On Fri, Jul 21, 2023 at 12:22:48PM +0200, Peter Zijlstra wrote: > @@ -217,32 +259,55 @@ static u64 get_inode_sequence_number(str > * > * lock_page() might sleep, the caller should not hold a spinlock. > */ > -int get_futex_key(u32 __user *uaddr, unsigned int flags, union futex_key *key, > +int get_futex_key(void __user *uaddr, unsigned int flags, union futex_key *key, > enum futex_access rw) > { > unsigned long address = (unsigned long)uaddr; > struct mm_struct *mm = current->mm; > struct page *page, *tail; > struct address_space *mapping; > + int node, err, size, ro = 0; > bool fshared; > > fshared = flags & FLAGS_SHARED; > + size = futex_size(flags); > > /* > * The futex address must be "naturally" aligned. > */ > key->both.offset = address % PAGE_SIZE; > + if (unlikely((address % size) != 0)) > return -EINVAL; This enforces u32 alignment for: struct futex_numa_32 { u32 val; u32 node; }; Or do we want to enfore u64 alignment for that? > address -= key->both.offset; > > + if (flags & FLAGS_NUMA) > + size *= 2; > + > + if (unlikely(!access_ok(uaddr, size))) > return -EFAULT;