Re: [Intel-wired-lan] [PATCH 15/61] trace: Prefer IS_ERR_OR_NULL over manual NULL check

2026-03-11 Thread Google 
On Tue, 10 Mar 2026 10:07:50 -0400
Steven Rostedt  wrote:

> On Tue, 10 Mar 2026 12:48:41 +0100
> Philipp Hahn  wrote:
> 
> > Prefer using IS_ERR_OR_NULL() over using IS_ERR() and a manual NULL
> > check.
> 
> Why?
> 
> > 
> > Change generated with coccinelle.
> > 
> > To: Steven Rostedt 
> > To: Masami Hiramatsu 
> > To: Mathieu Desnoyers 
> > Cc: [email protected]
> > Cc: [email protected]
> > Signed-off-by: Philipp Hahn 
> > ---
> >  kernel/trace/fprobe.c| 2 +-
> >  kernel/trace/kprobe_event_gen_test.c | 2 +-
> >  kernel/trace/trace_events_hist.c | 2 +-
> >  3 files changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
> > index 
> > dcadf1d23b8a31f571392d0c49cbd22df1716b4f..a94ce810d83b90f55d1178a9bd29c78fd068df4c
> >  100644
> > --- a/kernel/trace/fprobe.c
> > +++ b/kernel/trace/fprobe.c
> > @@ -607,7 +607,7 @@ static int fprobe_module_callback(struct notifier_block 
> > *nb,
> > do {
> > rhashtable_walk_start(&iter);
> >  
> > -   while ((node = rhashtable_walk_next(&iter)) && !IS_ERR(node))
> > +   while (!IS_ERR_OR_NULL((node = rhashtable_walk_next(&iter
> 
> Ug, No!
> 
> That looks so much worse than the original.

Hmm, now IS_ERR_OR_NULL() is an inline function, so it is safe.
But if you want to use IS_ERR_OR_NULL() here, it will be better something like

node = rhashtable_walk_next(&iter);
while (!IS_ERR_OR_NULL(node)) {
fprobe_remove_node_in_module(mod, node, &alist);
node = rhashtable_walk_next(&iter);
}

Thanks,

> 
> -- Steve
> 
> > fprobe_remove_node_in_module(mod, node, &alist);
> >  
> > rhashtable_walk_stop(&iter);
> > diff --git a/kernel/trace/kprobe_event_gen_test.c 
> > b/kernel/trace/kprobe_event_gen_test.c
> > index 
> > 5a4b722b50451bfdee42769a6d3be39c055690d1..a1735ca273f0b756aa1fcfcdab30ddad9bc51c5f
> >  100644
> > --- a/kernel/trace/kprobe_event_gen_test.c
> > +++ b/kernel/trace/kprobe_event_gen_test.c
> > @@ -75,7 +75,7 @@ static struct trace_event_file *gen_kretprobe_test;
> >  
> >  static bool trace_event_file_is_valid(struct trace_event_file *input)
> >  {
> > -   return input && !IS_ERR(input);
> > +   return !IS_ERR_OR_NULL(input);
> >  }
> >  
> >  /*
> > diff --git a/kernel/trace/trace_events_hist.c 
> > b/kernel/trace/trace_events_hist.c
> > index 
> > 73ea180cad555898693e92ee397a1c9493c7c167..59df215e1dfd9349eca1c0823ed709ec7285f766
> >  100644
> > --- a/kernel/trace/trace_events_hist.c
> > +++ b/kernel/trace/trace_events_hist.c
> > @@ -3973,7 +3973,7 @@ trace_action_create_field_var(struct 
> > hist_trigger_data *hist_data,
> >  */
> > field_var = create_target_field_var(hist_data, system, event, var);
> >  
> > -   if (field_var && !IS_ERR(field_var)) {
> > +   if (!IS_ERR_OR_NULL(field_var)) {
> > save_field_var(hist_data, field_var);
> > hist_field = field_var->var;
> > } else {
> > 
> 


-- 
Masami Hiramatsu (Google)

Re: [Intel-wired-lan] [PATCH 15/61] trace: Prefer IS_ERR_OR_NULL over manual NULL check

2026-03-11 Thread Geert Uytterhoeven 
Hi Steven,

On Wed, 11 Mar 2026 at 15:03, Steven Rostedt  wrote:
> On Wed, 11 Mar 2026 14:13:32 +0900
> Masami Hiramatsu (Google)  wrote:
>
> > Hmm, now IS_ERR_OR_NULL() is an inline function, so it is safe.
> > But if you want to use IS_ERR_OR_NULL() here, it will be better something 
> > like
> >
> > node = rhashtable_walk_next(&iter);
> > while (!IS_ERR_OR_NULL(node)) {
> >   fprobe_remove_node_in_module(mod, node, &alist);
> >   node = rhashtable_walk_next(&iter);
> > }
>
> But now you need to have a duplicate code in order to acquire "node"
>
> I think the patch just makes the code worse.

Obviously we need a new for_each_*() helper hiding all the gory internals?

Gr{oetje,eeting}s,

Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

Re: [Intel-wired-lan] [PATCH 15/61] trace: Prefer IS_ERR_OR_NULL over manual NULL check

2026-03-11 Thread Steven Rostedt 
On Wed, 11 Mar 2026 14:13:32 +0900
Masami Hiramatsu (Google)  wrote:

> Hmm, now IS_ERR_OR_NULL() is an inline function, so it is safe.
> But if you want to use IS_ERR_OR_NULL() here, it will be better something like
> 
> node = rhashtable_walk_next(&iter);
> while (!IS_ERR_OR_NULL(node)) {
>   fprobe_remove_node_in_module(mod, node, &alist);
>   node = rhashtable_walk_next(&iter);
> }

But now you need to have a duplicate code in order to acquire "node"

I think the patch just makes the code worse.

-- Steve

Re: [Intel-wired-lan] [PATCH 15/61] trace: Prefer IS_ERR_OR_NULL over manual NULL check

2026-03-10 Thread Steven Rostedt 
On Tue, 10 Mar 2026 12:48:41 +0100
Philipp Hahn  wrote:

> Prefer using IS_ERR_OR_NULL() over using IS_ERR() and a manual NULL
> check.

Why?

> 
> Change generated with coccinelle.
> 
> To: Steven Rostedt 
> To: Masami Hiramatsu 
> To: Mathieu Desnoyers 
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Philipp Hahn 
> ---
>  kernel/trace/fprobe.c| 2 +-
>  kernel/trace/kprobe_event_gen_test.c | 2 +-
>  kernel/trace/trace_events_hist.c | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
> index 
> dcadf1d23b8a31f571392d0c49cbd22df1716b4f..a94ce810d83b90f55d1178a9bd29c78fd068df4c
>  100644
> --- a/kernel/trace/fprobe.c
> +++ b/kernel/trace/fprobe.c
> @@ -607,7 +607,7 @@ static int fprobe_module_callback(struct notifier_block 
> *nb,
>   do {
>   rhashtable_walk_start(&iter);
>  
> - while ((node = rhashtable_walk_next(&iter)) && !IS_ERR(node))
> + while (!IS_ERR_OR_NULL((node = rhashtable_walk_next(&iter

Ug, No!

That looks so much worse than the original.

-- Steve

>   fprobe_remove_node_in_module(mod, node, &alist);
>  
>   rhashtable_walk_stop(&iter);
> diff --git a/kernel/trace/kprobe_event_gen_test.c 
> b/kernel/trace/kprobe_event_gen_test.c
> index 
> 5a4b722b50451bfdee42769a6d3be39c055690d1..a1735ca273f0b756aa1fcfcdab30ddad9bc51c5f
>  100644
> --- a/kernel/trace/kprobe_event_gen_test.c
> +++ b/kernel/trace/kprobe_event_gen_test.c
> @@ -75,7 +75,7 @@ static struct trace_event_file *gen_kretprobe_test;
>  
>  static bool trace_event_file_is_valid(struct trace_event_file *input)
>  {
> - return input && !IS_ERR(input);
> + return !IS_ERR_OR_NULL(input);
>  }
>  
>  /*
> diff --git a/kernel/trace/trace_events_hist.c 
> b/kernel/trace/trace_events_hist.c
> index 
> 73ea180cad555898693e92ee397a1c9493c7c167..59df215e1dfd9349eca1c0823ed709ec7285f766
>  100644
> --- a/kernel/trace/trace_events_hist.c
> +++ b/kernel/trace/trace_events_hist.c
> @@ -3973,7 +3973,7 @@ trace_action_create_field_var(struct hist_trigger_data 
> *hist_data,
>*/
>   field_var = create_target_field_var(hist_data, system, event, var);
>  
> - if (field_var && !IS_ERR(field_var)) {
> + if (!IS_ERR_OR_NULL(field_var)) {
>   save_field_var(hist_data, field_var);
>   hist_field = field_var->var;
>   } else {
>