[linux-2.6-block.git] / scripts / sortextable.c

/*
 * sortextable.c: Sort the kernel's exception table
 *
 * Copyright 2011 - 2012 Cavium, Inc.
 *
 * Based on code taken from recortmcount.c which is:
 *
 * 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 vmlinux file in-place.
 */

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

#include <tools/be_byteshift.h>
#include <tools/le_byteshift.h>

#ifndef EM_ARCOMPACT
#define EM_ARCOMPACT	93
#endif

#ifndef EM_XTENSA
#define EM_XTENSA	94
#endif

#ifndef EM_AARCH64
#define EM_AARCH64	183
#endif

#ifndef EM_MICROBLAZE
#define EM_MICROBLAZE	189
#endif

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 struct stat sb;	/* Remember .st_size, etc. */
static jmp_buf jmpenv;	/* setjmp/longjmp per-file error escape */

/* 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);
	close(fd_map);
}

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

/*
 * 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.
 */
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_SHARED,
		    fd_map, 0);
	if (addr == MAP_FAILED) {
		mmap_failed = 1;
		fprintf(stderr, "Could not mmap file: %s\n", fname);
		fail_file();
	}
	return addr;
}

static uint64_t r8be(const uint64_t *x)
{
	return get_unaligned_be64(x);
}
static uint32_t rbe(const uint32_t *x)
{
	return get_unaligned_be32(x);
}
static uint16_t r2be(const uint16_t *x)
{
	return get_unaligned_be16(x);
}
static uint64_t r8le(const uint64_t *x)
{
	return get_unaligned_le64(x);
}
static uint32_t rle(const uint32_t *x)
{
	return get_unaligned_le32(x);
}
static uint16_t r2le(const uint16_t *x)
{
	return get_unaligned_le16(x);
}

static void w8be(uint64_t val, uint64_t *x)
{
	put_unaligned_be64(val, x);
}
static void wbe(uint32_t val, uint32_t *x)
{
	put_unaligned_be32(val, x);
}
static void w2be(uint16_t val, uint16_t *x)
{
	put_unaligned_be16(val, x);
}
static void w8le(uint64_t val, uint64_t *x)
{
	put_unaligned_le64(val, x);
}
static void wle(uint32_t val, uint32_t *x)
{
	put_unaligned_le32(val, x);
}
static void w2le(uint16_t val, uint16_t *x)
{
	put_unaligned_le16(val, x);
}

static uint64_t (*r8)(const uint64_t *);
static uint32_t (*r)(const uint32_t *);
static uint16_t (*r2)(const uint16_t *);
static void (*w8)(uint64_t, uint64_t *);
static void (*w)(uint32_t, uint32_t *);
static void (*w2)(uint16_t, uint16_t *);

typedef void (*table_sort_t)(char *, int);

/*
 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
 * the way to -256..-1, to avoid conflicting with real section
 * indices.
 */
#define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))

static inline int is_shndx_special(unsigned int i)
{
	return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
}

/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
static inline unsigned int get_secindex(unsigned int shndx,
					unsigned int sym_offs,
					const Elf32_Word *symtab_shndx_start)
{
	if (is_shndx_special(shndx))
		return SPECIAL(shndx);
	if (shndx != SHN_XINDEX)
		return shndx;
	return r(&symtab_shndx_start[sym_offs]);
}

/* 32 bit and 64 bit are very similar */
#include "sortextable.h"
#define SORTEXTABLE_64
#include "sortextable.h"

static int compare_relative_table(const void *a, const void *b)
{
	int32_t av = (int32_t)r(a);
	int32_t bv = (int32_t)r(b);

	if (av < bv)
		return -1;
	if (av > bv)
		return 1;
	return 0;
}

static void sort_relative_table(char *extab_image, int image_size)
{
	int i;

	/*
	 * Do the same thing the runtime sort does, first normalize to
	 * being relative to the start of the section.
	 */
	i = 0;
	while (i < image_size) {
		uint32_t *loc = (uint32_t *)(extab_image + i);
		w(r(loc) + i, loc);
		i += 4;
	}

	qsort(extab_image, image_size / 8, 8, compare_relative_table);

	/* Now denormalize. */
	i = 0;
	while (i < image_size) {
		uint32_t *loc = (uint32_t *)(extab_image + i);
		w(r(loc) - i, loc);
		i += 4;
	}
}

static void
do_file(char const *const fname)
{
	table_sort_t custom_sort;
	Elf32_Ehdr *ehdr = mmap_file(fname);

	ehdr_curr = ehdr;
	switch (ehdr->e_ident[EI_DATA]) {
	default:
		fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
			ehdr->e_ident[EI_DATA], fname);
		fail_file();
		break;
	case ELFDATA2LSB:
		r = rle;
		r2 = r2le;
		r8 = r8le;
		w = wle;
		w2 = w2le;
		w8 = w8le;
		break;
	case ELFDATA2MSB:
		r = rbe;
		r2 = r2be;
		r8 = r8be;
		w = wbe;
		w2 = w2be;
		w8 = w8be;
		break;
	}  /* end switch */
	if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
	||  r2(&ehdr->e_type) != ET_EXEC
	||  ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
		fprintf(stderr, "unrecognized ET_EXEC file %s\n", fname);
		fail_file();
	}

	custom_sort = NULL;
	switch (r2(&ehdr->e_machine)) {
	default:
		fprintf(stderr, "unrecognized e_machine %d %s\n",
			r2(&ehdr->e_machine), fname);
		fail_file();
		break;
	case EM_386:
	case EM_X86_64:
	case EM_S390:
		custom_sort = sort_relative_table;
		break;
	case EM_ARCOMPACT:
	case EM_ARM:
	case EM_AARCH64:
	case EM_MICROBLAZE:
	case EM_MIPS:
	case EM_XTENSA:
		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 (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
		||  r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
			fprintf(stderr,
				"unrecognized ET_EXEC file: %s\n", fname);
			fail_file();
		}
		do32(ehdr, fname, custom_sort);
		break;
	case ELFCLASS64: {
		Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
		if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
		||  r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
			fprintf(stderr,
				"unrecognized ET_EXEC file: %s\n", fname);
			fail_file();
		}
		do64(ghdr, fname, custom_sort);
		break;
	}
	}  /* end switch */

	cleanup();
}

int
main(int argc, char *argv[])
{
	int n_error = 0;  /* gcc-4.3.0 false positive complaint */
	int i;

	if (argc < 2) {
		fprintf(stderr, "usage: sortextable vmlinux...\n");
		return 0;
	}

	/* Process each file in turn, allowing deep failure. */
	for (i = 1; i < argc; i++) {
		char *file = argv[i];
		int const sjval = setjmp(jmpenv);

		switch (sjval) {
		default:
			fprintf(stderr, "internal error: %s\n", file);
			exit(1);
			break;
		case SJ_SETJMP:    /* normal sequence */
			/* Avoid problems if early cleanup() */
			fd_map = -1;
			ehdr_curr = NULL;
			mmap_failed = 1;
			do_file(file);
			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
a79f248b DD	1	/*
	2	* sortextable.c: Sort the kernel's exception table
	3	*
d59a1683	4	* Copyright 2011 - 2012 Cavium, Inc.
a79f248b DD	5	*
	6	* Based on code taken from recortmcount.c which is:
	7	*
	8	* Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.
	9	* Licensed under the GNU General Public License, version 2 (GPLv2).
	10	*
	11	* Restructured to fit Linux format, as well as other updates:
	12	* Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
	13	*/
	14
	15	/*
	16	* Strategy: alter the vmlinux file in-place.
	17	*/
	18
	19	#include <sys/types.h>
	20	#include <sys/mman.h>
	21	#include <sys/stat.h>
	22	#include <getopt.h>
	23	#include <elf.h>
	24	#include <fcntl.h>
	25	#include <setjmp.h>
	26	#include <stdio.h>
	27	#include <stdlib.h>
	28	#include <string.h>
	29	#include <unistd.h>
	30
d59a1683 DD	31	#include <tools/be_byteshift.h>
	32	#include <tools/le_byteshift.h>
	33
f06d19e4 VG	34	#ifndef EM_ARCOMPACT
	35	#define EM_ARCOMPACT 93
	36	#endif
	37
25df8198 MF	38	#ifndef EM_XTENSA
	39	#define EM_XTENSA 94
	40	#endif
	41
adace895 WD	42	#ifndef EM_AARCH64
	43	#define EM_AARCH64 183
	44	#endif
	45
372c7209 MS	46	#ifndef EM_MICROBLAZE
	47	#define EM_MICROBLAZE 189
	48	#endif
	49
a79f248b DD	50	static int fd_map; /* File descriptor for file being modified. */
	51	static int mmap_failed; /* Boolean flag. */
	52	static void ehdr_curr; / current ElfXX_Ehdr * for resource cleanup */
	53	static struct stat sb; /* Remember .st_size, etc. */
	54	static jmp_buf jmpenv; /* setjmp/longjmp per-file error escape */
	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(ehdr_curr, sb.st_size);
	69	close(fd_map);
	70	}
	71
	72	static void __attribute__((noreturn))
	73	fail_file(void)
	74	{
	75	cleanup();
	76	longjmp(jmpenv, SJ_FAIL);
	77	}
	78
a79f248b DD	79	/*
	80	* Get the whole file as a programming convenience in order to avoid
	81	* malloc+lseek+read+free of many pieces. If successful, then mmap
	82	* avoids copying unused pieces; else just read the whole file.
	83	* Open for both read and write.
	84	*/
	85	static void mmap_file(char const fname)
	86	{
	87	void *addr;
	88
	89	fd_map = open(fname, O_RDWR);
	90	if (fd_map < 0 \|\| fstat(fd_map, &sb) < 0) {
	91	perror(fname);
	92	fail_file();
	93	}
	94	if (!S_ISREG(sb.st_mode)) {
	95	fprintf(stderr, "not a regular file: %s\n", fname);
	96	fail_file();
	97	}
	98	addr = mmap(0, sb.st_size, PROT_READ\|PROT_WRITE, MAP_SHARED,
	99	fd_map, 0);
	100	if (addr == MAP_FAILED) {
	101	mmap_failed = 1;
	102	fprintf(stderr, "Could not mmap file: %s\n", fname);
	103	fail_file();
	104	}
	105	return addr;
	106	}
	107
d59a1683	108	static uint64_t r8be(const uint64_t *x)
a79f248b	109	{
d59a1683	110	return get_unaligned_be64(x);
a79f248b	111	}
d59a1683	112	static uint32_t rbe(const uint32_t *x)
a79f248b	113	{
d59a1683	114	return get_unaligned_be32(x);
a79f248b	115	}
d59a1683	116	static uint16_t r2be(const uint16_t *x)
a79f248b	117	{
d59a1683	118	return get_unaligned_be16(x);
a79f248b	119	}
d59a1683	120	static uint64_t r8le(const uint64_t *x)
a79f248b	121	{
d59a1683	122	return get_unaligned_le64(x);
a79f248b	123	}
d59a1683 DD	124	static uint32_t rle(const uint32_t *x)
	125	{
	126	return get_unaligned_le32(x);
	127	}
	128	static uint16_t r2le(const uint16_t *x)
a79f248b	129	{
d59a1683	130	return get_unaligned_le16(x);
a79f248b DD	131	}
a79f248b DD	132
d59a1683 DD	133	static void w8be(uint64_t val, uint64_t *x)
	134	{
	135	put_unaligned_be64(val, x);
	136	}
	137	static void wbe(uint32_t val, uint32_t *x)
	138	{
	139	put_unaligned_be32(val, x);
	140	}
	141	static void w2be(uint16_t val, uint16_t *x)
	142	{
	143	put_unaligned_be16(val, x);
	144	}
	145	static void w8le(uint64_t val, uint64_t *x)
	146	{
	147	put_unaligned_le64(val, x);
	148	}
	149	static void wle(uint32_t val, uint32_t *x)
	150	{
	151	put_unaligned_le32(val, x);
	152	}
	153	static void w2le(uint16_t val, uint16_t *x)
a79f248b	154	{
d59a1683	155	put_unaligned_le16(val, x);
a79f248b DD	156	}
a79f248b DD	157
d59a1683 DD	158	static uint64_t (r8)(const uint64_t );
	159	static uint32_t (r)(const uint32_t );
	160	static uint16_t (r2)(const uint16_t );
	161	static void (w8)(uint64_t, uint64_t );
	162	static void (w)(uint32_t, uint32_t );
	163	static void (w2)(uint16_t, uint16_t );
a79f248b	164
d59a1683	165	typedef void (table_sort_t)(char , int);
a79f248b	166
59c36455 JI	167	/*
	168	* Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
	169	* the way to -256..-1, to avoid conflicting with real section
	170	* indices.
	171	*/
	172	#define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))
	173
	174	static inline int is_shndx_special(unsigned int i)
	175	{
	176	return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
	177	}
	178
	179	/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
	180	static inline unsigned int get_secindex(unsigned int shndx,
	181	unsigned int sym_offs,
	182	const Elf32_Word *symtab_shndx_start)
	183	{
	184	if (is_shndx_special(shndx))
	185	return SPECIAL(shndx);
	186	if (shndx != SHN_XINDEX)
	187	return shndx;
	188	return r(&symtab_shndx_start[sym_offs]);
	189	}
	190
a79f248b DD	191	/* 32 bit and 64 bit are very similar */
	192	#include "sortextable.h"
	193	#define SORTEXTABLE_64
	194	#include "sortextable.h"
	195
eb608fb3	196	static int compare_relative_table(const void a, const void b)
d59a1683 DD	197	{
	198	int32_t av = (int32_t)r(a);
	199	int32_t bv = (int32_t)r(b);
	200
	201	if (av < bv)
	202	return -1;
	203	if (av > bv)
	204	return 1;
	205	return 0;
	206	}
	207
eb608fb3	208	static void sort_relative_table(char *extab_image, int image_size)
d59a1683 DD	209	{
	210	int i;
	211
	212	/*
	213	* Do the same thing the runtime sort does, first normalize to
	214	* being relative to the start of the section.
	215	*/
	216	i = 0;
	217	while (i < image_size) {
	218	uint32_t loc = (uint32_t )(extab_image + i);
	219	w(r(loc) + i, loc);
	220	i += 4;
	221	}
	222
eb608fb3	223	qsort(extab_image, image_size / 8, 8, compare_relative_table);
d59a1683 DD	224
	225	/* Now denormalize. */
	226	i = 0;
	227	while (i < image_size) {
	228	uint32_t loc = (uint32_t )(extab_image + i);
	229	w(r(loc) - i, loc);
	230	i += 4;
	231	}
	232	}
a79f248b DD	233
	234	static void
	235	do_file(char const *const fname)
	236	{
d59a1683 DD	237	table_sort_t custom_sort;
d59a1683 DD	238	Elf32_Ehdr *ehdr = mmap_file(fname);
a79f248b DD	239
a79f248b DD	240	ehdr_curr = ehdr;
a79f248b	241	switch (ehdr->e_ident[EI_DATA]) {
a79f248b DD	242	default:
	243	fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
	244	ehdr->e_ident[EI_DATA], fname);
	245	fail_file();
	246	break;
	247	case ELFDATA2LSB:
d59a1683 DD	248	r = rle;
	249	r2 = r2le;
	250	r8 = r8le;
	251	w = wle;
	252	w2 = w2le;
	253	w8 = w8le;
a79f248b DD	254	break;
a79f248b DD	255	case ELFDATA2MSB:
d59a1683 DD	256	r = rbe;
	257	r2 = r2be;
	258	r8 = r8be;
	259	w = wbe;
	260	w2 = w2be;
	261	w8 = w8be;
a79f248b DD	262	break;
	263	} /* end switch */
	264	if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
d59a1683	265	\|\| r2(&ehdr->e_type) != ET_EXEC
a79f248b DD	266	\|\| ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
	267	fprintf(stderr, "unrecognized ET_EXEC file %s\n", fname);
	268	fail_file();
	269	}
	270
d59a1683 DD	271	custom_sort = NULL;
d59a1683 DD	272	switch (r2(&ehdr->e_machine)) {
a79f248b DD	273	default:
a79f248b DD	274	fprintf(stderr, "unrecognized e_machine %d %s\n",
d59a1683	275	r2(&ehdr->e_machine), fname);
a79f248b DD	276	fail_file();
	277	break;
	278	case EM_386:
a79f248b	279	case EM_X86_64:
3193a98d	280	case EM_S390:
eb608fb3 HC	281	custom_sort = sort_relative_table;
eb608fb3 HC	282	break;
f06d19e4	283	case EM_ARCOMPACT:
ee951c63	284	case EM_ARM:
adace895	285	case EM_AARCH64:
372c7209	286	case EM_MICROBLAZE:
d59a1683	287	case EM_MIPS:
25df8198	288	case EM_XTENSA:
a79f248b DD	289	break;
	290	} /* end switch */
	291
	292	switch (ehdr->e_ident[EI_CLASS]) {
	293	default:
	294	fprintf(stderr, "unrecognized ELF class %d %s\n",
	295	ehdr->e_ident[EI_CLASS], fname);
	296	fail_file();
	297	break;
	298	case ELFCLASS32:
d59a1683 DD	299	if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
d59a1683 DD	300	\|\| r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
a79f248b DD	301	fprintf(stderr,
	302	"unrecognized ET_EXEC file: %s\n", fname);
	303	fail_file();
	304	}
d59a1683	305	do32(ehdr, fname, custom_sort);
a79f248b DD	306	break;
	307	case ELFCLASS64: {
	308	Elf64_Ehdr const ghdr = (Elf64_Ehdr )ehdr;
d59a1683 DD	309	if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
d59a1683 DD	310	\|\| r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
a79f248b DD	311	fprintf(stderr,
	312	"unrecognized ET_EXEC file: %s\n", fname);
	313	fail_file();
	314	}
d59a1683	315	do64(ghdr, fname, custom_sort);
a79f248b DD	316	break;
	317	}
	318	} /* end switch */
	319
	320	cleanup();
	321	}
	322
	323	int
	324	main(int argc, char *argv[])
	325	{
	326	int n_error = 0; /* gcc-4.3.0 false positive complaint */
	327	int i;
	328
	329	if (argc < 2) {
	330	fprintf(stderr, "usage: sortextable vmlinux...\n");
	331	return 0;
	332	}
	333
	334	/* Process each file in turn, allowing deep failure. */
	335	for (i = 1; i < argc; i++) {
	336	char *file = argv[i];
	337	int const sjval = setjmp(jmpenv);
	338
	339	switch (sjval) {
	340	default:
	341	fprintf(stderr, "internal error: %s\n", file);
	342	exit(1);
	343	break;
	344	case SJ_SETJMP: /* normal sequence */
	345	/* Avoid problems if early cleanup() */
	346	fd_map = -1;
	347	ehdr_curr = NULL;
	348	mmap_failed = 1;
	349	do_file(file);
	350	break;
	351	case SJ_FAIL: /* error in do_file or below */
	352	++n_error;
	353	break;
	354	case SJ_SUCCEED: /* premature success */
	355	/* do nothing */
	356	break;
	357	} /* end switch */
	358	}
	359	return !!n_error;
	360	}