From 778c1f5ccbd95722cf84d2233c6acbf4d01a3ec7 Mon Sep 17 00:00:00 2001 From: Leonard Crestez Date: Tue, 16 Jul 2019 16:30:15 -0700 Subject: [PATCH] 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 Reviewed-by: Stephen Boyd Cc: Kieran Bingham Cc: Jan Kiszka Cc: "Rafael J. Wysocki" Cc: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- scripts/gdb/linux/device.py | 182 ++++++++++++++++++++++++++++++++++++ scripts/gdb/vmlinux-gdb.py | 1 + 2 files changed, 183 insertions(+) create mode 100644 scripts/gdb/linux/device.py diff --git a/scripts/gdb/linux/device.py b/scripts/gdb/linux/device.py new file mode 100644 index 000000000000..16376c5cfec6 --- /dev/null +++ b/scripts/gdb/linux/device.py @@ -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() diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py index a504f511e752..4136dc2c59df 100644 --- a/scripts/gdb/vmlinux-gdb.py +++ b/scripts/gdb/vmlinux-gdb.py @@ -36,3 +36,4 @@ else: import linux.timerlist import linux.clk import linux.genpd + import linux.device -- 2.34.1