Re: [PATCH v1] hugetlb: pass head page to remove_hugetlb_page()

[Oscar Salvador]

On Thu, May 27, 2021 at 08:52:57AM +0900, Naoya Horiguchi wrote:
> From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
> 
> When memory_failure() or soft_offline_page() is called on a tail page of
> some hugetlb page, "BUG: unable to handle page fault" error can be
> triggered.
> 
> remove_hugetlb_page() dereferences page->lru, so it's assumed that the
> page points to a head page, but one of the caller,
> dissolve_free_huge_page(), provides remove_hugetlb_page() with 'page'
> which could be a tail page.  So pass 'head' to it, instead.
> 
> Fixes: 6eb4e88a6d27 ("hugetlb: create remove_hugetlb_page() to separate functionality")
> Signed-off-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>

Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>

It is probably worth adding a comment in remove_hugetlb_page() noting
that we need a head page, so future users do not repeat the same
mistake.

Thanks 

-- 
Oscar Salvador
SUSE L3