linux-kernel - [PATCH 1/3] mm: use nth_page() in place of direct struct page manipulation.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230830182753.55367-2-zi.yan@sent.com>
Date:   Wed, 30 Aug 2023 14:27:51 -0400
From:   Zi Yan <zi.yan@...t.com>
To:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        linux-mips@...r.kernel.org
Cc:     Zi Yan <ziy@...dia.com>, Andrew Morton <akpm@...ux-foundation.org>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        "Matthew Wilcox (Oracle)" <willy@...radead.org>,
        David Hildenbrand <david@...hat.com>,
        Mike Kravetz <mike.kravetz@...cle.com>,
        Muchun Song <muchun.song@...ux.dev>,
        "Mike Rapoport (IBM)" <rppt@...nel.org>
Subject: [PATCH 1/3] mm: use nth_page() in place of direct struct page manipulation.

From: Zi Yan <ziy@...dia.com>

When dealing with hugetlb pages, manipulating struct page pointers
directly can get to wrong struct page, since struct page is not guaranteed
to be contiguous on SPARSEMEM without VMEMMAP. Use nth_page() to handle
it properly.

Signed-off-by: Zi Yan <ziy@...dia.com>
---
 mm/cma.c            | 2 +-
 mm/hugetlb.c        | 2 +-
 mm/memory_hotplug.c | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/cma.c b/mm/cma.c
index da2967c6a223..2b2494fd6b59 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -505,7 +505,7 @@ struct page *cma_alloc(struct cma *cma, unsigned long count,
 	 */
 	if (page) {
 		for (i = 0; i < count; i++)
-			page_kasan_tag_reset(page + i);
+			page_kasan_tag_reset(nth_page(page, i));
 	}
 
 	if (ret && !no_warn) {
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index ba6d39b71cb1..77e8d2cf4eed 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6474,7 +6474,7 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
 			}
 		}
 
-		page += ((address & ~huge_page_mask(h)) >> PAGE_SHIFT);
+		page = nth_page(page, ((address & ~huge_page_mask(h)) >> PAGE_SHIFT));
 
 		/*
 		 * Note that page may be a sub-page, and with vmemmap
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 1b03f4ec6fd2..3b301c4023ff 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1689,7 +1689,7 @@ static int scan_movable_pages(unsigned long start, unsigned long end,
 		 */
 		if (HPageMigratable(head))
 			goto found;
-		skip = compound_nr(head) - (page - head);
+		skip = compound_nr(head) - (pfn - page_to_pfn(head));
 		pfn += skip - 1;
 	}
 	return -ENOENT;
-- 
2.40.1