cpumask: remove dangerous CPU_MASK_ALL_PTR, &CPU_MASK_ALL

Impact: cleanup

(Thanks to Al Viro for reminding me of this, via Ingo)

CPU_MASK_ALL is the (deprecated) "all bits set" cpumask, defined as so:

	#define CPU_MASK_ALL (cpumask_t) { { ... } }

Taking the address of such a temporary is questionable at best,
unfortunately 321a8e9 (cpumask: add CPU_MASK_ALL_PTR macro) added
CPU_MASK_ALL_PTR:

	#define CPU_MASK_ALL_PTR (&CPU_MASK_ALL)

Which formalizes this practice.  One day gcc could bite us over this
usage (though we seem to have gotten away with it so far).

So replace everywhere which used &CPU_MASK_ALL or CPU_MASK_ALL_PTR
with the modern "cpu_all_mask" (a real const struct cpumask *).

Signed-off-by: Rusty Russell <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Reported-by: Al Viro <[email protected]>
Cc: Mike Travis <[email protected]>

init/main.c

@@ -842,7 +842,7 @@ static int __init kernel_init(void * unused)
 	/*
 	 * init can run on any cpu.
 	 */
-	set_cpus_allowed_ptr(current, CPU_MASK_ALL_PTR);
+	set_cpus_allowed_ptr(current, cpu_all_mask);
 	/*
 	 * Tell the world that we're going to be the grim
 	 * reaper of innocent orphaned children.

kernel/kmod.c

@@ -167,7 +167,7 @@ static int ____call_usermodehelper(void *data)
 	}
 
 	/* We can run anywhere, unlike our parent keventd(). */
-	set_cpus_allowed_ptr(current, CPU_MASK_ALL_PTR);
+	set_cpus_allowed_ptr(current, cpu_all_mask);
 
 	/*
 	 * Our parent is keventd, which runs with elevated scheduling priority.

kernel/kthread.c

@@ -110,7 +110,7 @@ static void create_kthread(struct kthread_create_info *create)
 		 */
 		sched_setscheduler(create->result, SCHED_NORMAL, &param);
 		set_user_nice(create->result, KTHREAD_NICE_LEVEL);
-		set_cpus_allowed_ptr(create->result, CPU_MASK_ALL_PTR);
+		set_cpus_allowed_ptr(create->result, cpu_all_mask);
 	}
 	complete(&create->done);
 }
@@ -240,7 +240,7 @@ int kthreadd(void *unused)
 	set_task_comm(tsk, "kthreadd");
 	ignore_signals(tsk);
 	set_user_nice(tsk, KTHREAD_NICE_LEVEL);
-	set_cpus_allowed_ptr(tsk, CPU_MASK_ALL_PTR);
+	set_cpus_allowed_ptr(tsk, cpu_all_mask);
 
 	current->flags |= PF_NOFREEZE | PF_FREEZER_NOSIG;
 

mm/pdflush.c

@@ -191,7 +191,7 @@ static int pdflush(void *dummy)
 
 	/*
 	 * Some configs put our parent kthread in a limited cpuset,
-	 * which kthread() overrides, forcing cpus_allowed == CPU_MASK_ALL.
+	 * which kthread() overrides, forcing cpus_allowed == cpu_all_mask.
 	 * Our needs are more modest - cut back to our cpusets cpus_allowed.
 	 * This is needed as pdflush's are dynamically created and destroyed.
 	 * The boottime pdflush's are easily placed w/o these 2 lines.