From: Joseph Cihula <joseph.cihula@intel.com>
To: linux-kernel@vger.kernel.org, arjan@linux.intel.com, mingo@elte.hu
Subject: [PATCH] x86: disable stack-protector for __restore_processor_state()
Date: Mon, 30 Mar 2009 14:03:01 -0700 [thread overview]
Message-ID: <49D13385.5060900@intel.com> (raw)
The __restore_processor_state() fn restores %gs on resume from S3. As
such, it cannot be protected by the stack-protector guard since %gs will
not be correct on function entry.
There are only a few other fns in this file and it should not negatively
impact kernel security that they will also have the stack-protector
guard removed (and so it's not worth moving them to another file).
Without this change, S3 resume on a kernel built with
CONFIG_CC_STACKPROTECTOR_ALL=y will fail.
Signed-off-by: Joseph Cihula <joseph.cihula@intel.com>
--- ../linux.trees.git/arch/x86/power/Makefile 2009-03-29
12:12:13.000000000 -0700
+++ arch/x86/power/Makefile 2009-03-30 12:21:19.000000000 -0700
@@ -1,2 +1,7 @@
+# __restore_processor_state() restores %gs after S3 resume and so
should not
+# itself be stack-protected
+nostackp := $(call cc-option, -fno-stack-protector)
+CFLAGS_cpu_$(BITS).o := $(nostackp)
+
obj-$(CONFIG_PM_SLEEP) += cpu_$(BITS).o
obj-$(CONFIG_HIBERNATION) += hibernate_$(BITS).o hibernate_asm_$(BITS).o
next reply other threads:[~2009-03-30 21:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-30 21:03 Joseph Cihula [this message]
2009-04-03 17:30 ` [PATCH] x86: disable stack-protector for __restore_processor_state() Ingo Molnar
2009-04-03 17:33 ` [tip:x86/urgent] " Joseph Cihula
2009-04-03 17:51 ` Joseph Cihula
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