Skip to content
Snippets Groups Projects
Select Git revision
  • 71378be91f5473e89c8be170c6e49edda3bdbb67
  • vme-testing default
  • ci-test
  • master
  • remoteproc
  • am625-sk-ov5640
  • pcal6534-upstreaming
  • lps22df-upstreaming
  • msc-upstreaming
  • imx8mp
  • iio/noa1305
  • vme-next
  • vme-next-4.14-rc4
  • v4.14-rc4
  • v4.14-rc3
  • v4.14-rc2
  • v4.14-rc1
  • v4.13
  • vme-next-4.13-rc7
  • v4.13-rc7
  • v4.13-rc6
  • v4.13-rc5
  • v4.13-rc4
  • v4.13-rc3
  • v4.13-rc2
  • v4.13-rc1
  • v4.12
  • v4.12-rc7
  • v4.12-rc6
  • v4.12-rc5
  • v4.12-rc4
  • v4.12-rc3
32 results

namespace.pl

Blame
  • namespace.pl 13.09 KiB
    #!/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$:
    		|| m:arch/i386/kernel/vsyscall-syms.o$:
    		|| 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/i386/kernel/vsyscall-int80.o" &&
    			    $def{$name}[1] eq "arch/i386/kernel/vsyscall-sysenter.o") {
    				&drop_def("arch/i386/kernel/vsyscall-sysenter.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";
    			}
    		}
    	}
    }