Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Liam Howlett <liam.howlett@oracle.com>
To:     "maple-tree@lists.infradead.org" <maple-tree@lists.infradead.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Hugh Dickins <hughd@google.com>
CC:     Yu Zhao <yuzhao@google.com>
Subject: [PATCH v12 69/69] mm/mmap.c: pass in mapping to __vma_link_file()
Thread-Topic: [PATCH v12 69/69] mm/mmap.c: pass in mapping to
 __vma_link_file()
Thread-Index: AQHYm97x7LISvJEFkkawcVa8OgJyEQ==
Date:   Wed, 20 Jul 2022 02:18:05 +0000
Message-ID: <20220720021727.17018-70-Liam.Howlett@oracle.com>
References: <20220720021727.17018-1-Liam.Howlett@oracle.com>
In-Reply-To: <20220720021727.17018-1-Liam.Howlett@oracle.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?iso-8859-1?Q?RuV8FoPv2zvcqb25S12075D0x7t6j9t3kuXu63c6ezyol4jIHBBlSYHGZ8?=
 =?iso-8859-1?Q?WzWZu8v7g4m6hTWnUPeQGid2ImI+IZhWlU7oEncT83opP/NvKIzMStx5/U?=
 =?iso-8859-1?Q?nx0WbexgKh4LAPQ9bmYNnACadOPqq6MB7n+frNFCIf+n5S7+fYw8hfUw2/?=
 =?iso-8859-1?Q?ORj28YTGGuNfWAtajL9pFG1JTY9QOLTu385Uu3ngrG+sOkZ7HvXXiYQrBp?=
 =?iso-8859-1?Q?jqXX5nSX7/WqgR4ngtNGFT+5jqCUnPBEczx3Oh2zF1BPchdnM34FxL270W?=
 =?iso-8859-1?Q?ee6kBUit/aZ6npOfIJ6j9x7dW8qqcfRPA7/L/tDBicapcWnhXqxiLuGyW2?=
 =?iso-8859-1?Q?CAawq1aaCEDsg4sJsXETqjMiHLhfeE2+GR+r82eIc3BnXxCHCiBYPDkjO9?=
 =?iso-8859-1?Q?D7ot7xWHvXrFggkhu0tdBZTCob9oNk0hqUgY1bKyQrNQ5VqV/QutD3Zktd?=
 =?iso-8859-1?Q?LnKXBXM0UDz7rxTZSMQDSbruqnGHvv+nQhH0ZUCE6wbeFEYacdCMxffx/v?=
 =?iso-8859-1?Q?Ueu66kBcfMG90QVlODwgU5LfkIe23URrP3/wRtul9cUh+RTcIWWMup3XB2?=
 =?iso-8859-1?Q?SmkUxE7GaSakj+fKoSpWvXgxl/6MOeAoF2G+j9yyCp6LP93layUdq/NFIM?=
 =?iso-8859-1?Q?fl7f/uIiHPiZz2Zpky00xGuYjB/3qhsrTO9a4CDH/Zy9XLxrBdWu7Z47f3?=
 =?iso-8859-1?Q?fykBxBh0cOygQXloZkHC/d/Hy867QFOK161ZvhQ4WL++hqrhkrX9mgj2uJ?=
 =?iso-8859-1?Q?KsthIk7gBVsLboCQqU/ajvVcJ0f1xYsY/ruIGkJfOr9vIBWXrv2WBEb2Jj?=
 =?iso-8859-1?Q?LW9A6dyh+vAOjjVBNz+dmPATYjUOL5RJH7aRsejjWc0m4aaLm9CTGUOGsf?=
 =?iso-8859-1?Q?9/YfDdJjY2HVY4mL1GvhimRMO1DVgE9XWZHSpbL3HcObtlZ0ZyZ52oilv3?=
 =?iso-8859-1?Q?3B5pdvJpMX7oZrRox5d+D0KMXHQLWt3W0txf03gHE5DtLfyzoNy0g0P9jW?=
 =?iso-8859-1?Q?9Tk9ccVxQqKBsBdYVeB3E7C2+hDeRwz18p+i0m+Ks5e23IKF0L50UaHq94?=
 =?iso-8859-1?Q?t6k6gcwbIDiRVdDKE8LS8J2AKHF28Fu8oDYfu9RjTFMBRwpfyacVJWwGnY?=
 =?iso-8859-1?Q?TODzTC6Zb7YmsjunXa84gp2EciREELq3Jf9sRGIcsqXRpxAAkO7UW/H3vk?=
 =?iso-8859-1?Q?a7k8bnYCqqrQ56qNcyTXyasIjFlruxtAZgDpcBgToGbWuV4qkks6GueIq0?=
 =?iso-8859-1?Q?irZ1e2Q84BrtI12H1Pc1oMjlYjNbbU5tpqtvoFlwhJNZfnLYq56MufUeF5?=
 =?iso-8859-1?Q?ted6CqKS/E1eOwYnyV2lpH7U2C9fkATayg+zeSQnlhy16xI+dgHC3u6hzH?=
 =?iso-8859-1?Q?dqWaPu8PXppA6dLHWn3OH9zIZB47pTNr/IK+Uqo+xIDm0hKqNdT15QbbvB?=
 =?iso-8859-1?Q?So31zHK7VmiWpOLbo7Jwii8ztluJHVlmEKQGAwUpnJnnHC/YxL8ZyoW4xf?=
 =?iso-8859-1?Q?iZG4Zz3/2jyokrCsZvkUoK5tFFqBMjwY1JgU2PtcBx6V0EqIFuFy0LsYUC?=
 =?iso-8859-1?Q?H+6CCZdS/OFcd2XMiomkfOsHzPB3dBFbDRbFsrf88ilXEFp/vttaxfCbO9?=
 =?iso-8859-1?Q?+UGEAddXeYunUwr8nkcL5IfgzbfeuDJQyCrL6zB86B4tjNZHKexOKnIA?=
 =?iso-8859-1?Q?=3D=3D?=
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: SN6PR10MB3022.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 53da1d90-d488-4b60-76fe-08da69f6418e
X-MS-Exchange-CrossTenant-originalarrivaltime: 20 Jul 2022 02:18:05.1640
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: gR8PKbnRNTaKUKctn1SBETOwiwoas1BLPvUXCQpDkA8jmoxPRTT9W5c69BKA4U+SoK0niB+exj7h6wFLW3U9Aw==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH2PR10MB3797
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1
 definitions=2022-07-19_10,2022-07-19_01,2022-06-22_01
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 bulkscore=0 malwarescore=0
 mlxscore=0 phishscore=0 mlxlogscore=999 suspectscore=0 adultscore=0
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2206140000
 definitions=main-2207200008
X-Proofpoint-GUID: DvFeBnsXRiRdW6skVLB9WjKrO5t94THj
X-Proofpoint-ORIG-GUID: DvFeBnsXRiRdW6skVLB9WjKrO5t94THj
X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_LOW,
        RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>

__vma_link_file() resolves the mapping from the file, if there is one.
Pass through the mapping and check the vm_file externally since most
places already have the required information and check of vm_file.

Link: https://lkml.kernel.org/r/20220504011345.662299-54-Liam.Howlett@oracl=
e.com
Link: https://lkml.kernel.org/r/20220621204632.3370049-70-Liam.Howlett@orac=
le.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/mmap.c | 33 +++++++++++++++------------------
 1 file changed, 15 insertions(+), 18 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index a9ebe25c5b09..37990e66feeb 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -246,6 +246,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 	if (brk < min_brk)
 		goto out;
=20
+
 	/*
 	 * Check against rlimit here. If this check is done later after the test
 	 * of oldbrk with newbrk then it can escape the test and let the data
@@ -322,7 +323,6 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 	if (populate)
 		mm_populate(oldbrk, newbrk - oldbrk);
 	return brk;
-
 out:
 	mmap_write_unlock(mm);
 	return origbrk;
@@ -454,21 +454,15 @@ static unsigned long count_vma_pages_range(struct mm_=
struct *mm,
 	return nr_pages;
 }
=20
-static void __vma_link_file(struct vm_area_struct *vma)
+static void __vma_link_file(struct vm_area_struct *vma,
+			    struct address_space *mapping)
 {
-	struct file *file;
-
-	file =3D vma->vm_file;
-	if (file) {
-		struct address_space *mapping =3D file->f_mapping;
-
-		if (vma->vm_flags & VM_SHARED)
-			mapping_allow_writable(mapping);
+	if (vma->vm_flags & VM_SHARED)
+		mapping_allow_writable(mapping);
=20
-		flush_dcache_mmap_lock(mapping);
-		vma_interval_tree_insert(vma, &mapping->i_mmap);
-		flush_dcache_mmap_unlock(mapping);
-	}
+	flush_dcache_mmap_lock(mapping);
+	vma_interval_tree_insert(vma, &mapping->i_mmap);
+	flush_dcache_mmap_unlock(mapping);
 }
=20
 /*
@@ -535,10 +529,11 @@ static int vma_link(struct mm_struct *mm, struct vm_a=
rea_struct *vma)
 	}
=20
 	vma_mas_store(vma, &mas);
-	__vma_link_file(vma);
=20
-	if (mapping)
+	if (mapping) {
+		__vma_link_file(vma, mapping);
 		i_mmap_unlock_write(mapping);
+	}
=20
 	mm->map_count++;
 	validate_mm(mm);
@@ -777,14 +772,14 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned=
 long start,
 			uprobe_munmap(next, next->vm_start, next->vm_end);
=20
 		i_mmap_lock_write(mapping);
-		if (insert) {
+		if (insert && insert->vm_file) {
 			/*
 			 * Put into interval tree now, so instantiated pages
 			 * are visible to arm/parisc __flush_dcache_page
 			 * throughout; but we cannot insert into address
 			 * space until vma start or end is updated.
 			 */
-			__vma_link_file(insert);
+			__vma_link_file(insert, insert->vm_file->f_mapping);
 		}
 	}
=20
@@ -2982,6 +2977,7 @@ static int do_brk_flags(struct ma_state *mas, struct =
vm_area_struct *vma,
 	struct mm_struct *mm =3D current->mm;
=20
 	validate_mm_mt(mm);
+
 	/*
 	 * Check against address space limits by the changed size
 	 * Note: This happens *after* clearing old mappings in some code paths.
@@ -3039,6 +3035,7 @@ static int do_brk_flags(struct ma_state *mas, struct =
vm_area_struct *vma,
 		goto mas_store_fail;
=20
 	mm->map_count++;
+
 out:
 	perf_event_mmap(vma);
 	mm->total_vm +=3D len >> PAGE_SHIFT;
--=20
2.35.1