The patch I submitted is based on the latest kernel, I checked the latest kernel has the same logic, so I send the patch to LKML. Thanks for your comments. -----Original Message----- From: Felipe Balbi [mailto:balbi@xxxxxxxxxx] Sent: Wednesday, July 19, 2017 3:51 PM To: He, Bo <bo.he@xxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx Cc: gregkh@xxxxxxxxxxxxxxxxxxx; peter.chen@xxxxxxx; k.opasiak@xxxxxxxxxxx; stefan@xxxxxxxx; felixhaedicke@xxxxxx; colin.king@xxxxxxxxxxxxx; rogerq@xxxxxx; f.fainelli@xxxxxxxxx; Zhang, Yanmin <yanmin.zhang@xxxxxxxxx> Subject: RE: [PATCH] usb: gadget: udc: fix the kernel NULL pointer in composite_setup Hi, (please don't top-post and also break your lines at 80-columns ;-) "He, Bo" <bo.he@xxxxxxxxx> writes: > 1. the issue reproduced very rarely, we run reboot test > reproduce the issue, it reproduced two times on two board after > more than 1500 cycles reboot. That's fine, we, somehow, got a use-after-free on the tracepoints. I'm interested in fixing that without touching udc-core since that's a dwc3-only bug. > 2. the kernel version is 4.4, the test case is cold reboot, I think it's not android patches cause it, it's the interrupt thread run after the udc->driver->unbind. Yeah, I need you to try v4.13-rc1. v4.4 is *really* old. I can't accept your patch unless I'm certain the bug still exists. > 3. I check more drivers, like amd5536_udc_stop, at91_stop, > atmel_usba_stop, bcm63xx_udc_stop, s3c_hsudc_stop, all the > interrupt disable will be in the udc_stop(), so we need > guarantee to stop the interrupt then release the resource. Right, we also disable the interrupt on ->udc_stop(). See below: static void __dwc3_gadget_stop(struct dwc3 *dwc) { dwc3_gadget_disable_irq(dwc); __dwc3_gadget_ep_disable(dwc->eps[0]); __dwc3_gadget_ep_disable(dwc->eps[1]); } static int dwc3_gadget_stop(struct usb_gadget *g) { struct dwc3 *dwc = gadget_to_dwc(g); unsigned long flags; int epnum; spin_lock_irqsave(&dwc->lock, flags); if (pm_runtime_suspended(dwc->dev)) goto out; __dwc3_gadget_stop(dwc); for (epnum = 2; epnum < DWC3_ENDPOINTS_NUM; epnum++) { struct dwc3_ep *dep = dwc->eps[epnum]; if (!dep) continue; if (!(dep->flags & DWC3_EP_END_TRANSFER_PENDING)) continue; wait_event_lock_irq(dep->wait_end_transfer, !(dep->flags & DWC3_EP_END_TRANSFER_PENDING), dwc->lock); } out: dwc->gadget_driver = NULL; spin_unlock_irqrestore(&dwc->lock, flags); free_irq(dwc->irq_gadget, dwc->ev_buf); return 0; } -- balbi -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
