[XEN PATCH][for-4.19 v2] xen: Add SAF deviations for MISRA C:2012 Rule 7.1

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

As specified in rules.rst, these constants can be used
in the code. Suitable deviations records are added in deviations.rst

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
---
Changes in v2:
- replace some SAF deviations with configurations
---
 automation/eclair_analysis/ECLAIR/deviations.ecl | 8 ++++----
 docs/misra/deviations.rst                        | 6 ++++++
 docs/misra/safe.json                             | 8 ++++++++
 xen/common/inflate.c                             | 4 ++--
 4 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
index fa56e5c00a27..3bf8e8b8fdec 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -85,10 +85,10 @@ conform to the directive."
 # Series 7.
 #

--doc_begin="Usage of the following constants is safe, since they are given as-is
-in the inflate algorithm specification and there is therefore no risk of them
-being interpreted as decimal constants."
--config=MC3R1.R7.1,literals={safe, "^0(007|37|070|213|236|300|321|330|331|332|333|334|335|337|371)$"}
+-doc_begin="Octal constants used as arguments to macro INSTR_ENC or MASK_EXTR
+can be used, because they appear as is in specifications, manuals, and
+algorithm descriptions."
+-config=MC3R1.R7.1,reports+={safe, "any_area(any_loc(any_exp(macro(^(INSTR_ENC|MASK_EXTR)$))))"}
 -doc_end

 -doc_begin="Violations in files that maintainers have asked to not modify in the
diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
index 8511a189253b..f26eb371f3e4 100644
--- a/docs/misra/deviations.rst
+++ b/docs/misra/deviations.rst
@@ -90,6 +90,12 @@ Deviations related to MISRA C:2012 Rules:
          - __emulate_2op and __emulate_2op_nobyte
          - read_debugreg and write_debugreg

+   * - R7.1
+     - It is safe to use certain octal constants the way they are defined in
+       specifications, manuals, and algorithm descriptions as arguments to
+       macros 'INSTR_ENC' and 'MASK_EXTR'.
+     - Tagged as `safe` for ECLAIR.
+
    * - R7.2
      - Violations caused by __HYPERVISOR_VIRT_START are related to the
        particular use of it done in xen_mk_ulong.
diff --git a/docs/misra/safe.json b/docs/misra/safe.json
index 39c5c056c7d4..7ea47344ffcc 100644
--- a/docs/misra/safe.json
+++ b/docs/misra/safe.json
@@ -20,6 +20,14 @@
         },
         {
             "id": "SAF-2-safe",
+            "analyser": {
+                "eclair": "MC3R1.R7.1"
+            },
+            "name": "Rule 7.1: constants defined in specifications, manuals, and algorithm descriptions",
+            "text": "It is safe to use certain octal constants the way they are defined in specifications, manuals, and algorithm descriptions."
+        },
+        {
+            "id": "SAF-3-safe",
             "analyser": {},
             "name": "Sentinel",
             "text": "Next ID to be used"
diff --git a/xen/common/inflate.c b/xen/common/inflate.c
index 8fa4b96d12a3..be6a9115187e 100644
--- a/xen/common/inflate.c
+++ b/xen/common/inflate.c
@@ -1201,8 +1201,8 @@ static int __init gunzip(void)
     magic[1] = NEXTBYTE();
     method   = NEXTBYTE();

-    if (magic[0] != 037 ||
-        ((magic[1] != 0213) && (magic[1] != 0236))) {
+    /* SAF-2-safe */
+    if (magic[0] != 037 || ((magic[1] != 0213) && (magic[1] != 0236))) {
         error("bad gzip magic numbers");
         return -1;
     }
--
2.34.1