[Xen-devel] [PATCH v2] xen/arm: Fix the issue in cmp_mmio_handler used in find_mmio_handler

[Bhupinder Thakur <bhupinder.thakur@xxxxxxxxxx>]

This function returns true/false based on whether the key value
is in the range (start, start+size). However, it should check against
(start, start+size-1) because start+size falls outside the range.

This resulted in returning a wrong mmio_handler for a given mmio address which
happened to be start+size.

This bug was introduced when the mmio region search was switched from
linear search to binary search in the following commit:

8047e09 "xen/arm: io: Use binary search for mmio handler lookup".

This change may have to be back-ported to 4.8 also.

Signed-off-by: Bhupinder Thakur <bhupinder.thakur@xxxxxxxxxx>
---
CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
CC: Julien Grall <julien.grall@xxxxxxx>

 xen/arch/arm/io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/arm/io.c b/xen/arch/arm/io.c
index e216128..c748d8f 100644
--- a/xen/arch/arm/io.c
+++ b/xen/arch/arm/io.c
@@ -79,7 +79,7 @@ static int cmp_mmio_handler(const void *key, const void *elem)
     if ( handler0->addr < handler1->addr )
         return -1;
 
-    if ( handler0->addr > (handler1->addr + handler1->size) )
+    if ( handler0->addr >= (handler1->addr + handler1->size) )
         return 1;
 
     return 0;
-- 
2.7.4


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel