On Thu, 23 Jun 2022 19:45:07 -0700
Dan Williams <dan.j.williams@xxxxxxxxx> 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>
LGTM
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> ---
> 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);
>
>
