From 33a154a96e71a34a1bcca9f40da343dbbf7b38b4 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 1 Oct 2026 14:52:55 +0000 Subject: selftests/bpf: Test packet range of pointers sharing an id Add tests where two packet pointers share an id and tightening one pointer's umax from its var_off would put it less than their constant distance from the other's umax: with an index & 0x38 capped at 50, the base pointer keeps umax 50, so the pointer 8 bytes further on must keep umax 58, even though its known bits allow at most 56. These refused a valid program or accepted an out-of-bounds access before the fix: - check the advanced copy, load through the base: valid, was refused; - check the base, load the byte at base + 1 through a copy advanced by 8: was accepted; - check base + 4, load 4 bytes at base + 2 through base + 8: reads two bytes past the checked range, was accepted; - the same as the second with data_meta pointers checked against data: was accepted. These pass with and without the fix and cover nearby paths: - subtract an unknown scalar from a checked pointer and load below it (the range is kept across a new id); - reach a load through two paths whose checks cover 8 and 7 bytes after the loaded pointer; the second path must not be pruned by the first; - spill a copy of a pointer, check the pointer, fill the copy and load one byte past the checked range: the load is refused, and the copy has the range of the check. Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- scripts/macro_checker.py | 131 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 131 insertions(+) create mode 100755 scripts/macro_checker.py (limited to 'scripts/macro_checker.py') diff --git a/scripts/macro_checker.py b/scripts/macro_checker.py new file mode 100755 index 000000000..ba550982e --- /dev/null +++ b/scripts/macro_checker.py @@ -0,0 +1,131 @@ +#!/usr/bin/python3 +# SPDX-License-Identifier: GPL-2.0 +# Author: Julian Sun + +""" Find macro definitions with unused parameters. """ + +import argparse +import os +import re + +parser = argparse.ArgumentParser() + +parser.add_argument("path", type=str, help="The file or dir path that needs check") +parser.add_argument("-v", "--verbose", action="store_true", + help="Check conditional macros, but may lead to more false positives") +args = parser.parse_args() + +macro_pattern = r"#define\s+(\w+)\(([^)]*)\)" +# below vars were used to reduce false positives +fp_patterns = [r"\s*do\s*\{\s*\}\s*while\s*\(\s*0\s*\)", + r"\(?0\)?", r"\(?1\)?"] +correct_macros = [] +cond_compile_mark = "#if" +cond_compile_end = "#endif" + +def check_macro(macro_line, report): + match = re.match(macro_pattern, macro_line) + if match: + macro_def = re.sub(macro_pattern, '', macro_line) + identifier = match.group(1) + content = match.group(2) + arguments = [item.strip() for item in content.split(',') if item.strip()] + + macro_def = macro_def.strip() + if not macro_def: + return + # used to reduce false positives, like #define endfor_nexthops(rt) } + if len(macro_def) == 1: + return + + for fp_pattern in fp_patterns: + if (re.match(fp_pattern, macro_def)): + return + + for arg in arguments: + # used to reduce false positives + if "..." in arg: + return + for arg in arguments: + if not arg in macro_def and report == False: + return + # if there is a correct macro with the same name, do not report it. + if not arg in macro_def and identifier not in correct_macros: + print(f"Argument {arg} is not used in function-line macro {identifier}") + return + + correct_macros.append(identifier) + + +# remove comment and whitespace +def macro_strip(macro): + comment_pattern1 = r"\/\/*" + comment_pattern2 = r"\/\**\*\/" + + macro = macro.strip() + macro = re.sub(comment_pattern1, '', macro) + macro = re.sub(comment_pattern2, '', macro) + + return macro + +def file_check_macro(file_path, report): + # number of conditional compiling + cond_compile = 0 + # only check .c and .h file + if not file_path.endswith(".c") and not file_path.endswith(".h"): + return + + with open(file_path, "r") as f: + while True: + line = f.readline() + if not line: + break + line = line.strip() + if line.startswith(cond_compile_mark): + cond_compile += 1 + continue + if line.startswith(cond_compile_end): + cond_compile -= 1 + continue + + macro = re.match(macro_pattern, line) + if macro: + macro = macro_strip(macro.string) + while macro[-1] == '\\': + macro = macro[0:-1] + macro = macro.strip() + macro += f.readline() + macro = macro_strip(macro) + if not args.verbose: + if file_path.endswith(".c") and cond_compile != 0: + continue + # 1 is for #ifdef xxx at the beginning of the header file + if file_path.endswith(".h") and cond_compile != 1: + continue + check_macro(macro, report) + +def get_correct_macros(path): + file_check_macro(path, False) + +def dir_check_macro(dir_path): + + for dentry in os.listdir(dir_path): + path = os.path.join(dir_path, dentry) + if os.path.isdir(path): + dir_check_macro(path) + elif os.path.isfile(path): + get_correct_macros(path) + file_check_macro(path, True) + + +def main(): + if os.path.isfile(args.path): + get_correct_macros(args.path) + file_check_macro(args.path, True) + elif os.path.isdir(args.path): + dir_check_macro(args.path) + else: + print(f"{args.path} doesn't exit or is neither a file nor a dir") + +if __name__ == "__main__": + main() \ No newline at end of file -- cgit v1.3.1