Yet another code simplification. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			135 lines
		
	
	
	
		
			3.5 KiB
			
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			135 lines
		
	
	
	
		
			3.5 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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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 cpu
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class PerCpu(gdb.Function):
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    """Return per-cpu variable.
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$lx_per_cpu("VAR"[, CPU]): Return the per-cpu variable called VAR for the
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given CPU number. If CPU is omitted, the CPU of the current context is used.
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Note that VAR has to be quoted as string."""
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    def __init__(self):
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        super(PerCpu, self).__init__("lx_per_cpu")
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    def invoke(self, var_name, cpu=-1):
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        var_ptr = gdb.parse_and_eval("&" + var_name.string())
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        return per_cpu(var_ptr, cpu)
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PerCpu()
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class LxCurrentFunc(gdb.Function):
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    """Return current task.
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$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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        var_ptr = gdb.parse_and_eval("¤t_task")
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        return per_cpu(var_ptr, cpu).dereference()
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LxCurrentFunc()
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