Revert previous commit. We should not get any FP traps from within

the kernel. We can guarantee this by resetting the FP status register.
This masks all FP traps. The reason we did get FP traps was that we
didn't reset the FP status register in all cases.

Make sure to reset the FP status register in syscall(). This is one of
the places where it was forgotten.

While on the subject, reset the FP status register only when we trapped
from user space.

1 files changed, 15 insertions, 18 deletions

diff --git a/sys/ia64/ia64/trap.c b/sys/ia64/ia64/trap.c
index 324be68..83946b1 100644
--- a/sys/ia64/ia64/trap.c
+++ b/sys/ia64/ia64/trap.c
@@ -358,9 +358,6 @@ trap(int vector, struct trapframe *tf)
 
 	user = TRAPF_USERMODE(tf) ? 1 : 0;
 
-	/* Sanitize the FP state in case the user has trashed it. */
-	ia64_set_fpsr(IA64_FPSR_DEFAULT);
-
 	atomic_add_int(&cnt.v_trap, 1);
 
 	td = curthread;
@@ -368,6 +365,7 @@ trap(int vector, struct trapframe *tf)
 	ucode = 0;
 
 	if (user) {
+		ia64_set_fpsr(IA64_FPSR_DEFAULT);
 		sticks = td->td_sticks;
 		td->td_frame = tf;
 		if (td->td_ucred != p->p_ucred)
@@ -668,10 +666,11 @@ trap(int vector, struct trapframe *tf)
 		FPSWA_BUNDLE bundle;
 		char *ip;
 
-		if (fpswa_interface == NULL) {
-			if (!user)
-				trap_panic(vector, tf);
+		/* Always fatal in kernel. Should never happen. */
+		if (!user)
+			trap_panic(vector, tf);
 
+		if (fpswa_interface == NULL) {
 			sig = SIGFPE;
 			ucode = 0;
 			break;
@@ -681,15 +680,12 @@ trap(int vector, struct trapframe *tf)
 		if (vector == IA64_VEC_FLOATING_POINT_TRAP &&
 		    (tf->tf_special.psr & IA64_PSR_RI) == 0)
 			ip -= 16;
-		if (user) {
-			error = copyin(ip, &bundle, 16);
-			if (error) {
-				sig = SIGBUS;	/* EFAULT, basically */
-				ucode = 0;	/* exception summary */
-				break;
-			}
-		} else
-			bcopy(ip, &bundle, 16);
+		error = copyin(ip, &bundle, 16);
+		if (error) {
+			sig = SIGBUS;	/* EFAULT, basically */
+			ucode = 0;	/* exception summary */
+			break;
+		}
 
 		/* f6-f15 are saved in exception_save */
 		fp_state.bitmask_low64 = 0xffc0;	/* bits 6 - 15 */
@@ -741,12 +737,11 @@ trap(int vector, struct trapframe *tf)
 			printf("FATAL: FPSWA err1 %lx, err2 %lx, err3 %lx\n",
 			    fpswa_ret.err1, fpswa_ret.err2, fpswa_ret.err3);
 			panic("fpswa fatal error on fp fault");
-		} else if (user) {
+		} else {
 			sig = SIGFPE;
 			ucode = 0;		/* XXX exception summary */
 			break;
-		} else
-			goto out;
+		}
 	}
 
 	case IA64_VEC_IA32_EXCEPTION:
@@ -897,6 +892,8 @@ syscall(struct trapframe *tf)
 	int code, error;
 	u_int sticks;
 
+	ia64_set_fpsr(IA64_FPSR_DEFAULT);
+
 	code = tf->tf_scratch.gr15;
 	args = &tf->tf_scratch.gr16;