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>,
        "damon @ lists . linux . dev" <damon@lists.linux.dev>,
        SeongJae Park <sj@kernel.org>,
        David Hildenbrand <david@redhat.com>
Subject: [PATCH v10 41/69] exec: use VMA iterator instead of linked list
Thread-Topic: [PATCH v10 41/69] exec: use VMA iterator instead of linked list
Thread-Index: AQHYhbAR93zMxAOlekSY+zL611woEw==
Date:   Tue, 21 Jun 2022 20:47:06 +0000
Message-ID: <20220621204632.3370049-42-Liam.Howlett@oracle.com>
References: <20220621204632.3370049-1-Liam.Howlett@oracle.com>
In-Reply-To: <20220621204632.3370049-1-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?sZzzom7MAuetdcc99n+3BH6NSpbNHZvM4P6RSV5zyHYEFTCcg1HUsq5t3B?=
 =?iso-8859-1?Q?qSKuomr4ZaFdD3UNca8xxHJKCvQlW0JAsF4fzaXcr7jWRNOp3+2PElBvoF?=
 =?iso-8859-1?Q?um8tQDzjErfSfOa8PCK/j7vpytk2QwmNp28xUTEgtAaSLXasawUT2H1iCB?=
 =?iso-8859-1?Q?2i1TKwM8CJlZgGU4TdP55vUlrZnC8NQ/gLlPoW/3ew/hHMFMlXuVBHAhZk?=
 =?iso-8859-1?Q?0Jv+d40v7Fj6XnrvAn+JlPlY/W6OACILTlksENQ37svNu0nGM8mF7TZhEU?=
 =?iso-8859-1?Q?IXtHG35xewwZSUoPsFEOSM7FTdYI3qN4VvimJ79BT3xYulFiatua9P4yvX?=
 =?iso-8859-1?Q?9GtI5meaG2RkZDmCHMPHWGYGaPaFPEowyHdn2tl5XJG2+YI3HPOncsuMrt?=
 =?iso-8859-1?Q?z/9E+PQWgtYDNSrDzRcug1cL1mkuqDKnqu5dz/Ms+fZUFmgQhCU3nHZXLL?=
 =?iso-8859-1?Q?hNdqAdFleZx/DvpVrd7Vo0ggKE2B5HoQ8tc+buvatLSXsScn4UA4GbuKP5?=
 =?iso-8859-1?Q?2GO4N8mAN9OnYZUFLWWhhqrWTG64H3LMd0rS/IIOzBPioUHgOCx3FKSdZA?=
 =?iso-8859-1?Q?o83KcxF2PEkUIfRP6WWa/iKRt72XZoug+hxiYmiVUqblTgW8NCGFkST4jf?=
 =?iso-8859-1?Q?9K2SeFrIqD3zpvRz5ZoAhJBMt6RKppoNftK9FlagXPl81D5Tsb44pAV3ht?=
 =?iso-8859-1?Q?U4KrJ1TBzXcgAjjvseFbhmS9IO2wfu9kANwn/3cEHZi41q7Ywl4IJkTfnR?=
 =?iso-8859-1?Q?q9xwcYI3wugiSarHlQ6y37Zy7OlvaDWVtiOelNRnMNeKBgTI3yNl+OeR3w?=
 =?iso-8859-1?Q?GpuHtN0Fgh22LvykYgHY7EtqGjhmPBFdQPQWuiurWJztdR1pbbehB5xnuV?=
 =?iso-8859-1?Q?8NGHsgxMhyNnvEzGOkU5fgvUBmQmViTTg88oYNICEHTXN8r3z6peWhW9lC?=
 =?iso-8859-1?Q?O3Y+QcbLWN5lt4zi7kjn10WlCF9wA0bbIMNsW7bTo/mq33xviT1VQTNFa6?=
 =?iso-8859-1?Q?uE7x6bG7kAwuYOHNOeH86vYUwcK4j8jdTpF+meMEsX5odLhjhLh21fgZAa?=
 =?iso-8859-1?Q?UgjYZyDaylpAnowWQ+jXjdJBbB7/5V5cx0h3JvaQ/3H5I5ru0fYkx63eax?=
 =?iso-8859-1?Q?CIvG9XwyW4zND+ly8aPsJDcMbPdfU33QYrj3hycf8plTBv1+bNLXGjDAd9?=
 =?iso-8859-1?Q?7Item4saqHrnJw7nb3+XJHsMCs5f0m+Gx7hSDJh3hXz1hu7ZoUtiOXnCLp?=
 =?iso-8859-1?Q?zqIi4+UC334VbJXDxqEPqoyMK4Sp7p2j2g+CSY2aFqWAd0HnrOm6/quWex?=
 =?iso-8859-1?Q?BQgLtrum2GR5YVzuBrG2wH7RqiBbl9bo7rMKylRK4d6FF4Pp6TlJcPRP8U?=
 =?iso-8859-1?Q?iUSGlMnoDFZZl9g9ZV3NSbqJtaTsPeK2pgj/OG1R5LR9Gx6wMkL7zilsjQ?=
 =?iso-8859-1?Q?UmtosZqO++exgn+iIo4vUkqVuNhqTw5fJhyxSYK4e1BPPzU53Ox0AJ2Ou5?=
 =?iso-8859-1?Q?94kLTBViemLqRetW6MbGK71SL2adjFbrgaJ9NQsck+F+6A/qfFVlwdXVXx?=
 =?iso-8859-1?Q?6G6pvXZ1Ztr6NkJU/6eRYsiUT+nQu6HK64vc/tuRmrMlKVYdhljx1gQOf7?=
 =?iso-8859-1?Q?O/Rdel9tMnsvPmu/tjH6GKw46PFt81X+fYWETrHA6FuQj6QAA35n4XpR5f?=
 =?iso-8859-1?Q?+esmduMOaOUHaMTlmPjEkqlXjeCzMEIouX9gNyHFXTuWD7OLueuUELfu+X?=
 =?iso-8859-1?Q?YSJP/E28wh3ITQj8wTTknHev+W7tw8PPLMZxnb0svvP1FG9v0eKYybTvOS?=
 =?iso-8859-1?Q?SwHtrTWlGC1t2fMaAKcpi85wYrywHLQ=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: 56727151-d728-4947-7bd3-08da53c74d52
X-MS-Exchange-CrossTenant-originalarrivaltime: 21 Jun 2022 20:47:06.8160
 (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: D4/RJDuG7xH6jVfjefgZht6yYVG9KpdPZLYYkPqQy3wSAh6Oo4T0X1EzEUaA5Xnpnu7fqW9Dp9SHTH/BgXYVOQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR10MB4025
X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.517,18.0.883
 definitions=2022-06-21_09:2022-06-21,2022-06-21 signatures=0
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 bulkscore=0 phishscore=0
 mlxlogscore=999 mlxscore=0 suspectscore=0 spamscore=0 malwarescore=0
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2204290000
 definitions=main-2206210087
X-Proofpoint-ORIG-GUID: -H15FqzSP12XkvY386vxYF1agaWP3cy8
X-Proofpoint-GUID: -H15FqzSP12XkvY386vxYF1agaWP3cy8
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,T_SCC_BODY_TEXT_LINE
        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: "Matthew Wilcox (Oracle)" <willy@infradead.org>

Remove a use of the vm_next list by doing the initial lookup with the VMA
iterator and then using it to find the next entry.

Link: https://lkml.kernel.org/r/20220504011345.662299-26-Liam.Howlett@oracl=
e.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Howells <dhowells@redhat.com>
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>
---
 fs/exec.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index b97afa682ffe..9843cecd031a 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -686,6 +686,8 @@ static int shift_arg_pages(struct vm_area_struct *vma, =
unsigned long shift)
 	unsigned long length =3D old_end - old_start;
 	unsigned long new_start =3D old_start - shift;
 	unsigned long new_end =3D old_end - shift;
+	VMA_ITERATOR(vmi, mm, new_start);
+	struct vm_area_struct *next;
 	struct mmu_gather tlb;
=20
 	BUG_ON(new_start > new_end);
@@ -694,7 +696,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, =
unsigned long shift)
 	 * ensure there are no vmas between where we want to go
 	 * and where we are
 	 */
-	if (vma !=3D find_vma(mm, new_start))
+	if (vma !=3D vma_next(&vmi))
 		return -EFAULT;
=20
 	/*
@@ -713,12 +715,13 @@ static int shift_arg_pages(struct vm_area_struct *vma=
, unsigned long shift)
=20
 	lru_add_drain();
 	tlb_gather_mmu(&tlb, mm);
+	next =3D vma_next(&vmi);
 	if (new_end > old_start) {
 		/*
 		 * when the old and new regions overlap clear from new_end.
 		 */
 		free_pgd_range(&tlb, new_end, old_end, new_end,
-			vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING);
+			next ? next->vm_start : USER_PGTABLES_CEILING);
 	} else {
 		/*
 		 * otherwise, clean from old_start; this is done to not touch
@@ -727,7 +730,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, =
unsigned long shift)
 		 * for the others its just a little faster.
 		 */
 		free_pgd_range(&tlb, old_start, old_end, new_end,
-			vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING);
+			next ? next->vm_start : USER_PGTABLES_CEILING);
 	}
 	tlb_finish_mmu(&tlb);
=20
--=20
2.35.1