This script allows sysctl documentation to be checked against the
kernel source code, to identify missing or obsolete entries. Running
it against 5.5 shows for example that sysctl/kernel.rst has two
obsolete entries and is missing 52 entries.
Signed-off-by: Stephen Kitt <steve@xxxxxxx>
---
Documentation/admin-guide/sysctl/kernel.rst | 3 +
scripts/check-sysctl-docs | 181 ++++++++++++++++++++
2 files changed, 184 insertions(+)
create mode 100755 scripts/check-sysctl-docs
diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index a67c218c4066..3d21e076aea4 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -2,6 +2,9 @@
Documentation for /proc/sys/kernel/
===================================
+.. See scripts/check-sysctl-docs to keep this up to date
+
+
Copyright (c) 1998, 1999, Rik van Riel <riel@xxxxxxxxxxxx>
Copyright (c) 2009, Shen Feng<shen@xxxxxxxxxxxxxx>
diff --git a/scripts/check-sysctl-docs b/scripts/check-sysctl-docs
new file mode 100755
index 000000000000..b3b47c188a2d
--- /dev/null
+++ b/scripts/check-sysctl-docs
@@ -0,0 +1,181 @@
+#!/usr/bin/gawk -f
+# SPDX-License-Identifier: GPL-2.0-only
+
+# Script to check sysctl documentation against source files
+#
+# Copyright © 2020 Stephen Kitt
+
+# Example invocation:
+# scripts/check-sysctl-docs -vtable="kernel" \
+# Documentation/admin-guide/sysctl/kernel.rst \
+# $(git grep -l register_sysctl_table)
+#
+# Specify -vdebug=1 to see debugging information
+
+BEGIN {
+ if (!table) {
+ print "Please specify the table to look for using the table variable" > "/dev/stderr"
+ exit 1
+ }
+}
+
+# The following globals are used:
+# children: maps ctl_table names and procnames to child ctl_table names
+# documented: maps documented entries (each key is an entry)
+# entries: maps ctl_table names and procnames to counts (so
+# enumerating the subkeys for a given ctl_table lists its
+# procnames)
+# files: maps procnames to source file names
+# paths: maps ctl_path names to paths
+# curpath: the name of the current ctl_path struct
+# curtable: the name of the current ctl_table struct
+# curentry: the name of the current proc entry (procname when parsing
+# a ctl_table, constructed path when parsing a ctl_path)
+
+
+# Remove punctuation from the given value
+function trimpunct(value) {
+ while (value ~ /^["&]/) {
+ value = substr(value, 2)
+ }
+ while (value ~ /[]["&,}]$/) {
+ value = substr(value, 1, length(value) - 1)
+ }
+ return value
+}
+
+# Print the information for the given entry
+function printentry(entry) {
+ seen[entry]++
+ printf "* %s from %s", entry, file[entry]
+ if (documented[entry]) {
+ printf " (documented)"
+ }
+ print ""
+}
+
+
+# Stage 1: build the list of documented entries
+FNR == NR && /^=+$/ {
+ if (prevline ~ /Documentation for/) {
+ # This is the main title
+ next
+ }
+
+ # The previous line is a section title, parse it
+ $0 = prevline
+ if (debug) print "Parsing " $0
+ inbrackets = 0
+ for (i = 1; i <= NF; i++) {
+ if (length($i) == 0) {
+ continue
+ }
+ if (!inbrackets && substr($i, 1, 1) == "(") {
+ inbrackets = 1
+ }
+ if (!inbrackets) {
+ token = trimpunct($i)
+ if (length(token) > 0 && token != "and") {
+ if (debug) print trimpunct($i)
+ documented[trimpunct($i)]++
+ }
+ }
+ if (inbrackets && substr($i, length($i), 1) == ")") {
+ inbrackets = 0
+ }
+ }
+}
+
+FNR == NR {
+ prevline = $0
+ next
+}
+
+
+# Stage 2: process each file and find all sysctl tables
+BEGINFILE {
+ delete children
+ delete entries
+ delete paths
+ curpath = ""
+ curtable = ""
+ curentry = ""
+ if (debug) print "Processing file " FILENAME
+}
+
+/^static struct ctl_path/ {
+ match($0, /static struct ctl_path ([^][]+)/, tables)
+ curpath = tables[1]
+ if (debug) print "Processing path " curpath
+}
+
+/^static struct ctl_table/ {
+ match($0, /static struct ctl_table ([^][]+)/, tables)
+ curtable = tables[1]
+ if (debug) print "Processing table " curtable
+}
+
+/^};$/ {
+ curpath = ""
+ curtable = ""
+ curentry = ""
+}
+
+curpath && /\.procname[\t ]*=[\t ]*".+"/ {
+ match($0, /.procname[\t ]*=[\t ]*"([^"]+)"/, names)
+ if (curentry) {
+ curentry = curentry "/" names[1]
+ } else {
+ curentry = names[1]
+ }
+ if (debug) print "Setting path " curpath " to " curentry
+ paths[curpath] = curentry
+}
+
+curtable && /\.procname[\t ]*=[\t ]*".+"/ {
+ match($0, /.procname[\t ]*=[\t ]*"([^"]+)"/, names)
+ curentry = names[1]
+ if (debug) print "Adding entry " curentry " to table " curtable
+ entries[curtable][curentry]++
+ file[curentry] = FILENAME
+}
+
+/\.child[\t ]*=/ {
+ child = trimpunct($NF)
+ if (debug) print "Linking child " child " to table " curtable " entry " curentry
+ children[curtable][curentry] = child
+}
+
+/register_sysctl_table\(.*\)/ {
+ match($0, /register_sysctl_table\(([^)]+)\)/, tables)
+ if (debug) print "Registering table " tables[1]
+ if (children[tables[1]][table]) {
+ for (entry in entries[children[tables[1]][table]]) {
+ printentry(entry)
+ }
+ }
+}
+
+/register_sysctl_paths\(.*\)/ {
+ match($0, /register_sysctl_paths\(([^)]+), ([^)]+)\)/, tables)
+ if (debug) print "Attaching table " tables[2] " to path " tables[1]
+ if (paths[tables[1]] == table) {
+ for (entry in entries[tables[2]]) {
+ printentry(entry)
+ }
+ }
+ split(paths[tables[1]], components, "/")
+ if (length(components) > 1 && components[1] == table) {
+ # Count the first subdirectory as seen
+ seen[components[2]]++
+ }
+}
+
+
+END {
+ for (entry in documented) {
+ if (!seen[entry]) {
+ print "No implementation for " entry
+ }
+ }
+}
--
2.20.1
