[PATCH 0/4] Misc MISRA fixes for default Xen build configurations

[PATCH 0/4] Misc MISRA fixes for default Xen build configurations

[Nicola Vetrini]

This series addresses some of the violations found by widening the scope of
application of MISRA checking to default builds of Xen for both ARM64 and x86_64.

While it has been tested on top of a patch yet to be applied (but with
the necessary R-by [1]) these fixes can go in independently of that.

As evidenced by the CI pipeline below, there are a number of regressions on
guidelines that were clean on the restricted scope but are not in the wider one;
the patches in this series address a subset of those.

CI pipeline: https://gitlab.com/xen-project/people/bugseng/xen/-/pipelines/2156782159

[1] https://lore.kernel.org/xen-devel/alpine.DEB.2.22.394.2511031448530.495094@ubuntu-linux-20-04-desktop/

Nicola Vetrini (4):
  xen/xsm: address violations of MISRA C rules 8.3 and 7.2
  xen/sched: address violation of MISRA C Rule 16.3
  xen/param: address violation of MISRA C Rule 20.7
  xen/param: address violation of MISRA C Rule 8.2

 xen/common/sched/credit.c | 2 +-
 xen/include/xen/param.h   | 6 +++---
 xen/include/xsm/xsm.h     | 6 +++---
 3 files changed, 7 insertions(+), 7 deletions(-)

-- 
2.51.2

[PATCH 1/4] xen/xsm: address violations of MISRA C rules 8.3 and 7.2

[Nicola Vetrini]

Rule 8.3 states: Function types shall be in prototype form
with named parameters.

add parameter to 'has_xsm_magic' to make it consistent with the
definition.

Rule 7.2 states: A `u' or `U' suffix shall be applied to all
integer constants that are represented in an unsigned type.

add missing `U' to both #define for `XSM_MAGIC` for consistency.

No functional change.

Signed-off-by: Nicola Vetrini <nicola.vetrini@gmail.com>
---
 xen/include/xsm/xsm.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/xen/include/xsm/xsm.h b/xen/include/xsm/xsm.h
index 9a23d2827c..074d61cd45 100644
--- a/xen/include/xsm/xsm.h
+++ b/xen/include/xsm/xsm.h
@@ -22,9 +22,9 @@
 typedef uint32_t xsm_magic_t;
 
 #ifdef CONFIG_XSM_FLASK
-#define XSM_MAGIC 0xf97cff8c
+#define XSM_MAGIC 0xf97cff8cU
 #else
-#define XSM_MAGIC 0x0
+#define XSM_MAGIC 0x0U
 #endif
 
 /*
@@ -815,7 +815,7 @@ int xsm_multiboot_policy_init(
  */
 int xsm_dt_init(void);
 int xsm_dt_policy_init(void **policy_buffer, size_t *policy_size);
-bool has_xsm_magic(paddr_t);
+bool has_xsm_magic(paddr_t start);
 #endif
 
 void xsm_fixup_ops(struct xsm_ops *ops);
-- 
2.51.2

Re: [PATCH 1/4] xen/xsm: address violations of MISRA C rules 8.3 and 7.2

[Daniel P. Smith]

On 11/20/25 2:32 PM, Nicola Vetrini wrote:
> Rule 8.3 states: Function types shall be in prototype form
> with named parameters.
> 
> add parameter to 'has_xsm_magic' to make it consistent with the
> definition.
> 
> Rule 7.2 states: A `u' or `U' suffix shall be applied to all
> integer constants that are represented in an unsigned type.
> 
> add missing `U' to both #define for `XSM_MAGIC` for consistency.
> 
> No functional change.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@gmail.com>
> ---
>   xen/include/xsm/xsm.h | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/xen/include/xsm/xsm.h b/xen/include/xsm/xsm.h
> index 9a23d2827c..074d61cd45 100644
> --- a/xen/include/xsm/xsm.h
> +++ b/xen/include/xsm/xsm.h
> @@ -22,9 +22,9 @@
>   typedef uint32_t xsm_magic_t;
>   
>   #ifdef CONFIG_XSM_FLASK
> -#define XSM_MAGIC 0xf97cff8c
> +#define XSM_MAGIC 0xf97cff8cU
>   #else
> -#define XSM_MAGIC 0x0
> +#define XSM_MAGIC 0x0U
>   #endif
>   
>   /*
> @@ -815,7 +815,7 @@ int xsm_multiboot_policy_init(
>    */
>   int xsm_dt_init(void);
>   int xsm_dt_policy_init(void **policy_buffer, size_t *policy_size);
> -bool has_xsm_magic(paddr_t);
> +bool has_xsm_magic(paddr_t start);
>   #endif
>   
>   void xsm_fixup_ops(struct xsm_ops *ops);

Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>

[PATCH 2/4] xen/sched: address violation of MISRA C Rule 16.3

[Nicola Vetrini]

The rule states: An unconditional `break' statement shall terminate
every switch-clause.

Use the `fallthrough' pseudo-keyword for which an ECLAIR deviation
is already in place.

No functional change.

Signed-off-by: Nicola Vetrini <nicola.vetrini@gmail.com>
---
 xen/common/sched/credit.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/common/sched/credit.c b/xen/common/sched/credit.c
index 6dcf6b2c8b..e9a91d11c3 100644
--- a/xen/common/sched/credit.c
+++ b/xen/common/sched/credit.c
@@ -1288,7 +1288,7 @@ csched_sys_cntl(const struct scheduler *ops,
         prv->unit_migr_delay = MICROSECS(params->vcpu_migr_delay_us);
         spin_unlock_irqrestore(&prv->lock, flags);
 
-        /* FALLTHRU */
+        fallthrough;
     case XEN_SYSCTL_SCHEDOP_getinfo:
         params->tslice_ms = prv->tslice / MILLISECS(1);
         params->ratelimit_us = prv->ratelimit / MICROSECS(1);
-- 
2.51.2

Re: [PATCH 2/4] xen/sched: address violation of MISRA C Rule 16.3

[Jürgen Groß]

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On 20.11.25 20:32, Nicola Vetrini wrote:
> The rule states: An unconditional `break' statement shall terminate
> every switch-clause.
> 
> Use the `fallthrough' pseudo-keyword for which an ECLAIR deviation
> is already in place.
> 
> No functional change.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@gmail.com>

Acked-by: Juergen Gross <jgross@suse.com>


Juergen

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[PATCH 3/4] xen/param: address violation of MISRA C Rule 20.7

[Nicola Vetrini]

The rule states: Expressions resulting from the expansion of
macro parameters shall be enclosed in parentheses.

Add parentheses in the defition of `custom_runtime_var_sz' to
address the violations.

No functional change.

Signed-off-by: Nicola Vetrini <nicola.vetrini@gmail.com>
---
 xen/include/xen/param.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/xen/include/xen/param.h b/xen/include/xen/param.h
index 1bdbab34ab..f5a2189400 100644
--- a/xen/include/xen/param.h
+++ b/xen/include/xen/param.h
@@ -102,8 +102,8 @@ extern struct param_hypfs __paramhypfs_start[], __paramhypfs_end[];
 
 #define custom_runtime_set_var_sz(parfs, var, sz) \
     { \
-        (parfs)->hypfs.u.content = var; \
-        (parfs)->hypfs.e.max_size = sz; \
+        (parfs)->hypfs.u.content = (var); \
+        (parfs)->hypfs.e.max_size = (sz); \
         (parfs)->hypfs.e.size = strlen(var) + 1; \
     }
 #define custom_runtime_set_var(parfs, var) \
-- 
2.51.2

Re: [PATCH 3/4] xen/param: address violation of MISRA C Rule 20.7

[Jan Beulich]

On 20.11.2025 20:32, Nicola Vetrini wrote:
> The rule states: Expressions resulting from the expansion of
> macro parameters shall be enclosed in parentheses.
> 
> Add parentheses in the defition of `custom_runtime_var_sz' to
> address the violations.
> 
> No functional change.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@gmail.com>

Acked-by: Jan Beulich <jbeulich@suse.com>

[PATCH 4/4] xen/param: address violation of MISRA C Rule 8.2

[Nicola Vetrini]

add missing parameter name in function pointer member declaration.

No functional change.

Signed-off-by: Nicola Vetrini <nicola.vetrini@gmail.com>
---
 xen/include/xen/param.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/include/xen/param.h b/xen/include/xen/param.h
index f5a2189400..3b6f134b07 100644
--- a/xen/include/xen/param.h
+++ b/xen/include/xen/param.h
@@ -90,7 +90,7 @@ extern const struct kernel_param __setup_start[], __setup_end[];
 struct param_hypfs {
     struct hypfs_entry_leaf hypfs;
     void (*init_leaf)(struct param_hypfs *par);
-    int (*func)(const char *);
+    int (*func)(const char *s);
 };
 
 extern struct param_hypfs __paramhypfs_start[], __paramhypfs_end[];
-- 
2.51.2

Re: [PATCH 4/4] xen/param: address violation of MISRA C Rule 8.2

[Jan Beulich]

On 20.11.2025 20:32, Nicola Vetrini wrote:
> add missing parameter name in function pointer member declaration.
> 
> No functional change.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@gmail.com>

Acked-by: Jan Beulich <jbeulich@suse.com>