tools/testing/selftests/x86/bugs/its_indirect_alignment.py

Source file repositories/reference/linux-study-clean/tools/testing/selftests/x86/bugs/its_indirect_alignment.py

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/x86/bugs/its_indirect_alignment.py
Extension
.py
Size
6554 bytes
Lines
151
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: tools
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0
#
# Copyright (c) 2025 Intel Corporation
#
# Test for indirect target selection (ITS) mitigation.
#
# Test if indirect CALL/JMP are correctly patched by evaluating
# the vmlinux .retpoline_sites in /proc/kcore.

# Install dependencies
# add-apt-repository ppa:michel-slm/kernel-utils
# apt update
# apt install -y python3-drgn python3-pyelftools python3-capstone
#
# Best to copy the vmlinux at a standard location:
# mkdir -p /usr/lib/debug/lib/modules/$(uname -r)
# cp $VMLINUX /usr/lib/debug/lib/modules/$(uname -r)/vmlinux
#
# Usage: ./its_indirect_alignment.py [vmlinux]

import os, sys, argparse
from pathlib import Path

this_dir = os.path.dirname(os.path.realpath(__file__))
sys.path.insert(0, this_dir + '/../../kselftest')
import ksft
import common as c

bug = "indirect_target_selection"

mitigation = c.get_sysfs(bug)
if not mitigation or "Aligned branch/return thunks" not in mitigation:
    ksft.test_result_skip("Skipping its_indirect_alignment.py: Aligned branch/return thunks not enabled")
    ksft.finished()

if c.sysfs_has("spectre_v2", "Retpolines"):
    ksft.test_result_skip("Skipping its_indirect_alignment.py: Retpolines deployed")
    ksft.finished()

c.check_dependencies_or_skip(['drgn', 'elftools', 'capstone'], script_name="its_indirect_alignment.py")

from elftools.elf.elffile import ELFFile
from drgn.helpers.common.memory import identify_address

cap = c.init_capstone()

if len(os.sys.argv) > 1:
    arg_vmlinux = os.sys.argv[1]
    if not os.path.exists(arg_vmlinux):
        ksft.test_result_fail(f"its_indirect_alignment.py: vmlinux not found at argument path: {arg_vmlinux}")
        ksft.exit_fail()
    os.makedirs(f"/usr/lib/debug/lib/modules/{os.uname().release}", exist_ok=True)
    os.system(f'cp {arg_vmlinux} /usr/lib/debug/lib/modules/$(uname -r)/vmlinux')

vmlinux = f"/usr/lib/debug/lib/modules/{os.uname().release}/vmlinux"
if not os.path.exists(vmlinux):
    ksft.test_result_fail(f"its_indirect_alignment.py: vmlinux not found at {vmlinux}")
    ksft.exit_fail()

ksft.print_msg(f"Using vmlinux: {vmlinux}")

retpolines_start_vmlinux, retpolines_sec_offset, size = c.get_section_info(vmlinux, '.retpoline_sites')
ksft.print_msg(f"vmlinux: Section .retpoline_sites (0x{retpolines_start_vmlinux:x}) found at 0x{retpolines_sec_offset:x} with size 0x{size:x}")

sites_offset = c.get_patch_sites(vmlinux, retpolines_sec_offset, size)
total_retpoline_tests = len(sites_offset)
ksft.print_msg(f"Found {total_retpoline_tests} retpoline sites")

prog = c.get_runtime_kernel()

Annotation

Implementation Notes