Re: [XEN PATCH 1/5] xen/common: address violations of MISRA C:2012 Rule 8.2

[Federico Serafini]

On 18/11/23 03:59, Stefano Stabellini wrote:

On Fri, 17 Nov 2023, Federico Serafini wrote:

diff --git a/xen/common/stop_machine.c b/xen/common/stop_machine.c
index 3adbe380de..398cfd507c 100644
--- a/xen/common/stop_machine.c
+++ b/xen/common/stop_machine.c
@@ -46,7 +46,7 @@ struct stopmachine_data {

unsigned int fn_cpu;

      int fn_result;
-    int (*fn)(void *);
+    int (*fn)(void *data);
      void *fn_data;
  };

At least one of the possible function used here calls the parameter
"arg", see take_cpu_down. But I don't think it is a MISRA requirement to
also harmonize those?

@@ -73,7 +73,7 @@ static void stopmachine_wait_state(void)
   * mandatory to be called only on an idle vcpu, as otherwise active core
   * scheduling might hang.
   */
-int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
+int stop_machine_run(int (*fn)(void *data), void *data, unsigned int cpu)
  {
      unsigned int i, nr_cpus;
      unsigned int this = smp_processor_id();
diff --git a/xen/common/tasklet.c b/xen/common/tasklet.c
index 3ad67b5c24..3649798e6b 100644
--- a/xen/common/tasklet.c
+++ b/xen/common/tasklet.c
@@ -199,7 +199,7 @@ static void migrate_tasklets_from_cpu(unsigned int cpu, 
struct list_head *list)
      spin_unlock_irqrestore(&tasklet_lock, flags);
  }

-void tasklet_init(struct tasklet *t, void (*func)(void *), void *data)

+void tasklet_init(struct tasklet *t, void (*func)(void *data), void *data)
  {
      memset(t, 0, sizeof(*t));
      INIT_LIST_HEAD(&t->list);
@@ -208,7 +208,8 @@ void tasklet_init(struct tasklet *t, void (*func)(void *), 
void *data)
      t->data = data;
  }

-void softirq_tasklet_init(struct tasklet *t, void (*func)(void *), void *data)

+void softirq_tasklet_init(struct tasklet *t,
+                          void (*func)(void *data), void *data)
  {
      tasklet_init(t, func, data);
      t->is_softirq = 1;
diff --git a/xen/common/timer.c b/xen/common/timer.c
index 0fddfa7487..bf7792dcb3 100644
--- a/xen/common/timer.c
+++ b/xen/common/timer.c
@@ -291,7 +291,7 @@ static bool active_timer(const struct timer *timer)

void init_timer(

      struct timer *timer,
-    void        (*function)(void *),
+    void        (*function)(void *data),
      void         *data,
      unsigned int  cpu)
  {
@@ -441,7 +441,7 @@ void kill_timer(struct timer *timer)

static void execute_timer(struct timers *ts, struct timer *t)

  {
-    void (*fn)(void *) = t->function;
+    void (*fn)(void *data) = t->function;
      void *data = t->data;

t->status = TIMER_STATUS_inactive;

diff --git a/xen/include/xen/rangeset.h b/xen/include/xen/rangeset.h
index 135f33f606..390f7b6082 100644
--- a/xen/include/xen/rangeset.h
+++ b/xen/include/xen/rangeset.h
@@ -68,7 +68,7 @@ bool_t __must_check rangeset_overlaps_range(
      struct rangeset *r, unsigned long s, unsigned long e);
  int rangeset_report_ranges(
      struct rangeset *r, unsigned long s, unsigned long e,
-    int (*cb)(unsigned long s, unsigned long e, void *), void *ctxt);
+    int (*cb)(unsigned long s, unsigned long e, void *data), void *ctxt);

Also here some of the functions use "arg" instead of ctxt

  /*
   * Note that the consume function can return an error value apart from
@@ -77,7 +77,7 @@ int rangeset_report_ranges(
   */
  int rangeset_consume_ranges(struct rangeset *r,
                              int (*cb)(unsigned long s, unsigned long e,
-                                      void *, unsigned long *c),
+                                      void *ctxt, unsigned long *c),
                              void *ctxt);

Also here some of the functions use "dom" like irq_remove_cb.


But I actually like the patch as is, so if that's OK from a MISRA point
of view then I would give my reviewed-by.

Yes, this is OK for MISRA.

--
Federico Serafini, M.Sc.

Software Engineer, BUGSENG (http://bugseng.com)