[PATCH v2] 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.
No functional changes.

Signed-off-by: Dmytro Prokopchuk <dmytro_prokopchuk1@xxxxxxxx>
---
Changes in v2:
- removed '-enable=MC3A2.R11.3' from the monitored.ecl file
- fixed typo: "Convesions" -> "Conversions"
- added parentheses for macros container_of() and offsetof()

Link to v1:
https://patchew.org/Xen/d6a8682c98880d66ea99f882520b3defda0e3fe0.1755672275.git.dmytro._5Fprokopchuk1@xxxxxxxx/
---
 automation/eclair_analysis/ECLAIR/deviations.ecl | 8 ++++++++
 docs/misra/deviations.rst                        | 8 ++++++++
 2 files changed, 16 insertions(+)

diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl 
b/automation/eclair_analysis/ECLAIR/deviations.ecl
index 7f3fd35a33..42b84429f0 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="Conversions 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/docs/misra/deviations.rst b/docs/misra/deviations.rst
index 2119066531..db9e09c3cb 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
+     - Conversions 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