Re: [alsa-devel] [PATCH] fix the kernel panic due to wrong use the dev memory API

On 11/5/18 2:29 AM, He, Bo wrote:

skl->dais is allocated with devm_kcalloc, can't free with the krealloc. Memory allocated with devm API is automatically freed on driver detach, Like all other devres resources.

Refer to drivers/base/devres.c devm_kmalloc for more details.

What code are you looking at?

I see this in the Mark's tree

int skl_platform_register(struct device *dev) {     int ret;     struct snd_soc_dai_driver *dais;     int num_dais = ARRAY_SIZE(skl_platform_dai);     struct hdac_bus *bus = dev_get_drvdata(dev);     struct skl *skl = bus_to_skl(bus);

INIT_LIST_HEAD(&skl->ppl_list);     INIT_LIST_HEAD(&skl->bind_list);

skl->dais = kmemdup(skl_platform_dai, sizeof(skl_platform_dai),                 GFP_KERNEL);     if (!skl->dais) {         ret = -ENOMEM;         goto err;     }

if (!skl->use_tplg_pcm) {         dais = krealloc(skl->dais, sizeof(skl_fe_dai) +                 sizeof(skl_platform_dai), GFP_KERNEL);

No trace of devm as you mention it? I checked the Chrome tree as well and it's not there.

What am I missing?

Signed-off-by: he, bo bo.he@intel.com

sound/soc/intel/skylake/skl-pcm.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/sound/soc/intel/skylake/skl-pcm.c b/sound/soc/intel/skylake/skl-pcm.c index 823e391..928d314 100644 --- a/sound/soc/intel/skylake/skl-pcm.c +++ b/sound/soc/intel/skylake/skl-pcm.c @@ -1438,7 +1438,8 @@ int skl_platform_register(struct device *dev) }

if (!skl->use_tplg_pcm) {

• dais = krealloc(skl->dais, sizeof(skl_fe_dai) +
  

• devm_kfree(dev, skl->dais);
  

• dais = devm_kcalloc(dev, skl->dais, sizeof(skl_fe_dai) +
  	sizeof(skl_platform_dai), GFP_KERNEL);
  

  if (!dais) { ret = -ENOMEM;

@@ -1472,7 +1473,5 @@ int skl_platform_unregister(struct device *dev) } }

• kfree(skl->dais);
• return 0; }