[Qemu-devel] [PATCH 5/7] address_space_access_valid: address_space_to_flatview needs RCU lock

[Paolo Bonzini <pbonzini@redhat.com>]

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.

Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 exec.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/exec.c b/exec.c
index 55b7452bd7..177583c2ee 100644
--- a/exec.c
+++ b/exec.c
@@ -3391,7 +3391,6 @@ static bool flatview_access_valid(FlatView *fv, hwaddr addr, int len,
     MemoryRegion *mr;
     hwaddr l, xlat;
 
-    rcu_read_lock();
     while (len > 0) {
         l = len;
         mr = flatview_translate(fv, addr, &xlat, &l, is_write);
@@ -3406,15 +3405,20 @@ static bool flatview_access_valid(FlatView *fv, hwaddr addr, int len,
         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
-- 
2.14.3