Hi Steve,
On 25 Jan 15:44, Steven Rostedt wrote:
> On Thu, 25 Jan 2024 17:16:21 -0300
> "Ricardo B. Marliere" <rica...@marliere.net> wrote:
>
> > Now that trace_seq_reset have been created, correct the places where the
> > buffers need to be initialized.
>
> This patch would need to come first. You don't ever want to intentionally
> create a broken kernel.
Indeed, sorry for the lack of attention.
>
> Also, the change log should be:
>
> In order to extend trace_seq into being dynamic, the struct trace_seq
> will no longer be valid if simply set to zero. Call trace_seq_init() for
> all trace_seq when they are first created.
Ack.
>
> >
> > Suggested-by: Steven Rostedt <rost...@goodmis.org>
> > Signed-off-by: Ricardo B. Marliere <rica...@marliere.net>
> > ---
> > kernel/trace/trace.c | 14 ++++++++++++++
> > 1 file changed, 14 insertions(+)
> >
>
> You also need to initialize iter.seq in ftrace_dump()
Thanks a lot for reviewing, I will send a v3.
- Ricardo
>
> -- Steve
>
> > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> > index d4c55d3e21c2..9827700d0164 100644
> > --- a/kernel/trace/trace.c
> > +++ b/kernel/trace/trace.c
> > @@ -4889,6 +4889,9 @@ __tracing_open(struct inode *inode, struct file
> > *file, bool snapshot)
> >
> > mutex_unlock(&trace_types_lock);
> >
> > + trace_seq_init(&iter->seq);
> > + trace_seq_init(&iter->tmp_seq);
> > +
> > return iter;
> >
> > fail:
> > @@ -6770,6 +6773,7 @@ static int tracing_open_pipe(struct inode *inode,
> > struct file *filp)
> > }
> >
> > trace_seq_init(&iter->seq);
> > + trace_seq_init(&iter->tmp_seq);
> > iter->trace = tr->current_trace;
> >
> > if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) {
> > @@ -6947,6 +6951,7 @@ tracing_read_pipe(struct file *filp, char __user
> > *ubuf,
> > trace_iterator_reset(iter);
> > cpumask_clear(iter->started);
> > trace_seq_init(&iter->seq);
> > + trace_seq_init(&iter->tmp_seq);
> >
> > trace_event_read_lock();
> > trace_access_lock(iter->cpu_file);
> > @@ -8277,6 +8282,9 @@ static int tracing_buffers_open(struct inode *inode,
> > struct file *filp)
> > if (ret < 0)
> > trace_array_put(tr);
> >
> > + trace_seq_init(&info->iter.seq);
> > + trace_seq_init(&info->iter.tmp_seq);
> > +
> > return ret;
> > }
> >
> > @@ -10300,6 +10308,9 @@ void trace_init_global_iter(struct trace_iterator
> > *iter)
> > iter->temp_size = STATIC_TEMP_BUF_SIZE;
> > iter->fmt = static_fmt_buf;
> > iter->fmt_size = STATIC_FMT_BUF_SIZE;
> > +
> > + trace_seq_init(&iter->seq);
> > + trace_seq_init(&iter->tmp_seq);
> > }
> >
> > void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
> > @@ -10712,6 +10723,9 @@ void __init early_trace_init(void)
> > tracepoint_printk = 0;
> > else
> > static_key_enable(&tracepoint_printk_key.key);
> > +
> > + trace_seq_init(&tracepoint_print_iter->seq);
> > + trace_seq_init(&tracepoint_print_iter->tmp_seq);
> > }
> > tracer_alloc_buffers();
> >
>
