On Sun, Jan 28, 2024 at 12:28:38AM -0800, Kuniyuki Iwashima wrote: > From: Kent Overstreet <kent.overstreet@xxxxxxxxx> > Date: Fri, 26 Jan 2024 21:08:31 -0500 > > Kill > > - unix_state_lock_nested > > - _nested usage for net->unx.table.locks[]. > > > > replace both with lock_set_cmp_fn_ptr_order(&u->lock). > > > > The lock ordering in sk_diag_dump_icons() looks suspicious; this may > > turn up a real issue. > > Yes, you cannot use lock_cmp_fn() for unix_state_lock_nested(). > > The lock order in sk_diag_dump_icons() is > > listening socket -> child socket in the listener's queue > > , and the inverse order never happens. ptr comparison does not make > sense in this case, and lockdep will complain about false positive. Is that a real lock ordering? Is this parent -> child relationship well defined? If it is, we should be able to write a lock_cmp_fn for it, as long as it's not some handwavy "this will never happen but _nested won't check for it" like I saw elsewhere in the net code... :)
