From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f173.google.com (mail-wi0-f173.google.com [209.85.212.173]) by kanga.kvack.org (Postfix) with ESMTP id 4AA4C6B0032 for ; Mon, 22 Jun 2015 04:46:05 -0400 (EDT) Received: by wiga1 with SMTP id a1so69588772wig.0 for ; Mon, 22 Jun 2015 01:46:04 -0700 (PDT) Received: from mail-wi0-x233.google.com (mail-wi0-x233.google.com. [2a00:1450:400c:c05::233]) by mx.google.com with ESMTPS id gn12si33817640wjc.137.2015.06.22.01.46.03 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 22 Jun 2015 01:46:03 -0700 (PDT) Received: by wicgi11 with SMTP id gi11so67967311wic.0 for ; Mon, 22 Jun 2015 01:46:03 -0700 (PDT) Date: Mon, 22 Jun 2015 10:46:01 +0200 From: Michal Hocko Subject: Re: [PATCH 3/4] dell-laptop: Fix allocating & freeing SMI buffer page Message-ID: <20150622084601.GE4430@dhcp22.suse.cz> References: <1434875967-13370-1-git-send-email-pali.rohar@gmail.com> <1434876063-13460-1-git-send-email-pali.rohar@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1434876063-13460-1-git-send-email-pali.rohar@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Pali =?iso-8859-1?Q?Roh=E1r?= Cc: Darren Hart , Matthew Garrett , platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org On Sun 21-06-15 10:41:03, Pali Rohar 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 Rohar Looks good to me. FWIW Acked-by: Michal Hocko > --- > 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org