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/cleanpatch | 260 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 260 insertions(+) create mode 100755 scripts/cleanpatch (limited to 'scripts/cleanpatch') diff --git a/scripts/cleanpatch b/scripts/cleanpatch new file mode 100755 index 000000000..9f1755271 --- /dev/null +++ b/scripts/cleanpatch @@ -0,0 +1,260 @@ +#!/usr/bin/env perl +# SPDX-License-Identifier: GPL-2.0 +# +# Clean a patch file -- or directory of patch files -- of stealth whitespace. +# WARNING: this can be a highly destructive operation. Use with caution. +# + +use warnings; +use bytes; +use File::Basename; + +# Default options +$max_width = 79; + +# Clean up space-tab sequences, either by removing spaces or +# replacing them with tabs. +sub clean_space_tabs($) +{ + no bytes; # Tab alignment depends on characters + + my($li) = @_; + my($lo) = ''; + my $pos = 0; + my $nsp = 0; + my($i, $c); + + for ($i = 0; $i < length($li); $i++) { + $c = substr($li, $i, 1); + if ($c eq "\t") { + my $npos = ($pos+$nsp+8) & ~7; + my $ntab = ($npos >> 3) - ($pos >> 3); + $lo .= "\t" x $ntab; + $pos = $npos; + $nsp = 0; + } elsif ($c eq "\n" || $c eq "\r") { + $lo .= " " x $nsp; + $pos += $nsp; + $nsp = 0; + $lo .= $c; + $pos = 0; + } elsif ($c eq " ") { + $nsp++; + } else { + $lo .= " " x $nsp; + $pos += $nsp; + $nsp = 0; + $lo .= $c; + $pos++; + } + } + $lo .= " " x $nsp; + return $lo; +} + +# Compute the visual width of a string +sub strwidth($) { + no bytes; # Tab alignment depends on characters + + my($li) = @_; + my($c, $i); + my $pos = 0; + my $mlen = 0; + + for ($i = 0; $i < length($li); $i++) { + $c = substr($li,$i,1); + if ($c eq "\t") { + $pos = ($pos+8) & ~7; + } elsif ($c eq "\n") { + $mlen = $pos if ($pos > $mlen); + $pos = 0; + } else { + $pos++; + } + } + + $mlen = $pos if ($pos > $mlen); + return $mlen; +} + +$name = basename($0); + +@files = (); + +while (defined($a = shift(@ARGV))) { + if ($a =~ /^-/) { + if ($a eq '-width' || $a eq '-w') { + $max_width = shift(@ARGV)+0; + } else { + print STDERR "Usage: $name [-width #] files...\n"; + exit 1; + } + } else { + push(@files, $a); + } +} + +foreach $f ( @files ) { + print STDERR "$name: $f\n"; + + if (! -f $f) { + print STDERR "$f: not a file\n"; + next; + } + + if (!open(FILE, '+<', $f)) { + print STDERR "$name: Cannot open file: $f: $!\n"; + next; + } + + binmode FILE; + + # First, verify that it is not a binary file; consider any file + # with a zero byte to be a binary file. Is there any better, or + # additional, heuristic that should be applied? + $is_binary = 0; + + while (read(FILE, $data, 65536) > 0) { + if ($data =~ /\0/) { + $is_binary = 1; + last; + } + } + + if ($is_binary) { + print STDERR "$name: $f: binary file\n"; + next; + } + + seek(FILE, 0, 0); + + $in_bytes = 0; + $out_bytes = 0; + $lineno = 0; + + @lines = (); + + $in_hunk = 0; + $err = 0; + + while ( defined($line = ) ) { + $lineno++; + $in_bytes += length($line); + + if (!$in_hunk) { + if ($line =~ + /^\@\@\s+\-([0-9]+),([0-9]+)\s+\+([0-9]+),([0-9]+)\s\@\@/) { + $minus_lines = $2; + $plus_lines = $4; + if ($minus_lines || $plus_lines) { + $in_hunk = 1; + @hunk_lines = ($line); + } + } else { + push(@lines, $line); + $out_bytes += length($line); + } + } else { + # We're in a hunk + + if ($line =~ /^\+/) { + $plus_lines--; + + $text = substr($line, 1); + $text =~ s/[ \t\r]*$//; # Remove trailing spaces + $text = clean_space_tabs($text); + + $l_width = strwidth($text); + if ($max_width && $l_width > $max_width) { + print STDERR + "$f:$lineno: adds line exceeds $max_width ", + "characters ($l_width)\n"; + } + + push(@hunk_lines, '+'.$text); + } elsif ($line =~ /^\-/) { + $minus_lines--; + push(@hunk_lines, $line); + } elsif ($line =~ /^ /) { + $plus_lines--; + $minus_lines--; + push(@hunk_lines, $line); + } else { + print STDERR "$name: $f: malformed patch\n"; + $err = 1; + last; + } + + if ($plus_lines < 0 || $minus_lines < 0) { + print STDERR "$name: $f: malformed patch\n"; + $err = 1; + last; + } elsif ($plus_lines == 0 && $minus_lines == 0) { + # End of a hunk. Process this hunk. + my $i; + my $l; + my @h = (); + my $adj = 0; + my $done = 0; + + for ($i = scalar(@hunk_lines)-1; $i > 0; $i--) { + $l = $hunk_lines[$i]; + if (!$done && $l eq "+\n") { + $adj++; # Skip this line + } elsif ($l =~ /^[ +]/) { + $done = 1; + unshift(@h, $l); + } else { + unshift(@h, $l); + } + } + + $l = $hunk_lines[0]; # Hunk header + undef @hunk_lines; # Free memory + + if ($adj) { + die unless + ($l =~ /^\@\@\s+\-([0-9]+),([0-9]+)\s+\+([0-9]+),([0-9]+)\s\@\@(.*)$/); + my $mstart = $1; + my $mlin = $2; + my $pstart = $3; + my $plin = $4; + my $tail = $5; # doesn't include the final newline + + $l = sprintf("@@ -%d,%d +%d,%d @@%s\n", + $mstart, $mlin, $pstart, $plin-$adj, + $tail); + } + unshift(@h, $l); + + # Transfer to the output array + foreach $l (@h) { + $out_bytes += length($l); + push(@lines, $l); + } + + $in_hunk = 0; + } + } + } + + if ($in_hunk) { + print STDERR "$name: $f: malformed patch\n"; + $err = 1; + } + + if (!$err) { + if ($in_bytes != $out_bytes) { + # Only write to the file if changed + seek(FILE, 0, 0); + print FILE @lines; + + if ( !defined($where = tell(FILE)) || + !truncate(FILE, $where) ) { + die "$name: Failed to truncate modified file: $f: $!\n"; + } + } + } + + close(FILE); +} -- cgit v1.3.1