Make intrframe the exact same size as trapframe: instead of pushing

the PPL on top, store it where trapframe puts the trap number.  This
makes interrupt handlers get called with the correct stack alignment.
Also, document the use of if_err to differentiate resumed/recursed
interrupts from 'real' ones.

tested in snaps
ok deraadt@

5 files changed, 28 insertions, 25 deletions

diff --git a/sys/arch/amd64/amd64/genassym.cf b/sys/arch/amd64/amd64/genassym.cf
index bd6892d9979..5d4ddd1c3e3 100644
--- a/sys/arch/amd64/amd64/genassym.cf
+++ b/sys/arch/amd64/amd64/genassym.cf
@@ -1,4 +1,4 @@
-#	$OpenBSD: genassym.cf,v 1.36 2018/06/05 06:39:10 guenther Exp $
+#	$OpenBSD: genassym.cf,v 1.37 2018/07/03 20:15:57 guenther Exp $
 #	Written by Artur Grabowski art@openbsd.org, Public Domain
 
 include <sys/param.h>
@@ -76,6 +76,10 @@ member	tf_rflags
 member	tf_rsp
 member	tf_ss
 
+struct	intrframe
+member	if_ppl
+member	if_err
+
 define  FRAMESIZE               sizeof(struct trapframe)
 
 struct iretq_frame
diff --git a/sys/arch/amd64/amd64/spl.S b/sys/arch/amd64/amd64/spl.S
index 0c2baffd532..e544520a491 100644
--- a/sys/arch/amd64/amd64/spl.S
+++ b/sys/arch/amd64/amd64/spl.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: spl.S,v 1.14 2018/06/07 04:09:35 guenther Exp $	*/
+/*	$OpenBSD: spl.S,v 1.15 2018/07/03 20:15:57 guenther Exp $	*/
 /*	$NetBSD: spl.S,v 1.3 2004/06/28 09:13:11 fvdl Exp $	*/
 
 /*
@@ -144,7 +144,7 @@ KIDTVEC(spllower)
  *   r13 - address to resume loop at
  */
 KIDTVEC(doreti)
-	popq	%rbx			# get previous priority
+	movq	IF_PPL(%rsp),%rbx	# get previous priority
 	decl	CPUVAR(IDEPTH)
 	leaq	1f(%rip),%r13
 1:	movl	%ebx,%eax
diff --git a/sys/arch/amd64/amd64/vector.S b/sys/arch/amd64/amd64/vector.S
index aa80e9ca7bb..1369da1e07c 100644
--- a/sys/arch/amd64/amd64/vector.S
+++ b/sys/arch/amd64/amd64/vector.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vector.S,v 1.67 2018/07/01 16:02:12 guenther Exp $	*/
+/*	$OpenBSD: vector.S,v 1.68 2018/07/03 20:15:57 guenther Exp $	*/
 /*	$NetBSD: vector.S,v 1.5 2004/06/28 09:13:11 fvdl Exp $	*/
 
 /*
@@ -472,12 +472,12 @@ _C_LABEL(x2apic_eoi):
 KIDTVEC(recurse_lapic_ipi)
 	INTR_RECURSE_HWFRAME
 	pushq	$0
-	subq	$8,%rsp			/* unused __if_trapno */
+	subq	$8,%rsp			/* if_ppl filled in below */
 	INTR_REENTRY
 	jmp	1f
 IDTVEC(intr_lapic_ipi)
 	pushq	$0
-	subq	$8,%rsp			/* unused __if_trapno */
+	subq	$8,%rsp			/* if_ppl filled in below */
 	INTRENTRY(intr_lapic_ipi)
 	CODEPATCH_START
 	movl	$0,_C_LABEL(local_apic)+LAPIC_EOI
@@ -492,7 +492,7 @@ KIDTVEC_FALLTHROUGH(resume_lapic_ipi)
 	sti
 	cld
 	SMAP_CLAC
-	pushq	%rbx
+	movq	%rbx,IF_PPL(%rsp)
 	call	_C_LABEL(x86_ipi_handler)
 	jmp	_C_LABEL(Xdoreti)
 2:
@@ -556,12 +556,12 @@ IDTVEC(ipi_invlrange)
 KIDTVEC(recurse_lapic_ltimer)
 	INTR_RECURSE_HWFRAME
 	pushq	$0
-	subq	$8,%rsp			/* unused __if_trapno */
+	subq	$8,%rsp			/* if_ppl filled in below */
 	INTR_REENTRY
 	jmp	1f
 IDTVEC(intr_lapic_ltimer)
 	pushq	$0
-	subq	$8,%rsp			/* unused __if_trapno */
+	subq	$8,%rsp			/* if_ppl filled in below */
 	INTRENTRY(intr_lapic_ltimer)
 	CODEPATCH_START
 	movl	$0,_C_LABEL(local_apic)+LAPIC_EOI
@@ -576,7 +576,7 @@ KIDTVEC_FALLTHROUGH(resume_lapic_ltimer)
 	sti
 	cld
 	SMAP_CLAC
-	pushq	%rbx
+	movq	%rbx,IF_PPL(%rsp)
 	xorq	%rdi,%rdi
 	call	_C_LABEL(lapic_clockintr)
 	jmp	_C_LABEL(Xdoreti)
@@ -593,12 +593,12 @@ KIDTVEC_FALLTHROUGH(resume_lapic_ltimer)
 KIDTVEC(recurse_xen_upcall)
 	INTR_RECURSE_HWFRAME
 	pushq	$0
-	subq	$8,%rsp			/* unused __if_trapno */
+	subq	$8,%rsp			/* if_ppl filled in below */
 	INTR_REENTRY
 	jmp	1f
 IDTVEC(intr_xen_upcall)
 	pushq	$0
-	subq	$8,%rsp			/* unused __if_trapno */
+	subq	$8,%rsp			/* if_ppl filled in below */
 	INTRENTRY(intr_xen_upcall)
 	call	_C_LABEL(xen_intr_ack)
 	movl	CPUVAR(ILEVEL),%ebx
@@ -611,7 +611,7 @@ KIDTVEC_FALLTHROUGH(resume_xen_upcall)
 	sti
 	cld
 	SMAP_CLAC
-	pushq	%rbx
+	movq	%rbx,IF_PPL(%rsp)
 	call	_C_LABEL(xen_intr)
 	jmp	_C_LABEL(Xdoreti)
 2:
@@ -628,12 +628,12 @@ KIDTVEC_FALLTHROUGH(resume_xen_upcall)
 KIDTVEC(recurse_hyperv_upcall)
 	INTR_RECURSE_HWFRAME
 	pushq	$0
-	subq	$8,%rsp			/* unused __if_trapno */
+	subq	$8,%rsp			/* if_ppl filled in below */
 	INTR_REENTRY
 	jmp	1f
 IDTVEC(intr_hyperv_upcall)
 	pushq	$0
-	subq	$8,%rsp			/* unused __if_trapno */
+	subq	$8,%rsp			/* if_ppl filled in below */
 	INTRENTRY(intr_hyperv_upcall)
 	movl	CPUVAR(ILEVEL),%ebx
 	cmpl	$IPL_NET,%ebx
@@ -645,7 +645,7 @@ KIDTVEC_FALLTHROUGH(resume_hyperv_upcall)
 	sti
 	cld
 	SMAP_CLAC
-	pushq	%rbx
+	movq	%rbx,IF_PPL(%rsp)
 	call	_C_LABEL(hv_intr)
 	jmp	_C_LABEL(Xdoreti)
 2:
@@ -666,7 +666,7 @@ KIDTVEC_FALLTHROUGH(resume_hyperv_upcall)
 #define	INTRSTUB(name, num, early_ack, late_ack, mask, unmask, level_mask) \
 KIDTVEC(recurse_##name##num)						;\
 	INTR_RECURSE_HWFRAME						;\
-	subq	$16,%rsp		/* space for __if_{trapno,err} */;\
+	subq	$16,%rsp		/* space for if_{ppl,err} */	;\
 	INTR_REENTRY							;\
 KIDTVEC_FALLTHROUGH(resume_##name##num)					\
 	movq	$IREENT_MAGIC,TF_ERR(%rsp)				;\
@@ -676,7 +676,7 @@ KIDTVEC_FALLTHROUGH(resume_##name##num)					\
 	jmp	1f							;\
 IDTVEC(intr_##name##num)						;\
 	pushq	$0			/* dummy error code */		;\
-	subq	$8,%rsp			/* unused __if_trapno */	;\
+	subq	$8,%rsp			/* if_ppl filled in below */	;\
 	INTRENTRY(intr_##name##num)					;\
 	movq	CPUVAR(ISOURCES) + (num) * 8, %r14			;\
 	mask(num)			/* mask it in hardware */	;\
@@ -689,7 +689,7 @@ IDTVEC(intr_##name##num)						;\
 	cmpl	%ebx,%r13d						;\
 	jae	10f			/* currently masked; hold it */	;\
 1:									\
-	pushq	%r13							;\
+	movq	%r13,IF_PPL(%rsp)					;\
 	movl	%ebx,CPUVAR(ILEVEL)					;\
 	sti								;\
 	cld								;\
diff --git a/sys/arch/amd64/include/frame.h b/sys/arch/amd64/include/frame.h
index c6a152398eb..68b72ec04db 100644
--- a/sys/arch/amd64/include/frame.h
+++ b/sys/arch/amd64/include/frame.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: frame.h,v 1.8 2018/04/26 12:47:02 guenther Exp $	*/
+/*	$OpenBSD: frame.h,v 1.9 2018/07/03 20:15:57 guenther Exp $	*/
 /*	$NetBSD: frame.h,v 1.1 2003/04/26 18:39:40 fvdl Exp $	*/
 
 /*-
@@ -116,7 +116,6 @@ struct trapframe {
  * Interrupt stack frame
  */
 struct intrframe {
-	int64_t	if_ppl;
 	int64_t	if_rdi;
 	int64_t	if_rsi;
 	int64_t	if_rdx;
@@ -129,14 +128,14 @@ struct intrframe {
 	int64_t if_r13;
 	int64_t if_r14;
 	int64_t if_r15;
-	u_int64_t __if_err;	/* for compat with trap frame - err */
+	int64_t	if_err;		/* IREENT_MAGIC if resume/recurse */
 	int64_t	if_rbx;
 	int64_t	if_rax;
 	int64_t	tf_gs;
 	int64_t	tf_fs;
 	int64_t	tf_es;
 	int64_t	tf_ds;
-	u_int64_t __if_trapno; /* for compat with trap frame - trapno */
+	int64_t if_ppl;		/* previous priority level */
 	int64_t	if_rbp;
 	/* below portion defined in hardware */
 	int64_t	if_rip;
diff --git a/sys/arch/amd64/include/i82093reg.h b/sys/arch/amd64/include/i82093reg.h
index e1fcfc9cd45..6f80d399a34 100644
--- a/sys/arch/amd64/include/i82093reg.h
+++ b/sys/arch/amd64/include/i82093reg.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: i82093reg.h,v 1.6 2016/06/29 06:05:15 mlarkin Exp $	*/
+/*	$OpenBSD: i82093reg.h,v 1.7 2018/07/03 20:15:57 guenther Exp $	*/
 /* 	$NetBSD: i82093reg.h,v 1.1 2003/02/26 21:26:10 fvdl Exp $ */
 
 /*-
@@ -160,7 +160,7 @@
 	ioapic_asm_unlock(num)
 
 #define ioapic_unmask(num) \
-	cmpq	$IREENT_MAGIC,(TF_ERR+8)(%rsp)			;\
+	cmpq	$IREENT_MAGIC,IF_ERR(%rsp)			;\
 	jne	79f						;\
 	movq	IS_PIC(%r14),%rdi				;\
 	ioapic_asm_lock(num)					;\