Re: [tip:bkl/drivers] drivers: Remove BKL from misc_open

[Ingo Molnar]

* Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:

> On Wed, 14 Oct 2009 15:47:39 GMT
> tip-bot for Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> 
> > Commit-ID:  40b798efe3460797a4ac928ee2e038774e2758eb
> > Gitweb:     http://git.kernel.org/tip/40b798efe3460797a4ac928ee2e038774e2758eb
> > Author:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > AuthorDate: Sat, 10 Oct 2009 15:35:43 +0000
> > Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > CommitDate: Wed, 14 Oct 2009 17:33:32 +0200
> > 
> > drivers: Remove BKL from misc_open
> > 
> > misc_open() is already serialized with misc_mtx. Remove the BKL
> > locking which got there via the BKL pushdown.
> 
> NAK.
> 
> You can't simply assume the mutex is enough - you have to either push 
> it down or review *every* possible called point below the lock_kernel 
> take.
> 
> In this case the open method of the misc devices below sometimes uses 
> the BKL.

We did that and it's safe in nvram.c. If you know an unsafe please let 
us know.

	Ingo
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