Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762598Ab3IDNMm (ORCPT ); Wed, 4 Sep 2013 09:12:42 -0400 Received: from smtp.nue.novell.com ([195.135.221.5]:47093 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752724Ab3IDNMk (ORCPT ); Wed, 4 Sep 2013 09:12:40 -0400 Subject: Re: [PATCH V2 10/10] Add option to automatically enforce module signatures when in Secure Boot mode From: joeyli To: Josh Boyer Cc: "H. Peter Anvin" , Matthew Garrett , "Linux-Kernel@Vger. Kernel. Org" , "linux-efi@vger.kernel.org" , Kees Cook In-Reply-To: References: <1376933171-9854-1-git-send-email-matthew.garrett@nebula.com> <1376933171-9854-11-git-send-email-matthew.garrett@nebula.com> <20130829183713.GT20828@hansolo.jdub.homelinux.org> <522104A6.5000700@zytor.com> <20130830234133.GR20828@hansolo.jdub.homelinux.org> <1378291877.6380.74.camel@linux-s257.site> Content-Type: text/plain; charset="UTF-8" Date: Wed, 04 Sep 2013 21:13:18 +0800 Message-ID: <1378300398.6380.76.camel@linux-s257.site> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3347 Lines: 75 於 三，2013-09-04 於 08:01 -0400，Josh Boyer 提到： > On Wed, Sep 4, 2013 at 6:51 AM, joeyli wrote: > > 於 五，2013-08-30 於 19:41 -0400，Josh Boyer 提到： > >> On Fri, Aug 30, 2013 at 01:46:30PM -0700, H. Peter Anvin wrote: > >> > On 08/29/2013 11:37 AM, Josh Boyer wrote: > >> > >> setup_efi_pci(boot_params); > >> > >> diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h > >> > >> index c15ddaf..d35da96 100644 > >> > >> --- a/arch/x86/include/uapi/asm/bootparam.h > >> > >> +++ b/arch/x86/include/uapi/asm/bootparam.h > >> > >> @@ -131,7 +131,8 @@ struct boot_params { > >> > >> __u8 eddbuf_entries; /* 0x1e9 */ > >> > >> __u8 edd_mbr_sig_buf_entries; /* 0x1ea */ > >> > >> __u8 kbd_status; /* 0x1eb */ > >> > >> - __u8 _pad5[3]; /* 0x1ec */ > >> > >> + __u8 secure_boot; /* 0x1ec */ > >> > >> + __u8 _pad5[2]; /* 0x1ec */ > >> > >> /* > >> > >> * The sentinel is set to a nonzero value (0xff) in header.S. > >> > >> * > >> > > > >> > > You need to include the following chunk of code with this, otherwise the > >> > > secure_boot variable gets cleared. > >> > > > >> > > >> > Not really. > >> > > >> > There are three cases: > >> > > >> > 1. Boot stub only. Here we do the right thing with the bootparams. > >> > 2. Boot loader bypasses the boot stub completely. Here we MUST NOT do > >> > what you suggest above. > >> > 3. Boot stub with a boot_params structure passed in. Here we should > >> > run sanitize_boot_params() (an inline for a reason) in the boot > >> > stub, before we set the secure_boot field. Once that is done, we > >> > again don't need that modification. > >> > >> OK. If 3 works, then great. All I know is that Fedora has been > >> carrying the above hunk for months and it was missing in this patch set. > >> So when I went to test it, the patches didn't do anything because the > >> secure_boot field was getting cleared. > >> > >> I'm more than happy to try option 3, and I'll poke at it next week > >> unless someone beats me to it. > >> > >> josh > > > > The secure_boot field cleaned by sanitize_boot_params() when using grub2 > > linuxefi to load efi stub kernel. > > I printed the boot_params->sentinel value, confirm this value is NOT 0 > > when running grub2 linuxefi path, the entry point is efi_stub_entry. > > > > On the other hand, > > the sentinel value is 0 when direct run efi stub kernel in UEFI shell, > > the secure_boot field can keep. > > > > Does that mean grub2 should clean the sentinel value? or we move the get > > secure_boot value to efi_init()? > > See V3 of this patch that Matthew sent yesterday. It calls > sanitize_boot_params in efi_main before calling get_secure_boot. I > tested that yesterday and it worked fine. > > josh Ah! Thanks for you point out, I missed his v3 patch. Joey Lee -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/