DM USB: xHCI: fix potential NULL pointer issue.

xiaoguangwu · wenlingz · commit 966c587260fc · 2018-12-04T19:59:00.000+08:00
During S3 process, the dev in the function pci_xhci_device_doorbell may be set to NULL when disconnection is detected by DM. This patch is used to remove this risk. Tracked-On: #1893 Signed-off-by: Xiaoguang Wu <xiaoguang.wu@intel.com> Reviewed-by: Liang Yang <liang3.yang@intel.com> Acked-by: Yu Wang <yu1.wang@intel.com>
diff --git a/devicemodel/hw/pci/xhci.c b/devicemodel/hw/pci/xhci.c
@@ -2937,6 +2937,9 @@ pci_xhci_device_doorbell(struct pci_xhci_vdev *xdev,
 	}
 
 	dev = XHCI_SLOTDEV_PTR(xdev, slot);
+	if (!dev)
+		return;
+
 	devep = &dev->eps[epid];
 	dev_ctx = pci_xhci_get_dev_ctx(xdev, slot);
 	if (!dev_ctx)

Original file line number	Diff line number	Diff line change
`@@ -2937,6 +2937,9 @@ pci_xhci_device_doorbell(struct pci_xhci_vdev *xdev,`
`2937`	`2937`	`}`
`2938`	`2938`
`2939`	`2939`	`dev = XHCI_SLOTDEV_PTR(xdev, slot);`
	`2940`	`+ if (!dev)`
	`2941`	`+ return;`
	`2942`	`+`
`2940`	`2943`	`devep = &dev->eps[epid];`
`2941`	`2944`	`dev_ctx = pci_xhci_get_dev_ctx(xdev, slot);`
`2942`	`2945`	`if (!dev_ctx)`