[Qemu-devel] [PATCH for v2.4.1] exec: fix a glitch in checking dma r/w access

[P J P <ppandit@redhat.com>]

From: Prasad J Pandit <pjp@fedoraproject.org>

While checking r/w access in 'memory_access_is_direct' routine
a glitch in the expression leads to segmentation fault while
performing dma read operation.

Reported-by: Donghai Zdh <donghai.zdh@alibaba-inc.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
 exec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exec.c b/exec.c
index 0a4a0c5..98d97d3 100644
--- a/exec.c
+++ b/exec.c
@@ -375,7 +375,7 @@ address_space_translate_internal(AddressSpaceDispatch *d, hwaddr addr, hwaddr *x
 static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write)
 {
     if (memory_region_is_ram(mr)) {
-        return !(is_write && mr->readonly);
+        return (is_write && !mr->readonly);
     }
     if (memory_region_is_romd(mr)) {
         return !is_write;
-- 
2.5.0