linux-kernel - Re: [PATCH v2 3/5] mm/memory_hotplug: 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: <C9420CC4-0EEF-4B7D-8B60-3434079137A2@nvidia.com>
Date:   Wed, 06 Sep 2023 13:39:23 -0400
From:   Zi Yan <ziy@...dia.com>
To:     David Hildenbrand <david@...hat.com>
Cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        linux-mips@...r.kernel.org,
        Andrew Morton <akpm@...ux-foundation.org>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        "\"Matthew Wilcox (Oracle)\"" <willy@...radead.org>,
        Mike Kravetz <mike.kravetz@...cle.com>,
        Muchun Song <muchun.song@...ux.dev>,
        "\"Mike Rapoport (IBM)\"" <rppt@...nel.org>,
        stable@...r.kernel.org, Muchun Song <songmuchun@...edance.com>
Subject: Re: [PATCH v2 3/5] mm/memory_hotplug: use nth_page() in place of
 direct struct page manipulation.

On 6 Sep 2023, at 13:17, David Hildenbrand wrote:

> On 06.09.23 17:03, Zi Yan wrote:
>> From: Zi Yan <ziy@...dia.com>
>
> Subject talks about "nth_page()" but that's not what this patch does.
>
>>
>> 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.
>
> ^ dito
>
>>
>> Fixes: eeb0efd071d8 ("mm,memory_hotplug: fix scan_movable_pages() for gigantic hugepages")
>> Cc: <stable@...r.kernel.org>
>> Signed-off-by: Zi Yan <ziy@...dia.com>
>> Reviewed-by: Muchun Song <songmuchun@...edance.com>
>> ---
>>   mm/memory_hotplug.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> 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;
>
> I suspect systems without VMEMMAP also don't usually support gigantic pages AND hotunplug :)
>
> With the subject+description fixed
>
> Acked-by: David Hildenbrand <david@...hat.com>

Sure. Thanks.


--
Best Regards,
Yan, Zi

Download attachment "signature.asc" of type "application/pgp-signature" (855 bytes)