tracing: use %*pb[l] to print bitmaps including cpumasks and nodemasks

printk and friends can now format bitmaps using '%*pb[l]'.  cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr_args()
respectively which can be used to generate the two printf arguments
necessary to format the specified cpu/nodemask.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/trace/trace.c

@@ -3353,12 +3353,12 @@ tracing_cpumask_read(struct file *filp, char __user *ubuf,
 
 	mutex_lock(&tracing_cpumask_update_lock);
 
-	len = cpumask_scnprintf(mask_str, count, tr->tracing_cpumask);
-	if (count - len < 2) {
+	len = snprintf(mask_str, count, "%*pb\n",
+		       cpumask_pr_args(tr->tracing_cpumask));
+	if (len >= count) {
 		count = -EINVAL;
 		goto out_err;
 	}
-	len += sprintf(mask_str + len, "\n");
 	count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1);
 
 out_err:

kernel/trace/trace_seq.c

@@ -120,7 +120,7 @@ void trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp,
 
 	__trace_seq_init(s);
 
-	seq_buf_bitmask(&s->seq, maskp, nmaskbits);
+	seq_buf_printf(&s->seq, "%*pb", nmaskbits, maskp);
 
 	if (unlikely(seq_buf_has_overflowed(&s->seq))) {
 		s->seq.len = save_len;