2022-07-01 02:27:13

by Zqiang

Subject: [PATCH] rcu: Make tiny RCU support leak callbacks for debug-object errors

Currently, only tree RCU support leak callbacks setting when do
duplicate call_rcu(). this commit add leak callbacks setting when
fo duplicate call_rcu() for tiny RCU.

Signed-off-by: Zqiang <[email protected]>
---
kernel/rcu/tiny.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index f0561ee16b9c..943d431b908f 100644
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -158,6 +158,10 @@ void synchronize_rcu(void)
}
EXPORT_SYMBOL_GPL(synchronize_rcu);

+static void tiny_rcu_leak_callback(struct rcu_head *rhp)
+{
+}
+
/*
* Post an RCU callback to be invoked after the end of an RCU grace
* period. But since we have but one CPU, that would be after any
@@ -165,9 +169,20 @@ EXPORT_SYMBOL_GPL(synchronize_rcu);
*/
void call_rcu(struct rcu_head *head, rcu_callback_t func)
{
+ static atomic_t doublefrees;
unsigned long flags;

- debug_rcu_head_queue(head);
+ if (debug_rcu_head_queue(head)) {
+ if (atomic_inc_return(&doublefrees) < 4) {
+ pr_err("%s(): Double-freed CB %p->%pS()!!! ", __func__, head, head->func);
+ mem_dump_obj(head);
+ }
+
+ if (!__is_kvfree_rcu_offset((unsigned long)head->func))
+ WRITE_ONCE(head->func, tiny_rcu_leak_callback);
+ return;
+ }
+
head->func = func;
head->next = NULL;

--
2.25.1

2022-07-01 03:03:08

by Zqiang

Subject: RE: [PATCH] rcu: Make tiny RCU support leak callbacks for debug-object errors

Sorry, Please this change.


Currently, only tree RCU support leak callbacks setting when do
duplicate call_rcu(). this commit add leak callbacks setting when
fo duplicate call_rcu() for tiny RCU.

Signed-off-by: Zqiang <[email protected]>
---
kernel/rcu/tiny.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index f0561ee16b9c..943d431b908f 100644
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -158,6 +158,10 @@ void synchronize_rcu(void)
}
EXPORT_SYMBOL_GPL(synchronize_rcu);

+static void tiny_rcu_leak_callback(struct rcu_head *rhp)
+{
+}
+
/*
* Post an RCU callback to be invoked after the end of an RCU grace
* period. But since we have but one CPU, that would be after any
@@ -165,9 +169,20 @@ EXPORT_SYMBOL_GPL(synchronize_rcu);
*/
void call_rcu(struct rcu_head *head, rcu_callback_t func)
{
+ static atomic_t doublefrees;
unsigned long flags;

- debug_rcu_head_queue(head);
+ if (debug_rcu_head_queue(head)) {
+ if (atomic_inc_return(&doublefrees) < 4) {
+ pr_err("%s(): Double-freed CB %p->%pS()!!! ", __func__, head, head->func);
+ mem_dump_obj(head);
+ }
+
+ if (!__is_kvfree_rcu_offset((unsigned long)head->func))
+ WRITE_ONCE(head->func, tiny_rcu_leak_callback);
+ return;
+ }
+
head->func = func;
head->next = NULL;

--
2.25.1