[PATCH v3 5/6] ACPI: Remove side effect of partly creating a node in acpi_get_node

[Jonathan Cameron]

acpi_get_node calls acpi_get_pxm to evaluate the _PXM AML method for
entries found in DSDT/SSDT. ACPI 6.3 sec 6.2.14 states
"_PXM evaluates to an integer that identifies a device as belonging to
 a Proximity Domain defined in the System Resource Affinity Table (SRAT)."

Hence a _PXM method should not result in creation of a new NUMA node.
Before this patch, _PXM could result in partial instantiation of
NUMA node, missing elements such as zone lists.  A call to devm_kzalloc
for example results in a null pointer dereference.

This patch therefore replaces the acpi_map_pxm_to_node with a call
to pxm_to_node.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron at huawei.com>
Reviewed-by: Hanjun Guo <guohanjun at huawei.com>
Reviewed-by: Barry Song <song.bao.hua at hisilicon.com>
---
 drivers/acpi/numa/srat.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
index 1fb486f46ee2..2c9a66c203ff 100644
--- a/drivers/acpi/numa/srat.c
+++ b/drivers/acpi/numa/srat.c
@@ -436,6 +436,6 @@ int acpi_get_node(acpi_handle handle)
 
 	pxm = acpi_get_pxm(handle);
 
-	return acpi_map_pxm_to_node(pxm);
+	return pxm_to_node(pxm);
 }
 EXPORT_SYMBOL(acpi_get_node);
-- 
2.19.1