On Wed, Apr 04, 2018 at 09:08:56AM +0300, Leon Romanovsky wrote:
> On Tue, Apr 03, 2018 at 09:07:41PM -0600, Jason Gunthorpe wrote:
> > This is done by auditing all callers of ucma_get_ctx and switching the
> > ones that unconditionally touch ->device to ucma_get_ctx_dev. This covers
> > a little less than half of the call sites.
> >
> > The 11 remaining call sites to ucma_get_ctx() were manually audited.
> >
> > It looks like none of these cases cause bugs due to the FSM system
> > inside the CMA, but documenting the requirement and the result of this
> > audit is still productive.
> >
> > Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
> > drivers/infiniband/core/ucma.c | 34 ++++++++++++++++++++++------------
> > 1 file changed, 22 insertions(+), 12 deletions(-)
> >
> > Inspired by Roland's patch, let us try hard to be sure we are done with
> > this issue.
> >
> > diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
> > index e74c82ee38a9f7..95e1eadae074ff 100644
> > +++ b/drivers/infiniband/core/ucma.c
> > @@ -153,6 +153,21 @@ static struct ucma_context *ucma_get_ctx(struct ucma_file *file, int id)
> > return ctx;
> > }
> >
> > +/*
> > + * Same as ucm_get_ctx but requires that ->cm_id->device is valid, eg that the
> > + * CM_ID is bound.
> > + */
> > +static struct ucma_context *ucma_get_ctx_dev(struct ucma_file *file, int id)
> > +{
> > + struct ucma_context *ctx = ucma_get_ctx(file, id);
> > +
> > + if (IS_ERR(ctx))
> > + return ctx;
> > + if (!ctx->cm_id->device)
> > + return ERR_PTR(-EINVAL);
> > + return ctx;
> > +}
>
> I like the idea, but the implementation needs to be improved a little bit.
> All old callers to ucma_get_ctx() expected that once that call fails
> they won't need to release "ctx". Now, the failures returned by ucma_get_ctx_dev()
> break that flow.
Oops, yes, thanks. v2 on its way
Jason
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