From: Prasad J Pandit <pjp@fedoraproject.org>
Date: Mon, 25 Jan 2016 14:29:50 +0000 (+0530)
Subject: exec: fix a glitch in checking dma r/w access
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=9a5a7327425fb18a210728f397df4fbc577019c7;p=qemu-upstream-4.5-testing.git

exec: fix a glitch in checking dma r/w access

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>
---

diff --git a/exec.c b/exec.c
index cf120496f..e739bed77 100644
--- a/exec.c
+++ b/exec.c
@@ -342,7 +342,7 @@ 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;