[linux-block.git] / scripts / recordmcount.c

/*
 * recordmcount.c: construct a table of the locations of calls to 'mcount'
 * so that ftrace can find them quickly.
 * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>.  All rights reserved.
 * Licensed under the GNU General Public License, version 2 (GPLv2).
 *
 * Restructured to fit Linux format, as well as other updates:
 *  Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
 */

/*
 * Strategy: alter the .o file in-place.
 *
 * Append a new STRTAB that has the new section names, followed by a new array
 * ElfXX_Shdr[] that has the new section headers, followed by the section
 * contents for __mcount_loc and its relocations.  The old shstrtab strings,
 * and the old ElfXX_Shdr[] array, remain as "garbage" (commonly, a couple
 * kilobytes.)  Subsequent processing by /bin/ld (or the kernel module loader)
 * will ignore the garbage regions, because they are not designated by the
 * new .e_shoff nor the new ElfXX_Shdr[].  [In order to remove the garbage,
 * then use "ld -r" to create a new file that omits the garbage.]
 */

#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <elf.h>
#include <fcntl.h>
#include <setjmp.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

static int fd_map;	/* File descriptor for file being modified. */
static int mmap_failed; /* Boolean flag. */
static void *ehdr_curr; /* current ElfXX_Ehdr *  for resource cleanup */
static char gpfx;	/* prefix for global symbol name (sometimes '_') */
static struct stat sb;	/* Remember .st_size, etc. */
static jmp_buf jmpenv;	/* setjmp/longjmp per-file error escape */
static const char *altmcount;	/* alternate mcount symbol name */

/* setjmp() return values */
enum {
	SJ_SETJMP = 0,  /* hardwired first return */
	SJ_FAIL,
	SJ_SUCCEED
};

/* Per-file resource cleanup when multiple files. */
static void
cleanup(void)
{
	if (!mmap_failed)
		munmap(ehdr_curr, sb.st_size);
	else
		free(ehdr_curr);
	close(fd_map);
}

static void __attribute__((noreturn))
fail_file(void)
{
	cleanup();
	longjmp(jmpenv, SJ_FAIL);
}

static void __attribute__((noreturn))
succeed_file(void)
{
	cleanup();
	longjmp(jmpenv, SJ_SUCCEED);
}

/* ulseek, uread, ...:  Check return value for errors. */

static off_t
ulseek(int const fd, off_t const offset, int const whence)
{
	off_t const w = lseek(fd, offset, whence);
	if (w == (off_t)-1) {
		perror("lseek");
		fail_file();
	}
	return w;
}

static size_t
uread(int const fd, void *const buf, size_t const count)
{
	size_t const n = read(fd, buf, count);
	if (n != count) {
		perror("read");
		fail_file();
	}
	return n;
}

static size_t
uwrite(int const fd, void const *const buf, size_t const count)
{
	size_t const n = write(fd, buf, count);
	if (n != count) {
		perror("write");
		fail_file();
	}
	return n;
}

static void *
umalloc(size_t size)
{
	void *const addr = malloc(size);
	if (addr == 0) {
		fprintf(stderr, "malloc failed: %zu bytes\n", size);
		fail_file();
	}
	return addr;
}

/*
 * Get the whole file as a programming convenience in order to avoid
 * malloc+lseek+read+free of many pieces.  If successful, then mmap
 * avoids copying unused pieces; else just read the whole file.
 * Open for both read and write; new info will be appended to the file.
 * Use MAP_PRIVATE so that a few changes to the in-memory ElfXX_Ehdr
 * do not propagate to the file until an explicit overwrite at the last.
 * This preserves most aspects of consistency (all except .st_size)
 * for simultaneous readers of the file while we are appending to it.
 * However, multiple writers still are bad.  We choose not to use
 * locking because it is expensive and the use case of kernel build
 * makes multiple writers unlikely.
 */
static void *mmap_file(char const *fname)
{
	void *addr;

	fd_map = open(fname, O_RDWR);
	if (fd_map < 0 || fstat(fd_map, &sb) < 0) {
		perror(fname);
		fail_file();
	}
	if (!S_ISREG(sb.st_mode)) {
		fprintf(stderr, "not a regular file: %s\n", fname);
		fail_file();
	}
	addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
		    fd_map, 0);
	mmap_failed = 0;
	if (addr == MAP_FAILED) {
		mmap_failed = 1;
		addr = umalloc(sb.st_size);
		uread(fd_map, addr, sb.st_size);
	}
	return addr;
}

/* w8rev, w8nat, ...: Handle endianness. */

static uint64_t w8rev(uint64_t const x)
{
	return   ((0xff & (x >> (0 * 8))) << (7 * 8))
	       | ((0xff & (x >> (1 * 8))) << (6 * 8))
	       | ((0xff & (x >> (2 * 8))) << (5 * 8))
	       | ((0xff & (x >> (3 * 8))) << (4 * 8))
	       | ((0xff & (x >> (4 * 8))) << (3 * 8))
	       | ((0xff & (x >> (5 * 8))) << (2 * 8))
	       | ((0xff & (x >> (6 * 8))) << (1 * 8))
	       | ((0xff & (x >> (7 * 8))) << (0 * 8));
}

static uint32_t w4rev(uint32_t const x)
{
	return   ((0xff & (x >> (0 * 8))) << (3 * 8))
	       | ((0xff & (x >> (1 * 8))) << (2 * 8))
	       | ((0xff & (x >> (2 * 8))) << (1 * 8))
	       | ((0xff & (x >> (3 * 8))) << (0 * 8));
}

static uint32_t w2rev(uint16_t const x)
{
	return   ((0xff & (x >> (0 * 8))) << (1 * 8))
	       | ((0xff & (x >> (1 * 8))) << (0 * 8));
}

static uint64_t w8nat(uint64_t const x)
{
	return x;
}

static uint32_t w4nat(uint32_t const x)
{
	return x;
}

static uint32_t w2nat(uint16_t const x)
{
	return x;
}

static uint64_t (*w8)(uint64_t);
static uint32_t (*w)(uint32_t);
static uint32_t (*w2)(uint16_t);

/* Names of the sections that could contain calls to mcount. */
static int
is_mcounted_section_name(char const *const txtname)
{
	return strcmp(".text",           txtname) == 0 ||
		strcmp(".ref.text",      txtname) == 0 ||
		strcmp(".sched.text",    txtname) == 0 ||
		strcmp(".spinlock.text", txtname) == 0 ||
		strcmp(".irqentry.text", txtname) == 0 ||
		strcmp(".kprobes.text", txtname) == 0 ||
		strcmp(".text.unlikely", txtname) == 0;
}

/* 32 bit and 64 bit are very similar */
#include "recordmcount.h"
#define RECORD_MCOUNT_64
#include "recordmcount.h"

/* 64-bit EM_MIPS has weird ELF64_Rela.r_info.
 * http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf
 * We interpret Table 29 Relocation Operation (Elf64_Rel, Elf64_Rela) [p.40]
 * to imply the order of the members; the spec does not say so.
 *	typedef unsigned char Elf64_Byte;
 * fails on MIPS64 because their <elf.h> already has it!
 */

typedef uint8_t myElf64_Byte;		/* Type for a 8-bit quantity.  */

union mips_r_info {
	Elf64_Xword r_info;
	struct {
		Elf64_Word r_sym;		/* Symbol index.  */
		myElf64_Byte r_ssym;		/* Special symbol.  */
		myElf64_Byte r_type3;		/* Third relocation.  */
		myElf64_Byte r_type2;		/* Second relocation.  */
		myElf64_Byte r_type;		/* First relocation.  */
	} r_mips;
};

static uint64_t MIPS64_r_sym(Elf64_Rel const *rp)
{
	return w(((union mips_r_info){ .r_info = rp->r_info }).r_mips.r_sym);
}

static void MIPS64_r_info(Elf64_Rel *const rp, unsigned sym, unsigned type)
{
	rp->r_info = ((union mips_r_info){
		.r_mips = { .r_sym = w(sym), .r_type = type }
	}).r_info;
}

static void
do_file(char const *const fname)
{
	Elf32_Ehdr *const ehdr = mmap_file(fname);
	unsigned int reltype = 0;

	ehdr_curr = ehdr;
	w = w4nat;
	w2 = w2nat;
	w8 = w8nat;
	switch (ehdr->e_ident[EI_DATA]) {
		static unsigned int const endian = 1;
	default:
		fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
			ehdr->e_ident[EI_DATA], fname);
		fail_file();
		break;
	case ELFDATA2LSB:
		if (*(unsigned char const *)&endian != 1) {
			/* main() is big endian, file.o is little endian. */
			w = w4rev;
			w2 = w2rev;
			w8 = w8rev;
		}
		break;
	case ELFDATA2MSB:
		if (*(unsigned char const *)&endian != 0) {
			/* main() is little endian, file.o is big endian. */
			w = w4rev;
			w2 = w2rev;
			w8 = w8rev;
		}
		break;
	}  /* end switch */
	if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
	||  w2(ehdr->e_type) != ET_REL
	||  ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
		fprintf(stderr, "unrecognized ET_REL file %s\n", fname);
		fail_file();
	}

	gpfx = 0;
	switch (w2(ehdr->e_machine)) {
	default:
		fprintf(stderr, "unrecognized e_machine %d %s\n",
			w2(ehdr->e_machine), fname);
		fail_file();
		break;
	case EM_386:	 reltype = R_386_32;                   break;
	case EM_ARM:	 reltype = R_ARM_ABS32;
			 altmcount = "__gnu_mcount_nc";
			 break;
	case EM_IA_64:	 reltype = R_IA64_IMM64;   gpfx = '_'; break;
	case EM_MIPS:	 /* reltype: e_class    */ gpfx = '_'; break;
	case EM_PPC:	 reltype = R_PPC_ADDR32;   gpfx = '_'; break;
	case EM_PPC64:	 reltype = R_PPC64_ADDR64; gpfx = '_'; break;
	case EM_S390:    /* reltype: e_class    */ gpfx = '_'; break;
	case EM_SH:	 reltype = R_SH_DIR32;                 break;
	case EM_SPARCV9: reltype = R_SPARC_64;     gpfx = '_'; break;
	case EM_X86_64:	 reltype = R_X86_64_64;                break;
	}  /* end switch */

	switch (ehdr->e_ident[EI_CLASS]) {
	default:
		fprintf(stderr, "unrecognized ELF class %d %s\n",
			ehdr->e_ident[EI_CLASS], fname);
		fail_file();
		break;
	case ELFCLASS32:
		if (w2(ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
		||  w2(ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
			fprintf(stderr,
				"unrecognized ET_REL file: %s\n", fname);
			fail_file();
		}
		if (w2(ehdr->e_machine) == EM_S390)
			reltype = R_390_32;
		if (w2(ehdr->e_machine) == EM_MIPS) {
			reltype = R_MIPS_32;
			is_fake_mcount32 = MIPS32_is_fake_mcount;
		}
		do32(ehdr, fname, reltype);
		break;
	case ELFCLASS64: {
		Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
		if (w2(ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
		||  w2(ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
			fprintf(stderr,
				"unrecognized ET_REL file: %s\n", fname);
			fail_file();
		}
		if (w2(ghdr->e_machine) == EM_S390)
			reltype = R_390_64;
		if (w2(ghdr->e_machine) == EM_MIPS) {
			reltype = R_MIPS_64;
			Elf64_r_sym = MIPS64_r_sym;
			Elf64_r_info = MIPS64_r_info;
			is_fake_mcount64 = MIPS64_is_fake_mcount;
		}
		do64(ghdr, fname, reltype);
		break;
	}
	}  /* end switch */

	cleanup();
}

int
main(int argc, char const *argv[])
{
	const char ftrace[] = "/ftrace.o";
	int ftrace_size = sizeof(ftrace) - 1;
	int n_error = 0;  /* gcc-4.3.0 false positive complaint */

	if (argc <= 1) {
		fprintf(stderr, "usage: recordmcount file.o...\n");
		return 0;
	}

	/* Process each file in turn, allowing deep failure. */
	for (--argc, ++argv; argc > 0; --argc, ++argv) {
		int const sjval = setjmp(jmpenv);
		int len;

		/*
		 * The file kernel/trace/ftrace.o references the mcount
		 * function but does not call it. Since ftrace.o should
		 * not be traced anyway, we just skip it.
		 */
		len = strlen(argv[0]);
		if (len >= ftrace_size &&
		    strcmp(argv[0] + (len - ftrace_size), ftrace) == 0)
			continue;

		switch (sjval) {
		default:
			fprintf(stderr, "internal error: %s\n", argv[0]);
			exit(1);
			break;
		case SJ_SETJMP:    /* normal sequence */
			/* Avoid problems if early cleanup() */
			fd_map = -1;
			ehdr_curr = NULL;
			mmap_failed = 1;
			do_file(argv[0]);
			break;
		case SJ_FAIL:    /* error in do_file or below */
			++n_error;
			break;
		case SJ_SUCCEED:    /* premature success */
			/* do nothing */
			break;
		}  /* end switch */
	}
	return !!n_error;
}
Commit	Line	Data
81d3858d JR	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 <elf.h>
	28	#include <fcntl.h>
	29	#include <setjmp.h>
	30	#include <stdio.h>
	31	#include <stdlib.h>
	32	#include <string.h>
	33	#include <unistd.h>
	34
	35	static int fd_map; /* File descriptor for file being modified. */
	36	static int mmap_failed; /* Boolean flag. */
	37	static void ehdr_curr; / current ElfXX_Ehdr * for resource cleanup */
	38	static char gpfx; /* prefix for global symbol name (sometimes '_') */
	39	static struct stat sb; /* Remember .st_size, etc. */
	40	static jmp_buf jmpenv; /* setjmp/longjmp per-file error escape */
ed60453f	41	static const char altmcount; / alternate mcount symbol name */
81d3858d JR	42
	43	/* setjmp() return values */
	44	enum {
	45	SJ_SETJMP = 0, /* hardwired first return */
	46	SJ_FAIL,
	47	SJ_SUCCEED
	48	};
	49
	50	/* Per-file resource cleanup when multiple files. */
	51	static void
	52	cleanup(void)
	53	{
	54	if (!mmap_failed)
	55	munmap(ehdr_curr, sb.st_size);
	56	else
	57	free(ehdr_curr);
	58	close(fd_map);
	59	}
	60
	61	static void __attribute__((noreturn))
	62	fail_file(void)
	63	{
	64	cleanup();
	65	longjmp(jmpenv, SJ_FAIL);
	66	}
	67
	68	static void __attribute__((noreturn))
	69	succeed_file(void)
	70	{
	71	cleanup();
	72	longjmp(jmpenv, SJ_SUCCEED);
	73	}
	74
	75	/* ulseek, uread, ...: Check return value for errors. */
	76
	77	static off_t
	78	ulseek(int const fd, off_t const offset, int const whence)
	79	{
	80	off_t const w = lseek(fd, offset, whence);
dd5477ff	81	if (w == (off_t)-1) {
81d3858d JR	82	perror("lseek");
	83	fail_file();
	84	}
	85	return w;
	86	}
	87
	88	static size_t
	89	uread(int const fd, void *const buf, size_t const count)
	90	{
	91	size_t const n = read(fd, buf, count);
	92	if (n != count) {
	93	perror("read");
	94	fail_file();
	95	}
	96	return n;
	97	}
	98
	99	static size_t
	100	uwrite(int const fd, void const *const buf, size_t const count)
	101	{
	102	size_t const n = write(fd, buf, count);
	103	if (n != count) {
	104	perror("write");
	105	fail_file();
	106	}
	107	return n;
	108	}
	109
	110	static void *
	111	umalloc(size_t size)
	112	{
	113	void *const addr = malloc(size);
dd5477ff	114	if (addr == 0) {
81d3858d JR	115	fprintf(stderr, "malloc failed: %zu bytes\n", size);
	116	fail_file();
	117	}
	118	return addr;
	119	}
	120
	121	/*
	122	* Get the whole file as a programming convenience in order to avoid
	123	* malloc+lseek+read+free of many pieces. If successful, then mmap
	124	* avoids copying unused pieces; else just read the whole file.
	125	* Open for both read and write; new info will be appended to the file.
	126	* Use MAP_PRIVATE so that a few changes to the in-memory ElfXX_Ehdr
	127	* do not propagate to the file until an explicit overwrite at the last.
	128	* This preserves most aspects of consistency (all except .st_size)
	129	* for simultaneous readers of the file while we are appending to it.
	130	* However, multiple writers still are bad. We choose not to use
	131	* locking because it is expensive and the use case of kernel build
	132	* makes multiple writers unlikely.
	133	*/
	134	static void mmap_file(char const fname)
	135	{
	136	void *addr;
	137
	138	fd_map = open(fname, O_RDWR);
dd5477ff	139	if (fd_map < 0 \|\| fstat(fd_map, &sb) < 0) {
81d3858d JR	140	perror(fname);
	141	fail_file();
	142	}
	143	if (!S_ISREG(sb.st_mode)) {
	144	fprintf(stderr, "not a regular file: %s\n", fname);
	145	fail_file();
	146	}
	147	addr = mmap(0, sb.st_size, PROT_READ\|PROT_WRITE, MAP_PRIVATE,
	148	fd_map, 0);
	149	mmap_failed = 0;
dd5477ff	150	if (addr == MAP_FAILED) {
81d3858d JR	151	mmap_failed = 1;
	152	addr = umalloc(sb.st_size);
	153	uread(fd_map, addr, sb.st_size);
	154	}
	155	return addr;
	156	}
	157
	158	/* w8rev, w8nat, ...: Handle endianness. */
	159
	160	static uint64_t w8rev(uint64_t const x)
	161	{
	162	return ((0xff & (x >> (0 * 8))) << (7 * 8))
	163	\| ((0xff & (x >> (1 * 8))) << (6 * 8))
	164	\| ((0xff & (x >> (2 * 8))) << (5 * 8))
	165	\| ((0xff & (x >> (3 * 8))) << (4 * 8))
	166	\| ((0xff & (x >> (4 * 8))) << (3 * 8))
	167	\| ((0xff & (x >> (5 * 8))) << (2 * 8))
	168	\| ((0xff & (x >> (6 * 8))) << (1 * 8))
	169	\| ((0xff & (x >> (7 * 8))) << (0 * 8));
	170	}
	171
	172	static uint32_t w4rev(uint32_t const x)
	173	{
	174	return ((0xff & (x >> (0 * 8))) << (3 * 8))
	175	\| ((0xff & (x >> (1 * 8))) << (2 * 8))
	176	\| ((0xff & (x >> (2 * 8))) << (1 * 8))
	177	\| ((0xff & (x >> (3 * 8))) << (0 * 8));
	178	}
	179
	180	static uint32_t w2rev(uint16_t const x)
	181	{
	182	return ((0xff & (x >> (0 * 8))) << (1 * 8))
	183	\| ((0xff & (x >> (1 * 8))) << (0 * 8));
	184	}
	185
	186	static uint64_t w8nat(uint64_t const x)
	187	{
	188	return x;
	189	}
	190
	191	static uint32_t w4nat(uint32_t const x)
	192	{
	193	return x;
	194	}
	195
	196	static uint32_t w2nat(uint16_t const x)
	197	{
	198	return x;
	199	}
	200
	201	static uint64_t (*w8)(uint64_t);
	202	static uint32_t (*w)(uint32_t);
	203	static uint32_t (*w2)(uint16_t);
	204
	205	/* Names of the sections that could contain calls to mcount. */
	206	static int
	207	is_mcounted_section_name(char const *const txtname)
	208	{
dd5477ff SR	209	return strcmp(".text", txtname) == 0 \|\|
	210	strcmp(".ref.text", txtname) == 0 \|\|
	211	strcmp(".sched.text", txtname) == 0 \|\|
	212	strcmp(".spinlock.text", txtname) == 0 \|\|
	213	strcmp(".irqentry.text", txtname) == 0 \|\|
9f087e76	214	strcmp(".kprobes.text", txtname) == 0 \|\|
dd5477ff	215	strcmp(".text.unlikely", txtname) == 0;
81d3858d JR	216	}
81d3858d JR	217
c28d5077 SR	218	/* 32 bit and 64 bit are very similar */
	219	#include "recordmcount.h"
	220	#define RECORD_MCOUNT_64
	221	#include "recordmcount.h"
81d3858d	222
a2d49358 JR	223	/* 64-bit EM_MIPS has weird ELF64_Rela.r_info.
	224	* http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf
	225	* We interpret Table 29 Relocation Operation (Elf64_Rel, Elf64_Rela) [p.40]
	226	* to imply the order of the members; the spec does not say so.
	227	* typedef unsigned char Elf64_Byte;
	228	* fails on MIPS64 because their <elf.h> already has it!
	229	*/
	230
	231	typedef uint8_t myElf64_Byte; /* Type for a 8-bit quantity. */
	232
	233	union mips_r_info {
	234	Elf64_Xword r_info;
	235	struct {
	236	Elf64_Word r_sym; /* Symbol index. */
	237	myElf64_Byte r_ssym; /* Special symbol. */
	238	myElf64_Byte r_type3; /* Third relocation. */
	239	myElf64_Byte r_type2; /* Second relocation. */
	240	myElf64_Byte r_type; /* First relocation. */
	241	} r_mips;
	242	};
	243
	244	static uint64_t MIPS64_r_sym(Elf64_Rel const *rp)
	245	{
	246	return w(((union mips_r_info){ .r_info = rp->r_info }).r_mips.r_sym);
	247	}
	248
	249	static void MIPS64_r_info(Elf64_Rel *const rp, unsigned sym, unsigned type)
	250	{
	251	rp->r_info = ((union mips_r_info){
	252	.r_mips = { .r_sym = w(sym), .r_type = type }
	253	}).r_info;
	254	}
	255
81d3858d JR	256	static void
	257	do_file(char const *const fname)
	258	{
	259	Elf32_Ehdr *const ehdr = mmap_file(fname);
	260	unsigned int reltype = 0;
	261
	262	ehdr_curr = ehdr;
	263	w = w4nat;
	264	w2 = w2nat;
	265	w8 = w8nat;
	266	switch (ehdr->e_ident[EI_DATA]) {
	267	static unsigned int const endian = 1;
e90b0c8b	268	default:
81d3858d JR	269	fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
	270	ehdr->e_ident[EI_DATA], fname);
	271	fail_file();
e90b0c8b SR	272	break;
e90b0c8b SR	273	case ELFDATA2LSB:
dd5477ff	274	if ((unsigned char const )&endian != 1) {
81d3858d JR	275	/* main() is big endian, file.o is little endian. */
	276	w = w4rev;
	277	w2 = w2rev;
	278	w8 = w8rev;
	279	}
e90b0c8b SR	280	break;
e90b0c8b SR	281	case ELFDATA2MSB:
dd5477ff	282	if ((unsigned char const )&endian != 0) {
81d3858d JR	283	/* main() is little endian, file.o is big endian. */
	284	w = w4rev;
	285	w2 = w2rev;
	286	w8 = w8rev;
	287	}
e90b0c8b	288	break;
81d3858d	289	} /* end switch */
dd5477ff SR	290	if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
	291	\|\| w2(ehdr->e_type) != ET_REL
	292	\|\| ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
81d3858d JR	293	fprintf(stderr, "unrecognized ET_REL file %s\n", fname);
	294	fail_file();
	295	}
	296
	297	gpfx = 0;
	298	switch (w2(ehdr->e_machine)) {
e90b0c8b	299	default:
81d3858d JR	300	fprintf(stderr, "unrecognized e_machine %d %s\n",
	301	w2(ehdr->e_machine), fname);
	302	fail_file();
e90b0c8b	303	break;
81d3858d	304	case EM_386: reltype = R_386_32; break;
ed60453f RV	305	case EM_ARM: reltype = R_ARM_ABS32;
	306	altmcount = "__gnu_mcount_nc";
	307	break;
81d3858d	308	case EM_IA_64: reltype = R_IA64_IMM64; gpfx = '_'; break;
a2d49358	309	case EM_MIPS: /* reltype: e_class */ gpfx = '_'; break;
81d3858d JR	310	case EM_PPC: reltype = R_PPC_ADDR32; gpfx = '_'; break;
	311	case EM_PPC64: reltype = R_PPC64_ADDR64; gpfx = '_'; break;
	312	case EM_S390: /* reltype: e_class */ gpfx = '_'; break;
	313	case EM_SH: reltype = R_SH_DIR32; break;
	314	case EM_SPARCV9: reltype = R_SPARC_64; gpfx = '_'; break;
	315	case EM_X86_64: reltype = R_X86_64_64; break;
	316	} /* end switch */
	317
	318	switch (ehdr->e_ident[EI_CLASS]) {
e90b0c8b	319	default:
81d3858d JR	320	fprintf(stderr, "unrecognized ELF class %d %s\n",
	321	ehdr->e_ident[EI_CLASS], fname);
	322	fail_file();
e90b0c8b SR	323	break;
e90b0c8b SR	324	case ELFCLASS32:
dd5477ff SR	325	if (w2(ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
dd5477ff SR	326	\|\| w2(ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
81d3858d JR	327	fprintf(stderr,
	328	"unrecognized ET_REL file: %s\n", fname);
	329	fail_file();
	330	}
dd5477ff	331	if (w2(ehdr->e_machine) == EM_S390)
81d3858d	332	reltype = R_390_32;
dd5477ff	333	if (w2(ehdr->e_machine) == EM_MIPS) {
a2d49358	334	reltype = R_MIPS_32;
412910cd WZ	335	is_fake_mcount32 = MIPS32_is_fake_mcount;
412910cd WZ	336	}
81d3858d	337	do32(ehdr, fname, reltype);
e90b0c8b	338	break;
81d3858d JR	339	case ELFCLASS64: {
81d3858d JR	340	Elf64_Ehdr const ghdr = (Elf64_Ehdr )ehdr;
dd5477ff SR	341	if (w2(ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
dd5477ff SR	342	\|\| w2(ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
81d3858d JR	343	fprintf(stderr,
	344	"unrecognized ET_REL file: %s\n", fname);
	345	fail_file();
	346	}
dd5477ff	347	if (w2(ghdr->e_machine) == EM_S390)
81d3858d	348	reltype = R_390_64;
dd5477ff	349	if (w2(ghdr->e_machine) == EM_MIPS) {
a2d49358 JR	350	reltype = R_MIPS_64;
	351	Elf64_r_sym = MIPS64_r_sym;
	352	Elf64_r_info = MIPS64_r_info;
412910cd	353	is_fake_mcount64 = MIPS64_is_fake_mcount;
a2d49358	354	}
81d3858d	355	do64(ghdr, fname, reltype);
e90b0c8b SR	356	break;
e90b0c8b SR	357	}
81d3858d JR	358	} /* end switch */
	359
	360	cleanup();
	361	}
	362
	363	int
	364	main(int argc, char const *argv[])
	365	{
cd3478f2	366	const char ftrace[] = "/ftrace.o";
44475863	367	int ftrace_size = sizeof(ftrace) - 1;
81d3858d	368	int n_error = 0; /* gcc-4.3.0 false positive complaint */
44475863 SR	369
44475863 SR	370	if (argc <= 1) {
81d3858d	371	fprintf(stderr, "usage: recordmcount file.o...\n");
44475863 SR	372	return 0;
	373	}
	374
	375	/* Process each file in turn, allowing deep failure. */
dd5477ff	376	for (--argc, ++argv; argc > 0; --argc, ++argv) {
81d3858d	377	int const sjval = setjmp(jmpenv);
44475863 SR	378	int len;
	379
	380	/*
	381	* The file kernel/trace/ftrace.o references the mcount
	382	* function but does not call it. Since ftrace.o should
	383	* not be traced anyway, we just skip it.
	384	*/
	385	len = strlen(argv[0]);
	386	if (len >= ftrace_size &&
	387	strcmp(argv[0] + (len - ftrace_size), ftrace) == 0)
	388	continue;
	389
81d3858d	390	switch (sjval) {
e90b0c8b	391	default:
81d3858d JR	392	fprintf(stderr, "internal error: %s\n", argv[0]);
81d3858d JR	393	exit(1);
e90b0c8b SR	394	break;
e90b0c8b SR	395	case SJ_SETJMP: /* normal sequence */
81d3858d JR	396	/* Avoid problems if early cleanup() */
	397	fd_map = -1;
	398	ehdr_curr = NULL;
	399	mmap_failed = 1;
	400	do_file(argv[0]);
e90b0c8b SR	401	break;
e90b0c8b SR	402	case SJ_FAIL: /* error in do_file or below */
81d3858d	403	++n_error;
e90b0c8b SR	404	break;
e90b0c8b SR	405	case SJ_SUCCEED: /* premature success */
81d3858d	406	/* do nothing */
e90b0c8b	407	break;
81d3858d JR	408	} /* end switch */
	409	}
	410	return !!n_error;
	411	}
	412
	413