scripts/gdb: add helpers to find and list devices

Add helper commands and functions for finding pointers to struct device
by enumerating linux device bus/class infrastructure.  This can be used
to fetch subsystem and driver-specific structs:

  (gdb) p *$container_of($lx_device_find_by_class_name("net", "eth0"), "struct net_device", "dev")
  (gdb) p *$container_of($lx_device_find_by_bus_name("i2c", "0-004b"), "struct i2c_client", "dev")
  (gdb) p *(struct imx_port*)$lx_device_find_by_class_name("tty", "ttymxc1")->parent->driver_data

Several generic "lx-device-list" functions are included to enumerate
devices by bus and class:

  (gdb) lx-device-list-bus usb
  (gdb) lx-device-list-class
  (gdb) lx-device-list-tree &platform_bus

Similar information is available in /sys but pointer values are
deliberately hidden.

Link: http://lkml.kernel.org/r/c948628041311cbf1b9b4cff3dda7d2073cb3eaa.1561492937.git.leonard.crestez@nxp.com
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Leonard Crestez 2019-07-16 16:30:15 -07:00 committed by Linus Torvalds
parent 8207d4a88e
commit 778c1f5ccb
2 changed files with 183 additions and 0 deletions

182
scripts/gdb/linux/device.py Normal file
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@ -0,0 +1,182 @@
# SPDX-License-Identifier: GPL-2.0
#
# Copyright (c) NXP 2019
import gdb
from linux.utils import CachedType
from linux.utils import container_of
from linux.lists import list_for_each_entry
device_private_type = CachedType('struct device_private')
device_type = CachedType('struct device')
subsys_private_type = CachedType('struct subsys_private')
kobject_type = CachedType('struct kobject')
kset_type = CachedType('struct kset')
bus_type = CachedType('struct bus_type')
class_type = CachedType('struct class')
def dev_name(dev):
dev_init_name = dev['init_name']
if dev_init_name:
return dev_init_name.string()
return dev['kobj']['name'].string()
def kset_for_each_object(kset):
return list_for_each_entry(kset['list'],
kobject_type.get_type().pointer(), "entry")
def for_each_bus():
for kobj in kset_for_each_object(gdb.parse_and_eval('bus_kset')):
subsys = container_of(kobj, kset_type.get_type().pointer(), 'kobj')
subsys_priv = container_of(subsys, subsys_private_type.get_type().pointer(), 'subsys')
yield subsys_priv['bus']
def for_each_class():
for kobj in kset_for_each_object(gdb.parse_and_eval('class_kset')):
subsys = container_of(kobj, kset_type.get_type().pointer(), 'kobj')
subsys_priv = container_of(subsys, subsys_private_type.get_type().pointer(), 'subsys')
yield subsys_priv['class']
def get_bus_by_name(name):
for item in for_each_bus():
if item['name'].string() == name:
return item
raise gdb.GdbError("Can't find bus type {!r}".format(name))
def get_class_by_name(name):
for item in for_each_class():
if item['name'].string() == name:
return item
raise gdb.GdbError("Can't find device class {!r}".format(name))
klist_type = CachedType('struct klist')
klist_node_type = CachedType('struct klist_node')
def klist_for_each(klist):
return list_for_each_entry(klist['k_list'],
klist_node_type.get_type().pointer(), 'n_node')
def bus_for_each_device(bus):
for kn in klist_for_each(bus['p']['klist_devices']):
dp = container_of(kn, device_private_type.get_type().pointer(), 'knode_bus')
yield dp['device']
def class_for_each_device(cls):
for kn in klist_for_each(cls['p']['klist_devices']):
dp = container_of(kn, device_private_type.get_type().pointer(), 'knode_class')
yield dp['device']
def device_for_each_child(dev):
for kn in klist_for_each(dev['p']['klist_children']):
dp = container_of(kn, device_private_type.get_type().pointer(), 'knode_parent')
yield dp['device']
def _show_device(dev, level=0, recursive=False):
gdb.write('{}dev {}:\t{}\n'.format('\t' * level, dev_name(dev), dev))
if recursive:
for child in device_for_each_child(dev):
_show_device(child, level + 1, recursive)
class LxDeviceListBus(gdb.Command):
'''Print devices on a bus (or all buses if not specified)'''
def __init__(self):
super(LxDeviceListBus, self).__init__('lx-device-list-bus', gdb.COMMAND_DATA)
def invoke(self, arg, from_tty):
if not arg:
for bus in for_each_bus():
gdb.write('bus {}:\t{}\n'.format(bus['name'].string(), bus))
for dev in bus_for_each_device(bus):
_show_device(dev, level=1)
else:
bus = get_bus_by_name(arg)
if not bus:
raise gdb.GdbError("Can't find bus {!r}".format(arg))
for dev in bus_for_each_device(bus):
_show_device(dev)
class LxDeviceListClass(gdb.Command):
'''Print devices in a class (or all classes if not specified)'''
def __init__(self):
super(LxDeviceListClass, self).__init__('lx-device-list-class', gdb.COMMAND_DATA)
def invoke(self, arg, from_tty):
if not arg:
for cls in for_each_class():
gdb.write("class {}:\t{}\n".format(cls['name'].string(), cls))
for dev in class_for_each_device(cls):
_show_device(dev, level=1)
else:
cls = get_class_by_name(arg)
for dev in class_for_each_device(cls):
_show_device(dev)
class LxDeviceListTree(gdb.Command):
'''Print a device and its children recursively'''
def __init__(self):
super(LxDeviceListTree, self).__init__('lx-device-list-tree', gdb.COMMAND_DATA)
def invoke(self, arg, from_tty):
if not arg:
raise gdb.GdbError('Please provide pointer to struct device')
dev = gdb.parse_and_eval(arg)
if dev.type != device_type.get_type().pointer():
raise gdb.GdbError('Please provide pointer to struct device')
_show_device(dev, level=0, recursive=True)
class LxDeviceFindByBusName(gdb.Function):
'''Find struct device by bus and name (both strings)'''
def __init__(self):
super(LxDeviceFindByBusName, self).__init__('lx_device_find_by_bus_name')
def invoke(self, bus, name):
name = name.string()
bus = get_bus_by_name(bus.string())
for dev in bus_for_each_device(bus):
if dev_name(dev) == name:
return dev
class LxDeviceFindByClassName(gdb.Function):
'''Find struct device by class and name (both strings)'''
def __init__(self):
super(LxDeviceFindByClassName, self).__init__('lx_device_find_by_class_name')
def invoke(self, cls, name):
name = name.string()
cls = get_class_by_name(cls.string())
for dev in class_for_each_device(cls):
if dev_name(dev) == name:
return dev
LxDeviceListBus()
LxDeviceListClass()
LxDeviceListTree()
LxDeviceFindByBusName()
LxDeviceFindByClassName()

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@ -36,3 +36,4 @@ else:
import linux.timerlist
import linux.clk
import linux.genpd
import linux.device