Messages in this thread | | | Subject | Re: [PATCH V2] n_gsm: race between ld close and gsmtty open | From | channing <> | Date | Tue, 26 Nov 2013 11:35:14 +0800 |
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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.
> > Also, please fix your "From:" line in your email client to match your > Signed-off-by: line, or else add the proper "From:" line to your patch, > as the Documentation/SubmittingPatches file says. > > Care to try again? Yes, I'll correct it. thanks. > > greg k-h
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