From: Paolo Bonzini <pbonzini@redhat.com>
Date: Thu, 31 Mar 2016 07:38:51 +0000 (+0200)
Subject: compiler-gcc: disable -ftracer for __noclone functions
X-Git-Tag: v3.10.102~41
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5d814ad8d35e5e23e0c27fb0f0b80c1044ecefad;p=thirdparty%2Fkernel%2Fstable.git

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@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: stable@vger.kernel.org
Cc: kvm@vger.kernel.org
Reported-by: Linda Walsh <lkml@tlinx.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 65856c3599b4a..953cd12175c42 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -177,7 +177,7 @@
 #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 */