[linux-block.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

&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$:
		|| m:arch/x86/kernel/vsyscall-syms.o$:
		|| 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$:
		|| m:^scripts/:
		|| m:sound/.*/snd-:
		|| m:^.*/\.tmp_:
		|| m:^\.tmp_:
		|| m:/vmlinux-obj.o$:
		)
	) {
		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 = $fullname) =~ s/\.o$//;
	if (-e "$objtree$source.c" || -e "$objtree$source.S") {
		$source = "$objtree$source";
	} else {
		$source = "$srctree$source";
	}
	if (! -e "$source.c" && ! -e "$source.S") {
		# No obvious source, exclude the object if it is conglomerate
		if (! open(OBJDUMPDATA, "$objdump $basename|")) {
			printf STDERR "$objdump $fullname failed $!\n";
			return;
		}
		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 $fullname\n";
		}
		return;
	}
	if (! open(NMDATA, "$nm $basename|")) {
		printf STDERR "$nm $fullname failed $!\n";
		return;
	}
	my @nmdata;
	while (<NMDATA>) {
		chop;
		($type, $name) = (split(/ +/, $_, 3))[1..2];
		# Expected types
		# A absolute symbol
		# B weak external reference to data that has been resolved
		# C global variable, uninitialised
		# D global variable, initialised
		# G global variable, initialised, small data section
		# R global array, initialised
		# S global variable, uninitialised, small bss
		# T global label/procedure
		# U external reference
		# W weak external reference to text that has been resolved
		# a assembler equate
		# b static variable, uninitialised
		# d static variable, initialised
		# g static variable, initialised, small data section
		# r static array, initialised
		# s static variable, uninitialised, small bss
		# t static label/procedures
		# w weak external reference to text that has not been resolved
		# ? undefined type, used a lot by modules
		if ($type !~ /^[ABCDGRSTUWabdgrstw?]$/) {
			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 =~ /[ABCDGRSTW]/ &&
				$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) {
		if (
			$fullname ne "lib/brlock.o"
			&& $fullname ne "lib/dec_and_lock.o"
			&& $fullname ne "fs/xfs/xfs_macros.o"
			&& $fullname ne "drivers/ide/ide-probe-mini.o"
			&& $fullname ne "usr/initramfs_data.o"
			&& $fullname ne "drivers/acpi/executer/exdump.o"
			&& $fullname ne "drivers/acpi/resources/rsdump.o"
			&& $fullname ne "drivers/acpi/namespace/nsdumpdv.o"
			&& $fullname ne "drivers/acpi/namespace/nsdump.o"
			&& $fullname ne "arch/ia64/sn/kernel/sn2/io.o"
			&& $fullname ne "arch/ia64/kernel/gate-data.o"
			&& $fullname ne "drivers/ieee1394/oui.o"
			&& $fullname ne "security/capability.o"
			&& $fullname ne "sound/core/wrappers.o"
			&& $fullname ne "fs/ntfs/sysctl.o"
			&& $fullname ne "fs/jfs/jfs_debug.o"
		) {
			printf "No nm data for $fullname\n";
		}
		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
{
	my ($name, $module);
	foreach $name (keys(%def)) {
		if ($#{$def{$name}} > 0) {
			# Special case for cond_syscall
			if ($#{$def{$name}} == 1 && $name =~ /^sys_/ &&
			    ($def{$name}[0] eq "kernel/sys.o" ||
			     $def{$name}[1] eq "kernel/sys.o")) {
				&drop_def("kernel/sys.o", $name);
				next;
			}
			# Special case for i386 entry code
			if ($#{$def{$name}} == 1 && $name =~ /^__kernel_/ &&
			    $def{$name}[0] eq "arch/x86/kernel/vsyscall-int80_32.o" &&
			    $def{$name}[1] eq "arch/x86/kernel/vsyscall-sysenter_32.o") {
				&drop_def("arch/x86/kernel/vsyscall-sysenter_32.o", $name);
				next;
			}
			printf "$name is multiply defined in :-\n";
			foreach $module (@{$def{$name}}) {
				printf "\t$module\n";
			}
		}
	}
}

sub resolve_external_references
{
	my ($object, $type, $name, $i, $j, $kstrtab, $ksymtab, $export);
	printf "\n";
	foreach $object (keys(%nmdata)) {
		my $nmdata = $nmdata{$object};
		for ($i = 0; $i <= $#{$nmdata}; ++$i) {
			($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";
					$export = 0;
					for ($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 (    $name ne "mod_use_count_"
					&& $name ne "__initramfs_end"
					&& $name ne "__initramfs_start"
					&& $name ne "_einittext"
					&& $name ne "_sinittext"
					&& $name ne "kallsyms_names"
					&& $name ne "kallsyms_num_syms"
					&& $name ne "kallsyms_addresses"
					&& $name ne "__this_module"
					&& $name ne "_etext"
					&& $name ne "_edata"
					&& $name ne "_end"
					&& $name ne "__bss_start"
					&& $name ne "_text"
					&& $name ne "_stext"
					&& $name ne "__gp"
					&& $name ne "ia64_unw_start"
					&& $name ne "ia64_unw_end"
					&& $name ne "__init_begin"
					&& $name ne "__init_end"
					&& $name ne "__bss_stop"
					&& $name ne "__nosave_begin"
					&& $name ne "__nosave_end"
					&& $name ne "pg0"
					&& $name ne "__module_text_address"
					&& $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 !~ /^jiffies/
					&& $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 = ();
	my ($name, @module, $module, $export);
	foreach $name (keys(%def)) {
		if (! exists($ref{$name})) {
			@module = @{$def{$name}};
			foreach $module (@module) {
				if (! exists($noref{$module})) {
					$noref{$module} = [];
				}
				push(@{$noref{$module}}, $name);
			}
		}
	}
	if (%noref) {
		printf "\nExternally defined symbols with no external references\n";
		foreach $module (sort(keys(%noref))) {
			printf "  $module\n";
			foreach (sort(@{$noref{$module}})) {
				if (exists($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
	87	&find(\&linux_objects, '.'); # find the objects and do_nm on them
	88	&list_multiply_defined();
	89	&resolve_external_references();
	90	&list_extra_externals();
	91
	92	exit(0);
	93
	94	sub linux_objects
	95	{
	96	# Select objects, ignoring objects which are only created by
	97	# merging other objects. Also ignore all of modules, scripts
	98	# and compressed. Most conglomerate objects are handled by do_nm,
	99	# this list only contains the special cases. These include objects
	100	# that are linked from just one other object and objects for which
	101	# there is really no permanent source file.
	102	my $basename = $_;
	103	$_ = $File::Find::name;
	104	s:^\./::;
	105	if (/.*\.o$/ &&
	106	! (
	107	m:/built-in.o$:
d2c75f2f	108	\|\| m:arch/x86/kernel/vsyscall-syms.o$:
1da177e4 LT	109	\|\| m:arch/ia64/ia32/ia32.o$:
	110	\|\| m:arch/ia64/kernel/gate-syms.o$:
	111	\|\| m:arch/ia64/lib/__divdi3.o$:
	112	\|\| m:arch/ia64/lib/__divsi3.o$:
	113	\|\| m:arch/ia64/lib/__moddi3.o$:
	114	\|\| m:arch/ia64/lib/__modsi3.o$:
	115	\|\| m:arch/ia64/lib/__udivdi3.o$:
	116	\|\| m:arch/ia64/lib/__udivsi3.o$:
	117	\|\| m:arch/ia64/lib/__umoddi3.o$:
	118	\|\| m:arch/ia64/lib/__umodsi3.o$:
	119	\|\| m:arch/ia64/scripts/check_gas_for_hint.o$:
	120	\|\| m:arch/ia64/sn/kernel/xp.o$:
	121	\|\| m:boot/bbootsect.o$:
	122	\|\| m:boot/bsetup.o$:
	123	\|\| m:/bootsect.o$:
	124	\|\| m:/boot/setup.o$:
	125	\|\| m:/compressed/:
	126	\|\| m:drivers/cdrom/driver.o$:
	127	\|\| m:drivers/char/drm/tdfx_drv.o$:
	128	\|\| m:drivers/ide/ide-detect.o$:
	129	\|\| m:drivers/ide/pci/idedriver-pci.o$:
	130	\|\| m:drivers/media/media.o$:
	131	\|\| m:drivers/scsi/sd_mod.o$:
	132	\|\| m:drivers/video/video.o$:
	133	\|\| m:fs/devpts/devpts.o$:
	134	\|\| m:fs/exportfs/exportfs.o$:
	135	\|\| m:fs/hugetlbfs/hugetlbfs.o$:
	136	\|\| m:fs/msdos/msdos.o$:
	137	\|\| m:fs/nls/nls.o$:
	138	\|\| m:fs/ramfs/ramfs.o$:
	139	\|\| m:fs/romfs/romfs.o$:
	140	\|\| m:fs/vfat/vfat.o$:
	141	\|\| m:init/mounts.o$:
	142	\|\| m:^modules/:
	143	\|\| m:net/netlink/netlink.o$:
	144	\|\| m:net/sched/sched.o$:
	145	\|\| m:/piggy.o$:
	146	\|\| m:^scripts/:
	147	\|\| m:sound/.*/snd-:
	148	\|\| m:^.*/\.tmp_:
	149	\|\| m:^\.tmp_:
	150	\|\| m:/vmlinux-obj.o$:
	151	)
	152	) {
	153	do_nm($basename, $_);
	154	}
	155	$_ = $basename; # File::Find expects $_ untouched (undocumented)
	156	}
	157
	158	sub do_nm
	159	{
	160	my ($basename, $fullname) = @_;
	161	my ($source, $type, $name);
	162	if (! -e $basename) {
	163	printf STDERR "$basename does not exist\n";
	164	return;
	165	}
	166	if ($fullname !~ /\.o$/) {
	167	printf STDERR "$fullname is not an object file\n";
	168	return;
	169	}
	170	($source = $fullname) =~ s/\.o$//;
	171	if (-e "$objtree$source.c" \|\| -e "$objtree$source.S") {
	172	$source = "$objtree$source";
173	} else {
174	$source = "$srctree$source";
175	}
176	if (! -e "$source.c" && ! -e "$source.S") {
177	# No obvious source, exclude the object if it is conglomerate
178	if (! open(OBJDUMPDATA, "$objdump $basename\|")) {
179	printf STDERR "$objdump $fullname failed $!\n";
180	return;
181	}
182	my $comment;
183	while (<OBJDUMPDATA>) {
184	chomp();
185	if (/^In archive/) {
186	# Archives are always conglomerate
187	$comment = "GCC:GCC:";
188	last;
189	}
190	next if (! /^[ 0-9a-f]{5,} /);
191	$comment .= substr($_, 43);
192	}
193	close(OBJDUMPDATA);
194	if (!defined($comment) \|\| $comment !~ /GCC\:.*GCC\:/m) {
195	printf STDERR "No source file found for $fullname\n";
196	}
197	return;
198	}
199	if (! open(NMDATA, "$nm $basename\|")) {
200	printf STDERR "$nm $fullname failed $!\n";
201	return;
202	}
203	my @nmdata;
204	while (<NMDATA>) {
205	chop;
206	($type, $name) = (split(/ +/, $_, 3))[1..2];
207	# Expected types
208	# A absolute symbol
209	# B weak external reference to data that has been resolved
210	# C global variable, uninitialised
211	# D global variable, initialised
212	# G global variable, initialised, small data section
213	# R global array, initialised
214	# S global variable, uninitialised, small bss
215	# T global label/procedure
216	# U external reference
217	# W weak external reference to text that has been resolved
218	# a assembler equate
219	# b static variable, uninitialised
220	# d static variable, initialised
221	# g static variable, initialised, small data section
222	# r static array, initialised
223	# s static variable, uninitialised, small bss
224	# t static label/procedures
225	# w weak external reference to text that has not been resolved
226	# ? undefined type, used a lot by modules
227	if ($type !~ /^[ABCDGRSTUWabdgrstw?]$/) {
228	printf STDERR "nm output for $fullname contains unknown type '$_'\n";
229	}
230	elsif ($name =~ /\./) {
231	# name with '.' is local static
232	}
233	else {
234	$type = 'R' if ($type eq '?'); # binutils replaced ? with R at one point
235	# binutils keeps changing the type for exported symbols, force it to R
236	$type = 'R' if ($name =~ /^__ksymtab/ \|\| $name =~ /^__kstrtab/);
237	$name =~ s/_R[a-f0-9]{8}$//; # module versions adds this
238	if ($type =~ /[ABCDGRSTW]/ &&
239	$name ne 'init_module' &&
240	$name ne 'cleanup_module' &&
241	$name ne 'Using_Versions' &&
242	$name !~ /^Version_[0-9]+$/ &&
243	$name !~ /^__parm_/ &&
244	$name !~ /^__kstrtab/ &&
245	$name !~ /^__ksymtab/ &&
246	$name !~ /^__kcrctab_/ &&
247	$name !~ /^__exitcall_/ &&
248	$name !~ /^__initcall_/ &&
249	$name !~ /^__kdb_initcall_/ &&
250	$name !~ /^__kdb_exitcall_/ &&
251	$name !~ /^__module_/ &&
252	$name !~ /^__mod_/ &&
253	$name !~ /^__crc_/ &&
254	$name ne '__this_module' &&
255	$name ne 'kernel_version') {
256	if (!exists($def{$name})) {
257	$def{$name} = [];
258	}
259	push(@{$def{$name}}, $fullname);
260	}
261	push(@nmdata, "$type $name");
262	if ($name =~ /^__ksymtab_/) {
263	$name = substr($name, 10);
264	if (!exists($ksymtab{$name})) {
265	$ksymtab{$name} = [];
266	}
267	push(@{$ksymtab{$name}}, $fullname);
268	}
269	}
270	}
271	close(NMDATA);
272	if ($#nmdata < 0) {
273	if (
274	$fullname ne "lib/brlock.o"
275	&& $fullname ne "lib/dec_and_lock.o"
276	&& $fullname ne "fs/xfs/xfs_macros.o"
277	&& $fullname ne "drivers/ide/ide-probe-mini.o"
278	&& $fullname ne "usr/initramfs_data.o"
279	&& $fullname ne "drivers/acpi/executer/exdump.o"
280	&& $fullname ne "drivers/acpi/resources/rsdump.o"
281	&& $fullname ne "drivers/acpi/namespace/nsdumpdv.o"
282	&& $fullname ne "drivers/acpi/namespace/nsdump.o"
283	&& $fullname ne "arch/ia64/sn/kernel/sn2/io.o"
284	&& $fullname ne "arch/ia64/kernel/gate-data.o"
285	&& $fullname ne "drivers/ieee1394/oui.o"
286	&& $fullname ne "security/capability.o"
287	&& $fullname ne "sound/core/wrappers.o"
288	&& $fullname ne "fs/ntfs/sysctl.o"
289	&& $fullname ne "fs/jfs/jfs_debug.o"
290	) {
291	printf "No nm data for $fullname\n";
292	}
293	return;
294	}
295	$nmdata{$fullname} = \@nmdata;
296	}
297
298	sub drop_def
299	{
300	my ($object, $name) = @_;
301	my $nmdata = $nmdata{$object};
302	my ($i, $j);
303	for ($i = 0; $i <= $#{$nmdata}; ++$i) {
304	if ($name eq (split(' ', $nmdata->[$i], 2))[1]) {
305	splice(@{$nmdata{$object}}, $i, 1);
306	my $def = $def{$name};
307	for ($j = 0; $j < $#{$def{$name}}; ++$j) {
308	if ($def{$name}[$j] eq $object) {
309	splice(@{$def{$name}}, $j, 1);
310	}
311	}
312	last;
313	}
314	}
315	}
316
317	sub list_multiply_defined
318	{
319	my ($name, $module);
320	foreach $name (keys(%def)) {
321	if ($#{$def{$name}} > 0) {
322	# Special case for cond_syscall
323	if ($#{$def{$name}} == 1 && $name =~ /^sys_/ &&
324	($def{$name}[0] eq "kernel/sys.o" \|\|
325	$def{$name}[1] eq "kernel/sys.o")) {
326	&drop_def("kernel/sys.o", $name);
327	next;
328	}
329	# Special case for i386 entry code
330	if ($#{$def{$name}} == 1 && $name =~ /^__kernel_/ &&
d2c75f2f TG	331	$def{$name}[0] eq "arch/x86/kernel/vsyscall-int80_32.o" &&
	332	$def{$name}[1] eq "arch/x86/kernel/vsyscall-sysenter_32.o") {
	333	&drop_def("arch/x86/kernel/vsyscall-sysenter_32.o", $name);
1da177e4 LT	334	next;
	335	}
	336	printf "$name is multiply defined in :-\n";
	337	foreach $module (@{$def{$name}}) {
	338	printf "\t$module\n";
	339	}
	340	}
	341	}
	342	}
	343
	344	sub resolve_external_references
	345	{
	346	my ($object, $type, $name, $i, $j, $kstrtab, $ksymtab, $export);
	347	printf "\n";
	348	foreach $object (keys(%nmdata)) {
	349	my $nmdata = $nmdata{$object};
	350	for ($i = 0; $i <= $#{$nmdata}; ++$i) {
	351	($type, $name) = split(' ', $nmdata->[$i], 2);
	352	if ($type eq "U" \|\| $type eq "w") {
	353	if (exists($def{$name}) \|\| exists($ksymtab{$name})) {
	354	# add the owning object to the nmdata
	355	$nmdata->[$i] = "$type $name $object";
	356	# only count as a reference if it is not EXPORT_...
	357	$kstrtab = "R __kstrtab_$name";
	358	$ksymtab = "R __ksymtab_$name";
	359	$export = 0;
	360	for ($j = 0; $j <= $#{$nmdata}; ++$j) {
	361	if ($nmdata->[$j] eq $kstrtab \|\|
	362	$nmdata->[$j] eq $ksymtab) {
	363	$export = 1;
	364	last;
	365	}
	366	}
	367	if ($export) {
	368	$export{$name} = "";
	369	}
	370	else {
	371	$ref{$name} = ""
	372	}
	373	}
	374	elsif ( $name ne "mod_use_count_"
	375	&& $name ne "__initramfs_end"
	376	&& $name ne "__initramfs_start"
	377	&& $name ne "_einittext"
	378	&& $name ne "_sinittext"
	379	&& $name ne "kallsyms_names"
	380	&& $name ne "kallsyms_num_syms"
	381	&& $name ne "kallsyms_addresses"
	382	&& $name ne "__this_module"
	383	&& $name ne "_etext"
	384	&& $name ne "_edata"
	385	&& $name ne "_end"
	386	&& $name ne "__bss_start"
	387	&& $name ne "_text"
	388	&& $name ne "_stext"
	389	&& $name ne "__gp"
	390	&& $name ne "ia64_unw_start"
	391	&& $name ne "ia64_unw_end"
	392	&& $name ne "__init_begin"
	393	&& $name ne "__init_end"
	394	&& $name ne "__bss_stop"
	395	&& $name ne "__nosave_begin"
	396	&& $name ne "__nosave_end"
	397	&& $name ne "pg0"
398	&& $name ne "__module_text_address"
399	&& $name !~ /^__sched_text_/
400	&& $name !~ /^__start_/
401	&& $name !~ /^__end_/
402	&& $name !~ /^__stop_/
403	&& $name !~ /^__scheduling_functions_.*_here/
404	&& $name !~ /^__.*initcall_/
405	&& $name !~ /^__.*per_cpu_start/
406	&& $name !~ /^__.*per_cpu_end/
407	&& $name !~ /^__alt_instructions/
408	&& $name !~ /^__setup_/
409	&& $name !~ /^jiffies/
410	&& $name !~ /^__mod_timer/
411	&& $name !~ /^__mod_page_state/
412	&& $name !~ /^init_module/
413	&& $name !~ /^cleanup_module/
414	) {
415	printf "Cannot resolve ";
416	printf "weak " if ($type eq "w");
417	printf "reference to $name from $object\n";
418	}
419	}
420	}
421	}
422	}
423
424	sub list_extra_externals
425	{
426	my %noref = ();
427	my ($name, @module, $module, $export);
428	foreach $name (keys(%def)) {
429	if (! exists($ref{$name})) {
430	@module = @{$def{$name}};
431	foreach $module (@module) {
432	if (! exists($noref{$module})) {
433	$noref{$module} = [];
434	}
435	push(@{$noref{$module}}, $name);
436	}
437	}
438	}
439	if (%noref) {
440	printf "\nExternally defined symbols with no external references\n";
441	foreach $module (sort(keys(%noref))) {
442	printf " $module\n";
443	foreach (sort(@{$noref{$module}})) {
444	if (exists($export{$_})) {
445	$export = " (export only)";
446	}
447	else {
448	$export = "";
449	}
450	printf " $_$export\n";
451	}
452	}
453	}
454	}