On Tue, 3 Nov 2026 12:11:47 +0100 Petr Mladek <[email protected]> wrote:
> I believe that trace_printk() has a similar problem. You could > not use it inside the code used by trace_printk() because > it might cause an unbound recursion. That is slightly incorrect. I use trace_printk() to debug tracing! ;-) Well, adding trace_printk() to the trace_printk() function itself will have issues, but the ring buffer logic allows trace_printk() to be injected into it. The ring buffer has recursion protection, so adding trace_printk() into the ftrace ring buffer will print the trace_printk(). You may need to add a way to not do the trace_printk() again, otherwise you may get multiple prints until the nested limit is reached. But I just wanted to point out that I do use trace_printk() to debug the ring buffer even though trace_printk itself uses the ring buffer too. -- Steve
