From cfd234794a54dcea07c55ee5b2fdadd7a18fbb5f Mon Sep 17 00:00:00 2001 From: notaz Date: Fri, 15 Nov 2013 03:44:41 +0200 Subject: [PATCH] .text cmp tool, updates for it to pass --- cmpmrg_text.c | 441 ++++++++++++++++++++++++++++++++++++++++++++++++ runsed.sh | 12 +- scr.x => scr.ld | 0 3 files changed, 450 insertions(+), 3 deletions(-) create mode 100644 cmpmrg_text.c rename scr.x => scr.ld (100%) diff --git a/cmpmrg_text.c b/cmpmrg_text.c new file mode 100644 index 0000000..ea7223c --- /dev/null +++ b/cmpmrg_text.c @@ -0,0 +1,441 @@ +#include +#include +#include +#include +#include +#include + +/* 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; + +static void my_assert_(int line, const char *name, long v, long expect, int is_eq) +{ + int ok; + if (is_eq) + ok = (v == expect); + else + ok = (v != expect); + + if (!ok) + { + printf("%d: '%s' is %lx, need %s%lx\n", line, name, + v, is_eq ? "" : "!", expect); + exit(1); + } +} +#define my_assert(v, exp) \ + my_assert_(__LINE__, #v, (long)(v), (long)(exp), 1) +#define my_assert_not(v, exp) \ + my_assert_(__LINE__, #v, (long)(v), (long)(exp), 0) + +void parse_headers(FILE *f, unsigned int *base_out, + long *sect_ofs, uint8_t **sect_data, long *sect_sz, + RELOC **relocs, long *reloc_cnt) +{ + unsigned int base = 0; + long opthdr_pos; + long reloc_size; + FILHDR hdr; + AOUTHDR opthdr; + SCNHDR scnhdr; + int s, val; + int ret; + + 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); + } + + for (s = 0; s < hdr.f_nscns; s++) { + ret = fread(&scnhdr, 1, sizeof(scnhdr), f); + my_assert(ret, sizeof(scnhdr)); + + if (scnhdr.s_size != 0) + break; + } + + 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"); + + ret = fseek(f, scnhdr.s_scnptr, SEEK_SET); + my_assert(ret, 0); + + *sect_data = malloc(scnhdr.s_size); + my_assert_not(*sect_data, NULL); + ret = fread(*sect_data, 1, scnhdr.s_size, f); + my_assert(ret, scnhdr.s_size); + + *sect_ofs = scnhdr.s_scnptr; + *sect_sz = scnhdr.s_size; + + ret = fseek(f, scnhdr.s_relptr, SEEK_SET); + my_assert(ret, 0); + + reloc_size = scnhdr.s_nreloc * sizeof((*relocs)[0]); + *relocs = malloc(reloc_size + 1); + my_assert_not(*relocs, NULL); + ret = fread(*relocs, 1, reloc_size, f); + my_assert(ret, reloc_size); + + *reloc_cnt = scnhdr.s_nreloc; + + if (base != 0) + *base_out = base + scnhdr.s_vaddr; +} + +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; +} + +int main(int argc, char *argv[]) +{ + FILE *f_obj, *f_exe; + long text_ofs_obj, text_ofs_exe; + long sztext_obj, sztext_exe, sztext_cmn; + RELOC *relocs_obj, *relocs_exe; + long reloc_cnt_obj, reloc_cnt_exe, reloc_cnt_cmn; + unsigned int base = 0; + uint8_t *d_obj, *d_exe; + int retval = 1; + int left; + int ret; + int i; + + if (argc != 3) { + printf("usage:\n%s \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[1]); + perror(""); + return 1; + } + + parse_headers(f_obj, &base, &text_ofs_obj, &d_obj, &sztext_obj, + &relocs_obj, &reloc_cnt_obj); + parse_headers(f_exe, &base, &text_ofs_exe, &d_exe, &sztext_exe, + &relocs_exe, &reloc_cnt_exe); + + sztext_cmn = sztext_obj; + if (sztext_cmn > sztext_exe) + sztext_cmn = sztext_exe; + reloc_cnt_cmn = reloc_cnt_obj; + if (reloc_cnt_cmn > reloc_cnt_exe) + reloc_cnt_cmn = reloc_cnt_exe; + + if (sztext_cmn == 0) { + printf("bad .text size(s): %ld, %ld\n", + sztext_obj, sztext_exe); + return 1; + } + + for (i = 0; i < reloc_cnt_obj; i++) // reloc_cnt_cmn + { + unsigned int a = relocs_obj[i].r_vaddr; + //printf("%04x %08x\n", relocs_obj[i].r_type, a); + + switch (relocs_obj[i].r_type) { + case 0x06: + memset(d_obj + a, 0, 4); + memset(d_exe + a, 0, 4); + break; + default: + printf("unknown reloc %x @%08x\n", + relocs_obj[i].r_type, base + a); + return 1; + } + } + + for (i = 0; i < sztext_cmn; i++) + { + if (d_obj[i] == d_exe[i]) + continue; + + left = sztext_cmn - i; + + if (d_exe[i] == 0xcc) { // padding + if (handle_pad(d_obj + i, d_exe + i, left)) + continue; + } + + ret = check_equiv(d_obj + i, d_exe + i, left); + if (ret >= 0) { + i += ret; + continue; + } + + printf("%x: %02x vs %02x\n", base + i, d_obj[i], d_exe[i]); + goto out; + } + +out: + return retval; +} diff --git a/runsed.sh b/runsed.sh index ba98e54..115ab6a 100755 --- a/runsed.sh +++ b/runsed.sh @@ -18,14 +18,20 @@ s/\\t\[esp+4+var_4\]/fldcw\tword ptr \[esp\]/;\ s/\/pushfd/;\ +s/\/popfd/;\ s/\(\\)\tloc_/\1\tnear ptr loc_/;\ +s/\> $f . $f # manual fixup: -# = 'end start' -> 'end' +# - 'end start' -> 'end' # - 'lea ecx, [ecx+0]' -> align # - add 'near ptr' to some jumps # - 'cmp [ebp+edx+0], cl' -> 'cmp [edx+ebp+0], cl' -# - 0FFFFh constant - masm treats a byte, sometimes prefix with 'word ptr' +# - 0FFxxh constants - masm treats a byte, ONLY sometimes prefix with 'word ptr' +# - jmp near: +# - jmp _strchr diff --git a/scr.x b/scr.ld similarity index 100% rename from scr.x rename to scr.ld -- 2.39.5