Hello Greg, Thank you for your feedback. > Subject: Re: [PATCH] dmaengine: ensure dmaengine helpers check valid callback > > On Mon, May 21, 2018 at 05:56:55PM +0100, Fabrizio Castro wrote: > > From: Vinod Koul <vinod.koul@xxxxxxxxx> > > > > commit 757d12e5849be549076901b0d33c60d5f360269c upstream. > > > > dmaengine has various device callbacks and exposes helper > > functions to invoke these. These helpers should check if channel, > > device and callback is valid or not before invoking them. > > > > Reported-by: Jon Hunter <jonathanh@xxxxxxxxxx> > > Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx> > > [fabrizio: cherry-pick to 4.4] > > Signed-off-by: Fabrizio Castro <fabrizio.castro@xxxxxxxxxxxxxx> > > Signed-off-by: Jianming Qiao <jianming.qiao@xxxxxxxxxxxxxx> > > --- > > Hello Greg, > > > > while backporting commit 757d12e5849be549076901b0d33c60d5f360269c > > to the CIP kernel Ben recommended to send the same patch to you > > for 4.4 stable. > > I hope the format of the commit is the one you expect (reference to > > the upstream commit, version to cherry-pick the patch to, and > > Signed-off-by tags). > > Format is fine, but why is this needed in the 4.4.y kernel tree? We work with the CIP kernel (v4.4), and from time to time we come across bug fixes we feel like stable could benefit from. Also, since Ben merges the CIP branch with stable, the fixes we make to stable will appear in the CIP kernel too at some point. If you feel like the patch is not worth considering for stable, it can still be applied to the CIP kernel if required. Ben has already taken this patch (for v4.4.126-cip22) therefore it's not on our critical path, but it would be nice to have in the stable kernel too. > What bug does it solve? Without this patch we managed to get the kernel to try and dereference a NULL pointer while playing around with ttys (basically by having the wrong tty with /etc/securetty). Are you happy to take this patch? Thanks, Fab > > thanks, > > greg k-h Renesas Electronics Europe Ltd, Dukes Meadow, Millboard Road, Bourne End, Buckinghamshire, SL8 5FH, UK. Registered in England & Wales under Registered No. 04586709.
