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#include "frida-gumjs.h"
#include "debug.h"
#include "cmplog.h"
#include "ctx.h"
#include "frida_cmplog.h"
#include "util.h"
#if defined(__i386__)
typedef struct {
x86_op_type type;
uint8_t size;
union {
x86_op_mem mem;
x86_reg reg;
int64_t imm;
};
} cmplog_ctx_t;
typedef struct {
cmplog_ctx_t operand1;
cmplog_ctx_t operand2;
} cmplog_pair_ctx_t;
static gboolean cmplog_read_mem(GumCpuContext *ctx, uint8_t size,
x86_op_mem *mem, gsize *val) {
gsize base = 0;
gsize index = 0;
gsize address;
if (mem->base != X86_REG_INVALID) base = ctx_read_reg(ctx, mem->base);
if (mem->index != X86_REG_INVALID) index = ctx_read_reg(ctx, mem->index);
address = base + (index * mem->scale) + mem->disp;
if (!cmplog_is_readable(address, size)) { return FALSE; }
switch (size) {
case 1:
*val = *((guint8 *)GSIZE_TO_POINTER(address));
return TRUE;
case 2:
*val = *((guint16 *)GSIZE_TO_POINTER(address));
return TRUE;
case 4:
*val = *((guint32 *)GSIZE_TO_POINTER(address));
return TRUE;
default:
FATAL("Invalid operand size: %d\n", size);
}
return FALSE;
}
static gboolean cmplog_get_operand_value(GumCpuContext *context,
cmplog_ctx_t *ctx, gsize *val) {
switch (ctx->type) {
case X86_OP_REG:
*val = ctx_read_reg(context, ctx->reg);
return TRUE;
case X86_OP_IMM:
*val = ctx->imm;
return TRUE;
case X86_OP_MEM:
return cmplog_read_mem(context, ctx->size, &ctx->mem, val);
default:
FATAL("Invalid operand type: %d\n", ctx->type);
}
return FALSE;
}
static void cmplog_call_callout(GumCpuContext *context, gpointer user_data) {
UNUSED_PARAMETER(user_data);
gsize address = ctx_read_reg(context, X86_REG_EIP);
gsize *esp = (gsize *)ctx_read_reg(context, X86_REG_ESP);
if (!cmplog_is_readable(GPOINTER_TO_SIZE(esp), 12)) return;
/*
* This callout is place immediately before the call instruction, and hence
* the return address is not yet pushed on the top of the stack.
*/
gsize arg1 = esp[0];
gsize arg2 = esp[1];
if (((G_MAXULONG - arg1) < 32) || ((G_MAXULONG - arg2) < 32)) return;
if (!cmplog_is_readable(arg1, 32) || !cmplog_is_readable(arg2, 32)) return;
void *ptr1 = GSIZE_TO_POINTER(arg1);
void *ptr2 = GSIZE_TO_POINTER(arg2);
uintptr_t k = address;
k = (k >> 4) ^ (k << 8);
k &= CMP_MAP_W - 1;
__afl_cmp_map->headers[k].type = CMP_TYPE_RTN;
u32 hits = __afl_cmp_map->headers[k].hits;
__afl_cmp_map->headers[k].hits = hits + 1;
__afl_cmp_map->headers[k].shape = 31;
hits &= CMP_MAP_RTN_H - 1;
gum_memcpy(((struct cmpfn_operands *)__afl_cmp_map->log[k])[hits].v0, ptr1,
32);
gum_memcpy(((struct cmpfn_operands *)__afl_cmp_map->log[k])[hits].v1, ptr2,
32);
}
static void cmplog_instrument_put_operand(cmplog_ctx_t *ctx,
cs_x86_op * operand) {
ctx->type = operand->type;
ctx->size = operand->size;
switch (operand->type) {
case X86_OP_REG:
gum_memcpy(&ctx->reg, &operand->reg, sizeof(x86_reg));
break;
case X86_OP_IMM:
gum_memcpy(&ctx->imm, &operand->imm, sizeof(int64_t));
break;
case X86_OP_MEM:
gum_memcpy(&ctx->mem, &operand->mem, sizeof(x86_op_mem));
break;
default:
FATAL("Invalid operand type: %d\n", operand->type);
}
}
static void cmplog_instrument_call(const cs_insn * instr,
GumStalkerIterator *iterator) {
cs_x86 x86 = instr->detail->x86;
cs_x86_op *operand;
if (instr->id != X86_INS_CALL) return;
if (x86.op_count != 1) return;
operand = &x86.operands[0];
if (operand->type == X86_OP_INVALID) return;
if (operand->type == X86_OP_MEM && operand->mem.segment != X86_REG_INVALID)
return;
gum_stalker_iterator_put_callout(iterator, cmplog_call_callout, NULL, NULL);
}
static void cmplog_handle_cmp_sub(GumCpuContext *context, gsize operand1,
gsize operand2, uint8_t size) {
gsize address = ctx_read_reg(context, X86_REG_EIP);
register uintptr_t k = (uintptr_t)address;
k = (k >> 4) ^ (k << 8);
k &= CMP_MAP_W - 1;
__afl_cmp_map->headers[k].type = CMP_TYPE_INS;
u32 hits = __afl_cmp_map->headers[k].hits;
__afl_cmp_map->headers[k].hits = hits + 1;
__afl_cmp_map->headers[k].shape = (size - 1);
hits &= CMP_MAP_H - 1;
__afl_cmp_map->log[k][hits].v0 = operand1;
__afl_cmp_map->log[k][hits].v1 = operand2;
}
static void cmplog_cmp_sub_callout(GumCpuContext *context, gpointer user_data) {
cmplog_pair_ctx_t *ctx = (cmplog_pair_ctx_t *)user_data;
gsize operand1;
gsize operand2;
if (ctx->operand1.size != ctx->operand2.size) FATAL("Operand size mismatch");
if (!cmplog_get_operand_value(context, &ctx->operand1, &operand1)) { return; }
if (!cmplog_get_operand_value(context, &ctx->operand2, &operand2)) { return; }
cmplog_handle_cmp_sub(context, operand1, operand2, ctx->operand1.size);
}
static void cmplog_instrument_cmp_sub_put_callout(GumStalkerIterator *iterator,
cs_x86_op * operand1,
cs_x86_op *operand2) {
cmplog_pair_ctx_t *ctx = g_malloc(sizeof(cmplog_pair_ctx_t));
if (ctx == NULL) return;
cmplog_instrument_put_operand(&ctx->operand1, operand1);
cmplog_instrument_put_operand(&ctx->operand2, operand2);
gum_stalker_iterator_put_callout(iterator, cmplog_cmp_sub_callout, ctx,
g_free);
}
static void cmplog_instrument_cmp_sub(const cs_insn * instr,
GumStalkerIterator *iterator) {
cs_x86 x86 = instr->detail->x86;
cs_x86_op *operand1;
cs_x86_op *operand2;
switch (instr->id) {
case X86_INS_CMP:
case X86_INS_SUB:
break;
default:
return;
}
if (x86.op_count != 2) return;
operand1 = &x86.operands[0];
operand2 = &x86.operands[1];
if (operand1->type == X86_OP_INVALID) return;
if (operand2->type == X86_OP_INVALID) return;
if ((operand1->type == X86_OP_MEM) &&
(operand1->mem.segment != X86_REG_INVALID))
return;
if ((operand2->type == X86_OP_MEM) &&
(operand2->mem.segment != X86_REG_INVALID))
return;
cmplog_instrument_cmp_sub_put_callout(iterator, operand1, operand2);
}
void cmplog_instrument(const cs_insn *instr, GumStalkerIterator *iterator) {
if (__afl_cmp_map == NULL) return;
cmplog_instrument_call(instr, iterator);
cmplog_instrument_cmp_sub(instr, iterator);
}
#endif
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