execregs.c revision 1.1
1 /* $NetBSD: execregs.c,v 1.1 2025/02/27 00:55:32 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2025 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __RCSID("$NetBSD: execregs.c,v 1.1 2025/02/27 00:55:32 riastradh Exp $"); 31 32 #include "execregs.h" 33 34 #include <errno.h> 35 #include <spawn.h> 36 #include <stddef.h> 37 #include <unistd.h> 38 39 extern char **environ; 40 41 static unsigned long 42 nonnull(unsigned long x) 43 { 44 45 x |= x << 8; 46 x |= x << 16; 47 return x; 48 } 49 50 int 51 execregschild(char *path) 52 { 53 register long t1 __asm("r22") = nonnull(22); 54 register long t2 __asm("r21") = nonnull(21); 55 /* r30/sp: stack pointer */ 56 register long t3 __asm("r20") = nonnull(20); 57 /* cr17/iisq_head: privileged */ 58 /* cr17/iisq_tail: privileged */ 59 /* cr18/iioq_head: privileged */ 60 /* cr18/iioq_tail: privileged */ 61 /* cr15/eiem: privileged */ 62 /* cr22/ipsw: privileged */ 63 /* sr3: privileged(?) */ 64 /* cr8/pidr1: privileged */ 65 /* cr20/isr: privileged */ 66 /* cr21/ior: privileged */ 67 /* cr19/iir: privileged */ 68 /* flags: N/A(?) */ 69 long sar = nonnull(0x8a); /* cr11 */ 70 /* r1: ADDIL (add immediate left) result, nonnull anyway */ 71 /* r2/rp: return pointer, nonnull anyway */ 72 /* r3: frame pointer, nonnull anyway */ 73 register long r4 __asm("r4") = nonnull(4); 74 register long r5 __asm("r5") = nonnull(5); 75 register long r6 __asm("r6") = nonnull(6); 76 register long r7 __asm("r7") = nonnull(7); 77 register long r8 __asm("r8") = nonnull(8); 78 register long r9 __asm("r9") = nonnull(9); 79 register long r10 __asm("r10") = nonnull(10); 80 register long r11 __asm("r11") = nonnull(11); 81 register long r12 __asm("r12") = nonnull(12); 82 register long r13 __asm("r13") = nonnull(13); 83 register long r14 __asm("r14") = nonnull(14); 84 register long r15 __asm("r15") = nonnull(15); 85 register long r16 __asm("r16") = nonnull(16); 86 register long r17 __asm("r17") = nonnull(17); 87 register long r18 __asm("r18") = nonnull(18); 88 register long t4 __asm("r19") = nonnull(19); 89 register long arg3 __asm("r23") = nonnull(23); 90 /* r24/arg2: envp, nonnull anyway */ 91 /* r25/arg1: argv, nonnull anyway */ 92 /* r26/arg0: path, nonnull anyway */ 93 /* r27/dp: data pointer, nonnull anyway */ 94 register long ret0 __asm("r28") = nonnull(28); 95 register long ret1 __asm("r29") = nonnull(29); 96 register long r31 __asm("r31") = nonnull(31); 97 /* sr0-sr7: space registers initialized by kernel */ 98 /* cr9/pidr2: privileged */ 99 /* cr12/pidr3: privileged */ 100 /* cr13/pidr4: privileged */ 101 /* cr0/rctr: privileged */ 102 /* cr10/ccr: privileged */ 103 /* cr23/eirr: privileged */ 104 /* cr24: privileged */ 105 /* cr25/vtop: privileged */ 106 /* cr27/tr3: _lwp_private, thread-local storage -- nonnull anyway */ 107 /* cr28: privileged */ 108 /* cr30/fpregs: privileged */ 109 /* cr31: privileged */ 110 111 char *argv[] = {path, NULL}; 112 char **envp = environ; 113 114 /* 115 * Not perfect -- compiler might use some registers for 116 * stack/argument transfers, but all the arguments are nonnull 117 * so this is probably a good test anyway. 118 */ 119 __asm volatile("mtctl %[sar], %%sar" /* cr11 */ 120 : /* outputs */ 121 : [sar] "r"(sar) 122 : "memory"); 123 __asm volatile("" : 124 "+r"(t1), 125 "+r"(t2), 126 "+r"(t3), 127 "+r"(r4), 128 "+r"(r5), 129 "+r"(r6), 130 "+r"(r7), 131 "+r"(r8), 132 "+r"(r9), 133 "+r"(r10), 134 "+r"(r11), 135 "+r"(r12) 136 :: "memory"); 137 /* pacify gcc error: more than 30 operands in 'asm' */ 138 __asm volatile("" : 139 "+r"(r13), 140 "+r"(r14), 141 "+r"(r15), 142 "+r"(r16), 143 "+r"(r17), 144 "+r"(r18), 145 "+r"(t4), 146 "+r"(arg3), 147 "+r"(ret0), 148 "+r"(ret1), 149 "+r"(r31) 150 :: "memory"); 151 152 return execve(path, argv, envp); 153 } 154 155 pid_t 156 spawnregschild(char *path, int fd) 157 { 158 register long t1 __asm("r22") = nonnull(22); 159 register long t2 __asm("r21") = nonnull(21); 160 /* r30/sp: stack pointer */ 161 register long t3 __asm("r20") = nonnull(20); 162 /* cr17/iisq_head: privileged */ 163 /* cr17/iisq_tail: privileged */ 164 /* cr18/iioq_head: privileged */ 165 /* cr18/iioq_tail: privileged */ 166 /* cr15/eiem: privileged */ 167 /* cr22/ipsw: privileged */ 168 /* sr3: privileged(?) */ 169 /* cr8/pidr1: privileged */ 170 /* cr20/isr: privileged */ 171 /* cr21/ior: privileged */ 172 /* cr19/iir: privileged */ 173 /* flags: N/A(?) */ 174 long sar = nonnull(0x8a); /* cr11 */ 175 /* r1: ADDIL (add immediate left) result, nonnull anyway */ 176 /* r2/rp: return pointer, nonnull anyway */ 177 /* r3: frame pointer, nonnull anyway */ 178 register long r4 __asm("r4") = nonnull(4); 179 register long r5 __asm("r5") = nonnull(5); 180 register long r6 __asm("r6") = nonnull(6); 181 register long r7 __asm("r7") = nonnull(7); 182 register long r8 __asm("r8") = nonnull(8); 183 register long r9 __asm("r9") = nonnull(9); 184 register long r10 __asm("r10") = nonnull(10); 185 register long r11 __asm("r11") = nonnull(11); 186 register long r12 __asm("r12") = nonnull(12); 187 register long r13 __asm("r13") = nonnull(13); 188 register long r14 __asm("r14") = nonnull(14); 189 register long r15 __asm("r15") = nonnull(15); 190 register long r16 __asm("r16") = nonnull(16); 191 register long r17 __asm("r17") = nonnull(17); 192 register long r18 __asm("r18") = nonnull(18); 193 register long t4 __asm("r19") = nonnull(19); 194 /* r23/arg3: attrp, nonnull anyway */ 195 /* r24/arg2: fileactsp, nonnull anyway */ 196 /* r25/arg1: path, nonnull anyway */ 197 /* r26/arg0: pidp, nonnull anyway */ 198 /* r27/dp: data pointer, nonnull anyway */ 199 register long ret0 __asm("r28") = nonnull(28); 200 register long ret1 __asm("r29") = nonnull(29); 201 register long r31 __asm("r31") = nonnull(31); 202 /* sr0-sr7: space registers initialized by kernel */ 203 /* cr9/pidr2: privileged */ 204 /* cr12/pidr3: privileged */ 205 /* cr13/pidr4: privileged */ 206 /* cr0/rctr: privileged */ 207 /* cr10/ccr: privileged */ 208 /* cr23/eirr: privileged */ 209 /* cr24: privileged */ 210 /* cr25/vtop: privileged */ 211 /* cr27/tr3: _lwp_private, thread-local storage -- nonnull anyway */ 212 /* cr28: privileged */ 213 /* cr30/fpregs: privileged */ 214 /* cr31: privileged */ 215 216 char *argv[] = {path, NULL}; 217 char **envp = environ; 218 posix_spawn_file_actions_t fileacts; 219 posix_spawnattr_t attr; 220 pid_t pid; 221 int error; 222 223 error = posix_spawn_file_actions_init(&fileacts); 224 if (error) 225 goto out; 226 error = posix_spawn_file_actions_adddup2(&fileacts, fd, STDOUT_FILENO); 227 if (error) 228 goto out; 229 error = posix_spawnattr_init(&attr); 230 if (error) 231 goto out; 232 233 /* 234 * Not perfect -- compiler might use some registers for 235 * stack/argument transfers, but all the arguments are nonnull 236 * so this is probably a good test anyway. 237 */ 238 __asm volatile("mtctl %[sar], %%sar" /* cr11 */ 239 : /* outputs */ 240 : [sar] "r"(sar) 241 : "memory"); 242 __asm volatile("" : 243 "+r"(t1), 244 "+r"(t2), 245 "+r"(t3), 246 "+r"(r4), 247 "+r"(r5), 248 "+r"(r6), 249 "+r"(r7), 250 "+r"(r8), 251 "+r"(r9), 252 "+r"(r10), 253 "+r"(r11), 254 "+r"(r12) 255 :: "memory"); 256 /* pacify gcc error: more than 30 operands in 'asm' */ 257 __asm volatile("" : 258 "+r"(r13), 259 "+r"(r14), 260 "+r"(r15), 261 "+r"(r16), 262 "+r"(r17), 263 "+r"(r18), 264 "+r"(t4), 265 "+r"(ret0), 266 "+r"(ret1), 267 "+r"(r31) 268 :: "memory"); 269 270 error = posix_spawn(&pid, path, &fileacts, &attr, argv, envp); 271 if (error) 272 goto out; 273 274 out: posix_spawnattr_destroy(&attr); 275 posix_spawn_file_actions_destroy(&fileacts); 276 if (error) { 277 errno = error; 278 return -1; 279 } 280 return 0; 281 } 282
Indexes created Thu Sep 25 06:09:39 GMT 2025