Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755781AbbLAItI (ORCPT ); Tue, 1 Dec 2015 03:49:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51703 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751849AbbLAItE (ORCPT ); Tue, 1 Dec 2015 03:49:04 -0500 Date: Tue, 1 Dec 2015 03:48:59 -0500 From: Jessica Yu To: Rusty Russell , Josh Poimboeuf , Seth Jennings , Jiri Kosina , Vojtech Pavlik , Jonathan Corbet , Miroslav Benes Cc: linux-api@vger.kernel.org, live-patching@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: module: preserve Elf information for livepatch modules Message-ID: <20151201084858.GB3974@packer-debian-8-amd64.digitalocean.com> References: <1448943679-3412-1-git-send-email-jeyu@redhat.com> <1448943679-3412-3-git-send-email-jeyu@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <1448943679-3412-3-git-send-email-jeyu@redhat.com> X-OS: Linux eisen.io 3.16.0-4-amd64 x86_64 User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1780 Lines: 51 +++ Jessica Yu [30/11/15 23:21 -0500]: >For livepatch modules, copy Elf section, symbol, and string information >from the load_info struct in the module loader. > >Livepatch uses special relocation sections in order to be able to patch >modules that are not yet loaded, as well as apply patches to the kernel >when the addresses of symbols cannot be determined at compile time (for >example, when kaslr is enabled). Livepatch modules must preserve Elf >information such as section indices in order to apply the remaining >relocation sections at the appropriate time (i.e. when the target module >loads). > >Signed-off-by: Jessica Yu >--- > include/linux/module.h | 9 +++++ > kernel/module.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++-- > 2 files changed, 105 insertions(+), 2 deletions(-) > >diff --git a/include/linux/module.h b/include/linux/module.h >index 3a19c79..9b46256 100644 >--- a/include/linux/module.h >+++ b/include/linux/module.h >@@ -425,6 +425,14 @@ struct module { > > /* Notes attributes */ > struct module_notes_attrs *notes_attrs; >+ >+ /* Elf information (optionally saved) */ >+ Elf_Ehdr *hdr; >+ Elf_Shdr *sechdrs; >+ char *secstrings; >+ struct { >+ unsigned int sym, str, mod, vers, info, pcpu; >+ } index; > #endif > > /* The command line arguments (may be mangled). People like >@@ -461,6 +469,7 @@ struct module { > #endif > > #ifdef CONFIG_LIVEPATCH >+ bool klp; /* Is this a livepatch module? */ Gah. I believe this field should be outside the #ifdef. Jessica -- 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/