Re: rcu: fix hlist_bl_set_first_rcu annotation
On Tue, Mar 12, 2013 at 09:44:29AM +, Steven Whitehouse wrote:
> Hi,
>
> On Sun, 2013-02-03 at 10:39 -0800, Paul E. McKenney wrote:
> > On Wed, Jan 30, 2013 at 07:07:57PM +, Steven Whitehouse wrote:
> > >
> > > Abhi noticed that we were getting a complaint from the RCU subsystem
> > > about access of an RCU protected list under the write side bit lock.
> > > This patch adds additional annotation to check both the RCU read
> > > lock and the write side bit lock before printing a message.
> > >
> > > Signed-off-by: Steven Whitehouse
> > > Reported-by: Abhijith Das
> > > Tested-by: Abhijith Das
> >
> > Looks plausible to me on first glance, copying Nick Piggin and Christoph
> > Hellwig. If they have no objections, I will queue this.
> >
> > Thanx, Paul
> >
>
> Just a quick query to see what happened to this patch... it doesn't
> appear to have landed in Linus' tree yet, and I can't spot it in your
> git trees at korg either,
Hello, Steve,
I have queued it for 3.10, and will push it to -rcu shortly.
Thanx, Paul
> Steve.
>
>
> > > diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
> > > index 31f9d75..2eb8855 100644
> > > --- a/include/linux/list_bl.h
> > > +++ b/include/linux/list_bl.h
> > > @@ -125,6 +125,11 @@ static inline void hlist_bl_unlock(struct
> > > hlist_bl_head *b)
> > > __bit_spin_unlock(0, (unsigned long *)b);
> > > }
> > >
> > > +static inline bool hlist_bl_is_locked(struct hlist_bl_head *b)
> > > +{
> > > + return bit_spin_is_locked(0, (unsigned long *)b);
> > > +}
> > > +
> > > /**
> > > * hlist_bl_for_each_entry - iterate over list of given type
> > > * @tpos:the type * to use as a loop cursor.
> > > diff --git a/include/linux/rculist_bl.h b/include/linux/rculist_bl.h
> > > index cf1244f..4f216c5 100644
> > > --- a/include/linux/rculist_bl.h
> > > +++ b/include/linux/rculist_bl.h
> > > @@ -20,7 +20,7 @@ static inline void hlist_bl_set_first_rcu(struct
> > > hlist_bl_head *h,
> > > static inline struct hlist_bl_node *hlist_bl_first_rcu(struct
> > > hlist_bl_head *h)
> > > {
> > > return (struct hlist_bl_node *)
> > > - ((unsigned long)rcu_dereference(h->first) & ~LIST_BL_LOCKMASK);
> > > + ((unsigned long)rcu_dereference_check(h->first,
> > > hlist_bl_is_locked(h)) & ~LIST_BL_LOCKMASK);
> > > }
> > >
> > > /**
> > >
> > >
> >
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: rcu: fix hlist_bl_set_first_rcu annotation
Hi,
On Sun, 2013-02-03 at 10:39 -0800, Paul E. McKenney wrote:
> On Wed, Jan 30, 2013 at 07:07:57PM +, Steven Whitehouse wrote:
> >
> > Abhi noticed that we were getting a complaint from the RCU subsystem
> > about access of an RCU protected list under the write side bit lock.
> > This patch adds additional annotation to check both the RCU read
> > lock and the write side bit lock before printing a message.
> >
> > Signed-off-by: Steven Whitehouse
> > Reported-by: Abhijith Das
> > Tested-by: Abhijith Das
>
> Looks plausible to me on first glance, copying Nick Piggin and Christoph
> Hellwig. If they have no objections, I will queue this.
>
> Thanx, Paul
>
Just a quick query to see what happened to this patch... it doesn't
appear to have landed in Linus' tree yet, and I can't spot it in your
git trees at korg either,
Steve.
> > diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
> > index 31f9d75..2eb8855 100644
> > --- a/include/linux/list_bl.h
> > +++ b/include/linux/list_bl.h
> > @@ -125,6 +125,11 @@ static inline void hlist_bl_unlock(struct
> > hlist_bl_head *b)
> > __bit_spin_unlock(0, (unsigned long *)b);
> > }
> >
> > +static inline bool hlist_bl_is_locked(struct hlist_bl_head *b)
> > +{
> > + return bit_spin_is_locked(0, (unsigned long *)b);
> > +}
> > +
> > /**
> > * hlist_bl_for_each_entry - iterate over list of given type
> > * @tpos: the type * to use as a loop cursor.
> > diff --git a/include/linux/rculist_bl.h b/include/linux/rculist_bl.h
> > index cf1244f..4f216c5 100644
> > --- a/include/linux/rculist_bl.h
> > +++ b/include/linux/rculist_bl.h
> > @@ -20,7 +20,7 @@ static inline void hlist_bl_set_first_rcu(struct
> > hlist_bl_head *h,
> > static inline struct hlist_bl_node *hlist_bl_first_rcu(struct
> > hlist_bl_head *h)
> > {
> > return (struct hlist_bl_node *)
> > - ((unsigned long)rcu_dereference(h->first) & ~LIST_BL_LOCKMASK);
> > + ((unsigned long)rcu_dereference_check(h->first,
> > hlist_bl_is_locked(h)) & ~LIST_BL_LOCKMASK);
> > }
> >
> > /**
> >
> >
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: rcu: fix hlist_bl_set_first_rcu annotation
Hi,
On Sun, 2013-02-03 at 10:39 -0800, Paul E. McKenney wrote:
On Wed, Jan 30, 2013 at 07:07:57PM +, Steven Whitehouse wrote:
Abhi noticed that we were getting a complaint from the RCU subsystem
about access of an RCU protected list under the write side bit lock.
This patch adds additional annotation to check both the RCU read
lock and the write side bit lock before printing a message.
Signed-off-by: Steven Whitehouse swhit...@redhat.com
Reported-by: Abhijith Das a...@redhat.com
Tested-by: Abhijith Das a...@redhat.com
Looks plausible to me on first glance, copying Nick Piggin and Christoph
Hellwig. If they have no objections, I will queue this.
Thanx, Paul
Just a quick query to see what happened to this patch... it doesn't
appear to have landed in Linus' tree yet, and I can't spot it in your
git trees at korg either,
Steve.
diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
index 31f9d75..2eb8855 100644
--- a/include/linux/list_bl.h
+++ b/include/linux/list_bl.h
@@ -125,6 +125,11 @@ static inline void hlist_bl_unlock(struct
hlist_bl_head *b)
__bit_spin_unlock(0, (unsigned long *)b);
}
+static inline bool hlist_bl_is_locked(struct hlist_bl_head *b)
+{
+ return bit_spin_is_locked(0, (unsigned long *)b);
+}
+
/**
* hlist_bl_for_each_entry - iterate over list of given type
* @tpos: the type * to use as a loop cursor.
diff --git a/include/linux/rculist_bl.h b/include/linux/rculist_bl.h
index cf1244f..4f216c5 100644
--- a/include/linux/rculist_bl.h
+++ b/include/linux/rculist_bl.h
@@ -20,7 +20,7 @@ static inline void hlist_bl_set_first_rcu(struct
hlist_bl_head *h,
static inline struct hlist_bl_node *hlist_bl_first_rcu(struct
hlist_bl_head *h)
{
return (struct hlist_bl_node *)
- ((unsigned long)rcu_dereference(h-first) ~LIST_BL_LOCKMASK);
+ ((unsigned long)rcu_dereference_check(h-first,
hlist_bl_is_locked(h)) ~LIST_BL_LOCKMASK);
}
/**
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: rcu: fix hlist_bl_set_first_rcu annotation
On Tue, Mar 12, 2013 at 09:44:29AM +, Steven Whitehouse wrote:
Hi,
On Sun, 2013-02-03 at 10:39 -0800, Paul E. McKenney wrote:
On Wed, Jan 30, 2013 at 07:07:57PM +, Steven Whitehouse wrote:
Abhi noticed that we were getting a complaint from the RCU subsystem
about access of an RCU protected list under the write side bit lock.
This patch adds additional annotation to check both the RCU read
lock and the write side bit lock before printing a message.
Signed-off-by: Steven Whitehouse swhit...@redhat.com
Reported-by: Abhijith Das a...@redhat.com
Tested-by: Abhijith Das a...@redhat.com
Looks plausible to me on first glance, copying Nick Piggin and Christoph
Hellwig. If they have no objections, I will queue this.
Thanx, Paul
Just a quick query to see what happened to this patch... it doesn't
appear to have landed in Linus' tree yet, and I can't spot it in your
git trees at korg either,
Hello, Steve,
I have queued it for 3.10, and will push it to -rcu shortly.
Thanx, Paul
Steve.
diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
index 31f9d75..2eb8855 100644
--- a/include/linux/list_bl.h
+++ b/include/linux/list_bl.h
@@ -125,6 +125,11 @@ static inline void hlist_bl_unlock(struct
hlist_bl_head *b)
__bit_spin_unlock(0, (unsigned long *)b);
}
+static inline bool hlist_bl_is_locked(struct hlist_bl_head *b)
+{
+ return bit_spin_is_locked(0, (unsigned long *)b);
+}
+
/**
* hlist_bl_for_each_entry - iterate over list of given type
* @tpos:the type * to use as a loop cursor.
diff --git a/include/linux/rculist_bl.h b/include/linux/rculist_bl.h
index cf1244f..4f216c5 100644
--- a/include/linux/rculist_bl.h
+++ b/include/linux/rculist_bl.h
@@ -20,7 +20,7 @@ static inline void hlist_bl_set_first_rcu(struct
hlist_bl_head *h,
static inline struct hlist_bl_node *hlist_bl_first_rcu(struct
hlist_bl_head *h)
{
return (struct hlist_bl_node *)
- ((unsigned long)rcu_dereference(h-first) ~LIST_BL_LOCKMASK);
+ ((unsigned long)rcu_dereference_check(h-first,
hlist_bl_is_locked(h)) ~LIST_BL_LOCKMASK);
}
/**
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: rcu: fix hlist_bl_set_first_rcu annotation
On Fri, Feb 15, 2013 at 12:01:30AM +, Andrew Price wrote:
> Hi,
>
> On 03/02/13 18:39, Paul E. McKenney wrote:
> >On Wed, Jan 30, 2013 at 07:07:57PM +, Steven Whitehouse wrote:
> >>
> >>Abhi noticed that we were getting a complaint from the RCU subsystem
> >>about access of an RCU protected list under the write side bit lock.
> >>This patch adds additional annotation to check both the RCU read
> >>lock and the write side bit lock before printing a message.
> >>
> >>Signed-off-by: Steven Whitehouse
> >>Reported-by: Abhijith Das
> >>Tested-by: Abhijith Das
> >
> >Looks plausible to me on first glance, copying Nick Piggin and Christoph
> >Hellwig. If they have no objections, I will queue this.
> >
> > Thanx, Paul
>
> Has this had any attention yet? I'm also seeing the complaint quite
> frequently:
>
> [ 68.738811] ===
> [ 68.741380] [ INFO: suspicious RCU usage. ]
> [ 68.748785] 3.8.0-0.rc7.git1.1.fc19.x86_64 #1 Not tainted
> [ 68.750841] ---
> [ 68.752418] include/linux/rculist_bl.h:23 suspicious
> rcu_dereference_check() usage!
> [ 68.755264]
> [ 68.755264] other info that might help us debug this:
> [ 68.755264]
> [ 68.758030]
> [ 68.758030] rcu_scheduler_active = 1, debug_locks = 0
> [ 68.760316] 1 lock held by mount/476:
> [ 68.761896] #0: (>s_umount_key#38/1){+.+.+.}, at:
> [] sget+0x39e/0x670
> [ 68.767115]
> [ 68.767115] stack backtrace:
> [ 68.769529] Pid: 476, comm: mount Not tainted
> 3.8.0-0.rc7.git1.1.fc19.x86_64 #1
> [ 68.772095] Call Trace:
> [ 68.772995] [] lockdep_rcu_suspicious+0xe7/0x120
> [ 68.775184] [] search_bucket+0x118/0x160 [gfs2]
> [ 68.777559] [] gfs2_glock_get+0x603/0x7b0 [gfs2]
> [ 68.780749] [] ? gfs2_glock_get+0x5/0x7b0 [gfs2]
> [ 68.784173] [] gfs2_glock_nq_num+0x29/0x90 [gfs2]
> [ 68.786551] [] gfs2_mount+0x869/0xf30 [gfs2]
> [ 68.788672] [] ? sched_clock_cpu+0xa8/0x100
> [ 68.790739] [] ? trace_hardirqs_off+0xd/0x10
> [ 68.793042] [] ? local_clock+0x5f/0x70
> [ 68.794940] [] ? __mutex_unlock_slowpath+0x80/0x170
> [ 68.798236] [] mount_fs+0x39/0x1b0
> [ 68.800409] [] ? __alloc_percpu+0x10/0x20
> [ 68.803692] [] vfs_kern_mount+0x63/0xf0
> [ 68.806773] [] do_mount+0x205/0xa90
> [ 68.809669] [] ? might_fault+0x5c/0xb0
> [ 68.812717] [] ? strndup_user+0x4b/0xf0
> [ 68.816066] [] sys_mount+0x83/0xc0
> [ 68.818284] [] system_call_fastpath+0x16/0x1b
>
> It would be good to have this silenced for 3.8 but I think there's
> not long to go.
I have queued this, thank you.
3.8 is getting close to the end, but there is always -stable if the 3.8
series is of particular interest for this bug.
Thanx, Paul
> Thanks,
> Andy
>
> >>diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
> >>index 31f9d75..2eb8855 100644
> >>--- a/include/linux/list_bl.h
> >>+++ b/include/linux/list_bl.h
> >>@@ -125,6 +125,11 @@ static inline void hlist_bl_unlock(struct
> >>hlist_bl_head *b)
> >>__bit_spin_unlock(0, (unsigned long *)b);
> >> }
> >>
> >>+static inline bool hlist_bl_is_locked(struct hlist_bl_head *b)
> >>+{
> >>+ return bit_spin_is_locked(0, (unsigned long *)b);
> >>+}
> >>+
> >> /**
> >> * hlist_bl_for_each_entry- iterate over list of given type
> >> * @tpos: the type * to use as a loop cursor.
> >>diff --git a/include/linux/rculist_bl.h b/include/linux/rculist_bl.h
> >>index cf1244f..4f216c5 100644
> >>--- a/include/linux/rculist_bl.h
> >>+++ b/include/linux/rculist_bl.h
> >>@@ -20,7 +20,7 @@ static inline void hlist_bl_set_first_rcu(struct
> >>hlist_bl_head *h,
> >> static inline struct hlist_bl_node *hlist_bl_first_rcu(struct
> >> hlist_bl_head *h)
> >> {
> >>return (struct hlist_bl_node *)
> >>- ((unsigned long)rcu_dereference(h->first) & ~LIST_BL_LOCKMASK);
> >>+ ((unsigned long)rcu_dereference_check(h->first,
> >>hlist_bl_is_locked(h)) & ~LIST_BL_LOCKMASK);
> >> }
> >>
> >> /**
> >>
> >>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: rcu: fix hlist_bl_set_first_rcu annotation
Hi,
On 03/02/13 18:39, Paul E. McKenney wrote:
On Wed, Jan 30, 2013 at 07:07:57PM +, Steven Whitehouse wrote:
Abhi noticed that we were getting a complaint from the RCU subsystem
about access of an RCU protected list under the write side bit lock.
This patch adds additional annotation to check both the RCU read
lock and the write side bit lock before printing a message.
Signed-off-by: Steven Whitehouse
Reported-by: Abhijith Das
Tested-by: Abhijith Das
Looks plausible to me on first glance, copying Nick Piggin and Christoph
Hellwig. If they have no objections, I will queue this.
Thanx, Paul
Has this had any attention yet? I'm also seeing the complaint quite
frequently:
[ 68.738811] ===
[ 68.741380] [ INFO: suspicious RCU usage. ]
[ 68.748785] 3.8.0-0.rc7.git1.1.fc19.x86_64 #1 Not tainted
[ 68.750841] ---
[ 68.752418] include/linux/rculist_bl.h:23 suspicious
rcu_dereference_check() usage!
[ 68.755264]
[ 68.755264] other info that might help us debug this:
[ 68.755264]
[ 68.758030]
[ 68.758030] rcu_scheduler_active = 1, debug_locks = 0
[ 68.760316] 1 lock held by mount/476:
[ 68.761896] #0: (>s_umount_key#38/1){+.+.+.}, at:
[] sget+0x39e/0x670
[ 68.767115]
[ 68.767115] stack backtrace:
[ 68.769529] Pid: 476, comm: mount Not tainted
3.8.0-0.rc7.git1.1.fc19.x86_64 #1
[ 68.772095] Call Trace:
[ 68.772995] [] lockdep_rcu_suspicious+0xe7/0x120
[ 68.775184] [] search_bucket+0x118/0x160 [gfs2]
[ 68.777559] [] gfs2_glock_get+0x603/0x7b0 [gfs2]
[ 68.780749] [] ? gfs2_glock_get+0x5/0x7b0 [gfs2]
[ 68.784173] [] gfs2_glock_nq_num+0x29/0x90 [gfs2]
[ 68.786551] [] gfs2_mount+0x869/0xf30 [gfs2]
[ 68.788672] [] ? sched_clock_cpu+0xa8/0x100
[ 68.790739] [] ? trace_hardirqs_off+0xd/0x10
[ 68.793042] [] ? local_clock+0x5f/0x70
[ 68.794940] [] ? __mutex_unlock_slowpath+0x80/0x170
[ 68.798236] [] mount_fs+0x39/0x1b0
[ 68.800409] [] ? __alloc_percpu+0x10/0x20
[ 68.803692] [] vfs_kern_mount+0x63/0xf0
[ 68.806773] [] do_mount+0x205/0xa90
[ 68.809669] [] ? might_fault+0x5c/0xb0
[ 68.812717] [] ? strndup_user+0x4b/0xf0
[ 68.816066] [] sys_mount+0x83/0xc0
[ 68.818284] [] system_call_fastpath+0x16/0x1b
It would be good to have this silenced for 3.8 but I think there's not
long to go.
Thanks,
Andy
diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
index 31f9d75..2eb8855 100644
--- a/include/linux/list_bl.h
+++ b/include/linux/list_bl.h
@@ -125,6 +125,11 @@ static inline void hlist_bl_unlock(struct hlist_bl_head *b)
__bit_spin_unlock(0, (unsigned long *)b);
}
+static inline bool hlist_bl_is_locked(struct hlist_bl_head *b)
+{
+ return bit_spin_is_locked(0, (unsigned long *)b);
+}
+
/**
* hlist_bl_for_each_entry- iterate over list of given type
* @tpos: the type * to use as a loop cursor.
diff --git a/include/linux/rculist_bl.h b/include/linux/rculist_bl.h
index cf1244f..4f216c5 100644
--- a/include/linux/rculist_bl.h
+++ b/include/linux/rculist_bl.h
@@ -20,7 +20,7 @@ static inline void hlist_bl_set_first_rcu(struct
hlist_bl_head *h,
static inline struct hlist_bl_node *hlist_bl_first_rcu(struct hlist_bl_head
*h)
{
return (struct hlist_bl_node *)
- ((unsigned long)rcu_dereference(h->first) & ~LIST_BL_LOCKMASK);
+ ((unsigned long)rcu_dereference_check(h->first,
hlist_bl_is_locked(h)) & ~LIST_BL_LOCKMASK);
}
/**
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: rcu: fix hlist_bl_set_first_rcu annotation
Hi,
On 03/02/13 18:39, Paul E. McKenney wrote:
On Wed, Jan 30, 2013 at 07:07:57PM +, Steven Whitehouse wrote:
Abhi noticed that we were getting a complaint from the RCU subsystem
about access of an RCU protected list under the write side bit lock.
This patch adds additional annotation to check both the RCU read
lock and the write side bit lock before printing a message.
Signed-off-by: Steven Whitehouse swhit...@redhat.com
Reported-by: Abhijith Das a...@redhat.com
Tested-by: Abhijith Das a...@redhat.com
Looks plausible to me on first glance, copying Nick Piggin and Christoph
Hellwig. If they have no objections, I will queue this.
Thanx, Paul
Has this had any attention yet? I'm also seeing the complaint quite
frequently:
[ 68.738811] ===
[ 68.741380] [ INFO: suspicious RCU usage. ]
[ 68.748785] 3.8.0-0.rc7.git1.1.fc19.x86_64 #1 Not tainted
[ 68.750841] ---
[ 68.752418] include/linux/rculist_bl.h:23 suspicious
rcu_dereference_check() usage!
[ 68.755264]
[ 68.755264] other info that might help us debug this:
[ 68.755264]
[ 68.758030]
[ 68.758030] rcu_scheduler_active = 1, debug_locks = 0
[ 68.760316] 1 lock held by mount/476:
[ 68.761896] #0: (type-s_umount_key#38/1){+.+.+.}, at:
[811dbbee] sget+0x39e/0x670
[ 68.767115]
[ 68.767115] stack backtrace:
[ 68.769529] Pid: 476, comm: mount Not tainted
3.8.0-0.rc7.git1.1.fc19.x86_64 #1
[ 68.772095] Call Trace:
[ 68.772995] [810d73b7] lockdep_rcu_suspicious+0xe7/0x120
[ 68.775184] [a00e3238] search_bucket+0x118/0x160 [gfs2]
[ 68.777559] [a00e47c3] gfs2_glock_get+0x603/0x7b0 [gfs2]
[ 68.780749] [a00e41c5] ? gfs2_glock_get+0x5/0x7b0 [gfs2]
[ 68.784173] [a00e6db9] gfs2_glock_nq_num+0x29/0x90 [gfs2]
[ 68.786551] [a00f2b79] gfs2_mount+0x869/0xf30 [gfs2]
[ 68.788672] [810ad428] ? sched_clock_cpu+0xa8/0x100
[ 68.790739] [810d561d] ? trace_hardirqs_off+0xd/0x10
[ 68.793042] [810ad56f] ? local_clock+0x5f/0x70
[ 68.794940] [81702500] ? __mutex_unlock_slowpath+0x80/0x170
[ 68.798236] [811dcb49] mount_fs+0x39/0x1b0
[ 68.800409] [811879c0] ? __alloc_percpu+0x10/0x20
[ 68.803692] [811fa8e3] vfs_kern_mount+0x63/0xf0
[ 68.806773] [811fcfb5] do_mount+0x205/0xa90
[ 68.809669] [8118c8ec] ? might_fault+0x5c/0xb0
[ 68.812717] [811819fb] ? strndup_user+0x4b/0xf0
[ 68.816066] [811fd8c3] sys_mount+0x83/0xc0
[ 68.818284] [8170ead9] system_call_fastpath+0x16/0x1b
It would be good to have this silenced for 3.8 but I think there's not
long to go.
Thanks,
Andy
diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
index 31f9d75..2eb8855 100644
--- a/include/linux/list_bl.h
+++ b/include/linux/list_bl.h
@@ -125,6 +125,11 @@ static inline void hlist_bl_unlock(struct hlist_bl_head *b)
__bit_spin_unlock(0, (unsigned long *)b);
}
+static inline bool hlist_bl_is_locked(struct hlist_bl_head *b)
+{
+ return bit_spin_is_locked(0, (unsigned long *)b);
+}
+
/**
* hlist_bl_for_each_entry- iterate over list of given type
* @tpos: the type * to use as a loop cursor.
diff --git a/include/linux/rculist_bl.h b/include/linux/rculist_bl.h
index cf1244f..4f216c5 100644
--- a/include/linux/rculist_bl.h
+++ b/include/linux/rculist_bl.h
@@ -20,7 +20,7 @@ static inline void hlist_bl_set_first_rcu(struct
hlist_bl_head *h,
static inline struct hlist_bl_node *hlist_bl_first_rcu(struct hlist_bl_head
*h)
{
return (struct hlist_bl_node *)
- ((unsigned long)rcu_dereference(h-first) ~LIST_BL_LOCKMASK);
+ ((unsigned long)rcu_dereference_check(h-first,
hlist_bl_is_locked(h)) ~LIST_BL_LOCKMASK);
}
/**
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: rcu: fix hlist_bl_set_first_rcu annotation
On Fri, Feb 15, 2013 at 12:01:30AM +, Andrew Price wrote:
Hi,
On 03/02/13 18:39, Paul E. McKenney wrote:
On Wed, Jan 30, 2013 at 07:07:57PM +, Steven Whitehouse wrote:
Abhi noticed that we were getting a complaint from the RCU subsystem
about access of an RCU protected list under the write side bit lock.
This patch adds additional annotation to check both the RCU read
lock and the write side bit lock before printing a message.
Signed-off-by: Steven Whitehouse swhit...@redhat.com
Reported-by: Abhijith Das a...@redhat.com
Tested-by: Abhijith Das a...@redhat.com
Looks plausible to me on first glance, copying Nick Piggin and Christoph
Hellwig. If they have no objections, I will queue this.
Thanx, Paul
Has this had any attention yet? I'm also seeing the complaint quite
frequently:
[ 68.738811] ===
[ 68.741380] [ INFO: suspicious RCU usage. ]
[ 68.748785] 3.8.0-0.rc7.git1.1.fc19.x86_64 #1 Not tainted
[ 68.750841] ---
[ 68.752418] include/linux/rculist_bl.h:23 suspicious
rcu_dereference_check() usage!
[ 68.755264]
[ 68.755264] other info that might help us debug this:
[ 68.755264]
[ 68.758030]
[ 68.758030] rcu_scheduler_active = 1, debug_locks = 0
[ 68.760316] 1 lock held by mount/476:
[ 68.761896] #0: (type-s_umount_key#38/1){+.+.+.}, at:
[811dbbee] sget+0x39e/0x670
[ 68.767115]
[ 68.767115] stack backtrace:
[ 68.769529] Pid: 476, comm: mount Not tainted
3.8.0-0.rc7.git1.1.fc19.x86_64 #1
[ 68.772095] Call Trace:
[ 68.772995] [810d73b7] lockdep_rcu_suspicious+0xe7/0x120
[ 68.775184] [a00e3238] search_bucket+0x118/0x160 [gfs2]
[ 68.777559] [a00e47c3] gfs2_glock_get+0x603/0x7b0 [gfs2]
[ 68.780749] [a00e41c5] ? gfs2_glock_get+0x5/0x7b0 [gfs2]
[ 68.784173] [a00e6db9] gfs2_glock_nq_num+0x29/0x90 [gfs2]
[ 68.786551] [a00f2b79] gfs2_mount+0x869/0xf30 [gfs2]
[ 68.788672] [810ad428] ? sched_clock_cpu+0xa8/0x100
[ 68.790739] [810d561d] ? trace_hardirqs_off+0xd/0x10
[ 68.793042] [810ad56f] ? local_clock+0x5f/0x70
[ 68.794940] [81702500] ? __mutex_unlock_slowpath+0x80/0x170
[ 68.798236] [811dcb49] mount_fs+0x39/0x1b0
[ 68.800409] [811879c0] ? __alloc_percpu+0x10/0x20
[ 68.803692] [811fa8e3] vfs_kern_mount+0x63/0xf0
[ 68.806773] [811fcfb5] do_mount+0x205/0xa90
[ 68.809669] [8118c8ec] ? might_fault+0x5c/0xb0
[ 68.812717] [811819fb] ? strndup_user+0x4b/0xf0
[ 68.816066] [811fd8c3] sys_mount+0x83/0xc0
[ 68.818284] [8170ead9] system_call_fastpath+0x16/0x1b
It would be good to have this silenced for 3.8 but I think there's
not long to go.
I have queued this, thank you.
3.8 is getting close to the end, but there is always -stable if the 3.8
series is of particular interest for this bug.
Thanx, Paul
Thanks,
Andy
diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
index 31f9d75..2eb8855 100644
--- a/include/linux/list_bl.h
+++ b/include/linux/list_bl.h
@@ -125,6 +125,11 @@ static inline void hlist_bl_unlock(struct
hlist_bl_head *b)
__bit_spin_unlock(0, (unsigned long *)b);
}
+static inline bool hlist_bl_is_locked(struct hlist_bl_head *b)
+{
+ return bit_spin_is_locked(0, (unsigned long *)b);
+}
+
/**
* hlist_bl_for_each_entry- iterate over list of given type
* @tpos: the type * to use as a loop cursor.
diff --git a/include/linux/rculist_bl.h b/include/linux/rculist_bl.h
index cf1244f..4f216c5 100644
--- a/include/linux/rculist_bl.h
+++ b/include/linux/rculist_bl.h
@@ -20,7 +20,7 @@ static inline void hlist_bl_set_first_rcu(struct
hlist_bl_head *h,
static inline struct hlist_bl_node *hlist_bl_first_rcu(struct
hlist_bl_head *h)
{
return (struct hlist_bl_node *)
- ((unsigned long)rcu_dereference(h-first) ~LIST_BL_LOCKMASK);
+ ((unsigned long)rcu_dereference_check(h-first,
hlist_bl_is_locked(h)) ~LIST_BL_LOCKMASK);
}
/**
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: rcu: fix hlist_bl_set_first_rcu annotation
On Wed, Jan 30, 2013 at 07:07:57PM +, Steven Whitehouse wrote:
>
> Abhi noticed that we were getting a complaint from the RCU subsystem
> about access of an RCU protected list under the write side bit lock.
> This patch adds additional annotation to check both the RCU read
> lock and the write side bit lock before printing a message.
>
> Signed-off-by: Steven Whitehouse
> Reported-by: Abhijith Das
> Tested-by: Abhijith Das
Looks plausible to me on first glance, copying Nick Piggin and Christoph
Hellwig. If they have no objections, I will queue this.
Thanx, Paul
> diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
> index 31f9d75..2eb8855 100644
> --- a/include/linux/list_bl.h
> +++ b/include/linux/list_bl.h
> @@ -125,6 +125,11 @@ static inline void hlist_bl_unlock(struct hlist_bl_head
> *b)
> __bit_spin_unlock(0, (unsigned long *)b);
> }
>
> +static inline bool hlist_bl_is_locked(struct hlist_bl_head *b)
> +{
> + return bit_spin_is_locked(0, (unsigned long *)b);
> +}
> +
> /**
> * hlist_bl_for_each_entry - iterate over list of given type
> * @tpos:the type * to use as a loop cursor.
> diff --git a/include/linux/rculist_bl.h b/include/linux/rculist_bl.h
> index cf1244f..4f216c5 100644
> --- a/include/linux/rculist_bl.h
> +++ b/include/linux/rculist_bl.h
> @@ -20,7 +20,7 @@ static inline void hlist_bl_set_first_rcu(struct
> hlist_bl_head *h,
> static inline struct hlist_bl_node *hlist_bl_first_rcu(struct hlist_bl_head
> *h)
> {
> return (struct hlist_bl_node *)
> - ((unsigned long)rcu_dereference(h->first) & ~LIST_BL_LOCKMASK);
> + ((unsigned long)rcu_dereference_check(h->first,
> hlist_bl_is_locked(h)) & ~LIST_BL_LOCKMASK);
> }
>
> /**
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: rcu: fix hlist_bl_set_first_rcu annotation
On Wed, Jan 30, 2013 at 07:07:57PM +, Steven Whitehouse wrote:
Abhi noticed that we were getting a complaint from the RCU subsystem
about access of an RCU protected list under the write side bit lock.
This patch adds additional annotation to check both the RCU read
lock and the write side bit lock before printing a message.
Signed-off-by: Steven Whitehouse swhit...@redhat.com
Reported-by: Abhijith Das a...@redhat.com
Tested-by: Abhijith Das a...@redhat.com
Looks plausible to me on first glance, copying Nick Piggin and Christoph
Hellwig. If they have no objections, I will queue this.
Thanx, Paul
diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
index 31f9d75..2eb8855 100644
--- a/include/linux/list_bl.h
+++ b/include/linux/list_bl.h
@@ -125,6 +125,11 @@ static inline void hlist_bl_unlock(struct hlist_bl_head
*b)
__bit_spin_unlock(0, (unsigned long *)b);
}
+static inline bool hlist_bl_is_locked(struct hlist_bl_head *b)
+{
+ return bit_spin_is_locked(0, (unsigned long *)b);
+}
+
/**
* hlist_bl_for_each_entry - iterate over list of given type
* @tpos:the type * to use as a loop cursor.
diff --git a/include/linux/rculist_bl.h b/include/linux/rculist_bl.h
index cf1244f..4f216c5 100644
--- a/include/linux/rculist_bl.h
+++ b/include/linux/rculist_bl.h
@@ -20,7 +20,7 @@ static inline void hlist_bl_set_first_rcu(struct
hlist_bl_head *h,
static inline struct hlist_bl_node *hlist_bl_first_rcu(struct hlist_bl_head
*h)
{
return (struct hlist_bl_node *)
- ((unsigned long)rcu_dereference(h-first) ~LIST_BL_LOCKMASK);
+ ((unsigned long)rcu_dereference_check(h-first,
hlist_bl_is_locked(h)) ~LIST_BL_LOCKMASK);
}
/**
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
