Debug Qt application on ubuntu with root permission using qt creator

Question

It is possible to run my application with root priviliges using sudo, like this:

sudo ./MyApp

Is it possible to debug my Qt application using root priviliges using QtCreator? How can I do this on an Ubuntu system?

Answer 1

1. Go to Tools-> Options-> Environment
2. In the Tab General under **System** Group there is a Terminal Option.
3. The default value is set to/usr/bin/xterm -e. Replace it with /usr/bin/xterm -e sudo or /usr/bin/gnome-terminal -x sudo.
4. Press Apply and OK Buttons.
5. Under Mode Selector click on Projects, select Run Option. Under Run Group Box select Run in Terminal.

Remember : sudo option must be there

Edit /etc/sudoers using sudo visudo

Next time when you run the program it will be invoked in a new xterm or gnome-terminal with Super User Permission and will ask for the root password.

Answer 2

I solved it by starting Qt Creator as root.

sudo /usr/bin/qtcreator

Now It will get the root permission to the application when I compile and debug. Now its possible to debug my application with root privilege.

Answer 3

I would run the program from a terminal with a GDB server (as root) and then connect to the server with gdb from QtCreator. You would start gdbserver with something like this:

$ sudo gdbserver host:2345 ./MyApp

Here, you are hosting the server with port 2345. You can also check if your application is indeed running with UID 0.

$ sudo ps -u

Now, in Qt Creator, go Debug -> Start Debugging -> Attach to Running Debug Server. Fill in the form... the most important is the port and server address. I chose 127.0.0.1 and 2345. You can select break at main to break at the beginning of the program. GDB server doesn't start the program until you connect.

Answer 4

The following actions were recommended on Qt support forum:

In Qt Creator, add remote Linux device in Options -> Devices. Set its address as localhost and user as root. Create a pair of authentication keys and paste public key to /root/.ssh/authorized_keys. Then clone Desktop kit in Options -> Kits and set the device for new kit to the device you've created on previous step.

Now, when you start debugging, Qt Creator should automatically connect over ssh to localhost as root, start gdbserver and perform debugging.

It works for running without debugging too.

Perhaps you should set up installation of your program on remote host, but that's a different story and it's done differently for Qmake and QBS.

https://forum.qt.io/post/185983

Answer 5

Running that as root is a horrible idea. Instead, use the source, and make qtcreator use sudo to launch gdb like this. Requires that you run qtcreator from a tty and auth sudo before you launch qtcreator, or configure your user for passwordless sudo (not recommended). I'll code a more complete solution later.

It took me to 1-2 hours code/debug with no prior knowledge of QT. Most that time was spent waiting for the compilation to complete

https://gist.github.com/ppetraki/a0080da047047ea184c6

--- qtcreator-3.0.1.orig/src/plugins/debugger/gdb/gdbprocess.cpp +++ qtcreator-3.0.1/src/plugins/debugger/gdb/gdbprocess.cpp @@ -59,7 +59,11 @@ QByteArray GdbProcess::readAllStandardEr

void GdbProcess::start(const QString &cmd, const QStringList &args) { - m_gdbProc.setCommand(cmd, Utils::QtcProcess::joinArgs(args)); + QStringList sudoArgs; + sudoArgs << cmd << args; + QString sudoCmd = QString::fromUtf8("/usr/bin/sudo"); + + m_gdbProc.setCommand(sudoCmd, Utils::QtcProcess::joinArgs(sudoArgs)); m_gdbProc.start(); }

Answer 6

One easy way is to run the project in a terminal check Run as a Root user.

Here is Screenshot to show steps: