On Thu, Nov 10, 2022 at 10:43:25AM -0800, Nadav Amit wrote: > On Nov 10, 2022, at 7:17 AM, Peter Xu <peterx@xxxxxxxxxx> wrote: > > > +#ifdef CONFIG_DEBUG_VM > > + /* > > + * Having write bit for wr-protect-marked present ptes is fatal, > > + * because it means the uffd-wp bit will be ignored and write will > > + * just go through. > > + * > > + * Use any chance of pgtable walking to verify this (e.g., when > > + * page swapped out or being migrated for all purposes). It means > > + * something is already wrong. Tell the admin even before the > > + * process crashes. We also nail it with wrong pgtable setup. > > + */ > > + WARN_ON_ONCE(wp && pte_write(pte)); > > How about VM_WARN_ON_ONCE() and no ifdef? Oops.. Will quickly respin, thanks. -- Peter Xu
