Merge tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from David Vrabel:
 "Features and fixes for 4.8-rc0:

   - ACPI support for guests on ARM platforms.
   - Generic steal time support for arm and x86.
   - Support cases where kernel cpu is not Xen VCPU number (e.g., if
     in-guest kexec is used).
   - Use the system workqueue instead of a custom workqueue in various
     places"

* tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (47 commits)
  xen: add static initialization of steal_clock op to xen_time_ops
  xen/pvhvm: run xen_vcpu_setup() for the boot CPU
  xen/evtchn: use xen_vcpu_id mapping
  xen/events: fifo: use xen_vcpu_id mapping
  xen/events: use xen_vcpu_id mapping in events_base
  x86/xen: use xen_vcpu_id mapping when pointing vcpu_info to shared_info
  x86/xen: use xen_vcpu_id mapping for HYPERVISOR_vcpu_op
  xen: introduce xen_vcpu_id mapping
  x86/acpi: store ACPI ids from MADT for future usage
  x86/xen: update cpuid.h from Xen-4.7
  xen/evtchn: add IOCTL_EVTCHN_RESTRICT
  xen-blkback: really don't leak mode property
  xen-blkback: constify instance of "struct attribute_group"
  xen-blkfront: prefer xenbus_scanf() over xenbus_gather()
  xen-blkback: prefer xenbus_scanf() over xenbus_gather()
  xen: support runqueue steal time on xen
  arm/xen: add support for vm_assist hypercall
  xen: update xen headers
  xen-pciback: drop superfluous variables
  xen-pciback: short-circuit read path used for merging write values
  ...

1 files changed, 11 insertions, 9 deletions

diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 2994cfa44c8a..3cc6d1d86f1e 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -379,7 +379,7 @@ static struct attribute *xen_vbdstat_attrs[] = {
         NULL
 };
 
-static struct attribute_group xen_vbdstat_group = {
+static const struct attribute_group xen_vbdstat_group = {
         .name = "statistics",
         .attrs = xen_vbdstat_attrs,
 };
@@ -715,8 +715,11 @@ static void backend_changed(struct xenbus_watch *watch,
 
         /* Front end dir is a number, which is used as the handle. */
         err = kstrtoul(strrchr(dev->otherend, '/') + 1, 0, &handle);
-        if (err)
+        if (err) {
+                kfree(be->mode);
+                be->mode = NULL;
                 return;
+        }
 
         be->major = major;
         be->minor = minor;
@@ -1022,9 +1025,9 @@ static int connect_ring(struct backend_info *be)
         pr_debug("%s %s\n", __func__, dev->otherend);
 
         be->blkif->blk_protocol = BLKIF_PROTOCOL_DEFAULT;
-        err = xenbus_gather(XBT_NIL, dev->otherend, "protocol",
-                            "%63s", protocol, NULL);
-        if (err)
+        err = xenbus_scanf(XBT_NIL, dev->otherend, "protocol",
+                           "%63s", protocol);
+        if (err <= 0)
                 strcpy(protocol, "unspecified, assuming default");
         else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_NATIVE))
                 be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE;
@@ -1036,10 +1039,9 @@ static int connect_ring(struct backend_info *be)
                 xenbus_dev_fatal(dev, err, "unknown fe protocol %s", protocol);
                 return -ENOSYS;
         }
-        err = xenbus_gather(XBT_NIL, dev->otherend,
-                            "feature-persistent", "%u",
-                            &pers_grants, NULL);
-        if (err)
+        err = xenbus_scanf(XBT_NIL, dev->otherend,
+                           "feature-persistent", "%u", &pers_grants);
+        if (err <= 0)
                 pers_grants = 0;
 
         be->blkif->vbd.feature_gnt_persistent = pers_grants;