freebsd-skq/lib/libproc/proc_create.c
Pedro F. Giffuni 5e53a4f90f lib: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-26 02:00:33 +00:00

268 lines
6.2 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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/cdefs.h>
__FBSDID("$FreeBSD$");
#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"
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, 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;
/* Fork a new process. */
if ((pid = vfork()) == -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);
/* Execute the specified file: */
execvp(file, argv);
/* Couldn't execute the file. */
_exit(2);
/* NOTREACHED */
} else {
/* The parent owns the process handle. */
error = proc_init(pid, 0, PS_IDLE, &phdl);
if (error != 0)
goto bad;
/* 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 = EBUSY;
DPRINTFX("ERROR: child process %d status 0x%x", pid, status);
goto bad;
}
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);
}