ftrace: Synchronize the initialization of ftrace_opsgrafted

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 <rostedt@goodmis.org>

1 files changed, 194 insertions, 0 deletions

diff --git a/scripts/parse-maintainers.pl b/scripts/parse-maintainers.pl
new file mode 100755
index 000000000..2ca4eb3f1
--- /dev/null
+++ b/scripts/parse-maintainers.pl
@@ -0,0 +1,194 @@
+#!/usr/bin/perl -w
+# SPDX-License-Identifier: GPL-2.0
+
+use strict;
+use Getopt::Long qw(:config no_auto_abbrev);
+
+my $input_file = "MAINTAINERS";
+my $output_file = "MAINTAINERS.new";
+my $output_section = "SECTION.new";
+my $help = 0;
+my $order = 0;
+my $P = $0;
+
+if (!GetOptions(
+		'input=s' => \$input_file,
+		'output=s' => \$output_file,
+		'section=s' => \$output_section,
+		'order!' => \$order,
+		'h|help|usage' => \$help,
+	    )) {
+    die "$P: invalid argument - use --help if necessary\n";
+}
+
+if ($help != 0) {
+    usage();
+    exit 0;
+}
+
+sub usage {
+    print <<EOT;
+usage: $P [options] <pattern matching regexes>
+
+  --input => MAINTAINERS file to read (default: MAINTAINERS)
+  --output => sorted MAINTAINERS file to write (default: MAINTAINERS.new)
+  --section => new sorted MAINTAINERS file to write to (default: SECTION.new)
+  --order => Use the preferred section content output ordering (default: 0)
+    Preferred ordering of section output is:
+      M:  Person acting as a maintainer
+      R:  Person acting as a patch reviewer
+      L:  Mailing list where patches should be sent
+      S:  Maintenance status
+      W:  URI for general information
+      Q:  URI for patchwork tracking
+      B:  URI for bug tracking/submission
+      C:  URI for chat
+      P:  URI or file for subsystem specific coding styles
+      T:  SCM tree type and location
+      F:  File and directory pattern
+      X:  File and directory exclusion pattern
+      N:  File glob
+      K:  Keyword - patch content regex
+
+If <pattern match regexes> exist, then the sections that match the
+regexes are not written to the output file but are written to the
+section file.
+
+EOT
+}
+
+# sort comparison functions
+sub by_category($$) {
+    my ($a, $b) = @_;
+
+    $a = uc $a;
+    $b = uc $b;
+
+    # This always sorts last
+    $a =~ s/THE REST/ZZZZZZ/g;
+    $b =~ s/THE REST/ZZZZZZ/g;
+
+    return $a cmp $b;
+}
+
+sub by_pattern($$) {
+    my ($a, $b) = @_;
+    my $preferred_order = 'MRLSWQBCPTFXNK';
+
+    my $a1 = uc(substr($a, 0, 1));
+    my $b1 = uc(substr($b, 0, 1));
+
+    my $a_index = index($preferred_order, $a1);
+    my $b_index = index($preferred_order, $b1);
+
+    $a_index = 1000 if ($a_index == -1);
+    $b_index = 1000 if ($b_index == -1);
+
+    if (($a1 =~ /^F$/ && $b1 =~ /^F$/) ||
+	($a1 =~ /^X$/ && $b1 =~ /^X$/)) {
+	return $a cmp $b;
+    }
+
+    if ($a_index < $b_index) {
+	return -1;
+    } elsif ($a_index == $b_index) {
+	return 0;
+    } else {
+	return 1;
+    }
+}
+
+sub trim {
+    my $s = shift;
+    $s =~ s/\s+$//;
+    $s =~ s/^\s+//;
+    return $s;
+}
+
+sub alpha_output {
+    my ($hashref, $filename) = (@_);
+
+    return if ! scalar(keys %$hashref);
+
+    open(my $file, '>', "$filename") or die "$P: $filename: open failed - $!\n";
+    my $separator;
+    foreach my $key (sort by_category keys %$hashref) {
+	if ($key eq " ") {
+	    print $file $$hashref{$key};
+	} else {
+	    if (! defined $separator) {
+		$separator = "\n";
+	    } else {
+		print $file $separator;
+	    }
+	    print $file $key . "\n";
+	    if ($order) {
+		foreach my $pattern (sort by_pattern split('\n', %$hashref{$key})) {
+		    print $file ($pattern . "\n");
+		}
+	    } else {
+		foreach my $pattern (split('\n', %$hashref{$key})) {
+		    print $file ($pattern . "\n");
+		}
+	    }
+	}
+    }
+    close($file);
+}
+
+sub file_input {
+    my ($hashref, $filename) = (@_);
+
+    my $lastline = "";
+    my $case = " ";
+    $$hashref{$case} = "";
+
+    open(my $file, '<', "$filename") or die "$P: $filename: open failed - $!\n";
+
+    while (<$file>) {
+        my $line = $_;
+
+        # Pattern line?
+        if ($line =~ m/^([A-Z]):\s*(.*)/) {
+            $line = $1 . ":\t" . trim($2) . "\n";
+            if ($lastline eq "") {
+                $$hashref{$case} = $$hashref{$case} . $line;
+                next;
+            }
+            $case = trim($lastline);
+            exists $$hashref{$case} and die "Header '$case' already exists";
+            $$hashref{$case} = $line;
+            $lastline = "";
+            next;
+        }
+
+        if ($case eq " ") {
+            $$hashref{$case} = $$hashref{$case} . $lastline;
+            $lastline = $line;
+            next;
+        }
+        trim($lastline) eq "" or die ("Odd non-pattern line '$lastline' for '$case'");
+        $lastline = $line;
+    }
+    $$hashref{$case} = $$hashref{$case} . $lastline;
+    close($file);
+}
+
+my %hash;
+my %new_hash;
+
+file_input(\%hash, $input_file);
+
+foreach my $type (@ARGV) {
+    foreach my $key (keys %hash) {
+	if ($key =~ /$type/ || $hash{$key} =~ /$type/) {
+	    $new_hash{$key} = $hash{$key};
+	    delete $hash{$key};
+	}
+    }
+}
+
+alpha_output(\%hash, $output_file);
+alpha_output(\%new_hash, $output_section);
+
+exit(0);