lkml.org 
[lkml]   [2016]   [Apr]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH 3.16 168/217] compiler-gcc: disable -ftracer for __noclone functions
3.16.35-rc1 review patch.  If anyone has any objections, please let me know.

------------------

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.
\
 
 \ /
  Last update: 2016-04-27 02:41    [W:0.690 / U:0.268 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site