On Sat, Jul 09, 2022 at 01:06:36PM -0700, Dan Williams wrote:
> Adam Manzanares wrote:
> > On Thu, Jun 23, 2022 at 07:45:07PM -0700, Dan Williams wrote:
> > > This failing signature:
> > >
> > > [ 8.392669] cxl_bus_probe: cxl_port endpoint2: probe: 970997760
> > > [ 8.392670] cxl_port: probe of endpoint2 failed with error 970997760
> > > [ 8.392719] create_endpoint: cxl_mem mem0: add: endpoint2
> > > [ 8.392721] cxl_mem mem0: endpoint2 failed probe
> > > [ 8.392725] cxl_bus_probe: cxl_mem mem0: probe: -6
> > >
> > > ...shows cxl_hdm_decode_init() resulting in a return code ("970997760")
> > > that looks like stack corruption. The problem goes away if
> > > cxl_hdm_decode_init() is not mocked via __wrap_cxl_hdm_decode_init().
> > >
> > > The corruption results from the mismatch that the calling convention for
> > > cxl_hdm_decode_init() is:
> > >
> > > int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm)
> > >
> > > ...and __wrap_cxl_hdm_decode_init() is:
> > >
> > > bool __wrap_cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm)
> > >
> > > ...i.e. an int is expected but __wrap_hdm_decode_init() returns bool.
> > >
> > > Fix the convention and cleanup the organization to match
> > > __wrap_cxl_await_media_ready() as the difference was a red herring that
> > > distracted from finding the bug.
> > >
> > > Fixes: 92804edb11f0 ("cxl/pci: Drop @info argument to cxl_hdm_decode_init()")
> > > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> > > ---
> > > tools/testing/cxl/test/mock.c | 8 +++++---
> > > 1 file changed, 5 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/tools/testing/cxl/test/mock.c b/tools/testing/cxl/test/mock.c
> > > index f1f8c40948c5..bce6a21df0d5 100644
> > > --- a/tools/testing/cxl/test/mock.c
> > > +++ b/tools/testing/cxl/test/mock.c
> > > @@ -208,13 +208,15 @@ int __wrap_cxl_await_media_ready(struct cxl_dev_state *cxlds)
> > > }
> > > EXPORT_SYMBOL_NS_GPL(__wrap_cxl_await_media_ready, CXL);
> > >
> > > -bool __wrap_cxl_hdm_decode_init(struct cxl_dev_state *cxlds,
> > > - struct cxl_hdm *cxlhdm)
> > > +int __wrap_cxl_hdm_decode_init(struct cxl_dev_state *cxlds,
> > > + struct cxl_hdm *cxlhdm)
> > > {
> > > int rc = 0, index;
> > > struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
> > >
> > > - if (!ops || !ops->is_mock_dev(cxlds->dev))
> > > + if (ops && ops->is_mock_dev(cxlds->dev))
> > > + rc = 0;
> > > + else
> > > rc = cxl_hdm_decode_init(cxlds, cxlhdm);
> > > put_cxl_mock_ops(index);
> > >
> > >
> >
> >
> > Looks good.
> >
> > Reviewed by: Adam Manzanares <a.manzanares@xxxxxxxxxxx>
>
> Just fyi, b4 did not auto-apply this tag due to the missing "-", caught
> it manually.
Ouch, thanks for pointing this out. Updated my template.
