Fix uninitialized variable use in arc disassembler

Fix invalid malloc in generic disasm

libr/asm/arch/arc/gnu/arc-dis.c

@@ -540,7 +540,7 @@ dsmOneArcInst (bfd_vma addr, struct arcDisState * state)
   int is_linked = 0;
   int offset = 0;
   int usesAuxReg = 0;
-  int flags;
+  int flags = 0;
   int ignoreFirstOpd;
   char formatString[60];
 

libr/asm/arch/arc/gnu/arc-dis.h

@@ -77,6 +77,7 @@ struct arcDisState
   unsigned char tcnt;
   unsigned char acnt;
 };
+int decodeInstr (bfd_vma address, disassemble_info * info);
 
 #define __TRANSLATION_REQUIRED(state) ((state).acnt != 0)
 

libr/asm/arch/arc/gnu/arc-opc.c

@@ -21,6 +21,7 @@
 
 #include "sysdep.h"
 #include <stdio.h>
+#include <string.h>
 #include "ansidecl.h"
 //#include "bfd.h"
 #include "arc.h"

libr/asm/asm.c

@@ -1,7 +1,6 @@
 /* radare - LGPL - Copyright 2009-2012 - nibble */
 
 #include <stdio.h>
-
 #include <r_types.h>
 #include <r_util.h>
 #include <r_asm.h>
@@ -286,6 +285,7 @@ R_API int r_asm_disassemble(RAsm *a, RAsmOp *op, const ut8 *buf, ut64 len) {
 		ret = a->cur->disassemble (a, op, buf, len);
 	if (ret > 0) {
 		int oplen = r_asm_op_get_size (op);
+		if (oplen>len) oplen = len;
 		if (a->ofilter)
 			r_parse_parse (a->ofilter, op->buf_asm, op->buf_asm);
 		else memcpy (op->buf, buf, oplen);

libr/asm/p/asm_arc.c

@@ -47,6 +47,7 @@ static int buf_fprintf(void *stream, const char *format, ...) {
 	return 0;
 }
 
+int decodeInstr (bfd_vma address, disassemble_info * info);
 static int disassemble(RAsm *a, struct r_asm_op_t *op, const ut8 *buf, ut64 len) {
 	static struct disassemble_info disasm_obj;
 	if (len<4) return -1;

libr/core/disasm.c

@@ -654,6 +654,7 @@ toro:
 		free (buf);
 	if (idx>=len) {// && (invbreak && !lastfail)) {
 		if (invbreak && lines<l) {
+			if (len<4) len = 4;
 			buf = nbuf = malloc (len);
 			addr += idx;
 			r_core_read_at (core, addr, buf, len);

libr/core/visual.c

@@ -444,6 +444,7 @@ R_API int r_core_visual_cmd(RCore *core, int ch) {
 			{
 				int offscreen = (core->cons->rows-3)*cols;
 				if (cursor>=offscreen) {
+					ut64 x = core->offset + cols;
 					r_core_seek (core, core->offset+cols, 1);
 					cursor-=cols;
 				}