@@ -2175,8 +2175,6 @@ static int gr_probe(struct platform_device *pdev)
return -ENOMEM;
}
- spin_lock(&dev->lock);
-
/* Inside lock so that no gadget can use this udc until probe is done */
retval = usb_add_gadget_udc(dev->dev, &dev->gadget);
if (retval) {
@@ -2185,15 +2183,21 @@ static int gr_probe(struct platform_device *pdev)
}
dev->added = 1;
+ spin_lock(&dev->lock);
+
retval = gr_udc_init(dev);
- if (retval)
+ if (retval) {
+ spin_unlock(&dev->lock);
goto out;
-
- gr_dfs_create(dev);
+ }
/* Clear all interrupt enables that might be left on since last boot */
gr_disable_interrupts_and_pullup(dev);
+ spin_unlock(&dev->lock);
+
+ gr_dfs_create(dev);
+
retval = gr_request_irq(dev, dev->irq);
if (retval) {
dev_err(dev->dev, "Failed to request irq %d\n", dev->irq);
@@ -2222,8 +2226,6 @@ static int gr_probe(struct platform_device *pdev)
dev_info(dev->dev, "regs: %p, irq %d\n", dev->regs, dev->irq);
out:
- spin_unlock(&dev->lock);
-
if (retval)
gr_remove(pdev);
The driver may sleep while holding a spinlock. The function call path (from bottom to top) in Linux 4.19 is: drivers/usb/gadget/udc/core.c, 1175: kzalloc(GFP_KERNEL) in usb_add_gadget_udc_release drivers/usb/gadget/udc/core.c, 1272: usb_add_gadget_udc_release in usb_add_gadget_udc drivers/usb/gadget/udc/gr_udc.c, 2186: usb_add_gadget_udc in gr_probe drivers/usb/gadget/udc/gr_udc.c, 2183: spin_lock in gr_probe drivers/usb/gadget/udc/core.c, 1195: mutex_lock in usb_add_gadget_udc_release drivers/usb/gadget/udc/core.c, 1272: usb_add_gadget_udc_release in usb_add_gadget_udc drivers/usb/gadget/udc/gr_udc.c, 2186: usb_add_gadget_udc in gr_probe drivers/usb/gadget/udc/gr_udc.c, 2183: spin_lock in gr_probe drivers/usb/gadget/udc/gr_udc.c, 212: debugfs_create_file in gr_probe drivers/usb/gadget/udc/gr_udc.c, 2197: gr_dfs_create in gr_probe drivers/usb/gadget/udc/gr_udc.c, 2183: spin_lock in gr_probe drivers/usb/gadget/udc/gr_udc.c, 2114: devm_request_threaded_irq in gr_request_irq drivers/usb/gadget/udc/gr_udc.c, 2202: gr_request_irq in gr_probe drivers/usb/gadget/udc/gr_udc.c, 2183: spin_lock in gr_probe kzalloc(GFP_KERNEL), mutex_lock(), debugfs_create_file() and devm_request_threaded_irq() can sleep at runtime. To fix these possible bugs, usb_add_gadget_udc(), gr_dfs_create() and gr_request_irq() are called without handling the spinlock. These bugs are found by a static analysis tool STCheck written by myself. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- drivers/usb/gadget/udc/gr_udc.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)