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authorPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>2019-04-30 10:52:29 -0500
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-05-01 10:06:08 +0200
commit23583f7795025e3c783b680d906509366b0906ad (patch)
treec1f165946de48089ee28a891263057eab620887b /drivers/acpi/property.c
parent0fcc2bdc8aff6e7feb3222930edb78b4b820cd3e (diff)
ACPI / property: fix handling of data_nodes in acpi_get_next_subnode()
When the DSDT tables expose devices with subdevices and a set of hierarchical _DSD properties, the data returned by acpi_get_next_subnode() is incorrect, with the results suggesting a bad pointer assignment. The parser works fine with device_nodes or data_nodes, but not with a combination of the two. The problem is traced to an invalid pointer used when jumping from handling device_nodes to data nodes. The existing code looks for data nodes below the last subdevice found instead of the common root. Fix by forcing the acpi_device pointer to be derived from the same fwnode for the two types of subnodes. This same problem of handling device and data nodes was already fixed in a similar way by 'commit bf4703fdd166 ("ACPI / property: fix data node parsing in acpi_get_next_subnode()")' but broken later by 'commit 34055190b19 ("ACPI / property: Add fwnode_get_next_child_node()")', so this should probably go to linux-stable all the way to 4.12 Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/property.c')
-rw-r--r--drivers/acpi/property.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 8832d0e13a72..9d460a859be0 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -1032,6 +1032,14 @@ struct fwnode_handle *acpi_get_next_subnode(const struct fwnode_handle *fwnode,
const struct acpi_data_node *data = to_acpi_data_node(fwnode);
struct acpi_data_node *dn;
+ /*
+ * We can have a combination of device and data nodes, e.g. with
+ * hierarchical _DSD properties. Make sure the adev pointer is
+ * restored before going through data nodes, otherwise we will
+ * be looking for data_nodes below the last device found instead
+ * of the common fwnode shared by device_nodes and data_nodes.
+ */
+ adev = to_acpi_device_node(fwnode);
if (adev)
head = &adev->data.subnodes;
else if (data)