Re: [PATCH 4/4] xen: Justify linker script defined symbols in include/xen/kernel.h

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Mon, 28 Nov 2022, Luca Fancellu wrote:
> Eclair and Coverity found violation of the MISRA rule 8.6 for the
> symbols _start, _end, start, _stext, _etext, _srodata, _erodata,
> _sinittext, _einittext which are declared in
> xen/include/xen/kernel.h.
> All those symbols are defined by the liker script so we can deviate
> from the rule 8.6 for these cases.
> 
> Signed-off-by: Luca Fancellu <luca.fancellu@xxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> ---
>  docs/misra/safe.json     | 9 +++++++++
>  xen/include/xen/kernel.h | 4 ++++
>  2 files changed, 13 insertions(+)
> 
> diff --git a/docs/misra/safe.json b/docs/misra/safe.json
> index e079d3038120..e3c8a1d8eb36 100644
> --- a/docs/misra/safe.json
> +++ b/docs/misra/safe.json
> @@ -3,6 +3,15 @@
>      "content": [
>          {
>              "id": "SAF-0-safe",
> +            "analyser": {
> +                "eclair": "MC3R1.R8.6",
> +                "coverity": "misra_c_2012_rule_8_6_violation"
> +            },
> +            "name": "Rule 8.6: linker script defined symbols",
> +            "text": "It is safe to declare this symbol because it is defined 
> in the linker script."
> +        },
> +        {
> +            "id": "SAF-1-safe",
>              "analyser": {},
>              "name": "Sentinel",
>              "text": "Next ID to be used"
> diff --git a/xen/include/xen/kernel.h b/xen/include/xen/kernel.h
> index 8cd142032d3b..f1a7713784fc 100644
> --- a/xen/include/xen/kernel.h
> +++ b/xen/include/xen/kernel.h
> @@ -65,24 +65,28 @@
>       1;                                      \
>  })
>  
> +/* SAF-0-safe */
>  extern char _start[], _end[], start[];
>  #define is_kernel(p) ({                         \
>      char *__p = (char *)(unsigned long)(p);     \
>      (__p >= _start) && (__p < _end);            \
>  })
>  
> +/* SAF-0-safe */
>  extern char _stext[], _etext[];
>  #define is_kernel_text(p) ({                    \
>      char *__p = (char *)(unsigned long)(p);     \
>      (__p >= _stext) && (__p < _etext);          \
>  })
>  
> +/* SAF-0-safe */
>  extern const char _srodata[], _erodata[];
>  #define is_kernel_rodata(p) ({                  \
>      const char *__p = (const char *)(unsigned long)(p);     \
>      (__p >= _srodata) && (__p < _erodata);      \
>  })
>  
> +/* SAF-0-safe */
>  extern char _sinittext[], _einittext[];
>  #define is_kernel_inittext(p) ({                \
>      char *__p = (char *)(unsigned long)(p);     \
> -- 
> 2.17.1
>