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| author | Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> | 2019-04-30 10:52:29 -0500 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-05-01 10:06:08 +0200 |
| commit | 23583f7795025e3c783b680d906509366b0906ad (patch) | |
| tree | c1f165946de48089ee28a891263057eab620887b /drivers/acpi/property.c | |
| parent | 0fcc2bdc8aff6e7feb3222930edb78b4b820cd3e (diff) | |
| download | lwn-23583f7795025e3c783b680d906509366b0906ad.tar.gz lwn-23583f7795025e3c783b680d906509366b0906ad.zip | |
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.c | 8 |
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) |