This is a note to let you know that I've just added the patch titled
cdc-wdm: untangle a circular dependency between callback and softint
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 18abf874367456540846319574864e6ff32752e2 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum(a)suse.com>
Date: Mon, 26 Apr 2021 11:26:22 +0200
Subject: cdc-wdm: untangle a circular dependency between callback and softint
We have a cycle of callbacks scheduling works which submit
URBs with those callbacks. This needs to be blocked, stopped
and unblocked to untangle the circle.
Signed-off-by: Oliver Neukum <oneukum(a)suse.com>
Link: https://lore.kernel.org/r/20210426092622.20433-1-oneukum@suse.com
Cc: stable <stable(a)vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/usb/class/cdc-wdm.c | 30 ++++++++++++++++++++++--------
1 file changed, 22 insertions(+), 8 deletions(-)
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 508b1c3f8b73..d1e4a7379beb 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -321,12 +321,23 @@ static void wdm_int_callback(struct urb *urb)
}
-static void kill_urbs(struct wdm_device *desc)
+static void poison_urbs(struct wdm_device *desc)
{
/* the order here is essential */
- usb_kill_urb(desc->command);
- usb_kill_urb(desc->validity);
- usb_kill_urb(desc->response);
+ usb_poison_urb(desc->command);
+ usb_poison_urb(desc->validity);
+ usb_poison_urb(desc->response);
+}
+
+static void unpoison_urbs(struct wdm_device *desc)
+{
+ /*
+ * the order here is not essential
+ * it is symmetrical just to be nice
+ */
+ usb_unpoison_urb(desc->response);
+ usb_unpoison_urb(desc->validity);
+ usb_unpoison_urb(desc->command);
}
static void free_urbs(struct wdm_device *desc)
@@ -741,11 +752,12 @@ static int wdm_release(struct inode *inode, struct file *file)
if (!desc->count) {
if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
dev_dbg(&desc->intf->dev, "wdm_release: cleanup\n");
- kill_urbs(desc);
+ poison_urbs(desc);
spin_lock_irq(&desc->iuspin);
desc->resp_count = 0;
spin_unlock_irq(&desc->iuspin);
desc->manage_power(desc->intf, 0);
+ unpoison_urbs(desc);
} else {
/* must avoid dev_printk here as desc->intf is invalid */
pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
@@ -1037,9 +1049,9 @@ static void wdm_disconnect(struct usb_interface *intf)
wake_up_all(&desc->wait);
mutex_lock(&desc->rlock);
mutex_lock(&desc->wlock);
+ poison_urbs(desc);
cancel_work_sync(&desc->rxwork);
cancel_work_sync(&desc->service_outs_intr);
- kill_urbs(desc);
mutex_unlock(&desc->wlock);
mutex_unlock(&desc->rlock);
@@ -1080,9 +1092,10 @@ static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
set_bit(WDM_SUSPENDING, &desc->flags);
spin_unlock_irq(&desc->iuspin);
/* callback submits work - order is essential */
- kill_urbs(desc);
+ poison_urbs(desc);
cancel_work_sync(&desc->rxwork);
cancel_work_sync(&desc->service_outs_intr);
+ unpoison_urbs(desc);
}
if (!PMSG_IS_AUTO(message)) {
mutex_unlock(&desc->wlock);
@@ -1140,7 +1153,7 @@ static int wdm_pre_reset(struct usb_interface *intf)
wake_up_all(&desc->wait);
mutex_lock(&desc->rlock);
mutex_lock(&desc->wlock);
- kill_urbs(desc);
+ poison_urbs(desc);
cancel_work_sync(&desc->rxwork);
cancel_work_sync(&desc->service_outs_intr);
return 0;
@@ -1151,6 +1164,7 @@ static int wdm_post_reset(struct usb_interface *intf)
struct wdm_device *desc = wdm_find_device(intf);
int rv;
+ unpoison_urbs(desc);
clear_bit(WDM_OVERFLOW, &desc->flags);
clear_bit(WDM_RESETTING, &desc->flags);
rv = recover_from_urb_loss(desc);
--
2.31.1
This is a note to let you know that I've just added the patch titled
usb: dwc3: pci: Enable usb2-gadget-lpm-disable for Intel Merrifield
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 04357fafea9c7ed34525eb9680c760245c3bb958 Mon Sep 17 00:00:00 2001
From: Ferry Toth <ftoth(a)exalondelft.nl>
Date: Sun, 25 Apr 2021 17:09:47 +0200
Subject: usb: dwc3: pci: Enable usb2-gadget-lpm-disable for Intel Merrifield
On Intel Merrifield LPM is causing host to reset port after a timeout.
By disabling LPM entirely this is prevented.
Fixes: 066c09593454 ("usb: dwc3: pci: Enable extcon driver for Intel Merrifield")
Reviewed-by: Andy Shevchenko <andy.shevchenko(a)gmail.com>
Signed-off-by: Ferry Toth <ftoth(a)exalondelft.nl>
Cc: stable <stable(a)vger.kernel.org>
Link: https://lore.kernel.org/r/20210425150947.5862-1-ftoth@exalondelft.nl
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/usb/dwc3/dwc3-pci.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/usb/dwc3/dwc3-pci.c b/drivers/usb/dwc3/dwc3-pci.c
index e7b932dcbf82..1e51460938b8 100644
--- a/drivers/usb/dwc3/dwc3-pci.c
+++ b/drivers/usb/dwc3/dwc3-pci.c
@@ -123,6 +123,7 @@ static const struct property_entry dwc3_pci_mrfld_properties[] = {
PROPERTY_ENTRY_STRING("linux,extcon-name", "mrfld_bcove_pwrsrc"),
PROPERTY_ENTRY_BOOL("snps,dis_u3_susphy_quirk"),
PROPERTY_ENTRY_BOOL("snps,dis_u2_susphy_quirk"),
+ PROPERTY_ENTRY_BOOL("snps,usb2-gadget-lpm-disable"),
PROPERTY_ENTRY_BOOL("linux,sysdev_is_parent"),
{}
};
--
2.31.1
Hi,
Can you please cherry-pick 4fff19ae4275 ("drm/qxl: use ttm bo
priorities") from 5.13-rc1 into stable branches? It is a clean
cherry-pick for 5.12 and 5.11. Looking into 5.10-lts right now,
will eventually follow up with a backported patch.
thanks,
Gerd
If an error is received when issuing a start or update transfer
command, the error handler will stop all active requests (including
the current USB request), and call dwc3_gadget_giveback() to notify
function drivers of the requests which have been stopped. Avoid
returning an error for kick transfer during EP queue, to remove
duplicate cleanup operations on the request being queued.
Fixes: 8d99087c2db8 ("usb: dwc3: gadget: Properly handle failed kick_transfer")
cc: stable(a)vger.kernel.org
Signed-off-by: Wesley Cheng <wcheng(a)codeaurora.org>
---
Changes in v2:
- Added Fixes tag and Cc'ed stable
Changes in v1:
- Renamed commit title due to new implementation
- Return success always for kick transfer during ep queue
Previous patchset:
https://lore.kernel.org/linux-usb/875yzxibur.fsf@kernel.org/T/#t
drivers/usb/dwc3/gadget.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index dd80e5c..a5b7fd9 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1684,7 +1684,9 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
}
}
- return __dwc3_gadget_kick_transfer(dep);
+ __dwc3_gadget_kick_transfer(dep);
+
+ return 0;
}
static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
do_mq_timedreceive calls wq_sleep with a stack local address. The
sender (do_mq_timedsend) uses this address to later call
pipelined_send.
This leads to a very hard to trigger race where a do_mq_timedreceive call
might return and leave do_mq_timedsend to rely on an invalid address,
causing the following crash:
[ 240.739977] RIP: 0010:wake_q_add_safe+0x13/0x60
[ 240.739991] Call Trace:
[ 240.739999] __x64_sys_mq_timedsend+0x2a9/0x490
[ 240.740003] ? auditd_test_task+0x38/0x40
[ 240.740007] ? auditd_test_task+0x38/0x40
[ 240.740011] do_syscall_64+0x80/0x680
[ 240.740017] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 240.740019] RIP: 0033:0x7f5928e40343
The race occurs as:
1. do_mq_timedreceive calls wq_sleep with the address of
`struct ext_wait_queue` on function stack (aliased as `ewq_addr` here)
- it holds a valid `struct ext_wait_queue *` as long as the stack has
not been overwritten.
2. `ewq_addr` gets added to info->e_wait_q[RECV].list in wq_add, and
do_mq_timedsend receives it via wq_get_first_waiter(info, RECV) to call
__pipelined_op.
3. Sender calls __pipelined_op::smp_store_release(&this->state, STATE_READY).
Here is where the race window begins. (`this` is `ewq_addr`.)
4. If the receiver wakes up now in do_mq_timedreceive::wq_sleep, it
will see `state == STATE_READY` and break.
5. do_mq_timedreceive returns, and `ewq_addr` is no longer guaranteed
to be a `struct ext_wait_queue *` since it was on do_mq_timedreceive's
stack. (Although the address may not get overwritten until another
function happens to touch it, which means it can persist around for an
indefinite time.)
6. do_mq_timedsend::__pipelined_op() still believes `ewq_addr` is a
`struct ext_wait_queue *`, and uses it to find a task_struct to pass
to the wake_q_add_safe call. In the lucky case where nothing has
overwritten `ewq_addr` yet, `ewq_addr->task` is the right task_struct.
In the unlucky case, __pipelined_op::wake_q_add_safe gets handed a
bogus address as the receiver's task_struct causing the crash.
do_mq_timedsend::__pipelined_op() should not dereference `this` after
setting STATE_READY, as the receiver counterpart is now free to return.
Change __pipelined_op to call wake_q_add before setting STATE_READY
which ensures that the receiver's task_struct can still be found via
`this`.
Fixes: c5b2cbdbdac563 ("ipc/mqueue.c: update/document memory barriers")
Signed-off-by: Varad Gautam <varad.gautam(a)suse.com>
Reported-by: Matthias von Faber <matthias.vonfaber(a)aox-tech.de>
Acked-by: Davidlohr Bueso <dbueso(a)suse.de>
Cc: <stable(a)vger.kernel.org> # 5.6
Cc: Christian Brauner <christian.brauner(a)ubuntu.com>
Cc: Oleg Nesterov <oleg(a)redhat.com>
Cc: "Eric W. Biederman" <ebiederm(a)xmission.com>
Cc: Manfred Spraul <manfred(a)colorfullife.com>
Cc: Andrew Morton <akpm(a)linux-foundation.org>
---
v2: Call wake_q_add before smp_store_release, instead of using a
get_task_struct/wake_q_add_safe combination across
smp_store_release. (Davidlohr Bueso)
v3: Comment/commit message fixup.
ipc/mqueue.c | 33 ++++++++++++++++++++++++---------
1 file changed, 24 insertions(+), 9 deletions(-)
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 8031464ed4ae..bf5dce399854 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -78,11 +78,13 @@ struct posix_msg_tree_node {
* MQ_BARRIER:
* To achieve proper release/acquire memory barrier pairing, the state is set to
* STATE_READY with smp_store_release(), and it is read with READ_ONCE followed
- * by smp_acquire__after_ctrl_dep(). In addition, wake_q_add_safe() is used.
+ * by smp_acquire__after_ctrl_dep(). The state change to STATE_READY must be
+ * the last write operation, after which the blocked task can immediately
+ * return and exit.
*
* This prevents the following races:
*
- * 1) With the simple wake_q_add(), the task could be gone already before
+ * 1) With wake_q_add(), the task could be gone already before
* the increase of the reference happens
* Thread A
* Thread B
@@ -97,10 +99,25 @@ struct posix_msg_tree_node {
* sys_exit()
* get_task_struct() // UaF
*
- * Solution: Use wake_q_add_safe() and perform the get_task_struct() before
- * the smp_store_release() that does ->state = STATE_READY.
+ * 2) With wake_q_add(), the receiver task could have returned from the
+ * syscall and had its stack-allocated waiter overwritten before the
+ * waker could add it to the wake_q
+ * Thread A
+ * Thread B
+ * WRITE_ONCE(wait.state, STATE_NONE);
+ * schedule_hrtimeout()
+ * ->state = STATE_READY
+ * <timeout returns>
+ * if (wait.state == STATE_READY) return;
+ * sysret to user space
+ * overwrite receiver's stack
+ * wake_q_add(A)
+ * if (cmpxchg()) // corrupted waiter
*
- * 2) Without proper _release/_acquire barriers, the woken up task
+ * Solution: Queue the task for wakeup before the smp_store_release() that
+ * does ->state = STATE_READY.
+ *
+ * 3) Without proper _release/_acquire barriers, the woken up task
* could read stale data
*
* Thread A
@@ -116,7 +133,7 @@ struct posix_msg_tree_node {
*
* Solution: use _release and _acquire barriers.
*
- * 3) There is intentionally no barrier when setting current->state
+ * 4) There is intentionally no barrier when setting current->state
* to TASK_INTERRUPTIBLE: spin_unlock(&info->lock) provides the
* release memory barrier, and the wakeup is triggered when holding
* info->lock, i.e. spin_lock(&info->lock) provided a pairing
@@ -1005,11 +1022,9 @@ static inline void __pipelined_op(struct wake_q_head *wake_q,
struct ext_wait_queue *this)
{
list_del(&this->list);
- get_task_struct(this->task);
-
+ wake_q_add(wake_q, this->task);
/* see MQ_BARRIER for purpose/pairing */
smp_store_release(&this->state, STATE_READY);
- wake_q_add_safe(wake_q, this->task);
}
/* pipelined_send() - send a message directly to the task waiting in
--
2.30.2
This is an automatic generated email to let you know that the following patch were queued:
Subject: media: i2c: ccs-core: fix pm_runtime_get_sync() usage count
Author: Mauro Carvalho Chehab <mchehab+huawei(a)kernel.org>
Date: Fri Apr 23 17:19:11 2021 +0200
The pm_runtime_get_sync() internally increments the
dev->power.usage_count without decrementing it, even on errors.
There is a bug at ccs_pm_get_init(): when this function returns
an error, the stream is not started, and RPM usage_count
should not be incremented. However, if the calls to
v4l2_ctrl_handler_setup() return errors, it will be kept
incremented.
At ccs_suspend() the best is to replace it by the new
pm_runtime_resume_and_get(), introduced by:
commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
in order to properly decrement the usage counter automatically,
in the case of errors.
Fixes: 96e3a6b92f23 ("media: smiapp: Avoid maintaining power state information")
Cc: stable(a)vger.kernel.org
Acked-by: Sakari Ailus <sakari.ailus(a)linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei(a)kernel.org>
drivers/media/i2c/ccs/ccs-core.c | 32 ++++++++++++++++++++++----------
1 file changed, 22 insertions(+), 10 deletions(-)
---
diff --git a/drivers/media/i2c/ccs/ccs-core.c b/drivers/media/i2c/ccs/ccs-core.c
index b05f409014b2..4a848ac2d2cd 100644
--- a/drivers/media/i2c/ccs/ccs-core.c
+++ b/drivers/media/i2c/ccs/ccs-core.c
@@ -1880,21 +1880,33 @@ static int ccs_pm_get_init(struct ccs_sensor *sensor)
struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
int rval;
+ /*
+ * It can't use pm_runtime_resume_and_get() here, as the driver
+ * relies at the returned value to detect if the device was already
+ * active or not.
+ */
rval = pm_runtime_get_sync(&client->dev);
- if (rval < 0) {
- pm_runtime_put_noidle(&client->dev);
+ if (rval < 0)
+ goto error;
- return rval;
- } else if (!rval) {
- rval = v4l2_ctrl_handler_setup(&sensor->pixel_array->
- ctrl_handler);
- if (rval)
- return rval;
+ /* Device was already active, so don't set controls */
+ if (rval == 1)
+ return 0;
- return v4l2_ctrl_handler_setup(&sensor->src->ctrl_handler);
- }
+ /* Restore V4L2 controls to the previously suspended device */
+ rval = v4l2_ctrl_handler_setup(&sensor->pixel_array->ctrl_handler);
+ if (rval)
+ goto error;
+ rval = v4l2_ctrl_handler_setup(&sensor->src->ctrl_handler);
+ if (rval)
+ goto error;
+
+ /* Keep PM runtime usage_count incremented on success */
return 0;
+error:
+ pm_runtime_put(&client->dev);
+ return rval;
}
static int ccs_set_stream(struct v4l2_subdev *subdev, int enable)
This is an automatic generated email to let you know that the following patch were queued:
Subject: media: i2c: ccs-core: fix pm_runtime_get_sync() usage count
Author: Mauro Carvalho Chehab <mchehab+huawei(a)kernel.org>
Date: Fri Apr 23 17:19:11 2021 +0200
The pm_runtime_get_sync() internally increments the
dev->power.usage_count without decrementing it, even on errors.
There is a bug at ccs_pm_get_init(): when this function returns
an error, the stream is not started, and RPM usage_count
should not be incremented. However, if the calls to
v4l2_ctrl_handler_setup() return errors, it will be kept
incremented.
At ccs_suspend() the best is to replace it by the new
pm_runtime_resume_and_get(), introduced by:
commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
in order to properly decrement the usage counter automatically,
in the case of errors.
Fixes: 96e3a6b92f23 ("media: smiapp: Avoid maintaining power state information")
Cc: stable(a)vger.kernel.org
Acked-by: Sakari Ailus <sakari.ailus(a)linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei(a)kernel.org>
drivers/media/i2c/ccs/ccs-core.c | 32 ++++++++++++++++++++++----------
1 file changed, 22 insertions(+), 10 deletions(-)
---
diff --git a/drivers/media/i2c/ccs/ccs-core.c b/drivers/media/i2c/ccs/ccs-core.c
index b05f409014b2..4a848ac2d2cd 100644
--- a/drivers/media/i2c/ccs/ccs-core.c
+++ b/drivers/media/i2c/ccs/ccs-core.c
@@ -1880,21 +1880,33 @@ static int ccs_pm_get_init(struct ccs_sensor *sensor)
struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
int rval;
+ /*
+ * It can't use pm_runtime_resume_and_get() here, as the driver
+ * relies at the returned value to detect if the device was already
+ * active or not.
+ */
rval = pm_runtime_get_sync(&client->dev);
- if (rval < 0) {
- pm_runtime_put_noidle(&client->dev);
+ if (rval < 0)
+ goto error;
- return rval;
- } else if (!rval) {
- rval = v4l2_ctrl_handler_setup(&sensor->pixel_array->
- ctrl_handler);
- if (rval)
- return rval;
+ /* Device was already active, so don't set controls */
+ if (rval == 1)
+ return 0;
- return v4l2_ctrl_handler_setup(&sensor->src->ctrl_handler);
- }
+ /* Restore V4L2 controls to the previously suspended device */
+ rval = v4l2_ctrl_handler_setup(&sensor->pixel_array->ctrl_handler);
+ if (rval)
+ goto error;
+ rval = v4l2_ctrl_handler_setup(&sensor->src->ctrl_handler);
+ if (rval)
+ goto error;
+
+ /* Keep PM runtime usage_count incremented on success */
return 0;
+error:
+ pm_runtime_put(&client->dev);
+ return rval;
}
static int ccs_set_stream(struct v4l2_subdev *subdev, int enable)