From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Fleming Subject: Re: [PATCH 1/8] x86, kaslr: get kaslr_enabled back correctly Date: Mon, 2 Mar 2015 13:13:58 +0000 Message-ID: <20150302131358.GD24476@codeblueprint.co.uk> References: <1425176259-30087-1-git-send-email-yinghai@kernel.org> <1425176259-30087-2-git-send-email-yinghai@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1425176259-30087-2-git-send-email-yinghai-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Yinghai Lu Cc: Matt Fleming , Thomas Gleixner , "H. Peter Anvin" , Ingo Molnar , Jiri Kosina , Borislav Petkov , Bjorn Helgaas , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-efi@vger.kernel.org On Sat, 28 Feb, at 06:17:32PM, Yinghai Lu wrote: > We should access variable with referrence instead of using physical > address as value. > > Cc: Matt Fleming > Cc: Borislav Petkov > Signed-off-by: Yinghai Lu > --- > arch/x86/kernel/setup.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c > index 98dc931..05d444f 100644 > --- a/arch/x86/kernel/setup.c > +++ b/arch/x86/kernel/setup.c > @@ -429,7 +429,13 @@ static void __init reserve_initrd(void) > > static void __init parse_kaslr_setup(u64 pa_data, u32 data_len) > { > - kaslr_enabled = (bool)(pa_data + sizeof(struct setup_data)); > + /* kaslr_setup_data is defined in aslr.c */ > + unsigned char *data; > + unsigned long offset = sizeof(struct setup_data); > + > + data = early_memremap(pa_data, offset + 1); > + kaslr_enabled = *(data + offset); > + early_memunmap(data, offset + 1); > } ACK in principle, but could we change 'offset' to 'size' or 'len' along with the commit log updates people have suggested? -- Matt Fleming, Intel Open Source Technology Center