freebsd-skq/lib/libproc/proc_create.c
Conrad Meyer ce601a2676 proc_init: Fix a few memory leaks of 'phdl'
In the normal case and correct failure cases, the 'phdl' pointer is passed to
callers to use or clean up as needed.  However, some failure cases returned
early, failing to export the phdl pointer.

This was introduced in the restructuring of r303533.

Reported by:	Coverity
CID:		1361070
Reviewed by:	markj
Sponsored by:	EMC / Isilon Storage Division
2016-08-02 18:13:50 +00:00

237 lines
5.5 KiB
C

/*-
* 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.
*
* $FreeBSD$
*/
#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->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())
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 (ptrace(PT_ATTACH, phdl->pid, 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;
out:
if (error && 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 = 0;
int status;
pid_t pid;
if (elf_version(EV_CURRENT) == EV_NONE)
return (ENOENT);
/* 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 = errno;
DPRINTFX("ERROR: child process %d status 0x%x", pid, status);
goto bad;
} else
phdl->status = PS_STOP;
}
bad:
if (error && phdl != NULL) {
proc_free(phdl);
phdl = NULL;
}
*pphdl = phdl;
return (error);
}
void
proc_free(struct proc_handle *phdl)
{
if (phdl->procstat != NULL)
procstat_close(phdl->procstat);
free(phdl);
}