include/linux/swapops.h index 30cded849ee4..862e5a2053b1 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -244,8 +244,10 @@ extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, spinlock_t *ptl); extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, unsigned long address); -extern void migration_entry_wait_huge(struct vm_area_struct *vma, - struct mm_struct *mm, pte_t *pte); +#ifdef CONFIG_HUGETLB_PAGE +extern void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl); +extern void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte); +#endif #else static inline swp_entry_t make_readable_migration_entry(pgoff_t offset) { @@ -271,8 +273,10 @@ static inline void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, spinlock_t *ptl) { } static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, unsigned long address) { } -static inline void migration_entry_wait_huge(struct vm_area_struct *vma, - struct mm_struct *mm, pte_t *pte) { } +#ifdef CONFIG_HUGETLB_PAGE +static inline void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl) { } +static inline void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte) { } +#endif static inline int is_writable_migration_entry(swp_entry_t entry) { return 0; diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 098f81e8550d..994361ec75e0 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5689,7 +5689,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, */ entry = huge_ptep_get(ptep); if (unlikely(is_hugetlb_entry_migration(entry))) { - migration_entry_wait_huge(vma, mm, ptep); + migration_entry_wait_huge(vma, ptep); return 0; } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) return VM_FAULT_HWPOISON_LARGE | @@ -6907,7 +6907,7 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address, } else { if (is_hugetlb_entry_migration(pte)) { spin_unlock(ptl); - __migration_entry_wait(mm, (pte_t *)pmd, ptl); + __migration_entry_wait_huge((pte_t *)pmd, ptl); goto retry; } /* diff --git a/mm/migrate.c b/mm/migrate.c index c937a496239b..7b31d0b06977 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -315,13 +315,28 @@ void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, __migration_entry_wait(mm, ptep, ptl); } -void migration_entry_wait_huge(struct vm_area_struct *vma, - struct mm_struct *mm, pte_t *pte) +#ifdef CONFIG_HUGETLB_PAGE +void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl) { - spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), mm, pte); - __migration_entry_wait(mm, pte, ptl); + pte_t pte; + + spin_lock(ptl); + pte = huge_ptep_get(ptep); + + if (unlikely(!is_hugetlb_entry_migration(pte))) + spin_unlock(ptl); + else + migration_entry_wait_on_locked(pte_to_swp_entry(pte), NULL, ptl); } +void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte) +{ + spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), vma->vm_mm, pte); + + __migration_entry_wait_huge(pte, ptl); +} +#endif + #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd) { -- 2.23.0