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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 07/07/23 11:38, Muchun Song wrote: > The local variable @page in __split_vmemmap_huge_pmd() to obtain a pmd > page without holding page_table_lock may possiblely get the page table > page instead of a huge pmd page. The effect may be in set_pte_at() > since we may pass an invalid page struct, if set_pte_at() wants to > access the page struct (e.g. CONFIG_PAGE_TABLE_CHECK is enabled), it > may crash the kernel. So fix it. And inline __split_vmemmap_huge_pmd() > since it only has one user. > > Fixes: d8d55f5616cf ("mm: sparsemem: use page table lock to protect kernel pmd operations") > Signed-off-by: Muchun Song > --- > mm/hugetlb_vmemmap.c | 34 ++++++++++++++-------------------- > 1 file changed, 14 insertions(+), 20 deletions(-) Sorry, for the very late reply! This code looks fine to me, Reviewed-by: Mike Kravetz The discussion about 'open code' or inline' has me a bit confused. I am perfectly happy with the code as it is. When I hear/see inline, I think of the inline function keyword. Since that is not happening in this patch, the mention of 'inline __split_vmemmap_huge_pmd()' does cause me to think a bit more than usual. Yes, the backports will need to be modified. -- Mike Kravetz