Re: [PATCH resend ] tracepoint: Print the function symbol when tracepoint_debug is set

[Steven Rostedt]

On Wed, 5 Mar 2025 08:53:43 -0500
Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote:

> On 2025-03-04 20:55, Huang Shijie wrote:
> > When tracepoint_debug is set, we may get the output in kernel log:
> >       [  380.013843] Probe 0 : 00000000f0d68cda
> > 
> > It is not readable, so change to print the function symbol.
> > After this patch, the output may becomes:
> >       [   54.930567] Probe 0 : perf_trace_sched_wakeup_template  
> 
> What would it print if the address is corrupted ?
> 
> Perhaps we could do like the backtrace code and print e.g.
> 
> [<00000000f0d68cda>] perf_trace_sched_wakeup_template+0xNN/0xMM
> 
> ?
> 
> I don't care about the actual layout, but removing the address
> from the formatted output appears to be removing useful data
> in debug situations.
> 

Perhaps this can use "%pS" which shows both the function entry and the
offset. If no function is found, it ends up being the same as "%p".
Also, it's likely that the "%p" is hashed here and one couldn't use it to
debug either.

-- Steve