From 5ab894aee0f171a682bcd90dd5d1930cb53c55dc Mon Sep 17 00:00:00 2001 From: Jarkko Nikula Date: Mon, 9 Oct 2017 16:28:37 +0300 Subject: [PATCH] device property: Track owner device of device property Deletion of subdevice will remove device properties associated to parent when they share the same firmware node after commit 478573c93abd (driver core: Don't leak secondary fwnode on device removal). This was observed with a driver adding subdevice that driver wasn't able to read device properties after rmmod/modprobe cycle. Consider the lifecycle of it: parent device registration ACPI_COMPANION_SET() device_add_properties() pset_copy_set() set_secondary_fwnode(dev, &p->fwnode) device_add() parent probe read device properties ACPI_COMPANION_SET(subdevice, ACPI_COMPANION(parent)) device_add(subdevice) parent remove device_del(subdevice) device_remove_properties() set_secondary_fwnode(dev, NULL); pset_free() Parent device will have its primary firmware node pointing to an ACPI node and secondary firmware node point to device properties. ACPI_COMPANION_SET() call in parent probe will set the subdevice's firmware node to point to the same 'struct fwnode_handle' and the associated secondary firmware node, i.e. the device properties as the parent. When subdevice is deleted in parent remove that will remove those device properties and attempt to read device properties in next parent probe call will fail. Fix this by tracking the owner device of device properties and delete them only when owner device is being deleted. Fixes: 478573c93abd (driver core: Don't leak secondary fwnode on device removal) Cc: 4.9+ # 4.9+ Signed-off-by: Jarkko Nikula Signed-off-by: Rafael J. Wysocki --- drivers/base/property.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/base/property.c b/drivers/base/property.c index d0b65bbe7e15..21fcc13013a5 100644 --- a/drivers/base/property.c +++ b/drivers/base/property.c @@ -21,6 +21,7 @@ #include struct property_set { + struct device *dev; struct fwnode_handle fwnode; const struct property_entry *properties; }; @@ -891,6 +892,7 @@ static struct property_set *pset_copy_set(const struct property_set *pset) void device_remove_properties(struct device *dev) { struct fwnode_handle *fwnode; + struct property_set *pset; fwnode = dev_fwnode(dev); if (!fwnode) @@ -900,16 +902,16 @@ void device_remove_properties(struct device *dev) * the pset. If there is no real firmware node (ACPI/DT) primary * will hold the pset. */ - if (is_pset_node(fwnode)) { + pset = to_pset_node(fwnode); + if (pset) { set_primary_fwnode(dev, NULL); - pset_free_set(to_pset_node(fwnode)); } else { - fwnode = fwnode->secondary; - if (!IS_ERR(fwnode) && is_pset_node(fwnode)) { + pset = to_pset_node(fwnode->secondary); + if (pset && dev == pset->dev) set_secondary_fwnode(dev, NULL); - pset_free_set(to_pset_node(fwnode)); - } } + if (pset && dev == pset->dev) + pset_free_set(pset); } EXPORT_SYMBOL_GPL(device_remove_properties); @@ -938,6 +940,7 @@ int device_add_properties(struct device *dev, p->fwnode.ops = &pset_fwnode_ops; set_secondary_fwnode(dev, &p->fwnode); + p->dev = dev; return 0; } EXPORT_SYMBOL_GPL(device_add_properties); -- 2.20.1