[PATCH v8 00/22] Add gdb python scripts as kernel debugging helpers

[PATCH v8 00/22] Add gdb python scripts as kernel debugging helpers

[Jan Kiszka]

Some time passed since the last posting. Basically, this round comes
with two changes:
 - make the code Python 3 compatible [Pantelis Koukousoulas]
 - rebase over recent Linux version, resolving a trivial conflict

See http://lkml.indiana.edu/hypermail/linux/kernel/1210.0/01598.html for
the original description and

    git://git.kiszka.org/linux.git queues/gdb-scripts

for the latest version.

I'm still hoping someone will move this forward via his tree towards
upstream. Please let me know if any changes are required to enable this.

Jan

CC: "David S. Miller" <davem@davemloft.net>
CC: Fenghua Yu <fenghua.yu@intel.com>
CC: Kay Sievers <kay@vrfy.org>
CC: linux-doc@vger.kernel.org
CC: linux-ia64@vger.kernel.org
CC: linux-kbuild@vger.kernel.org
CC: Michal Marek <mmarek@suse.cz>
CC: Pantelis Koukousoulas <pktoss@gmail.com>
CC: Rob Landley <rob@landley.net>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: sparclinux@vger.kernel.org
CC: Tony Luck <tony.luck@intel.com>

Jan Kiszka (21):
  scripts/gdb: Add infrastructure
  scripts/gdb: Add cache for type objects
  scripts/gdb: Add container_of helper and convenience function
  scripts/gdb: Add module iteration class
  scripts/gdb: Add lx-symbols command
  module: Do not inline do_init_module
  scripts/gdb: Add automatic symbol reloading on module insertion
  scripts/gdb: Add internal helper and convenience function to look up a
    module
  scripts/gdb: Add get_target_endianness helper
  scripts/gdb: Add read_u16/32/64 helpers
  scripts/gdb: Add lx-dmesg command
  scripts/gdb: Add task iteration class
  scripts/gdb: Add helper and convenience function to look up tasks
  scripts/gdb: Add is_target_arch helper
  scripts/gdb: Add internal helper and convenience function to retrieve
    thread_info
  scripts/gdb: Add get_gdbserver_type helper
  scripts/gdb: Add internal helper and convenience function for per-cpu
    lookup
  scripts/gdb: Add lx_current convenience function
  scripts/gdb: Add class to iterate over CPU masks
  scripts/gdb: Add lx-lsmod command
  scripts/gdb: Add basic documentation

Pantelis Koukousoulas (1):
  scripts/gdb: Port to python3 / gdb7.7

 Documentation/gdb-kernel-debugging.txt | 160 +++++++++++++++++++++++++++++++
 Makefile                               |   6 +-
 kernel/module.c                        |   9 +-
 lib/Kconfig.debug                      |  11 +++
 scripts/Makefile                       |   3 +-
 scripts/gdb/Makefile                   |  11 +++
 scripts/gdb/linux/Makefile             |   9 ++
 scripts/gdb/linux/__init__.py          |   0
 scripts/gdb/linux/cpus.py              | 142 ++++++++++++++++++++++++++++
 scripts/gdb/linux/dmesg.py             |  65 +++++++++++++
 scripts/gdb/linux/modules.py           | 114 ++++++++++++++++++++++
 scripts/gdb/linux/symbols.py           | 166 +++++++++++++++++++++++++++++++++
 scripts/gdb/linux/tasks.py             | 110 ++++++++++++++++++++++
 scripts/gdb/linux/utils.py             | 156 +++++++++++++++++++++++++++++++
 scripts/gdb/vmlinux-gdb.py             |  30 ++++++
 15 files changed, 988 insertions(+), 4 deletions(-)
 create mode 100644 Documentation/gdb-kernel-debugging.txt
 create mode 100644 scripts/gdb/Makefile
 create mode 100644 scripts/gdb/linux/Makefile
 create mode 100644 scripts/gdb/linux/__init__.py
 create mode 100644 scripts/gdb/linux/cpus.py
 create mode 100644 scripts/gdb/linux/dmesg.py
 create mode 100644 scripts/gdb/linux/modules.py
 create mode 100644 scripts/gdb/linux/symbols.py
 create mode 100644 scripts/gdb/linux/tasks.py
 create mode 100644 scripts/gdb/linux/utils.py
 create mode 100644 scripts/gdb/vmlinux-gdb.py

-- 
1.8.1.1.298.ge7eed54

[PATCH v8 15/22] scripts/gdb: Add internal helper and convenience function to retrieve thread_info

[Jan Kiszka]

Add the internal helper get_thread_info that calculates the thread_info
from a given task variable. Also export this service as a convenience
function.

Note: ia64 version is untested.

CC: Tony Luck <tony.luck@intel.com>
CC: Fenghua Yu <fenghua.yu@intel.com>
CC: linux-ia64@vger.kernel.org
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 scripts/gdb/linux/tasks.py | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/scripts/gdb/linux/tasks.py b/scripts/gdb/linux/tasks.py
index 13bb97c..63cd6c5 100644
--- a/scripts/gdb/linux/tasks.py
+++ b/scripts/gdb/linux/tasks.py
@@ -71,3 +71,38 @@ return that task_struct variable which PID matches."""
 
 
 LxTaskByPidFunc()
+
+
+thread_info_type = utils.CachedType("struct thread_info")
+
+ia64_task_size = None
+
+
+def get_thread_info(task):
+    global thread_info_type
+    thread_info_ptr_type = thread_info_type.get_type().pointer()
+    if utils.is_target_arch("ia64"):
+        global ia64_task_size
+        if ia64_task_size is None:
+            ia64_task_size = gdb.parse_and_eval("sizeof(struct task_struct)")
+        thread_info_addr = task.address + ia64_task_size
+        thread_info = thread_info_addr.cast(thread_info_ptr_type)
+    else:
+        thread_info = task['stack'].cast(thread_info_ptr_type)
+    return thread_info.dereference()
+
+
+class LxThreadInfoFunc (gdb.Function):
+    """Calculate Linux thread_info from task variable.
+
+$lx_thread_info(TASK): Given TASK, return the corresponding thread_info
+variable."""
+
+    def __init__(self):
+        super(LxThreadInfoFunc, self).__init__("lx_thread_info")
+
+    def invoke(self, task):
+        return get_thread_info(task)
+
+
+LxThreadInfoFunc()
-- 
1.8.1.1.298.ge7eed54

Re: [PATCH v8 00/22] Add gdb python scripts as kernel debugging helpers

[Andi Kleen]

I looked through the patches and from a quick look they all look good to
me. I especially like the support for per cpu variables. I had a lot of 
trouble with those in the past with various debugging setups.

Acked-by: Andi Kleen <ak@linux.intel.com>

-Andi
-- 
ak@linux.intel.com -- Speaking for myself only.