Revision be0f272bfc83797f70d44faca86954df62e2bbc0 authored by Ard Biesheuvel on 20 November 2017, 17:41:30 UTC, committed by Will Deacon on 01 December 2017, 13:04:59 UTC
When building the arm64 kernel with both CONFIG_ARM64_MODULE_PLTS and CONFIG_DYNAMIC_FTRACE enabled, the ftrace-mod.o object file is built with the kernel and contains a trampoline that is linked into each module, so that modules can be loaded far away from the kernel and still reach the ftrace entry point in the core kernel with an ordinary relative branch, as is emitted by the compiler instrumentation code dynamic ftrace relies on. In order to be able to build out of tree modules, this object file needs to be included into the linux-headers or linux-devel packages, which is undesirable, as it makes arm64 a special case (although a precedent does exist for 32-bit PPC). Given that the trampoline essentially consists of a PLT entry, let's not bother with a source or object file for it, and simply patch it in whenever the trampoline is being populated, using the existing PLT support routines. Cc: <stable@vger.kernel.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
1 parent 7e8b9c1
headers_check.pl
#!/usr/bin/env perl
# SPDX-License-Identifier: GPL-2.0
#
# headers_check.pl execute a number of trivial consistency checks
#
# Usage: headers_check.pl dir arch [files...]
# dir: dir to look for included files
# arch: architecture
# files: list of files to check
#
# The script reads the supplied files line by line and:
#
# 1) for each include statement it checks if the
# included file actually exists.
# Only include files located in asm* and linux* are checked.
# The rest are assumed to be system include files.
#
# 2) It is checked that prototypes does not use "extern"
#
# 3) Check for leaked CONFIG_ symbols
use warnings;
use strict;
use File::Basename;
my ($dir, $arch, @files) = @ARGV;
my $ret = 0;
my $line;
my $lineno = 0;
my $filename;
foreach my $file (@files) {
$filename = $file;
open(my $fh, '<', $filename)
or die "$filename: $!\n";
$lineno = 0;
while ($line = <$fh>) {
$lineno++;
&check_include();
&check_asm_types();
&check_sizetypes();
&check_declarations();
# Dropped for now. Too much noise &check_config();
}
close $fh;
}
exit $ret;
sub check_include
{
if ($line =~ m/^\s*#\s*include\s+<((asm|linux).*)>/) {
my $inc = $1;
my $found;
$found = stat($dir . "/" . $inc);
if (!$found) {
$inc =~ s#asm/#asm-$arch/#;
$found = stat($dir . "/" . $inc);
}
if (!$found) {
printf STDERR "$filename:$lineno: included file '$inc' is not exported\n";
$ret = 1;
}
}
}
sub check_declarations
{
# soundcard.h is what it is
if ($line =~ m/^void seqbuf_dump\(void\);/) {
return;
}
# drm headers are being C++ friendly
if ($line =~ m/^extern "C"/) {
return;
}
if ($line =~ m/^(\s*extern|unsigned|char|short|int|long|void)\b/) {
printf STDERR "$filename:$lineno: " .
"userspace cannot reference function or " .
"variable defined in the kernel\n";
}
}
sub check_config
{
if ($line =~ m/[^a-zA-Z0-9_]+CONFIG_([a-zA-Z0-9_]+)[^a-zA-Z0-9_]/) {
printf STDERR "$filename:$lineno: leaks CONFIG_$1 to userspace where it is not valid\n";
}
}
my $linux_asm_types;
sub check_asm_types
{
if ($filename =~ /types.h|int-l64.h|int-ll64.h/o) {
return;
}
if ($lineno == 1) {
$linux_asm_types = 0;
} elsif ($linux_asm_types >= 1) {
return;
}
if ($line =~ m/^\s*#\s*include\s+<asm\/types.h>/) {
$linux_asm_types = 1;
printf STDERR "$filename:$lineno: " .
"include of <linux/types.h> is preferred over <asm/types.h>\n"
# Warn until headers are all fixed
#$ret = 1;
}
}
my $linux_types;
my %import_stack = ();
sub check_include_typesh
{
my $path = $_[0];
my $import_path;
my $fh;
my @file_paths = ($path, $dir . "/" . $path, dirname($filename) . "/" . $path);
for my $possible ( @file_paths ) {
if (not $import_stack{$possible} and open($fh, '<', $possible)) {
$import_path = $possible;
$import_stack{$import_path} = 1;
last;
}
}
if (eof $fh) {
return;
}
my $line;
while ($line = <$fh>) {
if ($line =~ m/^\s*#\s*include\s+<linux\/types.h>/) {
$linux_types = 1;
last;
}
if (my $included = ($line =~ /^\s*#\s*include\s+[<"](\S+)[>"]/)[0]) {
check_include_typesh($included);
}
}
close $fh;
delete $import_stack{$import_path};
}
sub check_sizetypes
{
if ($filename =~ /types.h|int-l64.h|int-ll64.h/o) {
return;
}
if ($lineno == 1) {
$linux_types = 0;
} elsif ($linux_types >= 1) {
return;
}
if ($line =~ m/^\s*#\s*include\s+<linux\/types.h>/) {
$linux_types = 1;
return;
}
if (my $included = ($line =~ /^\s*#\s*include\s+[<"](\S+)[>"]/)[0]) {
check_include_typesh($included);
}
if ($line =~ m/__[us](8|16|32|64)\b/) {
printf STDERR "$filename:$lineno: " .
"found __[us]{8,16,32,64} type " .
"without #include <linux/types.h>\n";
$linux_types = 2;
# Warn until headers are all fixed
#$ret = 1;
}
}
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