| Message ID | 20211122105003.1089218-1-mathias.nyman@linux.intel.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [RFT] usb: hub: Fix locking issues with address0_mutex | expand |
Hi, On 22.11.2021 11:50, Mathias Nyman wrote: > Fix the circular lock dependency and unbalanced unlock of addess0_mutex > introduced when fixing an address0_mutex enumeration retry race in commit > ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") > > Make sure locking order between port_dev->status_lock and address0_mutex > is correct, and that address0_mutex is not unlocked in hub_port_connect > "done:" codepath which may be reached without locking address0_mutex > > Fixes: 6ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") > Cc: <stable@vger.kernel.org> > Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> This fixes the issue I've reported here: https://lore.kernel.org/all/f3bfcbc7-f701-c74a-09bd-6491d4c8d863@samsung.com/ Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> > --- > drivers/usb/core/hub.c | 20 ++++++++++++-------- > 1 file changed, 12 insertions(+), 8 deletions(-) > > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c > index 00c3506324e4..00070a8a6507 100644 > --- a/drivers/usb/core/hub.c > +++ b/drivers/usb/core/hub.c > @@ -5188,6 +5188,7 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, > struct usb_port *port_dev = hub->ports[port1 - 1]; > struct usb_device *udev = port_dev->child; > static int unreliable_port = -1; > + bool retry_locked; > > /* Disconnect any existing devices under this port */ > if (udev) { > @@ -5244,10 +5245,10 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, > > status = 0; > > - mutex_lock(hcd->address0_mutex); > - > for (i = 0; i < PORT_INIT_TRIES; i++) { > - > + usb_lock_port(port_dev); > + mutex_lock(hcd->address0_mutex); > + retry_locked = true; > /* reallocate for each attempt, since references > * to the previous one can escape in various ways > */ > @@ -5255,6 +5256,8 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, > if (!udev) { > dev_err(&port_dev->dev, > "couldn't allocate usb_device\n"); > + mutex_unlock(hcd->address0_mutex); > + usb_unlock_port(port_dev); > goto done; > } > > @@ -5276,13 +5279,13 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, > } > > /* reset (non-USB 3.0 devices) and get descriptor */ > - usb_lock_port(port_dev); > status = hub_port_init(hub, udev, port1, i); > - usb_unlock_port(port_dev); > if (status < 0) > goto loop; > > mutex_unlock(hcd->address0_mutex); > + usb_unlock_port(port_dev); > + retry_locked = false; > > if (udev->quirks & USB_QUIRK_DELAY_INIT) > msleep(2000); > @@ -5372,11 +5375,14 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, > > loop_disable: > hub_port_disable(hub, port1, 1); > - mutex_lock(hcd->address0_mutex); > loop: > usb_ep0_reinit(udev); > release_devnum(udev); > hub_free_dev(udev); > + if (retry_locked) { > + mutex_unlock(hcd->address0_mutex); > + usb_unlock_port(port_dev); > + } > usb_put_dev(udev); > if ((status == -ENOTCONN) || (status == -ENOTSUPP)) > break; > @@ -5399,8 +5405,6 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, > } > > done: > - mutex_unlock(hcd->address0_mutex); > - > hub_port_disable(hub, port1, 1); > if (hcd->driver->relinquish_port && !hub->hdev->parent) { > if (status != -ENOTCONN && status != -ENODEV) Best regards
Hi, On 11/22/21 11:50, Mathias Nyman wrote: > Fix the circular lock dependency and unbalanced unlock of addess0_mutex > introduced when fixing an address0_mutex enumeration retry race in commit > ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") > > Make sure locking order between port_dev->status_lock and address0_mutex > is correct, and that address0_mutex is not unlocked in hub_port_connect > "done:" codepath which may be reached without locking address0_mutex > > Fixes: 6ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") > Cc: <stable@vger.kernel.org> > Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Oh, this is great, with this patch I can finally hot-plug my thunderbolt dock (and thus a XHCI controller) without the XHCI controller given a whole bunch of weird errors (and some USB devices not working), which it does not when already connected at boot. I also tried the hotplug thingy with the previous fix without this locking fix and then I actually hit the deadlock and things like lsusb would hang. If we can get these 2 fixes together merged soon and also backported to the stable series that would be great: Acked-by: Hans de Goede <hdegoede@redhat.com> Tested-by: Hans de Goede <hdegoede@redhat.com> Regards, Hans > --- > drivers/usb/core/hub.c | 20 ++++++++++++-------- > 1 file changed, 12 insertions(+), 8 deletions(-) > > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c > index 00c3506324e4..00070a8a6507 100644 > --- a/drivers/usb/core/hub.c > +++ b/drivers/usb/core/hub.c > @@ -5188,6 +5188,7 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, > struct usb_port *port_dev = hub->ports[port1 - 1]; > struct usb_device *udev = port_dev->child; > static int unreliable_port = -1; > + bool retry_locked; > > /* Disconnect any existing devices under this port */ > if (udev) { > @@ -5244,10 +5245,10 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, > > status = 0; > > - mutex_lock(hcd->address0_mutex); > - > for (i = 0; i < PORT_INIT_TRIES; i++) { > - > + usb_lock_port(port_dev); > + mutex_lock(hcd->address0_mutex); > + retry_locked = true; > /* reallocate for each attempt, since references > * to the previous one can escape in various ways > */ > @@ -5255,6 +5256,8 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, > if (!udev) { > dev_err(&port_dev->dev, > "couldn't allocate usb_device\n"); > + mutex_unlock(hcd->address0_mutex); > + usb_unlock_port(port_dev); > goto done; > } > > @@ -5276,13 +5279,13 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, > } > > /* reset (non-USB 3.0 devices) and get descriptor */ > - usb_lock_port(port_dev); > status = hub_port_init(hub, udev, port1, i); > - usb_unlock_port(port_dev); > if (status < 0) > goto loop; > > mutex_unlock(hcd->address0_mutex); > + usb_unlock_port(port_dev); > + retry_locked = false; > > if (udev->quirks & USB_QUIRK_DELAY_INIT) > msleep(2000); > @@ -5372,11 +5375,14 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, > > loop_disable: > hub_port_disable(hub, port1, 1); > - mutex_lock(hcd->address0_mutex); > loop: > usb_ep0_reinit(udev); > release_devnum(udev); > hub_free_dev(udev); > + if (retry_locked) { > + mutex_unlock(hcd->address0_mutex); > + usb_unlock_port(port_dev); > + } > usb_put_dev(udev); > if ((status == -ENOTCONN) || (status == -ENOTSUPP)) > break; > @@ -5399,8 +5405,6 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, > } > > done: > - mutex_unlock(hcd->address0_mutex); > - > hub_port_disable(hub, port1, 1); > if (hcd->driver->relinquish_port && !hub->hdev->parent) { > if (status != -ENOTCONN && status != -ENODEV) >
On 22.11.2021 14.27, Marek Szyprowski wrote: > Hi, > > On 22.11.2021 11:50, Mathias Nyman wrote: >> Fix the circular lock dependency and unbalanced unlock of addess0_mutex >> introduced when fixing an address0_mutex enumeration retry race in commit >> ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") >> >> Make sure locking order between port_dev->status_lock and address0_mutex >> is correct, and that address0_mutex is not unlocked in hub_port_connect >> "done:" codepath which may be reached without locking address0_mutex >> >> Fixes: 6ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") >> Cc: <stable@vger.kernel.org> >> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> > This fixes the issue I've reported here: > https://lore.kernel.org/all/f3bfcbc7-f701-c74a-09bd-6491d4c8d863@samsung.com/ > Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> > Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Thank you for testing, I'll add these tags -Mathias
On 22.11.2021 17.41, Hans de Goede wrote: > Hi, > > On 11/22/21 11:50, Mathias Nyman wrote: >> Fix the circular lock dependency and unbalanced unlock of addess0_mutex >> introduced when fixing an address0_mutex enumeration retry race in commit >> ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") >> >> Make sure locking order between port_dev->status_lock and address0_mutex >> is correct, and that address0_mutex is not unlocked in hub_port_connect >> "done:" codepath which may be reached without locking address0_mutex >> >> Fixes: 6ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") >> Cc: <stable@vger.kernel.org> >> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> > > Oh, this is great, with this patch I can finally hot-plug my > thunderbolt dock (and thus a XHCI controller) without the XHCI > controller given a whole bunch of weird errors (and some USB > devices not working), which it does not when already connected at boot. > > I also tried the hotplug thingy with the previous fix without > this locking fix and then I actually hit the deadlock and things > like lsusb would hang. > > If we can get these 2 fixes together merged soon and also backported > to the stable series that would be great: > > Acked-by: Hans de Goede <hdegoede@redhat.com> > Tested-by: Hans de Goede <hdegoede@redhat.com> > > Regards, > > Hans > Thanks for testing, I'll add your tags and submit this. -Mathias
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 00c3506324e4..00070a8a6507 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -5188,6 +5188,7 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, struct usb_port *port_dev = hub->ports[port1 - 1]; struct usb_device *udev = port_dev->child; static int unreliable_port = -1; + bool retry_locked; /* Disconnect any existing devices under this port */ if (udev) { @@ -5244,10 +5245,10 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, status = 0; - mutex_lock(hcd->address0_mutex); - for (i = 0; i < PORT_INIT_TRIES; i++) { - + usb_lock_port(port_dev); + mutex_lock(hcd->address0_mutex); + retry_locked = true; /* reallocate for each attempt, since references * to the previous one can escape in various ways */ @@ -5255,6 +5256,8 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, if (!udev) { dev_err(&port_dev->dev, "couldn't allocate usb_device\n"); + mutex_unlock(hcd->address0_mutex); + usb_unlock_port(port_dev); goto done; } @@ -5276,13 +5279,13 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, } /* reset (non-USB 3.0 devices) and get descriptor */ - usb_lock_port(port_dev); status = hub_port_init(hub, udev, port1, i); - usb_unlock_port(port_dev); if (status < 0) goto loop; mutex_unlock(hcd->address0_mutex); + usb_unlock_port(port_dev); + retry_locked = false; if (udev->quirks & USB_QUIRK_DELAY_INIT) msleep(2000); @@ -5372,11 +5375,14 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, loop_disable: hub_port_disable(hub, port1, 1); - mutex_lock(hcd->address0_mutex); loop: usb_ep0_reinit(udev); release_devnum(udev); hub_free_dev(udev); + if (retry_locked) { + mutex_unlock(hcd->address0_mutex); + usb_unlock_port(port_dev); + } usb_put_dev(udev); if ((status == -ENOTCONN) || (status == -ENOTSUPP)) break; @@ -5399,8 +5405,6 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, } done: - mutex_unlock(hcd->address0_mutex); - hub_port_disable(hub, port1, 1); if (hcd->driver->relinquish_port && !hub->hdev->parent) { if (status != -ENOTCONN && status != -ENODEV)
Fix the circular lock dependency and unbalanced unlock of addess0_mutex introduced when fixing an address0_mutex enumeration retry race in commit ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") Make sure locking order between port_dev->status_lock and address0_mutex is correct, and that address0_mutex is not unlocked in hub_port_connect "done:" codepath which may be reached without locking address0_mutex Fixes: 6ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") Cc: <stable@vger.kernel.org> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> --- drivers/usb/core/hub.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-)