No side effects in BUG_ON statements in Xen.

Signed-off-by: Keir Fraser <keir@xensource.com>

xen/arch/x86/mm.c

@@ -1164,6 +1164,7 @@ static int mod_l3_entry(l3_pgentry_t *pl3e,
 {
     l3_pgentry_t ol3e;
     unsigned long vaddr;
+    int okay;
 
     if ( unlikely(!is_guest_l3_slot(pgentry_ptr_to_slot(pl3e))) )
     {
@@ -1218,7 +1219,9 @@ static int mod_l3_entry(l3_pgentry_t *pl3e,
         return 0;
     }
 
-    BUG_ON(!create_pae_xen_mappings(pl3e));
+    okay = create_pae_xen_mappings(pl3e);
+    BUG_ON(!okay);
+
     put_page_from_l3e(ol3e, pfn);
     return 1;
 }

xen/arch/x86/time.c

@@ -323,7 +323,7 @@ static u64 read_pit_count(void)
     return pit_counter64 + (u16)(pit_stamp - pit_read_counter());
 }
 
-static int init_pit(void)
+static void init_pit(void)
 {
     read_platform_count = read_pit_count;
 
@@ -333,8 +333,6 @@ static int init_pit(void)
 
     printk("Platform timer is %s PIT\n", freq_string(CLOCK_TICK_RATE));
     using_pit = 1;
-
-    return 1;
 }
 
 /************************************************************
@@ -563,7 +561,7 @@ static void platform_time_calibration(void)
 static void init_platform_timer(void)
 {
     if ( !init_cyclone() && !init_hpet() )
-        BUG_ON(!init_pit());
+        init_pit();
 }
 
 

xen/common/schedule.c

@@ -514,7 +514,7 @@ static void dom_timer_fn(void *data)
 /* Initialise the data structures. */
 void __init scheduler_init(void)
 {
-    int i;
+    int i, rc;
 
     open_softirq(SCHEDULE_SOFTIRQ, __enter_scheduler);
 
@@ -540,7 +540,9 @@ void __init scheduler_init(void)
 
     printk("Using scheduler: %s (%s)\n", ops.name, ops.opt_name);
 
-    BUG_ON(SCHED_OP(alloc_task, idle_task[0]) < 0);
+    rc = SCHED_OP(alloc_task, idle_task[0]);
+    BUG_ON(rc < 0);
+
     sched_add_domain(idle_task[0]);
 }