Messages in this thread | | | Date | Wed, 30 Mar 2022 18:29:18 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH] mm: page_alloc: validate buddy before check its migratetype. |
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On Wed, 30 Mar 2022 18:12:38 -0400 Zi Yan <zi.yan@sent.com> wrote:
> From: Zi Yan <ziy@nvidia.com> > > Whenever a buddy page is found, page_is_buddy() should be called to > check its validity. Add the missing check during pageblock merge check. > > Fixes: 1dd214b8f21c ("mm: page_alloc: avoid merging non-fallbackable pageblocks with others")
Link: https://lore.kernel.org/all/20220330154208.71aca532@gandalf.local.home/
> > Reported-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-- Steve
> Signed-off-by: Zi Yan <ziy@nvidia.com> > --- > mm/page_alloc.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index bdc8f60ae462..6c6af8658775 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1108,6 +1108,9 @@ static inline void __free_one_page(struct page *page, > > buddy_pfn = __find_buddy_pfn(pfn, order); > buddy = page + (buddy_pfn - pfn); > + > + if (!page_is_buddy(page, buddy, order)) > + goto done_merging; > buddy_mt = get_pageblock_migratetype(buddy); > > if (migratetype != buddy_mt
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