2018-11-02 11:27:09

by Arnd Bergmann

[permalink] [raw]
Subject: [PATCH] ASoC: wm97xx: fix uninitialized regmap pointer problem

gcc notices that without either the ac97 bus or the pdata, we never
initialize the regmap pointer, which leads to an uninitialized variable
access:

sound/soc/codecs/wm9712.c: In function 'wm9712_soc_probe':
sound/soc/codecs/wm9712.c:666:2: error: 'regmap' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Since that configuration is invalid, it's better to return an error
here. I tried to avoid adding complexity to the conditions, and turned
the #ifdef into a regular if(IS_ENABLED()) check for readability.
This in turn requires moving some header file declarations out of
an #ifdef.

The same code is used in three drivers, all of which I'm changing
the same way.

Fixes: 2ed1a8e0ce8d ("ASoC: wm9712: add ac97 new bus support")
Signed-off-by: Arnd Bergmann <[email protected]>
---
include/sound/soc.h | 2 +-
sound/soc/codecs/wm9705.c | 10 ++++------
sound/soc/codecs/wm9712.c | 10 ++++------
sound/soc/codecs/wm9713.c | 10 ++++------
4 files changed, 13 insertions(+), 19 deletions(-)

diff --git a/include/sound/soc.h b/include/sound/soc.h
index 70c10a8f3e90..3e0ac310a3df 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -553,12 +553,12 @@ static inline void snd_soc_jack_free_gpios(struct snd_soc_jack *jack, int count,
}
#endif

-#ifdef CONFIG_SND_SOC_AC97_BUS
struct snd_ac97 *snd_soc_alloc_ac97_component(struct snd_soc_component *component);
struct snd_ac97 *snd_soc_new_ac97_component(struct snd_soc_component *component,
unsigned int id, unsigned int id_mask);
void snd_soc_free_ac97_component(struct snd_ac97 *ac97);

+#ifdef CONFIG_SND_SOC_AC97_BUS
int snd_soc_set_ac97_ops(struct snd_ac97_bus_ops *ops);
int snd_soc_set_ac97_ops_of_reset(struct snd_ac97_bus_ops *ops,
struct platform_device *pdev);
diff --git a/sound/soc/codecs/wm9705.c b/sound/soc/codecs/wm9705.c
index ccdf088461b7..54c306707c02 100644
--- a/sound/soc/codecs/wm9705.c
+++ b/sound/soc/codecs/wm9705.c
@@ -325,8 +325,7 @@ static int wm9705_soc_probe(struct snd_soc_component *component)
if (wm9705->mfd_pdata) {
wm9705->ac97 = wm9705->mfd_pdata->ac97;
regmap = wm9705->mfd_pdata->regmap;
- } else {
-#ifdef CONFIG_SND_SOC_AC97_BUS
+ } else if (IS_ENABLED(CONFIG_SND_SOC_AC97_BUS)) {
wm9705->ac97 = snd_soc_new_ac97_component(component, WM9705_VENDOR_ID,
WM9705_VENDOR_ID_MASK);
if (IS_ERR(wm9705->ac97)) {
@@ -339,7 +338,8 @@ static int wm9705_soc_probe(struct snd_soc_component *component)
snd_soc_free_ac97_component(wm9705->ac97);
return PTR_ERR(regmap);
}
-#endif
+ } else {
+ return -ENXIO;
}

snd_soc_component_set_drvdata(component, wm9705->ac97);
@@ -350,14 +350,12 @@ static int wm9705_soc_probe(struct snd_soc_component *component)

static void wm9705_soc_remove(struct snd_soc_component *component)
{
-#ifdef CONFIG_SND_SOC_AC97_BUS
struct wm9705_priv *wm9705 = snd_soc_component_get_drvdata(component);

- if (!wm9705->mfd_pdata) {
+ if (IS_ENABLED(CONFIG_SND_SOC_AC97_BUS) && !wm9705->mfd_pdata) {
snd_soc_component_exit_regmap(component);
snd_soc_free_ac97_component(wm9705->ac97);
}
-#endif
}

static const struct snd_soc_component_driver soc_component_dev_wm9705 = {
diff --git a/sound/soc/codecs/wm9712.c b/sound/soc/codecs/wm9712.c
index e873baa9e778..01949eaba4fd 100644
--- a/sound/soc/codecs/wm9712.c
+++ b/sound/soc/codecs/wm9712.c
@@ -642,8 +642,7 @@ static int wm9712_soc_probe(struct snd_soc_component *component)
if (wm9712->mfd_pdata) {
wm9712->ac97 = wm9712->mfd_pdata->ac97;
regmap = wm9712->mfd_pdata->regmap;
- } else {
-#ifdef CONFIG_SND_SOC_AC97_BUS
+ } else if (IS_ENABLED(CONFIG_SND_SOC_AC97_BUS)) {
int ret;

wm9712->ac97 = snd_soc_new_ac97_component(component, WM9712_VENDOR_ID,
@@ -660,7 +659,8 @@ static int wm9712_soc_probe(struct snd_soc_component *component)
snd_soc_free_ac97_component(wm9712->ac97);
return PTR_ERR(regmap);
}
-#endif
+ } else {
+ return -ENXIO;
}

snd_soc_component_init_regmap(component, regmap);
@@ -673,14 +673,12 @@ static int wm9712_soc_probe(struct snd_soc_component *component)

static void wm9712_soc_remove(struct snd_soc_component *component)
{
-#ifdef CONFIG_SND_SOC_AC97_BUS
struct wm9712_priv *wm9712 = snd_soc_component_get_drvdata(component);

- if (!wm9712->mfd_pdata) {
+ if (IS_ENABLED(CONFIG_SND_SOC_AC97_BUS) && !wm9712->mfd_pdata) {
snd_soc_component_exit_regmap(component);
snd_soc_free_ac97_component(wm9712->ac97);
}
-#endif
}

static const struct snd_soc_component_driver soc_component_dev_wm9712 = {
diff --git a/sound/soc/codecs/wm9713.c b/sound/soc/codecs/wm9713.c
index 643863bb32e0..b2bb465c8e5a 100644
--- a/sound/soc/codecs/wm9713.c
+++ b/sound/soc/codecs/wm9713.c
@@ -1214,8 +1214,7 @@ static int wm9713_soc_probe(struct snd_soc_component *component)
if (wm9713->mfd_pdata) {
wm9713->ac97 = wm9713->mfd_pdata->ac97;
regmap = wm9713->mfd_pdata->regmap;
- } else {
-#ifdef CONFIG_SND_SOC_AC97_BUS
+ } else if (IS_ENABLED(CONFIG_SND_SOC_AC97_BUS)) {
wm9713->ac97 = snd_soc_new_ac97_component(component, WM9713_VENDOR_ID,
WM9713_VENDOR_ID_MASK);
if (IS_ERR(wm9713->ac97))
@@ -1225,7 +1224,8 @@ static int wm9713_soc_probe(struct snd_soc_component *component)
snd_soc_free_ac97_component(wm9713->ac97);
return PTR_ERR(regmap);
}
-#endif
+ } else {
+ return -ENXIO;
}

snd_soc_component_init_regmap(component, regmap);
@@ -1238,14 +1238,12 @@ static int wm9713_soc_probe(struct snd_soc_component *component)

static void wm9713_soc_remove(struct snd_soc_component *component)
{
-#ifdef CONFIG_SND_SOC_AC97_BUS
struct wm9713_priv *wm9713 = snd_soc_component_get_drvdata(component);

- if (!wm9713->mfd_pdata) {
+ if (IS_ENABLED(CONFIG_SND_SOC_AC97_BUS)) {
snd_soc_component_exit_regmap(component);
snd_soc_free_ac97_component(wm9713->ac97);
}
-#endif
}

static const struct snd_soc_component_driver soc_component_dev_wm9713 = {
--
2.18.0



2018-11-02 14:42:09

by Charles Keepax

[permalink] [raw]
Subject: Re: [PATCH] ASoC: wm97xx: fix uninitialized regmap pointer problem

On Fri, Nov 02, 2018 at 12:23:08PM +0100, Arnd Bergmann wrote:
> gcc notices that without either the ac97 bus or the pdata, we never
> initialize the regmap pointer, which leads to an uninitialized variable
> access:
>
> sound/soc/codecs/wm9712.c: In function 'wm9712_soc_probe':
> sound/soc/codecs/wm9712.c:666:2: error: 'regmap' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>
> Since that configuration is invalid, it's better to return an error
> here. I tried to avoid adding complexity to the conditions, and turned
> the #ifdef into a regular if(IS_ENABLED()) check for readability.
> This in turn requires moving some header file declarations out of
> an #ifdef.
>
> The same code is used in three drivers, all of which I'm changing
> the same way.
>
> Fixes: 2ed1a8e0ce8d ("ASoC: wm9712: add ac97 new bus support")
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> static void wm9713_soc_remove(struct snd_soc_component *component)
> {
> -#ifdef CONFIG_SND_SOC_AC97_BUS
> struct wm9713_priv *wm9713 = snd_soc_component_get_drvdata(component);
>
> - if (!wm9713->mfd_pdata) {
> + if (IS_ENABLED(CONFIG_SND_SOC_AC97_BUS)) {

Should this one not also have an && !wm9713->mfd_pdata?

Thanks,
Charles

> snd_soc_component_exit_regmap(component);
> snd_soc_free_ac97_component(wm9713->ac97);
> }
> -#endif
> }
>
> static const struct snd_soc_component_driver soc_component_dev_wm9713 = {
> --
> 2.18.0

2018-11-02 15:18:24

by Arnd Bergmann

[permalink] [raw]
Subject: Re: [PATCH] ASoC: wm97xx: fix uninitialized regmap pointer problem

On 11/2/18, Charles Keepax <[email protected]> wrote:
> On Fri, Nov 02, 2018 at 12:23:08PM +0100, Arnd Bergmann wrote:

>> static void wm9713_soc_remove(struct snd_soc_component *component)
>> {
>> -#ifdef CONFIG_SND_SOC_AC97_BUS
>> struct wm9713_priv *wm9713 = snd_soc_component_get_drvdata(component);
>>
>> - if (!wm9713->mfd_pdata) {
>> + if (IS_ENABLED(CONFIG_SND_SOC_AC97_BUS)) {
>
> Should this one not also have an && !wm9713->mfd_pdata?

Right, good catch!. I'll send a fixed version in a bit.

Arnd