cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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checkkconfigsymbols.py (15719B)


      1#!/usr/bin/env python3
      2# SPDX-License-Identifier: GPL-2.0-only
      3
      4"""Find Kconfig symbols that are referenced but not defined."""
      5
      6# (c) 2014-2017 Valentin Rothberg <valentinrothberg@gmail.com>
      7# (c) 2014 Stefan Hengelein <stefan.hengelein@fau.de>
      8#
      9
     10
     11import argparse
     12import difflib
     13import os
     14import re
     15import signal
     16import subprocess
     17import sys
     18from multiprocessing import Pool, cpu_count
     19
     20
     21# regex expressions
     22OPERATORS = r"&|\(|\)|\||\!"
     23SYMBOL = r"(?:\w*[A-Z0-9]\w*){2,}"
     24DEF = r"^\s*(?:menu){,1}config\s+(" + SYMBOL + r")\s*"
     25EXPR = r"(?:" + OPERATORS + r"|\s|" + SYMBOL + r")+"
     26DEFAULT = r"default\s+.*?(?:if\s.+){,1}"
     27STMT = r"^\s*(?:if|select|imply|depends\s+on|(?:" + DEFAULT + r"))\s+" + EXPR
     28SOURCE_SYMBOL = r"(?:\W|\b)+[D]{,1}CONFIG_(" + SYMBOL + r")"
     29
     30# regex objects
     31REGEX_FILE_KCONFIG = re.compile(r".*Kconfig[\.\w+\-]*$")
     32REGEX_SYMBOL = re.compile(r'(?!\B)' + SYMBOL + r'(?!\B)')
     33REGEX_SOURCE_SYMBOL = re.compile(SOURCE_SYMBOL)
     34REGEX_KCONFIG_DEF = re.compile(DEF)
     35REGEX_KCONFIG_EXPR = re.compile(EXPR)
     36REGEX_KCONFIG_STMT = re.compile(STMT)
     37REGEX_FILTER_SYMBOLS = re.compile(r"[A-Za-z0-9]$")
     38REGEX_NUMERIC = re.compile(r"0[xX][0-9a-fA-F]+|[0-9]+")
     39REGEX_QUOTES = re.compile("(\"(.*?)\")")
     40
     41
     42def parse_options():
     43    """The user interface of this module."""
     44    usage = "Run this tool to detect Kconfig symbols that are referenced but " \
     45            "not defined in Kconfig.  If no option is specified, "             \
     46            "checkkconfigsymbols defaults to check your current tree.  "       \
     47            "Please note that specifying commits will 'git reset --hard\' "    \
     48            "your current tree!  You may save uncommitted changes to avoid "   \
     49            "losing data."
     50
     51    parser = argparse.ArgumentParser(description=usage)
     52
     53    parser.add_argument('-c', '--commit', dest='commit', action='store',
     54                        default="",
     55                        help="check if the specified commit (hash) introduces "
     56                             "undefined Kconfig symbols")
     57
     58    parser.add_argument('-d', '--diff', dest='diff', action='store',
     59                        default="",
     60                        help="diff undefined symbols between two commits "
     61                             "(e.g., -d commmit1..commit2)")
     62
     63    parser.add_argument('-f', '--find', dest='find', action='store_true',
     64                        default=False,
     65                        help="find and show commits that may cause symbols to be "
     66                             "missing (required to run with --diff)")
     67
     68    parser.add_argument('-i', '--ignore', dest='ignore', action='store',
     69                        default="",
     70                        help="ignore files matching this Python regex "
     71                             "(e.g., -i '.*defconfig')")
     72
     73    parser.add_argument('-s', '--sim', dest='sim', action='store', default="",
     74                        help="print a list of max. 10 string-similar symbols")
     75
     76    parser.add_argument('--force', dest='force', action='store_true',
     77                        default=False,
     78                        help="reset current Git tree even when it's dirty")
     79
     80    parser.add_argument('--no-color', dest='color', action='store_false',
     81                        default=True,
     82                        help="don't print colored output (default when not "
     83                             "outputting to a terminal)")
     84
     85    args = parser.parse_args()
     86
     87    if args.commit and args.diff:
     88        sys.exit("Please specify only one option at once.")
     89
     90    if args.diff and not re.match(r"^[\w\-\.\^]+\.\.[\w\-\.\^]+$", args.diff):
     91        sys.exit("Please specify valid input in the following format: "
     92                 "\'commit1..commit2\'")
     93
     94    if args.commit or args.diff:
     95        if not args.force and tree_is_dirty():
     96            sys.exit("The current Git tree is dirty (see 'git status').  "
     97                     "Running this script may\ndelete important data since it "
     98                     "calls 'git reset --hard' for some performance\nreasons. "
     99                     " Please run this script in a clean Git tree or pass "
    100                     "'--force' if you\nwant to ignore this warning and "
    101                     "continue.")
    102
    103    if args.commit:
    104        if args.commit.startswith('HEAD'):
    105            sys.exit("The --commit option can't use the HEAD ref")
    106
    107        args.find = False
    108
    109    if args.ignore:
    110        try:
    111            re.match(args.ignore, "this/is/just/a/test.c")
    112        except:
    113            sys.exit("Please specify a valid Python regex.")
    114
    115    return args
    116
    117
    118def main():
    119    """Main function of this module."""
    120    args = parse_options()
    121
    122    global COLOR
    123    COLOR = args.color and sys.stdout.isatty()
    124
    125    if args.sim and not args.commit and not args.diff:
    126        sims = find_sims(args.sim, args.ignore)
    127        if sims:
    128            print("%s: %s" % (yel("Similar symbols"), ', '.join(sims)))
    129        else:
    130            print("%s: no similar symbols found" % yel("Similar symbols"))
    131        sys.exit(0)
    132
    133    # dictionary of (un)defined symbols
    134    defined = {}
    135    undefined = {}
    136
    137    if args.commit or args.diff:
    138        head = get_head()
    139
    140        # get commit range
    141        commit_a = None
    142        commit_b = None
    143        if args.commit:
    144            commit_a = args.commit + "~"
    145            commit_b = args.commit
    146        elif args.diff:
    147            split = args.diff.split("..")
    148            commit_a = split[0]
    149            commit_b = split[1]
    150            undefined_a = {}
    151            undefined_b = {}
    152
    153        # get undefined items before the commit
    154        reset(commit_a)
    155        undefined_a, _ = check_symbols(args.ignore)
    156
    157        # get undefined items for the commit
    158        reset(commit_b)
    159        undefined_b, defined = check_symbols(args.ignore)
    160
    161        # report cases that are present for the commit but not before
    162        for symbol in sorted(undefined_b):
    163            # symbol has not been undefined before
    164            if symbol not in undefined_a:
    165                files = sorted(undefined_b.get(symbol))
    166                undefined[symbol] = files
    167            # check if there are new files that reference the undefined symbol
    168            else:
    169                files = sorted(undefined_b.get(symbol) -
    170                               undefined_a.get(symbol))
    171                if files:
    172                    undefined[symbol] = files
    173
    174        # reset to head
    175        reset(head)
    176
    177    # default to check the entire tree
    178    else:
    179        undefined, defined = check_symbols(args.ignore)
    180
    181    # now print the output
    182    for symbol in sorted(undefined):
    183        print(red(symbol))
    184
    185        files = sorted(undefined.get(symbol))
    186        print("%s: %s" % (yel("Referencing files"), ", ".join(files)))
    187
    188        sims = find_sims(symbol, args.ignore, defined)
    189        sims_out = yel("Similar symbols")
    190        if sims:
    191            print("%s: %s" % (sims_out, ', '.join(sims)))
    192        else:
    193            print("%s: %s" % (sims_out, "no similar symbols found"))
    194
    195        if args.find:
    196            print("%s:" % yel("Commits changing symbol"))
    197            commits = find_commits(symbol, args.diff)
    198            if commits:
    199                for commit in commits:
    200                    commit = commit.split(" ", 1)
    201                    print("\t- %s (\"%s\")" % (yel(commit[0]), commit[1]))
    202            else:
    203                print("\t- no commit found")
    204        print()  # new line
    205
    206
    207def reset(commit):
    208    """Reset current git tree to %commit."""
    209    execute(["git", "reset", "--hard", commit])
    210
    211
    212def yel(string):
    213    """
    214    Color %string yellow.
    215    """
    216    return "\033[33m%s\033[0m" % string if COLOR else string
    217
    218
    219def red(string):
    220    """
    221    Color %string red.
    222    """
    223    return "\033[31m%s\033[0m" % string if COLOR else string
    224
    225
    226def execute(cmd):
    227    """Execute %cmd and return stdout.  Exit in case of error."""
    228    try:
    229        stdout = subprocess.check_output(cmd, stderr=subprocess.STDOUT, shell=False)
    230        stdout = stdout.decode(errors='replace')
    231    except subprocess.CalledProcessError as fail:
    232        exit(fail)
    233    return stdout
    234
    235
    236def find_commits(symbol, diff):
    237    """Find commits changing %symbol in the given range of %diff."""
    238    commits = execute(["git", "log", "--pretty=oneline",
    239                       "--abbrev-commit", "-G",
    240                       symbol, diff])
    241    return [x for x in commits.split("\n") if x]
    242
    243
    244def tree_is_dirty():
    245    """Return true if the current working tree is dirty (i.e., if any file has
    246    been added, deleted, modified, renamed or copied but not committed)."""
    247    stdout = execute(["git", "status", "--porcelain"])
    248    for line in stdout:
    249        if re.findall(r"[URMADC]{1}", line[:2]):
    250            return True
    251    return False
    252
    253
    254def get_head():
    255    """Return commit hash of current HEAD."""
    256    stdout = execute(["git", "rev-parse", "HEAD"])
    257    return stdout.strip('\n')
    258
    259
    260def partition(lst, size):
    261    """Partition list @lst into eveni-sized lists of size @size."""
    262    return [lst[i::size] for i in range(size)]
    263
    264
    265def init_worker():
    266    """Set signal handler to ignore SIGINT."""
    267    signal.signal(signal.SIGINT, signal.SIG_IGN)
    268
    269
    270def find_sims(symbol, ignore, defined=[]):
    271    """Return a list of max. ten Kconfig symbols that are string-similar to
    272    @symbol."""
    273    if defined:
    274        return difflib.get_close_matches(symbol, set(defined), 10)
    275
    276    pool = Pool(cpu_count(), init_worker)
    277    kfiles = []
    278    for gitfile in get_files():
    279        if REGEX_FILE_KCONFIG.match(gitfile):
    280            kfiles.append(gitfile)
    281
    282    arglist = []
    283    for part in partition(kfiles, cpu_count()):
    284        arglist.append((part, ignore))
    285
    286    for res in pool.map(parse_kconfig_files, arglist):
    287        defined.extend(res[0])
    288
    289    return difflib.get_close_matches(symbol, set(defined), 10)
    290
    291
    292def get_files():
    293    """Return a list of all files in the current git directory."""
    294    # use 'git ls-files' to get the worklist
    295    stdout = execute(["git", "ls-files"])
    296    if len(stdout) > 0 and stdout[-1] == "\n":
    297        stdout = stdout[:-1]
    298
    299    files = []
    300    for gitfile in stdout.rsplit("\n"):
    301        if ".git" in gitfile or "ChangeLog" in gitfile or      \
    302                ".log" in gitfile or os.path.isdir(gitfile) or \
    303                gitfile.startswith("tools/"):
    304            continue
    305        files.append(gitfile)
    306    return files
    307
    308
    309def check_symbols(ignore):
    310    """Find undefined Kconfig symbols and return a dict with the symbol as key
    311    and a list of referencing files as value.  Files matching %ignore are not
    312    checked for undefined symbols."""
    313    pool = Pool(cpu_count(), init_worker)
    314    try:
    315        return check_symbols_helper(pool, ignore)
    316    except KeyboardInterrupt:
    317        pool.terminate()
    318        pool.join()
    319        sys.exit(1)
    320
    321
    322def check_symbols_helper(pool, ignore):
    323    """Helper method for check_symbols().  Used to catch keyboard interrupts in
    324    check_symbols() in order to properly terminate running worker processes."""
    325    source_files = []
    326    kconfig_files = []
    327    defined_symbols = []
    328    referenced_symbols = dict()  # {file: [symbols]}
    329
    330    for gitfile in get_files():
    331        if REGEX_FILE_KCONFIG.match(gitfile):
    332            kconfig_files.append(gitfile)
    333        else:
    334            if ignore and re.match(ignore, gitfile):
    335                continue
    336            # add source files that do not match the ignore pattern
    337            source_files.append(gitfile)
    338
    339    # parse source files
    340    arglist = partition(source_files, cpu_count())
    341    for res in pool.map(parse_source_files, arglist):
    342        referenced_symbols.update(res)
    343
    344    # parse kconfig files
    345    arglist = []
    346    for part in partition(kconfig_files, cpu_count()):
    347        arglist.append((part, ignore))
    348    for res in pool.map(parse_kconfig_files, arglist):
    349        defined_symbols.extend(res[0])
    350        referenced_symbols.update(res[1])
    351    defined_symbols = set(defined_symbols)
    352
    353    # inverse mapping of referenced_symbols to dict(symbol: [files])
    354    inv_map = dict()
    355    for _file, symbols in referenced_symbols.items():
    356        for symbol in symbols:
    357            inv_map[symbol] = inv_map.get(symbol, set())
    358            inv_map[symbol].add(_file)
    359    referenced_symbols = inv_map
    360
    361    undefined = {}  # {symbol: [files]}
    362    for symbol in sorted(referenced_symbols):
    363        # filter some false positives
    364        if symbol == "FOO" or symbol == "BAR" or \
    365                symbol == "FOO_BAR" or symbol == "XXX":
    366            continue
    367        if symbol not in defined_symbols:
    368            if symbol.endswith("_MODULE"):
    369                # avoid false positives for kernel modules
    370                if symbol[:-len("_MODULE")] in defined_symbols:
    371                    continue
    372            undefined[symbol] = referenced_symbols.get(symbol)
    373    return undefined, defined_symbols
    374
    375
    376def parse_source_files(source_files):
    377    """Parse each source file in @source_files and return dictionary with source
    378    files as keys and lists of references Kconfig symbols as values."""
    379    referenced_symbols = dict()
    380    for sfile in source_files:
    381        referenced_symbols[sfile] = parse_source_file(sfile)
    382    return referenced_symbols
    383
    384
    385def parse_source_file(sfile):
    386    """Parse @sfile and return a list of referenced Kconfig symbols."""
    387    lines = []
    388    references = []
    389
    390    if not os.path.exists(sfile):
    391        return references
    392
    393    with open(sfile, "r", encoding='utf-8', errors='replace') as stream:
    394        lines = stream.readlines()
    395
    396    for line in lines:
    397        if "CONFIG_" not in line:
    398            continue
    399        symbols = REGEX_SOURCE_SYMBOL.findall(line)
    400        for symbol in symbols:
    401            if not REGEX_FILTER_SYMBOLS.search(symbol):
    402                continue
    403            references.append(symbol)
    404
    405    return references
    406
    407
    408def get_symbols_in_line(line):
    409    """Return mentioned Kconfig symbols in @line."""
    410    return REGEX_SYMBOL.findall(line)
    411
    412
    413def parse_kconfig_files(args):
    414    """Parse kconfig files and return tuple of defined and references Kconfig
    415    symbols.  Note, @args is a tuple of a list of files and the @ignore
    416    pattern."""
    417    kconfig_files = args[0]
    418    ignore = args[1]
    419    defined_symbols = []
    420    referenced_symbols = dict()
    421
    422    for kfile in kconfig_files:
    423        defined, references = parse_kconfig_file(kfile)
    424        defined_symbols.extend(defined)
    425        if ignore and re.match(ignore, kfile):
    426            # do not collect references for files that match the ignore pattern
    427            continue
    428        referenced_symbols[kfile] = references
    429    return (defined_symbols, referenced_symbols)
    430
    431
    432def parse_kconfig_file(kfile):
    433    """Parse @kfile and update symbol definitions and references."""
    434    lines = []
    435    defined = []
    436    references = []
    437
    438    if not os.path.exists(kfile):
    439        return defined, references
    440
    441    with open(kfile, "r", encoding='utf-8', errors='replace') as stream:
    442        lines = stream.readlines()
    443
    444    for i in range(len(lines)):
    445        line = lines[i]
    446        line = line.strip('\n')
    447        line = line.split("#")[0]  # ignore comments
    448
    449        if REGEX_KCONFIG_DEF.match(line):
    450            symbol_def = REGEX_KCONFIG_DEF.findall(line)
    451            defined.append(symbol_def[0])
    452        elif REGEX_KCONFIG_STMT.match(line):
    453            line = REGEX_QUOTES.sub("", line)
    454            symbols = get_symbols_in_line(line)
    455            # multi-line statements
    456            while line.endswith("\\"):
    457                i += 1
    458                line = lines[i]
    459                line = line.strip('\n')
    460                symbols.extend(get_symbols_in_line(line))
    461            for symbol in set(symbols):
    462                if REGEX_NUMERIC.match(symbol):
    463                    # ignore numeric values
    464                    continue
    465                references.append(symbol)
    466
    467    return defined, references
    468
    469
    470if __name__ == "__main__":
    471    main()