From 1b4a394fde7ee125bb7af82662ad3ea96d51265f Mon Sep 17 00:00:00 2001
From: guenther <guenther@openbsd.org>
Date: Sun, 30 Oct 2022 17:43:39 +0000
Subject: [PATCH] Simplfity setregs() by passing it the ps_strings and
 switching sys_execve() to return EJUSTRETURN.

setregs() is the MD routine used by sys_execve() to set up the
thread's trapframe and PCB such that, on 'return' to userspace, it
has the register values defined by the ABI and otherwise zero.  It
had to set the syscall retval[] values previously because the normal
syscall return path overwrites a couple registers with the retval[]
values.  By instead returning EJUSTRETURN that and some complexity
with program-counter handling on m88k and sparc64 goes away.

Also, give setregs() add a 'struct ps_strings *arginfo' argument
so powerpc, powerpc64, and sh can directly get argc/argv/envp
values for registers instead of copyin()ing the one in userspace.

Improvements from miod@ and millert@
Testing assistance miod@, kettenis@, and aoyama@
ok miod@ kettenis@
---
 sys/arch/alpha/alpha/machdep.c          | 15 +++----
 sys/arch/amd64/amd64/machdep.c          | 22 ++---------
 sys/arch/arm/arm/arm_machdep.c          |  8 ++--
 sys/arch/arm64/arm64/machdep.c          |  8 ++--
 sys/arch/hppa/hppa/machdep.c            | 17 +++-----
 sys/arch/i386/i386/machdep.c            |  6 +--
 sys/arch/m88k/m88k/m88k_machdep.c       | 52 ++++++++++---------------
 sys/arch/macppc/macppc/machdep.c        | 19 ++++-----
 sys/arch/mips64/mips64/mips64_machdep.c | 18 ++++-----
 sys/arch/powerpc64/powerpc64/machdep.c  | 13 +++----
 sys/arch/riscv64/riscv64/machdep.c      |  8 ++--
 sys/arch/sh/sh/sh_machdep.c             | 12 +++---
 sys/arch/sparc64/sparc64/machdep.c      | 11 ++----
 sys/kern/init_main.c                    |  4 +-
 sys/kern/kern_exec.c                    |  9 +++--
 sys/sys/exec.h                          |  5 ++-
 16 files changed, 86 insertions(+), 141 deletions(-)

diff --git a/sys/arch/alpha/alpha/machdep.c b/sys/arch/alpha/alpha/machdep.c
index f4687ad2349..9bdb9337518 100644
--- a/sys/arch/alpha/alpha/machdep.c
+++ b/sys/arch/alpha/alpha/machdep.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: machdep.c,v 1.198 2022/08/10 10:41:35 miod Exp $ */
+/* $OpenBSD: machdep.c,v 1.199 2022/10/30 17:43:39 guenther Exp $ */
 /* $NetBSD: machdep.c,v 1.210 2000/06/01 17:12:38 thorpej Exp $ */
 
 /*-
@@ -1595,11 +1595,8 @@ cpu_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
  * Set registers on exec.
  */
 void
-setregs(p, pack, stack, retval)
-	register struct proc *p;
-	struct exec_package *pack;
-	u_long stack;
-	register_t *retval;
+setregs(struct proc *p, struct exec_package *pack, u_long stack,
+    struct ps_strings *arginfo)
 {
 	struct trapframe *tfp = p->p_md.md_tf;
 #ifdef DEBUG
@@ -1619,9 +1616,9 @@ setregs(p, pack, stack, retval)
 		tfp->tf_regs[i] = 0xbabefacedeadbeef;
 	tfp->tf_regs[FRAME_A1] = 0;
 #else
-	bzero(tfp->tf_regs, FRAME_SIZE * sizeof tfp->tf_regs[0]);
+	memset(tfp->tf_regs, 0, FRAME_SIZE * sizeof tfp->tf_regs[0]);
 #endif
-	bzero(&p->p_addr->u_pcb.pcb_fp, sizeof p->p_addr->u_pcb.pcb_fp);
+	memset(&p->p_addr->u_pcb.pcb_fp, 0, sizeof p->p_addr->u_pcb.pcb_fp);
 	alpha_pal_wrusp(stack);
 	tfp->tf_regs[FRAME_PS] = ALPHA_PSL_USERSET;
 	tfp->tf_regs[FRAME_PC] = pack->ep_entry & ~3;
@@ -1639,8 +1636,6 @@ setregs(p, pack, stack, retval)
 #endif
 	if (p->p_addr->u_pcb.pcb_fpcpu != NULL)
 		fpusave_proc(p, 0);
-
-	retval[1] = 0;
 }
 
 /*
diff --git a/sys/arch/amd64/amd64/machdep.c b/sys/arch/amd64/amd64/machdep.c
index 03d11d98d20..b733ce6575f 100644
--- a/sys/arch/amd64/amd64/machdep.c
+++ b/sys/arch/amd64/amd64/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.281 2022/10/16 15:03:39 kettenis Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.282 2022/10/30 17:43:39 guenther Exp $	*/
 /*	$NetBSD: machdep.c,v 1.3 2003/05/07 22:58:18 fvdl Exp $	*/
 
 /*-
@@ -1138,7 +1138,7 @@ reset_segs(void)
  */
 void
 setregs(struct proc *p, struct exec_package *pack, u_long stack,
-    register_t *retval)
+    struct ps_strings *arginfo)
 {
 	struct trapframe *tf;
 
@@ -1161,28 +1161,12 @@ setregs(struct proc *p, struct exec_package *pack, u_long stack,
 	p->p_addr->u_pcb.pcb_fsbase = 0;
 
 	tf = p->p_md.md_regs;
-	tf->tf_rdi = 0;
-	tf->tf_rsi = 0;
-	tf->tf_rbp = 0;
-	tf->tf_rbx = 0;
-	tf->tf_rdx = 0;
-	tf->tf_rcx = 0;
-	tf->tf_rax = 0;
-	tf->tf_r8 = 0;
-	tf->tf_r9 = 0;
-	tf->tf_r10 = 0;
-	tf->tf_r11 = 0;
-	tf->tf_r12 = 0;
-	tf->tf_r13 = 0;
-	tf->tf_r14 = 0;
-	tf->tf_r15 = 0;
+	memset(tf, 0, sizeof *tf);
 	tf->tf_rip = pack->ep_entry;
 	tf->tf_cs = GSEL(GUCODE_SEL, SEL_UPL);
 	tf->tf_rflags = PSL_USERSET;
 	tf->tf_rsp = stack;
 	tf->tf_ss = GSEL(GUDATA_SEL, SEL_UPL);
-
-	retval[1] = 0;
 }
 
 /*
diff --git a/sys/arch/arm/arm/arm_machdep.c b/sys/arch/arm/arm/arm_machdep.c
index 0ec7aaf887c..7ae0c884610 100644
--- a/sys/arch/arm/arm/arm_machdep.c
+++ b/sys/arch/arm/arm/arm_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: arm_machdep.c,v 1.6 2021/03/25 04:12:00 jsg Exp $	*/
+/*	$OpenBSD: arm_machdep.c,v 1.7 2022/10/30 17:43:39 guenther Exp $	*/
 /*	$NetBSD: arm_machdep.c,v 1.7 2003/10/25 19:44:42 scw Exp $	*/
 
 /*
@@ -99,7 +99,7 @@ vaddr_t	vector_page;
 
 void
 setregs(struct proc *p, struct exec_package *pack, u_long stack,
-    register_t *retval)
+    struct ps_strings *arginfo)
 {
 	struct trapframe *tf;
 
@@ -110,13 +110,11 @@ setregs(struct proc *p, struct exec_package *pack, u_long stack,
 
 	tf = p->p_addr->u_pcb.pcb_tf;
 
-	memset(tf, 0, sizeof(*tf));
+	memset(tf, 0, sizeof *tf);
 /*	tf->tf_r0 = (u_int)p->p_proc->p_psstr; */
 	tf->tf_usr_sp = stack;
 	tf->tf_usr_lr = pack->ep_entry;
 	tf->tf_svc_lr = 0x77777777;		/* Something we can see */
 	tf->tf_pc = pack->ep_entry;
 	tf->tf_spsr = PSR_USR32_MODE;
-
-	retval[1] = 0;
 }
diff --git a/sys/arch/arm64/arm64/machdep.c b/sys/arch/arm64/arm64/machdep.c
index 6a1ad68c88f..31b0e2f472c 100644
--- a/sys/arch/arm64/arm64/machdep.c
+++ b/sys/arch/arm64/arm64/machdep.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: machdep.c,v 1.74 2022/10/04 19:41:21 kettenis Exp $ */
+/* $OpenBSD: machdep.c,v 1.75 2022/10/30 17:43:39 guenther Exp $ */
 /*
  * Copyright (c) 2014 Patrick Wildt <patrick@blueri.se>
  * Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
@@ -419,7 +419,7 @@ doreset:
 
 void
 setregs(struct proc *p, struct exec_package *pack, u_long stack,
-    register_t *retval)
+    struct ps_strings *arginfo)
 {
 	struct pcb *pcb = &p->p_addr->u_pcb;
 	struct trapframe *tf = pcb->pcb_tf;
@@ -429,13 +429,11 @@ setregs(struct proc *p, struct exec_package *pack, u_long stack,
 	pcb->pcb_flags &= ~PCB_FPU;
 	fpu_drop();
 
-	memset (tf,0, sizeof(*tf));
+	memset(tf, 0, sizeof *tf);
 	tf->tf_sp = stack;
 	tf->tf_lr = pack->ep_entry;
 	tf->tf_elr = pack->ep_entry; /* ??? */
 	tf->tf_spsr = PSR_M_EL0t | PSR_DIT;
-
-	retval[1] = 0;
 }
 
 void
diff --git a/sys/arch/hppa/hppa/machdep.c b/sys/arch/hppa/hppa/machdep.c
index d0ac0010e5a..71219263cf6 100644
--- a/sys/arch/hppa/hppa/machdep.c
+++ b/sys/arch/hppa/hppa/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.266 2022/08/10 03:18:19 jsg Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.267 2022/10/30 17:43:39 guenther Exp $	*/
 
 /*
  * Copyright (c) 1999-2003 Michael Shalayeff
@@ -1158,12 +1158,13 @@ setstack(struct trapframe *tf, u_long stack, register_t old_r3)
  */
 void
 setregs(struct proc *p, struct exec_package *pack, u_long stack,
-    register_t *retval)
+    struct ps_strings *arginfo)
 {
 	struct trapframe *tf = p->p_md.md_regs;
 	struct pcb *pcb = &p->p_addr->u_pcb;
+	struct fpreg *fpreg = &pcb->pcb_fpstate->hfp_regs;
 
-	bzero(tf, sizeof(*tf));
+	memset(tf, 0, sizeof *tf);
 	tf->tf_flags = TFF_SYS|TFF_LAST;
 	tf->tf_iioq_head = pack->ep_entry | HPPA_PC_PRIV_USER;
 	tf->tf_iioq_tail = tf->tf_iioq_head + 4;
@@ -1190,16 +1191,10 @@ setregs(struct proc *p, struct exec_package *pack, u_long stack,
 
 	/* clear the FPU */
 	fpu_proc_flush(p);
-	bzero(&pcb->pcb_fpstate->hfp_regs, sizeof(pcb->pcb_fpstate->hfp_regs));
-	pcb->pcb_fpstate->hfp_regs.fpr_regs[0] =
-	    ((u_int64_t)HPPA_FPU_INIT) << 32;
-	pcb->pcb_fpstate->hfp_regs.fpr_regs[1] = 0;
-	pcb->pcb_fpstate->hfp_regs.fpr_regs[2] = 0;
-	pcb->pcb_fpstate->hfp_regs.fpr_regs[3] = 0;
+	memset(fpreg, 0, sizeof *fpreg);
+	fpreg->fpr_regs[0] = ((u_int64_t)HPPA_FPU_INIT) << 32;
 
 	p->p_md.md_bpva = 0;
-
-	retval[1] = 0;
 }
 
 /*
diff --git a/sys/arch/i386/i386/machdep.c b/sys/arch/i386/i386/machdep.c
index 8611a2c5dcf..62e2c88bde7 100644
--- a/sys/arch/i386/i386/machdep.c
+++ b/sys/arch/i386/i386/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.656 2022/08/25 17:25:25 cheloha Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.657 2022/10/30 17:43:39 guenther Exp $	*/
 /*	$NetBSD: machdep.c,v 1.214 1996/11/10 03:16:17 thorpej Exp $	*/
 
 /*-
@@ -2858,7 +2858,7 @@ dumpsys(void)
  */
 void
 setregs(struct proc *p, struct exec_package *pack, u_long stack,
-    register_t *retval)
+    struct ps_strings *arginfo)
 {
 	struct pcb *pcb = &p->p_addr->u_pcb;
 	struct pmap *pmap = vm_map_pmap(&p->p_vmspace->vm_map);
@@ -2906,8 +2906,6 @@ setregs(struct proc *p, struct exec_package *pack, u_long stack,
 	tf->tf_eflags = PSL_USERSET;
 	tf->tf_esp = stack;
 	tf->tf_ss = GSEL(GUDATA_SEL, SEL_UPL);
-
-	retval[1] = 0;
 }
 
 /*
diff --git a/sys/arch/m88k/m88k/m88k_machdep.c b/sys/arch/m88k/m88k/m88k_machdep.c
index 0a32f419679..85ab0510cba 100644
--- a/sys/arch/m88k/m88k/m88k_machdep.c
+++ b/sys/arch/m88k/m88k/m88k_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: m88k_machdep.c,v 1.70 2019/10/15 10:05:43 mpi Exp $	*/
+/*	$OpenBSD: m88k_machdep.c,v 1.71 2022/10/30 17:43:39 guenther Exp $	*/
 /*
  * Copyright (c) 1998, 1999, 2000, 2001 Steve Murphree, Jr.
  * Copyright (c) 1996 Nivas Madhur
@@ -112,11 +112,8 @@ int   safepri = IPL_NONE;
  * Clear all except sp and pc.
  */
 void
-setregs(p, pack, stack, retval)
-	struct proc *p;
-	struct exec_package *pack;
-	u_long stack;
-	register_t retval[2];
+setregs(struct proc *p, struct exec_package *pack, u_long stack,
+    struct ps_strings *arginfo)
 {
 	struct trapframe *tf = (struct trapframe *)USER_REGS(p);
 
@@ -131,7 +128,7 @@ setregs(p, pack, stack, retval)
 	__asm__ volatile ("fstcr %r0, %fcr62");
 	__asm__ volatile ("fstcr %r0, %fcr63");
 
-	bzero((caddr_t)tf, sizeof *tf);
+	memset(tf, 0, sizeof *tf);
 
 #ifdef M88110
 	if (CPU_IS88110) {
@@ -171,38 +168,29 @@ setregs(p, pack, stack, retval)
 	 */
 #ifdef M88110
 	if (CPU_IS88110) {
-		/*
-		 * m88110_syscall() will resume at exip + 8... which
-		 * really is the first instruction we want to run.
-		 */
-		tf->tf_exip = pack->ep_entry & XIP_ADDR;
+                /*
+                 * The first instruction we want to run is at
+                 * ep_entry + 8. m88110_syscall() returning EJUSTRETURN
+                 * will resume at exip + 4, so make it point to
+                 * ep_entry + 4.
+                 */
+		tf->tf_exip = (pack->ep_entry & XIP_ADDR) + 4;
 	}
 #endif
 #ifdef M88100
 	if (CPU_IS88100) {
-		/*
-		 * m88100_syscall() will resume at sfip / sfip + 4...
-		 */
-		tf->tf_sfip = ((pack->ep_entry + 8) & FIP_ADDR) | FIP_V;
-
-		/*
-		 * ... unless we are starting init, in which case we
-		 * won't be returning through the regular path, and
-		 * need to explicitly set up nip and fip (note that
-		 * 88110 do not need such a test).
-		 * Note that this isn't 100% correct, as it mishandles
-		 * a real execve() from userspace by process 1.  However
-		 * our init will never do that, so it's okay.
-		 */
-		if (p->p_p->ps_pid == 1) {
-			tf->tf_snip = tf->tf_sfip;
-			tf->tf_sfip += 4;
-		}
+                /*
+                 * The first instruction we want to run is at
+                 * ep_entry + 8. m88100_syscall() returning EJUSTRETURN
+                 * will resume at snip, so make it point to
+                 * ep_entry + 8.
+                 */
+		tf->tf_snip = ((pack->ep_entry + 8) & FIP_ADDR) | FIP_V;
+		tf->tf_sfip = tf->tf_snip + 4;
 	}
 #endif
-	tf->tf_r[2] = retval[0] = stack;
+	tf->tf_r[2] = stack;
 	tf->tf_r[31] = stack;
-	retval[1] = 0;
 }
 
 int
diff --git a/sys/arch/macppc/macppc/machdep.c b/sys/arch/macppc/macppc/machdep.c
index c6f09bb9b9c..1406c18f36a 100644
--- a/sys/arch/macppc/macppc/machdep.c
+++ b/sys/arch/macppc/macppc/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.198 2022/10/21 22:42:36 gkoehler Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.199 2022/10/30 17:43:39 guenther Exp $	*/
 /*	$NetBSD: machdep.c,v 1.4 1996/10/16 19:33:11 ws Exp $	*/
 
 /*
@@ -418,24 +418,21 @@ consinit(void)
  */
 void
 setregs(struct proc *p, struct exec_package *pack, u_long stack,
-    register_t *retval)
+    struct ps_strings *arginfo)
 {
 	u_int32_t newstack;
 	u_int32_t pargs;
-	u_int32_t args[4];
-
 	struct trapframe *tf = trapframe(p);
+
 	pargs = -roundup(-stack + 8, 16);
 	newstack = (u_int32_t)(pargs - 32);
 
-	copyin ((void *)p->p_p->ps_strings, &args, 0x10);
-
-	bzero(tf, sizeof *tf);
+	memset(tf, 0, sizeof *tf);
 	tf->fixreg[1] = newstack;
-	tf->fixreg[3] = retval[0] = args[1];	/* XXX */
-	tf->fixreg[4] = retval[1] = args[0];	/* XXX */
-	tf->fixreg[5] = args[2];		/* XXX */
-	tf->fixreg[6] = args[3];		/* XXX */
+	tf->fixreg[3] = arginfo->ps_nargvstr;
+	tf->fixreg[4] = (register_t)arginfo->ps_argvstr;
+	tf->fixreg[5] = (register_t)arginfo->ps_envstr;
+	tf->fixreg[6] = arginfo->ps_nenvstr;
 	tf->srr0 = pack->ep_entry;
 	tf->srr1 = PSL_MBO | PSL_USERSET | PSL_FE_DFLT;
 	p->p_addr->u_pcb.pcb_flags = 0;
diff --git a/sys/arch/mips64/mips64/mips64_machdep.c b/sys/arch/mips64/mips64/mips64_machdep.c
index 77e452440a9..fb5a0fdc233 100644
--- a/sys/arch/mips64/mips64/mips64_machdep.c
+++ b/sys/arch/mips64/mips64/mips64_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mips64_machdep.c,v 1.38 2022/08/22 00:35:06 cheloha Exp $ */
+/*	$OpenBSD: mips64_machdep.c,v 1.39 2022/10/30 17:43:39 guenther Exp $ */
 
 /*
  * Copyright (c) 2009, 2010, 2012 Miodrag Vallat.
@@ -137,21 +137,21 @@ register_t protosr = SR_FR_32 | SR_XX | SR_UX | SR_KSU_USER | SR_EXL |
  */
 void
 setregs(struct proc *p, struct exec_package *pack, u_long stack,
-    register_t *retval)
+    struct ps_strings *arginfo)
 {
 	struct cpu_info *ci = curcpu();
+	struct trapframe *tf = p->p_md.md_regs;
+
+	memset(tf, 0, sizeof *tf);
+	tf->sp = stack;
+	tf->pc = pack->ep_entry & ~3;
+	tf->t9 = pack->ep_entry & ~3; /* abicall req */
+	tf->sr = protosr | (idle_mask & SR_INT_MASK);
 
-	bzero((caddr_t)p->p_md.md_regs, sizeof(struct trapframe));
-	p->p_md.md_regs->sp = stack;
-	p->p_md.md_regs->pc = pack->ep_entry & ~3;
-	p->p_md.md_regs->t9 = pack->ep_entry & ~3; /* abicall req */
-	p->p_md.md_regs->sr = protosr | (idle_mask & SR_INT_MASK);
 	if (CPU_HAS_FPU(ci))
 		p->p_md.md_flags &= ~MDP_FPUSED;
 	if (ci->ci_fpuproc == p)
 		ci->ci_fpuproc = NULL;
-
-	retval[1] = 0;
 }
 
 int
diff --git a/sys/arch/powerpc64/powerpc64/machdep.c b/sys/arch/powerpc64/powerpc64/machdep.c
index 37f482cdd96..df73b09ee64 100644
--- a/sys/arch/powerpc64/powerpc64/machdep.c
+++ b/sys/arch/powerpc64/powerpc64/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.72 2022/05/19 05:43:48 miod Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.73 2022/10/30 17:43:39 guenther Exp $	*/
 
 /*
  * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
@@ -887,19 +887,16 @@ parse_bootmac(const char *bootarg)
 
 void
 setregs(struct proc *p, struct exec_package *pack, u_long stack,
-    register_t *retval)
+    struct ps_strings *arginfo)
 {
 	struct trapframe *frame = p->p_md.md_regs;
 	struct pcb *pcb = &p->p_addr->u_pcb;
-	struct ps_strings arginfo;
-
-	copyin((void *)p->p_p->ps_strings, &arginfo, sizeof(arginfo));
 
 	memset(frame, 0, sizeof(*frame));
 	frame->fixreg[1] = stack;
-	frame->fixreg[3] = retval[0] = arginfo.ps_nargvstr;
-	frame->fixreg[4] = retval[1] = (register_t)arginfo.ps_argvstr;
-	frame->fixreg[5] = (register_t)arginfo.ps_envstr;
+	frame->fixreg[3] = arginfo->ps_nargvstr;
+	frame->fixreg[4] = (register_t)arginfo->ps_argvstr;
+	frame->fixreg[5] = (register_t)arginfo->ps_envstr;
 	frame->fixreg[6] = (register_t)pack->ep_auxinfo;
 	frame->fixreg[12] = pack->ep_entry;
 	frame->srr0 = pack->ep_entry;
diff --git a/sys/arch/riscv64/riscv64/machdep.c b/sys/arch/riscv64/riscv64/machdep.c
index 6685ad9481c..61ea8541113 100644
--- a/sys/arch/riscv64/riscv64/machdep.c
+++ b/sys/arch/riscv64/riscv64/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.28 2022/10/03 19:32:22 kettenis Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.29 2022/10/30 17:43:40 guenther Exp $	*/
 
 /*
  * Copyright (c) 2014 Patrick Wildt <patrick@blueri.se>
@@ -407,7 +407,7 @@ doreset:
 
 void
 setregs(struct proc *p, struct exec_package *pack, u_long stack,
-    register_t *retval)
+    struct ps_strings *arginfo)
 {
 	struct trapframe *tf = p->p_addr->u_pcb.pcb_tf;
 	struct pcb *pcb = &p->p_addr->u_pcb;
@@ -417,12 +417,10 @@ setregs(struct proc *p, struct exec_package *pack, u_long stack,
 	tf->tf_sstatus &= ~SSTATUS_FS_MASK;
 	tf->tf_sstatus |= SSTATUS_FS_OFF;
 
-	memset(tf, 0, sizeof(*tf));
+	memset(tf, 0, sizeof *tf);
 	tf->tf_sp = STACKALIGN(stack);
 	tf->tf_ra = pack->ep_entry;
 	tf->tf_sepc = pack->ep_entry;
-
-	retval[1] = 0;
 }
 
 void
diff --git a/sys/arch/sh/sh/sh_machdep.c b/sys/arch/sh/sh/sh_machdep.c
index 07b4f31c0f5..7c767a8a83c 100644
--- a/sys/arch/sh/sh/sh_machdep.c
+++ b/sys/arch/sh/sh/sh_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sh_machdep.c,v 1.54 2022/02/21 10:51:36 jsg Exp $	*/
+/*	$OpenBSD: sh_machdep.c,v 1.55 2022/10/30 17:43:40 guenther Exp $	*/
 /*	$NetBSD: sh3_machdep.c,v 1.59 2006/03/04 01:13:36 uwe Exp $	*/
 
 /*
@@ -561,7 +561,7 @@ sys_sigreturn(struct proc *p, void *v, register_t *retval)
  */
 void
 setregs(struct proc *p, struct exec_package *pack, u_long stack,
-    register_t rval[2])
+    struct ps_strings *arginfo)
 {
 	struct trapframe *tf;
 	struct pcb *pcb = p->p_md.md_pcb;
@@ -578,9 +578,9 @@ setregs(struct proc *p, struct exec_package *pack, u_long stack,
 	tf->tf_r1 = 0;
 	tf->tf_r2 = 0;
 	tf->tf_r3 = 0;
-	copyin((caddr_t)stack, &tf->tf_r4, sizeof(register_t));	/* argc */
-	tf->tf_r5 = stack + 4;			/* argv */
-	tf->tf_r6 = stack + 4 * tf->tf_r4 + 8;	/* envp */
+	tf->tf_r4 = arginfo->ps_nargvstr;
+	tf->tf_r5 = (register_t)arginfo->ps_argvstr;
+	tf->tf_r6 = (register_t)arginfo->ps_envstr;
 	tf->tf_r7 = 0;
 	tf->tf_r8 = 0;
 	tf->tf_r9 = (int)p->p_p->ps_strings;
@@ -603,8 +603,6 @@ setregs(struct proc *p, struct exec_package *pack, u_long stack,
 		fpu_restore(&pcb->pcb_fp);
 	}
 #endif
-
-	rval[1] = 0;
 }
 
 /*
diff --git a/sys/arch/sparc64/sparc64/machdep.c b/sys/arch/sparc64/sparc64/machdep.c
index d9e8311c7c2..40b05e5c07c 100644
--- a/sys/arch/sparc64/sparc64/machdep.c
+++ b/sys/arch/sparc64/sparc64/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.204 2022/10/25 06:05:57 guenther Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.205 2022/10/30 17:43:40 guenther Exp $	*/
 /*	$NetBSD: machdep.c,v 1.108 2001/07/24 19:30:14 eeh Exp $ */
 
 /*-
@@ -257,10 +257,9 @@ cpu_startup(void)
 
 #define CPOUTREG(l,v)	copyout(&(v), (l), sizeof(v))
 
-/* ARGSUSED */
 void
-setregs(struct proc *p, struct exec_package *pack, vaddr_t stack,
-    register_t *retval)
+setregs(struct proc *p, struct exec_package *pack, u_long stack,
+    struct ps_strings *arginfo)
 {
 	struct trapframe *tf = p->p_md.md_tf;
 	int64_t tstate;
@@ -324,18 +323,16 @@ setregs(struct proc *p, struct exec_package *pack, vaddr_t stack,
 		free(p->p_md.md_fpstate, M_SUBPROC, sizeof(struct fpstate));
 		p->p_md.md_fpstate = NULL;
 	}
-	bzero((caddr_t)tf, sizeof *tf);
+	memset(tf, 0, sizeof *tf);
 	tf->tf_tstate = tstate;
 	tf->tf_pc = pack->ep_entry & ~3;
 	tf->tf_npc = tf->tf_pc + 4;
-	tf->tf_global[2] = tf->tf_pc;
 	stack -= sizeof(struct rwindow);
 	tf->tf_out[6] = stack - BIAS;
 #ifdef NOTDEF_DEBUG
 	printf("setregs: setting tf %p sp %p pc %p\n", (long)tf, 
 	       (long)tf->tf_out[6], (long)tf->tf_pc);
 #endif
-	retval[1] = 0;
 }
 
 struct sigframe {
diff --git a/sys/kern/init_main.c b/sys/kern/init_main.c
index 4e0d2e4497f..be9348c0b15 100644
--- a/sys/kern/init_main.c
+++ b/sys/kern/init_main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: init_main.c,v 1.317 2022/08/14 01:58:27 jsg Exp $	*/
+/*	$OpenBSD: init_main.c,v 1.318 2022/10/30 17:43:40 guenther Exp $	*/
 /*	$NetBSD: init_main.c,v 1.84.4.1 1996/06/02 09:08:06 mrg Exp $	*/
 
 /*
@@ -710,7 +710,7 @@ start_init(void *arg)
 		 * Now try to exec the program.  If can't for any reason
 		 * other than it doesn't exist, complain.
 		 */
-		if ((error = sys_execve(p, &args, retval)) == 0) {
+		if ((error = sys_execve(p, &args, retval)) == EJUSTRETURN) {
 			KERNEL_UNLOCK();
 			return;
 		}
diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index f41c9c61cf2..06a8f67c554 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_exec.c,v 1.237 2022/10/21 19:13:31 deraadt Exp $	*/
+/*	$OpenBSD: kern_exec.c,v 1.238 2022/10/30 17:43:40 guenther Exp $	*/
 /*	$NetBSD: kern_exec.c,v 1.75 1996/02/09 18:59:28 christos Exp $	*/
 
 /*-
@@ -679,9 +679,9 @@ sys_execve(struct proc *p, void *v, register_t *retval)
 	if (exec_elf_fixup(p, &pack) != 0)
 		goto free_pack_abort;
 #ifdef MACHINE_STACK_GROWS_UP
-	setregs(p, &pack, (u_long)stack + slen, retval);
+	setregs(p, &pack, (u_long)stack + slen, &arginfo);
 #else
-	setregs(p, &pack, (u_long)stack, retval);
+	setregs(p, &pack, (u_long)stack, &arginfo);
 #endif
 
 	/* map the process's signal trampoline code */
@@ -711,7 +711,8 @@ sys_execve(struct proc *p, void *v, register_t *retval)
 	atomic_clearbits_int(&pr->ps_flags, PS_INEXEC);
 	single_thread_clear(p, P_SUSPSIG);
 
-	return (0);
+	/* setregs() sets up all the registers, so just 'return' */
+	return EJUSTRETURN;
 
 bad:
 	/* free the vmspace-creation commands, and release their references */
diff --git a/sys/sys/exec.h b/sys/sys/exec.h
index 40c71732d6a..d083c6d4ec4 100644
--- a/sys/sys/exec.h
+++ b/sys/sys/exec.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: exec.h,v 1.50 2022/10/27 22:48:17 deraadt Exp $	*/
+/*	$OpenBSD: exec.h,v 1.51 2022/10/30 17:43:40 guenther Exp $	*/
 /*	$NetBSD: exec.h,v 1.59 1996/02/09 18:25:09 christos Exp $	*/
 
 /*-
@@ -152,7 +152,8 @@ int	vmcmd_map_zero(struct proc *, struct exec_vmcmd *);
 int	vmcmd_mutable(struct proc *, struct exec_vmcmd *);
 int	vmcmd_randomize(struct proc *, struct exec_vmcmd *);
 int	copyargs(struct exec_package *, struct ps_strings *, void *, void *);
-void	setregs(struct proc *, struct exec_package *, u_long, register_t *);
+void	setregs(struct proc *, struct exec_package *, u_long,
+	    struct ps_strings *);
 int	check_exec(struct proc *, struct exec_package *);
 int	exec_setup_stack(struct proc *, struct exec_package *);
 int	exec_process_vmcmds(struct proc *, struct exec_package *);
-- 
2.20.1