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TOMOYO Linux Cross Reference
Linux/scripts/recordmcount.c

Version: ~ [ linux-5.1-rc1 ] ~ [ linux-5.0.3 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.30 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.107 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.164 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.176 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.136 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.63 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * recordmcount.c: construct a table of the locations of calls to 'mcount'
  3  * so that ftrace can find them quickly.
  4  * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>.  All rights reserved.
  5  * Licensed under the GNU General Public License, version 2 (GPLv2).
  6  *
  7  * Restructured to fit Linux format, as well as other updates:
  8  *  Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
  9  */
 10 
 11 /*
 12  * Strategy: alter the .o file in-place.
 13  *
 14  * Append a new STRTAB that has the new section names, followed by a new array
 15  * ElfXX_Shdr[] that has the new section headers, followed by the section
 16  * contents for __mcount_loc and its relocations.  The old shstrtab strings,
 17  * and the old ElfXX_Shdr[] array, remain as "garbage" (commonly, a couple
 18  * kilobytes.)  Subsequent processing by /bin/ld (or the kernel module loader)
 19  * will ignore the garbage regions, because they are not designated by the
 20  * new .e_shoff nor the new ElfXX_Shdr[].  [In order to remove the garbage,
 21  * then use "ld -r" to create a new file that omits the garbage.]
 22  */
 23 
 24 #include <sys/types.h>
 25 #include <sys/mman.h>
 26 #include <sys/stat.h>
 27 #include <getopt.h>
 28 #include <elf.h>
 29 #include <fcntl.h>
 30 #include <setjmp.h>
 31 #include <stdio.h>
 32 #include <stdlib.h>
 33 #include <string.h>
 34 #include <unistd.h>
 35 
 36 #ifndef EM_AARCH64
 37 #define EM_AARCH64      183
 38 #define R_AARCH64_NONE          0
 39 #define R_AARCH64_ABS64 257
 40 #endif
 41 
 42 static int fd_map;      /* File descriptor for file being modified. */
 43 static int mmap_failed; /* Boolean flag. */
 44 static char gpfx;       /* prefix for global symbol name (sometimes '_') */
 45 static struct stat sb;  /* Remember .st_size, etc. */
 46 static jmp_buf jmpenv;  /* setjmp/longjmp per-file error escape */
 47 static const char *altmcount;   /* alternate mcount symbol name */
 48 static int warn_on_notrace_sect; /* warn when section has mcount not being recorded */
 49 static void *file_map;  /* pointer of the mapped file */
 50 static void *file_end;  /* pointer to the end of the mapped file */
 51 static int file_updated; /* flag to state file was changed */
 52 static void *file_ptr;  /* current file pointer location */
 53 static void *file_append; /* added to the end of the file */
 54 static size_t file_append_size; /* how much is added to end of file */
 55 
 56 /* setjmp() return values */
 57 enum {
 58         SJ_SETJMP = 0,  /* hardwired first return */
 59         SJ_FAIL,
 60         SJ_SUCCEED
 61 };
 62 
 63 /* Per-file resource cleanup when multiple files. */
 64 static void
 65 cleanup(void)
 66 {
 67         if (!mmap_failed)
 68                 munmap(file_map, sb.st_size);
 69         else
 70                 free(file_map);
 71         file_map = NULL;
 72         free(file_append);
 73         file_append = NULL;
 74         file_append_size = 0;
 75         file_updated = 0;
 76 }
 77 
 78 static void __attribute__((noreturn))
 79 fail_file(void)
 80 {
 81         cleanup();
 82         longjmp(jmpenv, SJ_FAIL);
 83 }
 84 
 85 static void __attribute__((noreturn))
 86 succeed_file(void)
 87 {
 88         cleanup();
 89         longjmp(jmpenv, SJ_SUCCEED);
 90 }
 91 
 92 /* ulseek, uread, ...:  Check return value for errors. */
 93 
 94 static off_t
 95 ulseek(int const fd, off_t const offset, int const whence)
 96 {
 97         switch (whence) {
 98         case SEEK_SET:
 99                 file_ptr = file_map + offset;
100                 break;
101         case SEEK_CUR:
102                 file_ptr += offset;
103                 break;
104         case SEEK_END:
105                 file_ptr = file_map + (sb.st_size - offset);
106                 break;
107         }
108         if (file_ptr < file_map) {
109                 fprintf(stderr, "lseek: seek before file\n");
110                 fail_file();
111         }
112         return file_ptr - file_map;
113 }
114 
115 static size_t
116 uread(int const fd, void *const buf, size_t const count)
117 {
118         size_t const n = read(fd, buf, count);
119         if (n != count) {
120                 perror("read");
121                 fail_file();
122         }
123         return n;
124 }
125 
126 static size_t
127 uwrite(int const fd, void const *const buf, size_t const count)
128 {
129         size_t cnt = count;
130         off_t idx = 0;
131 
132         file_updated = 1;
133 
134         if (file_ptr + count >= file_end) {
135                 off_t aoffset = (file_ptr + count) - file_end;
136 
137                 if (aoffset > file_append_size) {
138                         file_append = realloc(file_append, aoffset);
139                         file_append_size = aoffset;
140                 }
141                 if (!file_append) {
142                         perror("write");
143                         fail_file();
144                 }
145                 if (file_ptr < file_end) {
146                         cnt = file_end - file_ptr;
147                 } else {
148                         cnt = 0;
149                         idx = aoffset - count;
150                 }
151         }
152 
153         if (cnt)
154                 memcpy(file_ptr, buf, cnt);
155 
156         if (cnt < count)
157                 memcpy(file_append + idx, buf + cnt, count - cnt);
158 
159         file_ptr += count;
160         return count;
161 }
162 
163 static void *
164 umalloc(size_t size)
165 {
166         void *const addr = malloc(size);
167         if (addr == 0) {
168                 fprintf(stderr, "malloc failed: %zu bytes\n", size);
169                 fail_file();
170         }
171         return addr;
172 }
173 
174 static unsigned char ideal_nop5_x86_64[5] = { 0x0f, 0x1f, 0x44, 0x00, 0x00 };
175 static unsigned char ideal_nop5_x86_32[5] = { 0x3e, 0x8d, 0x74, 0x26, 0x00 };
176 static unsigned char *ideal_nop;
177 
178 static char rel_type_nop;
179 
180 static int (*make_nop)(void *map, size_t const offset);
181 
182 static int make_nop_x86(void *map, size_t const offset)
183 {
184         uint32_t *ptr;
185         unsigned char *op;
186 
187         /* Confirm we have 0xe8 0x0 0x0 0x0 0x0 */
188         ptr = map + offset;
189         if (*ptr != 0)
190                 return -1;
191 
192         op = map + offset - 1;
193         if (*op != 0xe8)
194                 return -1;
195 
196         /* convert to nop */
197         ulseek(fd_map, offset - 1, SEEK_SET);
198         uwrite(fd_map, ideal_nop, 5);
199         return 0;
200 }
201 
202 static unsigned char ideal_nop4_arm_le[4] = { 0x00, 0x00, 0xa0, 0xe1 }; /* mov r0, r0 */
203 static unsigned char ideal_nop4_arm_be[4] = { 0xe1, 0xa0, 0x00, 0x00 }; /* mov r0, r0 */
204 static unsigned char *ideal_nop4_arm;
205 
206 static unsigned char bl_mcount_arm_le[4] = { 0xfe, 0xff, 0xff, 0xeb }; /* bl */
207 static unsigned char bl_mcount_arm_be[4] = { 0xeb, 0xff, 0xff, 0xfe }; /* bl */
208 static unsigned char *bl_mcount_arm;
209 
210 static unsigned char push_arm_le[4] = { 0x04, 0xe0, 0x2d, 0xe5 }; /* push {lr} */
211 static unsigned char push_arm_be[4] = { 0xe5, 0x2d, 0xe0, 0x04 }; /* push {lr} */
212 static unsigned char *push_arm;
213 
214 static unsigned char ideal_nop2_thumb_le[2] = { 0x00, 0xbf }; /* nop */
215 static unsigned char ideal_nop2_thumb_be[2] = { 0xbf, 0x00 }; /* nop */
216 static unsigned char *ideal_nop2_thumb;
217 
218 static unsigned char push_bl_mcount_thumb_le[6] = { 0x00, 0xb5, 0xff, 0xf7, 0xfe, 0xff }; /* push {lr}, bl */
219 static unsigned char push_bl_mcount_thumb_be[6] = { 0xb5, 0x00, 0xf7, 0xff, 0xff, 0xfe }; /* push {lr}, bl */
220 static unsigned char *push_bl_mcount_thumb;
221 
222 static int make_nop_arm(void *map, size_t const offset)
223 {
224         char *ptr;
225         int cnt = 1;
226         int nop_size;
227         size_t off = offset;
228 
229         ptr = map + offset;
230         if (memcmp(ptr, bl_mcount_arm, 4) == 0) {
231                 if (memcmp(ptr - 4, push_arm, 4) == 0) {
232                         off -= 4;
233                         cnt = 2;
234                 }
235                 ideal_nop = ideal_nop4_arm;
236                 nop_size = 4;
237         } else if (memcmp(ptr - 2, push_bl_mcount_thumb, 6) == 0) {
238                 cnt = 3;
239                 nop_size = 2;
240                 off -= 2;
241                 ideal_nop = ideal_nop2_thumb;
242         } else
243                 return -1;
244 
245         /* Convert to nop */
246         ulseek(fd_map, off, SEEK_SET);
247 
248         do {
249                 uwrite(fd_map, ideal_nop, nop_size);
250         } while (--cnt > 0);
251 
252         return 0;
253 }
254 
255 static unsigned char ideal_nop4_arm64[4] = {0x1f, 0x20, 0x03, 0xd5};
256 static int make_nop_arm64(void *map, size_t const offset)
257 {
258         uint32_t *ptr;
259 
260         ptr = map + offset;
261         /* bl <_mcount> is 0x94000000 before relocation */
262         if (*ptr != 0x94000000)
263                 return -1;
264 
265         /* Convert to nop */
266         ulseek(fd_map, offset, SEEK_SET);
267         uwrite(fd_map, ideal_nop, 4);
268         return 0;
269 }
270 
271 /*
272  * Get the whole file as a programming convenience in order to avoid
273  * malloc+lseek+read+free of many pieces.  If successful, then mmap
274  * avoids copying unused pieces; else just read the whole file.
275  * Open for both read and write; new info will be appended to the file.
276  * Use MAP_PRIVATE so that a few changes to the in-memory ElfXX_Ehdr
277  * do not propagate to the file until an explicit overwrite at the last.
278  * This preserves most aspects of consistency (all except .st_size)
279  * for simultaneous readers of the file while we are appending to it.
280  * However, multiple writers still are bad.  We choose not to use
281  * locking because it is expensive and the use case of kernel build
282  * makes multiple writers unlikely.
283  */
284 static void *mmap_file(char const *fname)
285 {
286         fd_map = open(fname, O_RDONLY);
287         if (fd_map < 0 || fstat(fd_map, &sb) < 0) {
288                 perror(fname);
289                 fail_file();
290         }
291         if (!S_ISREG(sb.st_mode)) {
292                 fprintf(stderr, "not a regular file: %s\n", fname);
293                 fail_file();
294         }
295         file_map = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
296                         fd_map, 0);
297         mmap_failed = 0;
298         if (file_map == MAP_FAILED) {
299                 mmap_failed = 1;
300                 file_map = umalloc(sb.st_size);
301                 uread(fd_map, file_map, sb.st_size);
302         }
303         close(fd_map);
304 
305         file_end = file_map + sb.st_size;
306 
307         return file_map;
308 }
309 
310 static void write_file(const char *fname)
311 {
312         char tmp_file[strlen(fname) + 4];
313         size_t n;
314 
315         if (!file_updated)
316                 return;
317 
318         sprintf(tmp_file, "%s.rc", fname);
319 
320         /*
321          * After reading the entire file into memory, delete it
322          * and write it back, to prevent weird side effects of modifying
323          * an object file in place.
324          */
325         fd_map = open(tmp_file, O_WRONLY | O_TRUNC | O_CREAT, sb.st_mode);
326         if (fd_map < 0) {
327                 perror(fname);
328                 fail_file();
329         }
330         n = write(fd_map, file_map, sb.st_size);
331         if (n != sb.st_size) {
332                 perror("write");
333                 fail_file();
334         }
335         if (file_append_size) {
336                 n = write(fd_map, file_append, file_append_size);
337                 if (n != file_append_size) {
338                         perror("write");
339                         fail_file();
340                 }
341         }
342         close(fd_map);
343         if (rename(tmp_file, fname) < 0) {
344                 perror(fname);
345                 fail_file();
346         }
347 }
348 
349 /* w8rev, w8nat, ...: Handle endianness. */
350 
351 static uint64_t w8rev(uint64_t const x)
352 {
353         return   ((0xff & (x >> (0 * 8))) << (7 * 8))
354                | ((0xff & (x >> (1 * 8))) << (6 * 8))
355                | ((0xff & (x >> (2 * 8))) << (5 * 8))
356                | ((0xff & (x >> (3 * 8))) << (4 * 8))
357                | ((0xff & (x >> (4 * 8))) << (3 * 8))
358                | ((0xff & (x >> (5 * 8))) << (2 * 8))
359                | ((0xff & (x >> (6 * 8))) << (1 * 8))
360                | ((0xff & (x >> (7 * 8))) << (0 * 8));
361 }
362 
363 static uint32_t w4rev(uint32_t const x)
364 {
365         return   ((0xff & (x >> (0 * 8))) << (3 * 8))
366                | ((0xff & (x >> (1 * 8))) << (2 * 8))
367                | ((0xff & (x >> (2 * 8))) << (1 * 8))
368                | ((0xff & (x >> (3 * 8))) << (0 * 8));
369 }
370 
371 static uint32_t w2rev(uint16_t const x)
372 {
373         return   ((0xff & (x >> (0 * 8))) << (1 * 8))
374                | ((0xff & (x >> (1 * 8))) << (0 * 8));
375 }
376 
377 static uint64_t w8nat(uint64_t const x)
378 {
379         return x;
380 }
381 
382 static uint32_t w4nat(uint32_t const x)
383 {
384         return x;
385 }
386 
387 static uint32_t w2nat(uint16_t const x)
388 {
389         return x;
390 }
391 
392 static uint64_t (*w8)(uint64_t);
393 static uint32_t (*w)(uint32_t);
394 static uint32_t (*w2)(uint16_t);
395 
396 /* Names of the sections that could contain calls to mcount. */
397 static int
398 is_mcounted_section_name(char const *const txtname)
399 {
400         return strncmp(".text",          txtname, 5) == 0 ||
401                 strcmp(".init.text",     txtname) == 0 ||
402                 strcmp(".ref.text",      txtname) == 0 ||
403                 strcmp(".sched.text",    txtname) == 0 ||
404                 strcmp(".spinlock.text", txtname) == 0 ||
405                 strcmp(".irqentry.text", txtname) == 0 ||
406                 strcmp(".softirqentry.text", txtname) == 0 ||
407                 strcmp(".kprobes.text", txtname) == 0 ||
408                 strcmp(".cpuidle.text", txtname) == 0 ||
409                 strcmp(".text.unlikely", txtname) == 0;
410 }
411 
412 /* 32 bit and 64 bit are very similar */
413 #include "recordmcount.h"
414 #define RECORD_MCOUNT_64
415 #include "recordmcount.h"
416 
417 /* 64-bit EM_MIPS has weird ELF64_Rela.r_info.
418  * http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf
419  * We interpret Table 29 Relocation Operation (Elf64_Rel, Elf64_Rela) [p.40]
420  * to imply the order of the members; the spec does not say so.
421  *      typedef unsigned char Elf64_Byte;
422  * fails on MIPS64 because their <elf.h> already has it!
423  */
424 
425 typedef uint8_t myElf64_Byte;           /* Type for a 8-bit quantity.  */
426 
427 union mips_r_info {
428         Elf64_Xword r_info;
429         struct {
430                 Elf64_Word r_sym;               /* Symbol index.  */
431                 myElf64_Byte r_ssym;            /* Special symbol.  */
432                 myElf64_Byte r_type3;           /* Third relocation.  */
433                 myElf64_Byte r_type2;           /* Second relocation.  */
434                 myElf64_Byte r_type;            /* First relocation.  */
435         } r_mips;
436 };
437 
438 static uint64_t MIPS64_r_sym(Elf64_Rel const *rp)
439 {
440         return w(((union mips_r_info){ .r_info = rp->r_info }).r_mips.r_sym);
441 }
442 
443 static void MIPS64_r_info(Elf64_Rel *const rp, unsigned sym, unsigned type)
444 {
445         rp->r_info = ((union mips_r_info){
446                 .r_mips = { .r_sym = w(sym), .r_type = type }
447         }).r_info;
448 }
449 
450 static void
451 do_file(char const *const fname)
452 {
453         Elf32_Ehdr *const ehdr = mmap_file(fname);
454         unsigned int reltype = 0;
455 
456         w = w4nat;
457         w2 = w2nat;
458         w8 = w8nat;
459         switch (ehdr->e_ident[EI_DATA]) {
460                 static unsigned int const endian = 1;
461         default:
462                 fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
463                         ehdr->e_ident[EI_DATA], fname);
464                 fail_file();
465                 break;
466         case ELFDATA2LSB:
467                 if (*(unsigned char const *)&endian != 1) {
468                         /* main() is big endian, file.o is little endian. */
469                         w = w4rev;
470                         w2 = w2rev;
471                         w8 = w8rev;
472                 }
473                 ideal_nop4_arm = ideal_nop4_arm_le;
474                 bl_mcount_arm = bl_mcount_arm_le;
475                 push_arm = push_arm_le;
476                 ideal_nop2_thumb = ideal_nop2_thumb_le;
477                 push_bl_mcount_thumb = push_bl_mcount_thumb_le;
478                 break;
479         case ELFDATA2MSB:
480                 if (*(unsigned char const *)&endian != 0) {
481                         /* main() is little endian, file.o is big endian. */
482                         w = w4rev;
483                         w2 = w2rev;
484                         w8 = w8rev;
485                 }
486                 ideal_nop4_arm = ideal_nop4_arm_be;
487                 bl_mcount_arm = bl_mcount_arm_be;
488                 push_arm = push_arm_be;
489                 ideal_nop2_thumb = ideal_nop2_thumb_be;
490                 push_bl_mcount_thumb = push_bl_mcount_thumb_be;
491                 break;
492         }  /* end switch */
493         if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
494         ||  w2(ehdr->e_type) != ET_REL
495         ||  ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
496                 fprintf(stderr, "unrecognized ET_REL file %s\n", fname);
497                 fail_file();
498         }
499 
500         gpfx = 0;
501         switch (w2(ehdr->e_machine)) {
502         default:
503                 fprintf(stderr, "unrecognized e_machine %u %s\n",
504                         w2(ehdr->e_machine), fname);
505                 fail_file();
506                 break;
507         case EM_386:
508                 reltype = R_386_32;
509                 rel_type_nop = R_386_NONE;
510                 make_nop = make_nop_x86;
511                 ideal_nop = ideal_nop5_x86_32;
512                 mcount_adjust_32 = -1;
513                 break;
514         case EM_ARM:     reltype = R_ARM_ABS32;
515                          altmcount = "__gnu_mcount_nc";
516                          make_nop = make_nop_arm;
517                          rel_type_nop = R_ARM_NONE;
518                          break;
519         case EM_AARCH64:
520                         reltype = R_AARCH64_ABS64;
521                         make_nop = make_nop_arm64;
522                         rel_type_nop = R_AARCH64_NONE;
523                         ideal_nop = ideal_nop4_arm64;
524                         gpfx = '_';
525                         break;
526         case EM_IA_64:   reltype = R_IA64_IMM64;   gpfx = '_'; break;
527         case EM_MIPS:    /* reltype: e_class    */ gpfx = '_'; break;
528         case EM_PPC:     reltype = R_PPC_ADDR32;   gpfx = '_'; break;
529         case EM_PPC64:   reltype = R_PPC64_ADDR64; gpfx = '_'; break;
530         case EM_S390:    /* reltype: e_class    */ gpfx = '_'; break;
531         case EM_SH:      reltype = R_SH_DIR32;                 break;
532         case EM_SPARCV9: reltype = R_SPARC_64;     gpfx = '_'; break;
533         case EM_X86_64:
534                 make_nop = make_nop_x86;
535                 ideal_nop = ideal_nop5_x86_64;
536                 reltype = R_X86_64_64;
537                 rel_type_nop = R_X86_64_NONE;
538                 mcount_adjust_64 = -1;
539                 break;
540         }  /* end switch */
541 
542         switch (ehdr->e_ident[EI_CLASS]) {
543         default:
544                 fprintf(stderr, "unrecognized ELF class %d %s\n",
545                         ehdr->e_ident[EI_CLASS], fname);
546                 fail_file();
547                 break;
548         case ELFCLASS32:
549                 if (w2(ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
550                 ||  w2(ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
551                         fprintf(stderr,
552                                 "unrecognized ET_REL file: %s\n", fname);
553                         fail_file();
554                 }
555                 if (w2(ehdr->e_machine) == EM_MIPS) {
556                         reltype = R_MIPS_32;
557                         is_fake_mcount32 = MIPS32_is_fake_mcount;
558                 }
559                 do32(ehdr, fname, reltype);
560                 break;
561         case ELFCLASS64: {
562                 Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
563                 if (w2(ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
564                 ||  w2(ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
565                         fprintf(stderr,
566                                 "unrecognized ET_REL file: %s\n", fname);
567                         fail_file();
568                 }
569                 if (w2(ghdr->e_machine) == EM_S390) {
570                         reltype = R_390_64;
571                         mcount_adjust_64 = -14;
572                 }
573                 if (w2(ghdr->e_machine) == EM_MIPS) {
574                         reltype = R_MIPS_64;
575                         Elf64_r_sym = MIPS64_r_sym;
576                         Elf64_r_info = MIPS64_r_info;
577                         is_fake_mcount64 = MIPS64_is_fake_mcount;
578                 }
579                 do64(ghdr, fname, reltype);
580                 break;
581         }
582         }  /* end switch */
583 
584         write_file(fname);
585         cleanup();
586 }
587 
588 int
589 main(int argc, char *argv[])
590 {
591         const char ftrace[] = "/ftrace.o";
592         int ftrace_size = sizeof(ftrace) - 1;
593         int n_error = 0;  /* gcc-4.3.0 false positive complaint */
594         int c;
595         int i;
596 
597         while ((c = getopt(argc, argv, "w")) >= 0) {
598                 switch (c) {
599                 case 'w':
600                         warn_on_notrace_sect = 1;
601                         break;
602                 default:
603                         fprintf(stderr, "usage: recordmcount [-w] file.o...\n");
604                         return 0;
605                 }
606         }
607 
608         if ((argc - optind) < 1) {
609                 fprintf(stderr, "usage: recordmcount [-w] file.o...\n");
610                 return 0;
611         }
612 
613         /* Process each file in turn, allowing deep failure. */
614         for (i = optind; i < argc; i++) {
615                 char *file = argv[i];
616                 int const sjval = setjmp(jmpenv);
617                 int len;
618 
619                 /*
620                  * The file kernel/trace/ftrace.o references the mcount
621                  * function but does not call it. Since ftrace.o should
622                  * not be traced anyway, we just skip it.
623                  */
624                 len = strlen(file);
625                 if (len >= ftrace_size &&
626                     strcmp(file + (len - ftrace_size), ftrace) == 0)
627                         continue;
628 
629                 switch (sjval) {
630                 default:
631                         fprintf(stderr, "internal error: %s\n", file);
632                         exit(1);
633                         break;
634                 case SJ_SETJMP:    /* normal sequence */
635                         /* Avoid problems if early cleanup() */
636                         fd_map = -1;
637                         mmap_failed = 1;
638                         file_map = NULL;
639                         file_ptr = NULL;
640                         file_updated = 0;
641                         do_file(file);
642                         break;
643                 case SJ_FAIL:    /* error in do_file or below */
644                         fprintf(stderr, "%s: failed\n", file);
645                         ++n_error;
646                         break;
647                 case SJ_SUCCEED:    /* premature success */
648                         /* do nothing */
649                         break;
650                 }  /* end switch */
651         }
652         return !!n_error;
653 }
654 

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