mm/mmap.c: use pr_emerg when printing BUG related information

Make sure we actually see the output of validate_mm() and browse_rb()
before triggering a BUG().  pr_info isn't shown by default so the reason
for the BUG() isn't obvious.
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/mmap.c

@@ -369,20 +369,20 @@ static int browse_rb(struct rb_root *root)
 		struct vm_area_struct *vma;
 		vma = rb_entry(nd, struct vm_area_struct, vm_rb);
 		if (vma->vm_start < prev) {
-			pr_info("vm_start %lx prev %lx\n", vma->vm_start, prev);
+			pr_emerg("vm_start %lx prev %lx\n", vma->vm_start, prev);
 			bug = 1;
 		}
 		if (vma->vm_start < pend) {
-			pr_info("vm_start %lx pend %lx\n", vma->vm_start, pend);
+			pr_emerg("vm_start %lx pend %lx\n", vma->vm_start, pend);
 			bug = 1;
 		}
 		if (vma->vm_start > vma->vm_end) {
-			pr_info("vm_end %lx < vm_start %lx\n",
+			pr_emerg("vm_end %lx < vm_start %lx\n",
 				vma->vm_end, vma->vm_start);
 			bug = 1;
 		}
 		if (vma->rb_subtree_gap != vma_compute_subtree_gap(vma)) {
-			pr_info("free gap %lx, correct %lx\n",
+			pr_emerg("free gap %lx, correct %lx\n",
 			       vma->rb_subtree_gap,
 			       vma_compute_subtree_gap(vma));
 			bug = 1;
@@ -396,7 +396,7 @@ static int browse_rb(struct rb_root *root)
 	for (nd = pn; nd; nd = rb_prev(nd))
 		j++;
 	if (i != j) {
-		pr_info("backwards %d, forwards %d\n", j, i);
+		pr_emerg("backwards %d, forwards %d\n", j, i);
 		bug = 1;
 	}
 	return bug ? -1 : i;
@@ -431,17 +431,17 @@ static void validate_mm(struct mm_struct *mm)
 		i++;
 	}
 	if (i != mm->map_count) {
-		pr_info("map_count %d vm_next %d\n", mm->map_count, i);
+		pr_emerg("map_count %d vm_next %d\n", mm->map_count, i);
 		bug = 1;
 	}
 	if (highest_address != mm->highest_vm_end) {
-		pr_info("mm->highest_vm_end %lx, found %lx\n",
+		pr_emerg("mm->highest_vm_end %lx, found %lx\n",
 		       mm->highest_vm_end, highest_address);
 		bug = 1;
 	}
 	i = browse_rb(&mm->mm_rb);
 	if (i != mm->map_count) {
-		pr_info("map_count %d rb %d\n", mm->map_count, i);
+		pr_emerg("map_count %d rb %d\n", mm->map_count, i);
 		bug = 1;
 	}
 	BUG_ON(bug);