[PATCH] mmc: cd-gpio: allow NULL context in mmc_cd_gpio_free()

[PATCH] mmc: cd-gpio: allow NULL context in mmc_cd_gpio_free()

[Guennadi Liakhovetski]

Do not Oops, even if mmc_cd_gpio_free() is mistakenly called on a
driver-cleanup path, even though a previous call to mmc_cd_gpio_request()
failed.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
---

Hi Chris

Unfortunately, as I submitted the final version of the original cd-gpio 
patch http://article.gmane.org/gmane.linux.kernel.mmc/12013 I forgot, that 
I'd already sent a v2 and hadn't incremented the version to v3. And that 
version contained the below fix, that went lost because of the wrong 
version number. So, please, push this incremental fix for 3.4, because 
otherwise some error-paths of the tmio-mmc driver can Oops.

 drivers/mmc/core/cd-gpio.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/core/cd-gpio.c b/drivers/mmc/core/cd-gpio.c
index 29de31e..56b854d 100644
--- a/drivers/mmc/core/cd-gpio.c
+++ b/drivers/mmc/core/cd-gpio.c
@@ -72,6 +72,9 @@ void mmc_cd_gpio_free(struct mmc_host *host)
 {
 	struct mmc_cd_gpio *cd = host->hotplug.handler_priv;
 
+	if (!cd)
+		return;
+
 	free_irq(host->hotplug.irq, host);
 	gpio_free(cd->gpio);
 	kfree(cd);
-- 
1.7.2.5

Re: [PATCH] mmc: cd-gpio: allow NULL context in mmc_cd_gpio_free()

[Chris Ball]

Hi Guennadi,

On Tue, Apr 24 2012, Guennadi Liakhovetski wrote:
> Do not Oops, even if mmc_cd_gpio_free() is mistakenly called on a
> driver-cleanup path, even though a previous call to mmc_cd_gpio_request()
> failed.
>
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> ---
>
> Hi Chris
>
> Unfortunately, as I submitted the final version of the original cd-gpio 
> patch http://article.gmane.org/gmane.linux.kernel.mmc/12013 I forgot, that 
> I'd already sent a v2 and hadn't incremented the version to v3. And that 
> version contained the below fix, that went lost because of the wrong 
> version number. So, please, push this incremental fix for 3.4, because 
> otherwise some error-paths of the tmio-mmc driver can Oops.

Sorry about that, I should have noticed this as well.

Pushed to mmc-next for 3.4 with a stable@ tag for 3.3.  (It's helpful if
you can add the stable@ tag yourself when submitting.)

- Chris.
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child