Translation functions may return an invalid address in case of errors.
If the address is not checked the further use of the invalid value
will cause an address corruption.
Consistently check for a valid address returned by translation
functions. Use RESOURCE_SIZE_MAX to indicate an invalid address for
type resource_size_t. Depending on the type either RESOURCE_SIZE_MAX
or ULLONG_MAX is used to indicate an address error.
Propagating an invalid address from a failed translation may cause
userspace to think it has received a valid SPA, when in fact it is
wrong. The CXL userspace API, using trace events, expects ULLONG_MAX
to indicate a translation failure. If ULLONG_MAX is not returned
immediately, subsequent calculations can transform that bad address
into a different value (!ULLONG_MAX), and an invalid SPA may be
returned to userspace. This can lead to incorrect diagnostics and
erroneous corrective actions.
[ dj: Added user impact statement from Alison. ]
[ dj: Fixed checkpatch tab alignment issue. ]
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Fixes: c3dd67681c ("cxl/region: Add inject and clear poison by region offset")
Fixes: b78b9e7b79 ("cxl/region: Refactor address translation funcs for testing")
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260107120544.410993-1-rrichter@amd.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Add a loadable test module that validates CXL address translation
calculations using parameterized test vectors. The module tests both
host-to-device and device-to-host address translations for Modulo and
XOR interleave arithmetic.
Two types of testing are provided:
1. Parameterized test vectors:
Test vectors are passed as module parameters in the format:
"dpa pos r_eiw r_eig hb_ways math expected_spa".
Round-trip validation is performed:
- Translate a DPA and position to a SPA
- Verify the result matches expected SPA
- Translate that SPA back to a DPA and position
- Verify round-trip consistency
2. Internal validation testing:
When no test vectors are provided, the module performs validation
of the translation functions by checking parameter boundaries and
running 10,000 iterations of randomly generated valid parameters
to exercise the core calculation functions.
The module uses the CXL Driver translation functions through symbols
exported exclusively for cxl_translate.
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
