lkml.org 
[lkml]   [2023]   [May]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v3 1/3] mm: Call arch_swap_restore() from do_swap_page()
From
On 17.05.23 05:40, Huang, Ying wrote:
> Peter Collingbourne <pcc@google.com> writes:
>
>> Commit c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") moved
>> the call to swap_free() before the call to set_pte_at(), which meant that
>> the MTE tags could end up being freed before set_pte_at() had a chance
>> to restore them. Fix it by adding a call to the arch_swap_restore() hook
>> before the call to swap_free().
>>
>> Signed-off-by: Peter Collingbourne <pcc@google.com>
>> Link: https://linux-review.googlesource.com/id/I6470efa669e8bd2f841049b8c61020c510678965
>> Cc: <stable@vger.kernel.org> # 6.1
>> Fixes: c145e0b47c77 ("mm: streamline COW logic in do_swap_page()")
>> Reported-by: Qun-wei Lin (林群崴) <Qun-wei.Lin@mediatek.com>
>> Closes: https://lore.kernel.org/all/5050805753ac469e8d727c797c2218a9d780d434.camel@mediatek.com/
>> ---
>> v2:
>> - Call arch_swap_restore() directly instead of via arch_do_swap_page()
>>
>> mm/memory.c | 7 +++++++
>> 1 file changed, 7 insertions(+)
>>
>> diff --git a/mm/memory.c b/mm/memory.c
>> index f69fbc251198..fc25764016b3 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -3932,6 +3932,13 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
>> }
>> }
>>
>> + /*
>> + * Some architectures may have to restore extra metadata to the page
>> + * when reading from swap. This metadata may be indexed by swap entry
>> + * so this must be called before swap_free().
>> + */
>> + arch_swap_restore(entry, folio);
>> +
>> /*
>> * Remove the swap entry and conditionally try to free up the swapcache.
>> * We're already holding a reference on the page but haven't mapped it
>
> Should you add
>
> Suggested-by: David Hildenbrand <david@redhat.com>
>
> for 1/3 and 2/3.

For 1/3, I think I rather only explained the problem in the first patch
and didn't really suggest this.

Acked-by: David Hildenbrand <david@redhat.com>

--
Thanks,

David / dhildenb

\
 
 \ /
  Last update: 2023-05-17 10:39    [W:0.076 / U:0.240 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site