[RFC PATCH v1.9 13/14] livepatch: add /proc/<pid>/patch_status

[Josh Poimboeuf]

Expose the per-task klp_universe value so users can determine which
tasks are holding up completion of a patching operation.

Call it "patch_status" rather than "universe": it's at least more
descriptive for the average user.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
 fs/proc/base.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index b1755b2..f90998b 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2801,6 +2801,15 @@ static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
 	return err;
 }
 
+#ifdef CONFIG_LIVEPATCH
+static int proc_pid_patch_status(struct seq_file *m, struct pid_namespace *ns,
+				 struct pid *pid, struct task_struct *task)
+{
+	seq_printf(m, "%d\n", task->klp_universe);
+	return 0;
+}
+#endif /* CONFIG_LIVEPATCH */
+
 /*
  * Thread groups
  */
@@ -2900,6 +2909,9 @@ static const struct pid_entry tgid_base_stuff[] = {
 	REG("timers",	  S_IRUGO, proc_timers_operations),
 #endif
 	REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
+#ifdef CONFIG_LIVEPATCH
+	ONE("patch_status",  S_IRUSR, proc_pid_patch_status),
+#endif
 };
 
 static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
-- 
2.4.3