1 /*- 2 * Copyright (c) 2008 John Birrell (jb@freebsd.org) 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: head/lib/libproc/proc_create.c 265255 2014-05-03 04:44:03Z markj $ 27 */ 28 #include <sys/cdefs.h> 29 __RCSID("$NetBSD: proc_create.c,v 1.3 2017/06/09 01:17:25 chs Exp $"); 30 31 #include <sys/types.h> 32 #include <sys/sysctl.h> 33 #include <sys/wait.h> 34 35 #include <err.h> 36 #include <errno.h> 37 #include <fcntl.h> 38 #include <limits.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <unistd.h> 42 43 #include "_libproc.h" 44 45 static int proc_init(pid_t, int, int, struct proc_handle *); 46 47 static int 48 proc_init(pid_t pid, int flags, int status, struct proc_handle *phdl) 49 { 50 struct kinfo_proc2 kp; 51 int mib[6], error; 52 size_t len; 53 54 memset(phdl, 0, sizeof(*phdl)); 55 phdl->pid = pid; 56 phdl->flags = flags; 57 phdl->status = status; 58 59 mib[0] = CTL_KERN; 60 mib[1] = KERN_PROC_ARGS; 61 mib[2] = pid; 62 mib[3] = KERN_PROC_PATHNAME; 63 len = sizeof(phdl->execname); 64 if (sysctl(mib, 4, phdl->execname, &len, NULL, 0) != 0) { 65 error = errno; 66 DPRINTF("ERROR: cannot get pathname for child process %d", pid); 67 return (error); 68 } 69 if (len == 0) 70 phdl->execname[0] = '\0'; 71 72 #ifdef _LP64 73 len = sizeof(kp); 74 mib[0] = CTL_KERN; 75 mib[1] = KERN_PROC2; 76 mib[2] = KERN_PROC_PID; 77 mib[3] = pid; 78 mib[4] = len; 79 mib[5] = 1; 80 if (sysctl(mib, 6, &kp, &len, NULL, 0) != 0) { 81 error = errno; 82 DPRINTF("ERROR: cannot get kinfo_proc2 for pid %d", pid); 83 return (error); 84 } 85 phdl->model = (kp.p_flag & P_32) ? PR_MODEL_ILP32 : PR_MODEL_LP64; 86 #else 87 phdl->model = PR_MODEL_ILP32; 88 #endif 89 90 return (0); 91 } 92 93 int 94 proc_attach(pid_t pid, int flags, struct proc_handle **pphdl) 95 { 96 struct proc_handle *phdl; 97 int error = 0; 98 int status; 99 100 if (pid == 0 || pid == getpid()) 101 return (EINVAL); 102 103 /* 104 * Allocate memory for the process handle, a structure containing 105 * all things related to the process. 106 */ 107 if ((phdl = malloc(sizeof(struct proc_handle))) == NULL) 108 return (ENOMEM); 109 110 elf_version(EV_CURRENT); 111 112 error = proc_init(pid, flags, PS_RUN, phdl); 113 if (error != 0) 114 goto out; 115 116 if (ptrace(PT_ATTACH, phdl->pid, 0, 0) != 0) { 117 error = errno; 118 DPRINTF("ERROR: cannot ptrace child process %d", pid); 119 goto out; 120 } 121 122 /* Wait for the child process to stop. */ 123 if (waitpid(pid, &status, WUNTRACED) == -1) { 124 error = errno; 125 DPRINTF("ERROR: child process %d didn't stop as expected", pid); 126 goto out; 127 } 128 129 /* Check for an unexpected status. */ 130 if (WIFSTOPPED(status) == 0) 131 DPRINTFX("ERROR: child process %d status 0x%x", pid, status); 132 else 133 phdl->status = PS_STOP; 134 135 out: 136 if (error) 137 proc_free(phdl); 138 else 139 *pphdl = phdl; 140 return (error); 141 } 142 143 int 144 proc_create(const char *file, char * const *argv, proc_child_func *pcf, 145 void *child_arg, struct proc_handle **pphdl) 146 { 147 struct proc_handle *phdl; 148 int error = 0; 149 int status; 150 pid_t pid; 151 152 /* 153 * Allocate memory for the process handle, a structure containing 154 * all things related to the process. 155 */ 156 if ((phdl = malloc(sizeof(struct proc_handle))) == NULL) 157 return (ENOMEM); 158 159 elf_version(EV_CURRENT); 160 161 /* Fork a new process. */ 162 if ((pid = vfork()) == -1) 163 error = errno; 164 else if (pid == 0) { 165 /* The child expects to be traced. */ 166 if (ptrace(PT_TRACE_ME, 0, 0, 0) != 0) 167 _exit(1); 168 169 if (pcf != NULL) 170 (*pcf)(child_arg); 171 172 /* Execute the specified file: */ 173 execvp(file, argv); 174 175 /* Couldn't execute the file. */ 176 _exit(2); 177 } else { 178 /* The parent owns the process handle. */ 179 error = proc_init(pid, 0, PS_IDLE, phdl); 180 if (error != 0) 181 goto bad; 182 183 /* Wait for the child process to stop. */ 184 if (waitpid(pid, &status, WUNTRACED) == -1) { 185 error = errno; 186 DPRINTF("ERROR: child process %d didn't stop as expected", pid); 187 goto bad; 188 } 189 190 /* Check for an unexpected status. */ 191 if (WIFSTOPPED(status) == 0) { 192 error = errno; 193 DPRINTFX("ERROR: child process %d status 0x%x", pid, status); 194 goto bad; 195 } else 196 phdl->status = PS_STOP; 197 } 198 bad: 199 if (error) 200 proc_free(phdl); 201 else 202 *pphdl = phdl; 203 return (error); 204 } 205 206 void 207 proc_free(struct proc_handle *phdl) 208 { 209 free(phdl); 210 } 211