[PATCH] misra: add deviation for MISRA C Rule R11.1.

[Alessandro Zucchelli <alessandro.zucchelli@xxxxxxxxxxx>]

Rule 11.1 states as following: "Conversions shall not be performed
between a pointer to a function and any other type".

In "xen/common/bug.c", in order to get additional debug information,
pointer "bug_fn_t *fn" in the data section is converted to a function
pointer, which is then used to get such information. This specific
conversion has been reviewed and found to have no undefined behaviour
associated to it, therefore it can be exempted from compliance.

Signed-off-by: Alessandro Zucchelli <alessandro.zucchelli@xxxxxxxxxxx>
---
As this patch introduces a deviation for service MC3A2.R11.1, it
depends on the following patch and shall not be applied prior to its
application.
https://lore.kernel.org/xen-devel/cf13be4779f15620e94b99b3b91f9cb040319989.1733826952.git.alessandro.zucchelli@xxxxxxxxxxx/T/#u
---
 docs/misra/safe.json | 8 ++++++++
 xen/common/bug.c     | 1 +
 2 files changed, 9 insertions(+)

diff --git a/docs/misra/safe.json b/docs/misra/safe.json
index 684346386e..d80fb3a48f 100644
--- a/docs/misra/safe.json
+++ b/docs/misra/safe.json
@@ -92,6 +92,14 @@
         },
         {
             "id": "SAF-11-safe",
+            "analyser": {
+                "eclair": "MC3A2.R11.1"
+            },
+            "name": "Rule 11.1: conversion for debugging purposes",
+            "text": "conversion of selected pointers to function pointers for 
debugging purposes are safe."
+        },
+        {
+            "id": "SAF-12-safe",
             "analyser": {},
             "name": "Sentinel",
             "text": "Next ID to be used"
diff --git a/xen/common/bug.c b/xen/common/bug.c
index 75cb35fcfa..2d08bb3d41 100644
--- a/xen/common/bug.c
+++ b/xen/common/bug.c
@@ -44,6 +44,7 @@ int do_bug_frame(const struct cpu_user_regs *regs, unsigned 
long pc)
 
     if ( id == BUGFRAME_run_fn )
     {
+        /* SAF-11-safe conversion for debugging purposes */
         bug_fn_t *fn = bug_ptr(bug);
 
         fn(regs);
-- 
2.43.0