Jan Kiszka | fe7f9ed | 2015-02-17 13:47:21 -0800 | [diff] [blame] | 1 | # |
| 2 | # gdb helper commands and functions for Linux kernel debugging |
| 3 | # |
| 4 | # per-cpu tools |
| 5 | # |
| 6 | # Copyright (c) Siemens AG, 2011-2013 |
| 7 | # |
| 8 | # Authors: |
| 9 | # Jan Kiszka <jan.kiszka@siemens.com> |
| 10 | # |
| 11 | # This work is licensed under the terms of the GNU GPL version 2. |
| 12 | # |
| 13 | |
| 14 | import gdb |
| 15 | |
| 16 | from linux import tasks, utils |
| 17 | |
| 18 | |
| 19 | MAX_CPUS = 4096 |
| 20 | |
| 21 | |
| 22 | def get_current_cpu(): |
| 23 | if utils.get_gdbserver_type() == utils.GDBSERVER_QEMU: |
| 24 | return gdb.selected_thread().num - 1 |
| 25 | elif utils.get_gdbserver_type() == utils.GDBSERVER_KGDB: |
| 26 | tid = gdb.selected_thread().ptid[2] |
| 27 | if tid > (0x100000000 - MAX_CPUS - 2): |
| 28 | return 0x100000000 - tid - 2 |
| 29 | else: |
| 30 | return tasks.get_thread_info(tasks.get_task_by_pid(tid))['cpu'] |
| 31 | else: |
| 32 | raise gdb.GdbError("Sorry, obtaining the current CPU is not yet " |
| 33 | "supported with this gdb server.") |
| 34 | |
| 35 | |
| 36 | def per_cpu(var_ptr, cpu): |
| 37 | if cpu == -1: |
| 38 | cpu = get_current_cpu() |
| 39 | if utils.is_target_arch("sparc:v9"): |
| 40 | offset = gdb.parse_and_eval( |
| 41 | "trap_block[{0}].__per_cpu_base".format(str(cpu))) |
| 42 | else: |
| 43 | try: |
| 44 | offset = gdb.parse_and_eval( |
| 45 | "__per_cpu_offset[{0}]".format(str(cpu))) |
| 46 | except gdb.error: |
| 47 | # !CONFIG_SMP case |
| 48 | offset = 0 |
| 49 | pointer = var_ptr.cast(utils.get_long_type()) + offset |
| 50 | return pointer.cast(var_ptr.type).dereference() |
| 51 | |
| 52 | |
Jan Kiszka | 3d4cd9c | 2015-02-17 13:47:27 -0800 | [diff] [blame] | 53 | cpu_mask = {} |
| 54 | |
| 55 | |
| 56 | def cpu_mask_invalidate(event): |
| 57 | global cpu_mask |
| 58 | cpu_mask = {} |
| 59 | gdb.events.stop.disconnect(cpu_mask_invalidate) |
| 60 | if hasattr(gdb.events, 'new_objfile'): |
| 61 | gdb.events.new_objfile.disconnect(cpu_mask_invalidate) |
| 62 | |
| 63 | |
| 64 | class CpuList(): |
| 65 | def __init__(self, mask_name): |
| 66 | global cpu_mask |
| 67 | self.mask = None |
| 68 | if mask_name in cpu_mask: |
| 69 | self.mask = cpu_mask[mask_name] |
| 70 | if self.mask is None: |
| 71 | self.mask = gdb.parse_and_eval(mask_name + ".bits") |
| 72 | if hasattr(gdb, 'events'): |
| 73 | cpu_mask[mask_name] = self.mask |
| 74 | gdb.events.stop.connect(cpu_mask_invalidate) |
| 75 | if hasattr(gdb.events, 'new_objfile'): |
| 76 | gdb.events.new_objfile.connect(cpu_mask_invalidate) |
| 77 | self.bits_per_entry = self.mask[0].type.sizeof * 8 |
| 78 | self.num_entries = self.mask.type.sizeof * 8 / self.bits_per_entry |
| 79 | self.entry = -1 |
| 80 | self.bits = 0 |
| 81 | |
| 82 | def __iter__(self): |
| 83 | return self |
| 84 | |
| 85 | def next(self): |
| 86 | while self.bits == 0: |
| 87 | self.entry += 1 |
| 88 | if self.entry == self.num_entries: |
| 89 | raise StopIteration |
| 90 | self.bits = self.mask[self.entry] |
| 91 | if self.bits != 0: |
| 92 | self.bit = 0 |
| 93 | break |
| 94 | |
| 95 | while self.bits & 1 == 0: |
| 96 | self.bits >>= 1 |
| 97 | self.bit += 1 |
| 98 | |
| 99 | cpu = self.entry * self.bits_per_entry + self.bit |
| 100 | |
| 101 | self.bits >>= 1 |
| 102 | self.bit += 1 |
| 103 | |
| 104 | return cpu |
| 105 | |
| 106 | |
Jan Kiszka | fe7f9ed | 2015-02-17 13:47:21 -0800 | [diff] [blame] | 107 | class PerCpu(gdb.Function): |
| 108 | """Return per-cpu variable. |
| 109 | |
| 110 | $lx_per_cpu("VAR"[, CPU]): Return the per-cpu variable called VAR for the |
| 111 | given CPU number. If CPU is omitted, the CPU of the current context is used. |
| 112 | Note that VAR has to be quoted as string.""" |
| 113 | |
| 114 | def __init__(self): |
| 115 | super(PerCpu, self).__init__("lx_per_cpu") |
| 116 | |
| 117 | def invoke(self, var_name, cpu=-1): |
| 118 | var_ptr = gdb.parse_and_eval("&" + var_name.string()) |
| 119 | return per_cpu(var_ptr, cpu) |
| 120 | |
| 121 | |
| 122 | PerCpu() |
Jan Kiszka | 116b47b | 2015-02-17 13:47:24 -0800 | [diff] [blame] | 123 | |
| 124 | |
| 125 | class LxCurrentFunc(gdb.Function): |
| 126 | """Return current task. |
| 127 | |
| 128 | $lx_current([CPU]): Return the per-cpu task variable for the given CPU |
| 129 | number. If CPU is omitted, the CPU of the current context is used.""" |
| 130 | |
| 131 | def __init__(self): |
| 132 | super(LxCurrentFunc, self).__init__("lx_current") |
| 133 | |
| 134 | def invoke(self, cpu=-1): |
| 135 | var_ptr = gdb.parse_and_eval("¤t_task") |
| 136 | return per_cpu(var_ptr, cpu).dereference() |
| 137 | |
| 138 | |
| 139 | LxCurrentFunc() |