194 lines
5.2 KiB
Python
194 lines
5.2 KiB
Python
#
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# gdb helper commands and functions for Linux kernel debugging
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#
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# per-cpu tools
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#
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# Copyright (c) Siemens AG, 2011-2013
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#
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# Authors:
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# Jan Kiszka <jan.kiszka@siemens.com>
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#
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# This work is licensed under the terms of the GNU GPL version 2.
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#
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import gdb
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from linux import tasks, utils
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task_type = utils.CachedType("struct task_struct")
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MAX_CPUS = 4096
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def get_current_cpu():
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if utils.get_gdbserver_type() == utils.GDBSERVER_QEMU:
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return gdb.selected_thread().num - 1
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elif utils.get_gdbserver_type() == utils.GDBSERVER_KGDB:
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tid = gdb.selected_thread().ptid[2]
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if tid > (0x100000000 - MAX_CPUS - 2):
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return 0x100000000 - tid - 2
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else:
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return tasks.get_thread_info(tasks.get_task_by_pid(tid))['cpu']
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else:
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raise gdb.GdbError("Sorry, obtaining the current CPU is not yet "
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"supported with this gdb server.")
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def per_cpu(var_ptr, cpu):
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if cpu == -1:
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cpu = get_current_cpu()
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if utils.is_target_arch("sparc:v9"):
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offset = gdb.parse_and_eval(
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"trap_block[{0}].__per_cpu_base".format(str(cpu)))
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else:
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try:
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offset = gdb.parse_and_eval(
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"__per_cpu_offset[{0}]".format(str(cpu)))
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except gdb.error:
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# !CONFIG_SMP case
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offset = 0
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pointer = var_ptr.cast(utils.get_long_type()) + offset
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return pointer.cast(var_ptr.type).dereference()
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cpu_mask = {}
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def cpu_mask_invalidate(event):
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global cpu_mask
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cpu_mask = {}
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gdb.events.stop.disconnect(cpu_mask_invalidate)
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if hasattr(gdb.events, 'new_objfile'):
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gdb.events.new_objfile.disconnect(cpu_mask_invalidate)
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def cpu_list(mask_name):
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global cpu_mask
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mask = None
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if mask_name in cpu_mask:
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mask = cpu_mask[mask_name]
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if mask is None:
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mask = gdb.parse_and_eval(mask_name + ".bits")
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if hasattr(gdb, 'events'):
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cpu_mask[mask_name] = mask
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gdb.events.stop.connect(cpu_mask_invalidate)
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if hasattr(gdb.events, 'new_objfile'):
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gdb.events.new_objfile.connect(cpu_mask_invalidate)
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bits_per_entry = mask[0].type.sizeof * 8
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num_entries = mask.type.sizeof * 8 / bits_per_entry
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entry = -1
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bits = 0
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while True:
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while bits == 0:
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entry += 1
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if entry == num_entries:
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return
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bits = mask[entry]
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if bits != 0:
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bit = 0
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break
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while bits & 1 == 0:
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bits >>= 1
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bit += 1
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cpu = entry * bits_per_entry + bit
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bits >>= 1
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bit += 1
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yield int(cpu)
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def each_online_cpu():
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for cpu in cpu_list("__cpu_online_mask"):
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yield cpu
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def each_present_cpu():
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for cpu in cpu_list("__cpu_present_mask"):
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yield cpu
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def each_possible_cpu():
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for cpu in cpu_list("__cpu_possible_mask"):
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yield cpu
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def each_active_cpu():
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for cpu in cpu_list("__cpu_active_mask"):
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yield cpu
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class LxCpus(gdb.Command):
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"""List CPU status arrays
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Displays the known state of each CPU based on the kernel masks
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and can help identify the state of hotplugged CPUs"""
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def __init__(self):
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super(LxCpus, self).__init__("lx-cpus", gdb.COMMAND_DATA)
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def invoke(self, arg, from_tty):
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gdb.write("Possible CPUs : {}\n".format(list(each_possible_cpu())))
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gdb.write("Present CPUs : {}\n".format(list(each_present_cpu())))
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gdb.write("Online CPUs : {}\n".format(list(each_online_cpu())))
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gdb.write("Active CPUs : {}\n".format(list(each_active_cpu())))
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LxCpus()
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class PerCpu(gdb.Function):
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"""Return per-cpu variable.
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$lx_per_cpu("VAR"[, CPU]): Return the per-cpu variable called VAR for the
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given CPU number. If CPU is omitted, the CPU of the current context is used.
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Note that VAR has to be quoted as string."""
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def __init__(self):
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super(PerCpu, self).__init__("lx_per_cpu")
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def invoke(self, var_name, cpu=-1):
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var_ptr = gdb.parse_and_eval("&" + var_name.string())
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return per_cpu(var_ptr, cpu)
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PerCpu()
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def get_current_task(cpu):
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task_ptr_type = task_type.get_type().pointer()
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if utils.is_target_arch("x86"):
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var_ptr = gdb.parse_and_eval("¤t_task")
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return per_cpu(var_ptr, cpu).dereference()
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elif utils.is_target_arch("aarch64"):
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current_task_addr = gdb.parse_and_eval("$SP_EL0")
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if((current_task_addr >> 63) != 0):
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current_task = current_task_addr.cast(task_ptr_type)
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return current_task.dereference()
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else:
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raise gdb.GdbError("Sorry, obtaining the current task is not allowed "
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"while running in userspace(EL0)")
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else:
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raise gdb.GdbError("Sorry, obtaining the current task is not yet "
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"supported with this arch")
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class LxCurrentFunc(gdb.Function):
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"""Return current task.
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$lx_current([CPU]): Return the per-cpu task variable for the given CPU
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number. If CPU is omitted, the CPU of the current context is used."""
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def __init__(self):
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super(LxCurrentFunc, self).__init__("lx_current")
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def invoke(self, cpu=-1):
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return get_current_task(cpu)
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LxCurrentFunc()
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