linux-stable/scripts/checkkconfigsymbols.py
Masahiro Yamada 87c7ee67de scripts: handle BrokenPipeError for python scripts
In the follow-up of commit fb3041d61f ("kbuild: fix SIGPIPE error
message for AR=gcc-ar and AR=llvm-ar"), Kees Cook pointed out that
tools should _not_ catch their own SIGPIPEs [1] [2].

Based on his feedback, LLVM was fixed [3].

However, Python's default behavior is to show noisy bracktrace when
SIGPIPE is sent. So, scripts written in Python are basically in the
same situation as the buggy llvm tools.

Example:

  $ make -s allnoconfig
  $ make -s allmodconfig
  $ scripts/diffconfig .config.old .config | head -n1
  -ALIX n
  Traceback (most recent call last):
    File "/home/masahiro/linux/scripts/diffconfig", line 132, in <module>
      main()
    File "/home/masahiro/linux/scripts/diffconfig", line 130, in main
      print_config("+", config, None, b[config])
    File "/home/masahiro/linux/scripts/diffconfig", line 64, in print_config
      print("+%s %s" % (config, new_value))
  BrokenPipeError: [Errno 32] Broken pipe

Python documentation [4] notes how to make scripts die immediately and
silently:

  """
  Piping output of your program to tools like head(1) will cause a
  SIGPIPE signal to be sent to your process when the receiver of its
  standard output closes early. This results in an exception like
  BrokenPipeError: [Errno 32] Broken pipe. To handle this case,
  wrap your entry point to catch this exception as follows:

    import os
    import sys

    def main():
        try:
            # simulate large output (your code replaces this loop)
            for x in range(10000):
                print("y")
            # flush output here to force SIGPIPE to be triggered
            # while inside this try block.
            sys.stdout.flush()
        except BrokenPipeError:
            # Python flushes standard streams on exit; redirect remaining output
            # to devnull to avoid another BrokenPipeError at shutdown
            devnull = os.open(os.devnull, os.O_WRONLY)
            os.dup2(devnull, sys.stdout.fileno())
            sys.exit(1)  # Python exits with error code 1 on EPIPE

    if __name__ == '__main__':
        main()

  Do not set SIGPIPE’s disposition to SIG_DFL in order to avoid
  BrokenPipeError. Doing that would cause your program to exit
  unexpectedly whenever any socket connection is interrupted while
  your program is still writing to it.
  """

Currently, tools/perf/scripts/python/intel-pt-events.py seems to be the
only script that fixes the issue that way.

tools/perf/scripts/python/compaction-times.py uses another approach
signal.signal(signal.SIGPIPE, signal.SIG_DFL) but the Python
documentation clearly says "Don't do it".

I cannot fix all Python scripts since there are so many.
I fixed some in the scripts/ directory.

[1]: https://lore.kernel.org/all/202211161056.1B9611A@keescook/
[2]: https://github.com/llvm/llvm-project/issues/59037
[3]: 4787efa380
[4]: https://docs.python.org/3/library/signal.html#note-on-sigpipe

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2023-01-26 12:43:33 +09:00

482 lines
16 KiB
Python
Executable file

#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0-only
"""Find Kconfig symbols that are referenced but not defined."""
# (c) 2014-2017 Valentin Rothberg <valentinrothberg@gmail.com>
# (c) 2014 Stefan Hengelein <stefan.hengelein@fau.de>
#
import argparse
import difflib
import os
import re
import signal
import subprocess
import sys
from multiprocessing import Pool, cpu_count
# regex expressions
OPERATORS = r"&|\(|\)|\||\!"
SYMBOL = r"(?:\w*[A-Z0-9]\w*){2,}"
DEF = r"^\s*(?:menu){,1}config\s+(" + SYMBOL + r")\s*"
EXPR = r"(?:" + OPERATORS + r"|\s|" + SYMBOL + r")+"
DEFAULT = r"default\s+.*?(?:if\s.+){,1}"
STMT = r"^\s*(?:if|select|imply|depends\s+on|(?:" + DEFAULT + r"))\s+" + EXPR
SOURCE_SYMBOL = r"(?:\W|\b)+[D]{,1}CONFIG_(" + SYMBOL + r")"
# regex objects
REGEX_FILE_KCONFIG = re.compile(r".*Kconfig[\.\w+\-]*$")
REGEX_SYMBOL = re.compile(r'(?!\B)' + SYMBOL + r'(?!\B)')
REGEX_SOURCE_SYMBOL = re.compile(SOURCE_SYMBOL)
REGEX_KCONFIG_DEF = re.compile(DEF)
REGEX_KCONFIG_EXPR = re.compile(EXPR)
REGEX_KCONFIG_STMT = re.compile(STMT)
REGEX_FILTER_SYMBOLS = re.compile(r"[A-Za-z0-9]$")
REGEX_NUMERIC = re.compile(r"0[xX][0-9a-fA-F]+|[0-9]+")
REGEX_QUOTES = re.compile("(\"(.*?)\")")
def parse_options():
"""The user interface of this module."""
usage = "Run this tool to detect Kconfig symbols that are referenced but " \
"not defined in Kconfig. If no option is specified, " \
"checkkconfigsymbols defaults to check your current tree. " \
"Please note that specifying commits will 'git reset --hard\' " \
"your current tree! You may save uncommitted changes to avoid " \
"losing data."
parser = argparse.ArgumentParser(description=usage)
parser.add_argument('-c', '--commit', dest='commit', action='store',
default="",
help="check if the specified commit (hash) introduces "
"undefined Kconfig symbols")
parser.add_argument('-d', '--diff', dest='diff', action='store',
default="",
help="diff undefined symbols between two commits "
"(e.g., -d commmit1..commit2)")
parser.add_argument('-f', '--find', dest='find', action='store_true',
default=False,
help="find and show commits that may cause symbols to be "
"missing (required to run with --diff)")
parser.add_argument('-i', '--ignore', dest='ignore', action='store',
default="",
help="ignore files matching this Python regex "
"(e.g., -i '.*defconfig')")
parser.add_argument('-s', '--sim', dest='sim', action='store', default="",
help="print a list of max. 10 string-similar symbols")
parser.add_argument('--force', dest='force', action='store_true',
default=False,
help="reset current Git tree even when it's dirty")
parser.add_argument('--no-color', dest='color', action='store_false',
default=True,
help="don't print colored output (default when not "
"outputting to a terminal)")
args = parser.parse_args()
if args.commit and args.diff:
sys.exit("Please specify only one option at once.")
if args.diff and not re.match(r"^[\w\-\.\^]+\.\.[\w\-\.\^]+$", args.diff):
sys.exit("Please specify valid input in the following format: "
"\'commit1..commit2\'")
if args.commit or args.diff:
if not args.force and tree_is_dirty():
sys.exit("The current Git tree is dirty (see 'git status'). "
"Running this script may\ndelete important data since it "
"calls 'git reset --hard' for some performance\nreasons. "
" Please run this script in a clean Git tree or pass "
"'--force' if you\nwant to ignore this warning and "
"continue.")
if args.commit:
if args.commit.startswith('HEAD'):
sys.exit("The --commit option can't use the HEAD ref")
args.find = False
if args.ignore:
try:
re.match(args.ignore, "this/is/just/a/test.c")
except:
sys.exit("Please specify a valid Python regex.")
return args
def print_undefined_symbols():
"""Main function of this module."""
args = parse_options()
global COLOR
COLOR = args.color and sys.stdout.isatty()
if args.sim and not args.commit and not args.diff:
sims = find_sims(args.sim, args.ignore)
if sims:
print("%s: %s" % (yel("Similar symbols"), ', '.join(sims)))
else:
print("%s: no similar symbols found" % yel("Similar symbols"))
sys.exit(0)
# dictionary of (un)defined symbols
defined = {}
undefined = {}
if args.commit or args.diff:
head = get_head()
# get commit range
commit_a = None
commit_b = None
if args.commit:
commit_a = args.commit + "~"
commit_b = args.commit
elif args.diff:
split = args.diff.split("..")
commit_a = split[0]
commit_b = split[1]
undefined_a = {}
undefined_b = {}
# get undefined items before the commit
reset(commit_a)
undefined_a, _ = check_symbols(args.ignore)
# get undefined items for the commit
reset(commit_b)
undefined_b, defined = check_symbols(args.ignore)
# report cases that are present for the commit but not before
for symbol in sorted(undefined_b):
# symbol has not been undefined before
if symbol not in undefined_a:
files = sorted(undefined_b.get(symbol))
undefined[symbol] = files
# check if there are new files that reference the undefined symbol
else:
files = sorted(undefined_b.get(symbol) -
undefined_a.get(symbol))
if files:
undefined[symbol] = files
# reset to head
reset(head)
# default to check the entire tree
else:
undefined, defined = check_symbols(args.ignore)
# now print the output
for symbol in sorted(undefined):
print(red(symbol))
files = sorted(undefined.get(symbol))
print("%s: %s" % (yel("Referencing files"), ", ".join(files)))
sims = find_sims(symbol, args.ignore, defined)
sims_out = yel("Similar symbols")
if sims:
print("%s: %s" % (sims_out, ', '.join(sims)))
else:
print("%s: %s" % (sims_out, "no similar symbols found"))
if args.find:
print("%s:" % yel("Commits changing symbol"))
commits = find_commits(symbol, args.diff)
if commits:
for commit in commits:
commit = commit.split(" ", 1)
print("\t- %s (\"%s\")" % (yel(commit[0]), commit[1]))
else:
print("\t- no commit found")
print() # new line
def reset(commit):
"""Reset current git tree to %commit."""
execute(["git", "reset", "--hard", commit])
def yel(string):
"""
Color %string yellow.
"""
return "\033[33m%s\033[0m" % string if COLOR else string
def red(string):
"""
Color %string red.
"""
return "\033[31m%s\033[0m" % string if COLOR else string
def execute(cmd):
"""Execute %cmd and return stdout. Exit in case of error."""
try:
stdout = subprocess.check_output(cmd, stderr=subprocess.STDOUT, shell=False)
stdout = stdout.decode(errors='replace')
except subprocess.CalledProcessError as fail:
exit(fail)
return stdout
def find_commits(symbol, diff):
"""Find commits changing %symbol in the given range of %diff."""
commits = execute(["git", "log", "--pretty=oneline",
"--abbrev-commit", "-G",
symbol, diff])
return [x for x in commits.split("\n") if x]
def tree_is_dirty():
"""Return true if the current working tree is dirty (i.e., if any file has
been added, deleted, modified, renamed or copied but not committed)."""
stdout = execute(["git", "status", "--porcelain"])
for line in stdout:
if re.findall(r"[URMADC]{1}", line[:2]):
return True
return False
def get_head():
"""Return commit hash of current HEAD."""
stdout = execute(["git", "rev-parse", "HEAD"])
return stdout.strip('\n')
def partition(lst, size):
"""Partition list @lst into eveni-sized lists of size @size."""
return [lst[i::size] for i in range(size)]
def init_worker():
"""Set signal handler to ignore SIGINT."""
signal.signal(signal.SIGINT, signal.SIG_IGN)
def find_sims(symbol, ignore, defined=[]):
"""Return a list of max. ten Kconfig symbols that are string-similar to
@symbol."""
if defined:
return difflib.get_close_matches(symbol, set(defined), 10)
pool = Pool(cpu_count(), init_worker)
kfiles = []
for gitfile in get_files():
if REGEX_FILE_KCONFIG.match(gitfile):
kfiles.append(gitfile)
arglist = []
for part in partition(kfiles, cpu_count()):
arglist.append((part, ignore))
for res in pool.map(parse_kconfig_files, arglist):
defined.extend(res[0])
return difflib.get_close_matches(symbol, set(defined), 10)
def get_files():
"""Return a list of all files in the current git directory."""
# use 'git ls-files' to get the worklist
stdout = execute(["git", "ls-files"])
if len(stdout) > 0 and stdout[-1] == "\n":
stdout = stdout[:-1]
files = []
for gitfile in stdout.rsplit("\n"):
if ".git" in gitfile or "ChangeLog" in gitfile or \
".log" in gitfile or os.path.isdir(gitfile) or \
gitfile.startswith("tools/"):
continue
files.append(gitfile)
return files
def check_symbols(ignore):
"""Find undefined Kconfig symbols and return a dict with the symbol as key
and a list of referencing files as value. Files matching %ignore are not
checked for undefined symbols."""
pool = Pool(cpu_count(), init_worker)
try:
return check_symbols_helper(pool, ignore)
except KeyboardInterrupt:
pool.terminate()
pool.join()
sys.exit(1)
def check_symbols_helper(pool, ignore):
"""Helper method for check_symbols(). Used to catch keyboard interrupts in
check_symbols() in order to properly terminate running worker processes."""
source_files = []
kconfig_files = []
defined_symbols = []
referenced_symbols = dict() # {file: [symbols]}
for gitfile in get_files():
if REGEX_FILE_KCONFIG.match(gitfile):
kconfig_files.append(gitfile)
else:
if ignore and re.match(ignore, gitfile):
continue
# add source files that do not match the ignore pattern
source_files.append(gitfile)
# parse source files
arglist = partition(source_files, cpu_count())
for res in pool.map(parse_source_files, arglist):
referenced_symbols.update(res)
# parse kconfig files
arglist = []
for part in partition(kconfig_files, cpu_count()):
arglist.append((part, ignore))
for res in pool.map(parse_kconfig_files, arglist):
defined_symbols.extend(res[0])
referenced_symbols.update(res[1])
defined_symbols = set(defined_symbols)
# inverse mapping of referenced_symbols to dict(symbol: [files])
inv_map = dict()
for _file, symbols in referenced_symbols.items():
for symbol in symbols:
inv_map[symbol] = inv_map.get(symbol, set())
inv_map[symbol].add(_file)
referenced_symbols = inv_map
undefined = {} # {symbol: [files]}
for symbol in sorted(referenced_symbols):
# filter some false positives
if symbol == "FOO" or symbol == "BAR" or \
symbol == "FOO_BAR" or symbol == "XXX":
continue
if symbol not in defined_symbols:
if symbol.endswith("_MODULE"):
# avoid false positives for kernel modules
if symbol[:-len("_MODULE")] in defined_symbols:
continue
undefined[symbol] = referenced_symbols.get(symbol)
return undefined, defined_symbols
def parse_source_files(source_files):
"""Parse each source file in @source_files and return dictionary with source
files as keys and lists of references Kconfig symbols as values."""
referenced_symbols = dict()
for sfile in source_files:
referenced_symbols[sfile] = parse_source_file(sfile)
return referenced_symbols
def parse_source_file(sfile):
"""Parse @sfile and return a list of referenced Kconfig symbols."""
lines = []
references = []
if not os.path.exists(sfile):
return references
with open(sfile, "r", encoding='utf-8', errors='replace') as stream:
lines = stream.readlines()
for line in lines:
if "CONFIG_" not in line:
continue
symbols = REGEX_SOURCE_SYMBOL.findall(line)
for symbol in symbols:
if not REGEX_FILTER_SYMBOLS.search(symbol):
continue
references.append(symbol)
return references
def get_symbols_in_line(line):
"""Return mentioned Kconfig symbols in @line."""
return REGEX_SYMBOL.findall(line)
def parse_kconfig_files(args):
"""Parse kconfig files and return tuple of defined and references Kconfig
symbols. Note, @args is a tuple of a list of files and the @ignore
pattern."""
kconfig_files = args[0]
ignore = args[1]
defined_symbols = []
referenced_symbols = dict()
for kfile in kconfig_files:
defined, references = parse_kconfig_file(kfile)
defined_symbols.extend(defined)
if ignore and re.match(ignore, kfile):
# do not collect references for files that match the ignore pattern
continue
referenced_symbols[kfile] = references
return (defined_symbols, referenced_symbols)
def parse_kconfig_file(kfile):
"""Parse @kfile and update symbol definitions and references."""
lines = []
defined = []
references = []
if not os.path.exists(kfile):
return defined, references
with open(kfile, "r", encoding='utf-8', errors='replace') as stream:
lines = stream.readlines()
for i in range(len(lines)):
line = lines[i]
line = line.strip('\n')
line = line.split("#")[0] # ignore comments
if REGEX_KCONFIG_DEF.match(line):
symbol_def = REGEX_KCONFIG_DEF.findall(line)
defined.append(symbol_def[0])
elif REGEX_KCONFIG_STMT.match(line):
line = REGEX_QUOTES.sub("", line)
symbols = get_symbols_in_line(line)
# multi-line statements
while line.endswith("\\"):
i += 1
line = lines[i]
line = line.strip('\n')
symbols.extend(get_symbols_in_line(line))
for symbol in set(symbols):
if REGEX_NUMERIC.match(symbol):
# ignore numeric values
continue
references.append(symbol)
return defined, references
def main():
try:
print_undefined_symbols()
except BrokenPipeError:
# Python flushes standard streams on exit; redirect remaining output
# to devnull to avoid another BrokenPipeError at shutdown
devnull = os.open(os.devnull, os.O_WRONLY)
os.dup2(devnull, sys.stdout.fileno())
sys.exit(1) # Python exits with error code 1 on EPIPE
if __name__ == "__main__":
main()