ALSA: hda: hda_component: Protect shared data with a mutex

The hda_component contains information shared from the amp drivers to
the codec that can be altered (for example as the driver unloads). Guard
the update and use of these to prevent use of stale data.

Signed-off-by: Simon Trimmer <simont@opensource.cirrus.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/20240617154105.108635-5-simont@opensource.cirrus.com

diff --git a/sound/pci/hda/hda_component.c b/sound/pci/hda/hda_component.c
index 1a9950b768663fccb450956ca4314eddf6890fc3..7b19cb38b4e025a363435595d2d8ca03ba86cf02 100644 (file)
--- a/sound/pci/hda/hda_component.c
+++ b/sound/pci/hda/hda_component.c
@@ -21,11 +21,13 @@ void hda_component_acpi_device_notify(struct hda_component_parent *parent,
        struct hda_component *comp;
        int i;
 
+       mutex_lock(&parent->mutex);
        for (i = 0; i < ARRAY_SIZE(parent->comps); i++) {
                comp = hda_component_from_index(parent, i);
                if (comp->dev && comp->acpi_notify)
                        comp->acpi_notify(acpi_device_handle(comp->adev), event, comp->dev);
        }
+       mutex_unlock(&parent->mutex);
 }
 EXPORT_SYMBOL_NS_GPL(hda_component_acpi_device_notify, SND_HDA_SCODEC_COMPONENT);
 
@@ -87,6 +89,7 @@ void hda_component_manager_playback_hook(struct hda_component_parent *parent, in
        struct hda_component *comp;
        int i;
 
+       mutex_lock(&parent->mutex);
        for (i = 0; i < ARRAY_SIZE(parent->comps); i++) {
                comp = hda_component_from_index(parent, i);
                if (comp->dev && comp->pre_playback_hook)
@@ -102,6 +105,7 @@ void hda_component_manager_playback_hook(struct hda_component_parent *parent, in
                if (comp->dev && comp->post_playback_hook)
                        comp->post_playback_hook(comp->dev, action);
        }
+       mutex_unlock(&parent->mutex);
 }
 EXPORT_SYMBOL_NS_GPL(hda_component_manager_playback_hook, SND_HDA_SCODEC_COMPONENT);
 
@@ -134,11 +138,18 @@ static int hda_comp_match_dev_name(struct device *dev, void *data)
 int hda_component_manager_bind(struct hda_codec *cdc,
                               struct hda_component_parent *parent)
 {
+       int ret;
+
        /* Init shared and component specific data */
        memset(parent, 0, sizeof(*parent));
+       mutex_init(&parent->mutex);
        parent->codec = cdc;
 
-       return component_bind_all(hda_codec_dev(cdc), parent);
+       mutex_lock(&parent->mutex);
+       ret = component_bind_all(hda_codec_dev(cdc), parent);
+       mutex_unlock(&parent->mutex);
+
+       return ret;
 }
 EXPORT_SYMBOL_NS_GPL(hda_component_manager_bind, SND_HDA_SCODEC_COMPONENT);
 

diff --git a/sound/pci/hda/hda_component.h b/sound/pci/hda/hda_component.h
index dd4dabeae9eefad2e5096da30d9309172f28cda0..9f786608144c0f74f7cbedcfe6038da4309c8fac 100644 (file)
--- a/sound/pci/hda/hda_component.h
+++ b/sound/pci/hda/hda_component.h
@@ -11,6 +11,7 @@
 
 #include <linux/acpi.h>
 #include <linux/component.h>
+#include <linux/mutex.h>
 #include <sound/hda_codec.h>
 
 #define HDA_MAX_COMPONENTS     4
@@ -28,6 +29,7 @@ struct hda_component {
 };
 
 struct hda_component_parent {
+       struct mutex mutex;
        struct hda_codec *codec;
        struct hda_component comps[HDA_MAX_COMPONENTS];
 };
@@ -93,7 +95,9 @@ static inline struct hda_component *hda_component_from_index(struct hda_componen
 static inline void hda_component_manager_unbind(struct hda_codec *cdc,
                                                struct hda_component_parent *parent)
 {
+       mutex_lock(&parent->mutex);
        component_unbind_all(hda_codec_dev(cdc), parent);
+       mutex_unlock(&parent->mutex);
 }
 
 #endif /* ifndef __HDA_COMPONENT_H__ */