Re: [PATCH stable-5.10] mm/memory-failure: fix an incorrect use of tail pages

[Liu Shixin]

Hi, Greg,

There is a bugfix for 5.10-stable, 5.4-stable, 4.19-stable. Introduced when backport

commit c79c5a0a00a9 ("mm/memory-failure: check the mapcount of the precise page").

[1]: https://lore.kernel.org/stable/20240307124841.2838010-1-liushixin2@xxxxxxxxxx/

[2]: https://lore.kernel.org/stable/20240307125053.2847205-1-liushixin2@xxxxxxxxxx/

[3]: https://lore.kernel.org/stable/20240307125150.2849068-1-liushixin2@xxxxxxxxxx/


Thanks,


On 2024/3/7 20:48, Liu Shixin wrote:
> When backport commit c79c5a0a00a9 to 5.10-stable, there is a mistake change.
> The head page instead of tail page should be passed to try_to_unmap(),
> otherwise unmap will failed as follows.
>
>  Memory failure: 0x121c10: failed to unmap page (mapcount=1)
>  Memory failure: 0x121c10: recovery action for unmapping failed page: Ignored
>
> Fixes: 70168fdc743b ("mm/memory-failure: check the mapcount of the precise page")
> Signed-off-by: Liu Shixin <liushixin2@xxxxxxxxxx>
> ---
>  mm/memory-failure.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index f320ff02cc19..dba2936292cf 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1075,7 +1075,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
>  				unmap_success = false;
>  			}
>  		} else {
> -			unmap_success = try_to_unmap(p, ttu);
> +			unmap_success = try_to_unmap(hpage, ttu);
>  		}
>  	}
>  	if (!unmap_success)