[PATCH 08/14] Arm/guestcopy: deviate copy_guest() uses just like their x86 counterparts

[Jan Beulich <jbeulich@xxxxxxxx>]

Like x86/HVM's __hvm_copy(), Arm's copy_guest() is used for both to-guest
and from-guest copying. Naturally in the latter case the hypervisor buffer
needs writing to, hence the function parameter cannot be pointer-to-const.

No functional change intended.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
Of course for both the pre-existing x86 deviation and the new Arm one it
might be more robust if the deviation was also limited to the respective
source file. Can this be expressed together with the needed regex?

--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -433,6 +433,12 @@ Fixing this violation would require to i
 
-config=MC3A2.R11.8,reports+={safe,"any_area(any_loc(any_exp(macro(^container_of$))))"}
 -doc_end
 
+-doc_begin="Function copy_guest() in xen/arch/arm/guestcopy.c is a double-use
+function, where the parameter needs to not be const because it can be set for
+write or not"
+-config=MC3A2.R11.8,reports+={safe,"any_area(any_loc(text(^.*copy_guest.*COPY_to_guest
 doesn't modify.*$)))"}
+-doc_end
+
 -doc_begin="Function __hvm_copy in xen/arch/x86/hvm/hvm.c is a double-use
 function, where the parameter needs to not be const because it can be set for
 write or not"
--- a/xen/arch/arm/guestcopy.c
+++ b/xen/arch/arm/guestcopy.c
@@ -109,14 +109,16 @@ static unsigned long copy_guest(void *bu
 
 unsigned long raw_copy_to_guest(void *to, const void *from, unsigned int len)
 {
-    return copy_guest((void *)from, (vaddr_t)to, len,
-                      GVA_INFO(current), COPY_to_guest | COPY_linear);
+    return copy_guest((void *)from, /* COPY_to_guest doesn't modify */
+                      (vaddr_t)to, len, GVA_INFO(current),
+                      COPY_to_guest | COPY_linear);
 }
 
 unsigned long raw_copy_to_guest_flush_dcache(void *to, const void *from,
                                              unsigned int len)
 {
-    return copy_guest((void *)from, (vaddr_t)to, len, GVA_INFO(current),
+    return copy_guest((void *)from, /* COPY_to_guest doesn't modify */
+                      (vaddr_t)to, len, GVA_INFO(current),
                       COPY_to_guest | COPY_flush_dcache | COPY_linear);
 }