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Commit 8f8d1d7f authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: x86: Fix racy access to chmap 



The access to chmap can be racy against the hotplug process, where it
recreates the chmap on the fly.  For protecting against it, a mutex is
introduced in this patch.  It's also used for protecting the change /
reference of eld and state fields, too.

Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent bcce775c

sound/x86/intel_hdmi_audio.c

+23 −9
Original line number Diff line number Diff line
@@ -555,11 +555,17 @@ static int had_chmap_ctl_get(struct snd_kcontrol *kcontrol, 


	if (intelhaddata->drv_status == HAD_DRV_DISCONNECTED)

		return -ENODEV;

	if (!intelhaddata->chmap->chmap)



	mutex_lock(&intelhaddata->mutex);

	if (!intelhaddata->chmap->chmap) {

		mutex_unlock(&intelhaddata->mutex);

		return -ENODATA;

	}



	chmap = intelhaddata->chmap->chmap;

	for (i = 0; i < chmap->channels; i++)

		ucontrol->value.integer.value[i] = chmap->map[i];

	mutex_unlock(&intelhaddata->mutex);



	return 0;

}
@@ -1352,6 +1358,7 @@ static int snd_intelhad_pcm_mmap(struct snd_pcm_substream *substream, 
			vma->vm_end - vma->vm_start, vma->vm_page_prot);

}



/* process mode change of the running stream; called in mutex */

static int hdmi_audio_mode_change(struct snd_intelhad *intelhaddata)

{

	struct snd_pcm_substream *substream;
@@ -1642,7 +1649,7 @@ static int had_process_buffer_underrun(struct snd_intelhad *intelhaddata) 
	return 0;

}



/* process hot plug, called from wq */

/* process hot plug, called from wq with mutex locked */

static int had_process_hot_plug(struct snd_intelhad *intelhaddata)

{

	enum intel_had_aud_buf_type buf_id;
@@ -1682,7 +1689,7 @@ static int had_process_hot_plug(struct snd_intelhad *intelhaddata) 
	return 0;

}



/* process hot unplug, called from wq */

/* process hot unplug, called from wq with mutex locked */

static int had_process_hot_unplug(struct snd_intelhad *intelhaddata)

{

	enum intel_had_aud_buf_type buf_id;
@@ -1751,12 +1758,14 @@ static int had_iec958_get(struct snd_kcontrol *kcontrol, 
{

	struct snd_intelhad *intelhaddata = snd_kcontrol_chip(kcontrol);



	mutex_lock(&intelhaddata->mutex);

	ucontrol->value.iec958.status[0] = (intelhaddata->aes_bits >> 0) & 0xff;

	ucontrol->value.iec958.status[1] = (intelhaddata->aes_bits >> 8) & 0xff;

	ucontrol->value.iec958.status[2] =

					(intelhaddata->aes_bits >> 16) & 0xff;

	ucontrol->value.iec958.status[3] =

					(intelhaddata->aes_bits >> 24) & 0xff;

	mutex_unlock(&intelhaddata->mutex);

	return 0;

}
@@ -1775,16 +1784,19 @@ static int had_iec958_put(struct snd_kcontrol *kcontrol, 
{

	unsigned int val;

	struct snd_intelhad *intelhaddata = snd_kcontrol_chip(kcontrol);

	int changed = 0;



	val = (ucontrol->value.iec958.status[0] << 0) |

		(ucontrol->value.iec958.status[1] << 8) |

		(ucontrol->value.iec958.status[2] << 16) |

		(ucontrol->value.iec958.status[3] << 24);

	mutex_lock(&intelhaddata->mutex);

	if (intelhaddata->aes_bits != val) {

		intelhaddata->aes_bits = val;

		return 1;

		changed = 1;

	}

	return 1;

	mutex_unlock(&intelhaddata->mutex);

	return changed;

}



static struct snd_kcontrol_new had_control_iec958_mask = {
@@ -1837,6 +1849,7 @@ static void had_audio_wq(struct work_struct *work) 
		container_of(work, struct snd_intelhad, hdmi_audio_wq);

	struct intel_hdmi_lpe_audio_pdata *pdata = ctx->dev->platform_data;



	mutex_lock(&ctx->mutex);

	if (!pdata->hdmi_connected) {

		dev_dbg(ctx->dev, "%s: Event: HAD_NOTIFY_HOT_UNPLUG\n",

			__func__);
@@ -1844,11 +1857,10 @@ static void had_audio_wq(struct work_struct *work) 
		if (ctx->state != hdmi_connector_status_connected) {

			dev_dbg(ctx->dev, "%s: Already Unplugged!\n",

				__func__);

			return;

		}



		} else {

			ctx->state = hdmi_connector_status_disconnected;

			had_process_hot_unplug(ctx);

		}



	} else {

		struct intel_hdmi_lpe_audio_eld *eld = &pdata->eld;
@@ -1888,6 +1900,7 @@ static void had_audio_wq(struct work_struct *work) 
				hdmi_audio_mode_change(ctx);

		}

	}

	mutex_unlock(&ctx->mutex);

}



/* release resources */
@@ -1948,6 +1961,7 @@ static int hdmi_lpe_audio_probe(struct platform_device *pdev) 


	ctx = card->private_data;

	spin_lock_init(&ctx->had_spinlock);

	mutex_init(&ctx->mutex);

	ctx->drv_status = HAD_DRV_DISCONNECTED;

	ctx->dev = &pdev->dev;

	ctx->card = card;

sound/x86/intel_hdmi_audio.h

+1 −0
Original line number Diff line number Diff line
@@ -139,6 +139,7 @@ struct snd_intelhad { 
	void __iomem *mmio_start;

	unsigned int had_config_offset;

	struct work_struct hdmi_audio_wq;

	struct mutex mutex; /* for protecting chmap, state and eld */

};



#endif /* _INTEL_HDMI_AUDIO_ */