On Sun 21-06-15 10:41:03, Pali Rohár wrote:
> This commit fix kernel crash when probing for rfkill devices in dell-laptop
> driver failed. Function free_page() was incorrectly used on struct page *
> instead of virtual address of SMI buffer.
> 
> This commit also simplify allocating page for SMI buffer by using
> __get_free_page() function instead of sequential call of functions
> alloc_page() and page_address().
> 
> Signed-off-by: Pali Rohár <[email protected]>

Looks good to me.
FWIW
Acked-by: Michal Hocko <[email protected]>

> ---
>  drivers/platform/x86/dell-laptop.c |    8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/platform/x86/dell-laptop.c 
> b/drivers/platform/x86/dell-laptop.c
> index aaef335..0a91599 100644
> --- a/drivers/platform/x86/dell-laptop.c
> +++ b/drivers/platform/x86/dell-laptop.c
> @@ -306,7 +306,6 @@ static const struct dmi_system_id dell_quirks[] 
> __initconst = {
>  };
>  
>  static struct calling_interface_buffer *buffer;
> -static struct page *bufferpage;
>  static DEFINE_MUTEX(buffer_mutex);
>  
>  static int hwswitch_state;
> @@ -2097,12 +2096,11 @@ static int __init dell_init(void)
>        * Allocate buffer below 4GB for SMI data--only 32-bit physical addr
>        * is passed to SMI handler.
>        */
> -     bufferpage = alloc_page(GFP_KERNEL | GFP_DMA32);
> -     if (!bufferpage) {
> +     buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32);
> +     if (!buffer) {
>               ret = -ENOMEM;
>               goto fail_buffer;
>       }
> -     buffer = page_address(bufferpage);
>  
>       ret = dell_setup_rfkill();
>  
> @@ -2165,7 +2163,7 @@ static int __init dell_init(void)
>  fail_backlight:
>       dell_cleanup_rfkill();
>  fail_rfkill:
> -     free_page((unsigned long)bufferpage);
> +     free_page((unsigned long)buffer);
>  fail_buffer:
>       platform_device_del(platform_device);
>  fail_platform_device2:
> -- 
> 1.7.9.5
> 

-- 
Michal Hocko
SUSE Labs
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to