1 1.1 riastrad /* $NetBSD: execregs.c,v 1.1 2025/02/27 00:55:32 riastradh Exp $ */ 2 1.1 riastrad 3 1.1 riastrad /*- 4 1.1 riastrad * Copyright (c) 2025 The NetBSD Foundation, Inc. 5 1.1 riastrad * All rights reserved. 6 1.1 riastrad * 7 1.1 riastrad * Redistribution and use in source and binary forms, with or without 8 1.1 riastrad * modification, are permitted provided that the following conditions 9 1.1 riastrad * are met: 10 1.1 riastrad * 1. Redistributions of source code must retain the above copyright 11 1.1 riastrad * notice, this list of conditions and the following disclaimer. 12 1.1 riastrad * 2. Redistributions in binary form must reproduce the above copyright 13 1.1 riastrad * notice, this list of conditions and the following disclaimer in the 14 1.1 riastrad * documentation and/or other materials provided with the distribution. 15 1.1 riastrad * 16 1.1 riastrad * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 1.1 riastrad * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 1.1 riastrad * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 1.1 riastrad * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 1.1 riastrad * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 1.1 riastrad * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 1.1 riastrad * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 1.1 riastrad * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 1.1 riastrad * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 1.1 riastrad * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 1.1 riastrad * POSSIBILITY OF SUCH DAMAGE. 27 1.1 riastrad */ 28 1.1 riastrad 29 1.1 riastrad #include <sys/cdefs.h> 30 1.1 riastrad __RCSID("$NetBSD: execregs.c,v 1.1 2025/02/27 00:55:32 riastradh Exp $"); 31 1.1 riastrad 32 1.1 riastrad #include "execregs.h" 33 1.1 riastrad 34 1.1 riastrad #include <errno.h> 35 1.1 riastrad #include <spawn.h> 36 1.1 riastrad #include <stddef.h> 37 1.1 riastrad #include <unistd.h> 38 1.1 riastrad 39 1.1 riastrad extern char **environ; 40 1.1 riastrad 41 1.1 riastrad static unsigned long 42 1.1 riastrad nonnull(unsigned long x) 43 1.1 riastrad { 44 1.1 riastrad 45 1.1 riastrad x |= x << 8; 46 1.1 riastrad x |= x << 16; 47 1.1 riastrad return x; 48 1.1 riastrad } 49 1.1 riastrad 50 1.1 riastrad int 51 1.1 riastrad execregschild(char *path) 52 1.1 riastrad { 53 1.1 riastrad /* fp: frame pointer, nonnull */ 54 1.1 riastrad /* ap: argument pointer, on user stack, nonnull */ 55 1.1 riastrad /* sp: stack pointer, nonnull */ 56 1.1 riastrad register long r0 __asm("r0") = nonnull(0x10); 57 1.1 riastrad register long r1 __asm("r1") = nonnull(1); 58 1.1 riastrad register long r2 __asm("r2") = nonnull(2); 59 1.1 riastrad register long r3 __asm("r3") = nonnull(3); 60 1.1 riastrad register long r4 __asm("r4") = nonnull(4); 61 1.1 riastrad register long r5 __asm("r5") = nonnull(5); 62 1.1 riastrad register long r6 __asm("r6") = nonnull(6); 63 1.1 riastrad register long r7 __asm("r7") = nonnull(7); 64 1.1 riastrad register long r8 __asm("r8") = nonnull(8); 65 1.1 riastrad register long r9 __asm("r9") = nonnull(9); 66 1.1 riastrad register long r10 __asm("r10") = nonnull(10); 67 1.1 riastrad register long r11 __asm("r11") = nonnull(11); 68 1.1 riastrad /* pc: user PC, will be nonnull */ 69 1.1 riastrad /* psl: processor status longword, will be nonnull */ 70 1.1 riastrad 71 1.1 riastrad char *argv[] = {path, NULL}; 72 1.1 riastrad char **envp = environ; 73 1.1 riastrad 74 1.1 riastrad /* 75 1.1 riastrad * Not perfect -- compiler might use some registers for 76 1.1 riastrad * stack/argument transfers, but all the arguments are nonnull 77 1.1 riastrad * so this is probably a good test anyway. 78 1.1 riastrad */ 79 1.1 riastrad __asm volatile("" : 80 1.1 riastrad "+r"(r0), 81 1.1 riastrad "+r"(r1), 82 1.1 riastrad "+r"(r2), 83 1.1 riastrad "+r"(r3), 84 1.1 riastrad "+r"(r4), 85 1.1 riastrad "+r"(r5), 86 1.1 riastrad "+r"(r6), 87 1.1 riastrad "+r"(r7), 88 1.1 riastrad "+r"(r8), 89 1.1 riastrad "+r"(r9), 90 1.1 riastrad "+r"(r10), 91 1.1 riastrad "+r"(r11) 92 1.1 riastrad :: "memory"); 93 1.1 riastrad 94 1.1 riastrad return execve(path, argv, envp); 95 1.1 riastrad } 96 1.1 riastrad 97 1.1 riastrad pid_t 98 1.1 riastrad spawnregschild(char *path, int fd) 99 1.1 riastrad { 100 1.1 riastrad /* fp: frame pointer, nonnull */ 101 1.1 riastrad /* ap: argument pointer, on user stack, nonnull */ 102 1.1 riastrad /* sp: stack pointer, nonnull */ 103 1.1 riastrad register long r0 __asm("r0") = nonnull(0x10); 104 1.1 riastrad register long r1 __asm("r1") = nonnull(1); 105 1.1 riastrad register long r2 __asm("r2") = nonnull(2); 106 1.1 riastrad register long r3 __asm("r3") = nonnull(3); 107 1.1 riastrad register long r4 __asm("r4") = nonnull(4); 108 1.1 riastrad register long r5 __asm("r5") = nonnull(5); 109 1.1 riastrad register long r6 __asm("r6") = nonnull(6); 110 1.1 riastrad register long r7 __asm("r7") = nonnull(7); 111 1.1 riastrad register long r8 __asm("r8") = nonnull(8); 112 1.1 riastrad register long r9 __asm("r9") = nonnull(9); 113 1.1 riastrad register long r10 __asm("r10") = nonnull(10); 114 1.1 riastrad register long r11 __asm("r11") = nonnull(11); 115 1.1 riastrad /* pc: user PC, will be nonnull */ 116 1.1 riastrad /* psl: processor status longword, will be nonnull */ 117 1.1 riastrad 118 1.1 riastrad char *argv[] = {path, NULL}; 119 1.1 riastrad char **envp = environ; 120 1.1 riastrad posix_spawn_file_actions_t fileacts; 121 1.1 riastrad posix_spawnattr_t attr; 122 1.1 riastrad pid_t pid; 123 1.1 riastrad int error; 124 1.1 riastrad 125 1.1 riastrad error = posix_spawn_file_actions_init(&fileacts); 126 1.1 riastrad if (error) 127 1.1 riastrad goto out; 128 1.1 riastrad error = posix_spawn_file_actions_adddup2(&fileacts, fd, STDOUT_FILENO); 129 1.1 riastrad if (error) 130 1.1 riastrad goto out; 131 1.1 riastrad error = posix_spawnattr_init(&attr); 132 1.1 riastrad if (error) 133 1.1 riastrad goto out; 134 1.1 riastrad 135 1.1 riastrad /* 136 1.1 riastrad * Not perfect -- compiler might use some registers for 137 1.1 riastrad * stack/argument transfers, but all the arguments are nonnull 138 1.1 riastrad * so this is probably a good test anyway. 139 1.1 riastrad */ 140 1.1 riastrad __asm volatile("" : 141 1.1 riastrad "+r"(r0), 142 1.1 riastrad "+r"(r1), 143 1.1 riastrad "+r"(r2), 144 1.1 riastrad "+r"(r3), 145 1.1 riastrad "+r"(r4), 146 1.1 riastrad "+r"(r5), 147 1.1 riastrad "+r"(r6), 148 1.1 riastrad "+r"(r7), 149 1.1 riastrad "+r"(r8), 150 1.1 riastrad "+r"(r9), 151 1.1 riastrad "+r"(r10), 152 1.1 riastrad "+r"(r11) 153 1.1 riastrad :: "memory"); 154 1.1 riastrad 155 1.1 riastrad error = posix_spawn(&pid, path, &fileacts, &attr, argv, envp); 156 1.1 riastrad if (error) 157 1.1 riastrad goto out; 158 1.1 riastrad 159 1.1 riastrad out: posix_spawnattr_destroy(&attr); 160 1.1 riastrad posix_spawn_file_actions_destroy(&fileacts); 161 1.1 riastrad if (error) { 162 1.1 riastrad errno = error; 163 1.1 riastrad return -1; 164 1.1 riastrad } 165 1.1 riastrad return 0; 166 1.1 riastrad } 167