| #!/usr/bin/env python |
| # |
| # trace Trace a function and print a trace message based on its |
| # parameters, with an optional filter. |
| # |
| # USAGE: trace [-h] [-p PID] [-v] [-Z STRING_SIZE] [-S] [-M MAX_EVENTS] [-o] |
| # probe [probe ...] |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License") |
| # Copyright (C) 2016 Sasha Goldshtein. |
| |
| from bcc import BPF |
| from time import sleep, strftime |
| import argparse |
| import re |
| import ctypes as ct |
| import multiprocessing |
| import os |
| import traceback |
| import sys |
| |
| class Time(object): |
| # BPF timestamps come from the monotonic clock. To be able to filter |
| # and compare them from Python, we need to invoke clock_gettime. |
| # Adapted from http://stackoverflow.com/a/1205762 |
| CLOCK_MONOTONIC_RAW = 4 # see <linux/time.h> |
| |
| class timespec(ct.Structure): |
| _fields_ = [ |
| ('tv_sec', ct.c_long), |
| ('tv_nsec', ct.c_long) |
| ] |
| |
| librt = ct.CDLL('librt.so.1', use_errno=True) |
| clock_gettime = librt.clock_gettime |
| clock_gettime.argtypes = [ct.c_int, ct.POINTER(timespec)] |
| |
| @staticmethod |
| def monotonic_time(): |
| t = Time.timespec() |
| if Time.clock_gettime( |
| Time.CLOCK_MONOTONIC_RAW, ct.pointer(t)) != 0: |
| errno_ = ct.get_errno() |
| raise OSError(errno_, os.strerror(errno_)) |
| return t.tv_sec * 1e9 + t.tv_nsec |
| |
| class Perf(object): |
| class perf_event_attr(ct.Structure): |
| _fields_ = [ |
| ('type', ct.c_uint), |
| ('size', ct.c_uint), |
| ('config', ct.c_ulong), |
| ('sample_period', ct.c_ulong), |
| ('sample_type', ct.c_ulong), |
| ('IGNORE1', ct.c_ulong), |
| ('IGNORE2', ct.c_ulong), |
| ('wakeup_events', ct.c_uint), |
| ('IGNORE3', ct.c_uint), |
| ('IGNORE4', ct.c_ulong), |
| ('IGNORE5', ct.c_ulong), |
| ('IGNORE6', ct.c_ulong), |
| ('IGNORE7', ct.c_uint), |
| ('IGNORE8', ct.c_int), |
| ('IGNORE9', ct.c_ulong), |
| ('IGNORE10', ct.c_uint), |
| ('IGNORE11', ct.c_uint) |
| ] |
| |
| NR_PERF_EVENT_OPEN = 298 |
| PERF_TYPE_TRACEPOINT = 2 |
| PERF_SAMPLE_RAW = 1024 |
| PERF_FLAG_FD_CLOEXEC = 8 |
| PERF_EVENT_IOC_SET_FILTER = 1074275334 |
| PERF_EVENT_IOC_ENABLE = 9216 |
| |
| libc = ct.CDLL('libc.so.6', use_errno=True) |
| syscall = libc.syscall # not declaring vararg types |
| ioctl = libc.ioctl # not declaring vararg types |
| |
| @staticmethod |
| def _open_for_cpu(cpu, attr): |
| pfd = Perf.syscall(Perf.NR_PERF_EVENT_OPEN, ct.byref(attr), |
| -1, cpu, -1, Perf.PERF_FLAG_FD_CLOEXEC) |
| if pfd < 0: |
| errno_ = ct.get_errno() |
| raise OSError(errno_, os.strerror(errno_)) |
| if Perf.ioctl(pfd, Perf.PERF_EVENT_IOC_SET_FILTER, |
| "common_pid == -17") < 0: |
| errno_ = ct.get_errno() |
| raise OSError(errno_, os.strerror(errno_)) |
| if Perf.ioctl(pfd, Perf.PERF_EVENT_IOC_ENABLE, 0) < 0: |
| errno_ = ct.get_errno() |
| raise OSError(errno_, os.strerror(errno_)) |
| |
| @staticmethod |
| def perf_event_open(tpoint_id): |
| attr = Perf.perf_event_attr() |
| attr.config = tpoint_id |
| attr.type = Perf.PERF_TYPE_TRACEPOINT |
| attr.sample_type = Perf.PERF_SAMPLE_RAW |
| attr.sample_period = 1 |
| attr.wakeup_events = 1 |
| for cpu in range(0, multiprocessing.cpu_count()): |
| Perf._open_for_cpu(cpu, attr) |
| |
| class Tracepoint(object): |
| tracepoints_enabled = 0 |
| trace_root = "/sys/kernel/debug/tracing" |
| event_root = os.path.join(trace_root, "events") |
| |
| @staticmethod |
| def generate_decl(): |
| if Tracepoint.tracepoints_enabled == 0: |
| return "" |
| return "\nBPF_HASH(__trace_di, u64, u64);\n" |
| |
| @staticmethod |
| def generate_entry_probe(): |
| if Tracepoint.tracepoints_enabled == 0: |
| return "" |
| return """ |
| int __trace_entry_update(struct pt_regs *ctx) |
| { |
| u64 tid = bpf_get_current_pid_tgid(); |
| u64 val = ctx->di; |
| __trace_di.update(&tid, &val); |
| return 0; |
| } |
| """ |
| |
| @staticmethod |
| def enable_tracepoint(category, event): |
| tp_id = Tracepoint.get_tpoint_id(category, event) |
| if tp_id == -1: |
| raise ValueError("no such tracepoint found: %s:%s" % |
| (category, event)) |
| Perf.perf_event_open(tp_id) |
| Tracepoint.tracepoints_enabled += 1 |
| |
| @staticmethod |
| def get_tpoint_id(category, event): |
| evt_dir = os.path.join(Tracepoint.event_root, category, event) |
| try: |
| return int( |
| open(os.path.join(evt_dir, "id")).read().strip()) |
| except: |
| return -1 |
| |
| @staticmethod |
| def get_tpoint_format(category, event): |
| evt_dir = os.path.join(Tracepoint.event_root, category, event) |
| try: |
| return open(os.path.join(evt_dir, "format")).readlines() |
| except: |
| return "" |
| |
| @staticmethod |
| def attach(bpf): |
| if Tracepoint.tracepoints_enabled > 0: |
| bpf.attach_kprobe(event="tracing_generic_entry_update", |
| fn_name="__trace_entry_update") |
| |
| class Probe(object): |
| probe_count = 0 |
| max_events = None |
| event_count = 0 |
| first_ts = 0 |
| use_localtime = True |
| |
| @classmethod |
| def configure(cls, args): |
| cls.max_events = args.max_events |
| cls.use_localtime = not args.offset |
| cls.first_ts = Time.monotonic_time() |
| |
| def __init__(self, probe, string_size): |
| self.raw_probe = probe |
| self.string_size = string_size |
| Probe.probe_count += 1 |
| self._parse_probe() |
| self.probe_num = Probe.probe_count |
| self.probe_name = "probe_%s_%d" % \ |
| (self.function, self.probe_num) |
| |
| def __str__(self): |
| return "%s:%s`%s FLT=%s ACT=%s/%s" % (self.probe_type, |
| self.library, self.function, self.filter, |
| self.types, self.values) |
| |
| def is_default_action(self): |
| return self.python_format == "" |
| |
| def _generate_tpoint_entry_struct_fields(self): |
| format_lines = Tracepoint.get_tpoint_format(self.tp_category, |
| self.tp_event) |
| text = "" |
| for line in format_lines: |
| match = re.search(r'field:([^;]*);.*size:(\d+);', line) |
| if match is None: |
| continue |
| parts = match.group(1).split() |
| field_name = parts[-1:][0] |
| field_type = " ".join(parts[:-1]) |
| field_size = int(match.group(2)) |
| if "__data_loc" in field_type: |
| continue |
| if field_name.startswith("common_"): |
| continue |
| text += " %s %s;\n" % (field_type, field_name) |
| return text |
| |
| def _generate_tpoint_entry_struct(self): |
| text = """ |
| struct %s { |
| u64 __do_not_use__; |
| %s |
| }; |
| """ |
| self.tp_entry_struct_name = self.probe_name + \ |
| "_trace_entry" |
| fields = self._generate_tpoint_entry_struct_fields() |
| return text % (self.tp_entry_struct_name, fields) |
| |
| def _generate_tpoint_entry_prefix(self): |
| text = """ |
| u64 tid = bpf_get_current_pid_tgid(); |
| u64 *di = __trace_di.lookup(&tid); |
| if (di == 0) { return 0; } |
| struct %s tp = {}; |
| bpf_probe_read(&tp, sizeof(tp), (void *)*di); |
| """ % self.tp_entry_struct_name |
| return text |
| |
| def _bail(self, error): |
| raise ValueError("error parsing probe '%s': %s" % |
| (self.raw_probe, error)) |
| |
| def _parse_probe(self): |
| text = self.raw_probe |
| |
| # Everything until the first space is the probe specifier |
| first_space = text.find(' ') |
| spec = text[:first_space] if first_space >= 0 else text |
| self._parse_spec(spec) |
| if first_space >= 0: |
| text = text[first_space:].lstrip() |
| else: |
| text = "" |
| |
| # If we now have a (, wait for the balanced closing ) and that |
| # will be the predicate |
| self.filter = None |
| if len(text) > 0 and text[0] == "(": |
| balance = 1 |
| for i in range(1, len(text)): |
| if text[i] == "(": |
| balance += 1 |
| if text[i] == ")": |
| balance -= 1 |
| if balance == 0: |
| self._parse_filter(text[:i+1]) |
| text = text[i+1:] |
| break |
| if self.filter is None: |
| self._bail("unmatched end of predicate") |
| |
| if self.filter is None: |
| self.filter = "1" |
| |
| # The remainder of the text is the printf action |
| self._parse_action(text.lstrip()) |
| |
| def _parse_spec(self, spec): |
| parts = spec.split(":") |
| # Two special cases: 'func' means 'p::func', 'lib:func' means |
| # 'p:lib:func'. Other combinations need to provide an empty |
| # value between delimiters, e.g. 'r::func' for a kretprobe on |
| # the function func. |
| if len(parts) == 1: |
| parts = ["p", "", parts[0]] |
| elif len(parts) == 2: |
| parts = ["p", parts[0], parts[1]] |
| if len(parts[0]) == 0: |
| self.probe_type = "p" |
| elif parts[0] in ["p", "r", "t"]: |
| self.probe_type = parts[0] |
| else: |
| self._bail("expected '', 'p', 't', or 'r', got '%s'" % |
| parts[0]) |
| if self.probe_type == "t": |
| self.tp_category = parts[1] |
| self.tp_event = parts[2] |
| Tracepoint.enable_tracepoint(self.tp_category, |
| self.tp_event) |
| self.library = "" # kernel |
| self.function = "perf_trace_%s" % self.tp_event |
| else: |
| self.library = parts[1] |
| self.function = parts[2] |
| |
| def _parse_filter(self, filt): |
| self.filter = self._replace_args(filt) |
| |
| def _parse_types(self, fmt): |
| for match in re.finditer( |
| r'[^%]%(s|u|d|llu|lld|hu|hd|x|llx|c)', fmt): |
| self.types.append(match.group(1)) |
| fmt = re.sub(r'([^%]%)(u|d|llu|lld|hu|hd)', r'\1d', fmt) |
| fmt = re.sub(r'([^%]%)(x|llx)', r'\1x', fmt) |
| self.python_format = fmt.strip('"') |
| |
| def _parse_action(self, action): |
| self.values = [] |
| self.types = [] |
| self.python_format = "" |
| if len(action) == 0: |
| return |
| |
| action = action.strip() |
| match = re.search(r'(\".*\"),?(.*)', action) |
| if match is None: |
| self._bail("expected format string in \"s") |
| |
| self.raw_format = match.group(1) |
| self._parse_types(self.raw_format) |
| for part in match.group(2).split(','): |
| part = self._replace_args(part) |
| if len(part) > 0: |
| self.values.append(part) |
| |
| aliases = { |
| "retval": "ctx->ax", |
| "arg1": "ctx->di", |
| "arg2": "ctx->si", |
| "arg3": "ctx->dx", |
| "arg4": "ctx->cx", |
| "arg5": "ctx->r8", |
| "arg6": "ctx->r9", |
| "$uid": "(unsigned)(bpf_get_current_uid_gid() & 0xffffffff)", |
| "$gid": "(unsigned)(bpf_get_current_uid_gid() >> 32)", |
| "$pid": "(unsigned)(bpf_get_current_pid_tgid() & 0xffffffff)", |
| "$tgid": "(unsigned)(bpf_get_current_pid_tgid() >> 32)", |
| "$cpu": "bpf_get_smp_processor_id()" |
| } |
| |
| def _replace_args(self, expr): |
| for alias, replacement in Probe.aliases.items(): |
| expr = expr.replace(alias, replacement) |
| return expr |
| |
| p_type = { "u": ct.c_uint, "d": ct.c_int, |
| "llu": ct.c_ulonglong, "lld": ct.c_longlong, |
| "hu": ct.c_ushort, "hd": ct.c_short, |
| "x": ct.c_uint, "llx": ct.c_ulonglong, |
| "c": ct.c_ubyte } |
| |
| def _generate_python_field_decl(self, idx, fields): |
| field_type = self.types[idx] |
| if field_type == "s": |
| ptype = ct.c_char * self.string_size |
| else: |
| ptype = Probe.p_type[field_type] |
| fields.append(("v%d" % idx, ptype)) |
| |
| def _generate_python_data_decl(self): |
| self.python_struct_name = "%s_%d_Data" % \ |
| (self.function, self.probe_num) |
| fields = [ |
| ("timestamp_ns", ct.c_ulonglong), |
| ("pid", ct.c_uint), |
| ("comm", ct.c_char * 16) # TASK_COMM_LEN |
| ] |
| for i in range(0, len(self.types)): |
| self._generate_python_field_decl(i, fields) |
| return type(self.python_struct_name, (ct.Structure,), |
| dict(_fields_=fields)) |
| |
| c_type = { "u": "unsigned int", "d": "int", |
| "llu": "unsigned long long", "lld": "long long", |
| "hu": "unsigned short", "hd": "short", |
| "x": "unsigned int", "llx": "unsigned long long", |
| "c": "char" } |
| fmt_types = c_type.keys() |
| |
| def _generate_field_decl(self, idx): |
| field_type = self.types[idx] |
| if field_type == "s": |
| return "char v%d[%d];\n" % (idx, self.string_size) |
| if field_type in Probe.fmt_types: |
| return "%s v%d;\n" % (Probe.c_type[field_type], idx) |
| self._bail("unrecognized format specifier %s" % field_type) |
| |
| def _generate_data_decl(self): |
| # The BPF program will populate values into the struct |
| # according to the format string, and the Python program will |
| # construct the final display string. |
| self.events_name = "%s_events" % self.probe_name |
| self.struct_name = "%s_data_t" % self.probe_name |
| |
| data_fields = "" |
| for i, field_type in enumerate(self.types): |
| data_fields += " " + \ |
| self._generate_field_decl(i) |
| |
| text = """ |
| struct %s |
| { |
| u64 timestamp_ns; |
| u32 pid; |
| char comm[TASK_COMM_LEN]; |
| %s |
| }; |
| |
| BPF_PERF_OUTPUT(%s); |
| """ |
| return text % (self.struct_name, data_fields, self.events_name) |
| |
| def _generate_field_assign(self, idx): |
| field_type = self.types[idx] |
| expr = self.values[idx] |
| if field_type == "s": |
| return """ |
| if (%s != 0) { |
| bpf_probe_read(&__data.v%d, sizeof(__data.v%d), (void *)%s); |
| } |
| """ % (expr, idx, idx, expr) |
| # return ("bpf_probe_read(&__data.v%d, " + \ |
| # "sizeof(__data.v%d), (char*)%s);\n") % (idx, idx, expr) |
| # return ("__builtin_memcpy(&__data.v%d, (void *)%s, " + \ |
| # "sizeof(__data.v%d));\n") % (idx, expr, idx) |
| if field_type in Probe.fmt_types: |
| return " __data.v%d = (%s)%s;\n" % \ |
| (idx, Probe.c_type[field_type], expr) |
| self._bail("unrecognized field type %s" % field_type) |
| |
| def generate_program(self, pid, include_self): |
| data_decl = self._generate_data_decl() |
| self.pid = pid |
| # kprobes don't have built-in pid filters, so we have to add |
| # it to the function body: |
| if len(self.library) == 0 and pid != -1: |
| pid_filter = """ |
| u32 __pid = bpf_get_current_pid_tgid(); |
| if (__pid != %d) { return 0; } |
| """ % pid |
| elif not include_self: |
| pid_filter = """ |
| u32 __pid = bpf_get_current_pid_tgid(); |
| if (__pid == %d) { return 0; } |
| """ % os.getpid() |
| else: |
| pid_filter = "" |
| |
| data_fields = "" |
| for i, expr in enumerate(self.values): |
| data_fields += self._generate_field_assign(i) |
| |
| prefix = "" |
| if self.probe_type == "t": |
| data_decl += self._generate_tpoint_entry_struct() |
| prefix = self._generate_tpoint_entry_prefix() |
| |
| text = """ |
| int %s(struct pt_regs *ctx) |
| { |
| %s |
| %s |
| if (!(%s)) return 0; |
| |
| struct %s __data = {0}; |
| __data.timestamp_ns = bpf_ktime_get_ns(); |
| __data.pid = bpf_get_current_pid_tgid(); |
| bpf_get_current_comm(&__data.comm, sizeof(__data.comm)); |
| %s |
| %s.perf_submit(ctx, &__data, sizeof(__data)); |
| return 0; |
| } |
| """ |
| text = text % (self.probe_name, pid_filter, prefix, |
| self.filter, self.struct_name, |
| data_fields, self.events_name) |
| |
| return data_decl + "\n" + text |
| |
| @classmethod |
| def _time_off_str(cls, timestamp_ns): |
| return "%.6f" % (1e-9 * (timestamp_ns - cls.first_ts)) |
| |
| auto_includes = { |
| "linux/time.h" : ["time"], |
| "linux/fs.h" : ["fs", "file"], |
| "linux/blkdev.h" : ["bio", "request"], |
| "linux/slab.h" : ["alloc"], |
| "linux/netdevice.h" : ["sk_buff"] |
| } |
| |
| @classmethod |
| def generate_auto_includes(cls, probes): |
| headers = "" |
| for header, keywords in cls.auto_includes.items(): |
| for keyword in keywords: |
| for probe in probes: |
| if keyword in probe: |
| headers += "#include <%s>\n" \ |
| % header |
| return headers |
| |
| def _display_function(self): |
| if self.probe_type != 't': |
| return self.function |
| else: |
| return self.function.replace("perf_trace_", "") |
| |
| def print_event(self, cpu, data, size): |
| # Cast as the generated structure type and display |
| # according to the format string in the probe. |
| event = ct.cast(data, ct.POINTER(self.python_struct)).contents |
| values = map(lambda i: getattr(event, "v%d" % i), |
| range(0, len(self.values))) |
| msg = self.python_format % tuple(values) |
| time = strftime("%H:%M:%S") if Probe.use_localtime else \ |
| Probe._time_off_str(event.timestamp_ns) |
| print("%-8s %-6d %-12s %-16s %s" % \ |
| (time[:8], event.pid, event.comm[:12], |
| self._display_function(), msg)) |
| |
| Probe.event_count += 1 |
| if Probe.max_events is not None and \ |
| Probe.event_count >= Probe.max_events: |
| exit() |
| |
| def attach(self, bpf, verbose): |
| if len(self.library) == 0: |
| self._attach_k(bpf) |
| else: |
| self._attach_u(bpf) |
| self.python_struct = self._generate_python_data_decl() |
| bpf[self.events_name].open_perf_buffer(self.print_event) |
| |
| def _attach_k(self, bpf): |
| if self.probe_type == "r": |
| bpf.attach_kretprobe(event=self.function, |
| fn_name=self.probe_name) |
| elif self.probe_type == "p" or self.probe_type == "t": |
| bpf.attach_kprobe(event=self.function, |
| fn_name=self.probe_name) |
| |
| def _attach_u(self, bpf): |
| libpath = BPF.find_library(self.library) |
| if libpath is None: |
| # This might be an executable (e.g. 'bash') |
| with os.popen("/usr/bin/which %s 2>/dev/null" % |
| self.library) as w: |
| libpath = w.read().strip() |
| if libpath is None or len(libpath) == 0: |
| self._bail("unable to find library %s" % self.library) |
| |
| if self.probe_type == "r": |
| bpf.attach_uretprobe(name=libpath, |
| sym=self.function, |
| fn_name=self.probe_name, |
| pid=self.pid) |
| else: |
| bpf.attach_uprobe(name=libpath, |
| sym=self.function, |
| fn_name=self.probe_name, |
| pid=self.pid) |
| |
| class Tool(object): |
| examples = """ |
| EXAMPLES: |
| |
| trace do_sys_open |
| Trace the open syscall and print a default trace message when entered |
| trace 'do_sys_open "%s", arg2' |
| Trace the open syscall and print the filename being opened |
| trace 'sys_read (arg3 > 20000) "read %d bytes", arg3' |
| Trace the read syscall and print a message for reads >20000 bytes |
| trace 'r::do_sys_return "%llx", retval' |
| Trace the return from the open syscall and print the return value |
| trace 'c:open (arg2 == 42) "%s %d", arg1, arg2' |
| Trace the open() call from libc only if the flags (arg2) argument is 42 |
| trace 'c:malloc "size = %d", arg1' |
| Trace malloc calls and print the size being allocated |
| trace 'p:c:write (arg1 == 1) "writing %d bytes to STDOUT", arg3' |
| Trace the write() call from libc to monitor writes to STDOUT |
| trace 'r::__kmalloc (retval == 0) "kmalloc failed!" |
| Trace returns from __kmalloc which returned a null pointer |
| trace 'r:c:malloc (retval) "allocated = %p", retval |
| Trace returns from malloc and print non-NULL allocated buffers |
| trace 't:block:block_rq_complete "sectors=%d", tp.nr_sector' |
| Trace the block_rq_complete kernel tracepoint and print # of tx sectors |
| """ |
| |
| def __init__(self): |
| parser = argparse.ArgumentParser(description= |
| "Attach to functions and print trace messages.", |
| formatter_class=argparse.RawDescriptionHelpFormatter, |
| epilog=Tool.examples) |
| parser.add_argument("-p", "--pid", type=int, |
| help="id of the process to trace (optional)") |
| parser.add_argument("-v", "--verbose", action="store_true", |
| help="print resulting BPF program code before executing") |
| parser.add_argument("-Z", "--string-size", type=int, |
| default=80, help="maximum size to read from strings") |
| parser.add_argument("-S", "--include-self", action="store_true", |
| help="do not filter trace's own pid from the trace") |
| parser.add_argument("-M", "--max-events", type=int, |
| help="number of events to print before quitting") |
| parser.add_argument("-o", "--offset", action="store_true", |
| help="use relative time from first traced message") |
| parser.add_argument(metavar="probe", dest="probes", nargs="+", |
| help="probe specifier (see examples)") |
| self.args = parser.parse_args() |
| |
| def _create_probes(self): |
| Probe.configure(self.args) |
| self.probes = [] |
| for probe_spec in self.args.probes: |
| self.probes.append(Probe( |
| probe_spec, self.args.string_size)) |
| |
| def _generate_program(self): |
| self.program = """ |
| #include <linux/ptrace.h> |
| #include <linux/sched.h> /* For TASK_COMM_LEN */ |
| |
| """ |
| self.program += Probe.generate_auto_includes( |
| map(lambda p: p.raw_probe, self.probes)) |
| self.program += Tracepoint.generate_decl() |
| self.program += Tracepoint.generate_entry_probe() |
| for probe in self.probes: |
| self.program += probe.generate_program( |
| self.args.pid or -1, self.args.include_self) |
| |
| if self.args.verbose: |
| print(self.program) |
| |
| def _attach_probes(self): |
| self.bpf = BPF(text=self.program) |
| Tracepoint.attach(self.bpf) |
| for probe in self.probes: |
| if self.args.verbose: |
| print(probe) |
| probe.attach(self.bpf, self.args.verbose) |
| |
| def _main_loop(self): |
| all_probes_trivial = all(map(Probe.is_default_action, |
| self.probes)) |
| |
| # Print header |
| print("%-8s %-6s %-12s %-16s %s" % \ |
| ("TIME", "PID", "COMM", "FUNC", |
| "-" if not all_probes_trivial else "")) |
| |
| while True: |
| self.bpf.kprobe_poll() |
| |
| def run(self): |
| try: |
| self._create_probes() |
| self._generate_program() |
| self._attach_probes() |
| self._main_loop() |
| except: |
| if self.args.verbose: |
| traceback.print_exc() |
| elif sys.exc_type is not SystemExit: |
| print(sys.exc_value) |
| |
| if __name__ == "__main__": |
| Tool().run() |