Unverified Commit 0fae253a authored by Pierre-Louis Bossart's avatar Pierre-Louis Bossart Committed by Mark Brown
Browse files

ASoC: soc-devres: add devm_snd_soc_register_dai() 



The registration of DAIs may be done at two distinct times, once
during a component registration and later when loading a
topology. Since devm_ managed resources are freed in the reverse order
they were allocated, when a component starts unregistering DAIs by
walking through the DAI list, the memory allocated for the
topology-registered DAIs was freed already, which leads to 100%
reproducible KASAN use-after-free reports.

This patch suggests a new devm_ function to force the DAI list to be
updated prior to freeing the memory chunks referenced by the list
pointers.

Suggested-by: default avatarBard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: default avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: default avatarRanjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: default avatarBard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: default avatarKai Vehmanen <kai.vehmanen@linux.intel.com>
BugLink: https://github.com/thesofproject/linux/issues/2186
Link: https://lore.kernel.org/r/20200612205938.26415-2-pierre-louis.bossart@linux.intel.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent b287a6d9

include/sound/soc.h

+4 −0
Original line number Diff line number Diff line
@@ -1363,6 +1363,10 @@ void snd_soc_remove_pcm_runtime(struct snd_soc_card *card, 
struct snd_soc_dai *snd_soc_register_dai(struct snd_soc_component *component,

					 struct snd_soc_dai_driver *dai_drv,

					 bool legacy_dai_naming);

struct snd_soc_dai *devm_snd_soc_register_dai(struct device *dev,

					      struct snd_soc_component *component,

					      struct snd_soc_dai_driver *dai_drv,

					      bool legacy_dai_naming);

void snd_soc_unregister_dai(struct snd_soc_dai *dai);



struct snd_soc_dai *snd_soc_find_dai(

sound/soc/soc-devres.c

+37 −0
Original line number Diff line number Diff line
@@ -9,6 +9,43 @@ 
#include <sound/soc.h>

#include <sound/dmaengine_pcm.h>



static void devm_dai_release(struct device *dev, void *res)

{

	snd_soc_unregister_dai(*(struct snd_soc_dai **)res);

}



/**

 * devm_snd_soc_register_dai - resource-managed dai registration

 * @dev: Device used to manage component

 * @component: The component the DAIs are registered for

 * @dai_drv: DAI driver to use for the DAI

 * @legacy_dai_naming: if %true, use legacy single-name format;

 *	if %false, use multiple-name format;

 */

struct snd_soc_dai *devm_snd_soc_register_dai(struct device *dev,

					      struct snd_soc_component *component,

					      struct snd_soc_dai_driver *dai_drv,

					      bool legacy_dai_naming)

{

	struct snd_soc_dai **ptr;

	struct snd_soc_dai *dai;



	ptr = devres_alloc(devm_dai_release, sizeof(*ptr), GFP_KERNEL);

	if (!ptr)

		return NULL;



	dai = snd_soc_register_dai(component, dai_drv, legacy_dai_naming);

	if (dai) {

		*ptr = dai;

		devres_add(dev, ptr);

	} else {

		devres_free(ptr);

	}



	return dai;

}

EXPORT_SYMBOL_GPL(devm_snd_soc_register_dai);



static void devm_component_release(struct device *dev, void *res)

{

	snd_soc_unregister_component(*(struct device **)res);

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