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#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0
"""Failed system call counts."""
from __future__ import annotations
import argparse
from collections import defaultdict
import sys
from typing import Optional
import perf
class FailedSyscalls:
"""Tracks and displays failed system call totals."""
def __init__(self, comm: Optional[str] = None) -> None:
self.failed_syscalls: dict[str, int] = defaultdict(int)
self.for_comm = comm
self.session: Optional[perf.session] = None
def process_event(self, sample: perf.sample_event) -> None:
"""Process sys_exit events."""
event_name = str(sample.evsel)
if not event_name.startswith("evsel(syscalls:sys_exit") and \
not event_name.startswith("evsel(raw_syscalls:sys_exit"):
return
try:
ret = sample.ret
except AttributeError:
print("ERROR: tracepoint fields missed", file=sys.stderr)
sys.exit(1)
if ret > 0:
if ret >= 0xfffffffffffff000: # 64-bit negative errors
ret -= 0x10000000000000000
elif 0xfffff000 <= ret <= 0xffffffff: # 32-bit negative errors
assert self.session is not None
if not self.session.is_64_bit:
ret -= 0x100000000
# Linux kernel syscalls only return error codes in the [-4095, -1] (-MAX_ERRNO)
# range; other negative signed values are valid unsigned user-space addresses.
if not -4095 <= ret < 0:
return
assert self.session is not None
try:
thread = self.session.find_thread(sample.sample_pid, sample.sample_tid)
comm = (thread.comm() if thread else None) or "unknown"
except (TypeError, AttributeError):
# find_thread returns None when the thread isn't known.
comm = "unknown"
if self.for_comm and comm != self.for_comm:
return
self.failed_syscalls[comm] += 1
def print_totals(self) -> None:
"""Print summary table."""
print("\nfailed syscalls by comm:\n")
print(f"{'comm':<20s} {'# errors':>10s}")
print(f"{'-'*20} {'-'*10}")
for comm, val in sorted(self.failed_syscalls.items(),
key=lambda kv: (-kv[1], kv[0])):
print(f"{comm:<20s} {val:10d}")
def run(self, input_file: str) -> None:
"""Run the session."""
self.session = perf.session(perf.data(input_file), sample=self.process_event)
try:
self.session.process_events()
finally:
# Break the reference cycle between perf.session and self.process_event
# because perf.session lacks cyclic GC support (tp_traverse).
self.session = None
self.print_totals()
def main() -> None:
"""Main function."""
parser = argparse.ArgumentParser(description="Trace failed syscalls")
parser.add_argument("comm", nargs="?", help="Filter by command name")
parser.add_argument("-i", "--input", default="perf.data", help="Input file")
args = parser.parse_args()
analyzer = FailedSyscalls(args.comm)
try:
analyzer.run(args.input)
except IOError as e:
print(e, file=sys.stderr)
sys.exit(1)
if __name__ == "__main__":
main()
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