When creating a new widget from a template the name string of the template is duplicated for the newly created widget. This is necessary because in some cases the string might be stored on the stack or other volatile memory locations.

But most of the time the string is static const data, which means it is possible to use it directly without having to worry that it might get freed or changed.

Use kstrdup_const() to handle duplicating the string. This function is capable of detecting whether a string is immutable and if it is returns the input without duplicating it. This will slightly reduce the runtime memory footprint of DAPM and also speed up initialization.

Signed-off-by: Lars-Peter Clausen lars@metafoo.de --- sound/soc/soc-dapm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c index 7a57b01..7f834a0 100644 --- a/sound/soc/soc-dapm.c +++ b/sound/soc/soc-dapm.c @@ -2332,7 +2332,7 @@ void snd_soc_dapm_free_widget(struct snd_soc_dapm_widget *w) dapm_free_path(p);

kfree(w->kcontrols); - kfree(w->name); + kfree_const(w->name); kfree(w); }

@@ -3353,7 +3353,7 @@ snd_soc_dapm_new_control_unlocked(struct snd_soc_dapm_context *dapm, if (prefix) w->name = kasprintf(GFP_KERNEL, "%s %s", prefix, widget->name); else - w->name = kasprintf(GFP_KERNEL, "%s", widget->name); + w->name = kstrdup_const(widget->name, GFP_KERNEL); if (w->name == NULL) { kfree(w); return NULL;

The patch

ASoC: dapm: Add helper function to free a widget

has been applied to the asoc tree at

git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git

All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying to this mail.

Thanks, Mark

From b97e26980f6c13afad4c249b60a8dca7f5f86116 Mon Sep 17 00:00:00 2001

From: Lars-Peter Clausen lars@metafoo.de Date: Tue, 21 Jul 2015 18:11:07 +0200 Subject: [PATCH] ASoC: dapm: Add helper function to free a widget

snd_soc_tplg_widget_remove_all() has a verbatim copy of an older version of the widget freeing code from dapm_free_widgets(). Add a new helper function that takes care of freeing a widget and use it in both places.

This removes the duplicated code and also makes sure that future changes to the widget freeing code only have to be made in one location.

Signed-off-by: Lars-Peter Clausen lars@metafoo.de Signed-off-by: Mark Brown broonie@kernel.org --- include/sound/soc-dapm.h | 1 + sound/soc/soc-dapm.c | 38 ++++++++++++++++++++++---------------- sound/soc/soc-topology.c | 25 +------------------------ 3 files changed, 24 insertions(+), 40 deletions(-)

diff --git a/include/sound/soc-dapm.h b/include/sound/soc-dapm.h index 37d95a898275..cadc7fc5d727 100644 --- a/include/sound/soc-dapm.h +++ b/include/sound/soc-dapm.h @@ -397,6 +397,7 @@ int snd_soc_dapm_del_routes(struct snd_soc_dapm_context *dapm, const struct snd_soc_dapm_route *route, int num); int snd_soc_dapm_weak_routes(struct snd_soc_dapm_context *dapm, const struct snd_soc_dapm_route *route, int num); +void snd_soc_dapm_free_widget(struct snd_soc_dapm_widget *w);

/* dapm events */ void snd_soc_dapm_stream_event(struct snd_soc_pcm_runtime *rtd, int stream, diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c index e0de8072c514..24ea692bd49e 100644 --- a/sound/soc/soc-dapm.c +++ b/sound/soc/soc-dapm.c @@ -2312,30 +2312,36 @@ static void dapm_free_path(struct snd_soc_dapm_path *path) kfree(path); }

+void snd_soc_dapm_free_widget(struct snd_soc_dapm_widget *w) +{ + struct snd_soc_dapm_path *p, *next_p; + + list_del(&w->list); + /* + * remove source and sink paths associated to this widget. + * While removing the path, remove reference to it from both + * source and sink widgets so that path is removed only once. + */ + list_for_each_entry_safe(p, next_p, &w->sources, list_sink) + dapm_free_path(p); + + list_for_each_entry_safe(p, next_p, &w->sinks, list_source) + dapm_free_path(p); + + kfree(w->kcontrols); + kfree(w->name); + kfree(w); +} + /* free all dapm widgets and resources */ static void dapm_free_widgets(struct snd_soc_dapm_context *dapm) { struct snd_soc_dapm_widget *w, *next_w; - struct snd_soc_dapm_path *p, *next_p;

list_for_each_entry_safe(w, next_w, &dapm->card->widgets, list) { if (w->dapm != dapm) continue; - list_del(&w->list); - /* - * remove source and sink paths associated to this widget. - * While removing the path, remove reference to it from both - * source and sink widgets so that path is removed only once. - */ - list_for_each_entry_safe(p, next_p, &w->sources, list_sink) - dapm_free_path(p); - - list_for_each_entry_safe(p, next_p, &w->sinks, list_source) - dapm_free_path(p); - - kfree(w->kcontrols); - kfree(w->name); - kfree(w); + snd_soc_dapm_free_widget(w); } }

diff --git a/sound/soc/soc-topology.c b/sound/soc/soc-topology.c index d0960683c409..56dd108d6f5f 100644 --- a/sound/soc/soc-topology.c +++ b/sound/soc/soc-topology.c @@ -1734,7 +1734,6 @@ void snd_soc_tplg_widget_remove_all(struct snd_soc_dapm_context *dapm, u32 index) { struct snd_soc_dapm_widget *w, *next_w; - struct snd_soc_dapm_path *p, *next_p;

list_for_each_entry_safe(w, next_w, &dapm->card->widgets, list) {

@@ -1746,31 +1745,9 @@ void snd_soc_tplg_widget_remove_all(struct snd_soc_dapm_context *dapm, if (w->dobj.index != index && w->dobj.index != SND_SOC_TPLG_INDEX_ALL) continue; - - list_del(&w->list); - - /* - * remove source and sink paths associated to this widget. - * While removing the path, remove reference to it from both - * source and sink widgets so that path is removed only once. - */ - list_for_each_entry_safe(p, next_p, &w->sources, list_sink) { - list_del(&p->list_sink); - list_del(&p->list_source); - list_del(&p->list); - kfree(p); - } - list_for_each_entry_safe(p, next_p, &w->sinks, list_source) { - list_del(&p->list_sink); - list_del(&p->list_source); - list_del(&p->list); - kfree(p); - } /* check and free and dynamic widget kcontrols */ snd_soc_tplg_widget_remove(w); - kfree(w->kcontrols); - kfree(w->name); - kfree(w); + snd_soc_dapm_free_widget(w); } } EXPORT_SYMBOL_GPL(snd_soc_tplg_widget_remove_all);