[PATCHv3 13/13] scripts/gdb: Add lx_thread_info_by_pid helper

[Kieran Bingham <kieran.bingham@linaro.org>]

The tasks module already provides helpers to find the task struct by
pid, and the thread_info by task struct; however this is cumbersome to
utilise on the gdb commandline.

Wrap these two functionalities together in an extra single helper to
allow exploring the thread info, from a PID value

Signed-off-by: Kieran Bingham <kieran.bingham@linaro.org>
---
 scripts/gdb/linux/tasks.py | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/scripts/gdb/linux/tasks.py b/scripts/gdb/linux/tasks.py
index 862a4ae24d49..1bf949c43b76 100644
--- a/scripts/gdb/linux/tasks.py
+++ b/scripts/gdb/linux/tasks.py
@@ -114,3 +114,22 @@ variable."""
 
 
 LxThreadInfoFunc()
+
+
+class LxThreadInfoByPidFunc (gdb.Function):
+    """Calculate Linux thread_info from task variable found by pid
+
+$lx_thread_info_by_pid(PID): Given PID, return the corresponding thread_info
+variable."""
+
+    def __init__(self):
+        super(LxThreadInfoByPidFunc, self).__init__("lx_thread_info_by_pid")
+
+    def invoke(self, pid):
+        task = get_task_by_pid(pid)
+        if task:
+            return get_thread_info(task.dereference())
+        else:
+            raise gdb.GdbError("No task of PID " + str(pid))
+
+LxThreadInfoByPidFunc()
-- 
2.5.0