Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20171011203027.11248-9-thgarnie@google.com>
Date: Wed, 11 Oct 2017 13:30:08 -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>,
	Kees Cook <keescook@...omium.org>,
	Andrey Ryabinin <aryabinin@...tuozzo.com>,
	Matthias Kaehlcke <mka@...omium.org>,
	Tom Lendacky <thomas.lendacky@....com>,
	Andy Lutomirski <luto@...nel.org>,
	"Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
	Borislav Petkov <bp@...e.de>,
	"Rafael J . Wysocki" <rjw@...ysocki.net>,
	Len Brown <len.brown@...el.com>,
	Pavel Machek <pavel@....cz>,
	Juergen Gross <jgross@...e.com>,
	Chris Wright <chrisw@...s-sol.org>,
	Alok Kataria <akataria@...are.com>,
	Rusty Russell <rusty@...tcorp.com.au>,
	Tejun Heo <tj@...nel.org>,
	Christoph Lameter <cl@...ux.com>,
	Boris Ostrovsky <boris.ostrovsky@...cle.com>,
	Paul Gortmaker <paul.gortmaker@...driver.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Alexey Dobriyan <adobriyan@...il.com>,
	"Paul E . McKenney" <paulmck@...ux.vnet.ibm.com>,
	Nicolas Pitre <nicolas.pitre@...aro.org>,
	Borislav Petkov <bp@...en8.de>,
	"Luis R . Rodriguez" <mcgrof@...nel.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Christopher Li <sparse@...isli.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Jason Baron <jbaron@...mai.com>,
	Mika Westerberg <mika.westerberg@...ux.intel.com>,
	Dou Liyang <douly.fnst@...fujitsu.com>,
	"Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
	Lukas Wunner <lukas@...ner.de>,
	Masahiro Yamada <yamada.masahiro@...ionext.com>,
	Alexei Starovoitov <ast@...nel.org>,
	Daniel Borkmann <daniel@...earbox.net>,
	Markus Trippelsdorf <markus@...ppelsdorf.de>,
	Paolo Bonzini <pbonzini@...hat.com>,
	Radim Krčmář <rkrcmar@...hat.com>,
	Joerg Roedel <joro@...tes.org>,
	Rik van Riel <riel@...hat.com>,
	David Howells <dhowells@...hat.com>,
	Ard Biesheuvel <ard.biesheuvel@...aro.org>,
	Waiman Long <longman@...hat.com>,
	Kyle Huey <me@...ehuey.com>,
	Jonathan Corbet <corbet@....net>,
	Michal Hocko <mhocko@...e.com>,
	Peter Foley <pefoley2@...oley.com>,
	Paul Bolle <pebolle@...cali.nl>,
	Jiri Kosina <jkosina@...e.cz>,
	"H . J . Lu" <hjl.tools@...il.com>,
	Rob Landley <rob@...dley.net>,
	Baoquan He <bhe@...hat.com>,
	Jan H . Schönherr <jschoenh@...zon.de>,
	Daniel Micay <danielmicay@...il.com>
Cc: x86@...nel.org,
	linux-crypto@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-pm@...r.kernel.org,
	virtualization@...ts.linux-foundation.org,
	xen-devel@...ts.xenproject.org,
	linux-arch@...r.kernel.org,
	linux-sparse@...r.kernel.org,
	kvm@...r.kernel.org,
	linux-doc@...r.kernel.org,
	kernel-hardening@...ts.openwall.com
Subject: [PATCH v1 08/27] x86/CPU: Adapt assembly for PIE support

Change the assembly code to use only relative references of symbols for the
kernel to be PIE compatible. Use the new _ASM_GET_PTR macro instead of
the 'mov $symbol, %dst' construct to not have an absolute reference.

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/include/asm/processor.h | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index b446c5a082ad..b09bd50b06c7 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -49,7 +49,7 @@ static inline void *current_text_addr(void)
 {
 	void *pc;
 
-	asm volatile("mov $1f, %0; 1:":"=r" (pc));
+	asm volatile(_ASM_GET_PTR(1f, %0) "; 1:":"=r" (pc));
 
 	return pc;
 }
@@ -695,6 +695,7 @@ static inline void sync_core(void)
 		: ASM_CALL_CONSTRAINT : : "memory");
 #else
 	unsigned int tmp;
+	unsigned long tmp2;
 
 	asm volatile (
 		UNWIND_HINT_SAVE
@@ -705,11 +706,13 @@ static inline void sync_core(void)
 		"pushfq\n\t"
 		"mov %%cs, %0\n\t"
 		"pushq %q0\n\t"
-		"pushq $1f\n\t"
+		"leaq 1f(%%rip), %1\n\t"
+		"pushq %1\n\t"
 		"iretq\n\t"
 		UNWIND_HINT_RESTORE
 		"1:"
-		: "=&r" (tmp), ASM_CALL_CONSTRAINT : : "cc", "memory");
+		: "=&r" (tmp), "=&r" (tmp2), ASM_CALL_CONSTRAINT
+		: : "cc", "memory");
 #endif
 }
 
-- 
2.15.0.rc0.271.g36b669edcc-goog

Powered by blists - more mailing lists

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