[mirror_ubuntu-bionic-kernel.git] / scripts / namespace.pl

#!/usr/bin/perl -w
#
#	namespace.pl.  Mon Aug 30 2004
#
#	Perform a name space analysis on the linux kernel.
#
#	Copyright Keith Owens <kaos@ocs.com.au>.  GPL.
#
#	Invoke by changing directory to the top of the kernel object
#	tree then namespace.pl, no parameters.
#
#	Tuned for 2.1.x kernels with the new module handling, it will
#	work with 2.0 kernels as well.
#
#	Last change 2.6.9-rc1, adding support for separate source and object
#	trees.
#
#	The source must be compiled/assembled first, the object files
#	are the primary input to this script.  Incomplete or missing
#	objects will result in a flawed analysis.  Compile both vmlinux
#	and modules.
#
#	Even with complete objects, treat the result of the analysis
#	with caution.  Some external references are only used by
#	certain architectures, others with certain combinations of
#	configuration parameters.  Ideally the source should include
#	something like
#
#	#ifndef CONFIG_...
#	static
#	#endif
#	symbol_definition;
#
#	so the symbols are defined as static unless a particular
#	CONFIG_... requires it to be external.
#
#	A symbol that is suffixed with '(export only)' has these properties
#
#	* It is global.
#	* It is marked EXPORT_SYMBOL or EXPORT_SYMBOL_GPL, either in the same
#	  source file or a different source file.
#	* Given the current .config, nothing uses the symbol.
#
#	The symbol is a candidate for conversion to static, plus removal of the
#	export.  But be careful that a different .config might use the symbol.
#
#
#	Name space analysis and cleanup is an iterative process.  You cannot
#	expect to find all the problems in a single pass.
#
#	* Identify possibly unnecessary global declarations, verify that they
#	  really are unnecessary and change them to static.
#	* Compile and fix up gcc warnings about static, removing dead symbols
#	  as necessary.
#	* make clean and rebuild with different configs (especially
#	  CONFIG_MODULES=n) to see which symbols are being defined when the
#	  config does not require them.  These symbols bloat the kernel object
#	  for no good reason, which is frustrating for embedded systems.
#	* Wrap config sensitive symbols in #ifdef CONFIG_foo, as long as the
#	  code does not get too ugly.
#	* Repeat the name space analysis until you can live with with the
#	  result.
#

require 5;	# at least perl 5
use strict;
use File::Find;

my $nm = ($ENV{'NM'} || "nm") . " -p";
my $objdump = ($ENV{'OBJDUMP'} || "objdump") . " -s -j .comment";
my $srctree = "";
my $objtree = "";
$srctree = "$ENV{'srctree'}/" if (exists($ENV{'srctree'}));
$objtree = "$ENV{'objtree'}/" if (exists($ENV{'objtree'}));

if ($#ARGV != -1) {
	print STDERR "usage: $0 takes no parameters\n";
	die("giving up\n");
}

my %nmdata = ();	# nm data for each object
my %def = ();		# all definitions for each name
my %ksymtab = ();	# names that appear in __ksymtab_
my %ref = ();		# $ref{$name} exists if there is a true external reference to $name
my %export = ();	# $export{$name} exists if there is an EXPORT_... of $name

my %nmexception = (
    'fs/ext3/bitmap'			=> 1,
    'fs/ext4/bitmap'			=> 1,
    'arch/x86/lib/thunk_32'		=> 1,
    'arch/x86/lib/cmpxchg'		=> 1,
    'arch/x86/vdso/vdso32/note'		=> 1,
    'lib/irq_regs'			=> 1,
    'usr/initramfs_data'		=> 1,
    'drivers/scsi/aic94xx/aic94xx_dump'	=> 1,
    'drivers/scsi/libsas/sas_dump'	=> 1,
    'lib/dec_and_lock'			=> 1,
    'drivers/ide/ide-probe-mini'	=> 1,
    'usr/initramfs_data'		=> 1,
    'drivers/acpi/acpia/exdump'		=> 1,
    'drivers/acpi/acpia/rsdump'		=> 1,
    'drivers/acpi/acpia/nsdumpdv'	=> 1,
    'drivers/acpi/acpia/nsdump'		=> 1,
    'arch/ia64/sn/kernel/sn2/io'	=> 1,
    'arch/ia64/kernel/gate-data'	=> 1,
    'security/capability'		=> 1,
    'fs/ntfs/sysctl'			=> 1,
    'fs/jfs/jfs_debug'			=> 1,
);

my %nameexception = (
    'mod_use_count_'	 => 1,
    '__initramfs_end'	=> 1,
    '__initramfs_start'	=> 1,
    '_einittext'	=> 1,
    '_sinittext'	=> 1,
    'kallsyms_names'	=> 1,
    'kallsyms_num_syms'	=> 1,
    'kallsyms_addresses'=> 1,
    'kallsyms_offsets'	=> 1,
    'kallsyms_relative_base'=> 1,
    '__this_module'	=> 1,
    '_etext'		=> 1,
    '_edata'		=> 1,
    '_end'		=> 1,
    '__bss_start'	=> 1,
    '_text'		=> 1,
    '_stext'		=> 1,
    '__gp'		=> 1,
    'ia64_unw_start'	=> 1,
    'ia64_unw_end'	=> 1,
    '__init_begin'	=> 1,
    '__init_end'	=> 1,
    '__bss_stop'	=> 1,
    '__nosave_begin'	=> 1,
    '__nosave_end'	=> 1,
    'pg0'		=> 1,
    'vdso_enabled'	=> 1,
    '__stack_chk_fail'  => 1,
    'VDSO32_PRELINK'	=> 1,
    'VDSO32_vsyscall'	=> 1,
    'VDSO32_rt_sigreturn'=>1,
    'VDSO32_sigreturn'	=> 1,
);


&find(\&linux_objects, '.');	# find the objects and do_nm on them
&list_multiply_defined();
&resolve_external_references();
&list_extra_externals();

exit(0);

sub linux_objects
{
	# Select objects, ignoring objects which are only created by
	# merging other objects.  Also ignore all of modules, scripts
	# and compressed.  Most conglomerate objects are handled by do_nm,
	# this list only contains the special cases.  These include objects
	# that are linked from just one other object and objects for which
	# there is really no permanent source file.
	my $basename = $_;
	$_ = $File::Find::name;
	s:^\./::;
	if (/.*\.o$/ &&
		! (
		m:/built-in.o$:
		|| m:arch/x86/vdso/:
		|| m:arch/x86/boot/:
		|| m:arch/ia64/ia32/ia32.o$:
		|| m:arch/ia64/kernel/gate-syms.o$:
		|| m:arch/ia64/lib/__divdi3.o$:
		|| m:arch/ia64/lib/__divsi3.o$:
		|| m:arch/ia64/lib/__moddi3.o$:
		|| m:arch/ia64/lib/__modsi3.o$:
		|| m:arch/ia64/lib/__udivdi3.o$:
		|| m:arch/ia64/lib/__udivsi3.o$:
		|| m:arch/ia64/lib/__umoddi3.o$:
		|| m:arch/ia64/lib/__umodsi3.o$:
		|| m:arch/ia64/scripts/check_gas_for_hint.o$:
		|| m:arch/ia64/sn/kernel/xp.o$:
		|| m:boot/bbootsect.o$:
		|| m:boot/bsetup.o$:
		|| m:/bootsect.o$:
		|| m:/boot/setup.o$:
		|| m:/compressed/:
		|| m:drivers/cdrom/driver.o$:
		|| m:drivers/char/drm/tdfx_drv.o$:
		|| m:drivers/ide/ide-detect.o$:
		|| m:drivers/ide/pci/idedriver-pci.o$:
		|| m:drivers/media/media.o$:
		|| m:drivers/scsi/sd_mod.o$:
		|| m:drivers/video/video.o$:
		|| m:fs/devpts/devpts.o$:
		|| m:fs/exportfs/exportfs.o$:
		|| m:fs/hugetlbfs/hugetlbfs.o$:
		|| m:fs/msdos/msdos.o$:
		|| m:fs/nls/nls.o$:
		|| m:fs/ramfs/ramfs.o$:
		|| m:fs/romfs/romfs.o$:
		|| m:fs/vfat/vfat.o$:
		|| m:init/mounts.o$:
		|| m:^modules/:
		|| m:net/netlink/netlink.o$:
		|| m:net/sched/sched.o$:
		|| m:/piggy.o$:
		|| m:^scripts/:
		|| m:sound/.*/snd-:
		|| m:^.*/\.tmp_:
		|| m:^\.tmp_:
		|| m:/vmlinux-obj.o$:
		|| m:^tools/:
		)
	) {
		do_nm($basename, $_);
	}
	$_ = $basename;		# File::Find expects $_ untouched (undocumented)
}

sub do_nm
{
	my ($basename, $fullname) = @_;
	my ($source, $type, $name);
	if (! -e $basename) {
		printf STDERR "$basename does not exist\n";
		return;
	}
	if ($fullname !~ /\.o$/) {
		printf STDERR "$fullname is not an object file\n";
		return;
	}
	($source = $basename) =~ s/\.o$//;
	if (-e "$source.c" || -e "$source.S") {
		$source = "$objtree$File::Find::dir/$source";
	} else {
		$source = "$srctree$File::Find::dir/$source";
	}
	if (! -e "$source.c" && ! -e "$source.S") {
		# No obvious source, exclude the object if it is conglomerate
	        open(my $objdumpdata, "$objdump $basename|")
		    or die "$objdump $fullname failed $!\n";

		my $comment;
		while (<$objdumpdata>) {
			chomp();
			if (/^In archive/) {
				# Archives are always conglomerate
				$comment = "GCC:GCC:";
				last;
			}
			next if (! /^[ 0-9a-f]{5,} /);
			$comment .= substr($_, 43);
		}
		close($objdumpdata);

		if (!defined($comment) || $comment !~ /GCC\:.*GCC\:/m) {
			printf STDERR "No source file found for $fullname\n";
		}
		return;
	}
	open (my $nmdata, "$nm $basename|")
	    or die "$nm $fullname failed $!\n";

	my @nmdata;
	while (<$nmdata>) {
		chop;
		($type, $name) = (split(/ +/, $_, 3))[1..2];
		# Expected types
		# A absolute symbol
		# B weak external reference to data that has been resolved
		# C global variable, uninitialised
		# D global variable, initialised
		# G global variable, initialised, small data section
		# R global array, initialised
		# S global variable, uninitialised, small bss
		# T global label/procedure
		# U external reference
		# W weak external reference to text that has been resolved
		# V similar to W, but the value of the weak symbol becomes zero with no error.
		# a assembler equate
		# b static variable, uninitialised
		# d static variable, initialised
		# g static variable, initialised, small data section
		# r static array, initialised
		# s static variable, uninitialised, small bss
		# t static label/procedures
		# w weak external reference to text that has not been resolved
		# v similar to w
		# ? undefined type, used a lot by modules
		if ($type !~ /^[ABCDGRSTUWVabdgrstwv?]$/) {
			printf STDERR "nm output for $fullname contains unknown type '$_'\n";
		}
		elsif ($name =~ /\./) {
			# name with '.' is local static
		}
		else {
			$type = 'R' if ($type eq '?');	# binutils replaced ? with R at one point
			# binutils keeps changing the type for exported symbols, force it to R
			$type = 'R' if ($name =~ /^__ksymtab/ || $name =~ /^__kstrtab/);
			$name =~ s/_R[a-f0-9]{8}$//;	# module versions adds this
			if ($type =~ /[ABCDGRSTWV]/ &&
				$name ne 'init_module' &&
				$name ne 'cleanup_module' &&
				$name ne 'Using_Versions' &&
				$name !~ /^Version_[0-9]+$/ &&
				$name !~ /^__parm_/ &&
				$name !~ /^__kstrtab/ &&
				$name !~ /^__ksymtab/ &&
				$name !~ /^__kcrctab_/ &&
				$name !~ /^__exitcall_/ &&
				$name !~ /^__initcall_/ &&
				$name !~ /^__kdb_initcall_/ &&
				$name !~ /^__kdb_exitcall_/ &&
				$name !~ /^__module_/ &&
				$name !~ /^__mod_/ &&
				$name !~ /^__crc_/ &&
				$name ne '__this_module' &&
				$name ne 'kernel_version') {
				if (!exists($def{$name})) {
					$def{$name} = [];
				}
				push(@{$def{$name}}, $fullname);
			}
			push(@nmdata, "$type $name");
			if ($name =~ /^__ksymtab_/) {
				$name = substr($name, 10);
				if (!exists($ksymtab{$name})) {
					$ksymtab{$name} = [];
				}
				push(@{$ksymtab{$name}}, $fullname);
			}
		}
	}
	close($nmdata);

	if ($#nmdata < 0) {
	    printf "No nm data for $fullname\n"
		unless $nmexception{$fullname};
	    return;
	}
	$nmdata{$fullname} = \@nmdata;
}

sub drop_def
{
	my ($object, $name) = @_;
	my $nmdata = $nmdata{$object};
	my ($i, $j);
	for ($i = 0; $i <= $#{$nmdata}; ++$i) {
		if ($name eq (split(' ', $nmdata->[$i], 2))[1]) {
			splice(@{$nmdata{$object}}, $i, 1);
			my $def = $def{$name};
			for ($j = 0; $j < $#{$def{$name}}; ++$j) {
				if ($def{$name}[$j] eq $object) {
					splice(@{$def{$name}}, $j, 1);
				}
			}
			last;
		}
	}
}

sub list_multiply_defined
{
	foreach my $name (keys(%def)) {
		if ($#{$def{$name}} > 0) {
			# Special case for cond_syscall
			if ($#{$def{$name}} == 1 &&
			   ($name =~ /^sys_/ || $name =~ /^compat_sys_/ ||
			    $name =~ /^sys32_/)) {
				if($def{$name}[0] eq "kernel/sys_ni.o" ||
				   $def{$name}[1] eq "kernel/sys_ni.o") {
					&drop_def("kernel/sys_ni.o", $name);
					next;
				}
			}

			printf "$name is multiply defined in :-\n";
			foreach my $module (@{$def{$name}}) {
				printf "\t$module\n";
			}
		}
	}
}

sub resolve_external_references
{
	my ($kstrtab, $ksymtab, $export);

	printf "\n";
	foreach my $object (keys(%nmdata)) {
		my $nmdata = $nmdata{$object};
		for (my $i = 0; $i <= $#{$nmdata}; ++$i) {
			my ($type, $name) = split(' ', $nmdata->[$i], 2);
			if ($type eq "U" || $type eq "w") {
				if (exists($def{$name}) || exists($ksymtab{$name})) {
					# add the owning object to the nmdata
					$nmdata->[$i] = "$type $name $object";
					# only count as a reference if it is not EXPORT_...
					$kstrtab = "R __kstrtab_$name";
					$ksymtab = "R __ksymtab_$name";
					$export = 0;
					for (my $j = 0; $j <= $#{$nmdata}; ++$j) {
						if ($nmdata->[$j] eq $kstrtab ||
						    $nmdata->[$j] eq $ksymtab) {
							$export = 1;
							last;
						}
					}
					if ($export) {
						$export{$name} = "";
					}
					else {
						$ref{$name} = ""
					}
				}
				elsif ( ! $nameexception{$name}
					&& $name !~ /^__sched_text_/
					&& $name !~ /^__start_/
					&& $name !~ /^__end_/
					&& $name !~ /^__stop_/
					&& $name !~ /^__scheduling_functions_.*_here/
					&& $name !~ /^__.*initcall_/
					&& $name !~ /^__.*per_cpu_start/
					&& $name !~ /^__.*per_cpu_end/
					&& $name !~ /^__alt_instructions/
					&& $name !~ /^__setup_/
					&& $name !~ /^__mod_timer/
					&& $name !~ /^__mod_page_state/
					&& $name !~ /^init_module/
					&& $name !~ /^cleanup_module/
				) {
					printf "Cannot resolve ";
					printf "weak " if ($type eq "w");
					printf "reference to $name from $object\n";
				}
			}
		}
	}
}

sub list_extra_externals
{
	my %noref = ();

	foreach my $name (keys(%def)) {
		if (! exists($ref{$name})) {
			my @module = @{$def{$name}};
			foreach my $module (@module) {
				if (! exists($noref{$module})) {
					$noref{$module} = [];
				}
				push(@{$noref{$module}}, $name);
			}
		}
	}
	if (%noref) {
		printf "\nExternally defined symbols with no external references\n";
		foreach my $module (sort(keys(%noref))) {
			printf "  $module\n";
			foreach (sort(@{$noref{$module}})) {
			    my $export;
			    if (exists($export{$_})) {
				$export = " (export only)";
			    } else {
				$export = "";
			    }
			    printf "    $_$export\n";
			}
		}
	}
}
Commit	Line	Data
1da177e4 LT	1	#!/usr/bin/perl -w
	2	#
	3	# namespace.pl. Mon Aug 30 2004
	4	#
	5	# Perform a name space analysis on the linux kernel.
	6	#
	7	# Copyright Keith Owens <kaos@ocs.com.au>. GPL.
	8	#
	9	# Invoke by changing directory to the top of the kernel object
	10	# tree then namespace.pl, no parameters.
	11	#
	12	# Tuned for 2.1.x kernels with the new module handling, it will
	13	# work with 2.0 kernels as well.
	14	#
	15	# Last change 2.6.9-rc1, adding support for separate source and object
	16	# trees.
	17	#
	18	# The source must be compiled/assembled first, the object files
	19	# are the primary input to this script. Incomplete or missing
	20	# objects will result in a flawed analysis. Compile both vmlinux
	21	# and modules.
	22	#
	23	# Even with complete objects, treat the result of the analysis
	24	# with caution. Some external references are only used by
	25	# certain architectures, others with certain combinations of
	26	# configuration parameters. Ideally the source should include
	27	# something like
	28	#
	29	# #ifndef CONFIG_...
	30	# static
	31	# #endif
	32	# symbol_definition;
	33	#
	34	# so the symbols are defined as static unless a particular
	35	# CONFIG_... requires it to be external.
	36	#
	37	# A symbol that is suffixed with '(export only)' has these properties
	38	#
	39	# * It is global.
	40	# * It is marked EXPORT_SYMBOL or EXPORT_SYMBOL_GPL, either in the same
	41	# source file or a different source file.
	42	# * Given the current .config, nothing uses the symbol.
	43	#
	44	# The symbol is a candidate for conversion to static, plus removal of the
	45	# export. But be careful that a different .config might use the symbol.
	46	#
	47	#
	48	# Name space analysis and cleanup is an iterative process. You cannot
	49	# expect to find all the problems in a single pass.
	50	#
	51	# * Identify possibly unnecessary global declarations, verify that they
	52	# really are unnecessary and change them to static.
	53	# * Compile and fix up gcc warnings about static, removing dead symbols
	54	# as necessary.
	55	# * make clean and rebuild with different configs (especially
	56	# CONFIG_MODULES=n) to see which symbols are being defined when the
	57	# config does not require them. These symbols bloat the kernel object
	58	# for no good reason, which is frustrating for embedded systems.
	59	# * Wrap config sensitive symbols in #ifdef CONFIG_foo, as long as the
	60	# code does not get too ugly.
	61	# * Repeat the name space analysis until you can live with with the
	62	# result.
	63	#
	64
65	require 5; # at least perl 5
66	use strict;
67	use File::Find;
68
3a25f0b1 AB	69	my $nm = ($ENV{'NM'} \|\| "nm") . " -p";
3a25f0b1 AB	70	my $objdump = ($ENV{'OBJDUMP'} \|\| "objdump") . " -s -j .comment";
1da177e4 LT	71	my $srctree = "";
	72	my $objtree = "";
	73	$srctree = "$ENV{'srctree'}/" if (exists($ENV{'srctree'}));
	74	$objtree = "$ENV{'objtree'}/" if (exists($ENV{'objtree'}));
	75
	76	if ($#ARGV != -1) {
	77	print STDERR "usage: $0 takes no parameters\n";
	78	die("giving up\n");
	79	}
	80
	81	my %nmdata = (); # nm data for each object
	82	my %def = (); # all definitions for each name
	83	my %ksymtab = (); # names that appear in __ksymtab_
	84	my %ref = (); # $ref{$name} exists if there is a true external reference to $name
	85	my %export = (); # $export{$name} exists if there is an EXPORT_... of $name
	86
43f683c9 SH	87	my %nmexception = (
	88	'fs/ext3/bitmap' => 1,
	89	'fs/ext4/bitmap' => 1,
	90	'arch/x86/lib/thunk_32' => 1,
	91	'arch/x86/lib/cmpxchg' => 1,
	92	'arch/x86/vdso/vdso32/note' => 1,
	93	'lib/irq_regs' => 1,
	94	'usr/initramfs_data' => 1,
	95	'drivers/scsi/aic94xx/aic94xx_dump' => 1,
	96	'drivers/scsi/libsas/sas_dump' => 1,
	97	'lib/dec_and_lock' => 1,
	98	'drivers/ide/ide-probe-mini' => 1,
	99	'usr/initramfs_data' => 1,
	100	'drivers/acpi/acpia/exdump' => 1,
	101	'drivers/acpi/acpia/rsdump' => 1,
	102	'drivers/acpi/acpia/nsdumpdv' => 1,
	103	'drivers/acpi/acpia/nsdump' => 1,
	104	'arch/ia64/sn/kernel/sn2/io' => 1,
	105	'arch/ia64/kernel/gate-data' => 1,
	106	'security/capability' => 1,
	107	'fs/ntfs/sysctl' => 1,
	108	'fs/jfs/jfs_debug' => 1,
	109	);
	110
	111	my %nameexception = (
	112	'mod_use_count_' => 1,
	113	'__initramfs_end' => 1,
	114	'__initramfs_start' => 1,
	115	'_einittext' => 1,
	116	'_sinittext' => 1,
	117	'kallsyms_names' => 1,
	118	'kallsyms_num_syms' => 1,
	119	'kallsyms_addresses'=> 1,
2213e9a6 AB	120	'kallsyms_offsets' => 1,
2213e9a6 AB	121	'kallsyms_relative_base'=> 1,
43f683c9 SH	122	'__this_module' => 1,
	123	'_etext' => 1,
	124	'_edata' => 1,
	125	'_end' => 1,
	126	'__bss_start' => 1,
	127	'_text' => 1,
	128	'_stext' => 1,
	129	'__gp' => 1,
	130	'ia64_unw_start' => 1,
	131	'ia64_unw_end' => 1,
	132	'__init_begin' => 1,
	133	'__init_end' => 1,
	134	'__bss_stop' => 1,
	135	'__nosave_begin' => 1,
	136	'__nosave_end' => 1,
	137	'pg0' => 1,
abb43852 AW	138	'vdso_enabled' => 1,
	139	'__stack_chk_fail' => 1,
	140	'VDSO32_PRELINK' => 1,
	141	'VDSO32_vsyscall' => 1,
	142	'VDSO32_rt_sigreturn'=>1,
	143	'VDSO32_sigreturn' => 1,
43f683c9 SH	144	);
	145
	146
1da177e4 LT	147	&find(\&linux_objects, '.'); # find the objects and do_nm on them
	148	&list_multiply_defined();
	149	&resolve_external_references();
	150	&list_extra_externals();
	151
	152	exit(0);
	153
	154	sub linux_objects
	155	{
	156	# Select objects, ignoring objects which are only created by
	157	# merging other objects. Also ignore all of modules, scripts
	158	# and compressed. Most conglomerate objects are handled by do_nm,
	159	# this list only contains the special cases. These include objects
	160	# that are linked from just one other object and objects for which
	161	# there is really no permanent source file.
	162	my $basename = $_;
	163	$_ = $File::Find::name;
	164	s:^\./::;
	165	if (/.*\.o$/ &&
	166	! (
	167	m:/built-in.o$:
abb43852 AW	168	\|\| m:arch/x86/vdso/:
abb43852 AW	169	\|\| m:arch/x86/boot/:
1da177e4 LT	170	\|\| m:arch/ia64/ia32/ia32.o$:
	171	\|\| m:arch/ia64/kernel/gate-syms.o$:
	172	\|\| m:arch/ia64/lib/__divdi3.o$:
	173	\|\| m:arch/ia64/lib/__divsi3.o$:
	174	\|\| m:arch/ia64/lib/__moddi3.o$:
	175	\|\| m:arch/ia64/lib/__modsi3.o$:
	176	\|\| m:arch/ia64/lib/__udivdi3.o$:
	177	\|\| m:arch/ia64/lib/__udivsi3.o$:
	178	\|\| m:arch/ia64/lib/__umoddi3.o$:
	179	\|\| m:arch/ia64/lib/__umodsi3.o$:
	180	\|\| m:arch/ia64/scripts/check_gas_for_hint.o$:
	181	\|\| m:arch/ia64/sn/kernel/xp.o$:
	182	\|\| m:boot/bbootsect.o$:
	183	\|\| m:boot/bsetup.o$:
	184	\|\| m:/bootsect.o$:
	185	\|\| m:/boot/setup.o$:
	186	\|\| m:/compressed/:
	187	\|\| m:drivers/cdrom/driver.o$:
	188	\|\| m:drivers/char/drm/tdfx_drv.o$:
	189	\|\| m:drivers/ide/ide-detect.o$:
	190	\|\| m:drivers/ide/pci/idedriver-pci.o$:
	191	\|\| m:drivers/media/media.o$:
	192	\|\| m:drivers/scsi/sd_mod.o$:
	193	\|\| m:drivers/video/video.o$:
	194	\|\| m:fs/devpts/devpts.o$:
	195	\|\| m:fs/exportfs/exportfs.o$:
	196	\|\| m:fs/hugetlbfs/hugetlbfs.o$:
	197	\|\| m:fs/msdos/msdos.o$:
	198	\|\| m:fs/nls/nls.o$:
	199	\|\| m:fs/ramfs/ramfs.o$:
	200	\|\| m:fs/romfs/romfs.o$:
	201	\|\| m:fs/vfat/vfat.o$:
	202	\|\| m:init/mounts.o$:
	203	\|\| m:^modules/:
	204	\|\| m:net/netlink/netlink.o$:
	205	\|\| m:net/sched/sched.o$:
	206	\|\| m:/piggy.o$:
	207	\|\| m:^scripts/:
	208	\|\| m:sound/.*/snd-:
	209	\|\| m:^.*/\.tmp_:
	210	\|\| m:^\.tmp_:
	211	\|\| m:/vmlinux-obj.o$:
abb43852	212	\|\| m:^tools/:
1da177e4 LT	213	)
	214	) {
	215	do_nm($basename, $_);
	216	}
	217	$_ = $basename; # File::Find expects $_ untouched (undocumented)
	218	}
	219
	220	sub do_nm
	221	{
	222	my ($basename, $fullname) = @_;
	223	my ($source, $type, $name);
	224	if (! -e $basename) {
	225	printf STDERR "$basename does not exist\n";
	226	return;
	227	}
	228	if ($fullname !~ /\.o$/) {
	229	printf STDERR "$fullname is not an object file\n";
	230	return;
	231	}
c25f4157 AW	232	($source = $basename) =~ s/\.o$//;
	233	if (-e "$source.c" \|\| -e "$source.S") {
	234	$source = "$objtree$File::Find::dir/$source";
1da177e4	235	} else {
c25f4157	236	$source = "$srctree$File::Find::dir/$source";
1da177e4 LT	237	}
	238	if (! -e "$source.c" && ! -e "$source.S") {
	239	# No obvious source, exclude the object if it is conglomerate
86d08e56 SH	240	open(my $objdumpdata, "$objdump $basename\|")
	241	or die "$objdump $fullname failed $!\n";
	242
1da177e4	243	my $comment;
86d08e56	244	while (<$objdumpdata>) {
1da177e4 LT	245	chomp();
	246	if (/^In archive/) {
	247	# Archives are always conglomerate
	248	$comment = "GCC:GCC:";
	249	last;
	250	}
	251	next if (! /^[ 0-9a-f]{5,} /);
	252	$comment .= substr($_, 43);
	253	}
86d08e56 SH	254	close($objdumpdata);
86d08e56 SH	255
1da177e4 LT	256	if (!defined($comment) \|\| $comment !~ /GCC\:.*GCC\:/m) {
	257	printf STDERR "No source file found for $fullname\n";
	258	}
	259	return;
	260	}
86d08e56 SH	261	open (my $nmdata, "$nm $basename\|")
	262	or die "$nm $fullname failed $!\n";
	263
1da177e4	264	my @nmdata;
86d08e56	265	while (<$nmdata>) {
1da177e4 LT	266	chop;
	267	($type, $name) = (split(/ +/, $_, 3))[1..2];
	268	# Expected types
	269	# A absolute symbol
	270	# B weak external reference to data that has been resolved
	271	# C global variable, uninitialised
	272	# D global variable, initialised
	273	# G global variable, initialised, small data section
	274	# R global array, initialised
	275	# S global variable, uninitialised, small bss
	276	# T global label/procedure
	277	# U external reference
	278	# W weak external reference to text that has been resolved
e8cf9813	279	# V similar to W, but the value of the weak symbol becomes zero with no error.
1da177e4 LT	280	# a assembler equate
	281	# b static variable, uninitialised
	282	# d static variable, initialised
	283	# g static variable, initialised, small data section
	284	# r static array, initialised
	285	# s static variable, uninitialised, small bss
	286	# t static label/procedures
	287	# w weak external reference to text that has not been resolved
e8cf9813	288	# v similar to w
1da177e4	289	# ? undefined type, used a lot by modules
e8cf9813	290	if ($type !~ /^[ABCDGRSTUWVabdgrstwv?]$/) {
1da177e4 LT	291	printf STDERR "nm output for $fullname contains unknown type '$_'\n";
	292	}
	293	elsif ($name =~ /\./) {
	294	# name with '.' is local static
	295	}
	296	else {
	297	$type = 'R' if ($type eq '?'); # binutils replaced ? with R at one point
	298	# binutils keeps changing the type for exported symbols, force it to R
	299	$type = 'R' if ($name =~ /^__ksymtab/ \|\| $name =~ /^__kstrtab/);
	300	$name =~ s/_R[a-f0-9]{8}$//; # module versions adds this
e8cf9813	301	if ($type =~ /[ABCDGRSTWV]/ &&
1da177e4 LT	302	$name ne 'init_module' &&
	303	$name ne 'cleanup_module' &&
	304	$name ne 'Using_Versions' &&
	305	$name !~ /^Version_[0-9]+$/ &&
	306	$name !~ /^__parm_/ &&
	307	$name !~ /^__kstrtab/ &&
	308	$name !~ /^__ksymtab/ &&
	309	$name !~ /^__kcrctab_/ &&
	310	$name !~ /^__exitcall_/ &&
	311	$name !~ /^__initcall_/ &&
	312	$name !~ /^__kdb_initcall_/ &&
	313	$name !~ /^__kdb_exitcall_/ &&
	314	$name !~ /^__module_/ &&
	315	$name !~ /^__mod_/ &&
	316	$name !~ /^__crc_/ &&
	317	$name ne '__this_module' &&
	318	$name ne 'kernel_version') {
	319	if (!exists($def{$name})) {
	320	$def{$name} = [];
	321	}
	322	push(@{$def{$name}}, $fullname);
	323	}
	324	push(@nmdata, "$type $name");
	325	if ($name =~ /^__ksymtab_/) {
	326	$name = substr($name, 10);
	327	if (!exists($ksymtab{$name})) {
	328	$ksymtab{$name} = [];
	329	}
	330	push(@{$ksymtab{$name}}, $fullname);
	331	}
	332	}
	333	}
86d08e56 SH	334	close($nmdata);
86d08e56 SH	335
1da177e4	336	if ($#nmdata < 0) {
43f683c9 SH	337	printf "No nm data for $fullname\n"
	338	unless $nmexception{$fullname};
	339	return;
1da177e4 LT	340	}
	341	$nmdata{$fullname} = \@nmdata;
	342	}
	343
	344	sub drop_def
	345	{
	346	my ($object, $name) = @_;
	347	my $nmdata = $nmdata{$object};
	348	my ($i, $j);
	349	for ($i = 0; $i <= $#{$nmdata}; ++$i) {
	350	if ($name eq (split(' ', $nmdata->[$i], 2))[1]) {
	351	splice(@{$nmdata{$object}}, $i, 1);
	352	my $def = $def{$name};
	353	for ($j = 0; $j < $#{$def{$name}}; ++$j) {
	354	if ($def{$name}[$j] eq $object) {
	355	splice(@{$def{$name}}, $j, 1);
	356	}
	357	}
	358	last;
	359	}
	360	}
	361	}
	362
	363	sub list_multiply_defined
	364	{
86d08e56	365	foreach my $name (keys(%def)) {
1da177e4 LT	366	if ($#{$def{$name}} > 0) {
1da177e4 LT	367	# Special case for cond_syscall
abb43852 AW	368	if ($#{$def{$name}} == 1 &&
	369	($name =~ /^sys_/ \|\| $name =~ /^compat_sys_/ \|\|
	370	$name =~ /^sys32_/)) {
e8cf9813 AW	371	if($def{$name}[0] eq "kernel/sys_ni.o" \|\|
	372	$def{$name}[1] eq "kernel/sys_ni.o") {
	373	&drop_def("kernel/sys_ni.o", $name);
	374	next;
	375	}
1da177e4	376	}
86d08e56	377
1da177e4	378	printf "$name is multiply defined in :-\n";
86d08e56	379	foreach my $module (@{$def{$name}}) {
1da177e4 LT	380	printf "\t$module\n";
	381	}
	382	}
	383	}
	384	}
	385
	386	sub resolve_external_references
	387	{
86d08e56 SH	388	my ($kstrtab, $ksymtab, $export);
86d08e56 SH	389
1da177e4	390	printf "\n";
86d08e56	391	foreach my $object (keys(%nmdata)) {
1da177e4	392	my $nmdata = $nmdata{$object};
86d08e56 SH	393	for (my $i = 0; $i <= $#{$nmdata}; ++$i) {
86d08e56 SH	394	my ($type, $name) = split(' ', $nmdata->[$i], 2);
1da177e4 LT	395	if ($type eq "U" \|\| $type eq "w") {
	396	if (exists($def{$name}) \|\| exists($ksymtab{$name})) {
	397	# add the owning object to the nmdata
	398	$nmdata->[$i] = "$type $name $object";
	399	# only count as a reference if it is not EXPORT_...
	400	$kstrtab = "R __kstrtab_$name";
	401	$ksymtab = "R __ksymtab_$name";
	402	$export = 0;
86d08e56	403	for (my $j = 0; $j <= $#{$nmdata}; ++$j) {
1da177e4 LT	404	if ($nmdata->[$j] eq $kstrtab \|\|
	405	$nmdata->[$j] eq $ksymtab) {
	406	$export = 1;
	407	last;
	408	}
	409	}
	410	if ($export) {
	411	$export{$name} = "";
	412	}
	413	else {
	414	$ref{$name} = ""
	415	}
	416	}
43f683c9	417	elsif ( ! $nameexception{$name}
1da177e4 LT	418	&& $name !~ /^__sched_text_/
	419	&& $name !~ /^__start_/
	420	&& $name !~ /^__end_/
	421	&& $name !~ /^__stop_/
	422	&& $name !~ /^__scheduling_functions_.*_here/
	423	&& $name !~ /^__.*initcall_/
	424	&& $name !~ /^__.*per_cpu_start/
	425	&& $name !~ /^__.*per_cpu_end/
	426	&& $name !~ /^__alt_instructions/
	427	&& $name !~ /^__setup_/
1da177e4 LT	428	&& $name !~ /^__mod_timer/
	429	&& $name !~ /^__mod_page_state/
	430	&& $name !~ /^init_module/
	431	&& $name !~ /^cleanup_module/
	432	) {
	433	printf "Cannot resolve ";
	434	printf "weak " if ($type eq "w");
	435	printf "reference to $name from $object\n";
	436	}
	437	}
	438	}
	439	}
	440	}
	441
	442	sub list_extra_externals
	443	{
	444	my %noref = ();
86d08e56 SH	445
86d08e56 SH	446	foreach my $name (keys(%def)) {
1da177e4	447	if (! exists($ref{$name})) {
86d08e56 SH	448	my @module = @{$def{$name}};
86d08e56 SH	449	foreach my $module (@module) {
1da177e4 LT	450	if (! exists($noref{$module})) {
	451	$noref{$module} = [];
	452	}
	453	push(@{$noref{$module}}, $name);
	454	}
	455	}
	456	}
	457	if (%noref) {
	458	printf "\nExternally defined symbols with no external references\n";
86d08e56	459	foreach my $module (sort(keys(%noref))) {
1da177e4 LT	460	printf " $module\n";
1da177e4 LT	461	foreach (sort(@{$noref{$module}})) {
86d08e56 SH	462	my $export;
	463	if (exists($export{$_})) {
	464	$export = " (export only)";
	465	} else {
	466	$export = "";
	467	}
	468	printf " $_$export\n";
1da177e4 LT	469	}
	470	}
	471	}
	472	}