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dell-laptop: Fix allocating & freeing SMI buffer page

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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 <pali.rohar@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
This commit is contained in:
Pali Rohár 2015-06-23 10:11:19 +02:00 committed by Darren Hart
parent 2e19f93fec
commit b8830a4e71
1 changed files with 3 additions and 5 deletions
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8
drivers/platform/x86/dell-laptop.c
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@ -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;
@ -2068,12 +2067,11 @@ 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();
@ -2135,7 +2133,7 @@ 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: