From: Mike Isely Date: Sat, 15 May 2010 03:15:38 +0000 (-0300) Subject: V4L/DVB: pvrusb2: Fix kernel oops at device unregistration X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d72baad3f0e59041d68db7524537046e3a4121a2;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git V4L/DVB: pvrusb2: Fix kernel oops at device unregistration pvrusb2: Fix oops caused by touching deleted memory after unregistration. This bug was introduced when we had started using video_device_node_name() - that function was being called potentially after the underlying structure (referenced by that function) had been deleted. The fix rearranges things slightly so that the function is called before destruction takes place. Signed-off-by: Mike Isely Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/video/pvrusb2/pvrusb2-v4l2.c b/drivers/media/video/pvrusb2/pvrusb2-v4l2.c index 5ffa0d2b0b0d..aaafa0398fd5 100644 --- a/drivers/media/video/pvrusb2/pvrusb2-v4l2.c +++ b/drivers/media/video/pvrusb2/pvrusb2-v4l2.c @@ -883,6 +883,17 @@ static void pvr2_v4l2_dev_destroy(struct pvr2_v4l2_dev *dip) { struct pvr2_hdw *hdw = dip->v4lp->channel.mc_head->hdw; enum pvr2_config cfg = dip->config; + char msg[80]; + unsigned int mcnt; + + /* Construct the unregistration message *before* we actually + perform the unregistration step. By doing it this way we don't + have to worry about potentially touching deleted resources. */ + mcnt = scnprintf(msg, sizeof(msg) - 1, + "pvrusb2: unregistered device %s [%s]", + video_device_node_name(&dip->devbase), + pvr2_config_get_name(cfg)); + msg[mcnt] = 0; pvr2_hdw_v4l_store_minor_number(hdw,dip->minor_type,-1); @@ -894,9 +905,7 @@ static void pvr2_v4l2_dev_destroy(struct pvr2_v4l2_dev *dip) are gone. */ video_unregister_device(&dip->devbase); - printk(KERN_INFO "pvrusb2: unregistered device %s [%s]\n", - video_device_node_name(&dip->devbase), - pvr2_config_get_name(cfg)); + printk(KERN_INFO "%s\n", msg); }