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-rw-r--r--kernel/scripts/gdb/linux/cpus.py135
1 files changed, 135 insertions, 0 deletions
diff --git a/kernel/scripts/gdb/linux/cpus.py b/kernel/scripts/gdb/linux/cpus.py
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+++ b/kernel/scripts/gdb/linux/cpus.py
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+#
+# 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
+
+
+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:
+ tid = gdb.selected_thread().ptid[2]
+ if tid > (0x100000000 - MAX_CPUS - 2):
+ return 0x100000000 - tid - 2
+ else:
+ return tasks.get_thread_info(tasks.get_task_by_pid(tid))['cpu']
+ 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 cpu
+
+
+class PerCpu(gdb.Function):
+ """Return per-cpu variable.
+
+$lx_per_cpu("VAR"[, CPU]): Return the per-cpu variable called VAR for the
+given CPU number. If CPU is omitted, the CPU of the current context is used.
+Note that VAR has to be quoted as string."""
+
+ def __init__(self):
+ super(PerCpu, self).__init__("lx_per_cpu")
+
+ def invoke(self, var_name, cpu=-1):
+ var_ptr = gdb.parse_and_eval("&" + var_name.string())
+ return per_cpu(var_ptr, cpu)
+
+
+PerCpu()
+
+
+class LxCurrentFunc(gdb.Function):
+ """Return current task.
+
+$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):
+ var_ptr = gdb.parse_and_eval("&current_task")
+ return per_cpu(var_ptr, cpu).dereference()
+
+
+LxCurrentFunc()