[PATCH 9/9] xen: add SAF deviation for safe cast removal.

[Simone Ballarin <simone.ballarin@xxxxxxxxxxx>]

From: Maria Celeste Cesario <maria.celeste.cesario@xxxxxxxxxxx>

The xen sources contain violations of MISRA C:2012 Rule 11.8 whose
headline states:
"A conversion shall not remove any const, volatile or _Atomic qualification
from the type pointed to by a pointer".

In function __hvm_copy, the const qualifier is cast away to comply with its
function signature. There's no modification of the pointee during its
execution, therefore its use can be deemed as safe.

Signed-off-by: Maria Celeste Cesario  <maria.celeste.cesario@xxxxxxxxxxx>
Signed-off-by: Simone Ballarin  <simone.ballarin@xxxxxxxxxxx>
---
 docs/misra/safe.json   | 8 ++++++++
 xen/arch/x86/hvm/hvm.c | 1 +
 2 files changed, 9 insertions(+)

diff --git a/docs/misra/safe.json b/docs/misra/safe.json
index 952324f85c..e748bc6cf5 100644
--- a/docs/misra/safe.json
+++ b/docs/misra/safe.json
@@ -28,6 +28,14 @@
         },
         {
             "id": "SAF-3-safe",
+            "analyser": {
+                "eclair": "MC3R1.R11.8"
+            },
+            "name": "MC3R1.R11.8: removal of const qualifier to comply with 
function signature",
+            "text": "It is safe to cast away const qualifiers to comply with 
function signature if the function does not modify the pointee."
+        },
+        {
+            "id": "SAF-4-safe",
             "analyser": {},
             "name": "Sentinel",
             "text": "Next ID to be used"
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 523e0df57c..414853254f 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3413,6 +3413,7 @@ static enum hvm_translation_result __hvm_copy(
 enum hvm_translation_result hvm_copy_to_guest_phys(
     paddr_t paddr, const void *buf, unsigned int size, struct vcpu *v)
 {
+    /* SAF-3-safe */
     return __hvm_copy((void *)buf /* HVMCOPY_to_guest doesn't modify */,
                       paddr, size, v,
                       HVMCOPY_to_guest | HVMCOPY_phys, 0, NULL);
-- 
2.40.0