Re: [PATCH] driver core: fix shutdown races with probe/remove(v1)

[Sergei Shtylyov]

Hello.

On 08-06-2012 9:38, Ming Lei wrote:

> Firstly, .shutdown callback may touch a uninitialized hardware
> if dev->driver is set and .probe is not completed.

> Secondly, device_shutdown() may dereference a null pointer to cause
> oops when dev->driver is cleared after it is checked in
> device_shutdown().

> So just hold device lock and its parent lock if it has to fix the
> races.

> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxxxxx>
> ---
>   drivers/base/core.c |    8 ++++++++
>   1 file changed, 8 insertions(+)

> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 346be8b..cbc8bd2 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -1820,6 +1820,11 @@ void device_shutdown(void)
>   		list_del_init(&dev->kobj.entry);
>   		spin_unlock(&devices_kset->list_lock);
>
> +		/*hold lock[s] to avoid races with .probe/.release*/

   Please add spaces after /* and before */. Or the applier please do it...

WBR, Sergei
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/