[S390] add TIF_SYSCALL thread flag
Add an explicit TIF_SYSCALL bit that indicates if a task is inside
a system call. The svc_code in the pt_regs structure is now only
valid if TIF_SYSCALL is set. With this definition TIF_RESTART_SVC
can be replaced with TIF_SYSCALL. Overall do_signal is a bit more
readable and it saves a few lines of code.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/syscall.h b/arch/s390/include/asm/syscall.h
index 614267f..b239ff5 100644
--- a/arch/s390/include/asm/syscall.h
+++ b/arch/s390/include/asm/syscall.h
@@ -26,7 +26,8 @@
static inline long syscall_get_nr(struct task_struct *task,
struct pt_regs *regs)
{
- return regs->svc_code ? (regs->svc_code & 0xffff) : -1;
+ return test_tsk_thread_flag(task, TIF_SYSCALL) ?
+ (regs->svc_code & 0xffff) : -1;
}
static inline void syscall_rollback(struct task_struct *task,