2023-04-05 02:24:18

by Zqiang

Subject: [PATCH] rcu/kvfree: Invoke debug_rcu_bhead_unqueue() with check bnode->snap is done

This commit make debug_rcu_bhead_unqueue() be invoked with check
the bnode structure's->snap is done in kvfree_rcu_bulk().

Signed-off-by: Zqiang <[email protected]>
---
kernel/rcu/tree.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 3461fc2640b9..17b5d115aec1 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2943,8 +2943,8 @@ kvfree_rcu_bulk(struct kfree_rcu_cpu *krcp,
unsigned long flags;
int i;

- debug_rcu_bhead_unqueue(bnode);
if (!WARN_ON_ONCE(!poll_state_synchronize_rcu_full(&bnode->gp_snap))) {
+ debug_rcu_bhead_unqueue(bnode);
rcu_lock_acquire(&rcu_callback_map);
if (idx == 0) { // kmalloc() / kfree().
trace_rcu_invoke_kfree_bulk_callback(
--
2.32.0

2023-04-05 14:48:12

by Uladzislau Rezki

Subject: Re: [PATCH] rcu/kvfree: Invoke debug_rcu_bhead_unqueue() with check bnode->snap is done

On Wed, Apr 05, 2023 at 10:13:59AM +0800, Zqiang wrote:
> This commit make debug_rcu_bhead_unqueue() be invoked with check
> the bnode structure's->snap is done in kvfree_rcu_bulk().
>
> Signed-off-by: Zqiang <[email protected]>
> ---
> kernel/rcu/tree.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> index 3461fc2640b9..17b5d115aec1 100644
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -2943,8 +2943,8 @@ kvfree_rcu_bulk(struct kfree_rcu_cpu *krcp,
> unsigned long flags;
> int i;
>
> - debug_rcu_bhead_unqueue(bnode);
> if (!WARN_ON_ONCE(!poll_state_synchronize_rcu_full(&bnode->gp_snap))) {
> + debug_rcu_bhead_unqueue(bnode);
> rcu_lock_acquire(&rcu_callback_map);
> if (idx == 0) { // kmalloc() / kfree().
> trace_rcu_invoke_kfree_bulk_callback(
> --
> 2.32.0
>
Since we leak, looks like correct to me:

Reviewed-by: Uladzislau Rezki (Sony) <[email protected]>

--
Uladzislau Rezki

2023-04-05 19:14:34

by Paul E. McKenney

Subject: Re: [PATCH] rcu/kvfree: Invoke debug_rcu_bhead_unqueue() with check bnode->snap is done

On Wed, Apr 05, 2023 at 04:45:27PM +0200, Uladzislau Rezki wrote:
> On Wed, Apr 05, 2023 at 10:13:59AM +0800, Zqiang wrote:
> > This commit make debug_rcu_bhead_unqueue() be invoked with check
> > the bnode structure's->snap is done in kvfree_rcu_bulk().
> >
> > Signed-off-by: Zqiang <[email protected]>
> > ---
> > kernel/rcu/tree.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> > index 3461fc2640b9..17b5d115aec1 100644
> > --- a/kernel/rcu/tree.c
> > +++ b/kernel/rcu/tree.c
> > @@ -2943,8 +2943,8 @@ kvfree_rcu_bulk(struct kfree_rcu_cpu *krcp,
> > unsigned long flags;
> > int i;
> >
> > - debug_rcu_bhead_unqueue(bnode);
> > if (!WARN_ON_ONCE(!poll_state_synchronize_rcu_full(&bnode->gp_snap))) {
> > + debug_rcu_bhead_unqueue(bnode);
> > rcu_lock_acquire(&rcu_callback_map);
> > if (idx == 0) { // kmalloc() / kfree().
> > trace_rcu_invoke_kfree_bulk_callback(
> > --
> > 2.32.0
> >
> Since we leak, looks like correct to me:
>
> Reviewed-by: Uladzislau Rezki (Sony) <[email protected]>

Queued for v6.5, thank you both!

Thanx, Paul