rcu: make rcutorture version numbers available through debugfs

It is not possible to accurately correlate rcutorture output with that
of debugfs.  This patch therefore adds a debugfs file that prints out
the rcutorture version number, permitting easy correlation.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c
index fc40e89a028c..3baa235786b5 100644
--- a/kernel/rcutree_trace.c
+++ b/kernel/rcutree_trace.c
@@ -394,6 +394,29 @@ static const struct file_operations rcu_pending_fops = {
         .release = single_release,
 };
 
+static int show_rcutorture(struct seq_file *m, void *unused)
+{
+        seq_printf(m, "rcutorture test sequence: %lu %s\n",
+                   rcutorture_testseq >> 1,
+                   (rcutorture_testseq & 0x1) ? "(test in progress)" : "");
+        seq_printf(m, "rcutorture update version number: %lu\n",
+                   rcutorture_vernum);
+        return 0;
+}
+
+static int rcutorture_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, show_rcutorture, NULL);
+}
+
+static const struct file_operations rcutorture_fops = {
+        .owner = THIS_MODULE,
+        .open = rcutorture_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .release = single_release,
+};
+
 static struct dentry *rcudir;
 
 static int __init rcutree_trace_init(void)
@@ -430,6 +453,11 @@ static int __init rcutree_trace_init(void)
                                                 NULL, &rcu_pending_fops);
         if (!retval)
                 goto free_out;
+
+        retval = debugfs_create_file("rcutorture", 0444, rcudir,
+                                                NULL, &rcutorture_fops);
+        if (!retval)
+                goto free_out;
         return 0;
 free_out:
         debugfs_remove_recursive(rcudir);