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Subject[PATCH] nfit: Fix nfit_intel_shutdown_status() command submission
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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);
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