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@xxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
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 d688d80..2c1d5f5 100644
--- a/drivers/platform/x86/dell-laptop.c
+++ b/drivers/platform/x86/dell-laptop.c
@@ -305,7 +305,6 @@ 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;
@@ -1896,12 +1895,11 @@ 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();
@@ -1965,7 +1963,7 @@ fail_backlight:
cancel_delayed_work_sync(&dell_rfkill_work);
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:
--
1.7.10.4
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