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Steven Rostedt8da38212008-08-14 15:45:07 -04001#!/usr/bin/perl -w
2# (c) 2008, Steven Rostedt <srostedt@redhat.com>
3# Licensed under the terms of the GNU GPL License version 2
4#
5# recordmcount.pl - makes a section called __mcount_loc that holds
6# all the offsets to the calls to mcount.
7#
8#
Li Hongd49f6aa2009-10-28 13:01:38 +08009# What we want to end up with this is that each object file will have a
10# section called __mcount_loc that will hold the list of pointers to mcount
11# callers. After final linking, the vmlinux will have within .init.data the
12# list of all callers to mcount between __start_mcount_loc and __stop_mcount_loc.
13# Later on boot up, the kernel will read this list, save the locations and turn
14# them into nops. When tracing or profiling is later enabled, these locations
15# will then be converted back to pointers to some function.
Steven Rostedt8da38212008-08-14 15:45:07 -040016#
17# This is no easy feat. This script is called just after the original
18# object is compiled and before it is linked.
19#
Li Hongd49f6aa2009-10-28 13:01:38 +080020# When parse this object file using 'objdump', the references to the call
21# sites are offsets from the section that the call site is in. Hence, all
22# functions in a section that has a call site to mcount, will have the
23# offset from the beginning of the section and not the beginning of the
24# function.
Steven Rostedt8da38212008-08-14 15:45:07 -040025#
Li Hongd49f6aa2009-10-28 13:01:38 +080026# But where this section will reside finally in vmlinx is undetermined at
27# this point. So we can't use this kind of offsets to record the final
28# address of this call site.
29#
30# The trick is to change the call offset referring the start of a section to
31# referring a function symbol in this section. During the link step, 'ld' will
32# compute the final address according to the information we record.
33#
Steven Rostedt8da38212008-08-14 15:45:07 -040034# e.g.
35#
Tim Abbott31b6e762009-04-30 20:06:11 -040036# .section ".sched.text", "ax"
Steven Rostedt8da38212008-08-14 15:45:07 -040037# [...]
Li Hongd49f6aa2009-10-28 13:01:38 +080038# func1:
39# [...]
40# call mcount (offset: 0x10)
Steven Rostedt8da38212008-08-14 15:45:07 -040041# [...]
42# ret
Li Hongd49f6aa2009-10-28 13:01:38 +080043# .globl fun2
44# func2: (offset: 0x20)
Steven Rostedt8da38212008-08-14 15:45:07 -040045# [...]
Li Hongd49f6aa2009-10-28 13:01:38 +080046# [...]
47# ret
48# func3:
49# [...]
50# call mcount (offset: 0x30)
Steven Rostedt8da38212008-08-14 15:45:07 -040051# [...]
52#
53# Both relocation offsets for the mcounts in the above example will be
Li Hongd49f6aa2009-10-28 13:01:38 +080054# offset from .sched.text. If we choose global symbol func2 as a reference and
55# make another file called tmp.s with the new offsets:
Steven Rostedt8da38212008-08-14 15:45:07 -040056#
57# .section __mcount_loc
Li Hongd49f6aa2009-10-28 13:01:38 +080058# .quad func2 - 0x10
59# .quad func2 + 0x10
Steven Rostedt8da38212008-08-14 15:45:07 -040060#
Li Hongd49f6aa2009-10-28 13:01:38 +080061# We can then compile this tmp.s into tmp.o, and link it back to the original
Steven Rostedt8da38212008-08-14 15:45:07 -040062# object.
63#
Li Hongd49f6aa2009-10-28 13:01:38 +080064# In our algorithm, we will choose the first global function we meet in this
65# section as the reference. But this gets hard if there is no global functions
66# in this section. In such a case we have to select a local one. E.g. func1:
Steven Rostedt8da38212008-08-14 15:45:07 -040067#
Tim Abbott31b6e762009-04-30 20:06:11 -040068# .section ".sched.text", "ax"
Li Hongd49f6aa2009-10-28 13:01:38 +080069# func1:
Steven Rostedt8da38212008-08-14 15:45:07 -040070# [...]
Li Hongd49f6aa2009-10-28 13:01:38 +080071# call mcount (offset: 0x10)
Steven Rostedt8da38212008-08-14 15:45:07 -040072# [...]
73# ret
Li Hongd49f6aa2009-10-28 13:01:38 +080074# func2:
Steven Rostedt8da38212008-08-14 15:45:07 -040075# [...]
Li Hongd49f6aa2009-10-28 13:01:38 +080076# call mcount (offset: 0x20)
Steven Rostedt8da38212008-08-14 15:45:07 -040077# [...]
Li Hongd49f6aa2009-10-28 13:01:38 +080078# .section "other.section"
Steven Rostedt8da38212008-08-14 15:45:07 -040079#
80# If we make the tmp.s the same as above, when we link together with
Li Hongd49f6aa2009-10-28 13:01:38 +080081# the original object, we will end up with two symbols for func1:
Steven Rostedt8da38212008-08-14 15:45:07 -040082# one local, one global. After final compile, we will end up with
Li Hongd49f6aa2009-10-28 13:01:38 +080083# an undefined reference to func1 or a wrong reference to another global
84# func1 in other files.
Steven Rostedt8da38212008-08-14 15:45:07 -040085#
86# Since local objects can reference local variables, we need to find
87# a way to make tmp.o reference the local objects of the original object
Li Hongd49f6aa2009-10-28 13:01:38 +080088# file after it is linked together. To do this, we convert func1
Steven Rostedt8da38212008-08-14 15:45:07 -040089# into a global symbol before linking tmp.o. Then after we link tmp.o
Li Hongd49f6aa2009-10-28 13:01:38 +080090# we will only have a single symbol for func1 that is global.
91# We can convert func1 back into a local symbol and we are done.
Steven Rostedt8da38212008-08-14 15:45:07 -040092#
93# Here are the steps we take:
94#
Li Hong306dcf42009-10-28 13:06:19 +080095# 1) Record all the local and weak symbols by using 'nm'
Steven Rostedt8da38212008-08-14 15:45:07 -040096# 2) Use objdump to find all the call site offsets and sections for
97# mcount.
98# 3) Compile the list into its own object.
99# 4) Do we have to deal with local functions? If not, go to step 8.
100# 5) Make an object that converts these local functions to global symbols
101# with objcopy.
102# 6) Link together this new object with the list object.
103# 7) Convert the local functions back to local symbols and rename
104# the result as the original object.
Steven Rostedt8da38212008-08-14 15:45:07 -0400105# 8) Link the object with the list object.
106# 9) Move the result back to the original object.
Steven Rostedt8da38212008-08-14 15:45:07 -0400107#
108
109use strict;
110
111my $P = $0;
112$P =~ s@.*/@@g;
113
114my $V = '0.1';
115
Wu Zhangjine6299d22009-11-20 20:34:31 +0800116if ($#ARGV != 11) {
117 print "usage: $P arch endian bits objdump objcopy cc ld nm rm mv is_module inputfile\n";
Steven Rostedt8da38212008-08-14 15:45:07 -0400118 print "version: $V\n";
119 exit(1);
120}
121
Wu Zhangjine6299d22009-11-20 20:34:31 +0800122my ($arch, $endian, $bits, $objdump, $objcopy, $cc,
Shaohua Li18c167f2009-01-12 10:00:51 +0800123 $ld, $nm, $rm, $mv, $is_module, $inputfile) = @ARGV;
Steven Rostedt8da38212008-08-14 15:45:07 -0400124
Shaohua Li25aac9d2009-01-09 11:29:40 +0800125# This file refers to mcount and shouldn't be ftraced, so lets' ignore it
Li Hongbdd3b052009-10-28 13:03:32 +0800126if ($inputfile =~ m,kernel/trace/ftrace\.o$,) {
Shaohua Li25aac9d2009-01-09 11:29:40 +0800127 exit(0);
128}
129
Steven Rostedt34698bc2008-10-23 09:32:58 -0400130# Acceptable sections to record.
131my %text_sections = (
132 ".text" => 1,
Liming Wangd144d5e2008-11-26 10:29:26 +0800133 ".sched.text" => 1,
134 ".spinlock.text" => 1,
Frederic Weisbeckera0343e82008-12-09 23:53:16 +0100135 ".irqentry.text" => 1,
Jiri Olsa4d828942009-10-13 16:33:54 -0400136 ".text.unlikely" => 1,
Steven Rostedt34698bc2008-10-23 09:32:58 -0400137);
138
Steven Rostedt8da38212008-08-14 15:45:07 -0400139$objdump = "objdump" if ((length $objdump) == 0);
140$objcopy = "objcopy" if ((length $objcopy) == 0);
141$cc = "gcc" if ((length $cc) == 0);
142$ld = "ld" if ((length $ld) == 0);
143$nm = "nm" if ((length $nm) == 0);
144$rm = "rm" if ((length $rm) == 0);
145$mv = "mv" if ((length $mv) == 0);
146
147#print STDERR "running: $P '$arch' '$objdump' '$objcopy' '$cc' '$ld' " .
148# "'$nm' '$rm' '$mv' '$inputfile'\n";
149
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400150my %locals; # List of local (static) functions
151my %weak; # List of weak functions
152my %convert; # List of local functions used that needs conversion
Steven Rostedt8da38212008-08-14 15:45:07 -0400153
154my $type;
Li Hong306dcf42009-10-28 13:06:19 +0800155my $local_regex; # Match a local function (return function)
156my $weak_regex; # Match a weak function (return function)
Steven Rostedt8da38212008-08-14 15:45:07 -0400157my $section_regex; # Find the start of a section
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400158my $function_regex; # Find the name of a function
159 # (return offset and func name)
Steven Rostedt8da38212008-08-14 15:45:07 -0400160my $mcount_regex; # Find the call site to mcount (return offset)
Matt Fleming3a3d04a2008-11-20 21:49:52 +0000161my $alignment; # The .align value to use for $mcount_section
Jim Radforde58918a2008-11-20 19:48:39 -0800162my $section_type; # Section header plus possible alignment command
Li Hong7b7edc22009-10-28 13:04:21 +0800163my $can_use_local = 0; # If we can use local function references
164
Steven Rostedt638adb02009-11-17 10:48:25 -0500165# Shut up recordmcount if user has older objcopy
166my $quiet_recordmcount = ".tmp_quiet_recordmcount";
167my $print_warning = 1;
168$print_warning = 0 if ( -f $quiet_recordmcount);
169
Li Hong7b7edc22009-10-28 13:04:21 +0800170##
171# check_objcopy - whether objcopy supports --globalize-symbols
172#
173# --globalize-symbols came out in 2.17, we must test the version
174# of objcopy, and if it is less than 2.17, then we can not
175# record local functions.
176sub check_objcopy
177{
178 open (IN, "$objcopy --version |") or die "error running $objcopy";
179 while (<IN>) {
180 if (/objcopy.*\s(\d+)\.(\d+)/) {
181 $can_use_local = 1 if ($1 > 2 || ($1 == 2 && $2 >= 17));
182 last;
183 }
184 }
185 close (IN);
186
Steven Rostedt638adb02009-11-17 10:48:25 -0500187 if (!$can_use_local && $print_warning) {
Li Hong7b7edc22009-10-28 13:04:21 +0800188 print STDERR "WARNING: could not find objcopy version or version " .
189 "is less than 2.17.\n" .
Steven Rostedt638adb02009-11-17 10:48:25 -0500190 "\tLocal function references are disabled.\n";
191 open (QUIET, ">$quiet_recordmcount");
192 printf QUIET "Disables the warning from recordmcount.pl\n";
193 close QUIET;
Li Hong7b7edc22009-10-28 13:04:21 +0800194 }
195}
Steven Rostedt8da38212008-08-14 15:45:07 -0400196
Jan Kiszkab82a4042010-01-11 11:31:44 +0100197if ($arch =~ /(x86(_64)?)|(i386)/) {
Steven Rostedtdce9d182008-10-23 09:32:57 -0400198 if ($bits == 64) {
199 $arch = "x86_64";
200 } else {
201 $arch = "i386";
202 }
203}
204
Steven Rostedtc204f722008-11-20 15:07:34 -0500205#
206# We base the defaults off of i386, the other archs may
207# feel free to change them in the below if statements.
208#
Li Hong306dcf42009-10-28 13:06:19 +0800209$local_regex = "^[0-9a-fA-F]+\\s+t\\s+(\\S+)";
210$weak_regex = "^[0-9a-fA-F]+\\s+([wW])\\s+(\\S+)";
Steven Rostedtc204f722008-11-20 15:07:34 -0500211$section_regex = "Disassembly of section\\s+(\\S+):";
212$function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
213$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount\$";
Jim Radforde58918a2008-11-20 19:48:39 -0800214$section_type = '@progbits';
Steven Rostedtc204f722008-11-20 15:07:34 -0500215$type = ".long";
216
Steven Rostedt8da38212008-08-14 15:45:07 -0400217if ($arch eq "x86_64") {
Steven Rostedt8da38212008-08-14 15:45:07 -0400218 $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount([+-]0x[0-9a-zA-Z]+)?\$";
219 $type = ".quad";
Matt Fleming7d5222a2008-11-07 13:26:25 +0000220 $alignment = 8;
Steven Rostedtd74fcd12008-08-15 11:40:24 -0400221
222 # force flags for this arch
223 $ld .= " -m elf_x86_64";
224 $objdump .= " -M x86-64";
225 $objcopy .= " -O elf64-x86-64";
226 $cc .= " -m64";
227
Steven Rostedt8da38212008-08-14 15:45:07 -0400228} elsif ($arch eq "i386") {
Matt Fleming7d5222a2008-11-07 13:26:25 +0000229 $alignment = 4;
Steven Rostedtd74fcd12008-08-15 11:40:24 -0400230
231 # force flags for this arch
232 $ld .= " -m elf_i386";
233 $objdump .= " -M i386";
234 $objcopy .= " -O elf32-i386";
235 $cc .= " -m32";
236
Heiko Carstensdfd9f7a2009-06-12 10:26:44 +0200237} elsif ($arch eq "s390" && $bits == 32) {
238 $mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_390_32\\s+_mcount\$";
239 $alignment = 4;
240 $ld .= " -m elf_s390";
241 $cc .= " -m31";
242
243} elsif ($arch eq "s390" && $bits == 64) {
244 $mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_390_(PC|PLT)32DBL\\s+_mcount\\+0x2\$";
245 $alignment = 8;
246 $type = ".quad";
247 $ld .= " -m elf64_s390";
248 $cc .= " -m64";
249
Matt Fleming0da85c02008-11-12 20:11:47 +0900250} elsif ($arch eq "sh") {
Matt Fleming3a3d04a2008-11-20 21:49:52 +0000251 $alignment = 2;
Matt Fleming0da85c02008-11-12 20:11:47 +0900252
253 # force flags for this arch
254 $ld .= " -m shlelf_linux";
255 $objcopy .= " -O elf32-sh-linux";
256 $cc .= " -m32";
257
Steven Rostedt42e007d2008-11-20 07:16:16 -0800258} elsif ($arch eq "powerpc") {
Li Hong306dcf42009-10-28 13:06:19 +0800259 $local_regex = "^[0-9a-fA-F]+\\s+t\\s+(\\.?\\S+)";
Steven Rostedt42e007d2008-11-20 07:16:16 -0800260 $function_regex = "^([0-9a-fA-F]+)\\s+<(\\.?.*?)>:";
261 $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s\\.?_mcount\$";
Steven Rostedtc204f722008-11-20 15:07:34 -0500262
Steven Rostedt42e007d2008-11-20 07:16:16 -0800263 if ($bits == 64) {
264 $type = ".quad";
Steven Rostedt42e007d2008-11-20 07:16:16 -0800265 }
266
Jim Radforde58918a2008-11-20 19:48:39 -0800267} elsif ($arch eq "arm") {
268 $alignment = 2;
269 $section_type = '%progbits';
270
Shaohua Li418071e2009-01-09 11:29:44 +0800271} elsif ($arch eq "ia64") {
272 $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$";
273 $type = "data8";
274
275 if ($is_module eq "0") {
276 $cc .= " -mconstant-gp";
277 }
David S. Miller9be12f92009-06-13 01:03:24 -0700278} elsif ($arch eq "sparc64") {
279 # In the objdump output there are giblets like:
280 # 0000000000000000 <igmp_net_exit-0x18>:
281 # As there's some data blobs that get emitted into the
282 # text section before the first instructions and the first
283 # real symbols. We don't want to match that, so to combat
284 # this we use '\w' so we'll match just plain symbol names,
285 # and not those that also include hex offsets inside of the
286 # '<>' brackets. Actually the generic function_regex setting
287 # could safely use this too.
288 $function_regex = "^([0-9a-fA-F]+)\\s+<(\\w*?)>:";
289
290 # Sparc64 calls '_mcount' instead of plain 'mcount'.
291 $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$";
292
293 $alignment = 8;
294 $type = ".xword";
295 $ld .= " -m elf64_sparc";
296 $cc .= " -m64";
297 $objcopy .= " -O elf64-sparc";
Wu Zhangjin538f1952009-11-20 20:34:32 +0800298} elsif ($arch eq "mips") {
299 # To enable module support, we need to enable the -mlong-calls option
300 # of gcc for module, after using this option, we can not get the real
301 # offset of the calling to _mcount, but the offset of the lui
302 # instruction or the addiu one. herein, we record the address of the
303 # first one, and then we can replace this instruction by a branch
304 # instruction to jump over the profiling function to filter the
305 # indicated functions, or swith back to the lui instruction to trace
306 # them, which means dynamic tracing.
307 #
308 # c: 3c030000 lui v1,0x0
309 # c: R_MIPS_HI16 _mcount
310 # c: R_MIPS_NONE *ABS*
311 # c: R_MIPS_NONE *ABS*
312 # 10: 64630000 daddiu v1,v1,0
313 # 10: R_MIPS_LO16 _mcount
314 # 10: R_MIPS_NONE *ABS*
315 # 10: R_MIPS_NONE *ABS*
316 # 14: 03e0082d move at,ra
317 # 18: 0060f809 jalr v1
318 #
319 # for the kernel:
320 #
321 # 10: 03e0082d move at,ra
322 # 14: 0c000000 jal 0 <loongson_halt>
323 # 14: R_MIPS_26 _mcount
324 # 14: R_MIPS_NONE *ABS*
325 # 14: R_MIPS_NONE *ABS*
326 # 18: 00020021 nop
327 if ($is_module eq "0") {
328 $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$";
329 } else {
330 $mcount_regex = "^\\s*([0-9a-fA-F]+): R_MIPS_HI16\\s+_mcount\$";
331 }
332 $objdump .= " -Melf-trad".$endian."mips ";
333
334 if ($endian eq "big") {
335 $endian = " -EB ";
336 $ld .= " -melf".$bits."btsmip";
337 } else {
338 $endian = " -EL ";
339 $ld .= " -melf".$bits."ltsmip";
340 }
341
342 $cc .= " -mno-abicalls -fno-pic -mabi=" . $bits . $endian;
343 $ld .= $endian;
344
345 if ($bits == 64) {
346 $function_regex =
347 "^([0-9a-fA-F]+)\\s+<(.|[^\$]L.*?|\$[^L].*?|[^\$][^L].*?)>:";
348 $type = ".dword";
349 }
Michal Simek7d241ff2009-12-10 14:15:44 +0100350} elsif ($arch eq "microblaze") {
351 # Microblaze calls '_mcount' instead of plain 'mcount'.
352 $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$";
Steven Rostedt8da38212008-08-14 15:45:07 -0400353} else {
354 die "Arch $arch is not supported with CONFIG_FTRACE_MCOUNT_RECORD";
355}
356
357my $text_found = 0;
358my $read_function = 0;
359my $opened = 0;
Steven Rostedt8da38212008-08-14 15:45:07 -0400360my $mcount_section = "__mcount_loc";
361
362my $dirname;
363my $filename;
364my $prefix;
365my $ext;
366
367if ($inputfile =~ m,^(.*)/([^/]*)$,) {
368 $dirname = $1;
369 $filename = $2;
370} else {
371 $dirname = ".";
372 $filename = $inputfile;
373}
374
375if ($filename =~ m,^(.*)(\.\S),) {
376 $prefix = $1;
377 $ext = $2;
378} else {
379 $prefix = $filename;
380 $ext = "";
381}
382
383my $mcount_s = $dirname . "/.tmp_mc_" . $prefix . ".s";
384my $mcount_o = $dirname . "/.tmp_mc_" . $prefix . ".o";
385
Li Hong7b7edc22009-10-28 13:04:21 +0800386check_objcopy();
Steven Rostedtf2f84582008-08-25 14:52:11 -0400387
Steven Rostedtf2f84582008-08-25 14:52:11 -0400388#
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400389# Step 1: find all the local (static functions) and weak symbols.
Li Hong306dcf42009-10-28 13:06:19 +0800390# 't' is local, 'w/W' is weak
Steven Rostedt8da38212008-08-14 15:45:07 -0400391#
392open (IN, "$nm $inputfile|") || die "error running $nm";
393while (<IN>) {
Li Hong306dcf42009-10-28 13:06:19 +0800394 if (/$local_regex/) {
Steven Rostedt8da38212008-08-14 15:45:07 -0400395 $locals{$1} = 1;
Li Hong306dcf42009-10-28 13:06:19 +0800396 } elsif (/$weak_regex/) {
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400397 $weak{$2} = $1;
Steven Rostedt8da38212008-08-14 15:45:07 -0400398 }
399}
400close(IN);
401
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400402my @offsets; # Array of offsets of mcount callers
403my $ref_func; # reference function to use for offsets
404my $offset = 0; # offset of ref_func to section beginning
405
406##
407# update_funcs - print out the current mcount callers
408#
409# Go through the list of offsets to callers and write them to
410# the output file in a format that can be read by an assembler.
411#
412sub update_funcs
413{
Li Hong60928582009-10-28 13:07:03 +0800414 return unless ($ref_func and @offsets);
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400415
Li Hongc4b8ac22009-10-28 13:07:43 +0800416 # Sanity check on weak function. A weak function may be overwritten by
417 # another function of the same name, making all these offsets incorrect.
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400418 if (defined $weak{$ref_func}) {
Li Hongc4b8ac22009-10-28 13:07:43 +0800419 die "$inputfile: ERROR: referencing weak function" .
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400420 " $ref_func for mcount\n";
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400421 }
422
423 # is this function static? If so, note this fact.
424 if (defined $locals{$ref_func}) {
Steven Rostedtf2f84582008-08-25 14:52:11 -0400425
426 # only use locals if objcopy supports globalize-symbols
Li Hong7b7edc22009-10-28 13:04:21 +0800427 if (!$can_use_local) {
Steven Rostedtf2f84582008-08-25 14:52:11 -0400428 return;
429 }
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400430 $convert{$ref_func} = 1;
431 }
432
433 # Loop through all the mcount caller offsets and print a reference
434 # to the caller based from the ref_func.
435 for (my $i=0; $i <= $#offsets; $i++) {
436 if (!$opened) {
437 open(FILE, ">$mcount_s") || die "can't create $mcount_s\n";
438 $opened = 1;
Jim Radforde58918a2008-11-20 19:48:39 -0800439 print FILE "\t.section $mcount_section,\"a\",$section_type\n";
Steven Rostedt42e007d2008-11-20 07:16:16 -0800440 print FILE "\t.align $alignment\n" if (defined($alignment));
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400441 }
442 printf FILE "\t%s %s + %d\n", $type, $ref_func, $offsets[$i] - $offset;
443 }
444}
445
Steven Rostedt8da38212008-08-14 15:45:07 -0400446#
447# Step 2: find the sections and mcount call sites
448#
Steven Rostedtb43f7092009-01-16 23:18:31 -0500449open(IN, "$objdump -hdr $inputfile|") || die "error running $objdump";
Steven Rostedt8da38212008-08-14 15:45:07 -0400450
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400451my $text;
452
Li Hongdb24c7d2009-10-28 13:05:23 +0800453
454# read headers first
Steven Rostedtb43f7092009-01-16 23:18:31 -0500455my $read_headers = 1;
456
Steven Rostedt8da38212008-08-14 15:45:07 -0400457while (<IN>) {
Li Hongdb24c7d2009-10-28 13:05:23 +0800458
459 if ($read_headers && /$mcount_section/) {
460 #
461 # Somehow the make process can execute this script on an
462 # object twice. If it does, we would duplicate the mcount
463 # section and it will cause the function tracer self test
464 # to fail. Check if the mcount section exists, and if it does,
465 # warn and exit.
466 #
467 print STDERR "ERROR: $mcount_section already in $inputfile\n" .
468 "\tThis may be an indication that your build is corrupted.\n" .
469 "\tDelete $inputfile and try again. If the same object file\n" .
470 "\tstill causes an issue, then disable CONFIG_DYNAMIC_FTRACE.\n";
471 exit(-1);
472 }
473
Steven Rostedt8da38212008-08-14 15:45:07 -0400474 # is it a section?
475 if (/$section_regex/) {
Steven Rostedtb43f7092009-01-16 23:18:31 -0500476 $read_headers = 0;
Steven Rostedt34698bc2008-10-23 09:32:58 -0400477
478 # Only record text sections that we know are safe
479 if (defined($text_sections{$1})) {
480 $read_function = 1;
481 } else {
482 $read_function = 0;
483 }
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400484 # print out any recorded offsets
Li Hong60928582009-10-28 13:07:03 +0800485 update_funcs();
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400486
487 # reset all markers and arrays
Steven Rostedt8da38212008-08-14 15:45:07 -0400488 $text_found = 0;
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400489 undef($ref_func);
490 undef(@offsets);
491
Steven Rostedt8da38212008-08-14 15:45:07 -0400492 # section found, now is this a start of a function?
493 } elsif ($read_function && /$function_regex/) {
Steven Rostedt8da38212008-08-14 15:45:07 -0400494 $text_found = 1;
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400495 $text = $2;
496
497 # if this is either a local function or a weak function
498 # keep looking for functions that are global that
499 # we can use safely.
500 if (!defined($locals{$text}) && !defined($weak{$text})) {
501 $ref_func = $text;
502 $read_function = 0;
Matt Flemingbd171d52009-07-23 17:16:15 +0100503 $offset = hex $1;
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400504 } else {
505 # if we already have a function, and this is weak, skip it
Steven Rostedt3f6e9682009-08-05 22:00:14 -0400506 if (!defined($ref_func) && !defined($weak{$text}) &&
507 # PPC64 can have symbols that start with .L and
508 # gcc considers these special. Don't use them!
509 $text !~ /^\.L/) {
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400510 $ref_func = $text;
Matt Flemingbd171d52009-07-23 17:16:15 +0100511 $offset = hex $1;
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400512 }
Steven Rostedt8da38212008-08-14 15:45:07 -0400513 }
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400514 }
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400515 # is this a call site to mcount? If so, record it to print later
516 if ($text_found && /$mcount_regex/) {
517 $offsets[$#offsets + 1] = hex $1;
Steven Rostedt8da38212008-08-14 15:45:07 -0400518 }
519}
520
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400521# dump out anymore offsets that may have been found
Li Hong60928582009-10-28 13:07:03 +0800522update_funcs();
Steven Rostedt8feff1c2008-08-20 10:07:35 -0400523
Steven Rostedt8da38212008-08-14 15:45:07 -0400524# If we did not find any mcount callers, we are done (do nothing).
525if (!$opened) {
526 exit(0);
527}
528
529close(FILE);
530
531#
532# Step 3: Compile the file that holds the list of call sites to mcount.
533#
534`$cc -o $mcount_o -c $mcount_s`;
535
536my @converts = keys %convert;
537
538#
539# Step 4: Do we have sections that started with local functions?
540#
541if ($#converts >= 0) {
542 my $globallist = "";
543 my $locallist = "";
544
545 foreach my $con (@converts) {
546 $globallist .= " --globalize-symbol $con";
547 $locallist .= " --localize-symbol $con";
548 }
549
550 my $globalobj = $dirname . "/.tmp_gl_" . $filename;
551 my $globalmix = $dirname . "/.tmp_mx_" . $filename;
552
553 #
554 # Step 5: set up each local function as a global
555 #
556 `$objcopy $globallist $inputfile $globalobj`;
557
558 #
559 # Step 6: Link the global version to our list.
560 #
561 `$ld -r $globalobj $mcount_o -o $globalmix`;
562
563 #
564 # Step 7: Convert the local functions back into local symbols
565 #
566 `$objcopy $locallist $globalmix $inputfile`;
567
568 # Remove the temp files
569 `$rm $globalobj $globalmix`;
570
571} else {
572
573 my $mix = $dirname . "/.tmp_mx_" . $filename;
574
575 #
576 # Step 8: Link the object with our list of call sites object.
577 #
578 `$ld -r $inputfile $mcount_o -o $mix`;
579
580 #
581 # Step 9: Move the result back to the original object.
582 #
583 `$mv $mix $inputfile`;
584}
585
586# Clean up the temp files
587`$rm $mcount_o $mcount_s`;
588
589exit(0);