Acquire RCU trace lock in filter_chain() to protect
list_for_each_entry_rcu() iteration, protecting the list iteration in a
RCU read section.
Prior to this fix, list_for_each_entry_srcu() was called without holding
the required lock, triggering warnings when RCU_PROVING is enabled:
kernel/events/uprobes.c:937 RCU-list traversed without holding the
required lock!!
Signed-off-by: Breno Leitao <[email protected]>
Fixes: cc01bd044e6a ("uprobes: travers uprobe's consumer list locklessly under
SRCU protection")
---
kernel/events/uprobes.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index
fa04b14a7d72353adc440742016b813da6c812d2..afdaa45a43ac3948f7983175eda808c989e8738a
100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1103,11 +1103,13 @@ static bool filter_chain(struct uprobe *uprobe, struct
mm_struct *mm)
bool ret = false;
down_read(&uprobe->consumer_rwsem);
+ rcu_read_lock_trace();
list_for_each_entry_rcu(uc, &uprobe->consumers, cons_node,
rcu_read_lock_trace_held()) {
ret = consumer_filter(uc, mm);
if (ret)
break;
}
+ rcu_read_unlock_trace();
up_read(&uprobe->consumer_rwsem);
return ret;
---
base-commit: 5b913f5d7d7fe0f567dea8605f21da6eaa1735fb
change-id: 20241107-rcu_probe-bef660d84990
Best regards,
--
Breno Leitao <[email protected]>
