On R8000, make trap() behave closer to interrupt() when servicing a real

interrupt by not invoking refreshcreds(), but closer to itsa() when servicing
a trap-reported-as-interrupt by invoking userret() in that case.
No change on !defined(CPU_R8000) kernels.

1 files changed, 27 insertions, 17 deletions

diff --git a/sys/arch/mips64/mips64/trap.c b/sys/arch/mips64/mips64/trap.c
index 65bc612da84..f05a6e7c5ab 100644
--- a/sys/arch/mips64/mips64/trap.c
+++ b/sys/arch/mips64/mips64/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.109 2015/08/19 16:40:10 visa Exp $	*/
+/*	$OpenBSD: trap.c,v 1.110 2015/09/27 09:11:11 miod Exp $	*/
 
 /*
  * Copyright (c) 1988 University of Utah.
@@ -206,9 +206,6 @@ trap(struct trap_frame *trapframe)
 		break;
 	}
 
-	if (type & T_USER)
-		refreshcreds(p);
-
 #ifdef CPU_R8000
 	/*
 	 * Some exception causes on R8000 are actually detected by external
@@ -218,34 +215,47 @@ trap(struct trap_frame *trapframe)
 	 * as if they were triggered as regular exceptions.
 	 */
 	if ((type & ~T_USER) == T_INT) {
-		/*
-		 * Similar reality check as done in interrupt(), in case
-		 * an interrupt occured between a write to COP_0_STATUS_REG
-		 * and it taking effect.
-		 */
-		if (!ISSET(trapframe->sr, SR_INT_ENAB))
-			return;
-
 		if (trapframe->cause & CR_VCE) {
 #ifndef DEBUG_INTERRUPT
 			trapdebug_enter(ci, trapframe, -1);
 #endif
 			panic("VCE or TLBX");
 		}
+
 		if (trapframe->cause & CR_FPE) {
 #ifndef DEBUG_INTERRUPT
 			trapdebug_enter(ci, trapframe, -1);
 #endif
+			atomic_inc_int(&uvmexp.traps);
+			if (type & T_USER)
+				refreshcreds(p);
 			itsa(trapframe, ci, p, T_FPE | (type & T_USER));
 			cp0_reset_cause(CR_FPE);
 		}
-		if (trapframe->cause & CR_INT_MASK)
-			interrupt(trapframe);
 
-		return;	/* no userret */
-	} else
+		if (trapframe->cause & CR_INT_MASK) {
+			/*
+			 * Similar reality check as done in interrupt(), in
+			 * case an interrupt occured between a write to
+			 * COP_0_STATUS_REG and it taking effect.
+			 * (I have never seen this occuring on R8000 but
+			 *  this is cheap)
+			 */
+			if (ISSET(trapframe->sr, SR_INT_ENAB))
+				interrupt(trapframe);
+		}
+
+		if ((trapframe->cause & CR_FPE) && (type & T_USER))
+			userret(p);
+
+		return;
+	}
 #endif
-		itsa(trapframe, ci, p, type);
+
+	if (type & T_USER)
+		refreshcreds(p);
+
+	itsa(trapframe, ci, p, type);
 
 	if (type & T_USER)
 		userret(p);