initial_commit

1 files changed, 470 insertions, 0 deletions

diff --git a/scripts/namespace.pl b/scripts/namespace.pl
new file mode 100755
index 00000000..a71be6b7
--- /dev/null
+++ b/scripts/namespace.pl
@@ -0,0 +1,470 @@
+#!/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,
+    '__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";
+			}
+		}
+	}
+}