commit 11e732a5ed46903f997985bed4c3767ca28a7eb6
author Paolo Bonzini <pbonzini@redhat.com> Mon Mar 05 00:23:26 2018 +0100
committer Paolo Bonzini <pbonzini@redhat.com> Tue Mar 06 14:01:28 2018 +0100
tree b2169eca05c7c611f7544c1d5008dcb8fa81609c
parent b2a44fcad74f1cc7a6786d38eba7db12ab2352ba

address_space_access_valid: address_space_to_flatview needs RCU lock

address_space_access_valid is calling address_space_to_flatview but it can
be called outside the RCU lock.  To fix it, push the rcu_read_lock/unlock
pair up from flatview_access_valid to address_space_access_valid.

Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

exec.c

diff --git a/exec.c b/exec.c
index e4552ee..62ed49d 100644
--- a/exec.c
+++ b/exec.c
@@ -3395,7 +3395,6 @@
     MemoryRegion *mr;
     hwaddr l, xlat;
 
-    rcu_read_lock();
     while (len > 0) {
         l = len;
         mr = flatview_translate(fv, addr, &xlat, &l, is_write);
@@ -3410,15 +3409,20 @@
         len -= l;
         addr += l;
     }
-    rcu_read_unlock();
     return true;
 }
 
 bool address_space_access_valid(AddressSpace *as, hwaddr addr,
                                 int len, bool is_write)
 {
-    return flatview_access_valid(address_space_to_flatview(as),
-                                 addr, len, is_write);
+    FlatView *fv;
+    bool result;
+
+    rcu_read_lock();
+    fv = address_space_to_flatview(as);
+    result = flatview_access_valid(fv, addr, len, is_write);
+    rcu_read_unlock();
+    return result;
 }
 
 static hwaddr