Clean up more ancient history: since 2015 the libc stubs for

fork/vfork/__tfork haven't cared about the second return register.
So, stop setting retval[1] in kern_fork.c and stop setting the
second return register in the MD child_return() routines.

With the above, we have no multi-register return values on LP64,
so stop touching that register in the trapframe on those archs.

testing miod@ and aoyama@
ok miod@

diff --git a/sys/arch/alpha/alpha/trap.c b/sys/arch/alpha/alpha/trap.c
index 3541c81..a0379b9 100644 (file)
--- a/sys/arch/alpha/alpha/trap.c
+++ b/sys/arch/alpha/alpha/trap.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: trap.c,v 1.103 2022/08/29 06:08:03 jsg Exp $ */
+/* $OpenBSD: trap.c,v 1.104 2022/11/02 07:20:07 guenther Exp $ */
 /* $NetBSD: trap.c,v 1.52 2000/05/24 16:48:33 thorpej Exp $ */
 
 /*-
@@ -569,7 +569,6 @@ syscall(code, framep)
        switch (error) {
        case 0:
                framep->tf_regs[FRAME_V0] = rval[0];
-               framep->tf_regs[FRAME_A4] = rval[1];
                framep->tf_regs[FRAME_A3] = 0;
                break;
        case ERESTART:
@@ -604,7 +603,6 @@ child_return(arg)
         * Return values in the frame set by cpu_fork().
         */
        framep->tf_regs[FRAME_V0] = 0;
-       framep->tf_regs[FRAME_A4] = 0;
        framep->tf_regs[FRAME_A3] = 0;
 
        KERNEL_UNLOCK();

diff --git a/sys/arch/amd64/amd64/trap.c b/sys/arch/amd64/amd64/trap.c
index 334502b..53707fb 100644 (file)
--- a/sys/arch/amd64/amd64/trap.c
+++ b/sys/arch/amd64/amd64/trap.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: trap.c,v 1.90 2021/12/09 00:26:11 guenther Exp $      */
+/*     $OpenBSD: trap.c,v 1.91 2022/11/02 07:20:07 guenther Exp $      */
 /*     $NetBSD: trap.c,v 1.2 2003/05/04 23:51:56 fvdl Exp $    */
 
 /*-
@@ -580,14 +580,13 @@ syscall(struct trapframe *frame)
        }
 
        rval[0] = 0;
-       rval[1] = frame->tf_rdx;
+       rval[1] = 0;
 
        error = mi_syscall(p, code, callp, argp, rval);
 
        switch (error) {
        case 0:
                frame->tf_rax = rval[0];
-               frame->tf_rdx = rval[1];
                frame->tf_rflags &= ~PSL_C;     /* carry bit */
                break;
        case ERESTART:
@@ -614,7 +613,6 @@ child_return(void *arg)
        struct trapframe *tf = p->p_md.md_regs;
 
        tf->tf_rax = 0;
-       tf->tf_rdx = 1;
        tf->tf_rflags &= ~PSL_C;
 
        KERNEL_UNLOCK();

diff --git a/sys/arch/arm64/arm64/syscall.c b/sys/arch/arm64/arm64/syscall.c
index e30e6fd..84653fe 100644 (file)
--- a/sys/arch/arm64/arm64/syscall.c
+++ b/sys/arch/arm64/arm64/syscall.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: syscall.c,v 1.10 2022/01/01 18:52:36 kettenis Exp $ */
+/* $OpenBSD: syscall.c,v 1.11 2022/11/02 07:20:08 guenther Exp $ */
 /*
  * Copyright (c) 2015 Dale Rahn <drahn@dalerahn.com>
  *
@@ -82,15 +82,13 @@ svc_handler(trapframe_t *frame)
        }
 
        rval[0] = 0;
-       rval[1] = frame->tf_x[1];
+       rval[1] = 0;
 
        error = mi_syscall(p, code, callp, args, rval);
 
        switch (error) {
        case 0:
                frame->tf_x[0] = rval[0];
-               frame->tf_x[1] = rval[1];
-
                frame->tf_spsr &= ~PSR_C;       /* carry bit */
                break;
 
@@ -122,7 +120,6 @@ child_return(void *arg)
        struct trapframe *frame = p->p_addr->u_pcb.pcb_tf;
 
        frame->tf_x[0] = 0;
-       frame->tf_x[1] = 1;
        frame->tf_spsr &= ~PSR_C;       /* carry bit */
 
        KERNEL_UNLOCK();

diff --git a/sys/arch/hppa/hppa/trap.c b/sys/arch/hppa/hppa/trap.c
index d5080df..da735f4 100644 (file)
--- a/sys/arch/hppa/hppa/trap.c
+++ b/sys/arch/hppa/hppa/trap.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: trap.c,v 1.158 2022/08/12 17:19:52 miod Exp $ */
+/*     $OpenBSD: trap.c,v 1.159 2022/11/02 07:20:07 guenther Exp $     */
 
 /*
  * Copyright (c) 1998-2004 Michael Shalayeff
@@ -641,7 +641,6 @@ child_return(void *arg)
         * Set up return value registers as libc:fork() expects
         */
        tf->tf_ret0 = 0;
-       tf->tf_ret1 = 1;        /* ischild */
        tf->tf_t1 = 0;          /* errno */
 
        KERNEL_UNLOCK();

diff --git a/sys/arch/m88k/m88k/trap.c b/sys/arch/m88k/m88k/trap.c
index b1956c8..d2937db 100644 (file)
--- a/sys/arch/m88k/m88k/trap.c
+++ b/sys/arch/m88k/m88k/trap.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: trap.c,v 1.122 2022/08/12 08:31:06 jsg Exp $  */
+/*     $OpenBSD: trap.c,v 1.123 2022/11/02 07:20:07 guenther Exp $     */
 /*
  * Copyright (c) 2004, Miodrag Vallat.
  * Copyright (c) 1998 Steve Murphree, Jr.
@@ -1397,7 +1397,6 @@ child_return(arg)
 
        tf = (struct trapframe *)USER_REGS(p);
        tf->tf_r[2] = 0;
-       tf->tf_r[3] = 0;
        tf->tf_epsr &= ~PSR_C;
        /* skip br instruction as in syscall() */
 #ifdef M88100

diff --git a/sys/arch/mips64/mips64/trap.c b/sys/arch/mips64/mips64/trap.c
index f4a0691..d044afd 100644 (file)
--- a/sys/arch/mips64/mips64/trap.c
+++ b/sys/arch/mips64/mips64/trap.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: trap.c,v 1.160 2022/10/07 14:59:39 deraadt Exp $      */
+/*     $OpenBSD: trap.c,v 1.161 2022/11/02 07:20:08 guenther Exp $     */
 
 /*
  * Copyright (c) 1988 University of Utah.
@@ -477,7 +477,7 @@ fault_common_no_miss:
                }
 
                rval[0] = 0;
-               rval[1] = locr0->v1;
+               rval[1] = 0;
 
 #if defined(DDB) || defined(DEBUG)
                trapdebug[TRAPSIZE * ci->ci_cpuid + (trppos[ci->ci_cpuid] == 0 ?
@@ -489,7 +489,6 @@ fault_common_no_miss:
                switch (error) {
                case 0:
                        locr0->v0 = rval[0];
-                       locr0->v1 = rval[1];
                        locr0->a3 = 0;
                        break;
 
@@ -839,7 +838,6 @@ child_return(void *arg)
 
        trapframe = p->p_md.md_regs;
        trapframe->v0 = 0;
-       trapframe->v1 = 1;
        trapframe->a3 = 0;
 
        KERNEL_UNLOCK();

diff --git a/sys/arch/powerpc/powerpc/trap.c b/sys/arch/powerpc/powerpc/trap.c
index da68970..6c7e433 100644 (file)
--- a/sys/arch/powerpc/powerpc/trap.c
+++ b/sys/arch/powerpc/powerpc/trap.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: trap.c,v 1.126 2022/10/22 00:58:56 gkoehler Exp $     */
+/*     $OpenBSD: trap.c,v 1.127 2022/11/02 07:20:07 guenther Exp $     */
 /*     $NetBSD: trap.c,v 1.3 1996/10/13 03:31:37 christos Exp $        */
 
 /*
@@ -563,7 +563,6 @@ child_return(void *arg)
 
        tf->fixreg[0] = 0;
        tf->fixreg[FIRSTARG] = 0;
-       tf->fixreg[FIRSTARG + 1] = 1;
        tf->cr &= ~0x10000000;
        /* Disable FPU, VECT, as we can't be fpuproc */
        tf->srr1 &= ~(PSL_FP|PSL_VEC);

diff --git a/sys/arch/powerpc64/powerpc64/syscall.c b/sys/arch/powerpc64/powerpc64/syscall.c
index 95fb92b..d47076d 100644 (file)
--- a/sys/arch/powerpc64/powerpc64/syscall.c
+++ b/sys/arch/powerpc64/powerpc64/syscall.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: syscall.c,v 1.8 2021/12/09 00:26:11 guenther Exp $    */
+/*     $OpenBSD: syscall.c,v 1.9 2022/11/02 07:20:08 guenther Exp $    */
 
 /*
  * Copyright (c) 2015 Dale Rahn <drahn@dalerahn.com>
@@ -64,7 +64,7 @@ syscall(struct trapframe *frame)
        }
 
        rval[0] = 0;
-       rval[1] = frame->fixreg[4];
+       rval[1] = 0;
 
        error = mi_syscall(p, code, callp, args, rval);
 
@@ -72,7 +72,6 @@ syscall(struct trapframe *frame)
        case 0:
                frame->fixreg[0] = 0;
                frame->fixreg[3] = rval[0];
-               frame->fixreg[4] = rval[1];
                frame->cr &= ~0x10000000;
                break;
 
@@ -102,7 +101,6 @@ child_return(void *arg)
 
        frame->fixreg[0] = 0;
        frame->fixreg[3] = 0;
-       frame->fixreg[4] = 1;
        frame->cr &= ~0x10000000;
 
        KERNEL_UNLOCK();

diff --git a/sys/arch/riscv64/riscv64/syscall.c b/sys/arch/riscv64/riscv64/syscall.c
index 81685bf..1e1b2ce 100644 (file)
--- a/sys/arch/riscv64/riscv64/syscall.c
+++ b/sys/arch/riscv64/riscv64/syscall.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: syscall.c,v 1.12 2022/02/22 13:34:23 visa Exp $       */
+/*     $OpenBSD: syscall.c,v 1.13 2022/11/02 07:20:08 guenther Exp $   */
 
 /*
  * Copyright (c) 2020 Brian Bamsch <bbamsch@google.com>
@@ -84,14 +84,13 @@ svc_handler(trapframe_t *frame)
        }
 
        rval[0] = 0;
-       rval[1] = frame->tf_a[1];
+       rval[1] = 0;
 
        error = mi_syscall(p, code, callp, args, rval);
 
        switch (error) {
        case 0:
                frame->tf_a[0] = rval[0];
-               frame->tf_a[1] = rval[1];
                frame->tf_t[0] = 0;             /* syscall succeeded */
                break;
 
@@ -119,7 +118,6 @@ child_return(void *arg)
        struct trapframe *frame = process_frame(p);
 
        frame->tf_a[0] = 0;
-       frame->tf_a[1] = 1;
        frame->tf_t[0] = 0;                     /* no error */
 
        KERNEL_UNLOCK();

diff --git a/sys/arch/sparc64/sparc64/trap.c b/sys/arch/sparc64/sparc64/trap.c
index 540b0b4..8682eef 100644 (file)
--- a/sys/arch/sparc64/sparc64/trap.c
+++ b/sys/arch/sparc64/sparc64/trap.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: trap.c,v 1.111 2022/10/21 18:55:42 miod Exp $ */
+/*     $OpenBSD: trap.c,v 1.112 2022/11/02 07:20:08 guenther Exp $     */
 /*     $NetBSD: trap.c,v 1.73 2001/08/09 01:03:01 eeh Exp $ */
 
 /*
@@ -1175,7 +1175,7 @@ syscall(struct trapframe *tf, register_t code, register_t pc)
        }
 
        rval[0] = 0;
-       rval[1] = tf->tf_out[1];
+       rval[1] = 0;
 
        error = mi_syscall(p, code, callp, args, rval);
 
@@ -1184,7 +1184,6 @@ syscall(struct trapframe *tf, register_t code, register_t pc)
        case 0:
                /* Note: fork() does not return here in the child */
                tf->tf_out[0] = rval[0];
-               tf->tf_out[1] = rval[1];
                if (new) {
                        /* jmp %g2 on success */
                        dest = tf->tf_global[2];
@@ -1247,7 +1246,6 @@ child_return(void *arg)
         * Return values in the frame set by cpu_fork().
         */
        tf->tf_out[0] = 0;
-       tf->tf_out[1] = 0;
 
        KERNEL_UNLOCK();
 

diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index 4c3b5d0..e02a40a 100644 (file)
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_fork.c,v 1.242 2022/08/14 01:58:27 jsg Exp $     */
+/*     $OpenBSD: kern_fork.c,v 1.243 2022/11/02 07:20:07 guenther Exp $        */
 /*     $NetBSD: kern_fork.c,v 1.29 1996/02/09 18:59:34 christos Exp $  */
 
 /*
@@ -502,10 +502,8 @@ fork1(struct proc *curp, int flags, void (*func)(void *), void *arg,
        /*
         * Return child pid to parent process
         */
-       if (retval != NULL) {
-               retval[0] = pr->ps_pid;
-               retval[1] = 0;
-       }
+       if (retval != NULL)
+               *retval = pr->ps_pid;
        return (0);
 }
 
@@ -574,8 +572,7 @@ thread_fork(struct proc *curp, void *stack, void *tcb, pid_t *tidptr,
        /*
         * Return tid to parent thread and copy it out to userspace
         */
-       retval[0] = tid = p->p_tid + THREAD_PID_OFFSET;
-       retval[1] = 0;
+       *retval = tid = p->p_tid + THREAD_PID_OFFSET;
        if (tidptr != NULL) {
                if (copyout(&tid, tidptr, sizeof(tid)))
                        psignal(curp, SIGSEGV);