You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
472 lines
13 KiB
472 lines
13 KiB
#!/usr/bin/env perl |
|
# |
|
# 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. |
|
# |
|
|
|
use warnings; |
|
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"; |
|
} |
|
} |
|
} |
|
}
|
|
|