From: "David Hildenbrand (Arm)" <david@kernel.org>
To: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>
Cc: Vernon Yang <vernon2gm@gmail.com>,
akpm@linux-foundation.org, nico.pache@linux.dev,
ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org,
lance.yang@linux.dev, usama.arif@linux.dev, zokeefe@google.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
stable@vger.kernel.org, Vernon Yang <yanglincheng@kylinos.cn>
Subject: Re: [PATCH v3 1/3] mm: khugepaged: fix swap entry value to folio_pfn()
Date: Wed, 26 Aug 2026 10:08:58 +0200 [thread overview]
Message-ID: <b6fbf952-c619-4fc7-8a8e-62a0ae64ff0d@kernel.org> (raw)
In-Reply-To: <ao6c6Oe_KV0O1LJn@gremlin>
On 8/26/26 10:07, Lorenzo Stoakes (ARM) wrote:
> On Wed, Aug 26, 2026 at 09:57:05AM +0200, David Hildenbrand (Arm) wrote:
>> On 8/26/26 04:44, Vernon Yang wrote:
>>>
>>> When the `xas_for_each()` iteration to terminate and the folio operation
>>> preceding is normal, but pfn will be incorrect.
>>
>> The PFN is only relevant when a folio participated in the failure. Maybe the
>> following would be cleanest?
>>
>> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
>> index 75639298efc27..371ee0b16d10c 100644
>> --- a/mm/khugepaged.c
>> +++ b/mm/khugepaged.c
>> @@ -2683,6 +2683,7 @@ static enum scan_result collapse_scan_file(struct
>> mm_struct *mm,
>> int present, swap;
>> int node = NUMA_NO_NODE;
>> enum scan_result result = SCAN_SUCCEED;
>> + unsigned long problematic_pfn = -1;
>
> I find this name... problematic :)
Elaborate.
--
Cheers,
David
next prev parent reply other threads:[~2026-08-26 8:09 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-24 9:29 [PATCH v3 0/3] mm: khugepaged: fix tracepoint UAF Vernon Yang
2026-08-24 9:29 ` [PATCH v3 1/3] mm: khugepaged: fix swap entry value to folio_pfn() Vernon Yang
2026-08-24 11:54 ` David Hildenbrand (Arm)
2026-08-26 2:44 ` Vernon Yang
2026-08-26 7:57 ` David Hildenbrand (Arm)
2026-08-26 8:07 ` Lorenzo Stoakes (ARM)
2026-08-26 8:08 ` David Hildenbrand (Arm) [this message]
2026-08-26 8:11 ` Lorenzo Stoakes (ARM)
2026-08-26 8:16 ` David Hildenbrand (Arm)
2026-08-26 8:24 ` David Hildenbrand (Arm)
2026-08-26 8:35 ` Lorenzo Stoakes (ARM)
2026-08-26 9:10 ` David Hildenbrand (Arm)
2026-08-26 9:21 ` Vernon Yang
2026-08-26 11:04 ` Lorenzo Stoakes (ARM)
2026-08-26 9:08 ` Vernon Yang
2026-08-24 9:29 ` [PATCH v3 2/3] mm: khugepaged: fix folio is used after pte_unmap_unlock() Vernon Yang
2026-08-24 11:57 ` David Hildenbrand (Arm)
2026-08-26 2:46 ` Vernon Yang
2026-08-26 7:58 ` David Hildenbrand (Arm)
2026-08-26 8:12 ` Lorenzo Stoakes (ARM)
2026-08-26 8:42 ` Lorenzo Stoakes (ARM)
2026-08-24 9:29 ` [PATCH v3 3/3] mm: khugepaged: fix folio is used after folio_put/unlock() Vernon Yang
2026-08-24 11:59 ` David Hildenbrand (Arm)
2026-08-26 2:47 ` Vernon Yang
2026-08-26 8:09 ` Lorenzo Stoakes (ARM)
2026-08-26 8:14 ` David Hildenbrand (Arm)
2026-08-26 8:23 ` Lorenzo Stoakes (ARM)
2026-08-26 8:41 ` Lorenzo Stoakes (ARM)
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