[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>

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);
}

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


/*
 * 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);

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

static int compare_x86_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_x86_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_x86_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:
		custom_sort = sort_x86_table;
		break;
	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 <[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
a79f248b DD	34	static int fd_map; /* File descriptor for file being modified. */
	35	static int mmap_failed; /* Boolean flag. */
	36	static void ehdr_curr; / current ElfXX_Ehdr * for resource cleanup */
	37	static struct stat sb; /* Remember .st_size, etc. */
	38	static jmp_buf jmpenv; /* setjmp/longjmp per-file error escape */
	39
	40	/* setjmp() return values */
	41	enum {
	42	SJ_SETJMP = 0, /* hardwired first return */
	43	SJ_FAIL,
	44	SJ_SUCCEED
	45	};
	46
	47	/* Per-file resource cleanup when multiple files. */
	48	static void
	49	cleanup(void)
	50	{
	51	if (!mmap_failed)
	52	munmap(ehdr_curr, sb.st_size);
	53	close(fd_map);
	54	}
	55
	56	static void __attribute__((noreturn))
	57	fail_file(void)
	58	{
	59	cleanup();
	60	longjmp(jmpenv, SJ_FAIL);
	61	}
	62
	63	static void __attribute__((noreturn))
	64	succeed_file(void)
	65	{
	66	cleanup();
	67	longjmp(jmpenv, SJ_SUCCEED);
	68	}
	69
	70
	71	/*
	72	* Get the whole file as a programming convenience in order to avoid
	73	* malloc+lseek+read+free of many pieces. If successful, then mmap
	74	* avoids copying unused pieces; else just read the whole file.
	75	* Open for both read and write.
	76	*/
	77	static void mmap_file(char const fname)
	78	{
	79	void *addr;
	80
	81	fd_map = open(fname, O_RDWR);
	82	if (fd_map < 0 \|\| fstat(fd_map, &sb) < 0) {
	83	perror(fname);
	84	fail_file();
	85	}
	86	if (!S_ISREG(sb.st_mode)) {
	87	fprintf(stderr, "not a regular file: %s\n", fname);
	88	fail_file();
	89	}
	90	addr = mmap(0, sb.st_size, PROT_READ\|PROT_WRITE, MAP_SHARED,
	91	fd_map, 0);
	92	if (addr == MAP_FAILED) {
	93	mmap_failed = 1;
	94	fprintf(stderr, "Could not mmap file: %s\n", fname);
	95	fail_file();
	96	}
	97	return addr;
98	}
99
d59a1683	100	static uint64_t r8be(const uint64_t *x)
a79f248b	101	{
d59a1683	102	return get_unaligned_be64(x);
a79f248b	103	}
d59a1683	104	static uint32_t rbe(const uint32_t *x)
a79f248b	105	{
d59a1683	106	return get_unaligned_be32(x);
a79f248b	107	}
d59a1683	108	static uint16_t r2be(const uint16_t *x)
a79f248b	109	{
d59a1683	110	return get_unaligned_be16(x);
a79f248b	111	}
d59a1683	112	static uint64_t r8le(const uint64_t *x)
a79f248b	113	{
d59a1683	114	return get_unaligned_le64(x);
a79f248b	115	}
d59a1683 DD	116	static uint32_t rle(const uint32_t *x)
	117	{
	118	return get_unaligned_le32(x);
	119	}
	120	static uint16_t r2le(const uint16_t *x)
a79f248b	121	{
d59a1683	122	return get_unaligned_le16(x);
a79f248b DD	123	}
a79f248b DD	124
d59a1683 DD	125	static void w8be(uint64_t val, uint64_t *x)
	126	{
	127	put_unaligned_be64(val, x);
	128	}
	129	static void wbe(uint32_t val, uint32_t *x)
	130	{
	131	put_unaligned_be32(val, x);
	132	}
	133	static void w2be(uint16_t val, uint16_t *x)
	134	{
	135	put_unaligned_be16(val, x);
	136	}
	137	static void w8le(uint64_t val, uint64_t *x)
	138	{
	139	put_unaligned_le64(val, x);
	140	}
	141	static void wle(uint32_t val, uint32_t *x)
	142	{
	143	put_unaligned_le32(val, x);
	144	}
	145	static void w2le(uint16_t val, uint16_t *x)
a79f248b	146	{
d59a1683	147	put_unaligned_le16(val, x);
a79f248b DD	148	}
a79f248b DD	149
d59a1683 DD	150	static uint64_t (r8)(const uint64_t );
	151	static uint32_t (r)(const uint32_t );
	152	static uint16_t (r2)(const uint16_t );
	153	static void (w8)(uint64_t, uint64_t );
	154	static void (w)(uint32_t, uint32_t );
	155	static void (w2)(uint16_t, uint16_t );
a79f248b	156
d59a1683	157	typedef void (table_sort_t)(char , int);
a79f248b DD	158
	159	/* 32 bit and 64 bit are very similar */
	160	#include "sortextable.h"
	161	#define SORTEXTABLE_64
	162	#include "sortextable.h"
	163
d59a1683 DD	164	static int compare_x86_table(const void a, const void b)
	165	{
	166	int32_t av = (int32_t)r(a);
	167	int32_t bv = (int32_t)r(b);
	168
	169	if (av < bv)
	170	return -1;
	171	if (av > bv)
	172	return 1;
	173	return 0;
	174	}
	175
	176	static void sort_x86_table(char *extab_image, int image_size)
	177	{
	178	int i;
	179
	180	/*
	181	* Do the same thing the runtime sort does, first normalize to
	182	* being relative to the start of the section.
	183	*/
	184	i = 0;
	185	while (i < image_size) {
	186	uint32_t loc = (uint32_t )(extab_image + i);
	187	w(r(loc) + i, loc);
	188	i += 4;
	189	}
	190
	191	qsort(extab_image, image_size / 8, 8, compare_x86_table);
	192
	193	/* Now denormalize. */
	194	i = 0;
	195	while (i < image_size) {
	196	uint32_t loc = (uint32_t )(extab_image + i);
	197	w(r(loc) - i, loc);
	198	i += 4;
	199	}
	200	}
a79f248b DD	201
	202	static void
	203	do_file(char const *const fname)
	204	{
d59a1683 DD	205	table_sort_t custom_sort;
d59a1683 DD	206	Elf32_Ehdr *ehdr = mmap_file(fname);
a79f248b DD	207
a79f248b DD	208	ehdr_curr = ehdr;
a79f248b	209	switch (ehdr->e_ident[EI_DATA]) {
a79f248b DD	210	default:
	211	fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
	212	ehdr->e_ident[EI_DATA], fname);
	213	fail_file();
	214	break;
	215	case ELFDATA2LSB:
d59a1683 DD	216	r = rle;
	217	r2 = r2le;
	218	r8 = r8le;
	219	w = wle;
	220	w2 = w2le;
	221	w8 = w8le;
a79f248b DD	222	break;
a79f248b DD	223	case ELFDATA2MSB:
d59a1683 DD	224	r = rbe;
	225	r2 = r2be;
	226	r8 = r8be;
	227	w = wbe;
	228	w2 = w2be;
	229	w8 = w8be;
a79f248b DD	230	break;
	231	} /* end switch */
	232	if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
d59a1683	233	\|\| r2(&ehdr->e_type) != ET_EXEC
a79f248b DD	234	\|\| ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
	235	fprintf(stderr, "unrecognized ET_EXEC file %s\n", fname);
	236	fail_file();
	237	}
	238
d59a1683 DD	239	custom_sort = NULL;
d59a1683 DD	240	switch (r2(&ehdr->e_machine)) {
a79f248b DD	241	default:
a79f248b DD	242	fprintf(stderr, "unrecognized e_machine %d %s\n",
d59a1683	243	r2(&ehdr->e_machine), fname);
a79f248b DD	244	fail_file();
	245	break;
	246	case EM_386:
a79f248b	247	case EM_X86_64:
d59a1683 DD	248	custom_sort = sort_x86_table;
	249	break;
	250	case EM_MIPS:
a79f248b DD	251	break;
	252	} /* end switch */
	253
	254	switch (ehdr->e_ident[EI_CLASS]) {
	255	default:
	256	fprintf(stderr, "unrecognized ELF class %d %s\n",
	257	ehdr->e_ident[EI_CLASS], fname);
	258	fail_file();
	259	break;
	260	case ELFCLASS32:
d59a1683 DD	261	if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
d59a1683 DD	262	\|\| r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
a79f248b DD	263	fprintf(stderr,
	264	"unrecognized ET_EXEC file: %s\n", fname);
	265	fail_file();
	266	}
d59a1683	267	do32(ehdr, fname, custom_sort);
a79f248b DD	268	break;
	269	case ELFCLASS64: {
	270	Elf64_Ehdr const ghdr = (Elf64_Ehdr )ehdr;
d59a1683 DD	271	if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
d59a1683 DD	272	\|\| r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
a79f248b DD	273	fprintf(stderr,
	274	"unrecognized ET_EXEC file: %s\n", fname);
	275	fail_file();
	276	}
d59a1683	277	do64(ghdr, fname, custom_sort);
a79f248b DD	278	break;
	279	}
	280	} /* end switch */
	281
	282	cleanup();
	283	}
	284
	285	int
	286	main(int argc, char *argv[])
	287	{
	288	int n_error = 0; /* gcc-4.3.0 false positive complaint */
	289	int i;
	290
	291	if (argc < 2) {
	292	fprintf(stderr, "usage: sortextable vmlinux...\n");
	293	return 0;
	294	}
	295
	296	/* Process each file in turn, allowing deep failure. */
	297	for (i = 1; i < argc; i++) {
	298	char *file = argv[i];
	299	int const sjval = setjmp(jmpenv);
	300
	301	switch (sjval) {
	302	default:
	303	fprintf(stderr, "internal error: %s\n", file);
	304	exit(1);
	305	break;
	306	case SJ_SETJMP: /* normal sequence */
	307	/* Avoid problems if early cleanup() */
	308	fd_map = -1;
	309	ehdr_curr = NULL;
	310	mmap_failed = 1;
	311	do_file(file);
	312	break;
	313	case SJ_FAIL: /* error in do_file or below */
	314	++n_error;
	315	break;
	316	case SJ_SUCCEED: /* premature success */
	317	/* do nothing */
	318	break;
	319	} /* end switch */
	320	}
	321	return !!n_error;
	322	}