From: Andi Kleen <andi@firstfloor.org>
To: tglx@linutronix.de
Cc: torvalds@linux-foundation.org, gregkh@linux-foundation.org,
linux-kernel@vger.kernel.org, tim.c.chen@linux.intel.com,
Dave Hansen <dave.hansen@linux.intel.com>,
David Woodhouse <dwmw@amazon.co.uk>
Subject: [PATCH v2 09/12] x86/retpoline: Finally enable retpoline for C code
Date: Wed, 3 Jan 2018 18:00:16 -0800 [thread overview]
Message-ID: <20180104020019.1173-10-andi@firstfloor.org> (raw)
In-Reply-To: <20180104020019.1173-1-andi@firstfloor.org>
From: Dave Hansen <dave.hansen@linux.intel.com>
From: David Woodhouse <dwmw@amazon.co.uk>
Add retpoline compile option in Makefile
Update Makefile with retpoline compile options. This requires a gcc with the
retpoline compiler patches enabled.
Print a warning when the compiler doesn't support retpoline
[Originally from David and Tim, but hacked by AK]
v2: Use CONFIG option to enable
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
---
arch/x86/Makefile | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 3e73bc255e4e..b02e35350244 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -230,6 +230,17 @@ KBUILD_CFLAGS += -Wno-sign-compare
#
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
+#
+ifdef CONFIG_RETPOLINE
+ RETPOLINE_CFLAGS += $(call cc-option,-mindirect-branch=thunk-extern)
+ ifneq ($(RETPOLINE_CFLAGS),)
+ KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) -DRETPOLINE
+ KBUILD_AFLAGS += -DRETPOLINE
+ else
+ $(warning Retpoline not supported in compiler. System may be insecure.)
+ endif
+endif
+
archscripts: scripts_basic
$(Q)$(MAKE) $(build)=arch/x86/tools relocs
--
2.14.3
next prev parent reply other threads:[~2018-01-04 2:01 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-04 2:00 Avoid speculative indirect calls in kernel Andi Kleen
2018-01-04 2:00 ` [PATCH v2 01/12] x86/retpoline: Define retpoline indirect thunk and macros Andi Kleen
2018-01-04 2:15 ` Brian Gerst
2018-01-04 2:32 ` Alan Cox
2018-01-04 2:00 ` [PATCH v2 02/12] x86/retpoline/crypto: Convert crypto assembler indirect jumps Andi Kleen
2018-01-04 2:00 ` [PATCH v2 03/12] x86/retpoline/entry: Convert entry " Andi Kleen
2018-01-04 8:42 ` David Woodhouse
2018-01-04 2:00 ` [PATCH v2 04/12] x86/retpoline/ftrace: Convert ftrace " Andi Kleen
2018-01-04 2:00 ` [PATCH v2 05/12] x86/retpoline/hyperv: Convert " Andi Kleen
2018-01-04 2:00 ` [PATCH v2 06/12] x86/retpoline/crypto: Convert xen " Andi Kleen
2018-01-04 6:48 ` Juergen Gross
2018-01-04 6:50 ` Andi Kleen
2018-01-04 2:00 ` [PATCH v2 07/12] x86/retpoline/checksum32: Convert " Andi Kleen
2018-01-04 2:00 ` [PATCH v2 08/12] x86/retpoline/irq32: " Andi Kleen
2018-01-04 2:00 ` Andi Kleen [this message]
2018-01-04 2:00 ` [PATCH v2 10/12] retpoline/taint: Taint kernel for missing retpoline in compiler Andi Kleen
2018-01-04 2:00 ` [PATCH v2 11/12] retpoline/objtool: Disable some objtool warnings Andi Kleen
2018-01-04 14:38 ` Josh Poimboeuf
2018-01-04 14:46 ` David Woodhouse
2018-01-04 15:59 ` Andi Kleen
2018-01-04 16:06 ` Josh Poimboeuf
2018-01-04 16:13 ` Andi Kleen
2018-01-04 16:32 ` Josh Poimboeuf
2018-01-04 17:35 ` Josh Poimboeuf
2018-01-04 2:00 ` [PATCH v2 12/12] retpoline: Attempt to quiten objtool warning for unreachable code Andi Kleen
2018-01-04 11:49 ` Avoid speculative indirect calls in kernel Pavel Machek
2018-01-04 12:09 ` Alan Cox
2018-01-04 13:32 ` Pavel Machek
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