Support for x86 (#920)

Co-authored-by: Your Name <you@example.com>

2 files changed, 280 insertions, 22 deletions

diff --git a/frida_mode/src/cmplog/cmplog_x64.c b/frida_mode/src/cmplog/cmplog_x64.c
index c3621a29..9f56c32a 100644
--- a/frida_mode/src/cmplog/cmplog_x64.c
+++ b/frida_mode/src/cmplog/cmplog_x64.c
@@ -31,12 +31,12 @@ typedef struct {
 
 } cmplog_pair_ctx_t;
 
-static gboolean cmplog_read_mem(GumX64CpuContext *ctx, uint8_t size,
-                                x86_op_mem *mem, guint64 *val) {
+static gboolean cmplog_read_mem(GumCpuContext *ctx, uint8_t size,
+                                x86_op_mem *mem, gsize *val) {
 
-  guint64 base = 0;
-  guint64 index = 0;
-  guint64 address;
+  gsize base = 0;
+  gsize index = 0;
+  gsize address;
 
   if (mem->base != X86_REG_INVALID) base = ctx_read_reg(ctx, mem->base);
 
@@ -49,16 +49,16 @@ static gboolean cmplog_read_mem(GumX64CpuContext *ctx, uint8_t size,
   switch (size) {
 
     case 1:
-      *val = *((guint8 *)address);
+      *val = *((guint8 *)GSIZE_TO_POINTER(address));
       return TRUE;
     case 2:
-      *val = *((guint16 *)address);
+      *val = *((guint16 *)GSIZE_TO_POINTER(address));
       return TRUE;
     case 4:
-      *val = *((guint32 *)address);
+      *val = *((guint32 *)GSIZE_TO_POINTER(address));
       return TRUE;
     case 8:
-      *val = *((guint64 *)address);
+      *val = *((guint64 *)GSIZE_TO_POINTER(address));
       return TRUE;
     default:
       FATAL("Invalid operand size: %d\n", size);
@@ -70,7 +70,7 @@ static gboolean cmplog_read_mem(GumX64CpuContext *ctx, uint8_t size,
 }
 
 static gboolean cmplog_get_operand_value(GumCpuContext *context,
-                                         cmplog_ctx_t *ctx, guint64 *val) {
+                                         cmplog_ctx_t *ctx, gsize *val) {
 
   switch (ctx->type) {
 
@@ -95,9 +95,9 @@ static void cmplog_call_callout(GumCpuContext *context, gpointer user_data) {
 
   UNUSED_PARAMETER(user_data);
 
-  guint64 address = ctx_read_reg(context, X86_REG_RIP);
-  guint64 rdi = ctx_read_reg(context, X86_REG_RDI);
-  guint64 rsi = ctx_read_reg(context, X86_REG_RSI);
+  gsize address = ctx_read_reg(context, X86_REG_RIP);
+  gsize rdi = ctx_read_reg(context, X86_REG_RDI);
+  gsize rsi = ctx_read_reg(context, X86_REG_RSI);
 
   if (((G_MAXULONG - rdi) < 32) || ((G_MAXULONG - rsi) < 32)) return;
 
@@ -169,10 +169,10 @@ static void cmplog_instrument_call(const cs_insn *     instr,
 
 }
 
-static void cmplog_handle_cmp_sub(GumCpuContext *context, guint64 operand1,
-                                  guint64 operand2, uint8_t size) {
+static void cmplog_handle_cmp_sub(GumCpuContext *context, gsize operand1,
+                                  gsize operand2, uint8_t size) {
 
-  guint64 address = ctx_read_reg(context, X86_REG_RIP);
+  gsize address = ctx_read_reg(context, X86_REG_RIP);
 
   register uintptr_t k = (uintptr_t)address;
 
@@ -195,8 +195,8 @@ static void cmplog_handle_cmp_sub(GumCpuContext *context, guint64 operand1,
 static void cmplog_cmp_sub_callout(GumCpuContext *context, gpointer user_data) {
 
   cmplog_pair_ctx_t *ctx = (cmplog_pair_ctx_t *)user_data;
-  guint64            operand1;
-  guint64            operand2;
+  gsize              operand1;
+  gsize              operand2;
 
   if (ctx->operand1.size != ctx->operand2.size) FATAL("Operand size mismatch");
 
diff --git a/frida_mode/src/cmplog/cmplog_x86.c b/frida_mode/src/cmplog/cmplog_x86.c
index 2401180c..a27df0af 100644
--- a/frida_mode/src/cmplog/cmplog_x86.c
+++ b/frida_mode/src/cmplog/cmplog_x86.c
@@ -1,17 +1,275 @@
 #include "frida-gum.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) {
 
-  UNUSED_PARAMETER(instr);
-  UNUSED_PARAMETER(iterator);
-  if (__afl_cmp_map == NULL) { return; }
-  FATAL("CMPLOG mode not supported on this architecture");
+  if (__afl_cmp_map == NULL) return;
+
+  cmplog_instrument_call(instr, iterator);
+  cmplog_instrument_cmp_sub(instr, iterator);
 
 }