Make cpu_single_env thread-local

Make cpu_single_env thread-local. This fixes a regression
in handling of multi-threaded programs in linux-user mode
(bug 823902).
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
[Peter Maydell: rename tls_cpu_single_env to cpu_single_env]
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

cpu-all.h

@@ -20,6 +20,7 @@
 #define CPU_ALL_H
 
 #include "qemu-common.h"
+#include "qemu-tls.h"
 #include "cpu-common.h"
 
 /* some important defines:
@@ -334,7 +335,8 @@ void cpu_dump_statistics(CPUState *env, FILE *f, fprintf_function cpu_fprintf,
 void QEMU_NORETURN cpu_abort(CPUState *env, const char *fmt, ...)
     GCC_FMT_ATTR(2, 3);
 extern CPUState *first_cpu;
-extern CPUState *cpu_single_env;
+DECLARE_TLS(CPUState *,cpu_single_env);
+#define cpu_single_env get_tls(cpu_single_env)
 
 /* Flags for use in ENV->INTERRUPT_PENDING.
 

exec.c

@@ -120,7 +120,7 @@ static MemoryRegion *system_io;
 CPUState *first_cpu;
 /* current CPU in the current thread. It is only valid inside
    cpu_exec() */
-CPUState *cpu_single_env;
+DEFINE_TLS(CPUState *,cpu_single_env);
 /* 0 = Do not count executed instructions.
    1 = Precise instruction counting.
    2 = Adaptive rate instruction counting.  */