[XEN PATCH for 4.19] automation/eclair: add deviations agreed in MISRA meetings

[Federico Serafini <federico.serafini@xxxxxxxxxxx>]

Update ECLAIR configuration to take into account the deviations
agreed during the MISRA meetings.

While doing this, remove the obsolete "Set [123]" comments.

Signed-off-by: Federico Serafini <federico.serafini@xxxxxxxxxxx>
---
 .../eclair_analysis/ECLAIR/deviations.ecl     | 93 +++++++++++++++++--
 docs/misra/deviations.rst                     | 68 +++++++++++++-
 2 files changed, 149 insertions(+), 12 deletions(-)

diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl 
b/automation/eclair_analysis/ECLAIR/deviations.ecl
index ae2eaf50f7..e6517a9142 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -1,5 +1,3 @@
-### Set 1 ###
-
 #
 # Series 2.
 #
@@ -23,6 +21,11 @@ Constant expressions and unreachable branches of if and 
switch statements are ex
 -config=MC3R1.R2.1,reports+={deliberate, 
"any_area(any_loc(any_exp(macro(name(ASSERT_UNREACHABLE||PARSE_ERR_RET||PARSE_ERR||FAIL_MSR||FAIL_CPUID)))))"}
 -doc_end
 
+-doc_begin="The asm-offset files are not linked deliberately, since they are 
used to generate definitions for asm modules."
+-file_tag+={asm_offsets, 
"^xen/arch/(arm|x86)/(arm32|arm64|x86_64)/asm-offsets\\.c$"}
+-config=MC3R1.R2.1,reports+={deliberate, 
"any_area(any_loc(file(asm_offsets)))"}
+-doc_end
+
 -doc_begin="Pure declarations (i.e., declarations without initialization) are
 not executable, and therefore it is safe for them to be unreachable."
 -config=MC3R1.R2.1,ignored_stmts+={"any()", "pure_decl()"}
@@ -63,6 +66,12 @@ they are not instances of commented-out code."
 
-config=MC3R1.D4.3,reports+={disapplied,"!(any_area(any_loc(file(^xen/arch/arm/arm64/.*$))))"}
 -doc_end
 
+-doc_begin="The inline asm in 'arm64/lib/bitops.c' is tightly coupled with the 
surronding C code that acts as a wrapper, so it has been decided not to add an 
additional encapsulation layer."
+-file_tag+={arm64_bitops, "^xen/arch/arm/arm64/lib/bitops\\.c$"}
+-config=MC3R1.D4.3,reports+={deliberate, 
"all_area(any_loc(file(arm64_bitops)&&any_exp(macro(^(bit|test)op$))))"}
+-config=MC3R1.D4.3,reports+={deliberate, 
"any_area(any_loc(file(arm64_bitops))&&context(name(int_clear_mask16)))"}
+-doc_end
+
 -doc_begin="This header file is autogenerated or empty, therefore it poses no
 risk if included more than once."
 -file_tag+={empty_header, "^xen/arch/arm/efi/runtime\\.h$"}
@@ -213,10 +222,25 @@ Therefore the absence of prior declarations is safe."
 -config=MC3R1.R8.4,declarations+={safe, 
"loc(file(asm_defns))&&^current_stack_pointer$"}
 -doc_end
 
+-doc_begin="The function apei_(read|check|clear)_mce are dead code and are 
excluded from non-debug builds, therefore the absence of prior declarations is 
safe."
+-config=MC3R1.R8.4,declarations+={safe, "^apei_(read|check|clear)_mce\\(.*$"}
+-doc_end
+
 -doc_begin="asmlinkage is a marker to indicate that the function is only used 
to interface with asm modules."
 -config=MC3R1.R8.4,declarations+={safe,"loc(text(^(?s).*asmlinkage.*$, 
-1..0))"}
 -doc_end
 
+-doc_begin="Given that bsearch and sort are defined with the attribute 
'gnu_inline', it's deliberate not to have a prior declaration.
+See Section \"6.33.1 Common Function Attributes\" of \"GCC_MANUAL\" for a full 
explanation of gnu_inline."
+-file_tag+={bsearch_sort, "^xen/include/xen/(sort|lib)\\.h$"}
+-config=MC3R1.R8.4,reports+={deliberate, 
"any_area(any_loc(file(bsearch_sort))&&decl(name(bsearch||sort)))"}
+-doc_end
+
+-doc_begin="first_valid_mfn is defined in this way because the current lack of 
NUMA support in Arm and PPC requires it."
+-file_tag+={first_valid_mfn, "^xen/common/page_alloc\\.c$"}
+-config=MC3R1.R8.4,declarations+={deliberate,"loc(file(first_valid_mfn))"}
+-doc_end
+
 -doc_begin="The following variables are compiled in multiple translation units
 belonging to different executables and therefore are safe."
 -config=MC3R1.R8.6,declarations+={safe, 
"name(current_stack_pointer||bsearch||sort)"}
@@ -257,8 +281,6 @@ dimension is higher than omitting the dimension."
 -config=MC3R1.R9.5,reports+={deliberate, "any()"}
 -doc_end
 
-### Set 2 ###
-
 #
 # Series 10.
 #
@@ -299,7 +321,6 @@ integers arguments on two's complement architectures
 -config=MC3R1.R10.1,reports+={safe, 
"any_area(any_loc(any_exp(macro(^ISOLATE_LSB$))))"}
 -doc_end
 
-### Set 3 ###
 -doc_begin="XEN only supports architectures where signed integers are
 representend using two's complement and all the XEN developers are aware of
 this."
@@ -323,6 +344,49 @@ constant expressions are required.\""
 # Series 11
 #
 
+-doc_begin="The conversion from a function pointer to unsigned long or (void 
*) does not lose any information, provided that the target type has enough bits 
to store it."
+-config=MC3R1.R11.1,casts+={safe,
+  "from(type(canonical(__function_pointer_types)))
+   &&to(type(canonical(builtin(unsigned long)||pointer(builtin(void)))))
+   &&relation(definitely_preserves_value)"
+}
+-doc_end
+
+-doc_begin="The conversion from a function pointer to a boolean has a 
well-known semantics that do not lead to unexpected behaviour."
+-config=MC3R1.R11.1,casts+={safe,
+  "from(type(canonical(__function_pointer_types)))
+   &&kind(pointer_to_boolean)"
+}
+-doc_end
+
+-doc_begin="The conversion from a pointer to an incomplete type to unsigned 
long does not lose any information, provided that the target type has enough 
bits to store it."
+-config=MC3R1.R11.2,casts+={safe,
+  "from(type(any()))
+   &&to(type(canonical(builtin(unsigned long))))
+   &&relation(definitely_preserves_value)"
+}
+-doc_end
+
+-doc_begin="Conversions to object pointers that have a pointee type with a 
smaller (i.e., less strict) alignment requirement are safe."
+-config=MC3R1.R11.3,casts+={safe,
+  "!relation(more_aligned_pointee)"
+}
+-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=MC3R1.R11.6,casts+={safe,
+    "(from(type(canonical(integral())))||to(type(canonical(integral()))))
+     &&relation(definitely_preserves_value)"}
+-doc_end
+
+-doc_begin="The conversion from a pointer to a boolean has a well-known 
semantics that do not lead to unexpected behaviour."
+-config=MC3R1.R11.6,casts+={safe,
+  "from(type(canonical(__pointer_types)))
+   &&kind(pointer_to_boolean)"
+}
+-doc_end
+
 -doc_begin="Violations caused by container_of are due to pointer arithmetic 
operations
 with the provided offset. The resulting pointer is then immediately cast back 
to its
 original type, which preserves the qualifier. This use is deemed safe.
@@ -354,9 +418,18 @@ activity."
 -config=MC3R1.R14.2,reports+={disapplied,"any()"}
 -doc_end
 
--doc_begin="The XEN team relies on the fact that invariant conditions of 'if'
-statements are deliberate"
--config=MC3R1.R14.3,statements={deliberate , "wrapped(any(),node(if_stmt))" }
+-doc_begin="The XEN team relies on the fact that invariant conditions of 'if' 
statements and conditional operators are deliberate"
+-config=MC3R1.R14.3,statements+={deliberate , 
"wrapped(any(),node(if_stmt||conditional_operator||binary_conditional_operator))"
 }
+-doc_end
+
+-doc_begin="Switches having a 'sizeof' operator as the condition are 
deliberate and have limited scope."
+-config=MC3R1.R14.3,statements+={safe , 
"wrapped(any(),node(switch_stmt)&&child(cond, operator(sizeof)))" }
+-doc_end
+
+-doc_begin="The use of an invariant size argument in {put,get}_unsafe_size and 
array_access_ok, as defined in arch/x86(_64)?/include/asm/uaccess.h is 
deliberate and is deemed safe."
+-file_tag+={x86_uaccess, "^xen/arch/x86(_64)?/include/asm/uaccess\\.h$"}
+-config=MC3R1.R14.3,reports+={deliberate, 
"any_area(any_loc(file(x86_uaccess)&&any_exp(macro(^(put|get)_unsafe_size$))))"}
+-config=MC3R1.R14.3,reports+={deliberate, 
"any_area(any_loc(file(x86_uaccess)&&any_exp(macro(^array_access_ok$))))"}
 -doc_end
 
 -doc_begin="A controlling expression of 'if' and iteration statements having 
integer, character or pointer type has a semantics that is well-known to all 
Xen developers."
@@ -527,8 +600,8 @@ falls under the jurisdiction of other MISRA rules."
 # General
 #
 
--doc_begin="do-while-0 is a well recognized loop idiom by the xen community."
--loop_idioms={do_stmt, "literal(0)"}
+-doc_begin="do-while-[01] is a well recognized loop idiom by the xen 
community."
+-loop_idioms={do_stmt, "literal(0)||literal(1)"}
 -doc_end
 -doc_begin="while-[01] is a well recognized loop idiom by the xen community."
 -loop_idioms+={while_stmt, "literal(0)||literal(1)"}
diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
index 16fc345756..0b048dc225 100644
--- a/docs/misra/deviations.rst
+++ b/docs/misra/deviations.rst
@@ -63,6 +63,11 @@ Deviations related to MISRA C:2012 Rules:
        switch statement.
      - ECLAIR has been configured to ignore those statements.
 
+   * - R2.1
+     - The asm-offset files are not linked deliberately, since they are used to
+       generate definitions for asm modules.
+     - Tagged as `deliberate` for ECLAIR.
+
    * - R2.2
      - Proving compliance with respect to Rule 2.2 is generally impossible:
        see `<https://arxiv.org/abs/2212.13933>`_ for details. Moreover, peer
@@ -203,6 +208,26 @@ Deviations related to MISRA C:2012 Rules:
        it.
      - Tagged as `safe` for ECLAIR.
 
+   * - R8.4
+     - Some functions are excluded from non-debug build, therefore the absence
+       of declaration is safe.
+     - Tagged as `safe` for ECLAIR, such functions are:
+         - apei_read_mce()
+         - apei_check_mce()
+         - apei_clear_mce()
+
+   * - R8.4
+     - Given that bsearch and sort are defined with the attribute 'gnu_inline',
+       it's deliberate not to have a prior declaration.
+       See Section \"6.33.1 Common Function Attributes\" of \"GCC_MANUAL\" for
+       a full explanation of gnu_inline.
+     - Tagged as `deliberate` for ECLAIR.
+
+   * - R8.4
+     - first_valid_mfn is defined in this way because the current lack of NUMA
+       support in Arm and PPC requires it.
+     - Tagged as `deliberate` for ECLAIR.
+
    * - R8.6
      - The following variables are compiled in multiple translation units
        belonging to different executables and therefore are safe.
@@ -282,6 +307,39 @@ Deviations related to MISRA C:2012 Rules:
        If no bits are set, 0 is returned.
      - Tagged as `safe` for ECLAIR.
 
+   * - R11.1
+     - The conversion from a function pointer to unsigned long or (void \*) 
does
+       not lose any information, provided that the target type has enough bits
+       to store it.
+     - Tagged as `safe` for ECLAIR.
+
+   * - R11.1
+     - The conversion from a function pointer to a boolean has a well-known
+       semantics that do not lead to unexpected behaviour.
+     - Tagged as `safe` for ECLAIR.
+
+   * - R11.2
+     - The conversion from a pointer to an incomplete type to unsigned long
+       does not lose any information, provided that the target type has enough
+       bits to store it.
+     - Tagged as `safe` for ECLAIR.
+
+   * - R11.3
+     - Conversions to object pointers that have a pointee type with a smaller
+       (i.e., less strict) alignment requirement are safe.
+     - 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.
+       See also Section \"4.7 Arrays and Pointers\" of \"GCC_MANUAL\"
+     - Tagged as `safe` for ECLAIR.
+
+   * - R11.6
+     - The conversion from a pointer to a boolean has a well-known semantics
+       that do not lead to unexpected behaviour.
+     - Tagged as `safe` for ECLAIR.
+
    * - R11.8
      - Violations caused by container_of are due to pointer arithmetic 
operations
        with the provided offset. The resulting pointer is then immediately 
cast back to its
@@ -308,8 +366,14 @@ Deviations related to MISRA C:2012 Rules:
 
    * - R14.3
      - The Xen team relies on the fact that invariant conditions of 'if'
-       statements are deliberate.
-     - Project-wide deviation; tagged as `disapplied` for ECLAIR.
+       statements and conditional operators are deliberate.
+     - Project-wide deviation; tagged as `deliberate` for ECLAIR.
+
+   * - R14.3
+     - The use of an invariant size argument in {put,get}_unsafe_size and
+       array_access_ok, as defined in arch/x86(_64)?/include/asm/uaccess.h is
+       deliberate and is deemed safe.
+     - Project-wide deviation; tagged as `deliberate` for ECLAIR.
 
    * - R14.4
      - A controlling expression of 'if' and iteration statements having
-- 
2.34.1