From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- Documentation/sphinx/maintainers_include.py | 415 ++++++++++++++++++++++++++++ 1 file changed, 415 insertions(+) create mode 100755 Documentation/sphinx/maintainers_include.py (limited to 'Documentation/sphinx/maintainers_include.py') diff --git a/Documentation/sphinx/maintainers_include.py b/Documentation/sphinx/maintainers_include.py new file mode 100755 index 000000000..dc9f9e188 --- /dev/null +++ b/Documentation/sphinx/maintainers_include.py @@ -0,0 +1,415 @@ +#!/usr/bin/env python +# SPDX-License-Identifier: GPL-2.0 +# -*- coding: utf-8; mode: python -*- +# pylint: disable=C0209, C0301, E0401, R0022, R0902, R0903, R0912, R0914 + +""" +Implementation of the ``maintainers-include`` reST-directive. + +:copyright: Copyright (C) 2019 Kees Cook +:license: GPL Version 2, June 1991 see linux/COPYING for details. + +The ``maintainers-include`` reST-directive performs extensive parsing +specific to the Linux kernel's standard "MAINTAINERS" file, in an +effort to avoid needing to heavily mark up the original plain text. +""" + +import os.path +import re + +from glob import glob + +from docutils import statemachine +from docutils.parsers.rst.directives.misc import Include + +# +# Base URL for intersphinx-like links to maintainer profiles +# +KERNELDOC_URL = "https://docs.kernel.org/" + +__version__ = "1.0" + +maint_parser = None # pylint: disable=C0103 + +JS_FILTER = """ +(function() { + function filterTable(table) { + const filter = document.getElementById("filter-table").value.trim(); + const rows = table.querySelectorAll("tbody tr"); + for (let i = 0; i < rows.length; i++) { + const tds = rows[i].getElementsByTagName("td"); + let match = false; + for (let j = 0; j < tds.length; j++) { + const cellText = (tds[j].textContent || tds[j].innerText); + if (cellText.includes(filter)) { + match = true; + break; + } + } + rows[i].style.display = match ? "table-row" : "none"; + } + } + function addInput() { + const table = document.getElementById("maintainers-table"); + if (!table) return; + let input = document.getElementById("filter-table"); + if (!input) { + const filt_div = document.createElement('div'); + filt_div.innerHTML = ` +

Filter: + + subsystem or property (case-sensitive) +

+ `; + table.parentNode.insertBefore(filt_div, table); + const input = document.getElementById("filter-table") + input.addEventListener('input', () => filterTable(table)); + } + } + if (document.readyState === 'loading') { + document.addEventListener('DOMContentLoaded', addInput); + } else { + addInput(); + } +})(); +""" + + +# Shamelessly stolen from docutils +def ErrorString(exc): # pylint: disable=C0103, C0116 + return f"{exc.__class__.__name}: {exc}" # pylint: disable=W0212 + +class MaintainersParser: + """Parse MAINTAINERS file(s) content""" + + def __init__(self, base_dir, app_dir, path): + self.path = path + + # Poor man's state machine. + self.descriptions = False + self.maintainers = False + self.subsystems = False + + self.subsystem_name = None + + self.base_dir = base_dir + self.app_dir = app_dir + + self.re_doc = re.compile(r'(Documentation/(\S*)\.rst)') + + # + # Output variables with maintainers content to be stored + # + self.profile_toc = set() + self.profile_entries = {} + self.header = "" + self.maint_entries = {} + self.fields = {} + + prev = None + with open(path, "r", encoding="utf-8") as fp: + for line in fp: + if self.descriptions: + self.parse_descriptions(line) + elif self.maintainers and not self.subsystems: + if re.search('^[A-Z0-9]', line): + self.subsystems = True + self.parse_subsystems(line) + else: + self.header += line + elif self.subsystems: + self.parse_subsystems(line) + else: + self.header += line + + # Update the state machine when we find heading separators. + if line.startswith("----------"): + if prev.startswith("Descriptions"): + self.descriptions = True + if prev.startswith("Maintainers"): + self.maintainers = True + + # Retain previous line for state machine transitions. + prev = line + + def get_entries(self, text): + """Generate refs to ReST files in Documentation/""" + + if "Documentation/" not in text: + return None + + if "*" in text or "?" in text: + m = self.re_doc.search(text) + if not m: + return None + + doc_list = glob(os.path.join(self.base_dir, m.group(1))) + else: + doc_list = [text] + + entries = {} + for doc in doc_list: + m = self.re_doc.search(doc) + if m: + fname = m.group(1) + ename = m.group(2) + + entry = os.path.relpath(self.base_dir + fname, self.app_dir) + entry = entry.removesuffix(".rst") + + if entry.startswith("../"): + html = KERNELDOC_URL + ename + ".html" + entries[entry] = f'`{ename} <{html}>`_' + else: + entries[entry] = f':doc:`{ename} `' + + return entries + + def linkify(self, text): + """Return a list of doc files converted to cross-references""" + + entries = self.get_entries(text) + if not entries: + return text + + return self.re_doc.sub(", ".join(entries.values()), text) + + def parse_descriptions(self, line): + """Handle contents of the descriptions section.""" + + # Have we reached the end of the preformatted Descriptions text? + if line.startswith("Maintainers"): + self.descriptions = False + self.header += "\n" + line + return + + # Look for and record field letter to field name mappings: + # R: Designated *reviewer*: FullName + m = re.match(r"\s+(\S):\s+(\S+)", line) + if m: + field = m.group(1) + details = m.group(2) + + if field not in self.fields: + m = re.search(r"\*([^\*]+)\*", line) + if m: + self.fields[field] = m.group(1) + elif field in ['F', 'N', 'X', 'K']: + line = line.replace(details, f'``{details}``') + + self.header += "| " + self.linkify(line) + + + def parse_subsystems(self, line): + """Handle contents of the per-subsystem sections.""" + + # Drop needless input whitespace. + line = line.rstrip() + + # Skip empty lines: subsystem parser adds them as needed. + if not line: + return + + if line[1] != ':': + self.subsystem_name = re.sub(r"\s+", " ", self.linkify(line)) + return + + # Render a subsystem field as: + # :Field: entry + # entry... + field, details = line.split(":", 1) + details = details.strip() + + # + # Handle profile entries - either as files or as https refs + # + if field == "P": + entries = self.get_entries(details) + if entries: + for e, link in entries.items(): + if "html" not in link: + self.profile_toc.add(e) + + self.profile_entries[self.subsystem_name] = link + + details = ", ".join(entries.values()) + else: + match = re.match(r"(https?://.*)", details) + if match: + entry = match.group(1).strip() + self.profile_entries[self.subsystem_name] = entry + else: + self.profile_entries[self.subsystem_name] = f"``{details}``" + + details = self.linkify(details) + else: + details = self.linkify(details) + + # + # Mark paths (and regexes) as literal text for improved + # readability and to escape any escapes. + # + if field in ['F', 'N', 'X', 'K']: + # But only if not already marked :) + if ':doc:' not in details and "http" not in details: + details = '``%s``' % (details) + + if self.subsystem_name not in self.maint_entries: + self.maint_entries[self.subsystem_name] = {} + + if field not in self.maint_entries[self.subsystem_name]: + self.maint_entries[self.subsystem_name][field] = [] + + self.maint_entries[self.subsystem_name][field].append(details) + + self.field_prev = field + + +class MaintainersInclude(Include): + """MaintainersInclude (``maintainers-include``) directive""" + + required_arguments = 0 + + def emit(self): + """Parse all the MAINTAINERS lines into ReST for human-readability""" + path = maint_parser.path + output = ".. _maintainers:\n\n" + output += maint_parser.header + + output += ".. _maintainers_table:\n\n" + output += ".. flat-table::\n" + output += " :header-rows: 1\n\n" + output += " * - Subsystem\n" + output += " - Properties\n\n" + + self.state.document['maintainers_included'] = True + + # Keep the last entry ("THE REST") in the end + entries = list(maint_parser.maint_entries.keys()) + entries = sorted(entries[:-1], key=str.casefold) + [entries[-1]] + + for name in entries: + fields = maint_parser.maint_entries[name] + output += f" * - {name}\n" + tag = "-" + for field, lines in fields.items(): + field_name = maint_parser.fields.get(field, field) + + output += f" {tag} :{field_name}:\n " + output += ",\n ".join(lines) + "\n" + tag = " " + + output += "\n" + + # For debugging the pre-rendered results... + #print(output, file=open("/tmp/MAINTAINERS.rst", "w")) + + self.state.document.settings.record_dependencies.add(path) + self.state_machine.insert_input(statemachine.string2lines(output), path) + + def run(self): + """Include the MAINTAINERS file as part of this reST file.""" + if not self.state.document.settings.file_insertion_enabled: + raise self.warning('"%s" directive disabled.' % self.name) + + try: + self.emit() + except IOError as error: + raise self.severe('Problems with "%s" directive path:\n%s.' % + (self.name, ErrorString(error))) + + return [] + + +class MaintainersProfile(Include): + """Generate a list with all maintainer's profiles""" + + required_arguments = 0 + + def emit(self): + """Parse all the MAINTAINERS lines looking for profile entries""" + env = self.state.document.settings.env + docdir = os.path.dirname(os.path.join(env.srcdir, env.docname)) + path = maint_parser.path + + # + # Produce a list with all maintainer profiles, sorted by subsystem name + # + output = "" + for profile, entry in sorted(maint_parser.profile_entries.items()): + name = profile.title() + + if entry.startswith("http"): + output += f"- `{name} <{entry}>`_\n" + elif entry.startswith("`"): + output += f"- {name}: {entry}\n" + self.warning(f"{profile}: Invalid 'P' tag: {entry}\n") + else: + output += f"- {entry}\n" + + # + # Create a hidden TOC table with all profiles. That allows adding + # profiles without needing to add them on any index.rst file. + # + output += "\n.. toctree::\n" + output += " :hidden:\n\n" + + for f in sorted(maint_parser.profile_toc): + fname = os.path.join(maint_parser.base_dir, "Documentation", f) + fname = os.path.relpath(fname, docdir) + output += f" {fname}\n" + + output += "\n" + + # For debugging the pre-rendered results... + #print(output, file=open("/tmp/profiles.rst", "w")) + + self.state.document.settings.record_dependencies.add(path) + self.state_machine.insert_input(statemachine.string2lines(output), path) + + def run(self): + """Include the MAINTAINERS file as part of this reST file.""" + if not self.state.document.settings.file_insertion_enabled: + raise self.warning('"%s" directive disabled.' % self.name) + + try: + self.emit() + except IOError as error: + raise self.severe('Problems with "%s" directive path:\n%s.' % + (self.name, ErrorString(error))) + + return [] + + +# pylint: disable=W0613 +def add_filter_script(app, pagename, templatename, context, doctree): + """Add Filter javascript only to maintainers page""" + + if doctree and doctree.get('maintainers_included'): + app.add_js_file(None, body=JS_FILTER) + + +def setup(app): + """Setup Sphinx extension""" + global maint_parser # pylint: disable=W0603 + + app_dir = os.path.abspath(app.srcdir) + match = re.match(r"(.*/)Documentation", app_dir) + if not match: + raise ValueError('Documentation directory not found.') + + base_dir = match.group(1) + path = os.path.join(base_dir, "MAINTAINERS") + + maint_parser = MaintainersParser(base_dir, app_dir, path) + + app.add_directive("maintainers-include", MaintainersInclude) + app.add_directive("maintainers-profile-toc", MaintainersProfile) + + app.connect("html-page-context", add_filter_script) + + return { + "version": __version__, + "parallel_read_safe": True, + "parallel_write_safe": True, + } -- cgit v1.3.1