grant: Release domain lock on 'map' path in cache_flush

common/grant_table.c:cache_flush() grabs the rcu lock for the current
domain, but only releases it on error paths.

Note that this is not a security issue, as the preempt count is used
exclusively for assertions at the moment.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
index 48c547930cc77cfbb5f281a755d27c41f34f164c..8346994de623015383a44c52017ab5903a8daf47 100644 (file)
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -3273,6 +3273,7 @@ static int cache_flush(const gnttab_cache_flush_t *cflush, grant_ref_t *cur_ref)
 
     unmap_domain_page(v);
     put_page(page);
+    rcu_unlock_domain(d);
 
     return ret;
 }