Root/
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 | |
69 | my $nm = ($ENV{'NM'} || "nm") . " -p"; |
70 | my $objdump = ($ENV{'OBJDUMP'} || "objdump") . " -s -j .comment"; |
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 | 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, |
120 | '__this_module' => 1, |
121 | '_etext' => 1, |
122 | '_edata' => 1, |
123 | '_end' => 1, |
124 | '__bss_start' => 1, |
125 | '_text' => 1, |
126 | '_stext' => 1, |
127 | '__gp' => 1, |
128 | 'ia64_unw_start' => 1, |
129 | 'ia64_unw_end' => 1, |
130 | '__init_begin' => 1, |
131 | '__init_end' => 1, |
132 | '__bss_stop' => 1, |
133 | '__nosave_begin' => 1, |
134 | '__nosave_end' => 1, |
135 | 'pg0' => 1, |
136 | 'vdso_enabled' => 1, |
137 | '__stack_chk_fail' => 1, |
138 | 'VDSO32_PRELINK' => 1, |
139 | 'VDSO32_vsyscall' => 1, |
140 | 'VDSO32_rt_sigreturn'=>1, |
141 | 'VDSO32_sigreturn' => 1, |
142 | ); |
143 | |
144 | |
145 | &find(\&linux_objects, '.'); # find the objects and do_nm on them |
146 | &list_multiply_defined(); |
147 | &resolve_external_references(); |
148 | &list_extra_externals(); |
149 | |
150 | exit(0); |
151 | |
152 | sub linux_objects |
153 | { |
154 | # Select objects, ignoring objects which are only created by |
155 | # merging other objects. Also ignore all of modules, scripts |
156 | # and compressed. Most conglomerate objects are handled by do_nm, |
157 | # this list only contains the special cases. These include objects |
158 | # that are linked from just one other object and objects for which |
159 | # there is really no permanent source file. |
160 | my $basename = $_; |
161 | $_ = $File::Find::name; |
162 | s:^\./::; |
163 | if (/.*\.o$/ && |
164 | ! ( |
165 | m:/built-in.o$: |
166 | || m:arch/x86/vdso/: |
167 | || m:arch/x86/boot/: |
168 | || m:arch/ia64/ia32/ia32.o$: |
169 | || m:arch/ia64/kernel/gate-syms.o$: |
170 | || m:arch/ia64/lib/__divdi3.o$: |
171 | || m:arch/ia64/lib/__divsi3.o$: |
172 | || m:arch/ia64/lib/__moddi3.o$: |
173 | || m:arch/ia64/lib/__modsi3.o$: |
174 | || m:arch/ia64/lib/__udivdi3.o$: |
175 | || m:arch/ia64/lib/__udivsi3.o$: |
176 | || m:arch/ia64/lib/__umoddi3.o$: |
177 | || m:arch/ia64/lib/__umodsi3.o$: |
178 | || m:arch/ia64/scripts/check_gas_for_hint.o$: |
179 | || m:arch/ia64/sn/kernel/xp.o$: |
180 | || m:boot/bbootsect.o$: |
181 | || m:boot/bsetup.o$: |
182 | || m:/bootsect.o$: |
183 | || m:/boot/setup.o$: |
184 | || m:/compressed/: |
185 | || m:drivers/cdrom/driver.o$: |
186 | || m:drivers/char/drm/tdfx_drv.o$: |
187 | || m:drivers/ide/ide-detect.o$: |
188 | || m:drivers/ide/pci/idedriver-pci.o$: |
189 | || m:drivers/media/media.o$: |
190 | || m:drivers/scsi/sd_mod.o$: |
191 | || m:drivers/video/video.o$: |
192 | || m:fs/devpts/devpts.o$: |
193 | || m:fs/exportfs/exportfs.o$: |
194 | || m:fs/hugetlbfs/hugetlbfs.o$: |
195 | || m:fs/msdos/msdos.o$: |
196 | || m:fs/nls/nls.o$: |
197 | || m:fs/ramfs/ramfs.o$: |
198 | || m:fs/romfs/romfs.o$: |
199 | || m:fs/vfat/vfat.o$: |
200 | || m:init/mounts.o$: |
201 | || m:^modules/: |
202 | || m:net/netlink/netlink.o$: |
203 | || m:net/sched/sched.o$: |
204 | || m:/piggy.o$: |
205 | || m:^scripts/: |
206 | || m:sound/.*/snd-: |
207 | || m:^.*/\.tmp_: |
208 | || m:^\.tmp_: |
209 | || m:/vmlinux-obj.o$: |
210 | || m:^tools/: |
211 | ) |
212 | ) { |
213 | do_nm($basename, $_); |
214 | } |
215 | $_ = $basename; # File::Find expects $_ untouched (undocumented) |
216 | } |
217 | |
218 | sub do_nm |
219 | { |
220 | my ($basename, $fullname) = @_; |
221 | my ($source, $type, $name); |
222 | if (! -e $basename) { |
223 | printf STDERR "$basename does not exist\n"; |
224 | return; |
225 | } |
226 | if ($fullname !~ /\.o$/) { |
227 | printf STDERR "$fullname is not an object file\n"; |
228 | return; |
229 | } |
230 | ($source = $basename) =~ s/\.o$//; |
231 | if (-e "$source.c" || -e "$source.S") { |
232 | $source = "$objtree$File::Find::dir/$source"; |
233 | } else { |
234 | $source = "$srctree$File::Find::dir/$source"; |
235 | } |
236 | if (! -e "$source.c" && ! -e "$source.S") { |
237 | # No obvious source, exclude the object if it is conglomerate |
238 | open(my $objdumpdata, "$objdump $basename|") |
239 | or die "$objdump $fullname failed $!\n"; |
240 | |
241 | my $comment; |
242 | while (<$objdumpdata>) { |
243 | chomp(); |
244 | if (/^In archive/) { |
245 | # Archives are always conglomerate |
246 | $comment = "GCC:GCC:"; |
247 | last; |
248 | } |
249 | next if (! /^[ 0-9a-f]{5,} /); |
250 | $comment .= substr($_, 43); |
251 | } |
252 | close($objdumpdata); |
253 | |
254 | if (!defined($comment) || $comment !~ /GCC\:.*GCC\:/m) { |
255 | printf STDERR "No source file found for $fullname\n"; |
256 | } |
257 | return; |
258 | } |
259 | open (my $nmdata, "$nm $basename|") |
260 | or die "$nm $fullname failed $!\n"; |
261 | |
262 | my @nmdata; |
263 | while (<$nmdata>) { |
264 | chop; |
265 | ($type, $name) = (split(/ +/, $_, 3))[1..2]; |
266 | # Expected types |
267 | # A absolute symbol |
268 | # B weak external reference to data that has been resolved |
269 | # C global variable, uninitialised |
270 | # D global variable, initialised |
271 | # G global variable, initialised, small data section |
272 | # R global array, initialised |
273 | # S global variable, uninitialised, small bss |
274 | # T global label/procedure |
275 | # U external reference |
276 | # W weak external reference to text that has been resolved |
277 | # V similar to W, but the value of the weak symbol becomes zero with no error. |
278 | # a assembler equate |
279 | # b static variable, uninitialised |
280 | # d static variable, initialised |
281 | # g static variable, initialised, small data section |
282 | # r static array, initialised |
283 | # s static variable, uninitialised, small bss |
284 | # t static label/procedures |
285 | # w weak external reference to text that has not been resolved |
286 | # v similar to w |
287 | # ? undefined type, used a lot by modules |
288 | if ($type !~ /^[ABCDGRSTUWVabdgrstwv?]$/) { |
289 | printf STDERR "nm output for $fullname contains unknown type '$_'\n"; |
290 | } |
291 | elsif ($name =~ /\./) { |
292 | # name with '.' is local static |
293 | } |
294 | else { |
295 | $type = 'R' if ($type eq '?'); # binutils replaced ? with R at one point |
296 | # binutils keeps changing the type for exported symbols, force it to R |
297 | $type = 'R' if ($name =~ /^__ksymtab/ || $name =~ /^__kstrtab/); |
298 | $name =~ s/_R[a-f0-9]{8}$//; # module versions adds this |
299 | if ($type =~ /[ABCDGRSTWV]/ && |
300 | $name ne 'init_module' && |
301 | $name ne 'cleanup_module' && |
302 | $name ne 'Using_Versions' && |
303 | $name !~ /^Version_[0-9]+$/ && |
304 | $name !~ /^__parm_/ && |
305 | $name !~ /^__kstrtab/ && |
306 | $name !~ /^__ksymtab/ && |
307 | $name !~ /^__kcrctab_/ && |
308 | $name !~ /^__exitcall_/ && |
309 | $name !~ /^__initcall_/ && |
310 | $name !~ /^__kdb_initcall_/ && |
311 | $name !~ /^__kdb_exitcall_/ && |
312 | $name !~ /^__module_/ && |
313 | $name !~ /^__mod_/ && |
314 | $name !~ /^__crc_/ && |
315 | $name ne '__this_module' && |
316 | $name ne 'kernel_version') { |
317 | if (!exists($def{$name})) { |
318 | $def{$name} = []; |
319 | } |
320 | push(@{$def{$name}}, $fullname); |
321 | } |
322 | push(@nmdata, "$type $name"); |
323 | if ($name =~ /^__ksymtab_/) { |
324 | $name = substr($name, 10); |
325 | if (!exists($ksymtab{$name})) { |
326 | $ksymtab{$name} = []; |
327 | } |
328 | push(@{$ksymtab{$name}}, $fullname); |
329 | } |
330 | } |
331 | } |
332 | close($nmdata); |
333 | |
334 | if ($#nmdata < 0) { |
335 | printf "No nm data for $fullname\n" |
336 | unless $nmexception{$fullname}; |
337 | return; |
338 | } |
339 | $nmdata{$fullname} = \@nmdata; |
340 | } |
341 | |
342 | sub drop_def |
343 | { |
344 | my ($object, $name) = @_; |
345 | my $nmdata = $nmdata{$object}; |
346 | my ($i, $j); |
347 | for ($i = 0; $i <= $#{$nmdata}; ++$i) { |
348 | if ($name eq (split(' ', $nmdata->[$i], 2))[1]) { |
349 | splice(@{$nmdata{$object}}, $i, 1); |
350 | my $def = $def{$name}; |
351 | for ($j = 0; $j < $#{$def{$name}}; ++$j) { |
352 | if ($def{$name}[$j] eq $object) { |
353 | splice(@{$def{$name}}, $j, 1); |
354 | } |
355 | } |
356 | last; |
357 | } |
358 | } |
359 | } |
360 | |
361 | sub list_multiply_defined |
362 | { |
363 | foreach my $name (keys(%def)) { |
364 | if ($#{$def{$name}} > 0) { |
365 | # Special case for cond_syscall |
366 | if ($#{$def{$name}} == 1 && |
367 | ($name =~ /^sys_/ || $name =~ /^compat_sys_/ || |
368 | $name =~ /^sys32_/)) { |
369 | if($def{$name}[0] eq "kernel/sys_ni.o" || |
370 | $def{$name}[1] eq "kernel/sys_ni.o") { |
371 | &drop_def("kernel/sys_ni.o", $name); |
372 | next; |
373 | } |
374 | } |
375 | |
376 | printf "$name is multiply defined in :-\n"; |
377 | foreach my $module (@{$def{$name}}) { |
378 | printf "\t$module\n"; |
379 | } |
380 | } |
381 | } |
382 | } |
383 | |
384 | sub resolve_external_references |
385 | { |
386 | my ($kstrtab, $ksymtab, $export); |
387 | |
388 | printf "\n"; |
389 | foreach my $object (keys(%nmdata)) { |
390 | my $nmdata = $nmdata{$object}; |
391 | for (my $i = 0; $i <= $#{$nmdata}; ++$i) { |
392 | my ($type, $name) = split(' ', $nmdata->[$i], 2); |
393 | if ($type eq "U" || $type eq "w") { |
394 | if (exists($def{$name}) || exists($ksymtab{$name})) { |
395 | # add the owning object to the nmdata |
396 | $nmdata->[$i] = "$type $name $object"; |
397 | # only count as a reference if it is not EXPORT_... |
398 | $kstrtab = "R __kstrtab_$name"; |
399 | $ksymtab = "R __ksymtab_$name"; |
400 | $export = 0; |
401 | for (my $j = 0; $j <= $#{$nmdata}; ++$j) { |
402 | if ($nmdata->[$j] eq $kstrtab || |
403 | $nmdata->[$j] eq $ksymtab) { |
404 | $export = 1; |
405 | last; |
406 | } |
407 | } |
408 | if ($export) { |
409 | $export{$name} = ""; |
410 | } |
411 | else { |
412 | $ref{$name} = "" |
413 | } |
414 | } |
415 | elsif ( ! $nameexception{$name} |
416 | && $name !~ /^__sched_text_/ |
417 | && $name !~ /^__start_/ |
418 | && $name !~ /^__end_/ |
419 | && $name !~ /^__stop_/ |
420 | && $name !~ /^__scheduling_functions_.*_here/ |
421 | && $name !~ /^__.*initcall_/ |
422 | && $name !~ /^__.*per_cpu_start/ |
423 | && $name !~ /^__.*per_cpu_end/ |
424 | && $name !~ /^__alt_instructions/ |
425 | && $name !~ /^__setup_/ |
426 | && $name !~ /^__mod_timer/ |
427 | && $name !~ /^__mod_page_state/ |
428 | && $name !~ /^init_module/ |
429 | && $name !~ /^cleanup_module/ |
430 | ) { |
431 | printf "Cannot resolve "; |
432 | printf "weak " if ($type eq "w"); |
433 | printf "reference to $name from $object\n"; |
434 | } |
435 | } |
436 | } |
437 | } |
438 | } |
439 | |
440 | sub list_extra_externals |
441 | { |
442 | my %noref = (); |
443 | |
444 | foreach my $name (keys(%def)) { |
445 | if (! exists($ref{$name})) { |
446 | my @module = @{$def{$name}}; |
447 | foreach my $module (@module) { |
448 | if (! exists($noref{$module})) { |
449 | $noref{$module} = []; |
450 | } |
451 | push(@{$noref{$module}}, $name); |
452 | } |
453 | } |
454 | } |
455 | if (%noref) { |
456 | printf "\nExternally defined symbols with no external references\n"; |
457 | foreach my $module (sort(keys(%noref))) { |
458 | printf " $module\n"; |
459 | foreach (sort(@{$noref{$module}})) { |
460 | my $export; |
461 | if (exists($export{$_})) { |
462 | $export = " (export only)"; |
463 | } else { |
464 | $export = ""; |
465 | } |
466 | printf " $_$export\n"; |
467 | } |
468 | } |
469 | } |
470 | } |
471 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9