From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
When issuing an IPI RT push, where an IPI is sent to each CPU that has more
than one RT task scheduled on it, it references the root domain's rto_mask,
that contains all the CPUs within the root domain that has more than one RT
task in the runable state. The problem is, after the IPIs are initiated, the
rq->lock is released. This means that the root domain that is associated to
the run queue could be freed while the IPIs are going around.
Add a sched_get_rd() and a sched_put_rd() that will increment and decrement
the root domain's ref count respectively. This way when initiating the IPIs,
the scheduler will up the root domain's ref count before releasing the
rq->lock, ensuring that the root domain does not go away until the IPI round
is complete.
Link: http://lkml.kernel.org/r/CAEU1=PkiHO35Dzna8EQqNSKW1fr1y1zRQ5y66X117MG06sQtN…
Cc: stable(a)vger.kernel.org
Fixes: 4bdced5c9a292 ("sched/rt: Simplify the IPI based RT balancing logic")
Reported-by: Pavan Kondeti <pkondeti(a)codeaurora.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
---
kernel/sched/rt.c | 9 +++++++--
kernel/sched/sched.h | 2 ++
kernel/sched/topology.c | 13 +++++++++++++
3 files changed, 22 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 274b55e4a560..3401f588c916 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1990,8 +1990,11 @@ static void tell_cpu_to_push(struct rq *rq)
rto_start_unlock(&rq->rd->rto_loop_start);
- if (cpu >= 0)
+ if (cpu >= 0) {
+ /* Make sure the rd does not get freed while pushing */
+ sched_get_rd(rq->rd);
irq_work_queue_on(&rq->rd->rto_push_work, cpu);
+ }
}
/* Called from hardirq context */
@@ -2021,8 +2024,10 @@ void rto_push_irq_work_func(struct irq_work *work)
raw_spin_unlock(&rd->rto_lock);
- if (cpu < 0)
+ if (cpu < 0) {
+ sched_put_rd(rd);
return;
+ }
/* Try the next RT overloaded CPU */
irq_work_queue_on(&rd->rto_push_work, cpu);
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 2e95505e23c6..fb5fc458547f 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -691,6 +691,8 @@ extern struct mutex sched_domains_mutex;
extern void init_defrootdomain(void);
extern int sched_init_domains(const struct cpumask *cpu_map);
extern void rq_attach_root(struct rq *rq, struct root_domain *rd);
+extern void sched_get_rd(struct root_domain *rd);
+extern void sched_put_rd(struct root_domain *rd);
#ifdef HAVE_RT_PUSH_IPI
extern void rto_push_irq_work_func(struct irq_work *work);
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 034cbed7f88b..519b024f4e94 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -259,6 +259,19 @@ void rq_attach_root(struct rq *rq, struct root_domain *rd)
call_rcu_sched(&old_rd->rcu, free_rootdomain);
}
+void sched_get_rd(struct root_domain *rd)
+{
+ atomic_inc(&rd->refcount);
+}
+
+void sched_put_rd(struct root_domain *rd)
+{
+ if (!atomic_dec_and_test(&rd->refcount))
+ return;
+
+ call_rcu_sched(&rd->rcu, free_rootdomain);
+}
+
static int init_rootdomain(struct root_domain *rd)
{
if (!zalloc_cpumask_var(&rd->span, GFP_KERNEL))
--
2.15.1
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
When the rto_push_irq_work_func() is called, it looks at the RT overloaded
bitmask in the root domain via the runqueue (rq->rd). The problem is that
during CPU up and down, nothing here stops rq->rd from changing between
taking the rq->rd->rto_lock and releasing it. That means the lock that is
released is not the same lock that was taken.
Instead of using this_rq()->rd to get the root domain, as the irq work is
part of the root domain, we can simply get the root domain from the irq work
that is passed to the routine:
container_of(work, struct root_domain, rto_push_work)
This keeps the root domain consistent.
Link: http://lkml.kernel.org/r/CAEU1=PkiHO35Dzna8EQqNSKW1fr1y1zRQ5y66X117MG06sQtN…
Cc: stable(a)vger.kernel.org
Fixes: 4bdced5c9a292 ("sched/rt: Simplify the IPI based RT balancing logic")
Reported-by: Pavan Kondeti <pkondeti(a)codeaurora.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
---
kernel/sched/rt.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 665ace2fc558..274b55e4a560 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1907,9 +1907,8 @@ static void push_rt_tasks(struct rq *rq)
* the rt_loop_next will cause the iterator to perform another scan.
*
*/
-static int rto_next_cpu(struct rq *rq)
+static int rto_next_cpu(struct root_domain *rd)
{
- struct root_domain *rd = rq->rd;
int next;
int cpu;
@@ -1985,7 +1984,7 @@ static void tell_cpu_to_push(struct rq *rq)
* Otherwise it is finishing up and an ipi needs to be sent.
*/
if (rq->rd->rto_cpu < 0)
- cpu = rto_next_cpu(rq);
+ cpu = rto_next_cpu(rq->rd);
raw_spin_unlock(&rq->rd->rto_lock);
@@ -1998,6 +1997,8 @@ static void tell_cpu_to_push(struct rq *rq)
/* Called from hardirq context */
void rto_push_irq_work_func(struct irq_work *work)
{
+ struct root_domain *rd =
+ container_of(work, struct root_domain, rto_push_work);
struct rq *rq;
int cpu;
@@ -2013,18 +2014,18 @@ void rto_push_irq_work_func(struct irq_work *work)
raw_spin_unlock(&rq->lock);
}
- raw_spin_lock(&rq->rd->rto_lock);
+ raw_spin_lock(&rd->rto_lock);
/* Pass the IPI to the next rt overloaded queue */
- cpu = rto_next_cpu(rq);
+ cpu = rto_next_cpu(rd);
- raw_spin_unlock(&rq->rd->rto_lock);
+ raw_spin_unlock(&rd->rto_lock);
if (cpu < 0)
return;
/* Try the next RT overloaded CPU */
- irq_work_queue_on(&rq->rd->rto_push_work, cpu);
+ irq_work_queue_on(&rd->rto_push_work, cpu);
}
#endif /* HAVE_RT_PUSH_IPI */
--
2.15.1
From: Josef Bacik <jbacik(a)fb.com>
In fixing the readdir+pagefault deadlock I accidentally introduced a
stale entry regression in readdir. If we get close to full for the
temporary buffer, and then skip a few delayed deletions, and then try to
add another entry that won't fit, we will emit the entries we found and
retry. Unfortunately we delete entries from our del_list as we find
them, assuming we won't need them. However our pos will be with
whatever our last entry was, which could be before the delayed deletions
we skipped, so the next search will add the deleted entries back into
our readdir buffer. So instead don't delete entries we find in our
del_list so we can make sure we always find our delayed deletions. This
is a slight perf hit for readdir with lots of pending deletions, but
hopefully this isn't a common occurrence. If it is we can revist this
and optimize it.
cc: stable(a)vger.kernel.org
Fixes: 23b5ec74943f ("btrfs: fix readdir deadlock with pagefault")
Signed-off-by: Josef Bacik <jbacik(a)fb.com>
---
fs/btrfs/delayed-inode.c | 26 ++++++++------------------
1 file changed, 8 insertions(+), 18 deletions(-)
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 1c0bab4080a0..c9f7b13a7847 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -1632,28 +1632,18 @@ void btrfs_readdir_put_delayed_items(struct inode *inode,
int btrfs_should_delete_dir_index(struct list_head *del_list,
u64 index)
{
- struct btrfs_delayed_item *curr, *next;
- int ret;
-
- if (list_empty(del_list))
- return 0;
+ struct btrfs_delayed_item *curr;
+ int ret = 0;
- list_for_each_entry_safe(curr, next, del_list, readdir_list) {
+ list_for_each_entry(curr, del_list, readdir_list) {
if (curr->key.offset > index)
break;
-
- list_del(&curr->readdir_list);
- ret = (curr->key.offset == index);
-
- if (refcount_dec_and_test(&curr->refs))
- kfree(curr);
-
- if (ret)
- return 1;
- else
- continue;
+ if (curr->key.offset == index) {
+ ret = 1;
+ break;
+ }
}
- return 0;
+ return ret;
}
/*
--
2.7.5
The Toshiba Click Mini uses an i2c attached keyboard/touchpad combo
(single i2c_hid device for both) which has a vid:pid of 04F3:0401,
which is also used by a bunch of Elan touchpads which are handled by the
drivers/input/mouse/elan_i2c driver, but that driver deals with pure
touchpads and does not work for a combo device such as the one on the
Toshiba Click Mini.
The combo on the Mini has an ACPI id of ELAN0800, which is not claimed
by the elan_i2c driver, so check for that and if it is found do not ignore
the device. This fixes the keyboard/touchpad combo on the Mini not working
(although with the touchpad in mouse emulation mode).
Cc: stable(a)vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede(a)redhat.com>
---
drivers/hid/hid-quirks.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/hid/hid-quirks.c b/drivers/hid/hid-quirks.c
index 1cf1e9a0d699..ed4b30bbdde3 100644
--- a/drivers/hid/hid-quirks.c
+++ b/drivers/hid/hid-quirks.c
@@ -729,7 +729,6 @@ static const struct hid_device_id hid_ignore_list[] = {
{ HID_USB_DEVICE(USB_VENDOR_ID_DELORME, USB_DEVICE_ID_DELORME_EARTHMATE) },
{ HID_USB_DEVICE(USB_VENDOR_ID_DELORME, USB_DEVICE_ID_DELORME_EM_LT20) },
{ HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, 0x0400) },
- { HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, 0x0401) },
{ HID_USB_DEVICE(USB_VENDOR_ID_ESSENTIAL_REALITY, USB_DEVICE_ID_ESSENTIAL_REALITY_P5) },
{ HID_USB_DEVICE(USB_VENDOR_ID_ETT, USB_DEVICE_ID_TC5UH) },
{ HID_USB_DEVICE(USB_VENDOR_ID_ETT, USB_DEVICE_ID_TC4UM) },
@@ -997,6 +996,17 @@ bool hid_ignore(struct hid_device *hdev)
strncmp(hdev->name, "www.masterkit.ru MA901", 22) == 0)
return true;
break;
+ case USB_VENDOR_ID_ELAN:
+ /*
+ * Many Elan devices have a product id of 0x0401 and are handled
+ * by the elan_i2c input driver. But the ACPI HID ELAN0800 dev
+ * is not (and cannot be) handled by that driver ->
+ * Ignore all 0x0401 devs except for the ELAN0800 dev.
+ */
+ if (hdev->product == 0x0401 &&
+ strncmp(hdev->name, "ELAN0800", 8) != 0)
+ return true;
+ break;
}
if (hdev->type == HID_TYPE_USBMOUSE &&
--
2.14.3
Touch toggle softkeys send a '1' while pressed and a '0' while released,
requring the kernel to keep track of wether touch should be enabled or
disabled. The code does not handle the state transitions properly,
however. If the key is pressed repeatedly, the following four states
of states are cycled through (assuming touch starts out enabled):
Press: shared->is_touch_on => 0, SW_MUTE_DEVICE => 1
Release: shared->is_touch_on => 0, SW_MUTE_DEVICE => 1
Press: shared->is_touch_on => 1, SW_MUTE_DEVICE => 0
Release: shared->is_touch_on => 1, SW_MUTE_DEVICE => 1
The hardware always properly enables/disables touch when the key is
pressed but applications that listen for SW_MUTE_DEVICE events to provide
feedback about the state will only ever show touch as being enabled while
the key is held, and only every-other time. This sequence occurs because
the fallthrough WACOM_HID_WD_TOUCHONOFF case is always handled, and it
uses the value of the *local* is_touch_on variable as the value to
report to userspace. The local value is equal to the shared value when
the button is pressed, but equal to zero when the button is released.
Reporting the shared value to userspace fixes this problem, but the
fallthrough case needs to update the shared value in an incompatible
way (which is why the local variable was introduced in the first place).
To work around this, we just handle both cases in a single block of code
and update the shared variable as appropriate.
Fixes: d793ff8187 ("HID: wacom: generic: support touch on/off softkey")
Cc: <stable(a)vger.kernel.org> # v4.12+
Signed-off-by: Jason Gerecke <jason.gerecke(a)wacom.com>
Reviewed-by: Aaron Skomra <aaron.skomra(a)wacom.com>
Tested-by: Aaron Skomra <aaron.skomra(a)wacom.com>
---
drivers/hid/wacom_wac.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index 16af6886e828..7dbff253c05c 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -1924,7 +1924,6 @@ static void wacom_wac_pad_event(struct hid_device *hdev, struct hid_field *field
struct wacom_features *features = &wacom_wac->features;
unsigned equivalent_usage = wacom_equivalent_usage(usage->hid);
int i;
- bool is_touch_on = value;
bool do_report = false;
/*
@@ -1969,16 +1968,17 @@ static void wacom_wac_pad_event(struct hid_device *hdev, struct hid_field *field
break;
case WACOM_HID_WD_MUTE_DEVICE:
- if (wacom_wac->shared->touch_input && value) {
- wacom_wac->shared->is_touch_on = !wacom_wac->shared->is_touch_on;
- is_touch_on = wacom_wac->shared->is_touch_on;
- }
-
- /* fall through*/
case WACOM_HID_WD_TOUCHONOFF:
if (wacom_wac->shared->touch_input) {
+ bool *is_touch_on = &wacom_wac->shared->is_touch_on;
+
+ if (equivalent_usage == WACOM_HID_WD_MUTE_DEVICE && value)
+ *is_touch_on = !(*is_touch_on);
+ else if (equivalent_usage == WACOM_HID_WD_TOUCHONOFF)
+ *is_touch_on = value;
+
input_report_switch(wacom_wac->shared->touch_input,
- SW_MUTE_DEVICE, !is_touch_on);
+ SW_MUTE_DEVICE, !(*is_touch_on));
input_sync(wacom_wac->shared->touch_input);
}
break;
--
2.15.1
Background: ExpressKey Remotes communicate their events via usb dongle.
Each dongle can hold up to 5 pairings at one time and one EKR (identified
by its serial number) can unfortunately be paired with its dongle
more than once. The pairing takes place in a round-robin fashion.
Input devices are only created once per EKR, when a new serial number
is seen in the list of pairings. However, if a device is created for
a "higher" paring index and subsequently a second pairing occurs at a
lower pairing index, unpairing the remote with that serial number from
any pairing index will currently cause a driver crash. This occurs
infrequently, as two remotes are necessary to trigger this bug and most
users have only one remote.
As an illustration, to trigger the bug you need to have two remotes,
and pair them in this order:
1. slot 0 -> remote 1 (input device created for remote 1)
2. slot 1 -> remote 1 (duplicate pairing - no device created)
3. slot 2 -> remote 1 (duplicate pairing - no device created)
4. slot 3 -> remote 1 (duplicate pairing - no device created)
5. slot 4 -> remote 2 (input device created for remote 2)
6. slot 0 -> remote 2 (1 destroyed and recreated at slot 1)
7. slot 1 -> remote 2 (1 destroyed and recreated at slot 2)
8. slot 2 -> remote 2 (1 destroyed and recreated at slot 3)
9. slot 3 -> remote 2 (1 destroyed and not recreated)
10. slot 4 -> remote 2 (2 was already in this slot so no changes)
11. slot 0 -> remote 1 (The current code sees remote 2 was paired over in
one of the dongle slots it occupied and attempts
to remove all information about remote 2 [1]. It
calls wacom_remote_destroy_one for remote 2, but
the destroy function assumes the lowest index is
where the remote's input device was created. The
code "cleans up" the other remote 2 pairings
including the one which the input device was based
on, assuming they were were just duplicate
pairings. However, the cleanup doesn't call the
devres release function for the input device that
was created in slot 4).
This issue is fixed by this commit.
[1] Remote 2 should subsequently be re-created on the next packet from the
EKR at the lowest numbered slot that it occupies (here slot 1).
Fixes: f9036bd43602 ("HID: wacom: EKR: use devres groups to manage resources")
Cc: stable <stable(a)vger.kernel.org> #4.9
Signed-off-by: Aaron Armstrong Skomra <aaron.skomra(a)wacom.com>
---
drivers/hid/wacom_sys.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index ee71ad9b6cc1..76531796bd3c 100644
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -2347,23 +2347,23 @@ static void wacom_remote_destroy_one(struct wacom *wacom, unsigned int index)
int i;
unsigned long flags;
- spin_lock_irqsave(&remote->remote_lock, flags);
- remote->remotes[index].registered = false;
- spin_unlock_irqrestore(&remote->remote_lock, flags);
+ for (i = 0; i < WACOM_MAX_REMOTES; i++) {
+ if (remote->remotes[i].serial == serial) {
- if (remote->remotes[index].battery.battery)
- devres_release_group(&wacom->hdev->dev,
- &remote->remotes[index].battery.bat_desc);
+ spin_lock_irqsave(&remote->remote_lock, flags);
+ remote->remotes[i].registered = false;
+ spin_unlock_irqrestore(&remote->remote_lock, flags);
- if (remote->remotes[index].group.name)
- devres_release_group(&wacom->hdev->dev,
- &remote->remotes[index]);
+ if (remote->remotes[i].battery.battery)
+ devres_release_group(&wacom->hdev->dev,
+ &remote->remotes[i].battery.bat_desc);
+
+ if (remote->remotes[i].group.name)
+ devres_release_group(&wacom->hdev->dev,
+ &remote->remotes[i]);
- for (i = 0; i < WACOM_MAX_REMOTES; i++) {
- if (remote->remotes[i].serial == serial) {
remote->remotes[i].serial = 0;
remote->remotes[i].group.name = NULL;
- remote->remotes[i].registered = false;
remote->remotes[i].battery.battery = NULL;
wacom->led.groups[i].select = WACOM_STATUS_UNKNOWN;
}
--
2.7.4