[PATCH v2 0/5] Handle the case when KernelShark is started as Root

[PATCH v2 0/5] Handle the case when KernelShark is started as Root

[Yordan Karadzhov (VMware)]

A patch set implementing the improvements suggested here:

https://bugzilla.kernel.org/show_bug.cgi?id=204475

Plus a minor improvements of the error messages printed when something goes
wrong withe the "Record" dialog.  

v2 changes:
  - Correcting typos in patch 1/5
  - Fixing a bug in patch 2/5. trace-cmd now gets correctly formatted list
  of command line arguments.
  - Patches 4/5 and 5/5 are new.

Yordan Karadzhov (VMware) (5):
  kernel-shark: Show warning message when running as Root
  kernel-shark: Don't use pkexec when running as Root
  kernel-shark: Use standart error message in KsMainWindow::_record()
  kernel-shark: Optimize the error messages when "Record" fails to start
  kernel-shark: Better formatting of the error messages from "Record"

 kernel-shark/src/KsMainWindow.cpp | 90 +++++++++++++++++++++++--------
 kernel-shark/src/KsMainWindow.hpp |  4 ++
 2 files changed, 71 insertions(+), 23 deletions(-)

-- 
2.20.1

[PATCH v2 1/5] kernel-shark: Show warning message when running as Root

[Yordan Karadzhov (VMware)]

Running the KernelShark GUI with Root privileges is not recommended due
to security reasons. The user will be allowed to continue on its own risk.

Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204475
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
---
 kernel-shark/src/KsMainWindow.cpp | 28 ++++++++++++++++++++++++++++
 kernel-shark/src/KsMainWindow.hpp |  2 ++
 2 files changed, 30 insertions(+)

diff --git a/kernel-shark/src/KsMainWindow.cpp b/kernel-shark/src/KsMainWindow.cpp
index 6439265..2f86517 100644
--- a/kernel-shark/src/KsMainWindow.cpp
+++ b/kernel-shark/src/KsMainWindow.cpp
@@ -76,6 +76,9 @@ KsMainWindow::KsMainWindow(QWidget *parent)
 	_createMenus();
 	_initCapture();
 
+	if (geteuid() == 0)
+		_rootWarning();
+
 	_splitter.addWidget(&_graph);
 	_splitter.addWidget(&_view);
 	setCentralWidget(&_splitter);
@@ -1271,3 +1274,28 @@ void KsMainWindow::_deselectB()
 	_mState.updateLabels();
 	_graph.glPtr()->model()->update();
 }
+
+void KsMainWindow::_rootWarning()
+{
+	QString cbFlag("noRootWarn");
+
+	if (_settings.value(cbFlag).toBool())
+		return;
+
+	QMessageBox warn;
+	warn.setText("KernelShark will have Root privileges.");
+	warn.setInformativeText("Continue on your own risk.");
+	warn.setIcon(QMessageBox::Warning);
+	warn.setStandardButtons(QMessageBox::Close);
+
+	QCheckBox cb("Don't show this message again.");
+
+	auto lamCbChec = [&] (int state) {
+		if (state)
+			_settings.setValue(cbFlag, true);
+	};
+
+	connect(&cb, &QCheckBox::stateChanged, lamCbChec);
+	warn.setCheckBox(&cb);
+	warn.exec();
+}
diff --git a/kernel-shark/src/KsMainWindow.hpp b/kernel-shark/src/KsMainWindow.hpp
index 62e66a0..4a7b8ab 100644
--- a/kernel-shark/src/KsMainWindow.hpp
+++ b/kernel-shark/src/KsMainWindow.hpp
@@ -238,6 +238,8 @@ private:
 
 	void _deselectB();
 
+	void _rootWarning();
+
 	void _updateFilterMenu();
 
 	void _filterSyncCBoxUpdate(kshark_context *kshark_ctx);
-- 
2.20.1

Re: [PATCH v2 1/5] kernel-shark: Show warning message when running as Root

[Steven Rostedt]

On Mon, 26 Aug 2019 18:58:07 +0300
"Yordan Karadzhov (VMware)" <y.karadz@gmail.com> wrote:

> +	warn.setText("KernelShark will have Root privileges.");
> +	warn.setInformativeText("Continue on your own risk.");

This wasn't updated.

 From: https://lore.kernel.org/linux-trace-devel/20190809091914.75f553b2@gandalf.local.home/

> > +	QMessageBox warn;
> > +	warn.setText("KernelShark will have Root privileges.");
> > +	warn.setInformativeText("Continue on your one risk.");  
> 
> Probably better to say:
> 
>   "KernelShark is running with Root privileges."
>   "Continue at your own risk."

I could update the patch if you like, instead of sending out another
series. Let me finish the rest of the series.

-- Steve

Re: [PATCH v2 1/5] kernel-shark: Show warning message when running as Root

[Steven Rostedt]

On Tue, 27 Aug 2019 18:22:53 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> On Mon, 26 Aug 2019 18:58:07 +0300
> "Yordan Karadzhov (VMware)" <y.karadz@gmail.com> wrote:
> 
> > +	warn.setText("KernelShark will have Root privileges.");
> > +	warn.setInformativeText("Continue on your own risk.");  
> 
> This wasn't updated.
> 
>  From: https://lore.kernel.org/linux-trace-devel/20190809091914.75f553b2@gandalf.local.home/
> 
> > > +	QMessageBox warn;
> > > +	warn.setText("KernelShark will have Root privileges.");
> > > +	warn.setInformativeText("Continue on your one risk.");    
> > 
> > Probably better to say:
> > 
> >   "KernelShark is running with Root privileges."
> >   "Continue at your own risk."  
> 
> I could update the patch if you like, instead of sending out another
> series. Let me finish the rest of the series.
> 

We decided in our meeting that you were going to send a v3, right? Just
want to make sure (too many things to keep track of ;-)

Thanks!

-- Steve

Re: [PATCH v2 1/5] kernel-shark: Show warning message when running as Root

[Yordan Karadzhov (VMware)]

On 19.09.19 г. 23:32 ч., Steven Rostedt wrote:
> On Tue, 27 Aug 2019 18:22:53 -0400
> Steven Rostedt <rostedt@goodmis.org> wrote:
> 
>> On Mon, 26 Aug 2019 18:58:07 +0300
>> "Yordan Karadzhov (VMware)" <y.karadz@gmail.com> wrote:
>>
>>> +	warn.setText("KernelShark will have Root privileges.");
>>> +	warn.setInformativeText("Continue on your own risk.");
>>
>> This wasn't updated.
>>
>>   From: https://lore.kernel.org/linux-trace-devel/20190809091914.75f553b2@gandalf.local.home/
>>
>>>> +	QMessageBox warn;
>>>> +	warn.setText("KernelShark will have Root privileges.");
>>>> +	warn.setInformativeText("Continue on your one risk.");
>>>
>>> Probably better to say:
>>>
>>>    "KernelShark is running with Root privileges."
>>>    "Continue at your own risk."
>>
>> I could update the patch if you like, instead of sending out another
>> series. Let me finish the rest of the series.
>>
> 
> We decided in our meeting that you were going to send a v3, right? Just
> want to make sure (too many things to keep track of ;-)

Yes, I am sending v3 right now.
Y.

> 
> Thanks!
> 
> -- Steve
> 

[PATCH v2 2/5] kernel-shark: Don't use pkexec when running as Root

[Yordan Karadzhov (VMware)]

If KernelShark GUI has been started as Root we do not need to use
"pkexec" when starting the Record dialog. Note that the actual place
where "pkexec" gets used is in the script "kshark-su-record".

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
---
 kernel-shark/src/KsMainWindow.cpp | 47 +++++++++++++++++++++----------
 1 file changed, 32 insertions(+), 15 deletions(-)

diff --git a/kernel-shark/src/KsMainWindow.cpp b/kernel-shark/src/KsMainWindow.cpp
index 2f86517..7c18391 100644
--- a/kernel-shark/src/KsMainWindow.cpp
+++ b/kernel-shark/src/KsMainWindow.cpp
@@ -883,23 +883,26 @@ void KsMainWindow::_pluginAdd()
 
 void KsMainWindow::_record()
 {
-#ifndef DO_AS_ROOT
+	bool canDoAsRoot(false);
 
-	QErrorMessage *em = new QErrorMessage(this);
-	QString message;
-
-	message = "Record is currently not supported.";
-	message += " Install \"pkexec\" and then do:<br>";
-	message += " cd build <br> sudo ./cmake_uninstall.sh <br>";
-	message += " ./cmake_clean.sh <br> cmake .. <br> make <br>";
-	message += " sudo make install";
+#ifdef DO_AS_ROOT
+	canDoAsRoot = true;
+#endif
 
-	em->showMessage(message);
-	qCritical() << "ERROR: " << message;
+	if (geteuid() && !canDoAsRoot) {
+		QErrorMessage *em = new QErrorMessage(this);
+		QString message;
 
-	return;
+		message = "Record is currently not supported.";
+		message += " Install \"pkexec\" and then do:<br>";
+		message += " cd build <br> sudo ./cmake_uninstall.sh <br>";
+		message += " ./cmake_clean.sh <br> cmake .. <br> make <br>";
+		message += " sudo make install";
 
-#endif
+		em->showMessage(message);
+		qCritical() << "ERROR: " << message;
+		return;
+	}
 
 	_capture.start();
 }
@@ -1134,9 +1137,24 @@ void KsMainWindow::loadSession(const QString &fileName)
 
 void KsMainWindow::_initCapture()
 {
+	bool canDoAsRoot(false);
+
 #ifdef DO_AS_ROOT
+	canDoAsRoot = true;
+#endif
+
+	if (geteuid() && !canDoAsRoot)
+		return;
 
-	_capture.setProgram("kshark-su-record");
+	if (geteuid()) {
+		_capture.setProgram("kshark-su-record");
+	} else {
+		QStringList argv;
+
+		_capture.setProgram("kshark-record");
+		argv << QString("-o") << QDir::homePath() + "/trace.dat";
+		_capture.setArguments(argv);
+	}
 
 	connect(&_capture,	&QProcess::started,
 		this,		&KsMainWindow::_captureStarted);
@@ -1155,7 +1173,6 @@ void KsMainWindow::_initCapture()
 	connect(&_captureLocalServer,	&QLocalServer::newConnection,
 		this,			&KsMainWindow::_readSocket);
 
-#endif
 }
 
 void KsMainWindow::_captureStarted()
-- 
2.20.1

[PATCH v2 3/5] kernel-shark: Use standart error message in KsMainWindow::_record()

[Yordan Karadzhov (VMware)]

The error message is printed using the method KsMainWindow::_error().
The message itself remains unchanged. If we want to change the message,
this can be done in another patch.

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
---
 kernel-shark/src/KsMainWindow.cpp | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/kernel-shark/src/KsMainWindow.cpp b/kernel-shark/src/KsMainWindow.cpp
index 7c18391..73d6877 100644
--- a/kernel-shark/src/KsMainWindow.cpp
+++ b/kernel-shark/src/KsMainWindow.cpp
@@ -890,7 +890,6 @@ void KsMainWindow::_record()
 #endif
 
 	if (geteuid() && !canDoAsRoot) {
-		QErrorMessage *em = new QErrorMessage(this);
 		QString message;
 
 		message = "Record is currently not supported.";
@@ -899,8 +898,7 @@ void KsMainWindow::_record()
 		message += " ./cmake_clean.sh <br> cmake .. <br> make <br>";
 		message += " sudo make install";
 
-		em->showMessage(message);
-		qCritical() << "ERROR: " << message;
+		_error(message, "recordCantStart", false, false);
 		return;
 	}
 
-- 
2.20.1

[PATCH v2 4/5] kernel-shark: Optimize the error messages when "Record" fails to start

[Yordan Karadzhov (VMware)]

Removing duplicate code.

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
---
 kernel-shark/src/KsMainWindow.cpp | 14 +++++++-------
 kernel-shark/src/KsMainWindow.hpp |  2 ++
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/kernel-shark/src/KsMainWindow.cpp b/kernel-shark/src/KsMainWindow.cpp
index 73d6877..651cf59 100644
--- a/kernel-shark/src/KsMainWindow.cpp
+++ b/kernel-shark/src/KsMainWindow.cpp
@@ -1199,18 +1199,18 @@ void KsMainWindow::_captureFinished(int ret, QProcess::ExitStatus st)
 		return;
 	}
 
-	if (ret != 0 && st == QProcess::NormalExit) {
-		QString message = "Capture process failed:<br>";
-
-		message += capture->errorString();
-		message += capture->readAllStandardError();
-		_error(message, "captureFinishedErr", false, false);
-	}
+	if (ret != 0 && st == QProcess::NormalExit)
+		_captureErrorMessage(capture);
 }
 
 void KsMainWindow::_captureError(QProcess::ProcessError error)
 {
 	QProcess *capture = (QProcess *)sender();
+	_captureErrorMessage(capture);
+}
+
+void KsMainWindow::_captureErrorMessage(QProcess *capture)
+{
 	QString message = "Capture process failed:<br>";
 
 	message += capture->errorString();
diff --git a/kernel-shark/src/KsMainWindow.hpp b/kernel-shark/src/KsMainWindow.hpp
index 4a7b8ab..eef4f96 100644
--- a/kernel-shark/src/KsMainWindow.hpp
+++ b/kernel-shark/src/KsMainWindow.hpp
@@ -215,6 +215,8 @@ private:
 
 	void _captureError(QProcess::ProcessError error);
 
+	void _captureErrorMessage(QProcess *capture);
+
 	void _readSocket();
 
 	void _splitterMoved(int pos, int index);
-- 
2.20.1

[PATCH v2 5/5] kernel-shark: Better formatting of the error messages from "Record"

[Yordan Karadzhov (VMware)]

Make the message easier to read and understand by separating the
QProcess's error and the Standard error.

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
---
 kernel-shark/src/KsMainWindow.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel-shark/src/KsMainWindow.cpp b/kernel-shark/src/KsMainWindow.cpp
index 651cf59..a3b5ce7 100644
--- a/kernel-shark/src/KsMainWindow.cpp
+++ b/kernel-shark/src/KsMainWindow.cpp
@@ -1211,9 +1211,10 @@ void KsMainWindow::_captureError(QProcess::ProcessError error)
 
 void KsMainWindow::_captureErrorMessage(QProcess *capture)
 {
-	QString message = "Capture process failed:<br>";
+	QString message = "Capture process failed: ";
 
 	message += capture->errorString();
+	message += "<br>Standard Error :";
 	message += capture->readAllStandardError();
 	_error(message, "captureFinishedErr", false, false);
 }
-- 
2.20.1

Re: [PATCH v2 5/5] kernel-shark: Better formatting of the error messages from "Record"

[Steven Rostedt]

On Mon, 26 Aug 2019 18:58:11 +0300
"Yordan Karadzhov (VMware)" <y.karadz@gmail.com> wrote:

> Make the message easier to read and understand by separating the
> QProcess's error and the Standard error.
> 
> Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
> ---
>  kernel-shark/src/KsMainWindow.cpp | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel-shark/src/KsMainWindow.cpp b/kernel-shark/src/KsMainWindow.cpp
> index 651cf59..a3b5ce7 100644
> --- a/kernel-shark/src/KsMainWindow.cpp
> +++ b/kernel-shark/src/KsMainWindow.cpp
> @@ -1211,9 +1211,10 @@ void KsMainWindow::_captureError(QProcess::ProcessError error)
>  
>  void KsMainWindow::_captureErrorMessage(QProcess *capture)
>  {
> -	QString message = "Capture process failed:<br>";
> +	QString message = "Capture process failed: ";
>  
>  	message += capture->errorString();
> +	message += "<br>Standard Error :";

I changed the above to: "<br>Standard Error: ", as I added:

 echo "this is an error" >&2
 exit 1

to kshark-su-record and the current patch produces:

  ERROR:  Capture process failed: Unknown error
  Standard Error :this is an error

Where I think the below looks better:

  ERROR:  Capture process failed: Unknown error
  Standard Error: this is an error

-- Steve


>  	message += capture->readAllStandardError();
>  	_error(message, "captureFinishedErr", false, false);
>  }