#! /usr/bin/python3
# @lint-avoid-python-3-compatibility-imports
#
# funccount Count functions, tracepoints, and USDT probes.
# For Linux, uses BCC, eBPF.
#
# USAGE: funccount [-h] [-p PID] [-i INTERVAL] [-d DURATION] [-T] [-r]
# [-c CPU] pattern
#
# The pattern is a string with optional '*' wildcards, similar to file
# globbing. If you'd prefer to use regular expressions, use the -r option.
#
# Copyright (c) 2015 Brendan Gregg.
# Licensed under the Apache License, Version 2.0 (the "License")
#
# 09-Sep-2015 Brendan Gregg Created this.
# 18-Oct-2016 Sasha Goldshtein Generalized for uprobes, tracepoints, USDT.
from __future__ import print_function
from bcc import ArgString, BPF, USDT
from time import sleep, strftime
import argparse
import re
import signal
import sys
import traceback
debug = False
def verify_limit(num):
probe_limit = BPF.get_probe_limit()
if num > probe_limit:
raise Exception("maximum of %d probes allowed, attempted %d" %
(probe_limit, num))
class Probe(object):
def __init__(self, pattern, use_regex=False, pid=None, cpu=None):
"""Init a new probe.
Init the probe from the pattern provided by the user. The supported
patterns mimic the 'trace' and 'argdist' tools, but are simpler because
we don't have to distinguish between probes and retprobes.
func -- probe a kernel function
lib:func -- probe a user-space function in the library 'lib'
/path:func -- probe a user-space function in binary '/path'
p::func -- same thing as 'func'
p:lib:func -- same thing as 'lib:func'
t:cat:event -- probe a kernel tracepoint
u:lib:probe -- probe a USDT tracepoint
"""
parts = bytes(pattern).split(b':')
if len(parts) == 1:
parts = [b"p", b"", parts[0]]
elif len(parts) == 2:
parts = [b"p", parts[0], parts[1]]
elif len(parts) == 3:
if parts[0] == b"t":
parts = [b"t", b"", b"%s:%s" % tuple(parts[1:])]
if parts[0] not in [b"p", b"t", b"u"]:
raise Exception("Type must be 'p', 't', or 'u', but got %s" %
parts[0])
else:
raise Exception("Too many ':'-separated components in pattern %s" %
pattern)
(self.type, self.library, self.pattern) = parts
if not use_regex:
self.pattern = self.pattern.replace(b'*', b'.*')
self.pattern = b'^' + self.pattern + b'$'
if (self.type == b"p" and self.library) or self.type == b"u":
libpath = BPF.find_library(self.library)
if libpath is None:
# This might be an executable (e.g. 'bash')
libpath = BPF.find_exe(str(self.library))
if libpath is None or len(libpath) == 0:
raise Exception("unable to find library %s" % self.library)
self.library = libpath
self.pid = pid
self.cpu = cpu
self.matched = 0
self.trace_functions = {} # map location number to function name
def is_kernel_probe(self):
return self.type == b"t" or (self.type == b"p" and self.library == b"")
def attach(self):
if self.type == b"p" and not self.library:
for index, function in self.trace_functions.items():
self.bpf.attach_kprobe(
event=function,
fn_name="trace_count_%d" % index)
elif self.type == b"p" and self.library:
for index, function in self.trace_functions.items():
self.bpf.attach_uprobe(
name=self.library,
sym=function,
fn_name="trace_count_%d" % index,
pid=self.pid or -1)
elif self.type == b"t":
for index, function in self.trace_functions.items():
self.bpf.attach_tracepoint(
tp=function,
fn_name="trace_count_%d" % index)
elif self.type == b"u":
pass # Nothing to do -- attach already happened in `load`
def _add_function(self, template, probe_name):
new_func = b"trace_count_%d" % self.matched
text = template.replace(b"PROBE_FUNCTION", new_func)
text = text.replace(b"LOCATION", b"%d" % self.matched)
self.trace_functions[self.matched] = probe_name
self.matched += 1
return text
def _generate_functions(self, template):
self.usdt = None
text = b""
if self.type == b"p" and not self.library:
functions = BPF.get_kprobe_functions(self.pattern)
verify_limit(len(functions))
for function in functions:
text += self._add_function(template, function)
elif self.type == b"p" and self.library:
# uprobes are tricky because the same function may have multiple
# addresses, and the same address may be mapped to multiple
# functions. We aren't allowed to create more than one uprobe
# per address, so track unique addresses and ignore functions that
# map to an address that we've already seen. Also ignore functions
# that may repeat multiple times with different addresses.
addresses, functions = (set(), set())
functions_and_addresses = BPF.get_user_functions_and_addresses(
self.library, self.pattern)
verify_limit(len(functions_and_addresses))
for function, address in functions_and_addresses:
if address in addresses or function in functions:
continue
addresses.add(address)
functions.add(function)
text += self._add_function(template, function)
elif self.type == b"t":
tracepoints = BPF.get_tracepoints(self.pattern)
verify_limit(len(tracepoints))
for tracepoint in tracepoints:
text += self._add_function(template, tracepoint)
elif self.type == b"u":
self.usdt = USDT(path=str(self.library), pid=self.pid)
matches = []
for probe in self.usdt.enumerate_probes():
if not self.pid and (probe.bin_path != self.library):
continue
if re.match(self.pattern, probe.name):
matches.append(probe.name)
verify_limit(len(matches))
for match in matches:
new_func = b"trace_count_%d" % self.matched
text += self._add_function(template, match)
self.usdt.enable_probe(match, new_func)
if debug:
print(self.usdt.get_text())
return text
def load(self):
trace_count_text = b"""
int PROBE_FUNCTION(void *ctx) {
FILTERPID
FILTERCPU
int loc = LOCATION;
counts.atomic_increment(loc);
return 0;
}
"""
bpf_text = b"""#include <uapi/linux/ptrace.h>
BPF_ARRAY(counts, u64, NUMLOCATIONS);
"""
# We really mean the tgid from the kernel's perspective, which is in
# the top 32 bits of bpf_get_current_pid_tgid().
if self.pid:
trace_count_text = trace_count_text.replace(b'FILTERPID',
b"""u32 pid = bpf_get_current_pid_tgid() >> 32;
if (pid != %d) { return 0; }""" % self.pid)
else:
trace_count_text = trace_count_text.replace(b'FILTERPID', b'')
if self.cpu:
trace_count_text = trace_count_text.replace(b'FILTERCPU',
b"""u32 cpu = bpf_get_smp_processor_id();
if (cpu != %d) { return 0; }""" % int(self.cpu))
else:
trace_count_text = trace_count_text.replace(b'FILTERCPU', b'')
bpf_text += self._generate_functions(trace_count_text)
bpf_text = bpf_text.replace(b"NUMLOCATIONS",
b"%d" % len(self.trace_functions))
if debug:
print(bpf_text)
if self.matched == 0:
raise Exception("No functions matched by pattern %s" %
self.pattern)
self.bpf = BPF(text=bpf_text,
usdt_contexts=[self.usdt] if self.usdt else [])
self.clear() # Initialize all array items to zero
def counts(self):
return self.bpf["counts"]
def clear(self):
counts = self.bpf["counts"]
for location, _ in list(self.trace_functions.items()):
counts[counts.Key(location)] = counts.Leaf()
class Tool(object):
def __init__(self):
examples = """examples:
./funccount 'vfs_*' # count kernel fns starting with "vfs"
./funccount -r '^vfs.*' # same as above, using regular expressions
./funccount -Ti 5 'vfs_*' # output every 5 seconds, with timestamps
./funccount -d 10 'vfs_*' # trace for 10 seconds only
./funccount -p 185 'vfs_*' # count vfs calls for PID 181 only
./funccount t:sched:sched_fork # count calls to the sched_fork tracepoint
./funccount -p 185 u:node:gc* # count all GC USDT probes in node, PID 185
./funccount c:malloc # count all malloc() calls in libc
./funccount go:os.* # count all "os.*" calls in libgo
./funccount -p 185 go:os.* # count all "os.*" calls in libgo, PID 185
./funccount ./test:read* # count "read*" calls in the ./test binary
./funccount -c 1 'vfs_*' # count vfs calls on CPU 1 only
"""
parser = argparse.ArgumentParser(
description="Count functions, tracepoints, and USDT probes",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog=examples)
parser.add_argument("-p", "--pid", type=int,
help="trace this PID only")
parser.add_argument("-i", "--interval",
help="summary interval, seconds")
parser.add_argument("-d", "--duration",
help="total duration of trace, seconds")
parser.add_argument("-T", "--timestamp", action="store_true",
help="include timestamp on output")
parser.add_argument("-r", "--regexp", action="store_true",
help="use regular expressions. Default is \"*\" wildcards only.")
parser.add_argument("-D", "--debug", action="store_true",
help="print BPF program before starting (for debugging purposes)")
parser.add_argument("-c", "--cpu",
help="trace this CPU only")
parser.add_argument("pattern",
type=ArgString,
help="search expression for events")
self.args = parser.parse_args()
global debug
debug = self.args.debug
self.probe = Probe(self.args.pattern, self.args.regexp, self.args.pid,
self.args.cpu)
if self.args.duration and not self.args.interval:
self.args.interval = self.args.duration
if not self.args.interval:
self.args.interval = 99999999
@staticmethod
def _signal_ignore(signal, frame):
print()
def run(self):
self.probe.load()
self.probe.attach()
print("Tracing %d functions for \"%s\"... Hit Ctrl-C to end." %
(self.probe.matched, bytes(self.args.pattern)))
exiting = 0 if self.args.interval else 1
seconds = 0
while True:
try:
sleep(int(self.args.interval))
seconds += int(self.args.interval)
except KeyboardInterrupt:
exiting = 1
# as cleanup can take many seconds, trap Ctrl-C:
signal.signal(signal.SIGINT, Tool._signal_ignore)
if self.args.duration and seconds >= int(self.args.duration):
exiting = 1
print()
if self.args.timestamp:
print("%-8s\n" % strftime("%H:%M:%S"), end="")
print("%-36s %8s" % ("FUNC", "COUNT"))
counts = self.probe.counts()
for k, v in sorted(counts.items(),
key=lambda counts: counts[1].value):
if v.value == 0:
continue
print("%-36s %8d" %
(self.probe.trace_functions[k.value].decode('utf-8', 'replace'), v.value))
if exiting:
print("Detaching...")
exit()
else:
self.probe.clear()
if __name__ == "__main__":
try:
Tool().run()
except Exception:
if debug:
traceback.print_exc()
elif sys.exc_info()[0] is not SystemExit:
print(sys.exc_info()[1])
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