[PATCH v8 3/6] Uprobes: Support SDT markers having reference count (semaphore)

+static int delayed_uprobe_install(struct vm_area_struct *vma)
+{
+	struct list_head *pos, *q;
+	struct delayed_uprobe *du;
+	unsigned long vaddr;
+	int ret = 0, err = 0;
+
+	mutex_lock(&delayed_uprobe_lock);
+	list_for_each_safe(pos, q, &delayed_uprobe_list) {
+		du = list_entry(pos, struct delayed_uprobe, list);
+
+		if (!valid_ref_ctr_vma(du->uprobe, vma))
+			continue;

I think we should compare mm here. I.e.:

    if (du->mm != vma->vm_mm || !valid_ref_ctr_vma(du->uprobe, vma))
            continue;

Otherwise things can mess up.

+
+		vaddr = offset_to_vaddr(vma, du->uprobe->ref_ctr_offset);
+		ret = __update_ref_ctr(vma->vm_mm, vaddr, 1);
+		/* Record an error and continue. */
+		if (ret && !err)
+			err = ret;
+		delayed_uprobe_delete(du);
+	}
+	mutex_unlock(&delayed_uprobe_lock);
+	return err;
+}