[PATCH v2] staging: greybus: fix stack size warning with UBSAN

From: Nathan Chancellor
Date: Thu Dec 09 2021 - 14:52:51 EST

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.

Link: https://github.com/ClangBuiltLinux/linux/issues/1535
Link: https://lore.kernel.org/r/20210103223541.2790855-1-arnd@xxxxxxxxxx/
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
[nathan: Address review comments from v1]
Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
---

v1 -> v2: https://lore.kernel.org/r/20210103223541.2790855-1-arnd@xxxxxxxxxx/

* Use NULL for name field in SND_DOC_DAPM_* in gbaudio_widgets (Alex).

* Do not eliminate *dw assignment within the switch cases, as invalid
enum values in-between valid enum values (such as snd_soc_dapm_demux)
would not be handled properly by the "if value is greater than the
array size" check (Alex). This addresses a few other comments by Alex
and Dan because w->type is not checked against the array's size.

Arnd, if you disagree with this approach, please let me know so that we
can get this fixed in a way that everyone is happy with.

drivers/staging/greybus/audio_topology.c | 92 ++++++++++++------------
1 file changed, 45 insertions(+), 47 deletions(-)

diff --git a/drivers/staging/greybus/audio_topology.c b/drivers/staging/greybus/audio_topology.c
index 1e613d42d823..7f7d558b76d0 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(NULL, gbcodec_event_spk),
+ [snd_soc_dapm_hp] = SND_SOC_DAPM_HP(NULL, gbcodec_event_hp),
+ [snd_soc_dapm_mic] = SND_SOC_DAPM_MIC(NULL, gbcodec_event_int_mic),
+ [snd_soc_dapm_output] = SND_SOC_DAPM_OUTPUT(NULL),
+ [snd_soc_dapm_input] = SND_SOC_DAPM_INPUT(NULL),
+ [snd_soc_dapm_switch] = SND_SOC_DAPM_SWITCH_E(NULL, 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(NULL, 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(NULL, 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(NULL, 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(NULL, 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(NULL, 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)
@@ -1052,77 +1090,37 @@ static int gbaudio_tplg_create_widget(struct gbaudio_module_info *module,

switch (w->type) {
case snd_soc_dapm_spk:
- *dw = (struct snd_soc_dapm_widget)
- SND_SOC_DAPM_SPK(w->name, gbcodec_event_spk);
+ *dw = gbaudio_widgets[w->type];
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);
+ *dw = gbaudio_widgets[w->type];
module->op_devices |= (GBAUDIO_DEVICE_OUT_WIRED_HEADSET
| 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);
+ *dw = gbaudio_widgets[w->type];
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);
+ *dw = gbaudio_widgets[w->type];
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);
+ *dw = gbaudio_widgets[w->type];
+ dw->sname = w->sname;
break;
default:
ret = -EINVAL;
goto error;
}
+ dw->name = w->name;

dev_dbg(module->dev, "%s: widget of type %d created\n", dw->name,
dw->id);

base-commit: 42eb8fdac2fc5d62392dcfcf0253753e821a97b0
--
2.34.1