1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * recordmcount.c: construct a table of the locations of calls to 'mcount'
  4 * so that ftrace can find them quickly.
  5 * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>.  All rights reserved.
 
  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 <stdio.h>
 31#include <stdlib.h>
 32#include <string.h>
 33#include <unistd.h>
 34
 35#ifndef EM_AARCH64
 36#define EM_AARCH64	183
 37#define R_AARCH64_NONE		0
 38#define R_AARCH64_ABS64	257
 39#endif
 40
 41#ifndef EM_LOONGARCH
 42#define EM_LOONGARCH		258
 43#define R_LARCH_32			1
 44#define R_LARCH_64			2
 45#define R_LARCH_MARK_LA			20
 46#define R_LARCH_SOP_PUSH_PLT_PCREL	29
 47#endif
 48
 49#define R_ARM_PC24		1
 50#define R_ARM_THM_CALL		10
 51#define R_ARM_CALL		28
 52
 53#define R_AARCH64_CALL26	283
 54
 55static int fd_map;	/* File descriptor for file being modified. */
 56static int mmap_failed; /* Boolean flag. */
 
 57static char gpfx;	/* prefix for global symbol name (sometimes '_') */
 58static struct stat sb;	/* Remember .st_size, etc. */
 
 59static const char *altmcount;	/* alternate mcount symbol name */
 60static int warn_on_notrace_sect; /* warn when section has mcount not being recorded */
 61static void *file_map;	/* pointer of the mapped file */
 62static void *file_end;	/* pointer to the end of the mapped file */
 63static int file_updated; /* flag to state file was changed */
 64static void *file_ptr;	/* current file pointer location */
 65
 66static void *file_append; /* added to the end of the file */
 67static size_t file_append_size; /* how much is added to end of file */
 
 
 
 
 68
 69/* Per-file resource cleanup when multiple files. */
 70static void file_append_cleanup(void)
 71{
 72	free(file_append);
 73	file_append = NULL;
 74	file_append_size = 0;
 75	file_updated = 0;
 76}
 77
 78static void mmap_cleanup(void)
 79{
 80	if (!mmap_failed)
 81		munmap(file_map, sb.st_size);
 82	else
 83		free(file_map);
 84	file_map = NULL;
 85}
 86
 87/* ulseek, uwrite, ...:  Check return value for errors. */
 88
 89static off_t ulseek(off_t const offset, int const whence)
 90{
 91	switch (whence) {
 92	case SEEK_SET:
 93		file_ptr = file_map + offset;
 94		break;
 95	case SEEK_CUR:
 96		file_ptr += offset;
 97		break;
 98	case SEEK_END:
 99		file_ptr = file_map + (sb.st_size - offset);
100		break;
101	}
102	if (file_ptr < file_map) {
103		fprintf(stderr, "lseek: seek before file\n");
104		return -1;
105	}
106	return file_ptr - file_map;
107}
108
109static ssize_t uwrite(void const *const buf, size_t const count)
 
110{
111	size_t cnt = count;
112	off_t idx = 0;
113	void *p = NULL;
114
115	file_updated = 1;
116
117	if (file_ptr + count >= file_end) {
118		off_t aoffset = (file_ptr + count) - file_end;
119
120		if (aoffset > file_append_size) {
121			p = realloc(file_append, aoffset);
122			if (!p)
123				free(file_append);
124			file_append = p;
125			file_append_size = aoffset;
126		}
127		if (!file_append) {
128			perror("write");
129			file_append_cleanup();
130			mmap_cleanup();
131			return -1;
132		}
133		if (file_ptr < file_end) {
134			cnt = file_end - file_ptr;
135		} else {
136			cnt = 0;
137			idx = aoffset - count;
138		}
139	}
 
 
140
141	if (cnt)
142		memcpy(file_ptr, buf, cnt);
143
144	if (cnt < count)
145		memcpy(file_append + idx, buf + cnt, count - cnt);
 
 
 
 
 
146
147	file_ptr += count;
148	return count;
 
 
 
 
 
 
 
149}
150
151static void * umalloc(size_t size)
 
152{
153	void *const addr = malloc(size);
154	if (addr == 0) {
155		fprintf(stderr, "malloc failed: %zu bytes\n", size);
156		file_append_cleanup();
157		mmap_cleanup();
158		return NULL;
159	}
160	return addr;
161}
162
163/*
164 * Get the whole file as a programming convenience in order to avoid
165 * malloc+lseek+read+free of many pieces.  If successful, then mmap
166 * avoids copying unused pieces; else just read the whole file.
167 * Open for both read and write; new info will be appended to the file.
168 * Use MAP_PRIVATE so that a few changes to the in-memory ElfXX_Ehdr
169 * do not propagate to the file until an explicit overwrite at the last.
170 * This preserves most aspects of consistency (all except .st_size)
171 * for simultaneous readers of the file while we are appending to it.
172 * However, multiple writers still are bad.  We choose not to use
173 * locking because it is expensive and the use case of kernel build
174 * makes multiple writers unlikely.
175 */
176static void *mmap_file(char const *fname)
177{
178	/* Avoid problems if early cleanup() */
179	fd_map = -1;
180	mmap_failed = 1;
181	file_map = NULL;
182	file_ptr = NULL;
183	file_updated = 0;
184	sb.st_size = 0;
185
186	fd_map = open(fname, O_RDONLY);
187	if (fd_map < 0) {
188		perror(fname);
189		return NULL;
190	}
191	if (fstat(fd_map, &sb) < 0) {
192		perror(fname);
193		goto out;
194	}
195	if (!S_ISREG(sb.st_mode)) {
196		fprintf(stderr, "not a regular file: %s\n", fname);
197		goto out;
198	}
199	file_map = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
200			fd_map, 0);
201	if (file_map == MAP_FAILED) {
202		mmap_failed = 1;
203		file_map = umalloc(sb.st_size);
204		if (!file_map) {
205			perror(fname);
206			goto out;
207		}
208		if (read(fd_map, file_map, sb.st_size) != sb.st_size) {
209			perror(fname);
210			free(file_map);
211			file_map = NULL;
212			goto out;
213		}
214	} else
215		mmap_failed = 0;
216out:
217	close(fd_map);
218	fd_map = -1;
219
220	file_end = file_map + sb.st_size;
221
222	return file_map;
223}
224
225
226static unsigned char ideal_nop5_x86_64[5] = { 0x0f, 0x1f, 0x44, 0x00, 0x00 };
227static unsigned char ideal_nop5_x86_32[5] = { 0x3e, 0x8d, 0x74, 0x26, 0x00 };
228static unsigned char *ideal_nop;
229
230static char rel_type_nop;
231
232static int (*make_nop)(void *map, size_t const offset);
233
234static int make_nop_x86(void *map, size_t const offset)
235{
236	uint32_t *ptr;
237	unsigned char *op;
238
239	/* Confirm we have 0xe8 0x0 0x0 0x0 0x0 */
240	ptr = map + offset;
241	if (*ptr != 0)
242		return -1;
243
244	op = map + offset - 1;
245	if (*op != 0xe8)
246		return -1;
247
248	/* convert to nop */
249	if (ulseek(offset - 1, SEEK_SET) < 0)
250		return -1;
251	if (uwrite(ideal_nop, 5) < 0)
252		return -1;
253	return 0;
254}
255
256static unsigned char ideal_nop4_arm_le[4] = { 0x00, 0x00, 0xa0, 0xe1 }; /* mov r0, r0 */
257static unsigned char ideal_nop4_arm_be[4] = { 0xe1, 0xa0, 0x00, 0x00 }; /* mov r0, r0 */
258static unsigned char *ideal_nop4_arm;
259
260static unsigned char bl_mcount_arm_le[4] = { 0xfe, 0xff, 0xff, 0xeb }; /* bl */
261static unsigned char bl_mcount_arm_be[4] = { 0xeb, 0xff, 0xff, 0xfe }; /* bl */
262static unsigned char *bl_mcount_arm;
263
264static unsigned char push_arm_le[4] = { 0x04, 0xe0, 0x2d, 0xe5 }; /* push {lr} */
265static unsigned char push_arm_be[4] = { 0xe5, 0x2d, 0xe0, 0x04 }; /* push {lr} */
266static unsigned char *push_arm;
267
268static unsigned char ideal_nop2_thumb_le[2] = { 0x00, 0xbf }; /* nop */
269static unsigned char ideal_nop2_thumb_be[2] = { 0xbf, 0x00 }; /* nop */
270static unsigned char *ideal_nop2_thumb;
271
272static unsigned char push_bl_mcount_thumb_le[6] = { 0x00, 0xb5, 0xff, 0xf7, 0xfe, 0xff }; /* push {lr}, bl */
273static unsigned char push_bl_mcount_thumb_be[6] = { 0xb5, 0x00, 0xf7, 0xff, 0xff, 0xfe }; /* push {lr}, bl */
274static unsigned char *push_bl_mcount_thumb;
275
276static int make_nop_arm(void *map, size_t const offset)
277{
278	char *ptr;
279	int cnt = 1;
280	int nop_size;
281	size_t off = offset;
282
283	ptr = map + offset;
284	if (memcmp(ptr, bl_mcount_arm, 4) == 0) {
285		if (memcmp(ptr - 4, push_arm, 4) == 0) {
286			off -= 4;
287			cnt = 2;
288		}
289		ideal_nop = ideal_nop4_arm;
290		nop_size = 4;
291	} else if (memcmp(ptr - 2, push_bl_mcount_thumb, 6) == 0) {
292		cnt = 3;
293		nop_size = 2;
294		off -= 2;
295		ideal_nop = ideal_nop2_thumb;
296	} else
297		return -1;
298
299	/* Convert to nop */
300	if (ulseek(off, SEEK_SET) < 0)
301		return -1;
302
303	do {
304		if (uwrite(ideal_nop, nop_size) < 0)
305			return -1;
306	} while (--cnt > 0);
307
308	return 0;
309}
310
311static unsigned char ideal_nop4_arm64[4] = {0x1f, 0x20, 0x03, 0xd5};
312static int make_nop_arm64(void *map, size_t const offset)
313{
314	uint32_t *ptr;
315
316	ptr = map + offset;
317	/* bl <_mcount> is 0x94000000 before relocation */
318	if (*ptr != 0x94000000)
319		return -1;
320
321	/* Convert to nop */
322	if (ulseek(offset, SEEK_SET) < 0)
323		return -1;
324	if (uwrite(ideal_nop, 4) < 0)
325		return -1;
326	return 0;
327}
328
329static int write_file(const char *fname)
330{
331	char tmp_file[strlen(fname) + 4];
332	size_t n;
333
334	if (!file_updated)
335		return 0;
336
337	sprintf(tmp_file, "%s.rc", fname);
338
339	/*
340	 * After reading the entire file into memory, delete it
341	 * and write it back, to prevent weird side effects of modifying
342	 * an object file in place.
343	 */
344	fd_map = open(tmp_file, O_WRONLY | O_TRUNC | O_CREAT, sb.st_mode);
345	if (fd_map < 0) {
346		perror(fname);
347		return -1;
348	}
349	n = write(fd_map, file_map, sb.st_size);
350	if (n != sb.st_size) {
351		perror("write");
352		close(fd_map);
353		return -1;
354	}
355	if (file_append_size) {
356		n = write(fd_map, file_append, file_append_size);
357		if (n != file_append_size) {
358			perror("write");
359			close(fd_map);
360			return -1;
361		}
362	}
363	close(fd_map);
364	if (rename(tmp_file, fname) < 0) {
365		perror(fname);
366		return -1;
 
 
 
367	}
368	return 0;
369}
370
371/* w8rev, w8nat, ...: Handle endianness. */
372
373static uint64_t w8rev(uint64_t const x)
374{
375	return   ((0xff & (x >> (0 * 8))) << (7 * 8))
376	       | ((0xff & (x >> (1 * 8))) << (6 * 8))
377	       | ((0xff & (x >> (2 * 8))) << (5 * 8))
378	       | ((0xff & (x >> (3 * 8))) << (4 * 8))
379	       | ((0xff & (x >> (4 * 8))) << (3 * 8))
380	       | ((0xff & (x >> (5 * 8))) << (2 * 8))
381	       | ((0xff & (x >> (6 * 8))) << (1 * 8))
382	       | ((0xff & (x >> (7 * 8))) << (0 * 8));
383}
384
385static uint32_t w4rev(uint32_t const x)
386{
387	return   ((0xff & (x >> (0 * 8))) << (3 * 8))
388	       | ((0xff & (x >> (1 * 8))) << (2 * 8))
389	       | ((0xff & (x >> (2 * 8))) << (1 * 8))
390	       | ((0xff & (x >> (3 * 8))) << (0 * 8));
391}
392
393static uint32_t w2rev(uint16_t const x)
394{
395	return   ((0xff & (x >> (0 * 8))) << (1 * 8))
396	       | ((0xff & (x >> (1 * 8))) << (0 * 8));
397}
398
399static uint64_t w8nat(uint64_t const x)
400{
401	return x;
402}
403
404static uint32_t w4nat(uint32_t const x)
405{
406	return x;
407}
408
409static uint32_t w2nat(uint16_t const x)
410{
411	return x;
412}
413
414static uint64_t (*w8)(uint64_t);
415static uint32_t (*w)(uint32_t);
416static uint32_t (*w2)(uint16_t);
417
418/* Names of the sections that could contain calls to mcount. */
419static int is_mcounted_section_name(char const *const txtname)
 
420{
421	return strncmp(".text",          txtname, 5) == 0 ||
422		strcmp(".init.text",     txtname) == 0 ||
423		strcmp(".ref.text",      txtname) == 0 ||
424		strcmp(".sched.text",    txtname) == 0 ||
425		strcmp(".spinlock.text", txtname) == 0 ||
426		strcmp(".irqentry.text", txtname) == 0 ||
427		strcmp(".softirqentry.text", txtname) == 0 ||
428		strcmp(".kprobes.text", txtname) == 0 ||
429		strcmp(".cpuidle.text", txtname) == 0;
430}
431
432static char const *already_has_rel_mcount = "success"; /* our work here is done! */
433
434/* 32 bit and 64 bit are very similar */
435#include "recordmcount.h"
436#define RECORD_MCOUNT_64
437#include "recordmcount.h"
438
439static int arm_is_fake_mcount(Elf32_Rel const *rp)
440{
441	switch (ELF32_R_TYPE(w(rp->r_info))) {
442	case R_ARM_THM_CALL:
443	case R_ARM_CALL:
444	case R_ARM_PC24:
445		return 0;
446	}
447
448	return 1;
449}
450
451static int arm64_is_fake_mcount(Elf64_Rel const *rp)
452{
453	return ELF64_R_TYPE(w8(rp->r_info)) != R_AARCH64_CALL26;
454}
455
456static int LARCH32_is_fake_mcount(Elf32_Rel const *rp)
457{
458	switch (ELF64_R_TYPE(w(rp->r_info))) {
459	case R_LARCH_MARK_LA:
460	case R_LARCH_SOP_PUSH_PLT_PCREL:
461		return 0;
462	}
463
464	return 1;
465}
466
467static int LARCH64_is_fake_mcount(Elf64_Rel const *rp)
468{
469	switch (ELF64_R_TYPE(w(rp->r_info))) {
470	case R_LARCH_MARK_LA:
471	case R_LARCH_SOP_PUSH_PLT_PCREL:
472		return 0;
473	}
474
475	return 1;
476}
477
478/* 64-bit EM_MIPS has weird ELF64_Rela.r_info.
479 * http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf
480 * We interpret Table 29 Relocation Operation (Elf64_Rel, Elf64_Rela) [p.40]
481 * to imply the order of the members; the spec does not say so.
482 *	typedef unsigned char Elf64_Byte;
483 * fails on MIPS64 because their <elf.h> already has it!
484 */
485
486typedef uint8_t myElf64_Byte;		/* Type for a 8-bit quantity.  */
487
488union mips_r_info {
489	Elf64_Xword r_info;
490	struct {
491		Elf64_Word r_sym;		/* Symbol index.  */
492		myElf64_Byte r_ssym;		/* Special symbol.  */
493		myElf64_Byte r_type3;		/* Third relocation.  */
494		myElf64_Byte r_type2;		/* Second relocation.  */
495		myElf64_Byte r_type;		/* First relocation.  */
496	} r_mips;
497};
498
499static uint64_t MIPS64_r_sym(Elf64_Rel const *rp)
500{
501	return w(((union mips_r_info){ .r_info = rp->r_info }).r_mips.r_sym);
502}
503
504static void MIPS64_r_info(Elf64_Rel *const rp, unsigned sym, unsigned type)
505{
506	rp->r_info = ((union mips_r_info){
507		.r_mips = { .r_sym = w(sym), .r_type = type }
508	}).r_info;
509}
510
511static int do_file(char const *const fname)
 
512{
 
513	unsigned int reltype = 0;
514	Elf32_Ehdr *ehdr;
515	int rc = -1;
516
517	ehdr = mmap_file(fname);
518	if (!ehdr)
519		goto out;
520
 
521	w = w4nat;
522	w2 = w2nat;
523	w8 = w8nat;
524	switch (ehdr->e_ident[EI_DATA]) {
525		static unsigned int const endian = 1;
526	default:
527		fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
528			ehdr->e_ident[EI_DATA], fname);
529		goto out;
 
530	case ELFDATA2LSB:
531		if (*(unsigned char const *)&endian != 1) {
532			/* main() is big endian, file.o is little endian. */
533			w = w4rev;
534			w2 = w2rev;
535			w8 = w8rev;
536		}
537		ideal_nop4_arm = ideal_nop4_arm_le;
538		bl_mcount_arm = bl_mcount_arm_le;
539		push_arm = push_arm_le;
540		ideal_nop2_thumb = ideal_nop2_thumb_le;
541		push_bl_mcount_thumb = push_bl_mcount_thumb_le;
542		break;
543	case ELFDATA2MSB:
544		if (*(unsigned char const *)&endian != 0) {
545			/* main() is little endian, file.o is big endian. */
546			w = w4rev;
547			w2 = w2rev;
548			w8 = w8rev;
549		}
550		ideal_nop4_arm = ideal_nop4_arm_be;
551		bl_mcount_arm = bl_mcount_arm_be;
552		push_arm = push_arm_be;
553		ideal_nop2_thumb = ideal_nop2_thumb_be;
554		push_bl_mcount_thumb = push_bl_mcount_thumb_be;
555		break;
556	}  /* end switch */
557	if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0 ||
558	    w2(ehdr->e_type) != ET_REL ||
559	    ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
560		fprintf(stderr, "unrecognized ET_REL file %s\n", fname);
561		goto out;
562	}
563
564	gpfx = '_';
565	switch (w2(ehdr->e_machine)) {
566	default:
567		fprintf(stderr, "unrecognized e_machine %u %s\n",
568			w2(ehdr->e_machine), fname);
569		goto out;
 
570	case EM_386:
571		reltype = R_386_32;
572		rel_type_nop = R_386_NONE;
573		make_nop = make_nop_x86;
574		ideal_nop = ideal_nop5_x86_32;
575		mcount_adjust_32 = -1;
576		gpfx = 0;
577		break;
578	case EM_ARM:
579		reltype = R_ARM_ABS32;
580		altmcount = "__gnu_mcount_nc";
581		make_nop = make_nop_arm;
582		rel_type_nop = R_ARM_NONE;
583		is_fake_mcount32 = arm_is_fake_mcount;
584		gpfx = 0;
585		break;
586	case EM_AARCH64:
587		reltype = R_AARCH64_ABS64;
588		make_nop = make_nop_arm64;
589		rel_type_nop = R_AARCH64_NONE;
590		ideal_nop = ideal_nop4_arm64;
591		is_fake_mcount64 = arm64_is_fake_mcount;
592		break;
593	case EM_MIPS:	/* reltype: e_class    */ break;
594	case EM_LOONGARCH:	/* reltype: e_class    */ break;
595	case EM_PPC:	reltype = R_PPC_ADDR32; break;
596	case EM_PPC64:	reltype = R_PPC64_ADDR64; break;
597	case EM_S390:	/* reltype: e_class    */ break;
598	case EM_SH:	reltype = R_SH_DIR32; gpfx = 0; break;
599	case EM_SPARCV9: reltype = R_SPARC_64; break;
600	case EM_X86_64:
601		make_nop = make_nop_x86;
602		ideal_nop = ideal_nop5_x86_64;
603		reltype = R_X86_64_64;
604		rel_type_nop = R_X86_64_NONE;
605		mcount_adjust_64 = -1;
606		gpfx = 0;
607		break;
608	}  /* end switch */
609
610	switch (ehdr->e_ident[EI_CLASS]) {
611	default:
612		fprintf(stderr, "unrecognized ELF class %d %s\n",
613			ehdr->e_ident[EI_CLASS], fname);
614		goto out;
 
615	case ELFCLASS32:
616		if (w2(ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
617		||  w2(ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
618			fprintf(stderr,
619				"unrecognized ET_REL file: %s\n", fname);
620			goto out;
 
 
 
 
621		}
622		if (w2(ehdr->e_machine) == EM_MIPS) {
623			reltype = R_MIPS_32;
624			is_fake_mcount32 = MIPS32_is_fake_mcount;
625		}
626		if (w2(ehdr->e_machine) == EM_LOONGARCH) {
627			reltype = R_LARCH_32;
628			is_fake_mcount32 = LARCH32_is_fake_mcount;
629		}
630		if (do32(ehdr, fname, reltype) < 0)
631			goto out;
632		break;
633	case ELFCLASS64: {
634		Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
635		if (w2(ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
636		||  w2(ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
637			fprintf(stderr,
638				"unrecognized ET_REL file: %s\n", fname);
639			goto out;
640		}
641		if (w2(ghdr->e_machine) == EM_S390) {
642			reltype = R_390_64;
643			mcount_adjust_64 = -14;
644		}
645		if (w2(ghdr->e_machine) == EM_MIPS) {
646			reltype = R_MIPS_64;
647			Elf64_r_sym = MIPS64_r_sym;
648			Elf64_r_info = MIPS64_r_info;
649			is_fake_mcount64 = MIPS64_is_fake_mcount;
650		}
651		if (w2(ghdr->e_machine) == EM_LOONGARCH) {
652			reltype = R_LARCH_64;
653			is_fake_mcount64 = LARCH64_is_fake_mcount;
654		}
655		if (do64(ghdr, fname, reltype) < 0)
656			goto out;
657		break;
658	}
659	}  /* end switch */
660
661	rc = write_file(fname);
662out:
663	file_append_cleanup();
664	mmap_cleanup();
665	return rc;
666}
667
668int main(int argc, char *argv[])
 
669{
670	const char ftrace[] = "/ftrace.o";
671	int ftrace_size = sizeof(ftrace) - 1;
672	int n_error = 0;  /* gcc-4.3.0 false positive complaint */
673	int c;
674	int i;
675
676	while ((c = getopt(argc, argv, "w")) >= 0) {
677		switch (c) {
678		case 'w':
679			warn_on_notrace_sect = 1;
680			break;
681		default:
682			fprintf(stderr, "usage: recordmcount [-w] file.o...\n");
683			return 0;
684		}
685	}
686
687	if ((argc - optind) < 1) {
688		fprintf(stderr, "usage: recordmcount [-w] file.o...\n");
689		return 0;
690	}
691
692	/* Process each file in turn, allowing deep failure. */
693	for (i = optind; i < argc; i++) {
694		char *file = argv[i];
 
695		int len;
696
697		/*
698		 * The file kernel/trace/ftrace.o references the mcount
699		 * function but does not call it. Since ftrace.o should
700		 * not be traced anyway, we just skip it.
701		 */
702		len = strlen(file);
703		if (len >= ftrace_size &&
704		    strcmp(file + (len - ftrace_size), ftrace) == 0)
705			continue;
706
707		if (do_file(file)) {
708			fprintf(stderr, "%s: failed\n", file);
 
 
 
 
 
 
 
 
 
 
 
709			++n_error;
710		}
 
 
 
 
711	}
712	return !!n_error;
713}