sparc: keep calling do_signal() as long as pending signals remain

Analog of what commit 494486a1 had done
to alpha (another architecture with similar bug).

One note: in rtrap_32.S part clr %l6 has been a rudiment of left after
commit 28e61036 (sparc: Fix debugger syscall
restart interactions) has killed %l6 use in there.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/kernel/rtrap_32.S

@@ -78,9 +78,9 @@ signal_p:
 	call	do_notify_resume
 	 add	%sp, STACKFRAME_SZ, %o0	! pt_regs ptr
 
-	/* Fall through. */
-	ld	[%sp + STACKFRAME_SZ + PT_PSR], %t_psr
-	clr	%l6
+	b	signal_p
+	 ld	[%curptr + TI_FLAGS], %g2
+
 ret_trap_continue:
 	sethi	%hi(PSR_SYSCALL), %g1
 	andn	%t_psr, %g1, %t_psr

arch/sparc/kernel/rtrap_64.S

@@ -34,37 +34,9 @@ __handle_preemption:
 __handle_user_windows:
 		call			fault_in_user_windows
 		 wrpr			%g0, RTRAP_PSTATE, %pstate
+		ba,pt			%xcc, __handle_preemption_continue
 		 wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
-		/* Redo sched+sig checks */
-		ldx			[%g6 + TI_FLAGS], %l0
-		andcc			%l0, _TIF_NEED_RESCHED, %g0
-
-		be,pt			%xcc, 1f
-		 nop
-		call			schedule
-		 wrpr			%g0, RTRAP_PSTATE, %pstate
-		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
-		ldx			[%g6 + TI_FLAGS], %l0
-
-1:		andcc			%l0, _TIF_DO_NOTIFY_RESUME_MASK, %g0
-		be,pt			%xcc, __handle_user_windows_continue
-		 nop
-		mov			%l5, %o1
-		add			%sp, PTREGS_OFF, %o0
-		mov			%l0, %o2
-
-		call			do_notify_resume
-		 wrpr			%g0, RTRAP_PSTATE, %pstate
-		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
-		/* Signal delivery can modify pt_regs tstate, so we must
-		 * reload it.
-		 */
-		ldx			[%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
-		sethi			%hi(0xf << 20), %l4
-		and			%l1, %l4, %l4
-		ba,pt			%xcc, __handle_user_windows_continue
 
-		 andn			%l1, %l4, %l1
 __handle_userfpu:
 		rd			%fprs, %l5
 		andcc			%l5, FPRS_FEF, %g0
@@ -87,7 +59,7 @@ __handle_signal:
 		ldx			[%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
 		sethi			%hi(0xf << 20), %l4
 		and			%l1, %l4, %l4
-		ba,pt			%xcc, __handle_signal_continue
+		ba,pt			%xcc, __handle_preemption_continue
 		 andn			%l1, %l4, %l1
 
 		/* When returning from a NMI (%pil==15) interrupt we want to
@@ -177,11 +149,9 @@ __handle_preemption_continue:
 		bne,pn			%xcc, __handle_preemption
 		 andcc			%l0, _TIF_DO_NOTIFY_RESUME_MASK, %g0
 		bne,pn			%xcc, __handle_signal
-__handle_signal_continue:
 		 ldub			[%g6 + TI_WSAVED], %o2
 		brnz,pn			%o2, __handle_user_windows
 		 nop
-__handle_user_windows_continue:
 		sethi			%hi(TSTATE_PEF), %o0
 		andcc			%l1, %o0, %g0