From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- scripts/bootgraph.pl | 224 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 224 insertions(+) create mode 100755 scripts/bootgraph.pl (limited to 'scripts/bootgraph.pl') diff --git a/scripts/bootgraph.pl b/scripts/bootgraph.pl new file mode 100755 index 000000000..79c903292 --- /dev/null +++ b/scripts/bootgraph.pl @@ -0,0 +1,224 @@ +#!/usr/bin/env perl +# SPDX-License-Identifier: GPL-2.0-only + +# Copyright 2008, Intel Corporation +# +# This file is part of the Linux kernel +# +# Authors: +# Arjan van de Ven + + +# +# This script turns a dmesg output into a SVG graphic that shows which +# functions take how much time. You can view SVG graphics with various +# programs, including Inkscape, The Gimp and Firefox. +# +# +# For this script to work, the kernel needs to be compiled with the +# CONFIG_PRINTK_TIME configuration option enabled, and with +# "initcall_debug" passed on the kernel command line. +# +# usage: +# dmesg | perl scripts/bootgraph.pl > output.svg +# + +use strict; +use Getopt::Long; +my $header = 0; + +sub help { + my $text = << "EOM"; +Usage: +1) dmesg | perl scripts/bootgraph.pl [OPTION] > output.svg +2) perl scripts/bootgraph.pl -h + +Options: + -header Insert kernel version and date +EOM + my $std=shift; + if ($std == 1) { + print STDERR $text; + } else { + print $text; + } + exit; +} + +GetOptions( + 'h|help' =>\&help, + 'header' =>\$header +); + +my %start; +my %end; +my %type; +my $done = 0; +my $maxtime = 0; +my $firsttime = 99999; +my $count = 0; +my %pids; +my %pidctr; + +my $headerstep = 20; +my $xheader = 15; +my $yheader = 25; +my $cyheader = 0; + +while (<>) { + my $line = $_; + if ($line =~ /([0-9\.]+)\] calling ([a-zA-Z0-9\_\.]+)\+/) { + my $func = $2; + if ($done == 0) { + $start{$func} = $1; + $type{$func} = 0; + if ($1 < $firsttime) { + $firsttime = $1; + } + } + if ($line =~ /\@ ([0-9]+)/) { + $pids{$func} = $1; + } + $count = $count + 1; + } + + if ($line =~ /([0-9\.]+)\] async_waiting @ ([0-9]+)/) { + my $pid = $2; + my $func; + if (!defined($pidctr{$pid})) { + $func = "wait_" . $pid . "_1"; + $pidctr{$pid} = 1; + } else { + $pidctr{$pid} = $pidctr{$pid} + 1; + $func = "wait_" . $pid . "_" . $pidctr{$pid}; + } + if ($done == 0) { + $start{$func} = $1; + $type{$func} = 1; + if ($1 < $firsttime) { + $firsttime = $1; + } + } + $pids{$func} = $pid; + $count = $count + 1; + } + + if ($line =~ /([0-9\.]+)\] initcall ([a-zA-Z0-9\_\.]+)\+.*returned/) { + if ($done == 0) { + $end{$2} = $1; + $maxtime = $1; + } + } + + if ($line =~ /([0-9\.]+)\] async_continuing @ ([0-9]+)/) { + my $pid = $2; + my $func = "wait_" . $pid . "_" . $pidctr{$pid}; + $end{$func} = $1; + $maxtime = $1; + } + if ($line =~ /Write protecting the/) { + $done = 1; + } + if ($line =~ /Freeing unused kernel memory/) { + $done = 1; + } +} + +if ($count == 0) { + print STDERR < \n"; +print "\n"; + + +if ($header) { + my $version = `uname -a`; + my $date = `date`; + print "Kernel version: $version\n"; + $cyheader = $yheader+$headerstep; + print "Date: $date\n"; +} + +my @styles; + +$styles[0] = "fill:rgb(0,0,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[1] = "fill:rgb(0,255,0);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[2] = "fill:rgb(255,0,20);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[3] = "fill:rgb(255,255,20);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[4] = "fill:rgb(255,0,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[5] = "fill:rgb(0,255,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[6] = "fill:rgb(0,128,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[7] = "fill:rgb(0,255,128);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[8] = "fill:rgb(255,0,128);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[9] = "fill:rgb(255,255,128);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[10] = "fill:rgb(255,128,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[11] = "fill:rgb(128,255,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; + +my $style_wait = "fill:rgb(128,128,128);fill-opacity:0.5;stroke-width:0;stroke:rgb(0,0,0)"; + +my $mult = 1950.0 / ($maxtime - $firsttime); +my $threshold2 = ($maxtime - $firsttime) / 120.0; +my $threshold = $threshold2/10; +my $stylecounter = 0; +my %rows; +my $rowscount = 1; +my @initcalls = sort { $start{$a} <=> $start{$b} } keys(%start); + +foreach my $key (@initcalls) { + my $duration = $end{$key} - $start{$key}; + + if ($duration >= $threshold) { + my ($s, $s2, $s3, $e, $w, $y, $y2, $style); + my $pid = $pids{$key}; + + if (!defined($rows{$pid})) { + $rows{$pid} = $rowscount; + $rowscount = $rowscount + 1; + } + $s = ($start{$key} - $firsttime) * $mult; + $s2 = $s + 6; + $s3 = $s + 1; + $e = ($end{$key} - $firsttime) * $mult; + $w = $e - $s; + + $y = $rows{$pid} * 150; + $y2 = $y + 4; + + $style = $styles[$stylecounter]; + $stylecounter = $stylecounter + 1; + if ($stylecounter > 11) { + $stylecounter = 0; + }; + + if ($type{$key} == 1) { + $y = $y + 15; + print "\n"; + } else { + print "\n"; + if ($duration >= $threshold2) { + print "$key\n"; + } else { + print "$key\n"; + } + } + } +} + + +# print the time line on top +my $time = $firsttime; +my $step = ($maxtime - $firsttime) / 15; +while ($time < $maxtime) { + my $s3 = ($time - $firsttime) * $mult; + my $tm = int($time * 100) / 100.0; + print "$tm\n"; + $time = $time + $step; +} + +print "\n"; -- cgit v1.3.1