On Fri, May 15, 2020 at 06:16:44AM -0700, Matthew Wilcox wrote: > From: "Matthew Wilcox (Oracle)" <wi...@infradead.org> > > A compound page in the page cache will not necessarily be of PMD size, > so check explicitly. > > Signed-off-by: Matthew Wilcox (Oracle) <wi...@infradead.org> > --- > mm/memory.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index f703fe8c8346..d68ce428ddd2 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -3549,13 +3549,14 @@ static vm_fault_t do_set_pmd(struct vm_fault *vmf, > struct page *page) > unsigned long haddr = vmf->address & HPAGE_PMD_MASK; > pmd_t entry; > int i; > - vm_fault_t ret; > + vm_fault_t ret = VM_FAULT_FALLBACK; > > if (!transhuge_vma_suitable(vma, haddr)) > - return VM_FAULT_FALLBACK; > + return ret; > > - ret = VM_FAULT_FALLBACK; > page = compound_head(page); > + if (page_order(page) != HPAGE_PMD_ORDER) > + return ret;
Maybe WARN() for page_order(page) > HPAGE_PMD_ORDER. It would be fun to handle :P > > /* > * Archs like ppc64 need additonal space to store information > -- > 2.26.2 > -- Kirill A. Shutemov
