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[XEN PATCH][for-4.19 v3] xen: Add deviations for MISRA C:2012 Rule 7.1

Nicola Vetrini posted 1 patch 2 years, 3 months ago
Patches applied successfully (tree, apply log)
git fetch https://gitlab.com/xen-project/patchew/xen tags/patchew/5e0f1bcd7b4325141e64a3c2d581034956b42293.1698136547.git.nicola.vetrini@bugseng.com
There is a newer version of this series
automation/eclair_analysis/ECLAIR/deviations.ecl | 10 ++++++----
docs/misra/deviations.rst                        |  5 +++++
docs/misra/safe.json                             |  8 ++++++++
xen/arch/x86/hvm/svm/emulate.c                   |  6 +++---
xen/common/inflate.c                             |  4 ++--
5 files changed, 24 insertions(+), 9 deletions(-)
[XEN PATCH][for-4.19 v3] xen: Add deviations for MISRA C:2012 Rule 7.1
Posted by Nicola Vetrini 2 years, 3 months ago 
As specified in rules.rst, these constants can be used
in the code.

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
---
Changes in v2:
- replace some SAF deviations with configurations
Changes in v3:
- refine configurations and justifications
---
 automation/eclair_analysis/ECLAIR/deviations.ecl | 10 ++++++----
 docs/misra/deviations.rst                        |  5 +++++
 docs/misra/safe.json                             |  8 ++++++++
 xen/arch/x86/hvm/svm/emulate.c                   |  6 +++---
 xen/common/inflate.c                             |  4 ++--
 5 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
index fa56e5c00a27..ea5e0eb1813f 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -85,10 +85,12 @@ 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)$"}
+-doc_begin="It is safe to use certain octal constants the way they are defined in
+specifications, manuals, and algorithm descriptions."
+-file_tag+={x86_svm_h, "^xen/arch/x86/hvm/svm/svm\\.h$"}
+-file_tag+={x86_emulate_c, "^xen/arch/x86/hvm/svm/emulate\\.c$"}
+-config=MC3R1.R7.1,reports+={safe, "any_area(any_loc(any_exp(file(x86_svm_h)&&macro(^INSTR_ENC$))))"}
+-config=MC3R1.R7.1,reports+={safe, "any_area(text(^.*octal-ok.*$)&&any_loc(any_exp(file(x86_emulate_c)&&macro(^MASK_EXTR$))))"}
 -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..26c6dbbc9ffe 100644
--- a/docs/misra/deviations.rst
+++ b/docs/misra/deviations.rst
@@ -90,6 +90,11 @@ 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.
+     - 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/arch/x86/hvm/svm/emulate.c b/xen/arch/x86/hvm/svm/emulate.c
index aa2c61c433b3..93ac1d3435f9 100644
--- a/xen/arch/x86/hvm/svm/emulate.c
+++ b/xen/arch/x86/hvm/svm/emulate.c
@@ -90,9 +90,9 @@ unsigned int svm_get_insn_len(struct vcpu *v, unsigned int instr_enc)
         if ( !instr_modrm )
             return emul_len;
 
-        if ( modrm_mod       == MASK_EXTR(instr_modrm, 0300) &&
-             (modrm_reg & 7) == MASK_EXTR(instr_modrm, 0070) &&
-             (modrm_rm  & 7) == MASK_EXTR(instr_modrm, 0007) )
+        if ( modrm_mod       == MASK_EXTR(instr_modrm, 0300) && /* octal-ok */
+             (modrm_reg & 7) == MASK_EXTR(instr_modrm, 0070) && /* octal-ok */
+             (modrm_rm  & 7) == MASK_EXTR(instr_modrm, 0007) )  /* octal-ok */
             return emul_len;
     }
 
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
Re: [XEN PATCH][for-4.19 v3] xen: Add deviations for MISRA C:2012 Rule 7.1
Posted by Stefano Stabellini 2 years, 3 months ago 
On Tue, 24 Oct 2023, Nicola Vetrini wrote:
> As specified in rules.rst, these constants can be used
> in the code.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
> ---
> Changes in v2:
> - replace some SAF deviations with configurations
> Changes in v3:
> - refine configurations and justifications
> ---
>  automation/eclair_analysis/ECLAIR/deviations.ecl | 10 ++++++----
>  docs/misra/deviations.rst                        |  5 +++++
>  docs/misra/safe.json                             |  8 ++++++++
>  xen/arch/x86/hvm/svm/emulate.c                   |  6 +++---
>  xen/common/inflate.c                             |  4 ++--
>  5 files changed, 24 insertions(+), 9 deletions(-)
> 
> diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
> index fa56e5c00a27..ea5e0eb1813f 100644
> --- a/automation/eclair_analysis/ECLAIR/deviations.ecl
> +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
> @@ -85,10 +85,12 @@ 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)$"}
> +-doc_begin="It is safe to use certain octal constants the way they are defined in
> +specifications, manuals, and algorithm descriptions."
> +-file_tag+={x86_svm_h, "^xen/arch/x86/hvm/svm/svm\\.h$"}
> +-file_tag+={x86_emulate_c, "^xen/arch/x86/hvm/svm/emulate\\.c$"}
> +-config=MC3R1.R7.1,reports+={safe, "any_area(any_loc(any_exp(file(x86_svm_h)&&macro(^INSTR_ENC$))))"}
> +-config=MC3R1.R7.1,reports+={safe, "any_area(text(^.*octal-ok.*$)&&any_loc(any_exp(file(x86_emulate_c)&&macro(^MASK_EXTR$))))"}
>  -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..26c6dbbc9ffe 100644
> --- a/docs/misra/deviations.rst
> +++ b/docs/misra/deviations.rst
> @@ -90,6 +90,11 @@ 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.

I think we should add that these cases have "octal-ok" as a in-code
comment. Everything else looks OK so this small change could be done on
commit.

Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>


> +     - 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/arch/x86/hvm/svm/emulate.c b/xen/arch/x86/hvm/svm/emulate.c
> index aa2c61c433b3..93ac1d3435f9 100644
> --- a/xen/arch/x86/hvm/svm/emulate.c
> +++ b/xen/arch/x86/hvm/svm/emulate.c
> @@ -90,9 +90,9 @@ unsigned int svm_get_insn_len(struct vcpu *v, unsigned int instr_enc)
>          if ( !instr_modrm )
>              return emul_len;
>  
> -        if ( modrm_mod       == MASK_EXTR(instr_modrm, 0300) &&
> -             (modrm_reg & 7) == MASK_EXTR(instr_modrm, 0070) &&
> -             (modrm_rm  & 7) == MASK_EXTR(instr_modrm, 0007) )
> +        if ( modrm_mod       == MASK_EXTR(instr_modrm, 0300) && /* octal-ok */
> +             (modrm_reg & 7) == MASK_EXTR(instr_modrm, 0070) && /* octal-ok */
> +             (modrm_rm  & 7) == MASK_EXTR(instr_modrm, 0007) )  /* octal-ok */
>              return emul_len;
>      }
>  
> 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
>
Re: [XEN PATCH][for-4.19 v3] xen: Add deviations for MISRA C:2012 Rule 7.1
Posted by Jan Beulich 2 years, 3 months ago 
On 24.10.2023 22:30, Stefano Stabellini wrote:
> On Tue, 24 Oct 2023, Nicola Vetrini wrote:
>> As specified in rules.rst, these constants can be used
>> in the code.
>>
>> Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
>> ---
>> Changes in v2:
>> - replace some SAF deviations with configurations
>> Changes in v3:
>> - refine configurations and justifications
>> ---
>>  automation/eclair_analysis/ECLAIR/deviations.ecl | 10 ++++++----
>>  docs/misra/deviations.rst                        |  5 +++++
>>  docs/misra/safe.json                             |  8 ++++++++
>>  xen/arch/x86/hvm/svm/emulate.c                   |  6 +++---
>>  xen/common/inflate.c                             |  4 ++--
>>  5 files changed, 24 insertions(+), 9 deletions(-)
>>
>> diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
>> index fa56e5c00a27..ea5e0eb1813f 100644
>> --- a/automation/eclair_analysis/ECLAIR/deviations.ecl
>> +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
>> @@ -85,10 +85,12 @@ 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)$"}
>> +-doc_begin="It is safe to use certain octal constants the way they are defined in
>> +specifications, manuals, and algorithm descriptions."
>> +-file_tag+={x86_svm_h, "^xen/arch/x86/hvm/svm/svm\\.h$"}
>> +-file_tag+={x86_emulate_c, "^xen/arch/x86/hvm/svm/emulate\\.c$"}
>> +-config=MC3R1.R7.1,reports+={safe, "any_area(any_loc(any_exp(file(x86_svm_h)&&macro(^INSTR_ENC$))))"}
>> +-config=MC3R1.R7.1,reports+={safe, "any_area(text(^.*octal-ok.*$)&&any_loc(any_exp(file(x86_emulate_c)&&macro(^MASK_EXTR$))))"}
>>  -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..26c6dbbc9ffe 100644
>> --- a/docs/misra/deviations.rst
>> +++ b/docs/misra/deviations.rst
>> @@ -90,6 +90,11 @@ 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.
> 
> I think we should add that these cases have "octal-ok" as a in-code
> comment. Everything else looks OK so this small change could be done on
> commit.

But that needs wording carefully, as it doesn't hold across the board:
Right now relevant MASK_EXTR() uses gain such comments, but INSTR_ENC()
ones (deliberately) don't.

Jan
Re: [XEN PATCH][for-4.19 v3] xen: Add deviations for MISRA C:2012 Rule 7.1
Posted by Stefano Stabellini 2 years, 3 months ago 
On Wed, 25 Oct 2023, Jan Beulich wrote:
> On 24.10.2023 22:30, Stefano Stabellini wrote:
> > On Tue, 24 Oct 2023, Nicola Vetrini wrote:
> >> As specified in rules.rst, these constants can be used
> >> in the code.
> >>
> >> Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
> >> ---
> >> Changes in v2:
> >> - replace some SAF deviations with configurations
> >> Changes in v3:
> >> - refine configurations and justifications
> >> ---
> >>  automation/eclair_analysis/ECLAIR/deviations.ecl | 10 ++++++----
> >>  docs/misra/deviations.rst                        |  5 +++++
> >>  docs/misra/safe.json                             |  8 ++++++++
> >>  xen/arch/x86/hvm/svm/emulate.c                   |  6 +++---
> >>  xen/common/inflate.c                             |  4 ++--
> >>  5 files changed, 24 insertions(+), 9 deletions(-)
> >>
> >> diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
> >> index fa56e5c00a27..ea5e0eb1813f 100644
> >> --- a/automation/eclair_analysis/ECLAIR/deviations.ecl
> >> +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
> >> @@ -85,10 +85,12 @@ 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)$"}
> >> +-doc_begin="It is safe to use certain octal constants the way they are defined in
> >> +specifications, manuals, and algorithm descriptions."
> >> +-file_tag+={x86_svm_h, "^xen/arch/x86/hvm/svm/svm\\.h$"}
> >> +-file_tag+={x86_emulate_c, "^xen/arch/x86/hvm/svm/emulate\\.c$"}
> >> +-config=MC3R1.R7.1,reports+={safe, "any_area(any_loc(any_exp(file(x86_svm_h)&&macro(^INSTR_ENC$))))"}
> >> +-config=MC3R1.R7.1,reports+={safe, "any_area(text(^.*octal-ok.*$)&&any_loc(any_exp(file(x86_emulate_c)&&macro(^MASK_EXTR$))))"}
> >>  -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..26c6dbbc9ffe 100644
> >> --- a/docs/misra/deviations.rst
> >> +++ b/docs/misra/deviations.rst
> >> @@ -90,6 +90,11 @@ 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.
> > 
> > I think we should add that these cases have "octal-ok" as a in-code
> > comment. Everything else looks OK so this small change could be done on
> > commit.
> 
> But that needs wording carefully, as it doesn't hold across the board:
> Right now relevant MASK_EXTR() uses gain such comments, but INSTR_ENC()
> ones (deliberately) don't.

What about:

* - R7.1
  - It is safe to use certain octal constants the way they are defined
    in specifications, manuals, and algorithm descriptions. Such places
    are marked safe with a /* octal-ok */ in-code comment, or with a SAF
    comment (see safe.json).
Re: [XEN PATCH][for-4.19 v3] xen: Add deviations for MISRA C:2012 Rule 7.1
Posted by Jan Beulich 2 years, 3 months ago 
On 26.10.2023 00:34, Stefano Stabellini wrote:
> On Wed, 25 Oct 2023, Jan Beulich wrote:
>> On 24.10.2023 22:30, Stefano Stabellini wrote:
>>> On Tue, 24 Oct 2023, Nicola Vetrini wrote:
>>>> As specified in rules.rst, these constants can be used
>>>> in the code.
>>>>
>>>> Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
>>>> ---
>>>> Changes in v2:
>>>> - replace some SAF deviations with configurations
>>>> Changes in v3:
>>>> - refine configurations and justifications
>>>> ---
>>>>  automation/eclair_analysis/ECLAIR/deviations.ecl | 10 ++++++----
>>>>  docs/misra/deviations.rst                        |  5 +++++
>>>>  docs/misra/safe.json                             |  8 ++++++++
>>>>  xen/arch/x86/hvm/svm/emulate.c                   |  6 +++---
>>>>  xen/common/inflate.c                             |  4 ++--
>>>>  5 files changed, 24 insertions(+), 9 deletions(-)
>>>>
>>>> diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
>>>> index fa56e5c00a27..ea5e0eb1813f 100644
>>>> --- a/automation/eclair_analysis/ECLAIR/deviations.ecl
>>>> +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
>>>> @@ -85,10 +85,12 @@ 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)$"}
>>>> +-doc_begin="It is safe to use certain octal constants the way they are defined in
>>>> +specifications, manuals, and algorithm descriptions."
>>>> +-file_tag+={x86_svm_h, "^xen/arch/x86/hvm/svm/svm\\.h$"}
>>>> +-file_tag+={x86_emulate_c, "^xen/arch/x86/hvm/svm/emulate\\.c$"}
>>>> +-config=MC3R1.R7.1,reports+={safe, "any_area(any_loc(any_exp(file(x86_svm_h)&&macro(^INSTR_ENC$))))"}
>>>> +-config=MC3R1.R7.1,reports+={safe, "any_area(text(^.*octal-ok.*$)&&any_loc(any_exp(file(x86_emulate_c)&&macro(^MASK_EXTR$))))"}
>>>>  -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..26c6dbbc9ffe 100644
>>>> --- a/docs/misra/deviations.rst
>>>> +++ b/docs/misra/deviations.rst
>>>> @@ -90,6 +90,11 @@ 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.
>>>
>>> I think we should add that these cases have "octal-ok" as a in-code
>>> comment. Everything else looks OK so this small change could be done on
>>> commit.
>>
>> But that needs wording carefully, as it doesn't hold across the board:
>> Right now relevant MASK_EXTR() uses gain such comments, but INSTR_ENC()
>> ones (deliberately) don't.
> 
> What about:
> 
> * - R7.1
>   - It is safe to use certain octal constants the way they are defined
>     in specifications, manuals, and algorithm descriptions. Such places
>     are marked safe with a /* octal-ok */ in-code comment, or with a SAF
>     comment (see safe.json).

Fine with me.

Jan
Re: [XEN PATCH][for-4.19 v3] xen: Add deviations for MISRA C:2012 Rule 7.1
Posted by Nicola Vetrini 2 years, 3 months ago 
On 26/10/2023 08:49, Jan Beulich wrote:
> On 26.10.2023 00:34, Stefano Stabellini wrote:
>> On Wed, 25 Oct 2023, Jan Beulich wrote:
>>> On 24.10.2023 22:30, Stefano Stabellini wrote:
>>>> On Tue, 24 Oct 2023, Nicola Vetrini wrote:
>>>>> As specified in rules.rst, these constants can be used
>>>>> in the code.
>>>>> 
>>>>> Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
>>>>> ---
>>>>> Changes in v2:
>>>>> - replace some SAF deviations with configurations
>>>>> Changes in v3:
>>>>> - refine configurations and justifications
>>>>> ---
>>>>>  automation/eclair_analysis/ECLAIR/deviations.ecl | 10 ++++++----
>>>>>  docs/misra/deviations.rst                        |  5 +++++
>>>>>  docs/misra/safe.json                             |  8 ++++++++
>>>>>  xen/arch/x86/hvm/svm/emulate.c                   |  6 +++---
>>>>>  xen/common/inflate.c                             |  4 ++--
>>>>>  5 files changed, 24 insertions(+), 9 deletions(-)
>>>>> 
>>>>> diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl 
>>>>> b/automation/eclair_analysis/ECLAIR/deviations.ecl
>>>>> index fa56e5c00a27..ea5e0eb1813f 100644
>>>>> --- a/automation/eclair_analysis/ECLAIR/deviations.ecl
>>>>> +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
>>>>> @@ -85,10 +85,12 @@ 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)$"}
>>>>> +-doc_begin="It is safe to use certain octal constants the way they 
>>>>> are defined in
>>>>> +specifications, manuals, and algorithm descriptions."
>>>>> +-file_tag+={x86_svm_h, "^xen/arch/x86/hvm/svm/svm\\.h$"}
>>>>> +-file_tag+={x86_emulate_c, "^xen/arch/x86/hvm/svm/emulate\\.c$"}
>>>>> +-config=MC3R1.R7.1,reports+={safe, 
>>>>> "any_area(any_loc(any_exp(file(x86_svm_h)&&macro(^INSTR_ENC$))))"}
>>>>> +-config=MC3R1.R7.1,reports+={safe, 
>>>>> "any_area(text(^.*octal-ok.*$)&&any_loc(any_exp(file(x86_emulate_c)&&macro(^MASK_EXTR$))))"}
>>>>>  -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..26c6dbbc9ffe 100644
>>>>> --- a/docs/misra/deviations.rst
>>>>> +++ b/docs/misra/deviations.rst
>>>>> @@ -90,6 +90,11 @@ 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.
>>>> 
>>>> I think we should add that these cases have "octal-ok" as a in-code
>>>> comment. Everything else looks OK so this small change could be done 
>>>> on
>>>> commit.
>>> 
>>> But that needs wording carefully, as it doesn't hold across the 
>>> board:
>>> Right now relevant MASK_EXTR() uses gain such comments, but 
>>> INSTR_ENC()
>>> ones (deliberately) don't.
>> 
>> What about:
>> 
>> * - R7.1
>>   - It is safe to use certain octal constants the way they are defined
>>     in specifications, manuals, and algorithm descriptions. Such 
>> places
>>     are marked safe with a /* octal-ok */ in-code comment, or with a 
>> SAF
>>     comment (see safe.json).
> 
> Fine with me.
> 
> Jan

Ok, I'll update the deviation record.

-- 
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)

Patchew 2.1-devel-b67e4c2

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