On Wed, 28 Jan 2026 10:16:11 -0800 Breno Leitao <[email protected]> wrote:
> The list_for_each_entry_rcu() in filter_chain() uses > rcu_read_lock_trace_held() as the lockdep condition, but the function > holds consumer_rwsem, not the RCU trace lock. > > This gives me the following output when running with some locking debug > option enabled: > > kernel/events/uprobes.c:1141 RCU-list traversed in non-reader section!! > filter_chain > register_for_each_vma > uprobe_unregister_nosync > __probe_event_disable > > Remove the incorrect lockdep condition since the rwsem provides > sufficient protection for the list traversal. > Looks good to me. Acked-by: Masami Hiramatsu (Google) <[email protected]> Thanks, > Cc: [email protected] > Fixes: cc01bd044e6a ("uprobes: travers uprobe's consumer list locklessly > under SRCU protection") > Acked-by: Oleg Nesterov <[email protected]> > Acked-by: Andrii Nakryiko <[email protected]> > Signed-off-by: Breno Leitao <[email protected]> > --- > Changes in v2: > - updated the "fixes" tag (Oleg) > - Link to v1: > https://patch.msgid.link/[email protected] > --- > kernel/events/uprobes.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c > index d546d32390a81..726d13b375f3d 100644 > --- a/kernel/events/uprobes.c > +++ b/kernel/events/uprobes.c > @@ -1138,7 +1138,7 @@ static bool filter_chain(struct uprobe *uprobe, struct > mm_struct *mm) > bool ret = false; > > down_read(&uprobe->consumer_rwsem); > - list_for_each_entry_rcu(uc, &uprobe->consumers, cons_node, > rcu_read_lock_trace_held()) { > + list_for_each_entry(uc, &uprobe->consumers, cons_node) { > ret = consumer_filter(uc, mm); > if (ret) > break; > > --- > base-commit: 1f97d9dcf53649c41c33227b345a36902cbb08ad > change-id: 20260128-uprobe_rcu-e21867ab4c1b > > Best regards, > -- > Breno Leitao <[email protected]> > -- Masami Hiramatsu (Google) <[email protected]>
