From: Pali Rohár Date: Tue, 23 Jun 2015 08:11:19 +0000 (+0200) Subject: dell-laptop: Fix allocating & freeing SMI buffer page X-Git-Tag: v3.18.20~11 X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bb91f0ab2a32dc6afa29e17e9ba865e5335ffb0e;p=linux dell-laptop: Fix allocating & freeing SMI buffer page [ Upstream commit b8830a4e71b15d0364ac8e6c55301eea73f211da ] 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 Acked-by: Michal Hocko Cc: stable@vger.kernel.org Signed-off-by: Darren Hart Signed-off-by: Sasha Levin --- diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c index 233d2ee598a6..be945fff61c3 100644 --- a/drivers/platform/x86/dell-laptop.c +++ b/drivers/platform/x86/dell-laptop.c @@ -272,7 +272,6 @@ 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; @@ -825,12 +824,11 @@ 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(); @@ -892,7 +890,7 @@ 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: