Re: [PATCH] kernel/trace: fixed static warnings
From: Abhijith Sriram
Date: Sat Apr 04 2026 - 02:03:28 EST
On Sat, Apr 4, 2026 at 2:18 AM Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:
>
> On Thu, 2 Apr 2026 21:54:04 +0200
> abhijithsriram95@xxxxxxxxx wrote:
>
> > From: Abhijith Sriram <abhijithsriram95@xxxxxxxxx>
> >
> > The change in the function argument description
> > was due to the static code checker script reading
> > the word filter back to back
> >
> > Signed-off-by: Abhijith Sriram <abhijithsriram95@xxxxxxxxx>
> > ---
> > kernel/trace/trace_events_trigger.c | 10 ++++++----
> > 1 file changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
> > index 655db2e82513..477d8dee3362 100644
> > --- a/kernel/trace/trace_events_trigger.c
> > +++ b/kernel/trace/trace_events_trigger.c
> > @@ -246,7 +246,7 @@ event_triggers_post_call(struct trace_event_file *file,
> > }
> > EXPORT_SYMBOL_GPL(event_triggers_post_call);
> >
> > -#define SHOW_AVAILABLE_TRIGGERS (void *)(1UL)
> > +#define SHOW_AVAILABLE_TRIGGERS ((void *)(1UL))
>
> This is OK.
>
> >
> > static void *trigger_next(struct seq_file *m, void *t, loff_t *pos)
> > {
> > @@ -325,6 +325,7 @@ static const struct seq_operations event_triggers_seq_ops = {
> > static int event_trigger_regex_open(struct inode *inode, struct file *file)
> > {
> > int ret;
> > + struct seq_file *m = NULL;
> >
> > ret = security_locked_down(LOCKDOWN_TRACEFS);
> > if (ret)
> > @@ -351,7 +352,7 @@ static int event_trigger_regex_open(struct inode *inode, struct file *file)
> > if (file->f_mode & FMODE_READ) {
> > ret = seq_open(file, &event_triggers_seq_ops);
> > if (!ret) {
> > - struct seq_file *m = file->private_data;
> > + *m = file->private_data;
>
> Why is this change required?
The original warning says "missing blank line after declaration". I
thought it was cleaner to have the
declaration in the beginning of the function. I made a mistake here
which I fixed in the version 2 of
the patch, please have a look here:
https://lore.kernel.org/linux-trace-kernel/20260403071108.23422-2-abhijithsriram95@xxxxxxxxx/T/#u
>
> > m->private = file;
> > }
> > }
> > @@ -388,9 +389,9 @@ static ssize_t event_trigger_regex_write(struct file *file,
> > const char __user *ubuf,
> > size_t cnt, loff_t *ppos)
> > {
> > + char *buf __free(kfree) = NULL;
> > struct trace_event_file *event_file;
> > ssize_t ret;
> > - char *buf __free(kfree) = NULL;
>
> What is this change?
The same missing blank lines after declaration was triggered here,
even though there is a blank line after the char *buf.
If I do give an empty line then there is another error "Trailing white
space". So I reordered it and the warning disappeared.
This change I am not super sure since it is usually recommended that
variables of larger size are declared first
for padding purposes. What do you think?
>
> Thanks,
>
> >
> > if (!cnt)
> > return 0;
> > @@ -633,6 +634,7 @@ clear_event_triggers(struct trace_array *tr)
> >
> > list_for_each_entry(file, &tr->events, list) {
> > struct event_trigger_data *data, *n;
> > +
> > list_for_each_entry_safe(data, n, &file->triggers, list) {
> > trace_event_trigger_enable_disable(file, 0);
> > list_del_rcu(&data->list);
> > @@ -785,7 +787,7 @@ static void unregister_trigger(char *glob,
> > * cmd - the trigger command name
> > * glob - the trigger command name optionally prefaced with '!'
> > * param_and_filter - text following cmd and ':'
> > - * param - text following cmd and ':' and stripped of filter
> > + * param - text following cmd and ':' and filter removed
> > * filter - the optional filter text following (and including) 'if'
> > *
> > * To illustrate the use of these components, here are some concrete
> > --
> > 2.43.0
> >
>
>
> --
> Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
--
Regards
Abhijith Sriram