Merge 4.4.258 into android-4.4-p

Changes in 4.4.258
	tracing: Do not count ftrace events in top level enable output
	fgraph: Initialize tracing_graph_pause at task creation
	af_key: relax availability checks for skb size calculation
	iwlwifi: pcie: add a NULL check in iwl_pcie_txq_unmap
	iwlwifi: mvm: guard against device removal in reprobe
	SUNRPC: Move simple_get_bytes and simple_get_netobj into private header
	SUNRPC: Handle 0 length opaque XDR object data properly
	lib/string: Add strscpy_pad() function
	include/trace/events/writeback.h: fix -Wstringop-truncation warnings
	memcg: fix a crash in wb_workfn when a device disappears
	squashfs: add more sanity checks in id lookup
	squashfs: add more sanity checks in inode lookup
	squashfs: add more sanity checks in xattr id lookup
	memblock: do not start bottom-up allocations with kernel_end
	netfilter: xt_recent: Fix attempt to update deleted entry
	h8300: fix PREEMPTION build, TI_PRE_COUNT undefined
	usb: dwc3: ulpi: fix checkpatch warning
	usb: dwc3: ulpi: Replace CPU-based busyloop with Protocol-based one
	net: watchdog: hold device global xmit lock during tx disable
	vsock: fix locking in vsock_shutdown()
	x86/build: Disable CET instrumentation in the kernel for 32-bit too
	trace: Use -mcount-record for dynamic ftrace
	tracing: Fix SKIP_STACK_VALIDATION=1 build due to bad merge with -mrecord-mcount
	tracing: Avoid calling cc-option -mrecord-mcount for every Makefile
	Xen/x86: don't bail early from clear_foreign_p2m_mapping()
	Xen/x86: also check kernel mapping in set_foreign_p2m_mapping()
	Xen/gntdev: correct dev_bus_addr handling in gntdev_map_grant_pages()
	Xen/gntdev: correct error checking in gntdev_map_grant_pages()
	xen/arm: don't ignore return errors from set_phys_to_machine
	xen-blkback: don't "handle" error by BUG()
	xen-netback: don't "handle" error by BUG()
	xen-scsiback: don't "handle" error by BUG()
	xen-blkback: fix error handling in xen_blkbk_map()
	scsi: qla2xxx: Fix crash during driver load on big endian machines
	kvm: check tlbs_dirty directly
	Linux 4.4.258

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ie1125773ccbc457f93c639c420dedf2c38a5e65a

1 files changed, 22 insertions, 11 deletions

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 1865bcfa869b..6f077ae0cf31 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -293,36 +293,47 @@ static int map_grant_pages(struct grant_map *map)
 		 * to the kernel linear addresses of the struct pages.
 		 * These ptes are completely different from the user ptes dealt
 		 * with find_grant_ptes.
+		 * Note that GNTMAP_device_map isn't needed here: The
+		 * dev_bus_addr output field gets consumed only from ->map_ops,
+		 * and by not requesting it when mapping we also avoid needing
+		 * to mirror dev_bus_addr into ->unmap_ops (and holding an extra
+		 * reference to the page in the hypervisor).
 		 */
+		unsigned int flags = (map->flags & ~GNTMAP_device_map) |
+				     GNTMAP_host_map;
+
 		for (i = 0; i < map->count; i++) {
 			unsigned long address = (unsigned long)
 				pfn_to_kaddr(page_to_pfn(map->pages[i]));
 			BUG_ON(PageHighMem(map->pages[i]));
 
-			gnttab_set_map_op(&map->kmap_ops[i], address,
-				map->flags | GNTMAP_host_map,
+			gnttab_set_map_op(&map->kmap_ops[i], address, flags,
 				map->grants[i].ref,
 				map->grants[i].domid);
 			gnttab_set_unmap_op(&map->kunmap_ops[i], address,
-				map->flags | GNTMAP_host_map, -1);
+				flags, -1);
 		}
 	}
 
 	pr_debug("map %d+%d\n", map->index, map->count);
 	err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL,
 			map->pages, map->count);
-	if (err)
-		return err;
 
 	for (i = 0; i < map->count; i++) {
-		if (map->map_ops[i].status) {
+		if (map->map_ops[i].status == GNTST_okay)
+			map->unmap_ops[i].handle = map->map_ops[i].handle;
+		else if (!err)
 			err = -EINVAL;
-			continue;
-		}
 
-		map->unmap_ops[i].handle = map->map_ops[i].handle;
-		if (use_ptemod)
-			map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
+		if (map->flags & GNTMAP_device_map)
+			map->unmap_ops[i].dev_bus_addr = map->map_ops[i].dev_bus_addr;
+
+		if (use_ptemod) {
+			if (map->kmap_ops[i].status == GNTST_okay)
+				map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
+			else if (!err)
+				err = -EINVAL;
+		}
 	}
 	return err;
 }