Add support for ASLR on Linux

src/dfinstancelinux.cpp

@@ -44,6 +44,8 @@ THE SOFTWARE.
 #include <sys/uio.h>
 #include <elf.h>
 
+#define DEFAULT_BASE_ADDR 0x555555554000ull
+
 DFInstanceLinux::DFInstanceLinux(QObject* parent)
     : DFInstance(parent)
 {
@@ -231,6 +233,33 @@ void DFInstanceLinux::find_running_copy() {
         return;
     }
 
+    auto exe_path = QFileInfo(QString::fromStdString(proc_path) + "/exe").symLinkTarget();
+    std::regex procmaps_re(
+            "([0-9a-f]+)-([0-9a-f]+)"   // address
+            " ([-r][-w][-x][sp])"       // perms
+            " ([0-9a-f]+)"              // offset
+            " ([0-9a-f]+):([0-9a-f]+)"  // dev
+            " ([0-9]+)"                 // inode
+            "(?:\\s*(.+))");            // pathname
+    if (auto maps = std::ifstream(proc_path + "/maps")) {
+        std::string line;
+        while (std::getline(maps, line)) {
+            std::smatch res;
+            if (!std::regex_search(line, res, procmaps_re))
+                continue;
+            auto start_address = std::stoull(res[1], nullptr, 16);
+            auto offset = std::stoull(res[4], nullptr, 16);
+            auto pathname = QString::fromStdString(res[8]);
+            if (pathname == exe_path && offset == 0) {
+                m_base_addr = start_address - DEFAULT_BASE_ADDR;
+                break;
+            }
+        }
+    }
+    else {
+        LOGE << "Failed to open memory maps";
+    }
+
     m_status = DFS_CONNECTED;
     set_memory_layout(md5);
 }