From 622dc83554563b3d6c74ee7936dbc08bfa6bfa1a Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Thu, 8 Mar 2018 15:58:18 +0100
Subject: [PATCH 05/17] address_space_map: address_space_to_flatview needs RCU
 lock

RH-Author: Paolo Bonzini <pbonzini@redhat.com>
Message-id: <20180308155819.20598-6-pbonzini@redhat.com>
Patchwork-id: 79196
O-Subject: [RHEL7.5 qemu-kvm-rhev PATCH 5/6] address_space_map: address_space_to_flatview needs RCU lock
Bugzilla: 1554930
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Laurent Vivier <lvivier@redhat.com>

address_space_map is calling address_space_to_flatview but it can
be called outside the RCU lock.  The function itself is calling
rcu_read_lock/rcu_read_unlock, just in the wrong place, so the
fix is easy.

Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry pick from commit ad0c60fa572d4050255b698ecdb67294dd4c0125)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 exec.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/exec.c b/exec.c
index 431b85b..58ad24b 100644
--- a/exec.c
+++ b/exec.c
@@ -3331,7 +3331,7 @@ void *address_space_map(AddressSpace *as,
     hwaddr l, xlat;
     MemoryRegion *mr;
     void *ptr;
-    FlatView *fv = address_space_to_flatview(as);
+    FlatView *fv;
 
     if (len == 0) {
         return NULL;
@@ -3339,6 +3339,7 @@ void *address_space_map(AddressSpace *as,
 
     l = len;
     rcu_read_lock();
+    fv = address_space_to_flatview(as);
     mr = flatview_translate(fv, addr, &xlat, &l, is_write);
 
     if (!memory_access_is_direct(mr, is_write)) {
-- 
1.8.3.1