From nobody Wed Sep 10 09:30:32 2025 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 42090C04FDF for ; Fri, 4 Aug 2023 15:28:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229780AbjHDP23 (ORCPT ); Fri, 4 Aug 2023 11:28:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232216AbjHDP14 (ORCPT ); Fri, 4 Aug 2023 11:27:56 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B34365593 for ; Fri, 4 Aug 2023 08:27:35 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-586a6269dbfso15062797b3.1 for ; Fri, 04 Aug 2023 08:27:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1691162854; x=1691767654; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=LfajP5IIbFpg2Y7BQRxvk1sHiLCqjf/rsCkC3jBCtoI=; b=jZlRzwl/sZxeKY0Q22GmSPxgFIqyr2sjFjG2dJWAnROoCqd561GTzeSUKMtg/2mqt1 ggyBLLrU1fznQHJEpV6iArmu4q/1ElFb+5c8i813a5QvYsRPPftZDP04yYsFkEpBfTFv biqZHQTtxZS7XMj4IKe/OZIiQ2Hzx3Sc4KiQkuiuVJ83Jibh5wp9rdvvqebLNTk9QL7W NA08SkaqEcu5wURtIv2bzCzal6v9uxf83gQzzLLvQVI6Kfk5jLDfOArO5bHqXdZSMQ1C ssQWic0dvDYtH0HIwM19ShxQ3BVwkNI58J3XyBg9Vj3lhfWdSX5jmfTA1qFRH0njGemz MjSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691162854; x=1691767654; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=LfajP5IIbFpg2Y7BQRxvk1sHiLCqjf/rsCkC3jBCtoI=; b=KX6Zj6hFPOtQiYKA8dapnpdgCtyF6gGauWXwmXFMypE5Dlli7iqr0fA25HhSqHE60J RRd3nfh9nhwyIOcTKFIG3VPFDxaOmS8+WGXxWRI7oR0fdfaJYZX2vC3MdNbGSa3uykiJ SfQQ49HlJ96Mv8jEkp8/Ist3ew50Xgw9ENGQotlgKAw3zYBeRd+SVaO8C/jDID++ODS/ d/5VSFesu6rr7TAl0pg8xSPf4nk6CbhOLOQ/LNwRRFxExCd7bE1nrxUdRIBx283PEHdF 3kG4DnvUWhyk9pAKcEfaquW97qPLiPyjF5CGxquGn/wWyINHepqe1oCgZHRdVcmf/hmN X9Yg== X-Gm-Message-State: AOJu0YyJuDR6vgjCkKr/l0YFBtgXHdxDbhboUvehqQT/RDI0Fa3bxLEU VnPgkYdR2j3MukMUmpVuJvFVRuTtoG0= X-Google-Smtp-Source: AGHT+IHa9ndTaenWukiguHAw5+MvFDtv8DkvZBd31Rp3irRnrIogFfiHRjgfkWXCeFLeklAX7f0FtCBLNkg= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:201:43a7:a50f:b0fd:a068]) (user=surenb job=sendgmr) by 2002:a05:690c:448a:b0:583:9d8d:fb0d with SMTP id gr10-20020a05690c448a00b005839d8dfb0dmr1503ywb.0.1691162854651; Fri, 04 Aug 2023 08:27:34 -0700 (PDT) Date: Fri, 4 Aug 2023 08:27:21 -0700 In-Reply-To: <20230804152724.3090321-1-surenb@google.com> Mime-Version: 1.0 References: <20230804152724.3090321-1-surenb@google.com> X-Mailer: git-send-email 2.41.0.585.gd2178a4bd4-goog Message-ID: <20230804152724.3090321-4-surenb@google.com> Subject: [PATCH v4 3/6] mm: replace mmap with vma write lock assertions when operating on a vma From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org, jannh@google.com, willy@infradead.org, liam.howlett@oracle.com, david@redhat.com, peterx@redhat.com, ldufour@linux.ibm.com, vbabka@suse.cz, michel@lespinasse.org, jglisse@google.com, mhocko@suse.com, hannes@cmpxchg.org, dave@stgolabs.net, hughd@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, kernel-team@android.com, Suren Baghdasaryan , "Liam R . Howlett" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Vma write lock assertion always includes mmap write lock assertion and additional vma lock checks when per-VMA locks are enabled. Replace weaker mmap_assert_write_locked() assertions with stronger vma_assert_write_locked() ones when we are operating on a vma which is expected to be locked. Suggested-by: Jann Horn Signed-off-by: Suren Baghdasaryan Reviewed-by: Liam R. Howlett --- mm/hugetlb.c | 2 +- mm/khugepaged.c | 5 +++-- mm/memory.c | 2 +- 3 files changed, 5 insertions(+), 4 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 64a3239b6407..1d871a1167d8 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5028,7 +5028,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, st= ruct mm_struct *src, src_vma->vm_start, src_vma->vm_end); mmu_notifier_invalidate_range_start(&range); - mmap_assert_write_locked(src); + vma_assert_write_locked(src_vma); raw_write_seqcount_begin(&src->write_protect_seq); } else { /* diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 78c8d5d8b628..1e43a56fba31 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1495,7 +1495,7 @@ static int set_huge_pmd(struct vm_area_struct *vma, u= nsigned long addr, }; =20 VM_BUG_ON(!PageTransHuge(hpage)); - mmap_assert_write_locked(vma->vm_mm); + vma_assert_write_locked(vma); =20 if (do_set_pmd(&vmf, hpage)) return SCAN_FAIL; @@ -1525,7 +1525,7 @@ static void collapse_and_free_pmd(struct mm_struct *m= m, struct vm_area_struct *v pmd_t pmd; struct mmu_notifier_range range; =20 - mmap_assert_write_locked(mm); + vma_assert_write_locked(vma); if (vma->vm_file) lockdep_assert_held_write(&vma->vm_file->f_mapping->i_mmap_rwsem); /* @@ -1570,6 +1570,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, uns= igned long addr, int count =3D 0, result =3D SCAN_FAIL; int i; =20 + /* Ensure vma can't change, it will be locked below after checks */ mmap_assert_write_locked(mm); =20 /* Fast check before locking page if already PMD-mapped */ diff --git a/mm/memory.c b/mm/memory.c index 603b2f419948..652d99b9858a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1312,7 +1312,7 @@ copy_page_range(struct vm_area_struct *dst_vma, struc= t vm_area_struct *src_vma) * Use the raw variant of the seqcount_t write API to avoid * lockdep complaining about preemptibility. */ - mmap_assert_write_locked(src_mm); + vma_assert_write_locked(src_vma); raw_write_seqcount_begin(&src_mm->write_protect_seq); } =20 --=20 2.41.0.585.gd2178a4bd4-goog