On Wed, Jul 27, 2022 at 03:14:07PM -0400, Zack Rusin wrote: > From: Zack Rusin <zackr@xxxxxxxxxx> > > Write page faults on last references might not have a valid page anymore. > wp_page_reuse has always dealt with that scenario by making > sure the page isn't null (or the reference was shared) before doing > anything with it. Recently added checks in VM_BUG_ON (enabled by the > CONFIG_DEBUG_VM option) use PageAnon helpers which assume the passed > page is never null, before making sure there is a valid page to work > with. > > Move the VM_BUG_ON, which unconditionally uses the page, after the > code that checks that we have a valid one. Message-ID: <CAHk-=wh_TrgNm6vz7=7CgZppr0UrZ9TwLyb3dgPXyG-w=a8kJQ@xxxxxxxxxxxxxx>