Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20171004212003.28296-4-thgarnie@google.com>
Date: Wed,  4 Oct 2017 14:19:39 -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>,
	Thomas Garnier <thgarnie@...gle.com>,
	Arnd Bergmann <arnd@...db.de>,
	Kees Cook <keescook@...omium.org>,
	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>,
	Alexey Dobriyan <adobriyan@...il.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Paul Gortmaker <paul.gortmaker@...driver.com>,
	Chris Metcalf <cmetcalf@...lanox.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>,
	Dou Liyang <douly.fnst@...fujitsu.com>,
	"Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
	Mika Westerberg <mika.westerberg@...ux.intel.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>,
	Andrey Ryabinin <aryabinin@...tuozzo.com>,
	Jonathan Corbet <corbet@....net>,
	Matthew Wilcox <mawilcox@...rosoft.com>,
	Michal Hocko <mhocko@...e.com>,
	Peter Foley <pefoley2@...oley.com>,
	Paul Bolle <pebolle@...cali.nl>,
	Jiri Kosina <jkosina@...e.cz>,
	Rob Landley <rob@...dley.net>,
	"H . J . Lu" <hjl.tools@...il.com>,
	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: [RFC v3 03/27] x86: Use symbol name in jump table for PIE support

Replace the %c constraint with %P. The %c is incompatible with PIE
because it implies an immediate value whereas %P reference a symbol.

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/jump_label.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h
index adc54c12cbd1..6e558e4524dc 100644
--- a/arch/x86/include/asm/jump_label.h
+++ b/arch/x86/include/asm/jump_label.h
@@ -36,9 +36,9 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran
 		".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t"
 		".pushsection __jump_table,  \"aw\" \n\t"
 		_ASM_ALIGN "\n\t"
-		_ASM_PTR "1b, %l[l_yes], %c0 + %c1 \n\t"
+		_ASM_PTR "1b, %l[l_yes], %P0 \n\t"
 		".popsection \n\t"
-		: :  "i" (key), "i" (branch) : : l_yes);
+		: :  "X" (&((char *)key)[branch]) : : l_yes);
 
 	return false;
 l_yes:
@@ -52,9 +52,9 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool
 		"2:\n\t"
 		".pushsection __jump_table,  \"aw\" \n\t"
 		_ASM_ALIGN "\n\t"
-		_ASM_PTR "1b, %l[l_yes], %c0 + %c1 \n\t"
+		_ASM_PTR "1b, %l[l_yes], %P0 \n\t"
 		".popsection \n\t"
-		: :  "i" (key), "i" (branch) : : l_yes);
+		: :  "X" (&((char *)key)[branch]) : : l_yes);
 
 	return false;
 l_yes:
-- 
2.14.2.920.gcf0c67979c-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.