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/headerdep.pl | 193 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 193 insertions(+) create mode 100755 scripts/headerdep.pl (limited to 'scripts/headerdep.pl') diff --git a/scripts/headerdep.pl b/scripts/headerdep.pl new file mode 100755 index 000000000..ebfcbef43 --- /dev/null +++ b/scripts/headerdep.pl @@ -0,0 +1,193 @@ +#! /usr/bin/env perl +# SPDX-License-Identifier: GPL-2.0 +# +# Detect cycles in the header file dependency graph +# Vegard Nossum +# + +use strict; +use warnings; + +use Getopt::Long; + +my $opt_all; +my @opt_include; +my $opt_graph; + +&Getopt::Long::Configure(qw(bundling pass_through)); +&GetOptions( + help => \&help, + version => \&version, + + all => \$opt_all, + "I=s" => \@opt_include, + graph => \$opt_graph, +); + +push @opt_include, 'include'; +my %deps = (); +my %linenos = (); + +my @headers = grep { strip($_) } @ARGV; + +parse_all(@headers); + +if($opt_graph) { + graph(); +} else { + detect_cycles(@headers); +} + + +sub help { + print "Usage: $0 [options] file...\n"; + print "\n"; + print "Options:\n"; + print " --all\n"; + print " --graph\n"; + print "\n"; + print " -I includedir\n"; + print "\n"; + print "To make nice graphs, try:\n"; + print " $0 --graph include/linux/kernel.h | dot -Tpng -o graph.png\n"; + exit; +} + +sub version { + print "headerdep version 2\n"; + exit; +} + +# Get a file name that is relative to our include paths +sub strip { + my $filename = shift; + + for my $i (@opt_include) { + my $stripped = $filename; + $stripped =~ s/^$i\///; + + return $stripped if $stripped ne $filename; + } + + return $filename; +} + +# Search for the file name in the list of include paths +sub search { + my $filename = shift; + return $filename if -f $filename; + + for my $i (@opt_include) { + my $path = "$i/$filename"; + return $path if -f $path; + } + return; +} + +sub parse_all { + # Parse all the headers. + my @queue = @_; + while(@queue) { + my $header = pop @queue; + next if exists $deps{$header}; + + $deps{$header} = [] unless exists $deps{$header}; + + my $path = search($header); + next unless $path; + + open(my $file, '<', $path) or die($!); + chomp(my @lines = <$file>); + close($file); + + for my $i (0 .. $#lines) { + my $line = $lines[$i]; + if(my($dep) = ($line =~ m/^#\s*include\s*<(.*?)>/)) { + push @queue, $dep; + push @{$deps{$header}}, [$i + 1, $dep]; + } + } + } +} + +sub print_cycle { + # $cycle[n] includes $cycle[n + 1]; + # $cycle[-1] will be the culprit + my $cycle = shift; + + # Adjust the line numbers + for my $i (0 .. $#$cycle - 1) { + $cycle->[$i]->[0] = $cycle->[$i + 1]->[0]; + } + $cycle->[-1]->[0] = 0; + + my $first = shift @$cycle; + my $last = pop @$cycle; + + my $msg = "In file included"; + printf "%s from %s,\n", $msg, $last->[1] if defined $last; + + for my $header (reverse @$cycle) { + printf "%s from %s:%d%s\n", + " " x length $msg, + $header->[1], $header->[0], + $header->[1] eq $last->[1] ? ' <-- here' : ''; + } + + printf "%s:%d: warning: recursive header inclusion\n", + $first->[1], $first->[0]; +} + +# Find and print the smallest cycle starting in the specified node. +sub detect_cycles { + my @queue = map { [[0, $_]] } @_; + while(@queue) { + my $top = pop @queue; + my $name = $top->[-1]->[1]; + + for my $dep (@{$deps{$name}}) { + my $chain = [@$top, [$dep->[0], $dep->[1]]]; + + # If the dep already exists in the chain, we have a + # cycle... + if(grep { $_->[1] eq $dep->[1] } @$top) { + print_cycle($chain); + next if $opt_all; + return; + } + + push @queue, $chain; + } + } +} + +sub mangle { + $_ = shift; + s/\//__/g; + s/\./_/g; + s/-/_/g; + $_; +} + +# Output dependency graph in GraphViz language. +sub graph { + print "digraph {\n"; + + print "\t/* vertices */\n"; + for my $header (keys %deps) { + printf "\t%s [label=\"%s\"];\n", + mangle($header), $header; + } + + print "\n"; + + print "\t/* edges */\n"; + for my $header (keys %deps) { + for my $dep (@{$deps{$header}}) { + printf "\t%s -> %s;\n", + mangle($header), mangle($dep->[1]); + } + } + + print "}\n"; +} -- cgit v1.3.1