The implementation is broken in all the ways the unit test did not touch:
1/ The local definition of in_buf and in_obj violated C99 initializer expectations for zeroing. By only initializing 2 out of the three struct members the compiler was free to zero-initialize the remaining entry even though the aliased location in the union was initialized.
2/ The implementation made assumptions about the state of the 'smart' payload after command execution that are satisfied by acpi_nfit_ctl(), but not acpi_evaluate_dsm().
3/ populate_shutdown_status() is skipped on Intel NVDIMMs due to the early return for skipping the common _LS{I,R,W} enabling.
4/ The input length should be zero.
This breakage was missed due to the unit test implementation only testing the case where nfit_intel_shutdown_status() returns a valid payload.
Much of this complexity would be saved if acpi_nfit_ctl() could be used, but that currently requires a 'struct nvdimm *' argument and one is not created until later in the init process. The health result is needed before the device is created because the payload gates whether the nmemX/nfit/dirty_shutdown property is visible in sysfs.
Cc: stable@vger.kernel.org Fixes: 0ead11181fe0 ("acpi, nfit: Collect shutdown status") Reported-by: Dexuan Cui decui@microsoft.com Signed-off-by: Dan Williams dan.j.williams@intel.com --- drivers/acpi/nfit/core.c | 41 ++++++++++++++++++++++++----------------- 1 file changed, 24 insertions(+), 17 deletions(-)
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index e18ade5d74e9..0a49c57334cc 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -1759,14 +1759,14 @@ static bool acpi_nvdimm_has_method(struct acpi_device *adev, char *method)
__weak void nfit_intel_shutdown_status(struct nfit_mem *nfit_mem) { + struct device *dev = &nfit_mem->adev->dev; struct nd_intel_smart smart = { 0 }; union acpi_object in_buf = { - .type = ACPI_TYPE_BUFFER, - .buffer.pointer = (char *) &smart, - .buffer.length = sizeof(smart), + .buffer.type = ACPI_TYPE_BUFFER, + .buffer.length = 0, }; union acpi_object in_obj = { - .type = ACPI_TYPE_PACKAGE, + .package.type = ACPI_TYPE_PACKAGE, .package.count = 1, .package.elements = &in_buf, }; @@ -1781,8 +1781,15 @@ __weak void nfit_intel_shutdown_status(struct nfit_mem *nfit_mem) return;
out_obj = acpi_evaluate_dsm(handle, guid, revid, func, &in_obj); - if (!out_obj) + if (!out_obj || out_obj->type != ACPI_TYPE_BUFFER + || out_obj->buffer.length < sizeof(smart)) { + dev_dbg(dev->parent, "%s: failed to retrieve initial health\n", + dev_name(dev)); + ACPI_FREE(out_obj); return; + } + memcpy(&smart, out_obj->buffer.pointer, sizeof(smart)); + ACPI_FREE(out_obj);
if (smart.flags & ND_INTEL_SMART_SHUTDOWN_VALID) { if (smart.shutdown_state) @@ -1793,7 +1800,6 @@ __weak void nfit_intel_shutdown_status(struct nfit_mem *nfit_mem) set_bit(NFIT_MEM_DIRTY_COUNT, &nfit_mem->flags); nfit_mem->dirty_shutdown = smart.shutdown_count; } - ACPI_FREE(out_obj); }
static void populate_shutdown_status(struct nfit_mem *nfit_mem) @@ -1915,18 +1921,19 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc, | 1 << ND_CMD_SET_CONFIG_DATA; if (family == NVDIMM_FAMILY_INTEL && (dsm_mask & label_mask) == label_mask) - return 0; - - if (acpi_nvdimm_has_method(adev_dimm, "_LSI") - && acpi_nvdimm_has_method(adev_dimm, "_LSR")) { - dev_dbg(dev, "%s: has _LSR\n", dev_name(&adev_dimm->dev)); - set_bit(NFIT_MEM_LSR, &nfit_mem->flags); - } + /* skip _LS{I,R,W} enabling */; + else { + if (acpi_nvdimm_has_method(adev_dimm, "_LSI") + && acpi_nvdimm_has_method(adev_dimm, "_LSR")) { + dev_dbg(dev, "%s: has _LSR\n", dev_name(&adev_dimm->dev)); + set_bit(NFIT_MEM_LSR, &nfit_mem->flags); + }
- if (test_bit(NFIT_MEM_LSR, &nfit_mem->flags) - && acpi_nvdimm_has_method(adev_dimm, "_LSW")) { - dev_dbg(dev, "%s: has _LSW\n", dev_name(&adev_dimm->dev)); - set_bit(NFIT_MEM_LSW, &nfit_mem->flags); + if (test_bit(NFIT_MEM_LSR, &nfit_mem->flags) + && acpi_nvdimm_has_method(adev_dimm, "_LSW")) { + dev_dbg(dev, "%s: has _LSW\n", dev_name(&adev_dimm->dev)); + set_bit(NFIT_MEM_LSW, &nfit_mem->flags); + } }
populate_shutdown_status(nfit_mem);