From: Oscar Salvador osalvador@suse.de
mainline inclusion from linux-v5.11-rc1 commit 17e395b60f5b3dea204fcae60c7b38e84a00d87a category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4LE22 CVE: NA
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A page with 0-refcount and !PageBuddy could perfectly be a pcppage. Currently, we bail out with an error if we encounter such a page, meaning that we do not handle pcppages neither from hard-offline nor from soft-offline path.
Fix this by draining pcplists whenever we find this kind of page and retry the check again. It might be that pcplists have been spilled into the buddy allocator and so we can handle it.
Signed-off-by: Oscar Salvador osalvador@suse.de Acked-by: Naoya Horiguchi naoya.horiguchi@nec.com Acked-by: Vlastimil Babka vbabka@suse.cz Signed-off-by: Ma Wupeng mawupeng1@huawei.com Reviewed-by: Kefeng Wang wangkefeng.wang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- mm/memory-failure.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 63b26a9cca335..7a69a295fc3ef 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -953,13 +953,13 @@ static int page_action(struct page_state *ps, struct page *p, }
/** - * get_hwpoison_page() - Get refcount for memory error handling: + * __get_hwpoison_page() - Get refcount for memory error handling: * @page: raw error page (hit by memory error) * * Return: return 0 if failed to grab the refcount, otherwise true (some * non-zero value.) */ -int get_hwpoison_page(struct page *page) +static int __get_hwpoison_page(struct page *page) { struct page *head = compound_head(page);
@@ -988,6 +988,26 @@ int get_hwpoison_page(struct page *page)
return 0; } + +int get_hwpoison_page(struct page *p) +{ + int ret; + bool drained = false; + +retry: + ret = __get_hwpoison_page(p); + if (!ret && !is_free_buddy_page(p) && !page_count(p) && !drained) { + /* + * The page might be in a pcplist, so try to drain those + * and see if we are lucky. + */ + drain_all_pages(page_zone(p)); + drained = true; + goto retry; + } + + return ret; +} EXPORT_SYMBOL_GPL(get_hwpoison_page);
/*