210 lines
6.0 KiB
Python
210 lines
6.0 KiB
Python
#
|
|
# gdb helper commands and functions for Linux kernel debugging
|
|
#
|
|
# per-cpu tools
|
|
#
|
|
# Copyright (c) Siemens AG, 2011-2013
|
|
#
|
|
# Authors:
|
|
# Jan Kiszka <jan.kiszka@siemens.com>
|
|
#
|
|
# This work is licensed under the terms of the GNU GPL version 2.
|
|
#
|
|
|
|
import gdb
|
|
|
|
from linux import tasks, utils
|
|
|
|
|
|
task_type = utils.CachedType("struct task_struct")
|
|
|
|
|
|
MAX_CPUS = 4096
|
|
|
|
|
|
def get_current_cpu():
|
|
if utils.get_gdbserver_type() == utils.GDBSERVER_QEMU:
|
|
return gdb.selected_thread().num - 1
|
|
elif utils.get_gdbserver_type() == utils.GDBSERVER_KGDB:
|
|
return gdb.parse_and_eval("kgdb_active.counter")
|
|
else:
|
|
raise gdb.GdbError("Sorry, obtaining the current CPU is not yet "
|
|
"supported with this gdb server.")
|
|
|
|
|
|
def per_cpu(var_ptr, cpu):
|
|
if cpu == -1:
|
|
cpu = get_current_cpu()
|
|
if utils.is_target_arch("sparc:v9"):
|
|
offset = gdb.parse_and_eval(
|
|
"trap_block[{0}].__per_cpu_base".format(str(cpu)))
|
|
else:
|
|
try:
|
|
offset = gdb.parse_and_eval(
|
|
"__per_cpu_offset[{0}]".format(str(cpu)))
|
|
except gdb.error:
|
|
# !CONFIG_SMP case
|
|
offset = 0
|
|
pointer = var_ptr.cast(utils.get_long_type()) + offset
|
|
return pointer.cast(var_ptr.type).dereference()
|
|
|
|
|
|
cpu_mask = {}
|
|
|
|
|
|
def cpu_mask_invalidate(event):
|
|
global cpu_mask
|
|
cpu_mask = {}
|
|
gdb.events.stop.disconnect(cpu_mask_invalidate)
|
|
if hasattr(gdb.events, 'new_objfile'):
|
|
gdb.events.new_objfile.disconnect(cpu_mask_invalidate)
|
|
|
|
|
|
def cpu_list(mask_name):
|
|
global cpu_mask
|
|
mask = None
|
|
if mask_name in cpu_mask:
|
|
mask = cpu_mask[mask_name]
|
|
if mask is None:
|
|
mask = gdb.parse_and_eval(mask_name + ".bits")
|
|
if hasattr(gdb, 'events'):
|
|
cpu_mask[mask_name] = mask
|
|
gdb.events.stop.connect(cpu_mask_invalidate)
|
|
if hasattr(gdb.events, 'new_objfile'):
|
|
gdb.events.new_objfile.connect(cpu_mask_invalidate)
|
|
bits_per_entry = mask[0].type.sizeof * 8
|
|
num_entries = mask.type.sizeof * 8 / bits_per_entry
|
|
entry = -1
|
|
bits = 0
|
|
|
|
while True:
|
|
while bits == 0:
|
|
entry += 1
|
|
if entry == num_entries:
|
|
return
|
|
bits = mask[entry]
|
|
if bits != 0:
|
|
bit = 0
|
|
break
|
|
|
|
while bits & 1 == 0:
|
|
bits >>= 1
|
|
bit += 1
|
|
|
|
cpu = entry * bits_per_entry + bit
|
|
|
|
bits >>= 1
|
|
bit += 1
|
|
|
|
yield int(cpu)
|
|
|
|
|
|
def each_online_cpu():
|
|
for cpu in cpu_list("__cpu_online_mask"):
|
|
yield cpu
|
|
|
|
|
|
def each_present_cpu():
|
|
for cpu in cpu_list("__cpu_present_mask"):
|
|
yield cpu
|
|
|
|
|
|
def each_possible_cpu():
|
|
for cpu in cpu_list("__cpu_possible_mask"):
|
|
yield cpu
|
|
|
|
|
|
def each_active_cpu():
|
|
for cpu in cpu_list("__cpu_active_mask"):
|
|
yield cpu
|
|
|
|
|
|
class LxCpus(gdb.Command):
|
|
"""List CPU status arrays
|
|
|
|
Displays the known state of each CPU based on the kernel masks
|
|
and can help identify the state of hotplugged CPUs"""
|
|
|
|
def __init__(self):
|
|
super(LxCpus, self).__init__("lx-cpus", gdb.COMMAND_DATA)
|
|
|
|
def invoke(self, arg, from_tty):
|
|
gdb.write("Possible CPUs : {}\n".format(list(each_possible_cpu())))
|
|
gdb.write("Present CPUs : {}\n".format(list(each_present_cpu())))
|
|
gdb.write("Online CPUs : {}\n".format(list(each_online_cpu())))
|
|
gdb.write("Active CPUs : {}\n".format(list(each_active_cpu())))
|
|
|
|
|
|
LxCpus()
|
|
|
|
|
|
class PerCpu(gdb.Function):
|
|
"""Return per-cpu variable.
|
|
|
|
$lx_per_cpu("VAR"[, CPU]): Return the per-cpu variable called VAR for the
|
|
given CPU number. If CPU is omitted, the CPU of the current context is used.
|
|
Note that VAR has to be quoted as string."""
|
|
|
|
def __init__(self):
|
|
super(PerCpu, self).__init__("lx_per_cpu")
|
|
|
|
def invoke(self, var, cpu=-1):
|
|
return per_cpu(var.address, cpu)
|
|
|
|
|
|
PerCpu()
|
|
|
|
def get_current_task(cpu):
|
|
task_ptr_type = task_type.get_type().pointer()
|
|
|
|
if utils.is_target_arch("x86"):
|
|
if gdb.lookup_global_symbol("cpu_tasks"):
|
|
# This is a UML kernel, which stores the current task
|
|
# differently than other x86 sub architectures
|
|
var_ptr = gdb.parse_and_eval("(struct task_struct *)cpu_tasks[0].task")
|
|
return var_ptr.dereference()
|
|
else:
|
|
var_ptr = gdb.parse_and_eval("&pcpu_hot.current_task")
|
|
return per_cpu(var_ptr, cpu).dereference()
|
|
elif utils.is_target_arch("aarch64"):
|
|
current_task_addr = gdb.parse_and_eval("$SP_EL0")
|
|
if (current_task_addr >> 63) != 0:
|
|
current_task = current_task_addr.cast(task_ptr_type)
|
|
return current_task.dereference()
|
|
else:
|
|
raise gdb.GdbError("Sorry, obtaining the current task is not allowed "
|
|
"while running in userspace(EL0)")
|
|
elif utils.is_target_arch("riscv"):
|
|
current_tp = gdb.parse_and_eval("$tp")
|
|
scratch_reg = gdb.parse_and_eval("$sscratch")
|
|
|
|
# by default tp points to current task
|
|
current_task = current_tp.cast(task_ptr_type)
|
|
|
|
# scratch register is set 0 in trap handler after entering kernel.
|
|
# When hart is in user mode, scratch register is pointing to task_struct.
|
|
# and tp is used by user mode. So when scratch register holds larger value
|
|
# (negative address as ulong is larger value) than tp, then use scratch register.
|
|
if (scratch_reg.cast(utils.get_ulong_type()) > current_tp.cast(utils.get_ulong_type())):
|
|
current_task = scratch_reg.cast(task_ptr_type)
|
|
|
|
return current_task.dereference()
|
|
else:
|
|
raise gdb.GdbError("Sorry, obtaining the current task is not yet "
|
|
"supported with this arch")
|
|
|
|
class LxCurrentFunc(gdb.Function):
|
|
"""Return current task.
|
|
|
|
$lx_current([CPU]): Return the per-cpu task variable for the given CPU
|
|
number. If CPU is omitted, the CPU of the current context is used."""
|
|
|
|
def __init__(self):
|
|
super(LxCurrentFunc, self).__init__("lx_current")
|
|
|
|
def invoke(self, cpu=-1):
|
|
return get_current_task(cpu)
|
|
|
|
|
|
LxCurrentFunc()
|