Fix the longstanding race between hv_pci_query_relations() and
survey_child_resources() by flushing the workqueue before we exit from
hv_pci_query_relations().
Fixes: 4daace0d8ce8 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs")
Signed-off-by: Dexuan Cui <decui(a)microsoft.com>
Cc: stable(a)vger.kernel.org
---
v2:
Removed the "debug code".
No change to the patch body.
Added Cc:stable
drivers/pci/controller/pci-hyperv.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index f33370b756283..b82c7cde19e66 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -3308,6 +3308,19 @@ static int hv_pci_query_relations(struct hv_device *hdev)
if (!ret)
ret = wait_for_response(hdev, &comp);
+ /*
+ * In the case of fast device addition/removal, it's possible that
+ * vmbus_sendpacket() or wait_for_response() returns -ENODEV but we
+ * already got a PCI_BUS_RELATIONS* message from the host and the
+ * channel callback already scheduled a work to hbus->wq, which can be
+ * running survey_child_resources() -> complete(&hbus->survey_event),
+ * even after hv_pci_query_relations() exits and the stack variable
+ * 'comp' is no longer valid. This can cause a strange hang issue
+ * or sometimes a page fault. Flush hbus->wq before we exit from
+ * hv_pci_query_relations() to avoid the issues.
+ */
+ flush_workqueue(hbus->wq);
+
return ret;
}
--
2.25.1
Since 32ef9e5054ec, -Wa,-gdwarf-2 is no longer used in KBUILD_AFLAGS.
Instead, it includes -g, the appropriate -gdwarf-* flag, and also the
-Wa versions of both of those if building with Clang and GNU as. As a
result, debug info was being generated for the purgatory objects, even
though the intention was that it not be.
Fixes: 32ef9e5054ec ("Makefile.debug: re-enable debug info for .S files")
Signed-off-by: Alyssa Ross <hi(a)alyssa.is>
Cc: stable(a)vger.kernel.org
---
Difference from v2: replace each AFLAGS_REMOVE_* assignment with a
single aflags-remove-y line, and use foreach to add the -Wa versions,
as suggested by Masahiro Yamada.
arch/riscv/purgatory/Makefile | 7 +------
arch/x86/purgatory/Makefile | 3 +--
2 files changed, 2 insertions(+), 8 deletions(-)
diff --git a/arch/riscv/purgatory/Makefile b/arch/riscv/purgatory/Makefile
index d16bf715a586..5730797a6b40 100644
--- a/arch/riscv/purgatory/Makefile
+++ b/arch/riscv/purgatory/Makefile
@@ -84,12 +84,7 @@ CFLAGS_string.o += $(PURGATORY_CFLAGS)
CFLAGS_REMOVE_ctype.o += $(PURGATORY_CFLAGS_REMOVE)
CFLAGS_ctype.o += $(PURGATORY_CFLAGS)
-AFLAGS_REMOVE_entry.o += -Wa,-gdwarf-2
-AFLAGS_REMOVE_memcpy.o += -Wa,-gdwarf-2
-AFLAGS_REMOVE_memset.o += -Wa,-gdwarf-2
-AFLAGS_REMOVE_strcmp.o += -Wa,-gdwarf-2
-AFLAGS_REMOVE_strlen.o += -Wa,-gdwarf-2
-AFLAGS_REMOVE_strncmp.o += -Wa,-gdwarf-2
+asflags-remove-y += $(foreach x, -g -gdwarf-4 -gdwarf-5, $(x) -Wa,$(x))
$(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE
$(call if_changed,ld)
diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile
index 17f09dc26381..82fec66d46d2 100644
--- a/arch/x86/purgatory/Makefile
+++ b/arch/x86/purgatory/Makefile
@@ -69,8 +69,7 @@ CFLAGS_sha256.o += $(PURGATORY_CFLAGS)
CFLAGS_REMOVE_string.o += $(PURGATORY_CFLAGS_REMOVE)
CFLAGS_string.o += $(PURGATORY_CFLAGS)
-AFLAGS_REMOVE_setup-x86_$(BITS).o += -Wa,-gdwarf-2
-AFLAGS_REMOVE_entry64.o += -Wa,-gdwarf-2
+asflags-remove-y += $(foreach x, -g -gdwarf-4 -gdwarf-5, $(x) -Wa,$(x))
$(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE
$(call if_changed,ld)
base-commit: da8e7da11e4ba758caf4c149cc8d8cd555aefe5f
--
2.37.1
Hi! Since kernel 6.1.22 starting a resume from hibernate by hitting a
key on the keyboard fails. However, if the PC was switched off and on
again (or reset), the resume is OK. The APU is a Ryzen 5600G.
Bisecting between 6.1.21/22 turned up this:
Author: Tim Huang <tim.huang(a)amd.com>
Date: Thu Mar 9 16:27:51 2023 +0800
drm/amdgpu: skip ASIC reset for APUs when go to S4
commit b589626674de94d977e81c99bf7905872b991197 upstream.
For GC IP v11.0.4/11, PSP TMR need to be reserved
for ASIC mode2 reset. But for S4, when psp suspend,
it will destroy the TMR that fails the ASIC reset.
[...]
Reverting the commit solves the problem.
Thanks.
Rainer Fiebig
--
The truth always turns out to be simpler than you thought.
Richard Feynman
Am 07.04.23 um 05:40 schrieb Huang, Tim:
> [AMD Official Use Only - General]
>
> On Thu, Apr 06, 2023 at 05:39:07PM +0200, Rainer Fiebig wrote:
>> Am 06.04.23 um 15:30 schrieb Linux regression tracking (Thorsten Leemhuis):
>>> [CCing the regression list, as it should be in the loop for regressions:
>>> https://docs.kernel.org/admin-guide/reporting-regressions.html]
>>>
>>> On 06.04.23 14:06, Rainer Fiebig wrote:
>>>> Hi! Since kernel 6.1.22 starting a resume from hibernate by hitting a
>>>> key on the keyboard fails. However, if the PC was switched off and on
>>>> again (or reset), the resume is OK. The APU is a Ryzen 5600G.
>>>>
>>>> Bisecting between 6.1.21/22 turned up this:
>>>>
>>>>
>>>> Author: Tim Huang <tim.huang(a)amd.com>
>>>> Date: Thu Mar 9 16:27:51 2023 +0800
>>>>
>>>> drm/amdgpu: skip ASIC reset for APUs when go to S4
>>>>
>>>> commit b589626674de94d977e81c99bf7905872b991197 upstream.
>>>>
>>>> For GC IP v11.0.4/11, PSP TMR need to be reserved
>>>> for ASIC mode2 reset. But for S4, when psp suspend,
>>>> it will destroy the TMR that fails the ASIC reset.
>>>> [...]
>>>>
>>>>
>>>> Reverting the commit solves the problem.
>>>> Thanks.
>>>
>>> Please try 6.1.23 and report back, because from the thread
>>> https://lore.kernel.org/all/20230330160740.1dbff94b@schienar/
>>> it sounds a lot like "drm/amdgpu: allow more APUs to do mode2 reset when
>>> go to S4" might be fixing this, which went into 6.1.23.
>> Yes, 6.1.23 seems OK so far.
>>
>
>
> The patch " drm/amdgpu: allow more APUs to do mode2 reset when go to S4" is to fix this hibernate regression issue.
>
> Sorry to have troubled you.
No problem, please don't take it personally. It wasn't a big deal and I
was just a bit grumpy yesterday.
Thanks for the info and have a good day!
Rainer
usb_udc_connect_control does not check to see if the udc has already
been started. This causes gadget->ops->pullup to be called through
usb_gadget_connect when invoked from usb_udc_vbus_handler even before
usb_gadget_udc_start is called. Guard this by checking for udc->started
in usb_udc_connect_control before invoking usb_gadget_connect.
Guarding udc->vbus, udc->started, gadget->connect, gadget->deactivate
related functions with connect_lock. usb_gadget_connect_locked,
usb_gadget_disconnect_locked, usb_udc_connect_control_locked,
usb_gadget_udc_start_locked, usb_gadget_udc_stop_locked are called with
this lock held as they can be simulataneously invoked from different code
paths.
Adding an additional check to make sure udc is started(udc->started)
before pullup callback is invoked.
Cc: stable(a)vger.kernel.org
Fixes: 628ef0d273a6 ("usb: udc: add usb_udc_vbus_handler")
Signed-off-by: Badhri Jagan Sridharan <badhri(a)google.com>
---
* Fixed commit message comments.
* Renamed udc_connect_control_lock to connect_lock and made it per
device.
* udc->vbus, udc->started, gadget->connect, gadget->deactivate are all
now guarded by connect_lock.
* Code now checks for udc->started to be set before invoking pullup
callback.
---
drivers/usb/gadget/udc/core.c | 140 +++++++++++++++++++++++-----------
1 file changed, 96 insertions(+), 44 deletions(-)
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 3dcbba739db6..41d3a1998cff 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -37,6 +37,10 @@ static struct bus_type gadget_bus_type;
* @vbus: for udcs who care about vbus status, this value is real vbus status;
* for udcs who do not care about vbus status, this value is always true
* @started: the UDC's started state. True if the UDC had started.
+ * @connect_lock: protects udc->vbus, udc->started, gadget->connect, gadget->deactivate related
+ * functions. usb_gadget_connect_locked, usb_gadget_disconnect_locked,
+ * usb_udc_connect_control_locked, usb_gadget_udc_start_locked, usb_gadget_udc_stop_locked are
+ * called with this lock held.
*
* This represents the internal data structure which is used by the UDC-class
* to hold information about udc driver and gadget together.
@@ -48,6 +52,7 @@ struct usb_udc {
struct list_head list;
bool vbus;
bool started;
+ struct mutex connect_lock;
};
static struct class *udc_class;
@@ -687,17 +692,8 @@ int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
}
EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect);
-/**
- * usb_gadget_connect - software-controlled connect to USB host
- * @gadget:the peripheral being connected
- *
- * Enables the D+ (or potentially D-) pullup. The host will start
- * enumerating this gadget when the pullup is active and a VBUS session
- * is active (the link is powered).
- *
- * Returns zero on success, else negative errno.
- */
-int usb_gadget_connect(struct usb_gadget *gadget)
+/* Internal version of usb_gadget_connect needs to be called with udc_connect_control_lock held. */
+int usb_gadget_connect_locked(struct usb_gadget *gadget)
{
int ret = 0;
@@ -706,10 +702,12 @@ int usb_gadget_connect(struct usb_gadget *gadget)
goto out;
}
- if (gadget->deactivated) {
+ if (gadget->deactivated || !gadget->udc->started) {
/*
* If gadget is deactivated we only save new state.
* Gadget will be connected automatically after activation.
+ *
+ * udc first needs to be started before gadget can be pulled up.
*/
gadget->connected = true;
goto out;
@@ -724,22 +722,31 @@ int usb_gadget_connect(struct usb_gadget *gadget)
return ret;
}
-EXPORT_SYMBOL_GPL(usb_gadget_connect);
/**
- * usb_gadget_disconnect - software-controlled disconnect from USB host
- * @gadget:the peripheral being disconnected
- *
- * Disables the D+ (or potentially D-) pullup, which the host may see
- * as a disconnect (when a VBUS session is active). Not all systems
- * support software pullup controls.
+ * usb_gadget_connect - software-controlled connect to USB host
+ * @gadget:the peripheral being connected
*
- * Following a successful disconnect, invoke the ->disconnect() callback
- * for the current gadget driver so that UDC drivers don't need to.
+ * Enables the D+ (or potentially D-) pullup. The host will start
+ * enumerating this gadget when the pullup is active and a VBUS session
+ * is active (the link is powered).
*
* Returns zero on success, else negative errno.
*/
-int usb_gadget_disconnect(struct usb_gadget *gadget)
+int usb_gadget_connect(struct usb_gadget *gadget)
+{
+ int ret;
+
+ mutex_lock(&gadget->udc->connect_lock);
+ ret = usb_gadget_connect_locked(gadget);
+ mutex_unlock(&gadget->udc->connect_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_connect);
+
+/* Internal version of usb_gadget_disconnect needs to be called with udc->connect_lock held. */
+int usb_gadget_disconnect_locked(struct usb_gadget *gadget)
{
int ret = 0;
@@ -751,10 +758,12 @@ int usb_gadget_disconnect(struct usb_gadget *gadget)
if (!gadget->connected)
goto out;
- if (gadget->deactivated) {
+ if (gadget->deactivated || !gadget->udc->started) {
/*
* If gadget is deactivated we only save new state.
* Gadget will stay disconnected after activation.
+ *
+ * udc should have been started before gadget being pulled down.
*/
gadget->connected = false;
goto out;
@@ -774,6 +783,30 @@ int usb_gadget_disconnect(struct usb_gadget *gadget)
return ret;
}
+
+/**
+ * usb_gadget_disconnect - software-controlled disconnect from USB host
+ * @gadget:the peripheral being disconnected
+ *
+ * Disables the D+ (or potentially D-) pullup, which the host may see
+ * as a disconnect (when a VBUS session is active). Not all systems
+ * support software pullup controls.
+ *
+ * Following a successful disconnect, invoke the ->disconnect() callback
+ * for the current gadget driver so that UDC drivers don't need to.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_disconnect(struct usb_gadget *gadget)
+{
+ int ret;
+
+ mutex_lock(&gadget->udc->connect_lock);
+ ret = usb_gadget_disconnect_locked(gadget);
+ mutex_unlock(&gadget->udc->connect_lock);
+
+ return ret;
+}
EXPORT_SYMBOL_GPL(usb_gadget_disconnect);
/**
@@ -794,10 +827,11 @@ int usb_gadget_deactivate(struct usb_gadget *gadget)
if (gadget->deactivated)
goto out;
+ mutex_lock(&gadget->udc->connect_lock);
if (gadget->connected) {
- ret = usb_gadget_disconnect(gadget);
+ ret = usb_gadget_disconnect_locked(gadget);
if (ret)
- goto out;
+ goto unlock;
/*
* If gadget was being connected before deactivation, we want
@@ -807,6 +841,8 @@ int usb_gadget_deactivate(struct usb_gadget *gadget)
}
gadget->deactivated = true;
+unlock:
+ mutex_unlock(&gadget->udc->connect_lock);
out:
trace_usb_gadget_deactivate(gadget, ret);
@@ -830,6 +866,7 @@ int usb_gadget_activate(struct usb_gadget *gadget)
if (!gadget->deactivated)
goto out;
+ mutex_lock(&gadget->udc->connect_lock);
gadget->deactivated = false;
/*
@@ -837,7 +874,8 @@ int usb_gadget_activate(struct usb_gadget *gadget)
* while it was being deactivated, we call usb_gadget_connect().
*/
if (gadget->connected)
- ret = usb_gadget_connect(gadget);
+ ret = usb_gadget_connect_locked(gadget);
+ mutex_unlock(&gadget->udc->connect_lock);
out:
trace_usb_gadget_activate(gadget, ret);
@@ -1078,12 +1116,13 @@ EXPORT_SYMBOL_GPL(usb_gadget_set_state);
/* ------------------------------------------------------------------------- */
-static void usb_udc_connect_control(struct usb_udc *udc)
+/* Acquire udc_connect_control_lock before calling this function. */
+static void usb_udc_connect_control_locked(struct usb_udc *udc)
{
- if (udc->vbus)
- usb_gadget_connect(udc->gadget);
+ if (udc->vbus && udc->started)
+ usb_gadget_connect_locked(udc->gadget);
else
- usb_gadget_disconnect(udc->gadget);
+ usb_gadget_disconnect_locked(udc->gadget);
}
/**
@@ -1099,10 +1138,12 @@ void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status)
{
struct usb_udc *udc = gadget->udc;
+ mutex_lock(&udc->connect_lock);
if (udc) {
udc->vbus = status;
- usb_udc_connect_control(udc);
+ usb_udc_connect_control_locked(udc);
}
+ mutex_unlock(&udc->connect_lock);
}
EXPORT_SYMBOL_GPL(usb_udc_vbus_handler);
@@ -1124,7 +1165,7 @@ void usb_gadget_udc_reset(struct usb_gadget *gadget,
EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
/**
- * usb_gadget_udc_start - tells usb device controller to start up
+ * usb_gadget_udc_start_locked - tells usb device controller to start up
* @udc: The UDC to be started
*
* This call is issued by the UDC Class driver when it's about
@@ -1136,7 +1177,7 @@ EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
*
* Returns zero on success, else negative errno.
*/
-static inline int usb_gadget_udc_start(struct usb_udc *udc)
+static inline int usb_gadget_udc_start_locked(struct usb_udc *udc)
{
int ret;
@@ -1153,7 +1194,7 @@ static inline int usb_gadget_udc_start(struct usb_udc *udc)
}
/**
- * usb_gadget_udc_stop - tells usb device controller we don't need it anymore
+ * usb_gadget_udc_stop_locked - tells usb device controller we don't need it anymore
* @udc: The UDC to be stopped
*
* This call is issued by the UDC Class driver after calling
@@ -1163,7 +1204,7 @@ static inline int usb_gadget_udc_start(struct usb_udc *udc)
* far as powering off UDC completely and disable its data
* line pullups.
*/
-static inline void usb_gadget_udc_stop(struct usb_udc *udc)
+static inline void usb_gadget_udc_stop_locked(struct usb_udc *udc)
{
if (!udc->started) {
dev_err(&udc->dev, "UDC had already stopped\n");
@@ -1322,6 +1363,7 @@ int usb_add_gadget(struct usb_gadget *gadget)
udc->gadget = gadget;
gadget->udc = udc;
+ mutex_init(&udc->connect_lock);
udc->started = false;
@@ -1523,11 +1565,15 @@ static int gadget_bind_driver(struct device *dev)
if (ret)
goto err_bind;
- ret = usb_gadget_udc_start(udc);
- if (ret)
+ mutex_lock(&udc->connect_lock);
+ ret = usb_gadget_udc_start_locked(udc);
+ if (ret) {
+ mutex_unlock(&udc->connect_lock);
goto err_start;
+ }
usb_gadget_enable_async_callbacks(udc);
- usb_udc_connect_control(udc);
+ usb_udc_connect_control_locked(udc);
+ mutex_unlock(&udc->connect_lock);
kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
return 0;
@@ -1558,12 +1604,14 @@ static void gadget_unbind_driver(struct device *dev)
kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
- usb_gadget_disconnect(gadget);
+ mutex_lock(&udc->connect_lock);
+ usb_gadget_disconnect_locked(gadget);
usb_gadget_disable_async_callbacks(udc);
if (gadget->irq)
synchronize_irq(gadget->irq);
udc->driver->unbind(gadget);
- usb_gadget_udc_stop(udc);
+ usb_gadget_udc_stop_locked(udc);
+ mutex_unlock(&udc->connect_lock);
mutex_lock(&udc_lock);
driver->is_bound = false;
@@ -1649,11 +1697,15 @@ static ssize_t soft_connect_store(struct device *dev,
}
if (sysfs_streq(buf, "connect")) {
- usb_gadget_udc_start(udc);
- usb_gadget_connect(udc->gadget);
+ mutex_lock(&udc->connect_lock);
+ usb_gadget_udc_start_locked(udc);
+ usb_gadget_connect_locked(udc->gadget);
+ mutex_unlock(&udc->connect_lock);
} else if (sysfs_streq(buf, "disconnect")) {
- usb_gadget_disconnect(udc->gadget);
- usb_gadget_udc_stop(udc);
+ mutex_lock(&udc->connect_lock);
+ usb_gadget_disconnect_locked(udc->gadget);
+ usb_gadget_udc_stop_locked(udc);
+ mutex_unlock(&udc->connect_lock);
} else {
dev_err(dev, "unsupported command '%s'\n", buf);
ret = -EINVAL;
base-commit: d629c0e221cd99198b843d8351a0a9bfec6c0423
--
2.40.0.348.gf938b09366-goog
usb_udc_connect_control does not check to see if the udc has already
been started. This causes gadget->ops->pullup to be called through
usb_gadget_connect when invoked from usb_udc_vbus_handler even before
usb_gadget_udc_start is called. Guard this by checking for udc->started
in usb_udc_connect_control before invoking usb_gadget_connect.
Guarding udc->vbus, udc->started, gadget->connect, gadget->deactivate
related functions with connect_lock. usb_gadget_connect_locked,
usb_gadget_disconnect_locked, usb_udc_connect_control_locked,
usb_gadget_udc_start_locked, usb_gadget_udc_stop_locked are called with
this lock held as they can be simulataneously invoked from different code
paths.
Adding an additional check to make sure udc is started(udc->started)
before pullup callback is invoked.
Cc: stable(a)vger.kernel.org
Fixes: 628ef0d273a6 ("usb: udc: add usb_udc_vbus_handler")
Signed-off-by: Badhri Jagan Sridharan <badhri(a)google.com>
---
Changes since v2:
* Added __must_hold marking for connect_lock
Changes since v1:
* Fixed commit message comments.
* Renamed udc_connect_control_lock to connect_lock and made it per
device.
* udc->vbus, udc->started, gadget->connect, gadget->deactivate are all
now guarded by connect_lock.
* Code now checks for udc->started to be set before invoking pullup
callback.
---
drivers/usb/gadget/udc/core.c | 146 ++++++++++++++++++++++++----------
1 file changed, 102 insertions(+), 44 deletions(-)
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 3dcbba739db6..3eb5d4e392db 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -37,6 +37,10 @@ static struct bus_type gadget_bus_type;
* @vbus: for udcs who care about vbus status, this value is real vbus status;
* for udcs who do not care about vbus status, this value is always true
* @started: the UDC's started state. True if the UDC had started.
+ * @connect_lock: protects udc->vbus, udc->started, gadget->connect, gadget->deactivate related
+ * functions. usb_gadget_connect_locked, usb_gadget_disconnect_locked,
+ * usb_udc_connect_control_locked, usb_gadget_udc_start_locked, usb_gadget_udc_stop_locked are
+ * called with this lock held.
*
* This represents the internal data structure which is used by the UDC-class
* to hold information about udc driver and gadget together.
@@ -48,6 +52,7 @@ struct usb_udc {
struct list_head list;
bool vbus;
bool started;
+ struct mutex connect_lock;
};
static struct class *udc_class;
@@ -687,17 +692,8 @@ int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
}
EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect);
-/**
- * usb_gadget_connect - software-controlled connect to USB host
- * @gadget:the peripheral being connected
- *
- * Enables the D+ (or potentially D-) pullup. The host will start
- * enumerating this gadget when the pullup is active and a VBUS session
- * is active (the link is powered).
- *
- * Returns zero on success, else negative errno.
- */
-int usb_gadget_connect(struct usb_gadget *gadget)
+/* Internal version of usb_gadget_connect needs to be called with connect_lock held. */
+int usb_gadget_connect_locked(struct usb_gadget *gadget) __must_hold(&gadget->udc->connect_lock)
{
int ret = 0;
@@ -706,10 +702,12 @@ int usb_gadget_connect(struct usb_gadget *gadget)
goto out;
}
- if (gadget->deactivated) {
+ if (gadget->deactivated || !gadget->udc->started) {
/*
* If gadget is deactivated we only save new state.
* Gadget will be connected automatically after activation.
+ *
+ * udc first needs to be started before gadget can be pulled up.
*/
gadget->connected = true;
goto out;
@@ -724,22 +722,31 @@ int usb_gadget_connect(struct usb_gadget *gadget)
return ret;
}
-EXPORT_SYMBOL_GPL(usb_gadget_connect);
/**
- * usb_gadget_disconnect - software-controlled disconnect from USB host
- * @gadget:the peripheral being disconnected
- *
- * Disables the D+ (or potentially D-) pullup, which the host may see
- * as a disconnect (when a VBUS session is active). Not all systems
- * support software pullup controls.
+ * usb_gadget_connect - software-controlled connect to USB host
+ * @gadget:the peripheral being connected
*
- * Following a successful disconnect, invoke the ->disconnect() callback
- * for the current gadget driver so that UDC drivers don't need to.
+ * Enables the D+ (or potentially D-) pullup. The host will start
+ * enumerating this gadget when the pullup is active and a VBUS session
+ * is active (the link is powered).
*
* Returns zero on success, else negative errno.
*/
-int usb_gadget_disconnect(struct usb_gadget *gadget)
+int usb_gadget_connect(struct usb_gadget *gadget)
+{
+ int ret;
+
+ mutex_lock(&gadget->udc->connect_lock);
+ ret = usb_gadget_connect_locked(gadget);
+ mutex_unlock(&gadget->udc->connect_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_connect);
+
+/* Internal version of usb_gadget_disconnect needs to be called with connect_lock held. */
+int usb_gadget_disconnect_locked(struct usb_gadget *gadget) __must_hold(&gadget->udc->connect_lock)
{
int ret = 0;
@@ -751,10 +758,12 @@ int usb_gadget_disconnect(struct usb_gadget *gadget)
if (!gadget->connected)
goto out;
- if (gadget->deactivated) {
+ if (gadget->deactivated || !gadget->udc->started) {
/*
* If gadget is deactivated we only save new state.
* Gadget will stay disconnected after activation.
+ *
+ * udc should have been started before gadget being pulled down.
*/
gadget->connected = false;
goto out;
@@ -774,6 +783,30 @@ int usb_gadget_disconnect(struct usb_gadget *gadget)
return ret;
}
+
+/**
+ * usb_gadget_disconnect - software-controlled disconnect from USB host
+ * @gadget:the peripheral being disconnected
+ *
+ * Disables the D+ (or potentially D-) pullup, which the host may see
+ * as a disconnect (when a VBUS session is active). Not all systems
+ * support software pullup controls.
+ *
+ * Following a successful disconnect, invoke the ->disconnect() callback
+ * for the current gadget driver so that UDC drivers don't need to.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_disconnect(struct usb_gadget *gadget)
+{
+ int ret;
+
+ mutex_lock(&gadget->udc->connect_lock);
+ ret = usb_gadget_disconnect_locked(gadget);
+ mutex_unlock(&gadget->udc->connect_lock);
+
+ return ret;
+}
EXPORT_SYMBOL_GPL(usb_gadget_disconnect);
/**
@@ -794,10 +827,11 @@ int usb_gadget_deactivate(struct usb_gadget *gadget)
if (gadget->deactivated)
goto out;
+ mutex_lock(&gadget->udc->connect_lock);
if (gadget->connected) {
- ret = usb_gadget_disconnect(gadget);
+ ret = usb_gadget_disconnect_locked(gadget);
if (ret)
- goto out;
+ goto unlock;
/*
* If gadget was being connected before deactivation, we want
@@ -807,6 +841,8 @@ int usb_gadget_deactivate(struct usb_gadget *gadget)
}
gadget->deactivated = true;
+unlock:
+ mutex_unlock(&gadget->udc->connect_lock);
out:
trace_usb_gadget_deactivate(gadget, ret);
@@ -830,6 +866,7 @@ int usb_gadget_activate(struct usb_gadget *gadget)
if (!gadget->deactivated)
goto out;
+ mutex_lock(&gadget->udc->connect_lock);
gadget->deactivated = false;
/*
@@ -837,7 +874,8 @@ int usb_gadget_activate(struct usb_gadget *gadget)
* while it was being deactivated, we call usb_gadget_connect().
*/
if (gadget->connected)
- ret = usb_gadget_connect(gadget);
+ ret = usb_gadget_connect_locked(gadget);
+ mutex_unlock(&gadget->udc->connect_lock);
out:
trace_usb_gadget_activate(gadget, ret);
@@ -1078,12 +1116,13 @@ EXPORT_SYMBOL_GPL(usb_gadget_set_state);
/* ------------------------------------------------------------------------- */
-static void usb_udc_connect_control(struct usb_udc *udc)
+/* Acquire connect_lock before calling this function. */
+static void usb_udc_connect_control_locked(struct usb_udc *udc) __must_hold(&udc->connect_lock)
{
- if (udc->vbus)
- usb_gadget_connect(udc->gadget);
+ if (udc->vbus && udc->started)
+ usb_gadget_connect_locked(udc->gadget);
else
- usb_gadget_disconnect(udc->gadget);
+ usb_gadget_disconnect_locked(udc->gadget);
}
/**
@@ -1099,10 +1138,12 @@ void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status)
{
struct usb_udc *udc = gadget->udc;
+ mutex_lock(&udc->connect_lock);
if (udc) {
udc->vbus = status;
- usb_udc_connect_control(udc);
+ usb_udc_connect_control_locked(udc);
}
+ mutex_unlock(&udc->connect_lock);
}
EXPORT_SYMBOL_GPL(usb_udc_vbus_handler);
@@ -1124,7 +1165,7 @@ void usb_gadget_udc_reset(struct usb_gadget *gadget,
EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
/**
- * usb_gadget_udc_start - tells usb device controller to start up
+ * usb_gadget_udc_start_locked - tells usb device controller to start up
* @udc: The UDC to be started
*
* This call is issued by the UDC Class driver when it's about
@@ -1135,8 +1176,11 @@ EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
* necessary to have it powered on.
*
* Returns zero on success, else negative errno.
+ *
+ * Caller should acquire connect_lock before invoking this function.
*/
-static inline int usb_gadget_udc_start(struct usb_udc *udc)
+static inline int usb_gadget_udc_start_locked(struct usb_udc *udc)
+ __must_hold(&udc->connect_lock)
{
int ret;
@@ -1153,7 +1197,7 @@ static inline int usb_gadget_udc_start(struct usb_udc *udc)
}
/**
- * usb_gadget_udc_stop - tells usb device controller we don't need it anymore
+ * usb_gadget_udc_stop_locked - tells usb device controller we don't need it anymore
* @udc: The UDC to be stopped
*
* This call is issued by the UDC Class driver after calling
@@ -1162,8 +1206,11 @@ static inline int usb_gadget_udc_start(struct usb_udc *udc)
* The details are implementation specific, but it can go as
* far as powering off UDC completely and disable its data
* line pullups.
+ *
+ * Caller should acquire connect lock before invoking this function.
*/
-static inline void usb_gadget_udc_stop(struct usb_udc *udc)
+static inline void usb_gadget_udc_stop_locked(struct usb_udc *udc)
+ __must_hold(&udc->connect_lock)
{
if (!udc->started) {
dev_err(&udc->dev, "UDC had already stopped\n");
@@ -1322,6 +1369,7 @@ int usb_add_gadget(struct usb_gadget *gadget)
udc->gadget = gadget;
gadget->udc = udc;
+ mutex_init(&udc->connect_lock);
udc->started = false;
@@ -1523,11 +1571,15 @@ static int gadget_bind_driver(struct device *dev)
if (ret)
goto err_bind;
- ret = usb_gadget_udc_start(udc);
- if (ret)
+ mutex_lock(&udc->connect_lock);
+ ret = usb_gadget_udc_start_locked(udc);
+ if (ret) {
+ mutex_unlock(&udc->connect_lock);
goto err_start;
+ }
usb_gadget_enable_async_callbacks(udc);
- usb_udc_connect_control(udc);
+ usb_udc_connect_control_locked(udc);
+ mutex_unlock(&udc->connect_lock);
kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
return 0;
@@ -1558,12 +1610,14 @@ static void gadget_unbind_driver(struct device *dev)
kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
- usb_gadget_disconnect(gadget);
+ mutex_lock(&udc->connect_lock);
+ usb_gadget_disconnect_locked(gadget);
usb_gadget_disable_async_callbacks(udc);
if (gadget->irq)
synchronize_irq(gadget->irq);
udc->driver->unbind(gadget);
- usb_gadget_udc_stop(udc);
+ usb_gadget_udc_stop_locked(udc);
+ mutex_unlock(&udc->connect_lock);
mutex_lock(&udc_lock);
driver->is_bound = false;
@@ -1649,11 +1703,15 @@ static ssize_t soft_connect_store(struct device *dev,
}
if (sysfs_streq(buf, "connect")) {
- usb_gadget_udc_start(udc);
- usb_gadget_connect(udc->gadget);
+ mutex_lock(&udc->connect_lock);
+ usb_gadget_udc_start_locked(udc);
+ usb_gadget_connect_locked(udc->gadget);
+ mutex_unlock(&udc->connect_lock);
} else if (sysfs_streq(buf, "disconnect")) {
- usb_gadget_disconnect(udc->gadget);
- usb_gadget_udc_stop(udc);
+ mutex_lock(&udc->connect_lock);
+ usb_gadget_disconnect_locked(udc->gadget);
+ usb_gadget_udc_stop_locked(udc);
+ mutex_unlock(&udc->connect_lock);
} else {
dev_err(dev, "unsupported command '%s'\n", buf);
ret = -EINVAL;
base-commit: d629c0e221cd99198b843d8351a0a9bfec6c0423
--
2.40.0.577.gac1e443424-goog
The si->lock must be held when deleting the si from
the available list. Otherwise, another thread can
re-add the si to the available list, which can lead
to memory corruption. The only place we have found
where this happens is in the swapoff path. This case
can be described as below:
core 0 core 1
swapoff
del_from_avail_list(si) waiting
try lock si->lock acquire swap_avail_lock
and re-add si into
swap_avail_head
acquire si->lock but
missing si already be
added again, and continuing
to clear SWP_WRITEOK, etc.
It can be easily found a massive warning messages can
be triggered inside get_swap_pages() by some special
cases, for example, we call madvise(MADV_PAGEOUT) on
blocks of touched memory concurrently, meanwhile, run
much swapon-swapoff operations (e.g. stress-ng-swap).
However, in the worst case, panic can be caused by the
above scene. In swapoff(), the memory used by si could
be kept in swap_info[] after turning off a swap. This
means memory corruption will not be caused immediately
until allocated and reset for a new swap in the swapon
path. A panic message caused:
(with CONFIG_PLIST_DEBUG enabled)
------------[ cut here ]------------
top: 00000000e58a3003, n: 0000000013e75cda, p: 000000008cd4451a
prev: 0000000035b1e58a, n: 000000008cd4451a, p: 000000002150ee8d
next: 000000008cd4451a, n: 000000008cd4451a, p: 000000008cd4451a
WARNING: CPU: 21 PID: 1843 at lib/plist.c:60 plist_check_prev_next_node+0x50/0x70
Modules linked in: rfkill(E) crct10dif_ce(E)...
CPU: 21 PID: 1843 Comm: stress-ng Kdump: ... 5.10.134+
Hardware name: Alibaba Cloud ECS, BIOS 0.0.0 02/06/2015
pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)
pc : plist_check_prev_next_node+0x50/0x70
lr : plist_check_prev_next_node+0x50/0x70
sp : ffff0018009d3c30
x29: ffff0018009d3c40 x28: ffff800011b32a98
x27: 0000000000000000 x26: ffff001803908000
x25: ffff8000128ea088 x24: ffff800011b32a48
x23: 0000000000000028 x22: ffff001800875c00
x21: ffff800010f9e520 x20: ffff001800875c00
x19: ffff001800fdc6e0 x18: 0000000000000030
x17: 0000000000000000 x16: 0000000000000000
x15: 0736076307640766 x14: 0730073007380731
x13: 0736076307640766 x12: 0730073007380731
x11: 000000000004058d x10: 0000000085a85b76
x9 : ffff8000101436e4 x8 : ffff800011c8ce08
x7 : 0000000000000000 x6 : 0000000000000001
x5 : ffff0017df9ed338 x4 : 0000000000000001
x3 : ffff8017ce62a000 x2 : ffff0017df9ed340
x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
plist_check_prev_next_node+0x50/0x70
plist_check_head+0x80/0xf0
plist_add+0x28/0x140
add_to_avail_list+0x9c/0xf0
_enable_swap_info+0x78/0xb4
__do_sys_swapon+0x918/0xa10
__arm64_sys_swapon+0x20/0x30
el0_svc_common+0x8c/0x220
do_el0_svc+0x2c/0x90
el0_svc+0x1c/0x30
el0_sync_handler+0xa8/0xb0
el0_sync+0x148/0x180
irq event stamp: 2082270
Now, si->lock locked before calling 'del_from_avail_list()'
to make sure other thread see the si had been deleted
and SWP_WRITEOK cleared together, will not reinsert again.
This problem exists in versions after stable 5.10.y.
Cc: stable(a)vger.kernel.org
Tested-by: Yongchen Yin <wb-yyc939293(a)alibaba-inc.com>
Signed-off-by: Rongwei Wang <rongwei.wang(a)linux.alibaba.com>
---
mm/swapfile.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 62ba2bf577d7..2c718f45745f 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -679,6 +679,7 @@ static void __del_from_avail_list(struct swap_info_struct *p)
{
int nid;
+ assert_spin_locked(&p->lock);
for_each_node(nid)
plist_del(&p->avail_lists[nid], &swap_avail_heads[nid]);
}
@@ -2434,8 +2435,8 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
spin_unlock(&swap_lock);
goto out_dput;
}
- del_from_avail_list(p);
spin_lock(&p->lock);
+ del_from_avail_list(p);
if (p->prio < 0) {
struct swap_info_struct *si = p;
int nid;
--
2.27.0