Re: [alsa-devel] [PATCH 7/12] wm8940: fix resource reclaim in wm8940_register error path

Hi Axel

On Thu, 15 Jul 2010, Axel Lin wrote:

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From 44c93254e5158e3086c4707148d24746067f6b14 Mon Sep 17 00:00:00 2001

From: Axel Lin axel.lin@gmail.com Date: Thu, 15 Jul 2010 10:13:34 +0800 Subject: [PATCH] wm8940: fix resource reclaim in wm8940_register error path

This patch fixes the error path in wm8940_register to properly free resources.

Signed-off-by: Axel Lin axel.lin@gmail.com

Ok, these bugs are real, but let's fix them properly, i.e., release resources at the same level, where they have been acquired:

static int register_codec(struct drv_priv *data) { int ret = snd_soc_register_codec(); if (ret < 0) return ret;

ret = try(); if (failed) goto err;

...

err: snd_soc_unregister_codec(); }

static int probe() { int ret; struct drv_priv *data = kzalloc(sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM;

ret = register_codec(data); if (ret < 0) goto err;

...

err: kfree(data); return ret; }

That is, kfree() belongs to probe() and not to register_codec. This, of course, concerns all aour patches, at least those of them, that I have seen.

Thanks Guennadi

---

sound/soc/codecs/wm8940.c | 22 ++++++++++++++-------- 1 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/sound/soc/codecs/wm8940.c b/sound/soc/codecs/wm8940.c index e3c4bbf..9673e6f 100644 --- a/sound/soc/codecs/wm8940.c +++ b/sound/soc/codecs/wm8940.c @@ -766,7 +766,8 @@ static int wm8940_register(struct wm8940_priv *wm8940, u16 reg; if (wm8940_codec) { dev_err(codec->dev, "Another WM8940 is registered\n");

• return -EINVAL;
  

• ret = -EINVAL;
  

• goto err;
  

  }

  INIT_LIST_HEAD(&codec->dapm_widgets);

@@ -785,7 +786,7 @@ static int wm8940_register(struct wm8940_priv *wm8940, ret = snd_soc_codec_set_cache_io(codec, 8, 16, control); if (ret < 0) { dev_err(codec->dev, "Failed to set cache I/O: %d\n", ret);

• return ret;
  

• goto err;
  

  }

  memcpy(codec->reg_cache, wm8940_reg_defaults,

@@ -794,7 +795,7 @@ static int wm8940_register(struct wm8940_priv *wm8940, ret = wm8940_reset(codec); if (ret < 0) { dev_err(codec->dev, "Failed to issue reset\n");

• return ret;
  

• goto err;
  

  }

  wm8940_dai.dev = codec->dev;

@@ -803,7 +804,7 @@ static int wm8940_register(struct wm8940_priv *wm8940,

ret = snd_soc_write(codec, WM8940_POWER1, 0x180); if (ret < 0)

• return ret;
  

• goto err;
  
  

  if (!pdata) dev_warn(codec->dev, "No platform data supplied\n");

@@ -811,7 +812,7 @@ static int wm8940_register(struct wm8940_priv *wm8940, reg = snd_soc_read(codec, WM8940_OUTPUTCTL); ret = snd_soc_write(codec, WM8940_OUTPUTCTL, reg | pdata->vroi); if (ret < 0)

• 	return ret;
  

• 	goto err;
  

  }

@@ -820,17 +821,22 @@ static int wm8940_register(struct wm8940_priv *wm8940, ret = snd_soc_register_codec(codec); if (ret) { dev_err(codec->dev, "Failed to register codec: %d\n", ret);

• return ret;
  

• goto err;
  

  }

  ret = snd_soc_register_dai(&wm8940_dai); if (ret) { dev_err(codec->dev, "Failed to register DAI: %d\n", ret);

• snd_soc_unregister_codec(codec);
  

• return ret;
  

• goto err_codec;
  

  }

  return 0;

+err_codec:

• snd_soc_unregister_codec(codec);

+err:

• kfree(wm8940);
• return ret;

}

static void wm8940_unregister(struct wm8940_priv *wm8940)

1.5.4.3

--- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/