Messages in this thread | | | Date | Mon, 25 Nov 2013 19:16:29 -0800 | From | Greg KH <> | Subject | Re: [PATCH V2] n_gsm: race between ld close and gsmtty open |
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On Tue, Nov 26, 2013 at 11:35:14AM +0800, channing wrote: > On Mon, 2013-11-25 at 18:54 -0800, Greg KH wrote: > > On Tue, Nov 26, 2013 at 11:14:05AM +0800, channing wrote: > > > > This patch is try to avoid it by: > > > > > > 1) in n_gsm driver, use a global gsm mutex lock to avoid gsm_dlci_release() run in > > > parallel with gsmtty_install(); > The commit is updated here than formal patch set: we use mutex lock in > patch V2, while use spin lock in patch V1. > > > > > > > 2) Increase dlci's ref count in gsmtty_install() instead of in gsmtty_open(), the > > > purpose is to prevent gsm_dlci_release() releasing dlci after gsmtty_install() > > > allocats dlci but before gsmtty_open increases dlci's ref count; > > > > > > 3) Decrease dlci's ref count in gsmtty_remove(), a tty framework API, this is the > > > opposite process of step 2). > > > > > > Signed-off-by: Chao Bi <chao.bi@intel.com> > > > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > > > I have not signed off on this additional patch. > > > > What is different from the previous version? That information needs to > > be somewhere, otherwise I'm just going to guess and say this is the same > > as your last one, which was incorrect. > The difference with previous one is to use a mutex instead of spin lock > to avoid race, purpose is to avoid sleep in atomic context. I've also > updated commit a little as above.
Then be explicit as to what has changed somewhere. We deal with thousands of patches a week, we can not know that you changed one sentance in a patch description of a few hundred lines long to know you made a change to the patch itself as well...
thanks,
greg k-h
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