Assuming big-endian relative jumptables for PPC

cfg.cc

@@ -14,6 +14,7 @@
 #include "cfg.h"
 #include "log.h"
 #include "options.h"
+#include "endian.h"
 
 
 void
@@ -236,15 +237,15 @@ CFG::find_switches_ppc()
           jmptab32 = (uint32_t*)&sec.bytes[jmptab_idx];
           jmptab64 = (uint64_t*)&sec.bytes[jmptab_idx];
           while(1) {
-            if((jmptab_idx+scale) >= sec.size) break;
+            if((jmptab_idx+scale) > sec.size) break;
             jmptab_end += scale;
             jmptab_idx += scale;
             switch(scale) {
             case 4:
-              case_addr = (*jmptab32++);
+              case_addr = uint32_t(read_be_i32(jmptab32++) + jmptab_addr);
               break;
             case 8:
-              case_addr = (*jmptab64++);
+              case_addr = uint64_t(read_be_i64(jmptab64++) + jmptab_addr);
               break;
             default:
               print_warn("Unexpected scale factor in memory operand: %d", scale);

disasm-ppc.cc

@@ -340,8 +340,8 @@ nucleus_disasm_bb_ppc(Binary *bin, DisasmSection *dis, BB *bb)
       } else if(op->type == Operand::OP_TYPE_REG) {
         op->ppc_value.reg = (ppc_reg)cs_op->reg;
       } else if(op->type == Operand::OP_TYPE_MEM) {
-        op->ppc_value.mem.base    = cs_op->mem.base;
-        op->ppc_value.mem.disp    = cs_op->mem.disp;
+        op->ppc_value.mem.base = cs_op->mem.base;
+        op->ppc_value.mem.disp = cs_op->mem.disp;
       }
     }
 
@@ -354,6 +354,14 @@ nucleus_disasm_bb_ppc(Binary *bin, DisasmSection *dis, BB *bb)
       }
     }
 
+    /* XXX: Some relocations entries point to symbols in sections
+     * that are ignored by Nucleus, e.g. calls to external functions.
+     * We ignore such calls directly at disasm level. */
+    if(call && ins->target == ins->start) {
+      ins->flags &= ~Instruction::INS_FLAG_CALL;
+      ins->flags &= ~Instruction::INS_FLAG_CFLOW;
+    }
+
     if(cflow) {
       /* end of basic block */
       break;

endian.cc

@@ -0,0 +1,87 @@
+#include "endian.h"
+
+/* Detect host endianness */
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+#define NUCLEUS_HOST_LE
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#define NUCLEUS_HOST_BE
+#endif
+
+/* Endian swap */
+#define SWAP_16(x) ( \
+  (((x) >> 8) & 0x00FF) | (((x) << 8) & 0xFF00) \
+)
+#define SWAP_32(x) ( \
+  (((x) >> 24) & 0x000000FF) | (((x) >>  8) & 0x0000FF00) | \
+  (((x) <<  8) & 0x00FF0000) | (((x) << 24) & 0xFF000000)   \
+)
+#define SWAP_64(x) ( \
+  (((x) >> 56) & 0x00000000000000FF) | (((x) >> 40) & 0x000000000000FF00) | \
+  (((x) >> 24) & 0x0000000000FF0000) | (((x) >>  8) & 0x00000000FF000000) | \
+  (((x) <<  8) & 0x000000FF00000000) | (((x) << 24) & 0x0000FF0000000000) | \
+  (((x) << 40) & 0x00FF000000000000) | (((x) << 56) & 0xFF00000000000000)   \
+)
+
+
+/* Little-Endian reads */
+uint16_t read_le_i16(const uint16_t* data)
+{
+  uint16_t value = *data;
+#if defined(NUCLEUS_HOST_LE)
+  return value;
+#elif defined(NUCLEUS_HOST_BE)
+  return SWAP_16(value);
+#endif
+}
+
+uint32_t read_le_i32(const uint32_t* data)
+{
+  uint32_t value = *data;
+#if defined(NUCLEUS_HOST_LE)
+  return value;
+#elif defined(NUCLEUS_HOST_BE)
+  return SWAP_32(value);
+#endif
+}
+
+uint64_t read_le_i64(const uint64_t* data)
+{
+  uint64_t value = *data;
+#if defined(NUCLEUS_HOST_LE)
+  return value;
+#elif defined(NUCLEUS_HOST_BE)
+  return SWAP_64(value);
+#endif
+}
+
+
+/* Big-Endian reads */
+uint16_t read_be_i16(const uint16_t* data)
+{
+  uint16_t value = *data;
+#if defined(NUCLEUS_HOST_BE)
+  return value;
+#elif defined(NUCLEUS_HOST_LE)
+  return SWAP_16(value);
+#endif
+}
+
+uint32_t read_be_i32(const uint32_t* data)
+{
+  uint32_t value = *data;
+#if defined(NUCLEUS_HOST_BE)
+  return value;
+#elif defined(NUCLEUS_HOST_LE)
+  return SWAP_32(value);
+#endif
+}
+
+uint64_t read_be_i64(const uint64_t* data)
+{
+  uint64_t value = *data;
+#if defined(NUCLEUS_HOST_BE)
+  return value;
+#elif defined(NUCLEUS_HOST_LE)
+  return SWAP_64(value);
+#endif
+}

endian.h

@@ -0,0 +1,14 @@
+#ifndef NUCLEUS_ENDIAN_H
+#define NUCLEUS_ENDIAN_H
+
+#include <stdint.h>
+
+uint16_t read_le_i16(const uint16_t* data);
+uint32_t read_le_i32(const uint32_t* data);
+uint64_t read_le_i64(const uint64_t* data);
+
+uint16_t read_be_i16(const uint16_t* data);
+uint32_t read_be_i32(const uint32_t* data);
+uint64_t read_be_i64(const uint64_t* data);
+
+#endif /* NUCLEUS_ENDIAN_H */