Re: [PATCH 2/4] irq: radix_tree_insert can fail

From: Thomas Gleixner
Date: Wed May 25 2011 - 04:18:49 EST


On Wed, 25 May 2011, Milton Miller wrote:

> Check the insert, and if it fails cleanup and free all partial work.
>
> Sparse irq was not checking the return code from radix_tree_insert,
> but it may need to allocate memory and can fail. If it failed,
> it still claimed success to the caller but the affected irq(s) are
> unavailable and the reference to the affected descriptors is leaked.
>
> Signed-off-by: Milton Miller <miltonm@xxxxxxx>
> ---
> I started by tring to change free_desc to take the descriptor pointer
> and pushing that down, but that soon ran into conflicts between the
> array and sparse implementations, and/or the old dynamic irq cleanup
> function that is still used by some architectures. This version is
> targeted, and also protects against scribbles to irq_data.irq.

The simpler solution is to move irq_insert_desc() into alloc_desc()
and deal with the error case there.

Thanks,

tglx
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