[mirror_ubuntu-artful-kernel.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_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:
		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
adace895 WD	38	#ifndef EM_AARCH64
	39	#define EM_AARCH64 183
	40	#endif
	41
372c7209 MS	42	#ifndef EM_MICROBLAZE
	43	#define EM_MICROBLAZE 189
	44	#endif
	45
a79f248b DD	46	static int fd_map; /* File descriptor for file being modified. */
	47	static int mmap_failed; /* Boolean flag. */
	48	static void ehdr_curr; / current ElfXX_Ehdr * for resource cleanup */
	49	static struct stat sb; /* Remember .st_size, etc. */
	50	static jmp_buf jmpenv; /* setjmp/longjmp per-file error escape */
	51
	52	/* setjmp() return values */
	53	enum {
	54	SJ_SETJMP = 0, /* hardwired first return */
	55	SJ_FAIL,
	56	SJ_SUCCEED
	57	};
	58
	59	/* Per-file resource cleanup when multiple files. */
	60	static void
	61	cleanup(void)
	62	{
	63	if (!mmap_failed)
	64	munmap(ehdr_curr, sb.st_size);
	65	close(fd_map);
	66	}
	67
	68	static void __attribute__((noreturn))
	69	fail_file(void)
	70	{
	71	cleanup();
	72	longjmp(jmpenv, SJ_FAIL);
	73	}
	74
a79f248b DD	75	/*
	76	* Get the whole file as a programming convenience in order to avoid
	77	* malloc+lseek+read+free of many pieces. If successful, then mmap
	78	* avoids copying unused pieces; else just read the whole file.
	79	* Open for both read and write.
	80	*/
	81	static void mmap_file(char const fname)
	82	{
	83	void *addr;
	84
	85	fd_map = open(fname, O_RDWR);
	86	if (fd_map < 0 \|\| fstat(fd_map, &sb) < 0) {
	87	perror(fname);
	88	fail_file();
	89	}
	90	if (!S_ISREG(sb.st_mode)) {
	91	fprintf(stderr, "not a regular file: %s\n", fname);
	92	fail_file();
	93	}
	94	addr = mmap(0, sb.st_size, PROT_READ\|PROT_WRITE, MAP_SHARED,
	95	fd_map, 0);
	96	if (addr == MAP_FAILED) {
	97	mmap_failed = 1;
	98	fprintf(stderr, "Could not mmap file: %s\n", fname);
	99	fail_file();
	100	}
	101	return addr;
	102	}
	103
d59a1683	104	static uint64_t r8be(const uint64_t *x)
a79f248b	105	{
d59a1683	106	return get_unaligned_be64(x);
a79f248b	107	}
d59a1683	108	static uint32_t rbe(const uint32_t *x)
a79f248b	109	{
d59a1683	110	return get_unaligned_be32(x);
a79f248b	111	}
d59a1683	112	static uint16_t r2be(const uint16_t *x)
a79f248b	113	{
d59a1683	114	return get_unaligned_be16(x);
a79f248b	115	}
d59a1683	116	static uint64_t r8le(const uint64_t *x)
a79f248b	117	{
d59a1683	118	return get_unaligned_le64(x);
a79f248b	119	}
d59a1683 DD	120	static uint32_t rle(const uint32_t *x)
	121	{
	122	return get_unaligned_le32(x);
	123	}
	124	static uint16_t r2le(const uint16_t *x)
a79f248b	125	{
d59a1683	126	return get_unaligned_le16(x);
a79f248b DD	127	}
a79f248b DD	128
d59a1683 DD	129	static void w8be(uint64_t val, uint64_t *x)
	130	{
	131	put_unaligned_be64(val, x);
	132	}
	133	static void wbe(uint32_t val, uint32_t *x)
	134	{
	135	put_unaligned_be32(val, x);
	136	}
	137	static void w2be(uint16_t val, uint16_t *x)
	138	{
	139	put_unaligned_be16(val, x);
	140	}
	141	static void w8le(uint64_t val, uint64_t *x)
	142	{
	143	put_unaligned_le64(val, x);
	144	}
	145	static void wle(uint32_t val, uint32_t *x)
	146	{
	147	put_unaligned_le32(val, x);
	148	}
	149	static void w2le(uint16_t val, uint16_t *x)
a79f248b	150	{
d59a1683	151	put_unaligned_le16(val, x);
a79f248b DD	152	}
a79f248b DD	153
d59a1683 DD	154	static uint64_t (r8)(const uint64_t );
	155	static uint32_t (r)(const uint32_t );
	156	static uint16_t (r2)(const uint16_t );
	157	static void (w8)(uint64_t, uint64_t );
	158	static void (w)(uint32_t, uint32_t );
	159	static void (w2)(uint16_t, uint16_t );
a79f248b	160
d59a1683	161	typedef void (table_sort_t)(char , int);
a79f248b	162
59c36455 JI	163	/*
	164	* Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
	165	* the way to -256..-1, to avoid conflicting with real section
	166	* indices.
	167	*/
	168	#define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))
	169
	170	static inline int is_shndx_special(unsigned int i)
	171	{
	172	return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
	173	}
	174
	175	/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
	176	static inline unsigned int get_secindex(unsigned int shndx,
	177	unsigned int sym_offs,
	178	const Elf32_Word *symtab_shndx_start)
	179	{
	180	if (is_shndx_special(shndx))
	181	return SPECIAL(shndx);
	182	if (shndx != SHN_XINDEX)
	183	return shndx;
	184	return r(&symtab_shndx_start[sym_offs]);
	185	}
	186
a79f248b DD	187	/* 32 bit and 64 bit are very similar */
	188	#include "sortextable.h"
	189	#define SORTEXTABLE_64
	190	#include "sortextable.h"
	191
eb608fb3	192	static int compare_relative_table(const void a, const void b)
d59a1683 DD	193	{
	194	int32_t av = (int32_t)r(a);
	195	int32_t bv = (int32_t)r(b);
	196
	197	if (av < bv)
	198	return -1;
	199	if (av > bv)
	200	return 1;
	201	return 0;
	202	}
	203
eb608fb3	204	static void sort_relative_table(char *extab_image, int image_size)
d59a1683 DD	205	{
	206	int i;
	207
	208	/*
	209	* Do the same thing the runtime sort does, first normalize to
	210	* being relative to the start of the section.
	211	*/
	212	i = 0;
	213	while (i < image_size) {
	214	uint32_t loc = (uint32_t )(extab_image + i);
	215	w(r(loc) + i, loc);
	216	i += 4;
	217	}
	218
eb608fb3	219	qsort(extab_image, image_size / 8, 8, compare_relative_table);
d59a1683 DD	220
	221	/* Now denormalize. */
	222	i = 0;
	223	while (i < image_size) {
	224	uint32_t loc = (uint32_t )(extab_image + i);
	225	w(r(loc) - i, loc);
	226	i += 4;
	227	}
	228	}
a79f248b DD	229
	230	static void
	231	do_file(char const *const fname)
	232	{
d59a1683 DD	233	table_sort_t custom_sort;
d59a1683 DD	234	Elf32_Ehdr *ehdr = mmap_file(fname);
a79f248b DD	235
a79f248b DD	236	ehdr_curr = ehdr;
a79f248b	237	switch (ehdr->e_ident[EI_DATA]) {
a79f248b DD	238	default:
	239	fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
	240	ehdr->e_ident[EI_DATA], fname);
	241	fail_file();
	242	break;
	243	case ELFDATA2LSB:
d59a1683 DD	244	r = rle;
	245	r2 = r2le;
	246	r8 = r8le;
	247	w = wle;
	248	w2 = w2le;
	249	w8 = w8le;
a79f248b DD	250	break;
a79f248b DD	251	case ELFDATA2MSB:
d59a1683 DD	252	r = rbe;
	253	r2 = r2be;
	254	r8 = r8be;
	255	w = wbe;
	256	w2 = w2be;
	257	w8 = w8be;
a79f248b DD	258	break;
	259	} /* end switch */
	260	if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
d59a1683	261	\|\| r2(&ehdr->e_type) != ET_EXEC
a79f248b DD	262	\|\| ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
	263	fprintf(stderr, "unrecognized ET_EXEC file %s\n", fname);
	264	fail_file();
	265	}
	266
d59a1683 DD	267	custom_sort = NULL;
d59a1683 DD	268	switch (r2(&ehdr->e_machine)) {
a79f248b DD	269	default:
a79f248b DD	270	fprintf(stderr, "unrecognized e_machine %d %s\n",
d59a1683	271	r2(&ehdr->e_machine), fname);
a79f248b DD	272	fail_file();
	273	break;
	274	case EM_386:
a79f248b	275	case EM_X86_64:
3193a98d	276	case EM_S390:
eb608fb3 HC	277	custom_sort = sort_relative_table;
eb608fb3 HC	278	break;
f06d19e4	279	case EM_ARCOMPACT:
ee951c63	280	case EM_ARM:
adace895	281	case EM_AARCH64:
372c7209	282	case EM_MICROBLAZE:
d59a1683	283	case EM_MIPS:
a79f248b DD	284	break;
	285	} /* end switch */
	286
	287	switch (ehdr->e_ident[EI_CLASS]) {
	288	default:
	289	fprintf(stderr, "unrecognized ELF class %d %s\n",
	290	ehdr->e_ident[EI_CLASS], fname);
	291	fail_file();
	292	break;
	293	case ELFCLASS32:
d59a1683 DD	294	if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
d59a1683 DD	295	\|\| r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
a79f248b DD	296	fprintf(stderr,
	297	"unrecognized ET_EXEC file: %s\n", fname);
	298	fail_file();
	299	}
d59a1683	300	do32(ehdr, fname, custom_sort);
a79f248b DD	301	break;
	302	case ELFCLASS64: {
	303	Elf64_Ehdr const ghdr = (Elf64_Ehdr )ehdr;
d59a1683 DD	304	if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
d59a1683 DD	305	\|\| r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
a79f248b DD	306	fprintf(stderr,
	307	"unrecognized ET_EXEC file: %s\n", fname);
	308	fail_file();
	309	}
d59a1683	310	do64(ghdr, fname, custom_sort);
a79f248b DD	311	break;
	312	}
	313	} /* end switch */
	314
	315	cleanup();
	316	}
	317
	318	int
	319	main(int argc, char *argv[])
	320	{
	321	int n_error = 0; /* gcc-4.3.0 false positive complaint */
	322	int i;
	323
	324	if (argc < 2) {
	325	fprintf(stderr, "usage: sortextable vmlinux...\n");
	326	return 0;
	327	}
	328
	329	/* Process each file in turn, allowing deep failure. */
	330	for (i = 1; i < argc; i++) {
	331	char *file = argv[i];
	332	int const sjval = setjmp(jmpenv);
	333
	334	switch (sjval) {
	335	default:
	336	fprintf(stderr, "internal error: %s\n", file);
	337	exit(1);
	338	break;
	339	case SJ_SETJMP: /* normal sequence */
	340	/* Avoid problems if early cleanup() */
	341	fd_map = -1;
	342	ehdr_curr = NULL;
	343	mmap_failed = 1;
	344	do_file(file);
	345	break;
	346	case SJ_FAIL: /* error in do_file or below */
	347	++n_error;
	348	break;
	349	case SJ_SUCCEED: /* premature success */
	350	/* do nothing */
	351	break;
	352	} /* end switch */
	353	}
	354	return !!n_error;
	355	}