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Commit f596c884 authored by Dan Williams's avatar Dan Williams
Browse files

nfit: Fix nfit_intel_shutdown_status() command submission 



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: 0ead1118 ("acpi, nfit: Collect shutdown status")
Reported-by: default avatarDexuan Cui <decui@microsoft.com>
Reviewed-by: default avatarDexuan Cui <decui@microsoft.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 966d23a0

drivers/acpi/nfit/core.c

+24 −17
Original line number Diff line number Diff line
@@ -1738,14 +1738,14 @@ 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,

	};
@@ -1760,8 +1760,15 @@ __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)
@@ -1772,7 +1779,6 @@ __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)
@@ -1887,8 +1893,8 @@ 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;



		/* 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));
@@ -1900,6 +1906,7 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc, 
			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);