sparc64: Use a TS_RESTORE_SIGMASK

This mirrors x86 changeset 5a8da0ea82db6fa9737041381079fd16f25dcce2
("signals: x86 TS_RESTORE_SIGMASK") on sparc64.

Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc64/kernel/rtrap.S

@@ -46,7 +46,7 @@ __handle_user_windows:
 		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
 		ldx			[%g6 + TI_FLAGS], %l0
 
-1:		andcc			%l0, (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK), %g0
+1:		andcc			%l0, _TIF_SIGPENDING, %g0
 		be,pt			%xcc, __handle_user_windows_continue
 		 nop
 		mov			%l5, %o1
@@ -86,7 +86,7 @@ __handle_perfctrs:
 		 wrpr			%g0, RTRAP_PSTATE, %pstate
 		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
 		ldx			[%g6 + TI_FLAGS], %l0
-1:		andcc			%l0, (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK), %g0
+1:		andcc			%l0, _TIF_SIGPENDING, %g0
 
 		be,pt			%xcc, __handle_perfctrs_continue
 		 sethi			%hi(TSTATE_PEF), %o0
@@ -195,7 +195,7 @@ __handle_preemption_continue:
 		 andcc			%l1, %o0, %g0
 		andcc			%l0, _TIF_NEED_RESCHED, %g0
 		bne,pn			%xcc, __handle_preemption
-		 andcc			%l0, (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK), %g0
+		 andcc			%l0, _TIF_SIGPENDING, %g0
 		bne,pn			%xcc, __handle_signal
 __handle_signal_continue:
 		 ldub			[%g6 + TI_WSAVED], %o2

arch/sparc64/kernel/signal.c

@@ -247,7 +247,9 @@ static long _sigpause_common(old_sigset_t set)
 
 	current->state = TASK_INTERRUPTIBLE;
 	schedule();
-	set_thread_flag(TIF_RESTORE_SIGMASK);
+
+	set_restore_sigmask();
+
 	return -ERESTARTNOHAND;
 }
 
@@ -537,7 +539,7 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 	} else
 		restart_syscall = 0;
 
-	if (test_thread_flag(TIF_RESTORE_SIGMASK))
+	if (current_thread_info()->status & TS_RESTORE_SIGMASK)
 		oldset = &current->saved_sigmask;
 	else
 		oldset = &current->blocked;
@@ -566,13 +568,12 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 			syscall_restart(orig_i0, regs, &ka.sa);
 		handle_signal(signr, &ka, &info, oldset, regs);
 
-		/* a signal was successfully delivered; the saved
+		/* A signal was successfully delivered; the saved
 		 * sigmask will have been stored in the signal frame,
 		 * and will be restored by sigreturn, so we can simply
-		 * clear the TIF_RESTORE_SIGMASK flag.
+		 * clear the TS_RESTORE_SIGMASK flag.
 		 */
-		if (test_thread_flag(TIF_RESTORE_SIGMASK))
-			clear_thread_flag(TIF_RESTORE_SIGMASK);
+		current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 		return;
 	}
 	if (restart_syscall &&
@@ -591,17 +592,17 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 		regs->tnpc -= 4;
 	}
 
-	/* if there's no signal to deliver, we just put the saved sigmask
+	/* If there's no signal to deliver, we just put the saved sigmask
 	 * back
 	 */
-	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
-		clear_thread_flag(TIF_RESTORE_SIGMASK);
+	if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
+		current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 	}
 }
 
 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
 {
-	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
+	if (thread_info_flags & _TIF_SIGPENDING)
 		do_signal(regs, orig_i0);
 }

arch/sparc64/kernel/signal32.c

@@ -788,13 +788,12 @@ void do_signal32(sigset_t *oldset, struct pt_regs * regs,
 			syscall_restart32(orig_i0, regs, &ka.sa);
 		handle_signal32(signr, &ka, &info, oldset, regs);
 
-		/* a signal was successfully delivered; the saved
+		/* A signal was successfully delivered; the saved
 		 * sigmask will have been stored in the signal frame,
 		 * and will be restored by sigreturn, so we can simply
-		 * clear the TIF_RESTORE_SIGMASK flag.
+		 * clear the TS_RESTORE_SIGMASK flag.
 		 */
-		if (test_thread_flag(TIF_RESTORE_SIGMASK))
-			clear_thread_flag(TIF_RESTORE_SIGMASK);
+		current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 		return;
 	}
 	if (restart_syscall &&
@@ -813,11 +812,11 @@ void do_signal32(sigset_t *oldset, struct pt_regs * regs,
 		regs->tnpc -= 4;
 	}
 
-	/* if there's no signal to deliver, we just put the saved sigmask
+	/* If there's no signal to deliver, we just put the saved sigmask
 	 * back
 	 */
-	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
-		clear_thread_flag(TIF_RESTORE_SIGMASK);
+	if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
+		current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 	}
 }

include/asm-sparc64/thread_info.h

@@ -38,7 +38,7 @@ struct thread_info {
 	struct task_struct	*task;
 	unsigned long		flags;
 	__u8			fpsaved[7];
-	__u8			pad;
+	__u8			status;
 	unsigned long		ksp;
 
 	/* D$ line 2 */
@@ -217,7 +217,7 @@ register struct thread_info *current_thread_info_reg asm("g6");
  *	 nop
  */
 #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
-#define TIF_RESTORE_SIGMASK	1	/* restore signal mask in do_signal() */
+/* flags bit 1 is available */
 #define TIF_SIGPENDING		2	/* signal pending */
 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
 #define TIF_PERFCTR		4	/* performance counters active */
@@ -244,14 +244,34 @@ register struct thread_info *current_thread_info_reg asm("g6");
 #define _TIF_32BIT		(1<<TIF_32BIT)
 #define _TIF_SECCOMP		(1<<TIF_SECCOMP)
 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
-#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
 #define _TIF_ABI_PENDING	(1<<TIF_ABI_PENDING)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 
 #define _TIF_USER_WORK_MASK	((0xff << TI_FLAG_WSAVED_SHIFT) | \
-				 (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK | \
+				 (_TIF_SIGPENDING | \
 				  _TIF_NEED_RESCHED | _TIF_PERFCTR))
 
+/*
+ * Thread-synchronous status.
+ *
+ * This is different from the flags in that nobody else
+ * ever touches our thread-synchronous status, so we don't
+ * have to worry about atomic accesses.
+ *
+ * Note that there are only 8 bits available.
+ */
+#define TS_RESTORE_SIGMASK	0x0001	/* restore signal mask in do_signal() */
+
+#ifndef __ASSEMBLY__
+#define HAVE_SET_RESTORE_SIGMASK	1
+static inline void set_restore_sigmask(void)
+{
+	struct thread_info *ti = current_thread_info();
+	ti->status |= TS_RESTORE_SIGMASK;
+	set_bit(TIF_SIGPENDING, &ti->flags);
+}
+#endif	/* !__ASSEMBLY__ */
+
 #endif /* __KERNEL__ */
 
 #endif /* _ASM_THREAD_INFO_H */