[PATCH] staging: greybus: fix stack size warning with UBSAN

[Arnd Bergmann]

From: Arnd Bergmann <arnd@xxxxxxxx>

clang warns about excessive stack usage in this driver when
UBSAN is enabled:

drivers/staging/greybus/audio_topology.c:977:12: error: stack frame size of 1836 bytes in function 'gbaudio_tplg_create_widget' [-Werror,-Wframe-larger-than=]

Rework this code to no longer use compound literals for
initializing the structure in each case, but instead keep
the common bits in a preallocated constant array and copy
them as needed.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 drivers/staging/greybus/audio_topology.c | 106 ++++++++++-------------
 1 file changed, 47 insertions(+), 59 deletions(-)

diff --git a/drivers/staging/greybus/audio_topology.c b/drivers/staging/greybus/audio_topology.c
index 96b8b29fe899..c03873915c20 100644
--- a/drivers/staging/greybus/audio_topology.c
+++ b/drivers/staging/greybus/audio_topology.c
@@ -974,6 +974,44 @@ static int gbaudio_widget_event(struct snd_soc_dapm_widget *w,
 	return ret;
 }
 
+static const struct snd_soc_dapm_widget gbaudio_widgets[] = {
+	[snd_soc_dapm_spk]	= SND_SOC_DAPM_SPK("spk", gbcodec_event_spk),
+	[snd_soc_dapm_hp]	= SND_SOC_DAPM_HP("hp", gbcodec_event_hp),
+	[snd_soc_dapm_mic]	= SND_SOC_DAPM_MIC("mic", gbcodec_event_int_mic),
+	[snd_soc_dapm_output]	= SND_SOC_DAPM_OUTPUT("output"),
+	[snd_soc_dapm_input]	= SND_SOC_DAPM_INPUT("input"),
+	[snd_soc_dapm_switch]	= SND_SOC_DAPM_SWITCH_E("switch", SND_SOC_NOPM,
+					0, 0, NULL,
+					gbaudio_widget_event,
+					SND_SOC_DAPM_PRE_PMU |
+					SND_SOC_DAPM_POST_PMD),
+	[snd_soc_dapm_pga]	= SND_SOC_DAPM_PGA_E("pga", SND_SOC_NOPM,
+					0, 0, NULL, 0,
+					gbaudio_widget_event,
+					SND_SOC_DAPM_PRE_PMU |
+					SND_SOC_DAPM_POST_PMD),
+	[snd_soc_dapm_mixer]	= SND_SOC_DAPM_MIXER_E("mixer", SND_SOC_NOPM,
+					0, 0, NULL, 0,
+					gbaudio_widget_event,
+					SND_SOC_DAPM_PRE_PMU |
+					SND_SOC_DAPM_POST_PMD),
+	[snd_soc_dapm_mux]	= SND_SOC_DAPM_MUX_E("mux", SND_SOC_NOPM,
+					0, 0, NULL,
+					gbaudio_widget_event,
+					SND_SOC_DAPM_PRE_PMU |
+					SND_SOC_DAPM_POST_PMD),
+	[snd_soc_dapm_aif_in]	= SND_SOC_DAPM_AIF_IN_E("aif_in", NULL, 0,
+					SND_SOC_NOPM, 0, 0,
+					gbaudio_widget_event,
+					SND_SOC_DAPM_PRE_PMU |
+					SND_SOC_DAPM_POST_PMD),
+	[snd_soc_dapm_aif_out]	= SND_SOC_DAPM_AIF_OUT_E("aif_out", NULL, 0,
+					SND_SOC_NOPM, 0, 0,
+					gbaudio_widget_event,
+					SND_SOC_DAPM_PRE_PMU |
+					SND_SOC_DAPM_POST_PMD),
+};
+
 static int gbaudio_tplg_create_widget(struct gbaudio_module_info *module,
 				      struct snd_soc_dapm_widget *dw,
 				      struct gb_audio_widget *w, int *w_size)
@@ -1050,78 +1088,28 @@ static int gbaudio_tplg_create_widget(struct gbaudio_module_info *module,
 	strlcpy(temp_name, w->name, NAME_SIZE);
 	snprintf(w->name, NAME_SIZE, "GB %d %s", module->dev_id, temp_name);
 
+	if (w->type > ARRAY_SIZE(gbaudio_widgets)) {
+		ret = -EINVAL;
+		goto error;
+	}
+	*dw = gbaudio_widgets[w->type];
+	dw->name = w->name;
+
 	switch (w->type) {
 	case snd_soc_dapm_spk:
-		*dw = (struct snd_soc_dapm_widget)
-			SND_SOC_DAPM_SPK(w->name, gbcodec_event_spk);
 		module->op_devices |= GBAUDIO_DEVICE_OUT_SPEAKER;
 		break;
 	case snd_soc_dapm_hp:
-		*dw = (struct snd_soc_dapm_widget)
-			SND_SOC_DAPM_HP(w->name, gbcodec_event_hp);
 		module->op_devices |= (GBAUDIO_DEVICE_OUT_WIRED_HEADSET
-					| GBAUDIO_DEVICE_OUT_WIRED_HEADPHONE);
+					| GBAUDIO_DEVICE_OUT_WIRED_HEADPHONE),
 		module->ip_devices |= GBAUDIO_DEVICE_IN_WIRED_HEADSET;
 		break;
 	case snd_soc_dapm_mic:
-		*dw = (struct snd_soc_dapm_widget)
-			SND_SOC_DAPM_MIC(w->name, gbcodec_event_int_mic);
 		module->ip_devices |= GBAUDIO_DEVICE_IN_BUILTIN_MIC;
 		break;
-	case snd_soc_dapm_output:
-		*dw = (struct snd_soc_dapm_widget)SND_SOC_DAPM_OUTPUT(w->name);
-		break;
-	case snd_soc_dapm_input:
-		*dw = (struct snd_soc_dapm_widget)SND_SOC_DAPM_INPUT(w->name);
-		break;
-	case snd_soc_dapm_switch:
-		*dw = (struct snd_soc_dapm_widget)
-			SND_SOC_DAPM_SWITCH_E(w->name, SND_SOC_NOPM, 0, 0,
-					      widget_kctls,
-					      gbaudio_widget_event,
-					      SND_SOC_DAPM_PRE_PMU |
-					      SND_SOC_DAPM_POST_PMD);
-		break;
-	case snd_soc_dapm_pga:
-		*dw = (struct snd_soc_dapm_widget)
-			SND_SOC_DAPM_PGA_E(w->name, SND_SOC_NOPM, 0, 0, NULL, 0,
-					   gbaudio_widget_event,
-					   SND_SOC_DAPM_PRE_PMU |
-					   SND_SOC_DAPM_POST_PMD);
-		break;
-	case snd_soc_dapm_mixer:
-		*dw = (struct snd_soc_dapm_widget)
-			SND_SOC_DAPM_MIXER_E(w->name, SND_SOC_NOPM, 0, 0, NULL,
-					     0, gbaudio_widget_event,
-					     SND_SOC_DAPM_PRE_PMU |
-					     SND_SOC_DAPM_POST_PMD);
-		break;
-	case snd_soc_dapm_mux:
-		*dw = (struct snd_soc_dapm_widget)
-			SND_SOC_DAPM_MUX_E(w->name, SND_SOC_NOPM, 0, 0,
-					   widget_kctls, gbaudio_widget_event,
-					   SND_SOC_DAPM_PRE_PMU |
-					   SND_SOC_DAPM_POST_PMD);
-		break;
 	case snd_soc_dapm_aif_in:
-		*dw = (struct snd_soc_dapm_widget)
-			SND_SOC_DAPM_AIF_IN_E(w->name, w->sname, 0,
-					      SND_SOC_NOPM,
-					      0, 0, gbaudio_widget_event,
-					      SND_SOC_DAPM_PRE_PMU |
-					      SND_SOC_DAPM_POST_PMD);
-		break;
 	case snd_soc_dapm_aif_out:
-		*dw = (struct snd_soc_dapm_widget)
-			SND_SOC_DAPM_AIF_OUT_E(w->name, w->sname, 0,
-					       SND_SOC_NOPM,
-					       0, 0, gbaudio_widget_event,
-					       SND_SOC_DAPM_PRE_PMU |
-					       SND_SOC_DAPM_POST_PMD);
-		break;
-	default:
-		ret = -EINVAL;
-		goto error;
+		dw->sname = w->sname;
 	}
 
 	dev_dbg(module->dev, "%s: widget of type %d created\n", dw->name,
-- 
2.29.2