[RFC,4/6] workqueue: Convert for_each_wq to use built-in list check
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Message ID 20190601222738.6856-5-joel@joelfernandes.org
State New
Headers show
Series
  • Harden list_for_each_entry_rcu() and family
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Commit Message

Joel Fernandes June 1, 2019, 10:27 p.m. UTC
list_for_each_entry_rcu now has support to check for RCU reader sections
as well as lock. Just use the support in it, instead of explictly
checking in the caller.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
---
 kernel/workqueue.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

Comments

Daniel Jordan June 5, 2019, 1:24 a.m. UTC | #1
On Sat, Jun 01, 2019 at 06:27:36PM -0400, Joel Fernandes (Google) wrote:
> list_for_each_entry_rcu now has support to check for RCU reader sections
> as well as lock. Just use the support in it, instead of explictly
> checking in the caller.
> 
> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> ---
>  kernel/workqueue.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index 9657315405de..91ed7aca16e5 100644
> --- a/kernel/workqueue.c
> +++ b/kernel/workqueue.c
> @@ -424,9 +424,8 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq);
>   * ignored.
>   */
>  #define for_each_pwq(pwq, wq)						\
> -	list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node)		\
> -		if (({ assert_rcu_or_wq_mutex(wq); false; })) { }	\
> -		else
> +	list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node,		\
> +				 lock_is_held(&(wq->mutex).dep_map))
>  

I think the definition of assert_rcu_or_wq_mutex can also be deleted.
Joel Fernandes June 5, 2019, 1:04 p.m. UTC | #2
On Tue, Jun 4, 2019 at 9:25 PM Daniel Jordan <daniel.m.jordan@oracle.com> wrote:
>
> On Sat, Jun 01, 2019 at 06:27:36PM -0400, Joel Fernandes (Google) wrote:
> > list_for_each_entry_rcu now has support to check for RCU reader sections
> > as well as lock. Just use the support in it, instead of explictly
> > checking in the caller.
> >
> > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> > ---
> >  kernel/workqueue.c | 5 ++---
> >  1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> > index 9657315405de..91ed7aca16e5 100644
> > --- a/kernel/workqueue.c
> > +++ b/kernel/workqueue.c
> > @@ -424,9 +424,8 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq);
> >   * ignored.
> >   */
> >  #define for_each_pwq(pwq, wq)                                                \
> > -     list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node)          \
> > -             if (({ assert_rcu_or_wq_mutex(wq); false; })) { }       \
> > -             else
> > +     list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node,          \
> > +                              lock_is_held(&(wq->mutex).dep_map))
> >
>
> I think the definition of assert_rcu_or_wq_mutex can also be deleted.

Sure, will do. Thank you.

Patch
diff mbox series

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 9657315405de..91ed7aca16e5 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -424,9 +424,8 @@  static void workqueue_sysfs_unregister(struct workqueue_struct *wq);
  * ignored.
  */
 #define for_each_pwq(pwq, wq)						\
-	list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node)		\
-		if (({ assert_rcu_or_wq_mutex(wq); false; })) { }	\
-		else
+	list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node,		\
+				 lock_is_held(&(wq->mutex).dep_map))
 
 #ifdef CONFIG_DEBUG_OBJECTS_WORK