I am experiencing a similar problem on Windows in Unity 2018.3.0f2

Confirmed that this is happening on Ubuntu with Unity 4.6.5f1

I tested by placing this component on the camera of an empty scene in a fresh project

[code]
#if UNITY_EDITOR
using UnityEditor;
#endif //UNITY_EDITOR
using UnityEngine;

public class ButtonTest : MonoBehaviour
{
int m_downCount = 0;
int m_holdCount = 0;
int m_upCount = 0;
bool m_isPressed = false;

//////////////////////////////////////////////////////////////////////////////
void Start()
{
m_downCount = 0;
m_holdCount = 0;
m_upCount = 0;
m_isPressed = false;
}

//////////////////////////////////////////////////////////////////////////////
void Update()
{
if (Input.GetButtonDown("Submit"))
{
++m_downCount;
}

m_isPressed = Input.GetButton("Submit");
if (m_isPressed)
{
++m_holdCount;
}

if (Input.GetButtonUp("Submit"))
{
++m_upCount;
}

if (Input.GetKeyDown(KeyCode.Escape))
{
#if UNITY_EDITOR
//Application.Quit does not work in the editor
EditorApplication.isPlaying = false;
#else
Application.Quit();
#endif //UNITY_EDITOR
}
}

//////////////////////////////////////////////////////////////////////////////
void OnGUI()
{
string msg = "Button0 or Return Pressed: " + m_isPressed.ToString() + "\n";
msg += "Down: " + m_downCount.ToString() + "\n";
msg += "Hold: " + m_holdCount.ToString() + "\n";
msg += "Up: " + m_upCount.ToString() + "\n";
msg += "Esc to exit.\n";
GUI.Label(new Rect(0, 0, Screen.width, Screen.height), msg);
}
}
[/code]

This issue is preventing us from releasing confidently on the Linux Platform. We are on version 4.6 as well.

We are seeing this issue in 4.6 as well, makes controllers unusable in Linux. Please fix ASAP

This affect UI Button, Button Script, On Click( ) on iOS devices.
Player have to tap on the "Target Graphic" very fast to prevent the desired function from executing every frame, which takes up all the memory, thus making the button not executing at all.
Works perfectly fine on computer, just not on iOS devices.