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From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: lkml@tlinx.org, Andrew Morton <akpm@linux-foundation.org>,
	Michal Marek <mmarek@suse.cz>,
	stable@vger.kernel.org
Subject: [PATCH] compiler-gcc: disable -ftracer for __noclone functions
Date: Thu, 31 Mar 2016 09:44:12 +0200	[thread overview]
Message-ID: <1459410252-15531-1-git-send-email-pbonzini@redhat.com> (raw)

-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>
---
 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 22ab246feed3..eeae401a2412 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 */
 
-- 
2.5.5


             reply	other threads:[~2016-03-31  7:44 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-31  7:44 Paolo Bonzini [this message]
2016-03-31  8:39 ` [PATCH] compiler-gcc: disable -ftracer for __noclone functions kbuild test robot
2018-05-05 17:22 ` Nadav Amit
2018-05-08 17:58   ` Paolo Bonzini
2018-05-08 18:12     ` Nadav Amit

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