From 0f133f3c8d8d31a85bc2e5d0115c8bc6eca2225e Mon Sep 17 00:00:00 2001 From: =?utf8?q?Pali=20Roh=C3=A1r?= Date: Tue, 23 Jun 2015 10:11:19 +0200 Subject: [PATCH] dell-laptop: Fix allocating & freeing SMI buffer page MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit b8830a4e71b15d0364ac8e6c55301eea73f211da upstream. 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 Signed-off-by: Darren Hart [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- 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 1d3bcce6fbdf..e57f5dec469f 100644 --- a/drivers/platform/x86/dell-laptop.c +++ b/drivers/platform/x86/dell-laptop.c @@ -215,7 +215,6 @@ static struct dmi_system_id __devinitdata dell_quirks[] = { }; static struct calling_interface_buffer *buffer; -static struct page *bufferpage; static DEFINE_MUTEX(buffer_mutex); static int hwswitch_state; @@ -715,11 +714,10 @@ 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); + buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32); - if (!bufferpage) + if (!buffer) goto fail_buffer; - buffer = page_address(bufferpage); ret = dell_setup_rfkill(); @@ -788,7 +786,7 @@ fail_backlight: fail_filter: 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: -- 2.39.2