[XEN PATCH v2 3/7] xen/arm: address MISRA C:2012 Rule 2.1

[Nicola Vetrini <nicola.vetrini@bugseng.com>]

There are no paths that can reach the last return statement
of function 'vgic_v3_its_mmio_write' in 'vcig-v3-its.c' and
'arch_memory_op' in 'arch/arm/mm.c', thus violating
MISRA C:2012 Rule 2.1:
"A project shall not contain unreachable code".

Therefore, an ASSERT_UNREACHABLE() is inserted to remove the unreachable
return statement and protect against possible mistakes.

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
---
Changes in v2:
- Changed resolution strategy to have an ASSERT_UNREACHABLE() before
  the return.
---
 xen/arch/arm/mm.c          | 1 +
 xen/arch/arm/vgic-v3-its.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index eeb65ca6bb79..b15a18a49412 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -283,6 +283,7 @@ long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
         return -ENOSYS;
     }
 
+    ASSERT_UNREACHABLE();
     return 0;
 }
 
diff --git a/xen/arch/arm/vgic-v3-its.c b/xen/arch/arm/vgic-v3-its.c
index 05429030b539..70b5aeb82219 100644
--- a/xen/arch/arm/vgic-v3-its.c
+++ b/xen/arch/arm/vgic-v3-its.c
@@ -1409,6 +1409,7 @@ static int vgic_v3_its_mmio_write(struct vcpu *v, mmio_info_t *info,
         return 0;
     }
 
+    ASSERT_UNREACHABLE();
     return 1;
 
 write_ignore_64:
-- 
2.34.1