On Mon, Jul 31, 2023 at 07:16:29PM +0200, Thomas Gleixner wrote: > On Mon, Jul 31 2023 at 18:11, Thomas Gleixner wrote: > > On Fri, Jul 21 2023 at 12:22, Peter Zijlstra wrote: > >> -#define FUTEX2_MASK (FUTEX2_32 | FUTEX2_PRIVATE) > >> +#define FUTEX2_MASK (FUTEX2_64 | FUTEX2_PRIVATE) > >> > >> /** > >> * futex_parse_waitv - Parse a waitv array from userspace > >> @@ -207,7 +207,12 @@ static int futex_parse_waitv(struct fute > >> if ((aux.flags & ~FUTEX2_MASK) || aux.__reserved) > >> return -EINVAL; > > > > With the above aux.flags with FUTEX2_32 set will result in -EINVAL. I > > don't think that's intentional. > > Also if you allow 64bit wide futexes, how is that supposed to work with > the existing code, which clearly expects a 32bit uval throughout the > place? Not allowed yet, these patches only allow 8,16,32. I still need to audit the whole futex core and do 'u32 -> unsigned long' (and everything else that follows from that), and only when that's done can the futex2 syscalls allow FUTEX2_64 on 64bit archs. So for now, these patches: - add the FUTEX2_64 flag, - add 'unsigned long' interface such that 64bit can potentiall use it, - explicitly disallow having it set.