6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
commit 48796104c864cf4dafa80bd8c2ce88f9c92a65ea upstream.
Prior to commit 0467cdde8c43 ("s390/pci: Sort PCI functions prior to
creating virtual busses") the IOMMU was initialized and the device was
registered as part of zpci_create_device() with the struct zpci_dev
freed if either resulted in an error. With that commit this was moved
into a separate function called zpci_add_device().
While this new function logs when adding failed, it expects the caller
not to use and to free the struct zpci_dev on error. This difference
between it and zpci_create_device() was missed while changing the
callers and the incompletely initialized struct zpci_dev may get used in
zpci_scan_configured_device in the error path. This then leads to
a crash due to the device not being registered with the zbus. It was
also not freed in this case. Fix this by handling the error return of
zpci_add_device(). Since in this case the zdev was not added to the
zpci_list it can simply be discarded and freed. Also make this more
explicit by moving the kref_init() into zpci_add_device() and document
that zpci_zdev_get()/zpci_zdev_put() must be used after adding.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 0467cdde8c43 ("s390/pci: Sort PCI functions prior to creating virtual busses")
Reviewed-by: Gerd Bayer <gbayer@xxxxxxxxxxxxx>
Reviewed-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/pci/pci.c | 21 +++++++++++++++++----
arch/s390/pci/pci_event.c | 10 ++++++++--
2 files changed, 25 insertions(+), 6 deletions(-)
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -779,8 +779,9 @@ int zpci_hot_reset_device(struct zpci_de
* @fh: Current Function Handle of the device to be created
* @state: Initial state after creation either Standby or Configured
*
- * Creates a new zpci device and adds it to its, possibly newly created, zbus
- * as well as zpci_list.
+ * Allocates a new struct zpci_dev and queries the platform for its details.
+ * If successful the device can subsequently be added to the zPCI subsystem
+ * using zpci_add_device().
*
* Returns: the zdev on success or an error pointer otherwise
*/
@@ -803,7 +804,6 @@ struct zpci_dev *zpci_create_device(u32
goto error;
zdev->state = state;
- kref_init(&zdev->kref);
mutex_init(&zdev->state_lock);
mutex_init(&zdev->fmb_lock);
mutex_init(&zdev->kzdev_lock);
@@ -816,6 +816,17 @@ error:
return ERR_PTR(rc);
}
+/**
+ * zpci_add_device() - Add a previously created zPCI device to the zPCI subsystem
+ * @zdev: The zPCI device to be added
+ *
+ * A struct zpci_dev is added to the zPCI subsystem and to a virtual PCI bus creating
+ * a new one as necessary. A hotplug slot is created and events start to be handled.
+ * If successful from this point on zpci_zdev_get() and zpci_zdev_put() must be used.
+ * If adding the struct zpci_dev fails the device was not added and should be freed.
+ *
+ * Return: 0 on success, or an error code otherwise
+ */
int zpci_add_device(struct zpci_dev *zdev)
{
int rc;
@@ -829,6 +840,7 @@ int zpci_add_device(struct zpci_dev *zde
if (rc)
goto error_destroy_iommu;
+ kref_init(&zdev->kref);
spin_lock(&zpci_list_lock);
list_add_tail(&zdev->entry, &zpci_list);
spin_unlock(&zpci_list_lock);
@@ -1105,7 +1117,8 @@ static void zpci_add_devices(struct list
list_sort(NULL, scan_list, &zpci_cmp_rid);
list_for_each_entry_safe(zdev, tmp, scan_list, entry) {
list_del_init(&zdev->entry);
- zpci_add_device(zdev);
+ if (zpci_add_device(zdev))
+ kfree(zdev);
}
}
--- a/arch/s390/pci/pci_event.c
+++ b/arch/s390/pci/pci_event.c
@@ -340,7 +340,10 @@ static void __zpci_event_availability(st
zdev = zpci_create_device(ccdf->fid, ccdf->fh, ZPCI_FN_STATE_CONFIGURED);
if (IS_ERR(zdev))
break;
- zpci_add_device(zdev);
+ if (zpci_add_device(zdev)) {
+ kfree(zdev);
+ break;
+ }
} else {
/* the configuration request may be stale */
if (zdev->state != ZPCI_FN_STATE_STANDBY)
@@ -354,7 +357,10 @@ static void __zpci_event_availability(st
zdev = zpci_create_device(ccdf->fid, ccdf->fh, ZPCI_FN_STATE_STANDBY);
if (IS_ERR(zdev))
break;
- zpci_add_device(zdev);
+ if (zpci_add_device(zdev)) {
+ kfree(zdev);
+ break;
+ }
} else {
zpci_update_fh(zdev, ccdf->fh);
}
