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, 159 insertions, 0 deletions

diff --git a/scripts/extract-sys-certs.pl b/scripts/extract-sys-certs.pl
new file mode 100755
index 000000000..fa8ab1511
--- /dev/null
+++ b/scripts/extract-sys-certs.pl
@@ -0,0 +1,159 @@
+#!/usr/bin/env perl
+# SPDX-License-Identifier: GPL-2.0
+#
+use warnings;
+use strict;
+use Math::BigInt;
+use Fcntl "SEEK_SET";
+
+die "Format: $0 [-s <systemmap-file>] <vmlinux-file> <keyring-file>\n"
+    if ($#ARGV != 1 && $#ARGV != 3 ||
+	$#ARGV == 3 && $ARGV[0] ne "-s");
+
+my $sysmap = "";
+if ($#ARGV == 3) {
+    shift;
+    $sysmap = $ARGV[0];
+    shift;
+}
+
+my $vmlinux = $ARGV[0];
+my $keyring = $ARGV[1];
+
+#
+# Parse the vmlinux section table
+#
+open FD, "objdump -h $vmlinux |" || die $vmlinux;
+my @lines = <FD>;
+close(FD) || die $vmlinux;
+
+my @sections = ();
+
+foreach my $line (@lines) {
+    chomp($line);
+    if ($line =~ /\s*([0-9]+)\s+(\S+)\s+([0-9a-f]+)\s+([0-9a-f]+)\s+([0-9a-f]+)\s+([0-9a-f]+)\s+2[*][*]([0-9]+)/
+	) {
+	my $seg  = $1;
+	my $name = $2;
+	my $len  = Math::BigInt->new("0x" . $3);
+	my $vma  = Math::BigInt->new("0x" . $4);
+	my $lma  = Math::BigInt->new("0x" . $5);
+	my $foff = Math::BigInt->new("0x" . $6);
+	my $align = 2 ** $7;
+
+	push @sections, { name => $name,
+			  vma => $vma,
+			  len => $len,
+			  foff => $foff };
+    }
+}
+
+print "Have $#sections sections\n";
+
+#
+# Try and parse the vmlinux symbol table.  If the vmlinux file has been created
+# from a vmlinuz file with extract-vmlinux then the symbol table will be empty.
+#
+open FD, "nm $vmlinux 2>/dev/null |" || die $vmlinux;
+@lines = <FD>;
+close(FD) || die $vmlinux;
+
+my %symbols = ();
+my $nr_symbols = 0;
+
+sub parse_symbols(@) {
+    foreach my $line (@_) {
+	chomp($line);
+	if ($line =~ /([0-9a-f]+)\s([a-zA-Z])\s(\S+)/
+	    ) {
+	    my $addr = "0x" . $1;
+	    my $type = $2;
+	    my $name = $3;
+
+	    $symbols{$name} = $addr;
+	    $nr_symbols++;
+	}
+    }
+}
+parse_symbols(@lines);
+
+if ($nr_symbols == 0 && $sysmap ne "") {
+    print "No symbols in vmlinux, trying $sysmap\n";
+
+    open FD, "<$sysmap" || die $sysmap;
+    @lines = <FD>;
+    close(FD) || die $sysmap;
+    parse_symbols(@lines);
+}
+
+die "No symbols available\n"
+    if ($nr_symbols == 0);
+
+print "Have $nr_symbols symbols\n";
+
+die "Can't find system certificate list"
+    unless (exists($symbols{"__cert_list_start"}) &&
+	    exists($symbols{"system_certificate_list_size"}));
+
+my $start = Math::BigInt->new($symbols{"__cert_list_start"});
+my $end;
+my $size;
+my $size_sym = Math::BigInt->new($symbols{"system_certificate_list_size"});
+
+open FD, "<$vmlinux" || die $vmlinux;
+binmode(FD);
+
+my $s = undef;
+foreach my $sec (@sections) {
+    my $s_name = $sec->{name};
+    my $s_vma = $sec->{vma};
+    my $s_len = $sec->{len};
+    my $s_foff = $sec->{foff};
+    my $s_vend = $s_vma + $s_len;
+
+    next unless ($start >= $s_vma);
+    next if ($start >= $s_vend);
+
+    die "Certificate list size was not found on the same section\n"
+	if ($size_sym < $s_vma || $size_sym > $s_vend);
+
+    die "Cert object in multiple sections: ", $s_name, " and ", $s->{name}, "\n"
+	if ($s);
+
+    my $size_off = $size_sym -$s_vma + $s_foff;
+    my $packed;
+    die $vmlinux if (!defined(sysseek(FD, $size_off, SEEK_SET)));
+    sysread(FD, $packed, 8);
+    $size = unpack 'L!', $packed;
+    $end = $start + $size;
+
+    printf "Have %u bytes of certs at VMA 0x%x\n", $size, $start;
+
+    die "Cert object partially overflows section $s_name\n"
+	if ($end > $s_vend);
+
+    $s = $sec;
+}
+
+die "Cert object not inside a section\n"
+    unless ($s);
+
+print "Certificate list in section ", $s->{name}, "\n";
+
+my $foff = $start - $s->{vma} + $s->{foff};
+
+printf "Certificate list at file offset 0x%x\n", $foff;
+
+die $vmlinux if (!defined(sysseek(FD, $foff, SEEK_SET)));
+my $buf = "";
+my $len = sysread(FD, $buf, $size);
+die "$vmlinux" if (!defined($len));
+die "Short read on $vmlinux\n" if ($len != $size);
+close(FD) || die $vmlinux;
+
+open FD, ">$keyring" || die $keyring;
+binmode(FD);
+$len = syswrite(FD, $buf, $size);
+die "$keyring" if (!defined($len));
+die "Short write on $keyring\n" if ($len != $size);
+close(FD) || die $keyring;