Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Thu, 10 Aug 2017 10:25:59 -0700
From: Thomas Garnier <thgarnie@...gle.com>
To: Herbert Xu <herbert@...dor.apana.org.au>,
	"David S . Miller" <davem@...emloft.net>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H . Peter Anvin" <hpa@...or.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Josh Poimboeuf <jpoimboe@...hat.com>,
	Arnd Bergmann <arnd@...db.de>,
	Thomas Garnier <thgarnie@...gle.com>,
	Matthias Kaehlcke <mka@...omium.org>,
	Boris Ostrovsky <boris.ostrovsky@...cle.com>,
	Juergen Gross <jgross@...e.com>,
	Paolo Bonzini <pbonzini@...hat.com>,
	Radim Krčmář <rkrcmar@...hat.com>,
	Joerg Roedel <joro@...tes.org>,
	Tom Lendacky <thomas.lendacky@....com>,
	Andy Lutomirski <luto@...nel.org>,
	Borislav Petkov <bp@...e.de>,
	Brian Gerst <brgerst@...il.com>,
	"Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
	"Rafael J . Wysocki" <rjw@...ysocki.net>,
	Len Brown <len.brown@...el.com>,
	Pavel Machek <pavel@....cz>,
	Tejun Heo <tj@...nel.org>,
	Christoph Lameter <cl@...ux.com>,
	Paul Gortmaker <paul.gortmaker@...driver.com>,
	Chris Metcalf <cmetcalf@...lanox.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"Paul E . McKenney" <paulmck@...ux.vnet.ibm.com>,
	Nicolas Pitre <nicolas.pitre@...aro.org>,
	Christopher Li <sparse@...isli.org>,
	"Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
	Lukas Wunner <lukas@...ner.de>,
	Mika Westerberg <mika.westerberg@...ux.intel.com>,
	Dou Liyang <douly.fnst@...fujitsu.com>,
	Daniel Borkmann <daniel@...earbox.net>,
	Alexei Starovoitov <ast@...nel.org>,
	Masahiro Yamada <yamada.masahiro@...ionext.com>,
	Markus Trippelsdorf <markus@...ppelsdorf.de>,
	Steven Rostedt <rostedt@...dmis.org>,
	Kees Cook <keescook@...omium.org>,
	Rik van Riel <riel@...hat.com>,
	David Howells <dhowells@...hat.com>,
	Waiman Long <longman@...hat.com>,
	Kyle Huey <me@...ehuey.com>,
	Peter Foley <pefoley2@...oley.com>,
	Tim Chen <tim.c.chen@...ux.intel.com>,
	Catalin Marinas <catalin.marinas@....com>,
	Ard Biesheuvel <ard.biesheuvel@...aro.org>,
	Michal Hocko <mhocko@...e.com>,
	Matthew Wilcox <mawilcox@...rosoft.com>,
	"H . J . Lu" <hjl.tools@...il.com>,
	Paul Bolle <pebolle@...cali.nl>,
	Rob Landley <rob@...dley.net>,
	Baoquan He <bhe@...hat.com>,
	Daniel Micay <danielmicay@...il.com>
Cc: x86@...nel.org,
	linux-crypto@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	xen-devel@...ts.xenproject.org,
	kvm@...r.kernel.org,
	linux-pm@...r.kernel.org,
	linux-arch@...r.kernel.org,
	linux-sparse@...r.kernel.org,
	kernel-hardening@...ts.openwall.com
Subject: [RFC v2 07/23] x86: relocate_kernel - Adapt assembly for PIE support

Change the assembly code to use only relative references of symbols for the
kernel to be PIE compatible.

Position Independent Executable (PIE) support will allow to extended the
KASLR randomization range below the -2G memory limit.

Signed-off-by: Thomas Garnier <thgarnie@...gle.com>
---
 arch/x86/kernel/relocate_kernel_64.S | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
index 307d3bac5f04..2ecbdcbe985b 100644
--- a/arch/x86/kernel/relocate_kernel_64.S
+++ b/arch/x86/kernel/relocate_kernel_64.S
@@ -200,9 +200,11 @@ identity_mapped:
 	movq	%rax, %cr3
 	lea	PAGE_SIZE(%r8), %rsp
 	call	swap_pages
-	movq	$virtual_mapped, %rax
-	pushq	%rax
-	ret
+	jmp	*virtual_mapped_addr(%rip)
+
+	/* Absolute value for PIE support */
+virtual_mapped_addr:
+	.quad virtual_mapped
 
 virtual_mapped:
 	movq	RSP(%r8), %rsp
-- 
2.14.0.434.g98096fd7a8-goog

Powered by blists - more mailing lists

Your e-mail address:

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.