Commit | Line | Data |
---|---|---|
8da3821b SR |
1 | #!/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 | # | |
d49f6aa7 LH |
9 | # 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. | |
8da3821b SR |
16 | # |
17 | # This is no easy feat. This script is called just after the original | |
18 | # object is compiled and before it is linked. | |
19 | # | |
d49f6aa7 LH |
20 | # 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. | |
25 | # | |
26 | # 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. | |
8da3821b | 33 | # |
8da3821b SR |
34 | # e.g. |
35 | # | |
31b6e76e | 36 | # .section ".sched.text", "ax" |
8da3821b | 37 | # [...] |
d49f6aa7 LH |
38 | # func1: |
39 | # [...] | |
40 | # call mcount (offset: 0x10) | |
41 | # [...] | |
42 | # ret | |
43 | # .globl fun2 | |
44 | # func2: (offset: 0x20) | |
45 | # [...] | |
8da3821b SR |
46 | # [...] |
47 | # ret | |
d49f6aa7 | 48 | # func3: |
8da3821b | 49 | # [...] |
d49f6aa7 | 50 | # call mcount (offset: 0x30) |
8da3821b SR |
51 | # [...] |
52 | # | |
53 | # Both relocation offsets for the mcounts in the above example will be | |
d49f6aa7 LH |
54 | # 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: | |
8da3821b SR |
56 | # |
57 | # .section __mcount_loc | |
d49f6aa7 LH |
58 | # .quad func2 - 0x10 |
59 | # .quad func2 + 0x10 | |
8da3821b | 60 | # |
d49f6aa7 | 61 | # We can then compile this tmp.s into tmp.o, and link it back to the original |
8da3821b SR |
62 | # object. |
63 | # | |
d49f6aa7 LH |
64 | # 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: | |
8da3821b | 67 | # |
31b6e76e | 68 | # .section ".sched.text", "ax" |
d49f6aa7 | 69 | # func1: |
8da3821b | 70 | # [...] |
d49f6aa7 | 71 | # call mcount (offset: 0x10) |
8da3821b SR |
72 | # [...] |
73 | # ret | |
d49f6aa7 | 74 | # func2: |
8da3821b | 75 | # [...] |
d49f6aa7 | 76 | # call mcount (offset: 0x20) |
8da3821b | 77 | # [...] |
d49f6aa7 | 78 | # .section "other.section" |
8da3821b SR |
79 | # |
80 | # If we make the tmp.s the same as above, when we link together with | |
d49f6aa7 | 81 | # the original object, we will end up with two symbols for func1: |
8da3821b | 82 | # one local, one global. After final compile, we will end up with |
d49f6aa7 LH |
83 | # an undefined reference to func1 or a wrong reference to another global |
84 | # func1 in other files. | |
8da3821b SR |
85 | # |
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 | |
d49f6aa7 | 88 | # file after it is linked together. To do this, we convert func1 |
8da3821b | 89 | # into a global symbol before linking tmp.o. Then after we link tmp.o |
d49f6aa7 LH |
90 | # 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. | |
8da3821b SR |
92 | # |
93 | # Here are the steps we take: | |
94 | # | |
306dcf47 | 95 | # 1) Record all the local and weak symbols by using 'nm' |
8da3821b SR |
96 | # 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. | |
8da3821b SR |
105 | # 8) Link the object with the list object. |
106 | # 9) Move the result back to the original object. | |
8da3821b SR |
107 | # |
108 | ||
109 | use strict; | |
110 | ||
111 | my $P = $0; | |
112 | $P =~ s@.*/@@g; | |
113 | ||
114 | my $V = '0.1'; | |
115 | ||
e6299d26 WZ |
116 | if ($#ARGV != 11) { |
117 | print "usage: $P arch endian bits objdump objcopy cc ld nm rm mv is_module inputfile\n"; | |
8da3821b SR |
118 | print "version: $V\n"; |
119 | exit(1); | |
120 | } | |
121 | ||
e6299d26 | 122 | my ($arch, $endian, $bits, $objdump, $objcopy, $cc, |
18c167fd | 123 | $ld, $nm, $rm, $mv, $is_module, $inputfile) = @ARGV; |
8da3821b | 124 | |
25aac9dc | 125 | # This file refers to mcount and shouldn't be ftraced, so lets' ignore it |
bdd3b052 | 126 | if ($inputfile =~ m,kernel/trace/ftrace\.o$,) { |
25aac9dc SL |
127 | exit(0); |
128 | } | |
129 | ||
34698bcb SR |
130 | # Acceptable sections to record. |
131 | my %text_sections = ( | |
132 | ".text" => 1, | |
1274a9c2 | 133 | ".ref.text" => 1, |
d144d5ee LW |
134 | ".sched.text" => 1, |
135 | ".spinlock.text" => 1, | |
a0343e82 | 136 | ".irqentry.text" => 1, |
9f087e76 | 137 | ".kprobes.text" => 1, |
4d828949 | 138 | ".text.unlikely" => 1, |
34698bcb SR |
139 | ); |
140 | ||
dfaa9e2c WS |
141 | # Note: we are nice to C-programmers here, thus we skip the '||='-idiom. |
142 | $objdump = 'objdump' if (!$objdump); | |
143 | $objcopy = 'objcopy' if (!$objcopy); | |
144 | $cc = 'gcc' if (!$cc); | |
145 | $ld = 'ld' if (!$ld); | |
146 | $nm = 'nm' if (!$nm); | |
147 | $rm = 'rm' if (!$rm); | |
148 | $mv = 'mv' if (!$mv); | |
8da3821b SR |
149 | |
150 | #print STDERR "running: $P '$arch' '$objdump' '$objcopy' '$cc' '$ld' " . | |
151 | # "'$nm' '$rm' '$mv' '$inputfile'\n"; | |
152 | ||
8feff1ca SR |
153 | my %locals; # List of local (static) functions |
154 | my %weak; # List of weak functions | |
155 | my %convert; # List of local functions used that needs conversion | |
8da3821b SR |
156 | |
157 | my $type; | |
306dcf47 LH |
158 | my $local_regex; # Match a local function (return function) |
159 | my $weak_regex; # Match a weak function (return function) | |
8da3821b | 160 | my $section_regex; # Find the start of a section |
8feff1ca SR |
161 | my $function_regex; # Find the name of a function |
162 | # (return offset and func name) | |
8da3821b | 163 | my $mcount_regex; # Find the call site to mcount (return offset) |
465c6cca | 164 | my $mcount_adjust; # Address adjustment to mcount offset |
3a3d04ae | 165 | my $alignment; # The .align value to use for $mcount_section |
e58918ab | 166 | my $section_type; # Section header plus possible alignment command |
7b7edc27 LH |
167 | my $can_use_local = 0; # If we can use local function references |
168 | ||
638adb05 SR |
169 | # Shut up recordmcount if user has older objcopy |
170 | my $quiet_recordmcount = ".tmp_quiet_recordmcount"; | |
171 | my $print_warning = 1; | |
172 | $print_warning = 0 if ( -f $quiet_recordmcount); | |
173 | ||
7b7edc27 LH |
174 | ## |
175 | # check_objcopy - whether objcopy supports --globalize-symbols | |
176 | # | |
177 | # --globalize-symbols came out in 2.17, we must test the version | |
178 | # of objcopy, and if it is less than 2.17, then we can not | |
179 | # record local functions. | |
180 | sub check_objcopy | |
181 | { | |
182 | open (IN, "$objcopy --version |") or die "error running $objcopy"; | |
183 | while (<IN>) { | |
184 | if (/objcopy.*\s(\d+)\.(\d+)/) { | |
185 | $can_use_local = 1 if ($1 > 2 || ($1 == 2 && $2 >= 17)); | |
186 | last; | |
187 | } | |
188 | } | |
189 | close (IN); | |
190 | ||
638adb05 | 191 | if (!$can_use_local && $print_warning) { |
7b7edc27 LH |
192 | print STDERR "WARNING: could not find objcopy version or version " . |
193 | "is less than 2.17.\n" . | |
638adb05 SR |
194 | "\tLocal function references are disabled.\n"; |
195 | open (QUIET, ">$quiet_recordmcount"); | |
196 | printf QUIET "Disables the warning from recordmcount.pl\n"; | |
197 | close QUIET; | |
7b7edc27 LH |
198 | } |
199 | } | |
8da3821b | 200 | |
b82a4045 | 201 | if ($arch =~ /(x86(_64)?)|(i386)/) { |
dce9d18a SR |
202 | if ($bits == 64) { |
203 | $arch = "x86_64"; | |
204 | } else { | |
205 | $arch = "i386"; | |
206 | } | |
207 | } | |
208 | ||
c204f726 SR |
209 | # |
210 | # We base the defaults off of i386, the other archs may | |
211 | # feel free to change them in the below if statements. | |
212 | # | |
306dcf47 LH |
213 | $local_regex = "^[0-9a-fA-F]+\\s+t\\s+(\\S+)"; |
214 | $weak_regex = "^[0-9a-fA-F]+\\s+([wW])\\s+(\\S+)"; | |
c204f726 SR |
215 | $section_regex = "Disassembly of section\\s+(\\S+):"; |
216 | $function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:"; | |
f02b625d | 217 | $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s(mcount|__fentry__)\$"; |
e58918ab | 218 | $section_type = '@progbits'; |
465c6cca | 219 | $mcount_adjust = 0; |
c204f726 SR |
220 | $type = ".long"; |
221 | ||
8da3821b | 222 | if ($arch eq "x86_64") { |
f02b625d | 223 | $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s(mcount|__fentry__)([+-]0x[0-9a-zA-Z]+)?\$"; |
8da3821b | 224 | $type = ".quad"; |
7d5222a6 | 225 | $alignment = 8; |
521ccb5c | 226 | $mcount_adjust = -1; |
d74fcd1e SR |
227 | |
228 | # force flags for this arch | |
229 | $ld .= " -m elf_x86_64"; | |
230 | $objdump .= " -M x86-64"; | |
231 | $objcopy .= " -O elf64-x86-64"; | |
232 | $cc .= " -m64"; | |
233 | ||
8da3821b | 234 | } elsif ($arch eq "i386") { |
7d5222a6 | 235 | $alignment = 4; |
521ccb5c | 236 | $mcount_adjust = -1; |
d74fcd1e SR |
237 | |
238 | # force flags for this arch | |
239 | $ld .= " -m elf_i386"; | |
240 | $objdump .= " -M i386"; | |
241 | $objcopy .= " -O elf32-i386"; | |
242 | $cc .= " -m32"; | |
243 | ||
dfd9f7ab HC |
244 | } elsif ($arch eq "s390" && $bits == 64) { |
245 | $mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_390_(PC|PLT)32DBL\\s+_mcount\\+0x2\$"; | |
f2963886 | 246 | $mcount_adjust = -8; |
dfd9f7ab HC |
247 | $alignment = 8; |
248 | $type = ".quad"; | |
249 | $ld .= " -m elf64_s390"; | |
250 | $cc .= " -m64"; | |
251 | ||
0da85c09 | 252 | } elsif ($arch eq "sh") { |
3a3d04ae | 253 | $alignment = 2; |
0da85c09 MF |
254 | |
255 | # force flags for this arch | |
256 | $ld .= " -m shlelf_linux"; | |
257 | $objcopy .= " -O elf32-sh-linux"; | |
258 | $cc .= " -m32"; | |
259 | ||
42e007d0 | 260 | } elsif ($arch eq "powerpc") { |
306dcf47 | 261 | $local_regex = "^[0-9a-fA-F]+\\s+t\\s+(\\.?\\S+)"; |
42e007d0 SR |
262 | $function_regex = "^([0-9a-fA-F]+)\\s+<(\\.?.*?)>:"; |
263 | $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s\\.?_mcount\$"; | |
c204f726 | 264 | |
42e007d0 SR |
265 | if ($bits == 64) { |
266 | $type = ".quad"; | |
42e007d0 SR |
267 | } |
268 | ||
e58918ab JR |
269 | } elsif ($arch eq "arm") { |
270 | $alignment = 2; | |
271 | $section_type = '%progbits'; | |
72dc43a9 | 272 | $mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_ARM_(CALL|PC24|THM_CALL)" . |
3b6c223b | 273 | "\\s+(__gnu_mcount_nc|mcount)\$"; |
e58918ab | 274 | |
af64d2aa AT |
275 | } elsif ($arch eq "arm64") { |
276 | $alignment = 3; | |
277 | $section_type = '%progbits'; | |
278 | $mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_AARCH64_CALL26\\s+_mcount\$"; | |
279 | $type = ".quad"; | |
418071eb SL |
280 | } elsif ($arch eq "ia64") { |
281 | $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$"; | |
282 | $type = "data8"; | |
283 | ||
284 | if ($is_module eq "0") { | |
285 | $cc .= " -mconstant-gp"; | |
286 | } | |
9be12f9b DM |
287 | } elsif ($arch eq "sparc64") { |
288 | # In the objdump output there are giblets like: | |
289 | # 0000000000000000 <igmp_net_exit-0x18>: | |
290 | # As there's some data blobs that get emitted into the | |
291 | # text section before the first instructions and the first | |
292 | # real symbols. We don't want to match that, so to combat | |
293 | # this we use '\w' so we'll match just plain symbol names, | |
294 | # and not those that also include hex offsets inside of the | |
295 | # '<>' brackets. Actually the generic function_regex setting | |
296 | # could safely use this too. | |
297 | $function_regex = "^([0-9a-fA-F]+)\\s+<(\\w*?)>:"; | |
298 | ||
299 | # Sparc64 calls '_mcount' instead of plain 'mcount'. | |
300 | $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$"; | |
301 | ||
302 | $alignment = 8; | |
303 | $type = ".xword"; | |
304 | $ld .= " -m elf64_sparc"; | |
305 | $cc .= " -m64"; | |
306 | $objcopy .= " -O elf64-sparc"; | |
538f1952 WZ |
307 | } elsif ($arch eq "mips") { |
308 | # To enable module support, we need to enable the -mlong-calls option | |
309 | # of gcc for module, after using this option, we can not get the real | |
310 | # offset of the calling to _mcount, but the offset of the lui | |
311 | # instruction or the addiu one. herein, we record the address of the | |
312 | # first one, and then we can replace this instruction by a branch | |
313 | # instruction to jump over the profiling function to filter the | |
314 | # indicated functions, or swith back to the lui instruction to trace | |
315 | # them, which means dynamic tracing. | |
316 | # | |
317 | # c: 3c030000 lui v1,0x0 | |
318 | # c: R_MIPS_HI16 _mcount | |
319 | # c: R_MIPS_NONE *ABS* | |
320 | # c: R_MIPS_NONE *ABS* | |
321 | # 10: 64630000 daddiu v1,v1,0 | |
322 | # 10: R_MIPS_LO16 _mcount | |
323 | # 10: R_MIPS_NONE *ABS* | |
324 | # 10: R_MIPS_NONE *ABS* | |
325 | # 14: 03e0082d move at,ra | |
326 | # 18: 0060f809 jalr v1 | |
327 | # | |
328 | # for the kernel: | |
329 | # | |
330 | # 10: 03e0082d move at,ra | |
331 | # 14: 0c000000 jal 0 <loongson_halt> | |
332 | # 14: R_MIPS_26 _mcount | |
333 | # 14: R_MIPS_NONE *ABS* | |
334 | # 14: R_MIPS_NONE *ABS* | |
335 | # 18: 00020021 nop | |
336 | if ($is_module eq "0") { | |
a484e54f | 337 | $mcount_regex = "^\\s*([0-9a-fA-F]+): R_MIPS_26\\s+_mcount\$"; |
538f1952 WZ |
338 | } else { |
339 | $mcount_regex = "^\\s*([0-9a-fA-F]+): R_MIPS_HI16\\s+_mcount\$"; | |
340 | } | |
341 | $objdump .= " -Melf-trad".$endian."mips "; | |
342 | ||
343 | if ($endian eq "big") { | |
344 | $endian = " -EB "; | |
345 | $ld .= " -melf".$bits."btsmip"; | |
346 | } else { | |
347 | $endian = " -EL "; | |
348 | $ld .= " -melf".$bits."ltsmip"; | |
349 | } | |
350 | ||
351 | $cc .= " -mno-abicalls -fno-pic -mabi=" . $bits . $endian; | |
352 | $ld .= $endian; | |
353 | ||
354 | if ($bits == 64) { | |
355 | $function_regex = | |
356 | "^([0-9a-fA-F]+)\\s+<(.|[^\$]L.*?|\$[^L].*?|[^\$][^L].*?)>:"; | |
357 | $type = ".dword"; | |
358 | } | |
7d241ff0 MS |
359 | } elsif ($arch eq "microblaze") { |
360 | # Microblaze calls '_mcount' instead of plain 'mcount'. | |
361 | $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$"; | |
465c6cca MF |
362 | } elsif ($arch eq "blackfin") { |
363 | $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s__mcount\$"; | |
364 | $mcount_adjust = -4; | |
2d8eedad TL |
365 | } elsif ($arch eq "tilegx" || $arch eq "tile") { |
366 | # Default to the newer TILE-Gx architecture if only "tile" is given. | |
a61fd5e3 TL |
367 | $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s__mcount\$"; |
368 | $type = ".quad"; | |
369 | $alignment = 8; | |
8da3821b SR |
370 | } else { |
371 | die "Arch $arch is not supported with CONFIG_FTRACE_MCOUNT_RECORD"; | |
372 | } | |
373 | ||
374 | my $text_found = 0; | |
375 | my $read_function = 0; | |
376 | my $opened = 0; | |
8da3821b SR |
377 | my $mcount_section = "__mcount_loc"; |
378 | ||
379 | my $dirname; | |
380 | my $filename; | |
381 | my $prefix; | |
382 | my $ext; | |
383 | ||
384 | if ($inputfile =~ m,^(.*)/([^/]*)$,) { | |
385 | $dirname = $1; | |
386 | $filename = $2; | |
387 | } else { | |
388 | $dirname = "."; | |
389 | $filename = $inputfile; | |
390 | } | |
391 | ||
392 | if ($filename =~ m,^(.*)(\.\S),) { | |
393 | $prefix = $1; | |
394 | $ext = $2; | |
395 | } else { | |
396 | $prefix = $filename; | |
397 | $ext = ""; | |
398 | } | |
399 | ||
400 | my $mcount_s = $dirname . "/.tmp_mc_" . $prefix . ".s"; | |
401 | my $mcount_o = $dirname . "/.tmp_mc_" . $prefix . ".o"; | |
402 | ||
7b7edc27 | 403 | check_objcopy(); |
f2f8458e | 404 | |
8da3821b | 405 | # |
8feff1ca | 406 | # Step 1: find all the local (static functions) and weak symbols. |
306dcf47 | 407 | # 't' is local, 'w/W' is weak |
8da3821b SR |
408 | # |
409 | open (IN, "$nm $inputfile|") || die "error running $nm"; | |
410 | while (<IN>) { | |
306dcf47 | 411 | if (/$local_regex/) { |
8da3821b | 412 | $locals{$1} = 1; |
306dcf47 | 413 | } elsif (/$weak_regex/) { |
8feff1ca | 414 | $weak{$2} = $1; |
8da3821b SR |
415 | } |
416 | } | |
417 | close(IN); | |
418 | ||
8feff1ca SR |
419 | my @offsets; # Array of offsets of mcount callers |
420 | my $ref_func; # reference function to use for offsets | |
421 | my $offset = 0; # offset of ref_func to section beginning | |
422 | ||
423 | ## | |
424 | # update_funcs - print out the current mcount callers | |
425 | # | |
426 | # Go through the list of offsets to callers and write them to | |
427 | # the output file in a format that can be read by an assembler. | |
428 | # | |
429 | sub update_funcs | |
430 | { | |
6092858c | 431 | return unless ($ref_func and @offsets); |
8feff1ca | 432 | |
c4b8ac2c LH |
433 | # Sanity check on weak function. A weak function may be overwritten by |
434 | # another function of the same name, making all these offsets incorrect. | |
8feff1ca | 435 | if (defined $weak{$ref_func}) { |
c4b8ac2c | 436 | die "$inputfile: ERROR: referencing weak function" . |
8feff1ca | 437 | " $ref_func for mcount\n"; |
8feff1ca SR |
438 | } |
439 | ||
440 | # is this function static? If so, note this fact. | |
441 | if (defined $locals{$ref_func}) { | |
f2f8458e SR |
442 | |
443 | # only use locals if objcopy supports globalize-symbols | |
7b7edc27 | 444 | if (!$can_use_local) { |
f2f8458e SR |
445 | return; |
446 | } | |
8feff1ca SR |
447 | $convert{$ref_func} = 1; |
448 | } | |
449 | ||
450 | # Loop through all the mcount caller offsets and print a reference | |
451 | # to the caller based from the ref_func. | |
dc4f8845 WS |
452 | if (!$opened) { |
453 | open(FILE, ">$mcount_s") || die "can't create $mcount_s\n"; | |
454 | $opened = 1; | |
455 | print FILE "\t.section $mcount_section,\"a\",$section_type\n"; | |
456 | print FILE "\t.align $alignment\n" if (defined($alignment)); | |
457 | } | |
458 | foreach my $cur_offset (@offsets) { | |
459 | printf FILE "\t%s %s + %d\n", $type, $ref_func, $cur_offset - $offset; | |
8feff1ca SR |
460 | } |
461 | } | |
462 | ||
8da3821b SR |
463 | # |
464 | # Step 2: find the sections and mcount call sites | |
465 | # | |
b43f7093 | 466 | open(IN, "$objdump -hdr $inputfile|") || die "error running $objdump"; |
8da3821b | 467 | |
8feff1ca SR |
468 | my $text; |
469 | ||
db24c7dc LH |
470 | |
471 | # read headers first | |
b43f7093 SR |
472 | my $read_headers = 1; |
473 | ||
8da3821b | 474 | while (<IN>) { |
db24c7dc LH |
475 | |
476 | if ($read_headers && /$mcount_section/) { | |
477 | # | |
478 | # Somehow the make process can execute this script on an | |
479 | # object twice. If it does, we would duplicate the mcount | |
480 | # section and it will cause the function tracer self test | |
481 | # to fail. Check if the mcount section exists, and if it does, | |
482 | # warn and exit. | |
483 | # | |
484 | print STDERR "ERROR: $mcount_section already in $inputfile\n" . | |
485 | "\tThis may be an indication that your build is corrupted.\n" . | |
486 | "\tDelete $inputfile and try again. If the same object file\n" . | |
487 | "\tstill causes an issue, then disable CONFIG_DYNAMIC_FTRACE.\n"; | |
488 | exit(-1); | |
489 | } | |
490 | ||
8da3821b SR |
491 | # is it a section? |
492 | if (/$section_regex/) { | |
b43f7093 | 493 | $read_headers = 0; |
34698bcb SR |
494 | |
495 | # Only record text sections that we know are safe | |
dfaa9e2c | 496 | $read_function = defined($text_sections{$1}); |
8feff1ca | 497 | # print out any recorded offsets |
6092858c | 498 | update_funcs(); |
8feff1ca SR |
499 | |
500 | # reset all markers and arrays | |
8da3821b | 501 | $text_found = 0; |
8feff1ca SR |
502 | undef($ref_func); |
503 | undef(@offsets); | |
504 | ||
8da3821b SR |
505 | # section found, now is this a start of a function? |
506 | } elsif ($read_function && /$function_regex/) { | |
8da3821b | 507 | $text_found = 1; |
8feff1ca SR |
508 | $text = $2; |
509 | ||
510 | # if this is either a local function or a weak function | |
511 | # keep looking for functions that are global that | |
512 | # we can use safely. | |
513 | if (!defined($locals{$text}) && !defined($weak{$text})) { | |
514 | $ref_func = $text; | |
515 | $read_function = 0; | |
bd171d5f | 516 | $offset = hex $1; |
8feff1ca SR |
517 | } else { |
518 | # if we already have a function, and this is weak, skip it | |
3f6e968e SR |
519 | if (!defined($ref_func) && !defined($weak{$text}) && |
520 | # PPC64 can have symbols that start with .L and | |
521 | # gcc considers these special. Don't use them! | |
522 | $text !~ /^\.L/) { | |
8feff1ca | 523 | $ref_func = $text; |
bd171d5f | 524 | $offset = hex $1; |
8feff1ca | 525 | } |
8da3821b | 526 | } |
8feff1ca | 527 | } |
8feff1ca SR |
528 | # is this a call site to mcount? If so, record it to print later |
529 | if ($text_found && /$mcount_regex/) { | |
465c6cca | 530 | push(@offsets, (hex $1) + $mcount_adjust); |
8da3821b SR |
531 | } |
532 | } | |
533 | ||
8feff1ca | 534 | # dump out anymore offsets that may have been found |
6092858c | 535 | update_funcs(); |
8feff1ca | 536 | |
8da3821b SR |
537 | # If we did not find any mcount callers, we are done (do nothing). |
538 | if (!$opened) { | |
539 | exit(0); | |
540 | } | |
541 | ||
542 | close(FILE); | |
543 | ||
544 | # | |
545 | # Step 3: Compile the file that holds the list of call sites to mcount. | |
546 | # | |
547 | `$cc -o $mcount_o -c $mcount_s`; | |
548 | ||
549 | my @converts = keys %convert; | |
550 | ||
551 | # | |
552 | # Step 4: Do we have sections that started with local functions? | |
553 | # | |
554 | if ($#converts >= 0) { | |
555 | my $globallist = ""; | |
556 | my $locallist = ""; | |
557 | ||
558 | foreach my $con (@converts) { | |
559 | $globallist .= " --globalize-symbol $con"; | |
560 | $locallist .= " --localize-symbol $con"; | |
561 | } | |
562 | ||
563 | my $globalobj = $dirname . "/.tmp_gl_" . $filename; | |
564 | my $globalmix = $dirname . "/.tmp_mx_" . $filename; | |
565 | ||
566 | # | |
567 | # Step 5: set up each local function as a global | |
568 | # | |
569 | `$objcopy $globallist $inputfile $globalobj`; | |
570 | ||
571 | # | |
572 | # Step 6: Link the global version to our list. | |
573 | # | |
574 | `$ld -r $globalobj $mcount_o -o $globalmix`; | |
575 | ||
576 | # | |
577 | # Step 7: Convert the local functions back into local symbols | |
578 | # | |
579 | `$objcopy $locallist $globalmix $inputfile`; | |
580 | ||
581 | # Remove the temp files | |
582 | `$rm $globalobj $globalmix`; | |
583 | ||
584 | } else { | |
585 | ||
586 | my $mix = $dirname . "/.tmp_mx_" . $filename; | |
587 | ||
588 | # | |
589 | # Step 8: Link the object with our list of call sites object. | |
590 | # | |
591 | `$ld -r $inputfile $mcount_o -o $mix`; | |
592 | ||
593 | # | |
594 | # Step 9: Move the result back to the original object. | |
595 | # | |
596 | `$mv $mix $inputfile`; | |
597 | } | |
598 | ||
599 | # Clean up the temp files | |
600 | `$rm $mcount_o $mcount_s`; | |
601 | ||
602 | exit(0); |