usb: gadget: udc: fix possible sleep-in-atomic-context bugs in gr_probe()
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: NJia-Ju Bai <baijiaju1990@gmail.com> Signed-off-by: NFelipe Balbi <balbi@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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