diff options
Diffstat (limited to 'toolkit/crashreporter/google-breakpad/src/third_party/libdisasm/ia32_modrm.c')
-rw-r--r-- | toolkit/crashreporter/google-breakpad/src/third_party/libdisasm/ia32_modrm.c | 310 |
1 files changed, 0 insertions, 310 deletions
diff --git a/toolkit/crashreporter/google-breakpad/src/third_party/libdisasm/ia32_modrm.c b/toolkit/crashreporter/google-breakpad/src/third_party/libdisasm/ia32_modrm.c deleted file mode 100644 index b0fe2ed3d..000000000 --- a/toolkit/crashreporter/google-breakpad/src/third_party/libdisasm/ia32_modrm.c +++ /dev/null @@ -1,310 +0,0 @@ -#include "ia32_modrm.h" -#include "ia32_reg.h" -#include "x86_imm.h" - -/* NOTE: when decoding ModR/M and SIB, we have to add 1 to all register - * values obtained from decoding the ModR/M or SIB byte, since they - * are encoded with eAX = 0 and the tables in ia32_reg.c use eAX = 1. - * ADDENDUM: this is only the case when the register value is used - * directly as an index into the register table, not when it is added to - * a genregs offset. */ - -/* -------------------------------- ModR/M, SIB */ -/* ModR/M flags */ -#define MODRM_RM_SIB 0x04 /* R/M == 100 */ -#define MODRM_RM_NOREG 0x05 /* R/B == 101 */ - -/* if (MODRM.MOD_NODISP && MODRM.RM_NOREG) then just disp32 */ -#define MODRM_MOD_NODISP 0x00 /* mod == 00 */ -#define MODRM_MOD_DISP8 0x01 /* mod == 01 */ -#define MODRM_MOD_DISP32 0x02 /* mod == 10 */ -#define MODRM_MOD_NOEA 0x03 /* mod == 11 */ - -/* 16-bit modrm flags */ -#define MOD16_MOD_NODISP 0 -#define MOD16_MOD_DISP8 1 -#define MOD16_MOD_DISP16 2 -#define MOD16_MOD_REG 3 - -#define MOD16_RM_BXSI 0 -#define MOD16_RM_BXDI 1 -#define MOD16_RM_BPSI 2 -#define MOD16_RM_BPDI 3 -#define MOD16_RM_SI 4 -#define MOD16_RM_DI 5 -#define MOD16_RM_BP 6 -#define MOD16_RM_BX 7 - -/* SIB flags */ -#define SIB_INDEX_NONE 0x04 -#define SIB_BASE_EBP 0x05 -#define SIB_SCALE_NOBASE 0x00 - -/* Convenience struct for modR/M bitfield */ -struct modRM_byte { - unsigned int mod : 2; - unsigned int reg : 3; - unsigned int rm : 3; -}; - -/* Convenience struct for SIB bitfield */ -struct SIB_byte { - unsigned int scale : 2; - unsigned int index : 3; - unsigned int base : 3; -}; - - -#if 0 -int modrm_rm[] = {0,1,2,3,MODRM_RM_SIB,MODRM_MOD_DISP32,6,7}; -int modrm_reg[] = {0, 1, 2, 3, 4, 5, 6, 7}; -int modrm_mod[] = {0, MODRM_MOD_DISP8, MODRM_MOD_DISP32, MODRM_MOD_NOEA}; -int sib_scl[] = {0, 2, 4, 8}; -int sib_idx[] = {0, 1, 2, 3, SIB_INDEX_NONE, 5, 6, 7 }; -int sib_bas[] = {0, 1, 2, 3, 4, SIB_SCALE_NOBASE, 6, 7 }; -#endif - -/* this is needed to replace x86_imm_signsized() which does not sign-extend - * to dest */ -static unsigned int imm32_signsized( unsigned char *buf, size_t buf_len, - int32_t *dest, unsigned int size ) { - if ( size > buf_len ) { - return 0; - } - - switch (size) { - case 1: - *dest = *((signed char *) buf); - break; - case 2: - *dest = *((signed short *) buf); - break; - case 4: - default: - *dest = *((signed int *) buf); - break; - } - - return size; -} - - - -static void byte_decode(unsigned char b, struct modRM_byte *modrm) { - /* generic bitfield-packing routine */ - - modrm->mod = b >> 6; /* top 2 bits */ - modrm->reg = (b & 56) >> 3; /* middle 3 bits */ - modrm->rm = b & 7; /* bottom 3 bits */ -} - - -static size_t sib_decode( unsigned char *buf, size_t buf_len, x86_ea_t *ea, - unsigned int mod ) { - /* set Address Expression fields (scale, index, base, disp) - * according to the contents of the SIB byte. - * b points to the SIB byte in the instruction-stream buffer; the - * byte after b[0] is therefore the byte after the SIB - * returns number of bytes 'used', including the SIB byte */ - size_t size = 1; /* start at 1 for SIB byte */ - struct SIB_byte sib; - - if ( buf_len < 1 ) { - return 0; - } - - byte_decode( *buf, (struct modRM_byte *)(void*)&sib ); /* get bit-fields */ - - if ( sib.base == SIB_BASE_EBP && ! mod ) { /* if base == 101 (ebp) */ - /* IF BASE == EBP, deal with exception */ - /* IF (ModR/M did not create a Disp */ - /* ... create a 32-bit Displacement */ - imm32_signsized( &buf[1], buf_len, &ea->disp, sizeof(int32_t)); - ea->disp_size = sizeof(int32_t); - ea->disp_sign = (ea->disp < 0) ? 1 : 0; - size += 4; /* add sizeof disp to count */ - - } else { - /* ELSE BASE refers to a General Register */ - ia32_handle_register( &ea->base, sib.base + 1 ); - } - - /* set scale to 1, 2, 4, 8 */ - ea->scale = 1 << sib.scale; - - if (sib.index != SIB_INDEX_NONE) { - /* IF INDEX is not 'ESP' (100) */ - ia32_handle_register( &ea->index, sib.index + 1 ); - } - - return (size); /* return number of bytes processed */ -} - -static size_t modrm_decode16( unsigned char *buf, unsigned int buf_len, - x86_op_t *op, struct modRM_byte *modrm ) { - /* 16-bit mode: hackish, but not as hackish as 32-bit mode ;) */ - size_t size = 1; /* # of bytes decoded [1 for modR/M byte] */ - x86_ea_t * ea = &op->data.expression; - - switch( modrm->rm ) { - case MOD16_RM_BXSI: - ia32_handle_register(&ea->base, REG_WORD_OFFSET + 3); - ia32_handle_register(&ea->index, REG_WORD_OFFSET + 6); - break; - case MOD16_RM_BXDI: - ia32_handle_register(&ea->base, REG_WORD_OFFSET + 3); - ia32_handle_register(&ea->index, REG_WORD_OFFSET + 7); - case MOD16_RM_BPSI: - op->flags |= op_ss_seg; - ia32_handle_register(&ea->base, REG_WORD_OFFSET + 5); - ia32_handle_register(&ea->index, REG_WORD_OFFSET + 6); - break; - case MOD16_RM_BPDI: - op->flags |= op_ss_seg; - ia32_handle_register(&ea->base, REG_WORD_OFFSET + 5); - ia32_handle_register(&ea->index, REG_WORD_OFFSET + 7); - break; - case MOD16_RM_SI: - ia32_handle_register(&ea->base, REG_WORD_OFFSET + 6); - break; - case MOD16_RM_DI: - ia32_handle_register(&ea->base, REG_WORD_OFFSET + 7); - break; - case MOD16_RM_BP: - if ( modrm->mod != MOD16_MOD_NODISP ) { - op->flags |= op_ss_seg; - ia32_handle_register(&ea->base, - REG_WORD_OFFSET + 5); - } - break; - case MOD16_RM_BX: - ia32_handle_register(&ea->base, REG_WORD_OFFSET + 3); - break; - } - - /* move to byte after ModR/M */ - ++buf; - --buf_len; - - if ( modrm->mod == MOD16_MOD_DISP8 ) { - imm32_signsized( buf, buf_len, &ea->disp, sizeof(char) ); - ea->disp_sign = (ea->disp < 0) ? 1 : 0; - ea->disp_size = sizeof(char); - size += sizeof(char); - } else if ( modrm->mod == MOD16_MOD_DISP16 ) { - imm32_signsized( buf, buf_len, &ea->disp, sizeof(short) ); - ea->disp_sign = (ea->disp < 0) ? 1 : 0; - ea->disp_size = sizeof(short); - size += sizeof(short); - } - - return size; -} - -/* TODO : Mark index modes - Use addressing mode flags to imply arrays (index), structure (disp), - two-dimensional arrays [disp + index], classes [ea reg], and so on. -*/ -size_t ia32_modrm_decode( unsigned char *buf, unsigned int buf_len, - x86_op_t *op, x86_insn_t *insn, size_t gen_regs ) { - /* create address expression and/or fill operand based on value of - * ModR/M byte. Calls sib_decode as appropriate. - * flags specifies whether Reg or mod+R/M fields are being decoded - * returns the number of bytes in the instruction, including modR/M */ - struct modRM_byte modrm; - size_t size = 1; /* # of bytes decoded [1 for modR/M byte] */ - x86_ea_t * ea; - - - byte_decode(*buf, &modrm); /* get bitfields */ - - /* first, handle the case where the mod field is a register only */ - if ( modrm.mod == MODRM_MOD_NOEA ) { - op->type = op_register; - ia32_handle_register(&op->data.reg, modrm.rm + gen_regs); - /* increase insn size by 1 for modrm byte */ - return 1; - } - - /* then deal with cases where there is an effective address */ - ea = &op->data.expression; - op->type = op_expression; - op->flags |= op_pointer; - - if ( insn->addr_size == 2 ) { - /* gah! 16 bit mode! */ - return modrm_decode16( buf, buf_len, op, &modrm); - } - - /* move to byte after ModR/M */ - ++buf; - --buf_len; - - if (modrm.mod == MODRM_MOD_NODISP) { /* if mod == 00 */ - - /* IF MOD == No displacement, just Indirect Register */ - if (modrm.rm == MODRM_RM_NOREG) { /* if r/m == 101 */ - /* IF RM == No Register, just Displacement */ - /* This is an Intel Moronic Exception TM */ - imm32_signsized( buf, buf_len, &ea->disp, - sizeof(int32_t) ); - ea->disp_size = sizeof(int32_t); - ea->disp_sign = (ea->disp < 0) ? 1 : 0; - size += 4; /* add sizeof disp to count */ - - } else if (modrm.rm == MODRM_RM_SIB) { /* if r/m == 100 */ - /* ELSE IF an SIB byte is present */ - /* TODO: check for 0 retval */ - size += sib_decode( buf, buf_len, ea, modrm.mod); - /* move to byte after SIB for displacement */ - ++buf; - --buf_len; - } else { /* modR/M specifies base register */ - /* ELSE RM encodes a general register */ - ia32_handle_register( &ea->base, modrm.rm + 1 ); - } - } else { /* mod is 01 or 10 */ - if (modrm.rm == MODRM_RM_SIB) { /* rm == 100 */ - /* IF base is an AddrExpr specified by an SIB byte */ - /* TODO: check for 0 retval */ - size += sib_decode( buf, buf_len, ea, modrm.mod); - /* move to byte after SIB for displacement */ - ++buf; - --buf_len; - } else { - /* ELSE base is a general register */ - ia32_handle_register( &ea->base, modrm.rm + 1 ); - } - - /* ELSE mod + r/m specify a disp##[base] or disp##(SIB) */ - if (modrm.mod == MODRM_MOD_DISP8) { /* mod == 01 */ - /* If this is an 8-bit displacement */ - imm32_signsized( buf, buf_len, &ea->disp, - sizeof(char)); - ea->disp_size = sizeof(char); - ea->disp_sign = (ea->disp < 0) ? 1 : 0; - size += 1; /* add sizeof disp to count */ - - } else { - /* Displacement is dependent on address size */ - imm32_signsized( buf, buf_len, &ea->disp, - insn->addr_size); - ea->disp_size = insn->addr_size; - ea->disp_sign = (ea->disp < 0) ? 1 : 0; - size += 4; - } - } - - return size; /* number of bytes found in instruction */ -} - -void ia32_reg_decode( unsigned char byte, x86_op_t *op, size_t gen_regs ) { - struct modRM_byte modrm; - byte_decode( byte, &modrm ); /* get bitfields */ - - /* set operand to register ID */ - op->type = op_register; - ia32_handle_register(&op->data.reg, modrm.reg + gen_regs); - - return; -} |