Messages in this thread | | | Date | Tue, 30 Apr 2019 19:30:41 +0300 | From | Andy Shevchenko <> | Subject | Re: [PATCH] ACPI / property: fix handling of data_nodes in acpi_get_next_subnode() |
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On Tue, Apr 30, 2019 at 10:52:29AM -0500, Pierre-Louis Bossart wrote: > 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
Period is missed in above sentence.
I think it make sense to add Fixes: tag.
Nevertheless, Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Thank you for fixing this interesting issue!
> > Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> > --- > drivers/acpi/property.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c > index 5815356ea6ad..efc74f912f39 100644 > --- a/drivers/acpi/property.c > +++ b/drivers/acpi/property.c > @@ -943,6 +943,16 @@ 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) > -- > 2.17.1 >
-- With Best Regards, Andy Shevchenko
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