Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 716 insertions, 0 deletions

diff --git a/scripts/kconfig/streamline_config.pl b/scripts/kconfig/streamline_config.pl
new file mode 100755
index 000000000..8677d1ca0
--- /dev/null
+++ b/scripts/kconfig/streamline_config.pl
@@ -0,0 +1,716 @@
+#!/usr/bin/env perl
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright 2005-2009 - Steven Rostedt
+#
+#  It's simple enough to figure out how this works.
+#  If not, then you can ask me at stripconfig@goodmis.org
+#
+# What it does?
+#
+#   If you have installed a Linux kernel from a distribution
+#   that turns on way too many modules than you need, and
+#   you only want the modules you use, then this program
+#   is perfect for you.
+#
+#   It gives you the ability to turn off all the modules that are
+#   not loaded on your system.
+#
+# Howto:
+#
+#  1. Boot up the kernel that you want to stream line the config on.
+#  2. Change directory to the directory holding the source of the
+#       kernel that you just booted.
+#  3. Copy the configuration file to this directory as .config
+#  4. Have all your devices that you need modules for connected and
+#      operational (make sure that their corresponding modules are loaded)
+#  5. Run this script redirecting the output to some other file
+#       like config_strip.
+#  6. Back up your old config (if you want too).
+#  7. copy the config_strip file to .config
+#  8. Run "make oldconfig"
+#
+#  Now your kernel is ready to be built with only the modules that
+#  are loaded.
+#
+# Here's what I did with my Debian distribution.
+#
+#    cd /usr/src/linux-2.6.10
+#    cp /boot/config-2.6.10-1-686-smp .config
+#    ~/bin/streamline_config > config_strip
+#    mv .config config_sav
+#    mv config_strip .config
+#    make oldconfig
+#
+use warnings;
+use strict;
+use Getopt::Long;
+
+# set the environment variable LOCALMODCONFIG_DEBUG to get
+# debug output.
+my $debugprint = 0;
+$debugprint = 1 if (defined($ENV{LOCALMODCONFIG_DEBUG}));
+
+sub dprint {
+    return if (!$debugprint);
+    print STDERR @_;
+}
+
+my $uname = `uname -r`;
+chomp $uname;
+
+my @searchconfigs = (
+	{
+	    "file" => ".config",
+	    "exec" => "cat",
+	},
+	{
+	    "file" => "/proc/config.gz",
+	    "exec" => "zcat",
+	},
+	{
+	    "file" => "/boot/config-$uname",
+	    "exec" => "cat",
+	},
+	{
+	    "file" => "/boot/vmlinuz-$uname",
+	    "exec" => "scripts/extract-ikconfig",
+	    "test" => "scripts/extract-ikconfig",
+	},
+	{
+	    "file" => "vmlinux",
+	    "exec" => "scripts/extract-ikconfig",
+	    "test" => "scripts/extract-ikconfig",
+	},
+	{
+	    "file" => "/lib/modules/$uname/kernel/kernel/configs.ko",
+	    "exec" => "scripts/extract-ikconfig",
+	    "test" => "scripts/extract-ikconfig",
+	},
+	{
+	    "file" => "kernel/configs.ko",
+	    "exec" => "scripts/extract-ikconfig",
+	    "test" => "scripts/extract-ikconfig",
+	},
+	{
+	    "file" => "kernel/configs.o",
+	    "exec" => "scripts/extract-ikconfig",
+	    "test" => "scripts/extract-ikconfig",
+	},
+);
+
+sub read_config {
+    foreach my $conf (@searchconfigs) {
+	my $file = $conf->{"file"};
+
+	next if ( ! -f "$file");
+
+	if (defined($conf->{"test"})) {
+	    `$conf->{"test"} $conf->{"file"} 2>/dev/null`;
+	    next if ($?);
+	}
+
+	my $exec = $conf->{"exec"};
+
+	print STDERR "using config: '$file'\n";
+
+	open(my $infile, '-|', "$exec $file") || die "Failed to run $exec $file";
+	my @x = <$infile>;
+	close $infile;
+	return @x;
+    }
+    die "No config file found";
+}
+
+my @config_file = read_config;
+
+# Parse options
+my $localmodconfig = 0;
+my $localyesconfig = 0;
+
+GetOptions("localmodconfig" => \$localmodconfig,
+	   "localyesconfig" => \$localyesconfig);
+
+# Get the build source and top level Kconfig file (passed in)
+my $ksource = ($ARGV[0] ? $ARGV[0] : '.');
+my $kconfig = $ARGV[1];
+my $lsmod_file = $ENV{'LSMOD'};
+
+my @makefiles = `find $ksource -name Makefile -or -name Kbuild 2>/dev/null`;
+chomp @makefiles;
+
+my %depends;
+my %selects;
+my %prompts;
+my %objects;
+my %config2kfile;
+my %defaults;
+my $var;
+my $iflevel = 0;
+my @ifdeps;
+
+# prevent recursion
+my %read_kconfigs;
+
+sub read_kconfig {
+    my ($kconfig) = @_;
+
+    my $state = "NONE";
+    my $config;
+
+    my $cont = 0;
+    my $line;
+
+    my $source = "$ksource/$kconfig";
+    my $last_source = "";
+
+    # Check for any environment variables used
+    while ($source =~ /\$\((\w+)\)/ && $last_source ne $source) {
+	my $env = $1;
+	$last_source = $source;
+	$source =~ s/\$\($env\)/$ENV{$env}/;
+    }
+
+    open(my $kinfile, '<', $source) || die "Can't open $source";
+    while (<$kinfile>) {
+	chomp;
+
+	# Make sure that lines ending with \ continue
+	if ($cont) {
+	    $_ = $line . " " . $_;
+	}
+
+	if (s/\\$//) {
+	    $cont = 1;
+	    $line = $_;
+	    next;
+	}
+
+	$cont = 0;
+
+	# collect any Kconfig sources
+	if (/^source\s+"?([^"]+)/) {
+	    my $kconfig = $1;
+	    # prevent reading twice.
+	    if (!defined($read_kconfigs{$kconfig})) {
+		$read_kconfigs{$kconfig} = 1;
+		read_kconfig($kconfig);
+	    }
+	    next;
+	}
+
+	# configs found
+	if (/^\s*(menu)?config\s+(\S+)\s*$/) {
+	    $state = "NEW";
+	    $config = $2;
+	    $config2kfile{"CONFIG_$config"} = $kconfig;
+
+	    # Add depends for 'if' nesting
+	    for (my $i = 0; $i < $iflevel; $i++) {
+		if ($i) {
+		    $depends{$config} .= " " . $ifdeps[$i];
+		} else {
+		    $depends{$config} = $ifdeps[$i];
+		}
+		$state = "DEP";
+	    }
+
+	# collect the depends for the config
+	} elsif ($state eq "NEW" && /^\s*depends\s+on\s+(.*)$/) {
+	    $state = "DEP";
+	    $depends{$config} = $1;
+	} elsif ($state eq "DEP" && /^\s*depends\s+on\s+(.*)$/) {
+	    $depends{$config} .= " " . $1;
+	} elsif ($state ne "NONE" && /^\s*def(_(bool|tristate)|ault)\s+(\S.*)$/) {
+	    my $dep = $3;
+            $defaults{$config} = 1;
+	    if ($dep !~ /^\s*(y|m|n)\s*$/) {
+		$dep =~ s/.*\sif\s+//;
+		$depends{$config} .= " " . $dep;
+		dprint "Added default depends $dep to $config\n";
+	    }
+
+	# Get the configs that select this config
+	} elsif ($state ne "NONE" && /^\s*select\s+(\S+)/) {
+	    my $conf = $1;
+	    if (defined($selects{$conf})) {
+		$selects{$conf} .= " " . $config;
+	    } else {
+		$selects{$conf} = $config;
+	    }
+
+	# configs without prompts must be selected
+	} elsif ($state ne "NONE" && /^\s*(tristate\s+\S|prompt\b)/) {
+	    # note if the config has a prompt
+	    $prompts{$config} = 1;
+
+	# Check for if statements
+	} elsif (/^if\s+(.*\S)\s*$/) {
+	    my $deps = $1;
+	    # remove beginning and ending non text
+	    $deps =~ s/^[^a-zA-Z0-9_]*//;
+	    $deps =~ s/[^a-zA-Z0-9_]*$//;
+
+	    my @deps = split /[^a-zA-Z0-9_]+/, $deps;
+
+	    $ifdeps[$iflevel++] = join ':', @deps;
+
+	} elsif (/^endif/) {
+
+	    $iflevel-- if ($iflevel);
+
+	# stop on "help" and keywords that end a menu entry
+	} elsif (/^\s*(---)?help(---)?\s*$/ || /^(comment|choice|menu)\b/) {
+	    $state = "NONE";
+	}
+    }
+    close($kinfile);
+}
+
+if ($kconfig) {
+    read_kconfig($kconfig);
+}
+
+# Makefiles can use variables to define their dependencies
+sub convert_vars {
+    my ($line, %vars) = @_;
+
+    my $process = "";
+
+    while ($line =~ s/^(.*?)(\$\((.*?)\))//) {
+	my $start = $1;
+	my $variable = $2;
+	my $var = $3;
+
+	if (defined($vars{$var})) {
+	    $process .= $start . $vars{$var};
+	} else {
+	    $process .= $start . $variable;
+	}
+    }
+
+    $process .= $line;
+
+    return $process;
+}
+
+# Read all Makefiles to map the configs to the objects
+foreach my $makefile (@makefiles) {
+
+    my $line = "";
+    my %make_vars;
+
+    open(my $infile, '<', $makefile) || die "Can't open $makefile";
+    while (<$infile>) {
+	# if this line ends with a backslash, continue
+	chomp;
+	if (/^(.*)\\$/) {
+	    $line .= $1;
+	    next;
+	}
+
+	$line .= $_;
+	$_ = $line;
+	$line = "";
+
+	my $objs;
+
+	# Convert variables in a line (could define configs)
+	$_ = convert_vars($_, %make_vars);
+
+	# collect objects after obj-$(CONFIG_FOO_BAR)
+	if (/obj-\$[({](CONFIG_[^})]*)[)}]\s*[+:]?=\s*(.*)/) {
+	    $var = $1;
+	    $objs = $2;
+
+	# check if variables are set
+	} elsif (/^\s*(\S+)\s*[:]?=\s*(.*\S)/) {
+	    $make_vars{$1} = $2;
+	}
+	if (defined($objs)) {
+	    foreach my $obj (split /\s+/,$objs) {
+		$obj =~ s/-/_/g;
+		if ($obj =~ /(.*)\.o$/) {
+		    # Objects may be enabled by more than one config.
+		    # Store configs in an array.
+		    my @arr;
+
+		    if (defined($objects{$1})) {
+			@arr = @{$objects{$1}};
+		    }
+
+		    $arr[$#arr+1] = $var;
+
+		    # The objects have a hash mapping to a reference
+		    # of an array of configs.
+		    $objects{$1} = \@arr;
+		}
+	    }
+	}
+    }
+    close($infile);
+}
+
+my %modules;
+my $linfile;
+
+if (defined($lsmod_file)) {
+    if ( ! -f $lsmod_file) {
+	if ( -f $ENV{'objtree'}."/".$lsmod_file) {
+	    $lsmod_file = $ENV{'objtree'}."/".$lsmod_file;
+	} else {
+		die "$lsmod_file not found";
+	}
+    }
+
+    my $otype = ( -x $lsmod_file) ? '-|' : '<';
+    open($linfile, $otype, $lsmod_file);
+
+} else {
+
+    # see what modules are loaded on this system
+    my $lsmod;
+
+    foreach my $dir ( ("/sbin", "/bin", "/usr/sbin", "/usr/bin") ) {
+	if ( -x "$dir/lsmod" ) {
+	    $lsmod = "$dir/lsmod";
+	    last;
+	}
+    }
+    if (!defined($lsmod)) {
+	# try just the path
+	$lsmod = "lsmod";
+    }
+
+    open($linfile, '-|', $lsmod) || die "Can not call lsmod with $lsmod";
+}
+
+while (<$linfile>) {
+	next if (/^Module/);  # Skip the first line.
+	if (/^(\S+)/) {
+		$modules{$1} = 1;
+	}
+}
+close ($linfile);
+
+# add to the configs hash all configs that are needed to enable
+# a loaded module. This is a direct obj-${CONFIG_FOO} += bar.o
+# where we know we need bar.o so we add FOO to the list.
+my %configs;
+foreach my $module (keys(%modules)) {
+    if (defined($objects{$module})) {
+	my @arr = @{$objects{$module}};
+	foreach my $conf (@arr) {
+	    $configs{$conf} = $module;
+	    dprint "$conf added by direct ($module)\n";
+	    if ($debugprint) {
+		my $c=$conf;
+		$c =~ s/^CONFIG_//;
+		if (defined($depends{$c})) {
+		    dprint " deps = $depends{$c}\n";
+		} else {
+		    dprint " no deps\n";
+		}
+	    }
+	}
+    } else {
+	# Most likely, someone has a custom (binary?) module loaded.
+	print STDERR "$module config not found!\n";
+    }
+}
+
+# Read the current config, and see what is enabled. We want to
+# ignore configs that we would not enable anyway.
+
+my %orig_configs;
+my $valid = "A-Za-z_0-9";
+
+foreach my $line (@config_file) {
+    $_ = $line;
+
+    if (/(CONFIG_[$valid]*)=(m|y)/) {
+	$orig_configs{$1} = $2;
+    }
+}
+
+my $repeat = 1;
+
+my $depconfig;
+
+#
+# Note, we do not care about operands (like: &&, ||, !) we want to add any
+# config that is in the depend list of another config. This script does
+# not enable configs that are not already enabled. If we come across a
+# config A that depends on !B, we can still add B to the list of depends
+# to keep on. If A was on in the original config, B would not have been
+# and B would not be turned on by this script.
+#
+sub parse_config_depends
+{
+    my ($p) = @_;
+
+    while ($p =~ /[$valid]/) {
+
+	if ($p =~ /^[^$valid]*([$valid]+)/) {
+	    my $conf = "CONFIG_" . $1;
+
+	    $p =~ s/^[^$valid]*[$valid]+//;
+
+	    # We only need to process if the depend config is a module
+	    if (!defined($orig_configs{$conf}) || $orig_configs{$conf} eq "y") {
+		next;
+	    }
+
+	    if (!defined($configs{$conf})) {
+		# We must make sure that this config has its
+		# dependencies met.
+		$repeat = 1; # do again
+		dprint "$conf selected by depend $depconfig\n";
+		$configs{$conf} = 1;
+	    }
+	} else {
+	    die "this should never happen";
+	}
+    }
+}
+
+# Select is treated a bit differently than depends. We call this
+# when a config has no prompt and requires another config to be
+# selected. We use to just select all configs that selected this
+# config, but found that that can balloon into enabling hundreds
+# of configs that we do not care about.
+#
+# The idea is we look at all the configs that select it. If one
+# is already in our list of configs to enable, then there's nothing
+# else to do. If there isn't, we pick the first config that was
+# enabled in the original config and use that.
+sub parse_config_selects
+{
+    my ($config, $p) = @_;
+
+    my $next_config;
+
+    while ($p =~ /[$valid]/) {
+
+	if ($p =~ /^[^$valid]*([$valid]+)/) {
+	    my $conf = "CONFIG_" . $1;
+
+	    $p =~ s/^[^$valid]*[$valid]+//;
+
+	    # Make sure that this config exists in the current .config file
+	    if (!defined($orig_configs{$conf})) {
+		dprint "$conf not set for $config select\n";
+		next;
+	    }
+
+	    # Check if something other than a module selects this config
+	    if (defined($orig_configs{$conf}) && $orig_configs{$conf} ne "m") {
+		dprint "$conf (non module) selects $config, we are good\n";
+		# we are good with this
+		return;
+	    }
+	    if (defined($configs{$conf})) {
+		dprint "$conf selects $config so we are good\n";
+		# A set config selects this config, we are good
+		return;
+	    }
+	    # Set this config to be selected
+	    if (!defined($next_config)) {
+		$next_config = $conf;
+	    }
+	} else {
+	    die "this should never happen";
+	}
+    }
+
+    # If no possible config selected this, then something happened.
+    if (!defined($next_config)) {
+
+	# Some config options have no prompt, and nothing selects them, but
+	# they stay turned on once the final checks for the configs
+	# are done. These configs have a default option, so turn off the
+	# warnings for configs with default options.
+	if (!defined($defaults{$config})) {
+	    print STDERR "WARNING: $config is required, but nothing in the\n";
+	    print STDERR "  current config selects it.\n";
+	}
+
+	return;
+    }
+
+    # If we are here, then we found no config that is set and
+    # selects this config. Repeat.
+    $repeat = 1;
+    # Make this config need to be selected
+    $configs{$next_config} = 1;
+    dprint "$next_config selected by select $config\n";
+}
+
+my %process_selects;
+
+# loop through all configs, select their dependencies.
+sub loop_depend {
+    $repeat = 1;
+
+    while ($repeat) {
+	$repeat = 0;
+
+      forloop:
+	foreach my $config (keys %configs) {
+
+	    # If this config is not a module, we do not need to process it
+	    if (defined($orig_configs{$config}) && $orig_configs{$config} ne "m") {
+		next forloop;
+	    }
+
+	    $config =~ s/^CONFIG_//;
+	    $depconfig = $config;
+
+	    if (defined($depends{$config})) {
+		# This config has dependencies. Make sure they are also included
+		parse_config_depends $depends{$config};
+	    }
+
+	    # If the config has no prompt, then we need to check if a config
+	    # that is enabled selected it. Or if we need to enable one.
+	    if (!defined($prompts{$config}) && defined($selects{$config})) {
+		$process_selects{$config} = 1;
+	    }
+	}
+    }
+}
+
+sub loop_select {
+
+    foreach my $config (keys %process_selects) {
+	$config =~ s/^CONFIG_//;
+
+	dprint "Process select $config\n";
+
+	# config has no prompt and must be selected.
+	parse_config_selects $config, $selects{$config};
+    }
+}
+
+while ($repeat) {
+    # Get the first set of configs and their dependencies.
+    loop_depend;
+
+    $repeat = 0;
+
+    # Now we need to see if we have to check selects;
+    loop_select;
+}
+
+my %setconfigs;
+my @preserved_kconfigs;
+if (defined($ENV{'LMC_KEEP'})) {
+	@preserved_kconfigs = split(/:/,$ENV{LMC_KEEP});
+}
+
+sub in_preserved_kconfigs {
+    my $kconfig = $config2kfile{$_[0]};
+    if (!defined($kconfig)) {
+	return 0;
+    }
+    foreach my $excl (@preserved_kconfigs) {
+	if($kconfig =~ /^$excl/) {
+	    return 1;
+	}
+    }
+    return 0;
+}
+
+# Finally, read the .config file and turn off any module enabled that
+# we could not find a reason to keep enabled.
+foreach my $line (@config_file) {
+    $_ = $line;
+
+    if (/CONFIG_IKCONFIG/) {
+	if (/# CONFIG_IKCONFIG is not set/) {
+	    # enable IKCONFIG at least as a module
+	    print "CONFIG_IKCONFIG=m\n";
+	    # don't ask about PROC
+	    print "# CONFIG_IKCONFIG_PROC is not set\n";
+	} else {
+	    print;
+	}
+	next;
+    }
+
+    if (/CONFIG_MODULE_SIG_KEY="(.+)"/) {
+	my $orig_cert = $1;
+	my $default_cert = "certs/signing_key.pem";
+
+	# Check that the logic in this script still matches the one in Kconfig
+	if (!defined($depends{"MODULE_SIG_KEY"}) ||
+	    $depends{"MODULE_SIG_KEY"} !~ /"\Q$default_cert\E"/) {
+	    print STDERR "WARNING: MODULE_SIG_KEY assertion failure, ",
+		"update needed to ", __FILE__, " line ", __LINE__, "\n";
+	    print;
+	} elsif ($orig_cert ne $default_cert && ! -f $orig_cert) {
+	    print STDERR "Module signature verification enabled but ",
+		"module signing key \"$orig_cert\" not found. Resetting ",
+		"signing key to default value.\n";
+	    print "CONFIG_MODULE_SIG_KEY=\"$default_cert\"\n";
+	} else {
+	    print;
+	}
+	next;
+    }
+
+    if (/CONFIG_SYSTEM_TRUSTED_KEYS="(.+)"/) {
+	my $orig_keys = $1;
+
+	if (! -f $orig_keys) {
+	    print STDERR "System keyring enabled but keys \"$orig_keys\" ",
+		"not found. Resetting keys to default value.\n";
+	    print "CONFIG_SYSTEM_TRUSTED_KEYS=\"\"\n";
+	} else {
+	    print;
+	}
+	next;
+    }
+
+    if (/^(CONFIG.*)=(m|y)/) {
+	if (in_preserved_kconfigs($1)) {
+	    dprint "Preserve config $1";
+	    print;
+	    next;
+	}
+	if (defined($configs{$1})) {
+	    if ($localyesconfig) {
+		$setconfigs{$1} = 'y';
+		print "$1=y\n";
+		next;
+	    } else {
+		$setconfigs{$1} = $2;
+	    }
+	} elsif ($2 eq "m") {
+	    print "# $1 is not set\n";
+	    next;
+	}
+    }
+    print;
+}
+
+# Integrity check, make sure all modules that we want enabled do
+# indeed have their configs set.
+loop:
+foreach my $module (keys(%modules)) {
+    if (defined($objects{$module})) {
+	my @arr = @{$objects{$module}};
+	foreach my $conf (@arr) {
+	    if (defined($setconfigs{$conf})) {
+		next loop;
+	    }
+	}
+	print STDERR "module $module did not have configs";
+	foreach my $conf (@arr) {
+	    print STDERR " " , $conf;
+	}
+	print STDERR "\n";
+    }
+}
+
+# vim: softtabstop=4