diff options
Diffstat (limited to 'kernel/scripts/gdb/linux')
| -rw-r--r-- | kernel/scripts/gdb/linux/.gitignore | 2 | ||||
| -rw-r--r-- | kernel/scripts/gdb/linux/Makefile | 11 | ||||
| -rw-r--r-- | kernel/scripts/gdb/linux/__init__.py | 1 | ||||
| -rw-r--r-- | kernel/scripts/gdb/linux/cpus.py | 135 | ||||
| -rw-r--r-- | kernel/scripts/gdb/linux/dmesg.py | 65 | ||||
| -rw-r--r-- | kernel/scripts/gdb/linux/modules.py | 96 | ||||
| -rw-r--r-- | kernel/scripts/gdb/linux/symbols.py | 177 | ||||
| -rw-r--r-- | kernel/scripts/gdb/linux/tasks.py | 100 | ||||
| -rw-r--r-- | kernel/scripts/gdb/linux/utils.py | 156 |
9 files changed, 743 insertions, 0 deletions
diff --git a/kernel/scripts/gdb/linux/.gitignore b/kernel/scripts/gdb/linux/.gitignore new file mode 100644 index 000000000..52e4e6114 --- /dev/null +++ b/kernel/scripts/gdb/linux/.gitignore @@ -0,0 +1,2 @@ +*.pyc +*.pyo diff --git a/kernel/scripts/gdb/linux/Makefile b/kernel/scripts/gdb/linux/Makefile new file mode 100644 index 000000000..6cf1ecf61 --- /dev/null +++ b/kernel/scripts/gdb/linux/Makefile @@ -0,0 +1,11 @@ +always := gdb-scripts + +SRCTREE := $(shell cd $(srctree) && /bin/pwd) + +$(obj)/gdb-scripts: +ifneq ($(KBUILD_SRC),) + $(Q)ln -fsn $(SRCTREE)/$(obj)/*.py $(objtree)/$(obj) +endif + @: + +clean-files := *.pyc *.pyo $(if $(KBUILD_SRC),*.py) diff --git a/kernel/scripts/gdb/linux/__init__.py b/kernel/scripts/gdb/linux/__init__.py new file mode 100644 index 000000000..4680fb176 --- /dev/null +++ b/kernel/scripts/gdb/linux/__init__.py @@ -0,0 +1 @@ +# nothing to do for the initialization of this package diff --git a/kernel/scripts/gdb/linux/cpus.py b/kernel/scripts/gdb/linux/cpus.py new file mode 100644 index 000000000..4297b83fe --- /dev/null +++ b/kernel/scripts/gdb/linux/cpus.py @@ -0,0 +1,135 @@ +# +# 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("¤t_task") + return per_cpu(var_ptr, cpu).dereference() + + +LxCurrentFunc() diff --git a/kernel/scripts/gdb/linux/dmesg.py b/kernel/scripts/gdb/linux/dmesg.py new file mode 100644 index 000000000..3c947f0c5 --- /dev/null +++ b/kernel/scripts/gdb/linux/dmesg.py @@ -0,0 +1,65 @@ +# +# gdb helper commands and functions for Linux kernel debugging +# +# kernel log buffer dump +# +# Copyright (c) Siemens AG, 2011, 2012 +# +# Authors: +# Jan Kiszka <jan.kiszka@siemens.com> +# +# This work is licensed under the terms of the GNU GPL version 2. +# + +import gdb +import string + +from linux import utils + + +class LxDmesg(gdb.Command): + """Print Linux kernel log buffer.""" + + def __init__(self): + super(LxDmesg, self).__init__("lx-dmesg", gdb.COMMAND_DATA) + + def invoke(self, arg, from_tty): + log_buf_addr = int(str(gdb.parse_and_eval("log_buf")).split()[0], 16) + log_first_idx = int(gdb.parse_and_eval("log_first_idx")) + log_next_idx = int(gdb.parse_and_eval("log_next_idx")) + log_buf_len = int(gdb.parse_and_eval("log_buf_len")) + + inf = gdb.inferiors()[0] + start = log_buf_addr + log_first_idx + if log_first_idx < log_next_idx: + log_buf_2nd_half = -1 + length = log_next_idx - log_first_idx + log_buf = inf.read_memory(start, length) + else: + log_buf_2nd_half = log_buf_len - log_first_idx + log_buf = inf.read_memory(start, log_buf_2nd_half) + \ + inf.read_memory(log_buf_addr, log_next_idx) + + pos = 0 + while pos < log_buf.__len__(): + length = utils.read_u16(log_buf[pos + 8:pos + 10]) + if length == 0: + if log_buf_2nd_half == -1: + gdb.write("Corrupted log buffer!\n") + break + pos = log_buf_2nd_half + continue + + text_len = utils.read_u16(log_buf[pos + 10:pos + 12]) + text = log_buf[pos + 16:pos + 16 + text_len] + time_stamp = utils.read_u64(log_buf[pos:pos + 8]) + + for line in memoryview(text).tobytes().splitlines(): + gdb.write("[{time:12.6f}] {line}\n".format( + time=time_stamp / 1000000000.0, + line=line)) + + pos += length + + +LxDmesg() diff --git a/kernel/scripts/gdb/linux/modules.py b/kernel/scripts/gdb/linux/modules.py new file mode 100644 index 000000000..25db8cff4 --- /dev/null +++ b/kernel/scripts/gdb/linux/modules.py @@ -0,0 +1,96 @@ +# +# gdb helper commands and functions for Linux kernel debugging +# +# module tools +# +# Copyright (c) Siemens AG, 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 cpus, utils + + +module_type = utils.CachedType("struct module") + + +def module_list(): + global module_type + module_ptr_type = module_type.get_type().pointer() + modules = gdb.parse_and_eval("modules") + entry = modules['next'] + end_of_list = modules.address + + while entry != end_of_list: + yield utils.container_of(entry, module_ptr_type, "list") + entry = entry['next'] + + +def find_module_by_name(name): + for module in module_list(): + if module['name'].string() == name: + return module + return None + + +class LxModule(gdb.Function): + """Find module by name and return the module variable. + +$lx_module("MODULE"): Given the name MODULE, iterate over all loaded modules +of the target and return that module variable which MODULE matches.""" + + def __init__(self): + super(LxModule, self).__init__("lx_module") + + def invoke(self, mod_name): + mod_name = mod_name.string() + module = find_module_by_name(mod_name) + if module: + return module.dereference() + else: + raise gdb.GdbError("Unable to find MODULE " + mod_name) + + +LxModule() + + +class LxLsmod(gdb.Command): + """List currently loaded modules.""" + + _module_use_type = utils.CachedType("struct module_use") + + def __init__(self): + super(LxLsmod, self).__init__("lx-lsmod", gdb.COMMAND_DATA) + + def invoke(self, arg, from_tty): + gdb.write( + "Address{0} Module Size Used by\n".format( + " " if utils.get_long_type().sizeof == 8 else "")) + + for module in module_list(): + gdb.write("{address} {name:<19} {size:>8} {ref}".format( + address=str(module['module_core']).split()[0], + name=module['name'].string(), + size=str(module['core_size']), + ref=str(module['refcnt']['counter']))) + + source_list = module['source_list'] + t = self._module_use_type.get_type().pointer() + entry = source_list['next'] + first = True + while entry != source_list.address: + use = utils.container_of(entry, t, "source_list") + gdb.write("{separator}{name}".format( + separator=" " if first else ",", + name=use['source']['name'].string())) + first = False + entry = entry['next'] + gdb.write("\n") + + +LxLsmod() diff --git a/kernel/scripts/gdb/linux/symbols.py b/kernel/scripts/gdb/linux/symbols.py new file mode 100644 index 000000000..cd5bea965 --- /dev/null +++ b/kernel/scripts/gdb/linux/symbols.py @@ -0,0 +1,177 @@ +# +# gdb helper commands and functions for Linux kernel debugging +# +# load kernel and module symbols +# +# 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 +import os +import re +import string + +from linux import modules, utils + + +if hasattr(gdb, 'Breakpoint'): + class LoadModuleBreakpoint(gdb.Breakpoint): + def __init__(self, spec, gdb_command): + super(LoadModuleBreakpoint, self).__init__(spec, internal=True) + self.silent = True + self.gdb_command = gdb_command + + def stop(self): + module = gdb.parse_and_eval("mod") + module_name = module['name'].string() + cmd = self.gdb_command + + # enforce update if object file is not found + cmd.module_files_updated = False + + # Disable pagination while reporting symbol (re-)loading. + # The console input is blocked in this context so that we would + # get stuck waiting for the user to acknowledge paged output. + show_pagination = gdb.execute("show pagination", to_string=True) + pagination = show_pagination.endswith("on.\n") + gdb.execute("set pagination off") + + if module_name in cmd.loaded_modules: + gdb.write("refreshing all symbols to reload module " + "'{0}'\n".format(module_name)) + cmd.load_all_symbols() + else: + cmd.load_module_symbols(module) + + # restore pagination state + gdb.execute("set pagination %s" % ("on" if pagination else "off")) + + return False + + +class LxSymbols(gdb.Command): + """(Re-)load symbols of Linux kernel and currently loaded modules. + +The kernel (vmlinux) is taken from the current working directly. Modules (.ko) +are scanned recursively, starting in the same directory. Optionally, the module +search path can be extended by a space separated list of paths passed to the +lx-symbols command.""" + + module_paths = [] + module_files = [] + module_files_updated = False + loaded_modules = [] + breakpoint = None + + def __init__(self): + super(LxSymbols, self).__init__("lx-symbols", gdb.COMMAND_FILES, + gdb.COMPLETE_FILENAME) + + def _update_module_files(self): + self.module_files = [] + for path in self.module_paths: + gdb.write("scanning for modules in {0}\n".format(path)) + for root, dirs, files in os.walk(path): + for name in files: + if name.endswith(".ko"): + self.module_files.append(root + "/" + name) + self.module_files_updated = True + + def _get_module_file(self, module_name): + module_pattern = ".*/{0}\.ko$".format( + module_name.replace("_", r"[_\-]")) + for name in self.module_files: + if re.match(module_pattern, name) and os.path.exists(name): + return name + return None + + def _section_arguments(self, module): + try: + sect_attrs = module['sect_attrs'].dereference() + except gdb.error: + return "" + attrs = sect_attrs['attrs'] + section_name_to_address = { + attrs[n]['name'].string() : attrs[n]['address'] + for n in range(int(sect_attrs['nsections']))} + args = [] + for section_name in [".data", ".data..read_mostly", ".rodata", ".bss"]: + address = section_name_to_address.get(section_name) + if address: + args.append(" -s {name} {addr}".format( + name=section_name, addr=str(address))) + return "".join(args) + + def load_module_symbols(self, module): + module_name = module['name'].string() + module_addr = str(module['module_core']).split()[0] + + module_file = self._get_module_file(module_name) + if not module_file and not self.module_files_updated: + self._update_module_files() + module_file = self._get_module_file(module_name) + + if module_file: + gdb.write("loading @{addr}: {filename}\n".format( + addr=module_addr, filename=module_file)) + cmdline = "add-symbol-file {filename} {addr}{sections}".format( + filename=module_file, + addr=module_addr, + sections=self._section_arguments(module)) + gdb.execute(cmdline, to_string=True) + if not module_name in self.loaded_modules: + self.loaded_modules.append(module_name) + else: + gdb.write("no module object found for '{0}'\n".format(module_name)) + + def load_all_symbols(self): + gdb.write("loading vmlinux\n") + + # Dropping symbols will disable all breakpoints. So save their states + # and restore them afterward. + saved_states = [] + if hasattr(gdb, 'breakpoints') and not gdb.breakpoints() is None: + for bp in gdb.breakpoints(): + saved_states.append({'breakpoint': bp, 'enabled': bp.enabled}) + + # drop all current symbols and reload vmlinux + gdb.execute("symbol-file", to_string=True) + gdb.execute("symbol-file vmlinux") + + self.loaded_modules = [] + module_list = modules.module_list() + if not module_list: + gdb.write("no modules found\n") + else: + [self.load_module_symbols(module) for module in module_list] + + for saved_state in saved_states: + saved_state['breakpoint'].enabled = saved_state['enabled'] + + def invoke(self, arg, from_tty): + self.module_paths = arg.split() + self.module_paths.append(os.getcwd()) + + # enforce update + self.module_files = [] + self.module_files_updated = False + + self.load_all_symbols() + + if hasattr(gdb, 'Breakpoint'): + if not self.breakpoint is None: + self.breakpoint.delete() + self.breakpoint = None + self.breakpoint = LoadModuleBreakpoint( + "kernel/module.c:do_init_module", self) + else: + gdb.write("Note: symbol update on module loading not supported " + "with this gdb version\n") + + +LxSymbols() diff --git a/kernel/scripts/gdb/linux/tasks.py b/kernel/scripts/gdb/linux/tasks.py new file mode 100644 index 000000000..e2037d9bb --- /dev/null +++ b/kernel/scripts/gdb/linux/tasks.py @@ -0,0 +1,100 @@ +# +# gdb helper commands and functions for Linux kernel debugging +# +# task & thread 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 utils + + +task_type = utils.CachedType("struct task_struct") + +def task_lists(): + global task_type + task_ptr_type = task_type.get_type().pointer() + init_task = gdb.parse_and_eval("init_task").address + t = g = init_task + + while True: + while True: + yield t + + t = utils.container_of(t['thread_group']['next'], + task_ptr_type, "thread_group") + if t == g: + break + + t = g = utils.container_of(g['tasks']['next'], + task_ptr_type, "tasks") + if t == init_task: + return + +def get_task_by_pid(pid): + for task in task_lists(): + if int(task['pid']) == pid: + return task + return None + + +class LxTaskByPidFunc(gdb.Function): + """Find Linux task by PID and return the task_struct variable. + +$lx_task_by_pid(PID): Given PID, iterate over all tasks of the target and +return that task_struct variable which PID matches.""" + + def __init__(self): + super(LxTaskByPidFunc, self).__init__("lx_task_by_pid") + + def invoke(self, pid): + task = get_task_by_pid(pid) + if task: + return task.dereference() + else: + raise gdb.GdbError("No task of PID " + str(pid)) + + +LxTaskByPidFunc() + + +thread_info_type = utils.CachedType("struct thread_info") + +ia64_task_size = None + + +def get_thread_info(task): + global thread_info_type + thread_info_ptr_type = thread_info_type.get_type().pointer() + if utils.is_target_arch("ia64"): + global ia64_task_size + if ia64_task_size is None: + ia64_task_size = gdb.parse_and_eval("sizeof(struct task_struct)") + thread_info_addr = task.address + ia64_task_size + thread_info = thread_info_addr.cast(thread_info_ptr_type) + else: + thread_info = task['stack'].cast(thread_info_ptr_type) + return thread_info.dereference() + + +class LxThreadInfoFunc (gdb.Function): + """Calculate Linux thread_info from task variable. + +$lx_thread_info(TASK): Given TASK, return the corresponding thread_info +variable.""" + + def __init__(self): + super(LxThreadInfoFunc, self).__init__("lx_thread_info") + + def invoke(self, task): + return get_thread_info(task) + + +LxThreadInfoFunc() diff --git a/kernel/scripts/gdb/linux/utils.py b/kernel/scripts/gdb/linux/utils.py new file mode 100644 index 000000000..128c306db --- /dev/null +++ b/kernel/scripts/gdb/linux/utils.py @@ -0,0 +1,156 @@ +# +# gdb helper commands and functions for Linux kernel debugging +# +# common utilities +# +# Copyright (c) Siemens AG, 2011-2013 +# +# Authors: +# Jan Kiszka <jan.kiszka@siemens.com> +# +# This work is licensed under the terms of the GNU GPL version 2. +# + +import gdb + + +class CachedType: + def __init__(self, name): + self._type = None + self._name = name + + def _new_objfile_handler(self, event): + self._type = None + gdb.events.new_objfile.disconnect(self._new_objfile_handler) + + def get_type(self): + if self._type is None: + self._type = gdb.lookup_type(self._name) + if self._type is None: + raise gdb.GdbError( + "cannot resolve type '{0}'".format(self._name)) + if hasattr(gdb, 'events') and hasattr(gdb.events, 'new_objfile'): + gdb.events.new_objfile.connect(self._new_objfile_handler) + return self._type + + +long_type = CachedType("long") + + +def get_long_type(): + global long_type + return long_type.get_type() + + +def offset_of(typeobj, field): + element = gdb.Value(0).cast(typeobj) + return int(str(element[field].address).split()[0], 16) + + +def container_of(ptr, typeobj, member): + return (ptr.cast(get_long_type()) - + offset_of(typeobj, member)).cast(typeobj) + + +class ContainerOf(gdb.Function): + """Return pointer to containing data structure. + +$container_of(PTR, "TYPE", "ELEMENT"): Given PTR, return a pointer to the +data structure of the type TYPE in which PTR is the address of ELEMENT. +Note that TYPE and ELEMENT have to be quoted as strings.""" + + def __init__(self): + super(ContainerOf, self).__init__("container_of") + + def invoke(self, ptr, typename, elementname): + return container_of(ptr, gdb.lookup_type(typename.string()).pointer(), + elementname.string()) + +ContainerOf() + + +BIG_ENDIAN = 0 +LITTLE_ENDIAN = 1 +target_endianness = None + + +def get_target_endianness(): + global target_endianness + if target_endianness is None: + endian = gdb.execute("show endian", to_string=True) + if "little endian" in endian: + target_endianness = LITTLE_ENDIAN + elif "big endian" in endian: + target_endianness = BIG_ENDIAN + else: + raise gdb.GdgError("unknown endianness '{0}'".format(str(endian))) + return target_endianness + + +def read_u16(buffer): + if get_target_endianness() == LITTLE_ENDIAN: + return ord(buffer[0]) + (ord(buffer[1]) << 8) + else: + return ord(buffer[1]) + (ord(buffer[0]) << 8) + + +def read_u32(buffer): + if get_target_endianness() == LITTLE_ENDIAN: + return read_u16(buffer[0:2]) + (read_u16(buffer[2:4]) << 16) + else: + return read_u16(buffer[2:4]) + (read_u16(buffer[0:2]) << 16) + + +def read_u64(buffer): + if get_target_endianness() == LITTLE_ENDIAN: + return read_u32(buffer[0:4]) + (read_u32(buffer[4:8]) << 32) + else: + return read_u32(buffer[4:8]) + (read_u32(buffer[0:4]) << 32) + + +target_arch = None + + +def is_target_arch(arch): + if hasattr(gdb.Frame, 'architecture'): + return arch in gdb.newest_frame().architecture().name() + else: + global target_arch + if target_arch is None: + target_arch = gdb.execute("show architecture", to_string=True) + return arch in target_arch + + +GDBSERVER_QEMU = 0 +GDBSERVER_KGDB = 1 +gdbserver_type = None + + +def get_gdbserver_type(): + def exit_handler(event): + global gdbserver_type + gdbserver_type = None + gdb.events.exited.disconnect(exit_handler) + + def probe_qemu(): + try: + return gdb.execute("monitor info version", to_string=True) != "" + except: + return False + + def probe_kgdb(): + try: + thread_info = gdb.execute("info thread 2", to_string=True) + return "shadowCPU0" in thread_info + except: + return False + + global gdbserver_type + if gdbserver_type is None: + if probe_qemu(): + gdbserver_type = GDBSERVER_QEMU + elif probe_kgdb(): + gdbserver_type = GDBSERVER_KGDB + if not gdbserver_type is None and hasattr(gdb, 'events'): + gdb.events.exited.connect(exit_handler) + return gdbserver_type |