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authorMike Isely <isely@pobox.com>2010-05-15 00:15:38 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2010-06-01 01:19:52 -0300
commitd72baad3f0e59041d68db7524537046e3a4121a2 (patch)
tree80556b09be921c6cfee98c6c70595e86bf5f1060
parent8fd0444817e557568d8bddd77828d9ae0d606e04 (diff)
downloadop-kernel-dev-d72baad3f0e59041d68db7524537046e3a4121a2.zip
op-kernel-dev-d72baad3f0e59041d68db7524537046e3a4121a2.tar.gz
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 <isely@pobox.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
-rw-r--r--drivers/media/video/pvrusb2/pvrusb2-v4l2.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/media/video/pvrusb2/pvrusb2-v4l2.c b/drivers/media/video/pvrusb2/pvrusb2-v4l2.c
index 5ffa0d2..aaafa03 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);
}
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