From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753685AbcDSJeH (ORCPT ); Tue, 19 Apr 2016 05:34:07 -0400 Received: from terminus.zytor.com ([198.137.202.10]:56436 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753235AbcDSJeE (ORCPT ); Tue, 19 Apr 2016 05:34:04 -0400 Date: Tue, 19 Apr 2016 02:32:53 -0700 From: tip-bot for Kees Cook Message-ID: Cc: keescook@chromium.org, bhe@redhat.com, hjl.tools@gmail.com, dvyukov@google.com, bp@suse.de, torvalds@linux-foundation.org, bp@alien8.de, peterz@infradead.org, luto@amacapital.net, jpoimboe@redhat.com, hpa@zytor.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, luto@kernel.org, tglx@linutronix.de, aryabinin@virtuozzo.com, mingo@kernel.org, brgerst@gmail.com, yinghai@kernel.org, dvlasenk@redhat.com Reply-To: luto@amacapital.net, bp@alien8.de, peterz@infradead.org, bp@suse.de, torvalds@linux-foundation.org, hjl.tools@gmail.com, dvyukov@google.com, bhe@redhat.com, keescook@chromium.org, yinghai@kernel.org, dvlasenk@redhat.com, brgerst@gmail.com, aryabinin@virtuozzo.com, mingo@kernel.org, luto@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, akpm@linux-foundation.org, hpa@zytor.com, jpoimboe@redhat.com In-Reply-To: <1460997735-24785-6-git-send-email-keescook@chromium.org> References: <1460997735-24785-6-git-send-email-keescook@chromium.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/boot] x86/KASLR: Clarify purpose of kaslr.c Git-Commit-ID: 7de828dfe607013546ece7ce25aa9839e8f93a66 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 7de828dfe607013546ece7ce25aa9839e8f93a66 Gitweb: http://git.kernel.org/tip/7de828dfe607013546ece7ce25aa9839e8f93a66 Author: Kees Cook AuthorDate: Mon, 18 Apr 2016 09:42:14 -0700 Committer: Ingo Molnar CommitDate: Tue, 19 Apr 2016 10:30:51 +0200 x86/KASLR: Clarify purpose of kaslr.c The name "choose_kernel_location" isn't specific enough, and doesn't describe the primary thing it does: choosing a random location. This patch renames it to "choose_random_location", and clarifies the what routines are contained in the kaslr.c source file. Suggested-by: Ingo Molnar Signed-off-by: Kees Cook Cc: Andrew Morton Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Baoquan He Cc: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Dmitry Vyukov Cc: H. Peter Anvin Cc: H.J. Lu Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Yinghai Lu Link: http://lkml.kernel.org/r/1460997735-24785-6-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar --- arch/x86/boot/compressed/kaslr.c | 13 ++++++++++++- arch/x86/boot/compressed/misc.c | 2 +- arch/x86/boot/compressed/misc.h | 4 ++-- 3 files changed, 15 insertions(+), 4 deletions(-) diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index a51ec84..9e03190 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -1,3 +1,14 @@ +/* + * kaslr.c + * + * This contains the routines needed to generate a reasonable level of + * entropy to choose a randomized kernel base address offset in support + * of Kernel Address Space Layout Randomization (KASLR). Additionally + * handles walking the physical memory maps (and tracking memory regions + * to avoid) in order to select a physical memory location that can + * contain the entire properly aligned running kernel image. + * + */ #include "misc.h" #include @@ -295,7 +306,7 @@ static unsigned long find_random_addr(unsigned long minimum, return slots_fetch_random(); } -unsigned char *choose_kernel_location(unsigned char *input, +unsigned char *choose_random_location(unsigned char *input, unsigned long input_size, unsigned char *output, unsigned long output_size) diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 0d69e80..ad8c01a 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -431,7 +431,7 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, * the entire decompressed kernel plus relocation table, or the * entire decompressed kernel plus .bss and .brk sections. */ - output = choose_kernel_location(input_data, input_len, output, + output = choose_random_location(input_data, input_len, output, output_len > run_size ? output_len : run_size); diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 1f750a51..9887e0d 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -67,7 +67,7 @@ int cmdline_find_option_bool(const char *option); #if CONFIG_RANDOMIZE_BASE /* kaslr.c */ -unsigned char *choose_kernel_location(unsigned char *input, +unsigned char *choose_random_location(unsigned char *input, unsigned long input_size, unsigned char *output, unsigned long output_size); @@ -75,7 +75,7 @@ unsigned char *choose_kernel_location(unsigned char *input, bool has_cpuflag(int flag); #else static inline -unsigned char *choose_kernel_location(unsigned char *input, +unsigned char *choose_random_location(unsigned char *input, unsigned long input_size, unsigned char *output, unsigned long output_size)