[PATCH] misra: add deviation for MISRA C Rule 11.3

[Dmytro Prokopchuk1 <dmytro_prokopchuk1@xxxxxxxx>]

MISRA C Rule 11.3 states: "A cast shall not be performed between a pointer
to object type and a pointer to a different object type."

Violations of this rule arise due to the 'container_of' macro, which casts
a member of a structure to its containing structure:
    container_of(ptr, type, member) ({                             \
           typeof_field(type, member) *__mptr = (ptr);             \
           (type *)( (char *)__mptr - offsetof(type,member) );})

The 'container_of' macro is safe because it relies on the standardized and
well-defined 'offsetof' macro to calculate the memory address of the
containing structure, while assuming proper alignment and ensuring no
undefined behavior, provided that the input pointer is valid and points to
the specified member.

Configure Eclair to suppress violation reports related to 'container_of
macro. Update 'deviations.rst' file accordingly. Add Rule 11.3 to the
monitored list.
No functional changes.

Signed-off-by: Dmytro Prokopchuk <dmytro_prokopchuk1@xxxxxxxx>
---
Test CI pipeline:
https://gitlab.com/xen-project/people/dimaprkp4k/xen/-/pipelines/1992968166
---
 automation/eclair_analysis/ECLAIR/deviations.ecl | 8 ++++++++
 automation/eclair_analysis/ECLAIR/monitored.ecl  | 1 +
 docs/misra/deviations.rst                        | 8 ++++++++
 3 files changed, 17 insertions(+)

diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl 
b/automation/eclair_analysis/ECLAIR/deviations.ecl
index 7f3fd35a33..3e595e3a8c 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -403,6 +403,14 @@ because the semantics of the 'noreturn' attribute do not 
alter the calling conve
 }
 -doc_end
 
+-doc_begin="Convesions in the 'container_of' macro are safe because it relies 
on
+the standardized and well-defined 'offsetof' macro to calculate the memory 
address
+of the containing structure, while assuming proper alignment and ensuring no
+undefined behavior, provided that the input pointer is valid and points to the
+specified member."
+-config=MC3A2.R11.3,reports+={safe,"any_area(any_loc(any_exp(macro(^container_of$))))"}
+-doc_end
+
 -doc_begin="Conversions from and to integral types are safe, in the assumption 
that the target type has enough bits to store the value.
 See also Section \"4.7 Arrays and Pointers\" of \"GCC_MANUAL\""
 -config=MC3A2.R11.6,casts+={safe,
diff --git a/automation/eclair_analysis/ECLAIR/monitored.ecl 
b/automation/eclair_analysis/ECLAIR/monitored.ecl
index 72698b2eb1..abfc102d60 100644
--- a/automation/eclair_analysis/ECLAIR/monitored.ecl
+++ b/automation/eclair_analysis/ECLAIR/monitored.ecl
@@ -45,6 +45,7 @@
 -enable=MC3A2.R10.2
 -enable=MC3A2.R11.1
 -enable=MC3A2.R11.2
+-enable=MC3A2.R11.3
 -enable=MC3A2.R11.6
 -enable=MC3A2.R11.7
 -enable=MC3A2.R11.8
diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
index 2119066531..33b045a5a9 100644
--- a/docs/misra/deviations.rst
+++ b/docs/misra/deviations.rst
@@ -393,6 +393,14 @@ Deviations related to MISRA C:2012 Rules:
        (i.e., less strict) alignment requirement are safe.
      - Tagged as `safe` for ECLAIR.
 
+   * - R11.3
+     - Convesions in the 'container_of' macro are safe because it relies on
+       the standardized and well-defined 'offsetof' macro to calculate the 
memory
+       address of the containing structure, while assuming proper alignment and
+       ensuring no undefined behavior, provided that the input pointer is valid
+       and points to the specified member.
+     - Tagged as `safe` for ECLAIR.
+
    * - R11.6
      - Conversions from and to integral types are safe, in the assumption that
        the target type has enough bits to store the value.
-- 
2.43.0