[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,
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index 0c4788e..a231834 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -85,10 +85,10 @@
/*
* thread information flags bit numbers
*/
+#define TIF_SYSCALL 0 /* inside a system call */
#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
#define TIF_SIGPENDING 2 /* signal pending */
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
-#define TIF_RESTART_SVC 4 /* restart svc with new svc number */
#define TIF_PER_TRAP 6 /* deliver sigtrap on return to user */
#define TIF_MCCK_PENDING 7 /* machine check handling is pending */
#define TIF_SYSCALL_TRACE 8 /* syscall trace active */
@@ -104,11 +104,11 @@
#define TIF_SINGLE_STEP 20 /* This task is single stepped */
#define TIF_FREEZE 21 /* thread is freezing for suspend */
+#define _TIF_SYSCALL (1<<TIF_SYSCALL)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
-#define _TIF_RESTART_SVC (1<<TIF_RESTART_SVC)
#define _TIF_PER_TRAP (1<<TIF_PER_TRAP)
#define _TIF_MCCK_PENDING (1<<TIF_MCCK_PENDING)
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)