[4.2.y-ckt stable] Patch "compiler-gcc: disable -ftracer for __noclone functions" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    compiler-gcc: disable -ftracer for __noclone functions

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt8.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From ba77bd99c16d9805467dc153cfb1bab92dbf7c62 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini at redhat.com>
Date: Thu, 31 Mar 2016 09:38:51 +0200
Subject: compiler-gcc: disable -ftracer for __noclone functions

commit 95272c29378ee7dc15f43fa2758cb28a5913a06d upstream.

-ftracer can duplicate asm blocks causing compilation to fail in
noclone functions.  For example, KVM declares a global variable
in an asm like

    asm("2: ... \n
         .pushsection data \n
         .global vmx_return \n
         vmx_return: .long 2b");

and -ftracer causes a double declaration.

Cc: Andrew Morton <akpm at linux-foundation.org>
Cc: Michal Marek <mmarek at suse.cz>
Cc: kvm at vger.kernel.org
Reported-by: Linda Walsh <lkml at tlinx.org>
Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 include/linux/compiler-gcc.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index dfaa7b3..cd7f603 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -199,7 +199,7 @@
 #define unreachable() __builtin_unreachable()

 /* Mark a function definition as prohibited from being cloned. */
-#define __noclone	__attribute__((__noclone__))
+#define __noclone	__attribute__((__noclone__, __optimize__("no-tracer")))

 #endif /* GCC_VERSION >= 40500 */

--
2.7.4