Re: [PATCH] iommu/core: fix bus notifier breakage

From: Joerg Roedel
Date: Thu Sep 25 2014 - 10:48:00 EST

On Sun, Sep 21, 2014 at 01:58:24PM -0400, Mark Salter wrote:
> iommu_bus_init() registers a bus notifier on the given bus by using
> a statically defined notifier block:
> static struct notifier_block iommu_bus_nb = {
> .notifier_call = iommu_bus_notifier,
> };
> This same notifier block is used for all busses. This causes a
> problem for notifiers registered after iommu has registered this
> callback on multiple busses. The problem is that a subsequent
> notifier being registered on a bus which has this iommu notifier
> will also get linked in to the notifier list of all other busses
> which have this iommu notifier.
> This patch fixes this by allocating the notifier_block at runtime.
> Some error checking is also added to catch any allocation failure
> or notifier registration error.
> Signed-off-by: Mark Salter <msalter@xxxxxxxxxx>
> ---
> drivers/iommu/iommu.c | 26 ++++++++++++++++----------
> 1 file changed, 16 insertions(+), 10 deletions(-)

Makes sense, applied. Where have you hit this condition where IOMMUs for
different buses are registered?


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