[linux.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 <[email protected]>.  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 <[email protected]>, 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

#ifndef EM_ARCV2
#define EM_ARCV2	195
#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 && r2(&ehdr->e_type) != ET_DYN)
	||  ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
		fprintf(stderr, "unrecognized ET_EXEC/ET_DYN 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_ARCV2:
	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/ET_DYN 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/ET_DYN 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 <[email protected]>. 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 <[email protected]>, 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
b3210d14 VG	50	#ifndef EM_ARCV2
	51	#define EM_ARCV2 195
	52	#endif
	53
a79f248b DD	54	static int fd_map; /* File descriptor for file being modified. */
	55	static int mmap_failed; /* Boolean flag. */
	56	static void ehdr_curr; / current ElfXX_Ehdr * for resource cleanup */
	57	static struct stat sb; /* Remember .st_size, etc. */
	58	static jmp_buf jmpenv; /* setjmp/longjmp per-file error escape */
	59
	60	/* setjmp() return values */
	61	enum {
	62	SJ_SETJMP = 0, /* hardwired first return */
	63	SJ_FAIL,
	64	SJ_SUCCEED
	65	};
	66
	67	/* Per-file resource cleanup when multiple files. */
	68	static void
	69	cleanup(void)
	70	{
	71	if (!mmap_failed)
	72	munmap(ehdr_curr, sb.st_size);
	73	close(fd_map);
	74	}
	75
	76	static void __attribute__((noreturn))
	77	fail_file(void)
	78	{
	79	cleanup();
	80	longjmp(jmpenv, SJ_FAIL);
	81	}
	82
a79f248b DD	83	/*
	84	* Get the whole file as a programming convenience in order to avoid
	85	* malloc+lseek+read+free of many pieces. If successful, then mmap
	86	* avoids copying unused pieces; else just read the whole file.
	87	* Open for both read and write.
	88	*/
	89	static void mmap_file(char const fname)
	90	{
	91	void *addr;
	92
	93	fd_map = open(fname, O_RDWR);
	94	if (fd_map < 0 \|\| fstat(fd_map, &sb) < 0) {
	95	perror(fname);
	96	fail_file();
	97	}
	98	if (!S_ISREG(sb.st_mode)) {
	99	fprintf(stderr, "not a regular file: %s\n", fname);
	100	fail_file();
	101	}
	102	addr = mmap(0, sb.st_size, PROT_READ\|PROT_WRITE, MAP_SHARED,
	103	fd_map, 0);
	104	if (addr == MAP_FAILED) {
	105	mmap_failed = 1;
	106	fprintf(stderr, "Could not mmap file: %s\n", fname);
	107	fail_file();
	108	}
	109	return addr;
	110	}
	111
d59a1683	112	static uint64_t r8be(const uint64_t *x)
a79f248b	113	{
d59a1683	114	return get_unaligned_be64(x);
a79f248b	115	}
d59a1683	116	static uint32_t rbe(const uint32_t *x)
a79f248b	117	{
d59a1683	118	return get_unaligned_be32(x);
a79f248b	119	}
d59a1683	120	static uint16_t r2be(const uint16_t *x)
a79f248b	121	{
d59a1683	122	return get_unaligned_be16(x);
a79f248b	123	}
d59a1683	124	static uint64_t r8le(const uint64_t *x)
a79f248b	125	{
d59a1683	126	return get_unaligned_le64(x);
a79f248b	127	}
d59a1683 DD	128	static uint32_t rle(const uint32_t *x)
	129	{
	130	return get_unaligned_le32(x);
	131	}
	132	static uint16_t r2le(const uint16_t *x)
a79f248b	133	{
d59a1683	134	return get_unaligned_le16(x);
a79f248b DD	135	}
a79f248b DD	136
d59a1683 DD	137	static void w8be(uint64_t val, uint64_t *x)
	138	{
	139	put_unaligned_be64(val, x);
	140	}
	141	static void wbe(uint32_t val, uint32_t *x)
	142	{
	143	put_unaligned_be32(val, x);
	144	}
	145	static void w2be(uint16_t val, uint16_t *x)
	146	{
	147	put_unaligned_be16(val, x);
	148	}
	149	static void w8le(uint64_t val, uint64_t *x)
	150	{
	151	put_unaligned_le64(val, x);
	152	}
	153	static void wle(uint32_t val, uint32_t *x)
	154	{
	155	put_unaligned_le32(val, x);
	156	}
	157	static void w2le(uint16_t val, uint16_t *x)
a79f248b	158	{
d59a1683	159	put_unaligned_le16(val, x);
a79f248b DD	160	}
a79f248b DD	161
d59a1683 DD	162	static uint64_t (r8)(const uint64_t );
	163	static uint32_t (r)(const uint32_t );
	164	static uint16_t (r2)(const uint16_t );
	165	static void (w8)(uint64_t, uint64_t );
	166	static void (w)(uint32_t, uint32_t );
	167	static void (w2)(uint16_t, uint16_t );
a79f248b	168
d59a1683	169	typedef void (table_sort_t)(char , int);
a79f248b	170
59c36455 JI	171	/*
	172	* Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
	173	* the way to -256..-1, to avoid conflicting with real section
	174	* indices.
	175	*/
	176	#define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))
	177
	178	static inline int is_shndx_special(unsigned int i)
	179	{
	180	return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
	181	}
	182
	183	/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
	184	static inline unsigned int get_secindex(unsigned int shndx,
	185	unsigned int sym_offs,
	186	const Elf32_Word *symtab_shndx_start)
	187	{
	188	if (is_shndx_special(shndx))
	189	return SPECIAL(shndx);
	190	if (shndx != SHN_XINDEX)
	191	return shndx;
	192	return r(&symtab_shndx_start[sym_offs]);
	193	}
	194
a79f248b DD	195	/* 32 bit and 64 bit are very similar */
	196	#include "sortextable.h"
	197	#define SORTEXTABLE_64
	198	#include "sortextable.h"
	199
eb608fb3	200	static int compare_relative_table(const void a, const void b)
d59a1683 DD	201	{
	202	int32_t av = (int32_t)r(a);
	203	int32_t bv = (int32_t)r(b);
	204
	205	if (av < bv)
	206	return -1;
	207	if (av > bv)
	208	return 1;
	209	return 0;
	210	}
	211
eb608fb3	212	static void sort_relative_table(char *extab_image, int image_size)
d59a1683 DD	213	{
	214	int i;
	215
	216	/*
	217	* Do the same thing the runtime sort does, first normalize to
	218	* being relative to the start of the section.
	219	*/
	220	i = 0;
	221	while (i < image_size) {
	222	uint32_t loc = (uint32_t )(extab_image + i);
	223	w(r(loc) + i, loc);
	224	i += 4;
	225	}
	226
eb608fb3	227	qsort(extab_image, image_size / 8, 8, compare_relative_table);
d59a1683 DD	228
	229	/* Now denormalize. */
	230	i = 0;
	231	while (i < image_size) {
	232	uint32_t loc = (uint32_t )(extab_image + i);
	233	w(r(loc) - i, loc);
	234	i += 4;
	235	}
	236	}
a79f248b DD	237
	238	static void
	239	do_file(char const *const fname)
	240	{
d59a1683 DD	241	table_sort_t custom_sort;
d59a1683 DD	242	Elf32_Ehdr *ehdr = mmap_file(fname);
a79f248b DD	243
a79f248b DD	244	ehdr_curr = ehdr;
a79f248b	245	switch (ehdr->e_ident[EI_DATA]) {
a79f248b DD	246	default:
	247	fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
	248	ehdr->e_ident[EI_DATA], fname);
	249	fail_file();
	250	break;
	251	case ELFDATA2LSB:
d59a1683 DD	252	r = rle;
	253	r2 = r2le;
	254	r8 = r8le;
	255	w = wle;
	256	w2 = w2le;
	257	w8 = w8le;
a79f248b DD	258	break;
a79f248b DD	259	case ELFDATA2MSB:
d59a1683 DD	260	r = rbe;
	261	r2 = r2be;
	262	r8 = r8be;
	263	w = wbe;
	264	w2 = w2be;
	265	w8 = w8be;
a79f248b DD	266	break;
	267	} /* end switch */
	268	if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
7b957b6e	269	\|\| (r2(&ehdr->e_type) != ET_EXEC && r2(&ehdr->e_type) != ET_DYN)
a79f248b	270	\|\| ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
7b957b6e	271	fprintf(stderr, "unrecognized ET_EXEC/ET_DYN file %s\n", fname);
a79f248b DD	272	fail_file();
	273	}
	274
d59a1683 DD	275	custom_sort = NULL;
d59a1683 DD	276	switch (r2(&ehdr->e_machine)) {
a79f248b DD	277	default:
a79f248b DD	278	fprintf(stderr, "unrecognized e_machine %d %s\n",
d59a1683	279	r2(&ehdr->e_machine), fname);
a79f248b DD	280	fail_file();
	281	break;
	282	case EM_386:
a79f248b	283	case EM_X86_64:
3193a98d	284	case EM_S390:
eb608fb3 HC	285	custom_sort = sort_relative_table;
eb608fb3 HC	286	break;
f06d19e4	287	case EM_ARCOMPACT:
b3210d14	288	case EM_ARCV2:
ee951c63	289	case EM_ARM:
adace895	290	case EM_AARCH64:
372c7209	291	case EM_MICROBLAZE:
d59a1683	292	case EM_MIPS:
25df8198	293	case EM_XTENSA:
a79f248b DD	294	break;
	295	} /* end switch */
	296
	297	switch (ehdr->e_ident[EI_CLASS]) {
	298	default:
	299	fprintf(stderr, "unrecognized ELF class %d %s\n",
	300	ehdr->e_ident[EI_CLASS], fname);
	301	fail_file();
	302	break;
	303	case ELFCLASS32:
d59a1683 DD	304	if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
d59a1683 DD	305	\|\| r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
a79f248b	306	fprintf(stderr,
7b957b6e	307	"unrecognized ET_EXEC/ET_DYN file: %s\n", fname);
a79f248b DD	308	fail_file();
a79f248b DD	309	}
d59a1683	310	do32(ehdr, fname, custom_sort);
a79f248b DD	311	break;
	312	case ELFCLASS64: {
	313	Elf64_Ehdr const ghdr = (Elf64_Ehdr )ehdr;
d59a1683 DD	314	if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
d59a1683 DD	315	\|\| r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
a79f248b	316	fprintf(stderr,
7b957b6e	317	"unrecognized ET_EXEC/ET_DYN file: %s\n", fname);
a79f248b DD	318	fail_file();
a79f248b DD	319	}
d59a1683	320	do64(ghdr, fname, custom_sort);
a79f248b DD	321	break;
	322	}
	323	} /* end switch */
	324
	325	cleanup();
	326	}
	327
	328	int
	329	main(int argc, char *argv[])
	330	{
	331	int n_error = 0; /* gcc-4.3.0 false positive complaint */
	332	int i;
	333
	334	if (argc < 2) {
	335	fprintf(stderr, "usage: sortextable vmlinux...\n");
	336	return 0;
	337	}
	338
	339	/* Process each file in turn, allowing deep failure. */
	340	for (i = 1; i < argc; i++) {
	341	char *file = argv[i];
	342	int const sjval = setjmp(jmpenv);
	343
	344	switch (sjval) {
	345	default:
	346	fprintf(stderr, "internal error: %s\n", file);
	347	exit(1);
	348	break;
	349	case SJ_SETJMP: /* normal sequence */
	350	/* Avoid problems if early cleanup() */
	351	fd_map = -1;
	352	ehdr_curr = NULL;
	353	mmap_failed = 1;
	354	do_file(file);
	355	break;
	356	case SJ_FAIL: /* error in do_file or below */
	357	++n_error;
	358	break;
	359	case SJ_SUCCEED: /* premature success */
	360	/* do nothing */
	361	break;
	362	} /* end switch */
	363	}
	364	return !!n_error;
	365	}