| From | Ben Hutchings <> | Date | Wed, 27 Apr 2016 01:02:21 +0200 | Subject | [PATCH 3.16 168/217] compiler-gcc: disable -ftracer for __noclone functions |
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3.16.35-rc1 review patch. If anyone has any objections, please let me know.
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From: Paolo Bonzini <pbonzini@redhat.com>
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: kvm@vger.kernel.org Reported-by: Linda Walsh <lkml@tlinx.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.16: apply to compiler-gcc{4,5}.h] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@ -54,7 +54,7 @@ #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 */ --- a/include/linux/compiler-gcc5.h +++ b/include/linux/compiler-gcc5.h @@ -40,7 +40,7 @@ #define unreachable() __builtin_unreachable() /* Mark a function definition as prohibited from being cloned. */ -#define __noclone __attribute__((__noclone__)) +#define __noclone __attribute__((__noclone__, __optimize__("no-tracer"))) /* * Tell the optimizer that something else uses this function or variable.
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