[ia32rtools.git] / tools / cmpmrg_text.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <linux/coff.h>
#include <assert.h>
#include <stdint.h>

#include "my_assert.h"

/* http://www.delorie.com/djgpp/doc/coff/ */

typedef struct {
  unsigned short f_magic;         /* magic number             */
  unsigned short f_nscns;         /* number of sections       */
  unsigned int   f_timdat;        /* time & date stamp        */
  unsigned int   f_symptr;        /* file pointer to symtab   */
  unsigned int   f_nsyms;         /* number of symtab entries */
  unsigned short f_opthdr;        /* sizeof(optional hdr)     */
  unsigned short f_flags;         /* flags                    */
} FILHDR;

typedef struct {
  unsigned short magic;          /* type of file                         */
  unsigned short vstamp;         /* version stamp                        */
  unsigned int   tsize;          /* text size in bytes, padded to FW bdry*/
  unsigned int   dsize;          /* initialized data    "  "             */
  unsigned int   bsize;          /* uninitialized data  "  "             */
  unsigned int   entry;          /* entry pt.                            */
  unsigned int   text_start;     /* base of text used for this file      */
  unsigned int   data_start;     /* base of data used for this file      */
} AOUTHDR;

typedef struct {
  char           s_name[8];  /* section name                     */
  unsigned int   s_paddr;    /* physical address, aliased s_nlib */
  unsigned int   s_vaddr;    /* virtual address                  */
  unsigned int   s_size;     /* section size                     */
  unsigned int   s_scnptr;   /* file ptr to raw data for section */
  unsigned int   s_relptr;   /* file ptr to relocation           */
  unsigned int   s_lnnoptr;  /* file ptr to line numbers         */
  unsigned short s_nreloc;   /* number of relocation entries     */
  unsigned short s_nlnno;    /* number of line number entries    */
  unsigned int   s_flags;    /* flags                            */
} SCNHDR;

typedef struct {
  unsigned int  r_vaddr;   /* address of relocation      */
  unsigned int  r_symndx;  /* symbol we're adjusting for */
  unsigned short r_type;    /* type of relocation         */
} __attribute__((packed)) RELOC;

typedef struct {
  union {
    char e_name[E_SYMNMLEN];
    struct {
      unsigned int e_zeroes;
      unsigned int e_offset;
    } e;
  } e;
  unsigned int e_value;
  short e_scnum;
  unsigned short e_type;
  unsigned char e_sclass;
  unsigned char e_numaux;
} __attribute__((packed)) SYMENT;

#define C_EXT 2

struct my_symtab {
  unsigned int addr;
  //unsigned int fpos; // for patching
  unsigned int is_text:1;
  char *name;
};

struct my_sect_info {
	long scnhdr_fofs;
	long sect_fofs;
	long reloc_fofs;
	uint8_t *data;
	long size;
	RELOC *relocs;
	long reloc_cnt;
};

static int symt_cmp(const void *p1_, const void *p2_)
{
	const struct my_symtab *p1 = p1_, *p2 = p2_;
	return p1->addr - p2->addr;
}

void parse_headers(FILE *f, unsigned int *base_out,
	struct my_sect_info *sect_i,
	struct my_symtab **symtab_out, long *sym_cnt,
	struct my_symtab **raw_symtab_out, long *raw_sym_cnt)
{
	struct my_symtab *symt_txt = NULL;
	struct my_symtab *symt_all = NULL;
	char *stringtab = NULL;
	unsigned int base = 0;
	int text_scnum = 0;
	long filesize;
	char symname[9];
	long opthdr_pos;
	long reloc_size;
	FILHDR hdr;
	AOUTHDR opthdr;
	SCNHDR scnhdr;
	SYMENT syment;
	int i, s, val;
	int ret;
	
	ret = fseek(f, 0, SEEK_END);
	my_assert(ret, 0);

	filesize = ftell(f);

	ret = fseek(f, 0, SEEK_SET);
	my_assert(ret, 0);

	ret = fread(&hdr, 1, sizeof(hdr), f);
	my_assert(ret, sizeof(hdr));

	if (hdr.f_magic == 0x5a4d) // MZ
	{
		ret = fseek(f, 0x3c, SEEK_SET);
		my_assert(ret, 0);
		ret = fread(&val, 1, sizeof(val), f);
		my_assert(ret, sizeof(val));

		ret = fseek(f, val, SEEK_SET);
		my_assert(ret, 0);
		ret = fread(&val, 1, sizeof(val), f);
		my_assert(ret, sizeof(val));
		my_assert(val, 0x4550); // PE

		// should be COFF now
		ret = fread(&hdr, 1, sizeof(hdr), f);
		my_assert(ret, sizeof(hdr));
	}

	my_assert(hdr.f_magic, COFF_I386MAGIC);

	if (hdr.f_opthdr != 0)
	{
		opthdr_pos = ftell(f);

		if (hdr.f_opthdr < sizeof(opthdr))
			my_assert(1, 0);

		ret = fread(&opthdr, 1, sizeof(opthdr), f);
		my_assert(ret, sizeof(opthdr));
		my_assert(opthdr.magic, COFF_ZMAGIC);

		//printf("text_start: %x\n", opthdr.text_start);

		if (hdr.f_opthdr > sizeof(opthdr)) {
			ret = fread(&base, 1, sizeof(base), f);
			my_assert(ret, sizeof(base));
			//printf("base: %x\n", base);
		}
		ret = fseek(f, opthdr_pos + hdr.f_opthdr, SEEK_SET);
		my_assert(ret, 0);
	}

	// note: assuming first non-empty one is .text ..
	for (s = 0; s < hdr.f_nscns; s++) {
		sect_i->scnhdr_fofs = ftell(f);

		ret = fread(&scnhdr, 1, sizeof(scnhdr), f);
		my_assert(ret, sizeof(scnhdr));

		if (scnhdr.s_size != 0) {
			text_scnum = s + 1;
			break;
		}
	}
	my_assert(s < hdr.f_nscns, 1);

#if 0
	printf("f_nsyms:  %x\n", hdr.f_nsyms);
	printf("s_name:   '%s'\n", scnhdr.s_name);
	printf("s_vaddr:  %x\n", scnhdr.s_vaddr);
	printf("s_size:   %x\n", scnhdr.s_size);
	//printf("s_scnptr: %x\n", scnhdr.s_scnptr);
	printf("s_nreloc: %x\n", scnhdr.s_nreloc);
	printf("--\n");
#endif

	ret = fseek(f, scnhdr.s_scnptr, SEEK_SET);
	my_assert(ret, 0);

	sect_i->data = malloc(scnhdr.s_size);
	my_assert_not(sect_i->data, NULL);
	ret = fread(sect_i->data, 1, scnhdr.s_size, f);
	my_assert(ret, scnhdr.s_size);

	sect_i->sect_fofs = scnhdr.s_scnptr;
	sect_i->size = scnhdr.s_size;

	// relocs
	ret = fseek(f, scnhdr.s_relptr, SEEK_SET);
	my_assert(ret, 0);

	reloc_size = scnhdr.s_nreloc * sizeof(sect_i->relocs[0]);
	sect_i->relocs = malloc(reloc_size + 1);
	my_assert_not(sect_i->relocs, NULL);
	ret = fread(sect_i->relocs, 1, reloc_size, f);
	my_assert(ret, reloc_size);

	sect_i->reloc_cnt = scnhdr.s_nreloc;
	sect_i->reloc_fofs = scnhdr.s_relptr;

	if (base != 0 && base_out != NULL)
		*base_out = base + scnhdr.s_vaddr;

	if (symtab_out == NULL || sym_cnt == NULL)
		return;

	// symtab
	if (hdr.f_nsyms != 0) {
		symname[8] = 0;

		symt_txt = malloc(hdr.f_nsyms * sizeof(symt_txt[0]) + 1);
		my_assert_not(symt_txt, NULL);
		symt_all = malloc(hdr.f_nsyms * sizeof(symt_all[0]) + 1);
		my_assert_not(symt_all, NULL);

		ret = fseek(f, hdr.f_symptr
				+ hdr.f_nsyms * sizeof(syment), SEEK_SET);
		my_assert(ret, 0);
		ret = fread(&i, 1, sizeof(i), f);
		my_assert(ret, sizeof(i));
		my_assert((unsigned int)i < filesize, 1);

		stringtab = malloc(i);
		my_assert_not(stringtab, NULL);
		memset(stringtab, 0, 4);
		ret = fread(stringtab + 4, 1, i - 4, f);
		my_assert(ret, i - 4);

		ret = fseek(f, hdr.f_symptr, SEEK_SET);
		my_assert(ret, 0);
	}

	for (i = s = 0; i < hdr.f_nsyms; i++) {
		//long pos = ftell(f);

		ret = fread(&syment, 1, sizeof(syment), f);
		my_assert(ret, sizeof(syment));

		strncpy(symname, syment.e.e_name, 8);
		//printf("%3d %2d %08x '%s'\n", syment.e_sclass,
		//	syment.e_scnum, syment.e_value, symname);

		symt_all[i].addr = syment.e_value;
		//symt_all[i].fpos = pos;
		if (syment.e.e.e_zeroes == 0)
			symt_all[i].name = stringtab + syment.e.e.e_offset;
		else
			symt_all[i].name = strdup(symname);

		symt_all[i].is_text = (syment.e_scnum == text_scnum);
		if (symt_all[i].is_text && syment.e_sclass == C_EXT) {
			symt_txt[s] = symt_all[i];
			s++;
		}

		if (syment.e_numaux) {
			ret = fseek(f, syment.e_numaux * sizeof(syment),
				    SEEK_CUR);
			my_assert(ret, 0);
			i += syment.e_numaux;
		}
	}

	if (symt_txt != NULL)
		qsort(symt_txt, s, sizeof(symt_txt[0]), symt_cmp);

	*sym_cnt = s;
	*symtab_out = symt_txt;
	*raw_sym_cnt = i;
	*raw_symtab_out = symt_all;
}

static int handle_pad(uint8_t *d_obj, uint8_t *d_exe, int maxlen)
{
	static const uint8_t p7[7] = { 0x8d, 0xa4, 0x24, 0x00, 0x00, 0x00, 0x00 };
	static const uint8_t p6[6] = { 0x8d, 0x9b, 0x00, 0x00, 0x00, 0x00 };
	static const uint8_t p5[5] = { 0x05, 0x00, 0x00, 0x00, 0x00 };
	static const uint8_t p4[4] = { 0x8d, 0x64, 0x24, 0x00 };
	static const uint8_t p3[3] = { 0x8d, 0x49, 0x00 };
	static const uint8_t p2[2] = { 0x8b, 0xff };
	static const uint8_t p1[1] = { 0x90 };
	int len;
	int i;

	for (i = 0; i < maxlen; i++)
		if (d_exe[i] != 0xcc)
			break;

	for (len = i; len > 0; )
	{
		i = len;
		if (i > 7)
			i = 7;

		switch (i) {
		#define CASE(x) \
		case sizeof(p ## x): \
			if (memcmp(d_obj, p ## x, sizeof(p ## x))) \
				return 0; \
			memset(d_obj, 0xcc, sizeof(p ## x)); \
			break;
		CASE(7)
		CASE(6)
		CASE(5)
		CASE(4)
		CASE(3)
		CASE(2)
		CASE(1)
		default:
			printf("%s: unhandled len: %d\n", __func__, len);
			return 0;
		#undef CASE
		}

		len -= i;
		d_obj += i;
	}

	return 1;
}

struct equiv_opcode {
	signed char len;
	signed char ofs;
	short cmp_rm;
	uint8_t v_masm[8];
	uint8_t v_masm_mask[8];
	uint8_t v_msvc[8];
	uint8_t v_msvc_mask[8];
} equiv_ops[] = {
	// cmp    $0x11,%ax
	{ 4, -1, 0,
	 { 0x66,0x83,0xf8,0x03 }, { 0xff,0xff,0xff,0x00 },
	 { 0x66,0x3d,0x03,0x00 }, { 0xff,0xff,0x00,0xff }, },
	// lea    -0x1(%ebx,%eax,1),%esi // op mod/rm sib offs
	// mov, test, imm grp 1
	{ 3, -2, 1,
	 { 0x8d,0x74,0x03 }, { 0xf0,0x07,0xc0 },
	 { 0x8d,0x74,0x18 }, { 0xf0,0x07,0xc0 }, },
	// movzbl 0x58f24a(%eax,%ecx,1),%eax
	{ 4, -3, 1,
	 { 0x0f,0xb6,0x84,0x08 }, { 0xff,0xff,0x07,0xc0 },
	 { 0x0f,0xb6,0x84,0x01 }, { 0xff,0xff,0x07,0xc0 }, },
	// inc/dec
	{ 3, -2, 1,
	 { 0xfe,0x4c,0x03 }, { 0xfe,0xff,0xc0 },
	 { 0xfe,0x4c,0x18 }, { 0xfe,0xff,0xc0 }, },
	// cmp
	{ 3, -2, 1,
	 { 0x38,0x0c,0x0c }, { 0xff,0xff,0xc0 },
	 { 0x38,0x0c,0x30 }, { 0xff,0xff,0xc0 }, },
	// test   %dl,%bl
	{ 2, -1, 1,
	 { 0x84,0xd3 }, { 0xfe,0xc0 },
	 { 0x84,0xda }, { 0xfe,0xc0 }, },
	// cmp	  r,r/m vs rm/r
	{ 2, 0, 1,
	 { 0x3a,0xca }, { 0xff,0xc0 },
	 { 0x38,0xd1 }, { 0xff,0xc0 }, },
	// rep + 66 prefix
	{ 2, 0, 0,
	 { 0xf3,0x66 }, { 0xfe,0xff },
	 { 0x66,0xf3 }, { 0xff,0xfe }, },
	// fadd   st, st(0) vs st(0), st
	{ 2, 0, 0,
	 { 0xd8,0xc0 }, { 0xff,0xf7 },
	 { 0xdc,0xc0 }, { 0xff,0xf7 }, },

	// broad filters (may take too much..)
	// testb  $0x4,0x1d(%esi,%eax,1)
	// movb, push, ..
	{ 3, -2, 1,
	 { 0xf6,0x44,0x06 }, { 0x00,0x07,0xc0 },
	 { 0xf6,0x44,0x30 }, { 0x00,0x07,0xc0 }, },
};

static int cmp_mask(uint8_t *d, uint8_t *expect, uint8_t *mask, int len)
{
	int i;

	for (i = 0; i < len; i++)
		if ((d[i] & mask[i]) != (expect[i] & mask[i]))
			return 1;

	return 0;
}

static int check_equiv(uint8_t *d_obj, uint8_t *d_exe, int maxlen)
{
	uint8_t vo, ve, vo2, ve2;
	int i, jo, je;
	int len, ofs;

	for (i = 0; i < sizeof(equiv_ops) / sizeof(equiv_ops[0]); i++)
	{
		struct equiv_opcode *op = &equiv_ops[i];

		len = op->len;
		if (maxlen < len)
			continue;

		ofs = op->ofs;
		if (cmp_mask(d_obj + ofs, op->v_masm,
			     op->v_masm_mask, len))
			continue;
		if (cmp_mask(d_exe + ofs, op->v_msvc,
			     op->v_msvc_mask, len))
			continue;

		jo = je = 0;
		d_obj += ofs;
		d_exe += ofs;
		while (1)
		{
			for (; jo < len; jo++)
				if (op->v_masm_mask[jo] != 0xff)
					break;
			for (; je < len; je++)
				if (op->v_msvc_mask[je] != 0xff)
					break;

			if ((jo == len && je != len) || (jo != len && je == len)) {
				printf("invalid equiv_ops\n");
				return -1;
			}
			if (jo == len)
				return len + ofs - 1; // matched

			// var byte
			vo = d_obj[jo] & ~op->v_masm_mask[jo];
			ve = d_exe[je] & ~op->v_msvc_mask[je];
			if (op->cmp_rm && op->v_masm_mask[jo] == 0xc0) {
				vo2 = vo >> 3;
				vo &= 7;
				ve2 = ve & 7;
				ve >>= 3;
				if (vo != ve || vo2 != ve2)
					return -1;
			}
			else {
				if (vo != ve)
					return -1;
			}

			jo++;
			je++;
		}
	}

	return -1;
}

static void fill_int3(unsigned char *d, int len)
{
	while (len-- > 0) {
		if (d[0] == 0xcc && d[1] == 0xcc)
			break;
		*d++ = 0xcc;
	}
}

int main(int argc, char *argv[])
{
	unsigned int base = 0, addr, addr2, end, sym, *t;
	struct my_sect_info s_text_obj, s_text_exe;
	struct my_symtab *raw_syms_obj = NULL;
	struct my_symtab *syms_obj = NULL;
	long sym_cnt_obj, raw_sym_cnt_obj;
	FILE *f_obj, *f_exe;
	SCNHDR tmphdr;
	long sztext_cmn;
	int retval = 1;
	int left;
	int ret;
	int i;

	if (argc != 3) {
		printf("usage:\n%s <a_obj> <exe>\n", argv[0]);
		return 1;
	}

	f_obj = fopen(argv[1], "r+b");
	if (f_obj == NULL) {
		fprintf(stderr, "%s", argv[1]);
		perror("");
		return 1;
	}

	f_exe = fopen(argv[2], "r");
	if (f_exe == NULL) {
		fprintf(stderr, "%s", argv[2]);
		perror("");
		return 1;
	}

	parse_headers(f_obj, NULL, &s_text_obj, &syms_obj, &sym_cnt_obj,
		      &raw_syms_obj, &raw_sym_cnt_obj);
	parse_headers(f_exe, &base, &s_text_exe, NULL, NULL, NULL, NULL);

	sztext_cmn = s_text_obj.size;
	if (sztext_cmn > s_text_exe.size)
		sztext_cmn = s_text_exe.size;

	if (sztext_cmn == 0) {
		printf("bad .text size(s): %ld, %ld\n",
			s_text_obj.size, s_text_exe.size);
		return 1;
	}

	for (i = 0; i < s_text_obj.reloc_cnt; i++)
	{
		unsigned int a = s_text_obj.relocs[i].r_vaddr;
		//printf("%04x %08x\n", s_text_obj.relocs[i].r_type, a);

		switch (s_text_obj.relocs[i].r_type) {
		case 0x06: // RELOC_ADDR32
		case 0x14: // RELOC_REL32
			// must preserve stored val,
			// so trash exe so that cmp passes
			memcpy(s_text_exe.data + a, s_text_obj.data + a, 4);
			break;
		default:
			printf("unknown reloc %x @%08x/%08x\n",
				s_text_obj.relocs[i].r_type, a, base + a);
			return 1;
		}
	}

	for (i = 0; i < sztext_cmn; i++)
	{
		if (s_text_obj.data[i] == s_text_exe.data[i])
			continue;

		left = sztext_cmn - i;

		if (s_text_exe.data[i] == 0xcc) { // padding
			if (handle_pad(s_text_obj.data + i,
			    s_text_exe.data + i, left))
				continue;
		}

		ret = check_equiv(s_text_obj.data + i, s_text_exe.data + i, left);
		if (ret >= 0) {
			i += ret;
			continue;
		}

		printf("%x: %02x vs %02x\n", base + i,
			s_text_obj.data[i], s_text_exe.data[i]);
		goto out;
	}

	// fill removed funcs with 'int3'
	for (i = 0; i < sym_cnt_obj; i++) {
		if (strncmp(syms_obj[i].name, "rm_", 3))
			continue;

		addr = syms_obj[i].addr;
		end = (i < sym_cnt_obj - 1)
			? syms_obj[i + 1].addr : s_text_obj.size;
		if (addr >= s_text_obj.size || end > s_text_obj.size) {
			printf("addr OOR: %x-%x '%s'\n", addr, end,
				syms_obj[i].name);
			goto out;
		}
		fill_int3(s_text_obj.data + addr, end - addr);
	}

	// remove relocs
	for (i = 0; i < s_text_obj.reloc_cnt; i++) {
		addr = s_text_obj.relocs[i].r_vaddr;
		sym = s_text_obj.relocs[i].r_symndx;
		if (addr > s_text_obj.size - 4) {
			printf("reloc addr OOR: %x\n", addr);
			goto out;
		}
		if (sym >= raw_sym_cnt_obj) {
			printf("reloc sym OOR: %d/%ld\n",
				sym, raw_sym_cnt_obj);
			goto out;
		}
#if 0
		printf("r %08x -> %08x %s\n", base + addr,
			raw_syms_obj[sym].addr,
			raw_syms_obj[sym].name);
#endif
		t = (unsigned int *)(s_text_obj.data + addr);
		if (t[0] == 0xcccccccc
		 || t[-1] == 0xcccccccc) { // jumptab of a func?
		 	t[0] = 0xcccccccc;
			memmove(&s_text_obj.relocs[i],
				&s_text_obj.relocs[i + 1],
				(s_text_obj.reloc_cnt - i - 1)
				 * sizeof(s_text_obj.relocs[0]));
			i--;
			s_text_obj.reloc_cnt--;
		}
		// note: branches/calls already linked,
		// so only useful for dd refs
		else if (raw_syms_obj[sym].is_text) {
			addr2 = raw_syms_obj[sym].addr;
			if (s_text_obj.data[addr2] == 0xcc) {
				printf("warning: reloc %08x -> %08x "
					"points to rm'd target '%s'\n",
					base + addr, base + addr2,
					raw_syms_obj[sym].name);
			}
		}
	}

	// patch .text
	ret = fseek(f_obj, s_text_obj.sect_fofs, SEEK_SET);
	my_assert(ret, 0);
	ret = fwrite(s_text_obj.data, 1, s_text_obj.size, f_obj);
	my_assert(ret, s_text_obj.size);

	// patch relocs
	ret = fseek(f_obj, s_text_obj.reloc_fofs, SEEK_SET);
	my_assert(ret, 0);
	ret = fwrite(s_text_obj.relocs, sizeof(s_text_obj.relocs[0]),
		s_text_obj.reloc_cnt, f_obj);
	my_assert(ret, s_text_obj.reloc_cnt);

	ret = fseek(f_obj, s_text_obj.scnhdr_fofs, SEEK_SET);
	my_assert(ret, 0);
	ret = fread(&tmphdr, 1, sizeof(tmphdr), f_obj);
	my_assert(ret, sizeof(tmphdr));

	tmphdr.s_nreloc = s_text_obj.reloc_cnt;

	ret = fseek(f_obj, s_text_obj.scnhdr_fofs, SEEK_SET);
	my_assert(ret, 0);
	ret = fwrite(&tmphdr, 1, sizeof(tmphdr), f_obj);
	my_assert(ret, sizeof(tmphdr));

	fclose(f_obj);
	fclose(f_exe);

	retval = 0;
out:
	return retval;
}
Commit	Line	Data
cfd23479	1	#include <stdio.h>
	2	#include <stdlib.h>
	3	#include <string.h>
	4	#include <linux/coff.h>
	5	#include <assert.h>
	6	#include <stdint.h>
	7
ede51255	8	#include "my_assert.h"
ede51255	9
cfd23479	10	/* http://www.delorie.com/djgpp/doc/coff/ */
	11
	12	typedef struct {
	13	unsigned short f_magic; /* magic number */
	14	unsigned short f_nscns; /* number of sections */
	15	unsigned int f_timdat; /* time & date stamp */
	16	unsigned int f_symptr; /* file pointer to symtab */
	17	unsigned int f_nsyms; /* number of symtab entries */
	18	unsigned short f_opthdr; /* sizeof(optional hdr) */
	19	unsigned short f_flags; /* flags */
	20	} FILHDR;
	21
	22	typedef struct {
	23	unsigned short magic; /* type of file */
	24	unsigned short vstamp; /* version stamp */
	25	unsigned int tsize; /* text size in bytes, padded to FW bdry*/
	26	unsigned int dsize; /* initialized data " " */
	27	unsigned int bsize; /* uninitialized data " " */
	28	unsigned int entry; /* entry pt. */
	29	unsigned int text_start; /* base of text used for this file */
	30	unsigned int data_start; /* base of data used for this file */
	31	} AOUTHDR;
	32
	33	typedef struct {
	34	char s_name[8]; /* section name */
	35	unsigned int s_paddr; /* physical address, aliased s_nlib */
	36	unsigned int s_vaddr; /* virtual address */
	37	unsigned int s_size; /* section size */
	38	unsigned int s_scnptr; /* file ptr to raw data for section */
	39	unsigned int s_relptr; /* file ptr to relocation */
	40	unsigned int s_lnnoptr; /* file ptr to line numbers */
	41	unsigned short s_nreloc; /* number of relocation entries */
	42	unsigned short s_nlnno; /* number of line number entries */
	43	unsigned int s_flags; /* flags */
	44	} SCNHDR;
	45
	46	typedef struct {
	47	unsigned int r_vaddr; /* address of relocation */
	48	unsigned int r_symndx; /* symbol we're adjusting for */
	49	unsigned short r_type; /* type of relocation */
	50	} __attribute__((packed)) RELOC;
	51
e86c9ee6	52	typedef struct {
	53	union {
	54	char e_name[E_SYMNMLEN];
	55	struct {
	56	unsigned int e_zeroes;
	57	unsigned int e_offset;
	58	} e;
	59	} e;
	60	unsigned int e_value;
	61	short e_scnum;
	62	unsigned short e_type;
	63	unsigned char e_sclass;
	64	unsigned char e_numaux;
	65	} __attribute__((packed)) SYMENT;
	66
	67	#define C_EXT 2
	68
	69	struct my_symtab {
	70	unsigned int addr;
a2f78da4	71	//unsigned int fpos; // for patching
a2f78da4	72	unsigned int is_text:1;
e86c9ee6	73	char *name;
	74	};
	75
572a6bea	76	struct my_sect_info {
	77	long scnhdr_fofs;
	78	long sect_fofs;
	79	long reloc_fofs;
	80	uint8_t *data;
	81	long size;
	82	RELOC *relocs;
	83	long reloc_cnt;
	84	};
	85
e86c9ee6	86	static int symt_cmp(const void p1_, const void p2_)
	87	{
	88	const struct my_symtab p1 = p1_, p2 = p2_;
	89	return p1->addr - p2->addr;
	90	}
	91
cfd23479	92	void parse_headers(FILE f, unsigned int base_out,
572a6bea	93	struct my_sect_info *sect_i,
a2f78da4	94	struct my_symtab *symtab_out, long sym_cnt,
a2f78da4	95	struct my_symtab *raw_symtab_out, long raw_sym_cnt)
cfd23479	96	{
a2f78da4	97	struct my_symtab *symt_txt = NULL;
a2f78da4	98	struct my_symtab *symt_all = NULL;
e86c9ee6	99	char *stringtab = NULL;
cfd23479	100	unsigned int base = 0;
e86c9ee6	101	int text_scnum = 0;
	102	long filesize;
	103	char symname[9];
cfd23479	104	long opthdr_pos;
	105	long reloc_size;
	106	FILHDR hdr;
	107	AOUTHDR opthdr;
	108	SCNHDR scnhdr;
e86c9ee6	109	SYMENT syment;
e86c9ee6	110	int i, s, val;
cfd23479	111	int ret;
cfd23479	112
e86c9ee6	113	ret = fseek(f, 0, SEEK_END);
	114	my_assert(ret, 0);
	115
	116	filesize = ftell(f);
	117
	118	ret = fseek(f, 0, SEEK_SET);
	119	my_assert(ret, 0);
	120
cfd23479	121	ret = fread(&hdr, 1, sizeof(hdr), f);
	122	my_assert(ret, sizeof(hdr));
	123
	124	if (hdr.f_magic == 0x5a4d) // MZ
	125	{
	126	ret = fseek(f, 0x3c, SEEK_SET);
	127	my_assert(ret, 0);
	128	ret = fread(&val, 1, sizeof(val), f);
	129	my_assert(ret, sizeof(val));
	130
	131	ret = fseek(f, val, SEEK_SET);
	132	my_assert(ret, 0);
	133	ret = fread(&val, 1, sizeof(val), f);
	134	my_assert(ret, sizeof(val));
	135	my_assert(val, 0x4550); // PE
	136
	137	// should be COFF now
	138	ret = fread(&hdr, 1, sizeof(hdr), f);
	139	my_assert(ret, sizeof(hdr));
	140	}
	141
	142	my_assert(hdr.f_magic, COFF_I386MAGIC);
	143
	144	if (hdr.f_opthdr != 0)
	145	{
	146	opthdr_pos = ftell(f);
	147
	148	if (hdr.f_opthdr < sizeof(opthdr))
	149	my_assert(1, 0);
	150
	151	ret = fread(&opthdr, 1, sizeof(opthdr), f);
	152	my_assert(ret, sizeof(opthdr));
	153	my_assert(opthdr.magic, COFF_ZMAGIC);
	154
2c605b97	155	//printf("text_start: %x\n", opthdr.text_start);
cfd23479	156
	157	if (hdr.f_opthdr > sizeof(opthdr)) {
	158	ret = fread(&base, 1, sizeof(base), f);
	159	my_assert(ret, sizeof(base));
2c605b97	160	//printf("base: %x\n", base);
cfd23479	161	}
	162	ret = fseek(f, opthdr_pos + hdr.f_opthdr, SEEK_SET);
	163	my_assert(ret, 0);
	164	}
	165
e86c9ee6	166	// note: assuming first non-empty one is .text ..
cfd23479	167	for (s = 0; s < hdr.f_nscns; s++) {
572a6bea	168	sect_i->scnhdr_fofs = ftell(f);
572a6bea	169
cfd23479	170	ret = fread(&scnhdr, 1, sizeof(scnhdr), f);
	171	my_assert(ret, sizeof(scnhdr));
	172
e86c9ee6	173	if (scnhdr.s_size != 0) {
e86c9ee6	174	text_scnum = s + 1;
cfd23479	175	break;
e86c9ee6	176	}
cfd23479	177	}
572a6bea	178	my_assert(s < hdr.f_nscns, 1);
cfd23479	179
2c605b97	180	#if 0
e86c9ee6	181	printf("f_nsyms: %x\n", hdr.f_nsyms);
cfd23479	182	printf("s_name: '%s'\n", scnhdr.s_name);
	183	printf("s_vaddr: %x\n", scnhdr.s_vaddr);
	184	printf("s_size: %x\n", scnhdr.s_size);
e86c9ee6	185	//printf("s_scnptr: %x\n", scnhdr.s_scnptr);
cfd23479	186	printf("s_nreloc: %x\n", scnhdr.s_nreloc);
cfd23479	187	printf("--\n");
2c605b97	188	#endif
cfd23479	189
	190	ret = fseek(f, scnhdr.s_scnptr, SEEK_SET);
	191	my_assert(ret, 0);
	192
572a6bea	193	sect_i->data = malloc(scnhdr.s_size);
	194	my_assert_not(sect_i->data, NULL);
	195	ret = fread(sect_i->data, 1, scnhdr.s_size, f);
cfd23479	196	my_assert(ret, scnhdr.s_size);
cfd23479	197
572a6bea	198	sect_i->sect_fofs = scnhdr.s_scnptr;
572a6bea	199	sect_i->size = scnhdr.s_size;
cfd23479	200
e86c9ee6	201	// relocs
cfd23479	202	ret = fseek(f, scnhdr.s_relptr, SEEK_SET);
	203	my_assert(ret, 0);
	204
572a6bea	205	reloc_size = scnhdr.s_nreloc * sizeof(sect_i->relocs[0]);
	206	sect_i->relocs = malloc(reloc_size + 1);
	207	my_assert_not(sect_i->relocs, NULL);
	208	ret = fread(sect_i->relocs, 1, reloc_size, f);
cfd23479	209	my_assert(ret, reloc_size);
cfd23479	210
572a6bea	211	sect_i->reloc_cnt = scnhdr.s_nreloc;
	212	sect_i->reloc_fofs = scnhdr.s_relptr;
	213
	214	if (base != 0 && base_out != NULL)
	215	*base_out = base + scnhdr.s_vaddr;
	216
	217	if (symtab_out == NULL \|\| sym_cnt == NULL)
	218	return;
cfd23479	219
e86c9ee6	220	// symtab
	221	if (hdr.f_nsyms != 0) {
	222	symname[8] = 0;
	223
a2f78da4	224	symt_txt = malloc(hdr.f_nsyms * sizeof(symt_txt[0]) + 1);
	225	my_assert_not(symt_txt, NULL);
	226	symt_all = malloc(hdr.f_nsyms * sizeof(symt_all[0]) + 1);
	227	my_assert_not(symt_all, NULL);
e86c9ee6	228
	229	ret = fseek(f, hdr.f_symptr
	230	+ hdr.f_nsyms * sizeof(syment), SEEK_SET);
	231	my_assert(ret, 0);
	232	ret = fread(&i, 1, sizeof(i), f);
	233	my_assert(ret, sizeof(i));
	234	my_assert((unsigned int)i < filesize, 1);
	235
	236	stringtab = malloc(i);
	237	my_assert_not(stringtab, NULL);
	238	memset(stringtab, 0, 4);
	239	ret = fread(stringtab + 4, 1, i - 4, f);
	240	my_assert(ret, i - 4);
	241
	242	ret = fseek(f, hdr.f_symptr, SEEK_SET);
	243	my_assert(ret, 0);
	244	}
	245
	246	for (i = s = 0; i < hdr.f_nsyms; i++) {
a2f78da4	247	//long pos = ftell(f);
e86c9ee6	248
	249	ret = fread(&syment, 1, sizeof(syment), f);
	250	my_assert(ret, sizeof(syment));
	251
	252	strncpy(symname, syment.e.e_name, 8);
	253	//printf("%3d %2d %08x '%s'\n", syment.e_sclass,
	254	// syment.e_scnum, syment.e_value, symname);
	255
a2f78da4	256	symt_all[i].addr = syment.e_value;
a2f78da4	257	//symt_all[i].fpos = pos;
e86c9ee6	258	if (syment.e.e.e_zeroes == 0)
a2f78da4	259	symt_all[i].name = stringtab + syment.e.e.e_offset;
e86c9ee6	260	else
a2f78da4	261	symt_all[i].name = strdup(symname);
	262
	263	symt_all[i].is_text = (syment.e_scnum == text_scnum);
	264	if (symt_all[i].is_text && syment.e_sclass == C_EXT) {
	265	symt_txt[s] = symt_all[i];
	266	s++;
	267	}
e86c9ee6	268
	269	if (syment.e_numaux) {
	270	ret = fseek(f, syment.e_numaux * sizeof(syment),
	271	SEEK_CUR);
	272	my_assert(ret, 0);
	273	i += syment.e_numaux;
	274	}
	275	}
	276
a2f78da4	277	if (symt_txt != NULL)
a2f78da4	278	qsort(symt_txt, s, sizeof(symt_txt[0]), symt_cmp);
e86c9ee6	279
e86c9ee6	280	*sym_cnt = s;
a2f78da4	281	*symtab_out = symt_txt;
	282	*raw_sym_cnt = i;
	283	*raw_symtab_out = symt_all;
cfd23479	284	}
	285
	286	static int handle_pad(uint8_t d_obj, uint8_t d_exe, int maxlen)
	287	{
	288	static const uint8_t p7[7] = { 0x8d, 0xa4, 0x24, 0x00, 0x00, 0x00, 0x00 };
	289	static const uint8_t p6[6] = { 0x8d, 0x9b, 0x00, 0x00, 0x00, 0x00 };
	290	static const uint8_t p5[5] = { 0x05, 0x00, 0x00, 0x00, 0x00 };
	291	static const uint8_t p4[4] = { 0x8d, 0x64, 0x24, 0x00 };
	292	static const uint8_t p3[3] = { 0x8d, 0x49, 0x00 };
	293	static const uint8_t p2[2] = { 0x8b, 0xff };
	294	static const uint8_t p1[1] = { 0x90 };
	295	int len;
	296	int i;
	297
	298	for (i = 0; i < maxlen; i++)
	299	if (d_exe[i] != 0xcc)
	300	break;
	301
	302	for (len = i; len > 0; )
	303	{
	304	i = len;
	305	if (i > 7)
	306	i = 7;
	307
	308	switch (i) {
	309	#define CASE(x) \
	310	case sizeof(p ## x): \
	311	if (memcmp(d_obj, p ## x, sizeof(p ## x))) \
	312	return 0; \
	313	memset(d_obj, 0xcc, sizeof(p ## x)); \
	314	break;
	315	CASE(7)
	316	CASE(6)
	317	CASE(5)
	318	CASE(4)
	319	CASE(3)
	320	CASE(2)
	321	CASE(1)
	322	default:
	323	printf("%s: unhandled len: %d\n", __func__, len);
	324	return 0;
	325	#undef CASE
	326	}
	327
	328	len -= i;
	329	d_obj += i;
	330	}
	331
	332	return 1;
	333	}
	334
	335	struct equiv_opcode {
	336	signed char len;
	337	signed char ofs;
	338	short cmp_rm;
	339	uint8_t v_masm[8];
	340	uint8_t v_masm_mask[8];
	341	uint8_t v_msvc[8];
	342	uint8_t v_msvc_mask[8];
	343	} equiv_ops[] = {
	344	// cmp $0x11,%ax
	345	{ 4, -1, 0,
	346	{ 0x66,0x83,0xf8,0x03 }, { 0xff,0xff,0xff,0x00 },
	347	{ 0x66,0x3d,0x03,0x00 }, { 0xff,0xff,0x00,0xff }, },
348	// lea -0x1(%ebx,%eax,1),%esi // op mod/rm sib offs
349	// mov, test, imm grp 1
350	{ 3, -2, 1,
351	{ 0x8d,0x74,0x03 }, { 0xf0,0x07,0xc0 },
352	{ 0x8d,0x74,0x18 }, { 0xf0,0x07,0xc0 }, },
353	// movzbl 0x58f24a(%eax,%ecx,1),%eax
354	{ 4, -3, 1,
355	{ 0x0f,0xb6,0x84,0x08 }, { 0xff,0xff,0x07,0xc0 },
356	{ 0x0f,0xb6,0x84,0x01 }, { 0xff,0xff,0x07,0xc0 }, },
357	// inc/dec
358	{ 3, -2, 1,
359	{ 0xfe,0x4c,0x03 }, { 0xfe,0xff,0xc0 },
360	{ 0xfe,0x4c,0x18 }, { 0xfe,0xff,0xc0 }, },
361	// cmp
362	{ 3, -2, 1,
363	{ 0x38,0x0c,0x0c }, { 0xff,0xff,0xc0 },
364	{ 0x38,0x0c,0x30 }, { 0xff,0xff,0xc0 }, },
365	// test %dl,%bl
366	{ 2, -1, 1,
367	{ 0x84,0xd3 }, { 0xfe,0xc0 },
368	{ 0x84,0xda }, { 0xfe,0xc0 }, },
369	// cmp r,r/m vs rm/r
370	{ 2, 0, 1,
371	{ 0x3a,0xca }, { 0xff,0xc0 },
372	{ 0x38,0xd1 }, { 0xff,0xc0 }, },
373	// rep + 66 prefix
374	{ 2, 0, 0,
375	{ 0xf3,0x66 }, { 0xfe,0xff },
376	{ 0x66,0xf3 }, { 0xff,0xfe }, },
377	// fadd st, st(0) vs st(0), st
378	{ 2, 0, 0,
379	{ 0xd8,0xc0 }, { 0xff,0xf7 },
380	{ 0xdc,0xc0 }, { 0xff,0xf7 }, },
381
382	// broad filters (may take too much..)
383	// testb $0x4,0x1d(%esi,%eax,1)
384	// movb, push, ..
385	{ 3, -2, 1,
386	{ 0xf6,0x44,0x06 }, { 0x00,0x07,0xc0 },
387	{ 0xf6,0x44,0x30 }, { 0x00,0x07,0xc0 }, },
388	};
389
390	static int cmp_mask(uint8_t d, uint8_t expect, uint8_t *mask, int len)
391	{
392	int i;
393
394	for (i = 0; i < len; i++)
395	if ((d[i] & mask[i]) != (expect[i] & mask[i]))
396	return 1;
397
398	return 0;
399	}
400
401	static int check_equiv(uint8_t d_obj, uint8_t d_exe, int maxlen)
402	{
403	uint8_t vo, ve, vo2, ve2;
404	int i, jo, je;
405	int len, ofs;
406
407	for (i = 0; i < sizeof(equiv_ops) / sizeof(equiv_ops[0]); i++)
408	{
409	struct equiv_opcode *op = &equiv_ops[i];
410
411	len = op->len;
412	if (maxlen < len)
413	continue;
414
415	ofs = op->ofs;
416	if (cmp_mask(d_obj + ofs, op->v_masm,
417	op->v_masm_mask, len))
418	continue;
419	if (cmp_mask(d_exe + ofs, op->v_msvc,
420	op->v_msvc_mask, len))
421	continue;
422
423	jo = je = 0;
424	d_obj += ofs;
425	d_exe += ofs;
426	while (1)
427	{
428	for (; jo < len; jo++)
429	if (op->v_masm_mask[jo] != 0xff)
430	break;
431	for (; je < len; je++)
432	if (op->v_msvc_mask[je] != 0xff)
433	break;
434
435	if ((jo == len && je != len) \|\| (jo != len && je == len)) {
436	printf("invalid equiv_ops\n");
437	return -1;
438	}
439	if (jo == len)
440	return len + ofs - 1; // matched
441
442	// var byte
443	vo = d_obj[jo] & ~op->v_masm_mask[jo];
444	ve = d_exe[je] & ~op->v_msvc_mask[je];
445	if (op->cmp_rm && op->v_masm_mask[jo] == 0xc0) {
446	vo2 = vo >> 3;
447	vo &= 7;
448	ve2 = ve & 7;
449	ve >>= 3;
450	if (vo != ve \|\| vo2 != ve2)
451	return -1;
452	}
453	else {
454	if (vo != ve)
455	return -1;
456	}
457
458	jo++;
459	je++;
460	}
461	}
462
463	return -1;
464	}
465
572a6bea	466	static void fill_int3(unsigned char *d, int len)
	467	{
	468	while (len-- > 0) {
a2f78da4	469	if (d[0] == 0xcc && d[1] == 0xcc)
572a6bea	470	break;
	471	*d++ = 0xcc;
	472	}
	473	}
	474
cfd23479	475	int main(int argc, char *argv[])
cfd23479	476	{
a2f78da4	477	unsigned int base = 0, addr, addr2, end, sym, *t;
572a6bea	478	struct my_sect_info s_text_obj, s_text_exe;
a2f78da4	479	struct my_symtab *raw_syms_obj = NULL;
572a6bea	480	struct my_symtab *syms_obj = NULL;
a2f78da4	481	long sym_cnt_obj, raw_sym_cnt_obj;
cfd23479	482	FILE f_obj, f_exe;
572a6bea	483	SCNHDR tmphdr;
572a6bea	484	long sztext_cmn;
cfd23479	485	int retval = 1;
	486	int left;
	487	int ret;
	488	int i;
	489
	490	if (argc != 3) {
e86c9ee6	491	printf("usage:\n%s <a_obj> <exe>\n", argv[0]);
cfd23479	492	return 1;
	493	}
	494
	495	f_obj = fopen(argv[1], "r+b");
	496	if (f_obj == NULL) {
	497	fprintf(stderr, "%s", argv[1]);
	498	perror("");
	499	return 1;
	500	}
	501
	502	f_exe = fopen(argv[2], "r");
	503	if (f_exe == NULL) {
e86c9ee6	504	fprintf(stderr, "%s", argv[2]);
cfd23479	505	perror("");
	506	return 1;
	507	}
	508
a2f78da4	509	parse_headers(f_obj, NULL, &s_text_obj, &syms_obj, &sym_cnt_obj,
	510	&raw_syms_obj, &raw_sym_cnt_obj);
	511	parse_headers(f_exe, &base, &s_text_exe, NULL, NULL, NULL, NULL);
cfd23479	512
572a6bea	513	sztext_cmn = s_text_obj.size;
	514	if (sztext_cmn > s_text_exe.size)
	515	sztext_cmn = s_text_exe.size;
cfd23479	516
	517	if (sztext_cmn == 0) {
	518	printf("bad .text size(s): %ld, %ld\n",
572a6bea	519	s_text_obj.size, s_text_exe.size);
cfd23479	520	return 1;
	521	}
	522
572a6bea	523	for (i = 0; i < s_text_obj.reloc_cnt; i++)
cfd23479	524	{
572a6bea	525	unsigned int a = s_text_obj.relocs[i].r_vaddr;
572a6bea	526	//printf("%04x %08x\n", s_text_obj.relocs[i].r_type, a);
cfd23479	527
572a6bea	528	switch (s_text_obj.relocs[i].r_type) {
2c605b97	529	case 0x06: // RELOC_ADDR32
	530	case 0x14: // RELOC_REL32
	531	// must preserve stored val,
572a6bea	532	// so trash exe so that cmp passes
572a6bea	533	memcpy(s_text_exe.data + a, s_text_obj.data + a, 4);
cfd23479	534	break;
cfd23479	535	default:
2c605b97	536	printf("unknown reloc %x @%08x/%08x\n",
572a6bea	537	s_text_obj.relocs[i].r_type, a, base + a);
cfd23479	538	return 1;
	539	}
	540	}
	541
	542	for (i = 0; i < sztext_cmn; i++)
	543	{
572a6bea	544	if (s_text_obj.data[i] == s_text_exe.data[i])
cfd23479	545	continue;
	546
	547	left = sztext_cmn - i;
	548
572a6bea	549	if (s_text_exe.data[i] == 0xcc) { // padding
	550	if (handle_pad(s_text_obj.data + i,
	551	s_text_exe.data + i, left))
cfd23479	552	continue;
	553	}
	554
572a6bea	555	ret = check_equiv(s_text_obj.data + i, s_text_exe.data + i, left);
cfd23479	556	if (ret >= 0) {
	557	i += ret;
	558	continue;
	559	}
	560
572a6bea	561	printf("%x: %02x vs %02x\n", base + i,
572a6bea	562	s_text_obj.data[i], s_text_exe.data[i]);
cfd23479	563	goto out;
	564	}
	565
572a6bea	566	// fill removed funcs with 'int3'
2c605b97	567	for (i = 0; i < sym_cnt_obj; i++) {
	568	if (strncmp(syms_obj[i].name, "rm_", 3))
	569	continue;
	570
	571	addr = syms_obj[i].addr;
	572	end = (i < sym_cnt_obj - 1)
572a6bea	573	? syms_obj[i + 1].addr : s_text_obj.size;
572a6bea	574	if (addr >= s_text_obj.size \|\| end > s_text_obj.size) {
2c605b97	575	printf("addr OOR: %x-%x '%s'\n", addr, end,
	576	syms_obj[i].name);
	577	goto out;
	578	}
572a6bea	579	fill_int3(s_text_obj.data + addr, end - addr);
	580	}
	581
	582	// remove relocs
	583	for (i = 0; i < s_text_obj.reloc_cnt; i++) {
	584	addr = s_text_obj.relocs[i].r_vaddr;
a2f78da4	585	sym = s_text_obj.relocs[i].r_symndx;
572a6bea	586	if (addr > s_text_obj.size - 4) {
	587	printf("reloc addr OOR: %x\n", addr);
	588	goto out;
	589	}
a2f78da4	590	if (sym >= raw_sym_cnt_obj) {
	591	printf("reloc sym OOR: %d/%ld\n",
	592	sym, raw_sym_cnt_obj);
	593	goto out;
	594	}
	595	#if 0
	596	printf("r %08x -> %08x %s\n", base + addr,
	597	raw_syms_obj[sym].addr,
	598	raw_syms_obj[sym].name);
	599	#endif
	600	t = (unsigned int *)(s_text_obj.data + addr);
	601	if (t[0] == 0xcccccccc
	602	\|\| t[-1] == 0xcccccccc) { // jumptab of a func?
	603	t[0] = 0xcccccccc;
572a6bea	604	memmove(&s_text_obj.relocs[i],
	605	&s_text_obj.relocs[i + 1],
	606	(s_text_obj.reloc_cnt - i - 1)
	607	* sizeof(s_text_obj.relocs[0]));
	608	i--;
	609	s_text_obj.reloc_cnt--;
	610	}
a2f78da4	611	// note: branches/calls already linked,
	612	// so only useful for dd refs
	613	else if (raw_syms_obj[sym].is_text) {
	614	addr2 = raw_syms_obj[sym].addr;
	615	if (s_text_obj.data[addr2] == 0xcc) {
	616	printf("warning: reloc %08x -> %08x "
	617	"points to rm'd target '%s'\n",
	618	base + addr, base + addr2,
	619	raw_syms_obj[sym].name);
	620	}
	621	}
2c605b97	622	}
2c605b97	623
572a6bea	624	// patch .text
	625	ret = fseek(f_obj, s_text_obj.sect_fofs, SEEK_SET);
	626	my_assert(ret, 0);
	627	ret = fwrite(s_text_obj.data, 1, s_text_obj.size, f_obj);
	628	my_assert(ret, s_text_obj.size);
	629
	630	// patch relocs
	631	ret = fseek(f_obj, s_text_obj.reloc_fofs, SEEK_SET);
	632	my_assert(ret, 0);
	633	ret = fwrite(s_text_obj.relocs, sizeof(s_text_obj.relocs[0]),
	634	s_text_obj.reloc_cnt, f_obj);
	635	my_assert(ret, s_text_obj.reloc_cnt);
	636
	637	ret = fseek(f_obj, s_text_obj.scnhdr_fofs, SEEK_SET);
	638	my_assert(ret, 0);
	639	ret = fread(&tmphdr, 1, sizeof(tmphdr), f_obj);
	640	my_assert(ret, sizeof(tmphdr));
	641
	642	tmphdr.s_nreloc = s_text_obj.reloc_cnt;
	643
	644	ret = fseek(f_obj, s_text_obj.scnhdr_fofs, SEEK_SET);
	645	my_assert(ret, 0);
	646	ret = fwrite(&tmphdr, 1, sizeof(tmphdr), f_obj);
	647	my_assert(ret, sizeof(tmphdr));
2c605b97	648
	649	fclose(f_obj);
	650	fclose(f_exe);
	651
	652	retval = 0;
cfd23479	653	out:
	654	return retval;
	655	}