powerpc/kprobe: Introduce a new thread flag

We need to add a new thread flag, TIF_EMULATE_STACK_STORE,
for emulating stack store operation while exiting exception.

Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/include/asm/thread_info.h

@@ -104,6 +104,8 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_NOTIFY_RESUME	13	/* callback before returning to user */
 #define TIF_UPROBE		14	/* breakpointed or single-stepping */
 #define TIF_SYSCALL_TRACEPOINT	15	/* syscall tracepoint instrumentation */
+#define TIF_EMULATE_STACK_STORE	16	/* Is an instruction emulation
+						for stack store? */
 
 /* as above, but as bit values */
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
@@ -121,6 +123,7 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
 #define _TIF_UPROBE		(1<<TIF_UPROBE)
 #define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
+#define _TIF_EMULATE_STACK_STORE	(1<<TIF_EMULATE_STACK_STORE)
 #define _TIF_SYSCALL_T_OR_A	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
 				 _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT)