Add a custom telescoping function and improve StackWidget's output (#1990)

* Add a custom telescoping function and improve StackWidget's output

* Use colors from the color configuration for stackswidget

* Improve telescoping output

src/core/Cutter.cpp

@@ -1139,9 +1139,144 @@ QJsonDocument CutterCore::getSignatureInfo()
     return cmdj("iCj");
 }
 
-QJsonDocument CutterCore::getStack(int size)
+QList<QJsonObject> CutterCore::getStack(int size, int depth)
 {
-    return cmdj("pxrj " + QString::number(size) + " @ r:SP");
+    QList<QJsonObject> stack;
+    if (!currentlyDebugging) {
+        return stack;
+    }
+
+    CORE_LOCK();
+    bool ret;
+    RVA addr = cmd("dr SP").toULongLong(&ret, 16);
+    if (!ret) {
+        return stack;
+    }
+
+    int base = core->anal->bits;
+    for (int i = 0; i < size; i += base / 8) {
+        if ((base == 32 && addr + i >= UT32_MAX) || (base == 16 && addr + i >= UT16_MAX)) {
+            break;
+        }
+
+        stack.append(getAddrRefs(addr + i, depth));
+    }
+
+    return stack;
+}
+
+QJsonObject CutterCore::getAddrRefs(RVA addr, int depth) {
+    QJsonObject json;
+    if (depth < 1 || addr == UT64_MAX) {
+        return json;
+    }
+
+    CORE_LOCK();
+    int bits = core->assembler->bits;
+    QByteArray buf = QByteArray();
+    ut64 type = r_core_anal_address(core, addr);
+
+    json["addr"] = QString::number(addr);
+
+    // Search for the section the addr is in, avoid duplication for heap/stack with type
+    if(!(type & R_ANAL_ADDR_TYPE_HEAP || type & R_ANAL_ADDR_TYPE_STACK)) {
+        // Attempt to find the address within a map
+        RDebugMap *map = r_debug_map_get(core->dbg, addr);
+        if (map && map->name && map->name[0]) {
+            json["mapname"] = map->name;
+        }
+
+        RBinSection *sect = r_bin_get_section_at(r_bin_cur_object (core->bin), addr, true);
+        if (sect && sect->name[0]) {
+            json["section"] = sect->name;
+        }
+    }
+
+    // Check if the address points to a register
+    RFlagItem *fi = r_flag_get_i(core->flags, addr);
+    if (fi) {
+        RRegItem *r = r_reg_get(core->dbg->reg, fi->name, -1);
+        if (r) {
+            json["reg"] = r->name;
+        }
+    }
+
+    // Attempt to find the address within a function
+    RAnalFunction *fcn = r_anal_get_fcn_in(core->anal, addr, 0);
+    if (fcn) {
+        json["fcn"] = fcn->name;
+    }
+
+    // Update type and permission information
+    if (type != 0) {
+        if (type & R_ANAL_ADDR_TYPE_HEAP) {
+            json["type"] = "heap";
+        } else if (type & R_ANAL_ADDR_TYPE_STACK) {
+            json["type"] = "stack";
+        } else if (type & R_ANAL_ADDR_TYPE_PROGRAM) {
+            json["type"] = "program";
+        } else if (type & R_ANAL_ADDR_TYPE_LIBRARY) {
+            json["type"] = "library";
+        } else if (type & R_ANAL_ADDR_TYPE_ASCII) {
+            json["type"] = "ascii";
+        } else if (type & R_ANAL_ADDR_TYPE_SEQUENCE) {
+            json["type"] = "sequence";
+        }
+
+        QString perms = "";
+        if (type & R_ANAL_ADDR_TYPE_READ) {
+            perms += "r";
+        }
+        if (type & R_ANAL_ADDR_TYPE_WRITE) {
+            perms += "w";
+        }
+        if (type & R_ANAL_ADDR_TYPE_EXEC) {
+            RAsmOp op;
+            buf.resize(32);
+            perms += "x";
+            // Instruction disassembly
+            r_io_read_at(core->io, addr, (unsigned char*)buf.data(), buf.size());
+            r_asm_set_pc(core->assembler, addr);
+            r_asm_disassemble(core->assembler, &op, (unsigned char*)buf.data(), buf.size());
+            json["asm"] = r_asm_op_get_asm(&op);
+        }
+
+        if (!perms.isEmpty()) {
+            json["perms"] = perms;
+        }
+    }
+
+    // Try to telescope further if depth permits it
+    if ((type & R_ANAL_ADDR_TYPE_READ) && !(type & R_ANAL_ADDR_TYPE_EXEC)) {
+        buf.resize(64);
+        ut32 *n32 = (ut32 *)buf.data();
+        ut64 *n64 = (ut64 *)buf.data();
+        r_io_read_at(core->io, addr, (unsigned char*)buf.data(), buf.size());
+        ut64 n = (bits == 64)? *n64: *n32;
+        // The value of the next address will serve as an indication that there's more to
+        // telescope if we have reached the depth limit
+        json["value"] = QString::number(n);
+        if (depth && n != addr) {
+            // Make sure we aren't telescoping the same address
+            QJsonObject ref = getAddrRefs(n, depth - 1);
+            if (!ref.empty() && !ref["type"].isNull()) {
+                // If the dereference of the current pointer is an ascii character we
+                // might have a string in this address
+                if (ref["type"].toString().contains("ascii")) {
+                    buf.resize(128);
+                    r_io_read_at(core->io, addr, (unsigned char*)buf.data(), buf.size());
+                    QString strVal = QString(buf);
+                    // Indicate that the string is longer than the printed value
+                    if (strVal.size() == buf.size()) {
+                        strVal += "...";
+                    }
+                    json["string"] = strVal;
+                }
+                json["ref"] = ref;
+            }
+        }
+    }
+    return json;
 }
 
 QJsonDocument CutterCore::getProcessThreads(int pid)

src/core/Cutter.h

@@ -286,7 +286,19 @@ public:
      * @brief Attach to a given pid from a debug session
      */
     void setCurrentDebugProcess(int pid);
-    QJsonDocument getStack(int size = 0x100);
+    /**
+     * @brief Returns a list of stack address and their telescoped references
+     * @param size number of bytes to scan
+     * @param depth telescoping depth 
+     */
+    QList<QJsonObject> getStack(int size = 0x100, int depth = 6);
+    /**
+     * @brief Recursively dereferences pointers starting at the specified address
+     *        up to a given depth
+     * @param addr telescoping addr
+     * @param depth telescoping depth 
+     */
+    QJsonObject getAddrRefs(RVA addr, int depth);
     /**
      * @brief Get a list of a given process's threads
      * @param pid The pid of the process, -1 for the currently debugged process

src/widgets/StackWidget.cpp

@@ -144,37 +144,66 @@ StackModel::StackModel(QObject *parent)
 {
 }
 
+// Utility function to check if a telescoped item exists and add it with prefixes to the desc
+static inline const QString append_var(QString &dst, const QString val, const QString prepend_val,
+                                       const QString append_val)
+{
+    if (!val.isEmpty()) {
+        dst += prepend_val + val + append_val;
+    }
+    return val;
+}
+
 void StackModel::reload()
 {
-    QJsonArray stackValues = Core()->getStack().array();
+    QList<QJsonObject> stackItems = Core()->getStack();
 
     beginResetModel();
     values.clear();
-    for (const QJsonValue &value : stackValues) {
+    for (const QJsonObject &stackItem : stackItems) {
-        QJsonObject stackItem = value.toObject();
         Item item;
 
         item.offset = stackItem["addr"].toVariant().toULongLong();
         item.value = RAddressString(stackItem["value"].toVariant().toULongLong());
 
+        QJsonObject refItem = stackItem["ref"].toObject();
+        if (!refItem.empty()) {
+            QString str = refItem["string"].toVariant().toString();
+            if (!str.isEmpty()) {
+                item.description = str;
+                item.descriptionColor = ConfigColor("comment");
+            } else {
+                QString type, string;
+                do {
+                    item.description += " ->";
+                    append_var(item.description, refItem["reg"].toVariant().toString(), " @", "");
+                    append_var(item.description, refItem["mapname"].toVariant().toString(), " (", ")");
+                    append_var(item.description, refItem["section"].toVariant().toString(), " (", ")");
+                    append_var(item.description, refItem["func"].toVariant().toString(), " ", "");
+                    type = append_var(item.description, refItem["type"].toVariant().toString(), " ", "");
+                    append_var(item.description, refItem["perms"].toVariant().toString(), " ", "");
+                    append_var(item.description, refItem["asm"].toVariant().toString(), " \"", "\"");
+                    string = append_var(item.description, refItem["string"].toVariant().toString(), " ", "");
+                    if (!string.isNull()) {
+                        // There is no point in adding ascii and addr info after a string
+                        break;
+                    }
+                    if (!refItem["value"].isNull()) {
+                        append_var(item.description, RAddressString(refItem["value"].toVariant().toULongLong()), " ", "");
+                    }
+                    refItem = refItem["ref"].toObject();
+                } while (!refItem.empty());
 
-        QJsonValue refObject = stackItem["ref"];
+                // Set the description's color according to the last item type
-        if (!refObject.isUndefined()) { // check that the key exists
+                if (type == "ascii" || !string.isEmpty()) {
-            QString ref = refObject.toString();
+                    item.descriptionColor = ConfigColor("comment");
-            if (ref.contains("ascii") && ref.count("-->") == 1) {
+                } else if (type == "program") {
-                ref = Core()->cmdj(QString("pszj @ [%1]").arg(item.offset)).object().value("string").toString();
+                    item.descriptionColor = ConfigColor("fname");
-            }
+                } else if (type == "library") {
-            item.description = ref;
+                    item.descriptionColor = ConfigColor("floc");
-
+                } else if (type == "stack") {
-
+                    item.descriptionColor = ConfigColor("offset");
-            if (refObject.toString().contains("ascii") && refObject.toString().count("-->") == 1) {
+                }
-                item.descriptionColor = QVariant(QColor(243, 156, 17));
-            } else if (ref.contains("program R X") && ref.count("-->") == 0) {
-                item.descriptionColor = QVariant(QColor(Qt::red));
-            } else if (ref.contains("stack") && ref.count("-->") == 0) {
-                item.descriptionColor = QVariant(QColor(Qt::cyan));
-            } else if (ref.contains("library") && ref.count("-->") == 0) {
-                item.descriptionColor = QVariant(QColor(Qt::green));
             }
         }
         values.push_back(item);