Hi Greg
>
>This still doesn't apply at all, please work on sending the patch to
>yourself and seeing if you can add it to my usb-next git branch.
>
Sorry for the inconvenience to you
I think its problem with my email client for sending patch.
Now, i will make new patch against latest linux-next tree and share with you using git-send-email.
Thanks & Regards,
Aman Deep
------- Original Message -------
Sender : Greg KH<gregkh@xxxxxxxxxxxxxxxxxxx>
Date : Aug 18, 2015 23:04 (GMT+06:00)
Title : Re: [PATCH v5]USB:OHCI: BugFix:Proper handling of ed_rm_list to handle race condition between usb_kill_urb() and finish_unlinks()
On Tue, Aug 18, 2015 at 12:25:05PM +0000, AMAN DEEP wrote:
> There is a race condition between
> finish_unlinks->finish_urb() function and
> usb_kill_urb() in ohci controller case. The finish_urb
> calls spin_unlock(&ohci->lock) before
> usb_hcd_giveback_urb() function call, then if during
> this time, usb_kill_urb is called for another endpoint,
> then new ed will be added to ed_rm_list at beginning
> for unlink. and ed_rm_list will point to newly added
> ed.
>
> When finish_urb() is completed in finish_unlinks() and
> ed->td_list becomes empty as in below code (in finish_unlinks() function)
> if (list_empty(&ed->td_list)) {
> *last = ed->ed_next;
> ed->ed_next = NULL;
> } else if (ohci->rh_state == OHCI_RH_RUNNING) {
> *last = ed->ed_next;
> ed->ed_next = NULL;
> ed_schedule(ohci, ed);
> }
> *last = ed->ed_next will make ed_rm_list to point to ed->ed_next and
> previously added ed by usb_kill_urb will be left unreferenced by
> ed_rm_list. This causes usb_kill_urb() hang forever waiting for
> finish_unlink to remove added ed from ed_rm_list.
>
> The main reason for hang in this race condtion is addition and removal
> of ed from ed_rm_list in the beginning during usb_kill_urb and later last*
> is modified in finish_unlinks().
> As suggested by Alan Stern, the solution for proper handling of
> ohci->ed_rm_list is to remove ed from the ed_rm_list before finishing
> any URBs. Then at the end, we can add ed back to the list if necessary.
> This properly handle the updated ohci->ed_rm_list in
> usb_kill_urb().
>
> Fixes:977dcfdc6031("USB:OHCI:don't lose track of EDs when a
> controller dies")
>
> Acked-by: Alan Stern
>
> Signed-off-by: Aman Deep
> CC:
> ---
> drivers/usb/host/ohci-q.c | 17 ++++++++++-------
> 1 file changed, 10 insertions(+), 7 deletions(-)
This still doesn't apply at all, please work on sending the patch to
yourself and seeing if you can add it to my usb-next git branch.
greg k-h
Thanks & Regards,
Aman Deepÿôèº{.nÇ+‰·Ÿ®‰†+%ŠËÿ±éݶ¥Šwÿº{.nÇ+‰·¥Š{±þëþ)í…æèw* jg¬±¨ ¶‰šŽŠÝ¢jÿ¾«þG«?éÿ¢¸ ¢·¦j:+v‰¨ŠwèjØm¶Ÿÿþø ¯ù ®w¥þŠàþf£¢·hš?â?úÿ†Ù¥
