3.16.75-rc1 review patch. If anyone has any objections, please let me know.
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From: Shuah Khan skhan@linuxfoundation.org
commit 3ea3091f1bd8586125848c62be295910e9802af0 upstream.
Fix the following sparse context imbalance regression introduced in a patch that fixed sleeping function called from invalid context bug.
kbuild test robot reported on:
tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-linus
Regressions in current branch:
drivers/usb/usbip/stub_dev.c:399:9: sparse: sparse: context imbalance in 'stub_probe' - different lock contexts for basic block drivers/usb/usbip/stub_dev.c:418:13: sparse: sparse: context imbalance in 'stub_disconnect' - different lock contexts for basic block drivers/usb/usbip/stub_dev.c:464:1-10: second lock on line 476
Error ids grouped by kconfigs:
recent_errors ├── i386-allmodconfig │ └── drivers-usb-usbip-stub_dev.c:second-lock-on-line ├── x86_64-allmodconfig │ ├── drivers-usb-usbip-stub_dev.c:sparse:sparse:context-imbalance-in-stub_disconnect-different-lock-contexts-for-basic-block │ └── drivers-usb-usbip-stub_dev.c:sparse:sparse:context-imbalance-in-stub_probe-different-lock-contexts-for-basic-block └── x86_64-allyesconfig └── drivers-usb-usbip-stub_dev.c:second-lock-on-line
This is a real problem in an error leg where spin_lock() is called on an already held lock.
Fix the imbalance in stub_probe() and stub_disconnect().
Signed-off-by: Shuah Khan skhan@linuxfoundation.org Fixes: 0c9e8b3cad65 ("usbip: usbip_host: fix BUG: sleeping function called from invalid context") Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/staging/usbip/stub_dev.c | 36 +++++++++++++++++++++++------------- 1 file changed, 23 insertions(+), 13 deletions(-)
--- a/drivers/staging/usbip/stub_dev.c +++ b/drivers/staging/usbip/stub_dev.c @@ -367,14 +367,17 @@ static int stub_probe(struct usb_device * See driver_probe_device() in driver/base/dd.c */ rc = -ENODEV; - goto sdev_free; + if (!busid_priv) + goto sdev_free; + + goto call_put_busid_priv; }
if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) { dev_dbg(&udev->dev, "%s is a usb hub device... skip!\n", udev_busid); rc = -ENODEV; - goto sdev_free; + goto call_put_busid_priv; }
if (!strcmp(udev->bus->bus_name, "vhci_hcd")) { @@ -383,7 +386,7 @@ static int stub_probe(struct usb_device udev_busid);
rc = -ENODEV; - goto sdev_free; + goto call_put_busid_priv; }
@@ -402,6 +405,9 @@ static int stub_probe(struct usb_device save_status = busid_priv->status; busid_priv->status = STUB_BUSID_ALLOC;
+ /* release the busid_lock */ + put_busid_priv(busid_priv); + /* * Claim this hub port. * It doesn't matter what value we pass as owner @@ -414,9 +420,6 @@ static int stub_probe(struct usb_device goto err_port; }
- /* release the busid_lock */ - put_busid_priv(busid_priv); - rc = stub_add_files(&udev->dev); if (rc) { dev_err(&udev->dev, "stub_add_files for %s\n", udev_busid); @@ -437,11 +440,17 @@ err_port: spin_lock(&busid_priv->busid_lock); busid_priv->sdev = NULL; busid_priv->status = save_status; -sdev_free: - stub_device_free(sdev); + spin_unlock(&busid_priv->busid_lock); + /* lock is released - go to free */ + goto sdev_free; + +call_put_busid_priv: /* release the busid_lock */ put_busid_priv(busid_priv);
+sdev_free: + stub_device_free(sdev); + return rc; }
@@ -477,7 +486,9 @@ static void stub_disconnect(struct usb_d /* get stub_device */ if (!sdev) { dev_err(&udev->dev, "could not get device"); - goto call_put_busid_priv; + /* release busid_lock */ + put_busid_priv(busid_priv); + return; }
dev_set_drvdata(&udev->dev, NULL); @@ -507,7 +518,7 @@ static void stub_disconnect(struct usb_d if (!busid_priv->shutdown_busid) busid_priv->shutdown_busid = 1; /* release busid_lock */ - put_busid_priv(busid_priv); + spin_unlock(&busid_priv->busid_lock);
/* shutdown the current connection */ shutdown_busid(busid_priv); @@ -522,10 +533,9 @@ static void stub_disconnect(struct usb_d
if (busid_priv->status == STUB_BUSID_ALLOC) busid_priv->status = STUB_BUSID_ADDED; - -call_put_busid_priv: /* release busid_lock */ - put_busid_priv(busid_priv); + spin_unlock(&busid_priv->busid_lock); + return; }
#ifdef CONFIG_PM