On 2021/8/31 下午5:11, HORIGUCHI NAOYA(堀口 直也) wrote:
> On Mon, Aug 30, 2021 at 06:07:56PM +0800, 王贇 wrote:
>> By commit 510d25c92ec4 ("mm/hwpoison: disable pcp for
>> page_handle_poison()"), __page_handle_poison() was
>> introduced, and if we mark:
>>
>> RET_A = dissolve_free_huge_page();
>> RET_B = take_page_off_buddy();
>>
>> then __page_handle_poison was supposed to return TRUE When
>> RET_A == 0 && RET_B == TRUE
>>
>> But since it failed to take care the case when RET_A is
>> -EBUSY or -ENOMEM, and just return the ret as a bool which
>> actually become TRUE, it break the original logical.
>
> s/logical/logic/ ?
Will Fix it in v2.
>
>>
>> The following result is a huge page in freelist but was
>> referenced as poisoned, and lead into the final panic:
>>
>> kernel BUG at mm/internal.h:95!
>> invalid opcode: 0000 [#1] SMP PTI
>> skip...
>> RIP: 0010:set_page_refcounted mm/internal.h:95 [inline]
>> RIP: 0010:remove_hugetlb_page+0x23c/0x240 mm/hugetlb.c:1371
>> skip...
>> Call Trace:
>> remove_pool_huge_page+0xe4/0x110 mm/hugetlb.c:1892
>> return_unused_surplus_pages+0x8d/0x150 mm/hugetlb.c:2272
>> hugetlb_acct_memory.part.91+0x524/0x690 mm/hugetlb.c:4017
>>
>> This patch replace 'bool' with 'int' to handle RET_A correctly.
>>
>> Reported-by: Abaci <abaci@xxxxxxxxxxxxxxxxx>
>> Signed-off-by: Michael Wang <yun.wang@xxxxxxxxxxxxxxxxx>
>
> Thank you very much, this fix is totally right.
>
> Acked-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
>
> Could you add the following tags, too?
>
> Fixes: 510d25c92ec4 ("mm/hwpoison: disable pcp for page_handle_poison()")
> Cc: <stable@xxxxxxxxxxxxxxx> # 5.14
Thanks for the review, will add in v2 and send out soon.
Regards,
Michael Wang
>
> Thanks,
> Naoya Horiguchi
>
