diff options
Diffstat (limited to 'lib/libproc/proc_create.c')
| -rw-r--r-- | lib/libproc/proc_create.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/lib/libproc/proc_create.c b/lib/libproc/proc_create.c new file mode 100644 index 000000000000..0b10b186b8ca --- /dev/null +++ b/lib/libproc/proc_create.c @@ -0,0 +1,265 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2008 John Birrell (jb@freebsd.org) + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/types.h> +#include <sys/sysctl.h> +#include <sys/user.h> +#include <sys/wait.h> + +#include <err.h> +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <libelf.h> +#include <libprocstat.h> + +#include "_libproc.h" + +extern char * const *environ; + +static int getelfclass(int); +static int proc_init(pid_t, int, int, struct proc_handle **); + +static int +getelfclass(int fd) +{ + GElf_Ehdr ehdr; + Elf *e; + int class; + + class = ELFCLASSNONE; + + if ((e = elf_begin(fd, ELF_C_READ, NULL)) == NULL) + goto out; + if (gelf_getehdr(e, &ehdr) == NULL) + goto out; + class = ehdr.e_ident[EI_CLASS]; +out: + (void)elf_end(e); + return (class); +} + +static int +proc_init(pid_t pid, int flags, int status, struct proc_handle **pphdl) +{ + struct kinfo_proc *kp; + struct proc_handle *phdl; + int error, class, count, fd; + + error = ENOMEM; + if ((phdl = malloc(sizeof(*phdl))) == NULL) + goto out; + + memset(phdl, 0, sizeof(*phdl)); + phdl->public.pid = pid; + phdl->flags = flags; + phdl->status = status; + phdl->procstat = procstat_open_sysctl(); + if (phdl->procstat == NULL) + goto out; + + /* Obtain a path to the executable. */ + if ((kp = procstat_getprocs(phdl->procstat, KERN_PROC_PID, pid, + &count)) == NULL) + goto out; + error = procstat_getpathname(phdl->procstat, kp, phdl->execpath, + sizeof(phdl->execpath)); + procstat_freeprocs(phdl->procstat, kp); + if (error != 0) + goto out; + + /* Use it to determine the data model for the process. */ + if ((fd = open(phdl->execpath, O_RDONLY)) < 0) { + error = errno; + goto out; + } + class = getelfclass(fd); + switch (class) { + case ELFCLASS64: + phdl->model = PR_MODEL_LP64; + break; + case ELFCLASS32: + phdl->model = PR_MODEL_ILP32; + break; + case ELFCLASSNONE: + default: + error = EINVAL; + break; + } + (void)close(fd); + +out: + *pphdl = phdl; + return (error); +} + +int +proc_attach(pid_t pid, int flags, struct proc_handle **pphdl) +{ + struct proc_handle *phdl; + int error, status; + + if (pid == 0 || (pid == getpid() && (flags & PATTACH_RDONLY) == 0)) + return (EINVAL); + if (elf_version(EV_CURRENT) == EV_NONE) + return (ENOENT); + + /* + * Allocate memory for the process handle, a structure containing + * all things related to the process. + */ + error = proc_init(pid, flags, PS_RUN, &phdl); + if (error != 0) + goto out; + + if ((flags & PATTACH_RDONLY) == 0) { + if (ptrace(PT_ATTACH, proc_getpid(phdl), 0, 0) != 0) { + error = errno; + DPRINTF("ERROR: cannot ptrace child process %d", pid); + goto out; + } + + /* Wait for the child process to stop. */ + if (waitpid(pid, &status, WUNTRACED) == -1) { + error = errno; + DPRINTF("ERROR: child process %d didn't stop as expected", pid); + goto out; + } + + /* Check for an unexpected status. */ + if (!WIFSTOPPED(status)) + DPRINTFX("ERROR: child process %d status 0x%x", pid, status); + else + phdl->status = PS_STOP; + + if ((flags & PATTACH_NOSTOP) != 0) + proc_continue(phdl); + } + +out: + if (error != 0 && phdl != NULL) { + proc_free(phdl); + phdl = NULL; + } + *pphdl = phdl; + return (error); +} + +int +proc_create(const char *file, char * const *argv, char * const *envp, + proc_child_func *pcf, void *child_arg, struct proc_handle **pphdl) +{ + struct proc_handle *phdl; + int error, status; + pid_t pid; + + if (elf_version(EV_CURRENT) == EV_NONE) + return (ENOENT); + + error = 0; + phdl = NULL; + + if ((pid = fork()) == -1) + error = errno; + else if (pid == 0) { + /* The child expects to be traced. */ + if (ptrace(PT_TRACE_ME, 0, 0, 0) != 0) + _exit(1); + + if (pcf != NULL) + (*pcf)(child_arg); + + if (envp != NULL) + environ = envp; + + execvp(file, argv); + + _exit(2); + /* NOTREACHED */ + } else { + /* Wait for the child process to stop. */ + if (waitpid(pid, &status, WUNTRACED) == -1) { + error = errno; + DPRINTF("ERROR: child process %d didn't stop as expected", pid); + goto bad; + } + + /* Check for an unexpected status. */ + if (!WIFSTOPPED(status)) { + error = ENOENT; + DPRINTFX("ERROR: child process %d status 0x%x", pid, status); + goto bad; + } + + /* The parent owns the process handle. */ + error = proc_init(pid, 0, PS_IDLE, &phdl); + if (error == 0) + phdl->status = PS_STOP; + +bad: + if (error != 0 && phdl != NULL) { + proc_free(phdl); + phdl = NULL; + } + } + *pphdl = phdl; + return (error); +} + +void +proc_free(struct proc_handle *phdl) +{ + struct file_info *file; + size_t i; + + for (i = 0; i < phdl->nmappings; i++) { + file = phdl->mappings[i].file; + if (file != NULL && --file->refs == 0) { + if (file->elf != NULL) { + (void)elf_end(file->elf); + (void)close(file->fd); + if (file->symtab.nsyms > 0) + free(file->symtab.index); + if (file->dynsymtab.nsyms > 0) + free(file->dynsymtab.index); + } + free(file); + } + } + if (phdl->maparrsz > 0) + free(phdl->mappings); + if (phdl->procstat != NULL) + procstat_close(phdl->procstat); + if (phdl->rdap != NULL) + rd_delete(phdl->rdap); + free(phdl); +} |