On 17-12-24 01:28 pm, 胡连勤 wrote: > From: Lianqin Hu <hulianqin@xxxxxxxx> > > Considering that in some extreme cases, when performing the > unbinding operation, gserial_disconnect has cleared gser->ioport, > which triggers gadget reconfiguration, and then calls gs_read_complete, > resulting in access to a null pointer. Therefore, ep is disabled before > gserial_disconnect sets port to null to prevent this from happening. gs_read_complete() gets port from ep->driver_data, and it shouldn't get affected if gser->ioport is null as long as port[port_num].port is valid. Am I missing something here? > > Call trace: > gs_read_complete+0x58/0x240 > usb_gadget_giveback_request+0x40/0x160 > dwc3_remove_requests+0x170/0x484 > dwc3_ep0_out_start+0xb0/0x1d4 > __dwc3_gadget_start+0x25c/0x720 > kretprobe_trampoline.cfi_jt+0x0/0x8 > kretprobe_trampoline.cfi_jt+0x0/0x8 > udc_bind_to_driver+0x1d8/0x300 > usb_gadget_probe_driver+0xa8/0x1dc > gadget_dev_desc_UDC_store+0x13c/0x188 > configfs_write_iter+0x160/0x1f4 > vfs_write+0x2d0/0x40c > ksys_write+0x7c/0xf0 > __arm64_sys_write+0x20/0x30 > invoke_syscall+0x60/0x150 > el0_svc_common+0x8c/0xf8 > do_el0_svc+0x28/0xa0 > el0_svc+0x24/0x84 > Regards, Prashanth K
