Re: [PATCH 4.7 FIX] brcmfmac: fix lockup when removing P2P interface after event timeout

On 17 June 2016 at 07:13, Kalle Valo [off-list ref] wrote:

Rafał Miłecki [off-list ref] writes:

quoted

On 16 June 2016 at 17:10, Kalle Valo [off-list ref] wrote:

quoted

Rafał Miłecki [off-list ref] writes:

quoted

Removing P2P interface is handled by sending a proper request to the
firmware. On success firmware triggers an event and driver's handler
removes a matching interface.

However on event timeout we remove interface directly from the cfg80211
callback. Current code doesn't handle this case correctly as it always
assumes rtnl to be unlocked.

Fix it by adding an extra rtnl_locked parameter to functions and calling
unregister_netdevice when needed.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

Failed to apply, please rebase:

Applying: brcmfmac: fix lockup when removing P2P interface after event timeout
Using index info to reconstruct a base tree...
Falling back to patching base and 3-way merge...
Auto-merging drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
Auto-merging drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.h
CONFLICT (content): Merge conflict in drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.h
Auto-merging drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
Auto-merging drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
Failed to merge in the changes.
Patch failed at 0001 brcmfmac: fix lockup when removing P2P interface after event timeout

What tree did you try it on?

I just went into a dir where I have cloned:
git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers.git

My HEAD commit is:
034fdd4 Merge ath-current from ath.git

And I can apply this patch cleanly doing:
curl https://patchwork.kernel.org/patch/9138925/mbox/ | git am

I was trying to apply this to wireless-drivers-next. I didn't get a
confirmation from Arend and I didn't consider the fix important enough
for 4.7. But of course I can reconsider if needed.

I think I agree it won't hurt to get it into -next. Noone earlier
reported this bug and it seems to be there for a long time. Also
applying it to -next will allow avoiding merge conflicts and immediate
development work on -next.

I'll resend this patch rebased on -next soon.

-- 
Rafał