Re: [PATCH] clk: Really fix deadlock with mmap_sem

From: Thomas Gleixner
Date: Fri Dec 12 2014 - 19:13:48 EST


On Fri, 12 Dec 2014, Stephen Boyd wrote:

> Commit 6314b6796e3c (clk: Don't hold prepare_lock across debugfs
> creation, 2014-09-04) forgot to update one place where we hold
> the prepare_lock while creating debugfs directories. This means
> we still have the chance of a deadlock that the commit was trying
> to fix. Actually fix it by moving the debugfs creation outside
> the prepare_lock.
>
> Reported-by: Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx>
> Fixes: 6314b6796e3c "clk: Don't hold prepare_lock across debugfs creation"
> Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>

> + lockdep_assert_held(clk_debug_lock);

That change is not mentioned in the changelog and seems to be
unrelated to the issue at hand.

Other than that:

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

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